No abstract

In situ x-ray diffraction studies of iron under shock conditions confirm unambiguously a phase change from the bcc (alpha) to hcp (epsilon) structure. Previous identification of this transition in shock-loaded iron has been inferred from the correlation between shock-wave-profile analyses and static high-pressure x-ray measurements. This correlation is intrinsically limited because dynamic loading can markedly affect the structural modifications of solids. The in situ measurements are consistent with a uniaxial collapse along the [001] direction and shuffling of alternate (110) planes of atoms, and are in good agreement with large-scale nonequilibrium molecular dynamics simulations.

The Military Suicide Research Consortium (MSRC) developed a 57-item questionnaire assessing suicide risk factors, referred to as the Common Data Elements (CDEs), in order to facilitate data sharing and improve collaboration across independent studies. All studies funded by MSRC are required to include the CDEs in their assessment protocol. The CDEs include shortened measures of the following: current and past suicide risk, lethality and intent of past suicide attempts, hopelessness, thwarted belongingness, anxiety sensitivity, posttraumatic stress disorder symptoms, traumatic brain injury, insomnia, and alcohol abuse. This study aimed to evaluate the psychometric properties of the CDE items drawn from empirically validated measures. Exploratory factor analysis was used to examine the overall structure of the CDE items, and confirmatory factor analyses were used to evaluate the distinct properties of each scale. Internal consistencies of the CDE scales and correlations with full measures were also examined. Merged data from 3,140 participants (81.0% military service members, 75.6% male) across 19 MSRC-funded studies were used in analyses. Results indicated that all measures exhibited adequate internal consistency, and all CDE shortened measures were significantly correlated with the corresponding full measures with moderate to strong effect sizes. Factor analyses indicated that the shortened CDE measures performed well in comparison with the full measures. Overall, our findings suggest that the CDEs are not only brief but also provide psychometrically valid scores when assessing suicide risk and related factors that may be used in future research. (PsycINFO Database Record

Solid state experiments at extreme pressures (10-100 GPa) and strain rates (~10 6 -10 8 s occur at shock strengths of ~20 GPa, whereas the corresponding transition for Cu shocked along the [134] direction occurs at higher shock strengths. This slip-twinning threshold also depends on the stacking fault energy (SFE), being lower for low SFE-

Ripple induced thermal loss effect on plasma rotation is investigated in a set of Ohmic L-mode plasmas performed in Tore Supra, and comparisons with neoclassical predictions including ripple are performed. Adjusting the size of the plasma, the ripple amplitude has been varied from 0.5% to 5.5% at the plasma boundary, keeping the edge safety factor constant. The toroidal flow dynamics is understood as being likely dominated by turbulence transport driven processes at low ripple amplitude, while the ripple induced toroidal friction becomes dominant at high ripple. In the latter case, the velocity tends remarkably towards the neoclassical prediction (counter-current rotation). The radial electric field is not affected by the ripple variation and remains well described by its neoclassical prediction. Finally, the poloidal velocity is fairly close to the neoclassical prediction at high ripple amplitude, but significantly departs from it at low ripple.