707 research outputs found

    Two-step rocket engine bipropellant valve Patent

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    Solenoid two-step valve for bipropellant flow rate control to rocket engin

    Two-step rocket engine bipropellant valve concept

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    Initiating combustion of altitude control rocket engines in a precombustion chamber of ductile material reduces high pressure surges generated by hypergolic propellants. Two-step bipropellant valve concepts control initial propellant flow into precombustion chamber and subsequent full flow into main chamber

    Soil inventory of Capps Forestland, Westminster, SC

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    The objectives of this study were to conduct a soil inventory of Capps Forestland in Westminster, SC, using Web Soil Survey, to collect soil samples, to analyze collected soil samples in the Clemson University Agricultural Service Laboratory, and to interpret the results for management recommendations. Two soil map units found on the property: Hayesville and Cecil fine sandy loams (15-25% slope), and Hayesville and Cecil fine sandy loams (25-45% slope) all belong to the soil order of Ultisols. The dominant soil type present was Hayesville and Cecil fine sandy loams (15-25% slope), (Fine, kaolonitic, mesic Typic Kanhapludults). All soils are not prime farmland. All soils are having tree site index of 85 feet for Eastern white pine (Pinus strobus L.). Soil samples were collected from each soil type and then analyzed to determine the soil chemical and physical properties. Soil nutrient analysis recommendations are discussed in terms of establishing Bermuda grass (Cynodon dactylon (L.) Pers.), and fruit orchard while minimizing environmental impact

    DETERMINANTS OF WHOLESALE BEEF-CUT PRICES

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    Key determinants of monthly wholesale prices for 12 beef cuts include the quantity of the specific cut, stickiness in prices, marketing costs, quantities of pork and chicken, and seasonality. Seasonal patterns across the respective cuts are very different. Relative to the price in December, prices at the wholesale level in other months can be as much as 6 percent lower to as much as 21 percent higher.Wholesale prices, Beef cuts, Seasonality, Demand and Price Analysis, Livestock Production/Industries,

    Valuing Transgenic Cotton Technologies Using a Risk/Return Framework

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    Stochastic Efficiency with Respect to a Function (SERF) is used to rank transgenic cotton technology groups and place an upper and lower bound on their value. Yield and production data from replicated plot experiments are used to build cumulative distribution functions of returns for nontransgenic, Roundup Ready, Bollgard, and stacked gene cotton cultivars. Analysis of Arkansas data indicated that the stacked gene and Roundup Ready technologies would be preferred by a large number of risk neutral and risk averse producers as long as the costs of the technology and seed are below the lower bounds calculated in this manuscript.cotton, financial risk, market value, SERF, transgenic, Agribusiness, Crop Production/Industries, Risk and Uncertainty, Q12, Q16,

    Effects of disorder in location and size of fence barriers on molecular motion in cell membranes

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    The effect of disorder in the energetic heights and in the physical locations of fence barriers encountered by transmembrane molecules such as proteins and lipids in their motion in cell membranes is studied theoretically. The investigation takes as its starting point a recent analysis of a periodic system with constant distances between barriers and constant values of barrier heights, and employs effective medium theory to treat the disorder. The calculations make possible, in principle, the extraction of confinement parameters such as mean compartment sizes and mean intercompartmental transition rates from experimentally reported published observations. The analysis should be helpful both as an unusual application of effective medium theory and as an investigation of observed molecular movements in cell membranes.Comment: 9 pages, 5 figure

    Medium Truck Duty Cycle Data from Real-World Driving Environments: Final Report

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    Since the early part of the 20th century, the US trucking industry has provided a safe and economical means of moving commodities across the country. At present, nearly 80% of US domestic freight movement involves the use of trucks. The US Department of Energy (DOE) is spearheading a number of research efforts to improve heavy vehicle fuel efficiencies. This includes research in engine technologies (including hybrid and fuel cell technologies), lightweight materials, advanced fuels, and parasitic loss reductions. In addition, DOE is developing advanced tools and models to support heavy vehicle research and is leading the 21st Century Truck Partnership and the SuperTruck development effort. Both of these efforts have the common goal of decreasing the fuel consumption of heavy vehicles. In the case of SuperTruck, a goal of improving the overall freight efficiency of a combination tractor-trailer has been established. This Medium Truck Duty Cycle (MTDC) project is a critical element in DOE s vision for improved heavy vehicle energy efficiency; it is unique in that there is no other existing national database of characteristic duty cycles for medium trucks based on collecting data from Class 6 and 7 vehicles. It involves the collection of real-world data on medium trucks for various situational characteristics (e.g., rural/urban, freeway/arterial, congested/free-flowing, good/bad weather) and looks at the unique nature of medium trucks drive cycles (stop-and-go delivery, power takeoff, idle time, short-radius trips). This research provides a rich source of data that can contribute to the development of new tools for FE and modeling, provide DOE a sound basis upon which to make technology investment decisions, and provide a national archive of real-world-based medium-truck operational data to support energy efficiency research. The MTDC project involved a two-part field operational test (FOT). For the Part-1 FOT, three vehicles each from two vocations (urban transit and dry-box delivery) were instrumented for the collection of one year of operational data. The Part-2 FOT involved the towing and recovery and utility vocations for a second year of data collection. The vehicles that participated in the MTDC project did so through gratis partnerships in return for early access to the results of this study. Partnerships such as these are critical to FOTs in which real-world data is being collected. In Part 1 of the project, Oak Ridge National Laboratory (ORNL) established partnerships with the H.T. Hackney Company (HTH), one of the largest wholesale distributors in the country, distributing products to 21 states; and with Knoxville Area Transit (KAT), the city of Knoxville s transit system, which operates across Knoxville and parts of Knox County. These partnerships and agreements provided ORNL access to three Class-7 day-cab tractors that regularly haul 28 ft pup trailers (HTH) and three Class-7 buses for the collection of duty cycle data. In addition, ORNL collaborated with the Federal Motor Carrier Safety Administration (FMCSA) to determine if there were possible synergies between this duty cycle data collection effort and FMCSA s need to learn more about the operation and duty cycles of medium trucks. FMCSA s primary interest was in collecting safety data relative to the driver, carrier, and vehicle. In Part 2 of the project, ORNL partnered with the Knoxville Utilities Board, which made available three Class-8 trucks. Fountain City Wrecker Service was also a Part 2 partner, providing three Class-6 rollback trucks. In order to collect the duty cycle and safety-related data, ORNL developed a data acquisition system (DAS) that was placed on each test vehicle. Each signal recorded in this FOT was collected by means of one of the instruments incorporated into each DAS. Other signals were obtained directly from the vehicle s J1939 and J1708 data buses. A VBOX II Lite collected information available from a global positioning system (GPS), including speed, acceleration, and spatial location information at a rate of 5 Hz for the Part 1 FOT. For the Part 2 FOT, this information was obtained from DAS-based GPS instrumentation. The Air-Weigh LoadMaxx, a self-weighing system that determines the vehicle s gross weight by means of pressure transducers, was used to collect vehicle payload information for the combination, urban transit, and towing and recovery vehicles. A cellular modem, the Raven X EVDO V4221, facilitated the communication between the eDAQ-lite (the data collection engine of the system) and the user. The modem functioned as a wireless gateway, allowing data retrievals and system checks to be performed remotely. Also, in partnership with FMCSA, two additional safety sensors were installed on the combination vehicles: the MGM e-Stroke brake monitoring system and the Tire SafeGuard tire pressure monitoring system. All of these sensors posted data to the J1939 data bus, enabling the signals to be read withou..

    Four Butterflies: End of Life Stories of Transition and Transformation

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    In this article, the author discusses her experiences as an Artist In Residence in the Department of Palliative Care and Rehabilitation Medicine at the University of Texas M. D. Anderson Cancer Center. Emphasis is placed on the ways in which end of life images and narratives often unfold in the fragile yet powerful space where conceptions of aesthetics and spirituality intersect with critical issues in the medical humanities. Drawing on four vivid case studies, the author examines the ways in which end of life narratives shed valuable light on conceptions of the subtlety of human embodiment; issues of violation, sorrow, and forgiveness; the mystical dimensions of traditional cultural beliefs; and the capacity for perceiving the natural world as a living symbol of grace. In so doing, she explores how the themes of transition and transformation become invested with meaningful existential and symbolic dimensions in artworks that give voice and presence to some of the most vulnerable, and often invisible, members of our societyラpeople at the end of life

    Reductions in all-cause, cancer, and coronary mortality in statin-treated patients with heterozygous familial hypercholesterolaemia: a prospective registry study

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    AIMS: To examine the changes in coronary, all-cause, and cancer mortality in patients with heterozygous familial hypercholesterolaemia (FH) before and after lipid-lowering therapy with statins. METHODS AND RESULTS: A total of 3382 patients (1650 men) aged <80 years were recruited from 21 lipid clinics in the United Kingdom and followed prospectively between 1980 and 2006 for 46 580 person-years. There were 370 deaths, including 190 from coronary heart disease (CHD) and 90 from cancer. The standardized mortality ratio (compared with the population in England and Wales) was calculated before and from 1 January 1992. In patients aged 20-79 years, CHD mortality fell significantly by 37% (95% CI = 7-56) from 3.4- to 2.1-fold excess. Primary prevention resulted in a 48% reduction in CHD mortality from 2.0-fold excess to none, with a smaller reduction of nearly 25% in patients with established disease. Coronary mortality was reduced more in women than in men. In patients without known CHD at registration, all-cause mortality from 1992 was 33% (21-43), lower than in the general population, mainly due to a 37% (21-50) lower risk of fatal cancer. CONCLUSION: The results emphasize the importance of early identification of FH and treatment with statins
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