387 research outputs found

    Field and temperature dependence of the photocurrent in polymer/fullerene bulk heterojunction solar cells

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    The photocurrent in polymer/fullerene blends is characterized as a function of bias at temperatures ranging from 125 to 300 K. Assuming a constant generation rate and bimolecular recombination, the results are numerically modeled within the drift-diffusion approximation. Bimolecular recombination is found to be a dominant factor in the field dependence of the photocurrent in the entire measured voltage range. Inclusion of field dependent geminate pair dissociation and recombination via the Onsager expressions gives a much stronger field dependence than experimentally observed. From the temperature dependence of the extracted mobilities, we can simultaneously estimate the broadening of the transporting highest occupied and lowest unoccupied molecular orbital levels. ©2005 American Institute of Physic

    Особливості планування інвестиційних проектів з відтворення виробничої потужності збиткових вуглевидобувних підприємств

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    Розкрито особливості планування інвестиційних проектів з відтворення виробничої потужності на збиткових вуглевидобувних підприємствах. Запропоновано алгоритм розрахунку ефективності інвестиційного проекту. Ключові слова: інвестиції, вугільна галузь, шахта, відтворення потужності, проект, очисний вибій, ефективність, собівартість, термін окупності, дисконтування.Раскрыты особенности планирования инвестиционных проектов по воспроизводству производственной мощности на убыточных угледобывающих предприятиях. Предложен алгоритм расчета эффективности инвестиционного проекта. Ключевые слова: инвестиции, угольная отрасль, шахта, воспроизводство мощности, проект, очистной забой, эффективность, себестоимость, срок окупаемости, дисконтирование.The planning of investment projects on reproduction of production capacity of unprofitable coal-mining enterprises is described. The algorithm for calculating the efficiency of the investment project is offered. Its economic efficiency has been proven. Keywords: investments, coal industry, mine, reproduction of capacity, project, stope, efficiency, prime price, period of recoupment, discounting

    An assessment of the Hua Oranga outcome instrument and comparison to other outcome measures in an intervention study with Maori and Pacific people following stroke

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    The Hua Oranga instrument, developed for Maori people with mental illness, showed good responsiveness and adequate psychometric properties in Maori and Pacific people after stroke. Its simplicity, relative brevity, minimal cost and adequate psychometric properties should favour its use in future studies with both Maori and Pacific people. Suggestions are made for refinements to the measure. These should be tested in a new population before Hua Oranga is recommended for general use in a clinical setting. Abstract Aim Health outcomes research for Maori has been hampered by the lack of adequately validated instruments that directly address outcomes of importance to Maori, framed by a Maori perspective of health. Hua Oranga is an outcome instrument developed for Maori with mental illness that uses a holistic view of Maori health to determine improvements in physical, mental, spiritual and family domains of health. Basic psychometric work for Hua Oranga is lacking. We sought to explore the psychometric properties of the instrument and compare its responsiveness alongside other, more established tools in an intervention study involving Maori and Pacific people following acute stroke. Method Randomised 2x2 controlled trial of Maori and Pacific people following acute stroke with two interventions aimed at facilitating self-directed rehabilitation, and with follow-up at 12 months after randomisation. Primary outcome measures were the Physical Component Summary (PCS) and Mental Component Summary (MCS) of the Short Form 36 (SF36) at 12 months. Hua Oranga was used as a secondary outcome measure for participants at 12 months and for carers and whanau (extended family). Psychometric properties of Hua Oranga were explored using plots and correlation coefficients, principal factors analysis and scree plots. Results 172 participants were randomised, of whom 139 (80.8%) completed follow-up. Of these, 135 (97%) completed the Hua Oranga and 117 (84.2%) completed the PCS and MCS of the SF36. Eighty-nine carers completed the Hua Oranga. Total Hua Oranga scores and PCS improved significantly for one intervention group but not the other. Total Hua Oranga scores for carers improved significantly for both interventions. Total Hua Oranga score correlated moderately with the PCS (correlation coefficient 0.55, p<0.001). Factor analysis suggested that Hua Oranga measures two and not four factors; one 'physical-mental' and one 'spiritual-family'. Conclusion The Hua Oranga instrument, developed for Maori people with mental illness, showed good responsiveness and adequate psychometric properties in Maori and Pacific people after stroke. Its simplicity, relative brevity, minimal cost and adequate psychometric properties should favour its use in future studies with both Maori and Pacific people. Suggestions are made for refinements to the measure. These should be tested in a new population before Hua Oranga is recommended for general use in a clinical setting

    Bromido(dodecafluorosubphthalo­cyaninato)boron(III)

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    The title compound, C24BBrF12N6 or Br-F12BsubPc (BsubPc is boronsubphtalocyanine), has a bowl-shaped structure with an approximate mol­ecular C 3v symmetry characteristic of boronsubphthalocyanine compounds. In the crystal, mol­ecules are arranged in one-dimensional columns and the boron–subphthalocyanine units within each column are offset and angled in a bowl-to-ligand packing arrangement such that the axial Br atom rests in the aromatic concaved bowl of the neighboring subphthalocyanine with an inter­molecular Br⋯B distance of 3.721 (3) Å

    (4-Nitro­phenolato)(subphthalo­cyaninato)boron(III)1

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    The main feature of the structure of the title compound, C30H16BN7O3 or NO2PhO-BsubPc, are pairs of mol­ecules linked through π-inter­actions between the concave faces of the BsubPc fragments at a distance of 3.5430 (11) Å across an inversion centre. However, the angle between the planes of the five- and six-menbered rings involved in this inter­action is 1.44 (10)°, causing the inter­acting BsubPcs units to be slightly askew rather than parallel as is typical for π-stacking inter­actions
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