2,864 research outputs found

    J0316+4328: a Probable "Asymmetric Double" Lens

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    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

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    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

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    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

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    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

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    We calculate non-linear Knight Shift KK vs. susceptibility χ\chi 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 K−vs.−χK-vs.- \chi non-linearity diminishes with decreasing Kondo temperature T0T_0 and nuclear spin- local moment separation. Treating the Ce ions as an incoherent array in CeSn3_3, we find excellent agreement with the observed Sn K(T)K(T) 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

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    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

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    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

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    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

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    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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