1,910 research outputs found
Bias Voltage and Temperature Dependence of Hot Electron Magnetotransport
We present a qualitative model study of energy and temperature dependence of
hot electron magnetotransport. This model calculations are based on a simple
argument that the inelastic scattering strength of hot electrons is strongly
spin and energy dependent in the ferromagnets. Since there is no clear
experimental data to compare with this model calculations, we are not able to
extract clear physics from this model calculations. However, interestingly this
calculations display that the magnetocurrent increases with bias voltage
showing high magnetocurrent if spin dependent imaginary part of proper self
energy effect has a substantial contribution to the hot electron
magnetotransport. Along with that, the hot electron magnetotransport is
strongly influence by the hot electron spin polarization at finite
temperatures
Shaping citizenship in the classroom:Peer influences on moral disengagement, social goals, and a sense of peer community
Despite the important role of peers in the social process of classroom citizenship, the peer influence related to moral disengagement, social goals, and a sense of peer community remain unclear. To this end, it was examined to what extent youth become similar to their friends in moral disengagement, social goals, and a sense of peer community. Participants were 283 South Korean third to sixth graders (Mage = 9.60 years, SD = 0.97; 51.6% girls) who completed an online survey for moral disengagement, social goals, the sense of peer community and friendship network across the beginning (Time 1) and end (Time 2) of the school semester (September to December). Longitudinal social network analyses indicated that youth became more similar to their friends concerning moral disengagement and a sense of peer community, but did not select friends based on these aspects. The strength of these influence effects varied in terms of different levels of these aspects. Specifically, youth were more likely to become similar to their friends at lower levels of moral disengagement. Youth tended to be similar to the friends' level of sense of peer community. This tendency was relatively strong at the lowest and the highest levels of a sense of peer community. Future research should address the role of friendship in shaping classroom citizenship and the importance of classroom daily teaching practice in youth citizenship development
Broilers fed a low protein diet supplemented with synthetic amino acids maintained growth performance and retained intestinal integrity while reducing nitrogen excretion when raised under poor sanitary conditions
The present study investigated the effects of supplementing a low protein (LP) diet supplemented with key essential amino acids (AA) to broilers on growth performance, intestinal tract function, blood metabolites, and nitrogen excretion when the animals were maintained under various sanitary conditions for 35 D after hatching. Three hundred eighty-four one-day-old male broilers (Ross 308) were randomly allotted to groups that received one of 6 dietary treatments in a 2 × 3 factorial arrangement (i.e., 2 environmental conditions and 3 dietary treatments) to give 8 replicates per treatment. Broilers were challenged with 2 environmental conditions (sanitary vs. poor sanitary). The dietary treatments were (1) high protein (HP) diet, (2) LP diet, and (3) LP diet with synthetic key essential AA (LPA): the LP diet was supplemented with synthetic AA up to the required levels for broilers. On day 14, birds consumed the LP diet impaired growth performance compared with those fed the HP diet, while the average daily weight gain-to-feed conversion ratio of birds fed the LPA diet improved to the level of birds fed the HP diet under poor sanitary conditions (P < 0.05). Broilers raised under poor sanitary conditions and fed the LP diet displayed higher (P < 0.05) zonula occludens (ZO-1) expression on day 14 than broilers fed either the HP or LPA diet. Under sanitary conditions, birds fed HP and LPA diets showed higher villus height and crypt depth compared with those of broilers fed the LP diet on day 35. Moreover, broilers raised in the poor sanitary environment had higher (P < 0.05) serum endotoxins than those raised in the sanitary environment. Broilers fed the LPA diet showed reduced (P < 0.05) nitrogen excretion on days 14 and 35 compared with those fed the LP and HP diets independent of the environment. In conclusion, the LPA diet did not impair growth performance under poor sanitary conditions for 14 D after hatch while resulting in lower nitrogen excretion in any environment conditions throughout the experiment
Surface Instability in Windblown Sand
We investigate the formation of ripples on the surface of windblown sand
based on the one-dimensional model of Nishimori and Ouchi [Phys. Rev. Lett. 71,
197 (1993)], which contains the processes of saltation and grain relaxation. We
carry out a nonlinear analysis to determine the propagation speed of the
restabilized ripple patterns, and the amplitudes and phases of their first,
second, and third harmonics. The agreement between the theory and our numerical
simulations is excellent near the onset of instability. We also determine the
Eckhaus boundary, outside which the steady ripple patterns are unstable.Comment: 23 pages, 8 figure
Nonmonotonic inelastic tunneling spectra due to surface spin excitations in ferromagnetic junctions
The paper addresses inelastic spin-flip tunneling accompanied by surface spin
excitations (magnons) in ferromagnetic junctions. The inelastic tunneling
current is proportional to the magnon density of states which is
energy-independent for the surface waves and, for this reason, cannot account
for the bias-voltage dependence of the observed inelastic tunneling spectra.
This paper shows that the bias-voltage dependence of the tunneling spectra can
arise from the tunneling matrix elements of the electron-magnon interaction.
These matrix elements are derived from the Coulomb exchange interaction using
the itinerant-electron model of magnon-assisted tunneling. The results for the
inelastic tunneling spectra, based on the nonequilibrium Green's function
calculations, are presented for both parallel and antiparallel magnetizations
in the ferromagnetic leads.Comment: 9 pages, 4 figures, version as publishe
Bullying as a Developmental Precursor to Sexual and Dating Violence Across Adolescence: Decade in Review
Adolescent bullying continues to be a major focus of scholarship across the globe. This article reviews research from 2010 to 2021 with a particular focus on longitudinal studies of the bully–sexual violence pathway (BSVP), where bullying serves as a precursor for sexual violence (SV) (e.g., sexual harassment, sexual coercion, and sexual assault) and teen dating violence via individual and socio-contextual mediators. Articles reviewed consisted of a total of 505, which included 17 meta-analyses and systematic reviews. Databases used for the search were Academic Search Complete, Education Full Text (H. W. Wilson), ERIC, National Criminal Justice Reference Service Abstracts, PsycINFO, PubMed (Medline), and Social Sciences Abstracts (H. W. Wilson). In total, 107 peer-reviewed articles were included in this review. Potential mechanisms underlying the BSVP include social dominance orientation, exposure to sexual education, and alcohol use. Several school-based intervention approaches have evidenced marginal success in reducing rates of bullying and SV by targeting factors undergirding both behaviors. The efficacy of international prevention approaches is summarized. Gaps in the literature are identified and future research is proposed
Bundle and annulus CHF correlations applicable for near critical pressure region
Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.Bundle and annulus CHF correlations are developed by
using CHF experimental data from the Freon R-134a Thermal
Hydraulic Experimental Loop developed at KAERI. The CHF
data are in the range of the pressure of 3200 ~ 4030 kPa
(Critical pressure of R-134a = 4059 kPa), the mass flux
150∼1500 kg/m2s, and the inlet subcooling 40 ~ 70 kJ/kg. We
obtained local T/H values using a subchannel analysis code and
produced CHF correlations for the matrix subchannel, coldwall
subchannel and annulus channel, respectively. A
subchannel code, The MATRA-α IBM PC version, is used to
obtain the local conditions in a hot subchannel (CHF observed
channel) in the 5x5 bundle geometry. All the CHF experimental
data are successfully calculated by the present correlations with
good prediction performance. The prediction accuracy of the
correlations is not distorted by much in any of the ranges of the
independent parameters. The bundle CHF correlations could
help one to conceptually design a SCWR, by adopting a fluidto-
fluid modeling technique for a CHF near a critical pressure.mp201
A nondiagrammatic calculation of the Rho parameter from heavy fermions
A simple nondiagrammatic evaluation of the nondecoupling effect of heavy
fermions on the Veltman's Rho parameter is presented in detail. This
calculation is based on the path integral approach, the electroweak chiral
Lagrangian formalism, and the Schwinger proper time method.Comment: 11 page
Liquid-Solid Transition of Hard Spheres Under Gravity
We investigate the liquid-solid transition of two dimensional hard spheres in
the presence of gravity. We determine the transition temperature and the
fraction of particles in the solid regime as a function of temperature via
Even-Driven molecular dynamics simulations and compare them with the
theoretical predictions. We then examine the configurational statistics of a
vibrating bed from the view point of the liquid-solid transition by explicitly
determining the transition temperature and the effective temperature, T, of the
bed, and present a relation between T and the vibration strength.Comment: 14 total pages, 4 figure
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