26,645 research outputs found

    Status and capabilities of sonic boom simulators

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    The current status and capabilities of sonic boom simulators which might be used in future studies of the effects of sonic boom on people, animals, or structures is summarized. The list of candidate simulators is based on a literature search which was confined to the United States and Canada. Some of the simulators are fully operational, others could be made operational with a modest investment, and still others would require a major investment. For the sake of the completeness, some simulators which were the subject of a previous review, but which no longer exist, are also included herein

    How an online questionnaire can explore leadership teaching in an undergraduate curriculum.

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    OBJECTIVES: To design a tool to explore current leadership teaching in an undergraduate curriculum, using the medical leadership competency framework (MLCF) DESIGN: An online questionnaire was designed based on the MLCF competences and sent to all course leads at Imperial College, London in Autumn 2011 SETTING: Imperial College, London PARTICIPANTS: Sixty-nine course leads were invited to participate in the questionnaire study MAIN OUTCOME MEASURES: Course leads were asked whether they teach each MLCF competence, which teaching methods they use, and how long they spend teaching each competency RESULTS: Overall there was a 78% questionnaire response rate (54/69). From the questionnaires received it was possible to extrapolate results across the remaining courses to achieve a 100% response rate. We were then able to produce a map of current leadership teaching showing that all MLCF competences are taught to varying degrees across the curriculum. The tool does not however provide information on the quality of teaching provided, or what students learn CONCLUSIONS: There is a strong emphasis on the development of teaching leadership skills to undergraduates in Tomorrow's Doctors 2009 (TD09). It is difficult to know what teaching occurs across the curriculum of a large medical school. The design of a simple, electronic questionnaire will enable medical schools to map their current leadership teaching to the TD09 outcomes. This will help to inform further curriculum development and integration as well as signposting of learning opportunities

    Global Epidemiology of Lung Cancer.

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    While lung cancer has been the leading cause of cancer-related deaths for many years in the United States, incidence and mortality statistics - among other measures - vary widely worldwide. The aim of this study was to review the evidence on lung cancer epidemiology, including data of international scope with comparisons of economically, socially, and biologically different patient groups. In industrialized nations, evolving social and cultural smoking patterns have led to rising or plateauing rates of lung cancer in women, lagging the long-declining smoking and cancer incidence rates in men. In contrast, emerging economies vary widely in smoking practices and cancer incidence but commonly also harbor risks from environmental exposures, particularly widespread air pollution. Recent research has also revealed clinical, radiologic, and pathologic correlates, leading to greater knowledge in molecular profiling and targeted therapeutics, as well as an emphasis on the rising incidence of adenocarcinoma histology. Furthermore, emergent evidence about the benefits of lung cancer screening has led to efforts to identify high-risk smokers and development of prediction tools. This review also includes a discussion on the epidemiologic characteristics of special groups including women and nonsmokers. Varying trends in smoking largely dictate international patterns in lung cancer incidence and mortality. With declining smoking rates in developed countries and knowledge gains made through molecular profiling of tumors, the emergence of new risk factors and disease features will lead to changes in the landscape of lung cancer epidemiology

    Towards mechanomagnetics in elastic crystals: insights from [Cu(acac)2_2]

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    We predict that the magnetic properties of \cuacac, an elastically flexible crystal, change dramatically when the crystal is bent. We find that unbent \cuacac\ is an almost perfect Tomonaga-Luttinger liquid. Broken-symmetry density functional calculations reveal that the magnetic exchange interactions along the chains is an order of magnitude larger than the interchain exchange. The geometrically frustrated interchain interactions cannot magnetically order the material at any experimentally accessible temperature. The ordering temperature (TNT_N), calculated from the chain random phase approximation, increases by approximately 24 orders of magnitude when the material is bent. We demonstrate that geometric frustration both suppresses TNT_N and enhances the sensitivity of TNT_N to bending. In \cuacac, TNT_N is extremely sensitive to bending, but remains too low for practical applications, even when bent. Partially frustrated materials could achieve the balance of high TNT_N and good sensitivity to bending required for practical applications of mechanomagnetic elastic crystals

    Doing Science: How to optimise patient and public involvement in your research

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    This paper considers how best to achieve patient and public involvement in research and how to get the most out of it http://ow.ly/R0hwV

    Doing Science: How to optimise patient and public involvement in your research

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    This paper considers how best to achieve patient and public involvement in research and how to get the most out of it http://ow.ly/R0hw

    Recent Langley helicopter acoustics contributions

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    The helicopter acoustics program at NASA Langley has included technology for elements of noise control ranging from sources of noise to receivers of noise. The scope of Langley contributions for about the last decade is discussed. Specifically, the resolution of two certification noise quantification issues by subjective acoustics research, the development status of the helicopter system noise prediction program ROTONET are reviewed and the highlights from research on blade rotational, broadband, and blade vortex interaction noise sources are presented. Finally, research contributions on helicopter cabin (or interior) noise control are presented. A bibliography of publications from the Langley helicopter acoustics program for the past 10 years is included

    Fabrication and test of a space power boiler feed electromagnetic pump. Part 1: Design and manufacture of pump

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    A three-phase helical induction electromagnetic (EM) pump has been designed and built. This pump was designed for use as the boiler-feed pump of a potassium Rankine-cycle space electric power system. The pump is constructed of high temperature materials including a T-111 duct, Hiperco 27 magnetic material, nickel clad silver conductor wire, and a completely inorganic insulation system. The pump is designed to deliver 3.25 lb/sec potassium at 1000 F with a developed head of 240 psi while being cooled by 800 F NaK. At these conditions, the overall pump efficiency is expected to be 18%

    Internal Migration and Regional Population Dynamics in Europe: Estonia Case Study

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    Estonia has experienced a long-lasting and strong influence of international migration on regional population growth. Post-war immigrants account for about 36 per cent of the total population, and are concentrated in larger cities of Northern Estonia. Regionally, the relative proportions of the native-born and immigrant origin sub-populations are important for the understanding of population change and internal migration flows in the 1980-1990s. In Estonia, the quality of migration data requires careful assessment. The preservation of Soviet-type record-keeping has reduced data quality in the 1990s, already low, and use of the data should keep data quality problems in mind. Otherwise, false conclusions can be reached. To describe internal migration patterns, it has proved technically feasible and very useful to disaggregate the county population into rural and urban components, and correspondingly, the migration flows into four directions (urban-urban, urban-rural, rural-urban and rural-rural). During the 1980s the pattern of population growth and internal migration has changed in Estonia. Reflecting the turnaround in long-term population processes, migration development reached the advanced stage with more or less regionally balanced in- and out-migration flows and decreasing importance of net migration. Accordingly, to understand current trends and patterns, explanations must be sought from the 1980s which has served a starting point for the present trends rather than from the period of economic transition in the 1990s. As a part of the turnaround, the century-long persistent rural depopulation has come to an end and the moderate growth has started reflecting natural population increase as well as deurbanization. In the 1980s two developments have occurred in parallel: migratory increase of rural population led by a deurbanizing native-born population, and continued urban population growth as a result of the population momentum of pre-transition immigrants. In future decades, the urban deconcentration will probably be the underlying trend in Estonia. In Estonia, noticeable proportion of territory and population is located in islands. However, the island population does not show any systematic difference in the type of internal migration. Particularly, the depopulation of island populations, observed in several comparable European cases, is not occurring. Each life-course stage was found to have its specific migration pattern, more stable than the pattern for the total population. In many cases the changes of internal migration are determined by the change in the proportion of population in different life-course stages. Additionally, the life-course approach has been useful in demonstrating the features of the present Estonian internal migration pattern which appear closer to the countries of comparable in demographic development, more or less regardless of the significant differences in the level of economic development. Among life-course groups, in Estonia the older working age population was characterized by the strongest deurbanization intensities in 1995. The same group has also undergone the largest modification of migration pattern during the economic transition (1987-1995)
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