13,953 research outputs found
Bellows, tunnel fuel tank summary report
Load transfer to end flanges for prevention of bellows buckling in tunnel fuel tan
Acoustic Kappa-Density Fluctuation Waves in Suprathermal Kappa Function Fluids
We describe a new wave mode similar to the acoustic wave in which both
density and velocity fluctuate. Unlike the acoustic wave in which the
underlying distribution is Maxwellian, this new wave mode occurs when the
underlying distribution is a suprathermal kappa function and involves
fluctuations in the power law index, kappa. This wave mode always propagates
faster than the acoustic wave with an equivalent effective temperature and
becomes the acoustic wave in the Maxwellian limit as kappa goes to infinity.Comment: 11 pages, 2 figures, in press AS
Exact solution of lossy asymmetrical coupled dielectric slab waveguides
This paper gives an exact characteristic equation for asymmetrical coupled dielectric slab waveguides with losses in both the guiding and surrounding regions. For the lossless case the solution of a single transcendental equation is all that is required for the evaluation of the propagation constant
What counts as creativity in education? An inquiry into the intersections of public, political, and policy discourses
In this essay, the authors examine the varied public, everyday, and academic discourses of creativity that combine to influence our current educational goals and policies, particularly in North America and Europe. From Sir Ken Robinson’s (2006) cutting remark that “Schools kill creativity!” to the Action Canada Foundation’s (2013) assessment that creativity is one of the seven core learning competencies required in the 21st century, this article portrays the compelling push and pull of creativity in education today. The authors found themselves in search of this seemingly crucial, yet increasingly undersupported aspect of their work in teacher education and research. Coming from literacy and arts education, the authors were called to question what they had always taken for granted. This article contextualizes creativity amid everyday, public, and academic discourses. Through engaging in this inquiry, the extent to which creativity is the recipe for success, as it is so often deemed to be, is assessed and a conceptual framework for creativity in action is proposed
New approaches for index insurance
The El Niño Southern Oscillation (ENSO) is a climate event associated with warming sea surface temperatures in the Pacific Ocean. In years of extreme El Niño events, areas in northern Peru experience catastrophic flooding. As of 2010, it is possible for stakeholders in northern Peru to purchase a new form of insurance that pays out just as flooding begins and stakeholders begin incurring extra costs and consequential losses. Given the high basis risk associated with selling index insurance to households, this insurance is designed for firms and institutions that serve households that are highly exposed to El Niño. ENSO insurance is sold by a Peruvian insurance company, and a major global reinsurer carries most of the risk. This new insurance product is the first insurance to use sea surface temperature as the proxy for catastrophic losses and also the first regulated “forecast index insurance” product in the world. This innovation could enhance progress in developing index-based insurance products for extreme weather events. Recent years have seen a growing number of pilot tests of index insurance for weather risk, motivated by an increased understanding of how natural disasters affect developing countries. Beyond immediate suffering (including deaths, destroyed assets, and lost income), disasters have troublesome indirect effects: economic growth can be disrupted, the poor are thrust into permanent poverty traps, and the mere presence of these risks constrains access to financial services and causes many decisionmakers to pursue low-return, low-risk strategies that impede economic progress. Much of the development of index insurance focuses on agriculture, because activities associated with agriculture remain the primary livelihood strategies for the rural poor in developing countries. Thus far, most index insurance pilots have involved products targeted at households—that is, micro-level products. Index insurance uses an objective measure (an index) of a natural event known to cause losses (such as excess rain, high river levels, or extreme sea surface temperatures). Using an index as the proxy for loss dispenses with expensive loss assessments. Furthermore, use of an index diminishes moral hazard and adverse selection, problems that plague traditional forms of insurance. Given these advantages, index insurance may be well suited to developing countries where data are sparse and delivery of financial services to smallholder households increases the per-unit cost of traditional insurance. Despite the promise of index insurance, uptake by smallholder households is slow. Presently, index insurance may be better suited for risk aggregators—that is, groups or institutions that aggregate the risk of households either through the services they provide or through informal risk-sharing arrangements (for example, agricultural lenders, firms in the value chain, and farmer associations). Focusing first on risk aggregators should also help build linkages and sustainable products that will directly serve smallholder households.ENSO insurance, Farmers, Flooding, forecast index, index insurance,
A microprocessor-based one dimensional optical data processor for spatial frequency analysis
A high degree of accuracy was obtained in measuring the spatial frequency spectrum of known samples using an optical data processor based on a microprocessor, which reliably collected intensity versus angle data. Stray light control, system alignment, and angle measurement problems were addressed and solved. The capabilities of the instrument were extended by the addition of appropriate optics to allow the use of different wavelengths of laser radiation and by increasing the travel limits of the rotating arm to + or - 160 degrees. The acquisition, storage, and plotting of data by the computer permits the researcher a free hand in data manipulation such as subtracting background scattering from a diffraction pattern. Tests conducted to verify the operation of the processor using a 25 mm diameter pinhole, a 39.37 line pairs per mm series of multiple slits, and a microscope slide coated with 1.091 mm diameter polystyrene latex spheres are described
Carbon thin film thermometry
The work concerning carbon thin film thermometry is reported. Optimum film deposition parameters were sought on an empirical basis for maximum stability of the films. One hundred films were fabricated for use at the Marshall Space Flight Center; 10 of these films were given a precise quasi-continuous calibration of temperature vs. resistance with 22 intervals between 5 and 80 K using primary platinum and germanium thermometers. Sensitivity curves were established and the remaining 90 films were given a three point calibration and fitted to the established sensitivity curves. Hydrogen gas-liquid discrimination set points are given for each film
Vulnerability of horticultural crop production to extreme weather events
The potential impact of future extreme weather events on horticultural crops was evaluated. A review was carried out of the sensitivities of a representative set of crops
to environmental challenges. It confirmed that a range of environmental factors are capable of causing a significant impact on production, either as yield or quality loss.
The most important of these were un-seasonal temperature, water shortage or excess,and storms. Future scenarios were produced by the LARS-WG1, a stochastic weather generator linked with UKCIP02 projections of future climate. For the analyses, 150 years of synthetic weather data were generated for baseline, 2020HI and 2050HI scenarios at defined locations. The output from the weather generator was used in case studies, either to estimate the frequency of a defined set of circumstances known to have impact on cropping, or as inputs to models of crop scheduling or pest phenology or survival. The analyses indicated that episodes of summer drought severe enough to interrupt the continuity of supply of salads and other vegetables will increase while the frequency of autumns with sufficient rainfall to restrict potato lifting will decrease. They also indicated that the scheduling of winter cauliflowers for continuity of supply will require the deployment of varieties with different temperature sensitivities from those in use currently. In the pest insect studies, the number of batches of Agrotis segetum (cutworm) larvae surviving to third instar increased with time, as did the potential number of generations of Plutella xylostella (diamond-back moth) in the growing season, across a range of locations. The study demonstrated the utility of high resolution scenarios in predicting the likelihood of specific weather patterns and their potential effect on horticultural production. Several limitations of the current scenarios and biological models were also identified
Research and development of superconducting thin films Final report, 15 Dec. 1965 - 15 Dec. 1966
Superconducting niobium thin film productio
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