125 research outputs found

    Results of thermal environment measurements on the thermal cannister experiment and get away special enclosure

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    Because the OSS-1 pallet contained a variety of instruments with irregular surface geometry and properties which limited predictability, the total absorbed flux on thermal canister radiators was measured to determine heat rejection capability. The instrumentation and sensor cup design and locations for the thermal canister experiment are illustrated. Graphs show flux sensor history in hot and coal orbits. Kapton erosion is also considered. Results show that the flux levels measured in all STS attitudes are higher than predictions. In cold and moderate attitudes, flight results are a factor of two to three higher than predicts. In hot attitude, much better agreement occurred. It is concluded that in cold or moderate attitudes other sources may be contributing to added inputs (albedo, Earth shine, shuttle background). In hot attitude, smaller differences could be attributed to coatings assumptions or calculation uncertainty

    OAO-3 end of mission tests report

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    Twelve engineering type tests were performed on several subsystems and experiment(s) of the OAO 3 spacecraft near its end of mission. The systems tested include: Princeton experiment package (PEP), fine error system guidance, inertial reference unit, star trackers, heat pipes, thermal control coatings, command and data handling, solar array; batteries, and onboard processor/power boost regulator. Generally, the systems performed well for the 8 1/2 years life of OAO 3, although some degradation was noted in the sensitivity of PEP and in the absorptivity of the skin coatings. Battery life was prolonged during the life of the mission in large part by carefully monitoring the charge-discharge cycle with careful attention not to overcharge

    Perspective and Costing in Cost-Effectiveness Analysis, 1974-2018

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    OBJECTIVE: Our objective was to examine perspective and costing approaches used in cost-effectiveness analyses (CEAs) and the distribution of reported incremental cost-effectiveness ratios (ICERs). METHODS: We analyzed the Tufts Medical Center's CEA and Global Health CEA registries, containing 6907 cost-per-quality-adjusted-life-year (QALY) and 698 cost-per-disability-adjusted-life-year (DALY) studies published through 2018. We examined how often published CEAs included non-health consequences and their impact on ICERs. We also reviewed 45 country-specific guidelines to examine recommended analytic perspectives. RESULTS: Study authors often mis-specified or did not clearly state the perspective used. After re-classification by registry reviewers, a healthcare sector or payer perspective was most prevalent (74%). CEAs rarely included unrelated medical costs and impacts on non-healthcare sectors. The most common non-health consequence included was productivity loss in the cost-per-QALY studies (12%) and patient transportation in the cost-per-DALY studies (21%). Of 19,946 cost-per-QALY ratios, the median ICER was US26,000/QALY(interquartilerange[IQR]2900−110,000),and18US26,000/QALY (interquartile range [IQR] 2900-110,000), and 18% were cost saving and QALY increasing. Of 5572 cost-per-DALY ratios, the median ICER was US430/DALY (IQR 67-3400), and 8% were cost saving and DALY averting. Based on 16 cost-per-QALY studies (2017-2018) reporting 68 ICERs from both the healthcare sector and societal perspectives, the median ICER from a societal perspective (US22,710/QALY[IQR11,991−49,603])wasmorefavorablethanfromahealthcaresectorperspective(US22,710/QALY [IQR 11,991-49,603]) was more favorable than from a healthcare sector perspective (US30,402/QALY [IQR 10,486-77,179]). Most governmental guidelines (67%) recommended either a healthcare sector or a payer perspective. CONCLUSION: Researchers should justify and be transparent about their choice of perspective and costing approaches. The use of the impact inventory and reporting of disaggregate outcomes can reduce inconsistencies and confusion

    Correction to : Perspective and Costing in Cost‑Effectiveness Analysis, 1974-2018

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    The article Perspective and Costing in Cost-Effectiveness Analysis

    Utilization of healthcare resources by U.S. children and adults with inflammatory bowel disease:

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    The inflammatory bowel diseases (IBDs), Crohn’s disease (CD) and ulcerative colitis (UC) affect over 1 million people in the United States, yet little is known about healthcare utilization by affected individuals

    The clinical and economic benefits of capecitabine and tegafur with uracil in metastatic colorectal cancer

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    Two oral fluoropyrimidine therapies have been introduced for metastatic colorectal cancer. One is a 5-fluorouracil pro-drug, capecitabine; the other is a combination of tegafur and uracil administered together with leucovorin. The purpose of this study was to compare the clinical effectiveness and cost-effectiveness of these oral therapies against standard intravenous 5-fluorouracil regimens. A systematic literature review was conducted to assess the clinical effectiveness of the therapies and costs were calculated from the UK National Health Service perspective for drug acquisition, drug administration, and the treatment of adverse events. A cost-minimisation analysis was used; this assumes that the treatments are of equal efficacy, although direct randomised controlled trial (RCT) comparisons of the oral therapies with infusional 5-fluorouracil schedules were not available. The cost-minimisation analysis showed that treatment costs for a 12-week course of capecitabine (£2132) and tegafur with uracil (£3385) were lower than costs for the intravenous Mayo regimen (£3593) and infusional regimens on the de Gramont (£6255) and Modified de Gramont (£3485) schedules over the same treatment period. Oral therapies result in lower costs to the health service than intravenous therapies. Further research is needed to determine the relative clinical effectiveness of oral therapies vs infusional regimens

    Review of recent progress in nanoscratch testing

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    Nanoscratch testing, as an important technique for the assessment of the mechanical failure behaviour and adhesion strength of ceramic coatings and a simulation tool of single asperity contact in tribological experiments, is increasingly becoming an established nanomechanical characterisation method. This paper reviews recent work in nanoscratch testing in different engineering applications including thin ceramic films, automotive organic coatings, chemical- mechanical polishing and biomaterials. In the main part of the paper, nanoscratch results from experiments performed using NanoTest systems fitted with tangential force sensors and spherical indenters as scratch probes are presented and discussed. The types of nanoscratch tests described include constant load nanoscratches, ramped load nanoscratch tests and multipass repetitive unidirectional constant load nanoscratch tests (nanowear). The results are discussed in terms of critical load sensitivity to intrinsic and extrinsic factors, impact of scan speed and loading rate, influence of probe radius and geometry, estimation of tip contact pressure, influence of surface roughness and film stress and thickness, and finally role of ploughing on friction evolution
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