1,085 research outputs found

    Skylab mobile laboratory

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    The Skylab mobile laboratory was designed to provide the capability to obtain necessary data on the Skylab crewmen 30 days before lift-off, within 1 hour after recovery, and until preflight physiological baselines were reattained. The mobile laboratory complex consisted of six laboratories that supported cardiovascular, metabolic, nutrition and endocrinology, operational medicine, blood, and microbiology experiments; a utility package; and two shipping containers. The objectives and equipment requirements of the Skylab mobile laboratory and the data acquisition systems are discussed along with processes such as permanently mounting equipment in the individual laboratories and methods of testing and transporting the units. The operational performance, in terms of amounts of data collected, and the concept of mobile laboratories for medical and scientific experiments are evaluated. The Skylab mobile laboratory succeeded in facilitating the data collection and sample preservation associated with the three Skylab manned flights

    Adjustment of inventories

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    Progress toward cascade cells made by OM-VPE

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    Organometallic Vapor Phase Epitaxy (COM-VPE) was used to make a sophisticated monolithic cascade cell, with a peak AMO efficiency of 16.6%, not corrected for 14% grid coverage. The cell has 9 epitaxial layers. The top cell is 1.35 microns thick with a 0.1 micron thich emitter. Both cells are heteroface n-p structures. The cascade cell uses metal interconnects. Details of growth and processing are described

    GaAs VLSI for aerospace electronics

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    Advanced aerospace electronics systems require high-speed, low-power, radiation-hard, digital components for signal processing, control, and communication applications. GaAs VLSI devices provide a number of advantages over silicon devices including higher carrier velocities, ability to integrate with high performance optical devices, and high-resistivity substrates that provide very short gate delays, good isolation, and tolerance to many forms of radiation. However, III-V technologies also have disadvantages, such as lower yield compared to silicon MOS technology. Achieving very large scale integration (VLSI) is particularly important for fast complex systems. At very short gate delays (less than 100 ps), chip-to-chip interconnects severely degrade circuit clock rates. Complex systems, therefore, benefit greatly when as many gates as possible are placed on a single chip. To fully exploit the advantages of GaAs circuits, attention must be focused on achieving high integration levels by reducing power dissipation, reducing the number of devices per logic function, and providing circuit designs that are more tolerant to process and environmental variations. In addition, adequate noise margin must be maintained to ensure a practical yield

    Federalism And The Law Of Securities Regulation: TheLegacy Of Brown V. Board Of Education

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    On the Early History of Current Algebra

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    The history of Current Algebra is reviewed up to the appearance of the Adler-Weisberger sum rule. Particular emphasis is given to the role current algebra played for the historical struggle in strong interaction physics of elementary particles between the S-matrix approach based on dispersion relations and field theory. The question whether there are fundamental particles or all hadrons are bound or resonant states of one another played an important role in this struggle and is thus also regarded.Comment: 17 page

    Adoption of site-specific variable rate sprinkler irrigation systems

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    More than 20 years of private and public research on site-specific variable rate sprinkler irrigation (SS-VRI) technology on self-propelled center pivot and linear move irrigation systems has resulted in limited commercial adoption of the technology. Competing patents, liability, and proprietary software have affected industry’s willingness to move into a new technology area. Documented and proven water conservation strategies using site specific irrigation are quite limited. Marginal costs associated with site-specific technologies are high. Although sales of SS-VRI are increasing, they are primarily being used for eliminating irrigation and chemigation on non-cropped areas of a field or for land application of liquid agricultural and municipal wastes. Various aspects of SS-VRI technologies for general crop production are beginning to slowly gain widespread acceptance; however, their uses are largely focused on addressing symptoms of poor design and suboptimal water and nutrient management. Although currently underutilized, SS-VRI technology has the potential to positively impact crop water productivity, water and energy conservation, and the environment. There are also few economic incentives to motivate growers to move to higher levels of SS-VRI management. Greater adoption rates will likely require higher costs for water and energy, severely restricted water diversions on a broad scale, and enforcement of compliance with environmental and other regulations. Sustainable use of SS-VRI will require strong research support, which is currently limited. In the short term, adoption of SS-VRI technologies will be enhanced by addressing equipment deficiencies and research developing basic criteria and systems for defining management zones and locations of various sensor systems for both arid and humid regions. Training adequate personnel to help write site-specific variable rate irrigation prescriptions in humid and arid areas to assist growers with the decision-making process is also a high priority. There is also a large need to educate government boards and bankers on the potential benefits of these systems. The long-term challenges will be to demonstrate that SS-VRI will improve water management or increase net returns. There is a critical need to develop fully integrated management systems with supporting elements that accurately and inexpensively define dynamic management zones, sense within-field variability in real time, and then adaptively control site-specific variable rate water applications, which will be challenging as significant knowledge gaps exist

    Evaluation des aménités urbaines par la méthode des prix hédoniques : une application au cas de la ville d'Angers

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    La question des choix résidentiels des ménages constitue l’une des problématiques centrales de l’économie urbaine actuelle. Si les premiers modèles monocentriques se focalisaient sur l’arbitrage des ménages entre les coûts de localisation et les coûts de déplacements entre le domicile et le lieu de travail supposé se situer au centre-ville économique, les travaux les plus récents cherchent à dépasser ce cadre simplificateur afin de rendre compte des évolutions urbaines actuelles et des différences observées entre les villes européennes et nord-américaines.En particulier, la prise en considération du rôle des aménités urbaines et naturelles améliore le pouvoir explicatif de ces modèles théoriques urbains. Largement utilisée dans le domaine de l’évaluation environnementale, la méthode des prix hédoniques peut apporter des éléments pertinents à cette problématique urbaine. Développée par Rosen (1974), elle permet de mesurer, à partir des comportements des ménages, la valeur que ces derniers accordent aux différentes caractéristiques intrinsèques et extrinsèques des logements, en particulier aux différentes aménités naturelles ou construites. L’estimation de ces prix hédoniques doit tenir compte du double caractère spatial et endogène des caractéristiques des logements : des estimations naïves par moindres carrés ordinaires sont potentiellement biaisées. Corriger ces biais requiert l’utilisation de la méthode FGS2SLS proposée par Fingleton et Le Gallo (2008), combinant variables instrumentales et correction de l’autocorrélation spatiale. Cette méthode est mise en œuvre dans le cas de la ville d’Angers : avec un centre bien pourvu en aménités historiques, il est en effet typique du cas européen. Au-delà du rôle prépondérant des caractéristiques intrinsèques des logements, la valorisation par les ménages des aménités « vertes » telles que les espaces verts souligne la complexité de l’espace urbain angevin

    Rice growth under water stress levels imposedat distinct developmental stages.

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    Made available in DSpace on 2017-10-18T09:30:45Z (GMT). No. of bitstreams: 1 GermaniConcenco11RCAV40n32017v2.pdf: 4312933 bytes, checksum: c932e8c978a062f22e625c49676c7092 (MD5) Previous issue date: 2017-10-17bitstream/item/165182/1/Germani-Concenco-11-RCA-V40-n3-2017-v2.pd

    Effect of Oral Iron Repletion on Exercise Capacity in Patients With Heart Failure With Reduced Ejection Fraction and Iron Deficiency: The IRONOUT HF Randomized Clinical Trial.

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    Importance: Iron deficiency is present in approximately 50% of patients with heart failure with reduced left ventricular ejection fraction (HFrEF) and is an independent predictor of reduced functional capacity and mortality. However, the efficacy of inexpensive readily available oral iron supplementation in heart failure is unknown. Objective: To test whether therapy with oral iron improves peak exercise capacity in patients with HFrEF and iron deficiency. Design, Setting, and Participants: Phase 2, double-blind, placebo-controlled randomized clinical trial of patients with HFrEF ( Interventions: Oral iron polysaccharide (n = 111) or placebo (n = 114), 150 mg twice daily for 16 weeks. Main Outcomes and Measures: The primary end point was a change in peak oxygen uptake (V̇o2) from baseline to 16 weeks. Secondary end points were change in 6-minute walk distance, plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, and health status as assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ, range 0-100, higher scores reflect better quality of life). Results: Among 225 randomized participants (median age, 63 years; 36% women) 203 completed the study. The median baseline peak V̇o2 was 1196 mL/min (interquartile range [IQR], 887-1448 mL/min) in the oral iron group and 1167 mL/min (IQR, 887-1449 mL/min) in the placebo group. The primary end point, change in peak V̇o2 at 16 weeks, did not significantly differ between the oral iron and placebo groups (+23 mL/min vs -2 mL/min; difference, 21 mL/min [95% CI, -34 to +76 mL/min]; P = .46). Similarly, at 16 weeks, there were no significant differences between treatment groups in changes in 6-minute walk distance (-13 m; 95% CI, -32 to 6 m), NT-proBNP levels (159; 95% CI, -280 to 599 pg/mL), or KCCQ score (1; 95% CI, -2.4 to 4.4), all P \u3e .05. Conclusions and Relevance: Among participants with HFrEF with iron deficiency, high-dose oral iron did not improve exercise capacity over 16 weeks. These results do not support use of oral iron supplementation in patients with HFrEF. Trial Registration: clinicaltrials.gov Identifier: NCT02188784
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