19,384 research outputs found

    Design evaluation criteria for commercial STOL transports

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    Handling qualities criteria and operational performance margins have been determined for the landing phase of commercial short-takeoff-and-landing airplanes. The requirements are the result of a literature survey, analysis of areas found to be inadequately covered by current criteria, and a subsequent piloted simulator investigation of critical criteria requiring substantiation. Three complete simulator models were used, each describing the characteristics of a different high-lift system, the externally blown flap, the augmentor flap, and the internally blown flap. The proposed criteria are presented with substantiating discussions from currently available data or directly from the results of this simulation work where it is applicable

    Remote sensing of the atmosphere from environmental satellites

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    Various applications of satellite remote sensing of the earth are reviewed, including (1) the use of meteorological satellites to obtain photographic and radiometric data for determining weather conditions; (2) determination of the earth radiation budget from measurements of reflected solar radiation and emitted long wave terrestrial radiation; (3) the use of microwave imagery for measuring ice and snow cover; (4) LANDSAT visual and near infrared observation of floods and crop growth; and (5) the use of the Nimbus 4 backscatter ultraviolet instrument to measure total ozone and vertical ozone distribution. Plans for future activities are also discussed

    A 4-node Bilinear Isoparametric Element in Rockwell NASTRAN

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    The development and evaluation of the Rockwell NASTRAN four node quadrilateral (QUAD4) element is presented. The element derivation utilizes bilinear isoparametric techniques both for membrane and bending characteristics. The QUAD4 element coordinate system, membrane properties, lumped mass matrix, and treatment of warping are based upon the COSMIC/NASTRAN QDMEMI element while the bending characteristics are based on a paper by T. J. R. Hughes. The effects of warping on the bending stiffness, consistent mass, and geometric stiffness are based upon a paper by R. H. MacNeal. Numerical integration is accomplished by Gaussian quadrature on a 2 x 2 grid. Practical user support features include variable element thickness, thermal analysis and layered composite material definitions

    The investigation of critical pressure burning of fuel droplets Annual report, 1 Jan. - 31 Dec. 1970

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    Experimental and theoretical results of critical pressure burning of fuel droplet

    Identification of LDH-A as a therapeutic target for cancer cell killing via (i) p53/NAD(H)-dependent and (ii) p53 independent pathways

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    Most cancer cells use aerobic glycolysis to fuel their growth. The enzyme lactate dehydrogenase-A (LDH-A) is key to cancer’s glycolytic phenotype, catalysing the regeneration of nicotinamide adenine dinucleotide (NAD þ ) from reduced nicotinamide adenine dinucleotide (NADH) necessary to sustain glycolysis. As such, LDH-A is a promising target for anticancer therapy. Here we ask if the tumour suppressor p53, a major regulator of cellular metabolism, influences the response of cancer cells to LDH-A suppression. LDH-A knockdown by RNA interference (RNAi) induced cancer cell death in p53 wild-type, mutant and p53-null human cancer cell lines, indicating that endogenous LDH-A promotes cancer cell survival irrespective of cancer cell p53 status. Unexpectedly,however,weuncoveredanovelroleforp53intheregulationofcancercellNADþ anditsreducedformNADH.Thus, LDH-A silencing by RNAi, or its inhibition using a small-molecule inhibitor, resulted in a p53-dependent increase in the cancer cell ratioofNADH:NADþ.Thiseffectwasspecificforp53þ/þ cancercellsandcorrelatedwith(i)reducedactivityofNADþ-dependent deacetylase sirtuin 1 (SIRT1) and (ii) an increase in acetylated p53, a known target of SIRT1 deacetylation activity. In addition, activation of the redox-sensitive anticancer drug EO9 was enhanced selectively in p53 þ / þ cancer cells, attributable to increased activity of NAD(P)H-dependent oxidoreductase NQO1 (NAD(P)H quinone oxidoreductase 1). Suppressing LDH-A increased EO9-inducedDNAdamageinp53þ/þ cancercells,butimportantlyhadnoadditiveeffectinnon-cancercells.Ourresultsidentifya unique strategy by which the NADH/NADþ cellular redox status can be modulated in a cancer-specific, p53-dependent manner and we show that this can impact upon the activity of important NAD(H)-dependent enzymes. To summarise, this work indicates two distinct mechanisms by which suppressing LDH-A could potentially be used to kill cancer cells selectively, (i) through induction of apoptosis, irrespective of cancer cell p53 status and (ii) as a part of a combinatorial approach with redox-sensitive anticancer drugs via a novel p53/NAD(H)-dependent mechanism

    Secondary prevention of stroke: Using the experiences of patients and carers to inform the development of an educational resource

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    Copyright @ The Author 2008. This article is available open access through the publisher’s website at the link below.Background. Patients who have had one stroke are at increased risk of another. Secondary prevention strategies that address medical risk factors and promote healthy lifestyles can reduce the risk. However, concordance with secondary prevention strategies is poor and there has been little research into patient and carer views. Objectives. To explore the experiences of patients and carers of receiving secondary prevention advice and use these to inform the development of an educational resource. Methods. A total of 38 participants (25 patients and 13 carers) took part in the study which used an action research approach. Focus groups and interviews were undertaken with patients and carers who had been discharged from hospital after stroke (between 3 and 24 months previously). Framework analysis was used to examine the data and elicit action points to develop an educational resource. Results. Participants’ main concern was their desire for early access to information. They commented on their priorities for what information or support they needed, the difficulty of absorbing complex information whilst still an in-patient and how health professionals’ use of language was often a barrier to understanding. They discussed the facilitators and barriers to making lifestyle changes. The educational resource was developed to include specific advice for medical and lifestyle risk factors and an individual action plan. Conclusion. An educational resource for secondary prevention of stroke was developed using a participatory methodology. Our findings suggest that this resource is best delivered in a one-to-one manner, but further work is needed to identify its potential utility.Peninsula Primary Care Research Networ

    Ab Initio Liquid Hydrogen Muon Cooling Simulations with ELMS in ICOOL

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    This paper presents new theoretical results on the passage of muons through liquid hydrogen which have been confirmed in a recent experiment. These are used to demonstrate that muon bunches may be compressed by ionisation cooling more effectively than suggested by previous calculations. Muon cooling depends on the differential cross section for energy loss and scattering of muons. We have calculated this cross section for liquid H2 from first principles and atomic data, avoiding traditional assumptions. Thence, 2-D probability maps of energy loss and scattering in mm-scale thicknesses are derived by folding, and stored in a database. Large first-order correlations between energy loss and scattering are found for H2, which are absent in other simulations. This code is named ELMS, Energy Loss & Multiple Scattering. Single particle trajectories may then be tracked by Monte Carlo sampling from this database on a scale of 1 mm or less. This processor has been inserted into the cooling code ICOOL. Significant improvements in 6-D muon cooling are predicted compared with previous predictions based on GEANT. This is examined in various geometries. The large correlation effect is found to have only a small effect on cooling. The experimental scattering observed for liquid H2 in the MUSCAT experiment has recently been reported to be in good agreement with the ELMS prediction, but in poor agreement with GEANT simulation.Comment: 6 pages, 3 figure

    ECONOMIC AND ENVIRONMENTAL EVALUATION OF DAIRY MANURE UTILIZATION FOR YEAR ROUND CROP PRODUCTION

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    The production of excess on-farm manure is placing continuous pressures on dairy producers to meet or exceed standards for environmental regulations while maintaining profitability and competitiveness. Evaluation of the effects of recycling nutrients on the profitability of the whole farm enterprise is important for a dairy operation. The objective of this study was to develop a linear programming model that evaluates the economic performance of a dairy operation considering production and environmental constraints. The main goal was to maximize profits from the dairy enterprise considering milk production, manure production, crop production while maintaining a balance of nutrients in the system. Results from simulation analyses showed greater effects on total farm profits at the more restrictive P-based than N-based manure application rates.Environmental Economics and Policy,
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