6,423 research outputs found

    Space Shuttle: MDAC/MMC space shuttle booster determination of stability and control characteristics and power effects at subsonic speed, Mach numbers zero and 0.26

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    Low speed wind tunnel tests of stability and control characteristics of space shuttle booster at subsonic speed

    Investigating people: a qualitative analysis of the search behaviours of open-source intelligence analysts

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    The Internet and the World Wide Web have become integral parts of the lives of many modern individuals, enabling almost instantaneous communication, sharing and broadcasting of thoughts, feelings and opinions. Much of this information is publicly facing, and as such, it can be utilised in a multitude of online investigations, ranging from employee vetting and credit checking to counter-terrorism and fraud prevention/detection. However, the search needs and behaviours of these investigators are not well documented in the literature. In order to address this gap, an in-depth qualitative study was carried out in cooperation with a leading investigation company. The research contribution is an initial identification of Open-Source Intelligence investigator search behaviours, the procedures and practices that they undertake, along with an overview of the difficulties and challenges that they encounter as part of their domain. This lays the foundation for future research in to the varied domain of Open-Source Intelligence gathering

    A survey of evidence-based practice, training, supervision and clinician confidence relating to post-traumatic stress disorder (PTSD) therapies in UK child and adolescent mental health professionals

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    Background: Post-Traumatic Stress Disorder (PTSD) in children and adolescents has received increasing recognition in recent decades. Despite development of treatments and improved dissemination efforts, research has identified a number of barriers to implementing these approaches. Objective: This study sought to understand what interventions mental health professionals working with children and adolescents utilised to treat PTSD, their training and supervision, their confidence in assessing and treating PTSD, and how these factors relate to clinicians characteristics (e.g. age, gender, professional background). Method: The study comprised an internet-delivered survey of clinicians working in child and adolescent mental health services in the UK (N = 716). Results: Many clinicians (>40%) had not received training in working with PTSD, with considerable variation between professional background. Lack of training and supervision was associated with reduced clinician confidence in treating children with PTSD (possible range 0–10; training M = 7.54, SD = 1.65, no training M = 5.49, SD = 2.29; supervision M = 7.53, SD = 1.63, no supervision M = 5.98, SD = 2.35). Evidence-based therapies for PTSD such as Trauma-Focused Cognitive-Behavioural Therapy and Eye Movement Desensitisation and Reprocessing were only endorsed modestly by clinicians (58.4% and 37.5%, respectively). Regression analyses identified that lack of training and supervision were significant barriers to the use of evidence-based interventions. Other predictors of clinician confidence and use of evidence-based interventions included profession and years of experience. Participants almost universally wanted more training in working with PTSD. Conclusions: Evidence-based treatments are not currently universally delivered by mental health professionals in the UK, with certain professions particularly lacking training and confidence with this condition. Training around trauma and PTSD may be an ongoing need to boost and maintain confidence in working with PTSD in youth

    Exact Site Percolation Thresholds Using the Site-to-Bond and Star-Triangle Transformations

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    I construct a two-dimensional lattice on which the inhomogeneous site percolation threshold is exactly calculable and use this result to find two more lattices on which the site thresholds can be determined. The primary lattice studied here, the ``martini lattice'', is a hexagonal lattice with every second site transformed into a triangle. The site threshold of this lattice is found to be 0.764826...0.764826..., while the others have 0.618034...0.618034... and 1/21/\sqrt{2}. This last solution suggests a possible approach to establishing the bound for the hexagonal site threshold, pc<1/2p_c<1/\sqrt{2}. To derive these results, I solve a correlated bond problem on the hexagonal lattice by use of the star-triangle transformation and then, by a particular choice of correlations, solve the site problem on the martini lattice.Comment: 12 pages, 10 figures. Submitted to Physical Review

    The study of thermal silicon dioxide electrets formed by corona discharge and rapid-thermal annealing

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    A silicon dioxide (SiO₂) electret passivates the surface of crystalline silicon (Si) in two ways: (i) when annealed and hydrogenated, the SiO₂–Si interface has a low density of interface states, offering few energy levels through which electrons and holes can recombine; and (ii) the electret’s quasipermanent charge repels carriers of the same polarity, preventing most from reaching the SiO₂–Si interface and thereby limiting interface recombination. In this work, we engineer a charged thermal SiO₂electret on Si by depositing corona charge onto the surface of an oxide-coated Si wafer and subjecting the wafer to a rapid thermal anneal (RTA). We show that the surface-located corona charge is redistributed deeper into the oxide by the RTA. With 80 s of charging, and an RTA at 380 °C for 60 s, we measure an electretcharge density of 5 × 10ÂčÂČ cm⁻ÂČ, above which no further benefit to surface passivation is attained. The procedure leads to a surface recombination velocity of less than 20 cm/s on 1 Ω-cm n-type Si, which is commensurate with the best passivation schemes employed on high-efficiency Si solar cells. In this paper, we introduce the method of SiO₂electret formation, analyze the relationship between charge density and interface recombination, and assess the redistribution of charge by the RTA

    The great ideas of biology: Exploration through experimentation in an undergraduate lab course

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    We developed an introductory laboratory course to provide a visceral experience that aims at getting students truly excited about scientific study of the living world. Our vehicle to do that was to focus on what Paul Nurse dubbed “the great ideas of biology” rather than an approach to biology that celebrates specific factual knowledge. To that end, we developed eight diverse experimental modules, each of which highlights a key biological concept and gives an opportunity to use theory to generate testable hypotheses, to perform high quality measurements to test those hypotheses (some of which are clearly wrong), and to perform sophisticated computational data analysis. Some modules incorporate modern microscopy and computational techniques in classic experiments, such as bacterial growth and the Luria‐DelbrĂŒck experiment, while others address current research questions using methods like optogenetics and single molecule measurements. We have offered the course eight times, and in the most recent edition of the course, we conducted pre/post‐course interviews and attitude surveys. The students, both bio and non‐bio majors alike, reported being captivated by seeing life occur across the broad range of experiments and model organisms. We observed demonstrable development of their curiosity and enthusiasm for biology. Additionally, we found that prior to the course, students had only vague notions about what it means to make quantitative biological measurements and interpret them. They completed the course with a clearer understanding of scientific inquiry in biology and the skills and confidence to actually perform and interpret measurements in living systems

    The elements of a computational infrastructure for social simulation

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    Applications of simulation modelling in social science domains are varied and increasingly widespread. The effective deployment of simulation models depends on access to diverse datasets, the use of analysis capabilities, the ability to visualize model outcomes and to capture, share and re-use simulations as evidence in research and policy-making. We describe three applications of e-social science that promote social simulation modelling, data management and visualization. An example is outlined in which the three components are brought together in a transport planning context. We discuss opportunities and benefits for the combination of these and other components into an e-infrastructure for social simulation and review recent progress towards the establishment of such an infrastructure

    The Solar Neighborhood XXV: Discovery of New Proper Motion Stars with 0.40 "/yr > mu > 0.18 "/yr between Declinations -47 degrees and 00 degrees

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    We present 2817 new southern proper motion systems with 0.40 "/yr > mu > 0.18 "/yr and declination between -47 degrees and 00 degrees. This is a continuation of the SuperCOSMOS-RECONS (SCR) proper motion searches of the southern sky. We use the same photometric relations as previous searches to provide distance estimates based on the assumption that the objects are single main sequence stars. We find 79 new red dwarf systems predicted to be within 25 pc, including a few new components of previously known systems. Two systems - SCR 1731-2452 at 9.5 pc and SCR 1746-3214 at 9.9 pc - are anticipated to be within 10 pc. We also find 23 new white dwarf candidates with distance estimates of 15-66 pc, as well as 360 new red subdwarf candidates. With this search, we complete the SCR sweep of the southern sky for stars with mu > 0.18 "/yr and R_59F < 16.5, resulting in a total of 5042 objects in 4724 previously unreported proper motion systems. Here we provide selected comprehensive lists from our SCR proper motion search to date, including 152 red dwarf systems estimated to be within 25 pc (nine within 10 pc), 46 white dwarfs (ten within 25 pc), and 598 subdwarf candidates. The results of this search suggest that there are more nearby systems to be found at fainter magnitudes and lower proper motion limits than those probed so far.Comment: 47 pages, 16 of text. 7 figure
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