2,814 research outputs found
Multiferroic properties of an \aa kermanite SrCoSiO single crystal in high magnetic fields
The magnetic and dielectric properties of \aa kermanite SrCoSiO
single crystals in high magnetic fields were investigated. We have observed
finite induced electric polarization along the c axis in high fields, wherein
all Co spins were forcibly aligned to the magnetic field direction. Existence
of the induced polarization in the spin-polarized state accompanied with the
finite slope in the magnetization curve suggests the possible role of the
orbital angular momenta in the excited states as its microscopic origin. The
emergence of the field-induced polarization without particular magnetic order
can be regarded as the magnetoelectric effects of the second order from the
symmetry point of view. A low magnetic field-driven electric polarization flip
induced by a rotating field, even at room temperature, has been successfully
demonstrated.Comment: 12 pages, 4 figure
Transient cavities and the excess chemical potentials of hard-spheroid solutes in dipolar hard sphere solvents
Monte Carlo computer simulations are used to study transient cavities and the
solvation of hard-spheroid solutes in dipolar hard sphere solvents. The
probability distribution of spheroidal cavities in the solvent is shown to be
well described by a Gaussian function, and the variations of fit parameters
with cavity elongation and solvent properties are analyzed. The excess chemical
potentials of hard-spheroid solutes with aspect ratios in the range , and with volumes between one and twenty times that of a solvent
molecule, are presented. It is shown that for a given molecular volume and
solvent dipole moment (or temperature) a spherical solute has the lowest excess
chemical potential and hence the highest solubility, while a prolate solute
with aspect ratio should be more soluble than an oblate solute with aspect
ratio . For a given solute molecule, the excess chemical potential
increases with increasing temperature; this same trend is observed in the case
of hydrophobic solvation. To help interpret the simulation results, comparison
is made with a scaled-particle theory that requires prior knowledge of a
solute-solvent interfacial tension and the pure-solvent equation of state,
which parameters are obtained from simulation results for spherical solutes.
The theory shows excellent agreement with simulation results over the whole
range of solute elongations considered.Comment: 10 pages, 10 figure
Landscape natural resources management with soil and water conservation practices
United States Agency for International Developmen
Classical gravitational spin-spin interaction
I obtain an exact, axially symmetric, stationary solution of Einstein's
equations for two massless spinning particles. The term representing the
spin-spin interaction agrees with recently published approximate work. The
spin-spin force appears to be proportional to the inverse fourth power of the
coordinate distance between the particles.Comment: six pages, no figures, journal ref:accepted for Classical and Quantum
Gravit
Dynamical Compactification and Inflation in Einstein-Yang-Mills Theory with Higher Derivative Coupling
We study cosmology of the Einstein-Yang-Mills theory in ten dimensions with a
quartic term in the Yang-Mills field strength. We obtain analytically a class
of cosmological solutions in which the extra dimensions are static and the
scale factor of the four-dimensional Friedmann-Lemaitre-Robertson-Walker metric
is an exponential function of time. This means that the model can explain
inflation. Then we look for solutions that describe dynamical compactification
of the extra dimensions. The effective cosmological constant in the
four-dimensional universe is determined from the gravitational coupling,
ten-dimensional cosmological constant, gauge coupling and higher derivative
coupling. By numerical integration, the solution with is found to
behave as a matter-dominated universe which asymptotically approaches flat
space-time, while the solution with a non-vanishing approaches de
Sitter space-time in the asymptotic future.Comment: 30 pages, 7 figure
Economic analysis of fertilizer options for maize production in Tanzania
United States Agency for International Developmen
Hypertension, its correlates and differences in access to healthcare services by gender among rural Zambian residents: a cross-sectional study
[Objectives] To examine the prevalence of hypertension and access to related healthcare services among rural residents of Mumbwa district in Zambia. [Design] Cross-sectional study with probability cluster sampling. [Setting] Rural Zambia. [Participants] We recruited 690 residents from Mumbwa district aged 25–64 years who had been living in the study area for ≥6 months and had adopted the lifestyle of the study area. Pregnant women and women who had given birth in the past 6 months were excluded. The data collection—questionnaire survey and anthropometric and biological measurements—was conducted between May and July 2016. [Results] In the overall sample, 39.7% and 33.5% of the men and women had hypertension (systolic blood pressure (BP)≥140 or diastolic BP ≥90 mm Hg), respectively. Among the participants without a previous diagnosis of hypertension, 30.3% presented with hypertension at the time of measurement. In the multivariable analysis, alcohol intake and urban residence in men, and older age group, higher education and body mass index ≥25 kg/m2 in women were significantly associated with hypertension. Among the 21.8% who never had their BP measured, 83.8% were men; among these men, older age (adjusted OR (AOR), 0.43; 95% CI 0.25 to 0.73) and HIV positive status (AOR, 0.37; 95% CI 0.14 to 0.97) were negatively associated, while current smoker status (AOR, 2.09; 95% CI 1.19 to 3.66) was positively associated with the lack of BP measurements. [Conclusion] We found that hypertension is prevalent in the target rural area. However, many were not aware of their hypertension status and many never had their BP measured, indicating a serious gap in cardiovascular disease prevention services in Zambia. There is an urgent need for health promotion and screening for hypertension, especially in the primary health services of rural Zambia. Issues related to healthcare accessibility in men require particular attention
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