2,864 research outputs found
J0316+4328: a Probable "Asymmetric Double" Lens
We report a probable gravitational lens J0316+4328, one of 19 candidate
asymmetric double lenses (2 images at a high flux density ratio) from CLASS.
Observations with the Very Large Array (VLA), MERLIN and the Very Long Baseline
Array (VLBA) imply that J0316+4328 is a lens with high confidence. It has 2
images separated by 0.40", with 6 GHz flux densities of 62 mJy and 3.2 mJy. The
flux density ratio of ~19 (constant over the frequency range 6-22 GHz) is the
largest for any 2 image gravitational lens. High resolution optical imaging and
deeper VLBI maps should confirm the lensing interpretation and provide inputs
to detailed lens models. The unique configuration will give strong constraints
on the lens galaxy's mass profile.Comment: Accepted to MNRAS Letters. 5 pages, 6 figures, 3 table
Bilateral symmetry breaking in a nonlinear Fabry-Perot cavity exhibiting optical tristability
We show the existence of a region in the parameter space that defines the
field dynamics in a Fabry-Perot cylindrical cavity, where three output stable
stationary states of the light are possible for a given localized incident
field. Two of these states do not preserve the bilateral (i.e. left-right)
symmetry of the entire system. These broken-symmetry states are the
high-transmission nonlinear modes of the system. We also discuss how to excite
these states.Comment: 5 pages, 5 figure
Pharmacists’ opinions of the value of CAPE Outcomes in hiring decisions
Objective. The Hiring Intent Reasoning Examination (HIRE) was designed to explore the utility of the CAPE 2013 outcomes attributes from the perspective of practicing pharmacists, examine how each attribute influences hiring decisions, and identify which of the attributes are perceived as most and least valuable by practicing pharmacists. Methods. An electronic questionnaire was developed and distributed to licensed pharmacists in four states to collect their opinions about 15 CAPE subdomains plus five additional business related attributes. The attributes that respondents identified were: necessary to be a good pharmacist, would impact hiring decisions, most important to them, and in short supply in the applicant pool. Data were analyzed using statistical analysis software to determine the relative importance of each to practicing pharmacists and various subsets of pharmacists. Results. The CAPE subdomains were considered necessary for most jobs by 51% or more of the 3723 respondents (range, 51% to 99%). The necessity for business-related attributes ranged from 21% to 92%. The percentage who would not hire an applicant who did not possess the attribute ranged from 2% to 71.5%; the percentage who considered the attribute most valuable ranged from 0.3% to 35%; and the percentage who felt the attribute was in short supply ranged from 5% to 36%. Opinions varied depending upon gender, practice setting and whether the pharmacist was an employee or employer. Conclusion. The results of this study can be used by faculty and administrators to inform curricular design and emphasis on CAPE domains and business-related education in pharmacy programs
Community based rehabilitation: a strategy for peace-building
BACKGROUND: Certain features of peace-building distinguish it from peacekeeping, and make it an appropriate strategy in dealing with vertical conflict and low intensity conflict. However, some theorists suggest that attempts, through peace-building, to impose liberal values upon non-democratic cultures are misguided and lack an ethical basis. DISCUSSION: We have been investigating the peace-building properties of community based approaches to disability in a number of countries. This paper describes the practice and impact of peace-building through Community Based Rehabilitation (CBR) strategies in the context of armed conflict. The ethical basis for peace-building through practical community initiatives is explored. A number of benefits and challenges to using CBR strategies for peace-building purposes are identified. SUMMARY: During post-conflict reconstruction, disability is a powerful emotive lever that can be used to mobilize cooperation between factions. We suggest that civil society, in contrast to state-level intervention, has a valuable role in reducing the risks of conflict through community initiatives
Knight Shift Anomalies in Heavy Electron Materials
We calculate non-linear Knight Shift vs. susceptibility anomalies
for Ce ions possessing local moments in metals. The ions are modeled with the
Anderson Hamiltonian and studied within the non-crossing approximation (NCA).
The non-linearity diminishes with decreasing Kondo temperature
and nuclear spin- local moment separation. Treating the Ce ions as an
incoherent array in CeSn, we find excellent agreement with the observed Sn
data.Comment: 4 pages, Revtex, 3 figures available upon request from
[email protected]
Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures
We report measurements of photon and neutron radiation levels observed while
transmitting a 0.43 MW electron beam through millimeter-sized apertures and
during beam-off, but accelerating gradient RF-on, operation. These measurements
were conducted at the Free-Electron Laser (FEL) facility of the Jefferson
National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an
energy-recovery linear accelerator. The beam was directed successively through
6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a
maximum current of 4.3 mA (430 kW beam power). This study was conducted to
characterize radiation levels for experiments that need to operate in this
environment, such as the proposed DarkLight Experiment. We find that sustained
transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is
feasible with manageable beam-related backgrounds. We also find that during
beam-off, RF-on operation, multipactoring inside the niobium cavities of the
accelerator cryomodules is the primary source of ambient radiation when the
machine is tuned for 130 MeV operation.Comment: 9 pages, 11 figures, submitted to Nuclear Instruments and Methods in
Physics Research Section
Transmission of High-Power Electron Beams Through Small Apertures
Tests were performed to pass a 100 MeV, 430 kWatt c.w. electron beam from the
energy-recovery linac at the Jefferson Laboratory's FEL facility through a set
of small apertures in a 127 mm long aluminum block. Beam transmission losses of
3 p.p.m. through a 2 mm diameter aperture were maintained during a 7 hour
continuous run.Comment: arXiv admin note: text overlap with arXiv:1305.019
Low Temperature Anomaly in Mesoscopic Kondo Wires
We report the observation of an anomalous magnetoresistance in extremely
dilute quasi-one-dimensional AuFe wires at low temperatures, along with a
hysteretic background at low fields. The Kondo resistivity does not show the
unitarity limit down to the lowest temperature, implying uncompensated spin
states. We suggest that the anomalous magnetoresistance may be understood as
the interference correction from the accumulation of geometric phase in the
conduction electron wave function around the localized impurity spin.Comment: Four pages, five figure
The Screening Cloud in the k-Channel Kondo Model: Perturbative and Large-k Results
We demonstrate the existence of a large Kondo screening cloud in the
k-channel Kondo model using both renormalization group improved perturbation
theory and the large-k limit. We study position (r) dependent spin Green's
functions in both static and equal time cases. The equal-time Green's function
provides a natural definition of the screening cloud profile, in which the
large Kondo scale appears. At large distances it consists of both a slowly
varying piece and a piece which oscillates at twice the Fermi wave-vector. This
function is calculated at all r in the large-k limit. Static Green's functions
(Knight shift or susceptibility) consist only of a term oscillating at 2kF, and
appear to factorize into a function of r times a function of T for rT << vF, in
agreement with NMR experiments. Most of the integrated susceptibility comes
from the impurity-impurity part with conduction electron contributions
suppressed by powers of the bare Kondo coupling. The single-channel and
overscreened multi-channel cases are rather similar although anomalous
power-laws occur in the latter case at large r and low T due to irrelevant
operator corrections.Comment: 22 Revtex pages, 12 figure
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