2,193 research outputs found

    Comparison of dimethyl sulfoxide treated highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) electrodes for use in indium tin oxide-free organic electronic photovoltaic devices

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    Indium tin oxide (ITO)-free organic photovoltaic (OPV) devices were fabricated using highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the transparent conductive electrode (TCE). The intrinsic conductivity of the PEDOT:PSS films was improved by two different dimethyl sulfoxide (DMSO) treatments – (i) DMSO was added directly to the PEDOT:PSS solution (PEDOT:PSSADD) and (ii) a pre-formed PEDOT:PSS film was immersed in DMSO (PEDOT:PSSIMM). X-ray photoelectron spectroscopy (XPS) and conductive atomic force microscopy (CAFM) studies showed a large amount of PSS was removed from the PEDOT:PSSIMM electrode surface. OPV devices based on a poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) bulk hetrojunction showed that the PEDOT:PSSIMM electrode out-performed the PEDOT:PSSADD electrode, primarily due to an increase in short circuit current density from 6.62 mA cm−2 to 7.15 mA cm−2. The results highlight the importance of optimising the treatment of PEDOT:PSS electrodes and demonstrate their potential as an alternative TCE for rapid processing and low-cost OPV and other organic electronic devices

    Hobson’s choice? Constraints on accessing spaces of creative production

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    Successful creative production is often documented to occur in urban areas that are more likely to be diverse, a source of human capital and the site of dense interactions. These accounts chart how, historically, creative industries have clustered in areas where space was once cheap in the city centre fringe and inner city areas, often leading to the development of a creative milieu, and thereby stimulating further creative production. Historical accounts of the development of creative areas demonstrate the crucial role of accessible low-cost business premises. This article reports on the findings of a case study that investigated the location decisions of firms in selected creative industry sectors in Greater Manchester. The study found that, while creative activity remains highly concentrated in the city centre, creative space there is being squeezed and some creative production is decentralizing in order to access cheaper premises. The article argues that the location choices of creative industry firms are being constrained by the extensive city centre regeneration, with the most vulnerable firms, notably the smallest and youngest, facing a Hobson’s choice of being able to access low-cost premises only in the periphery. This disrupts the delicate balance needed to sustain production and begs the broader question as to how the creative economy fits into the existing urban fabric, alongside the competing demands placed on space within a transforming industrial conurbation

    Changing Behaviour: Successful Environmental Programmes in the Workplace

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    There is an increasing focus on improving the pro-environmental attitudes, behaviour and habits of individuals whether at home, in education, traveling, shopping or in the workplace. This article focuses on the workplace by conducting a multi-disciplinary literature review of research that has examined the influence of organisation-based behaviour change initiatives. The review includes only research evidence that measured actual environmental performance (e.g. energy use) rather than solely using self-reported methods (e.g. questionnaires). The authors develop an ‘Employee Pro-Environmental Behaviour’ (e-PEB) framework that contains individual, group, organisational and contextual factors that have predictive relevance across different behaviours and organisations. The review shows that the strongest predictors are environmental awareness, performance feedback, financial incentives, environmental infrastructure management support and training. A key finding from this review is that attitude change is not necessarily a pre-requisite for behaviour change in the workplace

    Lorenz-like systems and classical dynamical equations with memory forcing: a new point of view for singling out the origin of chaos

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    A novel view for the emergence of chaos in Lorenz-like systems is presented. For such purpose, the Lorenz problem is reformulated in a classical mechanical form and it turns out to be equivalent to the problem of a damped and forced one dimensional motion of a particle in a two-well potential, with a forcing term depending on the ``memory'' of the particle past motion. The dynamics of the original Lorenz system in the new particle phase space can then be rewritten in terms of an one-dimensional first-exit-time problem. The emergence of chaos turns out to be due to the discontinuous solutions of the transcendental equation ruling the time for the particle to cross the intermediate potential wall. The whole problem is tackled analytically deriving a piecewise linearized Lorenz-like system which preserves all the essential properties of the original model.Comment: 48 pages, 25 figure

    Amine functionalization of cholecyst-derived extracellular matrix with generation 1 PAMAM dendrimer

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    This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Biomacromolecules, copyright © American Chemical Society after peer review. To access the final edited and published work, see http://pubs.acs.org/doi/pdf/10.1021/bm701055k.A method to functionalize cholecyst-derived extracellular matrix (CEM) with free amine groups was established in an attempt to improve its potential for tethering of bioactive molecules. CEM was incorporated with Generation-1 polyamidoamine (G1 PAMAM) dendrimer by using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide and N-hydroxysuccinimide cross-linking system. The nature of incorporation of PAMAM dendrimer was evaluated using shrink temperature measurements, Fourier transform infrared (FTIR) assessment, ninhydrin assay, and swellability. The effects of PAMAM incorporation on mechanical and degradation properties of CEM were evaluated using a uniaxial mechanical test and collagenase degradation assay, respectively. Ninhydrin assay and FTIR assessment confirmed the presence of increasing free amine groups with increasing quantity of PAMAM in dendrimer-incorporated CEM (DENCEM) scaffolds. The amount of dendrimer used was found to be critical in controlling scaffold degradation, shrink temperature, and free amine content. Cell culture studies showed that fibroblasts seeded on DENCEM maintained their metabolic activity and ability to proliferate in vitro. In addition, fluorescence cell staining and scanning electron microscopy analysis of cell-seeded DENCEM showed preservation of normal fibroblast morphology and phenotype

    Different views on Digital Scholarship: separate worlds or cohesive research field?

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    This article presents a systematic review of the literature on Digital Scholarship, aimed at better understanding the collocation of this research area at the crossroad of several disciplines and strands of research. The authors analysed 45 articlesin order to draw a picture of research in this area. In the first phase, the articles were classified, and relevant quantitative and qualitative data were analysed. Results showed that three clear strands of research do exist: Digital Libraries, Networked Scholarship and Digital Humanities. Moreover, researchers involved in this research area tackle the problems related to technological uptake in the scholar's profession from different points of view, and define the field in different – often complementary – ways, thus generating the perception of a research area still in need of a unifying vision. In the second phase, authors searched for evidence of the disciplinary contributions and interdisciplinary cohesion of research carried out in this area through the use of bibliometric maps. Results suggest that the area of Digital Scholarship, still in its infancy, is advancing in a rather fragmented way, shaping itself around the above-mentioned strands, each with its own research agenda. However, results from the cross-citation analysis suggest that the Networked Scholarship strand is more cohesive than the others in terms of cross-citations

    Comparison of the solophenyl-red polarization method and the immunohistochemical analysis for collagen type III

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    In the present study, we have compared the staining pattern of the Solophenyl-Red 3 BL-method for the visualization of collagen type III with the immunohistochemical staining in serial sections from 7 skin wounds (wound age 3 days up to 4 weeks) to elucidate the specifity of the histochemical staining method. Large amounts of collagen type III were clearly detectable in the investigated wounds using the immunohistochemical technique. In the sections stained with Solophenyl-Red, however, only 3 out of 7 skin lesions showed a significant positive red staining at the wound margin or in the granulation tissue, while the adjacent normal connective tissue revealed a typical intensive staining. Using polarization microscopy no characteristic bright green fibrils, as reported for collagen type 111, could be seen in the wound areas without positive Solophenyl-Red staining. Since the localization of collagen type III detected by immunohistochemistry and the presumed distribution of this collagen type by the Solophenyl-Red method was not identical, the histochemical polarization method has to be regarded as non-specific for visualization of this collagen type
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