Attractive stimuli cause faster pulsations, while negative stimuli cause the pulsations to slow.
|
|
It was a nightclub called Pulsations that opened in 1983.
|
|
So these are mysterious pulsations induced by the star's companion.
|
|
A fusillade of tense, razor-like roars ripped across the room, stabilizing as sinister pulsations.
|
|
"We think these pulsations must be induced by the planet, which is surprising," de Wit says.
|
|
Given their proximity, the red dwarf star's gravitational pull actually distorts the pulsations of the larger star.
|
|
It marries icy synth, muttering pulsations, dense forests of distortion, and shuddering tension with Leon's firm, warped shouts.
|
|
In the long run, Suicide's music, full of discursive mumbles, shrieks and crude electronic pulsations, earned great respect.
|
|
"To paraphrase William Blake, the creative act is the moment between the pulsations of an artery," Stucky said.
|
|
These periodic pulsations of light—or light curves, in the parlance of astronomers—is all but negligible in Ultima Thule.
|
|
I placed my fingers on his wrist, where I am used to feeling the rhythmic pulsations of the radial artery.
|
|
His voice lightly echoes around a loose, organic full band before warping around 808 pulsations and dub-style reverb drops.
|
|
The UFO device is not a mask in itself, but it does enhance face masks by using varying temperatures and pulsations.
|
|
Astronomers have observed star-on-star pulsations before, called "heartbeat stars," but such behavior is unprecedented for a star and a planet.
|
|
"The strength of the pulsations are unprecedented," lead study author Thomas Marsh of the University of Warwick told Gizmodo in an email.
|
|
Within seconds, there were rhythmic pulsations all around, then a strong thump-thump-thump-thump as the air beat against my window.
|
|
Within seconds, there were rhythmic pulsations all around, then a strong thump-thump-thump-thump as the air beat against my window.
|
|
Rich performed her ethical mission by writing lines sensitive to the pulsations and textures of material fact: animal, plant, human, stone, water, planet.
|
|
Dr. Strickland then tried to measure the pulsations and frequency spectrum, she said, but it did not turn out the way she expected.
|
|
A major discount will also be offered on the UFO, a "smart masking device" that boasts hyper-infusion technology, pulsations, and LED light therapy.
|
|
It was as if a C-clamp were tightened around her head and face, punctuated with pulsations of what seemed like an electrical current.
|
|
But near the end, firmer pulsations were clearer reminders of Mr. Glass, as was a cameo appearance by the violinist Tim Fain, a Glass specialist.
|
|
Though nobody talks about the crack, we feel it in the breaking of family dynamics, and we hear it in the deep pulsations of a song.
|
|
The symptoms caused by fistulas in the dura are usually headache and pulsatile tinnitus, in which the sound of arterial pulsations become audible to the patient.
|
|
Through the deployment of bounteous ornament and repeating linear motifs, Maghreb jewelry expresses the pulsations and throbs of our human heartbeats and repetitious breaths, of our copulating rhythms.
|
|
The pulsations of the laser are quick and short, so the pain is very minimal, but comes with a warming sensation throughout the duration of the 15-minute procedure.
|
|
Newer commerce is digital and carried through "trunk lines"; bartering is now done through packet-based pulsations of light and air whose results you can see but can't touch.
|
|
As the gas spirals inward, powerful X-ray bursts, flares and pulsations can explode in the innermost reaches of the accretion disk and on the surface of neutron stars.
|
|
In a way, the tracks merge the glacial symphonic raptures of Bruckner and Wagner with the loops and pulsations of dance music; they can be simultaneously serene and ominous.
|
|
Physicians once used a pulsograph to check patients' heart rates, and Montblanc's interpretation combined a blue-colored scale, graduated for 30 pulsations, with a chronograph and a special domed dial.
|
|
Their thoughts to their mouth to pulsations of air molecules to a vibrating membrane inside a hole in your skull to bones going clickety-click to waves of electrical activity to thoughts?
|
|
Resonating beyond the well-documented links among these leading lights, "The Club" captures their distinctly individual voices and invites us to feel the pulsations of contact over a period of 20 years.
|
|
" After she became debilitated, he said, they communed in "snatches of doggerel, song, teasing nonsense rituals" that functioned "like underwater sonar, each bouncing pulsations off the other, then listening for an echo.
|
|
Instead, the Foreo Luna go sends T-Sonic pulsations through your skin via soft silicone touch points to (apparently) remove 99.5% of dirt and oil, lift makeup residue, and unclog those pores.
|
|
The Luna 2's reverse side has a wave design and uses lower-frequency pulsations to massage your skin, working to reduce fine lines around the eyes and leaving skin more firm overall.
|
|
The app helps make each treatment customizable, allowing you to choose the intensity of pulsations as well as the level of red, blue, and green LED lights, depending on what your skin needs.
|
|
From the whimsical disco of "M," to the the balmy motorik pulsations of "I, Pt. 2," to the slinky dub pop of "T," he's expanded his horizon to make what is his most fully-formed album to date.
|
|
The silicone cleansing device harnesses the power of T-Sonic pulsations (with 16 intensities to choose from) to deeply clean, smooth, and firm your skin — and right now, you can add one to your daily regimen for less.
|
|
Paul Wraith from Scotland used a side-porthole to watch the effect produced by the sudden darkness on oxygen atoms in the Earth's atmosphere, while veteran American airborne eclipse chaser Donald Liebenberg looked up at the eclipse to measure pulsations in light intensity.
|
|
"The exquisite data from the TESS satellite meant that we could observe variations in brightness due to the gravitational distortion of the star as well as the pulsations," said Gerald Handler, lead study author and professor at the Nicolaus Copernicus Astronomical Centre in Poland.
|
|
As they break from a big pack into duets and solos, their physical impulses echo tremors and pulsations in the eclectic score (composed by Alex Menzies), although impulse is not quite the right word: Everything here seems put on from the outside, like clothing, rather than originating from within.
|
|
The impasto surface, with its gentle, throbbing monochromes, evoke the pulsations of the body — the heartbeat, blood cells, and veins — while the undulating, rusted sheet of metal, resembling a rib cage and spinal cord, is marked with delicate streaks of red, redolent of both blood and an electrical charge.
|
|
On one side an already fully fledged leisure, dining and hospitality sector has sought ever more inventive ways of packaging experience — from hotels staffed by robots and limited-edition Shinkansen bullet trains fitted out with Hello Kitty decor to many of the country's aquariums offering the opportunity to camp overnight surrounded by the relaxing pulsations of bioluminescent jellyfish.
|
|
Pulsations driven by the \kappa-mechanism are coherent and have relatively large amplitudes. It drives the pulsations in many of the longest-known variable stars, including the Cepheid and RR Lyrae variables.
|
|
Note within the endosarc an oval transparent body which shows no pulsations.
|
|
The pulsations of Alpha Cygni Variable stars are not fully understood. They are not confined to a narrow range of temperatures and luminosities in the way that most pulsating stars are. Instead, most luminous A and B supergiants, and possibly also O and F stars, show some type of unpredictable small-scale pulsations. Nonadiabatic strange mode radial pulsations are predicted but only for the most luminous supergiants.
|
|
The angular diameter of the disc has been directly observed to change during the pulsations.
|
|
These are identified as a series of even and odd p-mode (pressure-induced) pulsations.
|
|
Cepheid pulsations are excited by the kappa mechanism acting on the second ionization zone of helium.
|
|
Pulsations have also been modelled for less luminous supergiants by assuming they are low mass post-red supergiant stars, but most Alpha Cygni variables do not appear to have passed through the red supergiant stage. The pulsations are likely induced by kappa mechanism, caused by iron opacity variations, with strange modes producing the observed short periods for both radial and non- radial pulsations. Non-adiabatic g-modes may produce longer period variations, but these have not been observed in Alpha Cygni variables.
|
|
Pulse pressure (PP) is quantified using a blood pressure cuff and stethoscope (Korotkoff sounds), by measuring the variation of the systolic pressure during expiration and inspiration. To measure the pulsus paradoxus, place a blood pressure cuff on the patients arm and very slowly deflate the cuff while listening for brachial pulsations. Note the pressure that you first hear with pulsations during expiration (which will be the highest). Repeat the process, and record the pressure of pulsations heard during inspiration (which will be the lowest).
|
|
If the base of a surface convection zone is sharp and the convective timescales slower than the pulsation timescales, the convective flows react too slowly perturbations that can build up into large, coherent pulsations. This mechanism is known as convective blocking and is believed to drive pulsations in the \gamma Doradus variables.
|
|
Doppler sonography can be used to evaluate the pulsations in the fetal heart and bloods vessels for signs of abnormalities.
|
|
This technique has been used to estimate the mass of Cygnus X-1, providing a cross-check with other mass derivations. Pulsations with a stable period, similar to those resulting from the spin of a neutron star, have never been seen from Cygnus X-1. The pulsations from neutron stars are caused by the neutron star's magnetic field; however, the no-hair theorem guarantees that black holes do not have magnetic poles. For example, the X-ray binary V 0332+53 was thought to be a possible black hole until pulsations were found.
|
|
Alpha Cygni variables are variable stars which exhibit non-radial pulsations, meaning that some portions of the stellar surface are contracting at the same time other parts expand. They are supergiant stars of spectral types B or A. Variations in brightness on the order of 0.1 magnitudes are associated with the pulsations, which often seem irregular, due to beating of multiple pulsation periods. The pulsations typically have periods of several days to several weeks. The prototype of these stars, Deneb (α Cygni), exhibits fluctuations in brightness between magnitudes +1.21 and +1.29.
|
|
The blue giant varies slightly in brightness every 3.5 hours. The WR star may also be slightly variable. The pulsations of the B-type giant are characteristic of a β Cephei variable. Analysis of its pulsations and comparison to the expected properties of a WC7 star suggest that both stars could have evolved without mass exchange.
|
|
This means that the star is currently not undergoing any radical changes in structure involving large scale pulsations, flows or mass loss.
|
|
Troitskaya and described how her work on magnetic pulsations had provided the basis for major advances in understanding the magnetosphere and its dynamics.
|
|
The mass calculated by modelling the pulsations is . The discrepancies between the masses obtained by the different methods occurs for most Cepheid variables.
|
|
A blind search of more than four years of Fermi data, led by Holger Pletsch, revealed that 2FGL J1317.7–3429 was a millisecond pulsar with a 2.5 millisecond period, the first example of a millisecond pulsar detected via gamma-ray pulsations. With the discovery of the pulsations, it was named PSR J1311–3430, with "PSR" denoting pulsar. Follow-up radio observations were able to also detect intermittent radio pulsations with the Green Bank Telescope that were only visible for <10% of the time the source was observed. The authors suggested that the pulses could be eclipsed or scattered by material in the system.
|
|
Pulsating variable stars sometimes have a single well- defined period, but often they pulsate simultaneously with multiple frequencies and complex analysis is required to determine the separate interfering periods. In some cases, the pulsations do not have a defined frequency, causing a random variation, referred to as stochastic. The study of stellar interiors using their pulsations is known as asteroseismology. The expansion phase of a pulsation is caused by the blocking of the internal energy flow by material with a high opacity, but this must occur at a particular depth of the star to create visible pulsations.
|
|
It is currently core helium burning through the triple alpha process. ρ Cassiopeiae in optical light The relatively low mass and high luminosity of a post-red supergiant star is a source of instability, pushing it close to the Eddington Limit. However, yellow hypergiants lie in a temperature range where opacity variations in zones of partial ionisation of hydrogen and helium cause pulsations, similar to the cause of Cepheid variable pulsations. In hypergiants, these pulsations are generally irregular and small, but combined with the overall instability of the outer layers of the star they can result in larger outbursts.
|
|
While long term irregular behavior in the temporal variations of the pulsation amplitudes is possible when amplitude equations apply, this is not the general situation. Indeed, for the majority of the observations and modeling, the pulsations of these stars occur with constant Fourier amplitudes, leading to regular pulsations that can be periodic or multi-periodic (quasi-periodic in the mathematical literature).
|
|
Mira variables are mostly fundamental mode pulsators, while the semiregular and irregular variables on the asymptotic giant branch pulsate in the first, second, or third overtone. Many of the less regular LPVs pulsate in more than one mode. Long secondary periods cannot be caused by fundamental mode radial pulsations or their harmonics, but strange mode pulsations are one possible explanation.
|
|
They are known as the short period group and the GCVS acronym BCEPS. The pulsations of Beta Cephei variables are driven by the kappa mechanism and p-mode pulsations. At a depth within the star where the temperature reaches 200,000 K, there is an abundance of iron. Iron at these temperatures will increase (rather than decrease) in opacity, resulting in the buildup of energy within the layer.
|
|
Diamandis' vocal delivery is treated with a "layered" effect throughout "Power & Control", and is complemented by its subtle "hammering beats", "dance floor pulsations", and piano instrumentation.
|
|
It is believed that the very weak magnetic field normally found in AGB stars is amplified by the shock wave during the pulsations of the star's atmosphere.
|
|
These stars cross the instability strip and undergo very regular pulsations. RU Cam fits this model reasonably well despite its peculiarities. Its temperature of around 5,000 K and luminosity several hundred times the sun's place it on or near the instability strip, and its mass about is typical of AGB stars. The brightness variations of RU Cam are caused by pulsations which cause both the temperature and radius to vary.
|
|
Non-radial pulsations are when some parts of the surface move inwards and some outward at the same time. Radial pulsations are a special case, where the star expands and contracts around its equilibrium state by altering the radius to maintain its spherical shape. The variations are due to the swelling and shrinking of the star through the Eddington Valve or Kappa-mechanism. The stars have a helium rich atmosphere.
|
|
For the production of pulses at rates up to 50 pulsations per second, the use of rotating wheels introducing alternately neutron poison and fuel or neutron poison and non- neutron poison can be considered. However, for pulsations ranking the thousands of pulses per second (kHz), optical choppers or modern wheels employing magnetic bearings allow to revolve at 10 kHz. If even faster pulsations are desired it would be necessary to make use of a new type of pulsing mechanism that does not involve mechanical motion, for example, lasers (based in the 3He polarization) as early proposed by Bowman, or proton and neutron beams. Frequencies on the order of 1 kHz to 10 kHz are likely choices.
|
|
The stealthy augmenter had problems with pressure pulsations, or "screech", at low altitude and high speed early in its development.Warwick, Graham. "Screech, the F135 and the JSF Engine War" .
|
|
Jing, Z. 1983. Anatomy of the circulatory system of Radix auricularia. Acta Zoologica Sinica 29(2):133-140. The heart pulsations are slow and regular: thirty-four per minute.
|
|
The magnitude of Vega was measured again in 1981 at the David Dunlap Observatory and showed some slight variability. Thus it was suggested that Vega showed occasional low-amplitude pulsations associated with a Delta Scuti variable. This is a category of stars that oscillate in a coherent manner, resulting in periodic pulsations in the star's luminosity. Although Vega fits the physical profile for this type of variable, other observers have found no such variation.
|
|
The mechanism of variability for γ Coronae Borealis is not known. Spectroscopic variations with a period of 0.9 days have been observed, which matches the likely rotation period of the star, and radial velocity changes are also seen with a possible period of 0.45 days. Short-period non-radial pulsations may be carried around by the rotation of the star, but the driver of such pulsations in a star of this temperature is unknown.
|
|
Jagadish Chandra Bose suggested a mechanism for the ascent of sap in 1927. His theory can be explained with the help of galvanometer of electric probes. He found electrical ‘pulsations’ or oscillations in electric potentials, and came to believe these were coupled with rhythmic movements in the telegraph plant Codariocalyx motorius (then Desmodium). On the basis of this Bose theorized that regular wave-like ‘pulsations’ in cell electric potential and turgor pressure were an endogenous form of cell signaling.
|
|
Its variability was discovered by accident in 1981, when the star was used as a comparison star for the eclipsing binary AG Phoenicis. Photometric and spectroscopic data have allowed the detection of at least 13 modes of radial and non-radial pulsations, the strongest one having a period of 0.174 days and an amplitude of 11.1 milli-magnitudes. Observations in different epochs show evidence that the pulsations modes vary in amplitude, which is common among Delta Scuti variables.
|
|
This is one of the Mira variables where mode switching of pulsations have been observed; amplitude and periods have been seen decreasing and subsequently increasing back to values near the previous ones.
|
|
Discovered in 2002 during a radial velocity study of K-class giant stars, its eccentric orbit aided its detection, as giant stars have pulsations which can mimic the presence of a planet.
|
|
These correspond to singly periodic and doubly periodic pulsations of the star. It is important to emphasize that no other asymptotic solution of the above equations exists for physical (i.e., negative) coupling coefficients.
|
|
Regular variations in the doppler shift of the star's spectral lines with a period of a few days have suggested orbital motion about a companion star, but pulsations are a more likely explanation.
|
|
Pulsations of S Orionis, showing dust production and masers (ESO) The descriptive term long-period variable star refers to various groups of cool luminous pulsating variable stars. It is frequently abbreviated to LPV.
|
|
The surface gravity varies during the pulsations, dropping to extremely low values as the star passes through its largest size. The temperature varies by about 1,000 K, being hottest when the star is rising towards a maximum. Integrated radial velocities indicate that during the largest pulsations, the location of the reversing layer in the atmosphere moves by nearly 90% of the average stellar radius. U Mon is a metal-poor star, as expected for a low-mass post- AGB object.
|
|
Lines in the spectrum of Betelgeuse show doppler shifts indicating radial velocity changes corresponding, very roughly, to the brightness changes. This demonstrates the nature of the pulsations in size, although corresponding temperature and spectral variations are not clearly seen. Variations in the diameter of Betelgeuse have also been measured directly. First overtone pulsations of 185 days have been observed, and the ratio of the fundamental to overtone periods gives valuable information about the internal structure of the star and its age.
|
|
Mira variables are stars in the last stages of evolution whose instability comes from pulsations in its surface, causing changes in color and brightness. Some of them, including S Cassiopeiae show SiO maser emission.
|
|
The valve areas are palpated for abnormal pulsations (palpable heart murmurs known as thrills) and precordial movements (known as heaves). Heaves are best felt with the heel of the hand at the sternal border.
|
|
There is mild anterior uveitis. A cherry-red spot may be seen in the macula, along with cotton-wool spots elsewhere, due to retinal nerve fiber layer hemorrhages. The retinal arteries may show spontaneous pulsations.
|
|
The first pulsations of the ground were followed for about a minute of tremulous motion. Next came a quick vibration and several jerks much worse than the first. Houses rocked and cracked; furniture fell over.
|
|
John Poulos, Dennis Miccolis, George LeGros and Dennis Tufano were members of The Pulsations. These two groups merged to form The Buckinghams. One day, Sheldon Cooper, an executive at WGN-TV, witnessed a promotion of Carl's outside Lane Tech High School across the street from WGN-TV's studios. Carl's discussion with Cooper led to The Pulsations entering and winning a competition to appear for 13 weeks on The All-Time Hits, Chicago's first locally produced TV program broadcast in color, featuring a variety of musical guests.
|
|
V529 Andromedae was the first star known to combine Gamma Doradus and Delta Scuti type pulsations. Nine different pulsation frequencies have been observed, and three of them could arise from a previously unknown stellar pulsation mode.
|
|
Only 35% of TIF patients exhibit the pathognomonic warning signs which include sentinel bleeding, a small bleed from the tracheostomy in the preceding the TIF, and pulsations of the tracheostomy tube that coincides with the heartbeat.
|
|
Naukova dumka, Kiev, 215p. (In Russian) that refined the applied calculation techniques based on the principle of cavity expansion independence, theory of pulsations and stability of elongated axisymmetric cavities, etc.Knapp, RT, Daili, JW, Hammit, FG (1970) Cavitation.
|
|
Radial velocity changes were detected corresponding to the brightness variations, but the idea that these were caused by stellar pulsations and temperature changes was largely dismissed in favour of orbital motions of a binary star. More accurate observations eventually proved beyond doubt that the brightness variations were caused by pulsations in the atmospheres of the stars, with the stars being smallest and hottest near maximum brightness. RT Aurigae has been suspected to be a spectroscopic binary system, but this has not been confirmed. The strongest evidence was found in 2013 using CHARA array optical interferometry.
|
|
Light curve of a Delta Cephei variable, showing the regular light curve formed by intrinsic stellar pulsations Stellar pulsations are caused by expansions and contractions in the outer layers as a star seeks to maintain equilibrium. These fluctuations in stellar radius cause corresponding changes in the luminosity of the star. Astronomers are able to deduce this mechanism by measuring the spectrum and observing the Doppler effect. Many intrinsic variable stars that pulsate with large amplitudes, such as the classical Cepheids, RR Lyrae stars and large-amplitude Delta Scuti stars show regular light curves.
|
|
They referred to them as 53 Persei stars after the prototype 53 Persei. Ten had been discovered by 1993, though Waelkens was unsure if the prototype was actually a member and recommended referring to the group as slowly pulsating B (SPB) stars. The General Catalogue of Variable Stars uses the acronym LPB for "comparatively long-period pulsating B stars (periods exceeding one day)", although this terminology is rarely seen elsewhere. The similar Beta Cephei variables have shorter periods and have p-mode pulsations, while the SPB stars show g-mode pulsations.
|
|
Pulsations of S Orionis, showing dust production and masers (ESO) S Orionis is a Mira variable that pulsates with an approximately 420‑day cycle, and varies in radius from 2.0 to 2.3 astronomical units. The pulsations have been observed using VLTI and VLBA observations which measured an angular diameter varying between 7.9 and 9.7 mas. The mean period of variation has been shown to change over time, from less than 410 days to over 440 days. The variations are approximately sinusoidal with a weak, not statistically-significant, trend towards longer period.
|
|
However the lines do not change their shape or intensity, which would be expected from a pulsating star Non-radial pulsations have been proposed, with multiple pulsation periods of varying amplitude accounting for the apparently irregular brightness changes.
|
|
The optimal diameter of pipes sometimes was not determined. Some pipelines have experienced pressure loss, while some pipelines have experienced pulsations. Compensation of temperature extensions was implemented by curves in pipelines. Hydraulic calculations related to pipelines began in 2003.
|
|
The supergiant component W Sgr Aa1 is a variable star which pulsates regularly between magnitudes 4.3 and 5.1 every 7.59 days. During the pulsations, that temperature and spectral type also vary. It is classified as a Classical Cepheid (δ Cephei) variable.
|
|
They lie near the instability strip, cooler than type I Cepheids more luminous than type II Cepheids. Their pulsations are caused by the same basic mechanisms related to helium opacity, but they are at a very different stage of their lives.
|
|
The radius is about 6.6 times that of the Sun. It has an effective temperature of 26,530 in its outer atmosphere. Omega1 Scorpii is a β Cephei star that undergoes non-radial pulsations at a rate of 15 cycles per day.
|
|
However, the measurement of pulsations is very difficult, given the scarcity of variable blue stragglers, the small photometric amplitudes of their pulsations and the crowded fields in which these stars are often found. Some blue stragglers have been observed to rotate quickly, with one example in 47 Tucanae observed to rotate 75 times faster than the Sun, which is consistent with formation by collision. The other explanation relies on mass transfer between two stars born in a binary star system. The more massive of the two stars in the system will evolve first and as it expands, will overflow its Roche lobe.
|
|
New brain mapping technology, particularly fMRI and PET, allowed researchers to investigate experimental strategies of cognitive psychology by observing brain function. Although this is often thought of as a new method (most of the technology is relatively recent), the underlying principle goes back as far as 1878 when blood flow was first associated with brain function. Angelo Mosso, an Italian psychologist of the 19th century, had monitored the pulsations of the adult brain through neurosurgically created bony defects in the skulls of patients. He noted that when the subjects engaged in tasks such as mathematical calculations the pulsations of the brain increased locally.
|
|
From 1972 to 1974, Chen did his postdoctoral research with Akira Hasegawa at the Bell Labs. They developed a theory for long-period magnetic pulsations in the magnetosphere based on resonant coupling between hydromagnetic compressional waves and transverse Alfvén continuous spectrum. This theory, later referred to as Chen-Hasegawa field-line-resonance model, successfully explained the observations in the Earth's magnetosphere by Louis J. Lanzerotti, and has become the standard model for magnetic pulsations in the Earth’s and other planetary magnetospheres. Soon, their focus turned to the charged particle heating via resonant absorption within Alfvén wave continuous spectrum.
|
|
The source of the long secondary periods is unknown, but they cannot be explained by radial pulsations. Interferometric observations of Betelgeuse have shown hotspots that are thought to be created by massive convection cells, a significant fraction of the diameter of the star and each emitting 5–10% of the total light of the star. One theory to explain long secondary periods is that they are caused by the evolution of such cells combined with the rotation of the star. Other theories include close binary interactions, chromospheric magnetic activity influencing mass loss, or non-radial pulsations such as g-modes.
|
|
The planet candidate was discovered in March 2007 and published in September 2007. If it is confirmed, its survival would indicate that planets at Earth-like distances can survive their star's red- giant phase, though this is a much larger planet than Earth (about the same size as Jupiter and Saturn).Planet discovered that offers clues to Earth's future Its existence has been called into question with further monitoring of the pulsations of the star which show deviations from the predicted behavior if this were in fact a planet. The variations in the pulsations may be due to unknown stellar variability.
|
|
However, none of the currently-accepted explanations were adequate: it pulsated too slowly and was outside of the Delta Scuti instability strip, and there was no evidence for any eclipsing material, although Gamma Doradus and HD 96008 were noted to be similar. These three stars, as well as HD 224638, were soon hypothesized to belong to a new class of variable stars in which variability was produced by g-mode pulsations rather than the p-mode pulsations of Delta Scuti variables. HD 224945 and HD 164615 were noticed to be similar as well, while HD 96008 was ruled out on the basis of its more regular period. Eclipses and starspots were soon ruled out as the cause of the Gamma Doradus' variability, and the variability of 9 Aurigae was confirmed to be caused by g-mode pulsations a year later, thus confirming the stars as the prototypes of a new class of variable stars.
|
|
O(He) stars are characterized by HeII absorption while having CIV, NV and OVI emission lines. PG1159 stars, also termed O(C) stars, are dominated by carbon absorption line spectra. They are notable for complex pulsations and being among the hottest known stars.
|
|
The roAp stars oscillate in high-overtone, low-degree, non-radial pressure modes. The usual model that is used to explain the behavior of these pulsations is the oblique pulsator model.Kurtz, D. W. Monthly Notices of the Royal Astronomical Society, vol. 200, p.
|
|
Radial velocity variations with a period of 142 days hint about the possible presence of a planetary companion orbiting Beta Ophiuchi. Thus far, no planetary object has been confirmed; while periodic radial pulsations caused by intrinsic stellar variability could explain the observed variations.
|
|
Since she was still a young teenager, her Uncle accompanied her to Club Pulsations, where DJ Wasswa Junior taught her how to use the turntable. She also sites DJ Alex Ndawula for teaching her some skills. Other instructors included the late DJ Berry.
|
|
This star type varies in luminosity due to non-radial pulsations. Its apparent magnitude varies from 4.93 to 5.03 over a period of 1.25804 days. For that reason it has been given the variable star designation V398 Aurigae. 9 Aurigae is a multiple star system.
|
|
Astrosat-1 in deployed configuration Astrosat is India's first multi wavelength space observatory and full-fledged astronomy satellite. Its observation study includes active galactic nuclei, hot white dwarfs, pulsations of pulsars, binary star systems, supermassive black holes located at the centre of the galaxies, etc.
|
|
R Coronae Borealis in optical light R Coronae Borealis is about 90% helium and less than 1% hydrogen. The majority of the remainder is carbon. This classifies it as a carbon-enhanced extreme helium star. Modelling the pulsations suggests that the star's mass is .
|
|
The primary cycle of four beatsPolyrhythm 6:4 A great deal of African music is built upon a cycle of four main beats. This basic musical period has a bipartite structure; it is made up of two cells, consisting of two beats each. Ladzekpo states: "The first most useful measure scheme consists of four main beats with each main beat measuring off three equal pulsations [] as its distinctive feature … The next most useful measure scheme consists of four main beats with each main beat flavored by measuring off four equal pulsations []." (b: "Main Beat Schemes") The four-beat cycle is a shorter period than what is normally heard in European music.
|
|
A member of the galactic halo, it has a retrograde orbit around the center of the Milky Way, and has an extremely high peculiar velocity of . From its movement through space, it can be a member of the Kapteyn group, a moving group of stars with a similar movement as Kapteyn's Star. Discovered to be variable by Olin J. Eggen in 1952, SX Phoenicis has been targeted in many studies of its light curve and spectrum. These observations revealed that SX Phoenicis has two pulsations periods of 0.055 and 0.043 days, which correspond to radial pulsations in the fundamental mode and in the first overtone, respectively.
|
|
The vector sum of balanced three- phase currents, however, is zero, allowing for the neutral wires to be eliminated. In electrical power distribution, a requirement of only three conductors, rather than four, represented a considerable distribution-wire cost savings due to the expense of conductors and installation. While both two-phase and three-phase circuits have a constant combined power for an ideal load, practical devices such as motors can suffer from power pulsations in two-phase systems. These power pulsations tend to cause increased mechanical noise in transformer and motor laminations due to magnetostriction and torsional vibration in generator and motor drive shafts.
|
|
Deneb is the prototype of the Alpha Cygni (α Cygni) variable stars, whose small irregular amplitudes and rapid pulsations can cause its magnitude to vary anywhere between 1.21 and 1.29. Its variability was discovered by Lee in 1910, but was not formally placed as a unique class of variable stars until the 1985 4th edition of the General Catalogue of Variable Stars. The cause of the pulsations of Alpha Cygni variable stars are not fully understood, but their irregular nature seems to be due to beating of multiple pulsation periods. Analysis of radial velocities determined 16 different harmonic pulsation modes with periods ranging between 6.9 to 100.8 days.
|
|
The observed variability of GP Andromedae is typical for a Delta Scuti variable; it's a purely monoperiodic radial pulsating star with a period of 0.0787 days. The period of pulsations is slowly and continuously increasing, matching the predictions of stellar evolution models for Delta Scuti variables.
|
|
The period is given as 92.23 days, although this varies slightly from cycle to cycle. The brightness of the main pulsations varies over a long secondary period. This takes about 2,500 days, more than twice the length of the secondary period in any other RV Tauri variable.
|
|
The unusually short period of V473 Lyr is caused by pulsations in the second overtone and the fundamental pulsation period would be three times as long. The amplitude variations have an approximate period of 1,205 days, and there is a secondary modulation with a period of 5,300 days.
|
|
In 1984 it was demonstrated that the star's variability is due to nonradial gravity wave pulsations. As a consequence, its timescale for period change is directly proportional to its cooling timescale, allowing its cooling rate to be measured using astroseismological techniques. Its age is estimated at 400 million years.
|
|
Ground-based observations were taken also at the same time, for example, with the ESO Very Large Telescope in Chile, the Canadian-French-Hawaiian Telescope in Hawaii, the McDonald Observatory in Texas, or the Calar Alto Observatory in Spain. The CoRoT observations led to the discovery of about a dozen pulsating pre-main sequence (PMS) δ Scuti stars and the confirmation of the existence of γ Doradus pulsations in PMS stars. Also the presence of hybrid δ Scuti/γ Doradus pulsations was confirmed in members of NGC 2264. The CoRoT observations included also the well known pre-main sequence pulsators, V 588 Mon and V 589 Mon, which were the first discovered members of this group of stars.
|
|
MichaeliMichaeli, D.: WO00068647 (2000). proposed that ICP should be inferred from the magnitude and shape of pulsations of the third ventricle synchronous with the cardiac cycle or respiration, where the pulsations are measured along the propagation axis of an ultrasound wave. The method so far has not been independently validated, and the author provides no exact data from which one could estimate the accuracy of the method. However, the discussion in the body of the patent document suggests that the method is able to distinguish among three ranges of ICP (<20, 20–40 and >40mmHg) but cannot provide an exact value of ICP within the range because of the impossibility of the calibration to the individual patient.
|
|
After graduating, she worked at the Harvard–Smithsonian Center for Astrophysics, where she began analyzing data from X-ray astronomy satellites beginning with the UHURU satellite (and helping to compile the 4U catalog), prior to attending graduate school. While a graduate student at M. I. T., and using data from the SAS-3 satellite, she discovered X-ray pulsations from 4U0115+63 (together with George Clark); these pulsations were then used to show that transient X-ray. sources were in binary systems. Her thesis work with Walter Lewin and Paul Joss, was entitled "X-ray Burst Sources" and consisted of extensive analysis of the SAS-3 timing and spectral data, as well as theoretical thermonuclear flash modeling.
|
|
The birth of helioseismology occurred in 1976 with the publications of papers from Brookes, Isaak and van der Raay "Observation of free oscillations of the sun", Nature, vol. 259, January 15, 1976, pp. 92–95 and Severny, Kotov and Tsap,"Observations of solar pulsations", Nature, vol. 259, January 15, 1976, pp.
|
|
His research is on nonlinear dynamics, chaos, and lasers.Neal B. Abraham, Paul Mandel, and Loernzo M. Narducci. (1983) "Dynamical Instabilities and Pulsations in Lasers" Progress in Optics 24;1 He is an elected fellow of American Association for the Advancement of Science and two major physics societies."Neal B. Abraham". aaas.org.
|
|
The stars are usually A0 to F5 type giant or main sequence stars. The high-amplitude Delta Scuti variables are also called AI Velorum stars. They are the second most abundant variable source in the Milky Way after white dwarfs. Delta Scuti stars exhibit both radial and non-radial luminosity pulsations.
|
|
In tricuspid valve regurgitation, these pulsations are very strong. No valve divides the superior vena cava from the right atrium. As a result, the (right) atrial and (right) ventricular contractions are conducted up into the internal jugular vein and, through the sternocleidomastoid muscle, can be seen as the jugular venous pressure.
|
|
Therefore, it is difficult to state whether scroll compressors have lower pulsation levels than reciprocating compressors as has often been claimed by some suppliers of scroll compressors. The more steady flow yields lower gas pulsations, lower sound and lower vibration of attached piping, while having no influence on the compressor operating efficiency.
|
|
These stars are called GW Vir stars, after their prototype, or the class may be split into DOV and PNNV stars., § 1.1;§1, Detection of non- radial g-mode pulsations in the newly discovered PG 1159 star HE 1429-1209, T. Nagel and K. Werner, Astronomy and Astrophysics 426 (2004), pp. L45-L48.
|
|
"Street and gallery swap roles in Braamies". Business Day Live, by Chris Thurman, October 23, 2014 In 1999 she is invited for a residency at the Cité Internationale des Arts in Paris and receives the Photography Award from the HSBC Foundation."20th Anniversary Prix HSBC pour la Photographie : Catherine Gfeller, 1999 Winner". L'oeil de la Photographie, March 18, 2015 - Switzerland, written by Ericka Weidmann Paris inspires a new work (“Multi- Compositions”), focused on metaphorical urban subjects using various media: video, sound and the written word. Intimate spaces and daily gestures create new multi-layered compositions where urban rhythms still resonate as an acting presence (“The Insiders”, “Chimeras”, “Domestic Pieces”, “Waders”). In 2010-2012 her monographic exhibition "Pulsations""Exhibition Pulsations from Catherine Gfeller at Galerie Springer".
|
|
A transient X-ray source first discovered in 1996 by the Italian-Dutch BeppoSAX satellite, SAX J1808.4−3658 revealed X-ray pulsations at the 401 Hz neutron star spin frequency when it was observed during a subsequent outburst in 1998 by NASA's RXTE satellite. The neutron star is orbited by a brown dwarf binary companion with a likely mass of 0.05 solar masses, every 2.01 hours. X-ray burst oscillations and quasi-periodic oscillations in addition to coherent X-ray pulsations have been seen from SAX J1808.4-3658, making it a Rosetta stone for interpretation of the timing behavior of low-mass X-ray binaries. These accreting millisecond X-ray pulsars are thought to be the evolutionary progenitors of recycled radio millisecond pulsars.
|
|
In 1965, guitarists Carl Giammarese and Nick Fortuna, along with bassist Curtis Bachman, were invited to join a band called the Centuries. Giammarese and Bachman, plus keyboardist Dennis Miccolis, later became members of another band, the Pulsations, whose members included drummer John Poulos and vocalists George LeGros and Dennis Tufano. After winning a local battle of the bands competition in late 1965, the Pulsations secured a job as the house band on WGN-TV's variety show called All-Time Hits. The show's producers suggested they adopt a name reflective of the British invasion, which was popular at the time, and the band adopted the name The Buckinghams, which was suggested by a security guard named John Opager at the station.
|
|
The pulsations result from a process called the κ-mechanism. A part of the star's outer atmosphere becomes optically thick due to partial ionization of certain elements. When these atoms lose an electron, the likelihood that they will absorb energy increases. This results in an increase in temperature that causes the atmosphere to expand.
|
|
GD 358 is a variable white dwarf star of the DBV type. Like other pulsating white dwarfs, its variability arises from non-radial gravity wave pulsations within itself.Asteroseismology of white dwarf stars, D. E. Winget, Journal of Physics: Condensed Matter 10, #49 (December 14, 1998), pp. 11247-11261\. DOI 10.1088/0953-8984/10/49/014.
|
|
A New Short-Period Blue Variable, Arlo U. Landolt, Astrophysical Journal 153, #1 (July 1968), pp. 151-164. Like other DAV white dwarfs, its variability arises from non-radial gravity wave pulsations within itself.Physics of white dwarf stars, D. Koester and G. Chanmugam, Reports on Progress in Physics 53 (1990), pp. 837-915., § 7.
|
|
Beta Cephei pulsates regularly every 4 hours 34 minutes, producing a variation in its visual brightness of 0.11 magnitudes. It is the prototype of the Beta Cephei class of variables, hot main sequence and giant stars that pulsate analogously to Cepheid variables but with the pulsations driven by iron opacity rather than by helium.
|
|
The short- term oscillations were assumed to be a result of stellar pulsations, similar to the solar ones. A correlation between the variations in the asymmetry of the spectral line profile and the radial velocity has also been found. The multi-periodic oscillations make HD 81797 (Alphard) an object of interest for asteroseismologic investigations.
|
|
SAX J1808.4-3658 is a transient, accreting millisecond X-ray pulsar that is intermittent. In addition, X-ray burst oscillations and quasi- periodic oscillations in addition to coherent X-ray pulsations have been seen from SAX J1808.4-3658, making it a Rosetta stone for interpretation of the timing behavior of low-mass X-ray binaries.
|
|
The detected pulsation modes correspond to those for both and β Cephei variables and slowly pulsating B stars. Similar pulsations have not been detected in component Ab, but it is possible that it is also a variable star. Aa is 12.02 ± 0.13 times as massive as the Sun, while Ab is 10.58 ± 0.18 times as massive.
|
|
Many variable red giants and supergiants show variations over several hundred to several thousand days. The brightness may change by several magnitudes although it is often much smaller, with the more rapid primary variations are superimposed. The reasons for this type of variation are not clearly understood, being variously ascribed to pulsations, binarity, and stellar rotation.
|
|
NO Apodis (HD 156513) is semi-regular pulsating star located in the far southern constellation Apus. It varies between magnitudes 5.71 and 5.95, its pulsations of periods 26.2 and 26.6 days respectively. Located around 780 ± 20 light-years distant, it shines with a luminosity approximately 2059 times that of the Sun and has a surface temperature of 3568 K.
|
|
Other pulsation frequencies, combinations of these two, are also observed. The pulsations also cause the radial velocity of the star to vary by 38 km/s, with the same periods as the light variation. There is evidence that the pulsation periods change in a timescale of decades, with a possible cyclic variation period of 43 ± 10 years.
|
|
Querfurth, H.W.: US20067122007 (2006). or automate the method by adding a camera and an image processing software capable of recognizing venous pulsations from a sequence of images of the eye fundus.21\. Braxton, E.E.: US20060206037 (2006). Evaluation in patients confirmed a strong linear relationship and clinically negligible differences (2-3mmHg) between VOP and the invasively measured ICP.
|
|
There are several types of pulsating star not found on the instability strip and with pulsations driven by different mechanisms. At cooler temperatures are the long period variable AGB stars. At hotter temperatures are the Beta Cephei and PV Telescopii, variables. Right at the edge of the instability strip near the main sequence are Gamma Doradus variables.
|
|
Compared to single-phase motors and generators, polyphase motors are simpler, because they do not require external circuitry (using capacitors and inductors) to produce a starting torque. Polyphase machines can deliver constant power over each period of the alternating current, eliminating the pulsations found in a single-phase machine as the current passes through zero amplitude.
|
|
Electrons mainly responsible for diffuse and pulsating auroras have, in contrast, a smoothly falling energy distribution, and an angular (pitch-angle) distribution favouring directions perpendicular to the local magnetic field. Pulsations were discovered to originate at or close to the equatorial crossing point of auroral zone magnetic field lines. Protons are also associated with auroras, both discrete and diffuse.
|
|
The West Chester Railroad, a heritage railway, currently operates trains between Glen Mills and West Chester on weekends. A "wild west" themed restaurant/roadside attraction known as "The Longhorn Ranch" operated in Glen Mills during the 1960s. In the 1980s, that same site was the location of Pulsations nightclub. The site is currently the location of a retirement community.
|
|
It is written in the key of F#m and their vocal ranges span from the low-note of F#3 to C#6. The song is set in the signature of common time and has a moderate tempo of 120 pulsations per minute. It follows the basic chord progression of B7m—C#7m—F#7.
|
|
The giant primary star is a Mira variable, a star that pulsates and changes temperature, leading to very large visual brightness changes. The total range of 5.2 - 12.4 is a variation of 750 times in brightness, from a naked eye star to one beyond the range of binoculars. The pulsations occur every 390 days but are not entirely regular.
|
|
RT TrA is a cool giant star with a radius of , although its spectral luminosity class verges on the supergiant level at times during its pulsations. As it pulsates, the effective temperature varies between 5,200 and 6,500 K and its luminosity between . Its physical properties place it on the instability strip of the H–R diagram.
|
|
By 1975 it was becoming clear that these pulsations could be understood if the sun was considered as an enormous bell ringing at very low frequencies (one oscillation per minute and lower), and that they provided important insight into the structure of the sun.Lang, Kenneth R. (2000). The Sun from Space (Springer, New York), p. 93.
|
|
A careful analysis has shown that they were solar-like oscillations excited by turbulent bubbles origination from this convective iron opacity peak zone or even from the convective core. This is indeed a major discovery since it was the first time that pulsations excited by the κ mechanism acting in the iron opacity peak zone were present side by side in the same star with pulsations stochastically excited by this very same zone. This is the reason why Kevin Belkacem, main discoverer of these solar-like oscillations in V1449 Aquilae, added a new baptismal certificate to this β Cephei star and named it Chimera. The figure illustrates the behavior of the frequency versus time for two modes in the frequency spectrum of Chimera, a solar-like mode (top) and a β Cephei mode (bottom).
|
|
The regular behavior of the Cepheids has been successfully modeled with numerical hydrodynamics since the 1960s, and from a theoretical point of view it is easily understood as due to the presence of center manifold which arises because of the weakly dissipative nature of the dynamical system. This, and the fact that the pulsations are weakly nonlinear, allows a description of the system in terms of amplitude equations and a construction of the bifurcation diagram (see also bifurcation theory) of the possible types of pulsation (or limit cycles), such fundamental mode pulsation, first or second overtone pulsation, or more complicated, double- mode pulsations in which several modes are excited with constant amplitudes. The boundaries of the instability strip where pulsation sets in during the star's evolution correspond to a Hopf bifurcation.
|
|
Light curve of Delta Cephei, the prototype of classical cepheids, showing the regular variations produced by intrinsic stellar pulsations Classical Cepheids (also known as Population I Cepheids, type I Cepheids, or Delta Cepheid variables) undergo pulsations with very regular periods on the order of days to months. Classical Cepheids are Population I variable stars which are 4–20 times more massive than the Sun, and up to 100,000 times more luminous. These Cepheids are yellow bright giants and supergiants of spectral class F6 – K2 and their radii change by (~25% for the longer-period I Carinae) millions of kilometers during a pulsation cycle. Classical Cepheids are used to determine distances to galaxies within the Local Group and beyond, and are a means by which the Hubble constant can be established.
|
|
It is intrinsically variable, varying in brightness by 0.02 magnitude. It has pulsations of two periods, 92.5 days and 64.8 days in length. It has been classified as a UU Herculis variable—a class of yellow supergiant with semiregular variability. These stars are thought to have affinities with Cepheid variables and lie near the instability strip on the Hertzsprung–Russell diagram.
|
|
Also known as the S Doradus variables, the most luminous stars known belong to this class. Examples include the hypergiants η Carinae and P Cygni. They have permanent high mass loss, but at intervals of years internal pulsations cause the star to exceed its Eddington limit and the mass loss increases hugely. Visual brightness increases although the overall luminosity is largely unchanged.
|
|
The red supergiant primary star has been compared to Betelgeuse. It shows small amplitude irregular pulsations, and also some variation associated with the orbital motion. The nature of the secondary is less certain. The spectrum shows high excitation features that would indicate an early B or hotter spectral type, but these may be associated with the disc rather than that star itself.
|
|
Servomotors are used for mechanical displacement, positioning or precision motion control. DC stepper motors can also be used as servomotors; however, since they are operated with open loop control, they typically exhibit torque pulsations. Brushless DC motors are more suitable as servomotors since their precise motion is based upon a closed loop control system that provides tightly controlled and stable operation.
|
|
A. Gorlov proposed a similar design in 1995 (Gorlov's water turbines). Since the wind pulls each blade around on both the windward and leeward sides of the turbine, this feature spreads the torque evenly over the entire revolution, thus preventing destructive pulsations. This design is used by the Turby, Urban Green Energy, Enessere, Aerotecture and Quiet Revolution brands of wind turbine.
|
|
Among the stars of this class, Omega Orionis was the first where the magnetic field was measured and found to be 1000 times that of the Earth. Omega Orionis is, like many Be stars, a variable star whose brightness varies 0.19 magnitudes. Also, small variations have been observed due to non-radial pulsations with periods of 0.97 and 2.19 days.
|
|
After expansion, He III begins to recombine into He II and the opacity of the star drops. This lowers the surface temperature of the star. The outer layers contract and the cycle starts from the beginning. The phase shift between a star's radial pulsations and brightness variations depends on the distance of He II zone from the stellar surface in the stellar atmosphere.
|
|
By the end of the 13-week run, the Pulsations/Fabulous Centuries became The Buckinghams. He was on hand at the Chess Records studios in Chicago, Illinois to record "Kind of a Drag" with the Buckinghams co-producer 'Dan Belloc and arranger Frank Tesinsky. Jim Holvay of the local Chicago group The Mob was the composer of "Kind of a Drag".
|
|
Zenneck (1903), Secondary sources Criticism : To explain universal gravitation, one is forced to assume that all pulsations in the universe are in phase—which appears very implausible. In addition, the aether should be incompressible to ensure that attraction also arises at greater distances. And Maxwell argued that this process must be accompanied by a permanent new production and destruction of aether.
|
|
They adopt various highly stereotyped and ritualised postures and associated plumage displays, which reveal prominent ocelli on remiges and rectrices. These behaviors are likewise used in self-defense. When utilised in pair-bonding behavior copulation may occur subsequent to lateral displays. Anterior displays are also performed which may include curious clicking and vibrating pulsations of feather quills created via stridulation.
|
|
Petrol engines often use simple fuel systems consisting of a float-type carburetor with a fuel tank located above it (so that the fuel is delivered by gravity, avoiding the need for a fuel pump). Sometimes, the fuel tank is located below the carburettor and fuel is delivered using engine vacuum or crankcase pressure pulsations. Diesel engines use fuel injection.
|
|
This results in increased pressure that pushes the layer back out again, the cycle repeating itself in a matter of hours. This is known as the Fe bump or Z bump (Z standing for the star's metallicity). The similar Slowly pulsating B stars show g-mode pulsations driven by the same iron opacity changes, but in less massive stars and with longer periods.
|
|
In the case of χ Cygni, its pulsations offer a way to directly measure the gravitation acceleration of layers in the atmosphere. The mass measured in this way is . Applying an empirical relation for Mira stars to χ Cygni gives a mass of . χ Cygni is losing mass at a rate of nearly each year through a stellar wind at 8.5 km/s.
|
|
Variations in the profiles of Alpha Camelopardalis' spectral lines are caused by fluctuations in the photosphere and stellar wind. This may be caused by non-radial pulsations. The absorption lines in the optical spectrum show radial velocity variations, although there is significant uncertainty about the period. Estimates range from a period as low as 0.36 days up to 2.93 days.
|
|
The total mass of the rings is about 0.1 solar masses. The pulsations that formed the rings probably started 15,000 years ago and ceased about years ago, when the formation of the bright central part began (see above). Further, a large faint halo extends to large distances from the star. The halo again predates the formation of the main nebula.
|
|
Pulsaciones (literally Pulsations, title in English Lifeline) is a Spanish thriller series produced by Globomedia for Antena 3. It premiered on January 10 and ended on March 14, 2017, and was a one-season, 10-episode series with a closed ending. The series was selected by consulting agency The WIT among the most remarkable international shows in the 2016 MIPTV Media Market.
|
|
It can contain unpalatable and malodourous chemicals that will act as a deterrent to predators. Hemolymph contains molecules, ions and cells. Regulating chemical exchanges between tissues, hemolymph is encased in the insect body cavity or haemocoel. It is transported around the body by combined heart (posterior) and aorta (anterior) pulsations which are located dorsally just under the surface of the body.
|
|
Positive displacement types such as piston compressors, or rotary types such as a Roots blower could also be used with suitable provisions for damping the pulsations in the air flow (however, other rotary types such as twin screw compressors are capable of providing a steady supply of compressed fluid). The pressure ratio of a single fan blade is too low and cannot be used.
|
|
Beta Cephei (β Cep) variables (sometimes called Beta Canis Majoris variables, especially in Europe)Variable Star Of The Season, Winter 2005: The Beta Cephei Stars and Their Relatives, John Percy, AAVSO. Accessed October 2, 2008. undergo short period pulsations in the order of 0.1–0.6 days with an amplitude of 0.01–0.3 magnitudes (1% to 30% change in luminosity). They are at their brightest during minimum contraction.
|
|
AG Draconis spends most of its time in a quiescent phase near visual magnitude 9.8, with only small semi-regular variations thought to be due to pulsations of the giant star. At its faintest, it can reach magnitude 10.3. The semi-regular variations have periods of 340 - 370 days. Variations at ultraviolet wavelengths occur with a period of 550 days, which is the orbital period.
|
|
Musically, "Va Va Voom" was described as "a sultry, electro-pop thumper" by Digital Spy. Lyrically, the song talks about "seduction finds Minaj playing the temptress atop some delicious dub-lite pulsations." It contains the lyrics "I know that he got a wife at home, but I need just one night alone." The verses of the song are rapped, while the bridge and chorus are sung.
|
|
They are believed to eventually lose mass, cool, and become DO white dwarfs.; Determination of Mass-Loss Rates of PG 1159 Stars from Far-Ultraviolet Spectroscopy, Lars Koesterke and Klaus Werner, Astrophysical Journal 500 (June 1998), pp. L55-L59., §4. Some PG 1159 stars have varying luminosities. These stars vary slightly (5-10%) in brightness due to non-radial gravity wave pulsations within themselves.
|
|
Extremely low frequency (ELF) is the range of radiation frequencies from 300 Hz to 3 kHz. In atmosphere science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to be in the ULF range, which is thus also defined differently from the ITU Radio Bands.
|
|
It shows pulsations with multiple periods from a few hours to 22 days, and both p- and g-modes. Apart from p- and g-modes, strange mode and associated instabilities have also been found in models of this star. The spectrum also shows variation, leading to different classifications being given for the star. The exact properties of 55 Cygni are not known precisely and are also variable.
|
|
Kazemi, S., Ghorbani, A., Amindavar, H., & Morgan, D. R. (2016). Vital-Sign Extraction Using Bootstrap-Based Generalized Warblet Transform in Heart and Respiration Monitoring Radar System. Zelinsky, N. R., & Kleimenova, N. G. Chirplet transform as the useful tool for study the time-frequency structure of geomagnetic pulsations. is a particular example of the chirplet transform introduced by Mann and Haykin in 1992 and now widely used.
|
|
These pulsations occur when a relativistic beam from the white dwarf sweeps across the red dwarf, which then reprocesses the beam into the observed electromagnetic energy. At present, the white dwarf is not accreting significantly, and the system is powered by the spin-down of the white dwarf. The pulsar is about the same size as Earth. AR Sco's unusual nature was first noticed by amateur astronomers.
|
|
He joined the Military College of Science at Woolwich in 1921, as professor of mathematics. He would remain at Woolwich until he retired in 1940, becoming President of the Royal Astronomical Society from 1939 until 1941. During his career he contributed to the Astrographic Catalogue, and contributed scientific papers. His investigations included photometric observations of short-period variables, and the radial pulsations of cepheid variables.
|
|
In the case of piston-type pumps this accumulator is placed in the ideal location to absorb pulsations of energy from the multi-piston pump. It also helps protect the system from fluid hammer. This protects system components, particularly pipework, from both potentially destructive forces. An additional benefit is the additional energy that can be stored while the pump is subject to low demand.
|
|
This type of variable includes subgiant or main sequence stars of spectral classes F5–A0, having masses between 1.5–2.5 solar masses and nearing the end of their core hydrogen fusion lifetime. Their pulsations are related to the same helium instability strip on the Hertzsprung–Russell diagram as that of classical Cepheids. Delta Scuti stars are located at the intersection of the strip with the main sequence.
|
|
This star is classified as an Alpha Cygni-type variable star that undergoes periodic non-radial pulsations, which cause its brightness to cycle from magnitude +2.93 to +3.08 over a 24.44 day interval. It is losing mass from its stellar wind at the rate of around times the mass of the Sun per year, or the equivalent of the Sun's mass every 500 million years.
|
|
Comparison of its properties with model evolutionary tracks suggest that it is a main sequence star about three quarters of the way through its main sequence lifetime. The apparent magnitude varies from +4.33 to +4.36 with a period of 5.03 hours. Its pulsations cause its radius to vary by 1.0% to 1.5%. At the same time its effective temperature by about above and below its mean temperature.
|
|
The drop in brightness is less pronounced at longer wavelengths, and the overall luminosity of the star is thought to be largely unchanged. The variations are caused by condensation of dust which temporarily obscures the star. Short wavelengths of light are absorbed and re-emitted as infra-red. Many R CrB variables show small amplitude pulsations and W Mensae has a pulsation period of approximately 67 days.
|
|
This regular behavior is in contrast with the variability of stars that lie parallel to and to the high-luminosity/low-temperature side of the classical variable stars in the Hertzsprung–Russell diagram. These giant stars are observed to undergo pulsations ranging from weak irregularity, when one can still define an average cycling time or period, (as in most RV Tauri and semiregular variables) to the near absence of repetitiveness in the irregular variables. The W Virginis variables are at the interface; the short period ones are regular and the longer period ones show first relatively regular alternations in the pulsations cycles, followed by the onset of mild irregularity as in the RV Tauri stars into which they gradually morph as their periods get longer. Stellar evolution and pulsation theories suggest that these irregular stars have a much higher luminosity to mass (L/M) ratios.
|
|
The OGLE survey published up to three periods for each OSARG, indicating a complex combination of pulsations. Many thousands of OSARGs were quickly detected in the Magellanic Clouds, both AGB and RGB stars. A catalog has since been published of 192,643 OSARGs in the direction of the Milky Way central bulge. Although around a quarter of Magellanic Cloud OSARgs show long secondary periods, very few of the galactic OSARGs do.
|
|
HP Lyr varies by about 0.5 magnitude over a "halfperiod" of 68.4 days. The formal period, defined for an RV Tauri variable as being from deep minimum to deep minimum is twice that length. Its spectrum changes from A2-3 at maximum to F2 at the deepest minima. The radial velocity changes are typical for the pulsations of an RV Tauri variable, but not compatible with a binary orbit.
|
|
Relative to its neighbors, this star has a peculiar velocity of . This is a somewhat evolved B-type subgiant star with a stellar classification of B2.5 IV. Telting and colleagues report it as a Beta Cephei variable with a high degree of confidence as they found regular pulsations in its spectrum in a high-resolution spectroscopy study published in 2006. Its brightness varies irregularly by 0.034 magnitude every 1.137 days.
|
|
Spontaneous venous pulsations are present in about 80 percent of patients with ODD, but absent in cases of true disc edema. Other causes of disc elevation clinicians must exclude may be: hyaloid traction, epipapillary glial tissue, myelinated nerve fibres, scleral infiltration, vitreopapillary traction and high hyperopia. Disorders associated with disc elevation include: Alagille syndrome, Down syndrome, Kenny-Caffey syndrome, Leber Hereditary Optic Neuropathy and linear nevus sebaceous syndrome.
|
|
RS Puppis is a classical Cepheid variable and its brightness changes regularly due to pulsations during which its size and temperature both vary. Its visual magnitude changes from 6.52 at maximum to 7.67 at minimum. The light curve shows a rapid rise in brightness with the slower drop in brightness taking about three times as long. It has a regular period of 41.5 days but it changes very slowly and erratically.
|
|
Turby prototype - TU Delft The Turby is a brand of vertical-axis Darrieus wind turbine. The three vertical aerofoil blades have a helical twist of 60 degrees, similar to Gorlov's water turbines . The turbine consists of three vertical symmetrical airfoil blades, each having a helical twist. The helical feature spreads the torque evenly over the entire revolution, thus preventing the destructive pulsations of the straight-bladed giromill (Darrieus turbine).
|
|
In the spectrum of this star, this high rate of spin is causing absorption lines to blend together because of the Doppler effect, making them more difficult to analyze. It is a periodically variable star that undergoes non-radial pulsations with a primary period of 1.1811 days and a secondary period of 0.1281 days. There is some disagreement about the mass of this star in the literature. Tetzlaff et al.
|
|
The turbine consists of three vertical airfoil blades, each having a helical twist of 120 degrees. This feature spreads the torque evenly over the entire revolution, thus preventing the destructive pulsations of the straight-bladed giromill (Darrieus turbine). The wind pushes each blade around on both the windward and leeward sides of the turbine. The qr5 turbine, rated for 6 kW, measures 3.0m in diameter by 5m high.
|
|
It is thought that the pulsations are of highest amplitude high in the atmospheres of these stars, where the density is lower. As a result, the spectral lines that are formed by elements that are radiatively levitated high in the atmosphere are likely to be most sensitive to measuring the pulsation, whereas the lines of elements such as iron, which gravitationally settle, are not expected to exhibit radial velocity variations.
|
|
Its parallax has been measured by very-long-baseline interferometry (VLBI), yielding a result of 2.39 ± 0.17 millarcseconds, which converts to a distance of 1300 ± 100 light-years. The masses of AGB stars are poorly known and cannot be calculated from their physical properties, but they can be estimated using asteroseismology. The pulsations of S Coronae Borealis lead to a mass estimate of 1.34 times that of the Sun.
|
|
A total of thirteen accreting millisecond X-ray pulsars have been discovered as of January 2011. Three of them are Intermittent millisecond X-ray pulsars (HETE J1900.1-2455, Aql X-1 and SAX J1748.9-2021), i.e. they emit pulsations sporadically during the outburst. On 21 August 2019 (UTC; 20 August in the US), Neutron Star Interior Composition Explorer (NICER) spotted the brightest X-ray burst so far observed.
|
|
The conclusion that the exterior field must also be stationary is more surprising, and has an interesting consequence. Suppose we have a spherically symmetric star of fixed mass which is experiencing spherical pulsations. Then Birkhoff's theorem says that the exterior geometry must be Schwarzschild; the only effect of the pulsation is to change the location of the stellar surface. This means that a spherically pulsating star cannot emit gravitational waves.
|
|
Spektr-RG observed the remnant four days prior to FRB 200428 and found no evidence of flaring activity. Followup studies and observations have been reported. On 4 June 2020, astronomers reported "periodic radio pulsations" from the remnant with the Medicina Northern Cross (MNC) radio observatory on 30 May 2020. Another study was reported on 6 June 2020 of observations made earlier with the European VLBI Network on 13 May 2020.
|
|
The primary component of the pair, κ Sco A, is a variable star of Beta Cephei type. It is undergoing radial pulsations with a dominant frequency of 4.99922 cycles per day, or 4.8 hours per cycle. There are overlapping secondary pulsation frequencies of about 4.85 and 5.69 cycles per day. This star has about 17 times the mass of the Sun and is nearly 7 times the Sun's radius.
|
|
These can be both congenital or develop over time with the thinning of the otic capsule by the persistent pulsations of the intracranial pressures against the bones of the skull. Finally, disease conditions—for example cholesteatoma—can result in a labyrinthine fistula. Traumatic events, with excessive pressure changes to the inner ear such as in scuba diving, head trauma, or an extremely loud noise can lead to rupture and leakage.
|
|
Three common descriptions of palpitation are "flip-flopping" (or "stop and start"), often caused by premature contraction of the atrium or ventricle, with the perceived "stop" from the pause following the contraction, and the "start" from the subsequent forceful contraction; rapid "fluttering in the chest", with regular "fluttering" suggesting supraventricular or ventricular arrhythmias (including sinus tachycardia) and irregular "fluttering" suggesting atrial fibrillation, atrial flutter, or tachycardia with variable block; and "pounding in the neck" or neck pulsations, often due to cannon A waves in the jugular venous, pulsations that occur when the right atrium contracts against a closed tricuspid valve. Palpitation associated with chest pain suggests coronary artery disease, or if the chest pain is relieved by leaning forward, pericardial disease is suspected. Palpitation associated with light- headedness, fainting or near fainting suggest low blood pressure and may signify a life-threatening abnormal heart rhythm. Palpitation that occurs regularly with exertion suggests a rate-dependent bypass tract or hypertrophic cardiomyopathy.
|
|
Classical Cepheids (or Delta Cephei variables) are population I (young, massive, and luminous) yellow supergiants which undergo pulsations with very regular periods on the order of days to months. On September 10, 1784, Edward Pigott detected the variability of Eta Aquilae, the first known representative of the class of Cepheid variables. However, the namesake for classical Cepheids is the star Delta Cephei, discovered to be variable by John Goodricke a few months later.
|
|
Lightcurve of κ Pavonis recorded by NASA's Transiting Exoplanet Survey Satellite (TESS). κ Pavonis ranges between apparent magnitudes 3.91 and 4.78, and spectral types F5 to G5, over a period of 9.1 days. It is a W Virginis variable, a type II Cepheid thought to be evolving along a blue loop from the thermal pulsing asymptotic giant branch. κ Pav shows sudden small changes in the period of its otherwise highly regular pulsations.
|
|
This star has a stellar classification of B4IV, and was the prototype of a class of variable stars known as slowly pulsating B stars. It was one of the first mid-B type variable stars in the northern hemisphere to be studied. The star undergoes non-radial pulsations with a primary period of 2.36 days. Observation of the star with the BRITE satellite revealed eight separate frequencies in the star's light curve.
|
|
This causes the star to be an oblate spheroid, with the equatorial radius 20% larger than the polar radius. It is estimated that the temperature of the photosphere is 23,300 K at the equator and 29,000 K at the poles, due to gravity darkening. In addition, the surface has temperature variations due to its pulsations. The effective temperature for the star as a whole is 24,600 K, to match the bolometric luminosity of .
|
|
This is a double star and possible binary system. The primary component has a stellar classification of G2 Ib/II, which places it on the borderline between the bright giant and lower luminosity supergiant stars. It has passed the first dredge-up and may be undergoind Cepheid-like pulsations. With more than four times the mass of the Sun, this is an evolved star that has reached its current stage after only 135 million years.
|
|
The spatial locations of the chemical overabundances have been shown to be connected with the geometry of the magnetic field. Some of these stars have shown radial velocity variations arising from pulsations of a few minutes. For studying these stars high- resolution spectroscopy is used, together with Doppler imaging which uses the rotation to deduce a map of the stellar surface. These patches of overabundances are often referred to as abundance spots.
|
|
Cepheid variables may pulsate in a fundamental mode, the first overtone, or rarely a mixed mode. Pulsations in an overtone higher than first are rare but interesting. The majority of classical Cepheids are thought to be fundamental mode pulsators, although it is not easy to distinguish the mode from the shape of the light curve. Stars pulsating in an overtone are more luminous and larger than a fundamental mode pulsator with the same period.
|
|
Last Polka in Nancy? is the second album by the free jazz quartet Center of the World, consisting of saxophonist Frank Wright, pianist Bobby Few, bassist Alan Silva and drummer Muhammad Ali. It was recorded live in 1973 at the Nancy Jazz Pulsations Festival and released on the French Center of the World label. The album was reissued on CD in 1999 by Fractal with a previously unreleased performance from a 1978 reunion.
|
|
BB Phoenicis is a variable star in the constellation of Phoenix. It has an average visual apparent magnitude of 6.17, being visible to the naked eye with excellent viewing conditions. From parallax measurements by the Gaia spacecraft, it is located at a distance of from Earth. Its absolute magnitude is calculated at 0.6. BB Phoenicis is a Delta Scuti variable, and shows stellar pulsations that cause brightness variations with an amplitude of 0.04 magnitudes.
|
|
Compressor surge is a form of aerodynamic instability in axial compressors or centrifugal compressors. The term describes violent air flow oscillating in the axial direction of a compressor, which indicates the axial component of fluid velocity varies periodically and may even become negative. In early literature, the phenomenon of compressor surge was identified by audible thumping and honking at frequencies as low as 1 Hertz, pressure pulsations throughout the machine, and severe mechanical vibration.
|
|
Part of the criteria of PCOS diagnosis includes elevated levels of androgens in the bloodstream or other signs of androgen excess (hyperandrogenism). The procedure causes a drop in serum androgen levels and possibly in estrogen levels. After ovarian follicles and stroma are destroyed, there is a reduction in these hormone levels. The procedure results in a decrease in plasma luteinizing hormone (LH) and in pulsations as well as a periodic drop in inhibin B levels.
|
|
The star is a Gamma Doradus variable: its luminosity changes because of non-radial pulsations of its surface. The star is also classified as a Lambda Boötis star, which means its surface layers are depleted in iron peak elements. It is the only known star which is simultaneously a Gamma Doradus variable, a Lambda Boötis type, and a Vega-like star (a star with excess infrared emission caused by a circumstellar disk).
|
|
AAVSO light curve of recurrent nova T CrB from 1 Jan 2008 to 17 Nov 2010, showing the pulsations of the red giant primary. Up is brighter and down is fainter. Day numbers are Julian day. T CrB normally has a magnitude of about 10, which is near the limit of typical binoculars. It has been seen to outburst twice, reaching magnitude 2.0 on May 12, 1866 and magnitude 3.0 on February 9, 1946.
|
|
Beta Cephei variables, also known as Beta Canis Majoris stars, are variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures of 200,000 K in their interiors. These stars are usually hot blue-white stars of spectral class B and should not be confused with Cepheid variables, which are named after Delta Cephei and are luminous supergiant stars.
|
|
The theoretical explanation for this limit is that stars above this mass can not radiate energy fast enough to remain stable, so any additional mass will be ejected in a series of pulsations until the star reaches a stable limit. The lower limit for sustained proton–proton nuclear fusion is about 0.08 or 80 times the mass of Jupiter. Below this threshold are sub-stellar objects that can not sustain hydrogen fusion, known as brown dwarfs.
|
|
Omicron¹ Eridani is an evolved F-type giant star with a stellar classification of F0 III. It is a Delta Scuti variable star that undergoes non-radial pulsations, with a variation of just 0.03 magnitude over a period of 0.0747 days. The star is spinning rapidly with a projected rotational velocity of 108.1 km/s and a rotation period of less than around 1.9 days. This is creating an equatorial bulge that is 11% wider than the polar radius.
|
|
The semiregular variable stars fall on one of five main period-luminosity relationship sequences identified, differing from the Mira variables only in pulsating in an overtone mode. The closely related OSARG (OGLE small amplitude red giant) variables pulsate in an unknown mode. Many semiregular variables show long secondary periods around ten times the main pulsation period, with amplitudes of a few tenths of a magnitude at visual wavelengths. The cause of the pulsations is not known.
|
|
It is a hot luminous supergiant several hundred thousand times as luminous as the sun. This star was originally a standard for the B3 Ia spectral type. The type of pulsations that 55 Cyg exhibits suggest that it was previously a red supergiant that has shed its outer layers. The most massive red supergiants are expected to pass through a blue supergiant phase before becoming a Wolf-Rayet star and eventually exploding as a type Ib or Ic supernova.
|
|
LP Andromedae (often abbreviated to LP And) is a carbon star in the constellation Andromeda. It is also a Mira variable whose mean apparent visual magnitude is 15.12 and has pulsations with an amplitude of 1.50 magnitudes and a period of 614 days. In 1974 LP Andromedae, known then as IRC+40540, was identified as a carbon star and also shown to be variable. It had previously been suspected of variability during the 2 Micron All Sky Survey (2MASS).
|
|
The band of White dwarfs has three separate regions types of variable: DOV, DBV, and DAV (= ZZ Ceti variables) white dwarfs. Each of these types of pulsating variable has an associated instability strip created by variable opacity partial ionisation regions other than helium. Most high luminosity supergiants are somewhat variable, including the Alpha Cygni variables. In the specific region of more luminous stars above the instability strip are found the yellow hypergiants which have irregular pulsations and eruptions.
|
|
The heat released during the reaction affects the density and hence turbulence. While the turbulent flow induces changes concentration and temperature pulsations which enhance the mixing and heat transfer and affect the reaction rate. Turbulence also results in deformations in burning flame surface due to which folding occurs and the surface is also broken into pieces of different sizes. This enhances the total surface area of the flame and thus increases the combustible mixed gases burnt per unit time.
|
|
V382 Carinae The radial velocity of V382 Carinae has long been known to be variable, but variations in its brightness were unclear. Brightness variations were detected by some observers, but others found it to be constant. It was formally named as a variable star in 1981, listed in the General Catalogue of Variable Stars as a possible δ Cephei variable. It has been described as a pseudo-Cepheid, a supergiant with pulsations similar to a Cepheid but less regular.
|
|
Estimates based on the oxygen spectral line strengths give much higher values luminosities with an absolute magnitude of at least −8. The central star is variable, from about magnitude 9.33 to 9.50. A primary period of 41 days has been determined, but a slightly shorter secondary period leads to long beats causing variations in the amplitude and apparent period from year to year. The variations are caused by stellar pulsations, with the star being brightest when it is hottest.
|
|
Intense study of large numbers of stars suggest that 6.7% of stars with temperatures between and show rapid small-amplitude pulsations but are not members of other variable star classes. These are potentially Maia variables. Maia is surrounded by the Maia Nebula (also known as NGC 1432), a reflection nebula that is one of the brightest patches of nebulosity within the Pleiades star cluster. It is the only member of the New General Catalogue discovered photographically.
|
|
In an electric power system, a harmonic is a voltage or current at a multiple of the fundamental frequency of the system, produced by the action of non- linear loads such as rectifiers, discharge lighting, or saturated magnetic devices. Harmonic frequencies in the power grid are a frequent cause of power quality problems. Harmonics in power systems result in increased heating in the equipment and conductors, misfiring in variable speed drives, and torque pulsations in motors.
|
|
The apparent link between the magnetic axis and the pulsation axis gives clues to the nature of the driving mechanism of the pulsations. As the roAp stars seem to occupy the main sequence end of the δ Scuti instability strip, it has been suggested that the driving mechanism may be similar, i.e. the opacity mechanism operating in the hydrogen ionization zone. No standard pulsation model can be made to excite oscillations of the roAp type using the opacity mechanism.
|
|
It can be operated as two separate units, each of equal capacity and each being driven by an independent crankshaft. Attached to the pump is a large spherical "air dome" or chamber, which acts as a pressure equaliser, reducing pulsations in water pressure generated by a 1000gpm pumping rate, thereby ensuring a constant flow of water. Incorporated in the front of the pump are 2 x 6inch suction inlets and 4 x deliveries - two on either side.
|
|
In this picture, the boundaries of the instability strip where pulsation sets in during the star's evolution correspond to a Hopf bifurcation. The existence of a center manifold eliminates the possibility of chaotic (i.e. irregular) pulsations on the time scale of the period. Although resonant amplitude equations are sufficiently complex to also allow for chaotic solutions, this is a very different chaos because it is in the temporal variation of the amplitudes and occurs on a long time scale.
|
|
Liu Chen (; born 1946 in Hangzhou, Zhejiang) is an American theoretical physicist who has made original contributions to many aspects of plasma physics. He is known for the discoveries of kinetic Alfven waves, toroidal Alfven eigenmodes, and energetic particle modes; the theories of geomagnetic pulsations, Alfven wave heating, and fishbone oscillations; and the first formulation of nonlinear gyrokinetic equations. Chen retired from University of California, Irvine (UCI) in 2012, assuming the title Professor Emeritus of physics and astronomy.
|
|
From observations, a twisted accretion disk, in retrograde precession, modulates the X-rays illuminating HZ Her and Earth. Uhuru observations revealed the presence of X-ray pulsations in Her X-1 (1.2 s) and confirmed that it contains a rapidly rotating neutron star. Figure adapted from figures by E. Schreier, STScI, taken from Figure 7-2a in Charles and Seward. The 1.24 second pulsar period associated with Her X-1 is immediately evident from the data.
|
|
The energy source of the pulsar is the rotational energy of the neutron star. The majority of known neutron stars (about 2000, as of 2010) have been discovered as pulsars, emitting regular radio pulses. In 1971, Riccardo Giacconi, Herbert Gursky, Ed Kellogg, R. Levinson, E. Schreier, and H. Tananbaum discovered 4.8 second pulsations in an X-ray source in the constellation Centaurus, Cen X-3. They interpreted this as resulting from a rotating hot neutron star.
|
|
Subsequent studies have reported an angular diameter (i.e., apparent size) ranging from 0.042 to 0.056 arcseconds; that range of determinations is ascribed to non- sphericity, limb darkening, pulsations and varying appearance at different wavelengths. It is also surrounded by a complex, asymmetric envelope, roughly 250 times the size of the star, caused by mass loss from the star itself. The Earth-observed angular diameter of Betelgeuse is exceeded only by those of R Doradus and the Sun.
|
|
The evolution of a star executing a blue loop from the AGB is expected to be rapid. Period changes in RU Cam before 1965 suggest that it would cross the entire instability strip in 31,000 years. Any secular period changes since then have been masked by irregularities. It is predicted that the temperature of RU Cam is increasing and it is approaching, or leaving, the bluer edge of the instability strip, in which case the pulsations would stop completely.
|
|
Other F-type stars include Procyon's primary star, the brightest star in the constellation Canis Minor. The supergiant pulsates, showing small variations in its brightness and spectral lines. The pulsations have been given periods of 67 and 123 days, with an amplitude of about 0.05 magnitudes. The profiles of many spectral lines show variations that would be expected from a pulsating spergiant, but it isn't clear if they have the same period as the brightness variations.
|
|
Cardarelli's sign is an abnormal pulsation of the trachea that may be found in patients with a dilation or aneurysm of the aortic arch.Cardarelli, A: Movimento medico-chirurgico, volume 11, Napoli, 1878. Cardarelli's sign can be felt by a physician pressing on the thyroid cartilage and displacing it to the patient's left. This increases contact between the left bronchus and the aorta, allowing systolic pulsations from the aorta to be felt at the surface if an aneurysm is present.
|
|
Westinghouse employee C. F. Scott was assigned to assist Tesla and later took over development of the induction motor at Westinghouse.Electrical World, Volume 78, No 7. page 340 Steadfast in his promotion of three-phase development, Mikhail Dolivo- Dobrovolsky invented the cage-rotor induction motor in 1889 and the three-limb transformer in 1890. Furthermore, he claimed that Tesla's motor was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work.
|
|
50 Persei is a star in the constellation Perseus. Its apparent magnitude is 5.52, which is bright enough to be seen with the naked eye. Located around distant, it is a White main-sequence star of spectral type F7V, a star that is currently fusing its core hydrogen. In 1998 the star was named a candidate Gamma Doradus variable with a period of 3.05 days, which would means it displays variations in luminosity due to non-radial pulsations in the photosphere.
|
|
Air vibrations could not set up pulsations through the skull as in a proper auditory organ. The spiracle was retained as the otic notch, eventually closed in by the tympanum, a thin, tight membrane. The hyomandibula of fish migrated upwards from its jaw supporting position, and was reduced in size to form the stapes. Situated between the tympanum and braincase in an air-filled cavity, the stapes was now capable of transmitting vibrations from the exterior of the head to the interior.
|
|
Type II Cepheids (historically termed W Virginis stars) have extremely regular light pulsations and a luminosity relation much like the δ Cephei variables, so initially they were confused with the latter category. Type II Cepheids stars belong to older Population II stars, than do the type I Cepheids. The Type II have somewhat lower metallicity, much lower mass, somewhat lower luminosity, and a slightly offset period verses luminosity relationship, so it is always important to know which type of star is being observed.
|
|
Delta Apodis (δ Aps, δ Apodis) is the Bayer designation for a double star in the southern constellation of Apus. The brighter star, δ¹ Apodis, is a M-type red giant and has an apparent magnitude that varies from magnitude +4.66 to +4.87. It is classified as a semiregular variable with pulsations of multiple periods of 68.0, 94.9 and 101.7 days. At an angular separation of 102.9 arcseconds is δ² Apodis, an orange K-type giant with an apparent magnitude of +5.27.
|
|
59 Aurigae, often abbreviated as 59 Aur, is a star in the constellation Auriga. Its baseline apparent magnitude is 6.1, meaning it can just barely be seen with the naked eye as a dim, yellow-white hued star. Based on parallax measurements, it is located about away from the Sun. This object is a Delta Scuti variable, meaning it varies in luminosity due to pulsations on its surface, ranging in magnitude from 5.94 down to 6.14 with a period of .
|
|
Satomura initially worked in areas of physics and in 1955 applied microwave and ultrasonic radiation to study defects in industrial materials. His supervisor, Kinjiro Okabe, advised him to extend those techniques to medical diagnosis of the human body. He teamed with cardiac physicians of the Osaka University Hospital and attempted to monitor the pulsations of heart and blood vessels. In December 1955 they published their first measurements of the Doppler shift of ultrasonic signals from a beating heart irradiated by 3 MHz waves.
|
|
IK Pegasi (or HR 8210) is a binary star system in the constellation Pegasus. It is just luminous enough to be seen with the unaided eye, at a distance of about 154 light years from the Solar System. The primary (IK Pegasi A) is an A-type main-sequence star that displays minor pulsations in luminosity. It is categorized as a Delta Scuti variable star and it has a periodic cycle of luminosity variation that repeats itself about 22.9 times per day.
|
|
Pulsations are common among Lambda Boötis star and seem to be more common than on normal main sequence stars of the same spectral type. BD Phoenicis is an A-type main-sequence star with a spectral type of A1Va. Stellar evolution models indicate it has about double the solar mass and an age of about 800 million years, having completed 83% of its main sequence lifetime. It is radiating 21 times the Sun's luminosity from its photosphere at an effective temperature of .
|
|
For beginners, the simulator is used to teach blood pressure measurement techniques and help students recognize a heart murmur. For more senior level medical students, Harvey can mimic heart sound variation with respiration, along with a variety of cardiac issues, such as carotid or jugular venous pulsations. Medical students and cardiologists are not the only people who use mannequins such as Harvey to learn bedside techniques. Other specialties, such as anesthesiology, internal medicine, and Emergency Medicine, have also seen benefit from the trainer.
|
|
How pulsations are excited in GW Vir stars was first studied in the 1980s but remained puzzling for almost twenty years. From the beginning, the excitation mechanism was thought to be caused by the so-called κ-mechanism associated with ionized carbon and oxygen in the envelope below the photosphere, but it was thought this mechanism would not function if helium was present in the envelope. However, it now appears that instability can exist even in the presence of helium. §1.
|
|
It has now exhausted its core hydrogen and expanded and cooled into a supergiant. Elemental abundance analyses indicate that it has not yet spent time as a red supergiant, which would have brought about convection of fusion products to the surface in a Dredge-up. ν Cephei is currently about 15 times as massive as the sun, 190 times as large, and 100,000 times as luminous. Its large size and luminosity cause it to be somewhat unstable and produce irregular pulsations.
|
|
The brightness variation is maximum in the v band, with an amplitude of 0.13 magnitudes. The light curve in this band is symmetrical and has two distinct minima separated by half a rotation period, while the two maxima are igual. In other bands the variability is smaller or even absent, and doesn't show a regular pattern like in v. The star is similar in many aspects to rapidly oscillating Ap stars, but does not display the rapid pulsations typical of these stars.
|
|
Betelgeuse is listed in the General Catalogue of Variable Stars with a possible period of 2,335 days. More detailed analyses have shown a main period near 400 days, a short period of 185 days, and a longer secondary period around 2,100 days. The lowest reliably-recorded V-band magnitude of +1.614 was reported in February 2020. Radial pulsations of red supergiants are well-modelled and show that periods of a few hundred days are typically due to fundamental and first overtone pulsation.
|
|
One difficulty with this interpretation is that there are no contemporary written reports of any supernova at that time or in that part of the sky, which may be due to the fact that most observers at the time were from the Northern hemisphere. The central compact object (CCO) was discovered in 2001. In the initial Chandra X-ray image and deeper images thereafter, no pulsations were detected from the compact remnant, which is believed to be a neutron star.
|
|
Alpha Lupi is a giant star with a stellar classification of B1.5 III. It has about ten times the mass of the sun (~) yet is radiating 25,000 times the Sun's luminosity. The outer atmosphere has an effective temperature of 21,820 K, which gives it the blue-white glow of a B-type star. In 1956 it was identified as a Beta Cephei variable by Bernard Pagel and colleagues, which means it undergoes periodic changes in luminosity because of pulsations in the atmosphere.
|
|
Gertrude had a vision on the Feast of John the Evangelist. She was resting her head near the Wound in the Savior's Side and hearing the Beating of the Divine Heart. She asked John if on the night of the Last Supper he had felt these Pulsations, why he had never spoken of the fact. John replied that this revelation had been reserved for subsequent ages when the world, having grown cold, would have need of it to rekindle its love.
|
|
Contradicting Freud, she concluded that the superego was present from birth. After exploring ultra-aggressive fantasies of hate, envy, and greed in very young and disturbed children, Melanie Klein proposed a model of the human psyche that linked significant oscillations of state, with the postulated Eros or Thanatos pulsations. She named the state of the psyche in which the sustaining principle of life is in domination the depressive position. This is considered by many to be her great contribution to psychoanalytic thought.
|
|
Among the treatments are closing wounds with sutures (for wounds of the lip, throat, and shoulder), bandaging, splints, poultices, preventing and curing infection with honey, and stopping bleeding with raw meat. Immobilization is advised for head and spinal cord injuries, as well as other lower body fractures. The papyrus also describes realistic anatomical, physiological and pathological observations. It contains the first known descriptions of the cranial structures, the meninges, the external surface of the brain, the cerebrospinal fluid, and the intracranial pulsations.
|
|
The timing of their migration is very regular with their arrival in winter to India in August and September and departure in April. During their winter period, they go through a premigratory moult. Their song in the winter quarters is faint and somewhat resembles the call of the rosy starling and often includes mimicry of other birds. The beak remains closed when singing and only throat pulsations are visible although the bird moves its tail up and down while singing.
|
|
With the supply of hydrogen at its core exhausted, the star has cooled and expanded. It now has 80 times the radius of the Sun. Eta Sculptoris is classified as a semiregular variable with a visual magnitude that fluctuates between +4.80 and +4.90, The pulsations have periods of 22.7, 23.5, 24.6, 47.3, 128.7 and 158.7 days. On average, this star is radiating over a thousand times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,641 K.
|
|
Mass loss increases as the mass decreases, the luminosity increases, and more fusion products are dredged up to the surface. They "ascend" the AGB until the mass loss becomes so extreme that they start to increase in temperature and enter the post-AGB phase, eventually to become a white dwarf. The evolution of a Mira variable should cause its period to increase, assuming it stays with the unstable region of pulsations. However, this secular trend is interrupted by the thermal pulses.
|
|
The X-ray source is eclipsed by the star every ~3.4 days, but no pulsations have yet been observed. The source is one of the ten brightest persistent X-ray sources in the 10-100 keV hard X-ray energy region. Evidence of Compton cooling during an X-ray flare recorded by the Chandra X-ray telescope strongly suggests that the compact object is a neutron star; if verified it would be among the most massive known, and near the boundary of the theoretical maximum.
|
|
We could only enter the playing > room with hands pressed hard against our ears, and even then it was > physically stunning. We ran a sick, outmoded beatbox through the P.A. and it > blew out horrendous distorted pulsations. Of course, we recorded the whole > thing, and a few months later we mixed it down into sections, ultra- > processing it to a wholly other "piece". In a way, it's my favorite record > of ours – I hope Jason [Knuth, to whom the release is dedicated] digs it.
|
|
They are pulsating due to the entire star expanding and contracting. This produces a change in temperature along with radius, both of which factors cause the variation in luminosity. The pulsation depends on the mass and radius of the star and there is a well- defined relationship between period and luminosity (and colour). The very large visual amplitudes are not due to large luminosity changes, but due to a shifting of energy output between infra-red and visual wavelengths as the stars change temperature during their pulsations.
|
|
She was on the Steering Committee of the International Geosphere- Biosphere Program from its start until September 1990. In the early days of the space age, after extensively studying magnetograms from all over the world, Valery developed a system of names for different types of magnetic pulsations, identifying them as either continuous (Pc's), or irregular (Pi's). She introduced colorful language (such as “pearls”) to characterize the appearance of some of these waves on magnetic records. Among Valery's notable publications is a paper Jacobs, J. A. et al.
|
|
The band's sound was highlighted by the authoritative and versatile vocals provided by Bonniwell, with an energized technique that juxtaposed the styles of Mick Jagger and Sky Saxon. Unlike these two contemporaries, Bonniwell possessed unusually good intonation in long-sustained passages, and the ability to breakdown phrases into a series of slow pulsations. The Music Machine's artistic stance was also highlighted by Landon's wiry guitar playing, Olsen's reverberant bass, and Edgar's cymbal- punctuated drumming, which gave the band a harder-edged sound than many of their contemporaries.
|
|
The pulsating stars swell and shrink, affecting their brightness and spectrum. Pulsations are generally split into: radial, where the entire star expands and shrinks as a whole; and non-radial, where one part of the star expands while another part shrinks. Depending on the type of pulsation and its location within the star, there is a natural or fundamental frequency which determines the period of the star. Stars may also pulsate in a harmonic or overtone which is a higher frequency, corresponding to a shorter period.
|
|
The effective temperature of VX Sagittarii is apparently highly variable from around 2,400 K at visual minimum to around 3,300 K near maximum. Such low temperatures are comparable to the very coolest AGB stars and unprecedented for a massive supergiant. Its atmosphere is highly extended, irregular, and variable during the pulsations of the star, but the bolometric luminosity varies much less than the visual brightness and is calculated to be about . At an effective temperature of 3,300 K, the radius is expected to be somewhere between and .
|
|
The upper panel shows the full light curve. The second panel is a blow-up where tiny secondary minima are visible (their depth is 1% of the deeper minimum). The third panel shows the projection on the plane of the sky (i.e. as we see the system) at different phases. From Carla Maceroni and the CoRoT binary team # HD 174884: Tidally induced pulsations have been detected in the high eccentricity (e=0.29) and short period binary system HD 174884 consisting of two B stars.
|
|
Zeta Reticuli has no known exosolar planets. On September 20, 1996, a tentative discovery of a hot Jupiter around ζ2 was reported, but the discovery was quickly retracted as the signal was shown to be caused by pulsations of the star. In 2002, ζ1 was examined at an infrared wavelength of 25 μm, but no indication of an excess of infrared radiation was found. In 2007, the Spitzer Space Telescope was used to find an apparent infrared excess at a wavelength of 70 μm around ζ2.
|
|
Photometric observations dating back to 1946 provide a lengthy record of its pattern of pulsation; it undergoes periodic pulsations with a single period of 0.14088143(3) days, or 7.1 cycles per day. During each cycle, the star's magnitude varies with an amplitude of 0.15 and the radial velocity varies by 10 km s−1. The peak brightness occurs 28.8 minutes following the minimum radial velocity. The outer atmosphere's effective temperature of 6,920 K is one of the lowest known for a Delta Scuti variable.
|
|
They failed the test, the committee concluded the raps were produced by bone and feet movements. A report by the Seybert Commission in 1887 stated that after investigating various mediums including Margaret; the phenomena could have easily been produced by fraudulent methods. The report noted that the raps were heard close to Margaret and a séance sitter, Professor Furness had felt pulsations in her foot. Kate was one of mediums examined by William Crookes, the prominent physicist, between 1871 and 1874, who concluded the raps were genuine.
|
|
" In the mid-1970s, Graves became fascinated by the notion of "the heartbeat as a primary source of rhythm." He stumbled on a recording of heart rhythms, and "was astonished by the similarities between cardiac arrhythmias and Afro-Cuban drumming patterns. Beyond the simple da-DUM of the heartbeat, he heard polyrhythmic pulsations, variable duration between beats, and a whole spectrum of frequencies. All this strengthened his conviction that true rhythm isn't metronomic and that the tone of the beat is as important as its duration.
|
|
The first crossing of the instability strip is very rapid and T Antliae is judged to be crossing it for the third time (the second time occurs with increasing temperature at the start of the blue loop). The brightness changes of Cepheid variables are caused by pulsations in their outer layers, causing both the temperature and radius to change. The radius of T Antliae has been calculated to vary by as it pulsates, around 10% of its radius. The temperature, and hence the spectral type, also vary.
|
|
Possible examples of pulsational pair-instability supernovae include the 1843 eruption of Eta Carinae A, and possibly SN 1000+0216 which could have been either a pulsational pair-instability supernova or a supernova of pair-instability. The 1961 Supernova-like events SN 1961V and SN 2010dn are believed to be the potential supernova impostors involving a massive LBVs (Luminous Blue Variables) and could have been pair-instability pulsations, as could the repeating events at iPTF14hls.This star cheated death, exploding again and again. Lisa Grossman, Science News.
|
|
The luminosity apparently also increased to over , something which has been seen in other LBVs but is thought to be unusual. This is likely to be beyond than the empirical Humphreys–Davidson limit at which stars become unstable because of their high luminosity. The brightness variations shown during the unusually cool outburst may be related to those shown by Cepheid variables and RV Tauri variables. The particularly low temperature brings R71 close to the instability strip where temperature-related opacity changes in the atmosphere cause regular pulsations.
|
|
Nematocysts, which deliver the sting, are located mostly on the tentacles; true jellyfish also have them around the mouth and stomach. Jellyfish do not need a respiratory system because sufficient oxygen diffuses through the epidermis. They have limited control over their movement, but can navigate with the pulsations of the bell-like body; some species are active swimmers most of the time, while others largely drift. The rhopalia contain rudimentary sense organs which are able to detect light, water-borne vibrations, odour and orientation.
|
|
For resonant modes the appropriate amplitude equations have additional terms that describe the resonant coupling among the modes. The Hertzsprung progression in the light curve morphology of classical (singly periodic) Cepheids is the result of a well-known 2:1 resonance among the fundamental pulsation mode and the second overtone mode. The amplitude equation can be further extended to nonradial stellar pulsations. In the overall analysis of pulsating stars, the amplitude equations allow the bifurcation diagram between possible pulsational states to be mapped out.
|
|
The light curves of intrinsic variable stars with large amplitudes have been known for centuries to exhibit behavior that goes from extreme regularity, as for the classical Cepheids and the RR Lyrae stars, to extreme irregularity, as for the so-called Irregular variables. In the Population II stars this irregularity gradually increases from the low period W Virginis variables through the RV Tauri variables into the regime of the semiregular variables. Low-dimensional chaos in stellar pulsations is the current interpretation of this established phenomenon.
|
|
Astronomers made more sense of its pulsations when it became clear that it is also a binary star system. The main star is a white main sequence star of spectral type A4V that is around 1.85 ± 0.05 times as massive as the Sun. Its companion is most likely a red dwarf of spectral type M3V, around 0.3 times as massive as the Sun. The two are very close—possibly only 3 times the diameter of the Sun between them—and orbit each other every 1.15 days.
|
|
The City of Milwaukee was authorized by the Wisconsin Legislature to construct the water tower in 1871. Designed by Charles A. Gombert, it was built out of limestone from Wauwatosa, Wisconsin to house the wrought iron standpipe. A pumping station below the bluff drew water from Lake Michigan and pumped it onward into the municipal waterworks. With The pipe inside the tower - four feet across and 120 feet tall - served to buffer the rest of the waterworks from destructive pulsations from the massive pumps.
|
|
This is known to reduce pulsations especially at higher flow rates. The piston and housing are constructed of materials that are inert to many liquids and gasses. Because the piston and housing are non-plastic materials the positive displacement chamber does not change in dimension from flexing and distortion thus allowing inductive pumps to remain very accurate with no significant changes over time. Inductive pumps are extremely accurate as each stroke contains the same volume created by a solid piston inside a solid chamber.
|
|
This is the final stage of a low-mass star's life, like Earth's Sun. Stars with a mass up to 8–10 solar masses evolve into red giants and slowly lose their outer layers during pulsations in their atmospheres. When a star has lost enough material, its temperature increases and the ultraviolet radiation it emits can ionize the surrounding nebula that it has thrown off. Our Sun will produce a planetary nebula and its core will remain behind in the form of a white dwarf.
|
|
Extremely low frequency (ELF) is radiation frequencies from 3 to 30 Hz (108 to 107 meters respectively). In atmosphere science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to lie in the ULF range, which is thus also defined differently from the ITU Radio Bands. A massive military ELF antenna in Michigan radiates very slow messages to otherwise unreachable receivers, such as submerged submarines.
|
|
While she contemplates the sky, the Moon appears to emanate pulsations, and the perspective shifts to what appears to be a moth. Now on the moon, the singer is shown dressed as an astronaut, while she's planting a Soviet flag. Björk appears to fall down from the Moon, and seemingly falls down in the Bear's throat, however she keeps singing even in the animal's stomach. During the breakdown, she dances in her hut tapping and looking at a bulb, while a moth falls down in her plate.
|
|
As well as being the prototype of the Cepheid class of variable stars, Delta Cephei is among the closest stars of this type of variable to the Sun, with only Polaris being nearer. Its variability is caused by regular pulsations in the outer layers of the star. It varies from magnitude 3.48 to 4.37, and its stellar classification also varies, from about F5 to G3. The pulsation period is 5.366249 days, with a rise to maximum occurring quicker than the subsequent decline to minimum.
|
|
For comparison with other type II Cepheids such as W Virginis variables, this formal period is twice the fundamental pulsation period. Therefore, although the approximate division between W Vir variables and RV Tau variables is at a fundamental pulsation period of 20 days, RV Tau variables are typically described with periods of 40–150 days. The pulsations cause the star to be hottest and smallest approximately halfway from the primary minimum towards a maximum. The coolest temperatures are reached near to a deep minimum.
|
|
Muggiaea atlantica swims in an arc, propelled by pulsations of its bell, and then remains stationary for several minutes. It feeds almost entirely on copepods, consuming an estimated five to ten prey items daily, mostly during the night. In the eastern Pacific it is eaten by predatory fish such as the blue rockfish (Sebastes mystinus), and by the floating sea snail Carinaria cristata. Reproduction in this species is by an alternation of generations between an asexual polygastric animal (bearing both asexual and reproductive elements) and the sexual eudoxid stage which becomes detached from the nectophore.
|
|
PSR J1311–3430 is a pulsar with a spin period of 2.5 milliseconds. It is the first millisecond pulsar found via gamma-ray pulsations. The source was originally identified by the Energetic Gamma Ray Experiment Telescope as a bright gamma ray source, but was not recognized as a pulsar until observations with the Fermi Gamma-ray Space Telescope discovered pulsed gamma ray emission. The pulsar has a helium-dominated companion much less massive than itself, and the two are in an orbit with a period of 93.8 minutes.
|
|
Kepler-447b is a confirmed exoplanet. The planet's mass and radius indicate that it is a gas giant with a bulk composition similar to that of Jupiter. Unlike Jupiter, but similar to many planets detected around other stars, Kepler-447b is located very close to its star, and belongs to the class of planets known as hot Jupiters. It has an extremely grazing transit, a property that could be used to detect further properties such as perturbations of the orbit due to other nearby objects or stellar pulsations.
|
|
Troitskaya, V. A., T. A. Plyasova, and A. V. Gulelmi, 1971 "Connection of PC2-4 pulsations with interplanetary magnetic field", Doklady Akademii Nauk SSSR, v.197, pp.1312 This bold insight was confirmed by later work. In 1996, a special session was held at the spring meeting of the American Geophysical Union to honor her in anticipation of her 80th birthday. Organized by Margaret Kivelson and David Southwood, the symposium entitled “ULF Waves: A Tribute to Valeria Troitskaya” brought together colleagues from many countries who paid tribute to their beloved and much appreciated Mme.
|
|
Propulsion of lymph from one lymphangion to next A lymphangion is the functional unit of a lymph vessel that lies between two semilunar (half moon- shaped) valves. Lymph vessels are channels larger than the lymph capillaries that have thicker walls, valves in their lumen and smooth muscles in their walls, thus lymph vessel lymphangion is muscular and capable of contracting on its own. Additionally the lymph in it is propelled forward only because of force exerted on its walls from the exterior. Such forces include skeletal muscle contractions and arterial pulsations.
|
|
He said: "Part of my reason for wanting to do that was my annoyance at people telling me that black South Africans were not interested in astronomy." Medupe received his doctorate in astronomy from the University of Cape Town for a thesis that studied the oscillations in stellar atmospheres. In particular, he investigated the interaction of radiative transfer and pulsations in the atmospheres of stars by solving non-adiabatic pulsation equations. He works as a researcher at SAAO and as a lecturer at the University of Cape Town.
|
|
The shapes of variable star light curves give valuable information about the underlying physical processes producing the brightness changes. For eclipsing variables, the shape of the light curve indicates the degree of totality, the relative sizes of the stars, and their relative surface brightnesses. It may also show the eccentricity of the orbit and distortions in the shape of the two stars. For pulsating stars, the amplitude or period of the pulsations can be related to the luminosity of the star, and the light curve shape can be an indicator of the pulsation mode.
|
|
Thévenot studied astronomy, physics, medicine, and magnetism, and demonstrated in the 1660s the possibility that atmospheric pulsations had something to do with human and animal respiration. Between 1658 and 1661 Thévenot conducted experiments on capillarity and the siphon. He proposed the use of lemon juice as a cure for various maladies, as well as ipecac as a remedy for dysentery. Thévenot can be credited in sponsoring a scientific study that contributed to the discovery of the nature and mechanism of fertilization both in humans and in animals in general.
|
|
The spectrum of this star matches a stellar classification of B1.5 IV, which indicates this star has entered the subgiant stage and is in the process of evolving into a giant star. It is radiating around 10,000 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 23,000 K, giving it a blue-white hue. This star has nearly 12 times the mass of the Sun and is roughly 15 million years old. Delta Lupi is a Beta Cephei variable star that undergoes periodic pulsations.
|
|
The Hertzsprung-Russell diagram (HR diagram) is a plot of luminosity versus a color index for a set of stars. IK Pegasi A is currently a main sequence star—a term that is used to describe a nearly linear grouping of core hydrogen-fusing stars based on their position on the HR diagram. However, IK Pegasi A lies in a narrow, nearly vertical band of the HR diagram that is known as the instability strip. Stars in this band oscillate in a coherent manner, resulting in periodic pulsations in the star's luminosity.
|
|
350px The unqualified term instability strip usually refers to a region of the Hertzsprung–Russell diagram largely occupied by several related classes of pulsating variable stars: Delta Scuti variables, SX Phoenicis variables, and rapidly oscillating Ap stars (roAps) near the main sequence; RR Lyrae variables where it intersects the horizontal branch; and the Cepheid variables where it crosses the supergiants. RV Tauri variables are also often considered to lie on the instability strip, occupying the area to the right of the brighter Cepheids (at lower temperatures), since their pulsations are attributed to the same mechanism.
|
|
Polaris Aa, the supergiant primary component, is a low-amplitude Population I classical Cepheid variable, although it was once thought to be a type II Cepheid due to its high galactic latitude. Cepheids constitute an important standard candle for determining distance, so Polaris, as the closest such star, is heavily studied. The variability of Polaris had been suspected since 1852; this variation was confirmed by Ejnar Hertzsprung in 1911. The range of brightness of Polaris during its pulsations is given as 1.86–2.13, but the amplitude has changed since discovery.
|
|
Premature Ventricular Contraction (PVC) can be seen in the PPG just as in the EKG and the Blood Pressure (BP). Venous pulsations can be clearly seen in this PPG. Because the skin is so richly perfused, it is relatively easy to detect the pulsatile component of the cardiac cycle. The DC component of the signal is attributable to the bulk absorption of the skin tissue, while the AC component is directly attributable to variation in blood volume in the skin caused by the pressure pulse of the cardiac cycle.
|
|
XX Pyxidis is a star located in the constellation Pyxis. It is one of the more-studied members of a class of stars known as Delta Scuti variables—short period (six hours at most) pulsating stars that have been used as standard candles and as subjects to study astroseismology. Astronomers made more sense of its pulsations when it became clear that it is also a binary star system. The main star is a white main sequence star of spectral type A4V that is around 1.85 ± 0.05 times as massive as the Sun.
|
|
Note the similarity with the observed light curve. From an analysis of the fixed points of the evolution operator a nice physical picture can be inferred, namely that the pulsations arise from the excitation of an unstable pulsation mode that couples nonlinearly to a second, stable pulsation mode which is in a 2:1 resonance with the first one, a scenario described by the Shilnikov theorem. This resonance mechanism is not limited to R Scuti, but has been found to hold for several other stars for which the observational data are sufficiently good.
|
|
The brighter star is deformed into an egg shape. AK Pyxidis is a red giant of spectral type M5III and semi-regular variable that varies between magnitudes 6.09 and 6.51. Its pulsations take place over multiple periods simultaneously of 55.5, 57.9, 86.7, 162.9 and 232.6 days. UZ Pyxidis is another semi-regular variable red giant, this time a carbon star, that is around 3560 times as luminous as the Sun with a surface temperature of 3482 K, located 2116 light-years away from Earth. It varies between magnitudes 6.99 and 7.83 over 159 days.
|
|
It can contain unpalatable and malodourous chemicals that will act as a deterrent to predators. Haemolymph contains molecules, ions and cells; regulating chemical exchanges between tissues, haemolymph is encased in the insect body cavity or haemocoel. It is transported around the body by combined heart (posterior) and aorta (anterior) pulsations, which are located dorsally just under the surface of the body. It differs from vertebrate blood in that it doesn't contain any red blood cells and therefore is without high oxygen carrying capacity, and is more similar to lymph found in vertebrates.
|
|
It is approximately 63 times as luminous the Sun, with a surface temperature of 5279 K. Delta Apodis is a double star, the two components of which are 103 arcseconds apart and visible through binoculars. Delta1 is a red giant star of spectral type M4III located 630 ± 30 light-years away. It is a semiregular variable that varies from magnitude +4.66 to +4.87, with pulsations of multiple periods of 68.0, 94.9 and 101.7 days. Delta2 is an orange giant star of spectral type K3III, located 550 ± 10 light-years away, with a magnitude of 5.3.
|
|
Lion's mane jellyfish ephyrae form between two medusas Lion's mane jellyfish remain mostly very near the surface, at no more than depth. Their slow pulsations weakly drive them forward, so they depend on ocean currents to travel great distances. The jellyfish are most often spotted during the late summer and autumn, when they have grown to a large size and the currents begin to sweep them to shore. Like other jellyfish, lion's manes are capable of both sexual reproduction in the medusa stage and asexual reproduction in the polyp stage.
|
|
He attended Lodi High School. His career began playing with Dan Kidney and the Pulsations for eight years 1987–1994. During the early 1990s Dr. Chud did a lot of studio sessions with various artist which some include Specific Ocean and Sardonica. He also recorded an album with Sacred Trash just before joining Kryst the Conqueror which transformed itself into the newest incarnation of the Misfits Dr. Chud recorded 3 studio albums, a live album, and a few singles with the Misfits and is also credited as a songwriter and producer for the band.
|
|
TV Geminorum changes its size, temperature, and luminosity as its brightness varies. The temperature changes between 3,500 K and 3,850 K, the radius between and , and the bolometric luminosity between and . The majority of the electromagnetic radiation is emitted at wavelengths longer than the visual band, being only around 20,000 times brighter than the sun at visual wavelengths. The pulsations are not correlated with the brightness changes in the expected way; other pulsating variables are brightest when they are hottest and smallest, but TV Gem does not follow this rule.
|
|
In 1979, examination of the spectrum of this star found "moving bumps" in its helium line profiles. This feature has since been found in other stars, which have come to be called ζ Oph stars. These spectral properties are likely the result of non-radial pulsations. This star is roughly halfway through the initial phase of its stellar evolution and will, within the next few million years, expand into a red supergiant star wider than the orbit of Jupiter before ending its life in a supernova explosion, leaving behind a neutron star or pulsar.
|
|
These are not massive stars, though; instead, they are stars of intermediate mass that have particularly low surface gravities, often due to instability such as Cepheid pulsations. These intermediate mass stars' being classified as supergiants during a relatively long-lasting phase of their evolution account for the large number of low luminosity yellow supergiants. The most luminous yellow stars, the yellow hypergiants, are amongst the visually brightest stars, with absolute magnitudes around −9, although still less than . There is a strong upper limit to the luminosity of red supergiants at around .
|
|
A hydraulic accumulator is a pressure storage reservoir in which an incompressible hydraulic fluid is held under pressure that is applied by an external source of mechanical energy. The external source can be an engine, a spring, a raised weight, or a compressed gas.Although liquids are generally considered to be practically incompressible, gases may be compressed and this compressed gas is a convenient energy store. An accumulator enables a hydraulic system to cope with extremes of demand using a less powerful pump, to respond more quickly to a temporary demand, and to smooth out pulsations.
|
|
Although it appears quite close to the open cluster NGC 2301 it is much farther away and is not a member of the cluster. It is at least 2,900 parsecs away, more than twice the distance of NGC 2301 HD 50064 has variously been assigned spectral types of B6, B9, and B1, and is readily seen to have a bright supergiant luminosity class. It also shows Hα emission lines with P Cygni profiles, indicating mass loss through a powerful stellar wind. HD 50064 shows small-amplitude semi- regular pulsations.
|
|
One strong period of 37 days has been interpreted as a strange mode oscillation and used to calculate the physical structure of the star. A luminosity of approximately 1,260,000 times that of the Sun -placing it among the brightest stars of the Milky Way-, a radius 200 times that of the Sun, and a mass 45 times larguer than the Sun, are derived. The pulsations and its spectrum are similar to those of Luminous blue variables (LBVs). The moderate mass loss suggests that it is an LBV caught pulsating and creating a circumstellar shell.
|
|
Phase lightcurve of variable star Delta Cephei. Classical Cepheids (also known as Population I Cepheids, type I Cepheids, or Delta Cepheid variables) undergo pulsations with very regular periods on the order of days to months. Cepheid variables were discovered in 1784 by Edward Pigott, first with the variability of Eta Aquilae, and a few months later by John Goodricke with the variability of Delta Cephei, the eponymous star for classical Cepheids. Most of the Cepheids were identified by the distinctive light curve shape with a rapid increase in brightness and a sharp turnover.
|
|
Some manufacturers of pulsation dampeners provide items which do not dampen pulsations. The compressibility of a gas, often nitrogen because it is inert at normal temperatures, stores any sudden volume change. Storing sudden volume change enables volume to change against a soft gas cushion, without the need to accelerate all the existing liquid in the system out of the way of the new volume coming from a pump. Therefore, as all the volume in a system does not have to be suddenly accelerated, the cushion is preventing "acceleration head" (force) having to be generated.
|
|
The spectrum then develops hydrogen emission lines. For several days either side of maximum brightness, the spectrum becomes a relatively normal class K. RU Cam remained a somewhat unusual W Virginis variable until 1964, when the relatively regular pulsation of about 1 magnitude almost entirely stopped. Since then the pulsations have varied from cycle to cycle, with amplitudes changing from several tenths of a magnitude to almost zero. The light curve has a more sinusoidal shape than when it was pulsating at full amplitude and the period changes erratically between 17.4 and 26.6 days.
|
|
Cepheid variables are divided into two subclasses which exhibit markedly different masses, ages, and evolutionary histories: classical Cepheids and type II Cepheids. Delta Scuti variables are A-type stars on or near the main sequence at the lower end of the instability strip and were originally referred to as dwarf Cepheids. RR Lyrae variables have short periods and lie on the instability strip where it crosses the horizontal branch. Delta Scuti variables and RR Lyrae variables are not generally treated with Cepheid variables although their pulsations originate with the same helium ionisation kappa mechanism.
|
|
The single did not receive any airplay in Uganda until three years later.. 'ATOOBA became a favourite on the underground hip hop scene and is still regarded as a Ugandan hip hop classic. It was one of the first major hip hop songs sung in Luganda or Lugaflow, the native Ugandan language. In 1997, Bataka Underground recorded their second hit, Ssesetula. They were able to perform at numerous clubs in Kampala, including Club Pulsations to Lido Beach, Club Silk, Botanical Gardens, Little Flowers, Bingo Cinema, and Sharing youth Center.
|
|
They also likely used medicinal herbs of the time, such as coca and alcohol for pain while balsam and saponin would be employed for antibiotic purposes. The Buddha's physician, Jīvaka Komārabhacca, performed surgery to remove two parasites from a patient's brain in the 5th century BCE. An ancient Egyptian treatise concerning trauma surgery, the Edwin Smith papyrus, contains descriptions and suggests treatments for various injuries, including some of neurological nature. Specifically, there are descriptions of the meninges, the external surface of the brain, the cerebrospinal fluid and the intracranial pulsations.
|
|
Changes in the visual magnitude, temperature, radius, and bolometric luminosity as χ Cygni pulsates χ Cygni is much larger and cooler than the sun, so large that it is thousands of times more luminous despite the low temperature. It pulsates, with both the radius and temperature varying over approximately 409 days. The temperature varies from about 2,400 K to about 2,700 K and the radius varies from about to . These pulsations cause the luminosity of the star to vary from about to , but they cause the visual brightness to vary by over 10 magnitudes.
|
|
The frequency of the pulsations correspond to the electrical oscillations normally present in the human brain while relaxing. In 1996, the Los Angeles Times deemed David Woodard's iteration of the Dreamachine "the most interesting object" in Burroughs' major visual retrospective Ports of Entry at LACMA.Knight, C., "The Art of Randomness", Los Angeles Times, August 1, 1996.Bolles, D., "Dream Weaver", LA Weekly, July 26–August 1, 1996. In a 2019 critical study, Beat scholar Raj Chandarlapaty revisits and examines Woodard's “idea-shattering” approach to the near-forgotten Dreamachine.
|
|
Gamma Doradus variables are variable stars which display variations in luminosity due to non-radial pulsations of their surface. The stars are typically young, early F or late A type main sequence stars, and typical brightness fluctuations are 0.1 magnitudes with periods on the order of one day. This class of variable stars is relatively new, having been first characterized in the second half of the 1990s, and details on the underlying physical cause of the variations remains under investigation. The star 9 Aurigae was first noticed to be variable in 1990.
|
|
There is an 8.8pc wide empty cavity in the interstellar medium around the star, presumably cleared by fast winds earlier in the star's life. AG Carinae is apparently in a transitional phase between a massive class O blue supergiant and a Wolf–Rayet star, where it is highly unstable and suffers from erratic pulsations, occasional larger outbursts, and rare massive eruptions. The spectral type varies between WN11 at visual minimum and an early A hypergiant at maximum. At visual minimum the star is about and 20,000–24,000K, while at maximum it is and 8,000K.
|
|
In 1979, the blue magnitude of HR 8768 was reported to vary by about 0.025 every 28 minutes. Such variability was not known for any class of variable, but the position in the Hertzsprung–Russell diagram at the main sequence (low luminosity) end of the same instability strip as the β Cephei stars would make high-overtone radial pulsations the likely cause. Follow-up studies failed to find the same rapid variations, or any significant variations in brightness. However, HR 8768 was added to the General Catalogue of Variable Stars as LN Andromedae.
|
|
In an effort to detect a new origin of gamma-ray emission, Roger Romani performed a deep search for counterparts of the brightest unidentified gamma-ray sources. His search uncovered optical and X-ray emission at the same location as 2FGL J1317.7–3429 that changed amplitude with a period of roughly 1.5 hours, and suggested that the origin could be a millisecond pulsar in a black-widow-type system, but also noted that this would need to be confirmed by the discovery of pulsations in the gamma-ray data or at radio wavelengths.Romani (2012) Within a few months, this conjecture was confirmed.
|
|
The detection and timing of the gamma ray pulsations was used to determine the spin period of the pulsar to be 2.5 milliseconds. The presence of the companion to the pulsar causes very slight variations in the time at which these pulses appear to be emitted, meaning precise timing allows the minimum mass of the companion to be determined using Kepler's third law. The minimum mass found with this method is 8.2 x 10−3 M_\odot, or roughly 8 times the mass of Jupiter. Optical spectroscopy of this companion reveal that it is composed primarily of helium, with no hydrogen detected.
|
|
Several KOIs contain transiting objects which are hotter than the stars they transit, indicating that the smaller objects are white dwarfs formed through mass transfer. These objects include KOI 74, KOI 81 and KOI 959. KOI 54 is believed to be a binary system containing two Class-A stars in highly eccentric orbits with a semi-major axis of 0.4 AU. During periastron, tidal distortions cause a periodic brightening of the system. In addition, these tidal forces induce resonant pulsations in one (or both) of the stars, making it only the 4th known stellar system to exhibit such behavior.
|
|
Both Aa and Ab apparently have a stellar classification of B1 III, with the luminosity class of III indicating giant stars that are evolving away from the main sequence. Component Aa rotates much more rapidly than Ab, causing its spectral lines to be broader, and so the two components can be distinguished in the spectrum. Component Ab, the slow-rotating star, has a strong magnetic field although no detected abundance peculiarities in its spectrum. Multiple pulsations modes have been detected in component Aa, some of which correspond to brightness variations, so this star is considered to be variable.
|
|
Southwood conducted post-doctoral research at the University of California, Los Angeles, working on magnetometer data from the ATS-1 spacecraft. He then returned to Imperial College in 1971, where he produced a theory of field-line resonances in the Earth's magnetosphere which now underpins most work on geomagnetic pulsations. In 1982 Southwood founded what became the Space and Atmospheric Physics Group and together with André Balogh decided to focus the group's experimental work on space magnetometers. This led to Imperial's involvement in a series of missions including Ulysses, Mars 96, Cluster, Cassini, Rosetta, BepiColombo, and Solar Orbiter.
|
|
The pulsations cause changes in both temperature and size, leading to large changes in the luminosity and brightness. The maximum temperature occurs when the star is at its brightest visually, when the star is also at its smallest. The minimum temperature and maximum radius occur at around phase 0.5 when the brightness is decreasing and nearly at minimum. Because relatively more infrared radiation is produced when the star is cooler, the maximum brightness in the infrared occurs when the visual brightness is already decreasing, and the maximum bolometric luminosity occurs at around phase 0.25 around halfway from maximum to minimum visual brightness.
|
|
One aspect to be considered is the large amount of energy which must be evacuated as residual heat (almost 95% of the total energy). This implies a large dedicated heat transfer surface. As regards to the mechanism for pulsing the core, the pulsed mode can be produced using a variety of configurations depending on the desired frequency of the pulsations. For instance, the use of standard control rods in a single or banked configuration with motor driving mechanism or the use of standard pneumatically operated pulsing mechanisms are suitable for generating up to 10 pulses per minute.
|
|
Zeta Geminorum has been reported to be a spectroscopic binary on the basis of lunar occultation observations, but this has not been confirmed by other methods. Zeta Geminorum's primary (WDS J07041+2034 Aa) is a Classical Cepheid variable that undergoes regular, periodic variation in brightness because of radial pulsations. In the V band, the apparent magnitude varies between a high of 3.68 and a low of 4.16 (with a mean of 3.93) over a period of 10.148 days. This period of variation is decreasing at the rate of 3.1 seconds per year, or 0.085 seconds per cycle.
|
|
The apparent magnitude of TX Piscium varies between +4.9 and +5.5 and it is classified as a slow irregular variable. Photometry has shown some periodicity in the brightness of 224 days, and some spectral variation over 450 days, suggesting the star is not entirely irregular. The star apparently lies on the period-luminosity relation corresponding to fundamental mode pulsations, unusual for a low-amplitude semi-regular or irregular variable which usually pulsate in an overtone. The angular diameter has been measured at around 10 mas, although this varies depending on the observed wavelength and the atmosphere appears to be highly asymmetric.
|
|
TX Piscium is a thermally-pulsing asymptotic giant branch (TP- AGB) star, which means that it is alternately fusing helium in a shell around its core and fusing hydrogen in a shell closer to its surface. Stars on the TP-AGB are generally unstable, with high mass loss and pulsations. The periodic flashes of the helium shell in a TP-AGB star are known as thermal pulses and cause the hydrogen shell to be extinguished. This creates strong convection and the third dredge-up (TDU) which brings helium fusion products such as carbon to the surface.
|
|
The brecciated fault zone is exposed along the road from Bogotá to La Calera and a vertical displacement of at least has been determined. The hanging wall of the reverse fault contains the Late Cretaceous Chipaque Formation and Guadalupe Group and the footwall consists of the Paleogene and Neogene Guaduas, Cacho and Bogotá Formations. Pulsations of the fault movement in the early Quaternary have produced the alluvial fans of the Tunjuelo Formation. In part, the fault is covered by Late Pleistocene deposits of the Sabana Formation showing a pre-Holocene activity with no known historical seismicity or registered damages.
|
|
Upsilon Cygni holds 9.3 times the mass of the Sun and is 4.7 times the Sun's radius. The rapid rotation is giving the star an oblate shape with an equatorial bulge that is 18% wider than the polar radius. It is radiating 7,305 times the solar luminosity from its outer atmosphere at an effective temperature of 22,000 K. The star shows variations in luminosity, including short term non-radial pulsations with periods of 2.95 and 2.6 per day, as well as random outbursts occurring up to every few years. The latter may be associated with mass-loss episodes.
|
|
"Screaming Wildman: Carl Bonafede, Joel Bierig: 9781539420965: Amazon.com: Books". www.amazon.com. page 24 5Retrieved 2017-09-14 Jon Jon Poulos approached Carl Bonafede head deejay who spun records for Dan Belloc's dances at the Holiday ballroom about becoming the manager of John's high school band "The Pulsations"."Screaming Wildman: Carl Bonafede, Joel Bierig: 9781539420965: Amazon.com: Books". www.amazon.com. page 169 Retrieved 2017-09-10 When USA Records released The Buckinghams from their contract, the band had a #1 hit on the Billboard Hot 100 charts with Kind of a Drag. The members voted to part ways with personal manager Carl Bonafede.
|
|
As such, it is much brighter than the Sun, emitting 14 times the luminosity from its outer atmosphere at an effective temperature of 8,939 K. This heat causes it to glow with the white-hot hue of an A-type star. 35 Aquilae is spinning rapidly with a projected rotational velocity of 110 km/s. In 1994 it was discovered that 35 Aquilae is a variable star with a pulsation period of just 30 minutes. It was determined to be a Delta Scuti variable, which is a type of star found on the instability strip that undergoes short period pulsations.
|
|
The Stoics propounded that knowledge can be attained through the use of reason. Truth can be distinguished from fallacy—even if, in practice, only an approximation can be made. According to the Stoics, the senses constantly receive sensations: pulsations that pass from objects through the senses to the mind, where they leave an impression in the imagination (phantasiai) (an impression arising from the mind was called a phantasma). VII.49 The mind has the ability to judge (συγκατάθεσις, synkatathesis)—approve or reject—an impression, enabling it to distinguish a true representation of reality from one that is false.
|
|
It has steadily increased by around 4.5 seconds per year except for a hiatus in 1963–1965. This was originally thought to be due to secular redward evolution across the Cepheid instability strip, but it may be due to interference between the primary and the first-overtone pulsation modes. Authors disagree on whether Polaris is a fundamental or first-overtone pulsator and on whether it is crossing the instability strip for the first time or not. The temperature of Polaris varies by only a small amount during its pulsations, but the amount of this variation is variable and unpredictable.
|
|
While the symptoms are well written and detailed, the absence of a medical precedent is apparent. The author of the passage notes "the pulsations of the exposed brain" and compared the surface of the brain to the rippling surface of copper slag (which indeed has a gyral-sulcal pattern). The laterality of injury was related to the laterality of symptom, and both aphasia ("he speaks not to thee") and seizures ("he shudders exceedingly") after head injury were described. Observations by ancient civilizations of the human brain suggest only a relative understanding of the basic mechanics and the importance of cranial security.
|
|
On the other hand, the same type of analysis shows that for the high L/M models κ is considerably larger (30% or higher). For the regular variables the small relative growth rates κ imply that there are two distinct time scales, namely the period of oscillation and the longer time associated with the amplitude variation. Mathematically speaking, the dynamics has a center manifold, or more precisely a near center manifold. In addition, it has been found that the stellar pulsations are only weakly nonlinear in the sense that their description can be limited powers of the pulsation amplitudes.
|
|
The name ZZ Ceti also refers to this class of pulsating variable white dwarfs, which, as it consists of white dwarfs with hydrogen atmospheres, is also called DAV. These stars have periods between 30 seconds and 25 minutes and are found in a rather narrow range of effective temperatures between about 12,500 and 11,100 K. The measurement of the rate of change of period with time for the gravity wave pulsations in ZZ Ceti stars is a direct measurement of the cooling timescale for a DA white dwarf, which in turn can give an independent measurement of the age of the galactic disk.
|
|
AR Scorpii (AR Sco) is a binary pulsar that consists of white dwarf and a red dwarf. It is the first "white dwarf-pulsar" to be discovered. The 3.56-hour period in AR Sco's light curve caused it to be misclassified as a Delta Scuti variable, but in 2016, this period was found to be the binary orbital period. In addition, the system shows very strong optical, ultraviolet, and radio pulsations originating from the red dwarf with a period of just 1.97 minutes, which is a beat period from the orbital rotation and the white dwarf spin.
|
|
The whole sequence of events takes only a fraction of a second. These pulsations are caused by repeated microexplosions which are the results of the continuous pressure on the reservoir and the oscillatory opening and closing of the valve that controls access to the reaction chamber. This pulsed mechanism is beneficial for the beetles' survival because the system uses pressure instead of muscles to eject the spray at a constant velocity, saving the beetle energy. Also, the reintroduction of new reactants into the vestibule where enzymes are stored, reduces the temperature of the chamber, thereby protecting the peroxidases and catalases from thermal denaturation.
|
|
The variability increases with decreasing wavelength, thus they are more obviously variable in ultraviolet spectrum than visible light. Their pulsations are non-radial, that is, they vary in shape rather than volume; different parts of the star are expanding and contracting simultaneously. These stars were first identified as a group and named by astronomers Christoffel Waelkens and Fredy Rufener in 1985 while looking for and analysing variability in hot blue stars. Improvements in photometry had made finding smaller changes in magnitude easier, and they had found that a high percentage of hot stars were intrinsically variable.
|
|
In general, the star became bluer from 1899 until 1990, and then redder again. The colour changes most likely reflect changes in the effective temperature, and probably underlying evolutionary trends with the star performing a blue loop between temperatures of and . Pulsations for much of this time occurred with an approximate period of 100 to 150 days, although this increased to 250 days between 2010 and 2017, which is expected for stars which are decreasing in temperature. At its coolest, the spectral type has been recorded as K4, while near its hottest in 2007 it was classifies F7.
|
|
This Crab-like pulsar was first discovered in X-rays in 1984 and subsequently detected at radio wavelengths. Astronomers initially attributed the glow to collisions of subatomic particles accelerated in the shock waves produced by supernova explosions, and it took more than six years of observations by Fermi's Large Area Telescope to detect gamma-ray pulsations from J0540-6919. In 2015, it was determined that J0540-6919 is responsible for about half of the gamma-ray flux from the Tarantula Nebula in the Large Magellanic Cloud. It was identified as a bright source of gamma radiation early in the Fermi mission.
|
|
St. Mechtilde revelation, with two other mystics :Dear Lord, I adore Thy Sacred Heart, which I desire to enter with acts of love, praise, adoration, and thanksgiving. I offer Thee my own heart as I sigh to Thee from its very depths, asking that Thou will worketh through me in all that I do this day; thus may I draw Thee closer to me than Thou wert before. I offer Thee all the crosses and sufferings of the world, in union with Thy life on earth, in expiation for sins. Please join my every action and heartbeat to the pulsations of Thy Heart.
|
|
RV Tau variables exhibit changes in luminosity which are tied to radial pulsations of their surfaces. Their changes in brightness are also correlated with changes in their spectral type. While at their brightest, the stars have spectral types F or G. At their dimmest, their spectral types change to K or M. The difference between maximum and minimum brightness can be as much as four magnitudes. The period of brightness fluctuations from one deep minimum to the next is typically around 30 to 150 days, and exhibits alternating primary and secondary minima, which can change relative to each other.
|
|
RV Tau was discovered to be variable in 1905 by Lydia Ceraski, and by 1907 it was clear that it had minima of alternating brightness. Over a period of 78.5 days it shows two maxima at around magnitude 9.5, a minimum around magnitude 10.0, and another minimum about 0.5 magnitudes fainter. This change in brightness is caused by pulsations: the temperature and radius vary, causing some variation in luminosity but mostly a shift of the emitted radiation from visual to infrared. The spectral type varies in line with the temperature, being classified as G2 at its brightest and M2 at its dimmest.
|
|
UX Lyncis is a star in the constellation Lynx. It is a red giant of spectral type M3. It has been classified as a semiregular variable ranging from magnitude 6.6 to 6.78, Its changes in brightness are complex, with a shorter period of 37.3 days due to the star's pulsations, and a longer period of 420 days possibly due to the star's rotation or convectively induced oscillatory thermal (COT) mode. Located around 800 light-years distant, it shines with a luminosity approximately 2240 times that of the Sun and has a surface temperature of 3323 K.
|
|
The star exhibits periodic radial velocity variations that are attributed to stellar spots on the surface of the star, based on the correlation between the radial velocity and the bisector inverse slope (a quantity that parametrises the shape of the spectral lines). The time period of the variations makes it unlikely that they are caused by stellar pulsations as these would be expected to occur on much shorter timescales (hours rather than days), and the correlation with the bisector inverse slope makes it unlikely that an orbiting companion is responsible as reflex motion would not cause the line profile variations.
|
|
DJ Rachael began her career as a disc jockey in 1995 and when she could finally stand on her own, other club owners started offering her opportunities to work at their clubs. She left Club Pulsations and joined Club Silk where she worked for eight years as an official and professional disc jockey. While there, she had time to fulfil contracts to play at public and private parties. She gained increasing recognition and received contracts to play at Club Sombreros in Jinja and was hosted at Club Florida 2000 and at Club Carnival, both in Nairobi and Stone Club in Mwanza.
|
|
In this case, the heart rate is determined by auscultation or audible sounds at the heart apex, in which case it is not the pulse. The pulse deficit (difference between heart beats and pulsations at the periphery) is determined by simultaneous palpation at the radial artery and auscultation at the PMI, near the heart apex. It may be present in case of premature beats or atrial fibrillation. Pulse velocity, pulse deficits and much more physiologic data are readily and simplistically visualized by the use of one or more arterial catheters connected to a transducer and oscilloscope.
|
|
A second book, The Polar Aurora (Oxford Press, 1955), contains both his experimental work on aurorae and his mathematical attempts to model them. In his review of this book, Canadian astronomer John F. Heard calls Størmer "the acknowledged authority" on aurorae. Heard writes, "The Polar Aurora will undoubtedly remain for many years a standard reference book; it belongs on the desk of anyone whose work or interest is involved with aurorae." Other astrophysical phenomena investigated by Størmer include pulsations of the earth's magnetic field, echoing in radio transmissions, nacreous clouds and luminous night clouds, zodiacal light, meteor trails, the solar corona and solar vortices, and cosmic rays.
|
|
Carlo Giacomini Carlo Giacomini (Sale, 29 November 1840 – Torino, 5 July 1898), was a noted Italian anatomist, neuroscientist, and a professor at the University of Turin who also made significant contributions in anthropology and embryology. He worked with the physiologist, Angelo Mosso (1846-1910), which led to the first recording of human brain pulsations. Giacomini vein, a lower limb vein, and the band of Gaicomini, a band of uncus gyri parahippocampalis he discovered in 1882, and the Giacomini vertebrae are named after him. He contributed anthropological research regarding differences among human races, and also took an interest in teratology linked to the various cases.
|
|
Giacomini vein At the beginning of his scientific career, he conducted clinical trials with the physiologist Angelo Mosso that led to the first recording of human brain pulsations. His early research includes studies on nerve abnormalities of the hand and the venous circulation of the lower limbs and blood of the upper limbs. The so-called vertebrae Giacomini (from the fifth to the eighth thoracic vertebra) are a dorsal limit of the heart. Since 1882, followed an in-depth study of brain morphology: describing the limbic lobe, a part of the hippocampal gyrus door today the name of band of Giacomini; deduced a complete work on the cerebral convolutions (1882).
|
|
This group consists of several kinds of pulsating stars, all found on the instability strip, that swell and shrink very regularly caused by the star's own mass resonance, generally by the fundamental frequency. Generally the Eddington valve mechanism for pulsating variables is believed to account for cepheid-like pulsations. Each of the subgroups on the instability strip has a fixed relationship between period and absolute magnitude, as well as a relation between period and mean density of the star. The period-luminosity relationship was first established for Delta Cepheids by Henrietta Leavitt, and makes these high luminosity Cepheids very useful for determining distances to galaxies within the Local Group and beyond.
|
|
In 1999, the Malherbe/Ehrlich duo was joined by American percussionist Steve Shehan and released the album Shamanimal as Hadouk Trio. Helped by excellent critical reception, the trio appeared at major festivals such as Nancy Jazz Pulsations. In 2001 his mastery of the duduk also led for an invitation by Djivan Gasparyan to appear at the international duduk festival in Armenia, then in Moscow and St Petersburg. That same year, he published a book of sonnets on reeds, L'Anche des Métamorphoses, which he later turned into a solo show, mixing poetry reading and musical interludes. In 2003 the second Hadouk Trio CD, Now, saw the light of day.
|
|
However, he found that the curve departed from a keplerian orbit and even suggested that it was a triple star system to explain the irregularities. The periodic variation in radial velocity of the Cepheid variables was later explained as being due to pulsations in the atmosphere of the star. The periodicity of the star is itself variable, a trend first noted by German astronomer Paul Guthnick in 1920, who suspected that the period change was the result of an orbiting companion. In 1930, Danish astronomer Axel Nielsen suggested that the change was instead the result in a steady decrease of about 3.6 seconds per year in the period.
|
|
The variation in light may be caused by a combination of radial pulsations in the star's atmosphere and by dimming from circumstellar dust. L2 Puppis is most likely an asymptotic giant branch star that has passed through the main sequence and is evolving to become a white dwarf. It is shedding mass at the rate of about per year, forming a circumstellar dust disk and bipolar plumes of gas that are thought to be the start of a "butterfly"-type planetary nebula. It has been calculated that the mass of L2 Puppis is currently about and its original mass was close to about 10 billion years ago.
|
|
It was rated 15 kV and extended over 175 km from the Lauffen waterfall on the Neckar river. The Lauffen power station included a 240 kW 86 V 40 Hz alternator and a step-up transformer while at the exhibition a step-down transformer fed a 100-hp three-phase induction motor that powered an artificial waterfall, representing the transfer of the original power source. The three-phase induction is now used for the vast majority of commercial applications. Mikhail Dolivo-Dobrovolsky claimed that Tesla's motor was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work.
|
|
At breeding time, female gonophores contain one to four actinulae (mobile tentaculate larvae), and these are released into the water column in a series of pulsations over the course of a few minutes. They can not actively swim but are attracted towards suitable species of sponge on which to settle, and may be attracted by the presence of chemical cues emitted by the sponge. They can settle within ten minutes on favourable substrates and can survive for about three days if no suitable substrate can be found. When settled, they quickly undergo metamorphosis and the new polyps that form develop tentacles and start feeding in about two days.
|
|
This is a B-type subgiant star with a stellar classification of B2 IV. It has no known companions, but does show radial velocity variations and higher order pulsations in the spectrum. The star is just 18 million years old with 8.5 times the mass of the Sun and has 4.2 times the Sun's radius. It is radiating around 4,000 times the Sun's luminosity from its photosphere at an effective temperature of about 21,638 K. This star is a proper motion member of the Upper-Centaurus Lupus sub-group in the Scorpius-Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.
|
|
Hertzsprung–Russell diagram showing the location of several types of variable stars superimposed on a display of the different luminosity classes. Classical Cepheids (also known as Population I Cepheids, Type I Cepheids, or Delta Cepheid variables) are a type of Cepheid variable star. They are population I variable stars that exhibit regular radial pulsations with periods of a few days to a few weeks and visual amplitudes from a few tenths of a magnitude to about 2 magnitudes. There exists a well-defined relationship between a classical Cepheid variable's luminosity and pulsation period, securing Cepheids as viable standard candles for establishing the galactic and extragalactic distance scales.
|
|
BPM 37093 (V886 Centauri) is a variable white dwarf star of the DAV, or ZZ Ceti, type, with a hydrogen atmosphere and an unusually high mass of approximately 1.1 times the Sun's. It is about 50 light-years from Earth, in the constellation Centaurus, and vibrates; these pulsations cause its luminosity to vary. Like other white dwarfs, BPM 37093 is thought to be composed primarily of carbon and oxygen, which are created by thermonuclear fusion of helium nuclei in the triple-alpha process.Late stages of evolution for low-mass stars, Michael Richmond, lecture notes, Physics 230, Rochester Institute of Technology, accessed online May 3, 2007.
|
|
WR 46 exhibits complex variability on relatively short time scales of a few hours. In the past there have been regular but intermittent changes in the radial velocity, multiple periods and photometric variation at some wavelengths, particularly ultraviolet. It has been proposed that this short-term behavior is due to non-radial pulsations, fast rotational modulation, or the presence of a lower-mass companion. Theories that are now discounted include WR 46 being a Super soft X-ray source or a V Sagittae star, The radial velocity changes of the spectral lines originating most deeply within the stellar wind show clear radial velocity variations with a period of 7.9 hours.
|
|
Takens' theorem guarantees that under very general circumstances the topological properties of this reconstructed evolution operator are the same as that of the physical system, provided the embedding dimension N is large enough. Thus from the knowledge of a single observed variable one can infer properties about the real physical system which is governed by a number of independent variables. This approach has been applied to the AAVSO data for the star R Scuti It could be inferred that the irregular pulsations of this star arise from an underlying 4-dimensional dynamics. Phrased differently this says that from any 4 neighboring observations one can predict the next one.
|
|
Light curve of DY Persei from 2014 to 2017, showing pulsations interrupted by a deep decline DY Persei was reported to be variable in 1947. It was initially classified as a semiregular variable star with a brightness range of magnitude 10.6 to 13.2 and an approximate period of 900 days. Further study revealed that it showed deep declines every few years as well as continuous variations with a rough period of 792 days. The deep declines were considered to be related to the declines seem in R CrB stars, but DY Persei was a unique example being a cool Carbon star and showing large amplitude semiregular variations when not in decline.
|
|
At the relatively young age of 26 million years, this massive star has burned through the hydrogen fuel at its core and evolved into a supergiant, giving it a baseline stellar classification of F6 Ibv. The periodic pulsations of this star actually cause the stellar class to vary between (F6.5–G2)Ib over the course of each cycle. Compared to the Sun, Eta Aquilae has around 9 times the mass, roughly 66 times the radius, and is radiating 11,474 times as much luminosity. This energy is being emitted from the outer envelope at an effective temperature of 6,000 K, giving it the yellow-white hued glow of an F-type star.
|
|
The star is a pulsating white dwarf of type DAV, with an extremely stable period. Small variations in the phase of pulsation led to the suggestion that the star was being orbited by a giant planet which caused the pulsations to be delayed due to the varying distance to the star caused by the reflex motion about the system's centre-of-mass. Observations with the Spitzer Space Telescope failed to directly detect the planet, which put an upper limit on the mass of 5–6 Jupiter masses. Investigation of a separate pulsation mode revealed timing variations in antiphase with the variations in the originally- analysed pulsation mode.
|
|
This movement contains the same compositional principles as the previous ones but also introduces the technique of cyclic meter trains, which has the function of introducing musical structures with a certain number of beats on a metric with a different amount, which causes that the drop of the metric and the particular structure to not coincide until after a certain number of iterations (which will be the least common multiple of the pulsations that make up both elements). In particular, the following diagram (Figure 6) shows how each structure (a 9/8 and 7/8, respectively) sounds twice, adjusting with the 2/8 bar every 9 and 7 iterations, respectively.
|
|
Vela X-1 is a pulsing, eclipsing high-mass X-ray binary (HMXB) system, associated with the Uhuru source 4U 0900-40 and the supergiant star HD 77581\. The X-ray emission of the neutron star is caused by the capture and accretion of matter from the stellar wind of the supergiant companion. Vela X-1 is the prototypical detached HMXB. The orbital period of the system is 8.964 days, with the neutron star being eclipsed for about two days of each orbit by HD 77581. The spin period of the neutron star is about 283 seconds, and gives rise to strong X-ray pulsations.
|
|
It has expanded to 57 times the Sun's radius and has a projected rotational velocity of 8.7 km/s. The star is radiating 372 times as much luminosity compared to the Sun from its enlarged photosphere at an effective temperature of 5,624 K. 14 Persei has been calculated to lie within the Cepheid instability strip although it is not considered to be variable. Uncertainty in the absolute magnitude means that the star may actually lie near the instability strip but not on it. Small periodic radial velocity variations are seen, but an order of magnitude or more smaller than for Cepheid variables and with longer periods than would be expected for pulsations.
|
|
The RGB OSARGs follow three closely spaced period-luminosity relations, corresponding to the first, second, and third overtones of radial pulsation models for stars of certain masses and luminosities, but that dipole and quadrupole non-radial pulsations are also present leading to the semi-regular nature of the variations. The fundamental mode does not appear, and the underlying cause of the excitation is not known. Stochastic convection has been suggested as a cause, similar to solar-like oscillations. Two additional types of variation have been discovered in RGB stars: long secondary periods, which are associated with other variations but can show larger amplitudes with periods of hundreds or thousands of days; and ellipsoidal variations.
|
|
In 1950, Valery became a graduate student at the Institute of Physics of the Earth in Moscow. In 1953 she obtained her Ph.D. specializing in the study of geomagnetic micropulsations (magnetic pulsations in current parlance)—naturally occurring Ultra Low Frequency (ULF) sinusoidal variations of the geomagnetic field with periods of about one second to ten minutes as recorded on special magnetograms. She remained at the Institute of the Physics of the Earth until 1989, serving as chairman of the Electromagnetics Department for the last 27 years. Recognizing the importance of understanding the spatial and temporal properties of ULF waves, Valery advocated the installation of magnetic observatories in Russia and in other countries.
|
|
There is evidence in favor of this view, notably that blue stragglers appear to be much more common in dense regions of clusters, especially in the cores of globular clusters. Since there are more stars per unit volume, collisions and close encounters are far more likely in clusters than among field stars and calculations of the expected number of collisions are consistent with the observed number of blue stragglers. NGC 6752, a globular cluster that contains a high number of blue straggler stars One way to test this hypothesis is to study the pulsations of variable blue stragglers. The asteroseismological properties of merged stars may be measurably different from those of typical pulsating variables of similar mass and luminosity.
|
|
The resulting temperature pulsations in the gaseous phase are the prime cause of the pressure changes there. The amplitude of the traveling thermal wave decreases strongly (exponentially) along its propagation direction, but if its propagation distance in the condensed phase is not too long, its amplitude near the gaseous phase is sufficient to create detectable pressure changes. This property of the thermal wave confers unique features to the detection of light absorption by the photoacoustic method. The temperature and pressure changes involved are minute, compared to everyday scale – typical order of magnitude for the temperature changes, using ordinary light intensities, is about micro- to millidegrees and for the resulting pressure changes is about nano- to microbars.
|
|
In an in-depth review of the album's lyrics Ken Capobianco of The Boston Globe wrote; Brad Wete of Billboard called the album's lyrical style sharp and noted its wordplay; Wete also described the album as "insular" with lyrics containing "cuts" that "run deep, searing with spite and indifference", continuing to note the album's themes as revolving around love interests, inward thinking and "chronicling her wearisome romantic history". Erin Lowers from XXL noted relationships, dreams, and aspirations as the three main concepts layered throughout the album. Bradley Stern from Time, called the album's lyrical content "occasionally snappy", which he described as keeping the otherwise "gentle pulsations" of the album feeling "fresh" and "employing expressions".
|
|
It measures the changing absorbance at each of the wavelengths, allowing it to determine the absorbances due to the pulsing arterial blood alone, excluding venous blood, skin, bone, muscle, fat, and (in most cases) nail polish. Reflectance pulse oximetry is a less common alternative to transmissive pulse oximetry. This method does not require a thin section of the person's body and is therefore well suited to a universal application such as the feet, forehead, and chest, but it also has some limitations. Vasodilation and pooling of venous blood in the head due to compromised venous return to the heart can cause a combination of arterial and venous pulsations in the forehead region and lead to spurious SpO2 results.
|
|
Early calculations suggested that white dwarfs should vary with periods around 10 seconds, but searches in the 1960s failed to observe this. The first variable white dwarf found was HL Tau 76; in 1965 and 1966, Arlo U. Landolt observed it to vary with a period of approximately 12.5 minutes. The reason for this period being longer than predicted is that the variability of HL Tau 76, like that of the other pulsating variable white dwarfs known, arises from non-radial gravity wave pulsations. In 1970, another white dwarf, Ross 548, was found to have the same type of variability as HL Tau 76; in 1972, it was given the variable star designation ZZ Ceti.
|
|
Hydraulic power was used for various purposes throughout the Stirling. The nose and dorsal turrets were powered by a duplex pump driven by the inner port engine, while the dorsal turret was powered by a single pump driven by the inner starboard engine. Pulsations in the hydraulic lines were smoothed out by a series of recuperators; German fighter pilots soon learned that by shooting at the area around roundels painted on the fuselage, two of the three turrets could be disabled and the recuperators were moved in later models of the Stirling to reduce their vulnerability. The first production model of the Stirling was powered by the Bristol Hercules II radial engine, which were housed in fully monocoque nacelles.
|
|
It has been previously classified as a Be star, which would explain the variability as stellar pulsations, but this classification was probably due to accidental observation of the nearby Be star δ Centauri. A 2004 study showed that the 1.295 day period is actually the rotation period of the star, and that the variability is caused by non-homogeneous distribution of elements in the stellar surface. In particular, HD 105382 is a helium-weak chemically peculiar star with a helium abundance varying between 0.5% and 15% of the solar abundance, and a silicon abundance varying between 0.00044% and 0.0069% the solar value. Regions with more helium appear to coincide with the regions with less silicon, and vice versa.
|
|
29 Heriot Row, Edinburgh The grave of Patrick Newbigging, Dean Cemetery, Edinburgh He was born at 18 St Andrew SquareEdinburgh and Leith Post Office Directory 1813–14 in Edinburgh's New Town the son of Lilias Steuart and her husband, the Edinburgh surgeon Sir William Newbigging. He studied medicine at the University of Edinburgh. While a student he joined the Royal Medical Society and gave a dissertation to the Society in 1833 on the origin of heart sounds and pulsations. In this he suggested that the apex beat was produced by ventricular systole and not diastole as had been suggested by William Stokes and Dominic Corrigan and was the prevalent view at the time.
|
|
It is larger than the Sun, with nearly nine times the mass and almost five times the radius. This star is radiating around 4,000 times as much luminosity as the Sun from its outer atmosphere at an effective temperature of 21,400 K, giving it the blue-white hue of a B-type star. Alpha Muscae appears to be a Beta Cephei variable star. Telting and colleagues report it as a Beta Cephei with a high degree of confidence as they found regular pulsations in its spectrum in a high-resolution spectroscopy study published in 2006, although Stankov and Handler (2005) listed it as a poor or rejected candidate in their Catalog of Galactic β Cephei Stars.
|
|
It is a semiregular variable star that varies between a maximum magnitude of 6.14 and minimum magnitude of 6.42. Periods of 27.7, 143.3 and 208.3 days have been recorded in its pulsations. AZ, AD and BI Canis Minoris are Delta Scuti variables—short period (six hours at most) pulsating stars that have been used as standard candles and as subjects to study astroseismology. AZ is of spectral type A5IV, and ranges between magnitudes 6.44 and 6.51 over a period of 2.3 hours. AD has a spectral type of F2III, and has a maximum magnitude of 9.21 and minimum of 9.51, with a period of approximately 2.95 hours. BI is of spectral type F2 with an apparent magnitude varying around 9.19 and a period of approximately 2.91 hours.
|
|
For alternating current technology has been well established in the modern world, the parameter for measuring conducted emissions is well understood and is called Total harmonic distortion (%THD). It measures power quality of AC mains for different voltage levels as described in common EMC test standards. By definition, the AC harmonic is a multiple of the electrical quantity (voltage or current) at multiples of the fundamental frequency of the system, produced by the action of non-linear loads such as rectifier, lighting, or saturated magnetic devices. Harmonic frequencies in the power grid are a frequent cause of power quality problems and can result in increased heating in the equipment and conductors, misfiring in variable speed drives, and torque pulsations in motors.
|
|
Purely for illustrative purposes, a method to mitigate this would be to add an 0.5 volt constant bias to the input voltage so the it now can swing +/− 0.5 V about the bias. This now has zero pulses in the countstream when the input is −0.5 V. Then we must limit the input swing to +/− 0.4 V, say, so that the minimum countstream frequency is greater than zero. We can choose the clock frequency so that the minimum countstream frequency at −0.4 V is much greater than the Nyquist rate, so that even the highest input frequency component is resolved. We can increase the clock frequency still higher until a lowpass filter sufficiently removes the pulsations while fully recovering the input signal.
|
|
The primary component, Delta Aquilae A, is a subgiant star with a stellar classification of F0 IV, where the luminosity class of IV indicates it is in the process of exhausting the supply of hydrogen at its core and evolving into a giant star. The mass of the star is 65% greater than the Sun and it has expanded to more than double the Sun's radius. It is radiating around 7–8 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 7,016 K, giving it the yellow- white hue of an F-type star. Delta Aquilae A is a Delta Scuti variable that exhibits variations in luminosity caused by pulsations in its outer envelope.
|
|
In contrast with this approach, the statements made by Urechia in his conflict with Lazăr Şăineanu show an antisemitic side to his Romanianism, which academic Michael Shafir rates as "cultural" and "economic" rather than "racial". While debating Şăineanu's status in academia, Urechia claimed: "A person foreign to our nation's fiber could never awaken in the mind and heart of the young generation the image of our past [...]. How will that person recognize those pulsations in the historical life of Romanians, when he has nothing in common with [the people's] aspirations?" Urechia was especially adverse to Şăineanu's study on the traditional references to Jews as "Tatars" and Uriaşi, as a reference to an Early Medieval presence of Khazars in present-day Romanian territories.
|
|
Very few intrinsic S stars have had their mass directly measured using a binary orbit, although their masses have been estimated using Mira period-mass relations or pulsations properties. The observed masses were found to be around until very recently when Gaia parallaxes helped discover intrinsic S stars with solar-like masses and metallicities. Models of TP-AGB evolution show that the third dredge-up becomes larger as the shells move towards the surface, and that less massive stars experience fewer dredge-ups before leaving the AGB. Stars with masses of will experience enough dredge-ups to become carbon stars, but they will be large events and the star will usually skip straight past the crucial C/O ratio near 1 without becoming an S-type star.
|
|
American astronomer Edwin Brant Frost discovered the variation in radial velocity of Beta Cephei in 1902, initially concluding it was a spectroscopic binary. Paul Guthnick was the first to detect a variation in brightness, in 1913. Beta Canis Majoris and Sigma Scorpii were found to be variable not long afterwards, Vesto Slipher noted in 1904 that Sigma Scorpii's radial velocity was variable, and R.D. Levee and Otto Struve concluded this was due to the star's pulsations in 1952 and 1955 respectively. These variables were often called Beta Canis Majoris variables because Beta Canis Majoris was the most closely studied example in the first half of the 20th century, though its location in the southern sky meant that its lowness in the sky hampered observations.
|
|
Astronomical observations near the Earth's poles can be done over long periods, without the diurnal variations at lower latitudes. The South Pole is at an altitude of nearly , so the astronomical seeing should be comparable to other high- altitude observatories; the extreme cold in Antarctica also corresponds to relatively little water vapor in the atmosphere there, which is a particular advantage for infrared astronomy. Finally, the South Pole lies at the top of a very deep, nearly permanent ice sheet that has been used to advantage in experiments such as the IceCube Neutrino Detector. Pomerantz' own research is particularly noted for his development of helioseismology, which is study of pressure waves in the sun. In 1960, observations of the sun revealed unexpected pulsations in the image.
|
|
28, 29, 283, 326, 327, 386. Available on Google Books these two architectures, centered or not, are achieving some forms of "perspective" (within the meaning of the Renaissance) in which the vanishing point lies, in the first case, in a physical center (the server), in the second in a "code" under cover of which the network is sharing information (its sign of recognition in some way). He speaks in the first case of a "temporal perspective" because it is in the center where emerges moment by moment the "proper time" of the network (its rhythmic pulsations). In the second case, he speaks of a "digital perspective"Olivier Auber : Du Générateur poïétique à la perspective numérique, Revue d'esthétique 43 - 07/2003 - p.
|
|
RV Tauri variables like SX Centauri are supergiant pulsating stars and a subtype of the population II Cepheids. They are stars that have already passed the asymptotic giant branch (AGB) and are in the last stage of their evolution before becoming a planetary nebula. This transition phase is very fast, and may last for less than a thousand years. SX Centauri is in the beginning of this process and is estimated to be leaving the AGB right now, or to have left the AGB a few decades ago. Its pulsations are radial in nature and have a period of about 32.9 days (from deep minimum to deep minimum), causing the effective temperature of the star to vary between 5,000 and 6,500 K and the radius between 21 and 29 solar radii.
|
|
In the related magnetosphere science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to lie in the ULF range, which is thus also defined differently from the ITU radio bands. ELF radio waves are generated by lightning and natural disturbances in Earth's magnetic field, so they are a subject of research by atmospheric scientists. Because of the difficulty of building antennas that can radiate such long waves, ELF frequencies have been used in only a very few human-made communication systems. ELF waves can penetrate seawater, which makes them useful in communication with submarines, and a few nations have built military ELF transmitters to transmit signals to their submerged submarines, consisting of huge grounded wire antennas (ground dipoles) long driven by transmitters producing megawatts of power.
|
|
The HARPS can attain a precision of 0.97 m/s (3.5 km/h), with an effective precision of the order of 30 cm s−1, making it one of only two instruments worldwide with such accuracy. This is due to a design in which the target star and a reference spectrum from a thorium lamp are observed simultaneously using two identical optic fibre feeds, and to careful attention to mechanical stability: the instrument sits in a vacuum vessel which is temperature-controlled to within 0.01 kelvins. The precision and sensitivity of the instrument is such that it incidentally produced the best available measurement of the thorium spectrum. Planet- detection is in some cases limited by the seismic pulsations of the star observed rather than by limitations of the instrument.
|
|
UV HST images of Betelgeuse showing asymmetrical pulsations with corresponding spectral line profiles In the 1970s, astronomers saw some major advances in astronomical imaging technology, beginning with Antoine Labeyrie's invention of speckle interferometry, a process that significantly reduced the blurring effect caused by astronomical seeing. It increased the optical resolution of ground-based telescopes, allowing for more precise measurements of Betelgeuse's photosphere. With improvements in infrared telescopy atop Mount Wilson, Mount Locke, and Mauna Kea in Hawaii, astrophysicists began peering into the complex circumstellar shells surrounding the supergiant, causing them to suspect the presence of huge gas bubbles resulting from convection. But it was not until the late 1980s and early 1990s, when Betelgeuse became a regular target for aperture masking interferometry, that breakthroughs occurred in visible-light and infrared imaging.
|
|
The star is an aging red giant of spectral type M3IIIab, currently on the asymptotic giant branch, having exhausted the hydrogen at its core and evolved away from the main sequence. It has been classified as a slow irregular variable, after being found to be slightly variable in 1969 by Olin J. Eggen. Its changes in brightness are complex, with two shorter changeable periods of 35–40 and 47–50 days due to the star's pulsations, and a longer period of 1500 days possibly due to the star's rotation or convectively induced oscillatory thermal (COT) mode. The star has expanded to 156 times the Sun's radius and it is radiating 2,848 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,485 K.
|
|
Blood flow in the intracranial OA segment is affected by intracranial pressure, while flow in the extracranial (intraorbital) OA segment is influenced by the externally applied pressure (Pe) to the eyeball and orbital tissues. As with a sphygmomanometer, a special pressure cuff is used - in this case, to compress the tissues surrounding the eyeball and also intraorbital tissues surrounding the extracranial segment of OA. External pressure changes the characteristics of blood flowing from inside the skull cavity into the eye socket. In place of the stethoscope, a Doppler ultrasound beam measures the blood flow pulsations in intracranial and extracranial segments of the ophthalmic artery. The non- invasive ICP meter based on this method gradually increases the pressure over the eyeball and intraorbital tissues so that the blood flow pulsation parameters in two sections of the OA are equal.
|
|
In February 2016, BaDoinkVR announced a partnership with Amsterdam based sex-technology manufacturer KIIROO, who have been developing sex toys embedded with manufacturer of haptic technology, also known as teledildonics. The sex toys are able to connect remotely using an internet connection, which allows the paired devices to send haptic feedback to one another through kinaesthetic movements, vibrations and pulsations. The two-way flow of remote connection and haptic touch feedback facilitates the simulation of sexual relations over a distance.Sex, stress and teledildonics The Guardian Retrieved on 2016-08-17Virtual Sexology Is Here to Edutain the Eager Masses Sputnik News Retrieved on 2016-08-17VR porn therapy: BaDoinkVR Deccan Chronicle Retrieved on 2016-08-17 The two companies have also worked together on collaborative projects producing virtual reality videos focusing on sex education and virtual sexology.
|
|
Lispector worked on a book called Um sopro de vida: pulsações (A Breath of Life: Pulsations) that would be published posthumously in the mid-1970s. The book consists of a dialogue between an "Author" and his creation, Angela Pralini, a character whose name was borrowed from a character in a story in Where Were You at Night. She used this fragmentary form for her final and perhaps most famous novel, A Hora da estrela (The Hour of the Star, 1977), piecing the story together, with the help of Olga Borelli, from notes scrawled on loose bits of paper. The Hour of the Star tells the story of Macabéa, one of the iconic characters in Brazilian literature, a starving, poor typist from Alagoas, the state where Lispector's family first arrived, lost in the metropolis of Rio de Janeiro.
|
|
With Anna Żytkow, Thorne predicted the existence of red supergiant stars with neutron-star cores (Thorne–Żytkow objects). He laid the foundations for the theory of pulsations of relativistic stars and the gravitational radiation they emit. With James Hartle, Thorne derived from general relativity the laws of motion and precession of black holes and other relativistic bodies, including the influence of the coupling of their multipole moments to the spacetime curvature of nearby objects, as well as writing down the Hartle-Thorne metric, an approximate solution which describes the exterior of a slowly and rigidly rotating, stationary and axially symmetric body. Thorne has also theoretically predicted the existence of universally antigravitating "exotic matter" – the element needed to accelerate the expansion rate of the universe, keep traversable wormhole "Star Gates" open and keep timelike geodesic free float "warp drives" working.
|
|
With the hydrogen consumed in their core region, these unstable stars are now passing through later stages of nuclear burning. The estimated mass of Delta Cephei, as derived from the color index, is times the mass of the Sun. By comparison, the mass derived from evolutionary models is times the Sun's mass. At this stage of its evolution, the outer layers of the star have expanded to an average of 44.5 times the girth of the Sun. Bow shock around Delta Cephei Delta Cephei is emitting around 2,000 times the Sun’s luminosity from the outer atmosphere. This is producing a strong stellar wind, which, in combination with the pulsations and shocks in the star’s atmosphere, is ejecting mass at the rate of masses per year, or the equivalent to the mass of the Sun roughly every million years.
|
|
Appearing to have moved off the main sequence as their core hydrogen supply is being or has been exhausted, they are enlarging and cooling to eventually become red giant stars. Markab has an apparent magnitude of 2.48, while Algenib is a Beta Cephei variable that varies between magnitudes 2.82 and 2.86 every 3 hours 38 minutes, and also exhibits some slow pulsations every 1.47 days. Eta and Omicron Pegasi mark the left knee and Pi Pegasi the left hoof, while Iota and Kappa Pegasi mark the right knee and hoof. Also known as Matar, Eta Pegasi is the fifth-brightest star in the constellation. Shining with an apparent magnitude of 2.94, it is a multiple star system composed of a yellow giant of spectral type G2 and a yellow-white main sequence star of spectral type A5V that are 3.2 and 2.0 times as massive as our Sun.
|
|
The pulsar is estimated to be 5 million years old, which is relatively old for a pulsar. It has a rotational period of 1.1 seconds and emits both radio waves and X-rays. Ongoing research at the University of Vermont discovered that the pulsar was found to flip on a roughly a few hours timescale between a radio bright mode with highly organized pulsations and a quieter mode with rather chaotic temporal structure. Moreover, the observations of the pulsar performed simultaneously with the European Space Agency's XMM-Newton X-ray observatory and ground-based radio telescopes revealed that it exhibits variations in its X-ray emission that mimic in reverse the changes seen in radio waves – the pulsar has a weaker non-pulsing X-ray luminosity during the radio bright mode and is actually brighter during the radio quiet mode emitting distinct X-ray pulses.
|
|
The thermonuclear burn would produce (like the fission fuel in the primary) pulsations (generations) of high-energy neutrons with an average temperature of 14 MeV through Jetter's cycle. The cycle is a combination of endothermic and exothermic neutronic reactions involving lithium and deuterium/tritium. The reaction's neutronicity was estimated at ≈0.885 (for a Lawson criterion of ≈1.5). These figures do not count the Li isotope, where the LiD has a neutronicity of ≈0.835 and, along with the cross-sections, were given as group averages from about 2.40 to approximately 2.55 MeV and from 14.0 to 14.1 MeV; the small power group is not statistically present (see also Nuclear fusion). As SHRIMP, along with the RUNT I and ALARM CLOCK were to be high-yield shots required to assure the thermonuclear “emergency capability”, their fusion fuel may have been spiked with additional tritium, in the form of LiT.
|
|
When the pulsation mechanisms of the δ Scuti stars and the similar but hotter Slowly pulsating B-type (SPB) stars were identified, it became apparent that γ Coronae Borealis and a handful of similar low amplitude variable stars such as γ Ursae Minoris and Maia fell between those two classes in a region with no known driver for pulsations. The Maia variable class was named for these stars. Ironically, Maia itself has been shown not to be variable, and a number of other reported members of the class have been shown to be variables of other types, so the Maia variables appear to be very rare if they are even a real variable class. However, satellite observations have discovered a number of small-amplitude variables between the SPB and δ Scuti instability regions as well as a number of candidates in the open clusters NGC 3766 and NGC 1893.
|
|
Overall, the visual apparent magnitude of the star varies between 6.76 and 7.53. SX Phoenicis is an A-type main-sequence star with a stellar classification of A2 V. During the 1940s it was classed as a "probable subdwarf" because of its low luminosity for the spectral class. On average, it has a luminosity of 5.89 times the Sun's luminosity and an effective temperature of 7,700 K. During the primary pulsation cycle, the temperature varies between 7,230 K at minimum brightness up to 8,170 K at maximum brightness; when the two pulsation cycles are appropriately phased, the temperature can reach 8,400 K. Similarly, the pulsations cause the radius of the star to change, which is evidenced by changes in the surface gravity. Stellar evolution models by Petersen and Christensen-Dalsgaard (1996), taking into account the pulsating behavior of the star, indicate that the properties of the star are consistent with a mass of 1.0 solar mass and an age of 4 billion years.
|
|
The Madeira hotspot is considered to be responsible for the formation of a long chain of seamounts going from the 72 million years old Serra de Monchique in Iberia to the 14-0 million years old Porto Santo and Madeira, including Coral Patch Seamount. The plate motion history of the region is complicated and some seamounts formed off-track through pulsations of the mantle plume or through lithospheric anomalies. Buckling of the crust due to plate convergence is also responsible for the uplift of Coral Patch Seamount and has pushed it over the Horseshoes Abyssal Plain. Great Lisbon Earthquake of 1 November 1755, the epicentre of which may have been located between Coral Patch Seamount and Gorringe Bank Efforts at radiometric dating on Coral Patch Seamount have been unsuccessful, but fossil remains indicate that the seamount was volcanically active in the early Miocene together with the neighbouring Ampére Seamount, and a date of 31.2 ± 0.2 million years ago has been obtained for the Ampére-Coral Patch ridge.
|
|
The duration of the flare increased with its energy, again in accordance with the solar behaviour. Some Kepler data is taken at one minute sampling, though inevitably with lower accuracy. Using this data, on a smaller sample of stars, reveals flares that are too brief for reliable detection with 30-min integrations, allowing detection of events as low as 1032 ergs, comparable with the brightest flares on the Sun. The occurrence frequency as a function of energy remains a power law E−n when extended to lower energies, with n around 1.5. At this time resolution some superflares show multiple peaks with separations of 100 to 1000 seconds, again comparable to the pulsations in solar flares. The star KIC 9655129 showed two periods, of 78 and 32 minutes, suggesting magnetohydrodynamic oscillations in the flaring region. These observations suggest that superflares are different only in scale and not in type to solar flares.
|
|
Since 1943, this star has been consistently defined as a B0 main sequence star used as a reference for classifying the spectra of other stars on the MK scale, although in other studies it has been classified as O9V and O9.5V. The Galactic O-Star Spectroscopic Survey has defined it as the standard star for the O9.7 V spectral type. In a 1981 paper, υ Orionis was observed to have nonradial pulsations over a period of around 12 hours, and has been classified as a Slowly pulsating B star. Subsequent review of Hipparcos catalog data indicated it was most likely a Beta Cephei variable, and is hence considered a candidate for that class. These are blue-white main sequence stars of around 10 to 20 times the mass of the Sun that pulsate with periods of 0.1 to 0.3 days; their changes in magnitude are much more pronounced in the ultraviolet than in the visual spectrum.
|
|
Giclas 29-38, also known as ZZ Piscium, is a variable white dwarf star of the DAV, or ZZ Ceti, whose variability is due to large-amplitude, non-radial pulsations, known as gravity waves. It was first reported to be variable by Shulov and Kopatskaya in 1974.O. S. Shulov and E. N. Kopatskaya, Astrofizika 10, #1 (January-March, 1974), pp. 117-120\. Translated into English as Variability of the white dwarf G 29-38, Astrophysics, 10, #1 (January, 1974), pp. 72-74\. DOI 10.1007/BF01005183.G 29-38 and G 38-29: two new large- amplitude variable white dwarfs, J. T. McGraw and E. L. Robinson, Astrophysical Journal 200 (September 1975), pp. L89-L93. DAV stars are like normal white dwarfs but have luminosity variations with amplitudes as high as 30%, arising from a superposition of vibrational modes with periods from 100 to 1,000 seconds. Large-amplitude DAVs generally differ from lower-amplitude DAVs by having lower temperatures, longer primary periodicities, and many peaks in their vibrational spectra with frequencies which are sums of other vibrational modes.
|
|
After the success of the satellite-borne Indian X-ray Astronomy Experiment (IXAE), which was launched in 1996, the Indian Space Research Organization (ISRO) approved further development for a full- fledged astronomy satellite, Astrosat, in 2004. A number of astronomy research institutions in India, and abroad have jointly built instruments for the satellite. Important areas requiring coverage include studies of astrophysical objects ranging from nearby solar system objects to distant stars and objects at cosmological distances; timing studies of variables ranging from pulsations of hot white dwarfs to those of active galactic nuclei can be conducted with Astrosat as well, with time scales ranging from milliseconds to days. Astrosat is a multi-wavelength astronomy mission on an IRS-class satellite into a near- Earth, equatorial orbit. The five instruments on board cover the visible (320–530 nm), near UV (180–300 nm), far UV (130–180 nm), soft X-ray (0.3–8 keV and 2–10 keV) and hard X-ray (3–80 keV and 10–150 keV) regions of the electromagnetic spectrum.
|
|
Lars Graugaard is a prolific and chameleon-like pioneer with a background in musical styles that include classical, contemporary, improvised and urban. Initiated in the booming 70s’ hippie scene, he quickly turned to a wider notion of musical creation in performance and composition. While studying flute performance at the Royal Academy of Music he would undertake self-guided studies of musical scores and collaborate with a vast array of artists well versed in improvisation in what could be characterised as ‘practical field studies in the composer/performer amalgam’. In the late 80s he experimented with the computer as a compositional aid, but quickly shifted to using it for realtime music interaction, producing pieces such as Timid Souls (1989/90) and Incrustations (1994). In the early 90s he developed his current compositional technique of ‘intuitive constructivism’ where short, intense time-spans of sonic conception allows for unencumbered composing that by nature preclude any subsequent revisions. The first works with this method were River and Leaf (1991/92), The Circle And The Web (1992) and the orchestra work Sated Bodies (1993/94), whereas emphasis on pulsations combined with time-bound elasticity that harks back to his musical initiation in the 70s became apparent for the first time in Black Walls (1995).
|
|
He has since composed a variety of compositions in several genres including symphonic works, chamber music, film and television scores, operas, musical theater, and jazz music among others. He has written over 600 songs for the CTV children's series Let's Go and Rockets. His other compositions for stage, television, and film include, The Last Winter (1990), The Nutcracker Prince (1990), Tooth Fairy, Where Are You?, The Nature of Things (2002), For the Moment (1994), the music for the 1999 Pan American Games, and the musical The Importance of Being Ernest which was performed for the Stratford Festival in 2005. He has written music for several commissions including Pulsations (1978) for the CBC; Anerca (1969) for the Contemporary Dancers; Animal Capers (1983) for the Famous People Players; The Magic Trumpet (1969) and Reginald the Robot (1971) for the Manitoba Theatre Centre; Fun For Four (1980) for the Orford String Quartet; The Big Top (1985) for the Royal Winnipeg Ballet; numerous works for the Winnipeg Symphony Orchestra including Celebrations (1969), From Harmony (1968), A Short Symphony (1974), and the Jazz Piano Concerto (2001); Jazz Concerto for Organ and Orchestra (2000) for Wayne Marshall; and Yukon Scenes (1985/1997) for the Yukon Arts Council among others.
|
|