13,289 research outputs found
Magneto-Seebeck effect in spin-valve with in-plane thermal gradient
We present measurements of magneto-Seebeck effect on a spin valve with
in-plane thermal gradient. We measured open circuit voltage and short circuit
current by applying a temperature gradient across a spin valve stack, where one
of the ferromagnetic layers is pinned. We found a clear hysteresis in these two
quantities as a function of magnetic field. From these measurements, the
magneto-Seebeck effect was found to be 0.82%.Comment: 10 Pages, 7 figure
Quasi-dark Mode in a Metamaterial for Analogous Electromagnetically-induced Transparency
We study a planar metamaterial supporting electromagnetically-induced
transparency (EIT)-like effect by exploiting the coupling between bright and
quasi-dark eigenmodes. The specific design of such a metamaterial consists of a
cut-wire (CW) and a single-gap split-ring resonator (SRR). From the numerical
and the analytical results we demonstrate that the response of SRR, which is
weakly excited by external electric field, is mitigated to be a quasi-dark
eigenmode in the presence of strongly radiative CW. This result suggests more
relaxed conditions for the realization of devices utilizing the EIT-like
effects in metamaterial, and thereby widens the possibilities for many
different structural implementations.Comment: 11 pages, 4 figure
Abelian Landau-Pomeranchuk-Migdal effects
It is shown that the high-energy expansion of the scattering amplitude
calculated from Feynman diagrams factorizes in such a way that it can be
reduced to the eikonalized form up to the terms of inverse power in energy in
accordance with results obtained by solving the Klein-Gordon equation.
Therefore the two approaches when applied to the suppression of the emission of
soft photons by fast charged particles in dense matter should give rise to the
same results. A particular limit of thin targets is briefly discussed.Comment: 14 pages, LATEX, 1 Fig. ps, submitted to Mod. Phys. Lett.
Resolving the Large-N Nuclear Potential Puzzle
The large nuclear potential puzzle arose because three- and
higher-meson exchange contributions to the nucleon-nucleon potential did not
automatically yield cancellations that make these contributions consistent with
the general large scaling rules for the potential. Here it is proposed
that the resolution to this puzzle is that the scaling rules only apply for
energy-independent potentials while all of the cases with apparent
inconsistencies were for energy-dependent potentials. It is shown explicitly
how energy-dependent potentials can have radically different large N behavior
than an equivalent energy-independent one. One class of three-meson graphs is
computed in which the contribution to the energy-independent potential is
consistent with the general large N rules even though the energy-dependent
potential is not.Comment: Corrections to the toy mode
Superconductivity in correlated disordered two-dimensional electron gas
We calculate the dynamic effective electron-electron interaction potential
for a low density disordered two-dimensional electron gas. The disordered
response function is used to calculate the effective potential where the
scattering rate is taken from typical mobilities from recent experiments. We
investigate the development of an effective attractive pair potential for both
disordered and disorder free systems with correlations determined from existing
numerical simulation data. The effect of disorder and correlations on the
superconducting critical temperature Tc is discussed.Comment: 4 pages, RevTeX + epsf, 4 figure
Predictors of intention to quit at participation and six-month abstinence in the participants of Hong Kong Quit-to-Win Contest (2009-2013)
Poster Discussion 23. Cessation - Predictors and Policies: no. PD-864-20Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: Quit and Win Contests were organized in many countries to attract a large number of smokers, who mostly had not sought professional cessation support, to quit with the grand monetary prize as an incentive. The present study aims to explore the influential factors of being ready to quit (want to quit within 7 days) and abstinence in these participants. DESIGN/METHODS: The 4 rounds of Quit-to-Win Contests (2009, 2010, 2012 and 2013) recruited 4,093 adult daily …published_or_final_versio
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Trust in Government and Effective Nuclear Safety Governance in Great Britain
Nuclear power can play a role in reducing CO2 emissions and improving energy security. Public attitudes to nuclear safety governance will be critical in whether a large-scale rollout of nuclear power will be successful, so we commissioned a survey of 1,007 members of the British public to understand the determinants of such views. In particular, we focus on the role of trust in government, which has been largely neglected as a subject of study. We find that higher risk perceptions of new nuclear power technologies is associated with lower overall government trustworthiness, while higher engagement levels, being male and intentions to vote Conservative increase trustworthiness. Risk perceptions towards old and the new nuclear technologies do not differ significantly, which raises questions about the view that newer defence-in-depth nuclear technologies can reduce public fear of nuclear power. To build public trust, the UK government must demonstrate its trustworthiness in nuclear safety governance, especially along the dimensions of integrity, reliability and openness. Further, improving stakeholder engagement and thus increasing the levels of public satisfaction towards the government are necessary. Our novel research methodology of determining government trustworthiness in relation to public risk perceptions, technical knowledge, and stakeholder engagement is more broadly applicable and can be transferred to other subject areas and to countries where public concerns over nuclear safety and energy security are significant
The metaphysics of Machian frame-dragging
The paper investigates the kind of dependence relation that best portrays Machian frame-dragging in general relativity. The question is tricky because frame-dragging relates local inertial frames to distant distributions of matter in a time-independent way, thus establishing some sort of non-local link between the two. For this reason, a plain causal interpretation of frame-dragging faces huge challenges. The paper will shed light on the issue by using a generalized structural equation model analysis in terms of manipulationist counterfactuals recently applied in the context of metaphysical enquiry by Schaffer (2016) and Wilson (2017). The verdict of the analysis will be that frame-dragging is best understood in terms of a novel type of dependence relation that is half-way between causation and grounding
Spin Degree of Freedom in a Two-Dimensional Electron Liquid
We have investigated correlation between spin polarization and
magnetotransport in a high mobility silicon inversion layer which shows the
metal-insulator transition. Increase in the resistivity in a parallel magnetic
field reaches saturation at the critical field for the full polarization
evaluated from an analysis of low-field Shubnikov-de Haas oscillations. By
rotating the sample at various total strength of the magnetic field, we found
that the normal component of the magnetic field at minima in the diagonal
resistivity increases linearly with the concentration of ``spin-up'' electrons.Comment: 4 pages, RevTeX, 6 eps-figures, to appear in PR
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