The fast-moving ionised particles blasted copper atoms off the target.
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In space, the gas to be ionised, usually xenon, has to be carried by the craft.
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When this light encounters hydrogen atoms still lingering in the stellar nursery that produced the stars, the atoms become ionised.
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Only de-ionised water is used, a process that removes any chemicals such as chlorine or fluorine found in tap water.
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The third type of instrument, micropattern gaseous detectors, follow the passage of muons from the trails of ionised gas they leave behind.
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It works by injecting a solution of highly pure urea and de-ionised water into the exhaust ahead of the catalytic converter.
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It's essentially ionised H20 that is said to yield a load of benefits, including making you more hydrated, boosting your immunity, and neutralising your body's acidity.
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Auroras are produced when charged particles from the sun collide with the magnetic fields in Earth's ionised upper atmosphere (the ionosphere), generating a stunning light display.
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In it, lithium at the anode is ionised and the ions thus produced then move through an intervening electrolyte and into the spaces in the titanium disulphide cathode.
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Comet 252P/LINEAR is also a very pretty shade of green, because of the release of diatomic carbon (C2), a gas that glows green when its molecules become ionised.
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The Hubble Space Telescope image produced here is in false colour, designed to highlight regions of high and low ionisation. Three images were taken, in filters isolating the light emitted by singly ionised hydrogen at 656.3 nm, singly ionised nitrogen at 658.4 nm and doubly ionised oxygen at 500.7 nm. The images were combined as red, green and blue channels respectively, although their true colours are red, red and green. The image reveals two "caps" of less ionised material at the edge of the nebula.
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HD 183143 has been extensively studied because of the diffuse interstellar bands visible in its spectrum. The strongest lines are caused by interstellar atomic iron, potassium, lithium, sodium, and calcium, as well as ionised calcium, and CH and CN molecules. Infrared bands of ionised buckminsterfullerene have also been found in its spectrum.
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Nickel forms many known salts with organic acids. In many of these the ionised organic acid acts as a ligand.
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The winds are then accelerated to high velocity in the outer atmosphere by less highly ionised iron and by carbon and oxygen.
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The spectrum shows emission lines of hydrogen-alpha (Hα) and both neutral and ionised helium. The brightest recorded observations is at magnitude 5.6.
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He was predicted to exist by Linus Pauling in 1933. It was discovered when doing mass spectroscopy on ionised helium. The dihelium cation is formed by an ionised helium atom combining with a helium atom: He+ \+ He → He. The diionised dihelium He (1Σ) is in a singlet state. It breaks up He → He+ \+ He+ releasing 200 kcal/mol of energy.
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However, it should also be considered that the analyte of interest may not be ionised effectively in negative mode either, rendering this approach useless.
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The difference in energy between each ionised state and the ground state would be an ionisation energy, which yields two values in agreement with experiment.
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Bubbles of brand new stars LHA 120-N 180B. The term H II is pronounced "H two" by astronomers. "H" is the chemical symbol for hydrogen, and "II" is the Roman numeral for 2. It is customary in astronomy to use the Roman numeral I for neutral atoms, II for singly-ionised—H II is H+ in other sciences—III for doubly-ionised, e.g.
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He was an influential figure, founding the laser research department at St Andrews University in 1964. He led a group of 14 physicists there working in the areas of lasers and their applications, gas discharge tubes, ionised gases, optical methods of signal processing, and applications of ionised gases to fast switching (see Thyratrons). He became Professor of Physics at St Andrews in 1993. Professor Maitland was a fellow of the Institute of Physics, and published over 40 research papers on lasers, ionised gases and fast switching, and was co-author of Laser Physics (North Holland), Vacuum as an Insulator (Chapman and Hall) and posthumously contributing a chapter to High Voltage Vacuum Insulation (Academic Press).
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The study of photodissociation regions began from early observations of the star- forming regions Orion A and M17 which showed neutral areas bright in infrared radiation lying outside ionised HII regions.
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The spectrum of GR 290 shows prominent emission lines of hydrogen and atomic helium, along with a broad complex of ionised nitrogen emission lines and weak ionised helium emission. There are also some faint absorption lines attributed to interstellar material, and some forbidden emission lines. C is detectable but much weaker than the nitrogen lines. The spectral type of Romano's star is that of a Wolf–Rayet star on the nitrogen sequence, but also with hydrogen.
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The ionisation potential of PO is 8.39 eV. When ionised, PO forms the cation PO+. The adiabatic electron affinity of PO is 1.09 eV. On gaining an electron the PO− ion forms.
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The ample supply of UV photons generated by the star rapidly establishes an HII region and the expansion of this, sooner or later allows also for the ionisation of the inter cloud gas. Ionisation disrupts then the former pressure balance between the cloud and the inter-cloud gas as under the stellar radiation field all photo-ionised gas acquires a temperature of the order of 10000 K. In this way, the ionised cloud material acquires an excess pressure, a pressure larger than the ionised low density inter cloud gas and this provoques the supersonic expansion of the ionised cloud matter into the surrounding gas (the champagne flow). The streaming of matter out of the cloud allows for the ionisation of a larger portion of the original cloud sustaining in this way the pressure imbalance which eventually leads to the complete disruption of the parent cloud. The terms champagne model and champagne flow were coined by Mexican astrophysicist Guillermo Tenorio-Tagle in a paper in 1979 (Astronomy and Astrophysics 1979A&A....71...59T;).
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This makes H II regions more complicated than planetary nebulae, which have only one central ionising source. Typically H II regions reach temperatures of 10,000 K. They are mostly ionised gases with weak magnetic fields with strengths of several nanoteslas. Nevertheless, H II regions are almost always associated with a cold molecular gas, which originated from the same parent GMC. Magnetic fields are produced by these weak moving electric charges in the ionised gas, suggesting that H II regions might contain electric fields.
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The disks are formed mostly of helium from the donor star. As with dwarf novae, the high state corresponds to a hotter disk state with optically thick ionised helium, while in the low state the disk is cooler, not ionised, and transparent. The superhump variability is due to an eccentric accretion disc precessing. The precession period can be related to the ratio of the masses of the two stars, giving a way to determine the mass of even invisible donor stars.
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187Re normally beta decays to 187Os with a half-life of 41.6 × 109 years, but studies using fully ionised 187Re atoms (bare nuclei) have found that this can decrease to only 33 years. This is attributed to "bound-state β− decay" of the fully ionised atom – the electron is emitted into the "K-shell" (1s atomic orbital), which cannot occur for neutral atoms in which all low-lying bound states are occupied. Example of diurnal and seasonal variations in gamma ray detector response.
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As helium is heated it becomes more ionised, which is more opaque. So at the dimmest part in the cycle the star has highly ionised opaque helium in its atmosphere blocking part of the light from escaping. The energy from this “blocked light” causes the helium to heat up, expand, ionise, become more transparent and therefore allow more light through. As more light is let through the star appears brighter and, with the expansion, the helium begins to cool down.
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Many Be stars were discovered to have spectral peculiarities. One of these peculiarities was the presence of forbidden spectral lines of ionised iron and occasionally other elements. In 1973 a study of one of these stars, HD 45677 or FS CMa, showed an infrared excess as well as forbidden lines of [OI], [SII], [FeII], [NiII], and many more. In 1976 a study of Be stars with infrared excesses identified a subset of stars which showed forbidden emission lines from ionised iron and some other elements.
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9 Sgr is the main source of ionisation for much of the visible nebulosity in the region, although the young O star Herschel 36 ionises the dense Hourglass Nebula region. 9 Sgr itself is surrounded by an ionised HII region about 30 light years across including the reflection nebulae NGC 6523 and NGC 6533. This ionised region lies in front of a denser molecular cloud. The distances to 9 Sgr, M8, and NGC 6530 are uncertain, but generally estimated to be between 1,200 and 1,800 parsecs.
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This creates a so-called partially ionised plasma. At very high temperatures, such as those present in stars, it is assumed that essentially all electrons are "free", and that a very high-energy plasma is essentially bare nuclei swimming in a sea of electrons. This forms the so- called fully ionised plasma. The plasma state is often misunderstood, and although not freely existing under normal conditions on Earth, it is quite commonly generated by either lightning, electric sparks, fluorescent lights, neon lights or in plasma televisions.
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It is isoelectronic with hydrogen sulfate, . When an organic group is substituted for the anions, organic fluorosulfonates are formed. In solution the fluorosulfate anion is completely ionised. The volume of the ions is 47.8 cm3/mol.
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67 Indium is a soft, highly ductile metal (MH 1.0) with a low tensile strength.Chandler 1998, p. 59Russell & Lee 2005, p. 389 It has a partially distorted crystalline structure (BCN 4+8) associated with incompletely ionised atoms.
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Infrared emission also reveals the presence of un-ionised material such as molecular hydrogen (H2) and argon. In many planetary nebulae, molecular emission is greatest at larger distances from the star, where more material is un-ionised, but molecular hydrogen emission in NGC 6543 seems to be bright at the inner edge of its outer halo. This may be due to shock waves exciting the H2 as ejecta moving at different speeds collide. The overall appearance of the Cat's Eye Nebula in infrared (wavelengths 2–8 μm) is similar in visible light.
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As stars are born within a GMC, the most massive will reach temperatures hot enough to ionise the surrounding gas. Soon after the formation of an ionising radiation field, energetic photons create an ionisation front, which sweeps through the surrounding gas at supersonic speeds. At greater and greater distances from the ionising star, the ionisation front slows, while the pressure of the newly ionised gas causes the ionised volume to expand. Eventually, the ionisation front slows to subsonic speeds, and is overtaken by the shock front caused by the expansion of the material ejected from the nebula.
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Messier 94, a galaxy with a Seyfert-like LINER nucleus In addition to the Seyfert progression from Type I to Type II (including Type 1.2 to Type 1.9), there are other types of galaxies that are very similar to Seyferts or that can be considered as subclasses of them. Very similar to Seyferts are the low-ionisation narrow-line emission radio galaxies (LINER), discovered in 1980. These galaxies have strong emission lines from weakly ionised or neutral atoms, while the emission lines from strongly ionised atoms are relatively weak by comparison. LINERs share a large amount of traits with low luminosity Seyferts.
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One misconception concerning orbital hybridisation is that it incorrectly predicts the ultraviolet photoelectron spectra of many molecules. While this is true if Koopmans' theorem is applied to localised hybrids, quantum mechanics requires that the (in this case ionised) wavefunction obey the symmetry of the molecule which implies resonance in valence bond theory. For example, in methane, the ionised states (CH4+) can be constructed out of four resonance structures attributing the ejected electron to each of the four sp3 orbitals. A linear combination of these four structures, conserving the number of structures, leads to a triply degenerate T2 state and a A1 state.
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The terms galactic corona and gaseous corona have been used in the first decade of the 21st century to describe a hot, ionised, gaseous component in the galactic halo of the Milky Way. A similar body of very hot and tenuous gas in the halo of any spiral galaxy may also be described by these terms. This coronal gas may be sustained by the galactic fountain, in which superbubbles of ionised gas from supernova remnants expand vertically through galactic chimneys into the halo. As the gas cools, it is pulled back into the galactic disc of the galaxy by gravitational forces.
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Star B turned out to be the brightest single star. HD 97950B is a Wolf-Rayet (WR) star, with spectra dominated by strong broadened emission lines. Type WN6 indicates that ionised nitrogen lines are strong in comparison to ionised carbon lines, and the suffix h indicates that hydrogen is also seen in the spectrum. This type of WR star is not the classical stripped helium-burning aged star, but a young highly luminous object with CNO cycle fusion products showing at the surface due to strong conventional and rotational mixing, and high mass loss rates from the atmosphere.
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Star C was shown to be a binary, but its companion has not been observed. HD 97950C is a Wolf-Rayet (WR) star, with spectra dominated by strong broadened emission lines. Type WN6 indicates that ionised nitrogen lines are strong in comparison to ionised carbon lines, and the suffix h indicates that hydrogen is also seen in the spectrum. This type of WR star is not the classical stripped helium-burning aged star, but a young highly luminous object with CNO cycle fusion products showing at the surface due to strong conventional and rotational mixing, and high mass loss rates from the atmosphere.
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Ultraviolet image of Homunculus Nebula taken by Hubble The ultraviolet spectrum of the Eta Carinae system shows many emission lines of ionised metals such as FeII and CrII, as well as Lymanα (Lyα) and a continuum from a hot central source. The ionisation levels and continuum require the existence of a source with a temperature at least 37,000 K. Certain FeII UV lines are unusually strong. These originate in the Weigelt Blobs and are caused by a low-gain lasing effect. Ionised hydrogen between a blob and the central star generates intense Lyα emission which penetrates the blob.
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Each component is a Wolf-Rayet (WR) star, with spectra dominated by strong broadened emission lines. Type WN6 indicates that ionised nitrogen lines are strong in comparison to ionised carbon lines, and the suffix h indicates that hydrogen is also seen in the spectrum. This type of WR star is not the classical stripped helium-burning aged star, but a young highly luminous object with CNO cycle fusion products showing at the surface due to strong conventional and rotational mixing, and high mass loss rates from the atmosphere. The emission lines are generated in the stellar wind and the photosphere is completely hidden.
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More detailed observations have shown that the emission line profiles are variable and may be due to plage areas on the surface of the star. Emission can also be found in other lines such as the h and k lines of ionised magnesium.
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The spray is then ionised by extractive electrospray ionisation (EESI) and analysed using tandem mass spectrometry (MS/MS). An analysis requires 30 seconds per sample. The limit of detection of melamine is a few nanograms of melamine per gram of milk. Huang et al.
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ESO/Digitized Sky Survey 2) HR 5171 appears near the centre of the HII Region Gum 48d, a ring of material ionised most likely by one or both of the visible HR 5171 stars. The stars and the nebulosity all show similar space motions that would place them in the Centaurus spiral arm about 4,000 parsecs (4 kpc) away from Earth. It is apparently part of an extensive molecular cloud complex with a distance between 3.2 kpc and 5.5 kpc from Earth. Gum 48d would require one or two O-type stars to be ionised, presumably one or both of the HR 5171 stars a few million years ago.
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An HI region or H I region (read H one) is a cloud in the interstellar medium composed of neutral atomic hydrogen (HI), in addition to the local abundance of helium and other elements. (H is the chemical symbol for hydrogen, and "I" is the Roman numeral. It is customary in astronomy to use the Roman numeral I for neutral atoms, II for singly-ionised—HII is H+ in other sciences—III for doubly-ionised, e.g. OIII is O++, etc.) These regions do not emit detectable visible light (except in spectral lines from elements other than hydrogen) but are observed by the 21-cm (1,420 MHz) region spectral line.
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When the hydrogens of the clay hydroxyls are ionised into solution, they leave the oxygen with a negative charge (anionic clays). # Hydrogens of humus hydroxyl groups may also be ionised into solution, leaving, similarly to clay, an oxygen with a negative charge. Cations held to the negatively charged colloids resist being washed downward by water and out of reach of plants' roots, thereby preserving the fertility of soils in areas of moderate rainfall and low temperatures. There is a hierarchy in the process of cation exchange on colloids, as they differ in the strength of adsorption by the colloid and hence their ability to replace one another (ion exchange).
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His early research obtained observational evidence that verified a prediction that our galaxy is surrounded by a halo of hot ionised gas. Pettini was awarded the Herschel Medal of the Royal Astronomical Society in 2008. In May 2010, he was elected a Fellow of the Royal Society.
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Relative size of O-type stars with other main-sequence stars An O-type star is a hot, blue-white star of spectral type O in the Yerkes classification system employed by astronomers. They have temperatures in excess of 30,000 kelvin (K). Stars of this type have strong absorption lines of ionised helium, strong lines of other ionised elements, and hydrogen and neutral helium lines weaker than spectral type B. Stars of this type are very rare, but because they are very bright, they can be seen at great distances and four of the 90 brightest stars as seen from Earth are O type.Those four stars are Gamma Velorum, Alnitak (Zeta Orionis), Mintaka (Delta Orionis), and Zeta Puppis.
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Both emissions are caused by heavily ionised gas. The broad line emission arises in a region 0.1–1 parsec across. The broad line emission region, RBLR, can be estimated from the time delay corresponding to the time taken by light to travel from the continuum source to the line-emitting gas.
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Options include: air-conditioned, heated and massaging seats; heated armrests; a system to pump scented, ionised air around the cabin; and a 1540 watt Burmester 3D surround sound system with 24 speakers. Maybach S500 assembly in Pune, India, began in September 2015, making India the second country to produce a Maybach.
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The infrared Ca II triplet, commonly known as the calcium triplet, is a triplet of three ionised calcium spectral lines at the wavelengths of 8498 Å, 8542 Å and 8662 Å. The triplet has a strong emission, and is most prominently observed in the absorption of spectral type G, K and M stars.
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It also contains both singly and doubly ionised helium. Such HeII regions are rare and indicate an extremely hot ionising star. They are found only around a few of the hottest types of Wolf Rayet star. N76 is described as containing the open cluster NGC 371, although the reverse may be more accurate.
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Faint nebulosity was discovered around WR 102 in 1981 and was identified as a wind-blown bubble. In 1982, a set of five luminous stars with highly ionised oxygen emission lines, including WR 102, was used to define the WO class of Wolf–Rayet stars. They were identified as highly evolved massive stars.
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The Cat's Eye was the first planetary nebula to be observed with a spectroscope by William Huggins on August 29, 1864. See p. 438, "No. 4373". Huggins' observations revealed that the nebula's spectrum was non-continuous and made of a few bright emission lines, first indication that planetary nebulae consist of tenuous ionised gas.
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HD 93205 is a binary system of two large stars. The more massive member of the pair is an O3.5 main sequence star. The spectrum shows some ionised nitrogen and helium emission lines, indicating some mixing of fusion products to the surface and a strong stellar wind. The mass calculated from apsidal motion of the orbits is .
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However, the Canadian Olympic Committee had a more innovative solution. The Olympic flame was placed in front of a sensor that detects ionised particles and was then encoded into impulses and sent via satellite to Ottawa. The arrival of the signal activated a laser that recreated the Olympic flame in a 90 cm urn in the Canadian city.
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DEM 124 is described as a shell surrounding DEM 123. N76 is an HII region about 5 arc-minutes wide, 40–50 parsecs. It has the appearance of a ring but is actually an approximately spherical shell, interstellar material sculpted and ionised by the winds of the central stars, similar to a planetary nebula but much larger.
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The Reynolds Layer is a layer of ionised hydrogen gas in the plane of the Milky Way. It was named after Ron Reynolds who discovered that there is such gas. The layer is a disk 750,000 light years in diameter, and 6000 light years thick. The whole disk rotates in the same direction as the Milky Way.
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Absorption lines of metals dominate the visual spectrum, again indicating cool temperatures. A particularly unusual feature is the near-infrared forbidden emission lines of ionised calcium usually only seen in warm hypergiants, but also known from η Carinae during its great eruption. The spectral class is estimated to be as late as F9 to G1 during this outburst.
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At physiological pHs, acetic acid is usually fully ionised to acetate. The acetyl group, formally derived from acetic acid, is fundamental to all forms of life. When bound to coenzyme A, it is central to the metabolism of carbohydrates and fats. Unlike longer-chain carboxylic acids (the fatty acids), acetic acid does not occur in natural triglycerides.
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The doped droplets are ionised with high speed electrons. For sodium clusters appear with the formula Na+Hen with n from 1 to 26. Na+He is the most common, but Na+He2 is very close in abundance. Na+He8 is much more abundant than clusters with more helium. NaHen with n from 1 to 20 also appears.
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NGC 3861 is a large barred spiral galaxy with a ring-like structure located about 310 million light-years away in the constellation Leo. It was discovered by astronomer John Herschel on March 23, 1827. NGC 3861 is a member of the Leo Cluster and has a normal amount of neutral hydrogen (H I) and ionised hydrogen (H II).
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A close-up of an electrospray device. The jet of ionised spray is visible within the image. To simplify the discussion, the following paragraphs will address the case of a positive electrospray with the high voltage applied to a metallic emitter. A classical electrospray setup is considered, with the emitter situated at a distance d\, from a grounded counter-electrode.
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Other trivalent dopants include indium (In) and gallium (Ga). When substituting for a Si atom in the crystal lattice, the three valence electrons of boron form covalent bonds with three of the Si neighbours but the bond with the fourth neighbour remains unsatisfied. The initially electro-neutral acceptor becomes negatively charged (ionised). The unsatisfied bond attracts electrons from the neighbouring bonds.
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The observation of antitails contributed significantly to the discovery of solar wind. The ion tail is the result of ultraviolet radiation ejecting electrons off particles in the coma. Once the particles have been ionised, they form a plasma which in turn induces a magnetosphere around the comet. The comet and its induced magnetic field form an obstacle to outward flowing solar wind particles.
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For comparison, the Sun loses (2-3) x 10−14 solar masses per year due to its solar wind, several hundred million times less than WR 102. These winds and the strong ultraviolet radiation from the hot star have compressed and ionised the surrounding interstellar material into a complex series of arcs described as the bubble type of Wolf–Rayet nebula.
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Stark's 1913 model of triatomic hydrogen J. J. Thomson observed H3+ while experimenting with positive rays. He believed that it was an ionised form of H3 from about 1911. He believed that H3 was a stable molecule and wrote and lectured about it. He stated that the easiest way to make it was to target potassium hydroxide with cathode rays.
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However, the automatic bulge-disk fit would give an unreliably large bulge extending through the whole galaxy (lowermost row). A more reasonable fit is obtained by adding another exponential disk component to the inner part of the galaxy (upper profile). This inner component corresponds to the region of tightly wound spiral arms with higher surface brightness. Analysis of the NGC 1357's spectra revealed the ionised calcium.
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Diargon or the argon dimer is a molecule containing two argon atoms. Normally, this is only very weakly bound together by van der Waals forces (a van der Waals molecule). However, in an excited state, or ionised state, the two atoms can be more tightly bound together, with significant spectral features. At cryogenic temperatures, argon gas can have a few percent of diargon molecules.
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The SLOSHSAT-FLEVO is the first satellite entirely dedicated to liquid research in space. The satellite was equipped with an 87-litre cylindrical tank containing 33.5 litres of de-ionised water. 270 sensors were placed on the tank's walls to measure the sloshing behavior by calculating the thickness of the water. Three accelerometers and a fibre- optic gyroscope were used to measure the motion of the spacecraft.
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At physiological pHs, hydrogen fluoride is usually fully ionised to fluoride. In biochemistry, fluoride and hydrogen fluoride are equivalent. Fluorine, in the form of fluoride, is considered to be a micronutrient for human health, necessary to prevent dental cavities, and to promote healthy bone growth. The tea plant (Camellia sinensis L.) is a known accumulator of fluorine compounds, released upon forming infusions such as the common beverage.
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Using this theory and further experiments, he showed that the so-called Kennelly-Heaviside layer was heavily ionised and thus conducting. This led to the term ionosphere. He showed free electrons to be the ionising agents. He discovered that the layer could be penetrated by waves above a certain frequency and that this critical frequency could be used to calculate the electron density in the layer.
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It is this which is often referred to as the Appleton Layer as is responsible for enabling most long range short wave telecommunication. The magneto-ionic theory also allowed Appleton to explain the origin of the mysterious fadings heard on the radio around sunset. During the day, the light from the sun causes the molecules in the air to become ionised even at fairly low altitudes.
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Germane is weakly acidic. In liquid ammonia GeH4 is ionised forming NH4+ and GeH3−. With alkali metals in liquid ammonia GeH4 reacts to give white crystalline MGeH3 compounds. The potassium (potassium germyl KGeH3) and rubidium compounds (rubidium germyl RbGeH3) have the sodium chloride structure implying a free rotation of the GeH3− anion, the caesium compound, CsGeH3 in contrast has the distorted sodium chloride structure of TlI.
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For all radio transmissions above 30 MHz (which are not reflected by the ionosphere) there is a possibility of meteor reflection of the radio signal.P Harvey & KJ Bohlman. Stereo radio F.M. Handbook, Chapter 7, 1974 Meteors leave a trail of ionised particles and electrons as they pass through the upper atmosphere (a process called ablation) which reflect transmission radio waves which would usually flow into space.L.A. Manning et al.
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Layers of the ionosphere. The Kennelly–Heaviside layer is the E region The Heaviside layer, sometimes called the Kennelly–Heaviside layer, named after Arthur E. Kennelly and Oliver Heaviside, is a layer of ionised gas occurring between roughly 90 and 150 km (56 and 93 mi) above the ground -- one of several layers in the Earth's ionosphere. It is also known as the E region. It reflects medium-frequency radio waves.
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It is specified, that, not only the structure but also other LQGs are not real structures at all. Nevertheless, Clowes et al. found independent support for the reality of the structure from its coincidence with Mg II absorbers (once-ionised magnesium gas, commonly used to probe distant galaxies). The Mg II gas suggests that the Huge-LQG is associated with an enhancement of the mass, rather than being a false positive.
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The Primeval Structure Telescope (PaST), also called 21 Centimetre Array (21CMA), is a Chinese radio telescope array designed to detect the earliest luminous objects in the universe, including the first stars, supernova explosions, and black holes. All of these objects were strong sources of ultraviolet radiation, so they ionised the material surrounding them. The structure of this reionisation reflects the overall density structure at the redshift of luminous-object formation.
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He recognised in them the similarity between the spectrum of the new star and that of the solar chromosphere, rich in the pink light of ionised hydrogen. Equally significant results were obtained with the spectrum of Nova Perseii, in 1901. Angelo Secchi Sidgreaves was particularly interested in the connection between sunspots and fluctuations in earth's magnetic field. He published several papers on the subject based on observations made at Stonyhurst.
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One of the problems with providing coverage of an area the size of the UK was installing sufficient DF stations to cover the entire area to receive skywave signals reflected back from the ionised layers in the upper atmosphere. Even with the expanded network, some areas were not adequately covered and for this reason up to 1700 voluntary interceptors (radio amateurs) were recruited to detect illicit transmissions by ground wave.
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It will produce a type Ib or Ic supernova within the next few hundred thousand years. WR 102c is surrounded by a shell of nebulosity which contains dust made even hotter than the star itself by intense radiation. The nebula also includes nearly of molecular hydrogen and around of ionised hydrogen, all expelled from the star. There is a suggestion that WR 102c may be a binary star.
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There are also absorption lines of carbon, nitrogen, oxygen, sulphur, iron, and many ionised metals. It was studied in the ultraviolet by an early astronomical satellite, Gemini XI in 1966. The UV spectra were considered to be consistent with an F0 supergiant having a temperature of , the accepted parameters for Canopus at the time. New Zealand-based astronomers John Hearnshaw and Krishna Desikachary examined the spectrum in greater detail, publishing their results in 1982.
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Previous works have indicated that many of these galaxies may be triggered by galaxy mergers." Further on, the abstract states: "We find that to first order, the velocity field and velocity dispersions derived from stars and ionised gas agree. Hence the complexities reveal real dynamical disturbances providing further evidence for a merger in Haro 11. Through decomposition of emission lines, we find evidence for kinematically distinct components, for instance, a tidal arm.
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Corbett 1996, p. 143 Tin is a soft, exceptionallyRussell & Lee 2005, p. 405 weak metal (MH 1.5); a 1-cm thick rod will bend easily under mild finger pressure. It has an irregularly coordinated crystalline structure (BCN 4+2) associated with incompletely ionised atoms. All of the Group 14 elements form compounds in which they are in the +4, predominantly covalent, oxidation state; even in the +2 oxidation state tin generally forms covalent bonds.
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HD 93205, or V560 Carinae, is a binary stellar system, in the Carina Nebula (NGC 3372) in the constellation Carina. It consists of two massive O-stars that revolve around each other in 6 days. The more massive member of the pair is an O3.5 main sequence star. The spectrum shows some ionised nitrogen and helium emission lines, indicating some mixing of fusion products to the surface and a strong stellar wind.
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Arthur Maitland was born on 7 December 1928 in Blackburn, England. He gained his BSc Physics degree in 1956 as a part-time student studying for a London University External Degree. In 1972 St Andrews University, whom he was employed as a researcher and lecturer in 1963, awarded him a DSc degree on the basis of his published papers on ionised gases. At the time he was also working for several electrical engineering companies.
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The Experiment to Detect the Global EoR Signature (EDGES) is an experiment and radio telescope located in a radio quiet zone at the Murchison Radio-astronomy Observatory in Western Australia. It is a collaboration between Arizona State University and Haystack Observatory, with infrastructure provided by CSIRO. EoR stands for epoch of reionization, a time in cosmic history when neutral atomic hydrogen gas became ionised due to ultraviolet light from the first stars.
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The gas then scatters from the surface and is collected into a detector. In order to measure the flux of the neutral helium atoms, they must first be ionised. The inertness of helium that makes it a gentle probe now means that it is difficult to ionise and therefore reasonably aggressive electron bombardment is typically used to create the ions. A mass spectrometer setup is then used to select only the helium ions for detection.
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It is also catalogued as Sharpless 2-298 and Gum 4. The nebula has an overall bubble shape, but with complex filamentary structures. The nebula contains several hundred solar masses of ionised material, plus several thousand more of unionised gas. It is largely interstellar material swept up by winds from the central star, although some material does appear to be enriched with the products of fusion and is likely to come directly from the star.
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The spectral type of WN4 indicates an extremely hot star, and this leads to a very high luminosity, mostly emitted as ultraviolet radiation. The spectrum shows a star entirely devoid of hydrogen at the surface. EZ CMa is surrounded by a faint bubble nebula, a small HII region blown by stellar winds up to 1,700 km/s and ionised by the intense UV radiation. This is catalogued as Sharpless 308 or just S308.
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All GICs contain a basic glass and an acidic polymer liquid, which set by an acid-base reaction. The polymer is an ionomer, containing a small proportion – some 5 to 10% – of substituted ionic groups. These allow it to be acid decomposable and clinically set readily. The glass filler is generally a calcium alumino fluorosilicate powder, which upon reaction with a polyalkenoic acid gives a glass polyalkenoate-glass residue set in an ionised, polycarboxylate matrix.
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Other pentavalent dopants are antimony (Sb) and bismuth (Bi). When substituting a Si atom in the crystal lattice, four of the valence electrons of phosphorus form covalent bonds with the neighbouring Si atoms but the fifth one remains weakly bonded. The initially electro-neutral donor becomes positively charged (ionised). At room temperature, the fifth electron is liberated, can move around the Si crystal and carry a current, and thus act as a charge carrier.
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Typical x-ray film contains silver halide crystal "grains", typically primarily silver bromide. Grain size and composition can be adjusted to affect the film properties, for example to improve resolution in the developed image. When the film is exposed to radiation the halide is ionised and free electrons are trapped in crystal defects (forming a latent image). Silver ions are attracted to these defects and reduced, creating clusters of transparent silver atoms.
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The resulting nebula contains material from both stars and is complex in nature. From 1997 until 2015, AG Pegasi entered a quiescent phase with no further change to its brightness. Then the hot component increased in temperature, which caused the nebulosity around the stars to become more ionised and increase in brightness. The combination of the extremely slow nova and smaller outburst means that Z Andromedae is classed as a symbiotic nova.
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HR Carinae was first noticed at the start of the 20th century because of its Hβ emission. It was placed in Secchi class I, corresponding to modern A and F-type stars. It was catalogued in 1933 as a Be star and was discovered to be variable in 1940. A more detailed spectroscopic study gave it the type B2eq with emission line of hydrogen, helium, and ionised iron and P Cygni profiles on some lines.
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V1429 Aql has a peculiar spectrum dominated by emission lines of hydrogen and many ionised metals, with Fe being particularly strong and numerous. There are also comparatively weak forbidden lines, primarily [Fe], but also [N]. Some absorption lines are present, but are either very weak or hidden by the emission. Many lines have variable profiles, particularly the hydrogen and helium series which vary during the orbit from emission to P Cygni profiles.
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Other planetary nebula catalogue names include ESO 128-18 and Wray 15-682. Since 2013, the nebula has been considered not as a planetary nebula, but rather as a much larger expanding gas shell, formally classified as a Wolf–Rayet nebula or WR nebula. Its observed expansion velocity is , and is estimated to be some across. The dynamical age of the nebula is estimated at 18,000 years and the total mass of ionised gas at .
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The magnesium argide ion, MgAr+ is an ion composed of one ionised magnesium atom, Mg+ and an argon atom. It is important in inductively coupled plasma mass spectrometry and in the study of the field around the magnesium ion. The ionization potential of magnesium is lower than the first excitation state of argon, so the positive charge in MgAr+ will reside on the magnesium atom. Neutral MgAr molecules can also exist in an excited state.
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Helium is in the same category as alkaline earths with respect to spectroscopy, as it has two electrons in the S subshell as do the other alkaline earths. Helium has a diffuse series of doublet lines with wavelengths 5876, 4472 and 4026 Å. Helium when ionised is termed HeII and has a spectrum very similar to hydrogen but shifted to shorter wavelengths. This has a diffuse series as well with wavelengths at 6678, 4922 and 4388 Å.
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The ICM is composed primarily of ordinary baryons, mainly ionised hydrogen and helium. This plasma is enriched with heavier elements, including iron. The average amount of heavier elements relative to hydrogen, known as metallicity in astronomy, ranges from a third to a half of the value in the sun. Studying the chemical composition of the ICMs as a function of radius has shown that cores of the galaxy clusters are more metal rich than at larger radii.
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At the CSIR he developed a device called an ionosonde for measuring the Earth's ionosphere. It is a specialised form of a radar detector used to measure the height of the ionised layers of air between 50 and 600 kilometers. This information gives insight into what is occurring during an ionospheric storm. The ionosonde was used to provide a transmission frequency prediction service to the SABC, the South African Postal Service (SAPO) and South African Military.
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Ammonia toxicity is believed to be a cause of otherwise unexplained losses in fish hatcheries. Excess ammonia may accumulate and cause alteration of metabolism or increases in the body pH of the exposed organism. Tolerance varies among fish species. At lower concentrations, around 0.05 mg/L, un-ionised ammonia is harmful to fish species and can result in poor growth and feed conversion rates, reduced fecundity and fertility and increase stress and susceptibility to bacterial infections and diseases.
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Phenanthriplatin is thought to penetrate cell membranes in its ionised form by either passive diffusion or carrier-mediated active transport. The hydrophobic phenanthridine ligand of the drug is thought to maximise its cellular uptake, rendering it more effective and cytotoxic compared with cisplatin. Once it has entered the cell, phenanthriplatin is distributed in a similar manner to other platinum- based anticancer agents, residing primarily in the cell's nucleus. The ultimate target of the drug is nuclear DNA.
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The ultraviolet and optical emission also varies, although more smoothly, with time lag of two days. The cause of the lag and the smoothing of light curves is considered to be the reprocessing of the X-rays in the accretion disk. The cause of the active galactic nucleus is suspected to be a supermassive black hole with a mass about 18 million times that of the Sun. Many regions of ionised gas are studded along the dusty spiral arms.
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In astronomy, collisional excitation gives rise to spectral lines in the spectra of astronomical objects such as planetary nebulae and H II regions. In these objects, most atoms are ionised by photons from hot stars embedded within the nebular gas, stripping away electrons. The emitted electrons, (called photoelectrons), may collide with atoms or ions within the gas, and excite them. When these excited atoms or ions revert to their ground state, they will emit a photon.
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The avalanche occurs in a gaseous medium that can be ionised (such as air). The electric field and the mean free path of the electron must allow free electrons to acquire an energy level (velocity) that can cause impact ionisation. If the electric field is too small, then the electrons do not acquire enough energy. If the mean free path is too short, the electron gives up its acquired energy in a series of non-ionising collisions.
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This was later shown to be a mixture with sulfur dioxide, and not a new form of hydrogen. In the 1930s active hydrogen was found to be hydrogen with hydrogen sulfide contamination, and scientists stopped believing in triatomic hydrogen. Quantum mechanical calculations showed that neutral H3 was unstable but that ionised H3+ could exist. When the concept of isotopes came along, people such as Bohr then thought there may be an eka-hydrogen with atomic weight 3.
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Physicists showed in the 1920s that in gas at extremely low density, electrons can populate excited metastable energy levels in atoms and ions, which at higher densities are rapidly de-excited by collisions. Electron transitions from these levels in doubly ionized oxygen give rise to the 500.7 nm line. These spectral lines, which can only be seen in very low density gases, are called forbidden lines. Spectroscopic observations thus showed that planetary nebulae consisted largely of extremely rarefied ionised oxygen gas (OIII).
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Similarly, holes diffuse from P to N leaving behind fixed negative ionised dopants near the junction. These layers of fixed positive and negative charges are collectively known as the depletion layer because they are depleted of free electrons and holes. The depletion layer at the junction is at the origin of the diode's rectifying properties. This is due to the resulting internal field and corresponding potential barrier which inhibit current flow in reverse applied bias which increases the internal depletion layer field.
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N76A is the small dense HII region SE of AB7, part of the "ring", while AB7 lies at the centre of the less dense nebulosity within the ring. It may already be the home of a new generation of stars; N76A hosts at least five hot young stars, including a probable O9 main sequence star at its centre. A nearby unusual oxygen-rich supernova remnant has been intensively studied. It is visible as the knot of filaments growing green from ionised oxygen emission.
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MUSE has a field of view that is well-matched to a number of fascinating objects in the Milky Way, such as globular clusters and planetary nebulae. The high spatial resolution and sampling will enable MUSE to simultaneously observe the spectra of thousands of stars in one shot in dense regions such as globular clusters. In star-forming regions, with a mixture of ionised gas and stars, MUSE will provide information both on the stellar and nebular content across this region.
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The spectrum of R71 in quiescence (minimum brightness) shows weak emission lines of Hα and Hβ and absorption lines for the rest of the Balmer series. There are many strong forbidden emission lines, especially of ionised iron. The spectrum is readily classified as a B class supergiant, the peculiarities such as emission and forbidden lines not unusual for the most luminous stars. During the 1970s outburst, many spectral lines developed strong P Cygni profiles, while the forbidden emission lines weakened and eventually disappeared.
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In 1995, Andrew Steane began an experimental effort to study how quantum computers might be built from ionised atoms trapped by laser beams. In 1996, Jonathan Jones started a group working on a quantum computer based on the same techniques used in magnetic resonance imaging in medicine. And two years later, Dirk Bouwmeester arrived from Geneva to begin an experimental group working out how the quantum world could also revolutionise communication. The group changed its name to the Centre for Quantum Computation.
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Interatomic Coulombic decay can occur when one atom is ionised and excited. It can transfer energy to another atom in the trimer, even though they are separated. However this is much more likely to occur when the atoms are close together, and so the interatomic distances measured by this vary with half full height from 3.3 to 12 Å. The predicted mean distance for Interatomic Coulombic decay in 4He3 is 10.4 Å. For 3He4He2 this distance is even larger at 20.5 Å.
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His thesis was on New Techniques for the Study of Ionised Gases. In addition to helping create the MSSL, Boyd played an instrumental role in the founding of the European Space Research Organization and its subsequent incarnation the European Space Agency (1974/75). Boyd succeeded Harrie Massey as the chair of the British National Committee for Space Research in 1976. He became a Fellow of the Royal Society in 1969 and was knighted in 1983 in recognition of his services to space science.
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This idea was later proven with the existence of tritium, but that was not the explanation of why molecular weight 3 was observed in mass spectrometers. J. J. Thomson later believed that the molecular weight 3 molecule he observed was Hydrogen deuteride. In the Orion nebula lines were observed that were attributed to nebulium which could have been the new element eka-hydrogen, especially when its atomic weight was calculated as near 3. Later this was shown to be ionised nitrogen and oxygen.
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The forbidden emission, infrared excess, and other features indicative of the B[e] phenomenon, themselves provide strong hints at the nature of the stars. The stars are surrounded by ionised gas which produces intense emission lines in the same way as Be stars. The gas must be sufficiently extended to allow the formation of forbidden lines in the outer low density region, and also for dust to form which produces the infrared excess. These features are common to all the types of B[e] star.
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A diet with too much fried or spicy food, consumption of alcohol, stress, smoking, late nights and a humid weather are also some factors that can easily upset the body and cause the condition of "heatiness". Three Legs Cooling Water comprises de-ionised water and the natural mineral, gypsum fibrosum (simplified Chinese: 石膏; pinyin: shí gāo). Gypsum fibrosum is a type of plaster stone containing calcium sulphate and is said to be "cooling by nature"."Well-Being." Healthy Times Aug-Sept 2008: 65. Print.
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Hubble The spectrum of the Homunculus is complex, consisting of reflected, thermal, and emission components at wavelengths across the electromagnetic spectrum. The dominant feature is blackbody radiation from dust heated by the stars within. Overlaid on this is some light from the stars themselves reflected mostly from dense features within the nebulosity, showing strong visual and UV spectral lines in emission. There are also emission lines from ionised gas where it collides with slower moving material or is excited by high energy electromagnetic radiation from the stars.
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Physiologically, blood calcium is tightly regulated within a narrow range for proper cellular processes. Calcium in the blood exists in three primary states: bound to proteins (mainly albumin), bound to anions such as phosphate and citrate, and as free (unbound) ionized calcium; all of these forms are ionised. Only the unbound calcium is physiologically active. Normal blood calcium level is between 8.5 to 10.5 mg/dL (2.12 to 2.62 mmol/L) and that of unbound calcium is 4.65 to 5.25 mg/dL (1.16 to 1.31 mmol/L).
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The rocket engine nozzles were slightly offset to rotate the missile - this increased accuracy by evening out the effect of any slight asymmetry in thrust. This configuration drastically limited both range and flight duration, but was used because of fears that ionised particles in the hot, rocket motor exhaust stream would interfere with the guidance radar signals; further development showed the fears were unfounded. Steering was accomplished by four rudders in a cruciform configuration. These were moved by four pairs of pneumatic servos, operated by solenoid valves.
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Herbig–Haro (HH) objects are bright patches of nebulosity associated with newborn stars. They are formed when narrow jets of partially ionised gas ejected by stars collide with nearby clouds of gas and dust at several hundred kilometres per second. Herbig–Haro objects are commonly found in star-forming regions, and several are often seen around a single star, aligned with its rotational axis. Most of them lie within about one parsec (3.26 light-years) of the source, although some have been observed several parsecs away.
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The stellar disk is symmetric and there are evidence of weak spiral arms outside the primary bar. In the infrared Ks-band, the bar has ansae-type morphology and in the inner elliptical there is an inner disc showing two-armed spirals. Based on the fact that the spiral arms and the gas are rotating in different directions it has been suggested that the inner ionised gas and the outer HI gas are inclined, almost perpendicular to the stellar disk. The galaxy features also a secondary bar.
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Clathrates are also possible with helium under pressure in ice, and other small molecules such as nitrogen. Other ways to make helium reactive are: to convert it into an ion, or to excite an electron to a higher level, allowing it to form excimers. Ionised helium (He+), also known as He II, is a very high energy material able to extract an electron from any other atom. He+ has an electron configuration like hydrogen, so as well as being ionic it can form covalent bonds.
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At these low altitudes, the density of the air is great and thus the electron density of ionised air is very large. Due to this heavy ionisation, there is strong absorption of electromagnetic waves caused by ‘electron friction’. Thus in transmissions over any distance, there will be no reflections as any waves apart from the one at ground level will be absorbed rather than reflected. However, when the sun sets, the molecules slowly start to recombine with their electrons and the free electron density levels drop.
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Eta Carinae, surrounded by the Homunculus Nebula Within the large bright nebula is a much smaller feature, immediately surrounding Eta Carinae itself, known as the Homunculus Nebula (from Latin meaning Little Man). It is believed to have been ejected in an enormous outburst in 1841 which briefly made Eta Carinae the second-brightest star in the sky. The Homunculus Nebula is a small H II region, with gas shocked into ionised and excited states. It also absorbs much of the light from the extremely luminous central stellar system and re- radiates it as infrared (IR).
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The apparently large difference is due largely to a difference in the depth within the atmosphere at which the radius is defined. The luminosity of WR 111 is similar in both models at - , and the masses are found to be and , respectively. The stellar wind from WR 111 is ejecting 20 millionths of the Sun's mass every year at a speed of 2,398 km/s. The mechanism driving the intense stellar wind is found to be an opacity bump deep within the atmosphere caused by highly ionised iron.
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Hydrides of this type form according to either one of two main mechanisms. The first mechanism involves the adsorption of dihydrogen, succeeded by the cleaving of the H-H bond, the delocalisation of the hydrogen's electrons, and finally the diffusion of the protons into the metal lattice. The other main mechanism involves the electrolytic reduction of ionised hydrogen on the surface of the metal lattice, also followed by the diffusion of the protons into the lattice. The second mechanism is responsible for the observed temporary volume expansion of certain electrodes used in electrolytic experiments.
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By 1960, no compound with a covalently bound noble gas atom had yet been synthesized. The first published report, in June 1962, of a noble gas compound was by Neil Bartlett, who noticed that the highly oxidising compound platinum hexafluoride ionised O2 to . As the ionisation energy of O2 to (1165 kJ mol−1) is nearly equal to the ionisation energy of Xe to Xe+ (1170 kJ mol−1), he tried the reaction of Xe with PtF6. This yielded a crystalline product, xenon hexafluoroplatinate, whose formula was proposed to be .
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The total energy radiated in the first 50 days exceeded joules. According to Krzysztof Stanek of Ohio State University, one of the principal investigators at ASAS-SN, "If it was in our own galaxy, it would shine brighter than the full moon; there would be no night, and it would be easily seen during the day." The spectrum of ASASSN-15lh was relatively featureless, with no hydrogen or helium lines, but two very broad absorption bands. Ionised magnesium absorption doublets were detected and used to confirm the redshift at 0.2326.
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Capillary electrochromatography (CEC) combines the principles used in HPLC and CE. The mobile phase is driven across the chromatographic bed using electroosmosis instead of pressure (as in HPLC). Electroosmosis is the motion of liquid induced by an applied potential across a porous material, capillary tube, membrane or any other fluid conduit. Electroosmotic flow is caused by the Coulomb force induced by an electric field on net mobile electric charge in a solution. Under alkaline conditions, the surface silanol groups of the fused silica will become ionised leading to a negatively charged surface.
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Emission by molecular hydrogen and ionised gas has also been reported. The observed emission of the gas in the nuclear region has been suggested to be the result of the accretion of cold gas by the HI disk. NGC 4278 is home to a larger than average number of globular clusters compared with galaxies of similar luminosity, with an estimated total number of . As it has been found in other galaxies, the colour distribution of the globular clusters in the galaxy features bimodiality, with the clusters forming a red and a blue subpopulation.
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The 12 thyristor valves at each side are arranged in a conventional twelve-pulse bridge. The valves are cooled by a mixture of de-ionised water and ethylene glycol, which does not freeze at a temperature of -50°C. These were the first thyristor valves ever to use water/glycol mixtures directly inside the valve, with no separate secondary cooling circuit. The valves use 100mm, 5.2 kV electrically triggered thyristors with 11 in series per valve on the Alberta side and 12 in series per valve on the Saskatchewan side.
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As they sparked the tube into discharge, the spectrum obtained from it changed, as the alphas accumulated in the tube. Eventually, the clear spectrum of helium gas appeared, proving that alphas were at least ionised helium atoms, and probably helium nuclei. A long- standing myth existed, at least as early as 1948, running at least to 2017, that Rutherford was the first scientist to observe and report an artificial transmutation of a stable element into another element: nitrogen into oxygen. It was thought by many people to be one of Rutherford's greatest accomplishments.
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Orion's Belt with Alnitak on the left-hand side and the Horsehead Nebula directly below it. The dark cloud of dust and gas is a region in the Orion Molecular Cloud Complex where star formation is taking place. It is located in the constellation of Orion, which is prominent in the winter evening sky in the Northern Hemisphere and the summer evening sky in the Southern Hemisphere. Colour images reveal a deep-red colour that originates from ionised hydrogen gas (Hα) predominantly behind the nebula, and caused by the nearby bright star Sigma Orionis.
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R136 in NGC 2070, with Mk 34 just to the left of the central concentration The two components of Mk34 have identical spectral classes of WN5h, having spectra with prominent emission lines of highly-ionised helium, nitrogen, and carbon. The h suffix indicates that the spectrum also contains lines of hydrogen which are not usually seen in Wolf-Rayet spectra. The strength of the helium emission lines in the spectrum shows that the outer layers of the star consist of 35% helium. The WN5 spectral class indicates an extremely high photospheric temperature.
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Matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) is another method of phenotypic susceptibility testing. This is a form of time-of-flight mass spectrometry, in which the molecules of a bacterium are subject to matrix-assisted laser desorption. The ionised particles are then accelerated, and spectral peaks recorded, producing an expression profile, which is capable of differentiating specific bacterial strains after being compared to known profiles. This includes, in the context of antibiotic susceptibility testing, strains such as beta-lactamase producing E coli.
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WR 31a is surrounded by a shell of ionised gas nearly wide. The Hubble Space Telescope (HST) has captured a striking image of the nebula, rendering it as a thin blue bubble. In this false colour image, the blue colours represents red visible light (605 nm), while orange-red colours represent near infrared radiation at 814 nm. Some media sources have wrongly claimed this deep-sky object was recently discovered by the HST, but this nebula was originally found by Ellen Dorrit Hoffleit in 1953 and designated as the planetary nebula Hf 39.
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2 Thus, in an internal conversion process, a high-energy electron is emitted from the radioactive atom, but not from the nucleus. For this reason, the high-speed electrons resulting from internal conversion are not called beta particles, since the latter come from beta decay, where they are newly created in the nuclear decay process. Internal conversion is possible whenever gamma decay is possible, except in the case where the atom is fully ionised. During internal conversion, the atomic number does not change, and thus (as is the case with gamma decay) no transmutation of one element to another takes place.
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Bomb development called for large detectors of ionising radiation, whose response is proportional to the energy released in the detector and follows rapid changes in radiation intensity. From the earliest research on radioactivity, radiation had been measured in terms of Ionisation, but existing Ionisation chambers were slow to respond to changes. To address this problem, Rossi and Staub carried out a careful analysis of the pulses that result when individual charged particles create ions within an ionisation chamber. They realised that the high mobility of free electrons removed from ionised atoms means that the pulses produced by single particles can be very brief.
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Closer to the nucleus can be observed a dusty spiral pattern, with two arms, with the northwest arm being on the near side of the galaxy, and the southeast one to the far side. The ionised gas inflow rate towards the nucleus is estimated to be 0.2 per year. Although NGC 7213 appears undisturbed in visible light, it shows signs of having undergone a collision or merger when viewed at longer wavelengths, with disturbed patterns of ionized hydrogen including a filament of gas around 64,000 light-years long, itself being part of a larger HI tidal tail southwest of the nucleus.
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The more comprehensive approach to assessment of ion suppression is to constantly infuse an appropriate concentration into the mobile phase flow, downstream from the analytical column, using a syringe pump and a 'tee union'. A typical sample should then be injected through the HPLC inlet as per the usual analytical parameters. Monitoring of detector response during this experiment should yield a constant signal appropriate to the concentration of infused species. Once the sample has been injected, a drop in signal intensity (or a negative response) should be observed any time a species is ionised in the ion source.
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NGC 7424 is intermediate between normal spirals (SA) and strongly barred galaxies (SB). Other features include the presence of a central ring-like structure and a relatively low core brightness relative to the arms. The redder color of the prominent bar indicates an older population of stars while the bright blue color of the loose arms indicates the presence of ionised hydrogen and clusters of massive young stars. NGC 7424 is listed as a member of the IC 1459 Grus Group of galaxies, but is suspected of being a "field galaxy"; that is, not gravitationally bound to any group.
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RCW 120 is an emission nebula and H II region in the southern Milky Way and located some 4,300 light-years from Earth. Its designation appears in the RCW Catalogue published in 1960, whose circular diameter size is 6 arcmin. It also catalogued as Sh 2-3 and Gum 58. Veta S. Avedisova considers RCW 120 is being ionised by the O8 V star CD -38 11636 and the B2 V star VDBH 84B, and places the nebula in the star formation region SFR 348.26+0.47 along with 3 masers and the radio HII region CH87 347.386+0.266.
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It was an outpost of the university's botany department and had been a searchlight station during the war. In the course of his experiments, he was able to show that radar echoes could be obtained from daytime meteor showers as they entered the Earth's atmosphere and ionised the surrounding air. He was later able to determine the orbits of meteors in annual meteor showers to show they were in solar orbit and not of interstellar origin. With university funding, he constructed the then-largest steerable radio telescope in the world, which now bears his name: the Lovell Telescope.
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More plasma thrusters are likely to see flight time as the technologies mature. In May 2020, a team from the Institute of Technological Sciences at Wuhan University published a paper on a prototype plasma jet device they developed capable of lifting a 1kg (2.2lb) steel ball over a 24mm (one inch) diameter quartz tube. The thrust needed to achieve such lift is equivalent to the relative thrust of a commercial aircraft engine. In the design, pressurized air is injected into a chamber and subjected to over 1,000 degrees Celsius and microwaves to create an ionised plasma, which is then expelled to create propulsion.
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The high temperature of the Sun's corona gives it unusual spectral features, which led some in the 19th century to suggest that it contained a previously unknown element, "coronium". Instead, these spectral features have since been explained by highly ionized iron (Fe-XIV, or Fe13+). Bengt Edlén, following the work of Grotrian (1939), first identified the coronal spectral lines in 1940 (observed since 1869) as transitions from low- lying metastable levels of the ground configuration of highly ionised metals (the green Fe-XIV line from Fe13+ at , but also the red Fe-X line from Fe9+ at ).
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Rhenium–osmium dating is a form of radiometric dating based on the beta decay of the isotope 187Re to 187Os. This normally occurs with a half-life of 41.6 × 109 y, but studies using fully ionised 187Re atoms have found that this can decrease to only 33 y. Both rhenium and osmium are strongly siderophilic (iron loving), while Re is also chalcophilic (sulfur loving) making it useful in dating sulfide ores such as gold and Cu-Ni deposits. This dating method is based on an isochron calculated based on isotopic ratios measured using N-TIMS (Negative – Thermal Ionization Mass Spectrometry).
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The plot concerns a journey by a spaceship to enter through the layers of gas surrounding a comet and observe the nucleus at close range. This part of the mission is successful, but the ship's computer develops a malfunction and they are unable to compute the required orbit to escape the comet. The ionised gas in the comet's tail prevents any radio communication with Earth. George Pickett, a part-Japanese journalist on board the ship, recalls the use of the abacus used by his granduncle, a bank teller, and persuades the ship's astronomer to give it a try.
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The arm-ring found with the body was made from waterlogged leather, strands of fibres and four bronze mounts. According to Louise Mumford of the National Museum, the leather ring was made with two strands of leather joined together through numerous small slits. The ring was initially removed from the body and wet cleaned to remove elements like peat from the leather. To prevent further decay of the waterlogged leather work and mould growth the arm-ring was stored in a 20% solution of glycerol and de- ionised water for two weeks in a process called consolidation.
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WR 102 was first mentioned as the possible optical counterpart to a peculiar X-ray source GX 3+1. However, it became clear that it was a separate object and in 1971 it was highlighted as a luminous star with unusual OVI emission lines in its spectrum. It was classified as a WC star, an unusual one because of the highly ionised emission lines, and not the central star of a planetary nebula. It was seen to vary in brightness and was given the variable star designation V3893 Sagittarii in the 62nd name-list of variable stars.
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Sodium tungsten bronze, like other tungsten bronzes, is resistant to chemical reaction under both acidic and basic conditions. Colour is dependent upon the proportion of sodium in the compound, ranging from golden at x ≈ 0.9, through red, orange and deep purple, to blue-black when x ≈ 0.3. The electrical resistivity of the bronze depends on the proportion of sodium in the compound, with specific resistances of 1.66 mΩ being measured for some samples. It has been suggested that electrons, released when the sodium atoms are ionised, are conducted readily through the tungsten t2g and oxygen π orbitals.
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In the ion chamber region, there are no avalanches and the applied voltage only serves to move the ions towards the electrodes to prevent re-combination. In the proportional region, localised avalanches occur in the gas space immediately round the anode which are numerically proportional to the number of original ionising events. Increasing the voltage further increases the number of avalanches until the Geiger region is reached where the full volume of the fill gas around the anodes ionised, and all proportional energy information is lost. Beyond the Geiger region the gas is in continuous discharge owing to the high electric field strength.
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Bok globules in H II region IC 2944 Stars form in clumps of cool molecular gas that hide the nascent stars. It is only when the radiation pressure from a star drives away its 'cocoon' that it becomes visible. The hot, blue stars that are powerful enough to ionize significant amounts of hydrogen and form H II regions will do this quickly, and light up the region in which they just formed. The dense regions which contain younger or less massive still-forming stars and which have not yet blown away the material from which they are forming are often seen in silhouette against the rest of the ionised nebula.
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The solar wind had a velocity at the time of about , at which speed it would have taken eight days for the tail to be carried out to where the spacecraft was situated at 3.73 AU, approximately 45 degrees out of the ecliptic plane. The orientation of the ion tail inferred from the magnetic field measurements agreed with the source lying in Comet Hyakutake's orbital plane. The other team, working on data from the spacecraft's ion composition spectrometer, discovered a sudden large spike in detected levels of ionised particles at the same time. The relative abundances of chemical elements detected indicated that the object responsible was definitely a comet.
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Hubble image of a small region of the Crab Nebula, showing Rayleigh–Taylor instabilities in its intricate filamentary structure. In visible light, the Crab Nebula consists of a broadly oval-shaped mass of filaments, about 6 arcminutes long and 4 arcminutes wide (by comparison, the full moon is 30 arcminutes across) surrounding a diffuse blue central region. In three dimensions, the nebula is thought to be shaped either like an oblate spheroid (estimated as away) or a prolate spheroid (estimated as away). The filaments are the remnants of the progenitor star's atmosphere, and consist largely of ionised helium and hydrogen, along with carbon, oxygen, nitrogen, iron, neon and sulfur.
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The very large ensemble of solar-like stars included in this study enables detailed and robust estimates of the relation between chromospheric activity and the occurrence of superflares. All the stars showed the quasi- periodic brightness variations, ranging from 0.1% to nearly 10%, interpreted as the rotation of large starspots. When large spots exist on a star, the activity level of the chromosphere becomes high; in particular, large chromospheric plages form around sunspot groups. The intensities of certain solar and stellar lines generated in the chromosphere, particularly the lines of ionised calcium (Ca II) and the Hα line of hydrogen, are known to be indicators of magnetic activity.
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The "f" indicates that the spectrum has emission lines of ionised Helium and Nitrogen, not uncommon in somewhat evolved hot O stars and typically identified by the composite emission and absorption profile of the 468.6nm HeII spectral line. The "n" (for nebulous) indicates broadened absorption lines, caused by rapid rotation of the star, in this case over 220 km/s at the equator. The "p" is a general spectral indicator of peculiarity. This combination of spectral characters is unusual because evolved hot stars are expected to rotate relatively slowly after braking by a strong stellar wind, and only 8 stars of this type are known in the Milky Way.
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The geology that underlies a river or lake has a major impact on its chemistry. A river flowing across very ancient precambrian schists is likely to have dissolved very little from the rocks and maybe similar to de-ionised water at least in the headwaters. Conversely a river flowing through chalk hills, and especially if its source is in the chalk, will have a high concentration of carbonates and bicarbonates of Calcium and possibly Magnesium. As a river progresses along its course it may pass through a variety of geological types and it may have inputs from aquifers that do not appear on the surface anywhere in the locality.
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It is an evolved massive star which has an emission line spectrum from a strong stellar wind caused by high luminosity and the presence of elements heavier than hydrogen in the photosphere. The spectrum is dominated by ionised helium and nitrogen lines due to convectional and rotational mixing of fusion products to the surface of the star. However it is still in a core hydrogen burning phase and hydrogen lines are also visible in the spectrum, in contrast to WN stars without hydrogen which are older, less massive, and less luminous. Despite being a relatively unevolved star, WR 102ea has lost over half its mass already.
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The Advanced Vela satellites were additionally equipped with two non-imaging silicon photodiode sensors called bhangmeters which monitored light levels over sub-millisecond intervals. They could determine the location of a nuclear explosion to within about 3,000 miles. Atmospheric nuclear explosions produce a unique signature, often called a "double-humped curve": a short and intense flash lasting around 1 millisecond, followed by a second much more prolonged and less intense emission of light taking a fraction of a second to several seconds to build up. The effect occurs because the surface of the early fireball is quickly overtaken by the expanding atmospheric shock wave composed of ionised gas.
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Although this temperature (about 2000 K) is high compared to room temperature, it is much lower than electron temperatures that are usually found in discharge plasma. The low temperature makes it possible to create a plasma column that is several ion gyro radii across. Since the alkaline metals are solids at room temperature they will stick to the walls of the machine on impact, and therefore the neutral pressure can be kept so low that for all practical purposes the plasma is fully ionised. Plasma research that has been performed using Q-machines includes current driven ion cyclotron waves , Kelvin-Helmholtz waves, and electron phase space holes.
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WASP-12b absorbs 94% of the light shining on its surface, resulting in a very low albedo, the amount of light the exoplanet reflects. Since hot Jupiter exoplanets are “phase locked” by tidal interactions (that is, the same side always faces the host star, just as the same side of our moon always faces us), there will be a large flow of heat from the highly irradiated “day side” to the cooler “night side”. This is thought to result in very strong winds rushing around the planet's atmosphere. Taylor Bell and Nicolas Cowan have pointed out that hydrogen will tend to be ionised on the day-side face.
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Alfred Fowler gave the same attribution to similar lines that he observed in a hydrogen-helium mixture in 1912. Analysis by Niels Bohr included in his 'trilogy' on atomic structure argued that the spectral lines arose from ionised helium, He+, and not from hydrogen. Fowler was initially-skeptical but was ultimately convinced that Bohr was correct, and by 1915 "spectroscopists had transferred [the Pickering series] definitively [from hydrogen] to helium." Bohr's theoretical work on the Pickering series had demonstrated the need for "a re-examination of problems that seemed already to have been solved within classical theories" and provided important confirmation for his atomic theory.
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Shi et al. used data from Spitzer Space Telescope and ground-based optical spectropolarimeteric observations and observed lack of polarised broad emission lines in NGC 3147. NGC 3147 was observed by NuSTAR at the 3-40 keV X-ray spectrum, which is characterised by a simple power-law, with a standard Γ ∼ 1.7 and an iron emission line, with no need for any further component up to ∼ 40 keV. There is a debate whether the lack of broad lines detection observed with NGC 3147 is caused by the presence of an Compton-thick column with the presence of a highly ionised reflactor to account for the X-ray spectrum or not.
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In 1966, a search for Wolf-Rayet stars in the northern celestial hemisphere discovered seven new examples. One, designated as Stephenson 3, was classified as WC. It was later found to show unusual emission lines of highly ionised OVI. Because of the unusual oxygen lines, seen in only a handful of other stars, it was given the spectral type WC5pec in the Sixth Catalogue of Galactic Wolf-Rayet Stars. In 1981, described as a WC-OVI star, it was identified as being associated with the active star-forming region ON2, and then a heavily-obscured open cluster designated Berkeley 87, south of the red supergiant BC Cygni.
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The merger remnant is characterised as a "fast rotator" that indicates either that the galaxy retained the angular momentum of the original galaxy or that the two galaxies merged in a way that they attained angular momentum. The mean age of the stellar population of the central 0.3 kpc of NGC 680 is 7.8 billion years, while for the central 2.6 kpc the mean age is 6.5 billion years. Ionised gas has been detected in the nucleus of the galaxy, it is probably created by the gas emitted by stars at the end of their life. An arc of bluer and younger stars has been detected east of the galaxy.
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Ionised gas is detected north and south of the nucleus in a position similar to the radio emission but a comparison with optical images shows no direct association. A linear feature has also been observed by Hubble Space Telescope in [O III] and [N II] + Hα with similar characteristics as the radio one. An emission plume extending for one arcsecond east-northeast of the nucleus was also observed. No trace of polycyclic aromatic hydrocarbon (PAH) emission has been detected in mid- infrared observations of the central 20 pc of NGC 1386, while there is mild silicate absorption, which may be associated with a dust torus around the AGN.
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For Z > Zcr, if the innermost orbital (1s) is not filled, the electric field of the nucleus will pull an electron out of the vacuum, resulting in the spontaneous emission of a positron. , and references therein This diving of the 1s subshell into the negative continuum has often been taken to constitute an "end" to the periodic table, although more detailed treatments suggest a less bleak outcome. Atoms with atomic numbers above Zcr ≈ 173 have been termed supercritical atoms. Supercritical atoms cannot be totally ionised because their 1s subshell would be filled by spontaneous pair creation in which an electron-positron pair is created from the negative continuum, with the electron being bound and the positron escaping.
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Comparison of main sequence stars R136a1 is a high-luminosity WN5h star, placing it on the extreme top left corner of the Hertzsprung-Russell diagram. A Wolf–Rayet star is distinguished by the strong, broad emission lines in its spectrum. This includes ionized nitrogen, helium, carbon, oxygen and occasionally silicon, but with hydrogen lines usually weak or absent. A WN5 star is classified on the basis of ionised helium emission being considerably stronger than the neutral helium lines, and having roughly equal emission strength from NIII, NIV, and NV. The "h" in the spectral type indicates significant hydrogen emission in the spectrum, and hydrogen is calculated to make up 40% of the surface abundance by mass.
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The radiant point for the Perseid meteor shower A meteoroid of the Perseids with a size of about ten millimetres entering the Earth's atmosphere in slow motion (x 0.1). The meteoroid is at the bright head of the trail, and the recombination glow of the ionised mesosphere is still visible for about 0.7 seconds in the tail. (Variant of the animation in real time) A near-Earth perspective of its orbit, the radiant of the Perseid meteor shower, and the orbit of the shower's parent comet, 109P/Swift-Tuttle, to show their spatial relationships on August 12 00:00 UTC. The Perseid debris cloud is fairly wide (~0.1 AU), filling the frame.
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Aircraft passengers and the crew are more prone to dangerous exposure from radiation during an ionospheric storm. Flight altitudes are usually 10 km or more, so when an ionospheric storm occurs during the flight, people on the plane will potentially gain an approximate 0.1% chance of developing a lethal cancer during their lifetime. The plane when flying at a 10 km or above altitude will have around 300 times more exposure to ionised radiation than on sea level. The energised particles produced by the ionospheric storm will also potentially cause damage and disrupt "microelectronic circuitry" due to single event effect (SEE), when the energised particles interconnect with the semiconductor device and causes system failure.
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The history and development of SPADs and APDs shares a number of important points with the development of solid-state technologies such as diodes and early p–n junction transistors (particularly war-efforts at Bell Labs). John Townsend in 1901 and 1903 investigated the ionisation of trace gases within vacuum tubes, finding that as the electric potential increased, gaseous atoms and molecules could become ionised by the kinetic energy of free electrons accelerated though the electric field. The new liberated electrons were then themselves accelerated by the field, producing new ionisations once their kinetic energy has reached sufficient levels. This theory was later instrumental in the development of the thyratron and the Geiger-Mueller tube.
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WR 7 (HD 56925) is a Wolf–Rayet star in the constellation of Canis Major. It lies at the centre of a complex bubble of gas which is shocked and partially ionised by the star's radiation and winds. The distance is uncertain, with estimates between 3.5 kiloparsecs (11,410 light-years) and 6.9 kiloparsecs (22,500 light-years). Assuming a distance of 4.8 kiloparsecs (15,600 light- years), this star is calculated to be 280,000 times brighter than our Sun] 16 times more massive, and 1.41 times larger with a surface temperature of 112,000 K. Stars of its kind are characterised by a rapid loss of stellar mass, driven by chemically enriched high-speed stellar winds.
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In 1896, Edward Charles Pickering published observations of previously unknown lines in the spectra of the star ζ-Puppis, Also published as: which he attributed to hydrogen. Fowler managed to reproduce these lines experimentally from a hydrogen-helium mixture in 1912, and agreed with Pickering's interpretation that they were previously unknown features in the spectrum of hydrogen. These lines became known as the Pickering-Fowler series and turned out to be of great significance in understanding the nature of the atom. Niels Bohr included a theoretical examination of these lines in his 'trilogy' on atomic structure and concluded that they had been wrongly attributed to hydrogen, arguing instead that they arose from ionised helium, He+.
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The core of this system is called a protostar. Some of the accreting material is ejected out along the star's axis of rotation in two jets of partially ionised gas (plasma). The mechanism for producing these collimated bipolar jets is not entirely understood, but it is believed that interaction between the accretion disk and the stellar magnetic field accelerates some of the accreting material from within a few astronomical units of the star away from the disk plane. At these distances the outflow is divergent, fanning out at an angle in the range of 10−30°, but it becomes increasingly collimated at distances of tens to hundreds of astronomical units from the source, as its expansion is constrained.
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The tenuous atmosphere of Mars visible on the horizon Mars lost its magnetosphere 4 billion years ago, possibly because of numerous asteroid strikes, so the solar wind interacts directly with the Martian ionosphere, lowering the atmospheric density by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected ionised atmospheric particles trailing off into space behind Mars, and this atmospheric loss is being studied by the MAVEN orbiter. Compared to Earth, the atmosphere of Mars is quite rarefied. Atmospheric pressure on the surface today ranges from a low of on Olympus Mons to over in Hellas Planitia, with a mean pressure at the surface level of .
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In the Starfish Prime nuclear test, most damage was to the satellites' solar panels while passing through radiation belts created by the explosion. For detonations within the atmosphere, the situation is more complex. Within the range of gamma ray deposition, simple laws no longer hold as the air is ionised and there are other EMP effects, such as a radial electric field due to the separation of Compton electrons from air molecules, together with other complex phenomena. For a surface burst, absorption of gamma rays by air would limit the range of gamma ray deposition to approximately , while for a burst in the lower-density air at high altitudes, the range of deposition would be far greater.
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Planetary nebula IC 289 is a cloud of ionised gas being pushed out into space by the remnants of the star's core A rich section of the Milky Way runs through Cassiopeia, stretching from Perseus towards Cygnus, and it contains a number of open clusters, young luminous galactic disc stars, and nebulae. The Heart Nebula and the Soul Nebula are two neighboring emission nebulae about 7,500 light-years away. Two Messier objects, M52 (NGC 7654) and M103 (NGC 581), are located in Cassiopeia; both are open clusters. M52, once described as a "kidney-shaped" cluster, contains approximately 100 stars and is 5200 light-years from Earth. Its most prominent member is an orange-hued star of magnitude 8.0 near the cluster's edge.
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Spectrum of WR 137 showing the prominent emission lines of ionised Carbon and Helium WR 137 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus. WR 137, together with WR 134 and WR 135, was one of three stars in Cygnus observed in 1867 to have unusual spectra consisting of intense emission lines rather than the more normal continuum and absorption lines. These were the first members of the class of stars that came to be called Wolf-Rayet stars (WR stars) after Charles Wolf and Georges Rayet who discovered their unusual appearance. It is a member of the carbon sequence of WR stars, indicated by the lack of nitrogen lines and the strength of carbon emission.
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MF broadcasting stations use ground waves to cover their listening areas. MF waves can also travel longer distances via skywave propagation, in which radio waves radiated at an angle into the sky are reflected (actually refracted) back to Earth by layers of charged particles (ions) in the ionosphere, the E and F layers. However, at certain times the D layer (at a lower altitude than the refractive E and F layers) can be electronically noisy and absorb MF radio waves, interfering with skywave propagation. This happens when the ionosphere is heavily ionised, such as during the day, in summer and especially at times of high solar activity, At night, especially in winter months and at times of low solar activity, the ionospheric D layer can virtually disappear.
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The blob contains atomic hydrogen with a small admixture of other elements, including iron photo-ionised by radiation from the central stars. An accidental resonance (where emission coincidentally has a suitable energy to pump the excited state) allows the Lyα emission to pump the Fe+ ions to certain pseudo- metastable states, creating a population inversion that allows the stimulated emission to take place. This effect is similar to the maser emission from dense pockets surrounding many cool supergiant stars, but the latter effect is much weaker at optical and UV wavelengths and Eta Carinae is the only clear instance detected of an ultraviolet astrophysical laser. A similar effect from pumping of metastable OI states by Lyβ emission has also been confirmed as an astrophysical UV laser.
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Radio emissions have been observed from Eta Carinae across the microwave band. It has been detected in the 21 cm HI line, but has been particularly closely studied in the millimetre and centimetre bands. Masing hydrogen recombination lines (from the combining of an electron and proton to form a hydrogen atom) have been detected in this range. The emission is concentrated in a small non-point source less than 4 arcseconds across and appears to be mainly free-free emission (thermal bremsstrahlung) from ionised gas, consistent with a compact HII region at around 10,000 K. High resolution imaging shows the radio frequencies originating from a disk a few arcseconds in diameter, 10,000 astronomical units (AU) wide at the distance of Eta Carinae.
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The room temperature form α-MgH2 has a rutile structure. There are at least four high pressure forms: γ-MgH2 with α-PbO2 structure, cubic β-MgH2 with Pa-3 space group, orthorhombic HP1 with Pbc21 space group and orthorhombic HP2 with Pnma space group. Additionally a non stoichiometric MgH(2-δ) has been characterised, but this appears to exist only for very small particles (bulk MgH2 is essentially stoichiometric, as it can only accommodate very low concentrations of H vacancies). The bonding in the rutile form is sometimes described as being partially covalent in nature rather than purely ionic; charge density determination by synchrotron x-ray diffraction indicates that the magnesium atom is fully ionised and spherical in shape and the hydride ion is elongated.
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LISA Pathfinder was assembled by Airbus Defence and Space in Stevenage (UK), under contract to the European Space Agency. It carried a European "LISA Technology Package" comprising inertial sensors, interferometer and associated instrumentation as well as two drag-free control systems: a European one using cold gas micro-thrusters (similar to those used on Gaia), and a US-built "Disturbance Reduction System" using the European sensors and an electric propulsion system that uses ionised droplets of a colloid accelerated in an electric field.Ziemer, J.K.; and Merkowitz, S.M.: “Microthrust Propulsion of the LISA Mission,” AIAA–2004–3439, 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Fort Lauderdale FL, July 11–14, 2004. The colloid thruster (or "electrospray thruster") system was built by Busek and delivered to JPL for integration with the spacecraft.
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Herbig had initially paid little attention to the objects he had discovered, being primarily concerned with the nearby stars, but on hearing Haro's findings he carried out more detailed studies of them. The Soviet astronomer Viktor Ambartsumian gave the objects their name (Herbig–Haro objects, normally shortened to HH objects), and based on their occurrence near young stars (a few hundred thousand years old), suggested they might represent an early stage in the formation of T Tauri stars. Studies of the HH objects showed they were highly ionised, and early theorists speculated that they were reflection nebulae containing low-luminosity hot stars deep inside. But the absence of infrared radiation from the nebulae meant there could not be stars within them, as these would have emitted abundant infrared light.
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The urine test strip test for specific gravity is based on the change in dissociation constant (pKa) of an anionic polyelectrolyte (poly-(methyl vinyl ether/maleic anhydride)) in an alkali medium that is ionised and releases hydrogen ions in proportion to the number of cations present in the solution. The greater the cation concentration of the urine the more hydrogen ions are released, thereby reducing the pH. The pad also includes bromothymol blue, which measures this change in pH. It should be remembered that the test strip only measures cation concentration, it is therefore possible that urine with a high concentration of non-ionic solutes (such as glucose or urea) or with high molecular weight compounds (such as the media used to provide radiographic contrast) will yield a result that will be erroneously lower than that measured by densitometry.
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First interest in the ionised hydrogen of the interstellar medium came when Ron Reynolds pointed a spectrometer through a makeshift observing portal in an office of the University of Wisconsin-Madison's Physical Sciences Laboratory during the late 1970s. Reynolds and colleagues, including Matt Haffner, a senior scientist in UW-M's astronomy department, later developed WHAM.WHAM Brings Milky Way's Ionized Hydrogen into Focus, SpaceDaily.com, 2017-04-12 WHAM formally began life at Kitt Peak National Observatory (KPNO) in November 1996, using the flat mirrors of a two axis, all-sky siderostat passing light horizontally through a 0.6 m diameter, 8.6 m focal length objective lens into a 2.5 m x 2.5 m x 6 m trailer that contained the spectrometer, that used a low noise, high efficiency CCD camera as a multichannel detector behind a pair of diameter Fabry-Perot etalons/spectrometers.
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R99 has significant differences from those other stars which preclude it being given a simple WN spectral type: the ultraviolet spectrum is strongly blanketed over a different range of wavelengths; highly ionised iron lines are seen in absorption instead of emission; the H lines are unusually narrow and have no P Cygni profile; a lack of any significant absorption features near Hδ; a number of metal lines are unusually strong or weak compared to other stars of the type; there is a small unexplained infrared excess. The wind structure of R99 may be significantly different from most WR stars and LBVs. The normal temperature-stratified WR wind is accelerated to terminal velocity, causing lines of different ionisation levels of Helium to be created at different distances from the star. This does not seem to apply to R99.
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The components of the gas mixture are vital to the operation and application of a G-M tube. The mixture is composed of an inert gas such as helium, argon or neon which is ionised by incident radiation, and a "quench" gas of 5–10% of an organic vapor or a halogen gas to prevent spurious pulsing by quenching the electron avalanches. This combination of gases is known as a Penning mixture and makes use of the Penning ionization effect. The modern halogen-filled G–M tube was invented by Sidney H. Liebson in 1947 and has several advantages over the older tubes with organic mixtures. The halogen tube discharge takes advantage of a metastable state of the inert gas atom to more-readily ionize a halogen molecule than an organic vapor, enabling the tube to operate at much lower voltages, typically 400–600 volts instead of 900–1200 volts.
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Harvey-Smith worked as a support scientist at the Joint Institute for VLBI in Europe in the Netherlands, where she carried out real-time testing of the European VLBI Network telescope array, was responsible for science data quality control and took part in some of the first global real-time electronic VLBI experiments. During this time she worked on polarimetric studies of galactic masers and their relation to magnetic fields in regions of massive star-formation. Harvey-Smith was a Postdoctoral Research Fellow at The University of Sydney from 2007 to 2009, where she published work on the role of magnetic fields in the shaping of supernova remnants and a study of large-scale magnetic fields in galactic regions of ionised gas surrounding massive star clusters. From 2009 until 2011, Harvey-Smith was Chair of the Australia Telescope National Facility's Telescope Time Assignment Committee.
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An early calculated orbit based on faint absorption features gave a relatively large mass ratio which imply either a very high companion mass, meaning a black hole, or an unreasonably low primary mass for a luminous WR star. Another analysis of the spectrum finds absorption features consistent with an O5 star, similar masses for the two components, and only a small orbital inclination. Because of its erratic changes in apparent magnitude at so many frequencies WR 148 is classified in the General Catalogue of Variable Stars as a unique type of variable, not a member of any of the defined classes. The shape of the light curve is unusual and has been modelled as being produced by an extended secondary object which may be an ionised cavity in the dense wind of the primary star, produced as the secondary orbits at a distance comparable to the radius of the primary star.
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The system had an apparent visual magnitude around 11.7 and the primary is calculated to be slightly the brightest of the three known components. By November 1993, the spectral type was WN6 and the brightness had increased to around 10.9. The absorption lines in the spectrum were no longer detectable. The brightness increased for several weeks at the end of 1993, to above 10th magnitude, and the spectral type reached WN8, before the brightness dropped rapidly close to 11th magnitude. In June 1994, the star started to cool and become brighter again. It peaked at magnitude 8.6 in September and was comfortably the brightest star in the SMC, but there are no spectra at this exact time. Very shortly after the peak it was classified as WN11. In November the spectrum was considered to be B1.5Ia+, a blue hypergiant with strong hydrogen and ionised metal lines in emission or with P Cygni profiles.
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Greenhouse George early fireball evolution, showing the initial dimming of the first light pulse Graph of a nuclear fireball's surface temperature and diameter over time The silicon photodiode sensors are designed to detect the distinctive bright double pulse of visible light that is emitted from atmospheric nuclear weapons explosions. This signature consists of a short and intense flash lasting around 1 millisecond, followed by a second much more prolonged and less intense emission of light taking a fraction of a second to several seconds to build up. This signature, with a double intensity maximum, is characteristic of atmospheric nuclear explosions and is the result of the Earth's atmosphere becoming opaque to visible light and transparent again as the explosion's shock wave travels through it. The effect occurs because the surface of the early fireball is quickly overtaken by the expanding "case shock", the atmospheric shock wave composed of the ionised plasma of what was once the casing and other matter of the device.
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HII regions shine because their hydrogen gas is ionised by the ultraviolet radiation from a hot star. In 1922, Edwin Hubble proposed that Deneb may be responsible for lighting up the North America Nebula, but it soon became apparent that it is not hot enough: Deneb has a surface temperature of 8,500° K, while the nebula’s spectrum shows it is being heated by a star hotter than 30,000° K. In addition, Deneb is well away from the middle of the complete North America/Pelican nebula complex (Sh2-117), and by 1958 George Herbig realised that the ionizing star had to lie behind the central dark cloud L935. In 2004, European astronomers Fernando Comerón and Anna Pasquali searched for the ionizing star behind L935 at infrared wavelengths, using data from the 2MASS survey, and then made detailed observations of likely suspects with the 2.2 m telescope at the Calar Alto Observatory in Spain. One star, catalogued J205551.3+435225, fulfilled all the criteria. Lying right in the centre of Sh2-117, with a temperature of over 40,000° K, it is almost certainly the ionising star for the North America and Pelican Nebulae.
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In rodents that consume the rodenticidal bait, it causes hypercalcemia, raising the calcium level, mainly by increasing calcium absorption from food, mobilising bone-matrix-fixed calcium into ionised form (mainly monohydrogencarbonate calcium cation, partially bound to plasma proteins, [CaHCO3]+), which circulates dissolved in the blood plasma. After ingestion of a lethal dose, the free calcium levels are raised sufficiently that blood vessels, kidneys, the stomach wall and lungs are mineralised/calcificated (formation of calcificates, crystals of calcium salts/complexes in the tissues, damaging them), leading further to heart problems (myocardial tissue is sensitive to variations of free calcium levels, affecting both myocardial contractibility and excitation propagation between atrias and ventriculars), bleeding (due to capillary damage) and possibly kidney failure. It is considered to be single-dose, cumulative (depending on concentration used; the common 0.075% bait concentration is lethal to most rodents after a single intake of larger portions of the bait) or sub-chronic (death occurring usually within days to one week after ingestion of the bait). Applied concentrations are 0.075% cholecalciferol and 0.1% ergocalciferol when used alone, which can kill a rodent or a rat.
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