1,989 research outputs found
Ambipolar Nernst effect in NbSe
The first study of Nernst effect in NbSe reveals a large quasi-particle
contribution with a magnitude comparable and a sign opposite to the vortex
signal. Comparing the effect of the Charge Density Wave(CDW) transition on Hall
and Nernst coefficients, we argue that this large Nernst signal originates from
the thermally-induced counterflow of electrons and holes and indicates a
drastic change in the electron scattering rate in the CDW state. The results
provide new input for the debate on the origin of the anomalous Nernst signal
in high-T cuprates.Comment: 5 pages including 4 figure
Temperature scaling in a dense vibro-fluidised granular material
The leading order "temperature" of a dense two dimensional granular material
fluidised by external vibrations is determined. An asymptotic solution is
obtained where the particles are considered to be elastic in the leading
approximation. The velocity distribution is a Maxwell-Boltzmann distribution in
the leading approximation. The density profile is determined by solving the
momentum balance equation in the vertical direction, where the relation between
the pressure and density is provided by the virial equation of state. The
predictions of the present analysis show good agreement with simulation results
at higher densities where theories for a dilute vibrated granular material,
with the pressure-density relation provided by the ideal gas law, are in error.
The theory also predicts the scaling relations of the total dissipation in the
bed reported by McNamara and Luding (PRE v 58, p 813).Comment: ReVTeX (psfrag), 5 pages, 5 figures, Submitted to PR
A meta-analysis of randomised controlled trials of physical activity in people with Alzheimer's disease and mild cognitive impairment with a comparison to donepezil
OBJECTIVES: Physical exercise may benefit people with Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, randomised controlled trials (RCTs) of exercise have shown conflicting findings and it is unclear if positive outcomes are comparable to a commonly used cholinesterase inhibitor, donepezil. METHODS: Embase, Medline, PsycINFO, PsycARTICLES, SCOPUS were searched for RCTs of physical activity compared to a control condition, and donepezil compared to placebo in people with AD and MCI. Effect sizes were calculated from pre- and post-MMSE and ADAS-Cog scores and pooled using a random effects meta-analysis. RESULTS: Ninteen RCTs were included in the exercise meta-analysis (AD, N = 524; MCI, N = 1269). Physical exercise improved MMSE scores in AD (Hedges' g = 0.46) and MCI groups (g = 0.63). For the MCI group, exercise appeared to have a stronger effect for those with lower MMSE scores at baseline (p = 0.022). 18 RCTs were included in the donepezil meta-analysis (AD, N = 2984, MCI, N = 1559). In people with AD, donepezil improved cognition (MMSE g = 0.23; ADAS-Cog, g = −0.17) but there was no evidence of improved cognition in MCI. CONCLUSIONS: Physical exercise improved cognition in both AD and MCI groups. Where comparisons were possible, the effect size for physical exercise was generally comparable to donepezil. These results strengthen the evidence base for exercise as an effective intervention in AD and MCI, and future clinical trials should examine exercise type, intensity and frequency, in addition to cholinesterase inhibitors to determine the most effective interventions for AD and MCI
Indications & Warning for Amphibious Ops against Taiwan: Philosophy, Methodology, Applications, Results
NPS NRP Executive SummaryThis research applies an Indications and Warning (I&W) analytical philosophy and methodology to the problem of warning of an amphibious movement against the Island of Taiwan. It identifies the tenets and philosophy behind I&W analysis; the general issues that must be addressed to undertake effective I&W analysis related to an amphibious operation against Taiwan; the alternative warning scenarios and various indicators associated with different types of amphibious attack against Taiwan (i.e., a rough template for the conduct of I&W amphibious analysis); and the issues involved in developing an operational response to warning. The research will culminate in an effort to engage senior line officers about the crucial role played by theater commanders when it comes to utilizing I&W intelligence. Warning only works when commanders are prepared to utilize it.Office of Naval Intelligence (ONI)N2/N6 - Information WarfareThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Local governmental audit and accounting manual, as of March 1, 1991: a nonauthoritative practice aid;Notes to the illustrative combined financial statements;
https://egrove.olemiss.edu/aicpa_guides/1005/thumbnail.jp
Local governmental audit and accounting manual, as of March 1, 1991: a nonauthoritative practice aid
https://egrove.olemiss.edu/aicpa_guides/1211/thumbnail.jp
Local governmental audit and accounting manual, as of March 1, 1990 : a nonauthoritative practice aid
https://egrove.olemiss.edu/aicpa_guides/1210/thumbnail.jp
Indications & Warning for Amphibious Ops against Taiwan: Philosophy, Methodology, Applications, Results
NPS NRP Project PosterThis research applies an Indications and Warning (I&W) analytical philosophy and methodology to the problem of warning of an amphibious movement against the Island of Taiwan. It identifies the tenets and philosophy behind I&W analysis; the general issues that must be addressed to undertake effective I&W analysis related to an amphibious operation against Taiwan; the alternative warning scenarios and various indicators associated with different types of amphibious attack against Taiwan (i.e., a rough template for the conduct of I&W amphibious analysis); and the issues involved in developing an operational response to warning. The research will culminate in an effort to engage senior line officers about the crucial role played by theater commanders when it comes to utilizing I&W intelligence. Warning only works when commanders are prepared to utilize it.Office of Naval Intelligence (ONI)N2/N6 - Information WarfareThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Smoothing effect and delocalization of interacting Bose-Einstein condensates in random potentials
We theoretically investigate the physics of interacting Bose-Einstein
condensates at equilibrium in a weak (possibly random) potential. We develop a
perturbation approach to derive the condensate wavefunction for an amplitude of
the potential smaller than the chemical potential of the condensate and for an
arbitrary spatial variation scale of the potential. Applying this theory to
disordered potentials, we find in particular that, if the healing length is
smaller than the correlation length of the disorder, the condensate assumes a
delocalized Thomas-Fermi profile. In the opposite situation where the
correlation length is smaller than the healing length, we show that the random
potential can be significantly smoothed and, in the meanfield regime, the
condensate wavefunction can remain delocalized, even for very small correlation
lengths of the disorder.Comment: The word "screening" has been changed to "smoothing" to avoid
confusions with other effects discussed in the literature. This does not
affect the content of paper, nor the results, nor the physical discussio
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