12,848 research outputs found
Hall coefficient of tantalum carbide as function of carbon content
Hall coefficient of tantalum carbide as function of carbon conten
Approximate high energy alpha-particle nucleus collision model
Alpha particle-nucleus collision model for nucleon energy and angular distribution prediction and residual nuclei cross section
Primary and secondary particle contributions to the depth dose distribution in a phantom shielded from solar flare and Van Allen protons
Calculations have been made using the nucleon-meson transport code NMTC to estimate the absorbed dose and dose equivalent distributions in astronauts inside space vehicles bombarded by solar flare and Van Allen protons. A spherical shell shield of specific radius and thickness with a 30-cm-diam. tissue ball at the geometric center was used to simulate the spacecraft-astronaut configuration. The absorbed dose and the dose equivalent from primary protons, secondary protons, heavy nuclei, charged pions, muons, photons, and positrons and electrons are given as a function of depth in the tissue phantom. Results are given for solar flare protons with a characteristic rigidity of 100 MV and for Van Allen protons in a 240-nautical-mile circular orbit at 30 degree inclination angle incident on both 20-g/sq cm-thick aluminum and polyethylene spherical shell shields
The jet-ISM interaction in the Outer Filament of Centaurus A
The interaction between the radio plasma ejected by the active nucleus of a
galaxy and the surrounding medium is a key process that can have a strong
impact on the interstellar medium of the galaxy and hence on galaxy evolution.
The closest laboratory where we can observe and investigate this phenomenon is
the radio galaxy Centaurus A. About 15 kpc north-east of this galaxy, a
particularly complex region is found: the so-called Outer Filament where
jet-cloud interactions have been proposed to occur. We investigate the presence
of signatures of jet-ISM interaction by a detailed study of the kinematics of
the ionized gas, expanding on previous results obtained from the HI. We
observed two regions of the outer filament with VLT/VIMOS in the IFU observing
mode. Emission from Hbeta and [OIII]4959,5007\AA\ is detected in both
pointings. We found two distinct kinematical components of ionized gas that
well match the kinematics of the nearby HI cloud. One component follows the
regular kinematics of the rotating gas while the second shows similar
velocities to those of the nearby HI component thought to be disturbed by an
interaction with the radio jet. We suggest that the ionized and atomic gas are
part of the same dynamical gas structure originating as result of the merger
that shaped Centaurus A and which is regularly rotating around Centaurus A as
proposed by other authors. The gas (ionized and HI) with anomalous velocities
is tracing the interaction of the Large-Scale radio Jet with the ISM,
suggesting that, although poorly collimated as structure, the jet is still
active. However, we can exclude that a strong shock is driving the ionization
of the gas. It is likely that a combination of jet entrainment and
photoionization by the UV continuum from the central engine is needed in order
to explain both the ionization and the kinematics of the gas in the Outer
Filament.Comment: 6 pages, 6 figures, 1 table. Final version accepted for publication
on A&
"Credit Cycle" in an OLG Economy with Money and Bequest
In the late '90s Kiyotaki and Moore (KM) put forward a new framework (Kiyotaki and Moore,1997) to explore the Financial Accelerator hypothesis. The original model was framed in an Infinitely Lived Agent context (ILA-KM economy). As in KM we develop a dynamic model in which the durable asset ("land") is not only an input but also collateralizable wealth to secure lenders from the risk of borrowers' default. In this paper, however, we model an OLG-KM economy whose novel feature is the role of money as a store of value and of bequest as a vehicle of resources to be "invested" in landholding. The dynamics generated by the model are complex. Not only cyclical patterns are routinely generated but the periodicity and amplitude are irregular. A route to chaotic dynamics is open.
Absolute Efficiency Measurements of NE-213 ORGANIC Phosphors for Detecting 14.4 and 2.6 Mev Neutrons
Efficiency measurements of organic phosphor scintillator for detecting 14.4 and 2.6 MeV neutron
Faster annealing schedules for quantum annealing
New annealing schedules for quantum annealing are proposed based on the
adiabatic theorem. These schedules exhibit faster decrease of the excitation
probability than a linear schedule. To derive this conclusion, the asymptotic
form of the excitation probability for quantum annealing is explicitly obtained
in the limit of long annealing time. Its first-order term, which is inversely
proportional to the square of the annealing time, is shown to be determined
only by the information at the initial and final times. Our annealing schedules
make it possible to drop this term, thus leading to a higher order (smaller)
excitation probability. We verify these results by solving numerically the
time-dependent Schrodinger equation for small size systemsComment: 10 pages, 5 figures, minor correction
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