64,221 research outputs found

    Design, performance, and calculated error of a Faraday cup for absolute beam current measurements of 600-MeV protons

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    A mobile self-contained Faraday cup system for beam current measurments of nominal 600 MeV protons was designed, constructed, and used at the NASA Space Radiation Effects Laboratory. The cup is of reentrant design with a length of 106.7 cm and an outside diameter of 20.32 cm. The inner diameter is 15.24 cm and the base thickness is 30.48 cm. The primary absorber is commercially available lead hermetically sealed in a 0.32-cm-thick copper jacket. Several possible systematic errors in using the cup are evaluated. The largest source of error arises from high-energy electrons which are ejected from the entrance window and enter the cup. A total systematic error of -0.83 percent is calculated to be the decrease from the true current value. From data obtained in calibrating helium-filled ion chambers with the Faraday cup, the mean energy required to produce one ion pair in helium is found to be 30.76 + or - 0.95 eV for nominal 600 MeV protons. This value agrees well, within experimental error, with reported values of 29.9 eV and 30.2 eV

    Lithium-drifted silicon detectors as low-energy photon spectrometers

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    Fabrication and testing of lithium-drifted detectors as low energy photon spectrometer

    Phase III of USO Solar Vector Magnetograph

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    The Solar Vector Magnetograph (SVM) is a modern imaging spectropolarimeter installed at Udaipur Solar Observatory (USO). Earlier phases saw the development of the instrument using off-the-shelf components with in-house software development. Subsequently, improvements were done in the opto-mechanical design of the sub-systems and the telescope tracking system. The third phase of the instrument development saw three major improvements, these include: (i) installation of a web-camera based telescope guiding system, developed in-house, (ii) high-cadence spectropolarimetry using Liquid Crystal Variable Retarders and a fast CCD camera and (iii)inclusion of Na D1 line with regular photospheric Fe 630.2 nm line for chromospheric observations.Comment: 3 pages, 1 table; To appear in the Proceedings of Evershed Meeting, IIA, Bangalor

    Does the UK Local Finance Improvement Trust (Lift)Initiative Improve Risk Management in Public-Private Procurement?

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    The UK government introduced the Private Finance Initiative (PFI) and, latterly, the Local Improvement Finance Trust (LIFT) in an attempt to improve public service provision. As a variant of PFI, LIFT seeks to create a framework for the effective provision of primary care facilities. Like conventional PFI procurement, LIFT projects involve long-term contracts, complex multi-party interactions and thus create various risks to public sector clients. This paper investigates the advantages and disadvantages of LIFT with a focus on how this approach facilitates or impedes risk management from the public sector client perspective. Our paper concludes that LIFT has a potential for creating additional problems, including the further reduction of public sector control, conflicts of interest, the inappropriate use of enabling funds, and higher than market rental costs affecting the uptake of space in the buildings by local health care providers. However, there is also evidence that LIFT has facilitated new investment and that Primary Care Trusts (PCTs) have themselves started addressing some of the weaknesses of this procurement format through the bundling of projects and other forms of regional co-operation

    A new Miconia (Melastomatacaeae) from Bolivia, with remarks on angular-branched species in the Andes

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    A new species of Melastomataceae frorm Bolivia is described, illustrated and placed in a phenetic context within Miconia, a genus of 1000 species and about 2000 published names. Miconia quadrialata is readily distinguished from its Congeners by two-colored leaves and sharply four-angular and winged branchlets. A search for quadrangular-branched miconias revealed that 12 of 15 such species (in four sections), including the new species, occur in cloud forest in the Andes, raising the question of the adaptive significance of quadrangular branchlets

    The limits of market-based governance and accountability - PFI refinancing and the resurgence of the regulatory state

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    The refinancing of PFI (Private Finance Initiative) projects currently represents one of the most contentious aspects of Public Private Partnership in the UK. The negative publicity associated with UK PFI refinancing deals is associated with two main factors, namely evidence of massive private sector profit making in connection with past refinancing deals, and the ‘failure’ of private sector financiers to share refinancing profits with public sector organisations in line with government recommendations. This paper examines the ongoing ‘dance of non-regulation’ associated with PFI refinancing on the basis of traditional Marxist notions of ‘contradictions of capitalism’. Our analysis commences with the argument that PFI represents a prototypical case of an alliance between finance capital and the state, which has been created with the principal purpose of establishing a new source of profits for the private sector. A Marxist analysis of state-business relationships would predict such an alliance to show tendencies towards instability which could arise from a number of factors. These include, among others, the inherent lack of legitimacy of such an alliance vis a vis established policy goals and the stakeholders associated with them; a lack of a credible regulatory framework which, as a systemic prerequisite of private sector profit making, further exacerbates existing problems of legitimation; and, perhaps most importantly, the potentially self-defeating attempt by capital to maximise gains from the exploitation of the existing alliance without concern for the possibility of a political or regulatory backlash. Examining the recent history of PFI refinancing we find evidence of most of these destabilising tendencies which we expect to trigger calls for a greater regulation of PFI projects in the future

    The limits of market-based governance and accountability - PFI refinancing and the resurgence of the regulatory state

    Get PDF
    The refinancing of PFI (Private Finance Initiative) projects currently represents one of the most contentious aspects of Public Private Partnership in the UK. The negative publicity associated with UK PFI refinancing deals is associated with two main factors, namely evidence of massive private sector profit making in connection with past refinancing deals, and the ‘failure’ of private sector financiers to share refinancing profits with public sector organisations in line with government recommendations. This paper examines the ongoing ‘dance of non-regulation’ associated with PFI refinancing on the basis of traditional Marxist notions of ‘contradictions of capitalism’. Our analysis commences with the argument that PFI represents a prototypical case of an alliance between finance capital and the state, which has been created with the principal purpose of establishing a new source of profits for the private sector. A Marxist analysis of state-business relationships would predict such an alliance to show tendencies towards instability which could arise from a number of factors. These include, among others, the inherent lack of legitimacy of such an alliance vis a vis established policy goals and the stakeholders associated with them; a lack of a credible regulatory framework which, as a systemic prerequisite of private sector profit making, further exacerbates existing problems of legitimation; and, perhaps most importantly, the potentially self-defeating attempt by capital to maximise gains from the exploitation of the existing alliance without concern for the possibility of a political or regulatory backlash. Examining the recent history of PFI refinancing we find evidence of most of these destabilising tendencies which we expect to trigger calls for a greater regulation of PFI projects in the future

    Generation of Magnetic Field in the Pre-recombination Era

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    We study the possibility of generating magnetic fields during the evolution of electron, proton, and photon plasma in the pre-recombination era. We show that a small magnetic field can be generated in the second order of perturbation theory for scalar modes with adiabatic initial conditions. The amplitude of the field is \la 10^{-30} \rm G at the present epoch for scales from sub-kpc to \ga 100 \rm Mpc.Comment: 8 page
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