374 research outputs found

    Design integration and noise studies for jet STOL aircraft. Task 7A: Augmentor wing cruise blowing valveless system. Volume 1: System design and test integration

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    Exploratory design studies conducted to establish the configuration of an augmentor wing vruise blowing (valveless) system in a 150-passenger STOL airplane were reported in NASA CR-114570. Those studies have been updated to incorporate the results of static rig, flow duct, and wind tunnel tests. Minor adjustments in duct flow velocity, flap length, and blowing nozzle geometry were incorporated to provide airplane characteristics that minimize takeoff gross weight and achieve sideline noise objectives for an advanced commercial STOL airplane

    Social foundations of the mathematics curriculum: a rationale for change

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    The nature of educational aims as criteria for worthwhile curriculum\ud practice is explored and a cross-section of aims for mathematics education\ud is discussed. An aim for mathematics education which emphasises\ud the social aspect of the subject in its being, its conduct and its\ud applications is identified and epistemological foundations for such a\ud view of the nature of the subject are explored. It is argued that such\ud an epistemological perspective of mathematics would be reflected in the\ud social context of the mathematics classroom, arising from a methodology\ud in which the subject would become more problematic and open to change,\ud investigation and hypothesis.\ud The aims of two major mathematics curriculum development projects\ud (the Nuffield Mathematics Project and the School Mathematics Project)\ud are examined to determine the extent to which their aims may take the\ud 'social' nature of mathematics into account. The probable social\ud context of mathematics classrooms using their materials is postulated in\ud an attempt to characterise the nature of the subject as it is reflected\ud in these materials. A view of the nature of mathematics held by\ud practising teachers and by pupils is then established by drawing upon,\ud and extrapolating from, evidence relating to the social context of\ud mathematics classrooms at primary and secondary level.\ud Conclusions follow, which suggest that fundamental change in mathematics\ud education requires, as a first step, the adoption of a new epistemological\ud perspective of the subject in order that the pursuit of the\ud aim which emphasises the social nature of mathematics is achieved. It\ud is suggested that this, in turn, ultimately could lead to the desired\ud balance in the mathematics curriculum which hitherto has been lacking

    Kandungan Arsen (as), Berbentuk Suspensi Dan Terlarut, Di Perairan Teluk Manado

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    Penelitian tentang kandungan arsen (As) di Perairan Teluk Manado dan sekitarnya telah dilakukan dengan tujuan untuk: 1) mengukur kandungan As yang terdapat dalam kolom air Teluk Manado, baik berbentuk suspensi maupun terlarut; 2) mengevaluasi kandungan As yang berasal dari Sungai Bailang dan S. Tondano yang masuk ke Perairan Teluk Manado, dan mengevaluasi perbedaan kandungan As antara kedua sungai tersebut; 3) menilai status pencemaran As di Perairan Teluk Manado berdasarkan Peraturan Pemerintah Republik Indonesia. Hasil penelitian menunjukkan bahwa : 1) kandungan As dalam kolom air Perairan Teluk Manado sebesar < 0,0005 ppm; 2) konsentrasi As dalam kolom air yang masuk ke Perairan Teluk Manado sebesar < 0,0005 ppm untuk kedua bentuk As dari S. Bailang; 0,0012 ppm As bentuk suspensi dan 0,0011 ppm As bentuk terlarut dari S. Tondano; 3) status pencemaran As Perairan Teluk Manado masih dalam kondisi “aman”

    A comprehensive strategy to tackle arsenic contamination of drinking water in Uttar Pradesh in India

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    Exposure to naturally occurring arsenic through consumption of contaminated groundwater, food and soil is now widely recognized as a new threat to public health in several countries in South and South-East Asia, including parts of India. The realization that arsenic not only occurs in groundwater used for drinking in the Ganges-Brahmaputra delta of West Bengal in India, but also further upstream in Bihar and Uttar Pradesh in the middle and upper Gangetic plains, has necessitated the need to develop arsenic testing and mitigation strategies in these states. This paper outlines the strategy evolved by the state government of Uttar Pradesh, with the support of UNICEF, to tackle the problem of arsenic in groundwater used for drinking. The comprehensive approach includes testing, communication, mitigation and health aspects, and novel strategies used to overcome technological issues are detailed. A similar approach has been used in the neighbouring state of Bihar

    Predicting depression using electronic health records : a systematic review

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    Background Depression is one of the most significant health conditions in personal, social, and economic impact. The aim of this review is to summarize existing literature in which machine learning (ML) methods have been used in combination with Electronic Health Records (EHRs) for prediction of depression. Methods Systematic literature searches were conducted within arXiv, PubMed, PsycINFO, Science Direct, SCOPUS and Web of Science electronic databases. Searches were restricted to information published after 2010 (from 1st January 2011 onwards) and were updated prior to the final synthesis of data (27th January 2022). Results Following the PRISMA process, the initial 744 studies were reduced to 19 eligible for detailed evaluation. Data extraction identified machine learning methods used, types of predictors used, the definition of depression, classification performance achieved, sample size, and benchmarks used. Area Under the Curve (AUC) values more than 0.9 were claimed, though the average was around 0.8. Regression methods proved as effective as more developed machine learning techniques. Limitations The categorization, definition, and identification of the numbers of predictors used within models was sometimes difficult to establish, Studies were largely Western Educated Industrialised, Rich, Democratic (WEIRD) in demography. Conclusion This review supports the potential use of machine learning techniques with EHRs for the prediction of depression. All the selected studies used clinically based, though sometimes broad, definitions of depression as their classification criteria. The reported performance of the studies was comparable to or even better than that found in primary care. There are concerns over the generalizability and interpretability

    APLC-Optimization: an apodized pupil Lyot coronagraph design survey toolkit

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    We present a publicly available software package developed for exploring apodized pupil Lyot coronagraph (APLC) solutions for various telescope architectures. In particular, the package optimizes the apodizer component of the APLC for a given focal-plane mask and Lyot stop geometry to meet a set of constraints (contrast, bandwidth etc.) on the coronagraph intensity in a given focal-plane region (i.e. dark zone). The package combines a high-contrast imaging simulation package HCIPy with a third-party mathematical optimizer (Gurobi) to compute the linearly optimized binary mask that maximizes transmission. We provide examples of the application of this toolkit to several different telescope geometries, including the Gemini Planet Imager (GPI) and the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed. Finally, we summarize the results of a preliminary design survey for the case of a 6~m aperture off-axis space telescope, as recommended by the 2020 NASA Decadal Survey, exploring APLC solutions for different segment sizes. We then use the Pair-based Analytical model for Segmented Telescope Imaging from Space (PASTIS) to perform a segmented wavefront error tolerancing analysis on these solutions.Comment: 17 pages, 16 figures, SPIE conferenc
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