1,239 research outputs found

    Near Infrared Radiation as a Rapid Heating Technique for TiO2Films on Glass Mounted Dye-Sensitized Solar Cells

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    Near infrared radiation (NIR) has been used to enable the sintering of TiO2 films on fluorine-doped tin oxide (FTO) glass in 12.5 s. The 9 µm thick TiO2 films were constructed into working electrodes for dye-sensitized solar cells (DSCs) achieving similar photovoltaic performance to TiO2 films prepared by heating for 30 min in a convection oven. The ability of the FTO glass to heat upon 12.5 s exposure of NIR radiation was measured using an IR camera and demonstrated a peak temperature of 680°C; glass without the 600 nm FTO layer reached 350°C under identical conditions. In a typical DSC heating step, a TiO2 based paste is heated until the polymeric binder is removed leaving a mesoporous film. The weight loss associated with this step, as measured using thermogravimetric analysis, has been used to assess the efficacy of the FTO glass to heat sufficiently. Heat induced interparticle connectivity in the TiO2 film has also been assessed using optoelectronic transient measurements that can identify electron lifetime through the TiO2 film. An NIR treated device produced in 12.5 seconds shows comparable binder removal, electron lifetime, and efficiency to a device manufactured over 30 minutes in a conventional oven

    A Transparent Conductive Adhesive Laminate Electrode for High-Efficiency Organic-Inorganic Lead Halide Perovskite Solar Cells

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    A self-adhesive laminate solar-cell electrode is presented based on a metal grid embedded in a polymer film (x–y conduction) and set in contact with the active layer using a pressure-sensitive adhesive containing a very low quantity (1.8%) of organic conductor, which self-organizes to provide z conduction to the grid. This ITO-free material performs in an identical fashion to evaporated gold in high-efficiency perovskite solar cells

    Participatory Geographic Information Systems as an Organizational Platform for the Integration of Traditional and Scientific Knowledge in Contemporary Fire and Fuels Management

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    Traditional knowledge about fire and its effects held by indigenous people, who are connected to specific landscapes, holds promise for informing contemporary fire and fuels management strategies and augmenting knowledge and information derived from western science. In practice, however, inadequate means to organize and communicate this traditional knowledge with scientists and managers can limit its consideration in decisions, requiring novel approaches to interdisciplinary and cross-cultural communication and collaboration. We propose that Participatory Geographic Information Systems (PGIS) is one platform for the assemblage and communication of traditional knowledge vital to fire and fuels management, while preserving linkages to broader cultural contexts. We provide summaries of four preliminary case studies in the Intermountain West of North America to illustrate different potential applications of a PGIS tool in this context and describe some remaining challenges. Management and Policy Implications: Participatory Geographic Information Systems (PGIS) can offer a powerful approach for enhancing current decisionmaking by allowing for the integration of traditional and scientific knowledge systems with spatial environmental data in an interactive participatory process. Integrated data sets can allow traditional and scientific knowledge experts to share, explore, manage, analyze, and interpret multidimensional data in a common spatial context to develop more informed management decisions. Such combined data sets could provide a more comprehensive assessment of fire-related ecological change than is currently used in decisionmaking and enhance inclusion of effects on local resource utility values and areas of cultural significance. The use of a PGIS interface creates opportunities for traditional knowledge holders to share information and potential prescriptions while maintaining confidentiality. Knowledge integration efforts using PGIS as an organizational tool would help to bridge the communication gap that commonly exists between scientists, managers, and traditional knowledge holders as ecosystems continue to be altered through processes of land management and climate change

    Reconciling sovereignties, reconciling peoples: Should the Canadian Charter of Rights and Freedoms apply to inherent-right Aboriginal governments?

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    Should the Canadian Charter of Rights and Freedoms apply to constrain the actions of Aboriginal governments in Canada exercising the “inherent right” of self-government? Is the Charter’s application to these governments necessary to secure the human rights of those they govern, or would it amount to a violation of aboriginal sovereignty that, in any case, would do undue violence to the cultural practices and traditions of Aboriginal communities? This article seeks to contribute to the larger debate over how to balance the rights of individuals with the rights of groups by laying out a methodical, clear-eyed analysis of the strengths and weaknesses of the major arguments found in the literature for and against the Charter’s application. I argue that while the Charter’s application to inherent-right governments would amount to a limit on Aboriginal sovereignty, this is justifiable, in light of the fact that Aboriginal sovereignty should not be construed as absolute, and given the Supreme Court of Canada’s assertion that the purpose of the Canadian Constitution’s recognition of Aboriginal rights is reconciliation. I claim that requiring that the right of Aboriginal self-government be exercised in accordance with the Charter would further the goal of reconciliation, whereas allowing the right to be exercised irrespective of the requirements of the Charter would impede it. I thus conclude that the Charter should apply to inherent-right governments, although I stress that it should be applied in a flexible manner, in recognition of the fact that the proper safeguarding of rights can occur in different ways in different cultural contexts

    Economic analysis of service and delivery interventions in health care

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    There are well-developed guidelines for economic evaluation of clearly defined clinical interventions, but no such guidelines for economic analysis of service interventions. Distinctive challenges for analysis of service interventions include diffuse effects, wider system impacts, and variability in implementation, costs and effects. Cost-effectiveness evidence is as important for service interventions as for clinical interventions. There is also an important role for wider forms of economic analysis to increase our general understanding of context, processes and behaviours in the care system. Methods exist to estimate the cost-effectiveness of service interventions before and after introduction, to measure patient and professional preferences, to reflect the value of resources used by service interventions, and to capture wider system effects, but these are not widely applied. Future priorities for economic analysis should be to produce cost-effectiveness evidence and to increase our understanding of how service interventions affect, and are affected by, the care system

    Searching for Compton-thick active galactic nuclei at z~0.1

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    Using a suite of X-ray, mid-IR and optical active galactic nuclei (AGN) luminosity indicators, we search for Compton-thick (CT) AGNs with intrinsic L_X>10^42erg/s at z~0.03-0.2, a region of parameter space which is currently poorly constrained by deep narrow-field and high-energy (E>10keV) all-sky X-ray surveys. We have used the widest XMM-Newton survey (the serendipitous source catalogue) to select a representative sub-sample (14; ~10%) of the 147 X-ray undetected candidate CT AGNs in the Sloan Digital Sky Survey (SDSS) with f_X/f_[OIII]<1; the 147 sources account for ~50% of the overall Type-2 AGN population in the SDSS-XMM overlap region. We use mid-IR spectral decomposition analyses and emission-line diagnostics, determined from pointed Spitzer-IRS spectroscopic observations of these candidate CT AGNs, to estimate the intrinsic AGN emission (predicted L_X,2-10keV (0.2-30)x10^42erg/s). On the basis of the optical [OIII], mid-IR [OIV] and 6um AGN continuum luminosities we conservatively find that the X-ray emission in at least 6/14 (>43%) of our sample appear to be obscured by CT material with N_H>1.5x10^24cm^-2. Under the reasonable assumption that our 14 AGNs are representative of the overall X-ray undetected AGN population in the SDSS-XMM parent sample, we find that >20% of the optical Type-2 AGN population are likely to be obscured by CT material. This implies a space-density of log(Phi) >-4.9Mpc^-3 for CT AGNs with L_X>10^42erg/s at z~0.1, which we suggest may be consistent with that predicted by X-ray background synthesis models. Furthermore, using the 6um continuum luminosity to infer the intrinsic AGN luminosity and the stellar velocity dispersion to estimate M_BH, we find that the most conservatively identified CT AGNs in this sample may harbour some of the most rapidly growing black holes (median M_BH~3x10^7M_o) in the nearby Universe, with a median Eddington ratio of ~0.2.Comment: 16 pages, 2 tables, 6 figures. Accepted for publication in MNRA

    Evolution of Spin Direction of Accreting Magnetic Protostars and Spin-Orbit Misalignment in Exoplanetary Systems

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    Recent observations have shown that in many exoplanetary systems the spin axis of the parent star is misaligned with the planet's orbital axis. These have been used to argue against the scenario that short-period planets migrated to their present-day locations due to tidal interactions with their natal discs. However, this interpretation is based on the assumption that the spins of young stars are parallel to the rotation axes of protostellar discs around them. We show that the interaction between a magnetic star and its circumstellar disc can (but not always) have the effect of pushing the stellar spin axis away from the disc angular momentum axis toward the perpendicular state and even the retrograde state. Planets formed in the disc may therefore have their orbital axes misaligned with the stellar spin axis, even before any additional planet-planet scatterings or Kozai interactions take place. In general, magnetosphere--disc interactions lead to a broad distribution of the spin--orbit angles, with some systems aligned and other systems misaligned.Comment: 10 pages, 5 figures. Comments/clarifications and a new figure (Fig.3) are added. To be published in MNRA

    Translational neurophysiology in sheep:Measuring sleep and neurological dysfunction in CLN5 affected Batten disease sheep

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    This is the final published version of a paper originally published in BRAIN 2015: 138; 862?874, DOI: http://dx.doi.org/10.1093/brain/awv026Creating valid mouse models of slowly progressing human neurological diseases is challenging, not least because the short lifespan of rodents confounds realistic modelling of disease time course. With their large brains and long lives, sheep offer significant advantages for translational studies of human disease. Here we used normal and CLN5 Batten disease affected sheep to demonstrate the use of the species for studying neurological function in a model of human disease. We show that electroencephalography can be used in sheep, and that longitudinal recordings spanning many months are possible. This is the first time such an electroencephalography study has been performed in sheep. We characterized sleep in sheep, quantifying characteristic vigilance states and neurophysiological hallmarks such as sleep spindles. Mild sleep abnormalities and abnormal epileptiform waveforms were found in the electroencephalographies of Batten disease affected sheep. These abnormalities resemble the epileptiform activity seen in children with Batten disease and demonstrate the translational relevance of both the technique and the model. Given that both spontaneous and engineered sheep models of human neurodegenerative diseases already exist, sheep constitute a powerful species in which longitudinal in vivo studies can be conducted. This will advance our understanding of normal brain function and improve our capacity for translational research into neurological disorders.This work was funded by CHDI Inc. (AJM). Founding the\ud sheep flock, and costs in NZ relating to the rearing and\ud genotyping of the animals were funded by a series of grants\ud from the Neurological Foundation of NZ and the Batten\ud Disease Support and Research Association (DNP, NLM)
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