Science.gov

Sample records for magnetic compass orientation

  1. Magnetic Compass Orientation in the European Eel

    PubMed Central

    Durif, Caroline M. F.; Browman, Howard I.; Phillips, John B.; Skiftesvik, Anne Berit; Vøllestad, L. Asbjørn; Stockhausen, Hans H.

    2013-01-01

    European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (? 6000 km) and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at geographic North, South, East, or West. Eels oriented in a manner that was related to the tank in which they were housed before the test. At lower temperature (under 12°C), their orientation relative to magnetic North corresponded to the direction of their displacement from the holding tank. At higher temperatures (12–17°C), eels showed bimodal orientation along an axis perpendicular to the axis of their displacement. These temperature-related shifts in orientation may be linked to the changes in behavior that occur between the warm season (during which eels are foraging) and the colder fall and winter (during which eels undertake their migrations). These observations support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient in a direction that they have registered moments before they are displaced. The adaptive advantage of having a magnetic compass and learning the direction in which they have been displaced becomes clear when set in the context of the eel’s seaward migration. For example, if their migration is halted or blocked, as it is the case when environmental conditions become unfavorable or when they encounter a barrier, eels would be able to resume their movements along their old bearing when conditions become favorable again or when they pass by the barrier. PMID:23554997

  2. Magnetic compass orientation in the European eel.

    PubMed

    Durif, Caroline M F; Browman, Howard I; Phillips, John B; Skiftesvik, Anne Berit; Vøllestad, L Asbjørn; Stockhausen, Hans H

    2013-01-01

    European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km) and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at geographic North, South, East, or West. Eels oriented in a manner that was related to the tank in which they were housed before the test. At lower temperature (under 12°C), their orientation relative to magnetic North corresponded to the direction of their displacement from the holding tank. At higher temperatures (12-17°C), eels showed bimodal orientation along an axis perpendicular to the axis of their displacement. These temperature-related shifts in orientation may be linked to the changes in behavior that occur between the warm season (during which eels are foraging) and the colder fall and winter (during which eels undertake their migrations). These observations support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient in a direction that they have registered moments before they are displaced. The adaptive advantage of having a magnetic compass and learning the direction in which they have been displaced becomes clear when set in the context of the eel's seaward migration. For example, if their migration is halted or blocked, as it is the case when environmental conditions become unfavorable or when they encounter a barrier, eels would be able to resume their movements along their old bearing when conditions become favorable again or when they pass by the barrier. PMID:23554997

  3. Lateralization of magnetic compass orientation in a migratory bird

    NASA Astrophysics Data System (ADS)

    Wiltschko, Wolfgang; Traudt, Joachim; Güntürkün, Onur; Prior, Helmut; Wiltschko, Roswitha

    2002-10-01

    Lateralization of brain functions, once believed to be a human characteristic, has now been found to be widespread among vertebrates. In birds, asymmetries of visual functions are well studied, with each hemisphere being specialized for different tasks. Here we report lateralized functions of the birds' visual system associated with magnetoperception, resulting in an extreme asymmetry of sensing the direction of the magnetic field. We found that captive migrants tested in cages with the magnetic field as the only available orientation cue were well oriented in their appropriate migratory direction when using their right eye only, but failed to show a significant directional preference when using their left eye. This implies that magnetoreception for compass orientation, assumed to take place in the eyes alongside the visual processes, is strongly lateralized, with a marked dominance of the right eye/left brain hemisphere.

  4. A Visual Pathway Links Brain Structures Active during Magnetic Compass Orientation in Migratory Birds

    PubMed Central

    Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

    2007-01-01

    The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, “Cluster N”, show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds “see” the reference compass direction provided by the geomagnetic field. PMID:17895978

  5. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus.

    PubMed

    Oliveriusová, Ludmila; N?mec, Pavel; Pavelková, Zuzana; Sedlá?ek, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species-the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents. PMID:24913128

  6. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus

    NASA Astrophysics Data System (ADS)

    Oliveriusová, Ludmila; N?mec, Pavel; Pavelková, Zuzana; Sedlá?ek, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species—the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents.

  7. Migration, Orientation and Navigation: Magnetic Compasses in Insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of magnetic information for orientation and navigation is a widespread phenomenon in animals. In contrast to navigational systems in vertebrates, our understanding of the mechanisms underlying the insect magnetic perception and use of the information is at an early stage. Some insects use ma...

  8. Learned magnetic compass orientation by the Siberian hamster, Phodopus sungorus

    SciTech Connect

    Deutschlander, Mark E.; Freake, Michael J.; Borland, Christopher; Phillips, John B.; Madden, R C.; Anderson, Larry E.; Wilson, B W.

    2003-04-01

    Magnetic orientation has been demonstrated in Siberian hamsters, Phodopus sungorus. The behavior, using a nest building assay, shows a directional preference in nest position and appears in this animal to be a learned behavior. Hamsters were housed prior to testing in rectangular cages aligned along perpendicular axes. When subsequently tested in a radially-symmetrical arena, the hamsters positioned their nests in a bimodal distribution that coincided with the magnetic direction of the long-axis of the holding cages. In addition, results are presented that illustrate some of the factors that can influence behavioral responses to the magnetic field. In particular for P. sungorus, holding conditions prior to testing and the presence of non-magnetic cues may influence the strength and expression of magnetic orientation. Failure to consider these and other factors may help to explain why previous attempts to demonstrate magnetic orientation in a number of rodent species have failed or, when positive results have been obtained, have been difficult to replicate in other laboratories.

  9. Magnetic Compass Orientation in Larval Iberian Green Frogs, Pelophylax Perezi

    E-print Network

    Phillips, John B.

    Iberian green frog tadpoles Pelophylax perezi (formerly Rana perezi) are able of using the geomagnetic field for y-axis orientation (i.e. orientation toward and away from shore). Tadpoles were trained east­west axis, with shore located east, and similar to the shore­deep water axis (`y-axis') found

  10. Magnetic Compass Orientation in the European Eel Caroline M. F. Durif , Howard I. Browman, John B. Phillips, Anne Berit Skiftesvik, L. Asbjrn Vllestad, Hans H. Stockhausen

    E-print Network

    Phillips, John B.

    Magnetic Compass Orientation in the European Eel Caroline M. F. Durif , Howard I. Browman, John B. Phillips, Anne Berit Skiftesvik, L. Asbjørn Vøllestad, Hans H. Stockhausen Abstract European eel migrate magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered

  11. ADCM Based Orientation Estimation Algorithm with an Inertial Measurement Unit and a Magnetic Compass

    E-print Network

    compasses was first introduced in navigation area, but along with the development of MEMS technology, low with accelerometer data. There are generally three principal methods to propagate the orientation information from

  12. A magnetic compass aids monarch butterfly migration.

    PubMed

    Guerra, Patrick A; Gegear, Robert J; Reppert, Steven M

    2014-01-01

    Convincing evidence that migrant monarch butterflies (Danaus plexippus) use a magnetic compass to aid their fall migration has been lacking from the spectacular navigational capabilities of this species. Here we use flight simulator studies to show that migrants indeed possess an inclination magnetic compass to help direct their flight equatorward in the fall. The use of this inclination compass is light-dependent utilizing ultraviolet-A/blue light between 380 and 420?nm. Notably, the significance of light <420?nm for inclination compass function was not considered in previous monarch studies. The antennae are important for the inclination compass because they appear to contain light-sensitive magnetosensors. For migratory monarchs, the inclination compass may serve as an important orientation mechanism when directional daylight cues are unavailable and may also augment time-compensated sun compass orientation for appropriate directionality throughout the migration. PMID:24960099

  13. Exploring Magnetic Fields with a Compass

    ERIC Educational Resources Information Center

    Lunk, Brandon; Beichner, Robert

    2011-01-01

    A compass is an excellent classroom tool for the exploration of magnetic fields. Any student can tell you that a compass is used to determine which direction is north, but when paired with some basic trigonometry, the compass can be used to actually measure the strength of the magnetic field due to a nearby magnet or current-carrying wire. In this…

  14. ORIGINAL PAPER Use of a light-dependent magnetic compass for y-axis orientation

    E-print Network

    Phillips, John B.

    .e., orientation along the shore-deep water axis) by tadpoles of the European com- mon frog (Rana temporaria and Cohen 1997; Zug et al. 2001). Also, tadpoles in temperate ponds usually stay at warmer and deeper water frog (Rana temporaria) tadpoles Francisco J. Diego-Rasilla · Rosa M. Luengo · John B. Phillips Received

  15. Light-dependent magnetic compass in Iberian green frog tadpoles

    NASA Astrophysics Data System (ADS)

    Diego-Rasilla, Francisco Javier; Luengo, Rosa Milagros; Phillips, John B.

    2010-12-01

    Here, we provide evidence for a wavelength-dependent effect of light on magnetic compass orientation in Pelophylax perezi (order Anura), similar to that observed in Rana catesbeiana (order Anura) and Notophthalmus viridescens (order Urodela), and confirm for the first time in an anuran amphibian that a 90° shift in the direction of magnetic compass orientation under long-wavelength light (?500 nm) is due to a direct effect of light on the underlying magnetoreception mechanism. Although magnetic compass orientation in other animals (e.g., birds and some insects) has been shown to be influenced by the wavelength and/or intensity of light, these two amphibian orders are the only taxa for which there is direct evidence that the magnetic compass is light-dependent. The remarkable similarities in the light-dependent magnetic compasses of anurans and urodeles, which have evolved as separate clades for at least 250 million years, suggest that the light-dependent magnetoreception mechanism is likely to have evolved in the common ancestor of the Lissamphibia (Early Permian, ~294 million years) and, possibly, much earlier. Also, we discuss a number of similarities between the functional properties of the light-dependent magnetic compass in amphibians and blue light-dependent responses to magnetic stimuli in Drosophila melanogaster, which suggest that the wavelength-dependent 90° shift in amphibians may be due to light activation of different redox forms of a cryptochrome photopigment. Finally, we relate these findings to earlier studies showing that the pineal organ of newts is the site of the light-dependent magnetic compass and recent neurophysiological evidence showing magnetic field sensitivity in the frog frontal organ (an outgrowth of the pineal).

  16. nCompass Service Oriented Architecture for Tacit Collaboration Services

    NASA Astrophysics Data System (ADS)

    Schroh, David; Bozowsky, Neil; Savigny, Mike; Wright, William

    nCompass is a flexible, Service Oriented Architecture (SOA) designed to support the research and deployment of advanced tacit collaboration technology services for analysts. nCompass allows a significantly larger number of individual analytic capabilities, applications and services to be integrated together quickly and effectively. Service integration results arc described from several computational tacit collaboration experiments conducted with open source intelligence analysts working with open source data. Key to nCompass is the technical framework and unique analytic event logging schema that supports context sharing across diverse applications and services. It is by combining the analyst with shared context across multiple advanced computational capabilities in a system of systems that a breakthrough in collaborative open source analysis can be achieved. This paper introduces the nCompass framework and integration platform, describes key nCompass core services, and provides results on functional synergies achieved through technology service integration with nCompass.

  17. Exploring Magnetic Fields with a Compass

    NASA Astrophysics Data System (ADS)

    Lunk, Brandon; Beichner, Robert

    2011-01-01

    A compass is an excellent classroom tool for the exploration of magnetic fields. Any student can tell you that a compass is used to determine which direction is north, but when paired with some basic trigonometry, the compass can be used to actually measure the strength of the magnetic field due to a nearby magnet or current-carrying wire. In this paper, we present a series of simple activities adapted from the Matter & Interactions textbook for doing just this. Interestingly, these simple measurements are comparable to predictions made by the Bohr model of the atom. Although antiquated, Bohr's atom can lead the way to a deeper analysis of the atomic properties of magnets. Although originally developed for an introductory calculus-based course, these activities can easily be adapted for use in an algebra-based class or even at the high school level.

  18. Compass Games: An Introduction to Orienteering Skills

    ERIC Educational Resources Information Center

    Sension-Hall, Debra

    2011-01-01

    Compasses are useful tools for teaching the basics of navigation. Knowing where you are, where you are going, and how to get there are important facets of outdoor recreation. Compass games are a fun way to teach introductory navigation skills, and this article describes how they can be used as innovative, nontraditional activities in physical…

  19. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise service must have a magnetic compass. (b) Each self-propelled unit of...

  20. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b)...

  1. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b)...

  2. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b)...

  3. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108... DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise service must have a magnetic compass. (b) Each self-propelled unit of...

  4. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167... NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean or coastwise service must be fitted with a magnetic compass. (b)...

  5. Do leaf-cutter ants Atta colombica orient their path-integrated, home vector with a magnetic compass?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf-cutter ants Atta colombica forage over 250 m in structurally-complex, Neotropical rainforests that occlude sun or polarized light cues. Night foraging makes the use of celestial cues and landmarks all the more difficult. We investigated the directional cues used by leaf-cutter ants to orient h...

  6. Orientation at night: an innate moon compass in sandhoppers (Amphipoda: Talitridae).

    PubMed

    Ugolini, Alberto; Fantini, Tiziana; Innocenti, Riccardo

    2003-02-01

    The supralittoral amphipod Talitrus saltator is well known for its capacity for astronomical orientation using the sun and moon as compasses. It has also been demonstrated that the sun compass is innate in this species. In our experiments, we released inexpert (naive) young born in the laboratory into a confined environment under the full moon and in the absence of the horizontal component of the magnetic field. They were allowed to see the natural sky and the moon only at the moment of release. The young individuals were obtained in the laboratory by crossing adult individuals from the same and different populations of sandhoppers. The young from intrapopulation crosses were well oriented towards the directions corresponding to those of their parents, whereas the young from interpopulation crosses were oriented in an intermediate direction. Therefore, our experiments demonstrate in the sandhopper T. saltator that sea-land moon orientation relies on an innate chronometrically compensated mechanism. PMID:12614577

  7. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Magnetic compass and gyrocompass. 167.40-45 Section 167.40-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Certain Equipment Requirements § 167.40-45 Magnetic compass and gyrocompass. (a) All mechanically propelled vessels in ocean...

  8. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108.715 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise...

  9. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108.715 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each...

  10. 46 CFR 108.715 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Magnetic compass and gyrocompass. 108.715 Section 108.715 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.715 Magnetic compass and gyrocompass. (a) Each self-propelled unit in ocean or coastwise...

  11. Re-calibration of the magnetic compass in hand-raised European robins (Erithacus rubecula).

    PubMed

    Alert, Bianca; Michalik, Andreas; Thiele, Nadine; Bottesch, Michael; Mouritsen, Henrik

    2015-01-01

    Migratory birds can use a variety of environmental cues for orientation. A primary calibration between the celestial and magnetic compasses seems to be fundamental prior to a bird's first autumn migration. Releasing hand-raised or rescued young birds back into the wild might therefore be a problem because they might not have established a functional orientation system during their first calendar year. Here, we test whether hand-raised European robins that did not develop any functional compass before or during their first autumn migration could relearn to orient if they were exposed to natural celestial cues during the subsequent winter and spring. When tested in the geomagnetic field without access to celestial cues, these birds could orient in their species-specific spring migratory direction. In contrast, control birds that were deprived of any natural celestial cues throughout remained unable to orient. Our experiments suggest that European robins are still capable of establishing a functional orientation system after their first autumn. Although the external reference remains speculative, most likely, natural celestial cues enabled our birds to calibrate their magnetic compass. Our data suggest that avian compass systems are more flexible than previously believed and have implications for the release of hand-reared migratory birds. PMID:26388258

  12. Re-calibration of the magnetic compass in hand-raised European robins (Erithacus rubecula)

    PubMed Central

    Alert, Bianca; Michalik, Andreas; Thiele, Nadine; Bottesch, Michael; Mouritsen, Henrik

    2015-01-01

    Migratory birds can use a variety of environmental cues for orientation. A primary calibration between the celestial and magnetic compasses seems to be fundamental prior to a bird’s first autumn migration. Releasing hand-raised or rescued young birds back into the wild might therefore be a problem because they might not have established a functional orientation system during their first calendar year. Here, we test whether hand-raised European robins that did not develop any functional compass before or during their first autumn migration could relearn to orient if they were exposed to natural celestial cues during the subsequent winter and spring. When tested in the geomagnetic field without access to celestial cues, these birds could orient in their species-specific spring migratory direction. In contrast, control birds that were deprived of any natural celestial cues throughout remained unable to orient. Our experiments suggest that European robins are still capable of establishing a functional orientation system after their first autumn. Although the external reference remains speculative, most likely, natural celestial cues enabled our birds to calibrate their magnetic compass. Our data suggest that avian compass systems are more flexible than previously believed and have implications for the release of hand-reared migratory birds. PMID:26388258

  13. 20. View of magnetic compass; "bigeyes," used for surveying ships ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. View of magnetic compass; "bigeyes," used for surveying ships and shore; and signal lights (covered). - U.S. Coast Guard Cutter BRAMBLE, Waterfront at Lincoln Avenue, Port Huron, St. Clair County, MI

  14. Sun-Compass Orientation in Mediterranean Fish Larvae

    PubMed Central

    Faillettaz, Robin; Blandin, Agathe; Paris, Claire B.; Koubbi, Philippe; Irisson, Jean-Olivier

    2015-01-01

    Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally. PMID:26308915

  15. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  16. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  17. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  18. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  19. 46 CFR 32.15-35 - Magnetic Compass and Gyrocompass-T/OC.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Magnetic Compass and Gyrocompass-T/OC. 32.15-35 Section..., MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-35 Magnetic Compass and Gyrocompass—T/OC. (a) All tankships in ocean or coastwise service must be fitted with a magnetic compass. (b) All...

  20. Interacting Compasses

    ERIC Educational Resources Information Center

    Riveros, Hector G.; Betancourt, Julian

    2009-01-01

    The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting interactions that occur…

  1. Probing a chemical compass: novel variants of low-frequency reaction yield detected magnetic resonance.

    PubMed

    Maeda, Kiminori; Storey, Jonathan G; Liddell, Paul A; Gust, Devens; Hore, P J; Wedge, C J; Timmel, Christiane R

    2015-02-01

    We present a study of a carotenoid-porphyrin-fullerene triad previously shown to function as a chemical compass: the photogenerated carotenoid-fullerene radical pair recombines at a rate sensitive to the orientation of an applied magnetic field. To characterize the system we develop a time-resolved Low-Frequency Reaction Yield Detected Magnetic Resonance (tr-LF-RYDMR) technique; the effect of varying the relative orientation of applied static and 36 MHz oscillating magnetic fields is shown to be strongly dependent on the strength of the oscillating magnetic field. RYDMR is a diagnostic test for involvement of the radical pair mechanism in the magnetic field sensitivity of reaction rates or yields, and has previously been applied in animal behavioural experiments to verify the involvement of radical-pair-based intermediates in the magnetic compass sense of migratory birds. The spectroscopic selection rules governing RYDMR are well understood at microwave frequencies for which the so-called 'high-field approximation' is valid, but at lower frequencies different models are required. For example, the breakdown of the rotating frame approximation has recently been investigated, but less attention has so far been given to orientation effects. Here we gain physical insights into the interplay of the different magnetic interactions affecting low-frequency RYDMR experiments performed in the challenging regime in which static and oscillating applied magnetic fields as well as internal electron-nuclear hyperfine interactions are of comparable magnitude. Our observations aid the interpretation of existing RYDMR-based animal behavioural studies and will inform future applications of the technique to verify and characterize further the biological receptors involved in avian magnetoreception. PMID:25537133

  2. Sky Compass Orientation in Desert Locusts—Evidence from Field and Laboratory Studies

    PubMed Central

    Homberg, Uwe

    2015-01-01

    Locusts are long-range migratory insects. At high population density, immature animals form marching hopper bands while adults take off and form huge swarms of millions of animals. At low population densities animals are solitarious, but likewise migrate, mostly during the night. Numerous studies aimed at predicting locust infestations showed that migrations both as hopper bands and as adults are largely downwind following seasonal shifts of the tropical convergence zone taking the animals to areas of rainfall. Only a few studies provided evidence for active orientation mechanisms, including the involvement of a sun compass. This scarcity of evidence stands in contrast to recent neurobiological data showing sophisticated neuronal adaptations suited for sky compass navigation. These include a special dorsal eye region with photoreceptors suited to analyze the polarization pattern of the sky and a system of topographically arranged sky compass neurons in the central complex of the brain. Laboratory experiments, moreover, demonstrated polarotaxis in tethered flying animals. The discrepancy of these findings call for more rigorous field studies on active orientation mechanisms in locusts. It remains to be shown how locusts use their internal sky compass during mass migrations and what role it plays to guide solitarious locusts in their natural habitat.

  3. Rapid Learning of Magnetic Compass Direction by C57BL/6 Mice in a 4-Armed ‘Plus’ Water Maze

    PubMed Central

    Phillips, John B.; Youmans, Paul W.; Muheim, Rachel; Sloan, Kelly A.; Landler, Lukas; Painter, Michael S.; Anderson, Christopher R.

    2013-01-01

    Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze) have failed to provide evidence for the use of magnetic cues. Here we show that C57BL/6 mice can learn the magnetic direction of a submerged platform in a 4-armed (plus) water maze. Naïve mice were given two brief training trials. In each trial, a mouse was confined to one arm of the maze with the submerged platform at the outer end in a predetermined alignment relative to magnetic north. Between trials, the training arm and magnetic field were rotated by 180° so that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional preference of each mouse was tested once in one of four magnetic field alignments by releasing it at the center of the maze with access to all four arms. Equal numbers of responses were obtained from mice tested in the four symmetrical magnetic field alignments. Findings show that two training trials are sufficient for mice to learn the magnetic direction of the submerged platform in a plus water maze. The success of these experiments may be explained by: (1) absence of alternative directional cues (2), rotation of magnetic field alignment, and (3) electromagnetic shielding to minimize radio frequency interference that has been shown to interfere with magnetic compass orientation of birds. These findings confirm that mice have a well-developed magnetic compass, and give further impetus to the question of whether epigeic rodents (e.g., mice and rats) have a photoreceptor-based magnetic compass similar to that found in amphibians and migratory birds. PMID:24023673

  4. X-ray compass for determining device orientation

    DOEpatents

    Da Silva, Luiz B. (Danville, CA); Matthews, Dennis L. (Moss Beach, CA); Fitch, Joseph P. (Livermore, CA); Everett, Matthew J. (Pleasanton, CA); Colston, Billy W. (Livermore, CA); Stone, Gary F. (Livermore, CA)

    1999-01-01

    An apparatus and method for determining the orientation of a device with respect to an x-ray source. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source.

  5. X-ray compass for determining device orientation

    DOEpatents

    Da Silva, L.B.; Matthews, D.L.; Fitch, J.P.; Everett, M.J.; Colston, B.W.; Stone, G.F.

    1999-06-15

    An apparatus and method for determining the orientation of a device with respect to an x-ray source are disclosed. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source. 25 figs.

  6. Sun Compass Orientation Helps Coral Reef Fish Larvae Return to Their Natal Reef

    PubMed Central

    Mouritsen, Henrik; Atema, Jelle; Kingsford, Michael J.; Gerlach, Gabriele

    2013-01-01

    Reef fish sustain populations on isolated reefs and show genetic diversity between nearby reefs even though larvae of many species are swept away from the natal site during pelagic dispersal. Retention or recruitment to natal reefs requires orientation capabilities that enable larvae to find their way. Although olfactory and acoustically based orientation has been implicated in homing when larvae are in the reef’s vicinity, it is still unclear how they cope with greater distances. Here we show evidence for a sun compass mechanism that can bring the larvae to the vicinity of their natal reef. In a circular arena, pre-settlement larvae and early settlers (<24 hours) of the cardinal fish, Ostorhinchus doederleini, showed a strong SSE directional swimming response, which most likely has evolved to compensate for the locally prevailing large scale NNW current drift. When fish were clock-shifted 6 hours, they changed their orientation by ca. 180° as predicted by the tropical sun curve at One Tree Island, i.e. they used a time-compensated sun compass. Furthermore, the fish oriented most consistently at times of the day when the sun azimuth is easy to determine. Microsatellite markers showed that the larvae that had just arrived at One Tree Island genetically belonged to either the local reef population or to Fitzroy Reef located 12 kilometers to the SSE. The use of a sun compass adds a missing long-distance link to the hierarchy of other sensory abilities that can direct larvae to the region of origin, including their natal reef. Predominant local recruitment, in turn, can contribute to genetic isolation and potential speciation. PMID:23840396

  7. Discordant timing between antennae disrupts sun compass orientation in migratory monarch butterflies

    PubMed Central

    Guerra, Patrick A; Merlin, Christine; Gegear, Robert J; Reppert, Steven M

    2014-01-01

    To navigate during their long-distance migration, monarch butterflies (Danaus plexippus) use a time-compensated sun compass. The sun compass timing elements reside in light-entrained circadian clocks in the antennae. Here we show that either antenna is sufficient for proper time compensation. However, migrants with either antenna painted black (to block light entrainment) and the other painted clear (to permit light entrainment) display disoriented group flight. Remarkably, when the black-painted antenna is removed, re-flown migrants with a single, clear-painted antenna exhibit proper orientation behaviour. Molecular correlates of clock function reveal that period and timeless expression is highly rhythmic in brains and clear-painted antennae, while rhythmic clock gene expression is disrupted in black-painted antennae. Our work shows that clock outputs from each antenna are processed and integrated together in the monarch time-compensated sun compass circuit. This dual timing system is a novel example of the regulation of a brain-driven behaviour by paired organs. PMID:22805565

  8. Magnetic orientation of garden warblers (Sylvia borin) under 1.4 MHz radiofrequency magnetic field

    PubMed Central

    Kavokin, Kirill; Chernetsov, Nikita; Pakhomov, Alexander; Bojarinova, Julia; Kobylkov, Dmitry; Namozov, Barot

    2014-01-01

    We report on the experiments on orientation of a migratory songbird, the garden warbler (Sylvia borin), during the autumn migration period on the Courish Spit, Eastern Baltics. Birds in experimental cages, deprived of visual information, showed the seasonally appropriate direction of intended flight with respect to the magnetic meridian. Weak radiofrequency (RF) magnetic field (190 nT at 1.4 MHz) disrupted this orientation ability. These results may be considered as an independent replication of earlier experiments, performed by the group of R. and W. Wiltschko with European robins (Erithacus rubecula). Confirmed outstanding sensitivity of the birds' magnetic compass to RF fields in the lower megahertz range demands for a revision of one of the mainstream theories of magnetoreception, the radical-pair model of birds' magnetic compass. PMID:24942848

  9. Orientation with a Viking sun-compass, a shadow-stick, and two calcite sunstones under various weather conditions.

    PubMed

    Bernáth, Balázs; Blahó, Miklós; Egri, Adám; Barta, András; Kriska, György; Horváth, Gábor

    2013-09-01

    It is widely accepted that Vikings used sun-compasses to derive true directions from the cast shadow of a gnomon. It has been hypothesized that when a cast shadow was not formed, Viking navigators relied on crude skylight polarimetry with the aid of dichroic or birefringent crystals, called "sunstones." We demonstrate here that a simple tool, that we call "shadow-stick," could have allowed orientation by a sun-compass with satisfying accuracy when shadows were not formed, but the sun position could have reliably been estimated. In field tests, we performed orientation trials with a set composed of a sun-compass, two calcite sunstones, and a shadow-stick. We show here that such a set could have been an effective orientation tool for Vikings only when clear, blue patches of the sky were visible. PMID:24085076

  10. Freely oriented portable superconducting magnet

    SciTech Connect

    Schmierer, Eric N.; Prenger, F. Coyne; Hill, Dallas D.

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  11. The interaction of stars and magnetic field in the orientation system of night migrating birds. II. Spring experiments with european robins (Erithacus rubecula).

    PubMed

    Wiltschko, W; Wiltschko, R

    1975-01-01

    To investigate the relative importance of stellar and magnetic cues for the compass orientation of night migrating birds, 45 European robins (Erithacus rubecula) were tested in automatically registering cages with view of the clear natural night sky. One group was tested in the natural local geomagnetic field, the other group in a field pointing to 120 degrees ESE; birds from both groups were additionally tested in a magnetic field the horizontal component of which was compensated. The observed orientation behavior leads to the conclusion that star compass and magnetic compass are not independent, but that they are interlinked in the way that the star compass is established by information from the magnetic compass. PMID:1231422

  12. Quantum probe and design for a chemical compass with magnetic nanostructures

    E-print Network

    Jianming Cai

    2011-03-01

    Magnetic fields as weak as Earth's may affect the outcome of certain photochemical reactions that go through a radical pair intermediate. When the reaction environment is anisotropic, this phenomenon can form the basis of a chemical compass and has been proposed as a mechanism for animal magnetoreception. Here, we demonstrate how to optimize the design of a chemical compass with a much better directional sensitivity simply by a gradient field, e.g. from a magnetic nanostructure. We propose an experimental test of these predictions, and suggest design principles for a hybrid metallic-organic chemical compass. In addition to the practical interest in designing a biomimetic weak magnetic field sensor, our result shows that gradient fields can server as powerful tools to probe spin correlations in radical pair reactions.

  13. Orientation and Magnitude of Mars' Magnetic Field

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image shows the orientation and magnitude of the magnetic field measured by the MGS magnetometer as it sped over the surface of Mars during an early aerobraking pass (Day of the year, 264; 'P6' periapsis pass). At each point along the spacecraft trajectory we've drawn vectors in the direction of the magnetic field measured at that instant; the length of the line is scaled to show the relative magnitude of the field. Imagine traveling along with the MGS spacecraft, holding a string with a magnetized needle on one end: this essentially a compass with a needle that is free to spin in all directions. As you pass over the surface the needle would swing rapidly, first pointing towards the planet and then rotating quickly towards 'up' and back down again. All in a relatively short span of time, say a minute or two, during which time the spacecraft has traveled a couple of hundred miles. You've just passed over one of many 'magnetic anomalies' thus far detected near the surface of Mars. A second major anomaly appears a little later along the spacecraft track, about 1/4 the magnitude of the first - can you find it? The short scale length of the magnetic field signature locates the source near the surface of Mars, perhaps in the crust, a 10 to 75 kilometer thick outer shell of the planet (radius 3397 km).

    The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. JPL is an operating division of California Institute of Technology (Caltech).

  14. 46 CFR 169.709 - Compass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic steering compass. (b) Each vessel certificated for exposed water service must have an emergency compass in addition to the one required in...

  15. Migration along orthodromic sun compass routes by arctic birds.

    PubMed

    Alerstam, T; Gudmundsson, G A; Green, M; Hedenstrom, A

    2001-01-12

    Flight directions of birds migrating at high geographic and magnetic latitudes can be used to test bird orientation by celestial or geomagnetic compass systems under polar conditions. Migration patterns of arctic shorebirds, revealed by tracking radar studies during an icebreaker expedition along the Northwest Passage in 1999, support predicted sun compass trajectories but cannot be reconciled with orientation along either geographic or magnetic loxodromes (rhumb lines). Sun compass routes are similar to orthodromes (great circle routes) at high latitudes, showing changing geographic courses as the birds traverse longitudes and their internal clock gets out of phase with local time. These routes bring the shorebirds from high arctic Canada to the east coast of North America, from which they make transoceanic flights to South America. The observations are also consistent with a migration link between Siberia and the Beaufort Sea region by way of sun compass routes across the Arctic Ocean. PMID:11209079

  16. How do honeybees use their magnetic compass? Can they see the North?

    PubMed

    Válková, T; Vácha, M

    2012-08-01

    While seeking food sources and routes back to their hive, bees make use of their advanced nervous and sensory capacities, which underlie a diverse behavioral repertoire. One of several honeybee senses that is both exceptional and intriguing is magnetoreception - the ability to perceive the omnipresent magnetic field (MF) of the Earth. The mechanism by which animals sense MFs has remained fascinating as well as elusive because of the intricacies involved, which makes it one of the grand challenges for neural and sensory biology. However, investigations in recent years have brought substantial progress to our understanding of how such magneto-receptor(s) may work. Some terrestrial animals (birds) are reported to be equipped even with a dual perception system: one based on diminutive magnetic particles - in line with the original model which has also always been hypothesized for bees - and the other one, as the more recent model describes, based on a sensitivity of some photochemical reactions to MF (radical-pair or chemical mechanism). The latter model postulates a close link to vision and supposes that the animals can see the position of the geomagnetic North as a visible pattern superimposed on the picture of the environment. In recent years, a growing body of evidence has shown that radical-pair magnetoreception might also be used by insects. It is realistic to expect that such evidence will inspire a re-examination and extension or confirmation of established views on the honeybee magnetic-compass mechanism. However, the problem of bee magnetoreception will not be solved at the moment that a receptor is discovered. On the contrary, the meaning of magnetoreception in insect life and its involvement in the orchestration of other senses is yet to be fully understood. The crucial question to be addressed in the near future is whether the compass abilities of the honeybee could suffer from radio frequency (RF) smog accompanying modern civilization and whether the fitness of this dominant pollinator might be affected by RF fields. The goal of this review is to provide an overview of the path that the behavioral research on honeybee magnetoreception has taken and to discuss it in the context of contemporary data obtained on other insects. PMID:22313997

  17. Ethical advantages of using domestic bird species for magnetic orientation research.

    PubMed

    Freire, Rafael

    2011-01-01

    Identifying the mechanism in birds that controls magnetic orientation behavior is proving elusive and is currently attracting a plethora of research activity. Much of this research involves wild birds that are caught in nets, tested and released. Ethical concerns regarding these experiments are likely to encompass the welfare of animals, their "rights" and conservation issues. Recently, Pekin ducks derived from migratory ancestors have been shown to posses a magnetic compass in a simple conditioning procedure. The use of domestic bird species provides a refinement in the ethics of animal experimentation since these birds are not caught in nets, are less fearful of humans and their use does not raise conservation concerns. The study of magnetic orientation is a high profile and fascinating areas of animal behavior research and one in which behavioral scientists should be seen to actively embrace the principles of the 3R's. PMID:21509188

  18. 28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. MODIFIED CHAIN SAW FOR CUTTING ROCK CORES; BRUNTON COMPASS STAND FOR DETERMINING CORE'S FIELD ORIENTATION; INSECTICIDE DISPENSER MODIFIED TO LUBRICATE CORE DRILLING PROCESS. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

  19. Magnetoreception: activated cryptochrome 1a concurs with magnetic orientation in birds.

    PubMed

    Nießner, Christine; Denzau, Susanne; Stapput, Katrin; Ahmad, Margaret; Peichl, Leo; Wiltschko, Wolfgang; Wiltschko, Roswitha

    2013-11-01

    The radical pair model proposes that the avian magnetic compass is based on radical pair processes in the eye, with cryptochrome, a flavoprotein, suggested as receptor molecule. Cryptochrome 1a (Cry1a) is localized at the discs of the outer segments of the UV/violet cones of European robins and chickens. Here, we show the activation characteristics of a bird cryptochrome in vivo under natural conditions. We exposed chickens for 30 min to different light regimes and analysed the amount of Cry1a labelled with an antiserum against an epitope at the C-terminus of this protein. The staining after exposure to sunlight and to darkness indicated that the antiserum labels only an illuminated, activated form of Cry1a. Exposure to narrow-bandwidth lights of various wavelengths revealed activated Cry1a at UV, blue and turquoise light. With green and yellow, the amount of activated Cry1a was reduced, and with red, as in the dark, no activated Cry1a was labelled. Activated Cry1a is thus found at all those wavelengths at which birds can orient using their magnetic inclination compass, supporting the role of Cry1a as receptor molecule. The observation that activated Cry1a and well-oriented behaviour occur at 565 nm green light, a wavelength not absorbed by the fully oxidized form of cryptochrome, suggests that a state other than the previously suggested Trp/FAD radical pair formed during photoreduction is crucial for detecting magnetic directions. PMID:23966619

  20. Magnetoreception: activated cryptochrome 1a concurs with magnetic orientation in birds

    PubMed Central

    Nießner, Christine; Denzau, Susanne; Stapput, Katrin; Ahmad, Margaret; Peichl, Leo; Wiltschko, Wolfgang; Wiltschko, Roswitha

    2013-01-01

    The radical pair model proposes that the avian magnetic compass is based on radical pair processes in the eye, with cryptochrome, a flavoprotein, suggested as receptor molecule. Cryptochrome 1a (Cry1a) is localized at the discs of the outer segments of the UV/violet cones of European robins and chickens. Here, we show the activation characteristics of a bird cryptochrome in vivo under natural conditions. We exposed chickens for 30 min to different light regimes and analysed the amount of Cry1a labelled with an antiserum against an epitope at the C-terminus of this protein. The staining after exposure to sunlight and to darkness indicated that the antiserum labels only an illuminated, activated form of Cry1a. Exposure to narrow-bandwidth lights of various wavelengths revealed activated Cry1a at UV, blue and turquoise light. With green and yellow, the amount of activated Cry1a was reduced, and with red, as in the dark, no activated Cry1a was labelled. Activated Cry1a is thus found at all those wavelengths at which birds can orient using their magnetic inclination compass, supporting the role of Cry1a as receptor molecule. The observation that activated Cry1a and well-oriented behaviour occur at 565 nm green light, a wavelength not absorbed by the fully oxidized form of cryptochrome, suggests that a state other than the previously suggested Trp•/FAD• radical pair formed during photoreduction is crucial for detecting magnetic directions. PMID:23966619

  1. Optimizing magnetization orientation of permanent magnets for maximal gradient force

    NASA Astrophysics Data System (ADS)

    Kruusing, Arvi

    2001-09-01

    The force exercised on a permanent magnet (PM) in a nonuniform field (gradient force) is dependent on the magnetization orientation of the magnet. In this paper, it is shown theoretically that the gradient force is greatest when the magnetization through the magnet, or at least at its surface, is collinear with the external field. The formulae for calculating the force between an axis-symmetric optimal magnet and a coaxial axis-symmetric coil are presented. Using the finite element method (FEM), calculations of the magnetic field distribution of an optimal cylindrical magnet and some its approximations are performed. The forces between these magnets and a pancake coil are computed and compared. For a system consisting of a magnet with a height of 1 unit and a diameter of 2 units and magnetization invariant in field and an annular pancake coil with a diameter of 2.4 units, a thickness of 0.2 units, an inner diameter of 0.4 units and a distance from the magnet of 0.2 units, the force on the optimal magnet was 1.44 times greater than the force on an axially magnetized magnet of the same size and magnetization magnitude. The optimal magnetization may be approximated by magnetization inclined at a constant angle to the axis and by a combination of axially and radially magnetized sections. With magnetization at a constant angle to the axis in the axis plane, the force was greatest when the angle was about 45°, being 1.38-fold compared to the force on an axially magnetized magnet. When the magnet was composed of an axially magnetized cylindrical core and a radially magnetized outer ring, the force was greatest when the volume of the core was approximately equal to the volume of the ring, being 1.26-fold compared to the force on an axially magnetized magnet. The optimal magnet and its approximations also provided a reduced stray field. A short review of methods of the fabrication of permanent magnets (PMs) with a continuous variation of the magnetization orientation and with radial magnetization orientation is given. The results of this study can be used to design linear electromagnetic (micro)actuators.

  2. Sensitivity and entanglement in the avian chemical compass

    NASA Astrophysics Data System (ADS)

    Zhang, Yiteng; Berman, Gennady P.; Kais, Sabre

    2014-10-01

    The radical pair mechanism can help to explain avian orientation and navigation. Some evidence indicates that the intensity of external magnetic fields plays an important role in avian navigation. In this paper, using a two-stage model, we demonstrate that birds could reasonably detect the directions of geomagnetic fields and gradients of these fields using a yield-based chemical compass that is sensitive enough for navigation. Also, we find that the lifetime of entanglement in this proposed compass is angle dependent and long enough to allow adequate electron transfer between molecules.

  3. Magnetic material arrangement in oriented termites: a magnetic resonance study

    NASA Astrophysics Data System (ADS)

    Alves, O. C.; Wajnberg, E.; de Oliveira, J. F.; Esquivel, D. M. S.

    2004-06-01

    Temperature dependence of the magnetic resonance is used to study the magnetic material in oriented Neocapritermes opacus (N.o.) termite, the only prey of the migratory ant Pachycondyla marginata (P.m.). A broad line in the g=2 region, associated to isolated nanoparticles shows that at least 97% of the magnetic material is in the termite's body (abdomen + thorax). From the temperature dependence of the resonant field and from the spectral linewidths, we estimate the existence of magnetic nanoparticles 18.5 ± 0.3 nm in diameter and an effective magnetic anisotropy constant, Keff between 2.1 and 3.2 × 10 4 erg/cm 3. A sudden change in the double integrated spectra at about 100 K for N.o. with the long body axis oriented perpendicular to the magnetic field can be attributed to the Verwey transition, and suggests an organized film-like particle system.

  4. Trough Compass with Case, 1916

    USGS Multimedia Gallery

    The storage case has a sliding lid. The compass is marked Troughton & Simms Ltd, London, 1916, No.9214. A trough compass is used with either a plane table or a theodolite. The needle is a long magnetized bar of steel which is pointed at both ends. Object ID: USGS-000824...

  5. A Compass and Clinometer Modified for Structural Analysis

    ERIC Educational Resources Information Center

    Amenta, Roddy V.

    1977-01-01

    Describes the modification of the SUUNTO compass and clinometer precision sighting instruments to make a compact geologic compass useful for measuring orientations of S-surfaces and rake angles of lineations. (SL)

  6. The flexible migratory orientation system of the savannah sparrow (Passerculus sandwichensis)

    PubMed

    Able; Able

    1996-01-01

    The orientation system of the Savannah sparrow (Passerculus sandwichensis) is typical of nocturnal migrant passerine birds. It is based on a system of interacting compass senses: magnetic, star, polarized light and, perhaps, sun compasses. The magnetic compass capability develops in birds that have never seen the sky, but the preferred direction of magnetic orientation may be calibrated by celestial rotation (stars at night and polarized skylight patterns during the day). This ability to recalibrate magnetic orientation persists throughout life and enables the bird to compensate for variability in magnetic declination that may be encountered as it migrates. The polarized light compass may be manipulated by exposing young birds to altered patterns of skylight polarization. There is some evidence that the magnetic field may be involved in calibration of the polarized light compass. In short-term orientation decision-making during migration, visual information at sunset overrides both stars and magnetic cues, and polarized skylight is the relevant stimulus in dusk orientation. The star pattern compass seems to be of little importance. This extremely flexible orientation system enables the birds to respond to spatial and temporal variability in the quality and availability of orientation information. PMID:9317228

  7. A PURPOSE ORIENTED MAGNETIC SEPARATOR: SKIMMER

    SciTech Connect

    Salih Ersayin

    2005-08-09

    A magnetic separator was designed to selectively separate fine-liberated magnetite. The conceptual design was simulated using CFD techniques. A separator tank was fabricated and a magnetic drum was used to capture magnetic particles. The initial tank design was modified to eliminate application oriented problems. The new separator was able to produce a fine product as a concentrate at relatively high feed rates. A plant simulation showed that such a device could lower circulating loads around ball mills by 16%, thereby creating room for a 5-8% increase in throughput at the same energy level. However, it was concluded that further improvements in terms of both size and mineral selectivity are needed to have a marketable product.

  8. Conceptualizing and experiencing compassion

    PubMed Central

    Condon, Paul; Barrett, Lisa Feldman

    2014-01-01

    Does compassion feel pleasant or unpleasant? People tend to categorize compassion as a pleasant or positive emotion, but laboratory compassion inductions, which present another’s suffering, may elicit unpleasant feelings. Across two studies, we examined whether prototypical conceptualizations of compassion (as pleasant) differ from experiences of compassion (as unpleasant). Following laboratory-based neutral or compassion inductions, participants made abstract judgments about compassion relative to various emotion-related adjectives, thereby providing a prototypical conceptualization of compassion. Participants also rated their own affective states, thereby indicating experiences of compassion. Conceptualizations of compassion were pleasant across neutral and compassion inductions. Following exposure to others’ suffering, however, participants felt increased levels of compassion and unpleasant affect, but not pleasant affect. Following neutral inductions, participants reported more pleasant than unpleasant affect, with moderate levels of compassion. Thus, prototypical conceptualizations of compassion are pleasant, but experiences of compassion can feel pleasant or unpleasant. The implications for emotion theory in general are discussed. PMID:23914766

  9. The orientation and navigation of juvenile alligators: evidence of magnetic sensitivity

    USGS Publications Warehouse

    Rodda, Gordon H.

    1984-01-01

    Displaced juvenile alligators, Alligator mississipiensis, were released on land in a 9 m diameter dodecagonal arena to test their ability to orient in the absence of terrestrial landmarks. Navigational ability seemed to improve with age. When displaced along a fairly direct route yearlings (age 7–14 months) compensated for their displacement, moving in the direction from the arena to their home sites. When displaced by a circuitous route, yearlings failed to compensate for their displacement, exhibiting instead simple compass orientation in a direction that would have returned them to water had they been released on land near the site where they were captured. The older juveniles were oriented in a homeward direction under all displacement and test conditions. The latter animals may have been using geomagnetic map information to select their homeward directions as the errors in their homeward bearings correlated with small deviations in the geomagnetic field's dip angle at the time of the test (1980r s=?0.6047,P=0.0131, all testsr s= ?0.4652,P=0.0084). This effect appeared to depend on a very short-term assessment of geomagnetic conditions, as values measured 20 min before or 30 min after the tests began did not correlate with the directions the animals moved. The older juveniles appeared to use magnetically quiet hours on the night of their capture as the baseline from which to measure the geomagnetic deviations that occurred at the time of the arena test. The magnitude of the magnetic effect in the older animals suggests that the geomagnetic information may have been used to perform a ‘map’ step, as small fluctuations in dip angle correlated with much larger deviations in homeward bearings. In addition, the compass-oriented yearlings and the seemingly route-based behavior of the homeward-oriented yearlings did not appear to be influenced by geomagnetic conditions. These findings have many parallels in results obtained from bird orientation studies, providing evidence that navigation may share a common basis in different vertebrate groups.

  10. The sun compass revisited

    PubMed Central

    Guilford, Tim; Taylor, Graham K.

    2014-01-01

    Many animals, and birds in particular, are thought to use directional information from the sun in the form of a time-compensated sun compass, with predictably deviated orientation under clock shift being regarded as the litmus test of this. We suggest that this paradigm obscures a number of other ways in which solar-derived information could be important in animal orientation. We distinguish between the known use of the sun's azimuth to provide absolute geographical direction (compass mechanism) and its possible use to detect changes in heading (heading indicator mechanism). Just as in an aircraft, these two kinds of information may be provided by separate mechanisms and used for different functions, for example for navigation versus steering. We also argue that although a solar compass must be time-referenced to account for the sun's apparent diurnal movement, this need not entail full time compensation. This is because animals might also use time-dependent solar information in an associatively acquired, and hence time-limited, way. Furthermore, we show that a solar heading indicator, when used on a sufficiently short timescale, need not require time compensation at all. Finally, we suggest that solar-derived cues, such as shadows, could also be involved in navigation in ways that depend explicitly upon position, and are therefore not strictly compass-related. This could include giving directionality to landmarks, or acting as time-dependent landmarks involved in place recognition. We conclude that clock shift experiments alone are neither necessary nor sufficient to identify the occurrence of all conceivable uses of solar information in animal orientation, so that a predictable response to clock shift should not be regarded as an acid test of the use of solar information in navigation. PMID:25389374

  11. Compassion: An Evolutionary Analysis and Empirical Review

    PubMed Central

    Goetz, Jennifer L.; Keltner, Dacher; Simon-Thomas, Emiliana

    2010-01-01

    What is compassion? And how did it evolve? In this review, we integrate three evolutionary arguments that converge on the hypothesis that compassion evolved as a distinct affective experience whose primary function is to facilitate cooperation and protection of the weak and those who suffer. Our empirical review reveals compassion to have distinct appraisal processes attuned to undeserved suffering, distinct signaling behavior related to caregiving patterns of touch, posture, and vocalization, and a phenomenological experience and physiological response that orients the individual to social approach. This response profile of compassion differs from those of distress, sadness, and love, suggesting that compassion is indeed a distinct emotion. We conclude by considering how compassion shapes moral judgment and action, how it varies across different cultures, and how it may engage specific patterns of neural activation, as well as emerging directions of research. PMID:20438142

  12. Self-Compassion among College Counseling Center Clients: An Examination of Clinical Norms and Group Differences

    ERIC Educational Resources Information Center

    Lockard, Allison J.; Hayes, Jeffrey A.; Neff, Kristin; Locke, Benjamin D.

    2014-01-01

    There has been growing interest in the mental health benefits of self-compassion. This study was designed to establish norms on the Self-Compassion Scale-Short Form, a popular measure of self-compassion for individuals seeking counseling, and to examine group differences in self-compassion based on gender, race/ethnicity, sexual orientation,…

  13. Remotely readable fiber optic compass

    DOEpatents

    Migliori, Albert (Santa Fe, NM); Swift, Gregory W. (Los Alamos, NM); Garrett, Steven L. (Pebble Beach, CA)

    1986-01-01

    A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optical axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

  14. Remotely readable fiber optic compass

    DOEpatents

    Migliori, A.; Swift, G.W.; Garrett, S.L.

    1985-04-30

    A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optical axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

  15. Computational modeling of magnetically actuated propellant orientation

    NASA Technical Reports Server (NTRS)

    Hochstein, John I.

    1996-01-01

    Unlike terrestrial applications where gravity positions liquid at the 'bottom' of the tank, the location of liquid propellant in spacecraft tanks is uncertain unless specific actions are taken or special features are built into the tank. Some mission events require knowledge of liquid position prior to a particular action: liquid must be positioned over the tank outlet prior to starting the main engines and must be moved away from the tank vent before vapor can be released overboard to reduce pressure. It may also be desirable to positively position liquid to improve propulsion system performance: moving liquid away from the tank walls will dramatically decrease the rate of heat transfer to the propellant, suppressing the boil-off rate, thereby reducing overall mission propellant requirements. The process of moving propellant to a desired position is referred to as propellant orientation or reorientation. Several techniques have been developed to positively position propellant in spacecraft tanks and each technique imposes additional requirements on vehicle design. Propulsive reorientation relies on small auxiliary thrusters to accelerate the tank. The inertia of the liquid causes it to collect in the aft-end of the tank if the acceleration is forward. This technique requires that additional thrusters be added to the vehicle, that additional propellant be carried in the vehicle, and that an additional operational maneuver be executed. Another technique uses Liquid Acquisition Devices (LAD's) to positively position propellants. These devices rely on surface tension to hold the liquid within special geometries (i.e. vanes, wire-mesh channels, start-baskets). While avoiding some of the penalties of propulsive orientation, this technique requires the addition of complicated hardware inside the propellant tank and performance for long duration missions is uncertain. The subject of the present research is an alternate technique for positively positioning liquid within spacecraft propellant tanks: magnetic fields.

  16. A magnetic compass sense has been demonstrated in a large and taxonomically diverse group of organisms. In terrestrial

    E-print Network

    Phillips, John B.

    photoreceptors located in or near the pineal organ, and here we present new findings that indicate that the putative long- wavelength mechanism is also associated with pineal photoreceptors. Interestingly, the amphibian pineal organ mediates orientation to both the e-vector of plane- polarized light and the magnetic

  17. 46 CFR 169.709 - Compass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic...

  18. 46 CFR 169.709 - Compass.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic...

  19. 46 CFR 169.709 - Compass.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic...

  20. 46 CFR 169.709 - Compass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic...

  1. 46 CFR 169.709 - Compass.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Compass. 169.709 Section 169.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment § 169.709 Compass. (a) Each vessel must be fitted with a magnetic...

  2. TaskOriented Lossy Compression of Magnetic Resonance Images

    E-print Network

    Atkins, M. Stella

    Task­Oriented Lossy Compression of Magnetic Resonance Images by Mark Charles Anderson B.Sc. (Comp rates. Application of the new system to magnetic resonance images is shown to produce compression. Jacques Vaisey Supervisor Dr. Ze­Nian Li Examiner Date Approved: ii #12; Abstract Magnetic resonance

  3. Magnetic eld induced orientational bistability in a ferronematic cell

    E-print Network

    Sluckin, Tim

    using weak (magnetic elds. Magnetic suspensions in nematic liquid crystals were proposedMagnetic eld induced orientational bistability in a ferronematic cell S.V. BURYLOV1 , V The equilibrium states of a suspension of single-domain ferroparticles in a nematic liquid-crystalline homeotropic

  4. Environment-induced anisotropy and sensitivity of the radical pair mechanism in the avian compass

    NASA Astrophysics Data System (ADS)

    Carrillo, Alejandro; Cornelio, Marcio F.; de Oliveira, Marcos C.

    2015-07-01

    Several experiments over the years have shown that the earth's magnetic field is essential for orientation in birds' migration. The most promising explanation for this orientation is the photo-stimulated radical pair (RP) mechanism. In order to define a reference frame for the orientation task radicals must have an intrinsic anisotropy. We show that this kind of anisotropy and consequently the entanglement in the model are not necessary for the proper functioning of the compass. Classically correlated initial conditions for the RP, subjected to a fast decoherence process, are able to provide the anisotropy required. Even a dephasing environment can provide the necessary frame for the compass to work and also implies fast decay of any quantum correlation in the system without damaging the orientation ability. This fact significantly expands the range of applicability of the RP mechanism providing more elements for experimental search.

  5. The development of migratory orientation mechanisms.

    PubMed

    Able, K P

    1991-01-01

    Recent experimental studies (since ca. 1985) on the ontogeny of orientation mechanisms in migratory birds are reviewed. The processes and interactions are synthesized into a framework that may help identify critical research questions. Birds that grow up in the earth's magnetic field develop the ability to perform appropriate migratory orientation, even in the absence of any experience with relevant visual cues. In two species, large changes in direction during the course of migration seem to be controlled by an endogenous time program. In one of these, the Pied Flycatcher (Ficedula hypoleuca), the correct magnetic orientation seems to occur only when the magnetic fields appropriate to the latitudes encountered en route were experienced at the proper seasonal time. The magnetic compass may be modified by visual experience with either the day or night sky. Celestial rotation may be the calibrating reference in this case, as it is in the development of the star compass. Young Savannah Sparrows (Passerculus sandwichensis) learn to perform compass orientation at sunset based on polarized skylight. This compass capability seems to be calibrated by magnetic directions. Some problems of experimental design and the interpretation of results from experiments on development are discussed. PMID:1838514

  6. Control of magnetization reversal in oriented strontium ferrite thin films

    SciTech Connect

    Roy, Debangsu Anil Kumar, P. S.

    2014-02-21

    Oriented Strontium Ferrite films with the c axis orientation were deposited with varying oxygen partial pressure on Al{sub 2}O{sub 3}(0001) substrate using Pulsed Laser Deposition technique. The angle dependent magnetic hysteresis, remanent coercivity, and temperature dependent coercivity had been employed to understand the magnetization reversal of these films. It was found that the Strontium Ferrite thin film grown at lower (higher) oxygen partial pressure shows Stoner-Wohlfarth type (Kondorsky like) reversal. The relative importance of pinning and nucleation processes during magnetization reversal is used to explain the type of the magnetization reversal with different oxygen partial pressure during growth.

  7. Chemical compass model for avian magnetoreception as a quantum coherent device

    E-print Network

    Jianming Cai; Martin B. Plenio

    2013-12-09

    It is known that more than 50 species use the Earth's magnetic field for orientation and navigation. Intensive studies particularly behavior experiments with birds, provide support for a chemical compass based on magnetically sensitive free radical reactions as a source of this sense. However, the fundamental question of how quantum coherence plays an essential role in such a chemical compass model of avian magnetoreception yet remains controversial. Here, we show that the essence of the chemical compass model can be understood in analogy to a quantum interferometer exploiting global quantum coherence rather than any subsystem coherence. Within the framework of quantum metrology, we quantify global quantum coherence and correlate it with the function of chemical magnetoreception. Our results allow us to understand and predict how various factors can affect the performance of a chemical compass from the unique perspective of quantum coherence assisted metrology. This represents a crucial step to affirm a direct connection between quantum coherence and the function of a chemical compass.

  8. Chemical Compass Model for Avian Magnetoreception as a Quantum Coherent Device

    NASA Astrophysics Data System (ADS)

    Cai, Jianming; Plenio, Martin B.

    2013-12-01

    It is known that more than 50 species use the Earth’s magnetic field for orientation and navigation. Intensive studies, particularly behavior experiments with birds, provide support for a chemical compass based on magnetically sensitive free radical reactions as a source of this sense. However, the fundamental question of how quantum coherence plays an essential role in such a chemical compass model of avian magnetoreception yet remains controversial. Here, we show that the essence of the chemical compass model can be understood in analogy to a quantum interferometer exploiting global quantum coherence rather than any subsystem coherence. Within the framework of quantum metrology, we quantify global quantum coherence and correlate it with the function of chemical magnetoreception. Our results allow us to understand and predict how various factors can affect the performance of a chemical compass from the unique perspective of quantum coherence assisted metrology. This represents a crucial step to affirm a direct connection between quantum coherence and the function of a chemical compass.

  9. A DCM Based Orientation Estimation Algorithm with an Inertial Measurement Unit and a Magnetic Compass

    E-print Network

    in navigation area, but along with the development of MEMS technology, low-cost, small-size inertial sensors a propagating procedure with gyro sensor data and an updating procedure with accelerometer data

  10. Do leaf-cutter ants orient their path-integrated, home vector with a magnetic compass?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf-cutter ants Atta colombica forage over 250 m in structurally-complex, Neotropical rainforests that occlude sun or polarized light cues. Night foraging makes the use of celestial cues and landmarks all the more difficult. Typically leaf-cutter ants follow architecturally-modified, pheromonally-m...

  11. Deflection of the Interstellar Neutral Hydrogen Flow Across the Heliospheric Interface: an Interstellar Magnetic Compass

    NASA Astrophysics Data System (ADS)

    Lallement, R.; Eric, Q.; Jean-Loup, B.; Dimitra, K.; Risto, P.

    2005-05-01

    Analyses of SOHO-SWAN observations show that the interstellar neutral H flow direction differs by about 4 degrees from the neutral He flow direction recently derived with an unprecedented accuracy using combined data sets (Mobius et al, 2004). The most likely explanation is a distortion of the heliospheric interface under the action of an inclined interstellar magnetic field, with imprints of the distorsion on the neutral H flow due to charge-transfer reactions between H atoms and ions. The direction of the ambient interstellar magnetic field and the heliospheric shape can be derived from the observed deviation. Implications for Voyager trajectories are discussed.

  12. From Compass to Hard Drive--Integrated Activities for Studying Magnets

    ERIC Educational Resources Information Center

    Dean, J.; Allwood, D. A.

    2014-01-01

    We describe a range of practical activities that allows students to investigate the properties and applications of magnets. The activities can be used in isolation or used together to build a rounded understanding of the subject area. The activities include simple demonstrations using common or inexpensive equipment, hands-on experiments for small…

  13. From compass to hard drive—integrated activities for studying magnets

    NASA Astrophysics Data System (ADS)

    Dean, J.; Allwood, D. A.

    2014-11-01

    We describe a range of practical activities that allows students to investigate the properties and applications of magnets. The activities can be used in isolation or used together to build a rounded understanding of the subject area. The activities include simple demonstrations using common or inexpensive equipment, hands-on experiments for small groups, and interactive problem solving suitable for whole classes. These can be tailored for students in either primary or secondary education.

  14. Condensation, demixing, and orientational ordering of magnetic colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Cattes, Stefanie M.; Klapp, Sabine H. L.; Schoen, Martin

    2015-05-01

    In this work we study the phase behavior of magnetic particles suspended in a simple nonmagnetic solvent. Magnetic particles are modelled as spherical particles carrying a three-dimensional, classical Heisenberg spin, whereas solvent molecules are treated as spherically symmetric Lennard-Jones particles. The binary mixture of magnetic particles and solvent is studied within the framework of classical density functional theory (DFT). Within DFT pair correlations are treated at the modified mean-field level at which they are approximated by orientation dependent Mayer f functions. In the absence of an external magnetic field four generic types of phase diagrams are observed depending on the concentration of magnetic particles. In this case we observe liquid-liquid phase coexistence between an orientationally ordered (polarized) and a disordered phase characterized by slightly different concentrations of magnetic particles. Liquid-liquid phase coexistence is suppressed by an external field and vanishes completely if the strength of the field is sufficiently large.

  15. Condensation, demixing, and orientational ordering of magnetic colloidal suspensions.

    PubMed

    Cattes, Stefanie M; Klapp, Sabine H L; Schoen, Martin

    2015-05-01

    In this work we study the phase behavior of magnetic particles suspended in a simple nonmagnetic solvent. Magnetic particles are modelled as spherical particles carrying a three-dimensional, classical Heisenberg spin, whereas solvent molecules are treated as spherically symmetric Lennard-Jones particles. The binary mixture of magnetic particles and solvent is studied within the framework of classical density functional theory (DFT). Within DFT pair correlations are treated at the modified mean-field level at which they are approximated by orientation dependent Mayer f functions. In the absence of an external magnetic field four generic types of phase diagrams are observed depending on the concentration of magnetic particles. In this case we observe liquid-liquid phase coexistence between an orientationally ordered (polarized) and a disordered phase characterized by slightly different concentrations of magnetic particles. Liquid-liquid phase coexistence is suppressed by an external field and vanishes completely if the strength of the field is sufficiently large. PMID:26066139

  16. Conditioned discrimination of magnetic inclination in a spatial-orientation arena task by homing pigeons (Columba livia).

    PubMed

    Mora, Cordula V; Acerbi, Merissa L; Bingman, Verner P

    2014-12-01

    It has been well established that homing pigeons are able to use the Earth's magnetic field to obtain directional information when returning to their loft and that their magnetic compass is based, at least in part, on the perception of magnetic inclination. Magnetic inclination has also been hypothesized in pigeons and other long-distance navigators, such as sea turtles, to play a role providing positional information as part of a map. Here we developed a behavioral paradigm which allows us to condition homing pigeons to discriminate magnetic inclination cues in a spatial-orientation arena task. Six homing pigeons were required to discriminate in a circular arena between feeders located either in a zone with a close to 0 deg inclination cue or in a zone with a rapidly changing inclination cue (-3 deg to +85 deg when approaching the feeder and +85 deg to -3 deg when moving away from the feeder) to obtain a food reward. The pigeons consistently performed this task above chance level. Control experiments, during which the coils were turned off or the current was running anti-parallel through the double-wound coil system, confirmed that no alternative cues were used by the birds in the discrimination task. The results show that homing pigeons can be conditioned to discriminate differences in magnetic field inclination, enabling investigation into the peripheral and central neural processing of geomagnetic inclination under controlled laboratory conditions. PMID:25278470

  17. An Ultrasonic Compass for Context-Aware Mobile Applications

    E-print Network

    An Ultrasonic Compass for Context-Aware Mobile Applications by Kevin John Wang Submitted by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arthur C. Smith Chairman, Department Committee on Graduate Students #12;2 #12;An Ultrasonic Compass of methods to calculate 3-DOF orientation from an array of well placed ultrasonic sensors operating

  18. Are migrating raptors guided by a geomagnetic compass?

    USGS Publications Warehouse

    Thorup, Kasper; Fuller, Mark R.; Alerstam, T.; Hake, M.; Kjellen, N.; Standberg, R.

    2006-01-01

    We tested whether routes of raptors migrating over areas with homogeneous topography follow constant geomagnetic courses more or less closely than constant geographical courses. We analysed the routes taken over land of 45 individual raptors tracked by satellite-based radiotelemetry: 25 peregrine falcons, Falco peregrinus, on autumn migration between North and South America, and seven honey buzzards, Pernis apivorus, and 13 ospreys, Pandion haliaetus, on autumn migration between Europe and Africa. Overall, migration directions showed a better agreement with constant geographical than constant geomagnetic courses. Tracks deviated significantly from constant geomagnetic courses, but were not significantly different from geographical courses. After we removed movements directed far from the mean direction, which may not be migratory movements, migration directions still showed a better agreement with constant geographical than constant geomagnetic courses, but the directions of honey buzzards and ospreys were not significantly different from constant geomagnetic courses either. That migration routes of raptors followed by satellite telemetry are in closer accordance with constant geographical compass courses than with constant geomagnetic compass courses may indicate that geographical (e.g. based on celestial cues) rather than magnetic compass mechanisms are of dominating importance for the birds' long-distance orientation.

  19. Accurate Orientation Estimation Using AHRS under Conditions of Magnetic Distortion

    PubMed Central

    Yadav, Nagesh; Bleakley, Chris

    2014-01-01

    Low cost, compact attitude heading reference systems (AHRS) are now being used to track human body movements in indoor environments by estimation of the 3D orientation of body segments. In many of these systems, heading estimation is achieved by monitoring the strength of the Earth's magnetic field. However, the Earth's magnetic field can be locally distorted due to the proximity of ferrous and/or magnetic objects. Herein, we propose a novel method for accurate 3D orientation estimation using an AHRS, comprised of an accelerometer, gyroscope and magnetometer, under conditions of magnetic field distortion. The system performs online detection and compensation for magnetic disturbances, due to, for example, the presence of ferrous objects. The magnetic distortions are detected by exploiting variations in magnetic dip angle, relative to the gravity vector, and in magnetic strength. We investigate and show the advantages of using both magnetic strength and magnetic dip angle for detecting the presence of magnetic distortions. The correction method is based on a particle filter, which performs the correction using an adaptive cost function and by adapting the variance during particle resampling, so as to place more emphasis on the results of dead reckoning of the gyroscope measurements and less on the magnetometer readings. The proposed method was tested in an indoor environment in the presence of various magnetic distortions and under various accelerations (up to 3 g). In the experiments, the proposed algorithm achieves <2° static peak-to-peak error and <5° dynamic peak-to-peak error, significantly outperforming previous methods. PMID:25347584

  20. Accurate orientation estimation using AHRS under conditions of magnetic distortion.

    PubMed

    Yadav, Nagesh; Bleakley, Chris

    2014-01-01

    Low cost, compact attitude heading reference systems (AHRS) are now being used to track human body movements in indoor environments by estimation of the 3D orientation of body segments. In many of these systems, heading estimation is achieved by monitoring the strength of the Earth's magnetic field. However, the Earth's magnetic field can be locally distorted due to the proximity of ferrous and/or magnetic objects. Herein, we propose a novel method for accurate 3D orientation estimation using an AHRS, comprised of an accelerometer, gyroscope and magnetometer, under conditions of magnetic field distortion. The system performs online detection and compensation for magnetic disturbances, due to, for example, the presence of ferrous objects. The magnetic distortions are detected by exploiting variations in magnetic dip angle, relative to the gravity vector, and in magnetic strength. We investigate and show the advantages of using both magnetic strength and magnetic dip angle for detecting the presence of magnetic distortions. The correction method is based on a particle filter, which performs the correction using an adaptive cost function and by adapting the variance during particle resampling, so as to place more emphasis on the results of dead reckoning of the gyroscope measurements and less on the magnetometer readings. The proposed method was tested in an indoor environment in the presence of various magnetic distortions and under various accelerations (up to 3 g). In the experiments, the proposed algorithm achieves <2° static peak-to-peak error and <5° dynamic peak-to-peak error, significantly outperforming previous methods. PMID:25347584

  1. The Radical Pair Mechanism and the Avian Chemical Compass: Quantum Coherence and Entanglement

    SciTech Connect

    Zhang, Yiteng; Kais, Sabre; Berman, Gennady Petrovich

    2015-02-02

    We review the spin radical pair mechanism which is a promising explanation of avian navigation. This mechanism is based on the dependence of product yields on 1) the hyperfine interaction involving electron spins and neighboring nuclear spins and 2) the intensity and orientation of the geomagnetic field. One surprising result is that even at ambient conditions quantum entanglement of electron spins can play an important role in avian magnetoreception. This review describes the general scheme of chemical reactions involving radical pairs generated from singlet and triplet precursors; the spin dynamics of the radical pairs; and the magnetic field dependence of product yields caused by the radical pair mechanism. The main part of the review includes a description of the chemical compass in birds. We review: the general properties of the avian compass; the basic scheme of the radical pair mechanism; the reaction kinetics in cryptochrome; quantum coherence and entanglement in the avian compass; and the effects of noise. We believe that the quantum avian compass can play an important role in avian navigation and can also provide the foundation for a new generation of sensitive and selective magnetic-sensing nano-devices.

  2. Magnetorheological effect in the magnetic field oriented along the vorticity

    SciTech Connect

    Kuzhir, P. Magnet, C.; Fezai, H.; Meunier, A.; Bossis, G.; Rodríguez-Arco, L.; López-López, M. T.; Zubarev, A.

    2014-11-01

    In this work, we have studied the magnetorheological (MR) fluid rheology in the magnetic field parallel to the fluid vorticity. Experimentally, the MR fluid flow was realized in the Couette coaxial cylinder geometry with the magnetic field parallel to the symmetry axis. The rheological measurements were compared to those obtained in the cone-plate geometry with the magnetic field perpendicular to the lower rheometer plate. Experiments revealed a quasi-Bingham behavior in both geometries with the stress level being just a few dozens of percent smaller in the Couette cylindrical geometry at the same internal magnetic field. The unexpectedly high MR response in the magnetic field parallel to the fluid vorticity is explained by stochastic fluctuations of positions and orientations of the particle aggregates. These fluctuations are induced by magnetic interactions between them. Once misaligned from the vorticity direction, the aggregates generate a high stress independent of the shear rate, and thus assimilated to the suspension apparent (dynamic) yield stress. Quantitatively, the fluctuations of the aggregate orientation are modeled as a rotary diffusion process with a diffusion constant proportional to the mean square interaction torque. The model gives a satisfactory agreement with the experimental field dependency of the apparent yield stress and confirms the nearly quadratic concentration dependency ?{sub Y}??{sup 2.2}, revealed in experiments. The practical interest of this study lies in the development of MR smart devices with the magnetic field nonperpendicular to the channel walls.

  3. MD Simulation of Particle Orientation in Magnetic Inks

    NASA Astrophysics Data System (ADS)

    Visscher; Günal

    1997-03-01

    We have done molecular-dynamics type simulations of particle re-orientation in a magnetic colloid, by a magnetic field during tape and disk manufacture. The model takes into account switching (in a Stoner- Wohlfarth model) as well as particle translation and rotation in response to magnetic, steric, Brownian, and hydrodynamic drag forces and torques. Magnetic interactions are fully included; hysteresis loops with and without magnetic interaction will be displayed, with corresponding ? M curves. Images of the network structure at various points of the hysteresis loop will be shown. Further information is available at http:// www.mint.ua.edu/colloids/march.html.

  4. Orientational, kinetic, and magnetic energy of geodynamo, reversals, and asymmetries

    NASA Astrophysics Data System (ADS)

    Starchenko, S. V.

    2015-07-01

    Integral laws describing the evolution of the kinetic, magnetic, and orientational energy in the liquid core of the Earth, which are also valid in the interiors of the other terrestrial planets, are derived, simplified, and analyzed. These laws are coarsely approximated by a system of ordinary differential equations with a given energy of the convection. The characteristic velocities, magnetic fields, periods, and scales as the functions of the power of the convection are estimated for the states beyond and close to the reversal or excursion. With the assumed simplifications, the convection power should be close to a certain value in order to enable a relatively short reversal or excursion; significant deviation of the convection energy from this value will render the system into a long-term steady state. Here, two types of steady state are possible: the codirectional state with the magnetic field oriented along the velocity vector, and contradirectional state with the opposing orientations of the magnetic field and velocity. These states are not symmetric with respect to each other since, other factors being equal, the energy support of the convection and the average intensity of the magnetic field are typically higher in the contradirectional rather than codirectional state. The total duration of codirectional states is somewhat shorter than contradirectional states in the case when the convection power grows with time; in the case of a long-decreasing convection power, the situation is opposite. This asymmetry in the duration of steady states is confirmed by the paleomagnetic data on the timescale of the magnetic reversals. The length of the average interval between the reversals is controlled by the turbulent, thermal, electromagnetic, and visco-compositional diffusion. The predominant type of the diffusion can be in many cases identified from the dependence of the reversal frequency on the intensity of the magnetic field based on the paleomagnetic data. The existing data coarsely testify to the predominance of thermal processes.

  5. FEA Simulations of Magnets with Grain Oriented Steel

    SciTech Connect

    Witte H.

    2012-08-06

    One of the potential successors of the Large Hadron Collider is a Muon Col- lider. Muons are short-lived particles, which therefore require fast acceleration. One potential avenue is a very fast cycling cyclotron, where the bending is sup- plied by a combination of fixed-field superconducting magnets and fast ramping normal conducting iron-cored coils. Due to the high ramping rate (around 1 kHz) eddy current and hysteresis losses are a concern. One way to overcome these is by using grain-oriented soft-iron, which promises superior magnetic properties in the direction of the grains. This note summarizes efforts to include the anisotropic material properties of grain-oriented steel in finite element analysis to predict the behaviour of the dipole magnets for this accelerator. It was found that including anisotropic material properties has a detrimental effect on model convergence. During this study it was not possible to include grain oriented steel with an accuracy necessary to study the field quality of a dipole magnet.

  6. Magnetic anisotropy and organization of nanoparticles in heads and antennae of neotropical leaf-cutter ants, Atta colombica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oriented magnetic nanoparticles have been suggested as a good candidate for a magnetic sensor in ants. Behavioral evidence for a magnetic compass in Neotropical leafcutter ants, Atta colombica (Formicidae: Attini), motivated a study of the arrangement of magnetic particles in the ants’ four major bo...

  7. Orientation dependence of magnetization transfer parameters in human white matter.

    PubMed

    Pampel, André; Müller, Dirk K; Anwander, Alfred; Marschner, Henrik; Möller, Harald E

    2015-07-01

    Quantification of magnetization-transfer (MT) experiments is typically based on a model comprising a liquid pool "a" of free water and a semisolid pool "b" of motionally restricted macromolecules or membrane compounds. By a comprehensive fitting approach, high quality MT parameter maps of the human brain are obtained. In particular, a distinct correlation between the diffusion-tensor orientation with respect to the B0-magnetic field and the apparent transverse relaxation time, T2(b), of the semisolid pool (i.e., the width of its absorption line) is observed. This orientation dependence is quantitatively explained by a refined dipolar lineshape for pool b that explicitly considers the specific geometrical arrangement of lipid bilayers wrapped around a cylindrical axon. The model inherently reduces the myelin membrane to its lipid constituents, which is motivated by previous studies on efficient interaction sites (e.g., cholesterol or galactocerebrosides) in the myelin membrane and on the origin of ultrashort T2 signals in cerebral white matter. The agreement between MT orientation effects and corresponding forward simulations using empirical diffusion imaging results as input as well as results from fits employing the novel lineshape support previous suggestions that the fiber orientation distribution in a voxel can be modeled as a scaled Bingham distribution. PMID:25862261

  8. Perceptual Strategies of Pigeons to Detect a Rotational Centre—A Hint for Star Compass Learning?

    PubMed Central

    Helduser, Sascha; Mouritsen, Henrik; Güntürkün, Onur

    2015-01-01

    Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy. PMID:25807499

  9. Orientation in birds. Magnetic orientation and celestial cues in migratory orientation.

    PubMed

    Wiltschko, W; Wiltschko, R

    1991-01-01

    Young birds on their first migration possess innate information on the direction of their migration route. It is represented twice, using both celestial rotation and the geomagnetic field as references. These two systems, together with information provided by factors associated with sunset, interact in a complex way to establish the migratory direction. During ontogeny, celestial rotation appears to be dominant; during migration, however, celestial cues appear to be controlled by the magnetic field.--The factors associated with sunset--the view of the setting sun and the characteristic pattern of polarized light--are important secondary cues which seem to derive their directional significance from the magnetic field. Their role appears to be more variable, with possible species-specific differences. During spring migration and later autumn migrations, flying in the migratory direction is complemented by navigational processes which enable the birds to return to a specific home site known from previous stays. PMID:1838513

  10. Bats Use Magnetite to Detect the Earth's Magnetic Field Richard A. Holland1,2

    E-print Network

    Kirschvink, Joseph L.

    Bats Use Magnetite to Detect the Earth's Magnetic Field Richard A. Holland1,2 *, Joseph L magnetite (Fe3O4). Bats have recently been shown to use magnetic cues for compass orientation but the method demonstrate that the big brown bat Eptesicus fuscus uses single domain magnetite to detect the Earths magnetic

  11. Testing avian compass calibration: comparative experiments with diurnal and nocturnal passerine migrants in South Sweden

    PubMed Central

    Åkesson, Susanne; Odin, Catharina; Hegedüs, Ramón; Ilieva, Mihaela; Sjöholm, Christoffer; Farkas, Alexandra; Horváth, Gábor

    2015-01-01

    ABSTRACT Cue-conflict experiments were performed to study the compass calibration of one predominantly diurnal migrant, the dunnock (Prunella modularis), and two species of nocturnal passerine migrants, the sedge warbler (Acrocephalus schoenobaenus), and the European robin (Erithacus rubecula) during autumn migration in South Sweden. The birds' orientation was recorded in circular cages under natural clear and simulated overcast skies in the local geomagnetic field, and thereafter the birds were exposed to a cue-conflict situation where the horizontal component of the magnetic field (mN) was shifted +90° or ?90° at two occasions, one session starting shortly after sunrise and the other ca. 90?min before sunset and lasting for 60?min. The patterns of the degree and angle of skylight polarization were measured by full-sky imaging polarimetry during the cue-conflict exposures and orientation tests. All species showed orientation both under clear and overcast skies that correlated with the expected migratory orientation towards southwest to south. For the European robin the orientation under clear skies was significantly different from that recorded under overcast skies, showing a tendency that the orientation under clear skies was influenced by the position of the Sun at sunset resulting in more westerly orientation. This sun attraction was not observed for the sedge warbler and the dunnock, both orientating south. All species showed similar orientation after the cue-conflict as compared to the preferred orientation recorded before the cue-conflict, with the clearest results in the European robin and thus, the results did not support recalibration of the celestial nor the magnetic compasses as a result of the cue-conflict exposure. PMID:25505150

  12. Pigeon orientation: effects of the application of magnets under overcast skies

    NASA Astrophysics Data System (ADS)

    Ioalè, P.

    To verify the existence of a magnetic compass in birds, researchers have often released homing pigeons under overcast skies that are equipped with bar magnets on various parts of their body. In particular, Keeton was successful in finding disorientation in overcast conditions in a first series of tests, but not in a second series. The experiments reported here attempt to explain this contradiction on the basis of findings obtained by releasing pigeons equipped in a way similar to that reported in Keeton's tests and pigeons equipped in a way similar to that reported by other authors.

  13. The Enterprise Compass

    ERIC Educational Resources Information Center

    McCardle, Ken

    2005-01-01

    As a CIO leading an IT department through change and reorganization, the author developed the Enterprise Compass--a four-point guide to reaching goals and focusing achievement. The Enterprise Compass directs staff to look forward to future accomplishment, back for performance assessments, across campus for better understanding of practical working…

  14. Observation of the orientation of membrane protein crystals grown in high magnetic force fields

    NASA Astrophysics Data System (ADS)

    Numoto, Nobutaka; Shimizu, Ken-ichi; Matsumoto, Kazuya; Miki, Kunio; Kita, Akiko

    2013-03-01

    Crystallization of membrane proteins in magnetic fields is thought to reveal the magnetic orientations of crystals, and is expected to enhance crystal quality for X-ray crystallographic analysis. The light-harvesting complex 2 (LH2) from a photosynthetic bacterium, Thermochromatium tepidum was crystallized in steep-gradient magnetic fields. The rod-shaped crystals of LH2 grown in the magnetic fields were oriented parallel to the magnetic field direction. An X-ray diffraction experiment indicated that the overall R value and crystal mosaicity are improved for the magnetically oriented crystal, and the helix bundles of LH2 were located parallel to the magnetic field direction in the crystal packing.

  15. Magnetic Flux Circulation During Dawn-Dusk Oriented Interplanetary Magnetic Field

    NASA Technical Reports Server (NTRS)

    Mitchell, E. J.; Lopez, R. E.; Fok, M.-C.; Deng, Y.; Wiltberger, M.; Lyon, J.

    2010-01-01

    Magnetic flux circulation is a primary mode of energy transfer from the solar wind into the ionosphere and inner magnetosphere. For southward interplanetary magnetic field (IMF), magnetic flux circulation is described by the Dungey cycle (dayside merging, night side reconnection, and magnetospheric convection), and both the ionosphere and inner magnetosphere receive energy. For dawn-dusk oriented IMF, magnetic flux circulation is not well understood, and the inner magnetosphere does not receive energy. Several models have been suggested for possible reconnection patterns; the general pattern is: dayside merging; reconnection on the dayside or along the dawn/dusk regions; and, return flow on dayside only. These models are consistent with the lack of energy in the inner magnetosphere. We will present evidence that the Dungey cycle does not explain the energy transfer during dawn-dusk oriented IMF. We will also present evidence of how magnetic flux does circulate during dawn-dusk oriented IMF, specifically how the magnetic flux reconnects and circulates back.

  16. Magnetic preferential orientation of metal oxide superconducting materials

    DOEpatents

    Capone, Donald W. (Bolingbrook, IL); Dunlap, Bobby D. (Bolingbrook, IL); Veal, Boyd W. (Downers Grove, IL)

    1990-01-01

    A superconductor comprised of a polycrystalline metal oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-X (where 0magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state.

  17. Magnetic preferential orientation of metal oxide superconducting materials

    DOEpatents

    Capone, D.W.; Dunlap, B.D.; Veal, B.W.

    1990-07-17

    A superconductor comprised of a polycrystalline metal oxide such as YBa[sub 2]Cu[sub 3]O[sub 7[minus]X] (where 0 < X < 0.5) exhibits superconducting properties and is capable of conducting very large current densities. By aligning the two-dimensional Cu-O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the conduction of high current densities. The highly anisotropic diamagnetic susceptibility of the polycrystalline metal oxide material permits the use of an applied magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state. 4 figs.

  18. Magnetically simulated displacements In the experiments described in Fig. 3, the orientation arena was surrounded by a magnetic

    E-print Network

    Gu, Xun

    Magnetically simulated displacements In the experiments described in Fig. 3, the orientation arena was surrounded by a magnetic coil system that was used to control the field in which each lobster walked and tested in one of two magnetic fields. One field replicated magnetic conditions that exist at a location

  19. Fiber optic compass development 

    E-print Network

    Park, Kyongtae

    2005-11-01

    7-bit binary code giving coarse heading, using timing information to obtain fine heading, and measuring the apparent width of an analog bar to determine pitch. When monitoring multiple compass heads distributed along the fiber, a time-division...

  20. Bats Use Magnetite to Detect the Earth's Magnetic Field

    PubMed Central

    Holland, Richard A.; Kirschvink, Joseph L.; Doak, Thomas G.; Wikelski, Martin

    2008-01-01

    While the role of magnetic cues for compass orientation has been confirmed in numerous animals, the mechanism of detection is still debated. Two hypotheses have been proposed, one based on a light dependent mechanism, apparently used by birds and another based on a “compass organelle” containing the iron oxide particles magnetite (Fe3O4). Bats have recently been shown to use magnetic cues for compass orientation but the method by which they detect the Earth's magnetic field remains unknown. Here we use the classic “Kalmijn-Blakemore” pulse re-magnetization experiment, whereby the polarity of cellular magnetite is reversed. The results demonstrate that the big brown bat Eptesicus fuscus uses single domain magnetite to detect the Earths magnetic field and the response indicates a polarity based receptor. Polarity detection is a prerequisite for the use of magnetite as a compass and suggests that big brown bats use magnetite to detect the magnetic field as a compass. Our results indicate the possibility that sensory cells in bats contain freely rotating magnetite particles, which appears not to be the case in birds. It is crucial that the ultrastructure of the magnetite containing magnetoreceptors is described for our understanding of magnetoreception in animals. PMID:18301753

  1. Journal of Magnetism and Magnetic Materials 300 (2006) 127131 Electric current-induced spin orientation in quantum well structures

    E-print Network

    Ganichev, Sergey

    2006-01-01

    Journal of Magnetism and Magnetic Materials 300 (2006) 127­131 Electric current-induced spin is the orientation of spins by an electrical current flowing through low-dimensional carrier systems of sufficiently to orient the spin of charge carriers in GaAs based quantum wells (QWs) by driving an electric current

  2. Interplanetary magnetic field orientation for transient events in the outer magnetosphere

    SciTech Connect

    Sibeck, D.G.; Newell, P.T.

    1995-01-01

    It is generally believed that flux transfer events (FTEs) in the outer dayside magnetosphere, usually by transient bipolar magnetic field perturbations in the direction normal to the nominal magnetopause, occur when the magnetosheath magnetic field has a southward component. The authors compare the results of three methods for determining the magnetosheath magnetic field orientation at the times of previously identified UKS/IRM events: (1) the average magnetosheath magnetic field orientation in the 30-min period adjacent to the nearest magnetopause crossing, (2) the magnetosheath magnetic field orientation observed just outside the magnetopause, and (3) the lagged interplanetary magnetic field (IMF) orientation at the time of the transient events. Whereas the results of method 2 indicate that the events tend to occur for a southward magnetosheath magnetic field, the results of methods 1 and 3 show no such tendency. The fact that the three methods yield significantly different results emphasizes the need for caution in future studies. 23 refs., 5 figs., 1 tab.

  3. Friction and scratch resistance of polymer liquid crystals: Effects of magnetic field orientation

    E-print Network

    North Texas, University of

    Friction and scratch resistance of polymer liquid crystals: Effects of magnetic field orientation oriented along and perpendicularly to the flux of the magnetic field, were investigated. Static friction, dynamic friction, scratch penetration depth, and healing of the material were determined. Static

  4. Amorphous soft magnetic composite-cores with various orientations of the powder-flakes

    NASA Astrophysics Data System (ADS)

    Zheng, Y. Y.; Wang, Y. G.; Xia, G. T.

    2015-12-01

    Fe78Si9B13 amorphous powder cores were prepared by cold pressing the amorphous powders crushed from amorphous ribbons and orientated with an external magnetic field. Three orientations of magnetic powder cores were obtained: (i) the disorderedly orientated amorphous magnetic powder core (DOAMP), (ii) the circularly orientated amorphous magnetic powder core (COAMP), and (iii) the radially orientated amorphous magnetic powder core (ROAMP). The effect of the shape anisotropy of the flake powders on the magnetic properties of the powder cores was investigated. The powders parallel to external magnetic field is beneficial for achieving the excellent performance of the cores. Below 100 kHz the product of the effective permeability and the quality factor of COAMP core increases by 9.1% and 21.2% compared to that of the DOAMP and the ROAMP cores, respectively, while the coercive field and the magnetic induction intensity keep almost the same. Pressing magnetic powders under a magnetic field to form preferred orientation is suitable for optimal design of soft magnetic cores toward practical applications.

  5. Rapid Learning of Magnetic Compass Direction by C57BL/6 Mice in a 4-Armed `Plus' Water Maze

    E-print Network

    Phillips, John B.

    by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study in a 4-armed (plus) water maze. Naïve mice were given two brief training trials. In each trial, a mouse that the mouse had to swim in the same magnetic direction to reach the submerged platform. The directional

  6. Lodestone Compass: Chinese or Olmec Primacy?: Multidisciplinary analysis of an Olmec hematite artifact from San Lorenzo, Veracruz, Mexico.

    PubMed

    Carlson, J B

    1975-09-01

    Considering the unique morphology (purposefully shaped polished bar with a groove) and composition (magnetic mineral with magnetic moment vector in the floating plane) of M-160, and acknowledging that the Olmec were a sophisticated people who possessed advanced knowledge and skill in working iron ore minerals, I would suggest for consideration that the Early Formative artifact M-160 was probably manufactured and used as what I have called a zeroth-order compass, if not a first-order compass. The data I have presented in this article support this hypothesis, although they are not sufficient to prove it. That M-160 could be used today as a geomagnetically directed pointer is undeniable. The original whole bar may indeed have pointed close to magnetic north-south. The groove functions well as a sighting mark, and the slight angle it makes with the axis of the bar appears to be the result of calibration rather than accident. A negative supporting argument is that M-160 looks utilitarian rather than decorative, and no function for the object other than that of a compass pointer has been suggested by anyone who has examined it critically. Whether such a pointer would have been used to point to something astronomical (zeroth-order compass) or to geomagnetic north-south (first-order compass) is entirely open to speculation. The observation of the family of Olmec site alignments 8 degrees west of north is a curiosity in its own right, and the possibility that these alignments have an astronomical or geomagnetic origin should be explored. I also believe that it is constructive to compare the first millennium Chinese, who used the lodestone compass for geomancy, with the Gulf Coast Olmec since both were agrarian-terrestrial societies. The Olmec's apparent concern with orientation and skillful use of magnetic minerals also stimulates one to draw cross-cultural parallels. The evidence and analysis offered in this article provide a basis for hypotheses of parallel cultural developments in China and the Olmec New World. If the Olmec did discover the geomagnetic orienting properties of lodestone, as did the Han Chinese, it is most reasonable to speculate that they would have used their compass for comparable geomantic purposes. It should, however, be recognized that the Olmec claim, if documented, predates the Chinese discovery of the geomagnetic lodestone compass by more than a millennium. At present, M-160 is a unique artifact and San Lorenzo a unique site: "The first civilized center of Mesoamerica and probably of the New World" (19, p. 89). Further documentation of the Olmec claim must await the discovery of similar artifacts in museums, private collections, or as yet undiscovered Olmec sites. I would welcome communications from anyone possessing information relating to such artifacts. Regardless of shape, purposefully grooved and highly polished specimens of magnetic minerals are of particular interest. It would also be useful for the archeologist excavating Olmec burials and offerings to carefully note their alignments and consider them in a geomantic context. In addition to the discovery of supporting artifacts, establishment of Olmec primacy of the lodestone compass depends on the acquisition of the archeomagnetic data for the Early Formative period. I appeal to archeologists who find good archeomagnetic samples (burned hearths and post-holes) from the Formative periods to convey this information to R. DuBois of the University of Oklahoma. In a few years, the archeomagnetic data should be available for the last three millennia and the possibilities are very exciting. PMID:17777565

  7. Monolithic integration of focused 2D GMR spin valve magnetic field sensor for high-sensitivity (compass) applications (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Ueberschär, Olaf; Almeida, Maria J.; Matthes, Patrick; Müller, Mathias; Ecke, Ramona; Exner, Horst; Schulz, Stefan E.

    2015-09-01

    We have designed and fabricated 2D GMR spin valve sensors on the basis of IrMn/CoFe/Cu/CoFe/NiFe nanolayers in monolithic integration for high sensitivity applications. For a maximum signal-to-noise ratio, we realize a focused double full bridge layout featuring an antiparallel exchange bias pinning for neighbouring meanders and an orthogonal pinning for different bridges. This precise alignment is achieved with microscopic precision by laser heating and subsequent in-field cooling. Striving for maximum signal sensitivity and minimum hysteresis, we study in detail the impact of single meander geometry on the total magnetic structure and electronic transport properties. The investigated geometrical parameters include stripe width, stripe length, cross bar material and total meander length. In addition, the influence of the relative alignment between reference magnetization (pinned layer) and shape anisotropy (free layer) is studied. The experimentally obtained data are moreover compared to the predictions of tailored micromagnetic simulations. Using a set of optimum parameters, we demonstrate that our sensor may readily be employed to measure small magnetic fields, such as the ambient (geomagnetic) field, in terms of a 2D vector with high spatial (~200 ?m) and temporal (~1 ms) resolution.

  8. A molecular compass for bird navigation

    NASA Astrophysics Data System (ADS)

    Hore, Peter

    2015-03-01

    Migratory birds travel spectacular distances, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the sensing of such weak fields (25-65 microtesla) are scarce and in recent years just two proposals have emerged as frontrunners. One involves biogenic iron-containing nanoparticles; the other relies on the magnetic sensitivity of short-lived photochemical intermediates known as radical pairs. The latter began to attract attention following the proposal 15 years ago that the necessary physics and chemistry could take place in the bird's retina in specialised photoactive proteins called cryptochromes. The coherent dynamics of the electron-nuclear spin systems of pairs of photo-induced radicals is conjectured to form the basis of the sensing mechanism even though the interaction of an electron spin with the geomagnetic field is six orders of magnitude smaller than the thermal energy. The possibility that slowing decohering, entangled electron spins could form the basis of an important sensory mechanism has qualified radical pair magnetoreception for a place under the umbrella of ``Quantum Biology.'' In this talk, I will introduce the radical pair mechanism, comment on the roles of entanglement and quantum coherence, outline some of the experimental evidence for the cryptochrome hypothesis, and summarize what still needs to be done to determine whether birds (and maybe other animals) really do use a chemical compass to find their way around. This work was supported by grants from DARPA, AFOSR, ERC and the EMF Biological Research Trust.

  9. Object-Oriented Fast Multipole Simulation: Magnetic Colloids

    NASA Astrophysics Data System (ADS)

    Visscher, Pieter; Günal, Yüksel

    1997-08-01

    In simulating a system of N particles, if the interaction is long-ranged all pair interactions must be calculated, requiring CPU time of order N^2. Recently-developed ``fast multipole'' methods (FMM) can reduce this time to order N, at the cost of considerable programming complexity. We have developed an object-oriented approach which uses similar ideas but is conceptually much simpler. The system is represented by a hierarchical tree whose root is the entire system and whose lowest nodes are the particles. The entire calculation of the particle interactions consists of a single call to a recursive function CalculateInteractions(A,B) with A=B=root, which uses a simple opening-angle criterion to choose between multipole expansion and calling itself (subdividing A and B.) The resulting algorithm is essentially equivalent to the FMM, but the choice of when to subdivide (which is laboriously hard-wired in FMM) is made automatically. We will discuss the implementation of periodic BCs and the application of the method to continuum systems (cylindrical magnetic particles).

  10. Two-stage magnetic orientation of uric acid crystals as gout initiators

    NASA Astrophysics Data System (ADS)

    Takeuchi, Y.; Miyashita, Y.; Mizukawa, Y.; Iwasaka, M.

    2014-01-01

    The present study focuses on the magnetic behavior of uric acid crystals, which are responsible for gout. Under a sub-Tesla (T)-level magnetic field, rotational motion of the crystals, which were caused by diamagnetic torque, was observed. We used horizontal magnetic fields with a maximum magnitude of 500 mT generated by an electromagnet to observe the magnetic orientation of the uric acid microcrystals by a microscope. The uric acid crystals showed a perpendicular magnetic field orientation with a minimum threshold of 130 mT. We speculate that the distinct diamagnetic anisotropy in the uric acid crystals resulted in their rotational responses.

  11. Bow Compass with Case

    USGS Multimedia Gallery

    Bow Compass with Case. Also known as a Drop Bow Pen or Spring Bow, serial #760 C. This instrument was made by Eugene Dietzgen & Company, Chicago and New York and used by the U.S. Geological Survey Topographic Branch after 1945-1960s. Object ID: USGS-000645...

  12. Compassion: Practical Classroom Activities

    ERIC Educational Resources Information Center

    Wong, Lily; Duffy, Roslyn Ann

    2010-01-01

    Compassion is a deep feeling of sharing the suffering of another. It is a mixture of words, thoughts, and actions that allow a child to be sympathetic to the needs of others. Young children today witness many conflicting values. Values promoted in the media and popular culture often glorify disrespect and unkindness, with beauty and possessions…

  13. 78 FR 35073 - Compass Efficient Model Portfolios, LLC and Compass EMP Funds Trust; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... COMMISSION Compass Efficient Model Portfolios, LLC and Compass EMP Funds Trust; Notice of Application June 4.... Applicants: Compass Efficient Model Portfolios, LLC (the ``Adviser'') and Compass EMP Funds Trust (``the... are Compass EMP U.S. 500 Volatility Weighted Fund, Compass EMP U.S. Small Cap 500 Volatility...

  14. Orientation by solidification in a magnetic field: A new process to texture SmCo compounds used as permanent magnets

    NASA Astrophysics Data System (ADS)

    Legrand, B. A.; Chateigner, D.; Perrier de la Bathie, R.; Tournier, R.

    1997-02-01

    The solidification of molten alloys in a static magnetic field is proposed as a new way of orienting polycrystalline materials. A high degree of orientation is obtained with samarium-cobalt compounds solidified in a static magnetic field. Whatever the cooling condition used from the liquid state, a magnetic field of several tesla induces crystallographic orientation in the solid. The easy magnetization axis of the polycrystal lies along the direction of the field applied during solidification. This texturing process is applied to the elaboration of Sm 2Co 17 permanent magnets. Anisotropic bulk magnets with a coercive field up to 2250 kA/m and energy product above 160 kJ/m 3 are obtained. This process provides an alternative to the currently used industrial technology which is based on powder metallurgy. The paramagnetic susceptibility of the substituted Sm 2Co 17 compounds is measured at high temperatures from which the susceptibility anisotropy at solidification temperature is determined. The orientation of the sample, solidified in a cold induction crucible, is analysed as a function of the applied magnetic field. Assuming a model in which particles are free to orient before complete solidification takes place, a critical size of these particles is deduced.

  15. The role of the sun in the celestial compass of dung beetles

    PubMed Central

    Dacke, M.; el Jundi, Basil; Smolka, Jochen; Byrne, Marcus; Baird, Emily

    2014-01-01

    Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day. PMID:24395963

  16. Electro-optical sun compass with a very high degree of accuracy.

    PubMed

    Bollanti, Sarah; De Meis, Domenico; Di Lazzaro, Paolo; Flora, Francesco; Gallerano, Gian Piero; Mezi, Luca; Murra, Daniele; Torre, Amalia; Vicca, Davide

    2015-08-01

    We present a novel electro-optical solar compass that is able to determine the true North direction with an accuracy better than 1/100 of degree, superior to that of any other magnetic or electronic compass that does not resort to differential GPS. The compass has an electronic sensor to determine the line of sight of the Sun and a simple but effective algorithm to calculate the position of the Sun. The excellent results obtained during the experimental tests demonstrate the advantages of this compass, which is also compact and not expensive. PMID:26258372

  17. Noncontact orientation of objects in three-dimensional space using magnetic levitation

    PubMed Central

    Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K.; Soh, Siowling; Whitesides, George M.

    2014-01-01

    This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media. PMID:25157136

  18. Noncontact orientation of objects in three-dimensional space using magnetic levitation.

    PubMed

    Subramaniam, Anand Bala; Yang, Dian; Yu, Hai-Dong; Nemiroski, Alex; Tricard, Simon; Ellerbee, Audrey K; Soh, Siowling; Whitesides, George M

    2014-09-01

    This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media. PMID:25157136

  19. Interplanetary magnetic field orientation for transient events in the outer magnetosphere

    NASA Technical Reports Server (NTRS)

    Sibeck, D. G.; Newell, P. T.

    1995-01-01

    It is generally believed that flux transfer events (FTEs) in the outer dayside magneosphere, usually identified by transient (approximately 1 min) bipolar magneitc field perturbations in the direction normal to the nominal magnetopause, occur when the magnetosheath magetic field has a southward component. We compare the results of three methods for determining the magnetosheath magnetic field orientationat the times of previously identified UKS/IRM events: (1) the average magnetosheath magnetic field orientation in the 30-min period adjacent to the nearest magnetopause crossing, (2) the magnetosheath magnetic field orientation observed just outside the magnetopause, and (3) the lagged interplanetary magnetic field (IMF) orientation at the time of the transient events. Whereas the results of method 2 indicate that the events tend to occur for a southward magnetosheath magnetic field, the results of methods 1 and 3 show no such tnedency. The fact that the three methods yield significantly diffeent results emphasizes the need for caution in future studies.

  20. Estimating body segment orientation by applying inertial and magnetic sensing near ferromagnetic materials.

    PubMed

    Roetenberg, Daniel; Baten, Chris T M; Veltink, Peter H

    2007-09-01

    Inertial and magnetic sensors are very suitable for ambulatory monitoring of human posture and movements. However, ferromagnetic materials near the sensor disturb the local magnetic field and, therefore, the orientation estimation. A Kalman-based fusion algorithm was used to obtain dynamic orientations and to minimize the effect of magnetic disturbances. This paper compares the orientation output of the sensor fusion using three-dimensional inertial and magnetic sensors against a laboratory bound opto-kinetic system (Vicon) in a simulated work environment. With the tested methods, the difference between the optical reference system and the output of the algorithm was 2.6 degrees root mean square (rms) when no metal was near the sensor module. Near a large metal object instant errors up to 50 degrees were measured when no compensation was applied. Using a magnetic disturbance model, the error reduced significantly to 3.6 degrees rms. PMID:17894280

  1. Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome

    PubMed Central

    Wiltschko, Roswitha; Wiltschko, Wolfgang

    2014-01-01

    Birds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but can adapt to other intensities, (2) it is an “inclination compass”, not based on the polarity of the magnetic field, but the axial course of the field lines, and (3) it requires short-wavelength light from UV to 565 nm Green. The Radical Pair-Model of magnetoreception can explain these properties by proposing spin-chemical processes in photopigments as underlying mechanism. Applying radio frequency fields, a diagnostic tool for radical pair processes, supports an involvement of a radical pair mechanism in avian magnetoreception: added to the geomagnetic field, they disrupted orientation, presumably by interfering with the receptive processes. Cryptochromes have been suggested as receptor molecules. Cry1a is found in the eyes of birds, where it is located at the membranes of the disks in the outer segments of the UV-cones in chickens and robins. Immuno-histochemical studies show that it is activated by the wavelengths of light that allow magnetic compass orientation in birds. PMID:25587420

  2. Sensing magnetic directions in birds: radical pair processes involving cryptochrome.

    PubMed

    Wiltschko, Roswitha; Wiltschko, Wolfgang

    2014-09-01

    Birds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but can adapt to other intensities, (2) it is an "inclination compass", not based on the polarity of the magnetic field, but the axial course of the field lines, and (3) it requires short-wavelength light from UV to 565 nm Green. The Radical Pair-Model of magnetoreception can explain these properties by proposing spin-chemical processes in photopigments as underlying mechanism. Applying radio frequency fields, a diagnostic tool for radical pair processes, supports an involvement of a radical pair mechanism in avian magnetoreception: added to the geomagnetic field, they disrupted orientation, presumably by interfering with the receptive processes. Cryptochromes have been suggested as receptor molecules. Cry1a is found in the eyes of birds, where it is located at the membranes of the disks in the outer segments of the UV-cones in chickens and robins. Immuno-histochemical studies show that it is activated by the wavelengths of light that allow magnetic compass orientation in birds. PMID:25587420

  3. The COMPASS Project

    NASA Astrophysics Data System (ADS)

    Duley, A. R.; Sullivan, D.; Fladeland, M. M.; Myers, J.; Craig, M.; Enomoto, F.; Van Gilst, D. P.; Johan, S.

    2011-12-01

    The Common Operations and Management Portal for Airborne Science Systems (COMPASS) project is a multi-center collaborative effort to advance and extend the research capabilities of the National Aeronautics and Space Administration's (NASA) Airborne Science Program (ASP). At its most basic, COMPASS provides tools for visualizing the position of aircraft and instrument observations during the course of a mission, and facilitates dissemination, discussion, and analysis and of multiple disparate data sources in order to more efficiently plan and execute airborne science missions. COMPASS targets a number of key objectives. First, deliver a common operating picture for improved shared situational awareness to all participants in NASA's Airborne Science missions. These participants include scientists, engineers, managers, and the general public. Second, encourage more responsive and collaborative measurements between instruments on multiple aircraft, satellites, and on the surface in order to increase the scientific value of these measurements. Fourth, provide flexible entry points for data providers to supply model and advanced analysis products to mission team members. Fifth, provide data consumers with a mechanism to ingest, search and display data products. Finally, embrace an open and transparent platform where common data products, services, and end user components can be shared with the broader scientific community. In pursuit of these objectives, and in concert with requirements solicited by the airborne science research community, the COMPASS project team has delivered a suite of core tools intended to represent the next generation toolset for airborne research. This toolset includes a collection of loosely coupled RESTful web-services, a system to curate, register, and search, commonly used data sources, end-user tools which leverage web socket and other next generation HTML5 technologies to aid real time aircraft position and data visualization, and an extensible a framework to rapidly accommodate mission specific requirements and mission tools.

  4. Prediction of particle orientation in simple upsetting process of NdFeB magnets

    SciTech Connect

    Chang, Chao-Cheng; Hsiao, Po-Jen; You, Jr-Shiang; Chen, Yen-Ju; Chang, Can-Xun

    2013-12-16

    The magnetic properties of NdFeB magnets are strongly affected by crystallographic texture which is highly associated with particle orientation. This study proposed a method for predicting the particle orientation in the simple upsetting process of NdFeB magnets. The method is based on finite element simulation with flow net analysis. The magnets in a cylindrical form were compressed by two flat dies in a chamber filled with argon at 750°C. Three forming speeds were taken into account in order to obtain flow stress curves used in simulations. The micrographs of the cross sections of the deformed magnets show that the particle deformation significantly increases with the compression. The phenomenon was also predicted by the proposed method. Both simulated and experimental results show that the inhomogeneity of the texture of the NdFeB magnets can be increased by the simple upsetting process. The predicted particle orientations were in a good agreement with those examined in the deformed magnets. The proposed method for predicting particle orientations can also be used in other forming processes of NdFeB magnets.

  5. Magnetic field distortions produced by protective cages around sea turtle nests: unintended consequences for orientation

    E-print Network

    Lohmann, Kenneth J.

    Magnetic field distortions produced by protective cages around sea turtle nests: unintended field plays an important role in the orientation and navigation of sea turtles. Galvanized steel wire; Magnetoreception; Sea turtle conservation; Sea turtle 1. Introduction The EarthÕs magnetic field plays an important

  6. Orientation and thickness dependence of magnetization at the interfacesof highly spin-polarized manganite thin films

    SciTech Connect

    Chopdekar, Rajesh V.; Arenholz, Elke; Suzuki, Y.

    2008-08-18

    We have probed the nature of magnetism at the surface of (001), (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films. The spin polarization of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films is not intrinsically suppressed at all surfaces and interfaces but is highly sensitive to both the epitaxial strain state as well as the substrate orientation. Through the use of soft x-ray spectroscopy, the magnetic properties of (001), (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interfaces have been investigated and compared to bulk magnetometry and resistivity measurements. The magnetization of (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interfaces are more bulk-like as a function of thickness whereas the magnetization at the (001)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interface is suppressed significantly below a layer thickness of 20 nm. Such findings are correlated with the biaxial strain state of the La{sub 0.7}Sr{sub 0.3}MnO{sub 3} films; for a given film thickness it is the tetragonal distortion of (001) La{sub 0.7}Sr{sub 0.3}MnO{sub 3} that severely impacts the magnetization, whereas the trigonal distortion for (111)-oriented films and monoclinic distortion for (110)-oriented films have less of an impact. These observations provide evidence that surface magnetization and thus spin polarization depends strongly on the crystal surface orientation as well as epitaxial strain.

  7. Drastic effect of V film orientation on the Fe adatoms magnetism

    NASA Astrophysics Data System (ADS)

    Yartseva, N. S.; Yartsev, S. V.; Demangeat, C.

    2015-11-01

    Effect of surface orientation of nonmagnetic bed material on magnetic properties of the peculiar magnetic adatoms groups (MAGs) is found by simulation. Here we present the results of periodic Anderson model calculations for MAGs on V. The MAGs are formed of the Fe adatoms arranged in triangles, ovals, or short chains and placed over V substrate with (001) or (110) surface orientation. It is shown that magnetism of the Fe-MAGs on V(001) surface can be totally suppressed by the V surroundings, whereas the V(110) surface orientation results in magnetization of the Fe-MAGs and onset of noncollinear atomic moments distribution. Noncollinearity strictly depends on symmetry of the Fe-MAG.

  8. Daytime TV's day of compassion for AIDS.

    PubMed

    McFarlane, R

    1995-07-01

    Daytime television's national Day of Compassion programming, a Hollywood Supports-sponsored event where entire shows and storylines were devoted to HIV/AIDS topics, is highlighted. Programming successes are examined, including cable TV's contribution to the event and the general public's approval. Richard Jennings of Hollywood Supports, the entertainment industry group that works to counter workplace fears and discrimination based on HIV status and sexual orientation, states that he and his group are aiming at prime time next year. This mission is particularly important now given the tenor of hateful distortion about people with AIDS from the religious right and the current mood of Congress towards AIDS-related funding. PMID:11362727

  9. Cultivating Compassion: Rhetoric or Reality?

    ERIC Educational Resources Information Center

    Lovette-Colyer, Michael

    2014-01-01

    Despite the massive amounts of research conducted on the effect of college on students, almost no empirical work has been done on whether students grow in compassion during their undergraduate studies. Designed to address this gap, this longitudinal study of more than 500 students found that the majority demonstrated change in compassion across…

  10. An Orientation Measurement Method Based on Hall-effect Sensors for Permanent Magnet Spherical Actuators with 3D Magnet Array

    PubMed Central

    Yan, Liang; Zhu, Bo; Jiao, Zongxia; Chen, Chin-Yin; Chen, I-Ming

    2014-01-01

    An orientation measurement method based on Hall-effect sensors is proposed for permanent magnet (PM) spherical actuators with three-dimensional (3D) magnet array. As there is no contact between the measurement system and the rotor, this method could effectively avoid friction torque and additional inertial moment existing in conventional approaches. Curved surface fitting method based on exponential approximation is proposed to formulate the magnetic field distribution in 3D space. The comparison with conventional modeling method shows that it helps to improve the model accuracy. The Hall-effect sensors are distributed around the rotor with PM poles to detect the flux density at different points, and thus the rotor orientation can be computed from the measured results and analytical models. Experiments have been conducted on the developed research prototype of the spherical actuator to validate the accuracy of the analytical equations relating the rotor orientation and the value of magnetic flux density. The experimental results show that the proposed method can measure the rotor orientation precisely, and the measurement accuracy could be improved by the novel 3D magnet array. The study result could be used for real-time motion control of PM spherical actuators. PMID:25342000

  11. Magnetic properties and dynamic domain behavior in grain-oriented 3% Si-Fe

    SciTech Connect

    Nozawa, Tadao; Mizogami, Masato; Mogi, Hisasi; Matsuo, Yukio

    1996-03-01

    The magnetic properties of soft magnetic materials are based on dynamic behavior of magnetic domain walls. Many domain structure studies have contributed to the progress of magnetic materials. In this paper, the present state of new development in advanced grain-oriented silicon steel is introduced through the aid of dynamic domain observation of real materials with forsterite film. The basic magnetic phenomena of material, such as the dynamic behavior of surface closure domains, domain wall pinning, and domain structure under rotating magnetization, are explained mainly through the observation of static and dynamic domain wall movements under a high-voltage scanning electron microscope. A few techniques for manufacturing the latest grain-oriented silicon steel, such as improvement in alignment with (110) [001] orientation, increase in the number of mobile domain walls, and relaxation of domain wall pinning, are also described through the observation of dynamic domain patterns. Examples of core losses are given for ideal grain-oriented silicon steel as industrial material, and future developments are predicted.

  12. Quantitative vertebral compression fracture evaluation using a height compass

    NASA Astrophysics Data System (ADS)

    Yao, Jianhua; Burns, Joseph E.; Wiese, Tatjana; Summers, Ronald M.

    2012-03-01

    Vertebral compression fractures can be caused by even minor trauma in patients with pathological conditions such as osteoporosis, varying greatly in vertebral body location and compression geometry. The location and morphology of the compression injury can guide decision making for treatment modality (vertebroplasty versus surgical fixation), and can be important for pre-surgical planning. We propose a height compass to evaluate the axial plane spatial distribution of compression injury (anterior, posterior, lateral, and central), and distinguish it from physiologic height variations of normal vertebrae. The method includes four steps: spine segmentation and partition, endplate detection, height compass computation and compression fracture evaluation. A height compass is computed for each vertebra, where the vertebral body is partitioned in the axial plane into 17 cells oriented about concentric rings. In the compass structure, a crown-like geometry is produced by three concentric rings which are divided into 8 equal length arcs by rays which are subtended by 8 common central angles. The radius of each ring increases multiplicatively, with resultant structure of a central node and two concentric surrounding bands of cells, each divided into octants. The height value for each octant is calculated and plotted against octants in neighboring vertebrae. The height compass shows intuitive display of the height distribution and can be used to easily identify the fracture regions. Our technique was evaluated on 8 thoraco-abdominal CT scans of patients with reported compression fractures and showed statistically significant differences in height value at the sites of the fractures.

  13. Magnetic properties of biaxially oriented Ni-V substrates

    SciTech Connect

    Bettinelli, D.; Petrisor, T.; Gambardella, U.; Boffa, V.; Ceresara, S.; Nistor, L.; Pop, V.; Scardi, P.

    1999-04-20

    The paper presents the structural and magnetic properties of a new non-magnetic biaxially textured substrate based on Ni{sub 100{minus}x}V{sub x} solid-solution for YBa{sub 2}Cu{sub 3}O{sub 7{minus}y} tape fabrication. The effective atomic magnetic moment monotonously decreases with the vanadium concentration, causing a corresponding decrease of Curie temperature. The Curie temperature reaches the zero value at about 11.5% of vanadium. The texturing studies revealed that (100)[-001] cube texture can be easily developed up to x = 11 at.%, by a cold rolling process followed by a recrystallization thermal treatment. The X-ray {omega} and {phi} scans have demonstrated that the samples have a good out-of-plane and in-plane texture for the whole solubility range, with FWHM of 7{degree} and 11{degree}, respectively. The correlation between the magnetic and structural anisotropy was also studied.

  14. Orientation of X Lines in Asymmetric Magnetic Reconnection-Mass Ratio Dependency

    NASA Technical Reports Server (NTRS)

    Liu, Yi-Hsin; Hesse, M.; Kuznetsova, M.

    2015-01-01

    Using fully kinetic simulations, we study the X line orientation of magnetic reconnection in an asymmetric configuration. A spatially localized perturbation is employed to induce a single X line, which has sufficient freedom to choose its orientation in three-dimensional systems. The effect of ion to electron mass ratio is investigated, and the X line appears to bisect the magnetic shear angle across the current sheet in the large mass ratio limit. The orientation can generally be deduced by scanning through the corresponding 2-D simulations to find the reconnection plane that maximizes the peak reconnection electric field. The deviation from the bisection angle in the lower mass ratio limit is consistent with the orientation shift of the most unstable linear tearing mode in an electron-scale current sheet.

  15. Estimating Three-Dimensional Orientation of Human Body Parts by Inertial/Magnetic Sensing

    PubMed Central

    Sabatini, Angelo Maria

    2011-01-01

    User-worn sensing units composed of inertial and magnetic sensors are becoming increasingly popular in various domains, including biomedical engineering, robotics, virtual reality, where they can also be applied for real-time tracking of the orientation of human body parts in the three-dimensional (3D) space. Although they are a promising choice as wearable sensors under many respects, the inertial and magnetic sensors currently in use offer measuring performance that are critical in order to achieve and maintain accurate 3D-orientation estimates, anytime and anywhere. This paper reviews the main sensor fusion and filtering techniques proposed for accurate inertial/magnetic orientation tracking of human body parts; it also gives useful recipes for their actual implementation. PMID:22319365

  16. Spin orientation, structure, morphology, and magnetic properties of hematite nanoparticles

    NASA Astrophysics Data System (ADS)

    Xu, S.; Habib, A. H.; Gee, S. H.; Hong, Y. K.; McHenry, M. E.

    2015-05-01

    Monodisperse hematite (?-Fe2O3) nanoparticles were synthesized by forced hydrolysis of acidic Fe3+ solution. Rietveld analysis was applied to the X-ray powder diffraction data to refine the lattice constants and atomic positions. The lattice constants for a hexagonal unit cell were determined to be a ˜ 0.50327 and c ˜ 1.37521 nm. High resolution transmission electron microscopy was employed to study the morphology of the particles. Atomic scale micrographs and diffraction patterns from several zone axes were obtained. These reveal the high degree of crystallinity of the particles. A series of observations made on the particles by tilting them through a range of ±45° revealed the particles to be micaceous with stacking of platelets with well defined crystallographic orientations. The Morin transition in these nanoparticles was found to occur at 210 K, which is lower temperature than 263 K of bulk hematite. It was ascertained from the previous Mössbauer studies that the spin orientation for nano-sized hematite particle flips from 90° to 28° with respect to the c-axis of the hexagonal structure during the Morin transition, which is in contrast to that observed in bulk hematite where spin orientation flips from 90° to 0°.

  17. Spin orientation, structure, morphology, and magnetic properties of hematite nanoparticles

    SciTech Connect

    Xu, S.; Habib, A. H.; Gee, S. H.; Hong, Y. K.; McHenry, M. E.

    2015-05-07

    Monodisperse hematite (?-Fe{sub 2}O{sub 3}) nanoparticles were synthesized by forced hydrolysis of acidic Fe{sup 3+} solution. Rietveld analysis was applied to the X-ray powder diffraction data to refine the lattice constants and atomic positions. The lattice constants for a hexagonal unit cell were determined to be a???0.50327 and c???1.37521?nm. High resolution transmission electron microscopy was employed to study the morphology of the particles. Atomic scale micrographs and diffraction patterns from several zone axes were obtained. These reveal the high degree of crystallinity of the particles. A series of observations made on the particles by tilting them through a range of ±45° revealed the particles to be micaceous with stacking of platelets with well defined crystallographic orientations. The Morin transition in these nanoparticles was found to occur at 210?K, which is lower temperature than 263?K of bulk hematite. It was ascertained from the previous Mössbauer studies that the spin orientation for nano-sized hematite particle flips from 90° to 28° with respect to the c-axis of the hexagonal structure during the Morin transition, which is in contrast to that observed in bulk hematite where spin orientation flips from 90° to 0°.

  18. Local Magnetic Properties in Non-oriented Electrical Steel and Their Dependence on Magnetic Easy Axis and Misorientation Parameters

    NASA Astrophysics Data System (ADS)

    Gallaugher, Matthew; Samimi, Arash; Krause, Thomas W.; Clapham, Lynann C.; Chromik, Richard R.

    2015-03-01

    An understanding of how material parameters, especially orientation and misorientation, influence the magnetic properties of non-oriented electrical steel (NOES) is important for improving the efficiency of the material in service. In this study, the local magnetic properties were measured using magnetic Barkhausen noise (MBN) on different test locations on different strips of NOES material. Local variations in magnetic properties, texture, and misorientation were revealed. A new interpretation for misorientation, called the easy axis misorientation (EAM), was created to describe the alignment of the magnetic easy axes between neighboring grains. This new EAM, visualized as a single value parameter or graphed as a distribution, was shown to be more effective at predicting the isotropic magnetic properties than previously used texture parameters based on standard orientation/misorientation definitions. It was found that a larger EAM value, especially when associated with a lower small angle EAM intensity distribution, was associated with a larger MBN energy. A larger MBN energy has been previously associated with lower losses, and therefore a greater material efficiency.

  19. Field orientation dependent decorrelation of magnetization reversal in uniaxial Co-films

    NASA Astrophysics Data System (ADS)

    Arregi, J. A.; Idigoras, O.; Vavassori, P.; Berger, A.

    2012-06-01

    Magnetization reversal correlation is studied as a function of the applied field angle for thin Co-films showing in-plane uniaxial magnetocrystalline anisotropy. We find that the field orientation angle has a profound effect onto the magnetization reversal process leading to a suppression of long-range correlation at sufficiently large field angles in the presence of grain alignment disorder. Correspondingly, this behavior allows for a tuning and the local confinement of magnetization reversal even in strongly exchange-coupled films and therefore presents a most desirable scenario for ultrahigh density magnetic recording.

  20. Effects of Instructional Technology Integration Strategies in Orientation Programs on Nurse Retention in Magnet and Non-Magnet Hospitals

    ERIC Educational Resources Information Center

    Hancharik, Sharon D.

    2008-01-01

    This applied dissertation study was designed to learn if the increased use of instructional technology integration strategies in nursing orientation programs resulted in an increased retention of new nurses. The study attempted to uncover the current retention rate and use of technology at the participating hospitals. The data obtained from Magnet

  1. The effect of interplanetary magnetic field orientation on the solar wind flux impacting Mercury's surface

    NASA Astrophysics Data System (ADS)

    Varela, J.; Pantellini, F.; Moncuquet, M.

    2015-12-01

    The aim of this paper is to study the plasma flows on the Mercury surface for different interplanetary magnetic field orientations on the day side of the planet. We use a single fluid MHD model in spherical coordinates to simulate the interaction of the solar wind with the Hermean magnetosphere for six solar wind realistic configurations with different magnetic field orientations: Mercury-Sun, Sun-Mercury, aligned with the magnetic axis of Mercury (Northward and Southward) and with the orbital plane perpendicular to the previous cases. In the Mercury-Sun (Sun-Mercury) simulation the Hermean magnetic field is weakened in the South-East (North-East) of the magnetosphere leading to an enhancement of the flows on the South (North) hemisphere. For a Northward (Southward) orientation there is an enhancement (weakening) of the Hermean magnetic field in the nose of the bow shock so the fluxes are reduced and drifted to the poles (enhanced and drifted to the equator). If the solar wind magnetic field is in the orbital plane the magnetosphere is tilted to the West (East) and weakened at the nose of the shock, so the flows are enhanced and drifted to the East (West) in the Northern hemisphere and to the West (East) in the Southern hemisphere.

  2. Orientation of migratory birds under ultraviolet light.

    PubMed

    Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2014-05-01

    In view of the finding that cryptochrome 1a, the putative receptor molecule for the avian magnetic compass, is restricted to the ultraviolet single cones in European Robins, we studied the orientation behaviour of robins and Australian Silvereyes under monochromatic ultraviolet (UV) light. At low intensity UV light of 0.3 mW/m(2), birds showed normal migratory orientation by their inclination compass, with the directional information originating in radical pair processes in the eye. At 2.8 mW/m(2), robins showed an axial preference in the east-west axis, whereas silvereyes preferred an easterly direction. At 5.7 mW/m(2), robins changed direction to a north-south axis. When UV light was combined with yellow light, robins showed easterly 'fixed direction' responses, which changed to disorientation when their upper beak was locally anaesthetised with xylocaine, indicating that they were controlled by the magnetite-based receptors in the beak. Orientation under UV light thus appears to be similar to that observed under blue, turquoise and green light, albeit the UV responses occur at lower light levels, probably because of the greater light sensitivity of the UV cones. The orientation under UV light and green light suggests that at least at the level of the retina, magnetoreception and vision are largely independent of each other. PMID:24718656

  3. Transport driven plasma flows in the scrape-off layer of ADITYA Tokamak in different orientations of magnetic field

    SciTech Connect

    Sangwan, Deepak; Jha, Ratneshwar; Brotankova, Jana; Gopalkrishna, M. V.

    2014-06-15

    Parallel plasma flows in the scrape-off layer of ADITYA tokamak are measured in two orientations of total magnetic field. In each orientation, experiments are carried out by reversing the direction of the toroidal magnetic field and the plasma current. The transport-driven component is determined by averaging flow Mach numbers, measured in two directions of the toroidal magnetic field and the plasma current for the same orientation. It is observed that there is a significant transport-driven component in the measured flow and the component depends on the field orientation.

  4. Abstract -Kalman filters are used to overcome system latency by predicting head orientation using AC magnetic

    E-print Network

    Motai, Yuichi

    Abstract - Kalman filters are used to overcome system latency by predicting head orientation using AC magnetic tracker. To achieve optimum performance from the Kalman filter, the process assistive service. This paper discusses two adaptive Kalman filters, one using the well known fading memory

  5. Redstarts, Phoenicurus phoenicurus, can orient in a true-zero magnetic field.

    PubMed

    Mouritsen

    1998-05-01

    I tested the migratory orientation of redstarts in a true-zero magnetic field to elucidate the importance to this species of access to either magnetic or celestial cues. I also tested the validity of the assumption on which all funnel experiments are based: that what we observe in an orientation funnel reflects what the bird would do if actually migrating. In a set of funnel experiments, I tested 47 night-migrating redstarts caught during their first autumn migration. Each bird was tested once under each of four experimental conditions in a semi-randomized block-design. Upon completion of the final funnel tests the birds were fitted with light indicators and released. The results showed that redstarts can find the migratory direction on the basis of access to either celestial or magnetic cues. Thus, when celestial cues were available they could orient in a true-zero magnetic field. In addition, a starry sky facilitated high migratory activity as well as a clearly directed orientation. The release experiments showed that the vanishing bearings on nights with no wind were in good agreement with the direction of the funnel activity, but that the vanishing bearings were strongly influenced even by light wind. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9632514

  6. ORIENTATION REQUIREMENT TO DETECT MAGNETIC FIELD-INDUCTED ALTERATION OF GAP JUNCTION COMMUNICATION IN EPITHELIAL CELLS

    EPA Science Inventory

    ORIENTATION REQUIREMENT TO DETECT MAGNETIC FIELD-INDUCED ALTERATION OF GAP JUNCTION COMMUNICATION IN EPITHELIAL CELLS.
    OBJECTIVE: We have shown that functional gap junction communication as measured by Lucifer yellow dye transfer (DT) in Clone-9 rat liver epithelial cells, c...

  7. Orientation Dependence of the Critical Magnetic Field for Multiferroic BiFeO3

    SciTech Connect

    Fishman, Randy Scott

    2013-01-01

    Multiferroic BiFeO3 undergoes a transition from a distorted spiral phase to a G-type antiferromagnet above a critical field Hc that depends on the orientation m of the field. We show that Hc(m) has a maximum when oriented along a cubic diagonal parallel to the electric polarization P and a minimum in the equatorial plane normal to P when two magnetic domains with the highest critical fields are degenerate. The measured critical field along a cubic axis is about 19 T but Hc is predicted to vary by as much as 2.5 T above and below this value. The orientational dependence of Hc(m) is more complex than indicated by earlier work, which did not consider the competition between magnetic domains.

  8. Quantum limit for avian magnetoreception: How sensitive can a chemical compass be?

    E-print Network

    Jianming Cai; Filippo Caruso; Martin B. Plenio

    2011-10-31

    The chemical compass model, based on radical pair reactions, is a fascinating idea to explain avian magnetoreception. At present, questions concerning the key ingredients responsible for the high sensitivity of a chemical compass and the possible role of quantum coherence and decoherence remain unsolved. Here, we investigate the optimized hyperfine coupling for a chemical compass in order to achieve the best magnetic field sensitivity. We show that its magnetic sensitivity limit can be further extended by simple quantum control and may benefit from additional decoherence. With this, we clearly demonstrate how quantum coherence can be exploited in the functioning of a chemical compass. The present results also provide new routes towards the design of a biomimetic weak magnetic field sensor.

  9. Using an electronic compass to determine telemetry azimuths

    USGS Publications Warehouse

    Cox, R.R., Jr.; Scalf, J.D.; Jamison, B.E.; Lutz, R.S.

    2002-01-01

    Researchers typically collect azimuths from known locations to estimate locations of radiomarked animals. Mobile, vehicle-mounted telemetry receiving systems frequently are used to gather azimuth data. Use of mobile systems typically involves estimating the vehicle's orientation to grid north (vehicle azimuth), recording an azimuth to the transmitter relative to the vehicle azimuth from a fixed rosette around the antenna mast (relative azimuth), and subsequently calculating an azimuth to the transmitter (animal azimuth). We incorporated electronic compasses into standard null-peak antenna systems by mounting the compass sensors atop the antenna masts and evaluated the precision of this configuration. This system increased efficiency by eliminating vehicle orientation and calculations to determine animal azimuths and produced estimates of precision (azimuth SD=2.6 deg., SE=0.16 deg.) similar to systems that required orienting the mobile system to grid north. Using an electronic compass increased efficiency without sacrificing precision and should produce more accurate estimates of locations when marked animals are moving or when vehicle orientation is problematic.

  10. Orienteering for Sport and Pleasure.

    ERIC Educational Resources Information Center

    Bengtsson, Hans; Atkinson, George

    This text presents the principles of the sport of orienteering (navigating through an unknown area using a map and compass as guide) and is useful to beginners, experienced orienteers, and "armchair" orienteers. Included in the text are: (1) a glossary of key words; (2) a basic introduction to, and history of, the sport; (3) description of the…

  11. Sensitive chemical compass assisted by quantum criticality

    NASA Astrophysics Data System (ADS)

    Cai, C. Y.; Ai, Qing; Quan, H. T.; Sun, C. P.

    2012-02-01

    A radical-pair-based chemical reaction might be used by birds for navigation via the geomagnetic direction. The inherent physical mechanism is that the quantum coherent transition from a singlet state to triplet states of the radical pair could respond to a weak magnetic field and be sensitive to the direction of such a field; this then results in different photopigments to be sensed by the avian eyes. Here, we propose a quantum bionic setup, inspired by the avian compass, as an ultrasensitive probe of a weak magnetic field based on the quantum phase transition of the environments of the two electrons in the radical pair. We prove that the yield of the chemical products via recombination from the singlet state is determined by the Loschmidt echo of the environments with interacting nuclear spins. Thus quantum criticality of environments could enhance the sensitivity of detection of weak magnetic fields.

  12. [Changes in magnetic coil orientation affect the stimulation effects of human peripheral nerve].

    PubMed

    Sun, S J

    1996-03-01

    Transcranial magnetic stimulation is a non-invasive method for assessing the motor function in humans. It is well established that orientation of the magnetic coil plays an important role on the stimulation effects of the motor cortex. However, there has been a few study regarding the effect of magnetic coil orientation on the efficacy of peripheral nerve stimulation. Therefore, in the present study, I carried out two experiments to clarify the relationship between the magnetic coil orientation and the stimulation effects of human peripheral nerve. First, median nerve was stimulated at the elbow and compound muscle action potentials (CMAPs) of abductor pollicis brevis muscle were recorded in 8 subjects at 4 different directions of the induced current. Two eight-shaped coils, 10 cm and 3.5 cm in outer diameter, were used. Stimulus intensities of big and small coils were 850 V and 90%, respectively. Motor threshold was measured at 4 directions with the big coil by increasing stimulus intensity up to 850 V from 150 V at a step of 50 V. It was found that the amplitude of the CMAP was the greatest in outer direction (toward the radial side) using either the big coil or the small coil. There was no significant difference between the amplitude in outer direction and that of supramaximal electrical stimulation. Motor threshold was the lowest in outer direction. Then, I measured the induced current of the big and small coils in a tank filled with saline that mimicked the forearm. The induced currents by both big and small coils were the largest and the first spatial derivatives of the induced electric field were the greatest in outer direction. These results suggest that the orientation of the eight-shaped coil is important for peripheral nerve magnetic stimulation. The fact that the forearm is a restrictive volume conductor may result in the different effects of coil orientation on the excitement of the peripheral nerve. PMID:8727356

  13. RESEARCH PAPER Enhancing Compassion: A Randomized Controlled Trial

    E-print Network

    Gross, James J.

    --compassion for others, receiving compassion from others, and self-compassion. The amount of formal meditation practiced and well-being. Keywords Compassion Á Self-compassion Á Meditation Á Training 1 Introduction Most of the numerous benefits associated with increasing positive states such as compassion, it is important

  14. Synthesis, Magnetic Anisotropy and Optical Properties of Preferred Oriented Zinc Ferrite Nanowire Arrays

    PubMed Central

    2010-01-01

    Preferred oriented ZnFe2O4 nanowire arrays with an average diameter of 16 nm were fabricated by post-annealing of ZnFe2 nanowires within anodic aluminum oxide templates in atmosphere. Selected area electron diffraction and X-ray diffraction exhibit that the nanowires are in cubic spinel-type structure with a [110] preferred crystallite orientation. Magnetic measurement indicates that the as-prepared ZnFe2O4 nanowire arrays reveal uniaxial magnetic anisotropy, and the easy magnetization direction is parallel to the axis of nanowire. The optical properties show the ZnFe2O4 nanowire arrays give out 370–520 nm blue-violet light, and their UV absorption edge is around 700 nm. The estimated values of direct and indirect band gaps for the nanowires are 2.23 and 1.73 eV, respectively. PMID:20676211

  15. Preparation of non-oriented silicon steel with high magnetic induction using columnar grains

    NASA Astrophysics Data System (ADS)

    Cheng, Ling; Yang, Ping; Fang, Yupei; Mao, Weimin

    2012-11-01

    Columnar grains can lead to detrimental surface ridging and an inhomogeneous microstructure, although their {1 0 0}<0 v w> texture is considered desirable due to their good magnetic properties in non-oriented silicon steel. Based on the hereditary tendency of {1 0 0}<0 v w> texture, the effects of lubrication and heating rate on texture and on final magnetic properties were investigated using a cast slab containing 100% columnar grains. Hot rolling with lubrication, normalization at low heating rate, two-stage cold rolling, and final annealing at 1000 °C helped achieve high performance. As a result, a new non-oriented silicon steel with high magnetic induction (B50=1.82 T) and low core loss (P1.5=2.35 W/kg) was prepared. The possibility of further performance optimization was also discussed.

  16. Mechanics of a magnet and a Meissner superconducting ring at arbitrary position and orientation

    NASA Astrophysics Data System (ADS)

    Perez-Diaz, J. L.; Garcia-Prada, J. C.; Diaz-Garcia, J. A.

    2009-04-01

    The force and torque exerted by a magnetic dipole on a superconducting ring (or hollow cylinder) in the Meissner state at arbitrary position and orientation are calculated using a Maxwell-London model previously proposed by the authors. The center of the ring is an unstable equilibrium point for the magnet. At this point the ring tends to align the magnet but tends to expel it for any small axial deviation from the center. There is also a non-monotonic and oscillatory dependence of the forces and torques on the position caused by the finiteness of the ring and a torque arises when the magnet is displaced both radially and axially from the center of the cylinder which corresponds to the experimental data. Therefore, the use of a magnet in a Meissner superconducting ring as a self aligning bearing requires a centered position and that the axial unstability to be compensated by additional mechanical means.

  17. Biophysics of Magnetic Orientation: Radical Pairs, Biogenic Magnetite, or both?

    NASA Astrophysics Data System (ADS)

    Kirschvink, Joe

    2011-03-01

    Two major biophysical mechanisms for magnetoreception in terrestrial animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, have been the subject of experiment and debate for the past 30 years. The magnetite hypothesis has stood the test of time: biogenic magnetite is synthesized biochemically in Bacteria, Protists, and numerous Animal phyla, as well as in some plants. Chains of single-domain crystals have been detected by clean-lab based SQUID magnetometry in animal tissues in all major phyla, followed by high-resolution TEM in selected model organisms, as well as by electrophysiological studies demonstrating the role of the ophthalmic branch of the trigeminal nerve in the magnetoreceptive process. Pulse-remagnetization - configured to uniquely flip the polarity of single-domain ferromagnets - has dramatic effects on the behavior of many birds, honeybees, mole rats, turtles, and bats, to cite a growing list. Magnetite-containing cells in the vicinity of these neurons in fish are now the subject of intense study by our consortium. The existence of a specialized class of magnetite-containing magnetoreceptor cells in animal tissues is no longer controversial. In contrast, less success has been achieved in gaining experimental support across a range of taxa for the radical-pair hypothesis. Although this mechanism was proposed to explain an early observation that birds would not respond to complete inversion of the magnetic vector, many organisms (even some birds) do indeed respond to the field polarity. We also note that few, if any, of these critical experiments have been done using fully double-blind methods. This is joint work with: M. M. Walker (University of Auckland, New Zealand) and M. Winklhofer (LMU Munich, Germany).

  18. Compassion, compassion fatigue, and burnout: key insights for oncology professionals.

    PubMed

    Back, Anthony L; Deignan, Paul F; Potter, Patricia A

    2014-01-01

    When cancer care clinicians become stressed, sad, isolated--and unaware of this--they are placing themselves at risk for burnout and their patients at risk for suboptimal care. Despite their best intentions, clinicians can sink from a healthy work state of compassion, empathy, and well-being into compassion fatigue and burnout. Lessons from first responders demonstrate the importance for clinicians to recognize the warning signs of compassion and fatigue and burnout, as this recognition can enable them to take action towards prevention and/or recovery. The recognition of these issues as a threat to clinician performance has outstripped the development of evidence-based interventions, but interventions tested to date are effective, feasible, and scalable. These interventions could be incorporated systematically into cancer care. PMID:24857139

  19. Gluon Polarisation Measurements @ COMPASS

    E-print Network

    Luís Silva; for the COMPASS Collaboration

    2011-11-02

    One of the missing keys in the present understanding of the spin structure of the nucleon is the contribution from the gluons: the so-called gluon polarisation. This quantity can be determined in DIS through the photon-gluon fusion process, in which two analysis methods may be used: (i) identifying open charm events or (ii) selecting events with high p_T hadrons. The data used in the present work were collected in the COMPASS experiment, where a 160 GeV/c naturally polarised muon beam, impinging on a polarised nucleon fixed target is used. Preliminary results for the gluon polarisation from high p_T and open charm analyses are presented. The gluon polarisation result for high p_T hadrons is divided, for the first time, into three statistically independent measurements at LO. The result from open charm analysis is obtained at LO and NLO. In both analyses a new weighted method based on a neural network approach is used.

  20. Delta G from Compass

    E-print Network

    Krzysztof Kurek

    2006-07-26

    Measurements of the gluon polarization $\\frac{\\Delta G}{G}$ via the open charm channel and based on the helicity asymmetry of large transverse-momentum hadrons in the final state are presented. The data have been collected in the years 2002-2004 by the COMPASS experiment at CERN using a 160 GeV/c polarized muon beam scattered off a polarized $^6$LiD target. The new result for $\\frac{\\Delta G}{G}$ from the charm channel is $-0.57 \\pm 0.41 (stat.)$ at $x_G \\simeq 0.15$ and scale $\\mu^2 \\simeq 13 $ (GeV/c)$^2$. The gluon polarization from high-$p_T$ hadron pairs is $\\frac{\\Delta G}{G} = 0.016\\pm 0.058 (stat.)\\pm 0.055 (syst.)$ at $x_G \\simeq 0.085^{+0.07}_{-0.035}$ ($Q^2 < 1$ (GeV/c)$^2$ and $\\mu^2 \\simeq 3$ (GeV/c)$^2$)

  1. Self-Compassion and Automatic Thoughts

    ERIC Educational Resources Information Center

    Akin, Ahmet

    2012-01-01

    The aim of this research is to examine the relationships between self-compassion and automatic thoughts. Participants were 299 university students. In this study, the Self-compassion Scale and the Automatic Thoughts Questionnaire were used. The relationships between self-compassion and automatic thoughts were examined using correlation analysis…

  2. Compassion: An Evolutionary Analysis and Empirical Review

    ERIC Educational Resources Information Center

    Goetz, Jennifer L.; Keltner, Dacher; Simon-Thomas, Emiliana

    2010-01-01

    What is compassion? And how did it evolve? In this review, we integrate 3 evolutionary arguments that converge on the hypothesis that compassion evolved as a distinct affective experience whose primary function is to facilitate cooperation and protection of the weak and those who suffer. Our empirical review reveals compassion to have distinct…

  3. Signal Transduction Model of Magnetic Sensing in Cryptochrome Mediated Photoreception

    NASA Astrophysics Data System (ADS)

    Todd, Phillise Tiffeny

    While migratory birds have long been known to use the Earth's magnetic field for navigation, the precise biophysical mechanism behind this magnetic sense remains unconfirmed. A leading theory of magnetoreception suggests a chemical compass model with a yet undetermined molecular reaction site and unknown magnetically sensitive reactants. The cryptochrome photoreceptor has emerged as a promising candidate site. This investigation numerically models the first order kinetics of cryptochrome mediated photoreception, in order to evaluate its ability to function as a magnetic sensor and transduce orientation information along a neural pathway. A signal-to-noise ratio is defined to quantify the threshold for the functioning of a cryptochrome-based chemical compass. The model suggests that a flavin-superoxide radical pair in cryptochrome functions as the chemical reactants for magnetoreception. Such a cryptochrome-based signal transduction model reasonably predicts the general light intensity and wavelength effects that have been experimentally observed in migratory birds.

  4. Magnetic and transport properties of Mn{sub 2}CoAl oriented films

    SciTech Connect

    Jamer, Michelle E.; Assaf, Badih A.; Devakul, Trithep; Heiman, Don

    2013-09-30

    The structure, magnetic, and transport properties of thin films of the Heusler ferrimagnet Mn{sub 2}CoAl have been investigated for properties related to spin gapless semiconductors. Oriented films were grown by molecular beam epitaxy on GaAs substrates and the structure was found to transform from tetragonal to cubic for increasing annealing temperature. The anomalous Hall resistivity is found to be proportional to the square of the longitudinal resistivity and magnetization expected for a topological Berry curvature origin. A delicate balance of the spin-polarized carrier type when coupled with voltage gate-tuning could significantly impact advanced electronic devices.

  5. Modeling the behavior of oriented permanent magnet material using current double theory

    SciTech Connect

    Green, M.A.

    1987-11-01

    This paper presents a method for modeling two dimensional dipoles, quadrupoles and other higher multipoles built using oriented permanent magnet materials such as samarium cobalt (one of the rare earth cobalt REC materials). The technique presented here uses complex current doublet to model the magnetized material. This technique can be used in conjunction with an infinitely permeable circular iron shield which lies outside the REC material. Examples of two types of dipoles and quadrupoles are presented in this report. 15 refs., 4 figs., 1 tab.

  6. Orientation Measurement Based on Magnetic Inductance by the Extended Distributed Multi-Pole Model

    PubMed Central

    Wu, Fang; Moon, Seung Ki; Son, Hungsun

    2014-01-01

    This paper presents a novel method to calculate magnetic inductance with a fast-computing magnetic field model referred to as the extended distributed multi-pole (eDMP) model. The concept of mutual inductance has been widely applied for position/orientation tracking systems and applications, yet it is still challenging due to the high demands in robust modeling and efficient computation in real-time applications. Recently, numerical methods have been utilized in design and analysis of magnetic fields, but this often requires heavy computation and its accuracy relies on geometric modeling and meshing that limit its usage. On the other hand, an analytical method provides simple and fast-computing solutions but is also flawed due to its difficulties in handling realistic and complex geometries such as complicated designs and boundary conditions, etc. In this paper, the extended distributed multi-pole model (eDMP) is developed to characterize a time-varying magnetic field based on an existing DMP model analyzing static magnetic fields. The method has been further exploited to compute the mutual inductance between coils at arbitrary locations and orientations. Simulation and experimental results of various configurations of the coils are presented. Comparison with the previously published data shows not only good performance in accuracy, but also effectiveness in computation. PMID:24977389

  7. Local electrical control of magnetic order and orientation by ferroelastic domain arrangements just above room temperature

    PubMed Central

    Phillips, L. C.; Cherifi, R. O.; Ivanovskaya, V.; Zobelli, A.; Infante, I. C.; Jacquet, E.; Guiblin, N.; Ünal, A. A.; Kronast, F.; Dkhil, B.; Barthélémy, A.; Bibes, M.; Valencia, S.

    2015-01-01

    Ferroic materials (ferromagnetic, ferroelectric, ferroelastic) usually divide into domains with different orientations of their order parameter. Coupling between different ferroic systems creates new functionalities, for instance the electrical control of macroscopic magnetic properties including magnetization and coercive field. Here we show that ferroelastic domains can be used to control both magnetic order and magnetization direction at the nanoscale with a voltage. We use element-specific X-ray imaging to map the magnetic domains as a function of temperature and voltage in epitaxial FeRh on ferroelastic BaTiO3. Exploiting the nanoscale phase-separation of FeRh, we locally interconvert between ferromagnetic and antiferromagnetic states with a small electric field just above room temperature. Imaging and ab initio calculations show the antiferromagnetic phase of FeRh is favoured by compressive strain on c-oriented BaTiO3 domains, and the resultant magnetoelectric coupling is larger and more reversible than previously reported from macroscopic measurements. Our results emphasize the importance of nanoscale ferroic domain structure and the promise of first-order transition materials to achieve enhanced coupling in artificial multiferroics. PMID:25969926

  8. Local electrical control of magnetic order and orientation by ferroelastic domain arrangements just above room temperature.

    PubMed

    Phillips, L C; Cherifi, R O; Ivanovskaya, V; Zobelli, A; Infante, I C; Jacquet, E; Guiblin, N; Ünal, A A; Kronast, F; Dkhil, B; Barthélémy, A; Bibes, M; Valencia, S

    2015-01-01

    Ferroic materials (ferromagnetic, ferroelectric, ferroelastic) usually divide into domains with different orientations of their order parameter. Coupling between different ferroic systems creates new functionalities, for instance the electrical control of macroscopic magnetic properties including magnetization and coercive field. Here we show that ferroelastic domains can be used to control both magnetic order and magnetization direction at the nanoscale with a voltage. We use element-specific X-ray imaging to map the magnetic domains as a function of temperature and voltage in epitaxial FeRh on ferroelastic BaTiO3. Exploiting the nanoscale phase-separation of FeRh, we locally interconvert between ferromagnetic and antiferromagnetic states with a small electric field just above room temperature. Imaging and ab initio calculations show the antiferromagnetic phase of FeRh is favoured by compressive strain on c-oriented BaTiO3 domains, and the resultant magnetoelectric coupling is larger and more reversible than previously reported from macroscopic measurements. Our results emphasize the importance of nanoscale ferroic domain structure and the promise of first-order transition materials to achieve enhanced coupling in artificial multiferroics. PMID:25969926

  9. Effects of variation in solar conditions and crustal sources' orientation on the Martian magnetic field topology

    NASA Astrophysics Data System (ADS)

    Ulusen, D.; Luhmann, J. G.; Ma, Y.; Brain, D. A.

    2013-12-01

    Strong crustal magnetic sources on the surface of Mars directly interact with the solar magnetic field and plasma, resulting a very dynamic environment near the planet. Effects of the orientation of these remnant magnetic sources with respect to the sun and variation of the solar conditions on the Martian plasma interaction have been investigated in a previous paper. In this previous study, magnetic topology maps obtained from ~7 years of Mars Global Surveyor (MGS) directional electron observations (obtained by Dave Brain) were compared with the topology maps obtained from a set of BATS-R-US MHD simulations for Mars. One conclusion from this study was that although the MHD model is consistent with the data and provides insight about the global magnetic field topology variation with changing crustal field orientation and solar parameters, detailed investigation of local effects is difficult due to MGS orbital bias. Moreover, proper comparison of the observations with the model requires more careful data selection rather than using 7 years time averages. In this paper, we readdress the study to tackle the problems of our previous work by performing more detailed data analysis and present the results of the updated model-data comparison.

  10. Magnetically orientable phospholipid bilayers containing small amounts of a bile salt analogue, CHAPSO

    SciTech Connect

    Sanders, C.R. II; Prestegard, J.H. )

    1990-08-01

    Buffered mixtures of the detergent 3-(cholamidopropyl)dimethylammonio-2-hydroxy-1-propanesulfonate (CHAPSO) and dimyristoylphosphatidylcholine (DMPC) orient in the presence of a strong magnetic field over a wide range of water contents (at least 65-85%) and CHAPSO:DMPC molar ratios (typically 1:10-1:3). 31P NMR studies show that the phospholipid in such mixtures is oriented with its director axis perpendicular to the magnetic field. 31P and 2H NMR results also suggest that the structure and dynamics of the DMPC molecules are similar to that of pure phospholipids existing in the liquid crystalline (L alpha) bilayer phase. The ability of 1:5 CHAPSO:DMPC samples to orient is highly tolerant of large changes in temperature, pH, and ionic strength, as well as to the addition of substantial amounts of charged amphiphiles or soluble protein. However, 2H NMR studies of deuterated beta-dodecyl melibiose (DD-MB) solubilized in the system indicate the head group conformation and/or dynamics of this glycolipid analogue is dependent upon the CHAPSO concentration. Despite the latter results, the orientational versatility of the system, together with the nondenaturing properties of CHAPSO, makes this system useful in spectroscopic studies of membrane-associated phenomena.

  11. (001) Oriented L10 FeCuPt for Heat-Assisted Magnetic Recording

    NASA Astrophysics Data System (ADS)

    Liu, Kai

    2015-03-01

    High magnetic anisotropy materials are critical to key technologies such as ultrahigh density magnetic recording and permanent magnets. Among them, ordered FePt alloys in the L10 phase are particularly sought after, for the emerging heat-assisted magnetic recording (HAMR) media. However, the highly desirable properties are associated with the tetragonal L10 phase. Key challenges exist in the high annealing temperature necessary to transform the as-deposited disordered cubic A1 phase into the ordered tetragonal L10 phase and the ability to maintain the magnetic easy axis perpendicular to the film. We have achieved (001) oriented L10 FeCuPt thin films, with magnetic anisotropy up to 3.6 x 107 erg/cm3, using atomic-scale multilayer sputtering and rapid thermal annealing (RTA) at 400 °C for 10 seconds, which is much more benign compared to earlier studies. The artificial ordering in the multilayer structure and a significant tensile stress exerted by the underlying Si/SiO2 during RTA facilitate the formation of (001) oriented L10 phase. The A1 to L10 phase transformation has been investigated by x-ray diffraction and the first-order reversal curve (FORC) method. The L10 ordering takes place via a nucleation-and-growth mode. Traditional x-ray diffraction is not always reliable in generating a true order parameter, due to non-ideal crystallinity of the A1 phase in some of the samples. A magnetization-based L10 phase fraction is extracted, providing a quantitative measure of the L10 phase homogeneity. This work has been done in collaboration with D. A. Gilbert, J. W. Liao, L. W. Wang, J. W. Lau, T. J Klemmer, J. U. Thiele, and C. H. Lai, supported by the NSF (DMR-1008791).

  12. Magnetically Actuated Propellant Orientation, Controlling Fluids in a Low-Gravity Environment

    NASA Technical Reports Server (NTRS)

    Martin, James J.; Holt, James B.

    2000-01-01

    Cryogenic fluid management (CFM) is a technology area common to virtually every space transportation propulsion concept envisioned. Storage, supply, transfer and handling of sub-critical cryogenic fluids are basic capabilities that have long been needed by multiple programs and the need is expected to continue in the future. The use of magnetic fields provides another method, which could replace or augment current/traditional approaches, potentially simplifying vehicle operational constraints. The magnetically actuated propellant orientation (MAPO) program effort focused on the use of magnetic fields to control fluid motion as it relates to positioning (i.e. orientation and acquisition) of a paramagnetic substance such as LO2. Current CFM state- of-the-art systems used to control and acquire propellant in low gravity environments rely on liquid surface tension devices which employ vanes, fine screen mesh channels and baskets. These devices trap and direct propellant to areas where it's needed and have been used routinely with storable (non-cryogenic) propellants. However, almost no data exists r,egarding their operation in cryogenics and the use of such devices confronts designers with a multitude of significant technology issues. Typical problems include a sensitivity to screen dry out (due to thermal loads and pressurant gas) and momentary adverse accelerations (generated from either internal or external sources). Any of these problems can potentially cause the acquisition systems to ingest or develop vapor and fail. The use of lightweight high field strength magnets may offer a valuable means of augmenting traditional systems potentially mitigating or at least easing operational requirements. Two potential uses of magnetic fields include: 1) strategically positioning magnets to keep vent ports clear of liquid (enabling low G vented fill operations), and 2) placing magnets in the center or around the walls of the tank to create an insulating vapor pocket (between the liquid and the tank wall) which could effectively lower heat transfer to the liquid (enabling increased storage time).

  13. Is the blind cave salamander Proteus anguinus equiped for magnetic orientation ?

    NASA Astrophysics Data System (ADS)

    Bouquerel, H.; Valet, J. P.

    2003-04-01

    The Proteus anguinus is a blind cave salamander which can develop the ability of using the earth’s magnetic field for orientation and navigation. It has been shown that the strength of the geomagnetic field is not strong enough to excite the electroreceptors of these animals through induction mechanism so that the most likely hypothesis is that they would use cristals of magnetite as permanent magnets. We have been looking for evidence of remanent magnetism in several proteus collected from the underground CNRS laboratory at Moulis (France). Because the level of natural remanent magnetization, if any, was too low to be measured with confidence using a 3 axis squid 2G magnetometer (even bringing the animals as close as possible to the sensors), we stepwise remagnetized the samples between 0.2 and 1.2T. Measurements were performed in different parts of three proteus bodies. No significant magnetization was detected in the head, most of the signal being concentrated in the lower body of the animal. Saturation was attained after 0.2T while stepwise demagnetization by alternating field showed that most magnetization was removed after 40 mT (medium destructive field, MDF of about 10 mT), which is typical of magnetite. Independent measurements of clay soils taken from the surrounding immediate environment of the animals reveal a different magnetic signature for saturation, MDF and viscosity. Thus there is no apparent and direct link between food absorbed from their environment and the magnetic remamence of the animals. New experiments are currently in progress to determine whether magnetite is the unique magnetic carrier and also to provide better clue about the magnetic granulometry and its distribution.

  14. Structural and magnetic properties of Co films on highly textured and randomly oriented C60 layers

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Ok; Choi, Jun Woo; Lee, Dong Ryeol

    2016-03-01

    The structural and magnetic properties of Co/C60/pentacene and Co/C60 thin film structures were investigated. Atomic force microscopy and x-ray reflectivity analysis show that the presence or absence of a pentacene buffer layer leads to a highly textured or randomly oriented C60 layer, respectively. A Co film deposited on a randomly oriented C60 layer penetrates into the C60 layer when it is deposited at a slow deposition rate. The Co penetration can be minimized, regardless of the Co deposition rate, by growth on a highly textured and nanostructured C60/pentacene layer. Vibrating sample magnetometry measurements show that the saturation magnetization of Co/C60/pentacene is significantly reduced compared to that of Co/C60. On the other hand, the Co penetration does not seem to have an effect on the magnetic properties, suggesting that the structural properties of the Co and C60 layer, rather than the Co penetration into the organic C60 layer, are critical to the magnetic properties of the Co/C60.

  15. Magnetically Actuated Propellant Orientation Experiment, Controlling Fluid Motion With Magnetic Fields in a Low-Gravity Environment

    NASA Technical Reports Server (NTRS)

    Martin, J. J.; Holt, J. B.

    2000-01-01

    This report details the results of a series of fluid motion experiments to investigate the use of magnets to orient fluids in a low-gravity environment. The fluid of interest for this project was liquid oxygen (LO2) since it exhibits a paramagnetic behavior (is attracted to magnetic fields). However, due to safety and handling concerns, a water-based ferromagnetic mixture (produced by Ferrofluidics Corporation) was selected to simplify procedures. Three ferromagnetic fluid mixture strengths and a nonmagnetic water baseline were tested using three different initial fluid positions with respect to the magnet. Experiment accelerometer data were used with a modified computational fluid dynamics code termed CFX-4 (by AEA Technologies) to predict fluid motion. These predictions compared favorably with experiment video data, verifying the code's ability to predict fluid motion with and without magnetic influences. Additional predictions were generated for LO2 with the same test conditions and geometries used in the testing. Test hardware consisted of a cylindrical Plexiglas tank (6-in. bore with 10-in. length), a 6,000-G rare Earth magnet (10-in. ring), three-axis accelerometer package, and a video recorder system. All tests were conducted aboard the NASA Reduced-Gravity Workshop, a KC-135A aircraft.

  16. RESEARCHER PROFILE: Compassion and Curiosity

    Cancer.gov

    William Kim, M.D., is motivated by two things: compassion and curiosity. Dr. Kim has taken these dual motivations and created a career in which he cares directly for patients and spearheads research that may lead to improved treatment options.

  17. Classroom Compass, 1995-96.

    ERIC Educational Resources Information Center

    Classroom Compass, 1995

    1995-01-01

    This document is comprised of the four 1995-1996 issues of "Classroom Compass," a newsletter of the Eisenhower Southwest Consortium for the Improvement of Mathematics and Science Teaching. Each issue contains a "Resources and Opportunities" section, a reading list, excerpts from the National Science Education Standards, and learning activities.…

  18. Orientational and relaxation features of the dynamic magnetic susceptibility of PbFe12O19 upon transition from the magnetically ordered to paramagnetic state

    NASA Astrophysics Data System (ADS)

    Bezlepkin, A. A.; Kuntsevich, S. P.; Kostyukov, V. I.

    2015-11-01

    The dynamic magnetic susceptibility of lead hexaferrite has been experimentally studied in the temperature range of the transition from the magnetically ordered to paramagnetic state. As the vector of the ac magnetic field is oriented in the easy-magnetization direction along hexagonal axis c, anomalous peakshaped decrease in the real part of the magnetic susceptibility has been observed near the Curie temperature. The observed effect depends on the ac magnetic field frequency and disappears at a frequency near 12 MHz. The observed features have been interpreted as the effects caused by the relaxation resonance.

  19. Attachment and mental and physical health: self-compassion and mattering as mediators.

    PubMed

    Raque-Bogdan, Trisha L; Ericson, Sara K; Jackson, John; Martin, Helena M; Bryan, Nicole A

    2011-04-01

    Research shows a strong link between adult attachment and mental and physical health, but little is known about the mechanisms that underlie these relationships. The present study examined self-compassion and mattering, two constructs from positive psychology literature, as potential mediators. Using survey data from a sample of 208 college students, relationships among attachment, self-compassion, mattering, and functional health were explored. Correlational analyses indicated that attachment anxiety and avoidance were strongly related to the mental health component of functional health. Mediation analyses indicated that mattering and self-compassion mediated the relationships between attachment orientation (i.e., levels of avoidance and anxiety) and mental health. These findings suggest that individuals' abilities to be kind toward themselves and their sense of belonging and being important to others are pathways through which attachment orientation relates to mental health. PMID:21463033

  20. Orientation of hatchling loggerhead sea turtles to regional magnetic fields along a transoceanic migratory pathway.

    PubMed

    Fuxjager, Matthew J; Eastwood, Brian S; Lohmann, Kenneth J

    2011-08-01

    Young loggerhead sea turtles (Caretta caretta) from the east coast of Florida, USA, undertake a transoceanic migration around the North Atlantic Gyre, the circular current system that flows around the Sargasso Sea. Previous experiments indicated that loggerhead hatchlings, when exposed to magnetic fields replicating those that exist at five widely separated locations along the migratory pathway, responded by swimming in directions that would, in each case, help turtles remain in the gyre and advance along the migratory route. In this study, hatchlings were exposed to several additional magnetic fields that exist along or outside of the gyre's northern boundary. Hatchlings responded to fields that exist within the gyre currents by swimming in directions consistent with their migratory route at each location, whereas turtles exposed to a field that exists north of the gyre had an orientation that was statistically indistinguishable from random. These results are consistent with the hypothesis that loggerhead turtles entering the sea for the first time possess a navigational system in which a series of regional magnetic fields sequentially trigger orientation responses that help steer turtles along the migratory route. By contrast, hatchlings may fail to respond to fields that exist in locations beyond the turtles' normal geographic range. PMID:21753042

  1. Effect of metallurgical factors on the bulk magnetic properties of non-oriented electrical steels

    NASA Astrophysics Data System (ADS)

    Ghosh, Pampa; Chromik, Richard R.; Knight, Andrew M.; Wakade, Shekhar G.

    2014-04-01

    Non-oriented electrical steel (NOES) is one of the most common material used in electrical motors. Core loss and permeability are the most important properties that the motor manufacturers look for. Both these properties are structure sensitive and depend on several metallurgical factors; such as chemistry, grain size, crystallographic texture, cleanliness and stress states in non-oriented electrical steels. It has been observed in this course of the study that the grain size and Si content of NOES are the primary controlling factors to core loss, especially at higher frequencies. On the contrary, crystallographic texture plays an important role at lower frequencies. At higher frequency, core loss increases with increasing grain size and decreasing Si content of the steels. Small difference in grain size (~50 ?m) at lower frequency range has little influence on the magnetic properties but has significant adverse effect as frequency reaches high enough.

  2. Solving the Orientation Specific Constraints in Transcranial Magnetic Stimulation by Rotating Fields

    PubMed Central

    Neef, Nicole E.; Agudelo-Toro, Andres; Rakhmilevitch, David; Paulus, Walter; Moses, Elisha

    2014-01-01

    Transcranial Magnetic Stimulation (TMS) is a promising technology for both neurology and psychiatry. Positive treatment outcome has been reported, for instance in double blind, multi-center studies on depression. Nonetheless, the application of TMS towards studying and treating brain disorders is still limited by inter-subject variability and lack of model systems accessible to TMS. The latter are required to obtain a deeper understanding of the biophysical foundations of TMS so that the stimulus protocol can be optimized for maximal brain response, while inter-subject variability hinders precise and reliable delivery of stimuli across subjects. Recent studies showed that both of these limitations are in part due to the angular sensitivity of TMS. Thus, a technique that would eradicate the need for precise angular orientation of the coil would improve both the inter-subject reliability of TMS and its effectiveness in model systems. We show here how rotation of the stimulating field relieves the angular sensitivity of TMS and provides improvements in both issues. Field rotation is attained by superposing the fields of two coils positioned orthogonal to each other and operated with a relative phase shift in time. Rotating field TMS (rfTMS) efficiently stimulates both cultured hippocampal networks and rat motor cortex, two neuronal systems that are notoriously difficult to excite magnetically. This opens the possibility of pharmacological and invasive TMS experiments in these model systems. Application of rfTMS to human subjects overcomes the orientation dependence of standard TMS. Thus, rfTMS yields optimal targeting of brain regions where correct orientation cannot be determined (e.g., via motor feedback) and will enable stimulation in brain regions where a preferred axonal orientation does not exist. PMID:24505266

  3. Control of proliferation rate of N27 dopaminergic neurons using Transcranial Magnetic Stimulation orientation

    NASA Astrophysics Data System (ADS)

    Meng, Yiwen; Hadimani, Ravi; Anantharam, Vellareddy; Kanthasamy, Anumantha; Jiles, David

    2015-03-01

    Transcranial magnetic stimulation (TMS) has been used to investigate possible treatments for a variety of neurological disorders. However, the effect that magnetic fields have on neurons has not been well documented in the literature. We have investigated the effect of different orientation of magnetic field generated by TMS coils with a monophasic stimulator on the proliferation rate of N27 neuronal cells cultured in flasks and multi-well plates. The proliferation rate of neurons would increase by exposed horizontally adherent N27 cells to a magnetic field pointing upward through the neuronal proliferation layer compared with the control group. On the other hand, proliferation rate would decrease in cells exposed to a magnetic field pointing downward through the neuronal growth layer compared with the control group. We confirmed results obtained from the Trypan-blue and automatic cell counting methods with those from the CyQuant and MTS cell viability assays. Our findings could have important implications for the preclinical development of TMS treatments of neurological disorders and represents a new method to control the proliferation rate of neuronal cells.

  4. The impact of turbulence and magnetic field orientation on star-forming filaments

    NASA Astrophysics Data System (ADS)

    Seifried, D.; Walch, S.

    2015-09-01

    We present simulations of collapsing filaments studying the impact of turbulence and magnetic field morphologies on their evolution and star formation properties. We vary the mass per unit length of the filaments as well as the orientation of the magnetic field with respect to the major axis. We find that the filaments, which have no or a perpendicular magnetic field, typically reveal a smaller width than the universal width of 0.1 pc proposed by e.g. Arzoumanian et al. We show that this also holds in the presence of supersonic turbulence and that accretion driven turbulence is too weak to stabilize the filaments along their radial direction. On the other hand, we find that a magnetic field that is parallel to the major axis can stabilize the filament against radial collapse resulting in widths of 0.1 pc. Furthermore, depending on the filament mass and magnetic field configuration, gravitational collapse and fragmentation in filaments occurs either in an edge-on way, uniformly distributed across the entire length, or in a mixed way. In the presence of initially moderate density perturbations, a centralized collapse towards a common gravitational centre occurs. Our simulations can thus reproduce different modes of fragmentation observed recently in star-forming filaments. Moreover, we find that turbulent motions influence the distance between individual fragments along the filament, which does not always match the results of a Jeans analysis.

  5. The Astro-Compass Science Mural Alan Scott, 2008

    E-print Network

    Wu, Mingshen

    chart, geographical compass, and a time-line of major events in the Earth's geologic past. The mural . . . . . . . . . . . . . . . . 6 Astro-Compass Geographical Compass . . . . . . . . . . . . . . . . 9 Geologic Timeline-Rex . . . . . . . . . . . . 21 List of Student Activities . . . . . . . . . . . . . . . . 24 Astronomy and Geology Terminology

  6. Comparison of lattice preferred orientation and magnetic fabric of a chloritoid-bearing slate

    NASA Astrophysics Data System (ADS)

    Haerinck, Tom; Wenk, Hans-Rudolf; Debacker, Timothy N.; Sintubin, Manuel

    2014-05-01

    A regional analysis of the anisotropy of the magnetic susceptibility (AMS) on chloritoid-bearing slates of the Paleozoic Plougastel Formation in the low-grade metamorphic conditions (epizonal) of the Monts d'Arrée slate belt in Central Armorica (Brittany, France) reveals very high values for the degree of anisotropy (PJ), up to 1.43 (Haerinck et al. 2013a). In contrast, stratigraphically equivalent slates free of chloritoid, in the very low-grade metamorphic conditions (anchizonal) of the Crozon fold-and-thrust belt, show a lower degree of anisotropy, with PJ values up to 1.27. Classically, very strong magnetic fabrics (i.e. those with PJ above 1.35) are attributed to a contribution of ferromagnetic (s.l.) minerals. Nonetheless, high-field torque magnetometry indicates that the magnetic fabric of the chloritoid-bearing slates is dominantly paramagnetic. The ferromagnetic (sensu lato) contribution to the AMS is less than 10%. Based on these observations, it would seem that chloritoid has an intrinsic magnetic anisotropy that is significantly higher than that of most paramagnetic silicates and the frequently used upper limit for the paramagnetic contribution to the AMS. Using two independent approaches, i.e. (a) directional magnetic hysteresis measurements, and (b) torque magnetometry, on a collection of single chloritoid crystals, collected from different tectonometamorphic settings worldwide, the magnetocrystalline anisotropy of monoclinic chloritoid has been determined (Haerinck et al. 2013b). The determined paramagnetic high-field AMS ellipsoids have a highly oblate shape with the minimum susceptibility direction subparallel to the crystallographic c-axis of chloritoid and the degree of anisotropy of chloritoid is found to be 1.47 ± 0.06. The obtained very high magnetocrystalline degree of anisotropy suggests that chloritoid-bearing slates with a pronounced mineral alignment can have a high degree of anisotropy (PJ) without the need of invoking a significant contribution of strongly anisotropic ferromagnetic (s.l.)minerals. To validate this assumption a texture analysis has been performed on a representative sample of the chloritoid-bearing slates (PJ = 1.40), using hard X-ray synchrotron diffraction (e.g. Wenk et al. 2010). For estimation of the mineralogical composition and the preferred orientation a Rietveld refinement of the synchrotron X-ray diffraction images has been performed. The Rietveld refinement confirms that the slate contains a significant fraction of chloritoid (21 vol%). The resulting orientation distribution of both muscovite and chloritoid display an approximate axial symmetric (001) pole figure pattern with respect to the minimum magnetic susceptibility axis K3, that has an extremely strong preferred orientation (~36 m.r.d. for muscovite and ~19 m.r.d. for chloritoid). It is therefore fair to conclude that the strong preferred orientation of the chloritoid basal planes parallel to the magnetic fabric, in combination with the pronounced magnetocrystalline anisotropy of chloritoid, explains the very high values for the degree of magnetic anisotropy (PJ) observed in the chloritoid-bearing slates. References Haerinck et al. 2013a. Journal of the Geological Society, London 170, 263-280, doi:10.1144/jgs2012-062. Haerinck et al. 2013b. Journal of Geophysical Research: Solid Earth 118(8), 3886-3898, doi:10.1002/jgrb.50276. Wenk et al. 2010. Journal of Structural Geology 32(4), 478-489, doi:10.1016/j.jsg.2010.02.003.

  7. Strong orientational coupling of block copolymer microdomains to smectic layering revealed by magnetic field alignment

    E-print Network

    Manesh Gopinadhan; Youngwoo Choo; Chinedum O. Osuji

    2015-09-09

    We elucidate the roles of the isotropic-nematic (I-N) and nematic-smectic A (N-SmA) transitions in magnetic field directed self-assembly of a liquid crystalline block copolymer (BCP), using \\textit{in situ} x-ray scattering. Cooling into the nematic from the disordered melt yields poorly ordered and weakly aligned BCP microdomains. Continued cooling into the SmA however results in an abrupt increase in BCP orientational order with microdomain alignment tightly coupled to the translational order parameter of the smectic layers. These results underscore the significance of the N-SmA transition in generating highly aligned states under magnetic fields in these hierarchically ordered materials.

  8. Magnetic susceptibility anisotropy: cylindrical symmetry from macroscopically ordered anisotropic molecules and accuracy of MRI measurements using few orientations

    PubMed Central

    Wisnieff, Cynthia; Liu, Tian; Spincemaille, Pascal; Wang, Shuai; Zhou, Dong; Wang, Yi

    2013-01-01

    White matter is an essential component of the central nervous system and is of major concern in neurodegenerative diseases such as multiple sclerosis (MS). Recent MRI studies have explored the unique anisotropic magnetic properties of white matter using susceptibility tensor imaging. However, these measurements are inhibited in practice by the large number of different head orientations needed to accurately reconstruct the susceptibility tensor. Adding reasonable constraints reduces the number of model parameters and can help condition the tensor reconstruction from a small number of orientations. The macroscopic magnetic susceptibility is decomposed as a sum of molecular magnetic polarizabilities, demonstrating that macroscopic order in molecular arrangement is essential to the existence of and symmetry in susceptibility anisotropy and cylindrical symmetry is a natural outcome of an ordered molecular arrangement. Noise propagation in the susceptibility tensor reconstruction is analyzed through its condition number, showing that the tensor reconstruction is highly susceptible to the distribution of acquired subject orientations and to the tensor symmetry properties, with a substantial over- or under-estimation of susceptibility anisotropy in fiber directions not favorably oriented with respect to the acquired orientations. It was found that a careful acquisition of three non-coplanar orientations and the use of cylindrical symmetry guided by diffusion tensor imaging allowed reasonable estimation of magnetic susceptibility anisotropy in certain major white matter tracts in the human brain. PMID:23296181

  9. Magnetohydrodynamic Simulations of Hypersonic Flow over a Cylinder Using Axial- and Transverse-Oriented Magnetic Dipoles

    PubMed Central

    Guarendi, Andrew N.; Chandy, Abhilash J.

    2013-01-01

    Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow over a cylinder are presented for axial- and transverse-oriented dipoles with different strengths. ANSYS CFX is used to carry out calculations for steady, laminar flows at a Mach number of 6.1, with a model for electrical conductivity as a function of temperature and pressure. The low magnetic Reynolds number (?1) calculated based on the velocity and length scales in this problem justifies the quasistatic approximation, which assumes negligible effect of velocity on magnetic fields. Therefore, the governing equations employed in the simulations are the compressible Navier-Stokes and the energy equations with MHD-related source terms such as Lorentz force and Joule dissipation. The results demonstrate the ability of the magnetic field to affect the flowfield around the cylinder, which results in an increase in shock stand-off distance and reduction in overall temperature. Also, it is observed that there is a noticeable decrease in drag with the addition of the magnetic field. PMID:24307870

  10. Impact of a high magnetic field on the orientation of gravitactic unicellular organisms--a critical consideration about the application of magnetic fields to mimic functional weightlessness.

    PubMed

    Hemmersbach, Ruth; Simon, Anja; Waßer, Kai; Hauslage, Jens; Christianen, Peter C M; Albers, Peter W; Lebert, Michael; Richter, Peter; Alt, Wolfgang; Anken, Ralf

    2014-03-01

    The gravity-dependent behavior of Paramecium biaurelia and Euglena gracilis have previously been studied on ground and in real microgravity. To validate whether high magnetic field exposure indeed provides a ground-based facility to mimic functional weightlessness, as has been suggested earlier, both cell types were observed during exposure in a strong homogeneous magnetic field (up to 30 T) and a strong magnetic field gradient. While swimming, Paramecium cells were aligned along the magnetic field lines; orientation of Euglena was perpendicular, demonstrating that the magnetic field determines the orientation and thus prevents the organisms from the random swimming known to occur in real microgravity. Exposing Astasia longa, a flagellate that is closely related to Euglena but lacks chloroplasts and the photoreceptor, as well as the chloroplast-free mutant E. gracilis 1F, to a high magnetic field revealed no reorientation to the perpendicular direction as in the case of wild-type E. gracilis, indicating the existence of an anisotropic structure (chloroplasts) that determines the direction of passive orientation. Immobilized Euglena and Paramecium cells could not be levitated even in the highest available magnetic field gradient as sedimentation persisted with little impact of the field on the sedimentation velocities. We conclude that magnetic fields are not suited as a microgravity simulation for gravitactic unicellular organisms due to the strong effect of the magnetic field itself, which masks the effects known from experiments in real microgravity. PMID:24621307

  11. Impact of a High Magnetic Field on the Orientation of Gravitactic Unicellular Organisms—A Critical Consideration about the Application of Magnetic Fields to Mimic Functional Weightlessness

    PubMed Central

    Simon, Anja; Waßer, Kai; Hauslage, Jens; Christianen, Peter C.M.; Albers, Peter W.; Lebert, Michael; Richter, Peter; Alt, Wolfgang; Anken, Ralf

    2014-01-01

    Abstract The gravity-dependent behavior of Paramecium biaurelia and Euglena gracilis have previously been studied on ground and in real microgravity. To validate whether high magnetic field exposure indeed provides a ground-based facility to mimic functional weightlessness, as has been suggested earlier, both cell types were observed during exposure in a strong homogeneous magnetic field (up to 30 T) and a strong magnetic field gradient. While swimming, Paramecium cells were aligned along the magnetic field lines; orientation of Euglena was perpendicular, demonstrating that the magnetic field determines the orientation and thus prevents the organisms from the random swimming known to occur in real microgravity. Exposing Astasia longa, a flagellate that is closely related to Euglena but lacks chloroplasts and the photoreceptor, as well as the chloroplast-free mutant E. gracilis 1F, to a high magnetic field revealed no reorientation to the perpendicular direction as in the case of wild-type E. gracilis, indicating the existence of an anisotropic structure (chloroplasts) that determines the direction of passive orientation. Immobilized Euglena and Paramecium cells could not be levitated even in the highest available magnetic field gradient as sedimentation persisted with little impact of the field on the sedimentation velocities. We conclude that magnetic fields are not suited as a microgravity simulation for gravitactic unicellular organisms due to the strong effect of the magnetic field itself, which masks the effects known from experiments in real microgravity. Key Words: Levitation—Microgravity—Gravitaxis—Gravikinesis—Gravity. Astrobiology 14, 205–215. PMID:24621307

  12. Evaluation of Microcracks orientation at Stromboli volcano using a Magnetic Ferrofluid and the Method of Anisotropy of Magnetic Susceptibility

    NASA Astrophysics Data System (ADS)

    Lewis, O.; Benson, P. M.; Vinciguerra, S.; Meredith, P. G.

    2005-12-01

    Most crustal rocks are anisotropic. In volcanic areas, anisotropy primarily results due to preferred directions of microcracks as magma cools. This effect is, in turn, enhanced due to local stress fields during deposition. The combined effects of these processes may thus give rise to a complex anisotropic fabric. Such fabrics can play crucial roles when enhancing the formation of slip surfaces which can lead to sector collapses of volcanic edifices, as is the case of Stromboli volcano (Italy) which experienced 4 sector collapses in the past 13ka. However, the rapid analysis of anisotropic microcrack fabrics (in terms of magnitude and principal direction) remains non-trivial. Current methods range from time consuming microcrack analysis of thin sections to the preparation of oriented cores for elastic-wave velocity measurement. To further our understanding of how microcrack fabrics influence the bulk properties of volcanic basalt, we employ a novel method which rapidly evaluates the 3-D microcrack orientation using technique of Anisotropy of Magnetic Susceptibility (AMS). First, we determine the rock matrix AMS (mAMS) using standard methods (via a Agico KLY-4 Kappabridge). Samples are then saturated with a magnetic ferrofluid, filling the microcrack network with a magnetically susceptible suspension of microscopic (10nm) magnetite particles. The AMS is then re-measured, with the matrix susceptibility values subtracted from these readings to yield the average 3-D pore space shape, size and orientation (pAMS). We describe the use of this method using basalt from Stromboli and comparing to a granite (Takidani) from the Japanese Alps in order to verify the technique and to investigate the relationship between the basalt microcrack geometry and field scale observation. For Takidani granite we find the structural anisotropy formed by the void space, as measured by pAMS, is well described by elastic wave velocity measurement; exhibiting anisotropy values of 19.1% and 7.6% for P-waves and S-waves respectively. Stromboli basalt possesses a weaker anisotropy of 4.7% and 3.0% (P-wave and S-wave velocity). We relate our pore space AMS measurements to the layering observed in Stromboli basalt on the flanks of the volcanic edifice; and infer that the microcrack network is both formed by this deposition and active tectonics as well as providing a key control on its physical properties. Such data has crucial significance upon the accurate assessment of flank stability, with consequences to hazard assessment for the surrounding area.

  13. Bats respond to polarity of a magnetic field

    PubMed Central

    Wang, Yinan; Pan, Yongxin; Parsons, Stuart; Walker, Michael; Zhang, Shuyi

    2007-01-01

    Bats have been shown to use information from the Earth's magnetic field during orientation. However, the mechanism underlying this ability remains unknown. In this study we investigated whether bats possess a polarity- or inclination-based compass that could be used in orientation. We monitored the hanging position of adult Nyctalus plancyi in the laboratory in the presence of an induced magnetic field of twice Earth-strength. When under the influence of a normally aligned induced field the bats showed a significant preference for hanging at the northern end of their roosting basket. When the vertical component of the field was reversed, the bats remained at the northern end of the basket. However, when the horizontal component of the field was reversed, the bats changed their positions and hung at the southern end of the basket. Based on these results, we conclude that N. plancyi, unlike all other non-mammalian vertebrates tested to date, uses a polarity-based compass during orientation in the roost, and that the same compass is also likely to underlie bats' long-distance navigation abilities. PMID:17848365

  14. Magnetic moment of Ag-104(m) and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei

    E-print Network

    V. V. Golovko; I. S. Kraev; T. Phalet; B. Delaure; M. Beck; V. Yu. Kozlov; S. Coeck; F. Wauters; P. Herzog; Ch. Tramm; D. Zakoucky; D. Venos; D. Srnka; M. Honusek; U. Koester; N. Severijns

    2010-06-30

    Nuclear magnetic resonance (NMR/ON) measurements with beta- and gamma-ray detection have been performed on oriented Ag-104(g,m) nuclei with the NICOLE He-3-He-4 dilution refrigerator setup at ISOLDE/CERN. For Ag-104(g) (I-pi = 5(+)) the gamma-NMR/ON resonance signal was found at nu = 266.70(5) MHz. Combining this result with the known magnetic moment for this isotope, the magnetic hyperfine field of Ag impurities in an Fe host at low temperature (magnetic moment mu(Ag-104m) = +3.691(3) mu(N), which is significantly more precise than previous results. The magnetic moments of the even-A Ag102 -110 isotopes are discussed in view of the competition between the (pi g(9/2))(7/2+)(-3)(nu d(5/2)nu g(7/2))(5/2+) and the (pi g(9/2))(9/2+)(-3)(nu d(5/2)nu g(7/2))(5/2+) configurations. The magnetic moments of the ground and isomeric states of Ag-104 can be explained by an almost complete mixing of these two configurations.

  15. Orientation of lamellar phases of lyotropic multicomponent mixtures, based on cetyltrimethylammonium bromide cationic detergent, in magnetic field

    NASA Astrophysics Data System (ADS)

    Kiirend, E. O.; Chumakova, S. P.; Pekhk, T. I.; Ivanov, N. R.

    2013-11-01

    The orientation of the lamellar phases in lyotropic systems based on cetyltrimethylammonium bromide (CTAB) detergent has been studied by polarization optical microscopy and 2H-NMR methods. The lamellar lyotropics studied are shown to align under a strong magnetic field of 11.7 T. According to 2H-NMR data, structural transformations of the lamellar phases may occur during orientation when the sample temperature increases.

  16. Dayside Magnetopause Transients Correlated with Changes of the Magnetosheath Magnetic Field Orientation

    NASA Technical Reports Server (NTRS)

    Tkachenko, O.; Safrankova, J.; Nemecek, Z.; Sibeck, D. G.

    2011-01-01

    The paper analyses one long-term pass (26 August 2007) of the THEMIS spacecraft across the dayside low-latitude magnetopause. THEMIS B, serving partly as a magnetosheath monitor, observed several changes of the magnetic field that were accompanied by dynamic changes of the magnetopause location and/or the structure of magnetopause layers observed by THEMIS C, D, and E, whereas THEMIS A scanned the inner magnetosphere. We discuss the plasma and the magnetic field data with motivation to identify sources of observed quasiperiodic plasma transients. Such events at the magnetopause are usually attributed to pressure pulses coming from the solar wind, foreshock fluctuations, flux transfer events or surface waves. The presented transient events differ in nature (the magnetopause surface deformation, the low-latitude boundary layer thickening, the crossing of the reconnection site), but we found that all of them are associated with changes of the magnetosheath magnetic field orientation and with enhancements or depressions of the plasma density. Since these features are not observed in the data of upstream monitors, the study emphasizes the role of magnetosheath fluctuations in the solar wind-magnetosphere coupling.

  17. Self-Compassion and Internet Addiction

    ERIC Educational Resources Information Center

    Iskender, Murat; Akin, Ahmet

    2011-01-01

    The purpose of this research is to examine the relationship of self-compassion and internet addiction. Participants were 261 university students who completed a questionnaire package that included the Self-compassion Scale and the Online Cognition Scale. The hypothesis model was tested through structural equation modeling. In correlation analysis,…

  18. Willis Commission 2012 Quality with Compassion

    E-print Network

    Martin, Ralph R.

    B1 Willis Commission 2012 Quality with Compassion: the future of nursing education Report of the Willis Commission 2012 #12;2 Willis Commission 2012 Title: Quality with compassion: the future of nursing education. Report of the Willis Commission on Nursing Education, 2012. Key words: Nursing, education, future

  19. Ocelli contribute to the encoding of celestial compass information in the Australian desert ant Melophorus bagoti.

    PubMed

    Schwarz, Sebastian; Albert, Laurence; Wystrach, Antoine; Cheng, Ken

    2011-03-15

    Many animal species, including some social hymenoptera, use the visual system for navigation. Although the insect compound eyes have been well studied, less is known about the second visual system in some insects, the ocelli. Here we demonstrate navigational functions of the ocelli in the visually guided Australian desert ant Melophorus bagoti. These ants are known to rely on both visual landmark learning and path integration. We conducted experiments to reveal the role of ocelli in the perception and use of celestial compass information and landmark guidance. Ants with directional information from their path integration system were tested with covered compound eyes and open ocelli on an unfamiliar test field where only celestial compass cues were available for homing. These full-vector ants, using only their ocelli for visual information, oriented significantly towards the fictive nest on the test field, indicating the use of celestial compass information that is presumably based on polarised skylight, the sun's position or the colour gradient of the sky. Ants without any directional information from their path-integration system (zero-vector) were tested, also with covered compound eyes and open ocelli, on a familiar training field where they have to use the surrounding panorama to home. These ants failed to orient significantly in the homeward direction. Together, our results demonstrated that M. bagoti could perceive and process celestial compass information for directional orientation with their ocelli. In contrast, the ocelli do not seem to contribute to terrestrial landmark-based navigation in M. bagoti. PMID:21346116

  20. Effect of copper precipitates on the stability of microstructures and magnetic properties of non-oriented electrical steels

    NASA Astrophysics Data System (ADS)

    Wu, Meng; Zeng, Yanping

    2015-10-01

    Non-oriented electrical steels with different amounts of copper were prepared and the microstructure and magnetic properties of each kind of steel were studied. The results show that there exist a large number of Cu-rich metastable precipitates in the hot-rolled bands of the steels containing copper. They not only can decrease the sensitivity of the microstructures and magnetic properties of the steels to the change of process parameters but also can significantly reduce the core loss of the steels by improving the recrystallization textures without obviously decreasing the magnetic induction. Therefore, it is possible to control the microstructures and then magnetic properties of non-oriented electrical steels by the copper precipitates.

  1. Single-crystal NMR approach for determining chemical shift tensors from powder samples via magnetically oriented microcrystal arrays

    NASA Astrophysics Data System (ADS)

    Song, Guangjie; Kusumi, Ryosuke; Kimura, Fumiko; Kimura, Tsunehisa; Deguchi, Kenzo; Ohki, Shinobu; Fujito, Teruaki; Simizu, Tadashi

    2015-06-01

    The single-crystal rotation technique was applied to magnetically oriented microcrystal arrays (MOMAs) of cellobiose (monoclinic) to determine the principal values and principal axes of the chemical shift tensors of C1 and C1? carbons. Rotations were performed about the magnetic ?1, ?2, and ?3 axes of MOMA, and the measurements were taken at six different orientations with respect to the applied magnetic field. Under these rotations, crowded peaks were reduced and the peaks for the C1 and C1? carbons were identified by comparing with simulation results. Six components of the chemical shift tensor expressed with respect to the magnetic ?1?2?3-frame were determined. The tensors thus obtained were transformed into those relative to the molecular frame.

  2. Raman spectra and magnetization of all-ferromagnetic superlattices grown on (110) oriented SrTiO{sub 3}

    SciTech Connect

    Behera, B. C.; Ravindra, A. V.; Padhan, P.; Prellier, W.

    2014-03-03

    Superlattices consist of two ferromagnets La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO) and SrRuO{sub 3} (SRO) were grown in (110)-orientation on SrTiO{sub 3} (STO) substrates. The x-ray diffraction and Raman spectra of these superlattices show the presence of in-plane compressive strain and orthorhombic structure of less than 4 u.c. thick LSMO spacer, respectively. Magnetic measurements reveal several features including reduced magnetization, enhanced coercivity, antiferromagnetic coupling, and switching from antiferromagnetic to ferromagnetic coupling with magnetic field orientations. These magnetic properties are explained by the observed orthorhombic structure of spacer LSMO in Raman scattering which occurs due to the modification in the stereochemistry of Mn at the interfaces of SRO and LSMO.

  3. The importance of magnetic-field-oriented thermal conduction in the interaction of SNR shocks with interstellar clouds

    E-print Network

    S. Orlando; F. Bocchino; F. Reale; G. Peres; P. Pagano

    2008-01-09

    We explore the importance of magnetic-field-oriented thermal conduction in the interaction of supernova remnant (SNR) shocks with radiative gas clouds and in determining the mass and energy exchange between the clouds and the hot surrounding medium. We perform 2.5D MHD simulations of a shock impacting on an isolated gas cloud, including anisotropic thermal conduction and radiative cooling; we consider the representative case of a Mach 50 shock impacting on a cloud ten-fold denser than the ambient medium. We consider different configurations of the ambient magnetic field and compare MHD models with or without the thermal conduction. The efficiency of the thermal conduction in the presence of magnetic field is, in general, reduced with respect to the unmagnetized case. The reduction factor strongly depends on the initial magnetic field orientation, and it is minimum when the magnetic field is initially aligned with the direction of shock propagation. The thermal conduction contributes to suppress hydrodynamic instabilities, reducing the mass mixing of the cloud and preserving the cloud from complete fragmentation. Depending on the magnetic field orientation, the heat conduction may determine a significant energy exchange between the cloud and the hot surrounding medium which, while remaining always at levels less than those in the unmagnetized case, leads to a progressive heating and evaporation of the cloud. This additional heating may contrast the radiative cooling of some parts of the cloud, preventing the onset of thermal instabilities.

  4. Robustness of the filamentation instability in arbitrarily oriented magnetic field: Full three dimensional calculation

    SciTech Connect

    Bret, A.

    2014-02-15

    The filamentation (Weibel) instability plays a key role in the formation of collisionless shocks which are thought to produce Gamma-Ray-Bursts and High-Energy-Cosmic-Rays in astrophysical environments. While it has been known for long that a flow-aligned magnetic field can completely quench the instability, it was recently proved in 2D that in the cold regime, such cancelation is possible if and only if the field is perfectly aligned. Here, this result is finally extended to a 3D geometry. Calculations are conducted for symmetric and asymmetric counter-streaming relativistic plasma shells. 2D results are retrieved in 3D: the instability can never be completely canceled for an oblique magnetic field. In addition, the maximum growth-rate is always larger for wave vectors lying in the plan defined by the flow and the oblique field. On the one hand, this bears consequences on the orientation of the generated filaments. On the other hand, it certifies 2D simulations of the problem can be performed without missing the most unstable filamentation modes.

  5. Roe v. Wade. Reflective compassion.

    PubMed

    Padovano, A T

    1998-01-01

    The US has arrived at the correct legal status for induced abortion by permitting it on constitutional grounds within limits. In addition, the general consensus among American Catholics is in favor of abortion rights while disapproving of abortion and wishing to discourage it. Concerns about the morality of abortion, however, arise out of our uncertainty about the personhood of a fetus before birth or before viability. Early church leaders taught that a fetus did not obtain personhood until it acquired a human form, and the Catholic church did not baptize aborted fetuses without human shape or hold formal funeral services for dead fetuses. While official church teaching is adamant about the immorality of abortion, official church teaching has changed in the past in regard to the salvation of non-Catholics, slavery, inquisitions and torture, ecumenism, worship in the vernacular, and divorce and remarriage. No one is forced to have an abortion in the US because the legal right exists, and Catholics are more likely to heed Church teachings that do not seek legal force and punishment though "infallible" pronouncements and insensitive condemnation of women. If the Catholic church expects compassion for its wrong decisions in the past, then it should extend compassion to women in difficult situations. PMID:12178887

  6. Magnetic information calibrates celestial cues during migration.

    PubMed

    Sandberg; Bäckman; Moore; Lõhmus

    2000-10-01

    Migratory birds use celestial and geomagnetic directional information to orient on their way between breeding and wintering areas. Cue-conflict experiments involving these two orientation cue systems have shown that directional information can be transferred from one system to the other by calibration. We designed experiments with four species of North American songbirds to: (1) examine whether these species calibrate orientation information from one system to the other; and (2) determine whether there are species-specific differences in calibration. Migratory orientation was recorded with two different techniques, cage tests and free-flight release tests, during autumn migration. Cage tests at dusk in the local geomagnetic field revealed species-specific differences: red-eyed vireo, Vireo olivaceus, and northern waterthrush, Seiurus noveboracensis, selected seasonally appropriate southerly directions whereas indigo bunting, Passerina cyanea, and grey catbird, Dumetella carolinensis, oriented towards the sunset direction. When tested in deflected magnetic fields, vireos and waterthrushes responded by shifting their orientation according to the deflection of the magnetic field, but buntings and catbirds failed to show any response to the treatment. In release tests, all four species showed that they had recalibrated their star compass on the basis of the magnetic field they had just experienced in the cage tests. Since release tests were done in the local geomagnetic field it seems clear that once the migratory direction is determined, most likely during the twilight period, the birds use their recalibrated star compass for orientation at departure. Copyright 2000 The Association for the Study of Animal Behaviour. PMID:11032648

  7. The spin physics results from COMPASS

    SciTech Connect

    Kouznetsov, O.

    2015-04-10

    COMPASS (COmmon Muon and Proton Apparatus for Structure and Spectroscopy) is a fixed target experiment at CERN dedicated to studies of the spin structure of the nucleon and of the spectroscopy of hadrons. During the years 2002-2004, 2006-2007 and 2010-2011 the COMPASS collaboration has collected a large amount of data by scattering polarized 160(200) GeV/c muons on polarized {sup 6}LiD and NH{sub 3} targets. The COMPASS results on quark and gluon helicities are discussed, as well as results on transverse spin and transverse momentum effects in semi-inclusive deeply inelastic scattering.

  8. The COMPASS Experiment at CERN

    E-print Network

    COMPASS Collaboration; P. Abbon

    2007-03-30

    The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both hadron and electromagnetic calorimeters. The setup has been successfully operated from 2002 onwards using a muon beam. Data with a hadron beam were also collected in 2004. This article describes the main features and performances of the spectrometer in 2004; a short summary of the 2006 upgrade is also given.

  9. Control of the magnetization orientation in L10 FePt films by means of annealing in a magnetic field near the Curie temperature

    NASA Astrophysics Data System (ADS)

    Kamzin, A. S.; Cao, J. W.; Ma, B.; Wei, F. L.; Valiullin, A. A.; Ganeev, V. R.; Zaripova, L. D.

    2015-09-01

    Films of the L10 Fe50Pt50 phase with a thickness of 20 nm in the multilayer Fe(2 nm)/Fe50Pt50(20 nm)/Pt(2 nm) magnetic structure have been prepared by magnetron sputtering. The multilayer structures have been annealed at 700°C for 30 min and then at 430-600°C for 1 h either in an external magnetic field of ˜3500 Oe, which is applied perpendicular to the film plane (the A mode), or without an external magnetic field (the B mode). X-ray diffraction and Mössbauer studies have revealed that the annealing of FePt films in the composition of the multilayer magnetic structure in an external magnetic field at the temperature T C = 478°C ( T C is the Curie temperature for FePt films) leads to the formation of the L10 structure with the magnetic moments oriented along the normal to the film surface. In this case, the atomic force microscopy images have demonstrated changes in the grain sizes. When the annealing temperature is close to the Curie temperature T C for FePt films, the thermal perturbation is comparable in magnitude to the magnetization exchange energy; consequently, the external magnetic field of ˜3500 Oe, which is applied perpendicular to the film surface, effectively contributes to the formation of the L10 structure. The annealing of FePt structures in an external magnetic field makes it possible to form the L10 (001) texture in these materials and to orient magnetic moments in the direction of the field.

  10. Honeybee navigation: critically examining the role of the polarization compass

    PubMed Central

    Evangelista, C.; Kraft, P.; Dacke, M.; Labhart, T.; Srinivasan, M. V.

    2014-01-01

    Although it is widely accepted that honeybees use the polarized-light pattern of the sky as a compass for navigation, there is little direct evidence that this information is actually sensed during flight. Here, we ask whether flying bees can obtain compass cues derived purely from polarized light, and communicate this information to their nest-mates through the ‘waggle dance’. Bees, from an observation hive with vertically oriented honeycombs, were trained to fly to a food source at the end of a tunnel, which provided overhead illumination that was polarized either parallel to the axis of the tunnel, or perpendicular to it. When the illumination was transversely polarized, bees danced in a predominantly vertical direction with waggles occurring equally frequently in the upward or the downward direction. They were thus using the polarized-light information to signal the two possible directions in which they could have flown in natural outdoor flight: either directly towards the sun, or directly away from it. When the illumination was axially polarized, the bees danced in a predominantly horizontal direction with waggles directed either to the left or the right, indicating that they could have flown in an azimuthal direction that was 90° to the right or to the left of the sun, respectively. When the first half of the tunnel provided axial illumination and the second half transverse illumination, bees danced along all of the four principal diagonal directions, which represent four equally likely locations of the food source based on the polarized-light information that they had acquired during their journey. We conclude that flying bees are capable of obtaining and signalling compass information that is derived purely from polarized light. Furthermore, they deal with the directional ambiguity that is inherent in polarized light by signalling all of the possible locations of the food source in their dances, thus maximizing the chances of recruitment to it. PMID:24395964

  11. Compassion Fatigue, Compassion Satisfaction, and Burnout: Factors Impacting a Professional's Quality of Life

    ERIC Educational Resources Information Center

    Sprang, Ginny; Whitt-Woosley, Adrienne; Clark, James J.

    2007-01-01

    This study examined the relationship between three variables, compassion fatigue (CF), compassion satisfaction (CS), and burnout, and provider and setting characteristics in a sample of 1,121 mental health providers in a rural southern state. Respondents completed the Professional Quality of Life Scale as part of a larger survey of provider…

  12. 1938 IEEE TRANSACTIONS ON MAGNETICS, VOL. 37, NO. 4, JULY 2001 A New Method for Magnetic Position and Orientation

    E-print Network

    Paperno, Eugene

    1938 IEEE TRANSACTIONS ON MAGNETICS, VOL. 37, NO. 4, JULY 2001 A New Method for Magnetic Position-axis generation of a quasi-static rotating magnetic field and three-axis sensing. Two mutually orthogonal coils rotating magnetic dipole. The resulting excitation field rotates elliptically at any position in the near

  13. Distinctive uniaxial magnetic anisotropy and positive magnetoresistance in (110)-oriented Fe{sub 3}O{sub 4} films

    SciTech Connect

    Dho, Joonghoe Kim, Byeong-geon; Ki, Sanghoon

    2015-04-28

    Magnetite (Fe{sub 3}O{sub 4}) films were synthesized on (110)-oriented MgO, MgAl{sub 2}O{sub 4}, and SrTiO{sub 3} substrates for comparative studies of the substrates' effects on magnetic and magnetoresistance properties of the films. For the [-110] direction, the hysteresis loops of the Fe{sub 3}O{sub 4} film on MgAl{sub 2}O{sub 4} exhibited a good squareness with the largest coercivity of ?1090?Oe, and the ratio of remanent magnetization to saturation magnetization was ?0.995. For the [001] direction, positive magnetoresistance in weak magnetic fields was most distinct for the (110) SrTiO{sub 3} substrate with the largest lattice mismatch. Positive magnetoresistance in the (110) Fe{sub 3}O{sub 4} films was presumably affected by imperfect atomic arrangements at anti-phase boundaries.

  14. Domain wall assisted magnetization switching in (111) oriented L1{sub 0} FePt grown on a soft magnetic metallic glass

    SciTech Connect

    Kaushik, Neelam; Sharma, Parmanand; Yubuta, Kunio; Makino, Akihiro; Inoue, Akihisa

    2010-08-16

    We report on growth and magnetic properties of exchange-coupled (111)-L1{sub 0} FePt hard/CoFeTaB soft magnetic metallic glass bilayered structure processed at lower temperature ({approx}400 deg. C). Single phaselike hysteresis loops with tailorable coercivity (<8.2 kOe) in out of plane direction are obtained. The magnetization switching mechanism is identified as domain wall assisted. In views of excellent nanofabrication abilities of metallic glass thin film and the ability to grow preferred oriented L1{sub 0} FePt, the present bilayered structure is very promising for the fabrication of high density bit--patterned magnetic recording media and other spintronic devices.

  15. Magnetic monitoring of earth and space

    USGS Publications Warehouse

    Love, J.J.

    2008-01-01

    For centuries, navigators of the world's oceans have been familiar with an effect of Earth's magnetic field: It imparts a directional preference to the needle of a compass. Although in some settings magnetic orientation remains important, the modern science of geomagnetism has emerged from its romantic nautical origins and developed into a subject of great depth and diversity. The geomagnetic field is used to explore the dynamics of Earth's interior and its surrounding space environment, and geomagnetic data are used for geophysical mapping, mineral exploration, risk mitigation, and other practical applications. A global distribution of ground-based magnetic observatories supports those pursuits by providing accurate records of the magnetic-field direction and intensity at fixed locations and over long periods of time. ?? 2008 American Institute of Physics.

  16. Magnetic monitoring of earth and space

    USGS Publications Warehouse

    Love, J.J.

    2008-01-01

    For centuries, navigators of the world's oceans have been familiar with an effect of Earth's magnetic field: It imparts a directional preference to the needle of a compass. Although in some settings magnetic orientation remains important, the modern science of geomagnetism has emerged from its romantic nautical origins and developed into a subject of great depth and diversity. The geomagnetic field is used to explore the dynamics of Earth's interior and its surrounding space environment, and geomagnetic data are used for geophysical mapping, mineral exploration, risk mitigation, and other practical applications. A global distribution of ground-based magnetic observatories supports those pursuits by providing accurate records of the magnetic-field direction and intensity at fixed locations and over long periods of time.

  17. Quantum dynamics of the avian compass

    NASA Astrophysics Data System (ADS)

    Walters, Zachary B.

    2014-10-01

    The ability of migratory birds to orient relative to the Earth's magnetic field is believed to involve a coherent superposition of two spin states of a radical electron pair. However, the mechanism by which this coherence can be maintained in the face of strong interactions with the cellular environment has remained unclear. This paper addresses the problem of decoherence between two electron spins due to hyperfine interaction with a bath of spin-1/2 nuclei. Dynamics of the radical pair density matrix are derived and shown to yield a simple mechanism for sensing magnetic field orientation. Rates of dephasing and decoherence are calculated ab initio and found to yield millisecond coherence times, consistent with behavioral experiments.

  18. Study of the influence of the orientation of a 50-Hz magnetic field on fetal exposure using polynomial chaos decomposition.

    PubMed

    Liorni, Ilaria; Parazzini, Marta; Fiocchi, Serena; Ravazzani, Paolo

    2015-01-01

    Human exposure modelling is a complex topic, because in a realistic exposure scenario, several parameters (e.g., the source, the orientation of incident fields, the morphology of subjects) vary and influence the dose. Deterministic dosimetry, so far used to analyze human exposure to electromagnetic fields (EMF), is highly time consuming if the previously-mentioned variations are considered. Stochastic dosimetry is an alternative method to build analytical approximations of exposure at a lower computational cost. In this study, it was used to assess the influence of magnetic flux density (B) orientation on fetal exposure at 50 Hz by polynomial chaos (PC). A PC expansion of induced electric field (E) in each fetal tissue at different gestational ages (GA) was built as a function of B orientation. Maximum E in each fetal tissue and at each GA was estimated for different exposure configurations and compared with the limits of the International Commission of Non-Ionising Radiation Protection (ICNIRP) Guidelines 2010. PC theory resulted in an efficient tool to build accurate approximations of E in each fetal tissue. B orientation strongly influenced E, with a variability across tissues from 10% to 43% with respect to the mean value. However, varying B orientation, maximum E in each fetal tissue was below the limits of ICNIRP 2010 at all GAs. PMID:26024363

  19. Study of the Influence of the Orientation of a 50-Hz Magnetic Field on Fetal Exposure Using Polynomial Chaos Decomposition

    PubMed Central

    Liorni, Ilaria; Parazzini, Marta; Fiocchi, Serena; Ravazzani, Paolo

    2015-01-01

    Human exposure modelling is a complex topic, because in a realistic exposure scenario, several parameters (e.g., the source, the orientation of incident fields, the morphology of subjects) vary and influence the dose. Deterministic dosimetry, so far used to analyze human exposure to electromagnetic fields (EMF), is highly time consuming if the previously-mentioned variations are considered. Stochastic dosimetry is an alternative method to build analytical approximations of exposure at a lower computational cost. In this study, it was used to assess the influence of magnetic flux density (B) orientation on fetal exposure at 50 Hz by polynomial chaos (PC). A PC expansion of induced electric field (E) in each fetal tissue at different gestational ages (GA) was built as a function of B orientation. Maximum E in each fetal tissue and at each GA was estimated for different exposure configurations and compared with the limits of the International Commission of Non-Ionising Radiation Protection (ICNIRP) Guidelines 2010. PC theory resulted in an efficient tool to build accurate approximations of E in each fetal tissue. B orientation strongly influenced E, with a variability across tissues from 10% to 43% with respect to the mean value. However, varying B orientation, maximum E in each fetal tissue was below the limits of ICNIRP 2010 at all GAs. PMID:26024363

  20. Rheological properties and orientational distributions of dilute ferromagnetic spherocylinder particle dispersions. Part II. Analysis for the two typical magnetic field directions.

    PubMed

    Aoshima, Masayuki; Satoh, Akira; Chantrell, Roy W; Coverdale, Geoff N

    2002-09-15

    We have investigated the orientational distributions and rheological properties of dilute colloidal dispersions, which consist of ferromagnetic spherocylinder particles. First, the governing equation of the orientational distribution function has been derived for the typical two cases of magnetic field directions: the direction parallel to the shear flow and the direction parallel to the angular velocity vector of the shear flow. The equation has been solved approximately by Galerkin's method. With these numerical solutions we have obtained the results of the orientational distribution and viscosity. The results obtained for the magnetic field in the shear flow direction are summarized as follows. In the case of a weak magnetic field, the particle tends to orient nearly toward the shear flow direction and its opposite direction. As the magnetic field increases, the orientation of the particle is restricted and the viscosity increases significantly. As the influence of the magnetic field becomes dominant, an overshoot in the viscosity curve appears. This is due to the fact that there is a maximum deviation of the averaged particle direction from the magnetic field direction. When the strength of the magnetic field increases significantly, the particle inclines close to the magnetic field direction and the viscosity converges to a constant value. Particles with a larger aspect ratio give rise to a larger increment in the viscosity since such elongated particles induce larger resistance in a flow field. We also have obtained results for the case of the magnetic field in the direction parallel to the angular velocity vector of the shear flow. When the flow field is dominant over both the rotational Brownian motion and the magnetic interaction, the particle rotates in the plane nearly perpendicular to the magnetic field direction. As the magnetic field increases, the particle inclines toward the magnetic direction. For this direction of field, the viscosity is independent of the magnetic field and is always zero. PMID:16290877

  1. Influence of lattice-preferred orientation with respect to magnetizing field on intensity of remanent magnetization in polycrystalline hemo-ilmenite

    NASA Astrophysics Data System (ADS)

    Robinson, P.; Fabian, K.; McEnroe, S. A.; Heidelbach, F.

    2013-02-01

    New experimental and computational approaches to interpret orientation and intensity of natural remanent magnetization (NRM) carried by lamellar magnetism are applied to historic magnetic measurements on a collection of 82 massive hemo-ilmenite samples from the Allard Lake District in the Grenville Province, Quebec. The anisotropy of magnetic susceptibility (AMS), together with declination and inclination of NRM, indicate a systematic deflection ? of the NRM vector away from the unit vector v that represents the Mesoproterozoic magnetizing field direction. The deflection ? is caused by a statistical lattice-preferred orientation (LPO) of the individual (0001) basal planes, to which the NRM is confined in hemo-ilmenite crystals. Here, we study a second deflection ? that is the angle the NRM makes with the statistical (0001) basal plane of the crystal assemblage, in relation to the angle ? between the statistical (0001) basal plane and v. The relation between these two angles depends on the scatter of the distribution of crystal platelets, which also influences the AMS of the assemblage. For a Fisher distribution of basal planes, the distribution parameter K can be determined from ? and ?. It is then further possible to infer the single-crystal anisotropy of individual platelets. Typical crystals of hemo-ilmenite turn out to have a relatively weak AMS so that samples with a narrow Fisher distribution of platelets nevertheless can have a weak AMS. This has been confirmed in two samples by measurement of the (0001) basal plane distribution of crystals using electron backscatter diffraction, and in one of these two samples by measuring AMS and NRM of a single hemo-ilmenite crystal. Based on our estimated K values for selected samples, we calculate values of ?, NRM intensity and ? for any value of ?. These data provide striking examples of the influence of the orientation of the crystal LPO on the intensity of lamellar magnetism, and explain the large variation of observed NRM intensities by varying orientation with respect to the magnetizing field, without requiring large variations of the paleomagnetic field intensity. This relation between NRM and LPO is also important for anomaly interpretation in areas with strong foliation.

  2. First results from EBW emission diagnostics on COMPASS.

    PubMed

    Zajac, J; Preinhaelter, J; Urban, J; Aftanas, M; Bílková, P; Böhm, P; Fuchs, V; Nanobashvili, S; Weinzettl, V; Zácek, F

    2012-10-01

    COMPASS tokamak shots at low magnetic field feature overdense plasmas during the extended current flat-top phase. The first harmonic of the electron cyclotron emission is completely cutoff for O and X modes and so the emission caused by electron Bernstein waves (EBWs) propagating obliquely with respect to the magnetic field and undergoing so called EBW-X-O conversion process can be observed. We perform an angular scan of the EBW emission during a set of comparable shots in order to determine the optimum antenna direction. A weak dependence of the radiative temperature on the antenna angles indicates an influence of multiple reflections from the vessel wall. The low temperature at the mode conversion region is responsible for the collisional damping of EBW, which can explain several times lower measured radiative temperature than the electron temperature measured by the Thomson scattering system. PMID:23126985

  3. Self-Compassion and the Dynamics of Investigating Sexual Harassment

    ERIC Educational Resources Information Center

    Serri, Conchita Franco

    2006-01-01

    What role does compassion play in one's work? In the author's organization, the word "compassion" has been mostly linked to their values, mission, and programs. She has generally understood the concept of compassion as a deep feeling of empathy that flows from oneself towards others during certain situations and conditions. In her mind, "having…

  4. Nursing on empty: compassion fatigue signs, symptoms, and system interventions.

    PubMed

    Harris, Chelsia; Griffin, Mary T Quinn

    2015-01-01

    Few healthcare organizations acknowledge, discuss, or provide interventions for assisting with compassion fatigue. Yet, it is an important concept due to its individual, professional, and financial costs. This article defines compassion fatigue, differentiates it from burnout, and offers system interventions for supporting nurses and reducing compassion fatigue. PMID:25898441

  5. Evaluation of Compass Ambiguity Resolution Performance Using Geometric-Based

    E-print Network

    Calgary, University of

    performance in terms of ambiguity resolution compared to GPS and Galileo due to the fact that Compass signals of the performance of ambiguity resolution using Compass carrier phase measurements based on covariance simulationEvaluation of Compass Ambiguity Resolution Performance Using Geometric-Based Techniques

  6. Utilization of gyroscopic compass with borehole television camera in Devonian shale wells, Appalachian basin

    SciTech Connect

    Walbe, K.

    1988-08-01

    The color Borehole Television Camera has, in the three short years since its introduction in the Appalachian basin, become an extremely valuable tool in evaluating wells in Devonian shale. This has been due to the camera's ability to detect fracturing and small hydrocarbon entries that are below the resolution threshold of conventional geophysical logging. This potential of the camera has been greatly enhanced by the addition of a gyroscopic compass to the basic tool. This compass gives the added value of orientation to observed phenomena in both open and cased holes. In the open hole, the camera can be used to determine the orientation of fracturing. This feature is extremely important because fracture orientation can vary with depth, which may be the reason that some previously observed fractures make gas, whereas others within the same well bore do not. The productive fracture orientation can also be tied back to regional lineation studies. Within the open hole, the gyroscope can also be used to orient sidewall coring operations so that cores can, in addition to regular analyses, be evaluated for directional properties, such as permeability and direction of the source beds. Induced fractures, created by open-hole stress testing, can also be observed and their orientation determined.

  7. Mining-machine orientation control based on inertial, gravitational, and magnetic sensors. Report of Investigations/1990

    SciTech Connect

    Sammarco, J.J.

    1990-01-01

    The U.S. Bureau of Mines seeks to increase safety and efficiency in U.S. coal mines. One approach is to develop technology for automation of a continuous mining machine. Realization of an autonomous mining machine requires development of subsystems for machine intelligence, navigation-positioning, and computer control. The report focuses on investigation of one subsystem, an onboard heading system, which would be responsible for determining and controlling machine heading. The onboard heading system investigated is a multisensor system to determine machine heading, pitch, and roll. A directional gyroscope provides heading (yaw), fluxgate sensors provide a compass heading, and gravity-referenced clinometers give machine pitch and roll. The system utilizes a dedicated microcontroller networked to an external system of computers. Tram commands, supplied to the network from external computers, are executed by the onboard system. Sensor feedback is employed for closed-loop control of machine heading by controlling pivots and turns. The report discusses operating limitations and error sources of system sensors and presents test results of closed-loop control of machine heading.

  8. Investigation on magnetic properties of parallel and perpendicular oriented Nd2Fe14B/Fe65Co35/Nd2Fe14B films by the micro-magnetism finite element method

    NASA Astrophysics Data System (ADS)

    Li, Y. Q.; Yue, M.; Wu, Q.; Wang, T.; Cheng, C. X.; Chen, H. X.

    2015-11-01

    In present study, the hysteresis loops and the magnetic reversal process of both the parallel and the perpendicular oriented Nd2Fe14B/Fe65Co35/Nd2Fe14B trilayers with different soft phase thicknesses were studied by the micro-magnetism finite element method. Analysis of magnetization vectors' evolution in demagnetization process indicates that the parallel and the perpendicular oriented trilayers exhibit different magnetic reversal behaviors. All the demagnetization curves of the perpendicular oriented trilayers exhibits "single phase" behavior, while noticeable kinks presents in the demagnetization curves of the parallel oriented trilayers with the soft phase thickness equal to or larger than 12 nm. Moreover, as the thickness of the soft phase increases, the remanence (Br) of the parallel and the perpendicular oriented trilayers increases first, peaks respectively at 1.90 and 1.93 T, respectively, and then decreases again. On the other hand, the coercivity (?0Hc) of the parallel and the perpendicular oriented trilayers drops monotonically with the increase of soft layers thickness. As a result, the optimal maximum energy product [(BH)max] of the parallel and the perpendicular oriented trilayers are 630 kJ/m3 and 592 kJ/m3, respectively. Deviation degree of orientation was simulated for the perpendicular oriented trilayers with Ls=10 nm.

  9. Choreographing Compassion: A Clinical Adventure of Rhythms.

    PubMed

    Yopst, Charles George

    2015-06-01

    Compassion is a primary catalyst motivating positive human relationships, especially of those less fortunate. Our rhythms Expand-Contract of our own non-verbal body joints movements and of the law of counter-balance, enable us to identify which of nine innate affects-emotions is directing the body's movements. With this reading, a trained person can synchronize choreography of these into fully authentic compassion between two or more persons. Primary references for this are the late Silvan S. Tomkins's four volumes "Affect Imagery Consciousness," and choreographers the late Rudolf Laban, Warren Lamb, Irmgard Bartenieff, and Marian Chace. Professionals, clinicians, and laity counselors can all use these. PMID:26227934

  10. Conditions database system of the COMPASS experiment

    NASA Astrophysics Data System (ADS)

    Toeda, T.; Lamanna, M.; Duic, V.; Manara, A.

    2003-05-01

    The CERN SPS experiment COMPASS has integrated a Conditions Database System in its off-line software. The system is used to manage time-dependent information, detector condition, calibration, and geometrical alignment information, by using a package provided by the CERN IT/DB. This integrated system consists of administration tools, a data handling library, and data transfer software from the detector control system to the Conditions Database. In this paper, the status of the Conditions Database project is described, and the results of the performance test on the COMPASS computing farm are given.

  11. Transmedulla Neurons in the Sky Compass Network of the Honeybee (Apis mellifera) Are a Possible Site of Circadian Input.

    PubMed

    Zeller, Maximilian; Held, Martina; Bender, Julia; Berz, Annuska; Heinloth, Tanja; Hellfritz, Timm; Pfeiffer, Keram

    2015-01-01

    Honeybees are known for their ability to use the sun's azimuth and the sky's polarization pattern for spatial orientation. Sky compass orientation in bees has been extensively studied at the behavioral level but our knowledge about the underlying neuronal systems and mechanisms is very limited. Electrophysiological studies in other insect species suggest that neurons of the sky compass system integrate information about the polarization pattern of the sky, its chromatic gradient, and the azimuth of the sun. In order to obtain a stable directional signal throughout the day, circadian changes between the sky polarization pattern and the solar azimuth must be compensated. Likewise, the system must be modulated in a context specific way to compensate for changes in intensity, polarization and chromatic properties of light caused by clouds, vegetation and landscape. The goal of this study was to identify neurons of the sky compass pathway in the honeybee brain and to find potential sites of circadian and neuromodulatory input into this pathway. To this end we first traced the sky compass pathway from the polarization-sensitive dorsal rim area of the compound eye via the medulla and the anterior optic tubercle to the lateral complex using dye injections. Neurons forming this pathway strongly resembled neurons of the sky compass pathway in other insect species. Next we combined tracer injections with immunocytochemistry against the circadian neuropeptide pigment dispersing factor and the neuromodulators serotonin, and ?-aminobutyric acid. We identified neurons, connecting the dorsal rim area of the medulla to the anterior optic tubercle, as a possible site of neuromodulation and interaction with the circadian system. These neurons have conspicuous spines in close proximity to pigment dispersing factor-, serotonin-, and GABA-immunoreactive neurons. Our data therefore show for the first time a potential interaction site between the sky compass pathway and the circadian clock. PMID:26630286

  12. Transmedulla Neurons in the Sky Compass Network of the Honeybee (Apis mellifera) Are a Possible Site of Circadian Input

    PubMed Central

    Zeller, Maximilian; Held, Martina; Bender, Julia; Berz, Annuska; Heinloth, Tanja; Hellfritz, Timm; Pfeiffer, Keram

    2015-01-01

    Honeybees are known for their ability to use the sun’s azimuth and the sky’s polarization pattern for spatial orientation. Sky compass orientation in bees has been extensively studied at the behavioral level but our knowledge about the underlying neuronal systems and mechanisms is very limited. Electrophysiological studies in other insect species suggest that neurons of the sky compass system integrate information about the polarization pattern of the sky, its chromatic gradient, and the azimuth of the sun. In order to obtain a stable directional signal throughout the day, circadian changes between the sky polarization pattern and the solar azimuth must be compensated. Likewise, the system must be modulated in a context specific way to compensate for changes in intensity, polarization and chromatic properties of light caused by clouds, vegetation and landscape. The goal of this study was to identify neurons of the sky compass pathway in the honeybee brain and to find potential sites of circadian and neuromodulatory input into this pathway. To this end we first traced the sky compass pathway from the polarization-sensitive dorsal rim area of the compound eye via the medulla and the anterior optic tubercle to the lateral complex using dye injections. Neurons forming this pathway strongly resembled neurons of the sky compass pathway in other insect species. Next we combined tracer injections with immunocytochemistry against the circadian neuropeptide pigment dispersing factor and the neuromodulators serotonin, and ?-aminobutyric acid. We identified neurons, connecting the dorsal rim area of the medulla to the anterior optic tubercle, as a possible site of neuromodulation and interaction with the circadian system. These neurons have conspicuous spines in close proximity to pigment dispersing factor-, serotonin-, and GABA-immunoreactive neurons. Our data therefore show for the first time a potential interaction site between the sky compass pathway and the circadian clock. PMID:26630286

  13. Is it possible to receive information about the historical geomagnetic declination from church orientations?

    NASA Astrophysics Data System (ADS)

    Draxler, Andrea; Rauch, Roman; Gruber, Karin; Leohardt, Roman

    2013-04-01

    It is widely known that the main structure of many churches was planned and built in an east-ward direction. This procedure, called "easting", was used for centuries especially in catholic structures. "Easting" usually refers to the direction of sunrise at the church patron's day. Assuming however that this direction is estimated by compasses there could be a significant correlation between the geographic orientation of the churches and the value of magnetic declination at the date of building. In Europe compasses are known since the 11th century. For this study altogether 124 churches located in lower Austria and built between 1100 to 1900 were analysed. Of primary interest is the geographic orientation of the churches, which was extracted out of georeferenced satellite images in Google Earth and the NO Atlas. The measured orientation of the church's nave is then compared to the geographic east direction as well as to the magnetic east direction, according to the magnetic field in the church's construction year which is determined by published geomagnetic field models. The resulting deviations for the geographic east direction split our data into two groups: churches that were built before 1500 and churches that were constructed after 1500. The boundary between these two data sets is marked by the Ottoman wars in the 16th century, where a lot of churches were destroyed. After 1500 the differences between the church's orientation and the geographic east direction are significantly bigger than before the Ottoman wars, so we shifted our focus for the following calculations on the time span from 1100 to 1500, where we found quite small deviations for both the geographic and the magnetic east direction. The principle idea of church orientation, usually referred to as "Easting" is to direct the church to the point of sunrise on the patron saint's day. Therefore we also calculated the solar azimuth on the patron saint's day and compared it to the orientation of the church. The differences we found were bigger than the deviations we got from the comparisons to the geographic and magnetic east directions, so this indicates that practically the solar azimuth was not used for the church's direction. Furthermore, our investigations indicate that the orientation of the investigated churches is more likely to be related to the geographic east direction than to magnetic east.

  14. Equilibrium intermediate-state patterns in a type-I superconducting slab in an arbitrarily oriented applied magnetic field

    SciTech Connect

    Clem, John; Prozorov, Ruslan; Wijngaarden, Rinke J.

    2013-09-04

    The equilibrium topology of superconducting and normal domains in flat type-I superconductors is investigated. Important improvements with respect to previous work are that (1) the energy of the external magnetic field, as deformed by the presence of superconducting domains, is calculated in the same way for three different topologies and (2) calculations are made for arbitrary orientation of the applied field. A phase diagram is presented for the minimum-energy topology as a function of applied field magnitude and angle. For small (large) applied fields, normal (superconducting) tubes are found, while for intermediate fields, parallel domains have a lower energy. The range of field magnitudes for which the superconducting-tubes structure is favored shrinks when the field is more in-plane oriented.

  15. Equilibrium intermediate-state patterns in a type-I superconducting slab in an arbitrarily oriented applied magnetic field

    DOE PAGESBeta

    Clem, John; Prozorov, Ruslan; Wijngaarden, Rinke J.

    2013-09-04

    The equilibrium topology of superconducting and normal domains in flat type-I superconductors is investigated. Important improvements with respect to previous work are that (1) the energy of the external magnetic field, as deformed by the presence of superconducting domains, is calculated in the same way for three different topologies and (2) calculations are made for arbitrary orientation of the applied field. A phase diagram is presented for the minimum-energy topology as a function of applied field magnitude and angle. For small (large) applied fields, normal (superconducting) tubes are found, while for intermediate fields, parallel domains have a lower energy. Themore »range of field magnitudes for which the superconducting-tubes structure is favored shrinks when the field is more in-plane oriented.« less

  16. Rise of pairwise thermal entanglement for an alternating Ising and Heisenberg spin chain in an arbitrarily oriented magnetic field

    NASA Astrophysics Data System (ADS)

    Rojas, M.; de Souza, S. M.; Rojas, Onofre

    2014-03-01

    Typically two particles (spins) could be maximally entangled at zero temperature, and for a certain temperature the phenomenon of entanglement vanishes at the threshold temperature. For the Heisenberg coupled model or even the Ising model with a transverse magnetic field, one can observe some rise of entanglement even for a disentangled region at zero temperature. So we can understand this emergence of entanglement at finite temperature as being due to the mixing of some maximally entangled states with some other untangled states. Here, we present a simple one-dimensional Ising model with alternating Ising and Heisenberg spins in an arbitrarily oriented magnetic field, which can be mapped onto the classical Ising model with a magnetic field. This model does not show any evidence of entanglement at zero temperature, but surprisingly at finite temperature rise a pairwise thermal entanglement between two untangled spins at zero temperature when an arbitrarily oriented magnetic field is applied. This effect is a purely magnetic field, and the temperature dependence, as soon as the temperature increases, causes a small increase in concurrence, achieving its maximum at around 0.1. Even for long-range entanglement, a weak concurrence still survives. There are also some real materials that could serve as candidates that would exhibit this effect, such as Dy(NO3)(DMSO)2Cu(opba)(DMSO)2 [DMSO = dimethyl sulfoxide; opba = o-phenylenebis(oxamoto)] [J. Stre?ka, M. Hagiwara, Y. Han, T. Kida, Z. Honda, and M. Ikeda, Condens. Matter Phys. 15, 43002 (2012), 10.5488/CMP.15.43002].

  17. The orientation of night-migrating passerines without the directional influence of the starry sky and/or the earth magnetic field.

    PubMed

    Rabol, J

    1975-10-01

    During four seasons in 1972-73 a total of 598 orientation experiments -- including 157 displacements -- was carried out. The purpose of the experiments was to investigate the orientation under an overcast sky and/or when the earth magnetic field was screened by a strong artificial magnetic field. These experiments were compared with experiments carried out under the presumed maximum condition, i.e. under a starry sky and without magnetic disturbances. In general, little or no "reduction" of the sample mean vector, was observed under the "deprived" conditions. However, the concentration of the individual mean vectors and the activity were lowered. Clear compensation for a displacement was found in the absence of the stars and in a disturbed magnetic field. This means that directing cues from other sources than the stars and the earth magnetic field were involved. It is guessed that inertial orientation plays an important role. Reverse orientation -- including reverse compensation -- was found fairly frequently. It is supposed to be correlated with overcast, and perhaps in general stress conditions. In conclusion, simple one-direction orientation models are not thought to be sufficient to "explain" the observed orientations. PMID:1210810

  18. Néel-type skyrmion lattice with confined orientation in the polar magnetic semiconductor GaV4S8.

    PubMed

    Kézsmárki, I; Bordács, S; Milde, P; Neuber, E; Eng, L M; White, J S; Rønnow, H M; Dewhurst, C D; Mochizuki, M; Yanai, K; Nakamura, H; Ehlers, D; Tsurkan, V; Loidl, A

    2015-11-01

    Following the early prediction of the skyrmion lattice (SkL)-a periodic array of spin vortices-it has been observed recently in various magnetic crystals mostly with chiral structure. Although non-chiral but polar crystals with Cnv symmetry were identified as ideal SkL hosts in pioneering theoretical studies, this archetype of SkL has remained experimentally unexplored. Here, we report the discovery of a SkL in the polar magnetic semiconductor GaV4S8 with rhombohedral (C3v) symmetry and easy axis anisotropy. The SkL exists over an unusually broad temperature range compared with other bulk crystals and the orientation of the vortices is not controlled by the external magnetic field, but instead confined to the magnetic easy axis. Supporting theory attributes these unique features to a new Néel-type of SkL describable as a superposition of spin cycloids in contrast to the Bloch-type SkL in chiral magnets described in terms of spin helices. PMID:26343913

  19. Néel-type skyrmion lattice with confined orientation in the polar magnetic semiconductor GaV4S8

    NASA Astrophysics Data System (ADS)

    Kézsmárki, I.; Bordács, S.; Milde, P.; Neuber, E.; Eng, L. M.; White, J. S.; Rønnow, H. M.; Dewhurst, C. D.; Mochizuki, M.; Yanai, K.; Nakamura, H.; Ehlers, D.; Tsurkan, V.; Loidl, A.

    2015-11-01

    Following the early prediction of the skyrmion lattice (SkL)--a periodic array of spin vortices--it has been observed recently in various magnetic crystals mostly with chiral structure. Although non-chiral but polar crystals with Cnv symmetry were identified as ideal SkL hosts in pioneering theoretical studies, this archetype of SkL has remained experimentally unexplored. Here, we report the discovery of a SkL in the polar magnetic semiconductor GaV4S8 with rhombohedral (C3v) symmetry and easy axis anisotropy. The SkL exists over an unusually broad temperature range compared with other bulk crystals and the orientation of the vortices is not controlled by the external magnetic field, but instead confined to the magnetic easy axis. Supporting theory attributes these unique features to a new Néel-type of SkL describable as a superposition of spin cycloids in contrast to the Bloch-type SkL in chiral magnets described in terms of spin helices.

  20. Detrital remanent magnetization in the solar nebula

    E-print Network

    Fu, Roger Rennan

    We introduce the theoretical basis of a new form of remanent magnetization that likely formed on primitive bodies in the solar system. Accretional detrital remanent magnetization (ADRM) operates via “compass needle”-type ...

  1. Transfer of directional information between the polarization compass and the sun compass in desert ants.

    PubMed

    Lebhardt, Fleur; Ronacher, Bernhard

    2015-06-01

    Desert ants, Cataglyphis fortis, perform large foraging excursions during which they continuously compute a home vector that allows them to return to the nest on the shortest way. This type of navigation, termed path integration, needs a compass system and an odometer. Ants use several cues to determine their walking direction, two of the most important ones being the sun position and the polarization pattern of the sky. We tested whether an information transfer is possible from one compass system to the other, which depend on different anatomical substrates. Since the sky's polarization pattern is detected by UV-photoreceptors located in the dorsal rim area (DRA), we used an orange Perspex filter that eliminated the UV part of the spectrum to prevent the use of the polarization compass. The use of the sun compass could be excluded by appropriate screens. In the critical tests the ants had learned a nest-feeder direction with e.g. the sun compass only, and were later tested with the polarization compass, or vice versa. The results show that a transfer is possible in both directions. PMID:25062650

  2. Practical compassions: repertoires of practice and compassion talk in acute mental healthcare.

    PubMed

    Brown, Brian; Crawford, Paul; Gilbert, Paul; Gilbert, Jean; Gale, Corinne

    2014-03-01

    This article reports an exploratory study of the concept of compassion in the work of 20 mental health practitioners in a UK Midlands facility. Using notions of practice derived from phenomenology and Bourdieusian sociology and notions of emotional labour we identify two contrasting interpretive repertoires in discussions of compassion. The first, the practical compassion repertoire, evokes the practical, physical and bodily aspects of compassion. It involves organising being with patients, playing games, anticipating disruption and taking them outside for cigarettes. Practitioners described being aware that these practical, bodily activities could lead to patients 'opening up', disclosing their interior concerns and enabling practical, compassionate mental health work to take place. In contrast, the second, organisational repertoire, concerns organisational constraints on compassionate practice. The shortage of staff, the record-keeping and internal processes of quality control were seen as time-greedy and apt to detract from contact with patients. The findings are discussed in relation to Bourdieu and Merleau-Ponty's phenomenological accounts of practice and habit and set in context in the growing interest in placing compassion centrally in healthcare. We also explore how the exercise of compassion in the way our participants describe it can afford the more effective exercise of medical power. PMID:24117523

  3. Artifacts in the Wake: Leadership via an Oriented Compass Model

    ERIC Educational Resources Information Center

    Fallon, Paul D.

    2013-01-01

    Although inextricable, the act of leading, the leader, and outcome of leadership are unique entities. Lack of such differentiation may ensnare novice leaders in broad suppositions. This conceptual article introduces a tool for analyzing leadership. Leaders can leverage the model to evaluate the act of leading, in route, via a measurable trajectory…

  4. How dim is dim? Precision of the celestial compass in moonlight and sunlight.

    PubMed

    Dacke, M; Byrne, M J; Baird, E; Scholtz, C H; Warrant, E J

    2011-03-12

    Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim--and the polarization pattern too weak--to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision. PMID:21282173

  5. How dim is dim? Precision of the celestial compass in moonlight and sunlight

    PubMed Central

    Dacke, M.; Byrne, M. J.; Baird, E.; Scholtz, C. H.; Warrant, E. J.

    2011-01-01

    Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim—and the polarization pattern too weak—to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision. PMID:21282173

  6. Eurasian reed warblers compensate for virtual magnetic displacement.

    PubMed

    Kishkinev, Dmitry; Chernetsov, Nikita; Pakhomov, Alexander; Heyers, Dominik; Mouritsen, Henrik

    2015-10-01

    Displacement studies have shown that long-distance, night-migrating songbirds are able to perform true navigation from their first spring migration onwards [1,2]. True navigation requires both a map and a compass. Whereas birds are known to have sun, star, and magnetic compasses, the nature of the map cues used has remained highly controversial. There is quite strong experimental evidence for the involvement of olfactory map cues in pigeon and seabird homing [3]. In contrast, the evidence for the use of magnetic map cues has remained weak and very little is known about the map cues used by long-distance migratory songbirds. In earlier experiments [2,4], we have shown that Eurasian reed warblers physically displaced 1,000 km eastward from Rybachy to Zvenigorod (Figure 1) re-orient towards their breeding destinations by changing their orientation in Emlen funnels from the NE to the NW. We have also previously shown that this re-orientation cannot be explained by a 'jetlag effect' [5]. We have now used this model system to show that Eurasian reed warblers use geomagnetic map cues to determine their position. PMID:26439333

  7. Self-compassion and fear of self-compassion interact to predict response to eating disorders treatment: a preliminary investigation.

    PubMed

    Kelly, Allison C; Carter, Jacqueline C; Zuroff, David C; Borairi, Sahar

    2013-01-01

    Gilbert (2005) proposed that the capacity for self-compassion is integral to overcoming shame and psychopathology. We tested this model among 74 individuals with an eating disorder admitted to specialized treatment. Participants completed measures assessing self-compassion, fear of self-compassion, shame, and eating disorder symptoms at admission and every 3 weeks during treatment. At baseline, lower self-compassion and higher fear of self-compassion were associated with more shame and eating disorder pathology. Multilevel modeling also revealed that patients with combinations of low self-compassion and high fear of self-compassion at baseline had significantly poorer treatment responses, showing no significant change in shame or eating disorder symptoms over 12 weeks. Results highlight a new subset of treatment-resistant eating disorder patients. PMID:22917037

  8. DAVID R. COX PRIZE FOR RARE COMPASSION

    E-print Network

    Emmons, Scott

    . In preparation, students are required to build a relationship with a patient, family, or advocate affected David R. Cox Prize for Rare Compassion, in recognition of the inspiring essays of student doctors who, like Dr. Cox, have most identified with and understood a rare or neglected patient community they have

  9. Anchor node localization for wireless sensor networks using video and compass information fusion.

    PubMed

    Pescaru, Dan; Curiac, Daniel-Ioan

    2014-01-01

    Distributed sensing, computing and communication capabilities of wireless sensor networks require, in most situations, an efficient node localization procedure. In the case of random deployments in harsh or hostile environments, a general localization process within global coordinates is based on a set of anchor nodes able to determine their own position using GPS receivers. In this paper we propose another anchor node localization technique that can be used when GPS devices cannot accomplish their mission or are considered to be too expensive. This novel technique is based on the fusion of video and compass data acquired by the anchor nodes and is especially suitable for video- or multimedia-based wireless sensor networks. For these types of wireless networks the presence of video cameras is intrinsic, while the presence of digital compasses is also required for identifying the cameras' orientations. PMID:24594614

  10. Anchor Node Localization for Wireless Sensor Networks Using Video and Compass Information Fusion

    PubMed Central

    Pescaru, Dan; Curiac, Daniel-Ioan

    2014-01-01

    Distributed sensing, computing and communication capabilities of wireless sensor networks require, in most situations, an efficient node localization procedure. In the case of random deployments in harsh or hostile environments, a general localization process within global coordinates is based on a set of anchor nodes able to determine their own position using GPS receivers. In this paper we propose another anchor node localization technique that can be used when GPS devices cannot accomplish their mission or are considered to be too expensive. This novel technique is based on the fusion of video and compass data acquired by the anchor nodes and is especially suitable for video- or multimedia-based wireless sensor networks. For these types of wireless networks the presence of video cameras is intrinsic, while the presence of digital compasses is also required for identifying the cameras' orientations. PMID:24594614

  11. Influence of magnetic field on zebrafish activity and orientation in a plus maze.

    PubMed

    Osipova, Elena A; Pavlova, Vera V; Nepomnyashchikh, Valentin A; Krylov, Viacheslav V

    2016-01-01

    We describe an impact of the geomagnetic field (GMF) and its modification on zebrafish's orientation and locomotor activity in a plus maze with four arms oriented to the north, east, south and west. Zebrafish's directional preferences were bimodal in GMF: they visited two arms oriented in opposed directions (east-west) most frequently. This bimodal preference remained stable for same individuals across experiments divided by several days. When the horizontal GMF component was turned 90° clockwise, the preference accordingly shifted by 90° to arms oriented to the north and south. Other modifications of GMF (reversal of both vertical and horizontal GMF components; reversal of vertical component only; and reversal of horizontal component only) did not exert any discernible effect on the orientation of zebrafish. The 90° turn of horizontal component also resulted in a significant increase of fish's locomotor activity in comparison with the natural GMF. This increase became even more pronounced when the horizontal component was repeatedly turned by 90° and back with 1min interval between turns. Our results show that GMF and its variations should be taken into account when interpreting zebrafish's directional preferences and locomotor activity in mazes and other experimental devices. PMID:26589739

  12. The interaction of stars and magnetic field in the orientation system of night migrating birds. I. Autumn experiments with European Warblers (gen. Sylvia).

    PubMed

    Wiltschko, W; Wiltschko, R

    1975-06-01

    In the autumn migration periods of 1971, 1972, and 1973 the orientation behavior in registration cages of Sylvia communis, S. borin and S. cantillans was analyzed to find out what relative importance the birds assign to information from the stars and from the magnetic field for direction finding. We obtained the following results: 1. Under clear sky in the local earth's magnetic field (Control) the warblers showed directional preferences that corresponded to their expected migratory direction based on ringing recoveries. 2. When magnetic north was turned by 120 degrees to ESE (Test), all three species preferred on clear nights their migratory direction according to the magnetic field, in spite of contradicting information from the stars. 3. In a partly compensated magnetic field, which could not be used for orientation any more, no significant directional preference could be observed, although the stars were visible. Dividing these data into two groups according to whether the birds had been tested in Control or Test previously, we found a tendency for the directions selected here to depend upon the north direction of the magnetic field during the bird's previous tests. From this and from the observation that the concentration of orientation behavior decreases in the absence of stars, we derive the following orientational model: The magnetic field provides the primary directional information for migrating birds. The stars do not contain directional information in themselves, but they can become secondary sources of orientation when information from the magnetic field has been transferred to them previously. The importance of this mechanism lies in making it easier for the birds to maintain their migratory direction. The ecological advantages of such a system are discussed and critically compared to the other models of star orientation. PMID:1229769

  13. Sustained Quantum Coherence and Entanglement in the Avian Compass

    E-print Network

    Erik Gauger; Elisabeth Rieper; John J. L. Morton; Simon C. Benjamin; Vlatko Vedral

    2011-01-30

    In artificial systems, quantum superposition and entanglement typically decay rapidly unless cryogenic temperatures are used. Could life have evolved to exploit such delicate phenomena? Certain migratory birds have the ability to sense very subtle variations in Earth's magnetic field. Here we apply quantum information theory and the widely accepted "radical pair" model to analyze recent experimental observations of the avian compass. We find that superposition and entanglement are sustained in this living system for at least tens of microseconds, exceeding the durations achieved in the best comparable man-made molecular systems. This conclusion is starkly at variance with the view that life is too "warm and wet" for such quantum phenomena to endure.

  14. Magnetic anisotropy in (Ga,Mn)As grown on vicinal GaAs: Effects of the orientation of microwave magnetic field

    SciTech Connect

    Dziatkowski, K.; Liu, X.; Furdyna, J. K.; Twardowski, A.

    2011-04-01

    Ferromagnetic resonance (FMR) study of the magnetic anisotropy in epitaxial (Ga,Mn)As grown on vicinal GaAs is presented. The data collected in the growth plane reveal very limited dependence on the miscut angle {eta}, with a negligible effect of {eta} on the in-plane uniaxial anisotropy. In the out-of-plane configuration, the substrate misorientation has a pronounced influence on FMR, which features are partially explained with a phenomenological treatment of the atomic step-induced anisotropy. This simple model, however, does not account for the miscut-induced dependence of FMR on the orientation of microwave magnetic field, that is observed with the static field applied invariably along the growth direction.

  15. Polarized skylight does not calibrate the compass system of a migratory bat.

    PubMed

    Lindecke, Oliver; Voigt, Christian C; P?tersons, Gun?rs; Holland, Richard A

    2015-09-01

    In a recent study, Greif et al. (Greif et al. Nat Commun 5, 4488. (doi:10.1038/ncomms5488)) demonstrated a functional role of polarized light for a bat species confronted with a homing task. These non-migratory bats appeared to calibrate their magnetic compass by using polarized skylight at dusk, yet it is unknown if migratory bats also use these cues for calibration. During autumn migration, we equipped Nathusius' bats, Pipistrellus nathusii, with radio transmitters and tested if experimental animals exposed during dusk to a 90° rotated band of polarized light would head in a different direction compared with control animals. After release, bats of both groups continued their journey in the same direction. This observation argues against the use of a polarization-calibrated magnetic compass by this migratory bat and questions that the ability of using polarized light for navigation is a consistent feature in bats. This finding matches with observations in some passerine birds that used polarized light for calibration of their magnetic compass before but not during migration. PMID:26382077

  16. Compass Cells in the Brain of an Insect Are Sensitive to Novel Events in the Visual World

    PubMed Central

    Bockhorst, Tobias; Homberg, Uwe

    2015-01-01

    The central complex of the insect brain comprises a group of neuropils involved in spatial orientation and memory. In fruit flies it mediates place learning based on visual landmarks and houses neurons that encode the orientation for goal-directed locomotion, based on landmarks and self-motion cues for angular path-integration. In desert locusts, the central complex holds a compass-like representation of head directions, based on the polarization pattern of skylight. Through intracellular recordings from immobilized locusts, we investigated whether sky compass neurons of the central complex also represent the position or any salient feature of possible landmarks, in analogy to the observations in flies. Neurons showed strongest responses to the novel appearance of a small moving square, but we found no evidence for a topographic representation of object positions. Responses to an individual square were independent of direction of motion and trajectory, but showed rapid adaptation to successive stimulation, unaffected by changing the direction of motion. Responses reappeared, however, if the moving object changed its trajectory or if it suddenly reversed moving direction against the movement of similar objects that make up a coherent background-flow as induced by ego-motion. Response amplitudes co-varied with the precedent state of dynamic background activity, a phenomenon that has been related to attention-dependent saliency coding in neurons of the mammalian primary visual cortex. The data show that neurons of the central complex of the locust brain are visually bimodal, signaling sky compass direction and the novelty character of moving objects. These response properties might serve to attune compass-aided locomotor control to unexpected events in the environment. The difference to data obtained in fruit flies might relate to differences in the lifestyle of landmark learners (fly) and compass navigators (locust), point to the existence of parallel networks for the two orientation strategies, or reflect differences in experimental conditions. PMID:26636334

  17. The orientation of buildings: a catalogue of the conditioning factors 

    E-print Network

    Moseley, Hal Millard

    1950-01-01

    ; it is this constant variation in buildings plus the constant variation in building sites that requires each orientation problem/\\be considered separately. Since orientation is the relation of the building to the points of the compass, then any factor that influences...

  18. Effect of asymmetric hot rolling on texture, microstructure and magnetic properties in a non-grain oriented electrical steel

    NASA Astrophysics Data System (ADS)

    Chen, S.; Butler, J.; Melzer, S.

    2014-11-01

    In this study, both asymmetric hot rolling (AHR) and conventional hot rolling (CHR) were carried out to study the effect of the hot rolling conditions on the evolution of the texture and microstructure in a non-grain oriented (NGO) steel. The microstructure and texture in the subsequent processing stages were characterised and related to the final magnetic properties. The results show that AHR, compared with CHR, tends to homogenise texture through thickness of the hot band strips. AHR results in a higher fraction of the ?-fibre ({0 0 1}) and a lower fraction of the ?-fibre ({1 1 1}) in the hot band strips, which are favourable features in relation to the magnetic properties of the strip. However, the favourable features observed in hot rolled AHR strips are eliminated after cold rolling and annealing. Contrarily, the required ?-fibre is decreased and the unwanted ?-fibre is intensified in the AHR sheet after cold rolling and their strength is maintained in the subsequent process steps. On the other hand, AHR does not produce a discernible change in the grain size in the hot band annealed strip and in the final annealed sheet, except that the magnetic anisotropy in the AHR is improved after skin pass and extra annealing as the result of the redistribution of the texture components within the ?-fibre, no significant improvement of the magnetic properties as a direct consequence of the application of asymmetric hot rolling has been observed under the current AHR experimental conditions.

  19. Magnetic properties of in-plane oriented barium hexaferrite thin films prepared by direct current magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaozhi; Yue, Zhenxing; Meng, Siqin; Yuan, Lixin

    2014-12-01

    In-plane c-axis oriented Ba-hexaferrite (BaM) thin films were prepared on a-plane ( 11 2 ¯ 0 ) sapphire (Al2O3) substrates by DC magnetron sputtering followed by ex-situ annealing. The DC magnetron sputtering was demonstrated to have obvious advantages over the traditionally used RF magnetron sputtering in sputtering rate and operation simplicity. The sputtering power had a remarkable influence on the Ba/Fe ratio, the hematite secondary phase, and the grain morphology of the as-prepared BaM films. Under 80 W of sputtering power, in-plane c-axis highly oriented BaM films were obtained. These films had strong magnetic anisotropy with high hysteresis loop squareness (Mr/Ms of 0.96) along the in-plane easy axis and low Mr/Ms of 0.03 along the in-plane hard axis. X-ray diffraction patterns and pole figures revealed that the oriented BaM films grew via an epitaxy-like growth process with the crystallographic relationship BaM ( 10 1 ¯ 0 ) //?-Fe2O3 ( 11 2 ¯ 0 ) //Al2O3 ( 11 2 ¯ 0 ) .

  20. Magnetic properties of in-plane oriented barium hexaferrite thin films prepared by direct current magnetron sputtering

    SciTech Connect

    Zhang, Xiaozhi; Yue, Zhenxing Meng, Siqin; Yuan, Lixin

    2014-12-28

    In-plane c-axis oriented Ba-hexaferrite (BaM) thin films were prepared on a-plane (112{sup ¯}0) sapphire (Al{sub 2}O{sub 3}) substrates by DC magnetron sputtering followed by ex-situ annealing. The DC magnetron sputtering was demonstrated to have obvious advantages over the traditionally used RF magnetron sputtering in sputtering rate and operation simplicity. The sputtering power had a remarkable influence on the Ba/Fe ratio, the hematite secondary phase, and the grain morphology of the as-prepared BaM films. Under 80?W of sputtering power, in-plane c-axis highly oriented BaM films were obtained. These films had strong magnetic anisotropy with high hysteresis loop squareness (M{sub r}/M{sub s} of 0.96) along the in-plane easy axis and low M{sub r}/M{sub s} of 0.03 along the in-plane hard axis. X-ray diffraction patterns and pole figures revealed that the oriented BaM films grew via an epitaxy-like growth process with the crystallographic relationship BaM (101{sup ¯}0)//?-Fe{sub 2}O{sub 3}(112{sup ¯}0)//Al{sub 2}O{sub 3}(112{sup ¯}0)

  1. Measuring Earth's Magnetic Field Simply.

    ERIC Educational Resources Information Center

    Stewart, Gay B.

    2000-01-01

    Describes a method for measuring the earth's magnetic field using an empty toilet paper tube, copper wire, clear tape, a battery, a linear variable resistor, a small compass, cardboard, a protractor, and an ammeter. (WRM)

  2. On the Dependence of Solar Wind Speed on Local Magnetic Field Orientation in Highly Alfvénic Streams

    NASA Astrophysics Data System (ADS)

    Matteini, L.; Horbury, T. S.; Neugebauer, M.; Goldstein, B. E.

    2014-12-01

    Magnetic field fluctuations from the low frequency part of the solar wind turbulent spectrum have typical amplitudes of the order of the underlying mean field, and then result in large random variations in the instantaneous direction associated with the magnetic field vector on the scale of minutes/few hours. At the same time, since fluctuations are Alfvénic, these also introduce variations in solar wind speed, which reflecting the randomness of the process, are not expected to show a dependence on the direction of the magnetic field. On the contrary, and quite surprisingly, we have found that in highly Alfvénic solar wind streams there exists a remarkably strong correlation between the bulk speed of the plasma and the local direction of the magnetic field. This leads to a systematic increase in the solar wind speed when the magnetic field vector is locally transverse to the velocity, and to a decrease in the speed when the field is more aligned with the radial, regardless of the polarity of the underlying magnetic field. We demonstrate that such an effect is a consequence of Alfvénicity for a unidirectional flux of waves propagating away from the Sun and with approximatively constant magnetic field magnitude. This correlation is systematically present in highly Alfvénic streams observed by Ulysses and Helios from 0.3 AU to 5 AU. The variations in the speed being proportional to the local Alfvén speed results in a modulation of the solar wind profile that is particularly relevant close to the Sun.

  3. Biophysics of magnetic orientation: strengthening the interface between theory and experimental design

    PubMed Central

    Kirschvink, Joseph L.; Winklhofer, Michael; Walker, Michael M.

    2010-01-01

    The first demonstrations of magnetic effects on the behaviour of migratory birds and homing pigeons in laboratory and field experiments, respectively, provided evidence for the longstanding hypothesis that animals such as birds that migrate and home over long distances would benefit from possession of a magnetic sense. Subsequent identification of at least two plausible biophysical mechanisms for magnetoreception in animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, led to major efforts over recent decades to test predictions of the two models, as well as efforts to understand the ultrastructure and function of the possible magnetoreceptor cells. Unfortunately, progress in understanding the magnetic sense has been challenged by: (i) the availability of a relatively small number of techniques for analysing behavioural responses to magnetic fields by animals; (ii) difficulty in achieving reproducible results using the techniques; and (iii) difficulty in development and implementation of new techniques that might bring greater experimental power. As a consequence, laboratory and field techniques used to study the magnetic sense today remain substantially unchanged, despite the huge developments in technology and instrumentation since the techniques were developed in the 1950s. New methods developed for behavioural study of the magnetic sense over the last 30 years include the use of laboratory conditioning techniques and tracking devices based on transmission of radio signals to and from satellites. Here we consider methodological developments in the study of the magnetic sense and present suggestions for increasing the reproducibility and ease of interpretation of experimental studies. We recommend that future experiments invest more effort in automating control of experiments and data capture, control of stimulation and full blinding of experiments in the rare cases where automation is impossible. We also propose new experiments to confirm whether or not animals can detect magnetic fields using the radical-pair effect together with an alternate hypothesis that may explain the dependence on light of responses by animals to magnetic field stimuli. PMID:20071390

  4. Prediction of magnetic orientation in driver gas associated -Bz events. [in interplanetary medium observed at earth when solar source is identified

    NASA Technical Reports Server (NTRS)

    Hoeksema, J. T.; Zhao, Xuepu

    1992-01-01

    The source regions of five strong -Bz events detected at 1 AU for which solar sources were identified by Tang et al. (1989) and Tsurutani et al. (1992) are investigated in order to determine whether the magnetic orientation of driver gas in the interplanetary medium observed at the earth can be predicted when its solar source is identified. Three -Bz events were traced to flare-associated coronal mass ejections (CMEs), one to an eruptive prominence associated CME, and one to three possible solar sources. The computed magnetic orientations at the candidate 'release height' (the height where the front of a CME ceases to accelerate) above the flare sites associated with CMEs show the existence of the expected southward field component. It is concluded that the magnetic orientation in flare-associated CME generated driver gas may be predictable.

  5. Magnetic field-dependent polarization of (111)-oriented PZT-Co ferrite nanobilayer: Effect of Co ferrite composition

    NASA Astrophysics Data System (ADS)

    Khodaei, M.; Seyyed Ebrahimi, S. A.; Jun Park, Yong; Son, Junwoo; Baik, Sunggi

    2015-05-01

    The perfect (111)-oriented PZT/CFO (CFO=CoFe2O4, Co0.8Fe2.2O4 and Co0.6Mn0.2Fe2.2O4) bilayer multiferroic thin films were grown on Pt(111)/Si substrate at 600 °C using pulsed laser deposition technique. The precision X-ray diffraction analysis (avoiding the shift of peak due to the sample misalignment) revealed that the CFO films on Pt(111)/Si substrate were under an out-of-plane contraction and deposition of PZT top layer led to more increase in the out-of-plane contraction, i.e. increase in the residual stresses. The PZT and CFO layers have significant effects on magnetic and ferroelectric properties of PZT/CFO bilayer films, respectively, leading to an enhanced in-plane magnetic anisotropy as well as increased and asymmetric polarization. The effect of composition of CFO layer on magnetic field-dependent polarization of PZT/CFO bilayer films was investigated by applying the magnetic field during P-E measurement. The polarization of PZT films were increased by applying the magnetic field as a result of strain transferred from magnetostrictive CFO underlayer. This increase in polarization for PZT/Co0.6Mn0.2Fe2.2O4 was higher than that for PZT/Co0.8Fe2.2O4 and both of them were significantly higher than that for PZT/CoFe2O4 bilayer film, which was discussed based on their magnetostriction properties.

  6. The preferred orientation of Mn3 spins in magnetic multiferroic CaMn7O12

    NASA Astrophysics Data System (ADS)

    Dai, Jian-Qing; Zhang, Hu; Song, Yu-Min

    2015-12-01

    The remarkable ferroelectricity in CaMn7O12 originates from the helicoidal spin spiral, in which the Mn3 (3b Wyckoff position) spin direction remains controversial. In this paper, the total energy, phase transition path, and spontaneous polarization of CaMn7O12 are investigated by using first-principle methods. We show that, in order to account for the giant electric polarization and the correct phase transition sequence, the relative orientation between the spins of Mn3 and Mn2 (9d Wyckoff position) sites with the same coordinate along the hexagonal c-axis can not be antiparallel, i.e. their relative orientation angle should be ??0.84? instead of ?=?. The most likely reason for the observation of ?=? can be attributed to the withdrawal of spin-orbital coupling between the Mn2 and Mn3 spins, which is caused by doping Cu2+ in the samples for neutron powder diffraction measurements.

  7. Magnetic properties of Mn{sub 3}O{sub 4} film with a coexistence of two preferential orientations

    SciTech Connect

    Ren, Lizhu; Zhou, Wenqi; Wang, Yunjia; Meng, Meng; Wu, Shuxiang; Li, Shuwei

    2014-07-14

    A Mn{sub 3}O{sub 4} film with a coexistence of two preferential orientations has been grown on a Pt(111)//Si(100) substrate by plasma-assisted molecular beam epitaxy. The structural characteristics and chemical compositions of the film are investigated by using X-ray diffraction, Raman, and X-ray photoelectron spectra in detail. Together with the magnetic tests, the film is demonstrated to be a polycrystalline hausmannite Mn{sub 3}O{sub 4} with no other impurities. Moreover, the hysteresis loops of the film are found to display a step or a characteristic shrinking at low fields. On the other hand, similar magnetic characteristics have also been discovered on the film with two phases grown on a MgAl{sub 2}O{sub 4}(001) substrate. In our opinion, considering the large magnetocrystalline anisotropy and shape anisotropy of the single crystal Mn{sub 3}O{sub 4} film reported in previous works, the special structures and phases of the two films result in both of them as soft+hard magnetic composites, in agreement with some other reports.

  8. Oriented nanometric aggregates of partially inverted zinc ferrite: One-step processing and tunable high-frequency magnetic properties

    NASA Astrophysics Data System (ADS)

    Sai, Ranajit; Endo, Yasushi; Shimada, Yutaka; Yamaguchi, Masahiro; Shivashankar, S. A.

    2015-05-01

    In this work, it is demonstrated that the in situ growth of oriented nanometric aggregates of partially inverted zinc ferrite can potentially pave a way to alter and tune magnetocrystalline anisotropy that, in turn, dictates ferromagnetic resonance frequency (fFMR) by inducing strain due to aggregation. Furthermore, the influence of interparticle interaction on magnetic properties of the aggregates is investigated. Mono-dispersed zinc ferrite nanoparticles (<5 nm) with various degrees of aggregation were prepared through decomposition of metal-organic compounds of zinc (II) and iron (III) in an alcoholic solution under controlled microwave irradiation, below 200 °C. The nanocrystallites were found to possess high degree of inversion (>0.5). With increasing order of aggregation in the samples, saturation magnetization (at 5 K) is found to decrease from 38 emu/g to 24 emu/g, while coercivity is found to increase gradually by up to 100% (525 Oe to 1040 Oe). Anisotropy-mediated shift of fFMR has also been measured and discussed. In essence, the result exhibits an easy way to control the magnetic characteristics of nanocrystalline zinc ferrite, boosted with significant degree of inversion, at GHz frequencies.

  9. Texture and magnetic property evolution of non-oriented Fe-Si steel due to mechanical cutting

    NASA Astrophysics Data System (ADS)

    Xiong, Xuesong; Hu, Shubing; Hu, Ke; Zeng, Siqi

    2016-03-01

    Microstructures and textures as well as magnetic properties of a non-oriented Fe-Si steel with thickness of 0.5 mm and medium silicon content after mechanical cutting were investigated. The results from electron backscatter diffraction (EBSD) analysis indicated that in the cut edge zone, mechanical cutting resulted in a significant increase in low-angle boundaries (LAGBs, 2°???15°) and dislocation densities from both the upper surface (in the shear zone) and the lower surface (in the fracture zone). Mechanical cutting also led to a visible change in textures, such as, intensity decrease of ? fiber (<001>?normal direction [ND]) and ? fiber (<111>?ND) components from the upper surface as well as Goss texture ({110}<001>texture) from the lower surface. Microstructure and texture changes from the upper surface seem to be more obvious than these from the lower surface. The results from single sheet testing showed mechanical cutting induced an evident deterioration in magnetic properties and a clear change in hysteresis loop of the steel, and these variations became more obvious with increasing cutting length per mass from 0.86 m/kg to 2.57 m/kg. The largest increment of iron loss reached to 18.45% and 21.76% when the flux density was at 1.0 T and 1.5 T, respectively. The possible main reasons for the changes in magnetic properties and hysteresis loops were discussed in terms of the texture factor TF or residual stress.

  10. Combined effect of oriented strain and external magnetic field on electrical properties of superlattice-graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Khoeini, Farhad

    2015-10-01

    Using the tight-binding model, electronic quantum transport properties of strained superlattice-graphene nanoribbons (SGNRs) attached to two semi-infinite metallic leads are studied in real space and numerically. Then, with the combination of mode space (MS) and renormalization methods, general analytical formulas for the conductance and energy band gap of the strained system are derived. The formulas are useful in studying the impact of slice-like defects and uniaxial strains on the electronic transport properties of the system as well as in reducing the computation time. The calculations are based on the Green’s function method, in which the effects of uniaxial strains and the concentration of boron nitride (BN) slices as well as magnetic fields on the electrical conductance and the band gap of the armchair SGNR are studied. It is shown that the conductance of the system reduces with increasing BN concentration so a gap opens and its value increases. Both uniaxial strains and the BN impurities cause the metal-semiconductor phase transition, while the magnetic fields induce a periodic metal-semiconductor transition. The electronic transport properties of the systems can be controlled by tunable parameters such as the BN concentration, oriented strain and magnetic field.

  11. Oriented nanometric aggregates of partially inverted zinc ferrite: One-step processing and tunable high-frequency magnetic properties

    SciTech Connect

    Sai, Ranajit; Endo, Yasushi; Shimada, Yutaka; Yamaguchi, Masahiro; Shivashankar, S. A.

    2015-05-07

    In this work, it is demonstrated that the in situ growth of oriented nanometric aggregates of partially inverted zinc ferrite can potentially pave a way to alter and tune magnetocrystalline anisotropy that, in turn, dictates ferromagnetic resonance frequency (f{sub FMR}) by inducing strain due to aggregation. Furthermore, the influence of interparticle interaction on magnetic properties of the aggregates is investigated. Mono-dispersed zinc ferrite nanoparticles (<5?nm) with various degrees of aggregation were prepared through decomposition of metal-organic compounds of zinc (II) and iron (III) in an alcoholic solution under controlled microwave irradiation, below 200?°C. The nanocrystallites were found to possess high degree of inversion (>0.5). With increasing order of aggregation in the samples, saturation magnetization (at 5?K) is found to decrease from 38?emu/g to 24?emu/g, while coercivity is found to increase gradually by up to 100% (525?Oe to 1040?Oe). Anisotropy-mediated shift of f{sub FMR} has also been measured and discussed. In essence, the result exhibits an easy way to control the magnetic characteristics of nanocrystalline zinc ferrite, boosted with significant degree of inversion, at GHz frequencies.

  12. Recent results from COMPASS muon scattering measurements

    SciTech Connect

    Capozza, Luigi [Irfu Collaboration: COMPASS Collaboration

    2012-10-23

    A sample of recent results in muon scattering measurements from the COMPASS experiment at CERN will be reviewed. These include high energy processes with longitudinally polarised proton and deuteron targets. High energy polarised measurements provide important constraints for studying the nucleon spin structure and thus permit to test the applicability of the theoretical framework of factorisation theorems and perturbative QCD. Specifically, latest results on longitudinal quark polarisation, quark helicity densities and gluon polarisation will be reviewed.

  13. Compassion Practices and HCAHPS: Does Rewarding and Supporting Workplace Compassion Influence Patient Perceptions?

    PubMed Central

    McClelland, Laura E; Vogus, Timothy J

    2014-01-01

    Objective To examine the benefits of compassion practices on two indicators of patient perceptions of care quality—the Hospital Consumer Assessment of Healthcare Providers and systems (HCAHPS) overall hospital rating and likelihood of recommending. Study Setting Two hundred sixty-nine nonfederal acute care U.S. hospitals. Study Design Cross-sectional study. Data Collection Surveys collected from top-level hospital executives. Publicly reported HCAHPS data from October 2012 release. Principal Findings Compassion practices, a measure of the extent to which a hospital rewards compassionate acts and compassionately supports its employees (e.g., compassionate employee awards, pastoral care for employees), is significantly and positively associated with hospital ratings and likelihood of recommending. Conclusions Our findings illustrate the benefits for patients of specific and actionable organizational practices that provide and reinforce compassion. PMID:24837713

  14. Smartstones: a small e-compass, accelerometer and gyroscope embedded in stones

    NASA Astrophysics Data System (ADS)

    Gronz, Oliver; Hiller, Priska H.; Wirtz, Stefan; Becker, Kerstin; Iserloh, Thomas; Aberle, Jochen; Casper, Markus C.

    2015-04-01

    Pebbles or rock fragments influence soil erosion processes in various ways: they can protect the soil but also enhance the erosion as soon as they are moved by water and impact onto soil. So far, stone-embedded devices to measure the movements have been quite big, up to several decimetres, which does not allow for the analysis of pebbles from medium and coarse gravel classes. In this study, we used a novel device called Smartstones, which is significantly smaller. The Smartstone device's dimensions are 55 mm in length, 8 mm in diameter and an approximately 70 mm long flexible antenna (device developer: SMART-RFID solutions Rheinberg, Germany). It is powered by two button cells, contains an own data storage and is able to wait inactive for longer times until it is activated by movement. It communicates via active RFID (radio frequency identification) technology to a Linux gateway, which stores the sensor data in a database after transmission and is able to handle several devices simultaneously. The device contains a Bosch sensor that measures magnetic flux density, acceleration and rotation, in each case for / around three axes. In our study, the device has been used in a laboratory flume (270 cm in length, 5° to 10° slope, approx. 2 cm water level, mean flow velocities between 0.66 and 1 ms-1) in combination with a high speed camera to capture the movement of the pebbles. The simultaneous usage of two capture devices allows for a comparison of the results: movement patterns derived from image analysis and sensor data analysis. In the device's first software version, all three sensors - acceleration, compass, and gyroscope - were active. The acquisition of all values resulted in a sampling rate of 10 Hz. After the experiments using this setup, the data analysis of the high speed images and the device's data showed that the pebble reached rotation velocities beyond 5 rotations per second, even on the relatively short flume and low water levels. Thus, the device produced only sub-Nyquist sampling values and the rotation velocity of the pebble could not be derived correctly using solely the device's data. Consequently, the device's software was adapted by the developers: the second (and current) version of the device only acquires acceleration and compass, as the acquisition of the gyroscope's value does not allow for higher sampling rates. The second version samples every 12 ms. All aforementioned experiments have been repeated using the adapted device. For data analysis, the high-speed camera images were merged with the device data using a MATLAB script. Furthermore, the derived relative pebble orientation - yaw, pitch and roll - is illustrated using a rotated CAD model of the pebble. The pebble's orientation is derived from compass and accelerometer data using sensor fusion and algorithms for tilt compensated compasses. The results show that the device is perfectly able to capture the movement of the pebble such as rotation (including the rotation axis), sliding or saltation. The interacting forces between the pebble and the underground can be calculated from the acceleration data. However, the accelerometer data also showed that the range of the sensor is not sufficiently large: clipping of values occurred. According to present instrument specifications, the sensor is able to capture up to 4 g for each axis but the resulting vectors for acceleration along all three axes showed values greater than 4 g, even up to the theoretical maximum of approximately 6.9 g. Thus, an impact of this strength that only stresses one axis cannot be measured. As a result of this clipping, the derivation of the pebble's absolute position using double integration of acceleration values is associated with flaws. Besides this clipping, the derived position will deviate from the true position for larger distances or longer experiment durations as the noise of the data will be integrated, too. Several requirements for the next device version were formulated: The range of the accelerometer will be set to the sensor's maximum of 16 g. The device w

  15. Enhancement of in-plane magnetic anisotropy in (111)-oriented Co0.8Fe2.2O4 thin film by deposition of PZT top layer

    NASA Astrophysics Data System (ADS)

    Khodaei, M.; Seyyed Ebrahimi, S. A.; Park, Yong Jun; Ok, Jong Mok; Kim, Jun Sung; Son, Junwoo; Baik, Sunggi

    2014-05-01

    The CoFe2O4 and Co0.8Fe2.2O4 single layer (CFO) as well as PZT/CoFe2O4 and PZT/Co0.8Fe2.2O4 bilayer thin films were grown using the pulsed laser deposition technique on Pt(111)/Si substrates at 600 °C. All films had a perfect (111)-orientation and the degree of orientation of CFO films was improved by the deposition of a PZT top layer. Precision X-ray diffraction analysis (avoiding the shift of peaks due to sample misalignment) revealed that the CFO films on Pt(111)/Si substrate were under an out-of-plane contraction and the deposition of a PZT top layer led to the increase in the out-of-plane contraction. The (111)-oriented CFO single layer films had a strong in-plane magnetic anisotropy as a result of orientation as well as the stress-induced magnetic anisotropy. The magnetic properties of CFO film were altered by the deposition of a PZT top layer leading to the enhancement of in-plane magnetic anisotropy. The enhanced in-plane magnetic anisotropy was more detectable in PZT/Co0.8Fe2.2O4 rather than PZT/CoFe2O4 bilayer film, which could be expected from its higher magnetocrystalline as well as magnetostriction constants.

  16. Effect of the phosphate component of electrical insulating coating on the magnetic losses in grain-oriented electrical steel

    NASA Astrophysics Data System (ADS)

    Karenina, L. S.; Korzunin, G. S.; Puzhevich, R. B.

    2011-01-01

    It is shown that one of the main methods improving quality of a grain-oriented electrical sheet steel (GOES) is the deposition of an electrical insulating coating (EIC) on its surface, which produces elastic tensile stresses in the metal. The EIC represents a composite consisting of a glass film and a phosphate coating deposited on it. Investigations performed in this direction are reviewed. A complex of the industrial experiments has been carried out, which were directed to studying the effect of both the insulating coating as a whole and, separately, its phosphate component (PC) on the level of magnetic losses. The values of elastic tensile stresses produced in the metal by the EIC and PC are presented. This work has been performed under the conditions of the OOO VIZ-stal' (Verkneisetsk Factory).

  17. Improving magnetic properties by optimization of textures in non-oriented electrical steel with initial columnar grains

    NASA Astrophysics Data System (ADS)

    Zhang, N.; Yang, P.; Mao, W. M.

    2015-04-01

    This study investigates the processing route to optimize magnetic properties along both rolling and transverse directions, and the evolution of texture during the process is revealed by EBSD technique. The results show that, thinner hot-rolled bands accompanied with coarser structures after normalization are beneficial for promoting the magnetic properties of final sheets. Compared with the 35W300 high-grade NGO steel with a similar composition exhibiting B50 = 1.71T (along RD)/1.67 T (along TD), the B50 values of samples obtained by hot rolling to 1.5mm and subsequent processes are equal to or higher than 1.75T (along RD)/1.69T (along TD). Moreover, a greater quantity of {hk0}<001> oriented nuclei result in stronger {hk0}<001> recrystallization texture in recrystallized warm rolled samples heated at 300°C in advance, and stronger {100}<0vw> texture is achieved in the samples prepared by two-stage annealing method. In addition, the distinct deformation and recrystallization behaviors of {100}<001> and {100}<110> columnar grains are discussed.

  18. Estimating orientation using magnetic and inertial sensors and different sensor fusion approaches: accuracy assessment in manual and locomotion tasks.

    PubMed

    Bergamini, Elena; Ligorio, Gabriele; Summa, Aurora; Vannozzi, Giuseppe; Cappozzo, Aurelio; Sabatini, Angelo Maria

    2014-01-01

    Magnetic and inertial measurement units are an emerging technology to obtain 3D orientation of body segments in human movement analysis. In this respect, sensor fusion is used to limit the drift errors resulting from the gyroscope data integration by exploiting accelerometer and magnetic aiding sensors. The present study aims at investigating the effectiveness of sensor fusion methods under different experimental conditions. Manual and locomotion tasks, differing in time duration, measurement volume, presence/absence of static phases, and out-of-plane movements, were performed by six subjects, and recorded by one unit located on the forearm or the lower trunk, respectively. Two sensor fusion methods, representative of the stochastic (Extended Kalman Filter) and complementary (Non-linear observer) filtering, were selected, and their accuracy was assessed in terms of attitude (pitch and roll angles) and heading (yaw angle) errors using stereophotogrammetric data as a reference. The sensor fusion approaches provided significantly more accurate results than gyroscope data integration. Accuracy improved mostly for heading and when the movement exhibited stationary phases, evenly distributed 3D rotations, it occurred in a small volume, and its duration was greater than approximately 20 s. These results were independent from the specific sensor fusion method used. Practice guidelines for improving the outcome accuracy are provided. PMID:25302810

  19. Effectiveness of CompassLearning's Odyssey Reading for Middle School

    ERIC Educational Resources Information Center

    Empirical Education Inc., 2010

    2010-01-01

    Odyssey Reading, published by CompassLearning, is a comprehensive reading/language arts program using adaptive software for core instruction. This is the first study of CompassLearning's Odyssey Reading (CLO) in PUSD and was based on data from the school years 2006-2008. For this study, Odyssey Reading was implemented in reading classes in grades…

  20. Robustness of the filamentation instability for asymmetric plasma shells collision in arbitrarily oriented magnetic field

    SciTech Connect

    Bret, A.

    2013-10-15

    The filamentation instability triggered when two counter streaming plasma shells overlap appears to be the main mechanism by which collisionless shocks are generated. It has been known for long that a flow aligned magnetic field can completely suppress this instability. In a recent paper [Phys. Plasmas 18, 080706 (2011)], it was demonstrated in two dimensions that for the case of two cold, symmetric, relativistically colliding shells, such cancellation cannot occur if the field is not perfectly aligned. Here, this result is extended to the case of two asymmetric shells. The filamentation instability appears therefore as an increasingly robust mechanism to generate shocks.

  1. Collinear ferromagnetism and spin orientation in the molecule-based magnets M[N(CN){sub 2}]{sub 2} (M=Co,Ni)

    SciTech Connect

    Kmety, C.R.; Manson, J.L.; Huang, Q.; Lynn, J.W.; Erwin, R.W.; Miller, J.S.; Epstein, A.J.

    1999-07-01

    Zero-field unpolarized neutron powder diffraction has been used to study the low-T magnetic structure and {ital T}-dependent crystal structure of M[N(CN){sub 2}]{sub 2} (M=Co,Ni). Both compounds show collinear ferromagnetism with spin orientation along the {ital c} axis. The results provide the determination of a complete magnetic structure in the ordered state for a molecule-based magnet. The {ital c} lattice parameter exhibits negative thermal expansion, explained by a wine-rack-like deformation. {copyright} {ital 1999} {ital The American Physical Society}

  2. Compassion Fatigue Risk and Self-Care Practices among Residential Treatment Center Childcare Workers

    ERIC Educational Resources Information Center

    Eastwood, Callum D.; Ecklund, Kathryn

    2008-01-01

    Exploration of the presence of risk for compassion fatigue among residential childcare workers (RCW) at residential treatment facilities and the relationship between self-care practices and compassion fatigue were explored. Using the Professional Quality of Life Survey (ProQOL-R III) to assess compassion fatigue, burnout, and compassion

  3. Investigation of the influence of different cutting procedures on the global and local magnetic properties of non-oriented electrical steel

    NASA Astrophysics Data System (ADS)

    Naumoski, H.; Riedmüller, B.; Minkow, A.; Herr, U.

    2015-10-01

    The process of manufacturing iron cores for electric machines out of electrical steel sheets can strongly affect the magnetic properties of the material. In order to better understand the influence of cutting on the iron losses, a characterization of the magnetization behavior near the cutting edge is needed. The local magnetic properties of the material are modified by the cutting process which leads to an increase in the iron losses measured for 5 mm wide ring core samples by nearly 160% at low inductions. We present investigations on the effect of cutting by observation of the magnetic domain structure of 0.35 mm thick non-oriented electrical steel. By using the magneto-optical Kerr-effect on a ring samples the local magnetic properties of the material after processing are characterized in the form of domain wall displacements under an applied external ac-field. The influence of various cutting techniques on the magnetic properties was studied before and after stress relief annealing. This method allows a quantitative analysis of the influence of different cutting techniques on the micro-magnetic properties of non-oriented electrical steel for rotating machines.

  4. Hard Exclusive ?^0-Meson Production at COMPASS

    E-print Network

    H. Wollny for the COMPASS collaboration

    2012-05-30

    New results for the transverse target spin azimuthal asymmetry A_{UT}^{sin(\\phi-\\phi_S)} for hard exclusive \\rho^0-meson production on a transversely polarised ^6LiD and NH_3 target will be presented. The measurement was performed with the COMPASS detector using the 160 GeV/c muon beam of the SPS at CERN. The asymmetry is sensitive to the nucleon helicity-flip generalised parton distribution E, which is related to the orbital angular momentum of quarks in the nucleon.

  5. Anisotropy of magnetic susceptibility versus lattice- and shape-preferred orientation in the Lac Tio hemo-ilmenite ore body (Grenville province, Quebec)

    NASA Astrophysics Data System (ADS)

    Bolle, Olivier; Charlier, Bernard; Bascou, Jérôme; Diot, Hervé; McEnroe, Suzanne A.

    2014-08-01

    The Lac Tio hemo-ilmenite ore body crops out in the outer portion of the 1.06 Ga Lac Allard anorthosite, a member of the Havre-Saint-Pierre anorthosite suite from the Grenville province of North America. It is made up of ilmenitite (commonly with more than 95% hemo-ilmenite) associated with noritic lithologies and anorthosite. The present study compares the magnetic fabric of the ore body, as deduced from anisotropy of magnetic susceptibility (AMS) measurements, with the crystallographic and shape fabrics, obtained from lattice-preferred orientation (LPO) and shape-preferred orientation (SPO) measurements made using electron backscattered diffraction (EBSD) and 3D image analysis, respectively. Room-temperature hysteresis measurements, thermomagnetic curves and values of the bulk magnetic susceptibility reveal a magnetic mineralogy dominated by a mixed contribution of hemo-ilmenite and magnetite. The hemo-ilmenite grains display a LPO characterized by a strong preferred orientation of the basal (0001) plane of ilmenite along which hematite was exsolved. This LPO and the magnetic fabric fit well (angle between the crystallographic c-axis and the axis of minimum susceptibility ? ca. 15° for most samples), and the latter is thus strongly influenced by the hemo-ilmenite magneto-crystalline anisotropy. A magnetite SPO, concordant with the hemo-ilmenite LPO, may also influence and even dominate the magnetic fabric. The rock shape fabric is coaxial with the magnetic fabric that can thus be used to perform detailed structural mapping. Interpretation of the magnetic fabric and field structural data suggests that the Lac Tio ore body would be a sag point at the margin of the Lac Allard anorthosite, deformed by ballooning during the final stage of diapiric emplacement of the anorthosite body.

  6. Accelerating Fibre Orientation Estimation from Diffusion Weighted Magnetic Resonance Imaging Using GPUs

    PubMed Central

    Hernández, Moisés; Guerrero, Ginés D.; Cecilia, José M.; García, José M.; Inuggi, Alberto; Jbabdi, Saad; Behrens, Timothy E. J.; Sotiropoulos, Stamatios N.

    2013-01-01

    With the performance of central processing units (CPUs) having effectively reached a limit, parallel processing offers an alternative for applications with high computational demands. Modern graphics processing units (GPUs) are massively parallel processors that can execute simultaneously thousands of light-weight processes. In this study, we propose and implement a parallel GPU-based design of a popular method that is used for the analysis of brain magnetic resonance imaging (MRI). More specifically, we are concerned with a model-based approach for extracting tissue structural information from diffusion-weighted (DW) MRI data. DW-MRI offers, through tractography approaches, the only way to study brain structural connectivity, non-invasively and in-vivo. We parallelise the Bayesian inference framework for the ball & stick model, as it is implemented in the tractography toolbox of the popular FSL software package (University of Oxford). For our implementation, we utilise the Compute Unified Device Architecture (CUDA) programming model. We show that the parameter estimation, performed through Markov Chain Monte Carlo (MCMC), is accelerated by at least two orders of magnitude, when comparing a single GPU with the respective sequential single-core CPU version. We also illustrate similar speed-up factors (up to 120x) when comparing a multi-GPU with a multi-CPU implementation. PMID:23658616

  7. COMPASS Final Report: Lunar Relay Satellite (LRS)

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2012-01-01

    The Lunar Relay Satellite (LRS) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session was tasked to design a satellite to orbit in an elliptical lunar polar orbit to provide relay communications between lunar South Pole assets and the Earth. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The LRS is a half-TDRSS sized box spacecraft, which provides communications and navigation relay between lunar outposts (via Lunar Communications Terminals (LCT)) or Sortie parties (with user radios) and large ground antennas on Earth. The LRS consists of a spacecraft containing all the communications and avionics equipment designed by NASA Jet Propulsion Laboratory s (JPL) Team X to perform the relay between lunar-based assets and the Earth. The satellite design is a standard box truss spacecraft design with a thermal control system, 1.7 m solar arrays for 1 kWe power, a 1 m diameter Ka/S band dish which provides relay communications with the LCT, and a Q-band dish for communications to/from the Earth based assets. While JPL's Team X and Goddard Space Flight Center s (GSFC) I M Design Center (IMDC) have completed two other LRS designs, this NASA Glenn Research Center (GRC) COMPASS LRS design sits between them in terms of physical size and capabilities.

  8. Electric and Magnetic Field-Assisted Orientational Transitions in the Ensembles of Domains in a Nematic Liquid Crystal on the Polymer Surface

    PubMed Central

    Parshin, Alexander M.; Gunyakov, Vladimir A.; Zyryanov, Victor Y.; Shabanov, Vasily F.

    2014-01-01

    Using electro- and magneto-optical techniques, we investigated orientational transitions in the ensembles of domains in a nematic liquid crystal on the polycarbonate film surface under the conditions of competing surface forces that favor radial and uniform planar alignment of nematic molecules. Having analyzed field dependences of the intensity of light passed through a sample, we established the threshold character of the orientational effects, plotted the calculated intensity versus magnetic coherence length, and compared the latter with the equilibrium length that characterizes the balance of forces on the polymer surface. PMID:25279586

  9. (abstract) Realization of a Faster, Cheaper, Better Mission and Its New Paradigm Star Tracker, the Advanced Stellar Compass

    NASA Technical Reports Server (NTRS)

    Eisenman, Allan Read; Liebe, Carl Christian; Joergensen, John Lief; Jensen, Gunnar Bent

    1997-01-01

    The first Danish satellite, rsted, will be launched in August of 1997. The scientific objective of sted is to perform a precision mapping of the Earth's magnetic field. Attitude data for the payload and the satellite are provided by the Advanced Stellar Compass (ASC) star tracker. The ASC consists of a CCD star camera and a capable microprocessor which operates by comparing the star image frames taken by the camera to its internal star catalogs.

  10. Healthcare and Compassion: Towards an Awareness of Intersubjective Vulnerability

    PubMed Central

    Kenny, Kate

    2015-01-01

    How to instill compassion in a healthcare organization? In this article, I respond to Marianna Fotaki’s proposals in her piece,‘Why and how is compassion necessary to provide good quality healthcare?’ by drawing on insights from organization studies. Following Fotaki, I argue that to instill targets and formal measures for assessing compassion would be problematic. I conclude by drawing on psychoanalytic and feminist theories to introduce alternatives, specifically proposing an approach that is grounded in a shared sense of a common, embodied precarity, which necessitates our commitment to preserving the conditions in which life might flouris PMID:26340496

  11. Homing of invasive Burmese pythons in South Florida: evidence for map and compass senses in snakes.

    PubMed

    Pittman, Shannon E; Hart, Kristen M; Cherkiss, Michael S; Snow, Ray W; Fujisaki, Ikuko; Smith, Brian J; Mazzotti, Frank J; Dorcas, Michael E

    2014-03-01

    Navigational ability is a critical component of an animal's spatial ecology and may influence the invasive potential of species. Burmese pythons (Python molurus bivittatus) are apex predators invasive to South Florida. We tracked the movements of 12 adult Burmese pythons in Everglades National Park, six of which were translocated 21-36 km from their capture locations. Translocated snakes oriented movement homeward relative to the capture location, and five of six snakes returned to within 5 km of the original capture location. Translocated snakes moved straighter and faster than control snakes and displayed movement path structure indicative of oriented movement. This study provides evidence that Burmese pythons have navigational map and compass senses and has implications for predictions of spatial spread and impacts as well as our understanding of reptile cognitive abilities. PMID:24647727

  12. Homing of invasive Burmese pythons in South Florida: evidence for map and compass senses in snakes

    USGS Publications Warehouse

    Pittman, Shannon E.; Hart, Kristen M.; Cherkiss, Michael S.; Snow, Ray W.; Fujisaki, Ikuko; Mazzotti, Frank J.; Dorcas, Michael E.

    2014-01-01

    Navigational ability is a critical component of an animal's spatial ecology and may influence the invasive potential of species. Burmese pythons (Python molurus bivittatus) are apex predators invasive to South Florida. We tracked the movements of 12 adult Burmese pythons in Everglades National Park, six of which were translocated 21–36 km from their capture locations. Translocated snakes oriented movement homeward relative to the capture location, and five of six snakes returned to within 5 km of the original capture location. Translocated snakes moved straighter and faster than control snakes and displayed movement path structure indicative of oriented movement. This study provides evidence that Burmese pythons have navigational map and compass senses and has implications for predictions of spatial spread and impacts as well as our understanding of reptile cognitive abilities.

  13. Homing of invasive Burmese pythons in South Florida: evidence for map and compass senses in snakes

    PubMed Central

    Pittman, Shannon E.; Hart, Kristen M.; Cherkiss, Michael S.; Snow, Ray W.; Fujisaki, Ikuko; Smith, Brian J.; Mazzotti, Frank J.; Dorcas, Michael E.

    2014-01-01

    Navigational ability is a critical component of an animal's spatial ecology and may influence the invasive potential of species. Burmese pythons (Python molurus bivittatus) are apex predators invasive to South Florida. We tracked the movements of 12 adult Burmese pythons in Everglades National Park, six of which were translocated 21–36 km from their capture locations. Translocated snakes oriented movement homeward relative to the capture location, and five of six snakes returned to within 5 km of the original capture location. Translocated snakes moved straighter and faster than control snakes and displayed movement path structure indicative of oriented movement. This study provides evidence that Burmese pythons have navigational map and compass senses and has implications for predictions of spatial spread and impacts as well as our understanding of reptile cognitive abilities. PMID:24647727

  14. Effect of hot band grain size on development of textures and magnetic properties in 2.0% Si non-oriented electrical steel sheet

    NASA Astrophysics Data System (ADS)

    Lee, K. M.; Huh, M. Y.; Lee, H. J.; Park, J. T.; Kim, J. S.; Shin, E. J.; Engler, O.

    2015-12-01

    The effect of hot band grain size on the development of crystallographic texture and magnetic properties in non-oriented electrical steel sheet was studied. After cold rolling the samples with different initial grain sizes displayed different microstructures and micro-textures but nearly identical macro-textures. The homogeneous recrystallized microstructure and micro-texture in the sample having small grains caused normal continuous grain growth. The quite irregular microstructure and micro-texture in the recrystallized sample with large initial grain size provided a preferential growth of grains in <001>//ND and <113>//ND which were beneficial for developing superior magnetic properties.

  15. Mindfulness, self-compassion, and empathy among health care professionals: a review of the literature.

    PubMed

    Raab, Kelley

    2014-01-01

    The relationship between mindfulness and self-compassion is explored in the health care literature, with a corollary emphasis on reducing stress in health care workers and providing compassionate patient care. Health care professionals are particularly vulnerable to stress overload and compassion fatigue due to an emotionally exhausting environment. Compassion fatigue among caregivers in turn has been associated with less effective delivery of care. Having compassion for others entails self-compassion. In Kristin Neff's research, self-compassion includes self-kindness, a sense of common humanity, and mindfulness. Both mindfulness and self-compassion involve promoting an attitude of curiosity and nonjudgment towards one's experiences. Research suggests that mindfulness interventions, particularly those with an added lovingkindness component, have the potential to increase self-compassion among health care workers. Enhancing focus on developing self-compassion using MBSR and other mindfulness interventions for health care workers holds promise for reducing perceived stress and increasing effectiveness of clinical care. PMID:24926896

  16. Lack of relationship between geoeffectiveness and orientations of magnetic clouds with bipolar Bz and unipolar southward Bz

    NASA Astrophysics Data System (ADS)

    Teh, W.-L.; Abdullah, M.; Hasbi, A. M.

    2015-09-01

    In this study, 38 magnetic clouds (MCs) that caused significant geomagnetic storms (the minimum SYM-H, SHmin, ?-50 nT) are examined, in which 17 MCs were unipolar Bz in south (S-type) and 21 MCs were bipolar Bz (north-to-south, NS-type, or south-to-north, SN-type). For S-type MC, inclination angle of the axis of the MC, |?|, is ?45°, while |?|<45° for bipolar MC. This paper aims to address a question: is the intensity of a MC-driven storm correlated with the orientations of bipolar and S-type MCs? Our results demonstrate that there is no direct and significant relationship between geoeffectiveness and orientations of bipolar and S-type MCs. In other words, there is no MC preference (bipolar or S-type MC) to regulate the SHmin of the storm. On the whole, the SHmin is found to strongly correlate with southward field Bz (cc=0.96) and with the y component of the solar wind convective electric field (cc=-0.91) but to weakly correlate with solar wind speed (cc=-0.65). This result is consistent with previous studies by Wu and Lepping (2002), J. Geophys. Res. 107 (A10), 1314. doi:10.1029/2001JA000161. By separating MC-driven storms by size into moderate (-100 nT

  17. Quantum Coherence and Entanglement in the Avian Compass

    E-print Network

    James A. Pauls; Yiteng Zhang; Gennady P. Berman; Sabre Kais

    2012-11-18

    The radical pair mechanism is one of two distinct mechanisms used to explain the navigation of birds in geomagnetic fields. However, little research has been done to explore the role of quantum entanglement in this mechanism. In this paper, we study the lifetime of radical pair entanglement corresponding to the magnitude and direction of magnetic fields to show that the entanglement lasts long enough in birds to be used for navigation. We also demonstrate that, due to a lack of orientational sensitivity of the entanglement in the geomagnetic field, the birds are not able to orient themselves by the mechanism based directly on radical-pair entanglement. To explore the entanglement mechanism further, we propose a model in which the hyperfine interactions are replaced by local magnetic fields of similar strength. The entanglement of the radical pair in this model lasts longer and displays an angular sensitivity in weak magnetic fields, both of these factors are not present in the previous models.

  18. Self-Compassion in Overcontrolled, Undercontrolled, and Resilient Personality Types 

    E-print Network

    Ramkumar, Neeta

    2012-10-19

    . This study investigated the relationship between self-compassion, personality, and gender in order to shed light on the construct's relevance to an existing framework of resiliency personality research. One hundred and twenty-three college students completed...

  19. Beyond `Further': Collaboration, Community and Compassion in the Digital Age

    E-print Network

    DeRoux, Margaux

    2011-04-25

    , but also more able to work in collaboration with his or her peers. The thesis thus concludes with an exploration of notions of collaboration, community, and compassion. While the intertext assignment illuminates the connections inherent to dialogic...

  20. Sun compass integration of skylight cues in migratory monarch butterflies.

    PubMed

    Heinze, Stanley; Reppert, Steven M

    2011-01-27

    Migrating monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate from eastern North America to their overwintering grounds in central Mexico. Here we describe the neuronal layout of those aspects of the butterfly's central complex likely to establish part of the internal sun compass and find them highly homologous to those of the desert locust. Intracellular recordings from neurons in the monarch sun compass network reveal responses tuned to specific E-vector angles of polarized light, as well as azimuth-dependent responses to unpolarized light, independent of spectral composition. The neural responses to these two stimuli in individual neurons are mediated through different regions of the compound eye. Moreover, these dual responses are integrated to create a consistent representation of skylight cues in the sun compass throughout the day. The results advance our understanding of how ambiguous sensory signals are processed by the brain to elicit a robust behavioral response. PMID:21262471

  1. 52. Patent steering gear, hatch and steering compass binnacle, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. Patent steering gear, hatch and steering compass binnacle, view from starboard looking aft. Photograph by Jet Lowe, April 1988. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  2. State transitions and decoherence in the avian compass.

    PubMed

    Poonia, Vishvendra Singh; Saha, Dipankar; Ganguly, Swaroop

    2015-05-01

    The radical pair model has been successful in explaining behavioral characteristics of the geomagnetic compass believed to underlie the navigation capability of certain avian species. In this study, the spin dynamics of the radical pair model and decoherence therein are interpreted from a microscopic state transition point of view. This helps to elucidate the interplay between the hyperfine and Zeeman interactions that enables the avian compass and clarify the distinctive effects of nuclear and environmental decoherence on it. Three regimes have been identified for the strength of the hyperfine interaction with respect to that of the geomagnetic Zeeman. It is found that the compass is likely to function in the large hyperfine interaction regime. Using a quantum information theoretic quantifier of coherence, we find that nuclear decoherence induces new structure in the spin dynamics for intermediate hyperfine interaction strength. On the other hand, environmental decoherence-modeled by two different noise models-seems to disrupt the compass action. PMID:26066201

  3. State transitions and decoherence in the avian compass

    NASA Astrophysics Data System (ADS)

    Poonia, Vishvendra Singh; Saha, Dipankar; Ganguly, Swaroop

    2015-05-01

    The radical pair model has been successful in explaining behavioral characteristics of the geomagnetic compass believed to underlie the navigation capability of certain avian species. In this study, the spin dynamics of the radical pair model and decoherence therein are interpreted from a microscopic state transition point of view. This helps to elucidate the interplay between the hyperfine and Zeeman interactions that enables the avian compass and clarify the distinctive effects of nuclear and environmental decoherence on it. Three regimes have been identified for the strength of the hyperfine interaction with respect to that of the geomagnetic Zeeman. It is found that the compass is likely to function in the large hyperfine interaction regime. Using a quantum information theoretic quantifier of coherence, we find that nuclear decoherence induces new structure in the spin dynamics for intermediate hyperfine interaction strength. On the other hand, environmental decoherence—modeled by two different noise models—seems to disrupt the compass action.

  4. Phenomenology of COMPASS data: Multiplicities and phenomenology - part II

    SciTech Connect

    Anselmino, M.; Boglione, M.; Gonzalez H., J. O.; Melis, S.; Prokudin, A.

    2015-01-23

    In this study, we present some of the main features of the multidimensional COMPASS multiplicities, via our analysis using the simple Gaussian model. We briefly discuss these results in connection with azimuthal asymmetries.

  5. Diffractive Dissociation into ?- ?- ?+ Final States at COMPASS

    E-print Network

    Florian Haas; for the COMPASS Collaboration

    2011-12-15

    Diffractive dissociation reactions studied at the COMPASS experiment at CERN provide access to the light-meson spectrum. During a pilot run in 2004, using a pion beam and a lead target, 420k \\pi- \\pi- \\pi+ final-state events with masses below 2.5 GeV/c2 were recorded, yielding a significant spin-exotic signal for the controversial \\pi 1(1600) resonance. After a significant upgrade of the spectrometer in 2007, the following two years were dedicated to meson spectroscopy. Using again a pion beam, but now with a liquid hydrogen target, an unique statistics of ~60M events of the same final state was gathered in 2008. During a short campaign in 2009, the H2 target was exchanged by several solid state targets in order to compare final states produced on targets with different atomic numbers. A partial-wave Analysis (PWA) was performed on all these data sets and results are presented.

  6. The compass rose pattern in electricity prices.

    PubMed

    Batten, Jonathan A; Hamada, Mahmoud

    2009-12-01

    The "compass rose pattern" is known to appear in the phase portraits, or scatter diagrams, of the high-frequency returns of financial series. We first show that this pattern is also present in the returns of spot electricity prices. Early researchers investigating these phenomena hoped that these patterns signaled the presence of rich dynamics, possibly chaotic or fractal in nature. Although there is a definite autoregressive and conditional heteroscedasticity structure in electricity returns, we find that after simple filtering no pattern remains. While the series is non-normal in terms of their distribution and statistical tests fail to identify significant chaos, there is evidence of fractal structures in periodic price returns when measured over the trading day. The phase diagram of the filtered returns provides a useful visual check on independence, a property necessary for pricing and trading derivatives and portfolio construction, as well as providing useful insights into the market dynamics. PMID:20059202

  7. The Role of Compassion in Altruistic Helping and Punishment Behavior

    PubMed Central

    Weng, Helen Y.; Fox, Andrew S.; Hessenthaler, Heather C.; Stodola, Diane E.; Davidson, Richard J.

    2015-01-01

    Compassion, the emotional response of caring for another who is suffering and that results in motivation to relieve suffering, is thought to be an emotional antecedent to altruistic behavior. However, it remains unclear whether compassion enhances altruistic behavior in a uniform way or is specific to sub-types of behavior such as altruistic helping of a victim or altruistic punishment of a transgressor. We investigated the relationship between compassion and subtypes of altruistic behavior using third-party paradigms where participants 1) witnessed an unfair economic exchange between a transgressor and a victim, and 2) had the opportunity to either spend personal funds to either economically a) help the victim or b) punish the transgressor. In Study 1, we examined whether individual differences in self-reported empathic concern (the emotional component of compassion) was associated with greater altruistic helping or punishment behavior in two independent samples. For participants who witnessed an unfair transaction, trait empathic concern was associated with greater helping of a victim and had no relationship to punishment. However, in those who decided to punish the transgressor, participants who reported greater empathic concern decided to punish less. In Study 2, we directly enhanced compassion using short-term online compassion meditation training to examine whether altruistic helping and punishment were increased after two weeks of training. Compared to an active reappraisal training control group, the compassion training group gave more to help the victim and did not differ in punishment of the transgressor. Together, these two studies suggest that compassion is related to greater altruistic helping of victims and is not associated with or may mitigate altruistic punishment of transgressors. PMID:26655837

  8. SIDIS transverse spin azimuthal asymmetries at COMPASS: Multidimensional analysis

    E-print Network

    Bakur Parsamyan

    2015-12-22

    Exploration of transverse spin structure of the nucleon via study of the spin (in)dependent azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS) and Drell-Yan (DY) reactions is one of the main aspects of the broad physics program of the COMPASS experiment (CERN, Switzerland). In past decade COMPASS has collected a considerable amount of polarized deuteron and proton SIDIS data, while recent 2014 and 2015 runs were dedicated to the Drell-Yan measurements. Results on SIDIS azimuthal effects provided so far by COMPASS play an important role in general understanding of the three-dimensional nature of the nucleon. Giving access to the entire "twist-2" set of transverse momentum dependent (TMD) parton distribution functions (PDFs) and fragmentation functions (FFs) COMPASS data are being widely used in phenomenological analyses and experimental data fits. Recent unique and first ever x-$Q^{2}$-z-pT multidimensional results for transverse spin asymmetries obtained by COMPASS serve as a direct and unprecedented input for one of the hottest topics in the field of spin-physics: the TMD $Q^{2}$-evolution related studies. In addition, extraction of the Sivers and all other azimuthal effects from first ever polarized Drell-Yan data collected recently by COMPASS will reveal another side of the spin-puzzle clarifying the link between SIDIS and Drell-Yan branches. This will be a unique possibility to test predicted universality and key-features of TMD PDFs using essentially the same experimental setup and exploring the same kinematical domain. In this review main focus will be given to the very recent results from COMPASS multi-dimensional analysis of transverse spin asymmetries and to the physics aspects of COMPASS polarized Drell-Yan program.

  9. The Role of Compassion in Altruistic Helping and Punishment Behavior.

    PubMed

    Weng, Helen Y; Fox, Andrew S; Hessenthaler, Heather C; Stodola, Diane E; Davidson, Richard J

    2015-01-01

    Compassion, the emotional response of caring for another who is suffering and that results in motivation to relieve suffering, is thought to be an emotional antecedent to altruistic behavior. However, it remains unclear whether compassion enhances altruistic behavior in a uniform way or is specific to sub-types of behavior such as altruistic helping of a victim or altruistic punishment of a transgressor. We investigated the relationship between compassion and subtypes of altruistic behavior using third-party paradigms where participants 1) witnessed an unfair economic exchange between a transgressor and a victim, and 2) had the opportunity to either spend personal funds to either economically a) help the victim or b) punish the transgressor. In Study 1, we examined whether individual differences in self-reported empathic concern (the emotional component of compassion) was associated with greater altruistic helping or punishment behavior in two independent samples. For participants who witnessed an unfair transaction, trait empathic concern was associated with greater helping of a victim and had no relationship to punishment. However, in those who decided to punish the transgressor, participants who reported greater empathic concern decided to punish less. In Study 2, we directly enhanced compassion using short-term online compassion meditation training to examine whether altruistic helping and punishment were increased after two weeks of training. Compared to an active reappraisal training control group, the compassion training group gave more to help the victim and did not differ in punishment of the transgressor. Together, these two studies suggest that compassion is related to greater altruistic helping of victims and is not associated with or may mitigate altruistic punishment of transgressors. PMID:26655837

  10. Compassion Fatigue and Burnout Amongst Clinicians: A Medical Exploratory Study

    PubMed Central

    Bhutani, Jaikrit; Bhutani, Sukriti; Balhara, Yatan Pal Singh; Kalra, Sanjay

    2012-01-01

    Background: Compassion fatigue is a broad term comprising of two components – burnout and secondary traumatic stress. The current study is aimed at identifying ‘burnout’ and ‘compassion fatigue’ among clinicians involved in care of individuals suffering from medical illness. Materials and Methods: A total of 60 clinicians were included in the study. A semi-structured questionnaire was administered to gather information related to personal, professional, anthropometric, and metabolic profile of the study participants. Professional Quality of Life Scale (ProQoL Version V) was used to assess burnout, compassion satisfaction and secondary traumatic stress. Analysis was carried out using the SPSS version 19.0. Results: The mean age of clinicians was 46.68±11.06 (range 26-67 years). Burnout score was significantly higher in those involved in diabetology practice. Similarly, compassion satisfaction score was greater among those with greater years of practice as well as among those in private practice. Clinicians who reported a poor working condition, as opposed to good, had more burnout and less compassion satisfaction. Conclusion: The current study suggests that it is important to find out ways of decreasing burnout and compassion fatigue among clinicians. PMID:23723540

  11. Self-compassion: a potential resource for young women athletes.

    PubMed

    Mosewich, Amber D; Kowalski, Kent C; Sabiston, Catherine M; Sedgwick, Whitney A; Tracy, Jessica L

    2011-02-01

    Self-compassion has demonstrated many psychological benefits (Neff, 2009). In an effort to explore self-compassion as a potential resource for young women athletes, we explored relations among self-compassion, proneness to self-conscious emotions (i.e., shame, guilt-free shame, guilt, shame-free guilt, authentic pride, and hubristic pride), and potentially unhealthy self-evaluative thoughts and behaviors (i.e., social physique anxiety, obligatory exercise, objectified body consciousness, fear of failure, and fear of negative evaluation). Young women athletes (N = 151; Mage = 15.1 years) participated in this study. Self-compassion was negatively related to shame proneness, guilt-free shame proneness, social physique anxiety, objectified body consciousness, fear of failure, and fear of negative evaluation. In support of theoretical propositions, self-compassion explained variance beyond self-esteem on shame proneness, guilt-free shame proneness, shame-free guilt proneness, objectified body consciousness, fear of failure, and fear of negative evaluation. Results suggest that, in addition to self-esteem promotion, self-compassion development may be beneficial in cultivating positive sport experiences for young women. PMID:21451173

  12. A new therapeutic community: development of a compassion-focussed and contextual behavioural environment.

    PubMed

    Veale, David; Gilbert, Paul; Wheatley, Jon; Naismith, Iona

    2015-01-01

    Social relationships and communities provide the context and impetus for a range of psychological developments, from genetic expression to the development of core self-identities. This suggests a need to think about the therapeutic changes and processes that occur within a community context and how communities can enable therapeutic change. However, the 'therapeutic communities' that have developed since the Second World War have been under-researched. We suggest that the concept of community, as a change process, should be revisited within mainstream scientific research. This paper briefly reviews the historical development of therapeutic communities and critically evaluates their current theory, practice and outcomes in a systematic review. Attention is drawn to recent research on the nature of evolved emotion regulation systems, the way these are entrained by social relationships, the importance of affiliative emotions in the regulation of threat and the role of fear of affiliative emotions in psychopathology. We draw on concepts from compassion-focussed therapy, social learning theory and functional analytical psychotherapy to consider how members of a therapeutic community can be aware of each other's acts of courage and respond using compassion. Living in structured and affiliative-orientated communities that are guided by scientific models of affect and self-regulation offers potential therapeutic advantages over individual outpatient therapy for certain client groups. This conclusion should be investigated further. Copyright © 2014 John Wiley & Sons, Ltd. Key Practitioner Message Current therapeutic community practice is not sufficiently evidence based and may not be maximizing the potential therapeutic value of a community. Compassion-focussed therapy and social learning theory offer new approaches for a therapeutic environment, involving an understanding of the role, nature and complexities of compassionate and affiliative relationships from staff and members, behavioural change guided by learning theory, a clear formulation based on threat-derived safety strategies, goal setting and positive reinforcement. PMID:24733685

  13. Biomagnetism and Magnetotaxis in Bacteria: What Bacteria Know About Magnetic Materials and Permanent Magnet Design

    NASA Astrophysics Data System (ADS)

    Frankel, Richard

    2011-03-01

    Magnetotactic bacteria (mtb) migrate along geomagnetic field lines, i.e., they behave like self-propelled magnetic compass needles. Mtb make single-magnetic-domain crystals of magnetite (Fe 3 O4) and greigite (Fe 3 S4) in intracellular structures called magnetosomes. The magnetosomes are arranged in linear chains that comprise permanent magnetic dipoles with remanent moments approaching the saturation moment, causing the mtb to be oriented in the geomagnetic field as they swim. This allows them to keep their heading and efficiently migrate to, and remain in, a preferred, microaerobic, aquatic habitat. The mtb have solved the difficult problem of designing a permanent magnet that is sufficiently robust to cause the cell to be oriented in the geomagnetic field at ambient temperature, yet fit inside a micron-sized object, and be assembled in situ from potentially toxic materials scavenged from the environment. I will describe some recent advances in mtb genetics that illuminate the process by which they make and arrange their magnetosomes.

  14. Electronic and magnetic properties of (1 1 1)-oriented CoCr{sub 2}O{sub 4} epitaxial thin film

    SciTech Connect

    Liu, Xiaoran Kareev, M.; Cao, Yanwei; Middey, S.; Meyers, D.; Chakhalian, J.; Liu, Jian; Freeland, J. W.

    2014-07-28

    We report on the fabrication of high quality (1 1 1)-oriented ferrimagnetic normal spinel CoCr{sub 2}O{sub 4} epitaxial thin films on single crystal Al{sub 2}O{sub 3} substrates. The structural, electronic, and magnetic properties were characterized by in-situ reflection high energy electron diffraction, atomic force microscopy, X-ray diffraction, X-ray photoemission spectroscopy, dc magnetization measurement, and element resolved resonant X-ray magnetic scattering. The comprehensive characterization reveals that no disorder in the cation distribution or multivalency issue is present in the samples. As a result, Kagomé and triangular layers are naturally formed via this specific growth approach. These findings offer a pathway to fabricate two dimensional Kagomé heterostructures with exotic quantum many-body phenomena by means of geometrical design.

  15. Alignment-to-orientation conversion in a magnetic field at nonlinear excitation of the $D_2$ line of rubidium: experiment and theory

    E-print Network

    Auzinsh, M; Ferber, R; Gahbauer, F; Kalvans, L; Mozers, A; Spiss, A

    2015-01-01

    We studied alignment-to-orientation conversion caused by excited-state level crossings in a nonzero magnetic field of both atomic rubidium isotopes. Experimental measurements were performed on the transitions of the $D_2$ line of rubidium. These measured signals were described by a theoretical model that takes into account all neighboring hyperfine transitions, the mixing of magnetic sublevels in an external magnetic field, the coherence properties of the exciting laser radiation, and the Doppler effect. In the experiments laser induced fluorescence (LIF) components were observed at linearly polarized excitation and their difference was taken afterwards. By observing the two oppositely circularly polarized components we were able to see structures not visible in the difference graphs, which yields deeper insight into the processes responsible for these signals. We studied how these signals are dependent on laser power density and how they are affected when the exciting laser is tuned to different hyperfine tr...

  16. Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence

    SciTech Connect

    Meng, Hao; Naik, Vinayak Bharat; Liu, Ruisheng; Han, Guchang

    2014-07-28

    We report an investigation of electric-field (EF) control of spin re-orientation as functions of the thicknesses of CoFeB free layer (FL) and MgO layer in synthetic-antiferromagnetic pinned magnetic tunnel junctions with perpendicular magnetic anisotropy. It is found that the EF modulates the coercivity (Hc) of the FL almost linearly for all FL thicknesses, while the EF efficiency, i.e., the slope of the linearity, increases as the FL thickness increases. This linear variation in Hc is also observed for larger MgO thicknesses (?1.5?nm), while the EF efficiency increases only slightly from 370 to 410?Oe nm/V when MgO thickness increases from 1.5 to 1.76?nm. We have further observed the absence of quasi-DC unipolar switching. We discuss its origin and highlight the underlying challenges to implement the EF controlled switching in a practical magnetic memory.

  17. Influence of initial annealing on structure evolution and magnetic properties of 3.4% Si non-oriented steel during final annealing

    NASA Astrophysics Data System (ADS)

    Pedrosa, Josiane Simões Mendanha; Paolinelli, Sebastião da Costa; Cota, André Barros

    2015-11-01

    The effect of the initial annealing on structure evolution and magnetic properties during the final annealing of a 3.4% Si non-oriented grain steel was evaluated. Half of the samples were submitted to initial annealing at 1030 °C before cold rolling and all samples were subjected to final annealing process at temperatures from 540 °C to 1100 °C. The magnetic induction and core loss in the final samples, the microstructure by optical microscopy and the crystallographic texture by X-ray diffraction and EBSD were evaluated. The results show that the samples without initial annealing presented better magnetic properties than the samples with initial annealing, due to the higher ratio between Eta fiber and Gamma fiber volume fractions (Eta/Gamma ratio) in their structure after final annealing.

  18. Migrating songbirds tested in computer-controlled Emlen funnels use stellar cues for a time-independent compass.

    PubMed

    Mouritsen, H; Larsen, O N

    2001-11-01

    This paper investigates how young pied flycatchers, Ficedula hypoleuca, and blackcaps, Sylvia atricapilla, interpret and use celestial cues. In order to record these data, we developed a computer-controlled version of the Emlen funnel, which enabled us to make detailed temporal analyses. First, we showed that the birds use a star compass. Then, we tested the birds under a stationary planetarium sky, which simulated the star pattern of the local sky at 02:35 h for 11 consecutive hours of the night, and compared the birds' directional choices as a function of time with the predictions from five alternative stellar orientation hypotheses. The results supported the hypothesis suggesting that birds use a time-independent star compass based on learned geometrical star configurations to pinpoint the rotational point of the starry sky (north). In contrast, neither hypotheses suggesting that birds use the stars for establishing their global position and then perform true star navigation nor those suggesting the use of a time-compensated star compass were supported. PMID:11807103

  19. Electromagnetic Induction with Neodymium Magnets

    ERIC Educational Resources Information Center

    Wood, Deborah; Sebranek, John

    2013-01-01

    In April 1820, Hans Christian Ørsted noticed that the needle of a nearby compass deflected briefly from magnetic north each time the electric current of the battery he was using for an unrelated experiment was turned on or off. Upon further investigation, he showed that an electric current flowing through a wire produces a magnetic field. In 1831…

  20. Highly (001) oriented L1{sub 0}-CoPt/TiN multilayer films on glass substrates with perpendicular magnetic anisotropy

    SciTech Connect

    An, Hongyu; Sannomiya, Takumi; Muraishi, Shinji; Nakamura, Yoshio; Shi, Ji; Xie, Qian; Zhang, Zhengjun; Wang, Jian

    2015-03-15

    To obtain strong perpendicular magnetic anisotropy (PMA) based on L1{sub 0} structure for magnetic storage devices, costly single crystalline substrates are generally required to achieve (001) texture. Recently, various studies also have focused on depositing different kinds of seed layers on glass or other amorphous substrates to promote (001) preferred orientation of L1{sub 0} CoPt and FePt. TiN is a very promising seed layer material because of its cubic crystalline structure (similar to MgO) and excellent diffusion barring property even at high temperatures. In the present work, highly (001) oriented L1{sub 0}-CoPt/TiN multilayer films have been successfully deposited on glass substrates. After annealing at 700?°C, the film exhibits PMA, and a strong (001) peak is detected from the x-ray diffraction profiles, indicating the ordering transformation of CoPt layers from fcc (A1) to L1{sub 0} structure. It also is found that alternate deposition of cubic TiN and CoPt effectively improves the crystallinity and (001) preferred orientation of CoPt layers. This effect is verified by the substantial enhancement of (001) reflection and PMA with increasing the period number of the multilayer films.

  1. How could the Viking Sun compass be used with sunstones before and after sunset? Twilight board as a new interpretation of the Uunartoq artefact fragment

    PubMed Central

    Bernáth, Balázs; Farkas, Alexandra; Száz, Dénes; Blahó, Miklós; Egri, Ádám; Barta, András; Åkesson, Susanne; Horváth, Gábor

    2014-01-01

    Vikings routinely crossed the North Atlantic without a magnetic compass and left their mark on lands as far away as Greenland, Newfoundland and Baffin Island. Based on an eleventh-century dial fragment artefact, found at Uunartoq in Greenland, it is widely accepted that they sailed along chosen latitudes using primitive Sun compasses. Such instruments were tested on sea and proved to be efficient hand-held navigation tools, but the dimensions and incisions of the Uunartoq find are far from optimal in this role. On the basis of the sagas mentioning sunstones, incompatible hypotheses were formed for Viking solar navigation procedures and primitive skylight polarimetry with dichroic or birefringent crystals. We describe here a previously unconceived method of navigation based on the Uunartoq artefact functioning as a ‘twilight board’, which is a combination of a horizon board and a Sun compass optimized for use when the Sun is close to the horizon. We deduced an appropriate solar navigation procedure using a twilight board, a shadow-stick and birefringent crystals, which bring together earlier suggested methods in harmony and provide a true skylight compass function. This could have allowed Vikings to navigate around the clock, to use the artefact dial as a Sun compass during long parts of the day and to use skylight polarization patterns in the twilight period. In field tests, we found that true north could be appointed with such a medieval skylight compass with an error of about ±4° when the artificially occluded Sun had elevation angles between +10° and ?8° relative to the horizon. Our interpretation allows us to assign exact dates to the gnomonic lines on the artefact and outlines the schedule of the merchant ships that sustained the Viking colony in Greenland a millennium ago. PMID:24910520

  2. Orientation of vortices in a superconducting thin film: Quantitative comparison of spin-polarized neutron reflectivity and magnetization

    NASA Astrophysics Data System (ADS)

    Han, S.-W.; Farmer, J.; Kaiser, H.; Miceli, P. F.; Roshchin, I. V.; Greene, L. H.

    2000-10-01

    We present a quantitative comparison of the magnetization measured by spin-polarized neutron reflectivity (SPNR) and dc magnetometry on a 1370 Å-thick Nb superconducting film. As a function of magnetic field applied in the film plane, SPNR exhibits reversible behavior whereas the dc magnetization shows substantial hysteresis. The difference between these measurements is attributed to a rotation of the vortex magnetic field out of the film plane as the applied field is reduced. SPNR measures only the magnetization parallel to the film plane, whereas dc magnetization is strongly influenced by the perpendicular component of magnetization when there is a slight sample tilt; thus combining the two techniques allows one to distinguish two components of magnetization in a thin film.

  3. GARFIELD Computer Program Simulation of the COMPASS Drift Chamber 5

    NASA Astrophysics Data System (ADS)

    Oh, Seung Joon

    2014-09-01

    COMPASS is a nuclear physics experiment at the Super Proton Synchrotron (SPS) at CERN. The purpose of COMPASS is the study of hadron structure and hadron spectroscopy with high intensity muon and hadron beams. To further study the Drell-Yan process in scattering pion beams off polarized proton targets, COMPASS requires sophisticated tracking devices to determine the trajectory of scattered charged muon pairs. The University of Illinois at Urbana-Champaign is currently constructing the Drift Chamber 5 (DC5) to replace old straw-tube tracking detectors in the COMPASS spectrometer. DC5 is composed of 8 layers of anode and 13 layers of cathode frames made out of G10, a fiberglass-epoxy composite. The high rates for the Drell-Yan measurement require a small drift cell and precise mechanical tolerances have to meet in order to achieve good position resolution. GARFIELD simulations were carried out to study the impact of mechanical tolerances on the drift chamber performance in particular the position resolution that can be reached. The details of the DC5 GARFIELD simulation and results for signal development and position resolution will be presented. COMPASS is a nuclear physics experiment at the Super Proton Synchrotron (SPS) at CERN. The purpose of COMPASS is the study of hadron structure and hadron spectroscopy with high intensity muon and hadron beams. To further study the Drell-Yan process in scattering pion beams off polarized proton targets, COMPASS requires sophisticated tracking devices to determine the trajectory of scattered charged muon pairs. The University of Illinois at Urbana-Champaign is currently constructing the Drift Chamber 5 (DC5) to replace old straw-tube tracking detectors in the COMPASS spectrometer. DC5 is composed of 8 layers of anode and 13 layers of cathode frames made out of G10, a fiberglass-epoxy composite. The high rates for the Drell-Yan measurement require a small drift cell and precise mechanical tolerances have to meet in order to achieve good position resolution. GARFIELD simulations were carried out to study the impact of mechanical tolerances on the drift chamber performance in particular the position resolution that can be reached. The details of the DC5 GARFIELD simulation and results for signal development and position resolution will be presented. UIUC COMPASS group.

  4. Switching the orientation of Jahn-Teller axes in oxime-based Mn(III) dimers and its effect upon magnetic exchange: a combined experimental and theoretical study.

    PubMed

    Comar, Priyanka; Rajeshkumar, Thayalan; Nichol, Gary S; Pitak, Mateusz B; Coles, Simon J; Rajaraman, Gopalan; Brechin, Euan K

    2015-11-18

    A family of Mn(III) dimers of general formula [Mn(R-sao)2(dpa)2](ClO4)2 () has been synthesised using derivatised phenolic oximes (R-saoH2, where R = H, Me, Et, Ph) in combination with di-(2-picolyl)-amine (dpa). Their structures reveal a double-oxime bridged [Mn(III)(NO)]2 magnetic core in which the Jahn-Teller axes lie perpendicular to the bridging plane, in contrast to two previously reported family members (, ). The switch in the orientation of the Jahn-Teller axes is enforced through the use of the chelating ligand which is present in and absent in . Dc magnetic susceptibility measurements reveal that the exchange interactions between the Mn(III) metal centres in are antiferromagnetic in contrast to that observed for and which are ferromagnetic. DFT calculations performed on complexes reproduce both the sign and strength of the J values found experimentally. Molecular orbital analysis unlocks a common mechanism of magnetic coupling based upon the orientation of the Jahn-Teller axis, with the magneto-structural correlation also dependent upon the Mn-N-O-Mn angles - with ferromagnetic interactions at smaller dihedral angles. PMID:26474037

  5. Magnetic properties of epitaxial Fe{sub 3}O{sub 4} films with various crystal orientations and tunnel magnetoresistance effect at room temperature

    SciTech Connect

    Nagahama, Taro Matsuda, Yuya; Tate, Kazuya; Kawai, Tomohiro; Takahashi, Nozomi; Hiratani, Shungo; Watanabe, Yusuke; Yanase, Takashi; Shimada, Toshihiro

    2014-09-08

    Fe{sub 3}O{sub 4} is a ferrimagnetic spinel ferrite that exhibits electric conductivity at room temperature (RT). Although the material has been predicted to be a half metal according to ab-initio calculations, magnetic tunnel junctions (MTJs) with Fe{sub 3}O{sub 4} electrodes have demonstrated a small tunnel magnetoresistance (TMR) effect. Not even the sign of the tunnel magnetoresistance ratio has been experimentally established. Here, we report on the magnetic properties of epitaxial Fe{sub 3}O{sub 4} films with various crystal orientations. The films exhibited apparent crystal orientation dependence on hysteresis curves. In particular, Fe{sub 3}O{sub 4}(110) films exhibited in-plane uniaxial magnetic anisotropy. With respect to the squareness of hysteresis, Fe{sub 3}O{sub 4} (111) demonstrated the largest squareness. Furthermore, we fabricated MTJs with Fe{sub 3}O{sub 4}(110) electrodes and obtained a TMR effect of ?12% at RT. The negative TMR ratio corresponded to the negative spin polarization of Fe{sub 3}O{sub 4} predicted from band calculations.

  6. NMR determination of the orientation of the magnetic susceptibility tensor in cyanometmyoglobin: A new probe of steric tilt of bound ligand

    SciTech Connect

    Emerson, S.D.; La Mar, G.N. )

    1990-02-13

    The experimentally determined paramagnetic dipolar shifts for noncoordinated amino acid side-chain protons in the heme pocket of sperm whale cyanometmyoglobin were used to determine in solution the orientation of the principal axes for the paramagnetic susceptibility tensor relative to the heme iron molecular coordinates. The determination was made by a least-squares search for the unique Euler rotation angles which convert the geometric factors in the molecular (crystal) coordinates to ones that correctly predict each of 41 known dipolar shifts by using the magnetic anisotropies computed previously. An excellent fit to experimental shifts was obtained, which also provided predictions that allowed subsequent new assignments to be made. The magnetic axes are oriented so that the z axis is tipped {approximately}15{degree} from the heme normal toward the heme {delta}-meso-H and coincides approximately with the characterized FeCO tilt axis in the isostructural MbCO complex. Since the FeCO and FeCN units are isostructural, the authors propose that the dominant protein constraint that tips the magnetic z axis from the heme normal is the tilt of the FeCN by steric interactions with the distal residues. It is shown that the proximal His ring nonlabile proton hyperfine shifts provide direct and exquisitely sensitive indicators of the degree of the z axis tilt that may serve as a valuable probe for characterizing variable steric interactions in the distal pocket of both point mutants and natural genetic variants of myoglobin.

  7. Quasicoherent modes on the COMPASS tokamak

    NASA Astrophysics Data System (ADS)

    Melnikov, A. V.; Markovic, T.; Eliseev, L. G.; Adámek, J.; Aftanas, M.; Bilkova, P.; Boehm, P.; Gryaznevich, M.; Imrisek, M.; Lysenko, S. E.; Medvedev, S. Y.; Panek, R.; Peterka, M.; Seidl, J.; Stefanikova, E.; Stockel, J.; Weinzettl, V.; the COMPASS Team

    2015-06-01

    Multiple quasicoherent electromagnetic modes with steady-state frequency and different nature and location were observed in the COMPASS tokamak (R = 0.56?m, = 0.2?m) at Bt = 1.14?T with Co-NBI (PNBI = 0.2-0.5?MW, Eb = 32?keV) at frequencies 5?kHz < f < 250?kHz. Modes were observed in both low and high confinement (L- and H-modes) plasmas. Lower frequency modes with f < 50?kHz were identified as low m tearing and kink MHD modes, while higher frequency modes with 50?kHz < f < 250?kHz were considered as having Alfvénic nature. Unexpectedly, such modes were only observed in the H-mode, both in neutral beam injector-assisted and Ohmic, so the mode driving force is not yet clear. Using the linear MHD code KINX, we initially identified the observed mode with a ballooning structure is as beta induced Alfvén eigenmode (BAE) with m, n < 5, while an antiballooning mode is initially identified as toroidal Alfvén eigenmode (TAE) with m, n < 9.

  8. Pain, Palliative Care, and Compassion in India.

    PubMed

    Fox, Hannah; Jackson, Kate

    2015-12-01

    An estimated 1 million new cases of cancer occur each year in India, with over 80% presenting at the point at which the disease is incurable. Around 60% of the patients will already be in significant pain, and just under half will be experiencing excruciating, unbearable pain. With only a handful of outpatient palliative care clinics in Kolkata, few patients are able to access essential pain medication and palliative care services. This narrative includes five case studies exploring differing aspects of palliative care: pain management, the difficulties faced in accessing morphine, the importance of compassion in end-of-life care, and the psychological effects on families. They illustrate the degree of suffering some patients and families face, and the relatively simple measures that can be taken to alleviate this. For the current situation in India to improve, there needs to be better access to essential pain medications such as morphine, education of health care professionals and the public, as well as the implementation of government pain management and palliative care policies. PMID:26654418

  9. COMPASS Final Report: Lunar Communications Terminal (LCT)

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2010-01-01

    The Lunar Communications Terminal (LCT) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session designed a terminal to provide communications between lunar South Pole assets, communications relay to/from these assets through an orbiting Lunar Relay Satellite (LRS) and navigation support. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The Terminal consists of a pallet containing the communications and avionics equipment, surrounded by the thermal control system (radiator), an attached, deployable 10-m tower, upon which were mounted locally broadcasting and receiving modems and a deployable 1 m diameter Ka/S band dish which provides relay communications with the lunar relay satellites and, as a backup, Earth when it is in view. All power was assumed to come from the lunar outpost Habitat. Three LCT design options were explored: a stand-alone LCT servicing the manned outpost, an integrated LCT (into the Habitat or Lunar Lander), and a mini-LCT which provides a reduced level of communication for primarily robotic areas dealing as in situ resource utilization (ISRU) and remote science. Where possible all the designs assumed single fault tolerance. Significant mass savings were found when integrating the LCT into the Habitat or Lander but increases in costs occurred depending upon the level of man rating required for such designs.

  10. Magnetism and electronic structure of (001)- and (111)-oriented LaTiO3 bilayers sandwiched in LaScO3 barriers

    NASA Astrophysics Data System (ADS)

    Weng, Yakui; Dong, Shuai

    2015-05-01

    In this study, the magnetism and electronic structure of LaTiO3 bilayers along both the (001) and (111) orientations are calculated using the density functional theory. The band insulator LaScO3 is chosen as the barrier layer and substrate to obtain the isolating LaTiO3 bilayer. For both the (001)- and (111)-oriented cases, LaTiO3 demonstrates the G-type antiferromagnetism as the ground state, similar to the bulk material. However, the electronic structure is significantly changed. The occupied bands of Ti are much narrower in the (111) case, giving a nearly flat band. As a result, the exchange coupling between nearest-neighbor Ti ions is reformed in these superlattices, which will affect the Néel temperature significantly.

  11. Transverse spin azimuthal asymmetries in SIDIS at COMPASS: Multidimensional analysis

    E-print Network

    Bakur Parsamyan

    2015-12-01

    One of the important objectives of the COMPASS experiment (CERN, SPS north area) is the exploration of transverse spin structure of nucleon via study of spin (in)dependent azimuthal asymmetries with semi-inclusive deep inelastic scattering (SIDIS) processes and recently also with Drell-Yan (DY) reactions. In the past twelve years series of measurements were made in COMPASS, using 160 GeV/c longitudinally polarized muon beam and polarized $^6LiD$ and $NH_3$ targets. Drell-Yan measurements with high energy (190 GeV/c) pion beam and transversely polarized $NH_3$ target started in 2014 with a pilot-run have been followed by 140 days of data taking in 2015. The experimental results obtained by COMPASS for azimuthal effects in SIDIS play an important role in the general understanding of the three-dimensional nature of the nucleon and are widely used in theoretical analyses and global data fits. In addition, future first ever polarized DY-data from COMPASS compared with SIDIS results will open a new chapter probing general principles of QCD TMD-formalism. In this review main focus is given to the very recent results obtained by the COMPASS collaboration from first ever multi-dimensional extraction of SIDIS transverse spin asymmetries.

  12. Transverse spin azimuthal asymmetries in SIDIS at COMPASS: Multidimensional analysis

    E-print Network

    Bakur Parsamyan

    2015-12-22

    One of the important objectives of the COMPASS experiment (CERN, SPS north area) is the exploration of transverse spin structure of nucleon via study of spin (in)dependent azimuthal asymmetries with semi-inclusive deep inelastic scattering (SIDIS) processes and recently also with Drell-Yan (DY) reactions. In the past twelve years series of measurements were made in COMPASS, using 160 GeV/c longitudinally polarized muon beam and polarized $^6LiD$ and $NH_3$ targets. Drell-Yan measurements with high energy (190 GeV/c) pion beam and transversely polarized $NH_3$ target started in 2014 with a pilot-run have been followed by 140 days of data taking in 2015. The experimental results obtained by COMPASS for azimuthal effects in SIDIS play an important role in the general understanding of the three-dimensional nature of the nucleon and are widely used in theoretical analyses and global data fits. In addition, future first ever polarized DY-data from COMPASS compared with SIDIS results will open a new chapter probing general principles of QCD TMD-formalism. In this review main focus is given to the very recent results obtained by the COMPASS collaboration from first ever multi-dimensional extraction of SIDIS transverse spin asymmetries.

  13. Oxytocin improves compassion toward women among patients with PTSD.

    PubMed

    Palgi, Sharon; Klein, Ehud; Shamay-Tsoory, Simone G

    2016-02-01

    Although impairments in social skills, including empathic abilities, are common in post-traumatic stress disorder (PTSD), the ability to feel compassion-a pro-social behavior that is based on empathy and drives us to help others-has never been assessed among these patients. The first aim of this study was to examine whether patients with PTSD suffer from deficits in compassion and to examine the association between the clusters of PTSD symptoms and these deficits. Furthermore, given that intranasal oxytocin (OT) has been suggested to possibly modulate social behaviors, the second aim of this study was to investigate whether intranasal OT may enhance compassion in these patients. Using a randomized, double-blind, placebo-controlled crossover design, we administered 24 IU of OT and placebo at a one-week interval to 32 patients with PTSD and to 30 matched healthy control participants. The results indicate that patients with PTSD exhibit deficits in compassion and that the numbing cluster emerged as the key predictor of those deficits. Moreover, the results indicate that a single intranasal dose of OT enhances compassion toward women (but not towards men), both in patients with PTSD and in controls. These results offer support for recent suggestions that intranasal OT may potentially be an effective pharmacological intervention for patients with PTSD. PMID:26671007

  14. Self-Compassion as a Predictor of Psychological Entitlement in Turkish University Students

    ERIC Educational Resources Information Center

    Sahranç, Ümit

    2015-01-01

    The purpose of this study is to examine the predictive role of self-compassion on psychological entitlement. Participants were 331 university students (205 women, 126 men, M age = 20.5 years.). In this study, the Self-compassion Scale and the Psychological Entitlement Scale were used to assess self-compassion and psychological entitlement. The…

  15. Teacher's Resource Book for Magnets. Grade 1. Revised. Anchorage School District Elementary Science Program.

    ERIC Educational Resources Information Center

    Anchorage School District, AK.

    This resource book introduces first-grade children to the world of magnetism and magnetic effects. The students are provided the opportunity to observe interactions between magnets, identify what materials a magnet will and will not attract, study magnetic fields, induce temporary magnetism, make an electromagnet, and use compasses. The 16 lessons…

  16. Dung beetles ignore landmarks for straight-line orientation.

    PubMed

    Dacke, Marie; Byrne, Marcus; Smolka, Jochen; Warrant, Eric; Baird, Emily

    2013-01-01

    Upon locating a suitable dung pile, ball-rolling dung beetles shape a piece of dung into a ball and roll it away in a straight line. This guarantees that they will not return to the dung pile, where they risk having their ball stolen by other beetles. Dung beetles are known to use celestial compass cues such as the sun, the moon and the pattern of polarised light formed around these light sources to roll their balls of dung along straight paths. Here, we investigate whether terrestrial landmarks have any influence on straight-line orientation in dung beetles. We find that the removal or re-arrangement of landmarks has no effect on the beetle's orientation precision. Celestial compass cues dominate straight-line orientation in dung beetles so strongly that, under heavily overcast conditions or when prevented from seeing the sky, the beetles can no longer orient along straight paths. To our knowledge, this is the only animal with a visual compass system that ignores the extra orientation precision that landmarks can offer. PMID:23076443

  17. Compassion fatigue among registered nurses: connecting theory and research.

    PubMed

    Sheppard, Kate

    2015-02-01

    Unresolved compassion fatigue often causes physical and emotional exhaustion, and can significantly impair job performance. It is also known to cause increased absenteeism and even turnover among health care providers such as registered nurses. Often those experiencing compassion fatigue attempt to self-medicate in order to numb the intense emotions, and distance themselves from patients, colleagues, friends, and even family. This article describes the challenges of applying one widely used conceptual model to research among nurses who are at risk for experiencing this important and debilitating phenomenon. Through two qualitative studies that explored compassion fatigue among registered nurses, symptoms were identified that fit within the conceptual model. Several additional elements were not adequately captured by the conceptual model, and the term was perceived as being stigmatizing. PMID:25434861

  18. Compassion Is a Necessity and an Individual and Collective Responsibility

    PubMed Central

    Lown, Beth A.

    2015-01-01

    Compassion is a complex process that is innate, determined in part by individual traits, and modulated by a myriad of conscious and unconscious factors, immediate context, social structures and expectations, and organizational "culture." Compassion is an ethical foundation of healthcare and a widely shared value; it is not an optional luxury in the healing process. While the interrelations between individual motivation and social structure are complex, we can choose to act individually and collectively to remove barriers to the innate compassion that most healthcare professionals bring to their work. Doing so will reduce professional burnout, improve the well-being of the healthcare workforce, and facilitate our efforts to achieve the triple aim of improving patients’ experiences of care and health while lowering costs. PMID:26340491

  19. Comment on ``London model for the levitation force between a horizontally oriented point magnetic dipole and superconducting sphere''

    NASA Astrophysics Data System (ADS)

    Lin, Qiong-Gui

    2007-01-01

    In a recent paper the magnetostatic boundary-value problem for a magnetic dipole with transverse direction in the presence of a superconducting sphere was solved in both cases when the London penetration depth is zero and finite. It was concluded that the levitation force on the transverse magnetic dipole is exactly half that for a magnetic dipole with radial direction. We show that this conclusion is incorrect in either case. In the former case it is due to an incorrect boundary condition. In the latter case it is caused by calculational errors. Corrected results are presented. The distribution of supercurrent and the associated magnetic moment are also calculated.

  20. 46 CFR 167.40-45 - Magnetic compass and gyrocompass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...for the gyrocompass required under paragraph (b) of this section that is at the main steering stand unless the gyrocompass is illuminated and is at the main steering stand. [CFD 75-074, 42 FR 5964, Jan. 31,...

  1. Nanocolumnar interfaces and enhanced magnetic coercivity in preferentially oriented cobalt ferrite thin films grown using oblique-angle pulsed laser deposition.

    PubMed

    Mukherjee, Devajyoti; Hordagoda, Mahesh; Hyde, Robert; Bingham, Nicholas; Srikanth, Hariharan; Witanachchi, Sarath; Mukherjee, Pritish

    2013-08-14

    Highly textured cobalt ferrite (CFO) thin films were grown on Si (100) substrates using oblique-angle pulsed laser deposition (?-PLD). X-ray diffraction and in-depth strain analysis showed that the obliquely deposited CFO films had both enhanced orientation in the (111) crystal direction as well as tunable compressive strains as a function of the film thicknesses, in contrast to the almost strain-free polycrystalline CFO films grown using normal-incidence PLD under the same conditions. Using in situ optical plume diagnostics the growth parameters in the ?-PLD process were optimized to achieve smoother film surfaces with roughness values as low as 1-2 nm as compared to the typical values of 10-12 nm in the normal-incidence PLD grown films. Cross-sectional high resolution transmission electron microscope images revealed nanocolumnar growth of single-crystals of CFO along the (111) crystallographic plane at the film-substrate interface. Magnetic measurements showed larger coercive fields (?10 times) with similar saturation magnetization in the ?-PLD-grown CFO thin films as compared to those deposited using normal-incidence PLD. Such significantly enhanced magnetic coercivity observed in CFO thin films make them ideally suited for magnetic data storage applications. A growth mechanism based on the atomic shadowing effect and strain compression-relaxation mechanism was proposed for the obliquely grown CFO thin films. PMID:23829642

  2. Self-Compassion, Emotion Regulation and Stress among Australian Psychologists: Testing an Emotion Regulation Model of Self-Compassion Using Structural Equation Modeling

    PubMed Central

    Finlay-Jones, Amy L.; Rees, Clare S.; Kane, Robert T.

    2015-01-01

    Psychologists tend to report high levels of occupational stress, with serious implications for themselves, their clients, and the discipline as a whole. Recent research suggests that self-compassion is a promising construct for psychologists in terms of its ability to promote psychological wellbeing and resilience to stress; however, the potential benefits of self-compassion are yet to be thoroughly explored amongst this occupational group. Additionally, while a growing body of research supports self-compassion as a key predictor of psychopathology, understanding of the processes by which self-compassion exerts effects on mental health outcomes is limited. Structural equation modelling (SEM) was used to test an emotion regulation model of self-compassion and stress among psychologists, including postgraduate trainees undertaking clinical work (n = 198). Self-compassion significantly negatively predicted emotion regulation difficulties and stress symptoms. Support was also found for our preliminary explanatory model of self-compassion, which demonstrates the mediating role of emotion regulation difficulties in the self-compassion-stress relationship. The final self-compassion model accounted for 26.2% of variance in stress symptoms. Implications of the findings and limitations of the study are discussed. PMID:26207900

  3. The effect of Pt interlayers on the magnetic and structural properties of perpendicularly oriented barium ferrite media

    E-print Network

    Laughlin, David E.

    barium ferrite media Zailong Zhuang,a) Maithri Rao, David E. Laughlin, and Mark H. Kryder Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 Perpendicular barium ferrite Ba-axis orientation for thicker films, Pt interlayers were added into the barium ferrite films. This article thus

  4. Rare earth permanent magnets

    SciTech Connect

    Major-Sosias, M.A.

    1993-10-01

    Permanent magnets were discovered centuries ago from what was known as {open_quotes}lodestone{close_quotes}, a rock containing large quantities of the iron-bearing mineral magnetite (Fe{sub 3}O{sub 4}). The compass was the first technological use for permanent magnetic materials; it was used extensively for navigational purposes by the fifteenth century. During the twentieth century, as new applications for permanent magnets were developed, interest and research in permanent magnetic materials soared. Four major types of permanent magnets have been developed since the turn of the century.

  5. Pigeons combine compass and landmark guidance in familiar route navigation

    E-print Network

    Roberts, Stephen

    Pigeons combine compass and landmark guidance in familiar route navigation Dora Biro* , Robin terrain? In the best studied avian species, the homing pigeon (Columba livia), two apparently inde of simultaneous or oscillating dual control. clock shift homing pigeon sun pilotage route recapitulation

  6. Transverse spin azimuthal asymmetries in SIDIS at COMPASS: Multidimensional analysis

    E-print Network

    Parsamyan, Bakur

    2015-01-01

    One of the important objectives of the COMPASS experiment (CERN, SPS north area) is the exploration of transverse spin structure of nucleon via study of spin (in)dependent azimuthal asymmetries with semi-inclusive deep inelastic scattering (SIDIS) processes and recently also with Drell-Yan (DY) reactions. In the past twelve years series of measurements were made in COMPASS, using 160 GeV/c longitudinally polarized muon beam and polarized $^6LiD$ and $NH_3$ targets. Drell-Yan measurements with high energy (190 GeV/c) pion beam and transversely polarized $NH_3$ target started in 2014 with a pilot-run have been followed by 140 days of data taking in 2015. The experimental results obtained by COMPASS for azimuthal effects in SIDIS play an important role in the general understanding of the three-dimensional nature of the nucleon and are widely used in theoretical analyses and global data fits. In addition, future first ever polarized DY-data from COMPASS compared with SIDIS results will open a new chapter probing ...

  7. COMPASS identifies T-cell subsets correlated with clinical outcomes

    PubMed Central

    Lin, Lin; Finak, Greg; Ushey, Kevin; Seshadri, Chetan; Hawn, Thomas R.; Frahm, Nicole; Scriba, Thomas J.; Mahomed, Hassan; Hanekom, Willem; Bart, Pierre-Alexandre; Pantaleo, Giuseppe; Tomaras, Georgia D.; Rerks-Ngarm, Supachai; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Michael, Nelson L.; Kim, Jerome H.; Robb, Merlin L.; O’Connell, Robert J.; Karasavvas, Nicos; Gilbert, Peter; DeRosa, Stephen; McElrath, M. Juliana

    2015-01-01

    Advances in flow cytometry and other single-cell technologies have enabled high-dimensional, high-throughput measurements of individual cells and allowed interrogation of cell population heterogeneity. Computational tools to take full advantage of these technologies are lacking. Here, we present COMPASS, a computational framework for unbiased polyfunctionality analysis of antigen-specific T-cell subsets. COMPASS uses a Bayesian hierarchical framework to model all observed functional cell subsets and select those most likely to exhibit antigen-specific responses. Cell-subset responses are quantified by posterior probabilities, while subject-level responses are quantified by two novel summary statistics that can be correlated directly with clinical outcome, and describe the quality of an individual’s (poly)functional response. Using three clinical datasets of cytokine production we demonstrate how COMPASS improves characterization of antigen-specific T cells and reveals novel cellular correlates of protection in the RV144 HIV vaccine efficacy trial that are missed by other methods. COMPASS is available as open-source software. PMID:26006008

  8. Monte Carlo characterization of skin doses in 6 MV transverse field MRI-linac systems: Effect of field size, surface orientation, magnetic field strength, and exit bolus

    SciTech Connect

    Oborn, B. M.; Metcalfe, P. E.; Butson, M. J.; Rosenfeld, A. B.

    2010-10-15

    Purpose: The main focus of this work is to continue investigations into the Monte Carlo predicted skin doses seen in MRI-guided radiotherapy. In particular, the authors aim to characterize the 70 {mu}m skin doses over a larger range of magnetic field strength and x-ray field size than in the current literature. The effect of surface orientation on both the entry and exit sides is also studied. Finally, the use of exit bolus is also investigated for minimizing the negative effects of the electron return effect (ERE) on the exit skin dose. Methods: High resolution GEANT4 Monte Carlo simulations of a water phantom exposed to a 6 MV x-ray beam (Varian 2100C) have been performed. Transverse magnetic fields of strengths between 0 and 3 T have been applied to a 30x30x20 cm{sup 3} phantom. This phantom is also altered to have variable entry and exit surfaces with respect to the beam central axis and they range from -75 deg. to +75 deg. The exit bolus simulated is a 1 cm thick (water equivalent) slab located on the beam exit side. Results: On the entry side, significant skin doses at the beam central axis are reported for large positive surface angles and strong magnetic fields. However, over the entry surface angle range of -30 deg. to -60 deg., the entry skin dose is comparable to or less than the zero magnetic field skin dose, regardless of magnetic field strength and field size. On the exit side, moderate to high central axis skin dose increases are expected except at large positive surface angles. For exit bolus of 1 cm thickness, the central axis exit skin dose becomes an almost consistent value regardless of magnetic field strength or exit surface angle. This is due to the almost complete absorption of the ERE electrons by the bolus. Conclusions: There is an ideal entry angle range of -30 deg. to -60 deg. where entry skin dose is comparable to or less than the zero magnetic field skin dose. Other than this, the entry skin dose increases are significant, especially at higher magnetic fields. On the exit side there is mostly moderate to high skin dose increases for 0.2-3 T with the only exception being large positive angles. Exit bolus of 1 cm thickness will have a significant impact on lowering such exit skin dose increases that occur as a result of the ERE.

  9. Orientational alignment in solids from bidimensional isotropic-anisotropic nuclear magnetic resonance spectroscopy: applications to the analysis of aramide fibers.

    PubMed

    Sachleben, J R; Frydman, L

    1997-02-01

    The use of two-dimensional isotropic-anisotropic correlation spectroscopy for the analysis of orientational alignment in solids is presented. The theoretical background and advantages of this natural-abundance 13C NMR method of measurement are discussed, and demonstrated with a series of powder and single-crystal variable-angle correlation spectroscopy (VACSY) experiments on model systems. The technique is subsequently employed to analyze the orientational distributions of three polymer fibers: Kevlar 29, Kevlar 49 and Kevlar 149. Using complementary two-dimensional NMR data recorded on synthetic samples of poly(p-phenyleneterephthalamide), the precursor of Kevlar, it was found that these commercial fibers possess molecules distributed over a very narrow orientational range with respect to the macroscopic director. The widths measured for these director distribution arrangements were (12 +/- 1.5) degrees for Kevlar 29, (15 +/- 1.5) degrees for Kevlar 49, and (8 +/- 1.5) degrees for Kevlar 149. These figures compare well with previous results obtained for non-commercial fiber samples derived from the same polymer. PMID:9176935

  10. Narrow heat flux channels in the COMPASS limiter scrape-off layer

    NASA Astrophysics Data System (ADS)

    Horacek, J.; Vondracek, P.; Panek, R.; Dejarnac, R.; Komm, M.; Pitts, R. A.; Kocan, M.; Goldston, R. J.; Stangeby, P. C.; Gauthier, E.; Hacek, P.; Havlicek, J.; Hron, M.; Imrisek, M.; Janky, F.; Seidl, J.

    2015-08-01

    The ITER first wall is designed for start-up and ramp-down in limiter configuration. The wall panels are toroidally shaped in order to spread the incident parallel power flux q|| uniformly, assuming a single decay length ?q whose value is not known from first principles. In order to study the scaling of q|| with plasma parameters, infra-red viewing of specially-designed limiters has been used on the COMPASS tokamak in ?100 discharges with scans in Ip, ne and for all combinations of magnetic field and Ip directions. The IR measurement clearly shows that in addition to the main SOL heat flux profile with ?q > 40 mm, a steep gradient (?qnear = 4 ± 2 mm) dominates q|| near separatrix. This appears independently of limiter shaping, insertion with respect to neighbors and incident field-line angles. Good agreement is found between the measured ?qnear and the prediction of a heuristic drift-based model.

  11. Modelling an arbitrarily oriented magnetic dipole over a homogeneous half-space for a rapid topographic correction of airborne EM data

    NASA Astrophysics Data System (ADS)

    Guillemoteau, Julien; Sailhac, Pascal; Behaegel, Mickael

    2015-10-01

    Most airborne electromagnetic (EM) processing programs assume a flat ground surface. However, in mountainous areas, the system can be at an angle with regard to the ground. As the system is no longer parallel to the ground surface, the measured magnetic field has to be corrected and the ground induced eddy current has to be modelled in a better way when performing a very fine interpretation of the data. We first recall the theoretical background for the modelling of a magnetic dipole source and study it in regard to the case of an arbitrarily oriented magnetic dipole. We show in particular how transient central loop helicopter borne data are influenced by this inclination. The result shows that the effect of topography on airborne EM is more important at early time windows and for systems using a short cut-off source. In this paper, we suggest that an estimate be made off the locally averaged inclination of the system to the ground and then to correct the data for this before inverting it (whether the inversion assumes a flat 1D, 2D or 3D sub-surface). Both 1D and 2D inversions are applied to synthetic and real data sets with such a correction. The consequence on the ground imaging is small for slopes with an angle less than 25° but the correction factor can be useful for improving the estimation of depths in mountainous areas.

  12. Changing and shielded magnetic fields suppress c-Fos expression in the navigation circuit: input from the magnetosensory system contributes to the internal representation of space in a subterranean rodent

    PubMed Central

    Burger, Tomáš; Lucová, Marcela; Moritz, Regina E.; Oelschläger, Helmut H. A.; Druga, Rastislav; Burda, Hynek; Wiltschko, Wolfgang; Wiltschko, Roswitha; N?mec, Pavel

    2010-01-01

    The neural substrate subserving magnetoreception and magnetic orientation in mammals is largely unknown. Previous experiments have demonstrated that the processing of magnetic sensory information takes place in the superior colliculus. Here, the effects of magnetic field conditions on neuronal activity in the rodent navigation circuit were assessed by quantifying c-Fos expression. Ansell's mole-rats (Fukomys anselli), a mammalian model to study the mechanisms of magnetic compass orientation, were subjected to natural, periodically changing, and shielded magnetic fields while exploring an unfamiliar circular arena. In the undisturbed local geomagnetic field, the exploration of the novel environment and/or nesting behaviour induced c-Fos expression throughout the head direction system and the entorhinal–hippocampal spatial representation system. This induction was significantly suppressed by exposure to periodically changing and/or shielded magnetic fields; discrete decreases in c-Fos were seen in the dorsal tegmental nucleus, the anterodorsal and the laterodorsal thalamic nuclei, the postsubiculum, the retrosplenial and entorhinal cortices, and the hippocampus. Moreover, in inactive animals, magnetic field intensity manipulation suppressed c-Fos expression in the CA1 and CA3 fields of the hippocampus and the dorsal subiculum, but induced expression in the polymorph layer of the dentate gyrus. These findings suggest that key constituents of the rodent navigation circuit contain populations of neurons responsive to magnetic stimuli. Thus, magnetic information may be integrated with multimodal sensory and motor information into a common spatial representation of allocentric space within this circuit. PMID:20219838

  13. Texture and magnetic properties improvement of a 3% Si non-oriented electrical steel by Sb addition

    NASA Astrophysics Data System (ADS)

    Rodrigues, Marcio Ferreira; da Cunha, Marco Antonio; da Costa Paolinelli, Sebastião; Cota, André Barros

    2013-04-01

    The influence of small antimony addition and thermomechanical processing on the magnetic properties of a 3% Si steel was investigated. The samples were processed in the laboratory with 930 °C hot rolling finishing temperature, three different hot band thicknesses, hot band annealing at 1030 °C, cold rolling with three different reductions to 0.35 mm thickness and final annealing at 1030 °C. The results have shown that the best combination of core loss and magnetic induction can be obtained by Sb content of 0.045% and 76% cold rolling reduction, and that Eta/Gamma ratio is higher and grain size larger at this Sb content.

  14. Cryptochromes Define a Novel Circadian Clock Mechanism in Monarch Butterflies That May Underlie Sun Compass Navigation

    PubMed Central

    Zhu, Haisun; Sauman, Ivo; Yuan, Quan; Casselman, Amy; Emery-Le, Myai; Emery, Patrick; Reppert, Steven M

    2008-01-01

    The circadian clock plays a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, a process that is important for successful navigation. We therefore evaluated the monarch clockwork by focusing on the functions of a Drosophila-like cryptochrome (cry), designated cry1, and a vertebrate-like cry, designated cry2, that are both expressed in the butterfly and by placing these genes in the context of other relevant clock genes in vivo. We found that similar temporal patterns of clock gene expression and protein levels occur in the heads, as occur in DpN1 cells, of a monarch cell line that contains a light-driven clock. CRY1 mediates TIMELESS degradation by light in DpN1 cells, and a light-induced TIMELESS decrease occurs in putative clock cells in the pars lateralis (PL) in the brain. Moreover, monarch cry1 transgenes partially rescue both biochemical and behavioral light-input defects in cryb mutant Drosophila. CRY2 is the major transcriptional repressor of CLOCK:CYCLE-mediated transcription in DpN1 cells, and endogenous CRY2 potently inhibits transcription without involvement of PERIOD. CRY2 is co-localized with clock proteins in the PL, and there it translocates to the nucleus at the appropriate time for transcriptional repression. We also discovered CRY2-positive neural projections that oscillate in the central complex. The results define a novel, CRY-centric clock mechanism in the monarch in which CRY1 likely functions as a blue-light photoreceptor for entrainment, whereas CRY2 functions within the clockwork as the transcriptional repressor of a negative transcriptional feedback loop. Our data further suggest that CRY2 may have a dual role in the monarch butterfly's brain—as a core clock element and as an output that regulates circadian activity in the central complex, the likely site of the sun compass. PMID:18184036

  15. PUBLISHED ONLINE: 16 MAY 2010 | DOI: 10.1038/NPHYS1657 Detecting the orientation of magnetic fields in

    E-print Network

    Loss, Daniel

    for maintaining some clusters in a `non-cooling-core' state. R ecent high-resolution radio continuum observations lines, so magnetic fields strongly shape the cluster's thermal history; that some have not since cooled of fluid, and indeed happens even in incompressible flows13 . The layer's strength is set by a competition

  16. Highly c-axis oriented ZnO:Ni thin film nanostructure by RF magnetron sputtering: Structural, morphological and magnetic studies

    NASA Astrophysics Data System (ADS)

    Siddheswaran, R.; Savková, Jarmila; Medlín, Rostislav; O?enášek, Jan; Životský, Ond?ej; Novák, Petr; Šutta, Pavol

    2014-10-01

    Nickel doped zinc oxide (ZnO:Ni) thin films with different Ni concentrations were deposited on silicon substrates at 400 °C by reactive magnetron sputtering using a mixture of Ar and O2 gases. The X-ray diffraction and azimuthal patterns of the ZnO:Ni were carried out, and the quality of the strong preferred orientation of crystalline columns in the direction [0 0 1] perpendicular to the substrate surface were analysed. The grain size, distribution, and homogeneity of the thin film surfaces were studied by FE-SEM. The EDX and mapping confirmed that the Ni is incorporated into ZnO uniformly. The microstructure of the textured columns was analysed by TEM and HRTEM analyses. The average thickness and length of the columns were found to be about 50 nm and 600 nm, respectively. The rise of ferromagnetism by the influence of Ni content was studied by VSM magnetic studies at room temperature.

  17. Linear mode conversion of Langmuir/z-mode waves to radiation: Scalings of conversion efficiencies and propagation angles with temperature and magnetic field orientation

    SciTech Connect

    Schleyer, F.; Cairns, Iver H.; Kim, E.-H.

    2013-03-15

    Linear mode conversion (LMC) is the linear transfer of energy from one wave mode to another in an inhomogeneous plasma. It is relevant to laboratory plasmas and multiple solar system radio emissions, such as continuum radiation from planetary magnetospheres and type II and III radio bursts from the solar corona and solar wind. This paper simulates LMC of waves defined by warm, magnetized fluid theory, specifically the conversion of Langmuir/z-mode waves to electromagnetic (EM) radiation. The primary focus is the calculation of the energy and power conversion efficiencies for LMC as functions of the angle of incidence {theta} of the Langmuir/z-mode wave, temperature {beta}=T{sub e}/m{sub e}c{sup 2}, adiabatic index {gamma}, and orientation angle {phi} between the ambient density gradient {nabla}N{sub 0} and ambient magnetic field B{sub 0} in a warm, unmagnetized plasma. The ratio of these efficiencies is found to agree well as a function of {theta}, {gamma}, and {beta} with an analytical relation that depends on the group speeds of the Langmuir/z and EM wave modes. The results demonstrate that the energy conversion efficiency {epsilon} is strongly dependent on {gamma}{beta}, {phi} and {theta}, with {epsilon}{proportional_to}({gamma}{beta}){sup 1/2} and {theta}{proportional_to}({gamma}{beta}){sup 1/2}. The power conversion efficiency {epsilon}{sub p}, on the other hand, is independent of {gamma}{beta} but does vary significantly with {theta} and {phi}. The efficiencies are shown to be maximum for approximately perpendicular density gradients ({phi} Almost-Equal-To 90 Degree-Sign ) and minimal for parallel orientation ({phi}=0 Degree-Sign ) and both the energy and power conversion efficiencies peak at the same {theta}.

  18. Educational NASA Computational and Scientific Studies (enCOMPASS)

    NASA Technical Reports Server (NTRS)

    Memarsadeghi, Nargess

    2013-01-01

    Educational NASA Computational and Scientific Studies (enCOMPASS) is an educational project of NASA Goddard Space Flight Center aimed at bridging the gap between computational objectives and needs of NASA's scientific research, missions, and projects, and academia's latest advances in applied mathematics and computer science. enCOMPASS achieves this goal via bidirectional collaboration and communication between NASA and academia. Using developed NASA Computational Case Studies in university computer science/engineering and applied mathematics classes is a way of addressing NASA's goals of contributing to the Science, Technology, Education, and Math (STEM) National Objective. The enCOMPASS Web site at http://encompass.gsfc.nasa.gov provides additional information. There are currently nine enCOMPASS case studies developed in areas of earth sciences, planetary sciences, and astrophysics. Some of these case studies have been published in AIP and IEEE's Computing in Science and Engineering magazines. A few university professors have used enCOMPASS case studies in their computational classes and contributed their findings to NASA scientists. In these case studies, after introducing the science area, the specific problem, and related NASA missions, students are first asked to solve a known problem using NASA data and past approaches used and often published in a scientific/research paper. Then, after learning about the NASA application and related computational tools and approaches for solving the proposed problem, students are given a harder problem as a challenge for them to research and develop solutions for. This project provides a model for NASA scientists and engineers on one side, and university students, faculty, and researchers in computer science and applied mathematics on the other side, to learn from each other's areas of work, computational needs and solutions, and the latest advances in research and development. This innovation takes NASA science and engineering applications to computer science and applied mathematics university classes, and makes NASA objectives part of the university curricula. There is great potential for growth and return on investment of this program to the point where every major university in the U.S. would use at least one of these case studies in one of their computational courses, and where every NASA scientist and engineer facing a computational challenge (without having resources or expertise to solve it) would use enCOMPASS to formulate the problem as a case study, provide it to a university, and get back their solutions and ideas.

  19. Ureter tracking and segmentation in CT urography (CTU) using COMPASS

    SciTech Connect

    Hadjiiski, Lubomir Zick, David; Chan, Heang-Ping; Cohan, Richard H.; Caoili, Elaine M.; Cha, Kenny; Zhou, Chuan; Wei, Jun

    2014-12-15

    Purpose: The authors are developing a computerized system for automated segmentation of ureters in CTU, referred to as combined model-guided path-finding analysis and segmentation system (COMPASS). Ureter segmentation is a critical component for computer-aided diagnosis of ureter cancer. Methods: COMPASS consists of three stages: (1) rule-based adaptive thresholding and region growing, (2) path-finding and propagation, and (3) edge profile extraction and feature analysis. With institutional review board approval, 79 CTU scans performed with intravenous (IV) contrast material enhancement were collected retrospectively from 79 patient files. One hundred twenty-four ureters were selected from the 79 CTU volumes. On average, the ureters spanned 283 computed tomography slices (range: 116–399, median: 301). More than half of the ureters contained malignant or benign lesions and some had ureter wall thickening due to malignancy. A starting point for each of the 124 ureters was identified manually to initialize the tracking by COMPASS. In addition, the centerline of each ureter was manually marked and used as reference standard for evaluation of tracking performance. The performance of COMPASS was quantitatively assessed by estimating the percentage of the length that was successfully tracked and segmented for each ureter and by estimating the average distance and the average maximum distance between the computer and the manually tracked centerlines. Results: Of the 124 ureters, 120 (97%) were segmented completely (100%), 121 (98%) were segmented through at least 70%, and 123 (99%) were segmented through at least 50% of its length. In comparison, using our previous method, 85 (69%) ureters were segmented completely (100%), 100 (81%) were segmented through at least 70%, and 107 (86%) were segmented at least 50% of its length. With COMPASS, the average distance between the computer and the manually generated centerlines is 0.54 mm, and the average maximum distance is 2.02 mm. With our previous method, the average distance between the centerlines was 0.80 mm, and the average maximum distance was 3.38 mm. The improvements in the ureteral tracking length and both distance measures were statistically significant (p < 0.0001). Conclusions: COMPASS improved significantly the ureter tracking, including regions across ureter lesions, wall thickening, and the narrowing of the lumen.

  20. Towards First-principles Control-oriented Modeling of the Magnetic and Kinetic Plasma Profile Evolutions in ITER

    NASA Astrophysics Data System (ADS)

    Barton, Justin E.; Schuster, Eugenio; Besseghir, Karim; Lister, Jonathan

    2012-10-01

    The ``hybrid'' and ``steady-state'' advanced scenarios are characterized by q profiles higher or equal to one to mitigate plasma instabilities and improve confinement, which are key for ITER to achieve its operational objectives. To achieve these scenarios, active model-based control of the current profile and thermal state of the plasma is required. Towards this goal, two control-oriented, plasma-response models are proposed. First, the poloidal flux diffusion equation is combined with empirical models of the electron density and temperature profiles, plasma resistivity, and non-inductive current drives to obtain a physics-based model of the poloidal flux and stored energy evolutions. Second, the empirical electron temperature model is replaced by the electron heat transport equation, which is combined with empirical models of the electron heat conductivity and heat sources to obtain a physics-based model of the poloidal flux and electron temperature evolutions. Simulation results comparing the evolution of the plasma parameters predicted by the control-oriented, physic-based models and the DINA-CH+CRONOS simulation code are presented for ITER, and the control objectives and challenges are discussed.

  1. Compassion Fatigue in Adult Daughter Caregivers of a Parent with Dementia

    PubMed Central

    Day, Jennifer R.; Anderson, Ruth A.; Davis, Linda L.

    2015-01-01

    Adult daughters face distinct challenges caring for parents with dementia and may experience compassion fatigue: the combination of helplessness, hopelessness, an inability to be empathic, and a sense of isolation resulting from prolonged exposure to perceived suffering. Prior research on compassion fatigue has focused on professional healthcare providers and has overlooked filial caregivers. This study attempts to identify and explore risk factors for compassion fatigue in adult daughter caregivers and to substantiate further study of compassion fatigue in family caregivers. We used content analysis of baseline interviews with 12 adult daughter caregivers of a parent with dementia who participated in a randomized trial of homecare training. Four themes were identified in adult daughter caregiver interviews: (a) uncertainty; (b) doubt; (c) attachment; and (d) strain. Findings indicated adult daughter caregivers are at risk for compassion fatigue, supporting the need for a larger study exploring compassion fatigue in this population. PMID:25259643

  2. Using Acceptance and Commitment Therapy to Increase Self-Compassion: A Randomized Controlled Trial

    PubMed Central

    Yadavaia, James E.; Hayes, Steven C.; Vilardaga, Roger

    2014-01-01

    Self-compassion has been shown to be related to several types of psychopathology, including traumatic stress, and has been shown to improve in response to various kinds of interventions. Current conceptualizations of self-compassion fit well with the psychological flexibility model, which underlies acceptance and commitment therapy (ACT). However, there has been no research on ACT interventions specifically aimed at self-compassion. This randomized trial therefore compared a 6-hour ACT-based workshop targeting self-compassion to a wait-list control. From pretreatment to 2-month follow-up, ACT was significantly superior to the control condition in self-compassion, general psychological distress, and anxiety. Process analyses revealed psychological flexibility to be a significant mediator of changes in self-compassion, general psychological distress, depression, anxiety, and stress. Exploratory moderation analyses revealed the intervention to be of more benefit in terms of depression, anxiety, and stress to those with greater trauma history. PMID:25506545

  3. Exploring self-compassion and eudaimonic well-being in young women athletes.

    PubMed

    Ferguson, Leah J; Kowalski, Kent C; Mack, Diane E; Sabiston, Catherine M

    2014-04-01

    Using a mixed methods research design, we explored self-compassion and eudaimonic well-being in young women athletes. In a quantitative study (n = 83), we found that self-compassion and eudaimonic well-being were positively related (r = .76, p < .01). A model of multiple mediation was proposed, with self-compassion, passivity, responsibility, initiative, and self-determination accounting for 83% of the variance in eudaimonic well-being. In a qualitative study (n = 11), we explored when and how self-compassion might be useful in striving to reach one's potential in sport. Self-compassion was described as advantageous in difficult sport-specific situations by increasing positivity, perseverance, and responsibility, as well as decreasing rumination. Apprehensions about fully embracing a self-compassionate mindset in sport warrant additional research to explore the seemingly paradoxical role of self-compassion in eudaimonic well-being. PMID:24686956

  4. Neural coding underlying the cue preference for celestial orientation.

    PubMed

    el Jundi, Basil; Warrant, Eric J; Byrne, Marcus J; Khaldy, Lana; Baird, Emily; Smolka, Jochen; Dacke, Marie

    2015-09-01

    Diurnal and nocturnal African dung beetles use celestial cues, such as the sun, the moon, and the polarization pattern, to roll dung balls along straight paths across the savanna. Although nocturnal beetles move in the same manner through the same environment as their diurnal relatives, they do so when light conditions are at least 1 million-fold dimmer. Here, we show, for the first time to our knowledge, that the celestial cue preference differs between nocturnal and diurnal beetles in a manner that reflects their contrasting visual ecologies. We also demonstrate how these cue preferences are reflected in the activity of compass neurons in the brain. At night, polarized skylight is the dominant orientation cue for nocturnal beetles. However, if we coerce them to roll during the day, they instead use a celestial body (the sun) as their primary orientation cue. Diurnal beetles, however, persist in using a celestial body for their compass, day or night. Compass neurons in the central complex of diurnal beetles are tuned only to the sun, whereas the same neurons in the nocturnal species switch exclusively to polarized light at lunar light intensities. Thus, these neurons encode the preferences for particular celestial cues and alter their weighting according to ambient light conditions. This flexible encoding of celestial cue preferences relative to the prevailing visual scenery provides a simple, yet effective, mechanism for enabling visual orientation at any light intensity. PMID:26305929

  5. Highly oriented NdFeCoB nanocrystalline magnets from partially disproportionated compacts by reactive deformation under low pressure

    SciTech Connect

    Zheng, Qing; Li, Jun; Liu, Ying Yu, Yunping; Lian, Lixian

    2014-05-07

    In the present investigation, we take advantage of the ultrafine grain size of NdFeCoB partially hydrogen-disproportionated phases, and prepare anisotropic nanocrystalline magnets with full density and homogenous microstructure and texture by reactive deformation under low pressure. Our results suggest that the pressure could properly promote an occurrence of desorption-recombination reaction due to a shorter-range rearrangement of the atoms, and the newly recombined Nd{sub 2}Fe{sub 14}B grains with fine grain size could undergo deformation immediately after the phase transformation, and then an obvious anisotropy and uniform alignment would be obtained. The maximum magnetic properties, (BH){sub max}?=?25.8 MGOe, Br?=?11.8 kG, H{sub cj}?=?5.5 kOe, were obtained after being treated for 5?min at 820?°C in vacuum. The present study highlights the feasibility to prepare anisotropic nanocrystalline magnets with homogeneous microstructure and a strong (00l) texture of uniform grain size under low pressure.

  6. GPD physics with polarized muon beams at COMPASS-II

    SciTech Connect

    Ferrero, Andrea [CEA-Saclay, DSM Collaboration: COMPASS Collaboration

    2013-04-15

    A major part of the future COMPASS program is dedicated to the investigation of the nucleon structure through Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP). COMPASS will measure DVCS and DVMP reactions with a high intensity muon beam of 160 GeV and a 2.5 m-long liquid hydrogen target surrounded by a new TOF system. The availability of muon beams with high energy and opposite charge and polarization will allow to access the Compton form factor related to the dominant GPD H and to study the x{sub B}-dependence of the t-slope of the pure DVCS cross section and to study nucleon tomography. Projections on the achievable accuracies and preliminary results of pilot measurements will be presented.

  7. Post-disruptive runaway electron beams in the COMPASS tokamak

    NASA Astrophysics Data System (ADS)

    Vlainic, Milos; Mlynar, J.; Cavalier, J.; Weinzettl, V.; Paprok, R.; Imrisek, M.; Ficker, O.; Varavin, M.; Vondracek, P.; Noterdaeme, J.-M.; Noterdaeme

    2015-10-01

    > For ITER-relevant runaway electron studies, such as suppression, mitigation, termination and/or control of a runaway beam, it is important to obtain the runaway electrons after the disruption. In this paper we report on the first discharges achieved with a post-disruptive runaway electron beam, termed a `runaway plateau', in the COMPASS tokamak. The runaway plateau is produced by a massive gas injection of argon. Almost all of the disruptions with runaway electron plateaus occurred during the plasma current ramp-up phase. The Ar injection discharges with and without a runaway plateau were compared for various parameters. Parametrisation of the discharges shows that the COMPASS disruptions fulfil the range of parameters important for runaway plateau occurrence. These parameters include electron density, electric field, disruption speed, effective safety factor, and the maximum current quench electric field. In addition to these typical parameters, the plasma current value just before the massive gas injection proved to be surprisingly important.

  8. Smiling through clenched teeth: why compassion cannot be written into the rules.

    PubMed

    Wang, Yinchu

    2016-01-01

    The discourse on the failings of the National Health System often cites lack of compassion as an important factor. This has resulted in proposals to enact rules which aimed at enforcing compassion in healthcare workers so as to improve the quality of healthcare and avoid future scandals. This paper argues that compassion cannot be enforced by any rule. Moreover, the contractual nature of the current doctor-patient relationship does not foster it. Experience from other service industries shows that attempts to enforce compassion in workers are futile. Rather than improving service, these attempts result in a culture of perfunctoriness and cynicism. PMID:26530704

  9. Radio scintillations observed during atmospheric occultations of Voyager: Internal gravity waves at Titan and magnetic field orientations at Jupiter and Saturn. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Hinson, D. P.

    1983-01-01

    The refractive index of planetary atmospheres at microwave frequencies is discussed. Physical models proposed for the refractive irregularities in the ionosphere and neutral atmosphere serve to characterize the atmospheric scattering structures, and are used subsequently to compute theoretical scintillation spectra for comparison with the Voyager occultation measurements. A technique for systematically analyzing and interpreting the signal fluctuations observed during planetary occultations is presented and applied to process the dual-wavelength data from the Voyager radio occultations by Jupiter, Saturn, and Titan. Results concerning the plasma irregularities in the upper ionospheres of Jupiter and Saturn are reported. The measured orientation of the irregularities is used to infer the magnetic field direction at several locations in the ionospheres of these two planets; the occultation measurements conflict with the predictions of Jovian magnetic field models, but generally confirm current models of Saturn's field. Wave parameters, including the vertical fluxes of energy and momentum, are estimated, and the source of the internal gravity waves discovered in Titan's upper atmosphere is considered.

  10. Computerized segmentation of ureters in CT urography (CTU) using COMPASS

    NASA Astrophysics Data System (ADS)

    Hadjiiski, Lubomir M.; Chan, Heang-Ping; Niland, Luke; Cohan, Richard H.; Caoili, Elaine M.; Zhou, Chuan; Wei, Jun

    2013-03-01

    We are developing a computerized system for automated segmentation of ureters on CTU, as a critical component for computer-aided diagnosis of ureter cancer. A challenge for ureter segmentation is the presence of regions not well opacified with intravenous (IV) contrast. We propose a COmbined Model-guided Path-finding Analysis and Segmentation System (COMPASS) to track the ureters in CTU. COMPASS consists of three stages: (1) adaptive thresholding and region growing, (2) edge profile extraction and feature analysis, and (3) path-finding and propagation. 114 ureters, filled with IV contrast material, on 74 CTU scans from 74 patients were segmented. On average the ureter occupied 286 CT slices (range:164 to 399, median:301). More than half of the ureters contained malignant or benign lesions and some had ureter wall thickening due to malignancy. A starting point for each of the 114 ureters was selected manually, which served as an input to the COMPASS, to initialize the tracking. The path-finding and segmentation are guided by anatomical knowledge of the ureters in CTU. The segmentation performance was quantitatively assessed by estimating the percentage of the length that was successfully tracked and segmented for each ureter. Of the 114 ureters, 75 (66%) were segmented completely (100%), 99 (87%) were segmented through at least 70% of its length, and 104 (91%) were segmented at least 50%. Previously, without the model-guided approach, 61 (54%) ureters were segmented completely (100%), 80 (70%) were segmented through at least 70% of its length, and 96 (84%) were segmented at least 50%. COMPASS improved the ureter tracking, including regions across ureter lesions, wall thickening and the narrowing of the lumen.

  11. COMPASS-based ureter segmentation in CT urography (CTU)

    NASA Astrophysics Data System (ADS)

    Zick, David; Hadjiiyski, Lubomir; Chan, Heang-Ping; Cohan, Richard H.; Caoili, Elaine M.; Zhou, Chuan; Wei, Jun

    2014-03-01

    We are developing a computerized system for automated segmentation of ureters in CT urography (CTU), referred to as COmbined Model-guided Path-finding Analysis and Segmentation System (COMPASS). Ureter segmentation is a critical component for computer-aided diagnosis of ureter cancer. A challenge for ureter segmentation is the presence of regions not well opacified with intravenous (IV) contrast. COMPASS consists of three stages: (1) adaptive thresholding and region growing, (2) path-finding and propagation, and (3) edge profile extraction and feature analysis. One hundred fourteen ureters in 74 CTU scans with IV contrast were collected from 74 patient files. On average, the ureters spanned 283 CT slices (range: 116 to 399, median: 301). More than half of the ureters contained malignant or benign lesions and some had ureter wall thickening due to malignancy. A starting point for each of the 114 ureters was selected manually to initialize the tracking by COMPASS. Path-finding and segmentation were guided by the anatomical knowledge of ureters in CTU. The segmentation performance was quantitatively assessed by estimating the percentage of the length that was successfully tracked and segmented for each ureter. Of the 114 ureters, 110 (96%) were segmented completely (100%), 111 (97%) were segmented through at least 70% of its length, and 113 (99%) were segmented at least 50%. In comparison, using our previous method, 79 (69%) ureters were segmented completely (100%), 92 (81%) were segmented through at least 70% of its length, and 98 (86%) were segmented at least 50%. COMPASS improved significantly the ureter tracking, including regions across ureter lesions, wall thickening and the narrowing of the lumen.

  12. Evaluation of COMPASS ionospheric model in GNSS positioning

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoli; Hu, Xiaogong; Wang, Gang; Zhong, Huijuan; Tang, Chengpan

    2013-03-01

    As important products of GNSS navigation message, ionospheric delay model parameters are broadcasted for single-frequency users to improve their positioning accuracy. GPS provides daily Klobuchar ionospheric model parameters based on geomagnetic reference frame, while the regional satellite navigation system of China's COMPASS broadcasts an eight-parameter ionospheric model, COMPASS Ionospheric Model(CIM), which was generated by processing data from continuous monitoring stations, with updating the parameters every 2 h. To evaluate its performance, CIM predictions are compared to ionospheric delay measurements, along with GPS positioning accuracy comparisons. Real observed data analysis indicates that CIM provides higher correction precision in middle-latitude regions, but relatively lower correction precision for low-latitude regions where the ionosphere has much higher variability. CIM errors for some users show a common bias for in-coming COMPASS signals from different satellites, and hence ionospheric model errors are somehow translated into the receivers' clock error estimation. In addition, the CIM from the China regional monitoring network are further evaluated for global ionospheric corrections. Results show that in the Northern Hemisphere areas including Asia, Europe and North America, the three-dimensional positioning accuracy using the CIM for ionospheric delay corrections is improved by 7.8%-35.3% when compared to GPS single-frequency positioning ionospheric delay corrections using the Klobuchar model. However, the positioning accuracy in the Southern Hemisphere is degraded due apparently to the lack of monitoring stations there.

  13. Exploring compassion: implications for contemporary nursing. Part 2.

    PubMed

    Straughair, Collette

    A range of contemporary political and professional literature endorse the principle of compassion in nursing as a core and underpinning philosophy fundamental to the profession. However, despite pledges to ensure that compassion lies at the heart of nursing, the concept has not been clearly defined. It is evident that uncovering the true meaning is complex and challenging owing to its subjective nature. In light of this, several implications must be considered. Effective student nurse recruitment is essential to ensure that the most appropriate individuals are selected. Contemporary marketing campaigns must be implemented, and recruitment strategies developed, which consider specific values and attitudes. Service user involvement in recruitment and selection, curriculum planning and learning and teaching strategies, and post-qualification education, can enhance nurses' understanding of the patient perspective and make headway in embedding compassion as a core nursing value. Additionally, effective role modelling in practice which demonstrates high-quality compassionate nursing care is essential. Nurses must be adequately supported in the clinical environment to facilitate compassionate behaviours and clinical leadership at all levels must uphold political and professional pledges to achieve this. Consideration of these implications for practice is essential to ensure that nurses are able to respond to patients with humanity and kindness, and deliver high-quality, compassionate care to all. PMID:22398938

  14. Effects of rolling temperature on microstructure, texture, formability and magnetic properties in strip casting Fe-6.5 wt% Si non-oriented electrical steel

    NASA Astrophysics Data System (ADS)

    Liu, Hai-Tao; Li, Hao-Ze; Li, Hua-Long; Gao, Fei; Liu, Guo-Huai; Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin; Cao, Guang-Ming; Liu, Zhen-Yu; Wang, Guo-Dong

    2015-10-01

    Fe-6.5 wt% Si non-oriented electrical steel sheets with a thickness of 0.50 mm were produced by using a new processing route: strip casting followed by hot rolling, intermediate temperature (150-850 °C) rolling and final annealing. The present study focused on exploring the effects of rolling temperature varying from 150 to 850 °C on the microstructure and texture evolution, the formability and final magnetic properties. The microstructure and texture evolution at the various processing steps were investigated in detail by using OM, XRD, EBSD and TEM. It was found that the formability during rolling, the microstructure and texture before and after annealing and final magnetic properties highly depended on rolling temperature. The formability during rolling was gradually improved with increasing rolling temperature due to the slipping of dislocation. In particular, the rolling temperature dominated the formation of in-grain shear bands in the rolled microstructure, which played an important role in the development of final recrystallization microstructure and texture. In the case of lower temperature (150-450 °C) rolling, an inhomogeneous microstructure with a large amount of in-grain shear bands was formed in the rolled sheets, which finally resulted in a fine and inhomogeneous annealing microstructure dominated by mild ?-fiber texture composed of cube and {001}<210> components and ?*-fiber texture concentrated on {115}<5-10 1> component. By contrast, in the case of higher temperature (650-850 °C) rolling, a relatively homogeneous microstructure without in-grain shear bands was formed instead in the rolled sheets, which finally led to a coarse and relatively homogeneous annealing microstructure characterized by strong ?-fiber and ?-fiber texture. Accordingly, on the whole, both the magnetic induction (B8 and B50) and iron loss (P15/50 and P10/400) decreased with raising rolling temperature.

  15. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: Longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair

    NASA Astrophysics Data System (ADS)

    Chang, Zhiwei; Halle, Bertil

    2013-10-01

    In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water 1H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft-tissue contrast in clinical magnetic resonance imaging.

  16. Computer simulation of charged fusion-product trajectories and detection efficiency expected for future experiments within the COMPASS tokamak

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, Roch; Malinowski, Karol; Sadowski, Marek J.

    2014-05-01

    This paper presents results of computer simulations of charged particle motions and detection efficiencies for an ion-pinhole camera of a new diagnostic system to be used in future COMPASS tokamak experiments. A probe equipped with a nuclear track detector can deliver information about charged products of fusion reactions. The calculations were performed with a so-called Gourdon code, based on a single-particle model and toroidal symmetry. There were computed trajectories of fast ions (> 500 keV) in medium-dense plasma (ne < 1014 cm-3) and an expected detection efficiency (a ratio of the number of detected particles to that of particles emitted from plasma). The simulations showed that charged fusion products can reach the new diagnostic probe, and the expected detection efficiency can reach 2 × 10-8. Based on such calculations, one can determine the optimal position and orientation of the probe. The obtained results are of importance for the interpretation of fusion-product images to be recorded in future COMPASS experiments.

  17. Characterization of microstructure, texture and magnetic properties in twin-roll casting high silicon non-oriented electrical steel

    SciTech Connect

    Li, Hao-Ze; Liu, Hai-Tao Liu, Zhen-Yu Lu, Hui-Hu; Song, Hong-Yu; Wang, Guo-Dong

    2014-02-15

    An Fe-6.5 wt.% Si-0.3 wt.% Al as-cast sheet was produced by twin-roll strip casting process, then treated with hot rolling, warm rolling and annealing. A detailed study of the microstructure and texture evolution at different processing stages was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. The initial as-cast strip showed strong columnar grains and pronounced < 001 >//ND texture. The hot rolled and warm rolled sheets were characterized by large amounts of shear bands distributed through the thickness together with strong < 110 >//RD texture and weak < 111 >//ND texture. After annealing, detrimental < 111 >//ND texture almost disappeared while beneficial (001)<210 >, (001)<010 >, (115)<5 ? 10 1 > and (410) < 001 > recrystallization textures were formed, thus the magnetic induction of the annealed sheet was significantly improved. The recrystallization texture in the present study could be explained by preferred nucleation and grain growth mechanism. - Highlights: • A high silicon as-cast strip with columnar structure was produced. • A thin warm rolled sheet without large edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Beneficial (001)<210 >, (001)<010 >, (410)<001 > recrystallization textures were formed. • The magnetic induction of annealed sheet was significantly improved.

  18. A Reconsideration of the Self-Compassion Scale’s Total Score: Self-Compassion versus Self-Criticism

    PubMed Central

    López, Angélica; Sanderman, Robbert; Smink, Ans; Zhang, Ying; van Sonderen, Eric; Ranchor, Adelita; Schroevers, Maya J.

    2015-01-01

    The Self-Compassion Scale (SCS) is currently the only self-report instrument to measure self-compassion. The SCS is widely used despite the limited evidence for the scale’s psychometric properties, with validation studies commonly performed in college students. The current study examined the factor structure, reliability, and construct validity of the SCS in a large representative sample from the community. The study was conducted in 1,736 persons, of whom 1,643 were included in the analyses. Besides the SCS, data was collected on positive and negative indicators of psychological functioning, as well as on rumination and neuroticism. Analyses included confirmatory factor analyses (CFA), exploratory factor analyses (EFA), and correlations. CFA showed that the SCS’s proposed six-factor structure could not be replicated. EFA suggested a two-factor solution, formed by the positively and negatively formulated items respectively. Internal consistency was good for the two identified factors. The negative factor (i.e., sum score of the negatively formulated items) correlated moderately to strongly to negative affect, depressive symptoms, perceived stress, as well as to rumination and neuroticism. Compared to this negative factor, the positive factor (i.e., sum score of the positively formulated items) correlated weaker to these indicators, and relatively more strongly to positive affect. Results from this study do not justify the common use of the SCS total score as an overall indicator of self-compassion, and provide support for the idea, as also assumed by others, that it is important to make a distinction between self-compassion and self-criticism. PMID:26193654

  19. Colossal anisotropic resistivity and oriented magnetic domains in strained La{sub 0.325}Pr{sub 0.3}Ca{sub 0.375}MnO{sub 3} films

    SciTech Connect

    Jiang, Tao; Yang, Shengwei; Liu, Yukuai; Zhao, Wenbo; Feng, Lei; Li, Xiaoguang; Zhou, Haibiao; Lu, Qingyou; Hou, Yubin

    2014-05-19

    Magnetic and resistive anisotropies have been studied for the La{sub 0.325}Pr{sub 0.3}Ca{sub 0.375}MnO{sub 3} films with different thicknesses grown on low symmetric (011)-oriented (LaAlO{sub 3}){sub 0.3}(SrAl{sub 0.5}Ta{sub 0.5}O{sub 3}){sub 0.7} substrates. In the magnetic and electronic phase separation region, a colossal anisotropic resistivity (AR) of ?10{sup 5}% and an anomalous large anisotropic magnetoresistance can be observed for 30 nm film. However, for 120 nm film, the maximum AR decreases significantly (?2?×?10{sup 3}%) due to strain relaxation. The colossal AR is strongly associated with the oriented formation of magnetic domains, and the features of the strain effects are believed to be useful for the design of artificial materials and devices.

  20. Healthcare and Compassion: Towards an Awareness of Intersubjective Vulnerability Comment on "Why and How Is Compassion Necessary to Provide Good Quality Healthcare?".

    PubMed

    Kenny, Kate

    2015-09-01

    How to instill compassion in a healthcare organization? In this article, I respond to Marianna Fotaki's proposals in her piece, 'Why and how is compassion necessary to provide good quality healthcare?' by drawing on insights from organization studies. Following Fotaki, I argue that to instill targets and formal measures for assessing compassion would be problematic. I conclude by drawing on psychoanalytic and feminist theories to introduce alternatives, specifically proposing an approach that is grounded in a shared sense of a common, embodied precarity, which necessitates our commitment to preserving the conditions in which life might flouris. PMID:26340496

  1. Detection of Magnetic Field Intensity Gradient by Homing Pigeons (Columba livia) in a Novel “Virtual Magnetic Map” Conditioning Paradigm

    PubMed Central

    Mora, Cordula V.; Bingman, Verner P.

    2013-01-01

    It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a “virtual magnetic map” during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain. PMID:24039812

  2. Detection of magnetic field intensity gradient by homing pigeons (Columba livia) in a novel "virtual magnetic map" conditioning paradigm.

    PubMed

    Mora, Cordula V; Bingman, Verner P

    2013-01-01

    It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a "virtual magnetic map" during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain. PMID:24039812

  3. EDITORIAL: Optical orientation Optical orientation

    NASA Astrophysics Data System (ADS)

    SAME ADDRESS *, Yuri; Landwehr, Gottfried

    2008-11-01

    Boris Petrovitch Zakharchenya (1928-2005) This issue is dedicated to the memory of Boris Petrovich Zakharchenya, who died at the age of 77 in April 2005. He was an eminent scientist and a remarkable man. After studying physics at Leningrad University he joined the Physico-Technical Institute (now the A F Ioffe Institute) in 1952 and became the co-worker of Evgeny Feodorovich Gross, shortly after the exciton was discovered in his laboratory. The experiments on cuprous oxide crystals in the visible spectral range showed a hydrogen-like spectrum, which was interpreted as excitonic absorption. The concept of the exciton had been conceived some years earlier by Jacov Frenkel at the Physico-Technical Institute. Immediately after joining Gross, Zakharchenya succeeded in producing spectra of unprecedented quality. Subsequently the heavy and the light hole series were found. Also, Landau splitting was discovered when a magnetic field was applied. The interpretation of the discovery was thrown into doubt by Russian colleagues and it took some time, before the correct interpretation prevailed. Shortly before his death, Boris wrote the history of the discovery of the exciton, which has recently been published in Russian in a book celebrating the 80th anniversary of his birth [1]. The book also contains essays by Boris on various themes, not only on physics, but also on literature. Boris was a man of unusually wide interests, he was not only fascinated by physics, but also loved literature, art and music. This can be seen in the first article of this issue The Play of Light in Crystals which is an abbreviated version of his more complete history of the discovery of the exciton. It also gives a good impression of the personality of Boris. One of us (GL) had the privilege to become closely acquainted with him, while he was a guest professor at the University of Würzburg. During that time we had many discussions, and I recall his continuing rage on the wrong attribution of the priority of the discovery in the literature, which was partly caused by the existence of the Iron Curtain. I had already enjoyed contact with Boris in the 1980s when the two volumes of Landau Level Spectroscopy were being prepared [2]. He was one of the pioneers of magneto-optics in semiconductors. In the 1950s the band structure of germanium and silicon was investigated by magneto-optical methods, mainly in the United States. No excitonic effects were observed and the band structure parameters were determined without taking account of excitons. However, working with cuprous oxide, which is a direct semiconductor with a relative large energy gap, Zakharchenya and his co-worker Seysan showed that in order to obtain correct band structure parameters, it is necessary to take excitons into account [3]. About 1970 Boris started work on optical orientation. Early work by Hanle in Germany in the 1920s on the depolarization of luminescence in mercury vapour by a transverse magnetic field was not appreciated for a long time. Only in the late 1940s did Kastler and co-workers in Paris begin a systematic study of optical pumping, which led to the award of a Nobel prize. The ideas of optical pumping were first applied by Georges Lampel to solid state physics in 1968. He demonstrated optical orientation of free carriers in silicon. The detection method was nuclear magnetic resonance; optically oriented free electrons dynamically polarized the 29Si nuclei of the host lattice. The first optical detection of spin orientation was demonstrated by with the III-V semiconductor GaSb by Parsons. Due to the various interaction mechanisms of spins with their environment, the effects occurring in semiconductors are naturally more complex than those in atoms. Optical detection is now the preferred method to detect spin alignment in semiconductors. The orientation of spins in crystals pumped with circularly polarized light is deduced from the degree of circular polarization of the recombination radiation. The major results of the systematic work on optical orientation, both experimental and

  4. The Roles of Innate Information, Learning Rules and Plasticity in Migratory Bird Orientation

    NASA Astrophysics Data System (ADS)

    Able, Kenneth P.; Able, Mary A.

    This paper and the following three papers were presented at the RIN97 Conference held in Oxford under the auspices of the Animal Navigation Special Interest Group, April 1997. The full proceedings, under the title Orientation and Navigation - Birds, Humans and Other Animals, can be obtained from the Director (£30 to Members, £50 to non-Members).Studies of the compass mechanisms involved in the migratory orientation of birds have revealed a complex web of interactions, both during the development of orientation behaviour in young birds and in mature individuals exhibiting migratory activity. In young birds, the acquisition of compass orientation capabilities involves the interplay of apparently genetically programmed information with a suite of innate learning rules. The latter canalise the ways in which experience with relevant orientation information from the environment impinges on development. There are many general similarities with the development of singing behaviour in songbirds, although that system is more thoroughly understood, especially at the neuronal level.Here we shall attempt to synthesise what is known about the development of compass mechanisms in a framework of innate information and learning rules. The way in which orientation behaviour develops leaves open the possibility for plasticity that enables birds to compensate for variability in the environmental cues that form the basis of their compasses. For at least some components of the system, behavioural plasticity remains into adulthood, allowing the bird on migration to respond in apparently adaptive ways to spatial and temporal variability in orientation information that it may encounter while enroute. We have studied these questions in the Savannah sparrow (Passerculus sandwichensis), a medium-distance North American emberizine nocturnal migrant. We will focus on that species, relating the results of our work to relevant studies on others.

  5. Computer Modelling of Pigeon Navigation according to the "Map and Compass"-Model

    E-print Network

    Nehmzow, Ulrich

    Computer Modelling of Pigeon Navigation according to the "Map and Compass"-Model Ulrich Nehmzow@zoology.uni-frankfurt.de Abstract This paper presents a computer model of pigeon navigation (homing), based on Kramer's map-and-compass model. The model makes the assumption that pigeons navigate in environments that contain at least two

  6. Validity Evidence for ACT Compass® Placement Tests. ACT Research Report Series 2014 (2)

    ERIC Educational Resources Information Center

    Westrick, Paul A.; Allen, Jeff

    2014-01-01

    We examined the validity of using Compass® test scores and high school grade point average (GPA) for placing students in first-year college courses and for identifying students at risk of not succeeding. Consistent with other research, the combination of high school GPA and Compass scores performed better than either measure used alone. Results…

  7. Mindfulness-Based Awareness and Compassion: Predictors of Counselor Empathy and Anxiety

    ERIC Educational Resources Information Center

    Fulton, Cheryl L.; Cashwell, Craig S.

    2015-01-01

    Mindfulness-based awareness and compassion were examined as predictors of empathy and anxiety among 152 master's-level counseling interns. Results of hierarchical multiple regression analysis supported that awareness and compassion differentially contributed to explaining the variance in counselor empathy and anxiety. Implications for counselor…

  8. Self-Care in the New Millennium: Avoiding Burnout and Compassion Fatigue.

    ERIC Educational Resources Information Center

    Lynch, Sherry K.

    This report presents a workshop for counselors and psychologists who are at a high risk for burnout and compassion fatigue. The workshop focuses on increasing the awareness of participants about the issues of burnout and compassion fatigue, and highlights a number of steps toward prevention. A report, which accompanies the workshop documentation,…

  9. Mindfulness and Compassion in Human Development: Introduction to the Special Section

    ERIC Educational Resources Information Center

    Roeser, Robert W.; Eccles, Jacquelynne S.

    2015-01-01

    Research on contemplative practices (e.g., mindfulness or compassion training) is growing rapidly in the clinical, health and neuro-sciences, but almost none of this research takes an explicitly developmental life span perspective. At present, we know rather little about the naturalistic development of mindfulness or compassion in children and…

  10. The Influence of Self-Compassion on Academic Procrastination and Dysfunctional Attitudes

    ERIC Educational Resources Information Center

    Iskender, Murat

    2011-01-01

    In the present study, aims were (1) to determine gender differences in self-compassion, academic procrastination, and dysfunctional attitudes and (2) to examine the relationships between self-compassion, academic procrastination, and dysfunctional attitudes. Participants were 251 university students who completed a questionnaire package that…

  11. 78 FR 74189 - Compass Efficient Model Portfolios, LLC, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... From the Federal Register Online via the Government Printing Office SECURITIES AND EXCHANGE COMMISSION Compass Efficient Model Portfolios, LLC, et al.; Notice of Application December 4, 2013. AGENCY... companies as the series to acquire Shares. Applicants: Compass Efficient Model Portfolios, LLC...

  12. On the characteristics -extensions, orientation, density, magnetic field- of magnetic clouds/ejecta immediately following its driving part of the -SEP causing- strong-shock surface region

    NASA Astrophysics Data System (ADS)

    Berdichevsky, D. B.

    2012-12-01

    With multi-spacecraft identification of large solar energetic particles (SEP) -events starting 24 September 1977, 1 January and 23 September 1978, 26 March and 24 April, 1979- driven shocks we make a distinction between the shock driving part of the ejecta and its trailing region. We base our study on the analysis of plasma ions -H+, and He++-, and magnetic field observations. Here, we focus on the unique features of the trailing part, i.e., the region of the ejecta immediately behind a leading front moving very close to its driven shock. (I.e., the portion of the shock-surface labeled shock nose.) A shock nose that in an earlier presentation we have shown that generates in the upstream solar wind the unusual disturbance characteristics commonly observed at/near the stagnation point of the so much studied strong Earth's bow-shock, approximately centered in-front of the Earth, along the Sun-Earth line. These events, considered for illustrative purposes here, belong to the era of the HELIO-A, and HELIO-B spacecraft, and the dataset is further complemented with data from the ICE 3, VOYAGER 1, and 2, IMP-8 missions.

  13. A Community of Scientists and Educators: The Compass Project at UC Berkeley

    NASA Astrophysics Data System (ADS)

    Roth, Nathaniel; Schwab, Josiah

    2016-01-01

    The Berkeley Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences at the University of California, Berkeley. Its goals are to improve undergraduate physics education, provide opportunities for professional development, and increase retention of students from populations underrepresented in the physical sciences. For undergraduate students, the core Compass experience consists of a summer program and several seminar courses. These programs are designed to foster a diverse, collaborative student community in which students engage in authentic research practices and regular self-reflection. Graduate students, together with upper-level undergraduates, design and run all Compass programs. Compass strives to incorporate best practices from the science education literature. Experiences in Compass leave participants poised to be successful students researchers, teachers, and mentors.

  14. Why and how is compassion necessary to provide good quality healthcare?

    PubMed Central

    Fotaki, Marianna

    2015-01-01

    Recent disclosures of failures of care in the National Health Service (NHS) in England have led to debates about compassion deficits disallowing health professionals to provide high quality responsive care. While the link between high quality care and compassion is often taken for granted, it is less obvious how compassion – often originating in the individual’s emotional response – can become a moral sentiment and lead to developing a system of norms and values underpinning ethics of care. In this editorial, I argue why and how compassion might become a foundation of ethics guiding health professionals and a basis for ethics of care in health service organisations. I conclude by discussing a recent case of prominent healthcare failure in the NHS to highlight the relationship between compassion as an aspect of professional ethics on the one hand, and values and norms that institutions and specific policies promote on the other hand. PMID:25844380

  15. Why and how is compassion necessary to provide good quality healthcare?

    PubMed

    Fotaki, Marianna

    2015-04-01

    Recent disclosures of failures of care in the National Health Service (NHS) in England have led to debates about compassion deficits disallowing health professionals to provide high quality responsive care. While the link between high quality care and compassion is often taken for granted, it is less obvious how compassion - often originating in the individual's emotional response - can become a moral sentiment and lead to developing a system of norms and values underpinning ethics of care. In this editorial, I argue why and how compassion might become a foundation of ethics guiding health professionals and a basis for ethics of care in health service organisations. I conclude by discussing a recent case of prominent healthcare failure in the NHS to highlight the relationship between compassion as an aspect of professional ethics on the one hand, and values and norms that institutions and specific policies promote on the other hand. PMID:25844380

  16. Insight into the Chemical Compass Mechanism of Cryptochromes by Computational Investigation

    NASA Astrophysics Data System (ADS)

    Pachter, Ruth; Hong, Gongyi

    2014-03-01

    In this work we investigated aspects of the light-dependent inclination compass, largely assumed in avian magnetic perception, e.g. of European robins. It is postulated that radical pairs (RPs) are formed in cryptochrome (Cry) photoreceptors that contain a redox-active flavin adenine dinucleotide (FAD) in proximity to a Trp triad. The hypothesis was previously rationalized theoretically for the Cry from Arabidopsis thaliana (AtCry1), and the pKa of the proximate residue (PR) to the FAD we derived from QM/MM MD simulations is consistent with this assumption. However, attempts to extrapolate the results to other species are complicated. In the Cry from Drosophila melanogaster (DmCry1), which demonstrated a magnetic response, the FAD anionic radical ground state differs from an oxidized form in AtCry1, and the PR to the FAD is Cys rather than Asp in AtCry1. Investigation for DmCry1 model compounds, showing potential feasibility of a RP mechanism, will be described, where the calculated excitation energy is in agreement with experiment. Involvement of a Tyr instead of Trp in the triad was also considered. Because Crys from the garden warbler form RPs, a RP mechanism was examined, based on a 3D structure derived by homology modeling and MD simulations.

  17. Halo Current Asymmetries During Vertical Displacement Events in COMPASS--D

    NASA Astrophysics Data System (ADS)

    Castle, G. G.; Morris, A. W.

    1996-11-01

    A series of experiments were performed on COMPASS--D in a single null configuration (R=0.557 m, a=0.232 m, b=0.385 m) to investigate the properties of poloidal and toroidal halo currents flowing in the vacuum vessel during vertical displacement events, or VDEs. Both poloidal and toroidal halo currents are induced during a disruption and these currents can produce large forces on the vacuum vessel. Peak poloidal halo currents of up to 0.45 I_po (I_po is the pre--disruption plasma current) have been observed. A significant fraction of the poloidal halo current (>= 50%) can be toroidally asymmetric and this asymmetry produces torques and lateral forces on the vessel. These forces are an important consideration for the design of ITER. Resonant Magnetic Perturbations (RMP) were applied to make m=2, n=1 magnetic islands and helical deformations to improve understanding of the origins of the asymmetries in poloidal halo currents (and perhaps eliminate them). The results of these experiments show that the RMP fields can in some cases decrease the amplitude of the asymmetry and hence the severity of the peak torques and lateral forces acting on the vacuum vessel.\\vspace*0.5cm This work was jointly funded by the Department of Trade and Industry and Euratom

  18. Structural, Magnetic and Electronic Properties of (110)-OrientedEpitaxial Thin Films of Bilayer Manganite La1.2Sr1.8Mn2O7

    SciTech Connect

    Takamura, Yayoi; Grepstad, Jostein K.; Chopdekar, Rajesh V.; Suzuki, Yuri; Marshall, Ann F.; Zheng, Hong; Mitchell, John F.

    2005-05-09

    We have synthesized (110)-oriented epitaxial thin films of the bilayer (n=2) manganite, La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}, with the metallic/ferromagnetic a-b planes lying perpendicular to the substrate surface and the c-axis aligned in the plane of the film. X-ray diffraction and transmission electron microscopy confirm the alignment of the a-b planes along the [1{bar 1}0] substrate direction. The films consist primarily of the n=2 phase with a minor component of the n=1 (La,Sr){sub 2}MnO{sub 4} and n={infinity} (La,Sr)MnO{sub 3} phases. A resistivity maximum coincides with a ferromagnet/paramagnet transition at a reduced T{sub c}{approx}90K (vs. 120K for bulk), indicative of the effects of epitaxial strain. The films display similar anisotropic properties to their bulk counterpart with the magnetically easy direction confined to the a-b planes and 20-200 times lower resistivity for current flowing along the a-b planes compared to the c-axis.

  19. Clementine Star Tracker Stellar Compass: Final report part 1

    SciTech Connect

    Priest, R.E.; Kordas, J.F.; Lewis, I.T.

    1995-07-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star stracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing angle updates to the guidance and navigation system. These cameras served a secondary function by providing a wide field of view imaging capability for lunar horizon glow and other dark-side imaging data. This 290 g camera using a 576 x 384 focal plane array and a 17 mm entrance pupil, detected and centroided stars as dim and dimmer than 4.5 m{sub v}, providing rms pointing accuracy of better than 100 {mu}rad pitch and yaw and 450 {mu}rad roll. A description of this light-weight, low power star tracker camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights. Documentation generated during the design, analysis, build, test and characterization of the star tracker cameras are presented. Collectively, this documentation represents a small library of information for this camera, and may be used as a framework for producing copy units by commercial enterprises, and therefore satisfies a Department of Defense and Department of Energy goal to transfer technology to industry. However, the considerable knowledge gained from the experience of the individuals involved in the system trades, design, analysis, production, testing and characterization of the star tracker stellar compass is not contained in this documentation.

  20. "Leges artis, end(ing) of life, and compassion".

    PubMed

    Rueff, Maria do Céu

    2013-12-01

    I will problematize medical performances at the end of life, confronting them with the responses of Portuguese Criminal Law. By starting from a review of literature, both in Portugal and abroad, I will cross the criminal doctrine with a broader, interdisciplinary approach, including the reconsideration of medicine ethical tradition (notably the Hippocratic Writings) and the present developments in neurosciences. The frame of homeostasis (neurobiology of emotions) by Damisio, with compassion in the top, helps to clarify to which extent medical act according to legesart is becomes the centre of the problem. Indeed, it is within the medical act, understood as the meeting of two autonomies--patient's and doctor's autonomies--that the compassion takes place as a result of the agreement/compromise between the patient's will of ceasing her/his life in a situation of unbearable suffering and the doctor's duty to relieve that suffering. Compassion arises here as a "homeostasis instrument", that is, an emotion which is important in the regulation of life, even when we are speaking about end(ing) of life. This new perspective allows us to guess a shift of paradigm on the ethical and social levels. On the other hand, in so far as we have passed from the compassionate response in medical setting to its discussion, successively, in medical ethics, in the courts, and as a normative instrument, I claim that we are before the "transition from an automatic homeostasis to a deliberate homeostasis" (Damisio). Therefore, 1 seek for a balance between the spontaneous and the planned, concerning the issue of praxis. Indeed, what increasingly happens in medical praxis should be brought together with theory, whereby medical law has a word to say. PMID:24552116

  1. Why Good Quality Care Needs Philosophy More Than Compassion

    PubMed Central

    Leget, Carlo

    2015-01-01

    Although Marianna Fotaki’s Editorial is helpful and challenging by looking at both the professional and institutional requirements for reinstalling compassion in order to aim for good quality healthcare, the causes that hinder this development remain unexamined. In this commentary, 3 causes are discussed; the boundary between the moral and the political; Neoliberalism; and the underdevelopment of reflection on the nature of care. A plea is made for more philosophical reflection on the nature of care and its implications in healthcare education. PMID:26673178

  2. Compass & Vernier Type Models in Indo Archaeology: Engineering Heritage

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Deepak

    2015-09-01

    Two extant, dated, verifiable archaeological members are adduced to have radial type compass features, having scope for fractionation of angles (? operators) in a constant manner with lookout facilities. The Archaeological Survey of India celebrates their apex achievements in the domain of engineering/survey devices of erstwhile societies. Possible correlation has been drawn between the representatives of the elusive Gola yantra and the Vikhyana yantra (circular instrument & looking device) as referred in Indian history and culture. Dadhi nauti (curd level) has been explained for the first time. Now, all of these are accessible to everyone. This work is the first time report, which relates to historical archaeology of lower date c. 600 AD.

  3. Real Sky Performance of the Prototype sted Advanced Stellar Compass

    NASA Technical Reports Server (NTRS)

    Eisenman, Alan; Joergensen, John Leif; Liebe, Carl Christian

    1996-01-01

    The Danish microsatellite, sted, is equipped with an autonomous, advanced stellar compass (ASC). The ASC consists of two separate units, a Charge Coupled Device (CCD) camera head (based on a commercial Sony interline CCD detector) and a data processing unit with a powerful microcomputer (Intel 80486 type processor). The microcomputer memory contains a star catalogue which enables the microcomputer to recognize the constellations of stars in the field of vies and thus derive the attitude of the ASC camera head. The mission, and the design, operation and performance of the ASC are described. Results of the ASC prototype tests at the Jet Propulsion Laboratory (JPL) Table Mountain Observatory (TMO) facility are given.

  4. Remanent magnetism of sediment governs magnetofossil alignment

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-04-01

    Most bacteria navigate by reacting to different chemical signals in their surroundings, but some bacteria have another navigational tool in their arsenal—the Earth's magnetic field. Nestled inside these magnetotactic bacteria (MTB) are organelles called magnetosomes, filled with tiny magnetic crystals and arranged in chains, which form nano-sized compass needles. When MTB die and degrade, these tiny crystals can remain in sediment and eventually become magnetic fossils called magnetofossils.

  5. The influence of self-compassion on emotional well-being among early and older adolescent males and females

    PubMed Central

    Bluth, Karen; Blanton, Priscilla W.

    2014-01-01

    Self-compassion has been associated with well-being in adult samples, but has rarely been assessed in adolescents. In this study, 90 students ages 11–18 completed an online survey assessing self-compassion, life satisfaction, perceived stress and positive and negative affect. Findings indicated that older female adolescents had lower self-compassion than either older male adolescents or early adolescents of either gender, and self-compassion was associated significantly with all dimensions of emotional well-being with the exception of positive affect. Additionally, phase of adolescence, but not gender, was found to moderate the relationship between self-compassion and dimensions of well-being; for older adolescents, the inverse relationship between self-compassion and negative affect was stronger. Lastly, the influence of the various components of self-compassion was investigated and discussed. PMID:25750655

  6. Compassion meditation enhances empathic accuracy and related neural activity.

    PubMed

    Mascaro, Jennifer S; Rilling, James K; Tenzin Negi, Lobsang; Raison, Charles L

    2013-01-01

    The ability to accurately infer others' mental states from facial expressions is important for optimal social functioning and is fundamentally impaired in social cognitive disorders such as autism. While pharmacologic interventions have shown promise for enhancing empathic accuracy, little is known about the effects of behavioral interventions on empathic accuracy and related brain activity. This study employed a randomized, controlled and longitudinal design to investigate the effect of a secularized analytical compassion meditation program, cognitive-based compassion training (CBCT), on empathic accuracy. Twenty-one healthy participants received functional MRI scans while completing an empathic accuracy task, the Reading the Mind in the Eyes Test (RMET), both prior to and after completion of either CBCT or a health discussion control group. Upon completion of the study interventions, participants randomized to CBCT and were significantly more likely than control subjects to have increased scores on the RMET and increased neural activity in the inferior frontal gyrus (IFG) and dorsomedial prefrontal cortex (dmPFC). Moreover, changes in dmPFC and IFG activity from baseline to the post-intervention assessment were associated with changes in empathic accuracy. These findings suggest that CBCT may hold promise as a behavioral intervention for enhancing empathic accuracy and the neurobiology supporting it. PMID:22956676

  7. Star tracker stellar compass for the Clementine mission

    SciTech Connect

    Kordas, J.F.; Lewis, I.T.; Wilson, B.A.

    1995-04-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. Two star tracker stellar compasses (star tracker camera + stellar compass software) were included on the spacecraft, serving a primary function of providing angle updates to the guidance and navigation system. These cameras served a secondary function by providing a wide field of view imaging capability for lunar horizon glow and other dark-side imaging data. This 290 g camera using a 576 x 384 FPA and a 17 mm entrance pupil, detected and centroided stars as dim and dimmer than 4.5 m{sub v}, providing rms pointing accuracy of better than 100 {micro}rad pitch and yaw and 450 {micro}rad roll. A description of this light-weight, low power star tracker camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

  8. Compassion meditation enhances empathic accuracy and related neural activity

    PubMed Central

    Mascaro, Jennifer S.; Rilling, James K.; Tenzin Negi, Lobsang; Raison, Charles L.

    2013-01-01

    The ability to accurately infer others’ mental states from facial expressions is important for optimal social functioning and is fundamentally impaired in social cognitive disorders such as autism. While pharmacologic interventions have shown promise for enhancing empathic accuracy, little is known about the effects of behavioral interventions on empathic accuracy and related brain activity. This study employed a randomized, controlled and longitudinal design to investigate the effect of a secularized analytical compassion meditation program, cognitive-based compassion training (CBCT), on empathic accuracy. Twenty-one healthy participants received functional MRI scans while completing an empathic accuracy task, the Reading the Mind in the Eyes Test (RMET), both prior to and after completion of either CBCT or a health discussion control group. Upon completion of the study interventions, participants randomized to CBCT and were significantly more likely than control subjects to have increased scores on the RMET and increased neural activity in the inferior frontal gyrus (IFG) and dorsomedial prefrontal cortex (dmPFC). Moreover, changes in dmPFC and IFG activity from baseline to the post-intervention assessment were associated with changes in empathic accuracy. These findings suggest that CBCT may hold promise as a behavioral intervention for enhancing empathic accuracy and the neurobiology supporting it. PMID:22956676

  9. Compassion fatigue, moral distress, and work engagement in surgical intensive care unit trauma nurses: a pilot study.

    PubMed

    Mason, Virginia M; Leslie, Gail; Clark, Kathleen; Lyons, Pat; Walke, Erica; Butler, Christina; Griffin, Martha

    2014-01-01

    Preparation for replacing the large proportion of staff nurses reaching retirement age in the next few decades in the United States is essential to continue delivering high-quality nursing care and improving patient outcomes. Retaining experienced critical care nurses is imperative to successfully implementing the orientation of new inexperienced critical care nurses. It is important to understand factors that affect work engagement to develop strategies that enhance nurse retention and improve the quality of patient care. Nurses' experience of moral distress has been measured in medical intensive care units but not in surgical trauma care units, where nurses are exposed to patients and families faced with sudden life-threatening, life-changing patient consequences.This pilot study is a nonexperimental, descriptive, correlational design to examine the effect of compassion satisfaction, compassion fatigue, moral distress, and level of nursing education on critical care nurses' work engagement. This is a partial replication of Lawrence's dissertation. The study also asked nurses to describe sources of moral distress and self-care strategies for coping with stress. This was used to identify qualitative themes about the nurse experiences. Jean Watson's theory of human caring serves as a framework to bring meaning and focus to the nursing-patient caring relationship.A convenience sample of 26 of 34 eligible experienced surgical intensive care unit trauma nurses responded to this survey, indicating a 77% response rate. Twenty-seven percent of the nurses scored high, and 73% scored average on compassion satisfaction. On compassion fatigue, 58% scored average on burnout and 42% scored low. On the secondary traumatic stress subscale, 38% scored average, and 62% scored low. The mean moral distress situations subscale score was 3.4, which is elevated. The mean 9-item Utrecht Work Engagement Scale total score, measuring work engagement, was 3.8, which is considered low.Content analysis was used to identify themes of Role Conflict With Management/Rules, Death and Suffering, Dealing With Violence in the Intensive Care Unit, Dealing With Family, Powerlessness, Physical Distress, and Medical Versus Nursing Values. Additional themes identified were caring, helping families, long-time interdependent relationships of colleagues, and satisfaction in trauma nursing.As work engagement increased, compassion satisfaction significantly increased, and burnout significantly decreased. Results of this study support moral distress as a clinically meaningful issue for surgical intensive care unit nurses. Moral distress scales were elevated, whereas work engagement scales were low. This finding was congruent with Lawrence's study and may reflect ongoing need for greater supports for experienced intensive care unit nurses, from both education and management. Future recommendations for research include examining the interaction of these variables in larger samples to examine additional explanatory factors as well as strategies for self-care, motivation, and behavior change. PMID:24895952

  10. A Simple Demonstration of a General Rule for the Variation of Magnetic Field with Distance

    ERIC Educational Resources Information Center

    Kodama, K.

    2009-01-01

    We describe a simple experiment demonstrating the variation in magnitude of a magnetic field with distance. The method described requires only an ordinary magnetic compass and a permanent magnet. The proposed graphical analysis illustrates a unique method for deducing a general rule of magnetostatics. (Contains 1 table and 6 figures.)

  11. Self-Compassion and Relationship Maintenance: The Moderating Roles of Conscientiousness and Gender

    PubMed Central

    Baker, Levi; McNulty, James K.

    2010-01-01

    Should intimates respond to their interpersonal mistakes with self-criticism or with self-compassion? Although it is reasonable to expect self-compassion to benefit relationships by promoting self-esteem, it is also reasonable to expect self-compassion to hurt relationships by removing intimates’ motivation to correct their interpersonal mistakes. Two correlational studies, 1 experiment, and 1 longitudinal study demonstrated that whether self-compassion helps or hurts relationships depends on the presence versus absence of dispositional sources of the motivation to correct interpersonal mistakes. Among men, the implications of self-compassion were moderated by conscientiousness. Among men high in conscientiousness, self-compassion was associated with greater motivation to correct interpersonal mistakes (Studies 1 and 3), observations of more-constructive problem-solving behaviors (Study 2), reports of more accommodation (Study 3), and fewer declines in marital satisfaction that were mediated by decreases in interpersonal problem severity (Study 4); among men low in conscientiousness, self-compassion was associated with these outcomes in the opposite direction. Among women, in contrast, likely because women are inherently more motivated than men to preserve their relationships for cultural and/or biological reasons, self-compassion was never harmful to the relationship. Instead, women’s self-compassion was positively associated with the motivation to correct their interpersonal mistakes (Study 1) and changes in relationship satisfaction (Study 4), regardless of conscientiousness. Accordingly, theoretical descriptions of the implications of self-promoting thoughts for relationships may be most complete to the extent that they consider the presence versus absence of other sources of the motivation to correct interpersonal mistakes. PMID:21280964

  12. Comparison of three measuring systems at high frequency for non oriented silicon steels: influence of the rolling direction on magnetic losses and B(H) curve

    NASA Astrophysics Data System (ADS)

    Hamrit, Oussama; De la Barrière, Olivier; LoBue, Martino; Lécrivain, Michel; Mazaleyrat, Frédéric

    2015-09-01

    Loss data available in literature on laminated magnetic materials excited by alternating induction are often limited to rather low frequencies, (e.g., below 1 kHz). This is far below the frequencies experienced by materials used in high speed electrical machines. In this work, an appropriate measurement setup is used to evaluate losses in 0.35 mm thick iron silicon NO lamination up to an alternating peak induction of 1 T at a frequency of 10 kHz. In these conditions the capacitive effects are relevant on the B-coil and the H-coil when standard Epstein frame is used and might affect the measurements. A method to avoid this problem is proposed, based on a comparison between three characterization systems: a new single sheet tester that we use as a reference system, a conventional Epstein frame with 700 turns and a second Epstein frame with 200 turns dedicated to high-frequency. In the first part of the study we present an assessment of the limits of each system. An empirical correction factor is introduced to obtain the true loss value from measurement using the Epstein frame (700 turns from DC to 400 Hz and 200 turns from 400 Hz to 10 kHz). Finally, a comparison between two non-oriented FeSi of different quality and different thicknesses (0.35 mm and 0.2 mm) is presented in a wide range of frequencies (from DC to 10 kHz). Based on the loss separation theory, the skin effect on the two samples has been highlighted. Contribution to the topical issue "Electrical Engineering Symposium (SGE 2014)", edited by Adel Razek

  13. Structure and orientation of antibiotic peptide alamethicin in phospholipid bilayers as revealed by chemical shift oscillation analysis of solid state nuclear magnetic resonance and molecular dynamics simulation.

    PubMed

    Nagao, Takashi; Mishima, Daisuke; Javkhlantugs, Namsrai; Wang, Jun; Ishioka, Daisuke; Yokota, Kiyonobu; Norisada, Kazushi; Kawamura, Izuru; Ueda, Kazuyoshi; Naito, Akira

    2015-11-01

    The structure, topology and orientation of membrane-bound antibiotic alamethicin were studied using solid state nuclear magnetic resonance (NMR) spectroscopy. (13)C chemical shift interaction was observed in [1-(13)C]-labeled alamethicin. The isotropic chemical shift values indicated that alamethicin forms a helical structure in the entire region. The chemical shift anisotropy of the carbonyl carbon of isotopically labeled alamethicin was also analyzed with the assumption that alamethicin molecules rotate rapidly about the bilayer normal of the phospholipid bilayers. It is considered that the adjacent peptide planes form an angle of 100° or 120° when it forms ?-helix or 310-helix, respectively. These properties lead to an oscillation of the chemical shift anisotropy with respect to the phase angle of the peptide plane. Anisotropic data were acquired for the 4 and 7 sites of the N- and C-termini, respectively. The results indicated that the helical axes for the N- and C-termini were tilted 17° and 32° to the bilayer normal, respectively. The chemical shift oscillation curves indicate that the N- and C-termini form the ?-helix and 310-helix, respectively. The C-terminal 310-helix of alamethicin in the bilayer was experimentally observed and the unique bending structure of alamethicin was further confirmed by measuring the internuclear distances of [1-(13)C] and [(15)N] doubly-labeled alamethicin. Molecular dynamics simulation of alamethicin embedded into dimyristoyl phophatidylcholine (DMPC) bilayers indicates that the helical axes for ?-helical N- and 310-helical C-termini are tilted 12° and 32° to the bilayer normal, respectively, which is in good agreement with the solid state NMR results. PMID:26248014

  14. Salt concentration and solar orientation in two supralittoral sandhoppers: Talitrus saltator (Montagu) and Talorchestia ugolinii Bellan Santini and Ruffo.

    PubMed

    Ugolini, Alberto; Cincinelli, Alessandra; Martellini, Tania; Doumett, Saer

    2015-05-01

    The influence of salt concentration in the seawater on solar orientation in Talitrus saltator and Talorchestia ugolinii was studied in a confined environment (transparent plexiglass bowls). Sodium and calcium concentrations strongly affect both sea-land orientation and the sun compass mechanism in T.saltator, whereas the behaviour of T. ugolinii is less influenced. The absence of Na(+) does not influence the sun compass mechanism, but causes an inversion in the mean direction of orientation in T. saltator. In T. ugolinii, there was no influence on the compass mechanism for solar orientation and no inversion in the directional choice. In the absence of Ca(2+), a photonegative tendency was observed for T saltator together with marked reduction in the capacity to go in any direction. However, the effect of Ca(2+) absence on the orientation capacity of T. saltator is reversible and the orientation capacity can be reduced in a few minutes. The different behaviour of the two species of sandhoppers is discussed. PMID:25726016

  15. PHYSICAL REVIEW E 87, 062704 (2013) Quantum coherence and entanglement in the avian compass

    E-print Network

    Kais, Sabre

    2013-01-01

    -pair entanglement due to a lack of orientation sensitivity of the entanglement in the geomagnetic field. To explore and displays an angular sensitivity in weak magnetic fields, both of which are not present in previous models's eye, rather than the intrinsic ordering of their molecular precursors, could help the radical pairs

  16. [Magnetoreception: the angular stone in aerospace orientation, human balance and locomotion].

    PubMed

    Rizzo-Sierra, Carlos V; Bayona, Edgardo A; Leon-Sarmiento, Fidias E

    2011-01-01

    Current research is in agreement with the presence of a magnetic compass in living beings including humans. The two most accepted explanations that demonstrate the existence of magnetoreceptors in living beings are, the radical pair and the biogenic magnetite, which are discussed here with its respective experimental evidence and support. It indicates the presence of magnetite crystals in otoliths, among different inferior species of animals. Moreover, the magnetite found in several organs of human body allows predicting the existence of such element, in otoliths of vestibular system as well; further, anticipates that human magnetoreception is an additional function of the vestibular system. These geomagnetic signals would modulate balance, movement and spatial positioning of man in concordance of gravity values. This new field of otomagnetism opens new research areas for understanding the mechanisms involved in balance, equilibrium, orientation, and space positioning in normal and disease populations. Likewise, this could be the starting point for application of new human neurorehabilitation procedures, in those magnetoreception-associated neurological disorders that happen in the earth, the sea or the air. PMID:22468481

  17. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods

    SciTech Connect

    Imrisek, M.; Weinzettl, V.; Mlynar, J.; Panek, R.; Hron, M.; Odstrcil, T.; Odstrcil, M.; Ficker, O.; Pinzon, J. R.; Ehrlacher, C.

    2014-11-15

    The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side.

  18. The orientation of the sandhopper Talitrus saltator during a partial solar eclipse.

    PubMed

    Ugolini, A; Castellini, C; Tiribilli, B

    2004-10-01

    To acquire more information about the identification and use of the sun and other celestial cues in the sea-land orientation of the sandhopper Talitrus saltator, we carried out releases in a confined environment during a partial solar eclipse and at sunset. The sandhoppers were unable to identify the sun (86% covered) during the eclipse nor to use other celestial compass factors of orientation. This was probably due to the low level of light intensity (close to the minimum level for orientation recorded at sunset) and to the variations in intensity and pattern of skylight polarization. PMID:15351897

  19. Maplike Representation of Celestial E-Vector Orientations in the Brain of an Insect

    NASA Astrophysics Data System (ADS)

    Heinze, Stanley; Homberg, Uwe

    2007-02-01

    For many insects, the polarization pattern of the blue sky serves as a compass cue for spatial navigation. E-vector orientations are detected by photoreceptors in a dorsal rim area of the eye. Polarized-light signals from both eyes are finally integrated in the central complex, a brain area consisting of two subunits, the protocerebral bridge and the central body. Here we show that a topographic representation of zenithal E-vector orientations underlies the columnar organization of the protocerebral bridge in a locust. The maplike arrangement is highly suited to signal head orientation under the open sky.

  20. Magnetic effect on dancing bees

    NASA Technical Reports Server (NTRS)

    Lindauer, M.; Martin, H.

    1972-01-01

    Bee sensitivity to the earth's magnetic field is studied. Data cover sensitivity range and the use of magnetoreception for orientation purposes. Experimental results indicate bee orientation is aided by gravity fields when the magnetic field is compensated.

  1. Effect of NiO spin orientation on the magnetic anisotropy of the Fe film in epitaxially grown Fe/NiO/Ag(001) and Fe/NiO/MgO(001)

    SciTech Connect

    Kim, W.; Jin, E.; Wu, J.; Park, J.; Arenholz, E.; Scholl, A.; Hwang, C.; Qiu, Z.

    2010-02-10

    Single crystalline Fe/NiO bilayers were epitaxially grown on Ag(001) and on MgO(001), and investigated by Low Energy Electron Diffraction (LEED), Magneto-Optic Kerr Effect (MOKE), and X-ray Magnetic Linear Dichroism (XMLD). We find that while the Fe film has an in-plane magnetization in both Fe/NiO/Ag(001) and Fe/NiO/MgO(001) systems, the NiO spin orientation changes from in-plane direction in Fe/NiO/Ag(001) to out-of-plane direction in Fe/NiO/MgO(001). These two different NiO spin orientations generate remarkable different effects that the NiO induced magnetic anisotropy in the Fe film is much greater in Fe/NiO/Ag(001) than in Fe/NiO/MgO(001). XMLD measurement shows that the much greater magnetic anisotropy in Fe/NiO/Ag(001) is due to a 90{sup o}-coupling between the in-plane NiO spins and the in-plane Fe spins.

  2. North Pole, South Pole: the quest to understand the mystery of Earth's magnetism

    NASA Astrophysics Data System (ADS)

    Turner, G. M.

    2010-12-01

    The story of the quest to understand Earth’s magnetic field is one of the longest and richest in the history of science. It weaves together Greek philosophy, Chinese mysticism, the development of the compass and navigation, the physics of electromagnetism and the jig-saw like piecing together of the internal structure of the planet beneath our feet. The story begins with Magnes, an old shepherd, trudging up the mountainside after a violent thunder storm, astonished at how the iron studs in his boots stick to the rocks. It was Alexander von Humboldt who, three millennia on, pointed to lightning as the source of such magnetization. The first compass was made 2000 years ago in China - to divine the ways of feng shui - a guide to planting crops, planning streets, orienting buildings and more. It reached Europe as a navigational tool in the 12th century - no-one is quite sure how, but en route it changed from south-pointing to the north-pointing compasses of today. The earliest truly scientific experiments and writings concerned magnets and geomagnetism: Petrus Peregrinus’ Epistola of 1269, and William Gilbert’s De Magnete of1600, in which he declared Magnus magnes globus terrestris ipse est - the Earth itself is a great magnet. By then it was recognized that the compass didn’t point exactly north, and the discrepancy varied from place to place and changed over time - something of a problem for Gilbert’s idea of a geocentric axial dipole. However declination and secular variation were problems well known to Edmund Halley, who, in 1700, charted the angle of declination over the Atlantic Ocean, and in the process introduced the Halleyan line - the contour. Many of the world’s greatest scientists have turned their minds to the problem of magnetism and geomagnetism in particular - Coulomb, Gauss, Faraday, Maxwell - yet in 1905, Einstein described geomagnetism as “one of the great unsolved problems of physics”. In the mid-late nineteenth century new areas of geophysics emerged: geodesy and seismology, and from these came the discoveries of the liquid iron outer core and the inner core. Later, with the recognition and validation of the palaeomagnetic method came the amazing discovery that as well as the gradual secular variation, the polarity of the field has reversed, not once but many times over history. The idea of a simply connected, self-sustaining hydromagnetic dynamo was first proposed by Larmor in 1919, but through most of the 20th century attempts to demonstrate its feasibility were hampered by lack of computational power. When, in the 1990s, supercomputers burst onto the scene it became possible to programme, albeit with some compromises, the many calculations needed to simulate Earth’s core - its motion, electric currents and magnetic fields over a significant part of the life of the Earth. The result was a model that reproduced in character the predominant geocentric axial dipole, the secular variation, and, finally the ability to reverse polarity - the Earth itself is a great hydromagnetic dynamo. The story is told in a new book, published by Awa Press, New Zealand this year, and which is scheduled for publication in the United States early in 2011. Written for a wide audience, it is readily accessible to non-experts and students of any area of earth science.

  3. Helping the self help others: self-affirmation increases self-compassion and pro-social behaviors

    PubMed Central

    Lindsay, Emily K.; Creswell, J. David

    2014-01-01

    Reflecting on an important personal value in a self-affirmation activity has been shown to improve psychological functioning in a broad range of studies, but the underlying mechanisms for these self-affirmation effects are unknown. Here we provide an initial test of a novel self-compassion account of self-affirmation in two experimental studies. Study 1 shows that an experimental manipulation of self-affirmation (3-min of writing about an important personal value vs. writing about an unimportant value) increases feelings of self-compassion, and these feelings in turn mobilize more pro-social behaviors to a laboratory shelf-collapse incident. Study 2 tests and extends these effects by evaluating whether self-affirmation increases feelings of compassion toward the self (consistent with the self-compassion account) or increases feelings of compassion toward others (an alternative other-directed compassion account), using a validated storytelling behavioral task. Consistent with a self-compassion account, Study 2 demonstrates the predicted self-affirmation by video condition interaction, indicating that self-affirmation participants had greater feelings of self-compassion in response to watching their own storytelling performance (self-compassion) compared to watching a peer’s storytelling performance (other-directed compassion). Further, pre-existing levels of trait self-compassion moderated this effect, such that self-affirmation increased self-compassionate responses the most in participants low in trait self-compassion. This work suggests that self-compassion may be a promising mechanism for self-affirmation effects, and that self-compassionate feelings can mobilize pro-social behaviors. PMID:24860534

  4. Design of Drift Chamber 5 for the COMPASS II polarized Drell-Yan experiment

    NASA Astrophysics Data System (ADS)

    Mallon, James; Compass Dc5 Team

    2014-09-01

    The COMPASS project is a fixed-target nuclear physics experiment at CERN which explores the internal structure of the proton, and COMPASS ll's polarized Drell-Yan experiments will be exploring the quark angular momentum contribution to the spin of the proton through Semi-Inclusive Deep Inelastic Scattering. As a part of this process, Drift Chamber 5 (DC5), based on DC4 built by CEA-Saclay, must be constructed to replace a faulty straw chamber. The 23 total frames of DC5 have an outside measurement of 2.94 m by 2.54 m, with the 8 anode frames having a total of 4616 >2 m-long wires, giving a detection region of 4.19 m2 with a resolution of 200 microns. These wire planes are orientated with the x- and x'-frames in the vertical x-direction, the y- & y'-frames in the horizontal y-direction, the u- & u'- frames offset +10 deg from the vertical x-direction, and the v- &v'-frames offset -10 deg from the vertical x-direction, and are strung with Ø100 micron field wires and Ø20 micron sense wires. In order to solve left-right ambiguity, x', y', u', and v' are shifted by 4mm, or one drift cell. The x- and y-frames have 513 wires strung across them, with the field wires at 400 g of tension, the sense wires at 55 g on the x-frames, and 70 g on the y-frames. The u- and v-frames will have 641 wires, with the field wires at 400 g, and the sense wires at 55 g. DC5 will also have an updated front end electronics setup, using a new pre-amplifier-discriminator chip, in order to allow the recording of more events per second. The COMPASS project is a fixed-target nuclear physics experiment at CERN which explores the internal structure of the proton, and COMPASS ll's polarized Drell-Yan experiments will be exploring the quark angular momentum contribution to the spin of the proton through Semi-Inclusive Deep Inelastic Scattering. As a part of this process, Drift Chamber 5 (DC5), based on DC4 built by CEA-Saclay, must be constructed to replace a faulty straw chamber. The 23 total frames of DC5 have an outside measurement of 2.94 m by 2.54 m, with the 8 anode frames having a total of 4616 >2 m-long wires, giving a detection region of 4.19 m2 with a resolution of 200 microns. These wire planes are orientated with the x- and x'-frames in the vertical x-direction, the y- & y'-frames in the horizontal y-direction, the u- & u'- frames offset +10 deg from the vertical x-direction, and the v- &v'-frames offset -10 deg from the vertical x-direction, and are strung with Ø100 micron field wires and Ø20 micron sense wires. In order to solve left-right ambiguity, x', y', u', and v' are shifted by 4mm, or one drift cell. The x- and y-frames have 513 wires strung across them, with the field wires at 400 g of tension, the sense wires at 55 g on the x-frames, and 70 g on the y-frames. The u- and v-frames will have 641 wires, with the field wires at 400 g, and the sense wires at 55 g. DC5 will also have an updated front end electronics setup, using a new pre-amplifier-discriminator chip, in order to allow the recording of more events per second. This research was supported in part by the DOE under Grant Number DE-FG03-94ER40860.

  5. “We feel deep compassion for patients...” | NIH MedlinePlus the Magazine

    MedlinePLUS

    ... Feature: Medical Mysteries “We feel deep compassion for patients...” Past Issues / Spring 2011 Table of Contents Dr. ... kind of emotional support does your program offer patients? For some, real hope and maybe even relief. ...

  6. Design and Optimization of a Compass Robot with Subject to Stability Constraint 

    E-print Network

    Keshavarzbagheri, Zohreh

    2012-10-19

    In the first part of this thesis, the design of a compass robot is explored by considering its components and their interaction with each other. Three components including robot's structure, gear and motor are interacting during design process...

  7. 78 FR 42153 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel COMPASS ROSE; Invitation for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ...As described by the applicant the intended service of the vessel COMPASS ROSE is: Intended Commercial Use Of Vessel: ``Sailboat charters six passengers or less''. Geographic Region: ``Maine, New Hampshire, Massachusetts, Rhode Island,...

  8. Self-compassion and Risk Behavior among People Living with HIV/AIDS

    PubMed Central

    Webel, Allison; Sullivan, Kathleen M.; Cuca, Yvette P.; Wantland, Dean; Johnson, Mallory O.; Brion, John; Portillo, Carmen J.; Corless, Inge B.; Voss, Joachim; Chen, Wei-Ti; Phillips, J. Craig; Tyer-Viola, Lynda; Rivero-Méndez, Marta; Nicholas, Patrice K.; Nokes, Kathleen; Kemppainen, Jeanne; Sefcik, Elizabeth; Eller, Lucille Sanzero; Iipinge, Scholastika; Kirksey, Kenn; Chaiphibalsarisdi, Puangtip; Davila, Nancy; Hamilton, Mary Jane; Hickey, Dorothy; Maryland, Mary; Reid, Paula; Holzemer, William L.

    2014-01-01

    Sexual risk behavior and illicit drug use among people living with HIV/AIDS (PLWHA) contribute to poor health and onward transmission of HIV. The aim of this collaborative multi-site nursing research study was to explore the association between self-compassion and risk behaviors in PLWHA. Nurse researchers in Canada, China, Namibia, Puerto Rico, Thailand and the U.S. enrolled 2,182 PLWHA using convenience sampling. Over half of study participants were sexually active in the past three months. Participants with higher self-compassion were less likely to report sexual risk behavior. However, if a person also used illicit drugs, the relationship with self-compassion was reduced. Self-compassion may be a novel area for behavioral intervention development for PLWHA. PMID:24510757

  9. Commissioning of heating neutral beams for COMPASS-D tokamak

    SciTech Connect

    Deichuli, P.; Davydenko, V.; Belov, V.; Gorbovsky, A.; Dranichnikov, A.; Ivanov, A.; Sorokin, A.; Mishagin, V.; Abdrashitov, A.; Kolmogorov, V.; Kondakov, A.

    2012-02-15

    Two neutral beam injectors have been developed for plasma heating on COMPASS-D tokamak (Institute of Plasma Physics, Prague). The 4-electrodes multihole ion-optical system with beam focusing was chosen to provide the low divergence 300 kW power in both deuterium and hydrogen atoms. The accelerating voltage is 40 kV at extracted ion current up to 15 A. The power supply system provides the continuous and modulated mode of the beam injection at a maximal pulse length 300 ms. The optimal arrangement of the cryopanels and the beam duct elements provides sufficiently short-length beamline which reduces the beam losses. The evolution of the impurities and molecular fraction content is studied in the process of the high voltage conditioning of the newly made ion sources. Two injectors of the same type have been successfully tested and are ready for operation at tokamak in IPP, Prague.

  10. Quantum phase transitions in spin-1 compass chains

    NASA Astrophysics Data System (ADS)

    Liu, Guang-Hua; Kong, Long-Juan; You, Wen-Long

    2015-11-01

    The ground-state phase diagram and quantum phase transitions (QPTs) in a spin-1 compass chain are investigated by the infinite time-evolving block decimation (iTEBD) method. Various phases are discerned by energy densities, spin correlations and entanglement entropy. A generalized string correlator is found to be capable of describing the nonlocal string order in the disordered phase. Furthermore, in the noncritical disordered phase, the spin-spin correlations are found to decay exponentially. Except for a multicritical point ( J 1 = 0, J 2 = 0), the QPTs are determined to have second-order characters. In addition, the central charges on these critical phase boundaries are determined to be c = 1 / 2, therefore these QPTs belong to the Ising universality class.

  11. Composition And Electrical Properties Of Dust From Tokamak Compass

    SciTech Connect

    Vaverka, J.; Beranek, M.; Pavlu, J.; Richterova, I.; Vysinka, M.; Safrankova, J.; Nemecek, Z.

    2011-11-29

    In spite of the fact that fusion is a subject of the study for many years, there are still a lot of open questions. One of the interesting topics in fusion research is a presence of dust grains in reactors. In the paper, dust grains born in tokamak Compass are studied and compared with samples of a spherical geometry and well known composition. A unique experimental setup was used for investigations of charging properties of such grains and the SEM and EDX spectroscopy was applied for a study of grain composition. We focus on the secondary emission because this process plays a prominent role when a portion of energetic electrons is present in surroundings of a particular grain. It was shown that depending on the grain size and material, energetic electrons charge the grains to positive potentials comparable with the energy of impinging electrons.

  12. The COMPASS setup for physics with hadron beams

    NASA Astrophysics Data System (ADS)

    Abbon, P.; Adolph, C.; Akhunzyanov, R.; Alexandrov, Yu.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Bade?ek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Ciliberti, P.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Colantoni, M.; Cotte, D.; Crespo, M. L.; Curiel, Q.; Dafni, T.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Desforge, D.; Dinkelbach, A. M.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Durand, D.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gatignon, L.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giganon, A.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Gregori, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Höppner, Ch.; Horikawa, N.; d`Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jörg, P.; Joosten, R.; Kabuß, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Menon, G.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M. A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W.-D.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesaro, G.; Pesaro, V.; Peshekhonov, D. V.; Pires, C.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Reymond, J.-M.; Rocco, E.; Rossiyskaya, N. S.; Rousse, J.-Y.; Ryabchikov, D. I.; Rychter, A.; Samartsev, A.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Terça, G.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Weitzel, Q.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-04-01

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This paper describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.

  13. Compass: Clinical Evaluation of a New Instrument for the Diagnosis of Glaucoma

    PubMed Central

    Rossetti, Luca; Digiuni, Maurizio; Rosso, Alberto; Riva, Roberta; Barbaro, Giuliano; Smolek, Michael K.; Orzalesi, Nicola; De Cilla’, Stefano; Autelitano, Alessandro; Fogagnolo, Paolo

    2015-01-01

    Aims To evaluate Compass, a new instrument for glaucoma screening and diagnosis that combines scanning ophthalmoscopy, automated perimetry, and eye tracking. Materials and Methods A total of 320 human subjects (200 normal, 120 with glaucoma) underwent full ophthalmological evaluation and perimetric evaluation using the Humphrey SITA standard 24° test (HFA), and the Compass test that consisted of a full-threshold program on the central 24° with a photograph of the central 30° of the retina. A subgroup of normal subjects and glaucoma patients underwent a second Compass test during the same day in order to study test-retest variability. After exclusion of 30 patients due to protocol rules, a database was created to compare the Compass to the HFA, and to evaluate retinal image quality and fixation stability. Results The difference in mean sensitivity between Compass and HFA was -1.02 ± 1.55 dB in normal subjects (p<0.001) and -1.01 ± 2.81 dB in glaucoma (p<0.001). Repeatability SD for the average sensitivity was 1.53 for normal subjects and 1.84 for glaucoma. Test time with the Compass was 634±96 s (607±78 for normals, 678±108 for glaucoma). Compass analysis showed the percentage of fixation within the central 1° was 86.6% in normal subjects, and 79.3% in glaucoma patients. Color image quality was sufficient for diagnostic use in >65% of cases; Image-based diagnosis was in accordance with the initial diagnosis in 85% of the subjects. Conclusions Based on preliminary results, Compass showed useful diagnostic characteristics for the study of glaucoma, and combined morphological information with functional data. PMID:25807241

  14. Analyzing Orientations

    NASA Astrophysics Data System (ADS)

    Ruggles, Clive L. N.

    Archaeoastronomical field survey typically involves the measurement of structural orientations (i.e., orientations along and between built structures) in relation to the visible landscape and particularly the surrounding horizon. This chapter focuses on the process of analyzing the astronomical potential of oriented structures, whether in the field or as a desktop appraisal, with the aim of establishing the archaeoastronomical "facts". It does not address questions of data selection (see instead Chap. 25, "Best Practice for Evaluating the Astronomical Significance of Archaeological Sites", 10.1007/978-1-4614-6141-8_25) or interpretation (see Chap. 24, "Nature and Analysis of Material Evidence Relevant to Archaeoastronomy", 10.1007/978-1-4614-6141-8_22). The main necessity is to determine the azimuth, horizon altitude, and declination in the direction "indicated" by any structural orientation. Normally, there are a range of possibilities, reflecting the various errors and uncertainties in estimating the intended (or, at least, the constructed) orientation, and in more formal approaches an attempt is made to assign a probability distribution extending over a spread of declinations. These probability distributions can then be cumulated in order to visualize and analyze the combined data from several orientations, so as to identify any consistent astronomical associations that can then be correlated with the declinations of particular astronomical objects or phenomena at any era in the past. The whole process raises various procedural and methodological issues and does not proceed in isolation from the consideration of corroborative data, which is essential in order to develop viable cultural interpretations.

  15. Cognitions as mediators in the relationship between self-compassion and affect.

    PubMed

    Arimitsu, Kohki; Hofmann, Stefan G

    2015-02-01

    Previous studies suggest that self-compassion is related to numerous facets of mental health, but the role of cognitions in this relationship remains unknown. To examine the mediating role of cognitions in the relationship between self-compassion and anxiety, depression, and life satisfaction when controlling for self-esteem in Japanese people, we conducted two studies. Study 1 (N = 231) examined the relationship between self-compassion and affect by modeling negative automatic thoughts as a mediator; Study 2 (N = 233) tested whether positive and negative automatic thoughts meditate this relationship. Results suggested that both self-compassion and self-esteem increased positive automatic thoughts and decreased trait anxiety, whereas only self-esteem increased life satisfaction and decreased depression directly. Positive automatic thoughts increased life satisfaction and decreased depression and trait anxiety, and positive automatic thoughts mediated the relationship between self-compassion and negative affect. These findings suggest that both positive and negative automatic thoughts mediate the relationship between self-compassion and affect in Japanese people. PMID:25395717

  16. Compassion-based emotion regulation up-regulates experienced positive affect and associated neural networks.

    PubMed

    Engen, Haakon G; Singer, Tania

    2015-09-01

    Emotion regulation research has primarily focused on techniques that attenuate or modulate the impact of emotional stimuli. Recent evidence suggests that this mode regulation can be problematic in the context of regulation of emotion elicited by the suffering of others, resulting in reduced emotional connectedness. Here, we investigated the effects of an alternative emotion regulation technique based on the up-regulation of positive affect via Compassion-meditation on experiential and neural affective responses to depictions of individuals in distress, and compared these with the established emotion regulation strategy of Reappraisal. Using fMRI, we scanned 15 expert practitioners of Compassion-meditation either passively viewing, or using Compassion-meditation or Reappraisal to modulate their emotional reactions to film clips depicting people in distress. Both strategies effectively, but differentially regulated experienced affect, with Compassion primarily increasing positive and Reappraisal primarily decreasing negative affect. Imaging results showed that Compassion, relative to both passive-viewing and Reappraisal increased activation in regions involved in affiliation, positive affect and reward processing including ventral striatum and medial orbitfrontal cortex. This network was shown to be active prior to stimulus presentation, suggesting that the regulatory mechanism of Compassion is the stimulus-independent endogenous generation of positive affect. PMID:25698699

  17. Cognitions as mediators in the relationship between self-compassion and affect

    PubMed Central

    Arimitsu, Kohki; Hofmann, Stefan G.

    2014-01-01

    Previous studies suggest that self-compassion is related to numerous facets of mental health, but the role of cognitions in this relationship remains unknown. To examine the mediating role of cognitions in the relationship between self-compassion and anxiety, depression, and life satisfaction when controlling for self-esteem in Japanese people, we conducted two studies. Study 1 (N = 231) examined the relationship between self-compassion and affect by modeling negative automatic thoughts as a mediator; Study 2 (N = 233) tested whether positive and negative automatic thoughts meditate this relationship. Results suggested that both self-compassion and self-esteem increased positive automatic thoughts and decreased trait anxiety, whereas only self-esteem increased life satisfaction and decreased depression directly. Positive automatic thoughts increased life satisfaction and decreased depression and trait anxiety, and positive automatic thoughts mediated the relationship between self-compassion and negative affect. These findings suggest that both positive and negative automatic thoughts mediate the relationship between self-compassion and affect in Japanese people. PMID:25395717

  18. Self-compassion training modulates alpha-amylase, heart rate variability, and subjective responses to social evaluative threat in women.

    PubMed

    Arch, Joanna J; Brown, Kirk Warren; Dean, Derek J; Landy, Lauren N; Brown, Kimberley D; Laudenslager, Mark L

    2014-04-01

    A growing body of research has revealed that social evaluative stressors trigger biological and psychological responses that in chronic forms have been linked to aging and disease. Recent research suggests that self-compassion may protect the self from typical defensive responses to evaluation. We investigated whether brief training in self-compassion moderated biopsychological responses to the Trier Social Stress Test (TSST) in women. Compared to attention (placebo) and no-training control conditions, brief self-compassion training diminished sympathetic (salivary alpha-amylase), cardiac parasympathetic, and subjective anxiety responses, though not HPA-axis (salivary cortisol) responses to the TSST. Self-compassion training also led to greater self-compassion under threat relative to the control groups. In that social stress pervades modern life, self-compassion represents a promising approach to diminishing its potentially negative psychological and biological effects. PMID:24636501

  19. Self-compassion training modulates alpha-amylase, heart rate variability, and subjective responses to social evaluative threat in women

    PubMed Central

    Arch, Joanna J.; Brown, Kirk Warren; Dean, Derek J.; Landy, Lauren N.; Brown, Kimberley; Laudenslager, Mark L.

    2014-01-01

    A growing body of research has revealed that social evaluative stressors trigger biological and psychological responses that in chronic forms have been linked to aging and disease. Recent research suggests that self-compassion may protect the self from typical defensive responses to evaluation. We investigated whether brief training in self-compassion moderated biopsychological responses to the Trier Social Stress Test (TSST) in women. Compared to attention (placebo) and no-training control conditions, brief self-compassion training diminished sympathetic (salivary alpha-amylase), cardiac parasympathetic, and subjective anxiety responses, though not HPA-axis (salivary cortisol) responses to the TSST. Self-compassion training also led to greater self-compassion under threat relative to the control groups. In that social stress pervades modern life, self-compassion represents a promising approach to diminishing its potentially negative psychological and biological effects. PMID:24636501

  20. Probes for investigating the effect of magnetic field, field orientation, temperature and strain on the critical current density of anisotropic high-temperature superconducting tapes in a split-pair 15 T horizontal magnet

    SciTech Connect

    Sunwong, P.; Higgins, J. S.; Hampshire, D. P.

    2014-06-15

    We present the designs of probes for making critical current density (J{sub c}) measurements on anisotropic high-temperature superconducting tapes as a function of field, field orientation, temperature and strain in our 40 mm bore, split-pair 15 T horizontal magnet. Emphasis is placed on the design of three components: the vapour-cooled current leads, the variable temperature enclosure, and the springboard-shaped bending beam sample holder. The vapour-cooled brass critical-current leads used superconducting tapes and in operation ran hot with a duty cycle (D) of ?0.2. This work provides formulae for optimising cryogenic consumption and calculating cryogenic boil-off, associated with current leads used to make J{sub c} measurements, made by uniformly ramping the current up to a maximum current (I{sub max}) and then reducing the current very quickly to zero. They include consideration of the effects of duty cycle, static helium boil-off from the magnet and Dewar (b{sup ?}), and the maximum safe temperature for the critical-current leads (T{sub max}). Our optimized critical-current leads have a boil-off that is about 30% less than leads optimized for magnet operation at the same maximum current. Numerical calculations show that the optimum cross-sectional area (A) for each current lead can be parameterized by LI{sub max}/A=[1.46D{sup ?0.18}L{sup 0.4}(T{sub max}?300){sup 0.25D{sup ?{sup 0{sup .{sup 0{sup 9}}}}}}+750(b{sup ?}/I{sub max})D{sup 10{sup ?{sup 3I{sub m}{sub a}{sub x}?2.87b{sup ?}}}}]× 10{sup 6}A m{sup ?1} where L is the current lead's length and the current lead is operated in liquid helium. An optimum A of 132 mm{sup 2} is obtained when I{sub max} = 1000 A, T{sub max} = 400 K, D = 0.2, b{sup ?} = 0.3 l?h{sup ?1} and L = 1.0 m. The optimized helium consumption was found to be 0.7 l?h{sup ?1}. When the static boil-off is small, optimized leads have a boil-off that can be roughly parameterized by: b/I{sub max?} ? (1.35 × 10{sup ?3})D{sup 0.41} l?h{sup ?1}?A{sup ?1}. A split-current-lead design is employed to minimize the rotation of the probes during the high current measurements in our high-field horizontal magnet. The variable-temperature system is based on the use of an inverted insulating cup that operates above 4.2 K in liquid helium and above 77.4 K in liquid nitrogen, with a stability of ±80 mK to ±150 mK. Uniaxial strains of ?1.4% to 1.0% can be applied to the sample, with a total uncertainty of better than ±0.02%, using a modified bending beam apparatus which includes a copper beryllium springboard-shaped sample holder.

  1. Probes for investigating the effect of magnetic field, field orientation, temperature and strain on the critical current density of anisotropic high-temperature superconducting tapes in a split-pair 15 T horizontal magnet

    NASA Astrophysics Data System (ADS)

    Sunwong, P.; Higgins, J. S.; Hampshire, D. P.

    2014-06-01

    We present the designs of probes for making critical current density (Jc) measurements on anisotropic high-temperature superconducting tapes as a function of field, field orientation, temperature and strain in our 40 mm bore, split-pair 15 T horizontal magnet. Emphasis is placed on the design of three components: the vapour-cooled current leads, the variable temperature enclosure, and the springboard-shaped bending beam sample holder. The vapour-cooled brass critical-current leads used superconducting tapes and in operation ran hot with a duty cycle (D) of ˜0.2. This work provides formulae for optimising cryogenic consumption and calculating cryogenic boil-off, associated with current leads used to make Jc measurements, made by uniformly ramping the current up to a maximum current (Imax) and then reducing the current very quickly to zero. They include consideration of the effects of duty cycle, static helium boil-off from the magnet and Dewar (b'), and the maximum safe temperature for the critical-current leads (Tmax). Our optimized critical-current leads have a boil-off that is about 30% less than leads optimized for magnet operation at the same maximum current. Numerical calculations show that the optimum cross-sectional area (A) for each current lead can be parameterized by LI_{max} /A = [1.46D^{ - 0.18} L^{0.4} (T_{max } - 300)^{0.25D^{ - 0.09} } + 750(b^' /I_{max })D^{10^{ - 3} I_{max } - 2.87b^' }] × 10^6 A m^{ - 1} where L is the current lead's length and the current lead is operated in liquid helium. An optimum A of 132 mm2 is obtained when Imax = 1000 A, Tmax = 400 K, D = 0.2, b' = 0.3 l h-1 and L = 1.0 m. The optimized helium consumption was found to be 0.7 l h-1. When the static boil-off is small, optimized leads have a boil-off that can be roughly parameterized by: b/Imax ? (1.35 × 10-3)D0.41 l h-1 A-1. A split-current-lead design is employed to minimize the rotation of the probes during the high current measurements in our high-field horizontal magnet. The variable-temperature system is based on the use of an inverted insulating cup that operates above 4.2 K in liquid helium and above 77.4 K in liquid nitrogen, with a stability of ±80 mK to ±150 mK. Uniaxial strains of -1.4% to 1.0% can be applied to the sample, with a total uncertainty of better than ±0.02%, using a modified bending beam apparatus which includes a copper beryllium springboard-shaped sample holder.

  2. Probes for investigating the effect of magnetic field, field orientation, temperature and strain on the critical current density of anisotropic high-temperature superconducting tapes in a split-pair 15 T horizontal magnet.

    PubMed

    Sunwong, P; Higgins, J S; Hampshire, D P

    2014-06-01

    We present the designs of probes for making critical current density (Jc) measurements on anisotropic high-temperature superconducting tapes as a function of field, field orientation, temperature and strain in our 40 mm bore, split-pair 15 T horizontal magnet. Emphasis is placed on the design of three components: the vapour-cooled current leads, the variable temperature enclosure, and the springboard-shaped bending beam sample holder. The vapour-cooled brass critical-current leads used superconducting tapes and in operation ran hot with a duty cycle (D) of ~0.2. This work provides formulae for optimising cryogenic consumption and calculating cryogenic boil-off, associated with current leads used to make J(c) measurements, made by uniformly ramping the current up to a maximum current (I(max)) and then reducing the current very quickly to zero. They include consideration of the effects of duty cycle, static helium boil-off from the magnet and Dewar (b'), and the maximum safe temperature for the critical-current leads (T(max)). Our optimized critical-current leads have a boil-off that is about 30% less than leads optimized for magnet operation at the same maximum current. Numerical calculations show that the optimum cross-sectional area (A) for each current lead can be parameterized by LI(max)/A = [1.46D(-0.18)L(0.4)(T(max) - 300)(0.25D(-0.09)) + 750(b'/I(max))D(10(-3)I(max)-2.87b') × 10? A m?¹ where L is the current lead's length and the current lead is operated in liquid helium. An optimum A of 132 mm(2) is obtained when I(max) = 1000 A, T(max) = 400 K, D = 0.2, b' = 0.3 l?h(-1) and L = 1.0 m. The optimized helium consumption was found to be 0.7 l?h(-1). When the static boil-off is small, optimized leads have a boil-off that can be roughly parameterized by: b/I(max)? ? (1.35 × 10(-3))D(0.41) l?h(?1)?A(-1). A split-current-lead design is employed to minimize the rotation of the probes during the high current measurements in our high-field horizontal magnet. The variable-temperature system is based on the use of an inverted insulating cup that operates above 4.2 K in liquid helium and above 77.4 K in liquid nitrogen, with a stability of ±80 mK to ±150 mK. Uniaxial strains of -1.4% to 1.0% can be applied to the sample, with a total uncertainty of better than ±0.02%, using a modified bending beam apparatus which includes a copper beryllium springboard-shaped sample holder. PMID:24985856

  3. Moon orientation in adult and young sandhoppers under artificial light.

    PubMed

    Ugolini, Alberto; Boddi, Vieri; Mercatelli, Luca; Castellini, Carlo

    2005-10-22

    Our experiments, carried out at night and during the day on adults and laboratory-born young of the sandhopper Talitrus saltator, deal with the identification and use of the moon as an orientating factor. Sandhoppers were released in an apparatus (a Plexiglas dome) that produced a scenario similar to the natural one (with artificial sky, moon or sun illuminated at different intensities). When tested at night, the adult and young sandhoppers used the artificial moon like the natural one, independently of the intensity of illumination of the artificial sky and moon. In other words, sandhoppers tested at night always identified the artificial moon as the moon and never as the sun. In daytime releases, the seaward orientation failed at low intensities of artificial sky and sun illumination (3.07 and 1.55 microW cm2, respectively), whereas the sun compass was used effectively at higher levels of artificial sun and sky illumination. The innate ability of moon compass orientation in inexpert young sandhoppers was demonstrated even under artificial light. PMID:16188607

  4. Magnetic Protostars

    NASA Astrophysics Data System (ADS)

    Glagolevskij, Yu. V.

    2015-09-01

    A possible variant of the evolution of magnetic protostars "before the Hayashi phase" is discussed. Arguments are given in support of the following major properties of magnetic stars: (1) global magnetic dipole fields with predominant orientation of the magnetic lines of force in the plane of the equator of revolution; (2) slow rotation; (3) complex, two and three dipole structures of the magnetic field in a large part of the stars; (4) partition of stars into magnetic and normal in a proportion of 1:10 occurs during the period when the protostellar clouds undergo gravitational collapse "before the Hayashi phase."

  5. Nanoscale Mapping of the Magnetic Properties of (111)-Oriented La(0.67)Sr(0.33)MnO3.

    PubMed

    O'Shea, Kerry J; MacLaren, Donald A; McGrouther, Damien; Schwarzbach, Danny; Jungbauer, Markus; Hühn, Sebastian; Moshnyaga, Vasily; Stamps, Robert L

    2015-09-01

    Spatially resolved analysis of magnetic properties on the nanoscale remains challenging, yet strain and defects on this length-scale can profoundly affect a material's bulk performance. We present a detailed investigation of the magnetic properties of La0.67Sr0.33MnO3 thin films in both free-standing and nanowire form and assess the role of strain and local defects in modifying the films' magnetic properties. Lorentz transmission electron microscopy is used to measure the magnetocrystalline anisotropy and to map the Curie temperature and saturation magnetization with nanometric spatial resolution. Atomic-scale defects are identified as pinning sites for magnetic domain wall propagation. Measurement of domain wall widths and crystalline strain are used to identify a strong magnetoelastic contribution to the magnetic anisotropy. Together, these results provide unique insight into the relationship between the nanostructure and magnetic functionality of a ferromagnetic complex oxide film. PMID:26252745

  6. Mindfulness, Self-Compassion, Posttraumatic Stress Disorder Symptoms, and Functional Disability in U.S. Iraq and Afghanistan War Veterans.

    PubMed

    Dahm, Katherine A; Meyer, Eric C; Neff, Kristin D; Kimbrel, Nathan A; Gulliver, Suzy Bird; Morissette, Sandra B

    2015-10-01

    Mindfulness and self-compassion are overlapping, but distinct constructs that characterize how people relate to emotional distress. Both are associated with posttraumatic stress disorder (PTSD) and may be related to functional disability. Although self-compassion includes mindful awareness of emotional distress, it is a broader construct that also includes being kind and supportive to oneself and viewing suffering as part of the shared human experience-a potentially powerful way of dealing with distressing situations. We examined the association of mindfulness and self-compassion with PTSD symptom severity and functional disability in 115 trauma-exposed U.S. Iraq/Afghanistan war veterans. Mindfulness and self-compassion were each uniquely, negatively associated with PTSD symptom severity. After accounting for mindfulness, self-compassion accounted for unique variance in PTSD symptom severity (f(2) = .25; medium ES). After accounting for PTSD symptom severity, mindfulness and self-compassion were each uniquely negatively associated with functional disability. The combined association of mindfulness and self-compassion with disability over and above PTSD was large (f(2) = .41). After accounting for mindfulness, self-compassion accounted for unique variance in disability (f(2) = .13; small ES). These findings suggest that interventions aimed at increasing mindfulness and self-compassion could potentially decrease functional disability in returning veterans with PTSD symptoms. PMID:26426991

  7. Transport and Anisotropic Diffusion Models for Movement in Oriented Habitats

    E-print Network

    Hillen, Thomas

    Transport and Anisotropic Diffusion Models for Movement in Oriented Habitats Thomas Hillen on the specific case of animal movement in oriented habitats. The orientations can be given by magnetic cues features, and the diffusion is given by the variance-covariance matrix of the underlying oriented habitat

  8. Apparatus for investigating resonance with application to magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Murphy, Sytil; Jones, Dyan L.; Gross, Josh; Zollman, Dean

    2015-11-01

    Resonance is typically studied in the context of either a pendulum or a mass on a spring. We have developed an apparatus that enables beginning students to investigate resonant behavior of changing magnetic fields, in addition to the properties of the magnetic field due to a wire and the superposition of magnetic fields. In this resonant system, a compass oscillates at a frequency determined by the compass's physical properties and an external magnetic field. While the analysis is mathematically similar to that of the pendulum, this apparatus has an advantage that the magnetic field is easily controlled, while it is difficult to control the strength of gravity. This apparatus has been incorporated into a teaching module on magnetic resonance imaging.

  9. The Physics of Attraction and Repulsion: Magnetism and Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Nakotte, Heinz

    2001-11-01

    The development of new materials with improved magnetic properties completely changed the modern world in the past decades. Recent progress is predominantly due to a better understanding of magnetism that has gone far beyond compass needles rotating in a magnetic field and bar magnets attracting or repelling each other. New magnetic materials are used to build smaller and smaller read/write heads and hard disks with increased storage capacity, developments that are responsible the revolution in the computer industry. Another example is the field of magnetic levitation that became feasible for commercial applications with the discovery of new superconducting materials, and a prototype train is under development in Japan. In medicine, the development of magnetic resonance imaging (MRI) provides an alternative to other (destructive) radiation techniques.

  10. Transverse spin azimuthal asymmetries at COMPASS: SIDIS Multi-D analysis & Drell-Yan

    E-print Network

    Bakur Parsamyan

    2015-12-22

    COMPASS is a high-energy physics experiment operating on the M2 beam line at the SPS at CERN. Using high energy muon and hadron beams the experiment covers broad range of physics aspects in the field of the hadron structure and spectroscopy. One of the important objectives of the COMPASS experiment is the exploration of transverse spin structure of the nucleon via study of spin (in)dependent azimuthal asymmetries with semi-inclusive deep inelastic scattering (SIDIS) processes and starting from 2014 also with Drell-Yan (DY) reactions. Experimental results obtained by COMPASS for azimuthal effects in SIDIS play an important role in the general understanding of the three-dimensional nature of the nucleon. Giving access to the entire "twist-2" set of transverse momentum dependent (TMD) parton distribution functions (PDFs) and fragmentation functions (FFs) COMPASS data trigger constant theoretical interest and are being widely used in phenomenological analyses and global data fits. In particular, unique x-$Q^{2}$-z-pT multidimensional results for transverse spin asymmetries recently obtained by COMPASS will serve as a direct and unprecedented input for TMD $Q^{2}$-evolution related studies, one of the hottest topics in the field of spin-physics. In addition, measurement of the Sivers and all other azimuthal effects in polarized Drell-Yan at COMPASS will reveal another side of the spin-puzzle providing a link between SIDIS and Drell-Yan branches. This will be a unique possibility to test universality and key-features of TMD PDFs using essentially the same experimental setup and exploring the same kinematical domain. In this review main focus will be given to the very recent results obtained by the collaboration for multi-dimensional transverse spin asymmetries and to the physics aspects of COMPASS polarized Drell-Yan program.

  11. Immigration Orientation

    E-print Network

    Meyers, Steven D.

    Immigration Orientation: Maintaining Your F-1 Status International Services University of South Florida #12;F-1 Immigration Documents · Passport Your passport must be valid at least 6 months;F-1 Immigration Documents · Visa Stamp This is a travel document. It allows travel into the US

  12. Industrial Orientation.

    ERIC Educational Resources Information Center

    Rasor, Leslie; Brooks, Valerie

    These eight modules for an industrial orientation class were developed by a project to design an interdisciplinary program of basic skills training for disadvantaged students in a Construction Technology Program (see Note). The Drafting module overviews drafting career opportunities, job markets, salaries, educational requirements, and basic…

  13. COMPASS Final Report: Low Cost Robotic Lunar Lander

    NASA Technical Reports Server (NTRS)

    McGuire, Melissa L.; Oleson, Steven R.

    2010-01-01

    The COllaborative Modeling for the Parametric Assessment of Space Systems (COMPASS) team designed a robotic lunar Lander to deliver an unspecified payload (greater than zero) to the lunar surface for the lowest cost in this 2006 design study. The purpose of the low cost lunar lander design was to investigate how much payload can an inexpensive chemical or Electric Propulsion (EP) system deliver to the Moon s surface. The spacecraft designed as the baseline out of this study was a solar powered robotic lander, launched on a Minotaur V launch vehicle on a direct injection trajectory to the lunar surface. A Star 27 solid rocket motor does lunar capture and performs 88 percent of the descent burn. The Robotic Lunar Lander soft-lands using a hydrazine propulsion system to perform the last 10% of the landing maneuver, leaving the descent at a near zero, but not exactly zero, terminal velocity. This low-cost robotic lander delivers 10 kg of science payload instruments to the lunar surface.

  14. Advanced stellar compass deep space navigation, ground testing results

    NASA Astrophysics Data System (ADS)

    Betto, M.; Jørgensen, J. L.; Jørgensen, P. S.; Denver, T.

    2006-10-01

    Deep space exploration is in the agenda of the major space agencies worldwide and at least the European Space Agency (SMART & Aurora Programs) and the American NASA (New Millennium Program) have set up programs to allow the development and the demonstration of technologies that can reduce the risks and the costs of the deep space missions. Navigation is the Achilles’ heel of deep space. Being performed on ground, it imposes considerable constraints on the system and the operations, it is very expensive to execute, especially when the mission lasts several years and, above all, it is not failure tolerant. Nevertheless, up to now, ground navigation has been the only possible solution. The technological breakthrough of advanced star trackers, like the micro-advanced stellar compass (?ASC) might change this situation. Indeed, exploiting the capabilities of this instrument, the authors have devised a method to determine the orbit of a spacecraft autonomously, on-board and without any a priori knowledge of any kind. The solution is robust, elegant and fast. This paper presents the preliminary performances obtained during the ground tests. The results are very positive and encouraging.

  15. Teaching, Practice, Feedback: 15 years of COMPASS science communication training

    NASA Astrophysics Data System (ADS)

    Neeley, L.; Smith, B.; McLeod, K.; English, C. A.; Baron, N.

    2014-12-01

    COMPASS is focused on helping scientists build the skills and relationships they need to effectively participate in public discourse. Founded in 2001 with an emphasis on ocean science, and since expanding to a broader set of environmental sciences, we have advised, coached, and/or trained thousands of researchers of all career stages. Over the years, our primary work has notably shifted from needing to persuade scientists why communication matters to supporting them as they pursue the question of what their communication goals are and how best to achieve them. Since our earliest forays into media promotion, we have evolved with the state of the science communication field. In recent years, we have adapted our approach to one that facilitates dialogue and encourages engagement, helps scientists identify the most relevant people and times to engage, tests our own assumptions, and incorporates relevant social science as possible. In this case study, we will discuss more than a decade of experience in helping scientists find or initiate and engage in meaningful conversations with journalists and policymakers.

  16. Magnetism: Principles and Applications

    NASA Astrophysics Data System (ADS)

    Craik, Derek J.

    2003-09-01

    If you are studying physics, chemistry, materials science, electrical engineering, information technology or medicine, then you'll know that understanding magnetism is fundamental to success in your studies and here is the key to unlocking the mysteries of magnetism....... You can: obtain a simple overview of magnetism, including the roles of B and H, resonances and special techniques take full advantage of modern magnets with a wealth of expressions for fields and forces develop realistic general design programmes using isoparametric finite elements study the subtleties of the general theory of magnetic moments and their dynamics follow the development of outstanding materials appreciate how magnetism encompasses topics as diverse as rock magnetism, chemical reaction rates, biological compasses, medical therapies, superconductivity and levitation understand the basis and remarkable achievements of magnetic resonance imaging In his new book, Magnetism, Derek Craik throws light on the principles and applications of this fascinating subject. From formulae for calculating fields to quantum theory, the secrets of magnetism are exposed, ensuring that whether you are a chemist or engineer, physicist, medic or materials scientist Magnetism is the book for our course.

  17. ComPaSS: A communication package for scalable software design

    SciTech Connect

    Xu, H.; Kalns, E.T.; McKinley, P.K.; Ni, L.M. . Dept. of Computer Science)

    1994-09-01

    In massively parallel computers (MPCs), efficient communication among processors is critical to performance. This paper describes the initial implementation of the ComPaSS communication library to support scalable software development in MPCs. ComPaSS provides high-level global communication operations for both data manipulation and process control, many of which are based upon a small set of low-level communication primitives. The low-level operations of the ComPaSS library are provably optimal for a class of architectures representative of many commercial scalable systems, in particular those using wormhole routing and n-dimensional mesh network topologies. This paper concentrates on the multicast and multireceive components of the ComPaSS library, which are fundamental to implementing efficient high-level data parallel operations. The design of the multicast and multireceive primitives is described and an example of a data parallel application utilizing ComPaSS multicast is given. The scalability of these primitive is discussed, and improvements in performance resulting from use of the library on a 64-node nCUBE-2 are presented.

  18. The Role of Self-Compassion in Buffering Symptoms of Depression in the General Population

    PubMed Central

    Körner, Annett; Coroiu, Adina; Copeland, Laura; Gomez-Garibello, Carlos; Albani, Cornelia; Zenger, Markus; Brähler, Elmar

    2015-01-01

    Self-compassion, typically operationalized as the total score of the Self-Compassion Scale (SCS; Neff, 2003b), has been shown to be related to increased psychological well-being and lower depression in students of the social sciences, users of psychology websites and psychotherapy patients. The current study builds on the existing literature by examining the link between self-compassion and depressive symptomatology in a sample representative of the German general population (n = 2,404). The SCS subscales of self-judgment, isolation, and over-identification, and the “self-coldness”, composite score, which encompass these three negative subscales, consistently differed between subsamples of individuals without any depressive symptoms, with any depressive syndromes, and with major depressive disorder. The contribution of the positive SCS subscales of self-kindness, common humanity, and mindfulness to the variance in depressive symptomatology was almost negligible. However, when combined to a “self-compassion composite”, the positive SCS subscales significantly moderated the relationship between “self-coldness” and depressive symptoms in the general population. This speaks for self-compassion having the potential to buffer self-coldness related to depression—providing an argument for interventions that foster self-caring, kind, and forgiving attitudes towards oneself. PMID:26430893

  19. Mechanically Oriented, Low-Curie-Temperature Materials

    NASA Technical Reports Server (NTRS)

    Boltich, Edward B.

    1991-01-01

    Proposed fabrication process produces permanent magnets of greater flux density, intended for use at temperatures far below room temperature. Such magnets parts of electrical motors and other electromechanical actuators operating in cryogenic systems. Performances of actuators increase with flux densities available from their magnets. Based on use of mechanical metallurgical techniques to make oriented magnets of Dy3Al2, because these techniques produce alignments above Curie temperature.

  20. RF-compass: Robot object manipulation using RFIDs

    E-print Network

    Wang, Jue

    Modern robots have to interact with their environment, search for objects, and move them around. Yet, for a robot to pick up an object, it needs to identify the object's orientation and locate it to within centimeter-scale ...

  1. Compassion Fade: Affect and Charity Are Greatest for a Single Child in Need

    PubMed Central

    Västfjäll, Daniel; Slovic, Paul; Mayorga, Marcus; Peters, Ellen

    2014-01-01

    Charitable giving in 2013 exceeded $300 billion, but why do we respond to some life-saving causes while ignoring others? In our first two studies, we demonstrated that valuation of lives is associated with affective feelings (self-reported and psychophysiological) and that a decline in compassion may begin with the second endangered life. In Study 3, this fading of compassion was reversed by describing multiple lives in a more unitary fashion. Study 4 extended our findings to loss-frame scenarios. Our capacity to feel sympathy for people in need appears limited, and this form of compassion fatigue can lead to apathy and inaction, consistent with what is seen repeatedly in response to many large-scale human and environmental catastrophes. PMID:24940738

  2. Determination of Delta G/G from Open Charm events at COMPASS

    E-print Network

    S. Koblitz

    2007-07-06

    One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, Delta G/G. It is determined from spin asymmetries in the scattering of 160 GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. A very clean selection of PGF events can be obtained with charmed mesons in the final state. Their detection is based on the reconstruction of D* and D0 mesons in the COMPASS spectrometer. The analysis method for the first measurement of Delta G/G from the open charm channel is described and the result from COMPASS for the 2002-2004 data taking period is presented.

  3. A community of educators: professional development for graduate students within the Berkeley Compass Project

    NASA Astrophysics Data System (ADS)

    Schwab, Josiah; Roth, Nathaniel; Berkeley Compass Project

    2015-01-01

    The Berkeley Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences at UC Berkeley. Our goals are to improve undergraduate physics education, provide opportunities for professional development, and increase retention of students from populations typically underrepresented in the physical sciences. Graduate students, together with upper-level undergraduates, design and run all Compass programs. We strive to create a community of educators that incorporates best practices from the science education literature. Along the way, we develop experience in curriculum development, fundraising, grant writing, interfacing with university administration, and other aspects of running an effective organization. Our experience in Compass leaves us better poised to be successful researchers, teachers, and mentors.

  4. Embodying Compassion: A Virtual Reality Paradigm for Overcoming Excessive Self-Criticism

    PubMed Central

    Falconer, Caroline J.; Slater, Mel; Rovira, Aitor; King, John A.; Gilbert, Paul; Antley, Angus; Brewin, Chris R.

    2014-01-01

    Virtual reality has been successfully used to study and treat psychological disorders such as phobias and posttraumatic stress disorder but has rarely been applied to clinically-relevant emotions other than fear and anxiety. Self-criticism is a ubiquitous feature of psychopathology and can be treated by increasing levels of self-compassion. We exploited the known effects of identification with a virtual body to arrange for healthy female volunteers high in self-criticism to experience self-compassion from an embodied first-person perspective within immersive virtual reality. Whereas observation and practice of compassionate responses reduced self-criticism, the additional experience of embodiment also increased self-compassion and feelings of being safe. The results suggest potential new uses for immersive virtual reality in a range of clinical conditions. PMID:25389766

  5. New Method for Magnetometers Based Orientation Estimation

    E-print Network

    Calgary, University of

    New Method for Magnetometers Based Orientation Estimation Valérie Renaudin, Muhammad Haris Afzal of Calgary, 2500 University Drive N.W. Calgary, Alberta, Canada, T2N 1N4 Abstract- Low cost magnetometers can be used for estimating the orientation with respect to the magnetic North. Although magnetometers work

  6. COMPASS: A Geospatial Knowledge Infrastructure Managed with Ontologies

    NASA Astrophysics Data System (ADS)

    Stock, K.

    2009-04-01

    COMPASS: A Geospatial Knowledge Infrastructure Managed with Ontologies Dr Kristin Stock Allworlds Geothinking, United Kingdom and EDINA, University of Edinburgh, United Kingdom and Centre for Geospatial Science University of Nottingham Nottingham United Kingdom The research and decision-making process in any discipline is supported by a vast quantity and diversity of scientific resources, including journal articles; scientific models; scientific theories; data sets and web services that implement scientific models or provide other functionality. Improved discovery and access to these scientific resources has the potential to make the process of using and developing scientific knowledge more effective and efficient. Current scientific research or decision making that relies on scientific resources requires an extensive search for relevant resources. Published journal papers may be discovered using web searches on the basis of words that appear in the title or metadata, but this approach is limited by the need to select the appropriate words, and does not identify articles that may be of interest because they use a similar approach, methodology or technique but are in a different discipline, or that are likely to be helpful despite not sharing the same keywords. The COMPASS project is developing a knowledge infrastructure that is intended to enhance the user experience in discovering scientific resources. This is being achieved with an approach that uses ontologies to manage the knowledge infrastructure in two ways: 1. A set of ontologies describe the resources in the knowledge infrastructure (for example, publications and web services) in terms of the domain concepts to which they relate, the scientific theories and models that they depend on, and the characteristics of the resources themselves. These ontologies are provided to users either directly or with assisted search tools to aid them in the discovery process. OWL-S ontologies are being used to describe web service resources. 2. The knowledge infrastructure is supported by an ontology-registry that provides the traditional function of a registry to support a spatial data infrastructure, but that is implemented as a set of OWL ontologies. The architecture does not duplicate the content of the registry and ontologies, the ontologies are the registry. An OWL application profile for the CSW OGC registry standard is being developed to provide an OGC compliant solution for this unique architecture. The knowledge infrastructure is being developed with a set of use cases from coastal science, based around marine instrumentation. Distributed resources will be incorporated using a range of different standards with varying degrees of semantic richness, and dynamic user annotation is being included to allow both a formal ontology and an informal tagging view to be taken over the resources in the infrastructure. Discovery will combine options based on ontology concepts, user annotation, geography and temporality to provide users with an enhanced set of tools to assist their scientific endeavours.

  7. Tri-axis magnetometer with in-plane giant magnetoresistance sensors for compass application

    NASA Astrophysics Data System (ADS)

    Chiang, Chia-Yi; Jeng, Jen-Tzong; Lai, Bor-Lin; Luong, Van Su; Lu, Chih-Cheng

    2015-05-01

    A tri-axis magnetometer comprising three giant-magnetoresistance sensors and a cylindrical fluxguide are implemented for compass application. The sensors are mounted on a single printed circuit board (PCB) board with their sensing axes in a plane. A calibration process involving matrix manipulation was employed to make the device function as a tri-axis magnetometer with orthogonal sensing directions. The capability of the device for compass application was demonstrated by measuring its azimuth response to the geomagnetic field about different rotation axes. The proposed calibration technique can be used for the magnetometer system with either orthogonal or non-orthogonal sensor arrangement.

  8. Threshold resummation for polarized high-pT hadron production at COMPASS

    NASA Astrophysics Data System (ADS)

    Uebler, Claudia; Schäfer, Andreas; Vogelsang, Werner

    2015-11-01

    We study the cross section for the photoproduction process ? N ?h X where the incident photon and nucleon are longitudinally polarized and a hadron h is observed at high transverse momentum. Specifically, we address the "direct" part of the cross section, for which the photon interacts in a pointlike way. For this contribution we perform an all-order resummation of logarithmic threshold corrections generated by soft or collinear gluon emission to next-to-leading logarithmic accuracy. We present phenomenological results relevant for the COMPASS experiment and compare to recent COMPASS data.

  9. The alignment of a voltage-sensing peptide in dodecylphosphocholine micelles and in oriented lipid bilayers by nuclear magnetic resonance and molecular modeling.

    PubMed Central

    Mattila, K; Kinder, R; Bechinger, B

    1999-01-01

    The S4 segments of voltage-gated sodium channels are important parts of the voltage-sensing elements of these proteins. Furthermore, the addition of the isolated S4 polypeptide to planar lipid bilayers results in stepwise increases of ion conductivity. In order to gain insight into the mechanisms of pore formation by amphipathic peptides, the structure and orientation of the S4 segment of the first internal repeat of the rat brain II sodium channel was investigated in the presence of DPC micelles by multidimensional solution NMR spectroscopy and solid-state NMR spectroscopy on oriented phospholipid bilayers. Both the anisotropic chemical shift observed by proton-decoupled (15)N solid-state NMR spectroscopy and the attenuating effects of DOXYL-stearates on TOCSY crosspeak intensities of micelle-associated S4 indicate that the central alpha-helical portion of this peptide is oriented approximately parallel to the membrane surface. Simulated annealing and molecular dynamics calculations of the peptide in a biphasic tetrachloromethane-water environment indicate that the peptide alpha-helix extends over approximately 12 residues. A less regular structure further toward the C-terminus allows for the hydrophobic residues of this part of the peptide to be positioned in the tetrachloromethane environment. The implications for possible pore-forming mechanisms are discussed. PMID:10512830

  10. COMPASS Final Report: Enceladus Solar Electric Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2011-01-01

    The results of the NASA Glenn Research Center (GRC) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) internal Solar Electric Propulsion (SEP) stage design are documented in this report (Figure 1.1). The SEP Stage was designed to deliver a science probe to Saturn (the probe design was performed separately by the NASA Goddard Space Flight Center s (GSFC) Integrated Mission Design Center (IMDC)). The SEP Stage delivers the 2444 kg probe on a Saturn trajectory with a hyperbolic arrival velocity of 5.4 km/s. The design carried 30 percent mass, 10 percent power, and 6 percent propellant margins. The SEP Stage relies on the probe for substantial guidance, navigation and control (GN&C), command and data handling (C&DH), and Communications functions. The stage is configured to carry the probe and to minimize the packaging interference between the probe and the stage. The propulsion system consisted of a 1+1 (one active, one spare) configuration of gimbaled 7 kW NASA Evolutionary Xenon Thruster (NEXT) ion propulsion thrusters with a throughput of 309 kg Xe propellant. Two 9350 W GaAs triple junction (at 1 Astronomical Unit (AU), includes 10 percent margin) ultra-flex solar arrays provided power to the stage, with Li-ion batteries for launch and contingency operations power. The base structure was an Al-Li hexagonal skin-stringer frame built to withstand launch loads. A passive thermal control system consisted of heat pipes to north and south radiator panels, multilayer insulation (MLI) and heaters for the Xe tank. All systems except tanks and solar arrays were designed to be single fault tolerant.

  11. Advanced stellar compass onboard autonomous orbit determination, preliminary performance.

    PubMed

    Betto, Maurizio; Jørgensen, John L; Jørgensen, Peter S; Denver, Troelz

    2004-05-01

    Deep space exploration is in the agenda of the major space agencies worldwide; certainly the European Space Agency (SMART Program) and the American NASA (New Millennium Program) have set up programs to allow the development and the demonstration of technologies that can reduce the risks and the cost of deep space missions. From past experience, it appears that navigation is the Achilles heel of deep space missions. Performed on ground, this imposes considerable constraints on the entire system and limits operations. This makes it is very expensive to execute, especially when the mission lasts several years and, furthermore, it is not failure tolerant. Nevertheless, to date, ground navigation has been the only viable solution. The technology breakthrough of advanced star trackers, like the advanced stellar compass (ASC), might change this situation. Indeed, exploiting the capabilities of this instrument, the authors have devised a method to determine the orbit of a spacecraft autonomously, onboard, and without a priori knowledge of any kind. The solution is robust and fast. This paper presents the preliminary performance obtained during the ground testing in August 2002 at the Mauna Kea Observatories. The main goals were: (1) to assess the robustness of the method in solving autonomously, onboard, the position lost-in-space problem; (2) to assess the preliminary accuracy achievable with a single planet and a single observation; (3) to verify the autonomous navigation (AutoNav) module could be implemented into an ASC without degrading the attitude measurements; and (4) to identify the areas of development and consolidation. The results obtained are very encouraging. PMID:15220158

  12. Impression block with orientator

    NASA Astrophysics Data System (ADS)

    Brilin, V. I.; Ulyanova, O. S.

    2015-02-01

    Tool review, namely the impression block, applied to check the shape and size of the top of fish as well as to determine the appropriate tool for fishing operation was realized. For multiple application and obtaining of the impress depth of 3 cm and more, the standard volumetric impression blocks with fix rods are used. However, the registered impress of fish is not oriented in space and the rods during fishing are in the extended position. This leads to rods deformation and sinking due to accidental impacts of impression block over the borehole irregularity and finally results in faulty detection of the top end of fishing object in hole. The impression blocks with copy rods and fixed magnetic needle allow estimating the object configuration and fix the position of magnetic needle determining the position of the top end of object in hole. However, the magnetic needle fixation is realized in staged and the rods are in extended position during fishing operations as well as it is in standard design. The most efficient tool is the impression block with copy rods which directs the examined object in the borehole during readings of magnetic needles data from azimuth plate and averaging of readings. This significantly increases the accuracy of fishing toll direction. The rods during fishing are located in the body and extended only when they reach the top of fishing object.

  13. Orientational distribution of spin-labeled actin oriented by flow.

    PubMed Central

    Ostap, E M; Yanagida, T; Thomas, D D

    1992-01-01

    Previous studies on spin-labeled F-actin (MSL-actin), using saturation transfer electron paramagnetic resonance (ST-EPR), have demonstrated that actin has submillisecond rotational flexibility and that this flexibility is affected by the binding of myosin and its subfragments. This rotational flexibility does not change during the active interaction of myosin heads, actin, and adenosine triphosphate. However, these ST-EPR studies, performed on randomly oriented actin, would not be sensitive to orientational changes on the millisecond time scale or slower. In the present study, we have clarified these results by performing conventional EPR experiments on MSL-actin oriented by flow to detect changes in the orientational distribution. We have determined the orientational distribution of the spin labels relative to the magnetic field (flow direction) by comparing experimental EPR spectra to simulated EPR spectra corresponding to known orientational distributions. Spectra acquired during flow indicate two populations of probes: a highly ordered population and a disordered population. For the ordered population (28% of the total spin concentration), the angle between the actin filament axis and the nitroxide z axis (theta) fits a Gaussian distribution centered at 32.0 +/- 0.9 degrees, with a full width at half maximum of 20.7 +/- 3.9 degrees. The angle between the nitroxide x axis and the projection of the field in the xy plane (phi) is centered at 37.5 +/- 9.2 degrees with a full width of 24.9 +/- 10.7 degrees. This orientational distribution is not significantly changed upon the binding of phalloidin or myosin subfragment 1 (S1), indicating that these proteins do not affect the axial orientation of actin subunits. Spectra of spin-labeled S1 (MSL-S1) bound to actin oriented by flow have about the same orientational distribution as MSL-S1 bound to actin in oriented fibers. Thus, the oriented fraction of flow-oriented actin filaments has nearly the same high degree of alignment as the actin filaments in muscle fibers. PMID:1330042

  14. Beyond Compassion: Replacing a Blame Culture With Proper Emotional Support and Management Comment on "Why and How Is Compassion Necessary to Provide Good Quality Healthcare?".

    PubMed

    Gabriel, Yiannis

    2015-09-01

    The absence of compassion, argues the author, is not the cause of healthcare failures but rather a symptom of deeper systemic failures. The clinical encounter arouses strong emotions of anxiety, fear, and anger in patients which are often projected onto the clinicians. Attempts to protect clinicians through various bureaucratic devices and depersonalization of the patient, constitute as Menzies noted in her classic work, social defences, aimed at containing the anxieties of clinicians but ending up in reinforcing these anxieties. Instead of placing additional burdens on clinicians by bureaucratizing and benchmarking compassion, the author argues that proper emotional management and support is a precondition for a healthcare system that offers humane and effective treatment to patients and a humane working environment for those who work in it. PMID:26340493

  15. On the large COMPASS polarized deuteron target , N. Doshitac

    E-print Network

    Dutz, Hartmut

    implemented. The spin reversal by magnetic field rotation to decrease possible systematic error. Preliminary figures of the maximum aver- age longitudinal deuterium polarizations in three target cells

  16. Why Good Quality Care Needs Philosophy More Than Compassion Comment on "Why and How Is Compassion Necessary to Provide Good Quality Healthcare?".

    PubMed

    Leget, Carlo

    2015-01-01

    Although Marianna Fotaki's Editorial is helpful and challenging by looking at both the professional and institutional requirements for reinstalling compassion in order to aim for good quality healthcare, the causes that hinder this development remain unexamined. In this commentary, 3 causes are discussed; the boundary between the moral and the political; Neoliberalism; and the underdevelopment of reflection on the nature of care. A plea is made for more philosophical reflection on the nature of care and its implications in healthcare education. PMID:26673178

  17. Magnetic

    NASA Astrophysics Data System (ADS)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  18. Anisotropy of magnetic susceptibility versus lattice-and shape-preferred orientation in the Lac Tio hemo-ilmenite ore body

    E-print Network

    Bascou, Jérôme

    Keywords: Magnetic fabric EBSD Image analysis Iron­titanium ore Anorthosite The Lac Tio hemo-ilmenite ore body crops out in the outer portion of the 1.06 Ga Lac Allard anorthosite, a member of the Havre-Saint-Pierre anorthosite suite from the Grenville province of North America. It is made up of ilmenitite (commonly

  19. Self-compassion as a moderator of thinness-related pressures' associations with thin-ideal internalization and disordered eating.

    PubMed

    Tylka, Tracy L; Russell, Hannah L; Neal, Ashley A

    2015-04-01

    During situations that threaten personal adequacy, people high in self-compassion are kind and caring toward themselves, mindful of their distress, and recognize that being imperfect is part of the human experience. Therefore, self-compassion may offset certain disorders (e.g., eating disorders) associated with environmental threats (e.g., thinness-related pressures). In this cross-sectional study, we explored self-compassion's associations with threats involving thinness-related pressures (from friends, family, partners, and media), thin-ideal internalization, and disordered eating among an online sample of 435 U.S. community women. Findings indicated that self-compassion buffered the links from media thinness-related pressure to disordered eating and thin-ideal internalization. Furthermore, higher self-compassion was directly associated with fewer perceived thinness-related pressures, lower thin-ideal internalization, and lower disordered eating. Collectively, these findings add to the growing conceptualization of self-compassion as beneficial to eating behavior and help justify pursuing rigorous longitudinal and clinical examinations of self-compassion as a protective factor of disordered eating. PMID:25536526

  20. Flying Drosophila orient to sky polarization.

    PubMed

    Weir, Peter T; Dickinson, Michael H

    2012-01-10

    Insects maintain a constant bearing across a wide range of spatial scales. Monarch butterflies and locusts traverse continents [1, 2], and foraging bees and ants travel hundreds of meters to return to their nests [1, 3, 4], whereas many other insects fly straight for only a few centimeters before changing direction. Despite this variation in spatial scale, the brain region thought to underlie long-distance navigation is remarkably conserved [5, 6], suggesting that the use of a celestial compass is a general and perhaps ancient capability of insects. Laboratory studies of Drosophila have identified a local search mode in which short, straight segments are interspersed with rapid turns [7, 8]. However, this flight mode is inconsistent with measured gene flow between geographically separated populations [9-11], and individual Drosophila can travel 10 km across desert terrain in a single night [9, 12, 13]-a feat that would be impossible without prolonged periods of straight flight. To directly examine orientation behavior under outdoor conditions, we built a portable flight arena in which a fly viewed the natural sky through a liquid crystal device that could experimentally rotate the polarization angle. Our findings indicate that Drosophila actively orient using the sky's natural polarization pattern. PMID:22177905