2,989 research outputs found

    Design, evaluation and recommedation effort relating to the modification of a residential 3-ton absorption cycle cooling unit for operation with solar energy

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    The possible use of solar energy powered absorption units to provide cooling and heating of residential buildings is studied. Both, the ammonia-water and the water-lithium bromide cycles, are considered. It is shown that the air cooled ammonia water unit does not meet the criteria for COP and pump power on the cooling cycle and the heat obtained from it acting as a heat pump is at too low a temperature. If the ammonia machine is water cooled it will meet the design criteria for cooling but can not supply the heating needs. The water cooled lithium bromide unit meets the specified performance for cooling with appreciably lower generator temperatures and without a mechanical solution pump. It is recommeded that in the demonstration project a direct expansion lithium bromide unit be used for cooling and an auxiliary duct coil using the solar heated water be employed for heating

    Manual abort guidance from the midcourse region of a lunar mission

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    Manual abort guidance from midcourse region of lunar missio

    Decision Performance and Safety Performance: A Value-Focused Thinking Study in the Oil Industry

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    Considerable research has been performed to develop leading indicators of safety performance. We use value-focused thinking to understand the objectives and evaluation measures that frame a particular safety-related decision within an organization. These decisions are part of the safety culture. Our research partners were two oil shipping companies; we surveyed crewmembers on their tankers to evaluate performance in each decision objective on their vessel. We demonstrate that measurements of the achievement of these objectives are related to future safety performance and thus provide leading indicators of safety

    Development of oxide dispersion strengthened turbine blade alloy by mechanical alloying

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    There were three nickel-base alloys containing up to 18 wt. % of refractory metal examined initially for oxide dispersion strengthening. To provide greater processing freedom, however, a leaner alloy was finally selected. This base alloy, alloy D, contained 0.05C/15Cr / 2Mo/4W/2Ta/4.5Al/2.Ti/015Zr/0.01-B/Bal. Ni. Following alloy selection, the effect of extrusion, heat treatment, and oxide volume fraction and size on microstructure and properties were examined. The optimum structure was achieved in zone annealed alloy D which contained 2.5 vol. % of 35 mm Y2O3 and which was extruded 16:1 at 1038 C

    Implications of sperm banking for health-related quality of life up to 1 year after cancer diagnosis.

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    Sperm banking is recommended for all men diagnosed with cancer where treatment is associated with risk of long-term gonadatoxicity, to offer the opportunity of fatherhood and improved quality of life. However, uptake of sperm banking is lower than expected and little is known about why men refuse. Our aims were to determine: (i) demographic and medical variables associated with decisions about banking and (ii) differences in quality of life between bankers and non-bankers at diagnosis (Time 1 (T1)) and 1 year later (Time 2 (T2))

    Is Screening Cargo Containers for Smuggled Nuclear Threats Worthwhile?

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    In recent years, Customs and Border Protection (CBP) has installed radiation sensors to screen cargo containers entering theUnited States. They are concerned that terrorists could use containers to smuggle radiological material into the country and carry out attacks with dirty bombs or a nuclear device. Recent studies have questioned the value of improving this screening system with new sensor technology. The cost of delays caused by frequent false alarms outweighs any reduction in the probability of an attack in an expected cost analysis. We extend existing methodology in three ways to demonstrate how additional factors affect the value of screening investments. We examine the effect that screening has in discouraging terrorists. We model multiple levels of screening. Finally, we consider additional objectives beyond cost. We find that the conclusion about screening depends on key inputs to the probability model (reflecting uncertainties) and to the value function (reflecting the stakeholders’ fundamental objectives)

    Ternatin and improved synthetic variants kill cancer cells by targeting the elongation factor-1A ternary complex.

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    Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1A·GTP·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products

    A Multiple-Objective Decision Analysis of Stakeholder Values to Identify Watershed Improvement Needs

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    The paper describes the use of multiple objective decision analysis to qualitatively and quantitatively assess the quality of an endangered watershed and guide future efforts to improve the quality of the watershed. The Upham Brook watershed is an urban watershed that lies at the interface of declining inner city Richmond, Virginia and growth-oriented Henrico County. A section of stream within the watershed has been identified as so dangerously polluted that it threatens the health of the residents who live within the watershed boundaries. With funding provided by the National Science Foundation, the Upham Brook watershed project committee was formed to address the quality of the Upham Brook watershed; it consisted of experts from multiple disciplines: stream ecology, environmental policy, water policy, ground and surface water hydrology and quality, aquatic biology, political science, sociology, citizen participation, community interaction, psychology, and decision and risk analysis. Each members\u27 values and goals were brought together using a watershed management framework to meet the overall objective of the committee: to maximize the quality of the Upham Brook watershed. The resulting model was used to identify the largest value gaps and to identify future programs needed to improve the quality of the watershed

    Bostonia. Volume 4

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    Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
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