491 research outputs found

    The PRS approach and the Paris agenda: Experiences in Bolivia, Honduras and Nicaragua

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    Abstract The Paris Declaration on aid effectiveness stipulates that broadly owned and results oriented national plans will be the basis for establishing national ownership and leadership of the aid process and for improving alignment and harmonization. In this sense, there is a close link between the Poverty Reduction Strategy approach and the Paris Agenda, both of which form part of the new aid paradigm that started around the year 2000. This paper assesses the actual progress in the implementation of the new aid paradigm in three Latin American countries: Bolivia, Honduras and Nicaragua. The results are disappointing. Frequent government changes and the composition of the donor group in the countries are partially responsible for the disappointing results, but the main conclusion is that the new aid paradigm is based on unrealistic expectations about the role that national poverty reduction or development plans can play in promoting the principles of the Paris Agenda

    In-Situ Investigation of Gas Phase Radical Chemistry in the Catalytic Partial Oxidation of Methane on Pt

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    The catalytic partial oxidation of methane on platinum was studied in situ under atmospheric pressure and temperatures between 1000 and 1300 °C. By combining radical measurements using a molecular beam mass spectrometer and threshold ionization with GC, GC-MS and temperature profile measurements it was demonstrated that a homogeneous reaction pathway is opened at temperatures above 1100 °C, in parallel to hetero-geneous reactions which start already at 600 °C. Before ignition of gas phase chemistry, only CO, H2, CO2 and H2O are formed at the catalyst surface. Upon ignition of gas chemistry, CH3⋅ radicals, C2 coupling products and traces of C3 and C4 hydrocarbons are observed. Because the formation of CH3⋅ radicals correlates with the formation of C2 products it can be concluded that C2 products are formed by coupling of methyl radicals in the gas phase followed by dehydrogenation reactions. This formation pathway was predicted by numerical simulations and this work presents an experimental confirmation under high temperature atmospheric pressure conditions

    Heterogeneous–Homogeneous Catalytic Partial Oxidations Investigated by Molecular Beam Mass Spectrometry

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    Heterogeneous catalytic reactions are often insufficiently described by surface reaction steps only; gas phase contributions are neglected. Surface and gas phase reaction steps can take place simultaneously and are coupled by exchange of energy and reaction intermediates. Catalytic partial oxidations are suspected to proceed via combined heterogeneous–homogeneous mechanisms because of high reaction temperatures and the diradical oxygen as reactant. Gas phase radicals are thought to be key intermediates, but there is little understanding of mechanistic details [1]. To study the mechanism of such reactions we have developed a Molecular Beam Mass Spectrometer (MBMS) equipped with a high temperature catalytic wall reactor

    Platinum Group Metal-Doped Tungsten Phosphates for Selective C-H Activation of Lower Alkanes

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    Platinum group metal (PGM)-based catalysts are known to be highly active in the total combustion of lower hydrocarbons. However, through an alternative catalyst design reported in this paper by isolating PGM-based active sites in a tungsten phosphate matrix, we present a class of catalysts for selective oxidation of n-butane, propane, and propylene that do not contain Mo or V as redox-active elements. Two different catalyst concepts have been pursued. Concept A: isolating Ru-based active sites in a tungsten phosphate matrix coming upon as ReO3-type structure. Concept B: dilution of PGM-based active sites through the synthesis of X-ray amorphous Ru tungsten phosphates supported on SiO2. Using a high-throughput screening approach, model catalysts over a wide compositional range were evaluated for C3 and C4 partial oxidation. Bulk crystalline and supported XRD amorphous phases with similar Ru/W/P compositions showed comparable performance. Hence, for these materials, composition is more crucial than the degree of crystallinity. Further studies for optimization on second-generation supported systems revealed even better results. High selectivity for n-butane oxidation to maleic anhydride and propane oxidation to an acrolein/acrylic acid has been achieved

    The H1 Forward Proton Spectrometer at HERA

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    The forward proton spectrometer is part of the H1 detector at the HERA collider. Protons with energies above 500 GeV and polar angles below 1 mrad can be detected by this spectrometer. The main detector components are scintillating fiber detectors read out by position-sensitive photo-multipliers. These detectors are housed in so-called Roman Pots which allow them to be moved close to the circulating proton beam. Four Roman Pot stations are located at distances between 60 m and 90 m from the interaction point.Comment: 20 pages, 10 figures, submitted to Nucl.Instr.and Method

    Wii-Fit for Improving Gait and Balance in an Assisted Living Facility: A Pilot Study

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    Objectives. To determine the effects on balance and gait of a Wii-Fit program compared to a walking program in subjects with mild Alzheimer's dementia (AD). Methods. A prospective randomized (1 : 1) pilot study with two intervention arms was conducted in an assisted living facility with twenty-two mild AD subjects. In both groups the intervention occurred under supervision for 30 minutes daily, five times a week for eight weeks. Repeated measures ANOVA and paired t-tests were used to analyze changes. Results. Both groups showed improvement in Berg Balance Scale (BBS), Tinetti Test (TT) and Timed Up and Go (TUG) over 8 weeks. However, there was no statistically significant difference between the groups over time. Intragroup analysis in the Wii-Fit group showed significant improvement on BBS (P = 0.003), and TT (P = 0.013). The walking group showed a trend towards improvement on BBS (P = 0.06) and TUG (P = 0.07) and significant improvement in TT (P = 0.06). Conclusion. This pilot study demonstrates the safety and efficacy of Wii-Fit in an assisted living facility in subjects with mild AD. Use of Wii-Fit resulted in significant improvements in balance and gait comparable to those in the robust monitored walking program. These results need to be confirmed in a larger, methodologically sound study

    Meaningful time for professional growth or a waste of time? A study in five countries on teachers’ experiences within master’s dissertation/thesis work

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    The relationship between master’s thesis work and teachers’ professional development has rarely been explored empirically, yet. Drawing upon a larger study, this paper investigates how teachers who were studying for or who have recently graduated from Master of Education programmes offered in five countries – Poland, Portugal, England, Latvia, Romania – perceive the usefulness of dissertation/thesis work for their professional development and how they attempt to use their MA research results in their (future) teaching practice. Results suggest that although most respondents recognized their MA dissertation/thesis work as having a positive impact on their professional development by enhancing their professionalism, personal development and growth, and understanding the relationship between research and practice, they were less confident about the use of MA research findings in their (future) workplaces. These results are discussed in the context of current challenges regarding master’s level education for teachers, national governments’ educational policies, and the relationship between research, teachers’ practices and professional development
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