2,656 research outputs found
Iraq and Afghanistan veterans’ experiences living with their parents after separation from the military
When military service members separate from the military, many return to their families of origin, living with their parents for a period of several weeks to years. While research with veterans and their spouses has documented the particular strain of this reintegration period on veterans and their partners, little research to date has examined veterans’ experiences living with their parents. The present study sought to fill this research gap by investigating veterans’ experiences living with their parents using qualitative, in-depth interviews with Iraq and Afghanistan veterans in California. Overall, veterans appreciated the instrumental and emotional support their parents provided when they separated. However, in some cases, living with parents also produced conflict and strain. In situations where adult veteran children had difficulty with the transition to civilian life or returned with mental health problems, parents were often the first to identify these problems and to support their children in accessing appropriate care. We analyze these findings in light of family systems theory, identifying ways in which adult veteran children continue a process of differentiation while living with their parents and maintaining emotional connectedness. We suggest ways that clinicians can better support veterans and their parents through the reintegration period and recommend that programming for military families explicitly include parents of service members in addition to conjugal families
Coupled opto-electronic simulation of organic bulk-heterojunction solar cells: parameter extraction and sensitivity analysis
A general problem arising in computer simulations is the number of material
and device parameters, which have to be determined by dedicated experiments and
simulation-based parameter extraction. In this study we analyze measurements of
the short-circuit current dependence on the active layer thickness and
current-voltage curves in poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid
methyl ester (P3HT:PCBM) based solar cells. We have identified a set of
parameter values including dissociation parameters that describe the
experimental data. The overall agreement of our model with experiment is good,
however a discrepancy in the thickness dependence of the current-voltage curve
questions the influence of the electric field in the dissociation process. In
addition transient simulations are analyzed which show that a measurement of
the turn-off photocurrent can be useful for estimating charge carrier
mobilities.Comment: 10 pages, 12 figures, 2 tables, Accepted for publication in Journal
of Applied Physic
Physical properties of single crystalline BaSn5
We present a comprehensive study of the binary intermetallic superconductor,
BaSn5. High-quality single crystalline BaSn5 was grown out of Sn flux. Detailed
thermodynamic and transport measurements were performed to study BaSn5's normal
and superconducting state properties. This material appears to be a strongly
coupled, multiband superconductor. Hc2(T)is almost isotropic. De Haas-van
Alphen oscillations were observed and two effective masses were estimated from
the FFT spectra. Hydrostatic pressure causes a decrease in the superconducting
transition temperature at the rate of ~ -0.053 K/kbar.Comment: 8 pages and 9 figure
The Magellanic System: What have we learnt from FUSE?
I review some of the findings on the Magellanic System produced by the Far
Ultraviolet Spectroscopic Explorer (FUSE) during and after its eight years of
service. The Magellanic System with its high-velocity complexes provides a
nearby laboratory that can be used to characterize phenomena that involve
interaction between galaxies, infall and outflow of gas and metals in galaxies.
These processes are crucial for understanding the evolution of galaxies and the
intergalactic medium. Among the FUSE successes I highlight are the coronal gas
about the LMC and SMC, and beyond in the Stream, the outflows from these
galaxies, the discovery of molecules in the diffuse gas of the Stream and the
Bridge, an extremely sub-solar and sub-SMC metallicity of the Bridge, and a
high-velocity complex between the Milky Way and the Clouds.Comment: A contributed paper to the FUSE Annapolis Conference "Future
Directions in Ultraviolet Spectroscopy.", 5 pages. To appear as an AIP
Conference Proceedin
Tracking The Post-BBN Evolution Of Deuterium
The primordial abundance of deuterium produced during Big Bang
Nucleosynthesis (BBN) depends sensitively on the universal ratio of baryons to
photons, an important cosmological parameter probed independently by the Cosmic
Microwave Background (CMB) radiation. Observations of deuterium in
high-redshift, low-metallicity QSO Absorption Line Systems (QSOALS) provide a
key baryometer, determining the baryon abundance at the time of BBN to a
precision of 5%. Alternatively, if the CMB-determined baryon to photon ratio is
used in the BBN calculation of the primordial abundances, the BBN-predicted
deuterium abundance may be compared with the primordial value inferred from the
QSOALS, testing the standard cosmological model. In the post-BBN universe, as
gas is cycled through stars, deuterium is only destroyed so that its abundance
measured anytime, anywhere in the Universe, bounds the primordial abundance
from below. Constraints on models of post-BBN Galactic chemical evolution
follow from a comparison of the relic deuterium abundance with the
FUSE-inferred deuterium abundances in the chemically enriched, stellar
processed material of the local ISM.Comment: 8 pages, 5 figures, to appear in the Proceedings of the Future
Directions in Ultraviolet Spectroscopy Conferenc
Intergalactic Baryons in the Local Universe
Simulations predict that shocks from large-scale structure formation and
galactic winds have reduced the fraction of baryons in the warm, photoionized
phase (the Lya forest) from nearly 100% in the early universe to less than 50%
today. Some of the remaining baryons are predicted to lie in the warm-hot
ionized medium (WHIM) phase at T=10^5-10^7 K, but the quantity remains a highly
tunable parameter of the models. Modern UV spectrographs have provided
unprecedented access to both the Lya forest and potential WHIM tracers at z~0,
and several independent groups have constructed large catalogs of far-UV IGM
absorbers along ~30 AGN sight lines. There is general agreement between the
surveys that the warm, photoionized phase makes up ~30% of the baryon budget at
z~0. Another ~10% can be accounted for in collapsed structures (stars,
galaxies, etc.). However, interpretation of the ~100 high-ion (OVI, etc)
absorbers at z<0.5 is more controversial. These species are readily created in
the shocks expected to exist in the IGM, but they can also be created by
photoionization and thus not represent WHIM material. Given several pieces of
observational evidence and theoretical expectations, I argue that most of the
observed OVI absorbers represent shocked gas at T~300,000 K rather than
photoionized gas at T<30,000 K, and they are consequently valid tracers of the
WHIM phase. Under this assumption, enriched gas at T=10^5-10^6 K can account
for ~10% of the baryon budget at z<0.5, but this value may increase when bias
and incompleteness are taken into account and help close the gap on the 50% of
the baryons still "missing".Comment: Invited review to appear in "Future Directions in Ultraviolet
Spectroscopy", Oct 20-22, 2008, Annapolis, MD, M. E. Van Steenberg, ed.
(April 2009). 8 pages, five figure
Highly Ionized Envelopes of High Velocity Clouds
We present recent results on highly ionized gas in Galactic High-Velocity
Clouds (HVCs), originally surveyed in OVI (Sembach et al. 2003). In a new
FUSE/HST survey of SiII/III/IV (Shull et al. 2009) toward 37 AGN, we detected
SiIII (lambda 1206.500 A) absorption with a sky coverage fraction 81 +/- 5% (61
HVCs along 30 of 37 high-latitude sight lines). The SiIII (lambda 1206.500 A)
line is typically 4-5 times stronger than OVI (lambda 1031.926 A). The mean HVC
column density of perhaps 10^19 cm^-2 of low-metallicity (0.1 - 0.2 Z_sun)
ionized gas in the low halo. Recent determinations of HVC distances allow us to
estimate a total reservoir of ~10^8 M_sun. Estimates of infall velocities
indicate an infall rate of around 1 M_sun yr^-1, comparable to the
replenishment rate for star formation in the disk. HVCs appear to be sheathed
by intermediate-temperature gas (10^4.0 - 10^4.5 K) detectable in SiIII and
SiIV, as well as hotter gas seen in OVI and other high ions. To prepare for HST
observations of 10 HVC-selected sight lines with the Cosmic Origins
Spectrograph (COS), we compile FUSE/STIS spectra of these ions, plus FeIII,
CIII, CIV, and SIV. Better constraints on the physical properties of HVC
envelopes and careful treatment of HVC kinematics and infall rates should come
from high-quality (S/N ~ 30-40) COS data.Comment: 3 pages, 1 figure, published in Future Directions in Ultraviolet
Spectroscopy, Proceedings of the AIP Conference held October 20-22, 2008 in
Annapolis, Marylan
The Cosmic Origins Spectrograph and the Future of Ultraviolet Astronomy
I describe the capabilities of the Cosmic Origins Spectrograph, scheduled for
May 2009 installation on the Hubble Space Telescope. With a factor-of-ten
increase in far-UV throughput for moderate resolution spectroscopy, COS will
enable a range of scientific programs that study hot stars, AGN, and gas in the
interstellar medium, intergalactic medium, and galactic halos. We also plan a
large-scale HST Spectroscopic Legacy Project for QSO absorption lines, galactic
halos, and AGN outflows. Studies of next-generation telescopes for UV/O
astronomy are now underway, including small, medium, and large missions to fill
the imminent ten-year gap between the end of Hubble and a plausible launch of
the next large mission. Selecting a strategy for achieving these goals will
involve hard choices and tradeoffs in aperture, wavelength, and capability.Comment: To appear in Future Directions in Ultraviolet Astronomy (AIP Conf
Proc
Jovian equatorial H2 emission from 1979-1987
Ninety two IUE observations of the Jovian equatorial region taken between 2 Dec. 1978 and 1 Feb. 1988 were averaged together by date of observation, resulting in 22 averaged spectra which were fit with a model to determine the amount of H2 Lyman band emission in the region 1552 to 1624A. The data suggest that the H2 emission may vary with time. Especially suggestive is the marked downward trend of the emission between 1983 and 1987, during which time the strength of the emission in the 1552 to 1624A region decreases by a factor of 10. Uncertainty in the existing data and a gap in the data in 1980 and 1981 preclude a positive identification of a correlation between the brightness of the H2 emission and the major solar cycle
Analysis of RGB-D camera technologies for supporting different facial usage scenarios
Recently a wide variety of applications has been developed integrating 3D functionalities. Advantages given by the possibility of relying on depth information allows the developers to design new algorithms and to improve the existing ones. In particular, for what concerns face morphology, 3D has led to the possibility to obtain face depth maps highly close to reality and consequently an improvement of the starting point for further analysis such as Face Detection, Face Authentication, Face Identification and Face Expression Recognition. The development of the aforementioned applications would have been impossible without the progress of sensor technologies for obtaining 3D information. Several solutions have been adopted over time. In this paper, emphasis is put on passive stereoscopy, structured light, time-of-flight (ToF) and active stereoscopy, namely the most used technologies for the cameras design and fulfilment according to the literature. The aim of this article is to investigate facial applications and to examine 3D camera technologies to suggest some guidelines for addressing the correct choice of a 3D sensor according to the application that has to be developed
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