2,814 research outputs found

    Geothermal ORC Systems Using Large Screw Expanders

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    Geothermal ORC Systems using Large Screw Expanders Tim Biederman Cyrq Energy [email protected] Abstract This paper describes a low-temperature Organic Rankine Cycle Power Recovery system with a screw expander a derivative of developed of Kaishan\u27s line of screw compressors, as its power unit. The screw expander design is a modified version of its existing refrigeration compressor used on water-cooled chillers. Starting the ORC development program with existing refrigeration screw compressor hardware has resulted in reduced development time and lower development cost. Lower equipment cost has been realized by assembling the screw expanders in parallel with the higher volume screw compressors. The net electrical output power of the Kaishan ORC screw expander varies from 5kW to 950 kWel which is an order of magnitude larger than the output power of currently available ORC screw expanders. A 300 kWel unit, using R245fa as its working fluid, has been installed and commissioned at Chena Hot Springs near Fairbanks, AK and 4 950 kWel units using R245fa have been started at Lightning Dock in New Mexico. Initial operating experience with these ORC systems will be presented. The paper will conclude with a comparison between screw and turbine driven ORC systems for low temperature waste heat power recovery

    Fear information and the development of fears during childhood: effects on implicit fear responses and behavioural avoidance

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    Field, Argyris and Knowles (Behav Res Ther 39 (2001) 1259), and Field, Hamilton, Knowles and Plews (Behav Res Thera 41 (2003) 113) have developed a prospective paradigm for testing Rachman’s (Behav Res Ther 15 (1977) 375) proposition that fear information is important in the development of fears and phobias in children. Despite this paradigm being an advance on retrospective reports, the research so far has been restricted to self-reported fear beliefs measured after the information is given. This gives rise to two possible shortcomings: (1) the effects could simply reflect demand characteristics resulting from children conforming to the experimental demands, and (2) although fear information changes beliefs, this might not translate into the behavioural change that would be expected if this information has a powerful effect relevant to the development of pathological fear. This paper describes an experiment that attempts to address these concerns by improving Field et al.’s (2001, 2003) basic paradigm but with the addition of two measures: (1) a behavioural measure of avoidance, and (2) an implicit attitude task that should not be susceptible to deliberate attempts to conform to experimental demands. The result showed that negative and positive information have dramatic, and opposite, effects on self-reported fear beliefs, behavioural avoidance and implicit attitudes. There were no effects of gender on any of these results. This study fully supports Rachman’s model and suggests that past work does not merely reflect demand characteristics and that fear information increases behavioural avoidance as well as fear beliefs

    Plasma deposition of constrained layer damping coatings

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    Plasma techniques are used to generate constrained layer damping (CLD) coatings on metallic substrates. The process involves the deposition of relatively thick, hard ceramic layers on to soft polymeric damping materials while maintaining the integrity of both layers. Reactive plasma sputter-deposition from an aluminium alloy target is used to deposit alumina layers, with Young's modulus in the range 77-220GPa and thickness up to 335 μ, on top of a silicone film. This methodology is also used to deposit a 40 μ alumina layer on a conventional viscoelastic damping film to produce an integral damping coating. Plasma CLD systems are shown to give at least 50 per cent more damping than equivalent metal-foil-based treatments. Numerical methods for rapid prediction of the performance of such coatings are discussed and validated by comparison with experimental results

    Airspace Technology Demonstration 3 (ATD-3): Dynamic Routes for Arrivals in Weather (DRAW) Technology Transfer Document Summary Version 1.0

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    Airspace Technology Demonstration 3 (ATD-3) is part of NASAs Airspace Operations and Safety Program (AOSP) specifically, its Airspace Technology Demonstrations (ATD) Project. ATD-3 is a multi-year research and development effort which proposes to develop and demonstrate automation technologies and operating concepts that enable air navigation service providers and airspace users to continuously assess weather, winds, traffic, and other information to identify, evaluate, and implement workable opportunities for flight plan route corrections that can result in significant flight time and fuel savings in en route airspace. In order to ensure that the products of this tech-transfer are relevant and useful, NASA has created strong partnerships with the FAA and key industry stakeholders. This summary document and accompanying technology artifacts satisfy the third of three Research Transition Products (RTPs) defined in the Applied Traffic Flow Management (ATFM) Research Transition Team (RTT) Plan. This transfer consists of NASAs Dynamic Routes for Arrivals in Weather (DRAW) Arrival Metering Operations. This research enables continued use of arrival metering operations while efficiently rerouting traffic in weathe

    ADHD: Is There an App for That? A Suitability Assessment of Apps for the Parents of Children and Young People With ADHD

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    BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is a highly comorbid disorder that can impact significantly on the individual and their family. ADHD is managed via pharmacological and nonpharmacological interventions. Parents also gain support from parent support groups, which may include chat rooms, as well as face-to-face meetings. With the growth of technology use over recent years, parents have access to more resources that ever before. A number of mobile apps have been developed to help parents manage ADHD in their children and young people. Unfortunately many of these apps are not evidence-based, and little is known of their suitability for the parents or whether they are helpful in ADHD management. OBJECTIVE: The aim of this study was to explore the (1) parents' views of the suitability of the top ten listed apps for parents of children and young people with ADHD and (2) the views of clinicians that work with them on the suitability and value of the apps. METHODS: The top 10 listed apps specifically targeted toward the parents of children and young people with ADHD were identified via the Google Play (n=5) and iTunes store (n=5). Interviews were then undertaken with 7 parents of children or young people with ADHD and 6 clinicians who specialize in working with this population to explore their opinions of the 10 apps identified and what they believe the key components are for apps to be suitable and valuable for this population. RESULTS: Four themes emerged from clinician and parent interviews: (1) the importance of relating to the app, (2) apps that address ADHD-related difficulties, (3) how the apps can affect family relationships, and (4) apps as an educational tool. Two additional themes emerged from the clinician interviews alone: monitoring ADHD symptoms and that apps should be practical. Parents also identified an additional theme: the importance of the technology. Overall, the characteristics of the current top 10 listed apps did not appear to match well to the views of our sample. CONCLUSIONS: Findings suggest that these apps may not fully meet the complex needs of this parent population. Further research is required to explore the value of apps with this population and how they can be tailored to their very specific needs
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