8,748 research outputs found

    Meissner response of anisotropic superconductors

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    The response field of a half-space anisotropic superconductor is evaluated for an arbitrary weak external field source. Example sources of a point magnetic moment and a circular current are considered in detail. For the penetration depth λ≪L\lambda \ll L with LL being any other relevant distance (the source size, or the distance between the source and the superconductor), the major contribution to the response is the λ\lambda independent field of the source image. It is shown that the absolute value of λ\lambda cannot be extracted from the response field with a better accuracy than that for the source position. Similar problems are considered for thin films.Comment: 8 pages, 0 figures. 7 pages: section removed, refs. adde

    Barriers & facilitators to extended working life : a focus on a predominately female ageing workforce

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    Many countries are reforming their pension systems so people stay in work for longer to improve the long-term sustainability of public finances to support an increasing older population. This research aimed to explore the factors that enable or inhibit people to extend working life (EWL) in a large UK based retail organisation. Semi-structured interviews were carried out with a purposive sample (n=30): 15 employees aged ≥ 60 and 15 supervisors supporting these employees. Older workers were predominately female, reflecting the gender profile of the older workers in the organisation. Older workers and supervisors reported that key facilitators to EWL were: good health, the perception that older workers are of value; flexibility and choice; the need for an ongoing conversation across the life-course; the social and community aspect of work as a facilitator to EWL; and, the financial necessity to EWL. Perceived barriers to EWL included poor health, negative impacts of work on health, and a lack of respect and support

    Complete Genome Sequences of vB_LmoS_188 and vB_LmoS_293, Two Bacteriophages with Specificity for Listeria monocytogenes Strains of Serotypes 4b and 4e

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    peer-reviewedListeria monocytogenes is responsible for the rare disease listeriosis, which is associated with the consumption of contaminated food products. We report here the complete genome sequences of vB_LmoS_188 and vB_LmoS_293, phages isolated from environmental sources and that have host specificity for L. monocytogenes strains of the 4b and 4e serotypes.This work was supported by the EU 7th Framework projects PROMISE (project no. 265877) and FOODSEG (project no. 266061) and by a safefood mini-project

    Field dependence of the temperature at the peak of the ZFC magnetization

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    The effect of an applied magnetic field on the temperature at the maximum of the ZFC magnetization, MZFCM_{ZFC}, is studied using the recently obtained analytic results of Coffey et al. (Phys. Rev. Lett. {\bf 80}(1998) 5655) for the prefactor of the N\'{e}el relaxation time which allow one to precisely calculate the prefactor in the N\'{e}el-Brown model and thus the blocking temperature as a function of the coefficients of the Taylor series expansion of the magnetocrystalline anisotropy. The present calculations indicate that even a precise determination of the prefactor in the N\'{e}el-Brown theory, which always predicts a monotonic decrease of the relaxation time with increasing field, is insufficient to explain the effect of an applied magnetic field on the temperature at the maximum of the ZFC magnetization. On the other hand, we find that the non linear field-dependence of the magnetization along with the magnetocrystalline anisotropy appears to be of crucial importance to the existence of this maximum.Comment: 14 LaTex209 pages, 6 EPS figures. To appear in J. Phys.: Condensed Matte

    Searching for jet rotation in Class 0/I sources observed with GEMINI/GNIRS.

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    Original article can be found at: http://www.aanda.org/ Copyright The European Southern ObservatoryContext: In recent years, there has been a number of detections of gradients in the radial velocity profile across jets from young stars. The significance of these results is considerable. They may be interpreted as a signature of jet rotation about its symmetry axis, thereby representing the only existing observational indications supporting the theory that jets extract angular momentum from star-disk systems. However, the possibility that we are indeed observing jet rotation in pre-main sequence systems is undergoing active debate. Aims: To test the validity of a rotation argument, we must extend the survey to a larger sample, including younger sources. Methods: We present the latest results of a radial velocity analysis on jets from Class 0 and I sources, using high resolution data from the infrared spectrograph GNIRS on GEMINI South. We obtained infrared spectra of protostellar jets HH 34, HH 111-H, HH 212 NK1 and SK1. Results: The [Fe II] emission was unresolved in all cases and so Doppler shifts across the jet width could not be accessed. The H2 emission was resolved in all cases except HH 34. Doppler profiles across the molecular emission were obtained, and gradients in radial velocity of typically 3 km s-1 identified. Conclusions: Agreement with previous studies implies they may be interpreted as jet rotation, leading to toroidal velocity and angular momentum flux estimates of 1.5 km s-1 and 1 × 10-5 yr-1 AU km s-1 respectively. However, caution is needed. For example, emission is asymmetric across the jets from HH 212 suggesting a more complex interpretation is warranted. Furthermore, observations for HH 212 and HH 111-H are conducted far from the source implying external influences are more likely to confuse the intrinsic flow kinematics. These observations demonstrate the difficulty of conducting this study from the ground, and highlight the necessity for high angular resolution via adaptive optics or space-based facilities

    Extreme ultraviolet emission lines of Ni XII in laboratory and solar spectra

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    Wavelengths for emission lines arising from 3s23p5-3s3p6 and 3s23p5-3s23p43d transitions in Ni XII have been measured in extreme ultraviolet spectra of the Joint European Torus(JET) tokamak. The 3s23p5 2P1/2-3s23p4(3P)3d 2D3/2 line is found to lie at 152.90 ± 0.02 A, a significant improvement over the previous experimental determination of 152.95 ± 0.5 A. This new wavelength is in good agreement with a solar identification at 152.84 ± 0.06 A, confirming the presence of this line in the solar spectrum. The Ni XII feature at 152.15 A may be a result only of the 3s23p5 2P3/2-3s23p4(3P)3d 2D5/2 transition, rather than a blend of this line with 3s23p5 2P3/2-3s23p (3P)3d 2P1/2, as previously suggested. Unidentified emission lines at 295.32 and 317.61 A in solar flare spectra from the Skylab mission are tentatively identified as the 3s23p5 2P3/2-3s3p6 2S1/2 and 3s23p5 2P1/2-3s3p6 2S1/2 transitions in Ni XII, which have laboratory wavelengths of 295.33 and 317.50 A, respectively. Additional support for these identifications is provided by the line intensity ratio for the solar features, which shows good agreement between theory and observation

    Mechanisms of superconductivity investigated by nuclear radiation

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    Investigation focused on the behavior of superconducting magnet and its constituent materials during and after exposure to nuclear radiation. The results will indicate the feasibility of their use in diverse applications and various environments

    Thermally activated escape rates of uniaxial spin systems with transverse field

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    Classical escape rates of uniaxial spin systems are characterized by a prefactor differing from and much smaller than that of the particle problem, since the maximum of the spin energy is attained everywhere on the line of constant latitude: theta=const, 0 =< phi =< 2*pi. If a transverse field is applied, a saddle point of the energy is formed, and high, moderate, and low damping regimes (similar to those for particles) appear. Here we present the first analytical and numerical study of crossovers between the uniaxial and other regimes for spin systems. It is shown that there is one HD-Uniaxial crossover, whereas at low damping the uniaxial and LD regimes are separated by two crossovers.Comment: 4 PR pages, 3 figures, final published versio

    Some General Aspects of the Gadsden Treaty

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    Institutional Factors Affecting Candidate Performance on the CPA Exam

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    This study examines whether the existence and type of an academic institution’s accreditation and Beta Alpha Psi honor society chapter affect the performance of candidates from those institutions on the Uniform CPA exam. There are three accreditations this study will examine: Association to Advance Collegiate Schools of Business (AACSB), Accreditation Council for Business Schools and Programs (ACBSP), and International Assembly for Collegiate Business Education (IACBE). This paper reviews the processes to obtain these accreditations and whether certain accreditations are associated with candidate success on the CPA exam. It also studies whether Beta Alpha Psi chapters have had an impact on candidate scores over the years; and if the type of chapter (eligible to have a chapter but does not, non-award seeking chapter, award seeking chapter) plays a significant role. Across a five-year period (2015-2019), results indicate that students from AACSB accredited institutions consistently outperform students from institutions with some other type of accreditation (ACBSP or IACBE). In 2015 and 2017, there was a significant difference between students from accredited institutions and students from academic institutions with no accreditation in which students from accredited institutions performed better. In 2016, 2018, and 2019, there were no significant differences. In addition, students from academic institutions with a Beta Alpha Psi chapter performed better across all five years than students from institutions without a Beta Alpha Psi chapter
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