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Sample records for related interaction phenomena

  1. Spin-Orbit Interaction and Related Transport Phenomena in 2d Electron and Hole Systems

    NASA Astrophysics Data System (ADS)

    Khaetskii, A.

    Spin-orbit interaction is responsible for many physical phenomena which are under intensive study currently. Here we discuss several of them. The first phenomenon is the edge spin accumulation, which appears due to spin-orbit interaction in 2D mesoscopic structures in the presence of a charge current. We consider the case of a strong spin-orbit-related splitting of the electron spectrum, i.e. a spin precession length is small compared to the mean free path l. The structure can be either in a ballistic regime (when the mean free path is the largest scale in the problem) or quasi-ballistic regime (when l is much smaller than the sample size). We show how physics of edge spin accumulation in different situations should be understood from the point of view of unitarity of boundary scattering. Using transparent method of scattering states, we are able to explain some previous puzzling theoretical results. We clarify the important role of the form of the spin-orbit Hamiltonian, the role of the boundary conditions, etc., and reveal the wrong results obtained in the field by other researchers. The relation between the edge spin density and the bulk spin current in different regimes is discussed. The detailed comparison with the existing theoretical works is presented. Besides, we consider several new transport phenomena which appear in the presence of spin-orbit interaction, for example, magnetotransport phenomena in an external classical magnetic field. In particular, new mechanism of negative magneto-resistance appears which is due to destruction of spin fluxes by the magnetic field, and which can be really pronounced in 2D systems with strong scatterers.

  2. Studies of the Relativistic Electron Source and Related Phenomena in Petawatt Laser Matter Interactions

    SciTech Connect

    Key, M.H.; Campbell, E.M.; Cowen, T.E.; Hatchett, S.P.; Jenary, E.A.; Koch, J.A.; Langson, A.B.; Lasinski, B.F.; Lee, W.; Mackinnon, A.; Offenberger, A.A.; Perry, M.D.; Phillips, T.J.; Roth, M.; Sangster, T.C.; Singh, M.S.; Snavely, R.; Stoyer, M.A.; Wilks, S.C.; Yaskire, K.Y.

    1999-11-11

    The interaction of laser radiation with solid targets at 1 petawatt power and intensity up to 3 x 10{sup 20} Wcm{sup -2} has been studied with emphasis on relativistic electrons and high-energy ions. Secondary effects including Bremsstrahlung radiation, nuclear interactions and heating have been characterized. A collimated beam of protons with up to 55 MeV energy is emitted normal to the rear surface of thin targets and its characteristics and origin are discussed. The significance of the data for radiography, fast ignition and proton beam applications is summarized.

  3. Studies of the relativistic electron source and related phenomena in Petawatt Laser matter interactions

    SciTech Connect

    Key, M H; Campbell, E M; Cowan, T E; Hatchett, S P; Henry, E A; Koch, J A; Landgon, A B; Lasinski, B F; Lee, R W; MacKinnon, A; Offenberger, A; Pennington, D M; Perry, M D; Sangster, T C; Yasuike, K; Snavely, R; Roth, M; Phillips, T W; Stoyer, M A; Wilks, S C; Singh, M S

    1999-09-27

    The interaction of laser radiation with solid targets at 1 petawatt power and intensity up to 3x10{sup 20} Wcm{sup -2} has been studied with emphasis on relativistic electrons and high energy ions. Secondary effects including Bremsstrahlung radiation, nuclear interactions and heating have been characterized. A collimated beam of protons with up to 55 MeV energy is emitted normal to the rear surface of thin targets and its characteristics and origin are discussed. The significance of the data for radiography, fast ignition and proton beam applications is summarized.

  4. Results of literature search on dielectric properties and electron interaction phenomena related to spacecraft charging

    NASA Technical Reports Server (NTRS)

    Wall, J. A.; Burke, E. A.; Frederickson, A. R.

    1977-01-01

    The objective of the literature search was to determine the required material properties and electron interaction parameters needed for modeling charge buildup and breakdown in insulators. A brief overview of the results of the literature search is given. A partial list of the references covered is included in a bibliography. Although inorganic insulators were also considered in the search, coverage is limited to the organics, primarily Kapton and Teflon.

  5. Polarization phenomena in hadronic interactions

    NASA Astrophysics Data System (ADS)

    Arash, Firooz

    2002-03-01

    It is observed that the polarized scattering amplitudes in the Planar-Transverse frame exhibit a simple pattern in that all amplitudes are either pure real or pure imaginary relative to each other. It also suggests that one of the amplitudes is almost three times larger than the others. This pattern persists for a variety of exclusive reactions and becomes more pronounced at high energies and large scattering angles.

  6. Astrophysical phenomena related to supermassive black holes

    NASA Astrophysics Data System (ADS)

    Pott, Jörg-Uwe

    2006-12-01

    reactions in stars. In the most active galaxies known, the radiating accretion disc of the central SMBH engine easily outshines the stellar light of the entire galaxy (Blandford 1995). In addition to the light, plasma streams can emerge from the innermost regions at relativistic velocities, returning energy to the host galaxy (host) and creating jets and lobes with strong observational signatures, especially at radio and X-ray wavelengths (Wilson 2003). New insights in the wide field of SMBH/host interaction are often related to the development of new, more sensitive instruments and telescopes. For example the idea, that a high luminosity AGN may result from a merger event between two galaxies, could only develop with the upcoming high resolution and sensitive imaging capabilities needed to detect the highly distorted host galaxy morphologies of (post-)merger galaxies (Heckman et al. 1986). Furthermore multi-wavelength approaches, which combine the results of measurements at different wavelengths, often lead to new conclusions or confirm unsecured hypotheses. Thus developing a new instrument can be as valuable as combining different datasets. I follow both approaches and developed projects which (i) deal with new instrumentation and telescope technology, (ii) combine datasets from different wavelengths and resolutions, and (iii) incorporate recent theoretical models and predictions, which can be verified empirically. While some projects are more focused on investigating the power of new observational techniques, others incorporate acknowledged instruments to probe predictions based on previous observations and models and trace special phenomena of SMBH/host interaction. But in most cases aspects of all three items appear. The SMBH/host interaction results in phenomena at all linear size scales of the system, from the direct accretion of matter onto the central black hole up to radio jets crossing the entire galaxy. Thus interaction effects do not simply concentrate on the

  7. Viscous theory of surface noise interaction phenomena

    NASA Technical Reports Server (NTRS)

    Yates, J. E.

    1980-01-01

    A viscous linear surface noise interaction problem is formulated that includes noise production by an oscillating surface, turbulent or vortical interaction with a surface, and scattering of sound by a surface. The importance of viscosity in establishing uniqueness of solution and partitioning of energy into acoustic and vortical modes is discussed. The results of inviscid two dimensional airfoil theory are used to examine the interactive noise problem in the limit of high reduced frequency and small Helmholtz number. It is shown that in the case of vortex interaction with a surface, the noise produced with the full Kutta condition is 3 dB less than the no Kutta condition result. The results of a study of an airfoil oscillating in a medium at rest are discussed. It is concluded that viscosity can be a controlling factor in analyses and experiments of surface noise interaction phenomena and that the effect of edge bluntness as well as viscosity must be included in the problem formulation to correctly calculate the interactive noise.

  8. Phylogeny of Aging and Related Phenoptotic Phenomena.

    PubMed

    Libertini, G

    2015-12-01

    The interpretation of aging as adaptive, i.e. as a phenomenon genetically determined and modulated, and with an evolutionary advantage, implies that aging, as any physiologic mechanism, must have phylogenetic connections with similar phenomena. This review tries to find the phylogenetic connections between vertebrate aging and some related phenomena in other species, especially within those phenomena defined as phenoptotic, i.e. involving the death of one or more individuals for the benefit of other individuals. In particular, the aim of the work is to highlight and analyze similarities and connections, in the mechanisms and in the evolutionary causes, between: (i) proapoptosis in prokaryotes and apoptosis in unicellular eukaryotes; (ii) apoptosis in unicellular and multicellular eukaryotes; (iii) aging in yeast and in vertebrates; and (iv) the critical importance of the DNA subtelomeric segment in unicellular and multicellular eukaryotes. In short, there is strong evidence that vertebrate aging has clear similarities and connections with phenomena present in organisms with simpler organization. These phylogenetic connections are a necessary element for the sustainability of the thesis of aging explained as an adaptive phenomenon, and, on the contrary, are incompatible with the opposite view of aging as being due to the accumulation of random damages of various kinds. PMID:26638678

  9. Paramagnetic Meissner effect and related dynamical phenomena

    NASA Astrophysics Data System (ADS)

    Li, Mai Suan

    2003-03-01

    The hallmark of superconductivity is the diamagnetic response to external magnetic field. In striking contrast to this behavior, a paramagnetic response or paramagnetic Meissner effect was observed in ceramic high- Tc and in conventional superconductors. The present review is given on this interesting effect and related phenomena. We begin with a detailed discussion of experimental results on the paramagnetic Meissner effect in both granular and conventional superconductors. There are two main mechanisms leading to the paramagnetic response: the so-called d-wave and the flux compression. In the first scenario, the Josephson critical current between two d-wave superconductors becomes negative or equivalently one has a π junction. The paramagnetic signal occurs due to the nonzero spontaneous supercurrent circulating in a loop consisting of odd number of π junctions. In addition to the d-wave mechanism we present the flux compression mechanism for the paramagnetic Meissner effect. The compression may be due to either an inhomogeneous superconducting transition or flux trap inside the giant vortex state. The flux trapping which acts like a total nonzero spontaneous magnetic moment causes the paramagnetic signal. The anisotropic pairing scenario is believed to be valid for granular materials while the flux trap one can be applied to both conventional and high- Tc superconductors. The study of different phenomena by a three-dimensional lattice model of randomly distributed π Josephson junctions with finite self-inductance occupies the main part of our review. By simulations one can show that the chiral glass phase in which chiralities are frozen in time and in space may occur in granular superconductors possessing d-wave pairing symmetry. Experimental attempts on the search for the chiral glass phase are analysed. Experiments on dynamical phenomena such as AC susceptibility, compensation effect, anomalous microwave absorption, aging effect, AC resistivity and

  10. Astrophysical phenomena related to supermassive black holes

    NASA Astrophysics Data System (ADS)

    Pott, Jörg-Uwe

    2006-12-01

    reactions in stars. In the most active galaxies known, the radiating accretion disc of the central SMBH engine easily outshines the stellar light of the entire galaxy (Blandford 1995). In addition to the light, plasma streams can emerge from the innermost regions at relativistic velocities, returning energy to the host galaxy (host) and creating jets and lobes with strong observational signatures, especially at radio and X-ray wavelengths (Wilson 2003). New insights in the wide field of SMBH/host interaction are often related to the development of new, more sensitive instruments and telescopes. For example the idea, that a high luminosity AGN may result from a merger event between two galaxies, could only develop with the upcoming high resolution and sensitive imaging capabilities needed to detect the highly distorted host galaxy morphologies of (post-)merger galaxies (Heckman et al. 1986). Furthermore multi-wavelength approaches, which combine the results of measurements at different wavelengths, often lead to new conclusions or confirm unsecured hypotheses. Thus developing a new instrument can be as valuable as combining different datasets. I follow both approaches and developed projects which (i) deal with new instrumentation and telescope technology, (ii) combine datasets from different wavelengths and resolutions, and (iii) incorporate recent theoretical models and predictions, which can be verified empirically. While some projects are more focused on investigating the power of new observational techniques, others incorporate acknowledged instruments to probe predictions based on previous observations and models and trace special phenomena of SMBH/host interaction. But in most cases aspects of all three items appear. The SMBH/host interaction results in phenomena at all linear size scales of the system, from the direct accretion of matter onto the central black hole up to radio jets crossing the entire galaxy. Thus interaction effects do not simply concentrate on the

  11. Search for collective phenomena in hadron interactions

    SciTech Connect

    Kokoulina, E. S. Nikitin, V. A. Petukhov, Y. P.; Karpov, A. V. Kutov, A. Ya.

    2010-12-15

    New results of the search for collective phenomena have been obtained and analyzed in the present report. The experimental studies are carried out on U-70 accelerator of IHEP in Protvino. It is suggested that these phenomena can be discovered at the energy range of 50-70 GeV in the extreme multiplicity region since the high-density matter can form in this very region. The collective behavior of secondary particles is considered to manifest itself in the Bose-Einstein condensation of pions, Vavilov-Cherenkov gluon radiation, excess of soft-photon yield, and other unique phenomena. The perceptible peak in the angular distribution has been revealed. It was interpreted as the gluon radiation and so the parton matter refraction index was determined. The new software was designed for the track reconstruction based on Kalman Filter technique. This algorithm allows one to estimate more precisely the track parameters (especially momentum). The search for Bose-Einstein condensation can be continued by using the selected events with the multiplicity of more than eight charged particles. The gluon dominance model predictions have shown good agreement with the multiplicity distribution at high multiplicity and confirmed the guark-gluon medium formation under these conditions.

  12. Deep Inelastic Scattering and Related Phenomena

    NASA Astrophysics Data System (ADS)

    D'Agostini, G.; Nigro, A.

    1997-03-01

    Inelastic Scattering * Instantons and Forward Jets at HERA * Forward Jets at HERA and at the Tevatron * Distinguishing the DGLAP and BFKL Evolutions with Transverse Momentum Spectra * The Properties of Hadrons in Neutrino-Neon Interactions * Transverse Energy Flow Distributions in Deep Inelastic Scattering at HERA * WORKING GROUP 5: Polarized Structure Functions * A New Measurement of the Spin Dependent Structure Functions gp1 and gd1 * Spin Asymmetry in Muon-deuteron Deep Inelastic Scattering on a Transversely Polarized Target * Polarization of Valence and Light Sea Quarks in the Nucleon * Results from SLAC * Inclusive Spin-Dependent DIS from the Nucleon with HERMES * Semi-Inclusive Data from HERMES * Future Measurements of the g1 Spin Structure function with Polarized e - p Collisions and Determination of Δg * A Future Measurement of ΔG at CERN * The Polarized Two-Loop Splitting Functions * Polarized Parton Distributions from a Global NLO-QCD Analysis * Polarized Partons at Next-to-leading Order * Small-x Behaviour of the Structure Function g1 * On Small-x Resummations for the Evolution of Unpolarized and Polarized Non-Singlet and singlet Structure Functions * Parton Model Prediction for g2 * On the Twist-2 Contributions to Polarized Structure Functions and New Sum Rules * Some Aspects of the Polarized Structure Functions * Inclusive Production of Hadrons in l↑p↑ → h↑X and Spin Measurements * Polarized Structure Functions and QPMSR * Polarization Phenomena and Photon Dissociation in Deep-Inelastic Lepton-Nucleon Scattering * Prospects for Measuring Δg from Jets at HERA with Polarized Protons * On the Q2 Dependence of Asymmetry A1 * WORKING GROUP 6: Special Theoretical Topics * Coherence and Final States in DIS at Small x * Unitarity and Saturation in the Dipole Formulation * Radiative Corrections to the Leading log(1/x) Approximation for Structure Functions * Effective Action Approach for Small-x Physics in QCD * Unitarization of BFKL Pomeron * The Role of the

  13. Phenomena related to CP violation at CDF

    SciTech Connect

    Squillacioti, Paola

    2010-02-10

    We report recent CDF results on CP violation in B{sup -}->DK{sup -} modes, where D goes to Cabibbo suppressed (pipi, KK) or doubly cabibbo suppressed (K{sup +}pi{sup -}) modes, which are related to CKM angle gamma. We also describe direct CP violation measurements in charmless two-body decays of B{sub s}{sup 0}->Kpi and LAMBDA{sub b}{sup 0}->pK, ppi modes, which are unique to the CDF experiment. We also report on CP violation measurements in D{sup 0}->h{sup +}h{sup -} modes.

  14. Phenomena related to CP violation at CDF

    SciTech Connect

    Squillacioti, Paola; /Siena U. /INFN, Pisa

    2009-10-01

    We report recent CDF results on CP violation in B{sup -} {yields} DK{sup -} modes, where D goes to Cabibbo suppressed ({pi}{pi}, KK) or doubly cabibbo suppressed (K{sup +}{pi}{sup -}) modes, which are related to CKM angle gamma. We also describe direct CP violation measurements in charmless two-body decays of B{sub s}{sup 0} {yields} K{pi} and {Lambda}{sub b}{sup 0} {yields} pK, p{pi} modes, which are unique to the CDF experiment. We also report on CP violation measurements in D{sup 0} {yields} h{sup +}h{sup -} modes.

  15. Magnetotransport phenomena related to the chiral anomaly in Weyl semimetals

    NASA Astrophysics Data System (ADS)

    Spivak, B. Z.; Andreev, A. V.

    2016-02-01

    We present a theory of magnetotransport phenomena related to the chiral anomaly in Weyl semimetals. We show that conductivity, thermal conductivity, thermoelectric, and the sound absorption coefficients exhibit strong and anisotropic magnetic field dependencies. We also discuss properties of magnetoplasmons and magnetopolaritons, whose existences are entirely determined by the chiral anomaly. Finally, we discuss the conditions of applicability of the quasiclassical description of electron transport phenomena related to the chiral anomaly.

  16. Solid-state flow, mechanical alloying, and melt-related phenomena for [001] single-crystal tungsten ballistic rod penetrators interacting with steel targets

    NASA Astrophysics Data System (ADS)

    Pizana, Carlos

    This research program consists of a detailed microstructural investigation of in-target, single-crystal [001], clad (with Inconel 718) and unclad, W long-rod, ballistic penetrators. The rods were shot into rolled homogeneous armor (RHA) steel targets approximately 76 mm in thickness at impact velocities ranging from 1100 m/s to 1350 m/s. A comprehensive microstructural overview of the penetration process was obtained from this investigation. Solid-state flow/erosion, solid-state target/rod mixing as well as influencing factors such as strain rate, penetration performance, cladding interference and the interaction between target and projectile were emphasized. Some of the microstructural features observed, including deformation twins, cleaving, adiabatic shear bands and DRX support an overall solid-state penetration process. Furthermore they provide for a unifying perspective for the applicability of the hydrodynamic paradigm (DOP ≈ l∘rp/rt ) and earlier mechanistic erosion approaches. DRX and grain growth within adiabatic shear bands observed at specific high strain/strain-rate zones within the rods suggest that the projectile erodes by means of these microstructures in a solid-state form. This erosion process contributes to the performance of the rod by either allowing optimum flow of rod material which would increase penetration depth, or by maximizing rod material consumption which would reduce it. Since flow and/or erosion are also necessary in the target for perforation to occur, it is not surprising that the erosion process in the target was observed to mirror the one in the projectile. That is both target and projectile developed erosion zones with DRX facilitating the extreme deformation via dense overlapping shear band formation. Mechanical alloying and/or mixing of the target (steel) and rod (W, or W-Inconel 718) was also observed and investigated. Selective etching techniques as well as energy-dispersive x-ray mapping revealed unambiguous evidence of

  17. The Assessment of Object Relations Phenomena in Borderline Personality Disorder.

    ERIC Educational Resources Information Center

    Gustafson, Eric Wayne

    Recent attempts to empirically validate psychoanalytic theory and its contemporary object relational constructs have turned to measuring the concepts with a variety of recently developed assessment scales. This paper reviews the 27 research studies which utilize instruments designed to assess object relations phenomena in subjects diagnosed with…

  18. Analysis of interaction phenomena between liquid jets and materials

    SciTech Connect

    Kang, Sang-Wook; Reitter, T.; Carlson, G.

    1995-02-01

    The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to gain an understanding of the physical mechanisms involved in material removal by fluidjet machining processes. Experiments were performed to determine conditions under which the liquid jet impacting a solid material will cause material removal and also to delineate possible physical mechanisms of mass removal at optimum jet-cutting conditions. We have also carried out numerical simulations of jet-induced surface pressure rises and of the material deformation and spallation behavior due to multiple droplet impacts. Results obtained from the experiments and theoretical calculations and their physical implications are also discussed.

  19. Analysis of interaction phenomena between liquid jets and materials [preprint

    SciTech Connect

    Kang, S-W.; Reitter, T.; Carlson, G.

    1995-04-01

    The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to understand the physics of material removal by jet-machining processes. Experiments were performed to delineate conditions under which liquid jet impacts will cause mass removal and to determine optimum jet-cutting conditions. Theoretical analyses have also been carried out to study the effects of multiple jet-droplet impacts on a target surface as a material deformation mechanism. The calculated target response and spallation behavior following droplet impacts and their physical implications are also discussed.

  20. Unsteady Phenomena in Shock Wave/Boundary Layer Interaction

    NASA Technical Reports Server (NTRS)

    Dolling, D. S.

    1993-01-01

    A brief review is given of the unsteadiness of shock wave/turbulent boundary layer interaction. The focus is on interactions generated by swept and unswept compression ramps, by flares, steps and incident shock waves, by cylinders and blunt fins, and by glancing shock waves. The effects of Mach number, Reynolds number, and separated flow scale are discussed as are the physical causes of the unsteadiness. The implications that the unsteadiness has for interpreting time-average surface and flowfield data, and for comparisons of such experimental data with computation, is also briefly discussed. Finally, some suggestions for future work are given. It is clear that there are large gaps in the data base and that many aspects of such phenomena are poorly understood. Much work remains to be done.

  1. Seasonality of alcohol-related phenomena in Estonia

    NASA Astrophysics Data System (ADS)

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However

  2. Power-series expansion of the Boltzmann equation and reciprocal relations for nonlinear irreversible phenomena

    NASA Astrophysics Data System (ADS)

    Sharipov, Felix

    2011-12-01

    The Boltzmann equation subject to a general boundary condition is expanded in a power series with respect to a thermodynamic force disturbing a gaseous system. Recurrence relations between the terms of the expansion are obtained using the main properties of the collision integral and of the gas-surface interaction kernel. The reciprocal relation for nonlinear irreversible phenomena, i.e., a relation between the terms of different orders, is obtained. The relations can be used to estimate the range of applicability of linearized solutions and to predict nonlinear phenomena in gaseous systems.

  3. Scaling relations and multicritical phenomena from functional renormalization.

    PubMed

    Boettcher, Igor

    2015-06-01

    We investigate multicritical phenomena in O(N)+O(M) models by means of nonperturbative renormalization group equations. This constitutes an elementary building block for the study of competing orders in a variety of physical systems. To identify possible multicritical points in phase diagrams with two ordered phases, we compute the stability of isotropic and decoupled fixed point solutions from scaling potentials of single-field models. We verify the validity of Aharony's scaling relation within the scale-dependent derivative expansion of the effective average action. We discuss implications for the analysis of multicritical phenomena with truncated flow equations. These findings are an important step towards studies of competing orders and multicritical quantum phase transitions within the framework of functional renormalization. PMID:26172666

  4. Scaling of Quench Front and Entrainment-Related Phenomena

    SciTech Connect

    Aumiller, D. L.; Hourser, R. J.; Holowach, M. J.; Hochreiter, L. E.; Cheung, F-B.

    2002-04-01

    The scaling of thermal hydraulic systems is of great importance in the development of experiments in laboratory-scale test facilities that are used to replicate the response of full-size prototypical designs. One particular phenomenon that is of interest in experimental modeling is the quench front that develops during the reflood phase in a PWR (Pressurized Water Reactor) following a large-break LOCA (Loss of Coolant Accident). The purpose of this study is to develop a scaling methodology such that the prototypical quench front related phenomena can be preserved in a laboratory-scale test facility which may have material, geometrical, fluid, and flow differences as compared to the prototypical case. A mass and energy balance on a Lagrangian quench front control volume along with temporal scaling methods are utilized in developing the quench front scaling groups for a phenomena-specific second-tier scaling analysis. A sample calculation is presented comparing the quench front scaling groups calculated for a prototypical Westinghouse 17 x 17 PWR fuel design and that of the geometry and material configuration used in the FLECHT SEASET series of experiments.

  5. Presenteeism and absenteeism: differentiated understanding of related phenomena.

    PubMed

    Gosselin, Eric; Lemyre, Louise; Corneil, Wayne

    2013-01-01

    In the past it was assumed that work attendance equated to performance. It now appears that health-related loss of productivity can be traced equally to workers showing up at work as well as to workers choosing not to. Presenteeism in the workplace, showing up for work while sick, seems now more prevalent than absenteeism. These findings are forcing organizations to reconsider their approaches regarding regular work attendance. Given this, and echoing recommendations in the literature, this study seeks to identify the main behavioral correlates of presenteeism and absenteeism in the workplace. Comparative analysis of the data from a representative sample of executives from the Public Service of Canada enables us to draw a unique picture of presenteeism and absenteeism with regards not only to the impacts of health disorders but also to the demographic, organizational, and individual factors involved. Results provide a better understanding of the similarities and differences between these phenomena, and more specifically, of the differentiated influence of certain variables. These findings provide food for thought and may pave the way to the development of new organizational measures designed to manage absenteeism without creating presenteeism. PMID:23276197

  6. Magnetoelectric Effects and Related Phenomena in Spin-spiral Hexaferrites

    NASA Astrophysics Data System (ADS)

    Kimura, Tsuyoshi

    2012-02-01

    Among various multiferroics, extensive studies of ferroelectrics originating from magnetic orders, i.e., magnetically-induced ferroelectrics in which the inversion simmetry breaking and resultant ferroelectricity are induced by complex magnetic orders, have been triggered almost a decade ago by the discovery of multiferroic nature in a perovskite-type rare-earh manganites TbMnO3. The magnetically-induced ferroelectrics often show giant magnetoelectric effects, remarkable changes in electric polarization in response to a magnetic field, since the origin of their ferroelectricity is driven by magnetism which sensitively responds to an applied magnetic field. Though a large number of new magnetically-induced ferroelectrics have been reported in the past decade, so far there has been no practical application employing the magnetoelectric effect of the magnetically-induced ferroelectrics. This is partly because none of the existing magnetically-induced ferroelectrics have combined large and robust electric and magnetic polarizations at room temperature until quite recently. The situation is changed by the discoveries of magnetoelectricity in hexagonal ferrites (hexaferrites) with spin-spiral structures.ootnotetextT. Kimura, G. Lawes, and A. P. Ramirez, Phys. Rev. Lett. 94, 137201 (2005).^,ootnotetextY. Kitagawa et al., Nature Mater. 9, 797 (2010).^,ootnotetextK. Okumura et al., Appl. Phys. Lett. 98, 212504 (2011). In this presentation, I show our recent studies on magnetoelectric effects and related phenomena in the new series of magnetically-induced ferroelectrics which are promising candidates for multiferroics operating at room temperature and low fields. This work has been done in collaboration with Y. Hiraoka, T. Ishikura, K. Okumura, Y. Kitagawa, H. Nakamura, Y. Wakabayashi, M. Soda, T. Asaka, and Y. Tanaka.

  7. Interfacial Phenomena in Noble Metal-C{sub 60} Interactions

    SciTech Connect

    Hai-Ping Cheng

    2008-06-15

    We have accomplished major tasks concerning fundamental physical processes during particle-surface interaction, including structure and electronic structure of surfaces patterned with nanoarrays, dynamics and energy distribution of energetic particle-surface interaction, properties of nano-aggregates, as well as properties of high T{sub c} cuprates.

  8. Relevance of metric-free interactions in flocking phenomena.

    PubMed

    Ginelli, Francesco; Chaté, Hugues

    2010-10-15

    We show that the collective properties of self-propelled particles aligning with their topological (Voronoi) neighbors are qualitatively different from those of usual models where metric interaction ranges are used. This relevance of metric-free interactions, shown in a minimal setting, indicate that realistic models for the cohesive motion of cells, bird flocks, and fish schools may have to incorporate them, as suggested by recent observations. PMID:21231019

  9. Interaction phenomena in graphene seen through quantum capacitance.

    PubMed

    Yu, G L; Jalil, R; Belle, Branson; Mayorov, Alexander S; Blake, Peter; Schedin, Frederick; Morozov, Sergey V; Ponomarenko, Leonid A; Chiappini, F; Wiedmann, S; Zeitler, Uli; Katsnelson, Mikhail I; Geim, A K; Novoselov, Kostya S; Elias, Daniel C

    2013-02-26

    Capacitance measurements provide a powerful means of probing the density of states. The technique has proved particularly successful in studying 2D electron systems, revealing a number of interesting many-body effects. Here, we use large-area high-quality graphene capacitors to study behavior of the density of states in this material in zero and high magnetic fields. Clear renormalization of the linear spectrum due to electron-electron interactions is observed in zero field. Quantizing fields lead to splitting of the spin- and valley-degenerate Landau levels into quartets separated by interaction-enhanced energy gaps. These many-body states exhibit negative compressibility but the compressibility returns to positive in ultrahigh B. The reentrant behavior is attributed to a competition between field-enhanced interactions and nascent fractional states. PMID:23401538

  10. Polarization phenomena in electromagnetic interactions at intermediate energies

    SciTech Connect

    Burkert, V.

    1990-01-01

    Recent results of polarization measurements in electromagnetic interactions at intermediate energies are discussed. Prospects of polarization experiments at the new CW electron accelerators, as well as on upgraded older machines are outlined. It is concluded that polarization experiments will play a very important role in the study of the structure of the nucleon and of light nuclei. 72 refs.

  11. Hypersonic shock-interaction phenomena applicable to space shuttle configurations

    NASA Technical Reports Server (NTRS)

    Bertin, J. J.; Graumann, B. W.

    1972-01-01

    The convective heat transfer distribution for space shuttle configurations is discussed. The viscous/inviscid interactions associated with the complex three dimensional flow fields are examined. Two basic conditions are considered as follows: (1) models consisting of basic elemental combinations and (2) models of specific flight vehicles. The test facilities and test programs used to obtain data on the fuselage flow field and the wing flow field are described.

  12. EUV Dimmings as a Diagnostic of CMEs and Related Phenomena

    NASA Technical Reports Server (NTRS)

    Thompson, Barbara J.; Mays, M. Leila; Webb, David F.; West, Matthew J.

    2012-01-01

    Large-scale coronal EUV dimmings, developing on timescaJes of minutes to hours in association with a flare or filament eruption, are known to exhibit a high correlation with coronal mass ejections. While most observations indicate that the decrease in emission in a dimming is due, at least in part, to a density decrease, a complete understanding requires us to examine at least four mechanisms that have been observed to cause darkened regions in the corona: 1) mass loss, 2) cooling, 3) heating, and 4) absorption/obscuration. Recent advances in automatic detection, observations with improved cadence and resolution, multi-viewpoint imaging, and spectroscopic studies have continued to shed light on dimming formation, evolution, and recovery. However, there are still some outstanding questions, including 1) Why do some CMEs show dimming and some do not? 2) What determines the location of a dimming? 3) What determines the temporal evolution of a dimming? 4) How does the post-eruption dimming connect to the ICME? 5) What is the relationship between dimmings and other CME-associated phenomena? The talk will emphasize the different formation mechanisms of dimmings and their relationship to CMEs and CME-associated phenomena.

  13. The relative importance of transport phenomena in recycling isoelectric focusing.

    PubMed

    Burgaud, C; Clifton, M J; Sanchez, V

    1992-03-01

    The various transport phenomena involved in recycling isoelectric focusing are analyzed for their contributions to band spreading so as to find ways of improving the resolution of this liquid-phase protein purification method. A numerical model is proposed that takes into account diffusion, electroosmosis and electrophoretic migration as a function of pH. The electrohydrodynamic effects have so far been neglected in these calculations. The results of these calculations are compared with experimental measurements performed in different chamber geometries, with a variety of proteins and under different operating conditions, always chosen to avoid flow instabilities. This comparison shows that the resolution of this process is greatly impaired if the electroosmotic slip velocity at the wall is not suppressed. PMID:1592042

  14. Hydrogen-methane separation processes and related phenomena. [112 references

    SciTech Connect

    Saunders, J.T.; Wang, S.S.; Yang, R.T.

    1981-01-01

    A thorough and up-dated literature survey has been conducted on processes for separating hydrogen and methane. This was done in conjunction with our work of developing a more energy-efficient and lower-cost process based on cyclic, fixed-bed processes using coal chars as the sorbents. Although the review has covered all hydrocarbon separation processes, the focuses were on physical adsorption phenomena and theories (for both single and mixed gases), surface and pore characteristics of coals and heat-treated coals, and the continuous or semi-continuous chromatographic separation methods. There has been a sharply increasing interest in the past 10 to 15 years in developing processes for hydrocarbon separation based on adsorption/desorption; this is particularly true since the energy costs became increasingly higher recently. The rigorous work on competitive adsorption and on the cyclic (including parametric pumping) processes has all been done in the past 13 years. On the other hand, it is disappointing to find the absence of knowledge on adsorption on coal chars and the lack of it on adsorption on raw coals as well.

  15. Detection of surface glow related to spacecraft glow phenomena

    NASA Technical Reports Server (NTRS)

    Langer, W. D.; Cohen, S. A.; Manos, D. M.; Motley, R. W.; Ono, M.

    1986-01-01

    A source of low energy neutral atoms and molecules has been developed by using a biased limiter to scrape off and reflect neutralized ions from a toroidal plasma. Beams of nitrogen and nitrogen-oxygen mixtures with energies of 1 to 15 eV and fluxes greater than about 10 to the 14 per centimeter per second were directed onto target surfaces consisting of Z-302 and Z-306 paints. With the nitrogen beams, a glow due to beam-surface interactions was successfully detected. In addition, a volume glow effect due to beam-gas interactions was observed which may play a role in spacecraft glow.

  16. Wave-particle interaction phenomena associated with shocks in the solar wind

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.

    1977-01-01

    Microscopic wave-particle interaction phenomena must generally affect the evolution of a traveling interplanetary discontinuity such as a collisionless shock, and solar wind plasma instabilities should also be associated with interplanetary acceleration, diffusion, and dissipation. Recent local measurements from diagnostics on widely separated spacecraft illustrate some examples of these interaction phenomena, and two bounding cases are considered in detail here. It is shown that the interplanetary shock of September 14, 1974 (detected on IMP-7, 8, Hawkeye-1, and Pioneer 11) was associated with intense local electrostatic noise and ion acceleration, while the shock of January 6, 1975 (detected on IMP-7 and Helios-1) had no detectable electrostatic turbulence.

  17. Some phenomena in space plasmas attributed to wave-particle interactions

    NASA Technical Reports Server (NTRS)

    Wu, Ching-Sheng

    1990-01-01

    Three different wave-particle interaction processes are investigated: (1) the pickup of newborn ions by the solar wind, (2) the cyclotron maser mechanism, and (3) a special wave-particle interaction process which generalizes the conventional concept of the wave-particle interaction process. It is demonstrated on the basis of these three cases that wave-particle interactions can play an indispendable role in certain physical phenomena associated with space plasmas, whose nature is such as to preclude conventional hydrodynamic characterization. Wave-particle interactions can also generate such anomalous transport processes as spatial diffusion, anomalous heating, absorptions of radiation, etc., which also have significant consequence in space plasmas.

  18. Interactive phenomena in supersonic jet mixing problems. I Phenomenology and numerical modeling techniques

    NASA Technical Reports Server (NTRS)

    Dash, S. M.; Wolf, D. E.

    1984-01-01

    The interactive phenomena that occur in supersonic jet mixing flowfields, and numerical modeling techniques developed to analyze such phenomena are discussed. A spatial marching procedure based on solving the parabolized Navier-Stokes jet mixing equations is presented. This procedure combines shock-capturing methodology for the analysis of supersonic mixing regions with pressure-split methodology for the analysis of subsonic mixing regions. The two regions are coupled at viscous sonic lines utilizing a viscous-characteristic coupling procedure. Specialized techniques for the treatment of jet boundary growth, strong discontinuties (Mach disks), and small embedded subsonic zones (behind Mach disks) are presented. Turbulent processes are represented by two-equation turbulence model formulations. In Part II of this article, numerical studies are presented for a variety of supersonic jet interactive phenomena.

  19. Study of shock waves and related phenomena motivated by astrophysics

    NASA Astrophysics Data System (ADS)

    Drake, R. P.; Keiter, P. A.; Kuranz, C. C.; Malamud, G.; Manuel, M.; Di Stefano, C. A.; Gamboa, E. J.; Krauland, C. M.; MacDonald, M. J.; Wan, W. C.; Young, R. P.; Montgomery, D. S.; Stoeckl, C.; Froula, D. H.

    2016-03-01

    This paper discusses the recent research in High-Energy-Density Physics at our Center. Our work in complex hydrodynamics is now focused on mode coupling in the Richtmyer- Meshkov process and on the supersonic Kelvin-Helmholtz instability. These processes are believed to occur in a wide range of astrophysical circumstances. In radiation hydrodynamics, we are studying radiative reverse shocks relevant to cataclysmic variable stars. Our work on magnetized flows seeks to produce magnetized jets and study their interactions. We build the targets for all these experiments, and simulate them using our CRASH code. We also conduct diagnostic research, focused primarily on imaging x-ray spectroscopy and its applications to scattering and fluorescence.

  20. Physical phenomena related to crystal growth in the space environment

    NASA Technical Reports Server (NTRS)

    Chu, T. L.

    1973-01-01

    The mechanism of crystal growth which may be affected by the space environment was studied. Conclusions as to the relative technical and scientific advantages of crystal growth in space over earth bound growth, without regard to economic advantage, were deduced. It was concluded that the crucibleless technique will most directly demonstrate the unique effects of the greatly reduced gravity in the space environment. Several experiments, including crucibleless crystal growth using solar energy and determination of diffusion coefficients of common dopants in liquid silicon were recommended.

  1. BiSb and spin-related thermoelectric phenomena

    NASA Astrophysics Data System (ADS)

    Heremans, Joseph P.; Jin, Hyungyu; Zheng, Yuanhua; Watzman, Sarah J.; Prakash, Arati

    2016-05-01

    This article reviews the factors limiting the figure of merit zT of conventional thermoelectrics especially at cryogenic temperatures and then highlights modern approaches used to increase zT below 200 K. Two type of materials are discussed. The first are BiSb alloys, relatively conventional thermoelectrics in which the zT is enhanced by using resonant levels. The second is the spin- Seebeck effect (SSE), a new solid-state energy conversion technology. Classical thermoelectric and SSE physics are combined to provide new concepts, like magnon-drag, in which we hope to increase the performance of solid-state coolers by exploiting the spin degree of freedom.

  2. Migraine aura and related phenomena: beyond scotomata and scintillations

    PubMed Central

    Vincent, MB; Hadjikhani, N

    2013-01-01

    Migraine affects the cortical physiology and may induce dysfunction both ictally and interictally. Although visual symptoms predominate during aura, other contiguous cortical areas related to less impressive symptoms are also impaired in migraine. Answers from 72.2% migraine with aura and 48.6% of migraine without aura patients on human faces and objects recognition, colour perception, proper names recalling and memory in general showed dysfunctions suggestive of prosopagnosia, dyschromatopsia, ideational apraxia, alien hand syndrome, proper name anomia or aphasia, varying in duration and severity. Symptoms frequently occurred in a successively building-up pattern fitting with the geographical distribution of the various cortical functions. When specifically inquired, migraineurs reveal less evident symptoms that are not usually considered during routine examination. Spreading depression most likely underlies the aura symptoms progression. Interictal involvement indicates that MWA and MWoA are not completely silent outside attacks, and that both subforms of migraine may share common mechanisms. PMID:17944958

  3. Lightning and related phenomena in thunderstorms and squall lines

    NASA Technical Reports Server (NTRS)

    Rust, W. D.; Taylor, W. L.; Macgorman, D. R.; Brandes, E.; Mazur, V.; Arnold, R.; Marshall, T.; Christian, H.; Goodman, S. J.

    1984-01-01

    During the past few years, cooperative research on storm electricity has yielded the following results of both basic and applied interest: (1) the intracloud to cloud-to-ground flashing ratio can be as great as 40:1; (2) as storm cells in a squall line dissipate, longer flashes become predominant; (3) there are two centers of lightning activity maxima that are vertically separated, the lower maximum at about 5 km and the upper at about 12 km. In addition, (4) storms produce lightning in their upper regions at a high rate; (5) lightning appears to be related in time to convective motions; (6) positive cloud-to-ground flashes occur in the severe stage of storms and in the later, well-developed stage of squall line storms; (7) mesoscale convective complexes have been observed to have cloud-to-ground flashing rates of more than 48/min; and (8) the electric field in anvils well away from the main storm core (more than 60 km) can be very high, more than 94 kV/m.

  4. Groundwater flow pattern and related environmental phenomena in complex geologic setting based on integrated model construction

    NASA Astrophysics Data System (ADS)

    Tóth, Ádám; Havril, Tímea; Simon, Szilvia; Galsa, Attila; Monteiro Santos, Fernando A.; Müller, Imre; Mádl-Szőnyi, Judit

    2016-08-01

    Groundwater flow, driven, controlled and determined by topography, geology and climate, is responsible for several natural surface manifestations and affected by anthropogenic processes. Therefore, flowing groundwater can be regarded as an environmental agent. Numerical simulation of groundwater flow could reveal the flow pattern and explain the observed features. In complex geologic framework, where the geologic-hydrogeologic knowledge is limited, the groundwater flow model could not be constructed based solely on borehole data, but geophysical information could aid the model building. The integrated model construction was presented via the case study of the Tihany Peninsula, Hungary, with the aims of understanding the background and occurrence of groundwater-related environmental phenomena, such as wetlands, surface water-groundwater interaction, slope instability, and revealing the potential effect of anthropogenic activity and climate change. The hydrogeologic model was prepared on the basis of the compiled archive geophysical database and the results of recently performed geophysical measurements complemented with geologic-hydrogeologic data. Derivation of different electrostratigraphic units, revealing fracturing and detecting tectonic elements was achieved by systematically combined electromagnetic geophysical methods. The deduced information can be used as model input for groundwater flow simulation concerning hydrostratigraphy, geometry and boundary conditions. The results of numerical modelling were interpreted on the basis of gravity-driven regional groundwater flow concept and validated by field mapping of groundwater-related phenomena. The 3D model clarified the hydraulic behaviour of the formations, revealed the subsurface hydraulic connection between groundwater and wetlands and displayed the groundwater discharge pattern, as well. The position of wetlands, their vegetation type, discharge features and induced landslides were explained as

  5. The Use of the Principle of Relativity in the Interpretation of Phenomena by Undergraduate Physics Students.

    ERIC Educational Resources Information Center

    Pietrocola, Mauricio; Zylbersztajn, Arden

    1999-01-01

    Reports on the extent to which the Principle of Relativity was employed by students when dealing with various phenomena. Concludes that the Principle of Relativity is not used as an heuristic tool in students' answers, and that the situations presented were not regarded as "problematic" by the students, who primarily used interpretive structures…

  6. A generalized version of the Rankine-Hugoniot relations including ionization, dissociation and related phenomena

    NASA Technical Reports Server (NTRS)

    Nieuwenhuijzen, H.; De Jager, C.; Cuntz, M.; Lobel, A.; Achmad, L.

    1993-01-01

    For purposes of computing shocks in stellars atmospheres and winds we have developed a generalized version of the Rankine-Hugoniot relations including ionization, dissociation, radiation and related phenomena such as excitation, rotation and vibration of molecules. The new equations are given in analytical form. They are valid as long as the internal energy E, the total pressure P, and the first adiabatic coefficient gamma(sub 1) can be evaluated. However, we have not treated shock structures. In the case of non-LTE we have to employ an approximation for gamma(sub 1) because in that case no definition exists. Our new version of the Rankine-Hugoniot relations can easily be used for many purposes including ab-initio modeling. In our derivation we introduce a parameter gamma(sub H), which is definded as the ratio of the enthalpy H (sometimes called heat function w) to the internal energy E (sometimes called U). Using this parameter we solve the equations for changing mu and (d(natural log P)/d(natural log rho))(sub ad) identically equal to gamma(sub 1) on both sides of the shock. Both gamma(sub H) and gamma(sub 1), and also mu are functions of pressure P and temperature T. We present: (1) the derivation, (2) examples of gamma(sub 1) (P,T) and gamma(sub H) (P,T) which include/exclude ionization and radiation, and (3) as an example the differences in post-shock parameters as function of the pre-shock temperature for the case with ionization and without radiation.

  7. Apparatus and method for interaction phenomena with world modules in data-flow-based simulation

    DOEpatents

    Xavier, Patrick G.; Gottlieb, Eric J.; McDonald, Michael J.; Oppel, III, Fred J.

    2006-08-01

    A method and apparatus accommodate interaction phenomenon in a data-flow-based simulation of a system of elements, by establishing meta-modules to simulate system elements and by establishing world modules associated with interaction phenomena. World modules are associated with proxy modules from a group of meta-modules associated with one of the interaction phenomenon. The world modules include a communication world, a sensor world, a mobility world, and a contact world. World modules can be further associated with other world modules if necessary. Interaction phenomenon are simulated in corresponding world modules by accessing member functions in the associated group of proxy modules. Proxy modules can be dynamically allocated at a desired point in the simulation to accommodate the addition of elements in the system of elements such as a system of robots, a system of communication terminals, or a system of vehicles, being simulated.

  8. Mathematical, Constitutive and Numerical Modelling of Catastrophic Landslides and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Pastor, M.; Fernández Merodo, J. A.; Herreros, M. I.; Mira, P.; González, E.; Haddad, B.; Quecedo, M.; Tonni, L.; Drempetic, V.

    2008-02-01

    Mathematical and numerical models are a fundamental tool for predicting the behaviour of geostructures and their interaction with the environment. The term “mathematical model” refers to a mathematical description of the more relevant physical phenomena which take place in the problem being analyzed. It is indeed a wide area including models ranging from the very simple ones for which analytical solutions can be obtained to those more complicated requiring the use of numerical approximations such as the finite element method. During the last decades, mathematical, constitutive and numerical models have been very much improved and today their use is widespread both in industry and in research. One special case is that of fast catastrophic landslides, for which simplified methods are not able to provide accurate solutions in many occasions. Moreover, many finite element codes cannot be applied for propagation of the mobilized mass. The purpose of this work is to present an overview of the different alternative mathematical and numerical models which can be applied to both the initiation and propagation mechanisms of fast catastrophic landslides and other related problems such as waves caused by landslides.

  9. Effect of the short-range interaction on critical phenomena in elastic interaction systems

    NASA Astrophysics Data System (ADS)

    Nishino, Masamichi; Miyashita, Seiji

    2013-07-01

    The elastic interaction, induced by the lattice distortion due to the difference of the molecular size, causes an effective long-range interaction. In spin-crossover (SC) compounds, local bistable states, i.e., high-spin and low-spin states, have different molecular sizes, and the elastic interaction is important. In bipartite lattices, e.g., the square lattice, the ground state can be two types of phases: ferromagneticlike and antiferromagneticlike phases. In systems like SC compounds, the former phase consists of all small or large molecules, and the latter phase has the configuration of alternating small and large molecules. In fact, both cases are observed in SC systems. In this paper we have studied the effect of the short-range interaction in the elastic system on the properties of those order-disorder phase transitions. We have obtained a phase diagram in the coordinates of the temperature and the strength of the short-range interaction, including the metastable structures. We show that effects of the short-range interaction are essentially different for ferromagneticlike and antiferromagneticlike phase transitions. In the ferromagneticlike transition, the long-range interaction of elasticity is relevant, and the system exhibits a phase transition in the mean-filed universality class. In this case, the long-range interaction strongly enhances the ferromagneticlike order, and it works cooperatively with the short-range interaction. In contrast, in the antiferromagneticlike transition, the elastic interaction slightly enhances the antiferromagneticlike order, but essentially it does not contribute to the ordering, and the system shows a transition in the Ising universality class. We have found that in the border region between ferromagneticlike and antiferromagneticlike phases, the antiferromagneticlike phase has an advantage at finite temperatures. We discuss the critical properties of two-step SC transitions with comparison between the elastic interaction

  10. The Teacher Proximity Continuum: A Conceptual Framework for the Analysis of Teacher-Related Phenomena.

    ERIC Educational Resources Information Center

    Camp, William G.; Heath-Camp, Betty

    In conjunction with a national study on the induction process for beginning vocational teachers, researchers developed a general conceptual framework for the classification and analysis of teacher-related phenomena. The framework, called the Teacher Proximity Continuum, has proved useful in analysis of negative influences, positive influences,…

  11. Critical exponents and scaling relations for self-organized critical phenomena

    NASA Technical Reports Server (NTRS)

    Tang, Chao; Bak, Per

    1988-01-01

    Critical indices beta, gamma delta, nv, etc. are defined and calculated for self-organized critical phenomena. Scaling relations are derived and checked numerically. The order-parameter exponent beta describes the spontaneous current and the relaxation to the criticl point. The power spectrum has 'l/f' behavior with the exponent phi = nv x z, where z is the dynamical critical exponent.

  12. Analysis of interaction phenomena between liquid jets and materials. Revision 1

    SciTech Connect

    Kang, S.W.; Reitter, T.; Carlson, G.

    1995-04-01

    The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to understand the physics of material removal by jet-machining processes. Experiments were performed to delineate conditions under which liquid jet impacts will cause mass removal, and to determine optimum jet-cutting conditions. Theoretical analyses have also been carried out to study the effects of multiple jet-droplet impacts on a target surface as a material deformation mechanism. The calculated target response and spallation behavior following droplet impacts and their physical implications are also discussed.

  13. University Physics Students' Use of Models in Explanations of Phenomena Involving Interaction between Metals and Electromagnetic Radiation.

    ERIC Educational Resources Information Center

    Redfors, Andreas; Ryder, Jim

    2001-01-01

    Examines third year university physics students' use of models when explaining familiar phenomena involving interaction between metals and electromagnetic radiation. Concludes that few students use a single model consistently. (Contains 27 references.) (DDR)

  14. Theoretical and experimental studies of space-related plasma wave propagation and resonance phenomena

    NASA Technical Reports Server (NTRS)

    Crawford, F. W.

    1975-01-01

    A ten year summary was given of university research on the nature and characteristics of space related plasma resonance phenomena, whistler propagation in laboratory plasmas, and theoretical and experimental studies of plasma wave propagation. Data are also given on long delayed echoes, low frequency instabilities, ionospheric heating, and backscatter, and pulse propagation. A list is included of all conference papers, publications, and reports resulting from the study.

  15. Double Layers: Potential Formation and Related Nonlinear Phenomena in Plasmas: Proceedings of the 5th Symposium

    NASA Astrophysics Data System (ADS)

    Iizuka, S.

    1998-02-01

    Parallel Velocity Shear Instability (Invited) * Low-Frequency Instabilities under a Cross-Field Electric Field in a K+-C60- Plasma * 3.3 Vortex Formation * Vortex Dynamics in Low Frequency Electrostatic Turbulence * Development of Spiral-Vortex Structures of the Plasma During Rotation in a Neutral Gas * Vortex Formation of Particles in Magnetized Dusty Plasmas (Invited) * CHAPTER 4: SOLITONS, SHOCKS, WAVES AND INSTABILITIES, AND RELATED NONLINEAR PHENOMENA * 4.1 Solitons and Shocks * Refraction and Reflection of Ion Acoustic Solitons by Space Charge Sheath * 2D and 3D Solitons in Plasma: Structure, Stability, Dynamics * Solitary Waves in an Ion-Beam Multi-Component Plasma System * Shock Formation in a Q-Machine Plasma with Negative Ions * 4.2 Waves and Instabilities * Single-Ended Q-Machine as a Source of Oscillations (Invited) * Numerical and Experimental Investigations of Period Doubling of the Potential Relaxation Instability in an Electron-Rich Q-Machine Plasma * Large Amplitude Electrostatic Ion Waves in an e- - e+ - p Plasma * Measurements of Alfvén Waves around the CRIT Releases-Implications for Current Limitation in Alfvén Wings * 4.3 Nonlinear Phenomena * Self-Organization Phenomena in a Q-Machine Plasma * Nonlinearity Related to Self-Organization in a Thermionic Vacuum Arc Discharge * Spontaneous Formation of Ordered Spatio-Temporal Structures in Laboratory and Nature * Nonlinear Evolution and Stabilization of Linearly Unstable Waves in an Electron-Beam Plasma * Disruption of an Electron Hole Due to its Interaction with Ion Acoustic Waves in a Plasma * Expanding Plasma Clouds with Dust Particles (Invited) * LIST OF PARTICIPANTS * AUTHOR INDEX

  16. Numerical studies of wall-plasma interactions and ionization phenomena in an ablative pulsed plasma thruster

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Zeng, Guangshang; Tang, Haibin; Huang, Yuping; Liu, Xiangyang

    2016-07-01

    Wall-plasma interactions excited by ablation controlled arcs are very critical physical processes in pulsed plasma thrusters (PPTs). Their effects on the ionization processes of ablated vapor into discharge plasma directly determine PPT performances. To reveal the physics governing the ionization phenomena in PPT discharge, a modified model taking into account the pyrolysis effect of heated polytetrafluoroethylene propellant on the wall-plasma interactions was developed. The feasibility of the modified model was analyzed by creating a one-dimensional simulation of a rectangular ablative PPT. The wall-plasma interaction results based on this modified model were found to be more realistic than for the unmodified model; this reflects the dynamic changes of the inflow parameters during discharge in our model. Furthermore, the temporal and spatial variations of the different plasma species in the discharge chamber were numerically studied. The numerical studies showed that polytetrafluoroethylene plasma was mainly composed of monovalent ions; carbon and fluorine ions were concentrated in the upstream and downstream discharge chamber, respectively. The results based on this modified model were in good agreement with the experimental formation times of the various plasma species. A large number of short-lived and highly ionized carbon and fluorine species (divalent and trivalent ions) were created during initial discharge. These highly ionized species reached their peak density earlier than the singly ionized species.

  17. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    NASA Technical Reports Server (NTRS)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  18. Sociological phenomena as multiple nonlinearities: MTBI's new metaphor for complex human interactions.

    PubMed

    Kribs-Zaleta, Christopher M

    2013-01-01

    Mathematical models are well-established as metaphors for biological and epidemiological systems. The framework of epidemic modeling has also been applied to sociological phenomena driven by peer pressure, notably in two dozen dynamical systems research projects developed through the Mathematical and Theoretical Biology Institute, and popularized by authors such as Gladwell (2000). This article reviews these studies and their common structures, and identifies a new mathematical metaphor which uses multiple nonlinearities to describe the multiple thresholds governing the persistence of hierarchical phenomena, including the situation termed a "backward bifurcation'' in mathematical epidemiology, where established phenomena can persist in circumstances under which the phenomena could not initially emerge. PMID:24245636

  19. Carbonate mounds from the Gulf of Cadiz in relation to methane seepage: unrelated phenomena or coupling?

    NASA Astrophysics Data System (ADS)

    Stadnitskaia, Alina; Baas, Marianne; de Haas, Henk; van Weering, Tjeerd C. E.; Kreulen, Rob R.; Sinninghe Damsté, Jaap S.

    2010-05-01

    For more than decade, the formation of carbonate mounds, related ecosystem development and organization/functioning of the entire mound habitats are subjects for a growing amount of studies and discussions. Carbonate mounds from the Gulf of Cadiz are of special interest due to their association with active mud volcanoes within the El Arraiche mud volcano field. Such co-occurrence of ecologically contrasting phenomena anticipates complex biogeochemical interactions between a carbonate mound interior and seeping through hydrocarbon-rich fluids. To get closer in understanding of how methane affects a carbonate mound development in the gulf, a combination of inorganic and organic geochemical techniques was applied to two sedimentary cores collected from summits of Alfa and Beta mounds. These mounds were found at the NW slope of the Gimini MV at the Pen Duick Mound Province. We analyzed vertical distribution profiles of sulfate, sulfide, chlorinity, DIC in combination with hydrocarbon gas measurements and lipid biomarker study. To have estimates of Sea Surface Temperature (SST) during the carbonate mound formation, we applied the TEX86 (TetraEther indeX of tetraethers with 86 carbon atoms; Schouten et al., 2002) and the alkenone-based UK37 index (Müller et al., 1998). The pore-water data revealed the presence of brine inflow, which is consistent with the data of Hensen et al., (2007). The behavior of sulfide distribution profiles and δ13C values from dissolved inorganic carbon (DIC) indicated that most of the sulfide and DIC are resulted from the microbial anaerobic oxidation of methane (AOM) processes. In contrast, the analysis of archaeal membrane lipids from distinct clades of AOM-mediating anaerobic methanotrophs showed exceedingly low concentrations of specific biomarkers, which is in contradiction with pore-water and gas chemistry data. Besides, AOM is the main cause for the increase of sedimentary alkalinity that leads to carbonate precipitation. Instead, some

  20. Dynamic cross correlation studies of wave particle interactions in ULF phenomena

    NASA Technical Reports Server (NTRS)

    Mcpherron, R. L.

    1979-01-01

    Magnetic field observations made by satellites in the earth's magnetic field reveal a wide variety of ULF waves. These waves interact with the ambient particle populations in complex ways, causing modulation of the observed particle fluxes. This modulation is found to be a function of species, pitch angle, energy and time. The characteristics of this modulation provide information concerning the wave mode and interaction process. One important characteristic of wave-particle interactions is the phase of the particle flux modulation relative to the magnetic field variations. To display this phase as a function of time a dynamic cross spectrum program has been developed. The program produces contour maps in the frequency time plane of the cross correlation coefficient between any particle flux time series and the magnetic field vector. This program has been utilized in several studies of ULF wave-particle interactions at synchronous orbit.

  1. SMALL-SCALE LOCAL PHENOMENA RELATED TO THE MAGNETIC RECONNECTION AND TURBULENCE IN THE PROXIMITY OF THE HELIOPAUSE

    SciTech Connect

    Strumik, M.; Czechowski, A.; Grzedzielski, S.; Macek, W. M.; Ratkiewicz, R.

    2013-08-20

    We study processes related to magnetic reconnection and plasma turbulence occurring in the presence of the heliopause (HP) and the heliospheric current sheet. It is shown that the interaction of plasmoids initiated by magnetic reconnection may provide connections between the inner and outer heliosheath and lead to an exchange of particles between the interstellar medium and the solar wind plasma shocked at the heliospheric termination shock. The magnetic reconnection may also cause plasma density and magnetic field compressions in the proximity of the HP. We argue that these phenomena could possibly be detected by the Voyager spacecraft approaching and crossing the HP. These results could clarify the concepts of the ''magnetic highway'' and the ''heliosheath depletion region'' recently proposed to explain recent Voyager 1 observations.

  2. Best Estimate Code System to Calculate Thermal & Hydraulic Phenomena in a Nuclear Reactor or Related System.

    Energy Science and Technology Software Center (ESTSC)

    1999-05-19

    Version 00 RELAP4/MOD7/101 performs best estimate analyses of nuclear reactors or related systems undergoing a transient. Transient thermal-hydraulic, two-phase phenomena are calculated from formulations of one-dimensional, homogeneous, equilibrium conservation equations for water mass, momentum, and energy. Heat structures are modeled using a transient one-dimensional heat conduction solution that is coupled to the fluid through heat transfer relations. Various explicit models are used to calculate nonhomogeneous, nonequilibrium behavior including a phase separation model, a vertical slipmore » model, and a nonequilibrium model. Other models are used to represent critical flow, reactor kinetics, pressurized water reactor reflood behavior, nuclear fuel rod swelling and blockage, and components such as pumps, valves, and accumulators.« less

  3. Microsatellite instability in squamous cell carcinomas of the head and neck related to field cancerization phenomena.

    PubMed Central

    Piccinin, S.; Gasparotto, D.; Vukosavljevic, T.; Barzan, L.; Sulfaro, S.; Maestro, R.; Boiocchi, M.

    1998-01-01

    Patients affected by squamous cell carcinoma of the head and neck (HNSCC) show frequent occurrence of multiple cancers and widespread precancerous lesions in the mucosa of the upper respiratory tract, a phenomenon known as field cancerization. In this study, we investigated the role of genetic instability in the development of HNSCC and in particular in tumour multiplicity phenomena of the upper respiratory tract. For this purpose, we analysed microsatellite instability (MI) and loss of heterozygosity (LOH) at 20 loci mapping on five chromosomal arms in 67 HNSCC patients, 45 of whom had a single cancer and 22 had multiple primary tumours. The possible involvement of the hMLH1 gene in genetic instability and as a potential target of 3p21 deletion phenomena in head and neck cancers was also investigated. Our data indicate that mismatch repair-related genetic instability plays a minor role in the carcinogenesis of HNSCC and in tumour multiplicity of the head and neck region. Moreover, our results exclude a role for the hMLH1 gene as a determinant of MI and as a specific gene target of deletion at 3p21 in HNSCC. We conclude that presumably other genetic mechanisms, such as those hypothesized for MI-negative hereditary non-polyposis colorectal cancer patients, may play a major role in the carcinogenesis of the mucosa of the upper respiratory tract. Images Figure 1 Figure 2 PMID:9820170

  4. Anomalous cosmic ray interaction events for investigations in the SSC and Space Station era - 'Long lived she-devil phenomena'

    NASA Technical Reports Server (NTRS)

    Takahashi, Y.

    1985-01-01

    Observational data on anomalous cosmic-ray interaction events are compiled, classified, and briefly characterized. The events are divided into three groups: those confirmed by later observation or experiment, those shown to be the result of observational or analytical error, and those still unexplained. Among the phenomena in the latter group are magnetic-monopole candidates, fractionally charged particles, massive stable particles, anomalons, proton-decay and neutron-oscillation candidates, muon bundles, narrow showers, anomalous photons, fanlike phenomena, quark-gluon-plasma candidates, and anomalous long-range delta rays.

  5. Introduction to special section on pulsating aurora and related magnetospheric phenomena

    NASA Astrophysics Data System (ADS)

    Hosokawa, Keisuke; Miyoshi, Yoshizumi; Li, Wen

    2015-07-01

    Pulsating aurora (PsA) is known as one of the major classes of aurora, which almost always appears during the recovery phase of substorm. Since 1960s, PsA has been extensively studied by using ground-based observations combined with rocket and satellite measurements. Still, however, the underlying processes creating auroral pulsations remain to be understood. Because of these, vast numbers of ground-based optical and radio instruments have been employed during the last decade to better observe the dynamic nature of PsA. In addition, there are several ongoing and planned ground-based and satellite collaborations aimed at understanding the electromagnetic coupling between magnetospheric processes (whistler mode chorus and ECH waves) and PsA seen on the ground. This special section focuses on observational (ground-based/satellites), theoretical, and modeling aspects of PsA and related phenomena in the magnetosphere.

  6. Numerical simulation of fluid/structure interaction phenomena in viscous dominated flows

    NASA Astrophysics Data System (ADS)

    Tran, Hai Duong

    2001-12-01

    The accurate prediction of buffet boundaries is essential in modern military aircraft and suspension bridge design in order to avoid the potentially disastrous consequences of unsteady loads. The design of lightweight structures and thermal protection systems for supersonic and hypersonic vehicles depends on the accurate prediction of the aerothermal loads, the structural temperatures and their gradients, and the structural deformations and stresses. Despite their bounded nature, limit-cycle oscillations can exhibit important amplitudes which affect the fatigue life of aircraft structures. Therefore, the main objective of this thesis is to develop and design an integrated multidisciplinary computational methodology for the analyses of the coupled responses exhibited by these phenomena. To simulate fluid/structure interaction problems in turbulent flows, we formulate the k--epsilon turbulence model and Reichardt's wall law in ALE form for dynamic meshes. This law is used with the generalized boundary conditions on k and epsilon of Jaeger and Dhatt and allows a closer integration to the wall compared to standard logarithmic laws and boundary conditions on k and epsilon. In order to apply the methodology to buffeting problems dominated by vortex shedding, we validate our solution approach on the square cylinder benchmark problem. There, we stress the minimization of numerical dissipation induced by an upwinding scheme, and apply our methodology to the aeroelastic stability analysis of a sectional dynamic model of the Tacoma Narrows Bridge. Then, we extend the three field formulation of aeroelasticity to a four-field formulation of aerothermoelasticity for the analysis of aerodynamic heating on structures. With a k--epsilon model, the time-averaged Navier-Stokes equations are integrated up to a distance delta from the real wall. This gap creates a problem for the transmission of the structural temperature to the fluid system. To resolve this problem, we exchange the

  7. Current Transport and Onset-Related Phenomena in an MPD Thruster Modified by Applied Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Moeller, Robert Carlos

    field lowered terminal voltages below 10.7 kA. These significant reductions in onset-related behaviors should lead to improved thruster lifetime and increased efficiency. These results suggest a distinctive and more effective approach to influencing the near-anode phenomena and mitigating the effects of onset with appropriately designed applied magnetic fields that differ from those used in the vast majority of conventional, so-called "applied-field MPD thrusters."

  8. Novel techniques for detection and imaging of spin related phenomena: Towards sub-diffraction limited resolution

    NASA Astrophysics Data System (ADS)

    Wolfe, Christopher Stuart

    The idea that the spin degree of freedom of particles can be used to store and transport information has revolutionized the data storage industry and inspired a huge amount of research activity. Spin electronics, or spintronics, provides a plethora of potential improvements to conventional charge electronics that include increased functionality and energy efficiency. Scientists studying spintronics will need a multitude of characterization tools to sensitively detect spins in new materials and devices. There are already a handful of powerful techniques to image spin-related phenomena, but each has limitations. Magnetic resonance force microscopy, for example, offers sensitive detection of spin moments that are localized or nearly so but requires a high vacuum, cryogenic environment. Magnetometry based on nitrogen vacancy centers in diamond is a powerful approach, but requires the nitrogen vacancy center to be in very close contact to the spin system being studied to be able to measure the field generated by the system. Spin-polarized scanning tunneling microscopy provides perhaps the best demonstrated spatial resolution, but typically requires ultrahigh vacuum conditions and is limited to studying the surface of a sample. Traditional optical techniques such as Faraday or Kerr microscopy are limited in spatial resolution by the optical diffraction limit. In this dissertation I will present three new techniques we have developed to address some of these issues and to provide the community with new tools to help push forward spintronics and magnetism related research. I will start by presenting the first experimental demonstration of scanned spin-precession microscopy. This technique has the potential to turn any spin-sensitive detection technique into an imaging platform by providing the groundwork for incorporating a magnetic field gradient with that technique, akin to magnetic resonance imaging, and the mathematical tools to analyze the data and extract the local

  9. A Bayesian explanation of the ‘Uncanny Valley’ effect and related psychological phenomena

    PubMed Central

    Moore, Roger K.

    2012-01-01

    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the ‘uncanny valley’ effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions. PMID:23162690

  10. A Bayesian explanation of the "Uncanny Valley" effect and related psychological phenomena

    NASA Astrophysics Data System (ADS)

    Moore, Roger K.

    2012-11-01

    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the `uncanny valley' effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions.

  11. Curvilinear immersed boundary method for simulating coupled flow and bed morphodynamic interactions due to sediment transport phenomena

    NASA Astrophysics Data System (ADS)

    Khosronejad, Ali; Kang, Seokkoo; Borazjani, Iman; Sotiropoulos, Fotis

    2011-07-01

    The fluid-structure interaction curvilinear immersed boundary (FSI-CURVIB) numerical method of Borazjani et al. [3] is extended to simulate coupled flow and sediment transport phenomena in turbulent open-channel flows. The mobile channel bed is discretized with an unstructured triangular mesh and is treated as a sharp-interface immersed boundary embedded in a background curvilinear mesh used to discretize the general channel outline. The unsteady Reynolds-averaged Navier-Stokes (URANS) equations closed with the k - ω turbulence model are solved numerically on a hybrid staggered/non-staggered grid using a second-order accurate fractional step method. The bed deformation is calculated by solving the sediment continuity equation in the bed-load layer using an unstructured, finite-volume formulation that is consistent with the CURVIB framework. Both the first-order upwind and the higher-order hybrid GAMMA schemes [12] are implemented to discretize the bed-load flux gradients and their relative accuracy is evaluated through a systematic grid refinement study. The GAMMA scheme is employed in conjunction with a sand-slide algorithm for limiting the bed slope at locations where the material angle of repose condition is violated. The flow and bed deformation equations are coupled using the partitioned loose-coupling FSI-CURVIB approach [3]. The hydrodynamic module of the method is validated by applying it to simulate the flow in an 180° open-channel bend with fixed bed. To demonstrate the ability of the model to simulate bed morphodynamics and evaluate its accuracy, we apply it to calculate turbulent flow through two mobile-bed open channels, with 90° and 135° bends, respectively, for which experimental measurements are available.

  12. Three-phase interactions and interfacial transport phenomena in coacervate/oil/water systems.

    PubMed

    Dardelle, Gregory; Erni, Philipp

    2014-04-01

    Complex coacervation is an associative liquid/liquid phase separation resulting in the formation of two liquid phases: a polymer-rich coacervate phase and a dilute continuous solvent phase. In the presence of a third liquid phase in the form of disperse oil droplets, the coacervate phase tends to wet the oil/water interface. This affinity has long been known and used for the formation of core/shell capsules. However, while encapsulation by simple or complex coacervation has been used empirically for decades, there is a lack of a thorough understanding of the three-phase wetting phenomena that control the formation of encapsulated, compound droplets and the role of the viscoelasticity of the biopolymers involved. In this contribution, we review and discuss the interplay of wetting phenomena and fluid viscoelasticity in coacervate/oil/water systems from the perspective of colloid chemistry and fluid dynamics, focusing on aspects of rheology, interfacial tension measurements at the coacervate/solvent interface, and on the formation and fragmentation of three-phase compound drops. PMID:24268195

  13. Critical velocity phenomena and the LTP. [Lunar Transient Phenomena

    NASA Technical Reports Server (NTRS)

    Srnka, L. J.

    1977-01-01

    When the relative velocity between magnetized plasma and neutral gas exceeds a critical value, the gas-plasma interaction is dominated by collective phenomena which rapidly excite and ionize the neutrals. The interaction of the solar wind with a large cloud (between 10 to the 24th and 10 to the 28th power neutrals) vented from the moon should be of this type. Line radiation from such an interaction can yield an apparent lunar surface brightness rivaling reflected sunlight levels over small areas, if the kinetic-energy flow density of the gas is sufficiently high. The aberrated solar-wind flow past the moon would enhance the visibility of such interactions near the lunar sunrise terminator, supporting the statistical studies which indicate that the 'Lunar Transient Phenomena' (anomalous optical phenomena on the moon) are significantly correlated with the position of the terminator on the lunar surface.

  14. Strong commitment to traditional Protestant religious beliefs is negatively related to beliefs in paranormal phenomena.

    PubMed

    Hillstrom, E L; Strachan, M

    2000-02-01

    Numerous studies have yielded small, negative correlations between measures of paranormal and "traditional religious beliefs". This may partly reflect opinions of Christians in the samples who take biblical sanctions against many "paranormal" activities seriously. To test this, 391 college students (270 women and 121 men) rated their beliefs in various paranormal phenomena and were classified as Believers, Nominal Believers, and Nonbelievers on the strength of their self-rated commitment to key biblical (particularly Protestant) doctrines. As predicted, Believers were significantly less likely than Nominal Believers or Nonbelievers to endorse reincarnation, contact with the dead, UFOs, telepathy, prophecy, psychokinesis, or healing, while the beliefs of Nominal Believers were similar to those of Nonbelievers. Substantial percentages of Nominal and Nonbelievers (30-50%) indicated at least moderate acceptance of the paranormal phenomena surveyed. PMID:10778269

  15. Better late than Now-or-Never: The case of interactive repair phenomena.

    PubMed

    Healey, Patrick G T; Howes, Christine; Hough, Julian; Purver, Matthew

    2016-01-01

    Empirical evidence from dialogue, both corpus and experimental, highlights the importance of interaction in language use - and this raises some questions for Christiansen & Chater's (C&C's) proposals. We endorse C&C's call for an integrated framework but argue that their emphasis on local, individual production and comprehension makes it difficult to accommodate the ubiquitous, interactive, and defeasible processes of clarification and repair in conversation. PMID:27561706

  16. Dipolar interactions and hydrogen bonding in supramolecular aggregates: understanding cooperative phenomena for 1st hyperpolarizability.

    PubMed

    Datta, Ayan; Pati, Swapan K

    2006-12-01

    Weak intermolecular forces like dipolar interactions and hydrogen-bonding lead to a variety of different packing arrangements of molecules in crystals and self-assemblies. Such differences in the arrangements change the extent of excitonic splitting and excitation spectra in the multichromophore aggregates. In this tutorial review, the role of such interactions in fine tuning the linear and 1st non-linear optical (NLO) responses in molecular aggregates are discussed. The non-additivity of these optical properties arise specifically due to such cooperative interactions. Calculations performed on dimers, trimers and higher aggregates for model systems provide insights into the interaction mechanisms and strategies to enhance the 1st hyperpolarizabilities of pi-conjugated molecular assemblies. Flexible dipole orientations in the alkane bridged chromophores show odd-even variations in their second-harmonic responses that are explained through their dipolar interactions in different conformations. Parameters for the optical applications of molecules arranged in constrained geometry, like in Calix[n]arene, have been elucidated. We also highlight the recent developments in this field of research together with their future prospects. PMID:17225890

  17. Investigating high speed phenomena in laser plasma interactions using dilation x-ray imager (invited).

    PubMed

    Nagel, S R; Hilsabeck, T J; Bell, P M; Bradley, D K; Ayers, M J; Piston, K; Felker, B; Kilkenny, J D; Chung, T; Sammuli, B; Hares, J D; Dymoke-Bradshaw, A K L

    2014-11-01

    The DIlation X-ray Imager (DIXI) is a new, high-speed x-ray framing camera at the National Ignition Facility (NIF) sensitive to x-rays in the range of ≈2-17 keV. DIXI uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps, a ≈10× improvement over conventional framing cameras currently employed on the NIF (≈100 ps resolution), and otherwise only attainable with 1D streaked imaging. The pulse-dilation technique utilizes a voltage ramp to impart a velocity gradient on the signal-bearing electrons. The temporal response, spatial resolution, and x-ray sensitivity of DIXI are characterized with a short x-ray impulse generated using the COMET laser facility at Lawrence Livermore National Laboratory. At the NIF a pinhole array at 10 cm from target chamber center (tcc) projects images onto the photocathode situated outside the NIF chamber wall with a magnification of ≈64×. DIXI will provide important capabilities for warm-dense-matter physics, high-energy-density science, and inertial confinement fusion, adding important capabilities to temporally resolve hot-spot formation, x-ray emission, fuel motion, and mix levels in the hot-spot at neutron yields of up to 10(17). We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments. PMID:25430346

  18. Investigating high speed phenomena in laser plasma interactions using dilation x-ray imager (invited)

    SciTech Connect

    Nagel, S. R. Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Piston, K.; Felker, B.; Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B.; Hares, J. D.; Dymoke-Bradshaw, A. K. L.

    2014-11-15

    The DIlation X-ray Imager (DIXI) is a new, high-speed x-ray framing camera at the National Ignition Facility (NIF) sensitive to x-rays in the range of ≈2–17 keV. DIXI uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps, a ≈10× improvement over conventional framing cameras currently employed on the NIF (≈100 ps resolution), and otherwise only attainable with 1D streaked imaging. The pulse-dilation technique utilizes a voltage ramp to impart a velocity gradient on the signal-bearing electrons. The temporal response, spatial resolution, and x-ray sensitivity of DIXI are characterized with a short x-ray impulse generated using the COMET laser facility at Lawrence Livermore National Laboratory. At the NIF a pinhole array at 10 cm from target chamber center (tcc) projects images onto the photocathode situated outside the NIF chamber wall with a magnification of ≈64×. DIXI will provide important capabilities for warm-dense-matter physics, high-energy-density science, and inertial confinement fusion, adding important capabilities to temporally resolve hot-spot formation, x-ray emission, fuel motion, and mix levels in the hot-spot at neutron yields of up to 10{sup 17}. We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments.

  19. A study on flash sintering and related phenomena in titania and its composite with alumina

    NASA Astrophysics Data System (ADS)

    Shikhar

    In 2010, Cologna et. al. [1] reported that with a help of small electric field 120 Vcm-1, the sintering temperature of 3 mol % yittria stabilized zirconia could be brought down to 850°C from 1450°C. On top of reducing the temperature requirements, the green sample could be sintered from starting density of 50% to near full density in mere 5 seconds, a sintering rate three orders of magnitude higher than conventional methods. This discovery led to the emergence of a new field of enhanced sintering with electric field, named "Flash Sintering". The objective of this thesis is to understand the phenomenological behavior of flash-sintering and related phenomena on titania and its composites with alumina at elevated temperature. The possible mechanisms to explain flash sintering are discussed: Joule heating and the avalanche of defect generation [2], both induced by the rapid rise in conductivity just before the onset of the flash. Apparently, both mechanisms play a role. The thesis covers the response of pure titania and composites of titania-alumina under flash and compared with conventional sintering. We start with the sintering behavior of pure titania and observe lowering of sintering temperature requirements with higher applied electric field. The conductivity of titania during flash is also measured, and compared with the nominal conductivity of titania at equivalent temperatures. The conductivity during flash is determined to be have a different activation energy. For the composites of titania-alumina, effect of flash on the constrained sintering was studied. It is a known fact that sintering of one component of composite slows down when the other component of a different densification rate is added to it, called constrained sintering. In our case, large inclusions of alumina particles were added to nano-grained titania green compact that hindered its densification. Flash sintering was found to be overcoming this problem and near full densification was achieved

  20. Interactive Discovery of New Phenomena in Martian Point Spectra and Hyperspectral Data Sets

    NASA Astrophysics Data System (ADS)

    Wagstaff, K.; Lanza, N.; Thompson, D. R.; Blaney, D. L.

    2012-12-01

    In sifting through large martian data sets to find observations of particular scientific interest, there is always a lingering question of "what are we missing?" Targeted searches for materials such as phyllosilicates or carbonates might successfully identify key observations of each, but given limited analysis time we might inadvertently pass over other equally interesting compositions. Data sets with high dimensionality pose an additional challenge for efficient analysis and interpretation. Two prime examples are point spectra such as those collected by LIBS (Laser-Induced Breakdown Spectroscopy) instruments like ChemCam on the Mars Science Laboratory and hyperspectral data such as that collected by CRISM on Mars Reconnaissance Orbiter. We have developed DEMUD (Discovery through Eigenbasis Modeling of Uninteresting Data), a method that quickly scans through large data sets to identify observations that stand out as unusual or anomalous. It focuses attention on new or unexpected observations, accelerating the discovery of new phenomena. Further, DEMUD learns from feedback. Each item it selects can be designated 'interesting' or 'uninteresting'. DEMUD learns to ignore items deemed uninteresting even if they are otherwise anomalous (e.g., observations that contain noise, bad pixels, or even just novelties that are now well understood). DEMUD progressively peels back layers of anomalies in the data set, without specializing on one particular science goal. It therefore remains open to discovering new phenomena that may not have been anticipated by the mission prior to data collection. This data-driven analysis based on statistical properties can complement model-based interpretations of the observations. In addition to highlighting items of interest, DEMUD also provides explanations for individual decisions, e.g., highlighting specific wavelengths where the chosen sample has unusually high, or low, intensity. It therefore can greatly accelerate not just the discovery

  1. Wave phenomena at the Moon: interaction of solar wind with magnetic anomalies

    NASA Astrophysics Data System (ADS)

    Sadovski, Andrei; Skalsky, Alexander

    2016-07-01

    On the first sight the lunar plasma environment seems to be very simple matter but the interaction in Moon-plasma system shows that the physical processes are complex and varied. Moreover interactions have a kinetic nature and the kinetic theory is necessary for their studying. The solar wind interaction with Moon surface has received many attention last years. The regions of enhanced crustal magnetic field (magnetic anomalies), where a magnetic field may reach till several hundred nT were found. The observations of Kaguya and Chandrayaan revealed that significant deflected proton fluxes exist over magnetic anomalies at the lunar surface. Such proton fluxes allow to imply that the magnetic anomalies may act as magnetosphere-like obstacles (mini-magnetospheres), modifying the upstream plasma. The observations of energetic neutral atoms also confirm the existence of the enhanced fluxes of deflected particles. Variety of electric fluctuations was observed during the passage of Wind spacecraft across the lunar wake: langmuir waves, electrostatic modes above electron cyclotron frequency, whistlers. The investigations by Kuncic and Cairns (2004) revealed emissions on plasma frequency and its first harmonic. Electron reflection at quasi-shock at leading edge of magnetic anomaly could drive the electric field oscillations. The generation mechanism is similar to that known for foreshock of planetary bow shock.In KAGUYA and Lunar Prospector missions the monochromatic whistlers near the Moon were observed as narrow band magnetic fluctuations with frequencies close to 1 Hz, and are mostly left-hand polarized in the spacecraft frame. We review different mechanisms for wave generation in plasma environment near such mini-magnetosphere regions.

  2. Plasma flow interaction with ITER divertor related surfaces

    NASA Astrophysics Data System (ADS)

    Dojčinović, Ivan P.

    2010-11-01

    It has been found that the plasma flow generated by quasistationary plasma accelerators can be used for simulation of high energy plasma interaction with different materials of interest for fusion experiments. It is especially important for the studies of the processes such as ELMs (edge localized modes), plasma disruptions and VDEs (vertical displacement events), during which a significant part of the confined hot plasma is lost from the core to the SOL (scrape off layer) enveloping the core region. Experiments using plasma guns have been used to assess erosion from disruptions and ELMs. Namely, in this experiment modification of different targets, like tungsten, molybdenum, CFC and silicon single crystal surface by the action of hydrogen and nitrogen quasistationary compression plasma flow (CPF) generated by magnetoplasma compressor (MPC) has been studied. MPC plasma flow with standard parameters (1 MJ/m2 in 0.1 ms) can be used for simulation of transient peak thermal loads during Type I ELMs and disruptions. Analysis of the targets erosion, brittle destruction, melting processes, and dust formation has been performed. These surface phenomena are results of specific conditions during CPF interaction with target surface. The investigations are related to the fundamental aspects of high energy plasma flow interaction with different material of interest for fusion. One of the purposes is a study of competition between melting and cleavage of treated solid surface. The other is investigation of plasma interaction with first wall and divertor component materials related to the ITER experiment.

  3. Investigation of in vitro interactions between different polymeric surfaces and blood proteins via phagocytosis phenomena.

    PubMed

    Ayhan, F; Rad, A Yousefi; Ayhan, H

    2003-01-01

    The effect of various polymeric materials on blood components and their in vitro phagocytosis was the object of the present research. Polystyrene- (PS) and polymethylmetacrylate- (PMMA) based microspheres were produced by phase-inversion polymerization and chemically modified to obtain different surface hydrophilicities. The interactions between blood proteins and chemically- and biologically-modified surfaces were investigated and compared to plain microspheres. Adsorption properties of albumin, fibrinogen and total immunoglobulines on microspheres were tested. Hydrophilic surfaces have high ability for human serum albumin (HSA) adsorption, which also leads to less phagocytosis of microspheres in vitro. In the case of activated PMMA(PVA) microspheres, both protein adsorption and phagocytosis were significant. Interaction of blood proteins with microspheres did not cause any change in phagocytosis by leukocytes and monocytes. BSA adsorption on microspheres with different hydrophilicities showed the same blood protein adsorption results and phagocytosis was not detected. On the other hand, the highest level of phagocytosis was found with fibronectin-modified microspheres. The changes occurring in intrinsic and extrinsic coagulation mechanisms were determined by measuring the activated partial tromboplastin time (APTT) and the prothrombin time (PT). PT values of blood samples did not increase by treatment with microspheres, except for PS/HEMA, while chemical modification caused important prolongation in APTT. PMID:14870945

  4. A Study of Aircraft Fire Hazards Related to Natural Electrical Phenomena

    NASA Technical Reports Server (NTRS)

    Kester, Frank L.; Gerstein, Melvin; Plumer, J. A.

    1960-01-01

    The problems of natural electrical phenomena as a fire hazard to aircraft are evaluated. Assessment of the hazard is made over the range of low level electrical discharges, such as static sparks, to high level discharges, such as lightning strikes to aircraft. In addition, some fundamental work is presented on the problem of flame propagation in aircraft fuel vent systems. This study consists of a laboratory investigation in five parts: (1) a study of the ignition energies and flame propagation rates of kerosene-air and JP-6-air foams, (2) a study of the rate of flame propagation of n-heptane, n-octane, n-nonane, and n-decane in aircraft vent ducts, (3) a study of the damage to aluminum, titanium, and stainless steel aircraft skin materials by lightning strikes, (4) a study of fuel ignition by lightning strikes to aircraft skins, and (5) a study of lightning induced flame propagation in an aircraft vent system.

  5. Study of earthquakes and related phenomena using a satellite scalar magnetometer

    NASA Astrophysics Data System (ADS)

    Schwingenschuh, Konrad; Magnes, Werner; Xuhui, Shen; Wang, Jindong; Pollinger, Andreas; Hagen, Christian; Lammegger, Roland; Ellmeier, Michaela; Prattes, Gustav; Eichelberger, Hans-Ulrich; Wolbang, Daniel; Boudjada, Mohammed Y.; Besser, Bruno P.; Rozhnoi, Alexander A.; Zhang, Tielong

    2016-04-01

    A new type of scalar magnetometer for space applications has been developed (see Lammegger 2008). A first instrument of this type will be flown aboard the upcoming Chinese Seismo-Electromagnetic Satellite (CSES). The scalar magnetometer can measure the total magnetic field with an accuracy of about 50 pT/sqrt(Hz) in the frequency range between 0 and 30 Hz. In order to minimize the stray field of the satellite, the sensor of the scalar magnetometer is mounted at the tip of a five meter boom. The main scientific objective of the scalar magnetometer aboard the Chinese satellite is the investigation of seismic phenomena before, during and after earthquakes or volcanic activity. The expected variations of the total magnetic field above seismic active regions, are presented, using a model based on the groundbased tectonomagnetic measurements and are simplified lithospheric-ionospheric coupling coefficient. Patent: Lammegger, R., WO 2008/151344 A3, Method and Device for Measuring Magnetic Fields

  6. Exploring high temperature phenomena related to post-detonation using an electric arc

    SciTech Connect

    Dai, Z. R. Crowhurst, J. C.; Grant, C. D.; Knight, K. B.; Tang, V.; Chernov, A. A.; Cook, E. G.; Lotscher, J. P.; Hutcheon, I. D.

    2013-11-28

    We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100 μs. Samples took the form of a 4 μm-thick film deposited onto 8 pairs of 17 μm-thick Cu electrodes supported on a 25 μm-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO{sub 2}, UC{sub 2}, UCu{sub 5},) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ∼2300 K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.

  7. Exploring high temperature phenomena related to post-detonation using an electric arc

    NASA Astrophysics Data System (ADS)

    Dai, Z. R.; Crowhurst, J. C.; Grant, C. D.; Knight, K. B.; Tang, V.; Chernov, A. A.; Cook, E. G.; Lotscher, J. P.; Hutcheon, I. D.

    2013-11-01

    We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100 μs. Samples took the form of a 4 μm-thick U238 film deposited onto 8 pairs of 17 μm-thick Cu electrodes supported on a 25 μm-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO2, UC2, UCu5,) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ˜2300 K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.

  8. Severe wind flow of small spatial and temporal scales: The microburst and related phenomena

    NASA Technical Reports Server (NTRS)

    Roberts, Rita D.; Mccarthy, John

    1985-01-01

    Low-altitude winds on the meso- and microscale are the primary focus of study for the Research Applications Program (RAP) of NCAR. Local weather features such as microbursts, microburst lines, gust fronts, and convergent wind boundaries have been observed and documented extensively. A microburst is a strong, small-scale convective storm outflow which diverges horizontally in all directions upon impact with the ground (Fujita, 1981). A microburst line is composed of two or more microbursts which occur either simultaneously or consecutively, and subsequently form a diverging line of outflow. The temporal and spatial scales of these phenomena are shown. Microbursts and microburst lines generally occur on both the meso- and microscale, while gust fronts and convergent wind boundaries overlap into the mesoscale. Microbursts, in particular, not only are small spatially but are also a short-lived phenomenon. Clearly, some of these features are on a much smaller spatial and temporal scale than can be resolved by a global wind measurement. During the past three years, three experiments were held in the Denver, CO, area to observe boundary-layer winds. Their main objectives were observation and documentation of those weather features discussed above. The Joint Airport Weather Studies (JAWS) Project, which ran in the summer of 1982, was set up to study microbursts. The Convective Initiation Project (1984) was designed to document clear-air convergent wind boundaries, including gust fronts, and their role in convective storm initiation. This project was immediately followed by the Classify, Locate, and Avoid Wind Shear experiment that expanded upon the work done in JAWS. Details on the scales of these weather features are presented. The wind sensors used to detect these phenomena are also discussed. Concluding comments address the usefulness of a global wind measurement system as it pertains to our local scale of interest.

  9. Structural variation along the southwestern Nankai seismogenic zone related to various earthquake phenomena

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.; Shimomura, N.; Kodaira, S.; Obana, K.; Takahashi, T.; Yamamoto, Y.; Sato, T.; Kashiwase, K.; Fujimori, H.; Kaneda, Y.; Mochizuki, K.; Kato, A.; Iidaka, T.; Kurashimo, E.; Shinohara, M.; Takeda, T.; Shiomi, K.

    2011-12-01

    In the Nankai Trough subduction seismogenic zone, the Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. In order to reduce a great deal of damage to coastal area from both strong ground motion and tsunami generation, it is necessary to understand rupture synchronization and segmentation of the Nankai megathrust earthquake. For a precise estimate of the rupture area of the Nankai megathrust event, it is important to know the geometry of the subducting Philippine Sea plate and deep subduction structure along the Nankai Trough. To obtain the deep subduction structure of the coseismic rupture area of the Nankai earthquake in 1946 off Shikoku area, the large-scale high-resolution wide-angle seismic study was conducted in 2009 and 2010. In this study, 201 and 200 ocean bottom seismographs were deployed off the Shikoku Island and the Kii channel respectively. A tuned airgun system (7800 cu. in.) shot every 200m along 13 profiles. Airgun shots were also recorded along an onshore seismic profile (prepared by ERI, univ. of Tokyo and NIED) prolonged from the offshore profile off the Kii Peninsula. Long-term observation was conducted for ~9 months by 21 OBSs off the Shikoku area and 20 OBSs off the Kii channel.This research is part of 'Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. Structural images of the overriding plate indicate the old accreted sediments (the Cretaceous-Tertiary accretionary prism) with the velocity greater than 6km/s extend seaward from off the Shikoku to the Hyuga-nada. Moreover, the young accreted sediments become relatively thinner eastward from off the cape Ashizuri to Muroto. These structural variations might be related to the different rupture pattern of the Nankai event. Structural image of the deep low frequency earthquakes and tremors is shown by using the airgun shots recorded at onshore

  10. Macroscopic nucleation phenomena in continuum media with long-range interactions

    PubMed Central

    Nishino, Masamichi; Enachescu, Cristian; Miyashita, Seiji; Rikvold, Per Arne; Boukheddaden, Kamel; Varret, François

    2011-01-01

    Nucleation, commonly associated with discontinuous transformations between metastable and stable phases, is crucial in fields as diverse as atmospheric science and nanoscale electronics. Traditionally, it is considered a microscopic process (at most nano-meter), implying the formation of a microscopic nucleus of the stable phase. Here we show for the first time, that considering long-range interactions mediated by elastic distortions, nucleation can be a macroscopic process, with the size of the critical nucleus proportional to the total system size. This provides a new concept of “macroscopic barrier-crossing nucleation”. We demonstrate the effect in molecular dynamics simulations of a model spin-crossover system with two molecular states of different sizes, causing elastic distortions. PMID:22355677

  11. Effect of wake structure on blade-vortex interaction phenomena: Acoustic prediction and validation

    NASA Technical Reports Server (NTRS)

    Gallman, Judith M.; Tung, Chee; Schultz, Klaus J.; Splettstoesser, Wolf; Buchholz, Heino

    1995-01-01

    During the Higher Harmonic Control Aeroacoustic Rotor Test, extensive measurements of the rotor aerodynamics, the far-field acoustics, the wake geometry, and the blade motion for powered, descent, flight conditions were made. These measurements have been used to validate and improve the prediction of blade-vortex interaction (BVI) noise. The improvements made to the BVI modeling after the evaluation of the test data are discussed. The effects of these improvements on the acoustic-pressure predictions are shown. These improvements include restructuring the wake, modifying the core size, incorporating the measured blade motion into the calculations, and attempting to improve the dynamic blade response. A comparison of four different implementations of the Ffowcs Williams and Hawkings equation is presented. A common set of aerodynamic input has been used for this comparison.

  12. Interactive Visualization of Transient Solar Wind Phenomena for Space Weather Applications

    NASA Astrophysics Data System (ADS)

    Wang, C. X.; Hick, P. P.; Jackson, B. V.

    2003-12-01

    We present a volume rendering system developed for the visualization and manipulation of 3D heliospheric volume data such as solar wind density, velocity and magnetic field. Our system exploits the capabilities of the VolumePro 1000 board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of rendering a 512-cubed array of volume data in real time at up to 30 frames per second on a standard PC. Many operations have been implemented such as stereo/perspective views, animations of time-sequences, and determination of CME volumes and masses. We will show examples of three-dimensional heliospheric volumes from tomographic reconstructions of density and velocity using real-time interplanetary scintillation (IPS) data. In the near future we expect to add reconstructions based on the all-sky observations from the recently launched Solar Mass Ejection Imager and employ our system to interactively analyze and visualize the abundant information embedded in these data.

  13. Plasma Surface Interactions and Life-Limiting Phenomena in Ion Engines

    NASA Astrophysics Data System (ADS)

    Polk, James

    2000-10-01

    Ion propulsion is entering an age of application in NASA's planetary program as a key technology being demonstrated on Deep Space 1 (DS1). The single ion thruster on DS1 propelled it to an encounter with the asteroid Braille in July 1999 and is now used to provide the Delta-V for a flyby of the comet Borrelly in 2001. It will deliver a total Delta-V of 4.5 km/s to the 486 kg spacecraft in this mission while consuming less than 81 kg of xenon. With this demonstration, ion propulsion is now being considered for a range of future planetary missions. The high specific impulse capability of ion thrusters makes it possible to perform demanding outer planet and sample return missions with smaller, less expensive launch vehicles and shorter trip times. However, the low thrust levels that ion engines provide necessitate long burn times, typically thousands of hours per engine. Many of the potential failure modes that limit ion engine life are driven by plasma-surface interactions. The experimental characterization of wear processes from ground testing and current theoretical understanding of the erosion mechanisms will be discussed in this presentation.

  14. Effect of some smooth muscle relaxant drugs on calcium-related phenomena.

    PubMed

    Ronca-Testoni, S; Hrelia, S; Hakim, G; Ronca, G; Rossi, C A

    1984-04-30

    Some smooth muscle relaxant drugs devoid of anticholinergic action have been tested for their interaction with calmodulin, calmodulin-stimulated cyclic nucleotide phosphodiesterase activity, and uterine membrane binding sites for nitrendipine and adenosine. The myolytic activity of octylonium bromide and pinaverium bromide may be due to their interaction with calmodulin-dependent systems. Trimebutine maleate does not bind either to calmodulin or to nitrendipine and adenosine receptors. Tiropramide has no effect on calmodulin-dependent systems and on Ca2+ channels but it shows a competition for the A2-type adenosine receptors. PMID:6329247

  15. Detailed simulations of air-water interaction phenomena in ocean waves

    NASA Astrophysics Data System (ADS)

    Iafrati, A.; Durante, D.

    2012-04-01

    In the present contribution the flow induced in air by ocean waves is investigated. The air-water interaction problem is of obvious interest in the context of wind generated waves. However, the flow induced in the lower atmosphere layer by ocean waves has also important effects on the exchange processes between atmosphere and ocean and in some circumstances it influences weather conditions on large scales. The problem is studied numerically by a two-dimensional Navier-Stokes solver which models the flow in air and water as that of a single incompressible fluid with density and viscosity expressed as a smooth function of the distance from the interface. The free surface is captured as the zero level set of the distance function. The distance from the interface is reinitialized every time step, so that the thickness of the transition region remains constant in time. The method is applied to two problems characterized by quite different length scales and steepnesses. In both cases the limits associated to the numerical approach and possible effects on the results are discussed. The first application is an attempt of investigating the role played by the flow in air on the dissipation rate of swells. The interest for such problem stems from some studies according to which the flow in air has an important effect on the dissipation of the steepest swells (Ardhuin et al, 2009). Motivated by the above findings, numerical simulations are performed in order to investigate the characteristics of the flow induced in air by swell with wavelengths in a range 50 to 300 m. Results are presented in terms of vorticity field in air with quantitative analyses of the vertical flux of horizontal momentum and of the viscous dissipation in the air phase. The thickness of the air layer which is influenced by the passage of the swell is also given. The second study analyzes the flow induced in air by the evolution of modulated wave trains. In this case the fundamental wavelength is 0.6 m

  16. Observation of genetic relation among new phenomena Geminion, Chiron and mini-Centauro

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The threshold energy problem of exotic type interactions is discussed on the basis of available information from the Chacaltaya emulsion chamber experiment. The genetic hypothesis is proposed as a working hypothesis to explain the discrepancy seen in cosmic ray study and CERN p bar -p collider experiments.

  17. Analysis and control of nonlinear dynamical behavior with applications to selected interfacial and volumetric materials-related phenomena

    NASA Astrophysics Data System (ADS)

    Gupta, Arnab

    2000-10-01

    The objective of this study was to apply recently developed concepts in the area of nonlinear dynamics to a spectrum of materials-related problems. New models were developed to describe the Portevin---Le Chatelier (PLC) effect and the growth of thin films by ballistic deposition. In addition, a variety of control strategies were developed, intended to favorably alter the dynamical behavior of nonlinear systems. A generalized mathematical description of the PLC effect was presented in the form of delay differential equations. Existing dislocation evolution equations from literature were modified by including a time-delay effect and shown to reproduce experimentally measured characteristics. A new model, based on evolution of the fraction of mobile dislocations due to pinning and depinning by solute atoms, was developed is. The temperature and strain-rate conditions for the PLC effect were mathematically established based on this model. The existence of critical strains and negative strain-rate sensitivity was also explained. A cellular automata-based simple model was developed separately to study slip behavior during inhomogeneous deformation. The change in reloading time and serration amplitude of stress with applied strain-rate from simulations showed good agreement with experimental results. Existing models of chemisorption, thin film growth, plastic instabilities, and voltage collapse in electrical power systems were studied using established techniques for characterizing nonlinear processes. Simple feedback methods including derivative control were used to stabilize certain instabilities in these model systems. The robustness of the control methods was evaluated. Three new feedback methods for control were developed and successfully applied to stabilize an unstable fixed point in a model for dissociative chemisorption of a diatomic gas. A discrete model was developed to simulate the phenomena of surface growth by ballistic deposition. Three parameters were

  18. Dielectric phenomena associated with the keratin-glucose interactions of nail plate.

    PubMed

    Marzec, E; Wierzbicki, K; Olszewski, J; Samborski, W; Skorupska, E; Bahloul, K; Krzywicka, A; Krauss, H

    2013-09-01

    In this study, we analyzed the effect of water and frequency on the dielectric properties of the nail plate in healthy individuals and in diabetic patients. The temperature dependencies of the loss tangent for both healthy and diabetic nail represent the relation between the electrical energy lost and stored in keratin-glucose-water complexes of this tissue. The differences between these materials concern the temperature ranges in which there appears the decomposition of loosely bound water. The effect of glycation on the loss tangent of the wet and the dry nail is supported by higher values of this parameter than in those describing the healthy samples in the whole temperature range and above 100°C, respectively. In addition, glycation lead to distinct increase in the dielectric relaxation decrement in permittivity and dielectric loss between the frequency of 500 Hz and 100 kHz for the wet and the dry nail. The results of this study indicate that the dielectric spectroscopy may be useful in observing the decomposition of water in the diabetic nail plate. PMID:23632462

  19. Paranormal phenomena

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    1996-08-01

    Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

  20. Nonlinear quantum phenomena and biophysical aspects of complexity related to health and disease.

    PubMed

    Brizhik, L; Foletti, A

    2014-01-01

    In this paper we discuss living systems as a non-linear self-interacting phenomenon, stabilized by the non-linear interaction between matter and self-created electromagnetic field. Such electromagnetic field can arise, in particular, as the radiation from electrosolitons which mediate the charge transport along macromolecules in metabolic redox processes. The non-linear nature of solitons results in an effective mechanism and leads to the synchronization of redox processes. It allows intra- and intercellular communication and long-range coherence in the system. One peculiar property of solitons is the resonant effect of external weak stimuli on their dynamics, which can explain the mechanism of low-intensity (non-thermal) electromagnetic therapies. We also discuss the stabilizing role of noise and spatial symmetry breaking in living organisms as open dissipative structures far from equilibrium, and health/disease states as the corresponding attractors of the system in the multi-parametric phase diagram. The essential role of electromagnetic potentials in self-regulation and self-healing processes is analyzed, based on the long-range matter-field interaction and fast information transfer, provided by the electromagnetic potentials. PMID:25316124

  1. A new South American network to study the atmospheric electric field and its variations related to geophysical phenomena

    NASA Astrophysics Data System (ADS)

    Tacza, J.; Raulin, J.-P.; Macotela, E.; Norabuena, E.; Fernandez, G.; Correia, E.; Rycroft, M. J.; Harrison, R. G.

    2014-12-01

    In this paper we present the capability of a new network of field mill sensors to monitor the atmospheric electric field at various locations in South America; we also show some early results. The main objective of the new network is to obtain the characteristic Universal Time diurnal curve of the atmospheric electric field in fair weather, known as the Carnegie curve. The Carnegie curve is closely related to the current sources flowing in the Global Atmospheric Electric Circuit so that another goal is the study of this relationship on various time scales (transient/monthly/seasonal/annual). Also, by operating this new network, we may also study departures of the Carnegie curve from its long term average value related to various solar, geophysical and atmospheric phenomena such as the solar cycle, solar flares and energetic charged particles, galactic cosmic rays, seismic activity and specific meteorological events. We then expect to have a better understanding of the influence of these phenomena on the Global Atmospheric Electric Circuit and its time-varying behavior.

  2. Special relativity completed: The source of some 2s in the magnitude of physical phenomena

    NASA Astrophysics Data System (ADS)

    Strandberg, M. W. P.

    1986-04-01

    Some factors of 2 relate predictions made of relativistic systems by the special and the general theory. Conventional wisdom often assigns the source of the factors of 2 to complicated kinematical effects of general relativity. It is pointed out that special relativity plus the complete form of the equivalence postulate can be made into a logical structure which allow them, in a heuristic manner, to predict not only local effects, but also some global effects described by the general theory. Calculation of the gravitational deflection of light and the precession of the perihelion of planets using special relativity with the complete equivalence postulate makes the origin of some 2s simple to understand. From the time of Minkowski on, the requirements and constraints on the theory of relativity have been demonstrated using group theoretical arguments. The general observation is made that physics teaching would be improved in the persuasiveness of its epistemology if the properties of physical systems which are displayed by the group theory of representations played a larger role in the physics curriculum.

  3. Weld pool phenomena

    SciTech Connect

    David, S.A.; Vitek, J.M.; Zacharia, T.; DebRoy, T.

    1994-09-01

    During welding, the composition, structure and properties of the welded structure are affected by the interaction of the heat source with the metal. The interaction affects the fluid flow, heat transfer and mass transfer in the weld pool, and the solidification behavior of the weld metal. In recent years, there has been a growing recognition of the importance of the weld pool transport processes and the solid state transformation reactions in determining the composition, structure and properties of the welded structure. The relation between the weld pool transport processes and the composition and structure is reviewed. Recent applications of various solidification theories to welding are examined to understand the special problems of weld metal solidification. The discussion is focussed on the important problems and issues related to weld pool transport phenomena and solidification. Resolution of these problems would be an important step towards a science based control of composition, structure and properties of the weld metal.

  4. Examining classroom interactions related to difference in students' science achievement

    NASA Astrophysics Data System (ADS)

    Zady, Madelon F.; Portes, Pedro R.; Ochs, V. Dan

    2003-01-01

    The current study examines the cognitive supports that underlie achievement in science by using a cultural historical framework (L. S. Vygotsky (1934/1986), Thought and Language, MIT Press, Cambridge, MA.) and the activity setting (AS) construct (R. G. Tharp & R. Gallimore (1988), Rousing minds to life: Teaching, learning and schooling in social context, Cambridge University Press, Cambridge, MA.) with its five features: personnel, motivations, scripts, task demands, and beliefs. Observations were made of the classrooms of seventh-grade science students, 32 of whom had participated in a prior achievement-related parent-child interaction or home study (P. R. Portes, M. F. Zady, & R. M. Dunham (1998), Journal of Genetic Psychology, 159, 163-178). The results of a quantitative analysis of classroom interaction showed two features of the AS: personnel and scripts. The qualitative field analysis generated four emergent phenomena related to the features of the AS that appeared to influence student opportunity for conceptual development. The emergent phenomenon were science activities, the building of learning, meaning in lessons, and the conflict over control. Lastly, the results of the two-part classroom study were compared to those of the home science AS of high and low achievers. Mismatches in the AS features in the science classroom may constrain the opportunity to learn. Educational implications are discussed.

  5. Images of Gravitational and Magnetic Phenomena Derived from Two-dimensional Back-projection Doppler Tomography of Interacting Binary Stars

    NASA Astrophysics Data System (ADS)

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J.

    2014-11-01

    We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The Hα tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

  6. Images of gravitational and magnetic phenomena derived from two-dimensional back-projection Doppler tomography of interacting binary stars

    SciTech Connect

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J. E-mail: asc5097@psu.edu

    2014-11-10

    We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The Hα tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

  7. Supergranulation-driven Alfven waves in the solar chromosphere and related phenomena.

    NASA Technical Reports Server (NTRS)

    Hollweg, J. V.

    1972-01-01

    It has recently been recognized that Alfven waves frequently dominate the microstructure of the solar wind at the orbit of the earth. We seek a solar source for these waves, and consider here their excitation by the supergranular motions. The wave equation is solved in a horizontally stratified, bi-exponential solar atmosphere. The interaction of Alfven wave motions associated with adjacent supergranules is discussed qualitatively. The Alfven wave effectively conveys the supergranular motions to great heights in the chromosphere. These motions are oppositely directed above intersupergranule boundaries, and compress the magnetic field there. A naive calculation of the compression, based on balancing dynamic and magnetic pressures, leads to adequate agreement with observations of the chromospheric network. We find that the magnetic field is appreciably compressed only below about 1500 km, and on this basis we reject theories of spicule formation which require large vertical magnetic fields at the heights reached by spicules. We advance a theory for spicule formation, in which spicules form as a result of matter being squeezed upward, out of the compression region between adjacent supergranules.

  8. Plasma Flow Interaction With Iter Divertor Related Surfaces

    NASA Astrophysics Data System (ADS)

    Dojcinovic, I. P.

    2010-07-01

    It has been found that the plasma flow generated by quasistationary plasma accelerators can be used for simulation of high energy plasma interaction with different materials of interest for fusion experiments (Arkhipov et al. 2000, Federici et al. 2005). It is especially important for the studies of the processes such as ELMs (edge localized modes), plasma disruptions and VDEs (vertical displacement events), during which a significant part of the confined hot plasma is lost from the core to the SOL (scrape off layer) enveloping the core region. Experiments using plasma guns have been used to assess erosion from disruptions and ELMs. Namely, in this experiment modification of different targets, like molybdenum, CFC and silicon single crystal surface by the action of hydrogen and nitrogen quasistationary compression plasma flow (CPF) generated by magnetoplasma compressor (MPC) has been studied. MPC plasma flow with standard parameters (1 MJ/m^2 in 0.1 ms) can be used for simulation of transient peak thermal loads during Type I ELMs and disruptions (Dojcinovic et al. 2007). Analysis of the targets erosion, brittle destruction, melting processes, and dust formation has been performed (Dojcinovic et al. 2006). These surface phenomena are results of specific conditions during CPF interaction with target surface. The investigations are related to the fundamental aspects of high energy plasma flow interaction with different material of interest for fusion. One of the purposes is a study of competition between melting and cleavage of treated solid surface. The other is investigation of plasma interaction with first wall and divertor component materials related to the ITER experiment.

  9. Fluid mechanic phenomena relating to flow control in conduits and pumps

    NASA Astrophysics Data System (ADS)

    Bayazit, Yilmaz

    first time, thereby contradicting the prior limitation to inertial laminar flow. The Taguchi method was applied to pinpoint the most important among the independent variables with respect to the dimensionless pressure drop, highlighting the importance of the porosity. Control of the liquid flow produced by a pump was analyzed as a problem of fluid-structural interaction.

  10. Drift compression experiments on MBE-4 and related emittance growth phenomena

    SciTech Connect

    Eylon, S.; Faltens, A.; Fawley, W.; Garvey, T.; Hahn, K.; Henestroza, E.; Smith, L.

    1991-04-01

    We have recently conducted a series of experiments on the MBE-4 heavy ion accelerator in which a velocity tilt was placed on the beam in the first accelerating section beyond the injector, followed by drift compression over the remaining 11 meters. Depending upon the magnitude of the velocity tilt and the accompanying mismatch in the focusing lattice, emittance growth was observed, manifested by butterfly'' shapes in x {minus} x{prime} phase space. We discuss various analytical limits on ion beam compression and relate them to these experiments and also to a driver for a heavy ion fusion reactor. We also present numerical simulations which investigate various aspects of compression and consequent emittance growth. 2 refs., 3 figs., 1 tab.

  11. Electromagnetic emission memory phenomena related to LiF ionic crystal deformation

    NASA Astrophysics Data System (ADS)

    Mavromatou, C.; Tombras, G. S.; Ninos, D.; Hadjicontis, V.

    2008-04-01

    During the uniaxial compression of LiF ionic monocrystals, acoustic and electromagnetic emissions (EME) are detected. We observed that when the compression is performed in successive loading, unloading cycles and these emissions are being monitored, no new emissions will occur unless the maximum stress of the previous cycle is exceeded, meaning that the material presents memory characteristics. This is observed not only for the acoustic emission (AE), which is the well known Kaiser effect, but for the EME as well. In other words, the material appears to memorize and reveal the previously maximum stress it suffered while being deformed. The importance of an electromagnetic memory feature of a material can be related to various applications in material science, especially when the detection of AE is not feasible or gives false alert. Such cases may very well be earthquakes' predictive indications, monitoring of mines' stability, imminent landslides, etc.

  12. Physiological ischemia/reperfusion phenomena and their relation to endogenous melatonin production: a hypothesis.

    PubMed

    Tan, Dun-Xian; Manchester, Lucien C; Sainz, Rosa M; Mayo, Juan C; León, Josefa; Reiter, Russel J

    2005-07-01

    Ischemia/reperfusion is a frequently encountered phenomenon in organisms. Prolonged ischemia followed then by reperfusion results in severe oxidative injury in tissues and organs; however, some species can tolerate such events better than others. In nature, arousal from hibernation and resurfacing from diving causes animals to experience classic ischemia/reperfusion and, somehow, these animals cope well with the potential oxidative stress. It has been documented that during these physiological ischemia/reperfusion events, the activities of several antioxidant enzymes and the levels of some small-molecular-weight antioxidants become elevated. For example, the potent small-molecular-weight antioxidant melatonin often attains especially high levels during these physiological ischemia/reperfusion events including during arousal from hibernation or in the newborns during delivery. Highly elevated melatonin production during these physiological ischemia/reperfusion episodes exhibits several features. First, this high melatonin production is transient and fits well with the time schedule of the physiological ischemia/reperfusion period; therefore, it is not related to the normal endogenous melatonin rhythm. Yet, this transient peak protects the animals from destructive oxidative processes that occur during these transition periods. Second, these high levels of melatonin seem to derive from several organs since pinealectomy does not totally reduce circulating levels of this agent. Third, high melatonin production present at arousal from hibernation or in the newborns at birth does not appear to be controlled by light, i.e., it occurs both during the day and at night, and the amplitudes of elevated melatonin levels are equivalent at these times. The significance of these findings is discussed herein. Based on currently available data, we hypothesize that melatonin plays an important role in the physiological ischemia/reperfusion, i.e., as a member of antioxidant defense

  13. Investigation of the structure of the electromagnetic field and related phenomena, generated by the active satellite

    NASA Technical Reports Server (NTRS)

    Alpert, Yakov L.

    1992-01-01

    A short review is given for the general frequency and angle distribution of the electric field radiated by an electric dipole E = E(sub 0)cos(omega)t, in a magnetoplasma. Detailed results of numerical calculations of (E) were made in the Very Low Frequency (VLF) and the Low Frequency (LF) bands 0.02f(sub b) is less than or equal to F is less than or equal to 0.5f(sub b) (F is approximately (4-500) kHz) in the ionosphere and magnetosphere in the altitude region Z = (800-6000) km; f(sub b) is the electron gyro-frequency of the plasmas in the discussed region f(sub b) is approximately equal to (1.1 to 0.2) MHz. The amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth's magnetic field line (B(sub 0)), it is the so called Axis field (E(sub 0)) and in the Storey (E(sub St)), Reversed Storey (E(sub RevSt)), and Resonance (E(sub Res)) Cones. The maximal values of E(sub 0), E(sub Res), and E(sub RevSt) are very pronounced close to the low hybrid frequency, F approximately F(sub L). The flux of the electric field is concentrated in very narrow regions, the apex angles of the cones delta(beta) is approximately equal to (0.1 - 1) degree. The enhancement and focusing of the electric field is growing up, especially quickly at Z greater than 800 km. At Z is greater than 1000 up to 6000 km, the relative value of (E), in comparison with its value at Z = 800 km is about (10(exp 2) to 10(exp 4)) times larger. Thus, the flux of VLF and LF electromagnetic waves in the Earth magnetoplasma produces and is guided by very narrow pencil beams, similar, let us say, to laser beams.

  14. Ancient sandstone condition assessment in relation to degradation, cleaning and consolidation phenomena

    NASA Astrophysics Data System (ADS)

    Drdácký, Miloš; Frankeová, Dita; Slížková, Zuzana

    2015-04-01

    of cubes for non-destructive US tests and micro drilling. Then the cubes were cut into thin plates and they were tested for volumetric change due to hydric and temperature variations. That procedure allowed a comparison of results of the US tests on cubes and destructive bending tests on thin plates. The remains of these plates were used for porosity measurements. The overall test procedure was planned and carried out in a way which ensured testing of appropriately corresponding specimens. The results supplied data for studying efficiency of the consolidation treatment with silicic acid ester products in relation to three pre-treatment stone conditions, as well as to the type of sandstone cementation (the tested stones had mostly a kaolin or silica, rarely a goethit cementation). The tested stone types were documented by macroscopic and microscopic (thin section) descriptions. The results further indicate capacity of individual testing and assessment methods, and help to select methods suitable for in situ diagnostics.

  15. Roles of forebrain GABA receptors in controlling vasopressin secretion and related phenomena under basal and hyperosmotic circumstances in conscious rats.

    PubMed

    Yamaguchi, Ken'ichi; Yamada, Takaho

    2008-09-01

    Although the anteroventral third ventricular region (AV3V), a forebrain area essential for homeostatic responses, includes receptors for gamma-aminobutyric acid (GABA), the roles of these receptors in controlling vasopressin (AVP) secretion and related phenomena have not been clarified as yet. This study aimed to pursue this problem in conscious rats implanted with indwelling catheters. Cerebral injection sites were determined histologically. Applications of bicuculline, a GABA(A) receptor antagonist, to the AV3V induced prompt and marked augmentations in plasma AVP, osmolality, glucose, arterial pressure and heart rate, without affecting plasma electrolytes. Such phenomena did not occur when phaclofen, a GABA(B) receptor antagonist, was applied to the AV3V. All of the effects of AV3V-administered bicuculline were abolished by preadministration of the GABA(A) receptor agonist muscimol. Preadministration of either MK-801 or NBQX, ionotropic glutamatergic receptor antagonists, was also potent to abolish the AVP response to AV3V bicuculline. When hypertonic saline was infused intravenously, plasma AVP increased progressively, in parallel with rises in plasma osmolality, sodium and arterial pressure. AV3V application of muscimol or baclofen, a GABA(B) receptor agonist, was found to abolish the response of plasma AVP, without inhibiting that of the osmolality or sodium. The response of arterial pressure was also blocked by muscimol treatment, but not by baclofen treatment. Based on these results, we concluded that, under basal conditions, GABA receptors in the AV3V or vicinity may tonically operate to attenuate AVP secretion and cardiovascular functions through mechanisms associated with glutamatergic activity, and that plasma hyperosmolality may cause facilitation of AVP release by decreasing forebrain GABAergic activity. PMID:18639747

  16. Triplet exciton state and related phenomena in the β -phase of poly(9,9-dioctyl)fluorene

    NASA Astrophysics Data System (ADS)

    Rothe, C.; King, S. M.; Dias, F.; Monkman, A. P.

    2004-11-01

    Using both time-resolved emission and cw photoinduced absorption spectroscopy as a function of temperature, the aggregation phenomena ( β -phase formation) observed in poly(9,9-dioctyl)fluorene is studied. All spectra of the β phase, including absorption, prompt and delayed fluorescence, phosphorescence, and photoinduced triplet absorption feature very narrow linewidths, which are unique within the class of conjugated polymers. From the comparison of the latter data with amorphous polyfluorene, poly(9,9-diethylhexyl)fluorene, as well as with the fully planar ladder-type poly(paraphenylene), we conclude that the origin of the β phase cannot simply be an extended intrachain conjugation, but interchain interactions are involved. Furthermore, the β phase acts as an energetic trap for both singlet and triplet excitons initially created on amorphous chain segments. The delayed fluorescence kinetics of the β phase were measured at different temperatures. From the analysis of these decays within the framework of dispersive triplet migration in a Gaussian density of states distribution, further evidence is provided that the delayed fluorescence originates from triplet-triplet annihilation. At room temperature, it is clear that triplet excitons migrate over large distances, exceeding that of singlet excitons. Also, the segregation time between dispersive triplet migration and classical thermally activated hopping, is in the case of β -phase containing samples, dependent on the separation of the β -phase domains.

  17. Influence of Tailored Applied Magnetic Fields on High-Power MPD Thruster Current Transport and Onset-Related Phenomena

    NASA Technical Reports Server (NTRS)

    Moeller, Robert C.; Polk, James E.

    2013-01-01

    magnetic field configurations enabled significant reductions in onset-related behaviors relative to self-field operation. These improvements should lead to reduced anode erosion, i.e., improved thruster lifetime, and increased thruster efficiency with the applied fields. The applied fields used in this study differ from both the topologies and relative field strengths typically used in the vast majority of conventional, so-called "applied-field MPD thrusters" (AF-MPDTs). These results suggest a distinctive and more effective approach to influencing the near-anode phenomena and mitigating the deleterious effects of onset with appropriately designed applied magnetic fields.

  18. LUNAR OUTGASSING, TRANSIENT PHENOMENA, AND THE RETURN TO THE MOON. II. PREDICTIONS AND TESTS FOR OUTGASSING/REGOLITH INTERACTIONS

    SciTech Connect

    Crotts, Arlin P. S.; Hummels, Cameron

    2009-12-20

    We follow Paper I with predictions of how gas leaking through the lunar surface could influence the regolith, as might be observed via optical transient lunar phenomena (TLPs) and related effects. We touch on several processes, but concentrate on low and high flow rate extremes, which are perhaps the most likely. We model explosive outgassing for the smallest gas overpressure at the regolith base that releases the regolith plug above it. This disturbance's timescale and affected area are consistent with observed TLPs; we also discuss other effects. For slow flow, escape through the regolith is prolonged by low diffusivity. Water, found recently in deep magma samples, is unique among candidate volatiles, capable of freezing between the regolith base and surface, especially near the lunar poles. For major outgassing sites, we consider the possible accumulation of water ice. Over geological time, ice accumulation can evolve downward through the regolith. Depending on gases additional to water, regolith diffusivity might be suppressed chemically, blocking seepage and forcing the ice zone to expand to larger areas, up to km{sup 2} scales, again, particularly at high latitudes. We propose an empirical path forward, wherein current and forthcoming technologies provide controlled, sensitive probes of outgassing. The optical transient/outgassing connection, addressed via Earth-based remote sensing, suggests imaging and/or spectroscopy, but aspects of lunar outgassing might be more covert, as indicated above. TLPs betray some outgassing, but does outgassing necessarily produce TLPs? We also suggest more intrusive techniques from radar to in situ probes. Understanding lunar volatiles seems promising in terms of resource exploitation for human exploration of the Moon and beyond, and offers interesting scientific goals in its own right. Many of these approaches should be practiced in a pristine lunar atmosphere, before significant confusing signals likely to be produced upon

  19. Lunar Outgassing, Transient Phenomena, and the Return to the Moon. II. Predictions and Tests for Outgassing/Regolith Interactions

    NASA Astrophysics Data System (ADS)

    Crotts, Arlin P. S.; Hummels, Cameron

    2009-12-01

    We follow Paper I with predictions of how gas leaking through the lunar surface could influence the regolith, as might be observed via optical transient lunar phenomena (TLPs) and related effects. We touch on several processes, but concentrate on low and high flow rate extremes, which are perhaps the most likely. We model explosive outgassing for the smallest gas overpressure at the regolith base that releases the regolith plug above it. This disturbance's timescale and affected area are consistent with observed TLPs; we also discuss other effects. For slow flow, escape through the regolith is prolonged by low diffusivity. Water, found recently in deep magma samples, is unique among candidate volatiles, capable of freezing between the regolith base and surface, especially near the lunar poles. For major outgassing sites, we consider the possible accumulation of water ice. Over geological time, ice accumulation can evolve downward through the regolith. Depending on gases additional to water, regolith diffusivity might be suppressed chemically, blocking seepage and forcing the ice zone to expand to larger areas, up to km2 scales, again, particularly at high latitudes. We propose an empirical path forward, wherein current and forthcoming technologies provide controlled, sensitive probes of outgassing. The optical transient/outgassing connection, addressed via Earth-based remote sensing, suggests imaging and/or spectroscopy, but aspects of lunar outgassing might be more covert, as indicated above. TLPs betray some outgassing, but does outgassing necessarily produce TLPs? We also suggest more intrusive techniques from radar to in situ probes. Understanding lunar volatiles seems promising in terms of resource exploitation for human exploration of the Moon and beyond, and offers interesting scientific goals in its own right. Many of these approaches should be practiced in a pristine lunar atmosphere, before significant confusing signals likely to be produced upon humans

  20. Colloidal Phenomena.

    ERIC Educational Resources Information Center

    Russel, William B.; And Others

    1979-01-01

    Described is a graduate level engineering course offered at Princeton University in colloidal phenomena stressing the physical and dynamical side of colloid science. The course outline, reading list, and requirements are presented. (BT)

  1. Objects, Entities, Behaviors, and Interactions: A Typology of Student-Constructed Computer-Based Models of Physical Phenomena

    ERIC Educational Resources Information Center

    Louca, Loucas T.; Zacharia, Zacharias C.; Michael, Michalis; Constantinou, Constantinos P.

    2011-01-01

    The purpose of this study was to develop a framework for analyzing and evaluating student-constructed models of physical phenomena and monitoring the progress of these models. Moreover, we aimed to examine whether this framework could capture differences between models created using different computer-based modeling tools; namely, computer-based…

  2. Investigation of metallurgical phenomena related to process and product development by means of High Temperature Confocal Scanning Laser Microscopy

    NASA Astrophysics Data System (ADS)

    Diéguez-Salgado, U.; Michelic, S.; Bernhard, C.

    2016-03-01

    An increased interest for high temperature metallurgical processes appeared during the last decades, in order to achieve the high quality requirements in steel products. A defined steel cleanness and microstructure essentially influence the final product quality. The high temperatures involved in metallurgical processes and the lack of in situ observations do not only complicate the verification of simulation model predictions but also make significant conclusions regarding the industrial processes difficult. For that reason, new tools and techniques are necessary to develop. By combining the advances of a laser, confocal optics and an infrared image furnace, the High Temperature Confocal Scanning Laser Microscopy (HTCSLM) is a strong tool which enables high temperature in situ observations of different metallurgical phenomena. Next to solidification processes and phase transformations also the behavior of inclusions at different interfaces in the system steel-slag-refractory can be observed. The present study focuses on the aspects of inclusion agglomeration in the liquid steel and the inclusion behavior at the steel/refractory interface in two different steel grades. Out of the obtained experimental data, attraction forces are calculated and compared. This information provides an important basis for a better understanding of inclusion behavior in industrial processes and the therewith related process optimization, like for example the clogging phenomenon during continuous casting.

  3. Experiences of possession and paranormal phenomena among women in the general population: are they related to traumatic stress and dissociation?

    PubMed

    Sar, Vedat; Alioğlu, Firdevs; Akyüz, Gamze

    2014-01-01

    This study sought to determine the prevalence of experiences of possession and paranormal phenomena (PNP) in the general population and their possible relations to each other and to traumatic stress and dissociation. The study was conducted on a representative female sample recruited from a town in central eastern Turkey. The Dissociative Disorders Interview Schedule, the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interviews for DSM-IV Axis-I and Personality Disorders, and the Childhood Abuse and Neglect Questionnaire were administered to 628 women. Of these, 127 (20.2%) women reported at least 1 type of PNP and 13 (2.1%) women reported possession. Women with a dissociative disorder reported all types of possession and PNP (except telepathy) more frequently than those without. Whereas women with a trauma history in childhood and adulthood or PTSD reported possession more frequently than those without, PNP were associated with childhood trauma only. Factor analysis yielded 4 dimensions: possession by and/or contact with nonhuman entities, extrasensory communications, possession by a human entity, and precognition. These factors correlated with number of secondary features of dissociative identity disorder and Schneiderian symptoms. Latent class analysis identified 3 groups. The most traumatized group, with predominantly dissociative and trauma-related disorders, had the highest scores on all factors. Notwithstanding their presence in healthy individuals, possession and PNP were associated with trauma and dissociation in a subgroup of affected participants. Both types of experience seem to be normal human capacities of experiencing that may be involved in response to traumatic stress. Given the small numbers, this study should be considered preliminary. PMID:24228817

  4. Transport Phenomena.

    ERIC Educational Resources Information Center

    McCready, Mark J.; Leighton, David T.

    1987-01-01

    Discusses the problems created in graduate chemical engineering programs when students enter with a wide diversity of understandings of transport phenomena. Describes a two-semester graduate transport course sequence at the University of Notre Dame which focuses on fluid mechanics and heat and mass transfer. (TW)

  5. Effect of anisotropic exchange interactions and short-range phenomena on superfluidity in a homogeneous dipolar Fermi gas

    NASA Astrophysics Data System (ADS)

    Corro, I.; Martin, A. M.

    2016-08-01

    We develop a simple numerical method that allows us to calculate the BCS superfluid transition temperature Tc precisely for any interaction potential. We apply it to a polarized, ultracold Fermi gas with long-range, anisotropic, dipolar interactions and include the effects of anisotropic exchange interactions. We pay particular attention to the short-range behavior of dipolar gases and reexamine current renormalization methods. In particular, we find that dimerization of both atoms and molecules significantly hampers the formation of a superfluid. The end result is that at high density or interaction strengths, we find Tc is orders of magnitude lower than previous calculations.

  6. Prospective Teachers' Difficulties in Interpreting Elementary Phenomena of Electrostatic Interactions: Indicators of the Status of Their Intuitive Ideas

    ERIC Educational Resources Information Center

    Criado, Ana Maria; Garcia-Carmona, Antonio

    2010-01-01

    Student teachers were tested before and after a teaching unit on electrostatic interactions in an attempt to consider their intuitive ideas and concept development. A study was made of students' explanations of basic interactions: those between two charged bodies, and those between a charged body and a neutral body. Two indicators of the cognitive…

  7. Fluorescence Correlation Spectroscopy Simulations of Photophysical Phenomena and Molecular Interactions: A Molecular Dynamics/Monte Carlo Approach

    PubMed Central

    Dix, James A.; Hom, Erik F. Y.; Verkman, A. S.

    2011-01-01

    Fluorescence correlation spectroscopy (FCS) is being applied increasingly to study diffusion and interactions of fluorescently labeled macromolecules in complex biological systems. Fluctuations in detected fluorescence, δF(t), are expressed as time-correlation functions, G(τ), and photon-count histograms, P(k;ΔT). Here, we developed a generalized simulation approach to compute G(τ) and P(k;ΔT) for complex systems with arbitrary geometry, photophysics, diffusion, and macromolecular interactions. G(τ) and P(k;ΔT) were computed from δF(t) generated by a Brownian dynamics simulation of single-molecule trajectories followed by a Monte Carlo simulation of fluorophore excitation and detection statistics. Simulations were validated by comparing analytical and simulated G(τ) and P(k;ΔT) for diffusion of noninteracting fluorophores in a three-dimensional Gaussian excitation and detection volume. Inclusion of photobleaching and triplet-state relaxation produced significant changes in G(τ) and P(k;ΔT). Simulations of macromolecular interactions and complex diffusion were done, including transient fluorophore binding to an immobile matrix, cross-correlation analysis of interacting fluorophores, and anomalous sub- and superdiffusion. The computational method developed here is generally applicable for simulating FCS measurements on systems complicated by fluorophore interactions or molecular crowding, and experimental protocols for which G(τ) and P(k;ΔT) cannot be computed analytically. PMID:16471761

  8. Investigating high speed phenomena in laser plasma interactions using dilation x-ray imager (invited)a)

    NASA Astrophysics Data System (ADS)

    Nagel, S. R.; Hilsabeck, T. J.; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Piston, K.; Felker, B.; Kilkenny, J. D.; Chung, T.; Sammuli, B.; Hares, J. D.; Dymoke-Bradshaw, A. K. L.

    2014-11-01

    The DIlation X-ray Imager (DIXI) is a new, high-speed x-ray framing camera at the National Ignition Facility (NIF) sensitive to x-rays in the range of ≈2-17 keV. DIXI uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps, a ≈10× improvement over conventional framing cameras currently employed on the NIF (≈100 ps resolution), and otherwise only attainable with 1D streaked imaging. The pulse-dilation technique utilizes a voltage ramp to impart a velocity gradient on the signal-bearing electrons. The temporal response, spatial resolution, and x-ray sensitivity of DIXI are characterized with a short x-ray impulse generated using the COMET laser facility at Lawrence Livermore National Laboratory. At the NIF a pinhole array at 10 cm from target chamber center (tcc) projects images onto the photocathode situated outside the NIF chamber wall with a magnification of ≈64×. DIXI will provide important capabilities for warm-dense-matter physics, high-energy-density science, and inertial confinement fusion, adding important capabilities to temporally resolve hot-spot formation, x-ray emission, fuel motion, and mix levels in the hot-spot at neutron yields of up to 1017. We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments.

  9. Dynamic PIC-simulations of charging phenomena related to the ICE-spacecraft in both cometary and solar wind environments

    NASA Technical Reports Server (NTRS)

    Thiemann, H.; Schunk, R. W.; Zwickl, R.

    1989-01-01

    Spacecraft charging phenomena in the cometary environment of Giacobini-Zinner are less dramatic than expected. The potential of the ICE-probe is less than +1V in the vicinity of Giacobini-Zinner, while the potential may rise up to +6V in the solar wind environment. The paper presents results of PIC simulations that show the dominant influence of photoemission (photoelectrons or impact-induced electrons) in the presence of the solar wind core and halo electrons. Secondary electrons are also important in the cometary environment to explain positive potentials.

  10. The Study of Tone and Related Phenomena in an Amazonian Tone Language: Gavião of Rondônia

    ERIC Educational Resources Information Center

    Moore, Denny; Meyer, Julien

    2014-01-01

    This paper describes the methods used to study the tone and some related phenomena of the language of the Gavião of Rondônia, Brazil, which is part of the Mondé branch of the Tupi family. Whistling of words by indigenous informants was discovered to be a very effective method for obtaining phonetic accuracy in tone and length. Methods were devised…

  11. Soluto-inertial phenomena: Designing long-range, long-lasting, surface-specific interactions in suspensions.

    PubMed

    Banerjee, Anirudha; Williams, Ian; Azevedo, Rodrigo Nery; Helgeson, Matthew E; Squires, Todd M

    2016-08-01

    Equilibrium interactions between particles in aqueous suspensions are limited to distances less than 1 μm. Here, we describe a versatile concept to design and engineer nonequilibrium interactions whose magnitude and direction depends on the surface chemistry of the suspended particles, and whose range may extend over hundreds of microns and last thousands of seconds. The mechanism described here relies on diffusiophoresis, in which suspended particles migrate in response to gradients in solution. Three ingredients are involved: a soluto-inertial "beacon" designed to emit a steady flux of solute over long time scales; suspended particles that migrate in response to the solute flux; and the solute itself, which mediates the interaction. We demonstrate soluto-inertial interactions that extend for nearly half a millimeter and last for tens of minutes, and which are attractive or repulsive, depending on the surface chemistry of the suspended particles. Experiments agree quantitatively with scaling arguments and numerical computations, confirming the basic phenomenon, revealing design strategies, and suggesting a broad set of new possibilities for the manipulation and control of suspended particles. PMID:27410044

  12. The Effect Of Intraresonator Nonlinear Optical And Magneto-Optical Phenomena Upon The Competitive Interaction Of Oppositely Directed Light Waves

    NASA Astrophysics Data System (ADS)

    Kornienko, L. S.; Kravtsov, N. V.; Shelaev, A. N.

    1985-01-01

    It is found experimentally that the competitive interaction of the oppositely directed (OD) light waves in YAG:Nd3+ and ruby solid-state ring lasers OIRL) can be significantly reduced due to nonlinear optical effects (second harmonic generation, stimulated Raman scattering, resonant absorption) since the nonlinear losses for the wave of lower intensity are lower. It was established that in the SRL with a resonantly absorbing medium the spatially inhomogeneous burning-out and the slowness of the relaxation of the inverted population in the solid-state active medium may result in strong phase nonreciprocity due to the frequency shift of the OD waves after their reflection from the moving lattice of the inverted population. The beat frequency strongly depends on detuning between the gain and absorption lines and may be more than two orders of magnitude less in comparison with the resonator frequency difference in the rotating SRL. The possibility has been shown of active stabilization of the bidirectional generation in the beat regime using the nonreciprocal amplitude Faraday element controlled by the external feedback circuit via the difference of the OD waves intensities.

  13. Tidal interaction: A possible explanation for geysers and other fluid phenomena in the Neptune-Triton system

    NASA Technical Reports Server (NTRS)

    Kelly, W. D.; Wood, C. L.

    1993-01-01

    Discovery of geyser-like plumes on the surface of Triton was a highlight of Voyager 2's passage through the Neptune planetary system. Remarkable as these observations were, they were not entirely without precedent. Considering the confirmed predictions for the 1979 Voyager Jovian passage, it was logical to consider other solar system bodies beside Io where tidal effects could be a significant factor in surface processes. It was our intuition that the Neptune-Triton gravitational bond acting at high inclination to the Neptune equator and the fact that Neptune was a fluid body was significant oblateness would produce tidal and mechanical forces that could be transformed into thermal energy vented on Triton's surface. Prior to the Voyager flyby, others have noted that capture and evolution of Triton's orbit from extreme eccentricity to near circular state today would have resulted in significant tidal heating, but these analysts disregard current day forces. Our calculations indicate that the time varying forces between Neptune-Triton fall midway between those exerted in the Earth-Moon and Jupiter-Io systems, and considering the low level of other energy inputs, this source of internal energy should not be ignored when seeking an explanation for surface activity. In each planet-satellite case, residual or steady-state eccentricity causes time-varying stresses on internal satellite strata. In the case of Jupiter the residual eccentricity is due largely to Galilean satellite interactions, particularly Io-Europa, but in the case of Neptune-Triton, it is the effect of Triton's inclined orbit about an oblate primary.

  14. Factors controlling erosion/deposition phenomena related to lahars at Volcán de Colima, Mexico

    NASA Astrophysics Data System (ADS)

    Vázquez, Rosario; Capra, Lucia; Coviello, Velio

    2016-08-01

    One of the most common phenomena at Volcán de Colima is the annual development of lahars that runs mainly through the southern ravines of the edifice. Since 2011 the study and the monitoring of these flows and of the associated rainfall has been achieved by means of an instrumented station located along the Montegrande ravine, together with the systematic surveying of cross-topographic profiles of the main channel. From these, we present the comparison of the morphological changes experimented by this ravine during the 2013, 2014 and 2015 rainy seasons. The erosion/deposition effects of 11 lahars that occurred during this period of time were quantified by means of the topographic profiles taken at the beginning and at the end of the rainy seasons and before and after the major lahar event of 11 June 2013. We identified (i) an erosive zone between 2100 and 1950 m a.s.l., 8° in slope, with an annual erosional rate of 10.3 % mainly due to the narrowness of the channel and to its high slope angle and (ii) an erosive-depositional zone, between 1900 and 1700 m a.s.l., ( ˜ 8 % erosion and ˜ 16 % deposition), characterized by a wider channel that decreases in slope angle (4°). Based on these observations, the major factors controlling the erosion/deposition rates in the Montegrande ravine are the morphology of the gully (i.e., channel bed slope and the cross section width) and the joint effect of sediment availability and accumulated rainfall. On the distal reach of the ravine, the erosion/deposition processes tend to be promoted preferentially one over the other, mostly depending on the width of the active channel. Only for extraordinary rainfall events are the largest lahars mostly erosive all along the ravine up to the distal fan where the deposition takes place. In addition, as well as the morphological characteristics of the ravine, the flow depth is a critical factor in controlling erosion, as deeper flows will promote erosion against deposition. Finally, by

  15. Teaching Optical Phenomena with Tracker

    ERIC Educational Resources Information Center

    Rodrigues, M.; Carvalho, P. Simeão

    2014-01-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a…

  16. An experimental and numerical investigation of thermocapillary driven phenomena for evaporating menisci in capillary tubes related to microelectronics cooling

    NASA Astrophysics Data System (ADS)

    Buffone, Cosimo

    temperature revealed clearly the effect of the asymmetrical flow pattern on temperature field. The direction of the induced convection rolls can be reversed by applying a temperature gradient along the capillary wall. With the tubes plunged in a pool of liquid, it is interesting to note that providing external heating to the system can substantially change the convection patterns. In particular is was revealed that the flow is enhanced when the heating element lies below the meniscus; on the contrary, when the heating element is above the meniscus and sufficient power is provided, the flow pattern is reversed with respect to the unheated situation. This important result confirms the fact that the phenomena being studied are strongly dominated by the action of surface tension. The numerical code used is a FVM with coordinate transformation in order to take into account the curved meniscus. The code was used to first reproduce some of the results obtained experimentally and successively was used to investigate those cases not easily accessible to experiment. Good quantitative (when possible) and qualitative agreement was found between experimental and numerical results. Results gained, both of velocity and flow map, meniscus temperature and finally numerical confirmation clearly lead to the conclusion that the heat and mass transfer in such small systems is strongly affected by the mechanism taking place in the meniscus contact line region. In this work, two cases of practical interest were also examined. The first concerns a heat pipe module for micro-electronic cooling where the effect of surface coating on the fin stack unit was experimentally investigated. The second is an extension of existing heat pipe technology to cool a heavily thermally loaded nozzle of future spacecraft vehicles of high specific impulse. (Abstract shortened by UMI.)

  17. The Fermi-Pasta-Ulam recurrence and related phenomena for 1D shallow-water waves in a finite basin

    SciTech Connect

    Ruban, V. P.

    2012-02-15

    Different regimes of the Fermi-Pasta-Ulam (FPU) recurrence are simulated numerically for fully nonlinear 'one-dimensional' potential water waves in a finite-depth flume between two vertical walls. In such systems, the FPU recurrence is closely related to the dynamics of coherent structures approximately corresponding to solitons of the integrable Boussinesq system. A simplest periodic solution of the Boussinesq model, describing a single soliton between the walls, is presented in analytic form in terms of the elliptic Jacobi functions. In the numerical experiments, it is observed that depending on the number of solitons in the flume and their parameters, the FPU recurrence can occur in a simple or complicated manner, or be practically absent. For comparison, the nonlinear dynamics of potential water waves over nonuniform beds is simulated, with initial states taken in the form of several pairs of colliding solitons. With a mild-slope bed profile, a typical phenomenon in the course of evolution is the appearance of relatively high (rogue) waves, while for random, relatively short-correlated bed profiles it is either the appearance of tall waves or the formation of sharp crests at moderate-height waves.

  18. The relation of cool flames and auto-ignition phenomena to process safety at elevated pressure and temperature.

    PubMed

    Pekalski, A A; Zevenbergen, J F; Pasman, H J; Lemkowitz, S M; Dahoe, A E; Scarlett, B

    2002-07-01

    The cool-flame phenomenon can occur in fuel-oxygen (air) mixtures within the flammable range and outside the flammable range, at fuel-rich compositions, at temperatures below the auto-ignition temperature (AIT). It is caused by chemical reactions occurring spontaneously at relatively low temperatures and is favoured by elevated pressure. The hazards that cool flames generate are described. These vary from spoiling a product specification through contamination and explosive decomposition of condensed peroxides to the appearance of unexpected normal (hot) flame (two-stage ignition). PMID:12062956

  19. Helping Students Assess the Relative Importance of Different Intermolecular Interactions

    ERIC Educational Resources Information Center

    Jasien, Paul G.

    2008-01-01

    A semi-quantitative model has been developed to estimate the relative effects of dispersion, dipole-dipole interactions, and H-bonding on the normal boiling points ("T[subscript b]") for a subset of simple organic systems. The model is based upon a statistical analysis using multiple linear regression on a series of straight-chain organic…

  20. Material laws and related uncommon phenomena in the electromagnetic response of type-II superconductors in longitudinal geometry

    NASA Astrophysics Data System (ADS)

    Ruiz, H. S.; Badía-Majós, A.; López, C.

    2011-11-01

    Relying on our theoretical approach for the superconducting critical state problem in 3D magnetic field configurations, we present an exhaustive analysis of the electrodynamic response for the so-called longitudinal transport problem in the slab geometry. A wide set of experimental conditions have been considered, including modulation of the applied magnetic field either perpendicular or parallel (longitudinal) to the transport current density. The main objective of our work was to characterize the role of the macroscopic material law that should properly account for the underlying mechanisms of flux cutting and depinning. The intriguing occurrence of negative current patterns and the enhancement of the transport current flow along the center of the superconducting sample are reproduced as a straightforward consequence of the magnetically induced internal anisotropy. Moreover, we show that, related to a maximal projection of the current density vector onto the local magnetic field, a maximal transport current density occurs somewhere within the sample. The elusive measurement of the flux cutting threshold (critical value of such parallel component J_{ {c} \\parallel } ) is suggested on the basis of local measurements of the transport current density. Finally, we show that a high correlation exists between the evolution of the transport current density and the appearance of paramagnetic peak structures in terms of the applied longitudinal magnetic field.

  1. Stress-related phenomena and detoxification mechanisms induced by common pharmaceuticals in alfalfa (Medicago sativa L.) plants.

    PubMed

    Christou, Anastasis; Antoniou, Chrystalla; Christodoulou, Charalampia; Hapeshi, Evroula; Stavrou, Ioannis; Michael, Costas; Fatta-Kassinos, Despo; Fotopoulos, Vasileios

    2016-07-01

    Pharmaceutically active compounds (PhACs) have been recently shown to exert phytotoxic effects. The present study explores the uptake, systemic translocation, and abiotic stress responses and detoxification mechanisms induced by the exposure of alfalfa plants grown in sand under greenhouse conditions to four common, individually applied PhACs (10μgL(-1)) (diclofenac, sulfamethoxazole, trimethoprim, 17a-ethinylestradiol) and their mixture. Stress physiology markers (lipid peroxidation, proline, H2O2 and NO content, antioxidant activity assays) and gene expression levels of key plant detoxification components (including glutathione S-transferases, GST7, GST17; superoxide dismutases, CuZnSOD, FeSOD; proton pump, H(+)-ATP, and cytochrome c oxidase, CytcOx), were evaluated. PhACs were detected in significantly higher concentrations in roots compared with leaves. Stress related effects, manifested via membrane lipid peroxidation and oxidative burst, were local (roots) rather than systemic (leaves), and exacerbated when the tested PhACs were applied in mixture. Systemic accumulation of H2O2 in leaves suggests its involvement in signal transduction and detoxification responses. Increased antioxidant enzymatic activities, as well as upregulated transcript levels of GST7, GST17, H(+)-ATPase and CytcOx, propose their role in the detoxification of the selected PhACs in plants. The current findings provide novel biochemical and molecular evidence highlighting the studied PhACs as an emerging abiotic stress factor, and point the need for further research on wastewater flows under natural agricultural environments. PMID:27037887

  2. Relation between the variations in the global surface temperature, El Niño/La Niña phenomena, and the Atlantic Multidecadal Oscillation

    NASA Astrophysics Data System (ADS)

    Mokhov, I. I.; Smirnov, D. A.

    2016-04-01

    We analyzed directed couplings between the variations in the global surface temperature and modes of the natural climatic variability: the El NiñoLa Niña (ENSO) quasi-periodical phenomena and the long-period Atlantic Mutidecadal Oscillation (AMO) based on the data for 1870-2014. According to the quantitative estimates based on the monthly and annual mean data, the initial data, and the 10-year mean remote data, the most pronounced impact of the ENSO on the global surface temperature and the AMO was found. A weaker bidirectional coupling between the global surface temperature and the AMO is also pronounced. The analysis using running windows revealed an alternating effect of the ENSO and AMO on the variations in the global surface temperature related to the AMO phases.

  3. Computer Simulations of Critical Phenomena in Systems with Long-Range Interactions: a Study of Ising Dipoles and Self-Organized Criticality in Earthquakes.

    NASA Astrophysics Data System (ADS)

    Xu, Huang-Jian

    This thesis discusses scaling and critical behavior of two different models. One model describes Ising dipoles, originates in condensed matter physics, and depicts equilibrium critical phenomena. The other model, taken from the earth sciences, describes faulting instabilities and the resulting earthquakes, and involves self-organized criticality--a non-equilibrium phenomenon. Both models are characterized by long range interactions, with a resulting sensitivity to boundary conditions. The ordering properties of Ising dipoles on lattices are studied in a mean field theory and by Monte Carlo simulations. The mean field theory is manifestly shape independent in zero external field. In the case of dipoles on a diluted lattice the mean field theory predicts a critical concentration above which the low temperature phase is ferroelectric (or anti-ferroelectric depending on the lattice structure). Extensive Monte Carlo simulation results are in agreement with those of mean field theory. We propose a finite size scaling form that includes logarithmic corrections for systems at the critical dimensionality. In the case of dipoles on a body centered tetragonal lattice we found that the finite scaling form significantly improved the data collapse over the scaling form with mean field exponents. With lattice parameters appropriate to the Ising ferromagnetic compound LiHoF_4, we obtain a ferromagnetic transition temperature T -1.51 K in excellent agreement with experiment. This indicates that the material LiHoF_4 is dominated by the dipole-dipole interaction: since in the simulations we only include dipole dipole interactions. For dipoles on the simple cubic lattice, the ordered state is made up of anti-ferromagnetic rows. The critical exponents obtained by finite size scaling are beta~ 1/7, gamma ~ 8/7 and o~ 1/7. These results are in good agreement with those of high temperature series expansions. A model of self-organized ruptures in an elastic medium is developed; and applied

  4. Interactive relations among maternal depressive symptomatology, nutrition, and parenting.

    PubMed

    Aubuchon-Endsley, Nicki L; Thomas, David G; Kennedy, Tay S; Grant, Stephanie L; Valtr, Tabitha

    2012-01-01

    Theoretical models linking maternal nutrition, depressive symptomatology, and parenting are underdeveloped. However, existing literature suggests that iron status and depressive symptomatology interact in relation to problematic parenting styles (authoritarian, permissive). Therefore, in the current study the authors investigate these interactive relations in a sample of breastfeeding mothers (n = 105) interviewed at three months postpartum. Participants completed questionnaires (from December 2008 to January 2011) regarding their depressive symptomatology and parenting styles. Iron status (i.e., hemoglobin, soluble transferrin receptors, and serum ferritin concentrations) was assessed from blood samples. Significant interactions were found between iron status and depressive symptomatology in relation to authoritarian parenting style (low warmth, high punishment and directiveness). For those women with hemoglobin below 14.00 g/dL, depressive symptomatology was positively related to authoritarian parenting style (p < 0.001). Thus, screening for poor iron status and depressive sympatomology in postpartum women may help to identify those at risk for problematic parenting. Dietary interventions may help to eliminate relations between depressive symptoms and problematic parenting. PMID:22533896

  5. qPIPSA: Relating enzymatic kinetic parameters and interaction fields

    PubMed Central

    Gabdoulline, Razif R; Stein, Matthias; Wade, Rebecca C

    2007-01-01

    Background The simulation of metabolic networks in quantitative systems biology requires the assignment of enzymatic kinetic parameters. Experimentally determined values are often not available and therefore computational methods to estimate these parameters are needed. It is possible to use the three-dimensional structure of an enzyme to perform simulations of a reaction and derive kinetic parameters. However, this is computationally demanding and requires detailed knowledge of the enzyme mechanism. We have therefore sought to develop a general, simple and computationally efficient procedure to relate protein structural information to enzymatic kinetic parameters that allows consistency between the kinetic and structural information to be checked and estimation of kinetic constants for structurally and mechanistically similar enzymes. Results We describe qPIPSA: quantitative Protein Interaction Property Similarity Analysis. In this analysis, molecular interaction fields, for example, electrostatic potentials, are computed from the enzyme structures. Differences in molecular interaction fields between enzymes are then related to the ratios of their kinetic parameters. This procedure can be used to estimate unknown kinetic parameters when enzyme structural information is available and kinetic parameters have been measured for related enzymes or were obtained under different conditions. The detailed interaction of the enzyme with substrate or cofactors is not modeled and is assumed to be similar for all the proteins compared. The protein structure modeling protocol employed ensures that differences between models reflect genuine differences between the protein sequences, rather than random fluctuations in protein structure. Conclusion Provided that the experimental conditions and the protein structural models refer to the same protein state or conformation, correlations between interaction fields and kinetic parameters can be established for sets of related enzymes

  6. Debris Flows and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Ancey, C.

    Torrential floods are a major natural hazard, claiming thousands of lives and millions of dollars in lost property each year in almost all mountain areas on the Earth. After a catastrophic eruption of Mount St. Helen in the USA in May 1980, water from melting snow, torrential rains from the eruption cloud, and water displaced from Spirit Lake mixed with deposited ash and debris to produce very large debris flows and cause extensive damage and loss of life [1]. During the 1985 eruption of Nevado del Ruiz in Colombia, more than 20,000 people perished when a large debris flow triggered by the rapid melting of snow and ice at the volcano summit, swept through the town of Armero [2]. In 1991, the eruption of Pinatubo volcano in the Philippines disperses more than 5 cubic kilometres of volcanic ash into surrounding valleys. Much of that sediment has subsequently been mobilised as debris flows by typhoon rains and has devastated more than 300 square kilometres of agricultural land. Even, in Eur opean countries, recent events that torrential floods may have very destructive effects (Sarno and Quindici in southern Italy in May 1998, where approximately 200 people were killed). The catastrophic character of these floods in mountainous watersheds is a consequence of significant transport of materials associated with water flows. Two limiting flow regimes can be distinguished. Bed load and suspension refer to dilute transport of sediments within water. This means that water is the main agent in the flow dynamics and that the particle concentration does not exceed a few percent. Such flows are typically two-phase flows. In contrast, debris flows are mas s movements of concentrated slurries of water, fine solids, rocks and boulders. As a first approximation, debris flows can be treated as one-phase flows and their flow properties can be studied using classical rheological methods. The study of debris flows is a very exciting albeit immature science, made up of disparate elements borrowed from geomorphology, geology, hydrology, soil mechanics, and fluid mechanics. The purpose of this chapter is to provide an introduction to physical aspects of debris flows, with specific attention directed to their rheological features. Despite attempts to provide a coherent view on the topic, coverage is incomplete and the reader is referred to a series of papers and books. Three books are particularly commendable [3-5]. Some review papers provide interesting overviews, introducing the newcomers to the field to the main concepts [6-8]. The background material in rheology can be found in Chaps. 2 and 3.

  7. Ultrafast optical phenomena related to spin and orbital dynamics in the rare-earth cuprates R IICuO 4 (R = Pr, Nd, Sm)

    NASA Astrophysics Data System (ADS)

    Pavlov, Victor V.; Pisarev, Roman V.; Gridnev, Valery N.; Zhukov, Evgenie A.; Yakovlev, Dmitry R.; Bayer, Manfred

    2007-06-01

    Currently coherent spin phenomena are in the focus of wide research activity in such multidisciplinary fields as spintronics, quantum communication and information processing. 1-3 Among those, the optical orientation based on the transfer to media of the angular momentum carried by the circularly-polarized light plays very important role for disclosing basic processes that govern generation and relaxation of spin and orbital states. By using ultrafast pump-probe spectroscopy we show that optical pumping can induce spin-polarization in antiferromagnetic Mott insulators R IICuO 4 (R = Pr, Nd, Sm) providing a way for fast nonlinear manipulation of spin states on time scale of 100 fs and less. The driving mechanisms of the ultrafast spin orientation and dynamics in Mott insulators are the strong spin-orbit, spin-phonon and exchange interaction as inherent features of strongly-correlated systems both in the ground and excited states. High values of the corresponding nonlinear susceptibilities may have significant impact for novel ultrafast all-optical technologies.

  8. Natural phenomena hazards, Hanford Site, Washington

    SciTech Connect

    Conrads, T.J.

    1998-09-29

    This document presents the natural phenomena hazard loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, and supports development of double-shell tank systems specifications at the Hanford Site in south-central Washington State. The natural phenomena covered are seismic, flood, wind, volcanic ash, lightning, snow, temperature, solar radiation, suspended sediment, and relative humidity.

  9. Misconceptions of Emergent Semiconductor Phenomena

    NASA Astrophysics Data System (ADS)

    Nelson, Katherine G.

    The semiconductor field of Photovoltaics (PV) has experienced tremendous growth, requiring curricula to consider ways to promote student success. One major barrier to success students may face when learning PV is the development of misconceptions. The purpose of this work was to determine the presence and prevalence of misconceptions students may have for three PV semiconductor phenomena; Diffusion, Drift and Excitation. These phenomena are emergent, a class of phenomena that have certain characteristics. In emergent phenomena, the individual entities in the phenomena interact and aggregate to form a self-organizing pattern that can be observed at a higher level. Learners develop a different type of misconception for these phenomena, an emergent misconception. Participants (N=41) completed a written protocol. The pilot study utilized half of these protocols (n = 20) to determine the presence of both general and emergent misconceptions for the three phenomena. Once the presence of both general and emergent misconceptions was confirmed, all protocols (N=41) were analyzed to determine the presence and prevalence of general and emergent misconceptions, and to note any relationships among these misconceptions (full study). Through written protocol analysis of participants' responses, numerous codes emerged from the data for both general and emergent misconceptions. General and emergent misconceptions were found in 80% and 55% of participants' responses, respectively. General misconceptions indicated limited understandings of chemical bonding, electricity and magnetism, energy, and the nature of science. Participants also described the phenomena using teleological, predictable, and causal traits, indicating participants had misconceptions regarding the emergent aspects of the phenomena. For both general and emergent misconceptions, relationships were observed between similar misconceptions within and across the three phenomena, and differences in misconceptions were

  10. Expression and interaction analysis of Arabidopsis Skp1-related genes.

    PubMed

    Takahashi, Naoki; Kuroda, Hirofumi; Kuromori, Takashi; Hirayama, Takashi; Seki, Motoaki; Shinozaki, Kazuo; Shimada, Hiroaki; Matsui, Minami

    2004-01-01

    Specific protein degradation has been observed in several aspects of development and differentiation in many organisms. One example of such proteolysis is regulated by protein polyubiquitination that is promoted by the SCF complex consisting of Skp1, cullin, and an F-box protein. We examined the activities of the Arabidopsis Skp1-related proteins (ASKs). Among 19 annotated ASK genes, we isolated 16 of the corresponding cDNAs (ASK1, 2, 3, 4, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19), and examined their gene products for interactions with 24 representatives of F-box proteins carrying various classes of the C-terminal domains using the yeast two-hybrid system. As a result, we found diverse binding specificities: ASK1, ASK2, ASK11 and ASK12 interacted well with COI1, FKF1, UFO-like protein, LRR-containing F-box proteins, and other F-box proteins with unknown C-terminal motifs. We also observed specific interaction between F-box proteins and ASK3, ASK9, ASK13, ASK14, ASK16 and ASK18. In contrast, we detected no interaction between any of the 12 ASK proteins and F-box proteins containing CRFA, CRFB or CRFC domains. Both histochemical and RT-PCR analysis of eight ASK genes expression revealed unique expression patterns for the respective genes. PMID:14749489

  11. MULTISCALE PHENOMENA IN MATERIALS

    SciTech Connect

    A. BISHOP

    2000-09-01

    This project developed and supported a technology base in nonequilibrium phenomena underpinning fundamental issues in condensed matter and materials science, and applied this technology to selected problems. In this way the increasingly sophisticated synthesis and characterization available for classes of complex electronic and structural materials provided a testbed for nonlinear science, while nonlinear and nonequilibrium techniques helped advance our understanding of the scientific principles underlying the control of material microstructure, their evolution, fundamental to macroscopic functionalities. The project focused on overlapping areas of emerging thrusts and programs in the Los Alamos materials community for which nonlinear and nonequilibrium approaches will have decisive roles and where productive teamwork among elements of modeling, simulations, synthesis, characterization and applications could be anticipated--particularly multiscale and nonequilibrium phenomena, and complex matter in and between fields of soft, hard and biomimetic materials. Principal topics were: (i) Complex organic and inorganic electronic materials, including hard, soft and biomimetic materials, self-assembly processes and photophysics; (ii) Microstructure and evolution in multiscale and hierarchical materials, including dynamic fracture and friction, dislocation and large-scale deformation, metastability, and inhomogeneity; and (iii) Equilibrium and nonequilibrium phases and phase transformations, emphasizing competing interactions, frustration, landscapes, glassy and stochastic dynamics, and energy focusing.

  12. The anomalous Hall effect and related transport phenomena in ferromagnetic spinel copper chromium selenium bromide, manganese-doped chalcopyrite copper gallium ditelluride, and ruthenate bismuth ruthenate

    NASA Astrophysics Data System (ADS)

    Lee, Wei-Li

    One of the interesting and unsettled transport phenomena is the, so called, "anomalous Hall Effect". It generally refers to the phenomenon of a non-linear field dependence of the Hall resistivity rhoxy. An emerging idea relates to the "gauge field O" experienced by electrons. It gives rise to Berry phase accumulation. In ferromagnets, a non-vanishing O( k⃗ ) is related to the spin-orbit coupling and the time-reversal asymmetry. We show that, in the ferromagnetic spinel CuCr2Se 4-xBrx, the anomalous Hall conductivity sigma xy (normalized to per carrier, at 5K) remains unchanged with a 1000-fold increase in resistivity. From the anomalous Nernst effect, we uncover a simple relation for the off-diagonal Peltier conductivity tensor alphaxy, which is a measure of a transverse electrical current density generated per unit of applied temperature gradient. They both strongly support the anomalous-velocity theory based on the intrinsic spin-orbit coupling of the electrons. An alternative way to procure O is from the spin-chirality effect. In the Mn-doped chalcopyrite semiconductor CuGaTe2, with a few percent doping, the orbitals of the Mn ions overlap to form an impurity band. Therefore, the electrons will accumulate Berry phase while hopping around the Mn ions that have a non-collinear magnetic ground state. We observed the enhanced and non-monotonic field dependence of rhoxy, which may be understood from the spin-chirality effect. Finally, we studied the Hall effect and thermopower in the ruthenate Bi3Ru3O 11. From the Hall effect, we observed field-tuning of electron and hole populations. We also found a large field dependence of the thermopower at low temperature. The origin of the colossal field-dependence in the thermopower is still an open question, but it is linked to the unusual electronic properties in the Bi3Ru3O11.

  13. Relative Displacement Method for Track-Structure Interaction

    PubMed Central

    Ramos, Óscar Ramón; Pantaleón, Marcos J.

    2014-01-01

    The track-structure interaction effects are usually analysed with conventional FEM programs, where it is difficult to implement the complex track-structure connection behaviour, which is nonlinear, elastic-plastic and depends on the vertical load. The authors developed an alternative analysis method, which they call the relative displacement method. It is based on the calculation of deformation states in single DOF element models that satisfy the boundary conditions. For its solution, an iterative optimisation algorithm is used. This method can be implemented in any programming language or analysis software. A comparison with ABAQUS calculations shows a very good result correlation and compliance with the standard's specifications. PMID:24634610

  14. Relative displacement method for track-structure interaction.

    PubMed

    Schanack, Frank; Ramos, Óscar Ramón; Reyes, Juan Patricio; Pantaleón, Marcos J

    2014-01-01

    The track-structure interaction effects are usually analysed with conventional FEM programs, where it is difficult to implement the complex track-structure connection behaviour, which is nonlinear, elastic-plastic and depends on the vertical load. The authors developed an alternative analysis method, which they call the relative displacement method. It is based on the calculation of deformation states in single DOF element models that satisfy the boundary conditions. For its solution, an iterative optimisation algorithm is used. This method can be implemented in any programming language or analysis software. A comparison with ABAQUS calculations shows a very good result correlation and compliance with the standard's specifications. PMID:24634610

  15. Interactive exploration of implicit and explicit relations in faceted datasets.

    PubMed

    Zhao, Jian; Collins, Christopher; Chevalier, Fanny; Balakrishnan, Ravin

    2013-12-01

    Many datasets, such as scientific literature collections, contain multiple heterogeneous facets which derive implicit relations, as well as explicit relational references between data items. The exploration of this data is challenging not only because of large data scales but also the complexity of resource structures and semantics. In this paper, we present PivotSlice, an interactive visualization technique which provides efficient faceted browsing as well as flexible capabilities to discover data relationships. With the metaphor of direct manipulation, PivotSlice allows the user to visually and logically construct a series of dynamic queries over the data, based on a multi-focus and multi-scale tabular view that subdivides the entire dataset into several meaningful parts with customized semantics. PivotSlice further facilitates the visual exploration and sensemaking process through features including live search and integration of online data, graphical interaction histories and smoothly animated visual state transitions. We evaluated PivotSlice through a qualitative lab study with university researchers and report the findings from our observations and interviews. We also demonstrate the effectiveness of PivotSlice using a scenario of exploring a repository of information visualization literature. PMID:24051774

  16. Examining Classroom Interactions Related to Difference in Students' Science Achievement.

    ERIC Educational Resources Information Center

    Zady, Madelon F.; Portes, Pedro R.; Ochs, V. Dan

    2003-01-01

    Examines the cognitive supports that underlie achievement in science using a cultural historical framework and the activity setting (AS) construct with five features: personnel, motivation, scripts, task demands, and beliefs. Reports four emergent phenomena--science activities, the building of learning, meaning in lessons, and the conflict over…

  17. An exchange-Coulomb model potential energy surface for the Ne-CO interaction. II. Molecular beam scattering and bulk gas phenomena in Ne-CO mixtures.

    PubMed

    Dham, Ashok K; McBane, George C; McCourt, Frederick R W; Meath, William J

    2010-01-14

    Four potential energy surfaces are of current interest for the Ne-CO interaction. Two are high-level fully ab initio surfaces obtained a decade ago using symmetry-adapted perturbation theory and supermolecule coupled-cluster methods. The other two are very recent exchange-Coulomb (XC) model potential energy surfaces constructed by using ab initio Heitler-London interaction energies and literature long range dispersion and induction energies, followed by the determination of a small number of adjustable parameters to reproduce a selected subset of pure rotational transition frequencies for the (20)Ne-(12)C(16)O van der Waals cluster. Testing of the four potential energy surfaces against a wide range of available experimental microwave, millimeter-wave, and mid-infrared Ne-CO transition frequencies indicated that the XC potential energy surfaces gave results that were generally far superior to the earlier fully ab initio surfaces. In this paper, two XC model surfaces and the two fully ab initio surfaces are tested for their abilities to reproduce experiment for a wide range of nonspectroscopic Ne-CO gas mixture properties. The properties considered here are relative integral cross sections and the angle dependence of rotational state-to-state differential cross sections, rotational relaxation rate constants for CO(v=2) in Ne-CO mixtures at T=296 K, pressure broadening of two pure rotational lines and of the rovibrational lines in the CO fundamental and first overtone transitions at 300 K, and the temperature and, where appropriate, mole fraction dependencies of the interaction second virial coefficient, the binary diffusion coefficient, the interaction viscosity, the mixture shear viscosity and thermal conductivity coefficients, and the thermal diffusion factor. The XC model potential energy surfaces give results that lie within or very nearly within the experimental uncertainties for all properties considered, while the coupled-cluster ab initio surface gives

  18. CdCl{sub 2} treatment related diffusion phenomena in Cd{sub 1−x}Zn{sub x}S/CdTe solar cells

    SciTech Connect

    Kartopu, G. Clayton, A. J.; Barrioz, V.; Lamb, D. A.; Irvine, S. J. C.; Taylor, A. A.

    2014-03-14

    Utilisation of wide bandgap Cd{sub 1−x}Zn{sub x}S alloys as an alternative to the CdS window layer is an attractive route to enhance the performance of CdTe thin film solar cells. For successful implementation, however, it is vital to control the composition and properties of Cd{sub 1−x}Zn{sub x}S through device fabrication processes involving the relatively high-temperature CdTe deposition and CdCl{sub 2} activation steps. In this study, cross-sectional scanning transmission electron microscopy and depth profiling methods were employed to investigate chemical and structural changes in CdTe/Cd{sub 1−x}Zn{sub x}S/CdS superstrate device structures deposited on an ITO/boro-aluminosilicate substrate. Comparison of three devices in different states of completion—fully processed (CdCl{sub 2} activated), annealed only (without CdCl{sub 2} activation), and a control (without CdCl{sub 2} activation or anneal)—revealed cation diffusion phenomena within the window layer, their effects closely coupled to the CdCl{sub 2} treatment. As a result, the initial Cd{sub 1−x}Zn{sub x}S/CdS bilayer structure was observed to unify into a single Cd{sub 1−x}Zn{sub x}S layer with an increased Cd/Zn atomic ratio; these changes defining the properties and performance of the Cd{sub 1−x}Zn{sub x}S/CdTe device.

  19. Possible new antiaging strategies related to neuroendocrine-immune interactions.

    PubMed

    Mocchegiani, Eugenio; Malavolta, Marco

    2008-01-01

    The aging process demonstrates gradual and spontaneous changes, resulting in maturation through childhood, puberty and young adulthood, and then decline through middle and late age. However, animals and humans are capable of reaching the extreme limit of life span characteristic for the species with a very efficient network of antiaging mechanisms. Among them, neuroendocrine-immune interactions play a pivotal role. The loss of the capacity of the organism in remodeling the neuroendocrine-immune response leads to the appearance of age-associated pathologies. We herein report some substances which can be proposed as new antiaging strategies because of their capacity to remodel some biological functions in old animals and humans. These substances are: L-deprenyl, leptin, ghrelin, carnosine and NO donors. Their role as possible antiaging strategies in healthy people in relation to neuroendocrine-immune responses and zinc ion bioavailability is reported and discussed. PMID:19047810

  20. Wave propagation phenomena

    NASA Astrophysics Data System (ADS)

    Groenenboom, P. H. L.

    The phenomenon of wave propagation is encountered frequently in a variety of engineering disciplines. It has been realized that for a growing number of problems the solution can only be obtained by discretization of the boundary. Advantages of the Boundary Element Method (BEM) over domain-type methods are related to the reduction of the number of space dimensions and of the modelling effort. It is demonstrated how the BEM can be applied to wave propagation phenomena by establishing the fundamental relationships. A numerical solution procedure is also suggested. In connection with a discussion of the retarded potential formulation, it is shown how the wave propagation problem can be cast into a Boundary Integral Formulation (BIF). The wave propagation problem in the BIF can be solved by time-successive evaluation of the boundary integrals. The example of pressure wave propagation following a sodium-water reaction in a Liquid Metal cooled Fast Breeder Reactor steam generator is discussed.

  1. Teaching optical phenomena with Tracker

    NASA Astrophysics Data System (ADS)

    Rodrigues, M.; Simeão Carvalho, P.

    2014-11-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a relatively complex setup. Fortunately, nowadays it is possible to analyse optical phenomena in a simple and quantitative way using the freeware video analysis software ‘Tracker’. In this paper, we show the advantages of video-based experimental activities for teaching concepts in optics. We intend to show: (a) how easy the study of such phenomena can be, even at home, because only simple materials are needed, and Tracker provides the necessary measuring instruments; and (b) how we can use Tracker to improve students’ understanding of some optical concepts. We give examples using video modelling to study the laws of reflection, Snell’s laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

  2. Crystallization phenomena in slags

    NASA Astrophysics Data System (ADS)

    Orrling, Carl Folke

    2000-09-01

    The crystallization of the mold slag affects both the heat transfer and the lubrication between the mold and the strand in continuous casting of steel. In order for mold slag design to become an engineering science rather than an empirical exercise, a fundamental understanding of the melting and solidification behavior of a slag must be developed. Thus it is necessary to be able to quantify the phenomena that occur under the thermal conditions that are found in the mold of a continuous caster. The double hot thermocouple technique (DHTT) and the Confocal Laser Scanning Microscope used in this study are two novel techniques for investigating melting and solidification phenomena of transparent slags. Results from these techniques are useful in defining the phenomena that occur when the slag film infiltrates between the mold and the shell of the casting. TTT diagrams were obtained for various slags and indicated that the onset of crystallization is a function of cooling rate and slag chemistry. Crystal morphology was found to be dependent upon the experimental temperature and four different morphologies were classified based upon the degree of melt undercooling. Continuous cooling experiments were carried out to develop CCT diagrams and it was found that the amount and appearance of the crystalline fraction greatly depends on the cooling conditions. The DHTT can also be used to mimic the cooling profile encountered by the slag in the mold of a continuous caster. In this differential cooling mode (DCT), it was found that the details of the cooling rate determine the actual response of the slag to a thermal gradient and small changes can lead to significantly different results. Crystal growth rates were measured and found to be in the range between 0.11 mum/s to 11.73 mum/s depending on temperature and slag chemistry. Alumina particles were found to be effective innoculants in oxide melts reducing the incubation time for the onset of crystallization and also extending

  3. A Challenge for Developers: Preserving the Interactivity of Human Relations in a Standalone Application.

    ERIC Educational Resources Information Center

    Mazur, F. E.

    1993-01-01

    Describes the efforts taken by the Cornell Interactive Theater Ensemble to provide interactive human relations training on date rape using live dramatizations, video with facilitated audience participation, and an electronic multimedia format with decision trees for interactive involvement. (EA)

  4. Interaction of absorbing aerosols with high relative humidity

    NASA Astrophysics Data System (ADS)

    Flores, M.; Bluvshtein, N.; Abo Riziq, A.; Borrmann, S.; Rudich, Y.

    2011-12-01

    One of the major uncertainties in the understanding of Earth's climate system is the interaction between solar radiation and aerosols in the atmosphere. This interaction is dependent on the physical and chemical properties of the aerosols and on the wavelength of the incident light. Aerosols exposed to high humidity areas will change their chemical, physical, and optical properties. To model hydrated aerosols, atmospheric chemistry models use the volume weighted mixing rule to predict the complex refractive index (RI) of aerosols when they interact with high relative humidity areas, and, in general, assume homogeneous mixing. The validity of these assumptions is explored. The extinction coefficient and growth factor of humidified aerosols, at 80% and 90% RH, and at 532 nm and 355 nm wavelengths was measured for size-selected aerosols of ammonium sulfate, peat (a lightly absorbing humic-like substance proxy), nigrosine (a black dye to model highly absorbing substances), and a mixture of AS and nigrosine. The ratio of the humidified extinction coefficients to the dry (fRHext(%RH,Dry)) is explored. The measured fRHext(%RH,Dry) is compared to theoretical calculations based on Mie theory, and using the measured growth factors and assuming homogeneous mixing the expected RIs using the volume weighted mixing rule are compared to the RIs derived from the extinction measurements. Moreover, the differences between assuming a core-shell structure or a homogeneous mixing of the substances is examined. We found slightly linear to no dependency of fRH(%RH,Dry) with size for absorbing substances in contrast to the decreasing exponential behavior with size for purely scattering substances, but no discernable difference could be made between the two wavelengths used. Less than 5% differences were found between the real parts of the complex refractive indices derived and those calculated using the volume weighted mixing rule, and the imaginary parts had up to a 20% difference

  5. Particle Modelling of Fluid Phenomena in Three -

    NASA Astrophysics Data System (ADS)

    Mahmoudi, Mohsen

    A new, numerical approach is developed to simulate fluid phenomena by means of molecular type behavior. First, consider the large number of molecules to be approximated by a smaller number of aggregates called particles. Then, let the particles interact with each other according to a classical molecular type force vec F whose magnitude F is given (Hirchfelder, Curtiss and Bird (1954)) by: F = rm -{Gover r^{p}} + {Hover r^{q}}, in which G, H, p, q, are positive constants and r is the distance between two particles. The acceleration of each particle is related to the force by the Newtonian dynamical equations vec F = m vec a. Displacement, velocity, and acceleration of each particle are then approximated by the "Leap Frog" formulas. The CRAY X-MP/24 is used to solve numerically the resulting large system of nonlinear, ordinary differential equations. We then study fluid phenomena in the following order. Part 1. Generation of particle fluids in a cylindrical region. Part 2. Verification of basic fluid properties. Part 3. Simulation of surface motion. In this part, we simulate three phenomena, which can be observed physically, by dropping a small object into a container filled with liquid. First, there is a backdrop. Then, a wave will be generated and going outward from the point of entry of the object into the container. Last, a reaction which can be recorded only with a high speed camera (Trefethen (1972)) is that very small drops of the container fluid may actually pinch off from the backdrop. Part 4. Simulation of surface tension. This phenomena can be observed by performing the following experiment. A small needle placed gently upon a water surface will not be sunk but will be supported by the molecular forces in the liquid surface. The molecules in the surface are depressed slightly in the process.

  6. Pump instability phenomena generated by fluid forces

    NASA Technical Reports Server (NTRS)

    Gopalakrishnan, S.

    1985-01-01

    Rotor dynamic behavior of high energy centrifugal pumps is significantly affected by two types of fluid forces; one due to the hydraulic interaction of the impeller with the surrounding volute or diffuser and the other due to the effect of the wear rings. The available data on these forces is first reviewed. A simple one degree-of-freedom system containing these forces is analytically solved to exhibit the rotor dynamic effects. To illustrate the relative magnitude of these phenomena, an example of a multistage boiler feed pump is worked out. It is shown that the wear ring effects tend to suppress critical speed and postpone instability onset. But the volute-impeller forces tend to lower the critical speed and the instability onset speed. However, for typical boiler feed pumps under normal running clearances, the wear ring effects are much more significant than the destabilizing hydraulic interaction effects.

  7. Midcontinent Interactive Digital Carbon Atlas and Relational Database (MIDCARB)

    SciTech Connect

    Timothy R. Carr; Scott W. White

    2002-06-01

    This annual report describes progress of the project entitled ''Midcontinent Interactive Digital Carbon Atlas and Relational Database (MIDCARB)''. This project, funded by the Department of Energy, is a cooperative project that assembles a consortium of five states (Indiana, Illinois, Kansas, Kentucky and Ohio) to construct an online distributed Relational Database Management System (RDBMS) and Geographic Information System (GIS) covering aspects of carbon dioxide geologic sequestration (http://www.midcarb.org). The system links the five states in the consortium into a coordinated regional database system consisting of datasets useful to industry, regulators and the public. The project is working to provide advanced distributed computing solutions to link database servers across the five states into a single system where data is maintained at the local level but is accessed through a single Web portal and can be queried, assembled, analyzed and displayed. Each individual state has strengths in data gathering, data manipulation and data display, including GIS mapping, custom application development, web development, and database design. Sharing of expertise provides the critical mass of technical expertise to improve CO{sub 2} databases and data access in all states. This project improves the flow of data across servers in the five states and increases the amount and quality of available digital data. The MIDCARB project is developing improved online tools to provide real-time display and analyze CO{sub 2} sequestration data. The system links together data from sources, sinks and transportation within a spatial database that can be queried online. Visualization of high quality and current data can assist decision makers by providing access to common sets of high quality data in a consistent manner.

  8. Coupled Phenomena in Chemistry.

    ERIC Educational Resources Information Center

    Matsubara, Akira; Nomura, Kazuo

    1979-01-01

    Various phenomena in chemistry and biology can be understood through Gibbs energy utilization. Some common phenomena in chemistry are explained including neutralization, hydrolysis, oxidation and reaction, simultaneous dissociation equilibrium of two weak acids, and common ion effect on solubility. (Author/SA)

  9. Quantum Phenomena Tested By Neutron Interferometry

    SciTech Connect

    Rauch, Helmut

    2005-02-15

    Entanglement of two photons, or atoms is a complementary situation to a double slit situation of a single photon, neutron or atom. With neutrons single particle interference phenomena can be observed and the 'entanglement of degrees of freedom', i.e. contextuality can be verified. In this respect, neutrons are proper tools for testing quantum mechanics because they are massive, they couple to electromagnetic fields due to their magnetic moment and they are subject to all basic interactions, and they are sensitive to topological effects, as well. Related experiments will be discussed. Deterministic and stochastic partial absorption experiments can be described by Bell-type inequalities. Recent neutron interferometry experiments based on postselection methods renewed the discussion about quantum nonlocality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in phase space even in cases of spatially separated Schroedinger cat-like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other decoherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.

  10. (Theory of weak interactions and related topics; and study of e sup + e sup minus interactions)

    SciTech Connect

    Chang, Lay Nam; Tze, C.H.

    1990-01-01

    This report contains brief discussions on the following topics: Higher point anomalous amplitudes; topological phase of quantum gravity; chiral symmetry breaking at finite temperature; Skyrmions as representations of current algebras; D {ge} 4 critical phenomena: self-duality, infinite dimensional symmetries and hypercomplex analyticity; D {ge} 3 topological field theories: anionic membranes and division algebras, geometric quantization by the method of orbits; and novel non-perturbative approaches. (LSP)

  11. Eighty phenomena about the self: representation, evaluation, regulation, and change

    PubMed Central

    Thagard, Paul; Wood, Joanne V.

    2015-01-01

    We propose a new approach for examining self-related aspects and phenomena. The approach includes (1) a taxonomy and (2) an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation). The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation). The changing self is less time-limited than the effecting self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development). Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular). We illustrate our approach by focusing on seven self-related phenomena. PMID:25870574

  12. MIDCONTINENT INTERACTIVE DIGITAL CARBON ATLAS AND RELATIONAL DATABASE (MIDCARB)

    SciTech Connect

    Timothy R. Carr; Scott W. White

    2003-07-01

    This annual report describes progress in the second year of the three-year project entitled ''Midcontinent Interactive Digital Carbon Atlas and Relational Database (MIDCARB)''. This project, funded by the Department of Energy, is a cooperative project that assembles a consortium of five states (Indiana, Illinois, Kansas, Kentucky and Ohio) to construct an online distributed Relational Database Management System (RDBMS) and Geographic Information System (GIS) covering aspects of carbon dioxide geologic sequestration (http://www.midcarb.org). The system links the five states in the consortium into a coordinated regional database system consisting of datasets useful to industry, regulators and the public. The project is providing advanced distributed computing solutions to link database servers across the five states into a single system where data is maintained at the local level but is accessed through a single Web portal and can be queried, assembled, analyzed and displayed. Each individual state has strengths in data gathering, data manipulation and data display, including GIS mapping, custom application development, web development, and database design. Sharing of expertise provides the critical mass of technical expertise to improve CO{sub 2} databases and data access in all states. This project improves the flow of data across servers in the five states and increases the amount and quality of available digital data. Data is being assembled to analyze CO{sub 2} sequestration potential from a single object (e.g., power plant or well) to a region and across geographic boundaries. The MIDCARB system is robust and capable of being updated from multiple sources on a daily basis. The MIDCARB project has developed improved online tools to provide real-time display and analysis of CO{sub 2} sequestration data. The MIDCARB project is a functional template for distributed data systems to address CO{sub 2} sequestration and other natural resource issues that cross the

  13. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    NASA Astrophysics Data System (ADS)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    Back in 1967, Clifford Gardner, John Greene, Martin Kruskal and Robert Miura published a seminal paper in Physical Review Letters which was to become a cornerstone in the theory of integrable systems. In 2006, the authors of this paper received the AMS Steele Prize. In this award the AMS pointed out that `In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited.' From this discovery the modern theory of integrability bloomed, leading scientists to a deep understanding of many nonlinear phenomena which is by no means reachable by perturbation methods or other previous tools from linear theories. Nonlinear phenomena appear everywhere in nature, their description and understanding is therefore of great interest both from the theoretical and applicative point of view. If a nonlinear phenomenon can be represented by an integrable system then we have at our disposal a variety of tools to achieve a better mathematical description of the phenomenon. This special issue is largely dedicated to investigations of nonlinear phenomena which are related to the concept of integrability, either involving integrable systems themselves or because they use techniques from the theory of integrability. The idea of this special issue originated during the 18th edition of the Nonlinear Evolution Equations and Dynamical Systems (NEEDS) workshop, held at Isola Rossa, Sardinia, Italy, 16-23 May 2009 (http://needs-conferences.net/2009/). The issue benefits from the occasion offered by the meeting, in particular by its mini-workshops programme, and contains invited review papers and contributed papers. It is worth pointing out that there was an open call for papers and all contributions were peer reviewed

  14. Phenomena resulting from hypergolic contact

    NASA Astrophysics Data System (ADS)

    Forness, Jordan M.

    Understanding hypergolic ignition is critical for the safe and successful operation of hypergolic engines. The complex coupling of physical and chemical processes during hypergolic ignition complicates analysis of the event. Presently, hypergolic ignition models cannot simulate liquid contact and mixing or liquid-phase chemical reactions, and rely on experimental results for validation. In some cases, chemical kinetics of hypergolic propellants and fluid dynamics of droplet collisions couple to produce unexpected phenomena. This research investigates contact between droplets and pools of liquid hypergolic propellants under various conditions in order to investigate these liquid-phase reactions and categorize the resulting interaction. During this experiment, 142 drop tests were performed to investigate phenomena associated with hypergolic contact of various propellants. A drop of fuel impacted a semi-ellipsoidal pool of oxidizer at varying impact velocities and impact geometries. The temperature, pressure, ambient atmosphere, and propellant quality were all controlled during the experiment, as these factors have been shown to influence hypergolic ignition delay. Three distinct types of impacts were identified: explosions, bounces, and splashes. The impact type was found to depend on the impact Weber number and impact angle. Splashes occurred above a critical Weber number of 250, regardless of impact angle. Explosions occurred for Weber numbers less than 250, and for impact angles less than seven degrees. If the impact angle was greater than seven degrees then the test resulted in a bounce. Literature related to explosions induced by hypergolic contact was reviewed. Explosions were observed to occur inconsistently, a feature that has never been addressed. Literature related to non-reactive splashing, bouncing, and coalescence was reviewed for insight into the explosion phenomenon. I propose that the dependence of impact angle on the transition between explosion and

  15. 17 CFR 232.406T - Temporary rule related to Interactive Data Files.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Interactive Data Files. 232.406T Section 232.406T Commodity and Securities Exchanges SECURITIES AND EXCHANGE....406T Temporary rule related to Interactive Data Files. (a) Scope. Section 232.406T addresses the liability for the Interactive Data File. An Interactive Data File is subject to the same...

  16. 17 CFR 232.406T - Temporary rule related to Interactive Data Files.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Interactive Data Files. 232.406T Section 232.406T Commodity and Securities Exchanges SECURITIES AND EXCHANGE....406T Temporary rule related to Interactive Data Files. (a) Scope. Section 232.406T addresses the liability for the Interactive Data File. An Interactive Data File is subject to the same...

  17. 17 CFR 232.406T - Temporary rule related to Interactive Data Files.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Interactive Data Files. 232.406T Section 232.406T Commodity and Securities Exchanges SECURITIES AND EXCHANGE....406T Temporary rule related to Interactive Data Files. (a) Scope. Section 232.406T addresses the liability for the Interactive Data File. An Interactive Data File is subject to the same...

  18. 17 CFR 232.406T - Temporary rule related to Interactive Data Files.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Interactive Data Files. 232.406T Section 232.406T Commodity and Securities Exchanges SECURITIES AND EXCHANGE....406T Temporary rule related to Interactive Data Files. (a) Scope. Section 232.406T addresses the liability for the Interactive Data File. An Interactive Data File is subject to the same...

  19. 17 CFR 232.406T - Temporary rule related to Interactive Data Files.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Interactive Data Files. 232.406T Section 232.406T Commodity and Securities Exchanges SECURITIES AND EXCHANGE....406T Temporary rule related to Interactive Data Files. (a) Scope. Section 232.406T addresses the liability for the Interactive Data File. An Interactive Data File is subject to the same...

  20. Website on Protein Interaction and Protein Structure Related Work

    NASA Technical Reports Server (NTRS)

    Samanta, Manoj; Liang, Shoudan; Biegel, Bryan (Technical Monitor)

    2003-01-01

    In today's world, three seemingly diverse fields - computer information technology, nanotechnology and biotechnology are joining forces to enlarge our scientific knowledge and solve complex technological problems. Our group is dedicated to conduct theoretical research exploring the challenges in this area. The major areas of research include: 1) Yeast Protein Interactions; 2) Protein Structures; and 3) Current Transport through Small Molecules.

  1. Unconventional interaction in N(P)-related systems

    NASA Astrophysics Data System (ADS)

    Wang, Weizhou; Zhang, Yu; Huang, Kaixun

    2005-08-01

    Non-conventional intramolecular and intermolecular interactions have been investigated employing glycine (VIIp), NH 3⋯HCl, NH 3⋯H 2O and PH 3⋯H 2O as model systems. Geometries and harmonic frequencies were determined at a correlated ab initio level, which shows a elongating of the Cl-H or O-H bond of the proton donor and a red-shifting of the corresponding Cl-H or O-H bond stretching frequency. NBO analysis indicates there is a significant charge transfer from the proton acceptor to the proton donor. However, this type of interaction cannot be called hydrogen bond according to a comparative analysis of electron density topology in the four systems.

  2. Human Immunodeficiencies Related to Defective APC/T Cell Interaction

    PubMed Central

    Kallikourdis, Marinos; Viola, Antonella; Benvenuti, Federica

    2015-01-01

    The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APCs) in the T cell area of secondary lymphoid organs and the formation of highly organized intercellular junctions referred to as immune synapses (IS). In vivo live-cell imaging of APC–T cell interactions combined to functional studies unveiled that T cell fate is dictated, in large part, by the stability of the initial contact. Immune cell interaction is equally important during delivery of T cell help to B cells and for the killing of target cells by cytotoxic T cells and NK cells. The critical role of contact dynamics and synapse stability on the immune response is well illustrated by human immune deficiencies in which disease pathogenesis is linked to altered adhesion or defective cross-talk between the synaptic partners. The Wiskott–Aldrich syndrome (WAS) is a severe primary immunodeficiency caused by mutations in the Wiskott–Aldrich syndrome protein (WASp), a scaffold that promotes actin polymerization and links TCR stimulation to T cell activation. Absence or mutations in WASp affects intercellular APC–T cell communications by interfering with multiple mechanisms on both sides of the IS. The warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is caused by mutations in CXCR4, a chemokine receptor that in mutant form leads to impairment of APC–T cell interactions. Present evidences suggest that other recently characterized primary immune deficiencies caused by mutation in genes linked to actin cytoskeletal reorganization, such as WIP and DOCK8, may also depend on altered synapse stability. Here, we will discuss in details the mechanisms of disturbed APC–T cell interactions in WAS and WHIM. Moreover, we will summarize the evidence pointing to a compromised conjugate formation in WIP, DOCK8, and X-linked lymphoproliferative syndrome. PMID:26379669

  3. Phase transitions and critical phenomena in the two-dimensional Ising model with dipole interactions: A short-time dynamics study

    NASA Astrophysics Data System (ADS)

    Horowitz, C. M.; Bab, M. A.; Mazzini, M.; Puzzo, M. L. Rubio; Saracco, G. P.

    2015-10-01

    The ferromagnetic Ising model with antiferromagnetic dipole interactions is investigated by means of Monte Carlo simulations, focusing on the characterization of the phase transitions between the tetragonal liquid and stripe of width h phases. The dynamic evolution of the physical observables is analyzed within the short-time regime for 0.5 ≤δ ≤1.3 , where δ is the ratio between the short-range exchange and the long-range dipole interaction constants. The obtained results for the interval 0.5 ≤δ ≤1.2 indicate that the phase transition line between the h =1 stripe and tetragonal liquid phases is continuous. This finding contributes to clarifying the controversy about the order of this transition. This controversy arises from the difficulties introduced in the simulations due to the presence of long-range dipole interactions, such as an important increase in the simulation times that limits the system size used, strong finite size effects, as well as to the existence of multiple metastable states at low temperatures. The study of the short-time dynamics of the model allows us to avoid these hindrances. Moreover, due to the fact that the finite-size effects do not significantly affect the power-law behavior exhibited in the observables within the short-time regime, the results could be attributed to those corresponding to the thermodynamic limit. As a consequence of this, a careful characterization of the critical behavior for the whole transition line is performed by giving the complete set of critical exponents.

  4. Ion exchange phenomena

    SciTech Connect

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  5. Parent-Child Interactions and Relational Aggression in Peer Relationships

    ERIC Educational Resources Information Center

    Michiels, Daisy; Grietens, Hans; Onghena, Patrick; Kuppens, Sofie

    2008-01-01

    The major aim of this review is to propose new ways of thinking about the role of parents in the development and course of children's relationally aggressive behavior. An important theoretical framework from which to start thinking about linkages between parenting and relational aggression is provided by attachment theory. Attachment theory…

  6. Near real-time model to monitor SST anomalies related to undersea earthquakes and SW monsoon phenomena from TRMM-AQUA satellite data

    NASA Astrophysics Data System (ADS)

    Chakravarty, Subhas

    impending under-sea earthquakes sometimes leading to tsunamis. The results of the analysis for the ENSO-Monsoon rainfall relation show that the time series of SST distribution within the Nino 4 or Nino-BP regions with larger number of pixels with SSTs between 27-28° C is generally a favourable condition for normal rainfall condi-tion. While both Nino 4 and Nino-BP provide similar results, Nino-BP region is found to be a more sensitive region for such assessment of monitoring the trend of SW monsoon rainfall over India. This result has the potential to be used in the prognosis of overall rainfall pattern of the monsoon season at weekly intervals which may serve as vital information for Indian agricul-tural production. While simple geophysical models are able to explain the above correlations, more detailed modelling of the plate tectonics and heat fluxes (for undersea earthquakes) and ocean-cloud interaction/dynamics (for ENSO and Monsoon rainfall pattern) would need to be undertaken.

  7. Some remarks about simulation of cosmic ray phenomena with use of nuclear interaction models based on the current SPS proton-antiproton data

    NASA Technical Reports Server (NTRS)

    Wrotniak, J. A.; Yodh, G. B.

    1985-01-01

    The x-y controversy is studied by introducing models with as many features (except for x and y distributions) in common, as possible, to avoid an extrapolation problem, only primary energies of 500 TeV are considered. To prove the point, Monte Carlo simulations are performed of EAS generated by 500 TeV vertical primary protons. Four different nuclear interaction models were used. Two of them are described elsewhere. Two are: (1) Model M-Y00 - with inclusive x and y distributions behaving in a scaling way; and (2) Model M-F00 - at and below ISR energies (1 TeV in Lab) exactly equivalent to the above, then gradually changing to provide the distributions in rapidity at 155 TeV as given by SPS proton-antiproton. This was achieved by gradual decrease in the scale unit in x distributions of produced secondaries, as interaction energy increases. Other modifications to the M-Y00 model were made.

  8. Imaging of snapping phenomena

    PubMed Central

    Guillin, R; Marchand, A J; Roux, A; Niederberger, E; Duvauferrier, R

    2012-01-01

    Snapping phenomena result from the sudden impingement between anatomical and/or heterotopical structures with subsequent abrupt movement and noise. Snaps are variously perceived by patients, from mild discomfort to significant pain requiring surgical management. Identifying the precise cause of snaps may be challenging when no abnormality is encountered on routinely performed static examinations. In this regard, dynamic imaging techniques have been developed over time, with various degrees of success. This review encompasses the main features of each imaging technique and proposes an overview of the main snapping phenomena in the musculoskeletal system. PMID:22744321

  9. Stress pulse phenomena

    SciTech Connect

    McGlaun, M.

    1993-08-01

    This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.

  10. Our Professional Responsibilities Relative to Human-Animal Interactions

    PubMed Central

    Bustad, L. K.; Hines, L.

    1984-01-01

    An interesting area with great potential for benefiting and enriching the lives and conditions of people and animals is opening to us in research, service and teaching. By working with colleagues in other disciplines, we can develop new and creative ways to realize the great promise inherent in people-animal interactions properly studied and utilized. Veterinarians who understand that a strong human-companion animal bond can augment people's mental and physical states will help develop sound and effective companion animal programs for individuals who are lonely or handicapped and for persons in the school systems of the community, as well as its hospices, nursing and convalescent homes, prisons and other institutions. Children experiencing the deep satisfaction of interacting with animals while young will more likely become responsible pet owners and advocates as adults. The image of the profession is enhanced when children and adults see veterinarians as concerned teachers and compassionate health professionals. We as professionals will be required not only to update our knowledge and skills, but to acquire new knowledge in fields of animal and human behavior, psychology and sociology. We are needed on interdisciplinary research teams to study human-animal interactions. We will also be asked to commit time and personal energies in community programs, sometimes with no remuneration. But if skilled health professionals like veterinarians do not take the lead in establishing sound, long-term companion animal programs in their own communities, everyone will suffer including the animals. How we, as individual professionals, respond will be an important reflection of our compassion and our humanity. PMID:17422458

  11. Laser-matter interactions, phase changes and diffusion phenomena during laser annealing of plasmonic AlN:Ag templates and their applications in optical encoding

    NASA Astrophysics Data System (ADS)

    Siozios, A.; Koutsogeorgis, D. C.; Lidorikis, E.; Dimitrakopulos, G. P.; Pliatsikas, N.; Vourlias, G.; Kehagias, T.; Komninou, P.; Cranton, W.; Kosmidis, C.; Patsalas, P.

    2015-07-01

    Nanocomposite thin films incorporating silver nanoparticles are emerging as photosensitive templates for optical encoding applications. However, a deep understanding of the fundamental physicochemical mechanisms occurring during laser-matter interactions is still lacking. In this work, the photosensitivity of AlN:Ag plasmonic nanocomposites is thoroughly examined and a series of UV laser annealing parameters, such as wavelength, fluence and the number of pulses are investigated. We report and study effects such as the selective crystallization of the AlN matrix, the enlargement of the Ag nanoparticle inclusions by diffusion of laser-heated Ag and the outdiffusion of Ag to the film’s surface. Detailed optical calculations contribute to the identification and understanding of the aforementioned physical mechanisms and of their dependency on the laser processing parameters. We are then able to predetermine the plasmonic response of processed AlN:Ag nanocomposites and demonstrate its potential by means of optically encoding an overt or covert cryptographic pattern.

  12. Interactions of Hsp90 with histones and related peptides.

    PubMed

    Schnaider, T; Oikarinen, J; Ishiwatari-Hayasaka, H; Yahara, I; Csermely, P

    1999-01-01

    The 90 kDa heat shock protein (Hsp90) induces the condensation of the chromatin structure [Csermely, P., Kajtár, J., Hollósi, M., Oikarinen, J., and Somogyi, J. (1994) Biochem. Biophys. Res. Commun. 202, 1657-1663]. In our present studies we used surface plasmon resonance measurements to demonstrate that Hsp90 binds histones H1, H2A, H2B, H3 and H4 with high affinity having dissociation constants in the submicromolar range. Strong binding of the C-terminal peptide of histone H1 containing the SPKK-motif and a pentaeicosa-peptide including the Hsp90 bipartite nuclear localization signal sequence was also observed. However, a lysine/arginine-rich peptide of casein, and the lysine-rich platelet factor 4 did not display a significant interaction with Hsp90. Histones and positively charged peptides modulated the Hsp90-associated kinase activity. Interactions between Hsp90, histones, and high mobility group (HMG) protein-derived peptides raise the possibility of the involvement of Hsp90 in chromatin reorganization during steroid action, mitosis, or after cellular stress. PMID:10597896

  13. Nonstationary Phenomena in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Pogorelov, N. V.; Borovikov, S. N.; Ebert, R. W.; Heerikhuisen, J.; Kim, T. K.; Kryukov, I.; Richardson, J. D.; Suess, S. T.; Zank, G. P.

    2012-12-01

    As Voyagers (V1 and V2) are approaching the heliopause (HP), they keep delivering important information about the solar wind (SW) behavior which sometimes appears to be substantially different at V1 and V2 locations. We argue that the observed differences may be attributed to SW variations. In particular, negative values of the radial velocity component derived from V1 observations may be due to the presence of time-dependent magnetic barriers formed due to the slow/fast wind interactions in the vicinity of solar cycle minima. The inner heliosheath is the venue of wave interaction, MHD instabilities, and turbulence. We further investigate these phenomena in the HP vicinity using a new, based on the Ulysses observations, solar cycle model. We show that some puzzling observational data, such as the difference in the heliocentric distances at which V1 and V2 crossed the termination shock, may be attributed to time-dependent effects. We also use other time-dependent sets of observational boundary conditions, e.g., interplanetary scintillation and OMNI data. Phenomena affecting the stability and shape of the HP are also discussed in the context of our time-dependent simulations. The satisfaction of the 2-3 kHz radio emission criteria beyond the HP is analyzed. Numerical results are validated by their comparison with observational data.

  14. Quantum phenomena in superconductors

    SciTech Connect

    Clarke, J.

    1987-08-01

    This paper contains remarks by the author on aspects of macroscopic quantum phenomena in superconductors. Some topics discussed are: Superconducting low-inductance undulatory galvanometer (SLUGS), charge imbalance, cylindrical dc superconducting quantum interference device (SQUIDS), Geophysics, noise theory, magnetic resonance with SQUIDS, and macroscopic quantum tunneling. 23 refs., 4 figs. (LSP)

  15. Preschool Contexts and Teacher Interactions: Relations with School Readiness

    ERIC Educational Resources Information Center

    Goble, Priscilla; Hanish, Laura D.; Martin, Carol Lynn; Eggum-Wilkens, Natalie D.; Foster, Stacie A.; Fabes, Richard A.

    2016-01-01

    The majority of early education programs promote children's learning through a mix of experiences in child- and teacher-managed contexts. The current study examined time spent in child- and teacher-managed contexts and the nature of children's experiences with teachers in these contexts as they relate to children's skill development. Participants…

  16. Interacting varying ghost dark energy models in general relativity

    NASA Astrophysics Data System (ADS)

    Khurshudyan, Martiros; Khurshudyan, Amalya; Myrzakulov, Ratbay

    2015-06-01

    Motivated by recent developments in Cosmology we would like to consider an extension of the Ghost DE which we will name as varying Ghost DE. Ghost DE like other models was introduced recently as a possible way to explain accelerated expansion of the Universe. For the phenomenological origin of the varying Ghost dark energy in our Universe we can suggest an existence of some unknown dynamics between the Ghost Dark energy and a fluid which evaporated completely making sense of the proposed effect. Moreover, we assume that this was in the epochs and scales which are unreachable by present-day experiments, like in very early Universe. In this study we will investigate the model for cosmological validity. We will apply observational and causality constraints to illuminate physically correct behavior of the model from the phenomenological one. We saw that an interaction between the varying Ghost DE and cold DM (CDM) also provides a solution to the cosmological coincidence problem. And we found that the Ghost DE behaves as a fluid-like matter in early Universe.

  17. Relating Things and Stuff via Object Property Interactions.

    PubMed

    Sun, Min; Kim, Byung-Soo; Kohli, Pushmeet; Savarese, Silvio

    2013-10-01

    In the last few years, substantially different approaches have been adopted for segmenting and detecting "things" (object categories that have a well defined shape such as people and cars) and "stuff" (object categories which have an amorphous spatial extent such as grass and sky). While things have been typically detected by sliding window or Hough transform based methods, detection of stuff is generally formulated as a pixel or segment-wise classification problem. This paper proposes a framework for scene understanding that models both things and stuff using a common representation while preserving their distinct nature by using a property list. This representation allows us to enforce sophisticated geometric and semantic relationships between thing and stuff categories via property interactions in a single graphical model. We use the latest advances made in the field of discrete optimization to efficiently perform maximum a posteriori (MAP) inference in this model. We evaluate our method on the Stanford dataset by comparing it against state-of-the-art methods for object segmentation and detection. We also show that our method achieves competitive performances on the challenging PASCAL'09 segmentation dataset. PMID:24101332

  18. Relating Things and Stuff via ObjectProperty Interactions.

    PubMed

    Min Sun; Byung-Soo Kim; Kohli, Pushmeet; Savarese, Silvio

    2014-07-01

    In the last few years, substantially different approaches have been adopted for segmenting and detecting "things" (object categories that have a well defined shape such as people and cars) and "stuff" (object categories which have an amorphous spatial extent such as grass and sky). While things have been typically detected by sliding window or Hough transform based methods, detection of stuff is generally formulated as a pixel or segment-wise classification problem. This paper proposes a framework for scene understanding that models both things and stuff using a common representation while preserving their distinct nature by using a property list. This representation allows us to enforce sophisticated geometric and semantic relationships between thing and stuff categories via property interactions in a single graphical model. We use the latest advances made in the field of discrete optimization to efficiently perform maximum a posteriori (MAP) inference in this model. We evaluate our method on the Stanford dataset by comparing it against state-of-the-art methods for object segmentation and detection. We also show that our method achieves competitive performances on the challenging PASCAL '09 segmentation dataset. PMID:26353309

  19. TPP - An interactive database of cataclysmic variables and related objects

    NASA Astrophysics Data System (ADS)

    Kube, J.; Gänsicke, B. T.; Hoffmann, B.

    2002-01-01

    We introduce our interactive online catalogue of cataclysmic variables, historically dubbed TPP. Similar to the Downes et al. catalogue, we include all systems which have been -- even remotely -- mentioned as a cataclysmic variable. However, TPP is intended to include all the available published information on the listed systems, such as, e.g. orbital period, inclination, distance, primary and secondary masses, magnetic field strength, etc. A major difference to the established catalogues is that every member of the community can contribute information to the database. Technically speaking, the catalogue is contained in a MySQL database and accessed through a Perl script running on our web server. Hence, the user interface is displayed in the client's web browser. On July 30, 2001, our data base contained 1167 single objects with 4071 pieces of information drawn from 1958 different literature sources. Literature references are directly linked to the ADS abstract system, the arXive preprint server and the VSNET mail archive. You find TPP in the World Wide Web at TPP, where we also provide a complete user manual. TPP was made possible by using the free scripting language Perl and the free data base MySQL. A big ``thank you'' to the developers of these powerful tools and to the whole GNU community!

  20. Synchronization Phenomena and Epoch Filter of Electroencephalogram

    NASA Astrophysics Data System (ADS)

    Matani, Ayumu

    Nonlinear electrophysiological synchronization phenomena in the brain, such as event-related (de)synchronization, long distance synchronization, and phase-reset, have received much attention in neuroscience over the last decade. These phenomena contain more electrical than physiological keywords and actually require electrical techniques to capture with electroencephalography (EEG). For instance, epoch filters, which have just recently been proposed, allow us to investigate such phenomena. Moreover, epoch filters are still developing and would hopefully generate a new paradigm in neuroscience from an electrical engineering viewpoint. Consequently, electrical engineers could be interested in EEG once again or from now on.

  1. Relation between hadronic interactions and ultra-high energy extensive air showers

    NASA Astrophysics Data System (ADS)

    Ulrich, Ralf; Baus, Colin; Engel, Ralph

    2015-08-01

    The simulation of hadronic interactions is of fundamental importance for the analysis of extensive air showers. The details of the relation between the measurement of hadronic interactions at accelerators and the impact on the air shower development is very difficult to evaluate. Several possibilities to study this relation are presented here.

  2. Interaction in the Research Interview and Drug-Related Disclosures among Respondents.

    ERIC Educational Resources Information Center

    Myers, Vincent

    1979-01-01

    Interviewers and respondents judged interview interactions during a survey of drug-related sentiments. Pronounced variability in interviewer-respondent judgements occurred in unanticipated ways related to gender, role, and ethnicity of participants. Positive interaction yielded different respondent cognitions and reports of illicit drug ingestion…

  3. Relation and Interactions among Reading Fluency and Competence for Adult Education Learners

    ERIC Educational Resources Information Center

    Mellard, Daryl F.; Fall, Emily E.; Woods, Kari L.

    2013-01-01

    Statistical analyses of data from an academically diverse sample of 276 adult basic and secondary education learners extends understanding of the relation of and interactions between oral reading fluency and reading competence indices. Significant interactions between total word rate and word error rate that differed in relation to two measures of…

  4. PPI-IRO: a two-stage method for protein-protein interaction extraction based on interaction relation ontology.

    PubMed

    Li, Chuan-Xi; Chen, Peng; Wang, Ru-Jing; Wang, Xiu-Jie; Su, Ya-Ru; Li, Jinyan

    2014-01-01

    Mining Protein-Protein Interactions (PPIs) from the fast-growing biomedical literature resources has been proven as an effective approach for the identification of biological regulatory networks. This paper presents a novel method based on the idea of Interaction Relation Ontology (IRO), which specifies and organises words of various proteins interaction relationships. Our method is a two-stage PPI extraction method. At first, IRO is applied in a binary classifier to determine whether sentences contain a relation or not. Then, IRO is taken to guide PPI extraction by building sentence dependency parse tree. Comprehensive and quantitative evaluations and detailed analyses are used to demonstrate the significant performance of IRO on relation sentences classification and PPI extraction. Our PPI extraction method yielded a recall of around 80% and 90% and an F1 of around 54% and 66% on corpora of AIMed and BioInfer, respectively, which are superior to most existing extraction methods. PMID:25757257

  5. Identification of Crew-Systems Interactions and Decision Related Trends

    NASA Technical Reports Server (NTRS)

    Jones, Sharon Monica; Evans, Joni K.; Reveley, Mary S.; Withrow, Colleen A.; Ancel, Ersin; Barr, Lawrence

    2013-01-01

    NASA Vehicle System Safety Technology (VSST) project management uses systems analysis to identify key issues and maintain a portfolio of research leading to potential solutions to its three identified technical challenges. Statistical data and published safety priority lists from academic, industry and other government agencies were reviewed and analyzed by NASA Aviation Safety Program (AvSP) systems analysis personnel to identify issues and future research needs related to one of VSST's technical challenges, Crew Decision Making (CDM). The data examined in the study were obtained from the National Transportation Safety Board (NTSB) Aviation Accident and Incident Data System, Federal Aviation Administration (FAA) Accident/Incident Data System and the NASA Aviation Safety Reporting System (ASRS). In addition, this report contains the results of a review of safety priority lists, information databases and other documented references pertaining to aviation crew systems issues and future research needs. The specific sources examined were: Commercial Aviation Safety Team (CAST) Safety Enhancements Reserved for Future Implementation (SERFIs), Flight Deck Automation Issues (FDAI) and NTSB Most Wanted List and Open Recommendations. Various automation issues taxonomies and priority lists pertaining to human factors, automation and flight design were combined to create a list of automation issues related to CDM.

  6. Membrane Transport Phenomena (MTP)

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    1997-01-01

    The third semi-annual period of the MTP project has been involved with performing experiments using the Membrane Transport Apparatus (MTA), development of analysis techniques for the experiment results, analytical modeling of the osmotic transport phenomena, and completion of a DC-9 microgravity flight to test candidate fluid cell geometries. Preparations were also made for the MTP Science Concept Review (SCR), held on 13 June 1997 at Lockheed Martin Astronautics in Denver. These activities are detailed in the report.

  7. In-vessel phenomena -- CORA

    SciTech Connect

    Ott, L.J.; van Rij, W.I.

    1991-01-01

    Experiment-specific models have been employed since 1986 by Oak Ridge National Laboratory (ORNL) severe accident analysis programs for the purpose of boiling water reactor experimental planning and optimum interpretation of experimental results. The large integral tests performed to date, which start from an initial undamaged core state, have involved significantly different-from-prototypic boundary and experimental conditions because of either normal facility limitations or specific experimental constraints. These experiments (ACRR: DF-4, NRU: FLHT-6, and CORA) were designed to obtain specific phenomenological information such as the degradation and interaction of prototypic components and the effects on melt progression of control-blade materials and channel boxes. Applications of ORNL models specific to the KfK CORA-16 and CORA-17 experiments are discussed and significant findings from the experimental analyses such as the following are presented: applicability of available Zircaloy oxidation kinetics correlations; influence of cladding strain on Zircaloy oxidation; influence of spacer grids on the structural heatup; and the impact of treating the gaseous coolant as a gray interacting medium. The experiment-specific models supplement and support the systems-level accident analysis codes. They allow the analyst to accurately quantify the observed experimental phenomena and to compensate for the effect of known uncertainties. They provide a basis for the efficient development of new models for phenomena that are currently not modeled (such as material interactions). They can provide validated phenomenological models (from the results of the experiments) as candidates for incorporation in the systems-level whole-core'' codes.

  8. Nanoflares, Spicules, and Other Small-Scale Dynamic Phenomena on the Sun

    NASA Technical Reports Server (NTRS)

    Klimchuk, James

    2010-01-01

    There is abundant evidence of highly dynamic phenomena occurring on very small scales in the solar atmosphere. For example, the observed pr operties of many coronal loops can only be explained if the loops are bundles of unresolved strands that are heated impulsively by nanoflares. Type II spicules recently discovered by Hinode are an example of small-scale impulsive events occurring in the chromosphere. The exist ence of these and other small-scale phenomena is not surprising given the highly structured nature of the magnetic field that is revealed by photospheric observations. Dynamic phenomena also occur on much lar ger scales, including coronal jets, flares, and CMEs. It is tempting to suggest that these different phenomena are all closely related and represent a continuous distribution of sizes and energies. However, this is a dangerous over simplification in my opinion. While it is tru e that the phenomena all involve "magnetic reconnection" (the changin g of field line connectivity) in some form, how this occurs depends s trongly on the magnetic geometry. A nanoflare resulting from the interaction of tangled magnetic strands within a confined coronal loop is much different from a major flare occurring at the current sheet form ed when a CME rips open an active region. I will review the evidence for ubiquitous small-scale dynamic phenomena on the Sun and discuss wh y different phenomena are not all fundamentally the same.

  9. The Seminole Serpent Warrior At Miramar, FL, Shows Settlement Locations Enabled Environmental Monitoring Reminiscent Of the Four-corners Kokopelli-like EMF Phenomena, and Related to Earthquakes, Tornados and Hurricanes.

    NASA Astrophysics Data System (ADS)

    Balam Matagamon, Chan; Pawa Matagamon, Sagamo

    2004-03-01

    Certain Native Americans of the past seem to have correctly deduced that significant survival information for their tradition-respecting cultures resided in EMF-based phenomena that they were monitoring. This is based upon their myths and the place or cult-hero names they bequeathed us. The sites we have located in FL have been detectable by us visually, usually by faint blue light, or by the elicitation of pin-like prickings, by somewhat intense nervous-system response, by EMF interactions with aural electrochemical systems that can elicit tinitus, and other ways. In the northeast, Cautantowit served as a harbinger of Indian summer, and appears to be another alter ego of the EMF. The Miami, FL Tequesta site along the river clearly correlates with tornado, earthquake and hurricane locations. Sites like the Mohave Deserts giant man may have had similar significance.

  10. Wave phenomena in sunspots

    NASA Astrophysics Data System (ADS)

    Löhner-Böttcher, Johannes

    2016-03-01

    Context: The dynamic atmosphere of the Sun exhibits a wealth of magnetohydrodynamic (MHD) waves. In the presence of strong magnetic fields, most spectacular and powerful waves evolve in the sunspot atmosphere. Allover the sunspot area, continuously propagating waves generate strong oscillations in spectral intensity and velocity. The most prominent and fascinating phenomena are the 'umbral flashes' and 'running penumbral waves' as seen in the sunspot chromosphere. Their nature and relation have been under intense discussion in the last decades. Aims: Waves are suggested to propagate upward along the magnetic field lines of sunspots. An observational study is performed to prove or disprove the field-guided nature and coupling of the prevalent umbral and penumbral waves. Comprehensive spectroscopic observations at high resolution shall provide new insights into the wave characteristics and distribution across the sunspot atmosphere. Methods: Two prime sunspot observations were carried out with the Dunn Solar Telescope at the National Solar Observatory in New Mexico and with the Vacuum Tower Telescope at the Teide Observatory on Tenerife. The two-dimensional spectroscopic observations were performed with the interferometric spectrometers IBIS and TESOS. Multiple spectral lines are scanned co-temporally to sample the dynamics at the photospheric and chromospheric layers. The time series (1 – 2.5 h) taken at high spatial and temporal resolution are analyzed according to their evolution in spectral intensities and Doppler velocities. A wavelet analysis was used to obtain the wave power and dominating wave periods. A reconstruction of the magnetic field inclination based on sunspot oscillations was developed. Results and conclusions: Sunspot oscillations occur continuously in spectral intensity and velocity. The obtained wave characteristics of umbral flashes and running penumbral waves strongly support the scenario of slow-mode magnetoacoustic wave propagation along

  11. Wolf-Rayet phenomena

    NASA Technical Reports Server (NTRS)

    Conti, P. S.

    1982-01-01

    The properties of stars showing Wolf-Rayet phenomena are outlined along with the direction of future work. Emphasis is placed on the characteristics of W-R spectra. Specifically the following topics are covered: the absolute visual magnitudes; the heterogeneity of WN spectra; the existence of transition type spectra and compositions the mass loss rates; and the existence of very luminous and possibly very massive W-R stars. Also, a brief overview of current understanding of the theoretical aspects of stellar evolution and stellar winds and the various scenarios that have been proposed to understand W-R spectra are included.

  12. Evidence for universal relations describing a gas with p-wave interactions

    NASA Astrophysics Data System (ADS)

    Smale, S.; Luciuk, C.; Trotzky, S.; Yu, Zhenhua; Zhang, Shizhong; Thywissen, J. H.

    2016-05-01

    A remarkable set of universal relations is known to directly connect thermodynamic and microscopic properties of interacting Fermi gases. So far, these contact relations have been established only for interactions with s-wave symmetry, i.e., with zero relative angular momentum. We report measurements of two new physical quantities, the p-wave contacts, and present evidence that they encode the universal aspects of p-wave interactions through recently proposed relations. Our experiments use a spin-polarized ultracold Fermi gas of 40 K, in which s-wave interactions are suppressed, while p-wave interactions are enhanced near a Feshbach resonance. Using time-resolved spectroscopy and momentum distribution measurements, we study how correlations in the system develop after quenching the atoms into an interacting state. Combining quasi-steady-state measurements with new contact relations, we infer an attractive p-wave interaction energy as large as the Fermi energy. Our results reveal new ways to understand and characterize the properties of resonantly interacting p-wave quantum gases.

  13. Ultraintense laser-solid interaction phenomena

    SciTech Connect

    Mulser, P.; Bauer, D.; Hain, S.; Cornolti, F.

    1998-02-20

    In the variety of processes occurring in matter under the action of superstrong laser fields rapid field ionization and ponderomotive effects play a dominant role. We investigate field ionization by solving the time-dependent Schroedinger equation numerically and compare the results with classical calculations. We obtain the ionization rates of hydrogen-like ions, the ejection energy spectrum of the electrons, and we show the transition to classical behavior at high energies. In addition, we are able to give a physical explanation of non-sequential ionization. Our ionization rates differ by more than an order of magnitude from the standard expressions. A model is presented which allows to calculate the back action of field ionization on the laser beam. Finally, we present the most general relativistic derivation of ponderomotive forces on single particles and present their transformation properties. Ponderomotive forces are of non-Newtonian character.

  14. Solution‐crystallization and related phenomena in 9,9‐dialkyl‐fluorene polymers. II. Influence of side‐chain structure

    PubMed Central

    Perevedentsev, Aleksandr; Stavrinou, Paul N.; Smith, Paul

    2015-01-01

    ABSTRACT Solution‐crystallization is studied for two polyfluorene polymers possessing different side‐chain structures. Thermal analysis and temperature‐dependent optical spectroscopy are used to clarify the nature of the crystallization process, while X‐ray diffraction and scanning electron microscopy reveal important differences in the resulting microstructures. It is shown that the planar‐zigzag chain conformation termed the β‐phase, which is observed for certain linear‐side‐chain polyfluorenes, is necessary for the formation of so‐called polymer‐solvent compounds for these polymers. Introduction of alternating fluorene repeat units with branched side‐chains prevents formation of the β‐phase conformation and results in non‐solvated, i.e. melt‐crystallization‐type, polymer crystals. Unlike non‐solvated polymer crystals, for which the chain conformation is stabilized by its incorporation into a crystalline lattice, the β‐phase conformation is stabilized by complexation with solvent molecules and, therefore, its formation does not require specific inter‐chain interactions. The presented results clarify the fundamental differences between the β‐phase and other conformational/crystalline forms of polyfluorenes. © 2015 The Authors. Journal of Polymer Science Part B: Polymer Physics published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1492–1506

  15. Causes of Sex Ratio Bias May Account for Unisexual Sterility in Hybrids: A New Explanation of Haldane's Rule and Related Phenomena

    PubMed Central

    Hurst, L. D.; Pomiankowski, A.

    1991-01-01

    Unisexual hybrid disruption can be accounted for by interactions between sex ratio distorters which have diverged in the species of the hybrid cross. One class of unisexual hybrid disruption is described by Haldane's rule, namely that the sex which is absent, inviable or sterile is the heterogametic sex. This effect is mainly due to incompatibility between X and Y chromosomes. We propose that this incompatibility is due to a mutual imbalance between meiotic drive genes, which are more likely to evolve on sex chromosomes than autosomes. The incidences of taxa with sex chromosome drive closely matches those where Haldane's rule applies: Aves, Mammalia, Lepidoptera and Diptera. We predict that Haldane's rule is not universal but is correct for taxa with sex chromosome meiotic drive. A second class of hybrid disruption affects the male of the species regardless of which sex is heterogametic. Typically the genes responsible for this form of disruption are cytoplasmic. These instances are accounted for by the release from suppression of cytoplasmic sex ratio distorters when in a novel nuclear cytotype. Due to the exclusively maternal transmission of cytoplasm, cytoplasmic sex ratio distorters cause only female-biased sex ratios. This asymmetry explains why hybrid disruption is limited to the male. PMID:1916248

  16. Long term puzzles of the CH and CD energetics and related phenomena revisited; solutions sought through REMPI-photofragmentations of bromomethanes.

    PubMed

    Hafliðason, Arnar; Wang, Huasheng; Kvaran, Ágúst

    2016-01-21

    Ever since the pioneering work by Herzberg and Johns in 1969 (The Astrophysical Journal, 1969, 158, 399) the spectral assignment and the energetics of the fundamental molecular fragment CH, in the region of 63 000-65 000 cm(-1) (7.81-8.06 eV), have remained a puzzle to a large extent. The dissociation of bromoform and deuterated bromoform following two-photon resonance excitations to molecular Rydberg states forms the fragment species CH* and CD* in the excited state A(2)Δ(v' =0) as well as carbon and bromine atoms in the ground and first excited states, C/C* and Br/Br*. Further (1r + 1i)REMPI of CH* and CD* resonance excites the fragments to the energy region of concern, whereas the atom fragments were identified by further (2r + 1i)REMPI. Analysis based on spectral simulations, isotope shifts and comparison with other data allowed spectral identifications, assignments and partial characterization of four highly excited bound states for each of the molecular fragments (CH**/CD**); including the (3)(2)Π valence state and the (4)(2)Π Rydberg state, for the first time. Perturbations, shown as line-shifts, line-intensity and/or line-width alterations, due to the level-to-level state interactions between the bound states and predissociations by a repulsive state are recognized. Recording of C(+) signals in REMPI of several bromomethanes for a one-photon energy of about 40 333 cm(-1) allows the clarification of a mystery concerning a broad C(+) band frequently observed. This work, presented, demonstrates the usefulness of molecular REMPI for fragment analysis. PMID:26674135

  17. Phenomena Associated with EIT Waves

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.; Fisher, Richard R. (Technical Monitor)

    2002-01-01

    We discuss phenomena associated with 'EIT Wave' transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to infer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  18. Phenomena Associated With EIT Waves

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.

    2003-01-01

    We discuss phenomena associated with "EIT Wave" transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to mfer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  19. Modeling of fundamental phenomena in welds

    SciTech Connect

    Zacharia, T.; Vitek, J.M.; Goldak, J.A.; DebRoy, T.A.; Rappaz, M.; Bhadeshia, H.K.D.H.

    1993-12-31

    Recent advances in the mathematical modeling of fundamental phenomena in welds are summarized. State-of-the-art mathematical models, advances in computational techniques, emerging high-performance computers, and experimental validation techniques have provided significant insight into the fundamental factors that control the development of the weldment. The current status and scientific issues in the areas of heat and fluid flow in welds, heat source metal interaction, solidification microstructure, and phase transformations are assessed. Future research areas of major importance for understanding the fundamental phenomena in weld behavior are identified.

  20. Correlated randomness and switching phenomena

    NASA Astrophysics Data System (ADS)

    Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Kumar, P.; Plerou, V.; Preis, T.

    2010-08-01

    One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines have no perfect metronome in time and no perfect spatial architecture-crystalline or otherwise. Nonetheless, as if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time and remarkably fine-tuned structures in space. Further, many of these processes and structures have the remarkable feature of “switching” from one behavior to another as if by magic. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many spatial and temporal patterns in biology, medicine, and economics and even begin to characterize the switching phenomena that enables a system to pass from one state to another. Inspired by principles developed by A. Nihat Berker and scores of other statistical physicists in recent years, we discuss some applications of correlated randomness to understand switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water’s anomalies are related to a switching point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not “outliers” (another Gladwell immortalization). Though more speculative, we support the idea of disease as arising from some kind of yet-to-be-understood complex switching phenomenon, by discussing data on selected examples, including heart disease and Alzheimer disease.

  1. Measured Gene-by-Environment Interaction in Relation to Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Nigg, Joel; Nikolas, Molly; Burt, S. Alexandra

    2010-01-01

    Objective: To summarize and evaluate the state of knowledge regarding the role of measured gene-by-environment interactions in relation to attention-deficit/hyperactivity disorder. Method: A selective review of methodologic issues was followed by a systematic search for relevant articles on measured gene-by-environment interactions; the search…

  2. Peer-Related Social Interactions of Developmentally Delayed Young Children: Development and Characteristics.

    ERIC Educational Resources Information Center

    Guralnick, Michael J.; Weinhouse, Ellen

    1984-01-01

    A short-term longitudinal study of the peer-related social interactions of 111 developmentally delayed toddlers and preschool children was carried out. Results suggested the existence of unusually marked deficits in peer interactions. Possible contributing factors were discussed. (Author/RH)

  3. Physical and Relational Aggression in Young Children: The Role of Mother-Child Interactional Synchrony

    ERIC Educational Resources Information Center

    Ambrose, Holly N.; Menna, Rosanne

    2013-01-01

    This study examined the relationships between the quality of parent-child interactions, specifically interactional synchrony (IS), and physical and relational aggression in young children. Seventy-three children (3-6 years; 44 males, 29 females) and their mothers participated in this study. The children's level of aggression was assessed through…

  4. Detection of moisture and moisture related phenomena from Skylab. [correlation of brightness and antenna temperature with soil moisture for Texas and Kansas test sites

    NASA Technical Reports Server (NTRS)

    Eagleman, J. R.; Pogge, E. C.; Moore, R. K. (Principal Investigator); Hardy, N.; Lin, W.; League, L.

    1974-01-01

    The author has identified the following significant results. Skylab 2 data for June 5, 1973 (Texas site) relates favorably with previously calculated aircraft data when correlating brightness temperature to soil moisture. However, more detailed work is needed to determine the corrected surface temperature. In addition, correlations between the S194 antenna temperature and soil moisture have been obtained for five sets of Skylab data. The best correlations were obtained for the surface to one inch depth in four cases and for surface to two inches depth for the fifth case. Correlation coefficients for the surface to one inch depth were -0.98, -0.95, -0.90, -0.82, and -0.80.

  5. Relations between Hormone Levels and Observational Measures of Aggressive Behavior of Young Adolescents in Family Interactions.

    ERIC Educational Resources Information Center

    Inoff-Germain, Gale; And Others

    1988-01-01

    Relations between hormone levels and aggressive behavior of adolescents in family interactions were examined. Higher estradiol and androstenedione levels were associated with higher degrees of aggressive behaviors in girls. Findings for boys were sparse. (PCB)

  6. Entanglement and boundary critical phenomena

    SciTech Connect

    Zhou Huanqiang; Barthel, Thomas; Schollwoeck, Ulrich; Fjaerestad, John Ove

    2006-11-15

    We investigate boundary critical phenomena from a quantum-information perspective. Bipartite entanglement in the ground state of one-dimensional quantum systems is quantified using the Renyi entropy S{sub {alpha}}, which includes the von Neumann entropy ({alpha}{yields}1) and the single-copy entanglement ({alpha}{yields}{infinity}) as special cases. We identify the contribution of the boundaries to the Renyi entropy, and show that there is an entanglement loss along boundary renormalization group (RG) flows. This property, which is intimately related to the Affleck-Ludwig g theorem, is a consequence of majorization relations between the spectra of the reduced density matrix along the boundary RG flows. We also point out that the bulk contribution to the single-copy entanglement is half of that to the von Neumann entropy, whereas the boundary contribution is the same.

  7. Unidentified phenomena - Unusual plasma behavior?

    NASA Astrophysics Data System (ADS)

    Avakian, S. V.; Kovalenok, V. V.

    1992-06-01

    The paper describes observations of a phenomenon belonging to the UFO category and the possible causes of these events. Special attention is given to an event which occurred during the night of September 19-20, 1974, when a huge 'star' was observed over Pertrozavodsk (Russia), consisting of a bright-white luminous center, emitting beams of light, and a less bright light-blue shell. The star gradually formed a cometlike object with a tail consisting of beams of light and started to descend. It is suggested that this event was related to cosmic disturbances caused by an occurrence of unusually strong solar flares. Other examples are presented that relate unusual phenomena observed in space to the occurrence of strong magnetic turbulence events.

  8. High-Field Phenomena of Qubits.

    PubMed

    van Tol, Johan; Morley, G W; Takahashi, S; McCamey, D R; Boehme, C; Zvanut, M E

    2009-12-01

    Electron and nuclear spins are very promising candidates to serve as quantum bits (qubits) for proposed quantum computers, as the spin degrees of freedom are relatively isolated from their surroundings and can be coherently manipulated, e.g., through pulsed electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR). For solid-state spin systems, impurities in crystals based on carbon and silicon in various forms have been suggested as qubits, and very long relaxation rates have been observed in such systems. We have investigated a variety of these systems at high magnetic fields in our multifrequency pulsed EPR/ENDOR (electron nuclear double resonance) spectrometer. A high magnetic field leads to large electron spin polarizations at helium temperatures, giving rise to various phenomena that are of interest with respect to quantum computing. For example, it allows the initialization of both the electron spin as well as hyperfine-coupled nuclear spins in a well-defined state by combining millimeter and radio-frequency radiation. It can increase the T(2) relaxation times by eliminating decoherence due to dipolar interaction and lead to new mechanisms for the coherent electrical readout of electron spins. We will show some examples of these and other effects in Si:P, SiC:N and nitrogen-related centers in diamond. PMID:19946596

  9. Thermal Wave Phenomena

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This map from the MGS Horizon Sensor Assembly (HORSE) shows middle atmospheric temperatures near the 1 mbar level of Mars between Ls 170 to 175 (approx. July 14 - 23, 1999). Local Mars times between 1:30 and 4:30 AM are included. Infrared radiation measured by the Mars Horizon Sensor Assembly was used to make the map. That device continuously views the 'limb' of Mars in four directions, to help orient the spacecraft instruments to the nadir: straight down.

    The map shows thermal wave phenomena that are caused by the large topographic variety of Mars' surface, as well the latitudinally symmetric behavior expected at this time of year near the equinox.

  10. Novel QCD Phenomena

    SciTech Connect

    Brodsky, Stanley J.; /SLAC

    2007-07-06

    I discuss a number of novel topics in QCD, including the use of the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. In particular, there is an exact correspondence between the fifth-dimension coordinate z of AdS space and a specific impact variable {zeta} which measures the separation of the quark constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and allow the computation of exclusive scattering amplitudes. I also discuss a number of novel phenomenological features of QCD. Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss tests of hidden color in nuclear wavefunctions, the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high centrality heavy ion collisions.

  11. Something Blossoms in Between: Silence-Phenomena as a Bordering Notions in Psychology.

    PubMed

    Lehmann Oliveros, Olga V

    2016-03-01

    Mysterious yet unavoidable, silence-phenomena appear to us in inherent ambiguity. In its plurality of meanings, phenomena related to silence are often perceived as overwhelming because they transcend the communicative capacity of language making it a challenge for cultural psychology to understand its involvement in our processes of making sense of experience and existence. Human growth and development involve processes where presence, void and content, voice, sound and noise, motion, transition and stillness, have dialectic interactions. In this article I discuss silence-phenomena as a bordering notion in terms of its discursive quality, the silent quality of speech, and the awareness of the ineffable. In addition, I highlight the possible implications of such notion in the understanding of affect from the perspective of Semiotic Cultural Psychology. I also emphasize the importance of considering psychological borders as multi-dimensional, taking the phenomenological experience of temporality as an illustration, which is also related to high emotional involvement of attention. PMID:26232279

  12. Anomalous Light Phenomena vs. Bioelectric Brain Activity

    NASA Astrophysics Data System (ADS)

    Teodorani, M.; Nobili, G.

    We present a research proposal concerning the instrumented investigation of anomalous light phenomena that are apparently correlated with particular mind states, such as prayer, meditation or psi. Previous research by these authors demonstrate that such light phenomena can be monitored and measured quite efficiently in areas of the world where they are reported in a recurrent way. Instruments such as optical equipment for photography and spectroscopy, VLF spectrometers, magnetometers, radar and IR viewers were deployed and used massively in several areas of the world. Results allowed us to develop physical models concerning the structural and time-variable behaviour of light phenomena, and their kinematics. Recent insights and witnesses have suggested to us that a sort of "synchronous connection" seems to exist between plasma-like phenomena and particular mind states of experiencers who seem to trigger a light manifestation which is very similar to the one previously investigated. The main goal of these authors is now aimed at the search for a concrete "entanglement-like effect" between the experiencer's mind and the light phenomena, in such a way that both aspects are intended to be monitored and measured simultaneously using appropriate instrumentation. The goal of this research project is twofold: a) to verify quantitatively the existence of one very particular kind of mind-matter interaction and to study in real time its physical and biophysical manifestations; b) to repeat the same kind of experiment using the same test-subject in different locations and under various conditions of geomagnetic activity.

  13. Evidence for universal relations describing a gas with p-wave interactions

    NASA Astrophysics Data System (ADS)

    Luciuk, Christopher; Trotzky, Stefan; Smale, Scott; Yu, Zhenhua; Zhang, Shizhong; Thywissen, Joseph H.

    2016-06-01

    In dilute gases, a set of universal relations, known as the contact relations, directly connects thermodynamics and microscopic properties. So far, they have been established only for interactions with s-wave symmetry--that is, without relative angular momentum. Here we report measurements of two new physical quantities, the p-wave contacts, and, using recently proposed relations, present evidence that they encode the universal aspects of p-wave interactions. Our experiments use an ultracold Fermi gas of 40K, in which s-wave interactions are suppressed by polarizing the sample, whereas p-wave interactions are enhanced by working near a scattering resonance. Using time-resolved spectroscopy, we study how correlations in the system develop after quenching the atoms into an interacting state. By combining quasi-steady-state measurements with new contact relations, we infer an attractive p-wave interaction energy as large as half the Fermi energy. Our results reveal new ways to understand and characterize the properties of a resonant p-wave quantum gas.

  14. Reciprocal and Complementary Sibling Interactions: Relations with Socialization Outcomes in the Kindergarten Classroom

    PubMed Central

    Harrist, Amanda W.; Achacoso, Joseph A.; John, Aesha; Pettit, Gregory S.; Bates, John E.; Dodge, Kenneth A.

    2013-01-01

    Research Findings To examine associations between sibling interaction patterns and later social outcomes in single- and two-parent families, 113 kindergarteners took part in naturalistic observations at home with siblings, classmates participated in sociometric interviews, and teachers completed behavior ratings. Sibling interactions were coded using a newly-developed 39-item checklist, and proportions of complementary and reciprocal sibling interactions computed. Complementarity occurred more among dyads where kindergartners were with toddler or infant siblings than among kindergartners with older or near-age younger siblings. Higher levels of complementarity predicted lower levels of internalizing but were not related to externalizing problems. Kindergartners’ sociometric status in the classroom differed as a function of sibling interaction patterns, with neglected and controversial children experiencing less complementarity/more reciprocity than popular, average, and rejected children. Finally, there was some evidence for differential associations of sibling interaction patterns with social outcomes for children in single- versus two-parent families: regressions testing interaction effects show sibling reciprocity positively associated with kindergartners’ social skills only in single-parent families, and complementary sibling interactions positively related to internalizing problems only in two-parent families. Implications for Practice Those working with divorcing or other single-parent families might consider sibling interactions as a potential target for social skill building. PMID:26005311

  15. Maternal ADHD: Parent-Child Interactions and Relations with Child Disruptive Behavior

    ERIC Educational Resources Information Center

    Zisser, Alison R.; Eyberg, Sheila M.

    2012-01-01

    This study examined how ADHD symptoms in mothers of children with ADHD relate to their behavior during parent-child interactions and to their children's disruptive behavior. Findings indicated that mothers' retrospective self-ratings of ADHD symptoms were related to their present negativity during parent-led play. Mothers' self-ratings of current…

  16. Interactive Links between Relational Aggression, Theory of Mind, and Moral Disengagement among Early Adolescents

    ERIC Educational Resources Information Center

    Kokkinos, Constantinos M.; Voulgaridou, Ioanna; Mandrali, Marianna; Parousidou, Chrysoula

    2016-01-01

    The aim of this study was to investigate possible interactive links between theory of mind (ToM), moral disengagement and relational aggression, using a moderated mediation analysis, with gender as a moderator, in a sample of 120 Greek preadolescents. Results indicated that relational aggression was significantly positively associated with moral…

  17. Investigating the students' understanding of surface phenomena

    NASA Astrophysics Data System (ADS)

    Hamed, Kastro Mohamad

    1999-11-01

    This study investigated students' understanding of surface phenomena. The main purpose for conducting this research endeavor was to understand how students think about a complex topic about which they have little direct or formal instruction. The motivation for focusing on surface phenomena stemmed from an interest in integrating research and education. Despite the importance of surfaces and interfaces in research laboratories, in technological applications, and in everyday experiences, no previous systematic effort was done on pedagogy related to surface phenomena. The design of this research project was qualitative, exploratory, based on a Piagetian semi-structured clinical piloted interview, focused on obtaining a longitudinal view of the intended sample. The sampling was purposeful and the sample consisted of forty-four undergraduate students at Kansas State University. The student participants were enrolled in physics classes that spanned a wide academic spectrum. The data were analyzed qualitatively. The main themes that emerged from the analysis were: (a) students used analogies when confronted with novel situations, (b) students mixed descriptions and explanations, (c) students used the same explanation for several phenomena, (d) students manifested difficulties transferring the meaning of vocabulary across discipline boundaries, (e) in addition to the introductory chemistry classes, students used everyday experiences and job-related experiences as sources of knowledge, and (f) students' inquisitiveness and eagerness to investigate and discuss novel phenomena seemed to peak about the time students were enrolled in second year physics classes.

  18. Hydrodynamic interactions between two forced objects of arbitrary shape. II. Relative translation

    NASA Astrophysics Data System (ADS)

    Goldfriend, Tomer; Diamant, Haim; Witten, Thomas A.

    2016-04-01

    We study the relative translation of two arbitrarily shaped objects, caused by their hydrodynamic interaction as they are forced through a viscous fluid in the limit of zero Reynolds number. It is well known that in the case of two rigid spheres in an unbounded fluid, the hydrodynamic interaction does not produce relative translation. More generally, such an effective pair-interaction vanishes in configurations with spatial inversion symmetry; for example, an enantiomorphic pair in mirror image positions has no relative translation. We show that the breaking of inversion symmetry by boundaries of the system accounts for the interactions between two spheres in confined geometries, as observed in experiments. The same general principle also provides new predictions for interactions in other object configurations near obstacles. We examine the time-dependent relative translation of two self-aligning objects, extending the numerical analysis of our preceding publication [Goldfriend, Diamant, and Witten, Phys. Fluids 27, 123303 (2015)], 10.1063/1.4936894. The interplay between the orientational interaction and the translational one, in most cases, leads over time to repulsion between the two objects. The repulsion is qualitatively different for self-aligning objects compared to the more symmetric case of uniform prolate spheroids. The separation between the two objects increases with time t as t1 /3 in the former case, and more strongly, as t , in the latter.

  19. Relative abundance of an invasive alien plant affects insect-flower interaction networks in Ireland

    NASA Astrophysics Data System (ADS)

    Stout, Jane C.; Casey, Leanne M.

    2014-02-01

    Invasive alien flowering plants may affect native plant pollinator interactions and have knock on impacts on populations of native plants and animals. The magnitude of these impacts, however, may be modified by the relative abundance of the invasive plant and the number of flowers it presents.We tested this by examining the structure of insect-flower interaction networks in six sites with increasing levels of invasion by Rhododendron ponticum in Ireland.Neither flower-visiting insect abundance, species richness nor diversity were related to R. ponticum flower abundance, but the composition of insect communities was. The total number of flowers in a site increased with the relative abundance of R. ponticum flowers but the number of co-flowering native plant species in these sites was low (<6), making interaction networks relatively small.As a result, changes in interaction network properties (connectance, interaction evenness and network level specialisation), which correlated with R. ponticum flower abundance, were a result of the small network size rather than due to changes in the resilience of networks.Overall, we conclude that the impacts of invasive alien plants on native plant-pollinator interactions are not only species specific, but site specific, according to the abundance of flowers produced by both the invasive and the native plants.

  20. Supercritical droplet combustion and related transport phenomena

    NASA Technical Reports Server (NTRS)

    Yang, Vigor; Hsieh, K. C.; Shuen, J. S.

    1993-01-01

    An overview of recent advances in theoretical analyses of supercritical droplet vaporization and combustion is conducted. Both hydrocarbon and cryogenic liquid droplets over a wide range of thermodynamic states are considered. Various important high-pressure effects on droplet behavior, such as thermodynamic non-ideality, transport anomaly, and property variation, are reviewed. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influence on fluid transport, gas-liquid interfacial thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibit a considerable change in the combustion mechanism at the criticl pressure, mainly as a result of reduced mass diffusivity and latent heat of vaporization with increased pressure. The influence of droplet size on the burning characteristics is also noted.

  1. Arcjet Cathode Phenomena

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  2. Arcjet cathode phenomena

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  3. ON DETECTING TRANSIENT PHENOMENA

    SciTech Connect

    Belanger, G.

    2013-08-10

    Transient phenomena are interesting and potentially highly revealing of details about the processes under observation and study that could otherwise go unnoticed. It is therefore important to maximize the sensitivity of the method used to identify such events. In this article, we present a general procedure based on the use of the likelihood function for identifying transients which is particularly suited for real-time applications because it requires no grouping or pre-processing of the data. The method makes use of all the information that is available in the data throughout the statistical decision-making process, and is suitable for a wide range of applications. Here we consider those most common in astrophysics, which involve searching for transient sources, events or features in images, time series, energy spectra, and power spectra, and demonstrate the use of the method in the case of a weak X-ray flare in a time series and a short-lived quasi-periodic oscillation in a power spectrum. We derive a fit statistic that is ideal for fitting arbitrarily shaped models to a power density distribution, which is of general interest in all applications involving periodogram analysis.

  4. Microscopical characterization of carbon materials derived from coal and petroleum and their interaction phenomena in making steel electrodes, anodes and cathode blocks for the Microscopy of Carbon Materials Working Group of the ICCP

    USGS Publications Warehouse

    Predeanu, G.; Panaitescu, C.; Bălănescu, M.; Bieg, G.; Borrego, A.G.; Diez, M. A.; Hackley, Paul C.; Kwiecińska, B.; Marques, M.; Mastalerz, Maria; Misz-Kennan, M.; Pusz, S.; Suarez-Ruiz, I.; Rodrigues, S.; Singh, A. K.; Varma, A. K.; Zdravkov, A.; Zivotić, D.

    2015-01-01

    This paper describes the evaluation of petrographic textures representing the structural organization of the organic matter derived from coal and petroleum and their interaction phenomena in the making of steel electrodes, anodes and cathode blocks.This work represents the results of the Microscopy of Carbon Materials Working Group in Commission III of the International Committee for Coal and Organic Petrology between the years 2009 and 2013. The round robin exercises were run on photomicrograph samples. For textural characterization of carbon materials the existing ASTM classification system for metallurgical coke was applied.These round robin exercises involved 15 active participants from 12 laboratories who were asked to assess the coal and petroleum based carbons and to identify the morphological differences, as optical texture (isotropic/anisotropic), optical type (punctiform, mosaic, fibre, ribbon, domain), and size. Four sets of digital black and white microphotographs comprising 151 photos containing 372 fields of different types of organic matter were examined. Based on the unique ability of carbon to form a wide range of textures, the results showed an increased number of carbon occurrences which have crucial role in the chosen industrial applications.The statistical method used to evaluate the results was based on the “raw agreement indices”. It gave a new and original view on the analysts' opinion by not only counting the correct answers, but also all of the knowledge and experience of the participants. Comparative analyses of the average values of the level of overall agreement performed by each analyst in the exercises during 2009–2013 showed a great homogeneity in the results, the mean value being 90.36%, with a minimum value of 83% and a maximum value of 95%.

  5. The early development of executive function and its relation to social interaction: a brief review

    PubMed Central

    Moriguchi, Yusuke

    2014-01-01

    Executive function (EF) refers to the ability to execute appropriate actions and to inhibit inappropriate actions for the attainment of a specific goal. Research has shown that this ability develops rapidly during the preschool years. Recently, it has been proposed that research on EF should consider the importance of social interaction. In this article, recent evidence regarding the early development of EF and its relation to social interaction has been reviewed. Research consistently showed that social interaction can influence EF skills in young children. However, the development of EF may facilitate the cognitive skills that are important for social interaction. Taken together, there might be functional dependency between the development of EF and social interaction. PMID:24808885

  6. Universal relations for the two-dimensional spin-1/2 Fermi gas with contact interactions

    NASA Astrophysics Data System (ADS)

    Valiente, Manuel; Zinner, Nikolaj T.; Mølmer, Klaus

    2011-12-01

    We present universal relations for a two-dimensional Fermi gas with pairwise contact interactions. The derivation of these relations is made possible by obtaining the explicit form of a generalized function—selector—in the momentum representation. The selector implements the short-distance boundary condition between two fermions in a straightforward manner and leads to simple derivations of the universal relations, in the spirit of Tan's original method for the three-dimensional gas.

  7. Toll-like receptor 4-related immunostimulatory polysaccharides: Primary structure, activity relationships, and possible interaction models.

    PubMed

    Zhang, Xiaorui; Qi, Chunhui; Guo, Yan; Zhou, Wenxia; Zhang, Yongxiang

    2016-09-20

    Toll-like receptor (TLR) 4 is an important polysaccharide receptor; however, the relationships between the structures and biological activities of TLR4 and polysaccharides remain unknown. Many recent findings have revealed the primary structure of TLR4/MD-2-related polysaccharides, and several three-dimensional structure models of polysaccharide-binding proteins have been reported; and these models provide insights into the mechanisms through which polysaccharides interact with TLR4. In this review, we first discuss the origins of polysaccharides related to TLR4, including polysaccharides from higher plants, fungi, bacteria, algae, and animals. We then briefly describe the glucosidic bond types of TLR4-related heteroglycans and homoglycans and describe the typical molecular weights of TLR4-related polysaccharides. The primary structures and activity relationships of polysaccharides with TLR4/MD-2 are also discussed. Finally, based on the existing interaction models of LPS with TLR4/MD-2 and linear polysaccharides with proteins, we provide insights into the possible interaction models of polysaccharide ligands with TLR4/MD-2. To our knowledge, this review is the first to summarize the primary structures and activity relationships of TLR4-related polysaccharides and the possible mechanisms of interaction for TLR4 and TLR4-related polysaccharides. PMID:27261743

  8. Asymmetric current-phase relation due to spin-orbit interaction in semiconductor nanowire Josephson junction

    SciTech Connect

    Yokoyama, Tomohiro; Eto, Mikio; Nazarov, Yuli V.

    2013-12-04

    We theoretically study the current-phase relation in semiconductor nanowire Josephson junction in the presence of spin-orbit interaction. In the nanowire, the impurity scattering with strong SO interaction is taken into account using the random matrix theory. In the absence of magnetic field, the Josephson current I and phase difference φ between the superconductors satisfy the relation of I(φ) = –I(–φ). In the presence of magnetic field along the nanowire, the interplay between the SO interaction and Zeeman effect breaks the current-phase relation of I(φ) = –I(–φ). In this case, we show that the critical current depends on the current direction, which qualitatively agrees with recent experimental findings.

  9. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    NASA Astrophysics Data System (ADS)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    Back in 1967, Clifford Gardner, John Greene, Martin Kruskal and Robert Miura published a seminal paper in Physical Review Letters which was to become a cornerstone in the theory of integrable systems. In 2006, the authors of this paper received the AMS Steele Prize. In this award the AMS pointed out that `In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited.' From this discovery the modern theory of integrability bloomed, leading scientists to a deep understanding of many nonlinear phenomena which is by no means reachable by perturbation methods or other previous tools from linear theories. Nonlinear phenomena appear everywhere in nature, their description and understanding is therefore of great interest both from the theoretical and applicative point of view. If a nonlinear phenomenon can be represented by an integrable system then we have at our disposal a variety of tools to achieve a better mathematical description of the phenomenon. This special issue is largely dedicated to investigations of nonlinear phenomena which are related to the concept of integrability, either involving integrable systems themselves or because they use techniques from the theory of integrability. The idea of this special issue originated during the 18th edition of the Nonlinear Evolution Equations and Dynamical Systems (NEEDS) workshop, held at Isola Rossa, Sardinia, Italy, 16-23 May 2009 (http://needs-conferences.net/2009/). The issue benefits from the occasion offered by the meeting, in particular by its mini-workshops programme, and contains invited review papers and contributed papers. It is worth pointing out that there was an open call for papers and all contributions were peer reviewed

  10. The making of extraordinary psychological phenomena.

    PubMed

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. PMID:25363382