1,424 research outputs found
Conceptualizing Mentorship in Contemporary Professional Settings
Although there are many mentorship-related scholarships, there is still a lack of understanding of how mentorship is implemented effectively in professional settings. This paper explores mentorship strategies in workplaces
Resources for Military Veterans in Higher Education: A Web-Based Content Analysis
The purpose of this proposed web-based content analysis presentation is to explore the available resources for military veterans pursuing higher educational opportunities
Electronic susceptibilities in systems with anisotropic Fermi surfaces
The low temperature dependence of the spin and charge susceptibilities of an
anisotropic electron system in two dimensions is analyzed. It is shown that the
presence of inflection points at the Fermi surface leads, generically, to a dependence, and a more singular behavior, ,
is also possible. Applications to quasi two-dimensional materials are
discussed.Comment: 8 pages, 5 figures, revtex 4 styl
The Advantage of Increased Resolution in the Study of Quasar Absorption Systems
We compare a new R = 120,000 spectrum of PG1634+706 (z_QSO = 1.337,m_V =
14.9) obtained with the HDS instrument on Subaru to a R = 45, 000 spectrum
obtained previously with HIRES/Keck. In the strong MgII system at z = 0.9902
and the multiple cloud, weak MgII system at z = 1.0414, we find that at the
higher resolution, additional components are resolved in a blended profile. We
find that two single-cloud weak MgII absorbers were already resolved at R =
45,000, to have b = 2 - 4 km/s. The narrowest line that we measure in the R =
120, 000 spectrum is a component of the Galactic NaI absorption, with b =
0.90+/-0.20 km/s. We discuss expectations of similarly narrow lines in various
applications, including studies of DLAs, the MgI phases of strong MgII
absorbers, and high velocity clouds. By applying Voigt profile fitting to
synthetic lines, we compare the consistency with which line profile parameters
can be accurately recovered at R = 45,000 and R = 120,000. We estimate the
improvement gained from superhigh resolution in resolving narrowly separated
velocity components in absorption profiles. We also explore the influence of
isotope line shifts and hyperfine splitting in measurements of line profile
parameters, and the spectral resolution needed to identify these effects. Super
high resolution spectra of quasars, which will be routinely possible with
20-meter class telescopes, will lead to greater sensitivity for absorption line
surveys, and to determination of more accurate physical conditions for cold
phases of gas in various environments.Comment: To appear in AJ. Paper with better resolution images available at
http://www.astro.psu.edu/users/anand/superhigh.AJ.pd
U-Th-Pb isotopic systematics of lherzolitic shergottite Yamato-793605
We have undertaken U-Th-Pb isotopic studies on lherzolitic shergottite, Yamato-793605. Four mineral separates (olivine, plagioclase, and two phases of pyroxene) and a whole-rock sample were leached with dilute acid in order to remove secondary Pb contamination. However, preferential leaching of U and Th over Pb occurred. The Pb isotopic data points of five residue fractions scattered, and a calculated Pb-Pb age does not clearly indicate either crystallization from a melt or a later disturbance to the U-Pb system, in contrast with other shergottites. The chord through U-Pb data points for pyroxene (PXl) leaches and residue intersects concordia at 4439±9 Ma and 212±62 Ma, suggesting a young disturbance event resulting in Pb loss. The later disturbance event partially reset the U-Pb system. The estimated ^U/^Pb (≡μ) value from the whole-rock residue for the source of Y-793605 is about 5,suggesting that Y-793605 was derived from a volatile-rich source environment and confirms a low-μ source for shergottites compared to volcanic rocks of the Earth
Neutron scattering and molecular correlations in a supercooled liquid
We show that the intermediate scattering function for neutron
scattering (ns) can be expanded naturely with respect to a set of molecular
correlation functions that give a complete description of the translational and
orientational two-point correlations in the liquid. The general properties of
this expansion are discussed with special focus on the -dependence and hints
for a (partial) determination of the molecular correlation functions from
neutron scattering results are given. The resulting representation of the
static structure factor is studied in detail for a model system using
data from a molecular dynamics simulation of a supercooled liquid of rigid
diatomic molecules. The comparison between the exact result for and
different approximations that result from a truncation of the series
representation demonstrates its good convergence for the given model system. On
the other hand it shows explicitly that the coupling between translational
(TDOF) and orientational degrees of freedom (ODOF) of each molecule and
rotational motion of different molecules can not be neglected in the
supercooled regime.Further we report the existence of a prepeak in the
ns-static structure factor of the examined fragile glassformer, demonstrating
that prepeaks can occur even in the most simple molecular liquids. Besides
examining the dependence of the prepeak on the scattering length and the
temperature we use the expansion of into molecular correlation
functions to point out intermediate range orientational order as its principle
origin.Comment: 13 pages, 7 figure
Leading Temperature Corrections to Fermi Liquid Theory in Two Dimensions
We calculate the basic parameters of the Fermi Liquid: the scattering vertex,
the Landau interaction function, the effective mass, and physical
susceptibilities for a model of two-dimensional (2D) fermions with a short
ranged interaction at non-zero temperature. The leading temperature dependences
of the spin components of the scattering vertex, the Landau function, and the
spin susceptibility are found to be linear. T-linear terms in the effective
mass and in the ``charge-sector''- quantities are found to cancel to second
order in the interaction, but the cancellation is argued not to be generic. The
connection with previous studies of the 2D Fermi-Liquid parameters is
discussed.Comment: 4 pages, 1 figur
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