1,014 research outputs found
The Shape of Things to Come: Obesity, Aging, and Disability
Rising obesity represents one of the most disturbing health trends in the U.S. and elsewhere. Obese people are at greater risk for diabetes, cardiovascular disease, disability, and mortality. However, recent studies also suggest that the obese population has grown “healthier” since the 1960s, probably due to improved medical care for cardiovascular disease. It isunclear whether these improvements have resulted in more or less disability in obese people as they age. This Issue Brief summarizes two studies that examine the prevalence of obesity over time in the elderly and disabled, and the changing relationship of obesity and disability
Cosmological test of the Yilmaz theory of gravity
We test the Yilmaz theory of gravitation by working out the corresponding
Friedmann-type equations generated by assuming the Friedmann-Robertson-Walker
cosmological metrics. In the case that space is flat the theory is consistent
only with either a completely empty universe or a negative energy vacuum that
decays to produce a constant density of matter. In both cases the total energy
remains zero at all times, and in the latter case the acceleration of the
expansion is always negative. To obtain a more flexible and potentially more
realistic cosmology, the equation of state relating the pressure and energy
density of the matter creation process must be different from the vacuum, as
for example is the case in the steady-state models of Gold, Bondi, Hoyle and
others. The theory does not support the cosmological principle for curved space
K =/= 0 cosmological metrics
Manufacture of cream cheese involving the use of dry skim milk
Caption title.Digitized 2006 AES MoU
The relation of dry skim milk to several of the physical and chemical properties of cream cheese
Publication authorized June 28, 1934."The data presented in this bulletin were taken from a paper submitted by the junior author in partial fulfillment of the requirements for the degree of Master of Arts in the Graduate School of the University of Missouri, 1933"--P. [3].Includes bibliographical references (page 40)
Short-wavelength collective modes in a binary hard-sphere mixture
We use hard-sphere generalized hydrodynamic equations to discuss the extended
hydrodynamic modes of a binary mixture. The theory presented here is analytic
and it provides us with a simple description of the collective excitations of a
dense binary mixture at molecular length scales. The behavior we predict is in
qualitative agreement with molecular-dynamics results for soft-sphere mixtures.
This study provides some insight into the role of compositional disorder in
forming glassy configurations.Comment: Published; withdrawn since already published. Ordering in the archive
gives misleading impression of new publicatio
Realistic Calculation of the hep Astrophysical Factor
The astrophysical factor for the proton weak capture on 3He is calculated
with correlated-hyperspherical-harmonics bound and continuum wave functions
corresponding to a realistic Hamiltonian consisting of the Argonne v18
two-nucleon and Urbana-IX three-nucleon interactions. The nuclear weak charge
and current operators have vector and axial-vector components, that include
one- and many-body terms. All possible multipole transitions connecting any of
the p-3He S- and P-wave channels to the 4He bound state are considered. The
S-factor at a p-3He center-of-mass energy of 10 keV, close to the Gamow-peak
energy, is predicted to be 10.1 10^{-20} keV b, a factor of five larger than
the standard-solar-model value. The P-wave transitions are found to be
important, contributing about 40 % of the calculated S-factor.Comment: 8 pages RevTex file, submitted to Phys. Rev. Let
The Ay Problem for p-3He Elastic Scattering
We present evidence that numerically accurate quantum calculations employing
modern internucleon forces do not reproduce the proton analyzing power, A_y,
for p-3He elastic scattering at low energies. These calculations underpredict
new measured analyzing powers by approximately 30% at E_{c.m.} = 1.20 MeV and
by 40% at E_{c.m.} = 1.69 MeV, an effect analogous to a well-known problem in
p-d and n-d scattering. The calculations are performed using the complex Kohn
variational principle and the (correlated) Hyperspherical Harmonics technique
with full treatment of the Coulomb force. The inclusion of the three-nucleon
interaction does not improve the agreement with the experimental data.Comment: Latex file, 4 pages, 2 figures, to be published on Phys. Rev. Let
Nonlinear Hydrodynamics of a Hard Sphere Fluid Near the Glass Transition
We conduct a numerical study of the dynamic behavior of a dense hard sphere
fluid by deriving and integrating a set of Langevin equations. The statics of
the system is described by a free energy functional of the
Ramakrishnan-Yussouff form. We find that the system exhibits glassy behavior as
evidenced through stretched exponential decay and two-stage relaxation of the
density correlation function. The characteristic times grow with increasing
density according to the Vogel-Fulcher law. The wavenumber dependence of the
kinetics is extensively explored. The connection of our results with
experiment, mode coupling theory, and molecular dynamics results is discussed.Comment: 34 Pages, Plain TeX, 12 PostScript Figures (not included, available
on request
Bell State Preparation using Pulsed Non-Degenerate Two-Photon Entanglement
We report a novel Bell state preparation experiment. High-purity Bell states
are prepared by using femtosecond pulse pumped \emph{nondegenerate} collinear
spontaneous parametric down-conversion. The use of femtosecond pump pulse {\em
does not} result in reduction of quantum interference visibility in our scheme
in which post-selection of amplitudes and other traditional mechanisms, such
as, using thin nonlinear crystals or narrow-band spectral filters are not used.
Another distinct feature of this scheme is that the pump, the signal, and the
idler wavelengths are all distinguishable, which is very useful for quantum
communications.Comment: 4 pages, submitted to PR
Hydrodynamic fluctuations in the Kolmogorov flow: Linear regime
The Landau-Lifshitz fluctuating hydrodynamics is used to study the
statistical properties of the linearized Kolmogorov flow. The relative
simplicity of this flow allows a detailed analysis of the fluctuation spectrum
from near equilibrium regime up to the vicinity of the first convective
instability threshold. It is shown that in the long time limit the flow behaves
as an incompressible fluid, regardless of the value of the Reynolds number.
This is not the case for the short time behavior where the incompressibility
assumption leads in general to a wrong form of the static correlation
functions, except near the instability threshold. The theoretical predictions
are confirmed by numerical simulations of the full nonlinear fluctuating
hydrodynamic equations.Comment: 20 pages, 4 figure
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