4,704 research outputs found

    Empowerment in the Public Sector: Testing the Influence of Goal Orientation

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    Empowerment has emerged as an important new issue in the public sector organization setting in the wake of mainstream new public management (NPM). Nevertheless, few studies in this frame have combined structural (managerial) and psychological (individual) approaches in an integrative study of empowerment. There is also a need to examine the moderating variables involved in this relationship, as well as to extend research on work motivation in public management. This study explores the effect of structural empowerment on psychological empowerment, and it also draws on goal orientation (GO) theory to examine the moderating role of employees’ GO in this link. The model is tested on a sample of 521 Spanish local authority employees. The results do not confirm the direct link between structural and psychological empowerment, but show that learning GO has considerable moderating power in this relationship, and its interaction with structural empowerment affects employees’ psychological empowerment levels

    Thermal contact resistance in a non-ideal joint

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    The contact conductance at an interface can be determined by knowing the material and surface properties and the interfacial pressure distribution. This pressure distribution can be influenced strongly by the roughness of the mating surfaces but until now this effect has been ignored in studies of joint conductance. This thesis considers this effect and shows the circumstances when it is an important factor. Furthermore, it is shown that one can either raise or lower the total resistance of a joint by changing the surface properties in the proper manner for the particular system being considered. Specifically, this thesis deals with three systems: the contact of two rough, wavy surfaces; the contact of two rough but nominally flat plates pressed together over a concentrated area; and the contact of two rough but nominally flat plates bolted together. In each case the pressure distribution is calculated as a function of the surface properties. In the case of wavy surfaces it is found that all necessary information for any combination of parameters can be reduced to one master graph. In the other two cases one such graph is needed for each geometry used. The resulting pressure distributions are used in a specific heat transfer example and the total joint resistance versus roughness is presented. It is shown how one can actually decrease the resistance by increasing the roughness - a seemingly contradictory phenomenon. Heat transfer experiments performed by Joseph Pigott qualitatively confirmed the theoretical findings.Sponsored by George C. Marshall Space Flight Center, NAS

    Examining nonlinear relationships between quality management and financial performance

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    Purpose A thorough analysis of nonlinear relationships between quality management (QM) and organizational outcomes has largely been ignored in the current empirical QM literature, which can have profound theoretical and managerial implications. The existence of nonlinear relationships implies taking a contingent view in that QM practices are more effective depending on their level of implementation in an organization. The purpose of this paper is to focus on this possibility and undertake an in-depth study of the sparse nonlinear relationship suggested by the literature. Design/methodology/approach The authors introduce an empirical study carried out on a sample of 168 service firms belonging to sectors experienced in QM and, through polynomial regression analysis, identify the nature of the relationship between QM and financial performance (return on assets). Findings The results, by showing an S-shaped curve, support a nonlinear association between these two variables. The presence of this functional form provides a satisfactory solution to the growing debate among researchers who, from a linear perspective, defend the positive effects of QM on organizational outcomes, those who find no significant effect, and still others who claim that QM has a negative effect. Originality/value The results show that in organizations with a low level of QM implementation, managers should increase investment in QM, even though this increase will not be correspondingly beneficial in the same proportion. In contrast, in organizations with a high level of QM implementation, managers are advised to reflect on undertaking projects that represent an additional investment in QM, with the aim of finding their optimal level

    Sensitivity of the electric dipole polarizability to the neutron skin thickness in 208{}^{208}Pb

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    The static dipole polarizability, αD\alpha_{\rm D}, in 208{}^{208}Pb has been recently measured with high-resolution via proton inelastic scattering at the Research Center for Nuclear Physics (RCNP). This observable is thought to be intimately connected with the neutron skin thickness, rskinr_{\rm skin}, of the same nucleus and, more fundamentally, it is believed to be associated with the density dependence of the nuclear symmetry energy. The impact of rskinr_{\rm skin} on αD\alpha_{\rm D} in 208{}^{208}Pb is investigated and discussed on the basis of a large and representative set of relativistic and non-relativistic nuclear energy density functionals (EDF).Comment: Proceedings of NSD12, Opatija, Croatia, 9-13 July 201

    Mesoscopic superpositions of Tonks-Girardeau states and the Bose-Fermi mapping

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    We study a one dimensional gas of repulsively interacting ultracold bosons trapped in a double-well potential as the atom-atom interactions are tuned from zero to infinity. We concentrate on the properties of the excited states which evolve from the so-called NOON states to the NOON Tonks-Girardeau states. The relation between the latter and the Bose-Fermi mapping limit is explored. We state under which conditions NOON Tonks-Girardeau states, which are not predicted by the Bose-Fermi mapping, will appear in the spectrum.Comment: 5 pages, 5 figure

    Surfactant effects in monodisperse magnetite nanoparticles of controlled size

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    Monodisperse magnetite Fe3O4 nanoparticles of controlled size within 6 and 20 nm in diameter were synthesized by thermal decomposition of an iron organic precursor in an organic medium. Particles were coated with oleic acid. For all samples studied, saturation magnetization Ms reaches the expected value for bulk magnetite, in contrast to results in small particle systems for which Ms is usually much smaller due to surface spin disorder. The coercive field for the 6 nm particles is also similar to that of bulk magnetite. Both results suggest that the oleic acid molecules covalently bonded to the nanoparticle surface yield a strong reduction in the surface spin disorder. However, although the saturated state may be similar, the approach to saturation is different and, in particular, the high-field differential susceptibility is one order of magnitude larger than in bulk materials. The relevance of these results in biomedical applications is discussed.Comment: 3 pages, 3 figures. Presented at JEMS 2006 (San Sebastian, Spain). Submitted to JMM

    Development and validation of the Spanish hazard perception test

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    Objective: The aim of the current study is to develop and obtain validity evidence for a Hazard Perception test suitable for the Spanish driving population. To obtain validity evidence to support the use of the test, the effect of hazardous and quasi-hazardous situations on the participants’ Hazard Prediction is analysed and the pattern of results of drivers of different driving experience: learner, novice and expert drivers and re-offender vs. non-offender drivers, is compared. Potentially hazardous situations are those that develop without involving any real hazard (i.e., the driver didn’t actually have to decelerate or make any evasive manoeuvre to avoid a potential collision). The current study analysed multiple offender drivers attending compulsory re-education programmes as a result of reaching the maximum number of penalty points on their driving licence, due to repeated violations of traffic laws. Method: A new video-based hazard perception test was developed, using a total of 20 hazardous situation videos plus 8 quasi-hazardous situation videos. They were selected from 167 recordings of natural hazards in real Spanish driving settings

    Giant Quadrupole Resonances in 208Pb, the nuclear symmetry energy and the neutron skin thickness

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    Recent improvements in the experimental determination of properties of the Isovector Giant Quadrupole Resonance (IVGQR), as demonstrated in the A=208 mass region, may be instrumental for characterizing the isovector channel of the effective nuclear interaction. We analyze properties of the IVGQR in 208Pb, using both macroscopic and microscopic approaches. The microscopic method is based on families of non-relativistic and covariant Energy Density Functionals (EDF), characterized by a systematic variation of isoscalar and isovector properties of the corresponding nuclear matter equations of state. The macroscopic approach yields an explicit dependence of the nuclear symmetry energy at some subsaturation density, for instance S(\rho=0.1 fm^{-3}), or the neutron skin thickness \Delta r_{np} of a heavy nucleus, on the excitation energies of isoscalar and isovector GQRs. Using available data it is found that S(\rho=0.1 fm{}^{-3})=23.3 +/- 0.6 MeV. Results obtained with the microscopic framework confirm the correlation of the \Delta r_{np} to the isoscalar and isovector GQR energies, as predicted by the macroscopic model. By exploiting this correlation together with the experimental values for the isoscalar and isovector GQR energies, we estimate \Delta r_{np} = 0.14 +/- 0.03 fm for 208Pb, and the slope parameter of the symmetry energy: L = 37 +/- 18 MeV

    Localized form of Fock terms in nuclear covariant density functional theory

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    In most of the successful versions of covariant density functional theory in nuclei, the Fock terms are not included explicitly, which leads to local functionals and forms the basis of their widespread applicability at present. However, it has serious consequences for the description of Gamow-Teller resonances (GTR) and spin-dipole resonances (SDR) which can only be cured by adding further phenomenological parameters. Relativistic Hartree-Fock models do not suffer from these problems. They can successfully describe the GTR and SDR as well as the isovector part of the Dirac effective mass without any additional parameters. However, they are non-local and require considerable numerical efforts. By the zero-range reduction and the Fierz transformation, a new method is proposed to take into account the Fock terms in local functionals, which retains the simplicity of conventional models and provides proper descriptions of the spin-isospin channels and the Dirac masses.Comment: 6 pages, 4 figures, Phys. Rev. C in pres
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