In a completely different process, magnetic grains in sediments may align with the magnetic field during or soon after deposition; this is known as detrital remanent magnetization (DRM). If the magnetization is acquired as the grains are deposited, the result is a depositional detrital remanent magnetization (dDRM); if it is acquired soon after deposition, it is a post-depositional detrital remanent magnetization (pDRM).
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Sediments acquire a depositional remanent magnetization during their formation or a post-depositional remanent magnetization afterwards. Some kinds of remanence are undesirable and must be removed before the useful remanence is measured. One is isothermal remanent magnetization (IRM), which as a component of NRM induced through exposing a particle to a large magnetic field, causing the field to flip its lower coercivity magnetic moments to a field-favored direction. A commonly cited mechanism of IRM acquisition is through lightning strikes.
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Another is viscous remanent magnetization (VRM), a remanence acquired when the rock sits in the Earth's field for long periods. The most important component of remanence is acquired when a rock is formed. This is called its primary component or characteristic remanent magnetization (ChRM). Any later component is called a secondary component.
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Viscous remanent magnetization is remanence that is acquired by ferromagnetic materials by sitting in a magnetic field for some time. In rocks, this remanence is typically aligned in the direction of the modern-day geomagnetic field. The fraction of a rocks overall magnetization that is a viscous remanent magnetization is dependent on the magnetic mineralogy.
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Lightning- induced remanent magnetization (LIRM) mapped during a magnetic field gradient survey of an archaeological site located in Wyoming, United States.
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Viscous remanent magnetization (abbreviated VRM), also known as viscous magnetization, is remanence that is acquired by ferromagnetic materials by sitting in a magnetic field for some time. The natural remanent magnetization of an igneous rock can be altered by this process. This is generally an unwanted component and some form of stepwise demagnetization must be used to remove it.
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Natural remanent magnetization (NRM) is the permanent magnetism of a rock or sediment. This preserves a record of the Earth's magnetic field at the time the mineral was laid down as sediment or crystallized in magma and also the tectonic movement of the rock over millions of years from its original position. Natural remanent magnetization forms the basis of paleomagnetism and magnetostratigraphy.
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In a third process, magnetic grains grow during chemical reactions, and record the direction of the magnetic field at the time of their formation. The field is said to be recorded by chemical remanent magnetization (CRM). A common form of chemical remanent magnetization is held by the mineral hematite, another iron oxide. Hematite forms through chemical oxidation reactions of other minerals in the rock including magnetite.
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When an organism dies the magnetosomes become trapped in sediments. Under the right conditions, primarily if the redox conditions are correct, the magnetite can then be fossilized and therefore stored in the sedimentary record. The fossilization of the magnetite (magnetofossils) within sediments contributes largely to the natural remanent magnetization of the sediment layers. The natural remanent magnetization is the permanent magnetism remaining in a rock or sediment after it has formed.
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However, these samples are only good for retrieving intensity values, not directions. The Thellier-Thellier method is gradually replacing the Natural Remanent Magnetization (NRM) by an artificial Thermal Remanent Magnetization (TRM) in a laboratory using an oven with a controlled magnetic field. The changes in magnetic remanence during experiments are commonly represented graphically. The furthest known deposits from the Arabah Valley are three slag scatters at the center of this site.
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Paleomagnetists are interested in the primary natural remanent magnetization (NRM) in a rock, acquired when the rock was originally formed. Viscous remanent magnetization is regarded as noise. Any component of the NRM that is in the direction of the present Earth's field is suspect because it may have been acquired since the last geomagnetic reversal. VRM is often removed by the first steps in a stepwise thermal demagnetization of the NRM.
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Remanence that is acquired at a fixed temperature is called isothermal remanent magnetization (IRM). Remanence of this sort is not useful for paleomagnetism, but it can be acquired as a result of lightning strikes. Lightning-induced remanent magnetization can be distinguished by its high intensity and rapid variation in direction over scales of centimeters. IRM is often induced in drill cores by the magnetic field of the steel core barrel.
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Such an electrically latching reed relay requires continuous power to maintain state, unlike magnetically latching relays, such as ferreed (ferrite and reed relay) or the later remreed (remanent reed relay).
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The Koenigsberger ratio is the proportion of remanent magnetization relative to induced magnetization in natural rocks. It was first described by .Koenigsberger, J. G. (1938). Natural residual magnetism of eruptive rocks.
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Some colleagues were skeptical of the hypothesis because of the numerous assumptions made—seafloor spreading, geomagnetic reversals, and remanent magnetism—all hypotheses that were still not widely accepted. The Vine–Matthews–Morley hypothesis describes the magnetic reversals of oceanic crust. Further evidence for this hypothesis came from Cox and colleagues (1964) when they measured the remanent magnetization of lavas from land sites. Walter C. Pitman and J.R. Heirtzler offered further evidence with a remarkably symmetric magnetic anomaly profile from the Pacific-Antarctic Ridge.
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The intensity of the remanent magnetization in the crust is greater than the induced magnetization. Consequently, the shape and amplitude of the magnetic anomaly is controlled predominately by the primary remanent vector in the crust. In addition, where the anomaly is measured on Earth affects its shape when measured with a magnetometer. This is because the field vector generated by the magnetized crust and the direction of the Earth's magnetic field vector are both measured by the magnetometers used in marine surveys.
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Magnetostratigraphy is a geophysical correlation technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout the section. The samples are analyzed to determine their characteristic remanent magnetization (ChRM), that is, the polarity of Earth's magnetic field at the time a stratum was deposited. This is possible because volcanic flows acquire a thermoremanent magnetization and sediments acquire a depositional remanent magnetization, both of which reflect the direction of the Earth's field at the time of formation.
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That is, the magnetite (or greigite) aligns in the direction of the geomagnetic field. The magnetite crystals can be thought of as being a simple magnet with a north and south pole, this north-south orientation aligns with the north-south magnetic poles of the Earth. These fossils are then buried within the rock record. Researchers can examine these rock samples in a remanent magnetometer where the effects of Earth's current magnetic field is removed, to determine the remanent, or initial, magnetization of the rock sample when it was formed.
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FMR spectroscopy of chains of cultured magnetotactic bacteria compared to sediment samples are being used to infer magnetofossil preservation over geological time frames. Research suggests that magnetofossils retain their remanent magnetization at deeper burial depths, although this is not entirely confirmed. FMR measurements of saturation isothermal remanent magnetization (SIRM) in some samples, compared with FMR and rainfall measurements taken over the past 70 years, have shown that magnetofossils can retain a record of paleorainfall variations on a shorter time-scale (hundreds of years), making a very useful recent history paleoclimate indicator.
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Paleomagnetic data are obtained by taking oriented samples of rocks and measuring their remanent magnetizations in the laboratory. Good quality data can be recovered from different rock types. In igneous rocks, magnetic minerals crystallize from the melt, and when the rock is cooled below their Curie temperature, it acquires a thermoremanent magnetization (TRM) in the direction of the Earth's magnetic field. In sedimentary rocks, magnetic grains will align their magnetic moments with the direction of the magnetic field during or soon after the deposition, resulting in a detrital or post-detrital remanent magnetization (DRM).
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Both Clearwater impact structures also carry different geophysical (natural remanent magnetization) signaturesScott, R. G., Pilkington, M. and Tanczyk, E. I. 1997. Magnetic investigations of the West Hawk, Deep Bay, and Clearwater impact structures, Canada. Meteoritics Planet. Sci. 32, 293–308.
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From 2001–2014, both New Zealand and Spain contributed to troops to the NATO led Afghan war. In 2014, both nations also supported each other, and were successful, in obtaining non-remanent seats for the 2015–2016 United Nations Security Council period.
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These standards include, but are not limited to: 1) Average REM (ratio between natural remanent magnetization to a laboratory standard value) greater than 0.2, and 2) Average Koenigsberger ratio (ratio between natural remanent magnetization and the natural field created by Earth's magnetic field). The findings indicated the evidence of LIRM at the archaeological site. LIRM anomalies also complicated the determination of the relative location of the poles during the late Cretaceous from the magnetic field record of basaltic lava flows in Mongolia. The presence of LIRM-affected rocks was determined when calculated Koenigsberger ratios were drastically higher than other magnetic signatures in the region.
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There are several ways for experimental measurement of the anhysteretic magnetization curve, based on fluxmeters and DC biased demagnetization. ARM has also been studied because of its similarity to the write process in some magnetic recording technology and to the acquisition of natural remanent magnetization in rocks.
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SQUID measurements on polycrystalline Mn3.1Al0.9C revealed a soft ferromagnetic behaviour of this κ-carbide with a Curie temperature of 295±13 K, a remanent magnetic moment of 3.22 μB and a coercive field of 1.9 mT. DFT-simulations confirmed these findings and indicated that other κ-carbides behave similarly.
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This phenomenon is called hysteresis and the remaining magnetic field is called remanent magnetism. The residual magnetization of the core can be removed by degaussing. In alternating current electromagnets, such as are used in motors, the core's magnetization is constantly reversed, and the remanence contributes to the motor's losses.
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Fruiting occurs in late summer or early autumn, typically January to March, and results in a drupe style fruit. The fruit is small and globular or egg shaped. It is glossy and ranges in colouration from orange to dark red. The fruit is crowned by the remanent calyx of the flower.
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The presence of fulgurites in an area can be used to estimate the frequency of lightning over a period of time, which can help to understand past regional climates. Paleolightning is the study of various indicators of past lightning strikes, primarily in the form of fulgurites and lightning-induced remanent magnetization (LIRM) signatures.
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Erotics and sex :VI. Man and superman :VII. Remanent ::Lem writes that before starting with the two last huge subjects of the book, he would like to briefly dwell upon a large number of topics not covered in the book. Some of them, such as horror in science fiction and space opera, are only mentioned in passing.
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The aplite is the lowest melting remanent of the granite magma, that is poor in volatiles. The aplite minerals include tourmaline, topaz and fluorite. At St Brelade's Bay there are two aplogranites: Beau Port Granite and La Moye Granite. This is coloured yellow brown to pink and contains fine crystals of perthite, and oligoclase and quartz, coloured by limonite.
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In knowing the orientation of the rock in-situ and the remanent magnetization, researchers can determine the Earth's geomagnetic field at the time the rock was formed. This can be used as an indicator of magnetic field direction, or reversals in the Earth's magnetic field, where the Earth's north and south magnetic poles switch (which happen on average every 450,000 years).
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The remains of the Marne river to the north of this new dyke, is called the Harnzer Feart. It was crossed by the Marnedyk with a sluice gate, the Kimswerter syl. This stream was diverted north to Harlingen, and the remanent heading to the coast was called Bidlersfeart. Bidlersfeart was crossed by the Griene Dyk at a sluice gate called Bantumer syl.
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A number of samples are removed from the feature by encasement in non-magnetic plaster within non-magnetic moulds. These samples are marked for true north at the time of collection. The samples are sent to an Archaeomagnetic Laboratory for processing. Each of the samples is measured in a spinner magnetometer to determine the thermal remanent magnetism of each sample.
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There are several kinds of NRM that can occur in a sample. Many samples have more than one kind superimposed. Thermoremanent magnetization (TRM) is acquired during cooling through the Curie temperature of the magnetic minerals and is the best source of information on the past Earth's field. Magnetization formed by phase change, chemical action or growth of crystals at low temperature is called chemical remanent magnetization.
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Basalt, being a ferromagnetic mineral, becomes magnetically polarised when exposed to a large external field such as those generated in a lightning strike. See Anomalous Remanent Magnetization of Basalt pubs.usgs.gov/bul/1083e/report.pdf for more. Discoveries about the electrification of the atmosphere via sensitive electrical instruments and ideas on how the Earth's negative charge is maintained were developed mainly in the 20th century, with CTR Wilson playing an important part.
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Because of the intensity of this electric current, when lightning hits the ground, it can produce a strong, albeit brief, magnetic field. Thus, as the electric current travels through soils, rocks, plant roots, etc., it locks a unique magnetic signature within these materials through a process known as lightning-induced remanent magnetization (LIRM). Evidence of LIRM is manifested in concentric magnetic field lines surrounding the location of the lightning strike point.
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In geomagnetism, paleointensity (or palaeointensity) is the study of changes in the strength of the geomagnetic field over Earth's history. Émile and Odette Thellier were the first to make laboratory measurements to determine the strength of the ancient field responsible for producing remanent magnetization in a rock or archeological artifacts.Thellier, E. & Thellier, O. (1959). Sur l'intensité du champ magnétique terrestre dans le passé historique et géologique. Ann. Geophys.
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That is, most of the electrons favored a very specific direction of decay, specifically opposite to that of the nuclear spin. The observed electron asymmetry also did not change sign when the polarizing field was reversed, meaning that the asymmetry was not being caused by remanent magnetization in the samples. It was later established that parity violation was in fact maximal. The results greatly surprised the physics community.
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The remanent or residue of materials used, such as aluminum, steel, and oil, among others, can be gathered and recycled, and commonly, it may be sold. However, not all machine shops practice recycling, and not all have personnel dedicated to enforcing the habit of separating and keeping materials separated. In larger and organized operations, such responsibility may be delegated to the Health, Safety, Environment, and Quality (HSEQ) department.
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The word remanence is from remanent + -ence, meaning "that which remains". The equivalent term residual magnetization is generally used in engineering applications. In transformers, electric motors and generators a large residual magnetization is not desirable (see also electrical steel) as it is an unwanted contamination, for example a magnetization remaining in an electromagnet after the current in the coil is turned off. Where it is unwanted, it can be removed by degaussing.
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One way of doing this is first demagnetizing the magnet in an AC field, and then applying a field H and removing it. This remanence, denoted by Mr(H), depends on the field. It is called the initial remanence or the isothermal remanent magnetization (IRM). Another kind of IRM can be obtained by first giving the magnet a saturation remanence in one direction and then applying and removing a magnetic field in the opposite direction.
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The information these domains represent is commonly called magnetic remanence or remanent magnetization. Proper degaussing will ensure there is insufficient magnetic remanence to reconstruct the data. Erasure via degaussing may be accomplished in two ways: in AC erasure, the medium is degaussed by applying an alternating field that is reduced in amplitude over time from an initial high value (i.e., AC powered); in DC erasure, the medium is saturated by applying a unidirectional field (i.e.
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Thus, while a telephone call in a typical crossbar exchange like 5XB passed through four switches, a call in a reed system such as 1ESS typically passed through eight. In the later 1AESS, the reeds were of remanent magnetic material. This "Remreed" design allowed further reduction in size and power consumption. A "grid" of 1024 2-wire crosspoints, arranged as two stages of eight 8×8 switches, was permanently packaged in a box.
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A model for a mantle plume origin for the hemispheric dichotomy. Single plume mantle convection generates new crust in southern hemisphere with alternating bands of normal and reversed remanent magnetism, adapted from Vita-Finzi & Fortes, 2013. Single plume mantle convection has also been invoked to explain the hemispheric dichotomy. This process would have caused substantial melting and crustal production above a single rising mantle plume in the southern hemisphere, resulting in a thickened crust.
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When the external field is removed, the remanent magnetization can recover to a value close to its original. The name "exchange spring magnet" is derived from the reversibility of magnetization. The dimension of the soft phase inside the exchange spring magnet should be kept small enough so as to retain reversible magnetization. Additionally, the volume fraction of the soft phase needs to be as large as possible in order to achieve a high magnetization saturation.
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Samples are first analyzed in their natural state to obtain their natural remanent magnetization (NRM). The NRM is then stripped away in a stepwise manner using thermal or alternating field demagnetization techniques to reveal the stable magnetic component. Magnetic orientations of all samples from a site are then compared and their average magnetic polarity is determined with directional statistics, most commonly Fisher statistics or bootstrapping. The statistical significance of each average is evaluated.
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As the meteorite cools below 750 °C iron becomes magnetic as it moves into the kamacite phase. During this cooling the meteorite takes on non-conventional thermoremanent magnetization. Thermoremanent magnetization on Earth gives iron minerals formed in the Earth's crust, a higher magnetization than if they were formed in the same field at room temperature. This is a non- conventional thermoremanent magnetization because it appears to be due to a chemical remanent process which is induced as taenite is cooled to kamacite.
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Relative paleointensity determinations are often used in materials that may be destroyed or strongly altered during heating, such as lake and marine sedimentsLevi, S., & Banerjee, S. K. (1976). On the possibility of obtaining relative paleointensities from lake sediments. Earth and Planetary Science Letters, 29(1), 219-226.. A measure of relative changes in paleointensity may be obtained by normalizing the NRM by a factor that represents the concentration of magnetic grains in a sample, such as the anhysteretic remanent magnetization.
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Aspects of this technical achievement can be seen in the remanent quarantine technology at the Station e.g. The fumigation chamber, shower blocks and autoclaves. ;Natural heritage The aesthetic characteristics derived from the natural values of heath vegetation and sandstone cliff geomorphology within the Quarantine Station are an integral part of the outstanding aesthetic values of North Head conserved as part of the Sydney Harbour National Park. These values are derived from the expanse of uninterrupted cliff face and vegetated headlands.
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The theory of plate tectonics, which is supported by seismology, volcanology, gravimetry, and paleomagnetism (remanent magnetism), explains the origin of the physical features of the Pacific. The islands of the Pacific have developed in a number of ways. Some have originated as chains of volcanic islands on the tectonic plates either as a result of mantle plumes or by fracture propagation. Atolls have developed in tropical waters when, after volcanos sink, coral growth results in reefs as evidenced by the Cook Islands.
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Terrestrial Magnetism and Atmospheric Electricity, 43(3), 299-320. It is a dimensionless parameter often used in geophysical exploration to describe the magnetic characteristics of a geological body for help in interpreting magnetic anomaly patterns. The total magnetization of a rock is the sum of its natural remanent magnetization and the magnetization induced by the ambient geomagnetic field. Thus, a Koenigsberger ratio, Q, greater than 1 indicates that the remanence properties contribute the majority of the total magnetization of the rock.
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In the 1950s a few speakers was reported who used the language probably only as a trade lingo or secret language. In 1966, A. G. Gasanov collected a few words and phrases.Sources of kilit language (Источники о килитском языке) Although the possibility of a migration cannot be ruled out, however it is more likely, given more data about Tatic languages and proto-Tatic, that this group extended at least as far as the areas in which the remanent languages are spoken today.
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Remanence or remanent magnetization or residual magnetism is the magnetization left behind in a ferromagnetic material (such as iron) after an external magnetic field is removed. Colloquially, when a magnet is "magnetized" it has remanence.Strictly speaking, it is still in the Earth's field, but that has little effect on the remanence of a hard magnet. The remanence of magnetic materials provides the magnetic memory in magnetic storage devices, and is used as a source of information on the past Earth's magnetic field in paleomagnetism.
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Dating of these rocks can provide information about the time period of this climate change and can be correlated to other rock formations or depositional environments in which the Earth's climate at that time may not have been as clear. Sediment aging and dissolution or alteration of magnetite present problems with providing useful measurements as the crystals structural integrity may not be preserved. Magnetofossils are not only being studied for their paleoenvironmental or paleoclimatic indicators. As mentioned above, magnetofossils hold a remanent magnetization when they are formed.
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Another characteristic feature of an LIRM anomaly compared to other magnetic anomalies is that the electric current intensity is generally stronger. However, some have suggested that the anomalies, like other characteristics in the geologic record, might fade over time as the magnetic field redistributes. LIRM anomalies can often be problematic when examining the magnetic characteristics of rock types. LIRM anomalies can disguise the natural remanent magnetization (NRM) of the rocks in question because the subsequent magnetization caused by the lightning strike reconfigures the magnetic record.
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Scripps Institution of Oceanography Tauxe's contributions include the study of remanent magnetism in geological and archaeological materials, as well as co- founding a collaborative data system for compiling and sharing geological magnetic data from around the globe, the Magnetics Information Consortium (MagIC). To facilitate paleomagnetic measurements, Tauxe uses a demagnetized space in San Diego. Tauxe is a leader in research that documents when the earth's magnetic poles reversed. Because technology and electrical grids depend on the Earth's magnetic field to protect it from the sun's magnetic storms, Prof.
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Another kind of laboratory remanence is anhysteretic remanence or anhysteretic remanent magnetization (ARM). This is induced by exposing a magnet to a large alternating field plus a small DC bias field. The amplitude of the alternating field is gradually reduced to zero to get an anhysteretic magnetization, and then the bias field is removed to get the remanence. The anhysteretic magnetization curve is often close to an average of the two branches of the hysteresis loop, and is assumed in some models to represent the lowest-energy state for a given field.
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When the generator first starts to turn, the small amount of remanent magnetism present in the iron core provides a magnetic field to get it started, generating a small current in the armature. This flows through the field coils, creating a larger magnetic field which generates a larger armature current. This "bootstrap" process continues until the magnetic field in the core levels off due to saturation and the generator reaches a steady state power output. Very large power station generators often utilize a separate smaller generator to excite the field coils of the larger.
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On 7 March 2013, the Internet Engineering Task Force created a working group for IPv4 sunset in preparation for protocol changes that could be used to support sunset / shutdown of remanent IPv4 networks. However, in May 2018 this working group was closed as no immediate work could be identified due to the slow transition to IPv6. The Internet Engineering Task Force expects IPv6 to coexist with IPv4 as it is considered impractical to transition to IPv6 in the short term. The coexistence is expected to be based on dual-stack, tunneling or translation mechanisms.
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Let us now consider what happens, if the external field is then decreased: Due to induction, an opposed critical current is generated at the outer surface of the cylinder keeping inside the magnetic field for H0 < H < H1 constant. For H > H1, the opposed critical current penetrates the whole cylinder and the inner magnetic field starts to decrease with decreasing external field. When the external field vanishes, a remnant internal magnetic field occurs (comparable to the remanent magnetization of a ferromagnet). With an opposed external field H0, the internal magnetic field finally reaches 0T (H0 equates the coercive field of a ferromagnet).
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When measurable magnetic properties of rocks vary stratigraphically they may be the basis for related but different kinds of stratigraphic units known collectively as magnetostratigraphic units (magnetozones). The magnetic property most useful in stratigraphic work is the change in the direction of the remanent magnetization of the rocks, caused by reversals in the polarity of the Earth's magnetic field. The direction of the remnant magnetic polarity recorded in the stratigraphic sequence can be used as the basis for the subdivision of the sequence into units characterized by their magnetic polarity. Such units are called "magnetostratigraphic polarity units" or chrons.
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The treble boost of Nakamichi's cassette decks was well known to the press before the advent of the Dragon; it had been discussed in American journals in 1981 and 1982. The root of the problem was hidden in the language of the IEC standard enacted in 1978 and based on the original, outdated 1963 Philips specification. The standard was written in terms of remanent magnetic flux recorded on tape. Flux, the principal metric of recorded signals, cannot be directly measured; it can only be picked up with a magnetic head, which converts the faint magnetic field into electrical current, losing some energy in the process of conversion.
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Lithospheric creation at the ridge is considered continuous and symmetrical as the new crust intrudes into the diverging plate boundary. The old crust moves laterally and equally on either side of the ridge. Therefore, as geomagnetic reversals occur, the crust on either side of the ridge will contain a record of remanent normal (parallel) or reversed (antiparallel) magnetizations in comparison to the current geomagnetic field. A magnetometer towed above (near bottom, sea surface, or airborne) the seafloor will record positive (high) or negative (low) magnetic anomalies when over crust magnetized in the normal or reversed direction. The ridge crest is analogous to “twin-headed tape recorder”, recording the Earth's magnetic history.
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Cambridge: University Press, 1970, p. 241. Based on his discovery of an Olmec artifact (a shaped and grooved magnetic bar) in North America, astronomer John Carlson suggests that lodestone may have been used by the Olmec more than a thousand years prior to the Chinese discovery. Carlson speculates that the Olmecs, for astrological or geomantic purposes, used similar artifacts as a directional device, or to orient their temples, the dwellings of the living, or the interments of the dead. Detailed analysis of the Olmec artifact revealed that the "bar" was composed of hematite with titanium lamellae of Fe2–xTixO3 that accounted for the anomalous remanent magnetism of the artifact.
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Progressive demagnetization techniques are used to identify secondary magnetization components (e.g., magnetic overprints that could have been imparted on the rock due to chemical alteration or reheating) and to isolate the primary magnetization, which records the direction of the magnetic field at the time when the rock was formed. Various rock-magnetic and paleomagnetic tests are normally performed to establish the primary nature of the isolated remanent magnetization. The recovered paleomagnetic directions are used to derive paleomagnetic poles, which provide constrains on the latitudinal position of the crustal block from which the rock samples were taken, and its original orientation with respect to the lines of longitude.
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In the Bell System Stored Program Control exchange systems of the 1970s, reed relays were no longer needed for data storage, but tens of millions of them were packaged in arrays for voice path switching. In the 1ESS switch, the cores were made of a magnetically remanent alloy, so the relay could latch magnetically instead of latching electrically. This "Ferreed" method reduced power consumption and allowed both contacts to be used for voice path. The coils were wired for coincident current selection similar to a magnetic core memory, so operating the contacts for one crosspoint would release the other crosspoints in its row and column.
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Print-through is a category of noise caused by contact transfer of signal patterns from one layer of tape to another. Print-through can take two forms: # thermo-remanent magnetization induced by temperature, and # anhysteretic magnetization caused by an external magnetic field. The former is unstable over time and can be easily erased by rewinding a tape and letting it sit so that the patterns formed by the contact of upper and lower layers begin to erase each other and form new patterns with the repositioning of upper/lower layers after rewinding. This type of contact printing begins immediately after a recording and increases over time at a rate dependent on the temperature of the storage conditions.
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The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low- energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Disturbing as it may sound, imagine cancer cells located near a human organ, cells that need to be treated. One of the most promising treatments is to irradiate cancer cells with high energy particles in order to ionize the DNA molecules in the cancer cells, breaking the molecules and killing the cells.
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Mr. Brown of Wamphray, in a testament executed by him at Rotterdam, in 1676, ordered 100 guineas "to be put into the hands of Mr. Wallace, to be given out by him to such as he knoweth indigent and honest;" and while he leaves the half of his remanent gold to Mr. Macward, he leaves the other half to Mr. Wallace. Mr. Macward, who was honoured to close the eyes of his valued friend and fellow-Christian, exclaims, "Great Wallace is gone to glory; of whom I have no doubt it may be said, he hath left no man behind him in that church, minister nor professor," who hath gone through such a variety of tentations, without turning aside to the right hand or to the left.
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The Earth's field is roughly like a tilted dipole, but it changes over time (a phenomenon called geomagnetic secular variation). Mostly the geomagnetic pole stays near the geographic pole, but at random intervals averaging 440,000 to a million years or so, the polarity of the Earth's field reverses. These geomagnetic reversals, analyzed within a Geomagnetic Polarity Time Scale, contain 184 polarity intervals in the last 83 million years, with change in frequency over time, with the most recent brief complete reversal of the Laschamp event occurring 41,000 years ago during the last glacial period. Geologists observed geomagnetic reversal recorded in volcanic rocks, through magnetostratigraphy correlation (see natural remanent magnetization) and their signature can be seen as parallel linear magnetic anomaly stripes on the seafloor.
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Murck, Barbara W. and Skinner, Brian J. (1999) Geology Today: Understanding Our Planet, Study Guide, Wiley, Paleomagnetic study of apparent polar wandering paths also support the theory of a supercontinent. Geologists can determine the movement of continental plates by examining the orientation of magnetic minerals in rocks; when rocks are formed, they take on the magnetic properties of the Earth and indicate in which direction the poles lie relative to the rock. Since the magnetic poles drift about the rotational pole with a period of only a few thousand years, measurements from numerous lavas spanning several thousand years are averaged to give an apparent mean polar position. Samples of sedimentary rock and intrusive igneous rock have magnetic orientations that are typically an average of the "secular variation" in the orientation of magnetic north because their remanent magnetizations are not acquired instantaneously.
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CrO2 cassette tape The crystal's magnetic properties, derived from its ideal shape such as anisotropy which imparted high coercivity and remanent magnetization intensities, resulted in exceptional stability and efficiency for short wavelengths, and it almost immediately appeared in high performance audio tape used in audio cassette for which treble response and hiss were always problems. Unlike the imperfectly formed ferric oxide coating commonly used, the chromium dioxide crystals were perfectly formed and could be evenly and densely dispersed in a magnetic coating leading to higher signal/noise ratios in audio recordings. Chrome tapes did, however, require audio cassette recorders to be equipped with a higher bias current capability (roughly 50% greater) than that used by ferric oxide to properly magnetize the tape particles. Also introduced was a new equalization (70 μs) that traded some of the extended high-frequency response for lower noise resulting in a 5–6 dB improvement in signal-to-noise ratio over ferric-oxide audio tapes.
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A paleomagnetic pole is defined by taking the average direction of the primary remanent magnetization for the sampled rocks (expressed as the mean declination and inclination) and calculating the position of a geomagnetic pole for the field of a geocentric magnetic dipole that would produce the observed mean direction at the sampled locality in its present geographic coordinates. An alternative way of defining paleomagnetic poles is to calculate a virtual geomagnetic pole (VGP) for each individual rock unit and then estimate the mean location for all VGPs. Fisher statistics on the sphere is normally used to obtain the mean direction of magnetization, or the mean VGP location, and to estimate their uncertainties. Both approaches are used in paleomagnetic studies, but it has been recognized that averaging directions instead of full remanence vectors can lead to biased estimates of the mean direction of the paleomagnetic field, so that the calculation of paleomagnetic poles by averaging VGPs is currently the preferred technique.
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