1,569 research outputs found
Design Guide for glass fiber reinforced metal pressure vessel
Design Guide has been prepared for pressure vessel engineers concerned with specific glass fiber reinforced metal tank design or general tank tradeoff study. Design philosophy, general equations, and curves are provided for safelife design of tanks operating under anticipated space shuttle service conditions
Analysis of filament reinforced metal-shell pressure vessels
Computer program analyzes design requirements and computes designs for metal-lined filament-wound pressure vessels with either geodesic /helical/ or in-plane filament winding patterns on the cylindrical portion and over the ends, reinforced by circumferential windings on the cylindrical portion
Analysis of filament-wound dome and polar boss of metal-lined glass-filament-wound pressure vessels
Structural analysis of glass filament wound, aluminum lined pressure vessel design
Growth and Equity Effects of Agricultural Marketing Efficiency Gains in India
Agriculture is the largest source of employment in India, and food accounts for about half of consumer expenditures. Moving agricultural products from the farm to consumers more efficiently could result in large gains to producers, consumers, and India’s overall economy. This analysis uses a computable general equilibrium model with agricultural commodity detail and households disaggregated by rural, urban, and income class to study the potential impacts of reforms that achieve efficiency gains in agricultural marketing and reduce agricultural input subsidies and import tariffs. More efficient agricultural marketing generates economywide gains in output and wages, raises agricultural producer prices, reduces consumer food prices, and increases private consumption, particularly by low-income households. These gains could help to offset some of the medium-term adjustment costs for some commodity markets and households associated with reducing agricultural subsidies and tariffs.India, agriculture, policy reform, marketing efficiency, tariffs, subsidies, households, computable general equilibrium model., Agricultural and Food Policy, Agricultural Finance, Crop Production/Industries, International Relations/Trade, Marketing,
The thin film microwave iris
Development of waveguide iris for microwave coupling applications using thin film techniques is discussed. Production process and installation of iris are described. Iris improves power transmission properties of waveguide window
Filament-reinforced metal composite pressure vessel evaluation and performance demonstration
Two different Kevlar-49 filament-reinforced metal sphere designs were developed, and six vessels of each type were fabricated and subjected to fatigue cycling, sustained loading, and hydrostatic burst. The 61 cm (24 inch) diameter Kevlar-49/cryoformed 301 stainless steel pressure vessels demonstrated the required pressure cycle capability, burst factor of safety, and a maximum pressure times volume divided by weight (pV/W) performance of 210 J/g (834 000 in-lb/lbm) at burst; this represented a 25 to 30% weight saving over the lightest weight comparable, 6A1-4V Ti, homogeneous pressure vessel. Both the Kevlar/stainless steel design and the 97 cm (38 inch) diameter Kevlar-49/2219-T62 aluminum sphere design demonstrated nonfragmentation and controlled failure mode features when pressure cycled to failure at operating pressure. When failure occurred during pressure cycling, the mode was localized leakage and not catastrophic. Kevlar/stainless steel vessels utilized a unique conical boss design, and Kevlar/aluminum vessels incorporated a tie-rod to carry port loads; both styles of polar fittings performed as designed during operational testing of the vessels
Differential expansion fitting for cryogenic liquid tanks
Sliding contact between liner and interior surface of fitting accommodates stresses and strains developed in shell composite and metal liner system. Stresses and strains are transmitted to liner portion which is recessed in fitting and which acts as differential expansion fitting
NONLINEAR MODELS FOR MULTI-FACTOR PLANT NUTRITION EXPERIMENTS
Plant scientists are interested in measuring plant response to quantitative treatment factors, e.g. amount of nutrient applied. Response surface methods are often used for experiments with multiple quantitative factors. However, in many plant nutrition studies, second-order response surface models result in unacceptable lack of fit. This paper explores multi-factor nonlinear models as an alternative. We have developed multi-factor extensions of Mitscherlich and Gompertz models, and fit them to data from experiments conducted at the University of Nebraska-Lincoln Horticulture department. These data are typical of experiments for which conventional response surface models perform poorly. We propose design selection strategies to facilitate economical multi-factor experiments when second-order response surface models are unlikely to fit
Indications for phosphorus fertilizer-derived uranium mobilization from arable soils to groundwater
Uranium (U) and many trace elements are enriched in phosphorus fertilizers. Concentrations up to 260 mg/kg P2O5 indicate the potential of U contamination of the environment. Two fertilized long-time soil monitoring fields (BDF) in Lower Saxony have higher top soil concentration than comparable unfertilized top soils sampled at the Green-Belt in the vicinity of the BDFs. Extraction experiments could show that fertilizer-derived U is easier mobilized and hence might be leached faster to the groundwater than the geogenic U in soils. Groundwater analyses in an area of intense agricultural production show U in correlation with nitrate, indicating an impact of anthropogenic fertilization on the U concentration in shallow groundwater. The results of soil, soil extract and groundwater analyses are giving indications for fertilizer-derived U leaching to groundwater aquifers and hence show the potential hazard for our drinking water resources
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