12,990 research outputs found

    A dialectical approach to theoretical integration in developmental-contextual identity research

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    Future advances in identity research will depend on integration across major theoretical traditions. Developmental-contextualism has established essential criteria to guide this effort, including specifying the context of identity development, its timing over the life course, and its content. This article assesses four major traditions of identity research - identify status, eudaimonic identity, sociocultural theory, and narrative identity - in light of these criteria, and describes the contribution of each tradition to the broader enterprise of developmental-contextual research. This article proposes dialectical integration of the four traditions, for the purpose of generating new questions when the tensions and contradictions among theoretical traditions are acknowledged. We provide examples from existing literature of the kinds of research that could address these questions and consider ways of addressing the validity issues involved in developmental-contextual identity research

    On the theory of resonant scattering of gamma rays by nuclei bound in crystals

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    An attempt is made in the present paper to give a physical description of the process in which a gamma quantum is resonantly scattered or absorbed by nuclei bound in a crystal structure. The discussion includes a description of the time development of these processes as well as a critical study of the limits imposed upon such a description by the laws of quantum mechanics.(1

    Self-Consistent Determination of Coupling Shifts in Broken SU(3)

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    The possibility that certain patterns of SU(3) symmetry breaking are dynamically enhanced in baryon-meson couplings is studied by bootstrap methods. For the strong couplings, a single dominant enhancement is found. It produces very large symmetry-breaking terms, transforming like an octet, as often conjectured. Experimental consequences are listed, such as a reduction of K-baryon couplings relative to π-baryon couplings which is in accord with the experimental weakness of K relative to π production in many circumstances, such as photoproduction and multi-BeV cosmic-ray collisions. For parity-violating nonleptonic couplings, a dominant octet enhancement is again found, as mentioned in a previous paper, which leads to an excellent fit with experiment. For parity-conserving nonleptonic couplings, on the other hand, several different enhancements compete, and the only conclusion we can draw is that terms with the "abnormal" transformation properties brought in by strong symmetry-breaking corrections are present. Our work provides a dynamical derivation of various phenomenological facts associated with SU(6), such as the dominance of the 35 representation in parity-violating nonleptonic decays

    The swept angle retarding mass spectrometer: Initial results from the Michigan auroral probe sounding rocket

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    Data from a sounding rocket flight of the swept angle retarding ion mass spectrometer (SARIMS) are presented to demonstrate the capability of the instrument to make measurements of thermal ions which are differential in angle, energy, and mass. The SARIMS was flown on the Michigan auroral probe over regions characterized first by discrete auroral arcs and later by diffuse precipitation. The instrument measured the temperature, densities, and flow velocities of the ions NO(+) and O(+). Measured NO(+) densities ranged from 10 to the 5th power up to 3 x 10 to the 5th power ions/cu cm, while the measured O(+) densities were a factor of 5-10 less. Ion temperatures ranged from 0.15 up to 0.33 eV. Eastward ion flows approximately 0.5 km/sec were measured near the arcs, and the observed flow magnitude decreased markedly inside the arcs

    Unsung heroes: who supports social work students on placement?

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    Since the introduction of the three year degree programme in 2003, social work education has undergone a number of significant changes. The time students spend on placement has been increased to two hundred days, and the range of placement opportunities and the way in which these placements have been configured has significantly diversified. A consistent feature over the years, however, has been the presence of a Practice Educator (PE) who has guided, assessed and taught the student whilst on placement. Unsurprisingly, the role of the PE and the pivotal relationship they have with the student has been explored in the past and features in social work literature. This paper, however, concentrates on a range of other relationships which are of significance in providing support to students on placement. In particular it draws on research to discuss the role of the university contact tutor, the place of the wider team in which the student is sited, and the support offered by family, friends and others. Placements and the work undertaken by PE’s will continue to be integral to the delivery of social work education. It is, however, essential to recognise and value the often over looked role of others in providing support to students on placement

    Electrometer system measures nanoamps at high voltage

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    Floating electrometer eliminates major source of error since any leakage from electrometer case, which is at high voltage, appears only as load on high voltage supply and not as part of current being measured. Commands to and data from floating electrometer are transferred across high voltage interface by means of optical channels

    Communications technology satellite output-tube design and development

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    The design and development of a 200-watt-output, traveling-wave tube (TWT) for the Communications Technology Satellite (CTS) is discussed, with emphasis on the design evolution during the manufacturing phase of the development program. Possible further improvements to the tube design are identified

    Anisotropic Distribution of SDSS Satellite Galaxies: Planar (not Polar) Alignment

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    The distribution of satellite galaxies relative to isolated host galaxies in the Sloan Digital Sky Survey (SDSS) is investigated. Host-satellite systems are selected using three different methods, yielding samples of ~3300, ~1600, and \~950 satellites. In the plane of the sky, the distributions of all three samples show highly significant deviations from circular symmetry (> 99.99%, > 99.99%, and 99.79% confidence levels, respectively), and the degree of anisotropy is a strong function of the projected radius, r_p, at which the satellites are found. For r_p < 100 kpc, the SDSS satellites are aligned preferentially with the major axes of the hosts. This is in stark contrast to the Holmberg effect, in which satellites are aligned with the minor axes of host galaxies. The degree of anisotropy in the distribution of the SDSS satellites decreases with r_p and is consistent with an isotropic distribution at of order the 1-sigma level for 250 kpc < r_p < 500 kpc.Comment: ApJ Letters (in press); Discussion section substantially revised, SDSS DR3 included in the analysis, no significant changes to the result

    Mapping the sensitivity of split ring resonators using a localized analyte

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    Split ring resonator (SRR) based metamaterials have frequently been demonstrated for use as optical sensors of organic materials. This is made possible by matching the wavelength of the SRR plasmonic resonance with a molecular resonance of a specific analyte, which is usually placed on top of the metal structure. However, systematic studies of SRRs that identify the regions that exhibit a high electric field strength are commonly performed using simulations. In this paper we demonstrate that areas of high electric field strength, termed “hot-spots,” can be found by localizing a small quantity of organic analyte at various positions on or near the structure. Furthermore, the sensitivity of the SRR to the localized analyte can be quantified to determine, experimentally, suitable regions for optical sensing

    Economic benefits of Mt. Cook National Park

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    Market and non-market valued decisions are associated with New Zealand's system of national parks. The use benefits of Mount Cook National Park are not priced by the market mechanism, whereas many of the inputs necessary to operate and maintain the Park are priced. Estimates of the economic benefits are relevant information when deciding upon the allocation of resources to, and within, a system of national parks. In 1984, the consumers' surplus for adult New Zealand visitors was about 2.2million.AnestimateofthenetnationalbenefitsisgivenbytheconsumerssurplusobtainedbyNewZealandvisitors,plusthenetbenefitsassociatedwithforeignvisitors,lessthecostofParkmanagementandlandrental.ThenetbenefitofMountCookNationalPark,asitwasin1984,islikelytobepositive,indicatingthatthebenefitsassociatedwiththecurrentusepatternofresourcesexceedstheiropportunitycosttothenation.However,thisresultcannotbeusedtoestablishtheoptimalityofcurrentexpenditureandmanagement.Approximately170,000adultsvisitedMountCookNationalParkover1984;292.2 million. An estimate of the net national benefits is given by the consumers' surplus obtained by New Zealand visitors, plus the net benefits associated with foreign visitors, less the cost of Park management and land rental. The net benefit of Mount Cook National Park, as it was in 1984, is likely to be positive, indicating that the benefits associated with the current use pattern of resources exceeds their opportunity cost to the nation. However, this result cannot be used to establish the optimality of current expenditure and management. Approximately 170,000 adults visited Mount Cook National Park over 1984; 29% were from New Zealand, 25% were from Australia, 18% were from the United States, and 7% were from Japan. Visitors to the Park spend money in towns and villages in the Mackenzie Basin area. Average adult visitor expenditure in the Mackenzie Basin area is 58. These expenditures give rise to secondary economic benefits and create opportunities for regional development. Visitor expenditures in the Mackenzie Basin area are associated with 13.4millionofadditionalregionaloutput,13.4 million of additional regional output, 6.8 million of additional regional income, and 196 jobs. These effects derive their significance from regional objectives; they are not indicators of the national benefits associated with Mount Cook National Park
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