1,756 research outputs found
Victims of Victims: The Concept of Victimhood in Two War Memoirs of the Sierra Leonean Civil War
This research analyzes the portrayal and view of war victimhood in the genre of war stories and remembrance using two firsthand accounts of the Sierra Leonean Civil War
Blood Cries Out From the Ground: The Einsatzgruppen and the Holocaust in Ukraine
After the Nazi invasion of the Soviet Union on June 22, 1941, the Wehrmacht occupied much of the western Soviet regions. The Third Reich deployed special killing squads known as the Einsatzgruppen to protect its military and ideological interests. These units were responsible for murdering over two million Jews from 1941 to 1944, primarily through mass shootings. Ukraine was one of the most afflicted countries by this “Holocaust by Bullets.” Because of the efficient genocidal techniques of Einsatzgruppen units operating in the region, one in four Jews who perished in the Holocaust was Ukrainian. The scale on which these killings was perpetrated demonstrates that the Holocaust by Bullets was a significant part of the Nazi extermination of European Jewry
Before Barbarossa: The Nazi Occupation of Western Poland, September 1,1939-June 22, 1941
The Nazi invasion and occupation of Western Poland was a vital first step to the development and fulfillment of the genocidal processes of the Holocaust. The utilization of mass arrests, executions, and shootings led to the persecution and death of hundreds of thousands of Poles and Polish Jews prior to the invasion of the Soviet Union and inception of the Final Solution in the summer of 1941
The Survival of Planetary Nebulae in the Intracluster Medium
The stellar population stripped from galaxies in clusters evolve under the
extreme conditions imposed by the intracluster (IC) medium. Intracluster stars
generally suffer very high systemic velocities, and evolve within a rarefied
and extremely hot IC medium. We present numerical simulations which aim to
explore the evolution and survival of IC Asymptotic Giant Branch (AGB)
envelopes and Planetary Nebula (PN) shells. Our models reflect the evolution of
a low-mass star under the observed conditions in the Virgo IC medium. We find
that the integrated hydrogen-recombination line emission of a PN is dominated
by the inner dense shell, whose evolution is unaffected by the environment. Ram
pressure stripping affects mainly the outermost IC PN shell, which hardly
influences the emission when the PN is observed as a point source. More
importantly, we find that a PN with progenitor mass of 1 Msun fades to ~30% and
10% of its maximum emission, in 5,000 and 10,000 yr respectively, disclosing an
actual PN lifetime t_PN several times shorter to what is usually adopted
(25,000 yr). This result affects the theoretical calculation of the
luminosity-specific density of IC PNe, which scales with t_PN. For t_PN=10,000
yr, our more conservative estimate, we obtain that the luminosity-specific
density of PNe is in fair agreement with the value obtained from Red Giants.
With our more realistic PN lifetime we infer a higher fraction (above 15%) of
IC starlight in the Virgo core than current estimates.Comment: Accepted for publication in the Astrophysical Journal 14 pages,
including 2 figure
Entanglement sharing in Jahn-Teller model in the presence of a magnetic field
We discuss the ground state entanglement of the
Jahn-Teller model in the presence of a strong transverse magnetic field as a
function of the vibronic coupling strength. A complete characterization is
given of the phenomenon of entanglement sharing in a system composed by a qubit
coupled to two bosonic modes. Using the residual -tangle, we find that
three-partite entanglement is significantly present in the system in the
parameter region near the bifurcation point of the corresponding classical
model
Large Signal Analysis of a New Meander Line Topology for W-band Traveling Wave Tubes
Satellite distribution of high data rate needs wide frequency band. The millimeter waves, in particular the W-band, provide wide bandwidth and relatively low attenuation. The link transmission power can be provided only by Traveling Wave Tubes (TWTs). A new meander line topology to be used as slow wave structure for 71-76 GHz TWTs, with improved performance in comparison to the conventional one, is proposed. The new meander line compared to a standard meander line shows flatter gain and higher output power. © 2019 IEEE
Entanglement of a qubit coupled to a resonator in the adiabatic regime
We discuss the ground state entanglement of a bi-partite system, composed by
a qubit strongly interacting with an oscillator mode, as a function of the
coupling strenght, the transition frequency and the level asymmetry of the
qubit. This is done in the adiabatic regime in which the time evolution of the
qubit is much faster than the oscillator one. Within the adiabatic
approximation, we obtain a complete characterization of the ground state
properties of the system and of its entanglement content.Comment: 6 pages, 7 figure
Extragalactic Planetary Nebulae: tracers of the chemical evolution of nearby galaxies
The study of the chemical composition of Planetary Nebulae in external
galaxies is of paramount importance in the fields of stellar evolution and of
the chemical enrichment history of galaxies. In the last years a number of
spectroscopic studies with 6-8m-class telescopes have been devoted to this
subject improving our knowledge of, among other, the time-evolution of the
radial metallicity gradient in disk galaxies, the chemical evolution of dwarf
galaxies, and the stellar evolution at low metallicity.Comment: 8 pages, 4 figures, Invited Review to IAU Symposium 283, "Planetary
Nebulae: an Eye to the Future", Tenerife, 25-29 July 201
Large Magellanic Cloud Planetary Nebula Morphology: Probing Stellar Populations and Evolution
Planetary Nebulae (PNe) in the Large Magellanic Cloud (LMC) offer the unique
opportunity to study both the Population and evolution of low- and
intermediate-mass stars, by means of the morphological type of the nebula.
Using observations from our LMC PN morphological survey, and including images
available in the HST Data Archive, and published chemical abundances, we find
that asymmetry in PNe is strongly correlated with a younger stellar Population,
as indicated by the abundance of elements that are unaltered by stellar
evolution (Ne, Ar, S). While similar results have been obtained for Galactic
PNe, this is the first demonstration of the relationship for extra-galactic
PNe. We also examine the relation between morphology and abundance of the
products of stellar evolution. We found that asymmetric PNe have higher
nitrogen and lower carbon abundances than symmetric PNe. Our two main results
are broadly consistent with the predictions of stellar evolution if the
progenitors of asymmetric PNe have on average larger masses than the
progenitors of symmetric PNe. The results bear on the question of formation
mechanisms for asymmetric PNe, specifically, that the genesis of PNe structure
should relate strongly to the Population type, and by inference the mass, of
the progenitor star, and less strongly on whether the central star is a member
of a close binary system.Comment: The Astrophysical Journal Letters, in press 4 figure
Nuclear halo and the coherent nuclear interaction
The unusual structure of Li11, the first halo nucleus found, is analyzed by
the Preparata model of nuclear structure. By applying Coherent Nucleus Theory,
we obtain an interaction potential for the halo-neutrons that rightly
reproduces the fundamental state of the system.Comment: 9 pages Submitted to International Journal of Modern Physics E
(IJMPE
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