1,418 research outputs found
Release from Terminal Suffering? The Impact of AIDS on Medically Assisted Suicide Legislation
Die 'Westforschung' zum europäischen Nordwesten als Gegenstand der Zeit- und Wissenschaftsgeschichte
The German \"Westforschung\" (Western Research) of the 1920s to 1960s, i.e. the interdisciplinary cross-border study of the region west of the Rhine into Germany\'s neighbouring countries, has recently become topical within the wider discussion on the contribution of German scholars to National Socialism. Developed after World War I in a defensive stance against French claims on the Rhineland, it later served, intentionally or not, as a (pseudo-)legitimisation for the national-socialist aggression to the west in 1940. The article presents an overview of the northern variant of Westforschung regarding the Low Countries, a special case, not the least because important contributions came from Dutch and Belgian scholars and because this paradigm did not end in 1945 but continued to prevail until the early 1960s
Elemental Abundances in NGC 3516
We present RGS data from an XMM-Newton observation of the Seyfert 1 galaxy
NGC 3516, taken while the continuum source was in an extreme low state. The
spectrum shows numerous emission lines including the H-like lines of C, N and O
and the He-like lines of N, O and Ne. These data show that the N lines are far
stronger than would be expected from gas of solar abundances. Based on our
photoionization models, we find that N is overabundant compared to C, O and Ne
by at least a factor of 2.5. We suggest this is the result of secondary
production of N in intermediate mass stars, and indicative of the history of
star formation in NGC 3516.Comment: 19 pages, 3 color figures. ApJ in pres
Dynamic Singularities in Cooperative Exclusion
We investigate cooperative exclusion, in which the particle velocity can be
an increasing function of the density. Within a hydrodynamic theory, an initial
density upsteps and downsteps can evolve into: (a) shock waves, (b) continuous
compression or rarefaction waves, or (c) a mixture of shocks and continuous
waves. These unusual phenomena arise because of an inflection point in the
current versus density relation. This anomaly leads to a group velocity that
can either be an increasing or a decreasing function of the density on either
side of these wave singularities.Comment: 4 pages, 4 figures, 2 column revtex 4-1 format; version 2:
substantially rewritten and put in IOP format, mail results unchanged;
version 3: minor changes, final version for publication in JSTA
A new method for microscale cyclic crack growth characterization from notched microcantilevers and application to single crystalline tungsten and a metallic glass
The lifetime of most metals is limited by cyclic loads, ending in fatigue
failure. The progressive growth of cracks ends up in catastrophic failure. An
advanced method is presented for the determination of cyclic crack growth on
the microscale using a nanoindenter, which allows the characterization of >
10,000 loading cycles. It uses focused ion beam fabricated notched
microcantilevers. The method has been validated by cyclic bending metallic
glass and tungsten microcantilevers. The experiments reveal a stable crack
growth during the lifetime of both samples. The metallic glass shows less
plasticity due to the absence of dislocations, but shows shearing caused by the
deformation. The crack growth rates determined in the tests follow Paris' power
law relationship. The results are reliable, reproducible and comparable with
macroscopic setups. Due to the flexibility of the method, it is suitable for
the characterization of specific microstructural features, like single phases,
grain boundaries or different grain orientations
The AGN Outflow in the HDFS Target QSO J2233-606 from a High-Resolution VLT/UVES Spectrum
We present a detailed analysis of the intrinsic UV absorption in the central
HDFS target QSO J2233-606, based on a high-resolution, high S/N (~25 -- 50)
spectrum obtained with VLT/UVES. This spectrum samples the cluster of intrinsic
absorption systems outflowing from the AGN at radial velocities v ~ -5000 --
-3800 km/s in the key far-UV diagnostic lines - the lithium-like CNO doublets
and H I Lyman series. We fit the absorption troughs using a global model of all
detected lines to solve for the independent velocity-dependent covering factors
of the continuum and emission-line sources and ionic column densities. This
reveals increasing covering factors in components with greater outflow
velocity. Narrow substructure is revealed in the optical depth profiles,
suggesting the relatively broad absorption is comprised of a series of multiple
components. We perform velocity-dependent photoionization modeling, which
allows a full solution to the C, N, and O abundances, as well as the velocity
resolved ionization parameter and total column density. The absorbers are found
to have supersolar abundances, with [C/H] and [O/H] ~0.5 -- 0.9, and [N/H] ~
1.1 -- 1.3, consistent with enhanced nitrogen production expected from
secondary nucleosynthesis processes. Independent fits to each kinematic
component give consistent results for the abundances. The lowest-ionization
material in each of the strong absorbers is modeled with similar ionization
parameters. Components of higher-ionization (indicated by stronger O VI
relative to C IV and N V) are present at velocities just redward of each
low-ionization absorber. We explore the implications of these results for the
kinematic-geometric-ionization structure of the outflow.Comment: 12 pages, 10 figures, emulateapj, accepted for publication in Ap
Antarctic meteorite newsletter. Volume 4: Number 1, February 1981: Antarctic meteorite descriptions, 1976, 1977, 1978, 1979
This issue of the Newsletter is essentially a catalog of all antarctic meteorites in the collections of the Johnson Space Center Curation Facility and the Smithsonian except for 288 pebbles now being classed. It includes listings of all previously distributed data sheets plus a number of new ones for 1979. Indexes of samples include meteorite name/number, classification, and weathering category. Separate indexes list type 3 and 4 chondrites, all irons, all achondrites, and all carbonaceous chondrites
Antarctic meteorite descriptions 1976-1977-1978-1979
All previously distributed meteorite data sheets, plus a number of new ones for 1979 chondrites are included. A comprehensive sample index listing meteorite name/number, classification, and weathering category is also included. Separate indexes listing all petrologic type 3 and type 4 chondrites, all irons, all achondrites, and all carbonaceous chondrites in the collection is provided
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