8,497 research outputs found
Neutron capture rates and r-process nucleosynthesis
Simulations of r-process nucleosynthesis require nuclear physics information
for thousands of neutron-rich nuclear species from the line of stability to the
neutron drip line. While arguably the most important pieces of nuclear data for
the r-process are the masses and beta decay rates, individual neutron capture
rates can also be of key importance in setting the final r-process abundance
pattern. Here we consider the influence of neutron capture rates in forming the
A~80 and rare earth peaks.Comment: 10 pages, 5 figures, appears in the Proceedings of the 14th
International Symposium on Capture Gamma-Ray Spectroscopy and Related Topic
Simulations of a Scintillator Compton Gamma Imager for Safety and Security
We are designing an all-scintillator Compton gamma imager for use in security
investigations and remediation actions involving radioactive threat material.
To satisfy requirements for a rugged and portable instrument, we have chosen
solid scintillator for the active volumes of both the scatter and absorber
detectors. Using the BEAMnrc/EGSnrc Monte Carlo simulation package, we have
constructed models using four different materials for the scatter detector:
LaBr_3, NaI, CaF_2 and PVT. We have compared the detector performances using
angular resolution, efficiency, and image resolution. We find that while PVT
provides worse performance than that of the detectors based entirely on
inorganic scintillators, all of the materials investigated for the scatter
detector have the potential to provide performance adequate for our purposes.Comment: Revised text and figures, Presented at SORMA West 2008, Published in
IEEE Transactions on Nuclear Scienc
Vitamin D enzymes (CYP27A1, CYP27B1 and CYP24A1) and receptor expression in non-melanoma skin cancer
No abstract available for this paper
Off with their heads: Terrorism and electoral support for capital punishment in Australia
Recent terrorist attacks such as the attacks on the World Trade Centre in September 2001 have generated new interest in the debate on capital punishment. It has been suggested that support for the death penalty could be higher in the wake of terrorist activity. Using data from the Australian Election Study we investigate voters' attitudes towards capital punishment. Paradoxically, overall support for the death penalty at the 2001 Federal election was lower than at previous elections. In this paper we utilise both simultaneous binary probit and treatment effects models to model the determinants of those attitudes and to investigate the impact of terrorism on support for the death penalty at the 2001 Federal election. In particular, we address the question of whether voters who felt terrorism was an important issue had higher levels of support for the death penalty than voters who did not feel that terrorism was importantsimultaneous binary probit, treatment effects models
S-band omnidirectional antenna for the SERT-C satellite
The program to design an S-band omnidirectional antenna system for the SERT-C spacecraft is discussed. The program involved the tasks of antenna analyses by computer techniques, scale model radiation pattern measurements of a number of antenna systems, full-scale RF measurements, and the recommended design, including detailed drawings. A number of antenna elements were considered: the cavity-backed spiral, quadrifilar helix, and crossed-dipoles were chosen for in-depth studies. The final design consisted of a two-element array of cavity-backed spirals mounted on opposite sides of spacecraft and fed in-phase through a hybrid junction. This antenna system meets the coverage requirement of having a gain of at least minus 10 dBi over 50 percent of a 4 pi steradian sphere with the solar panels in operation. This coverage level is increased if the ground station has the capability to change polarization
Evaluation of the School Administration Manager Project
Examines the results to date of a Wallace-supported project to help principals delegate some administrative and managerial tasks to school administration managers and spend more time interacting with teachers, students and others on instructional matters
Spectroscopy, Equation Of State And Monopole Percolation In Lattice QED With Two Flavors
Non-compact lattice QED with two flavors of light dynamical quarks is
simulated on lattices, and the chiral condensate, monopole density and
susceptibility and the meson masses are measured. Data from relatively high
statistics runs at relatively small bare fermion masses of 0.005, 0.01, 0.02
and 0.03 (lattice units) are presented. Three independent methods of data
analysis indicate that the critical point occurs at and that
the monopole condensation and chiral symmetry breaking transitions are
coincident. The monopole condensation data satisfies finite size scaling
hypotheses with critical indices compatible with four dimensional percolation.
The best chiral equation of state fit produces critical exponents
(, ) which deviate significantly from mean
field expectations. Data for the ratio of the sigma to pion masses produces an
estimate of the critical index in good agreement with chiral
condensate measurements. In the strong coupling phase the ratio of the meson
masses are ,
and , while on the weak coupling side of the
transition , ,
indicating the restoration of chiral symmetry.\footnote{\,^{}}{August 1992}Comment: 21 pages, 24 figures (not included
Memento Mori: The development and validation of the Death Reflection Scale
Despite its potential for advancing organizational behavior (OB) research, the topic of death awareness has been vastly understudied. Moreover, research on death awareness has predominantly focused on the anxiety‐provoking aspect of death‐related cognitions, thus overlooking the positive aspect of death awareness, death reflection. This gap is exacerbated by the lack of a valid research instrument to measure death reflection. To address this issue, we offer a systematic conceptualization of death reflection, develop the Death Reflection Scale, and assess its psychometric properties across four studies. Further, using a sample of 268 firefighters, we examine whether death reflection buffers the detrimental impact of mortality cues at work on employee well‐being and safety performance. Results provide strong support for the psychometric properties of the Death Reflection Scale. Further, moderation analysis indicates death reflection weakens the negative effect of mortality cues on firefighters' safety performance. Overall, these findings suggest the newly developed Death Reflection Scale will prove useful in future research on death‐related cognitions
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