399 research outputs found
XUV Opacity of Aluminum between the Cold-Solid to Warm-Plasma Transition
We present calculations of the free-free XUV opacity of warm, solid-density
aluminum at photon energies between the plasma frequency at 15 eV and the
L-edge at 73 eV, using both density functional theory combined with molecular
dynamics and a semi-analytical model in the RPA framework with the inclusion of
local field corrections. As the temperature is increased from room temperature
to 10 eV, with the ion and electron temperatures equal, we calculate an
increase in the opacity in the range over which the degree of ionization is
constant. The effect is less pronounced if only the electron temperature is
allowed to increase. The physical significance of these increases is discussed
in terms of intense XUV-laser matter interactions on both femtosecond and
picosecond time-scales.Comment: 4 pages, 3 figure
Empowerment and the Transition to Housing for Homeless Mentally Ill People: An Anthropological Perspective
Often lacking in scholarly and policy-oriented discussions of homelessness are contextualized understandings of the problems faced, and the values held, by homeless mentally ill people. This article, using an anthropological perspective, examines issues that arise for homeless mentally ill individuals in making the transition from shelter living to permanent residences. The transition occurs as part of a housing initiative driven by the philosophy of consumer empowerment. Project participants are placed in independent apartments or evolving consumer households (ECH) — shared, staffed residences designed to transform themselves into consumer-directed living situations over time. The effects of an empowerment paradigm on the organization of space, the nature of social relations, and the management of economic resources in the ECHs are discussed to show that consumers and staff sometimes have contrasting views of what empowerment entails. It is suggested that anthropological research can help to illuminate the issues at stake in determining policy for homeless people with major mental illness
Anthropology, Brokerage and Collaboration in the development of a Tongan Public Psychiatry: Local Lessons for Global Mental Health
The Global Mental Health (GMH) movement has revitalised questions of the translatability of psychiatric concepts and the challenges of community engagement in countries where knowledge of the biomedical basis for psychiatric diagnosis is limited or challenged by local cultural codes. In Tonga, the local psychiatrist Dr Puloka has successfully established a publicly accessible psychiatry that has raised admission rates for serious mental illness and addressed some of the stigma attached to diagnosis. On the basis of historical analysis and ethnographic fieldwork with healers, doctors and patients since 1998, this article offers an ethnographic contextualization of the development and reception of three key interventions during the 1990s inspired by traditional healing and reliant on the translation of psychiatric terms and diagnosis. Dr Puloka’s use of medical anthropological and transcultural psychiatry research informed a community engaged brokerage between the implications of psychiatric nosologies and local needs. As such it reveals deficiencies in current polarised positions on the GMH project and offers suggestions to address current challenges of the Global Mental Health movement
Annular fast electron transport in silicon arising from low-temperature resistivity
Fast electron transport in Si, driven by ultra-intense laser pulses, is investigated experimentally and via 3D hybrid-PIC simulations. A transition from a Gaussian-like to an annular fast electron beam profile is demonstrated and explained by resistively generated magnetic fields. The results highlight the potential to completely transform the beam transport pattern by tailoring the resistivity-temperature profile at temperatures as low as a few eV
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