761 research outputs found
Development of an improved protective cover/light block for multilayer insulation
The feasibility of using a scrim-reinforced, single metallized, 4-mil Tedlar film as a replacement for the Teflon coated Beta-cloth/single metallized 3-mil Kapton film presently used as the protective cover/light block for multilayer insulation (MLI) on the Orbiter, Spacelab, and other space applications was demonstrated. The proposed Tedlar concept is lighter and potentially lower in cost. Thermal analysis with the proper concept was much simpler than with the present system. Tests have already demonstrated that white Tedlar has low alpha (adsorption) degradation in space from U.V. The proposed concept was 4400 percent cheaper with nominal weight savings of 50 percent
Insulation for cryogenic tanks has reduced thickness and weight
Dual seal insulation, consisting of an inner layer of sealed-cell Mylar honeycomb core and an outer helium purge channel of fiber glass reinforced phenolic honeycomb core, is used as a thin, lightweight insulation for external surfaces of cryogenic-propellant tanks
Roles for Faculty in Reducing Barriers to Success for Part-Time Graduate Students
There is limited research on the barriers to successful degree completion for part-time graduate students. The purpose of this paper is to present the results of a survey on former part-time graduate students at Penn State Harrisburg and to discuss the influence that faculty and advisors can have on their success in completing graduate degrees
SRB Environment Evaluation and Analysis. Volume 3: ASRB Plume Induced Environments
Contract NAS8-37891 was expanded in late 1989 to initiate analysis of Shuttle plume induced environments as a result of the substitution of the Advanced Solid Rocket Booster (ASRB) for the Redesigned Solid Rocket Booster (RSRB). To support this analysis, REMTECH became involved in subscale and full-scale solid rocket motor test programs which further expanded the scope of work. Later contract modifications included additional tasks to produce initial design cycle environments and to specify development flight instrumentation. Volume 3 of the final report describes these analyses and contains a summary of reports resulting from various studies
Full-scale aircraft cabin flammability tests of improved fire-resistant materials
Full-scale aircraft cabin flammability tests to evaluate the effectiveness of new fire-resistant materials by comparing their burning characteristics with those of older aircraft materials are described. Three tests were conducted and are detailed. Test 1, using pre-1968 materials, was run to correlate the procedures and to compare the results with previous tests by other organizations. Test 2 included newer, improved fire-resistant materials. Test 3 was essentially a duplicate of test 2, but a smokeless fuel was used. Test objectives, methods, materials, and results are presented and discussed. Results indicate that the pre-1968 materials ignited easily, allowed the fire to spread, produced large amounts of smoke and toxic combustion products, and resulted in a flash fire and major fire damage. The newer fire-resistant materials did not allow the fire to spread. Furthermore, they produced less, lower concentrations of toxic combustion products, and lower temperatures. The newer materials did not produce a flash fire
Thermal and aerothermal performance of a titanium multiwall thermal protection system
A metallic thermal protection system (TPS) concept the multiwall designed for temperature and pressure at Shuttle body point 3140 where the maximum surface temperature is approximately 811 K was tested to evaluate thermal performance and structural integrity. A two tile model of titanium multiwall and a model consisting of a low temperature reusable surface insulation (LRSI) tiles were exposed to 25 simulated thermal and pressure Shuttle entry missions. The two systems performed the same, and neither system deteriorated during the tests. It is indicated that redesign of the multiwall tiles reduces tile thickness and/or weight. A nine tile model of titanium multiwal was tested for radiant heating and aerothermodynamics. Minor design changes that improve structural integrity without having a significant impact on the thermal protection ability of the titanium multiwall TPS are identified. The capability of a titanium multiwall thermal protection system to protect an aluminum surface during a Shuttle type entry trajectory at locations on the vehicle where the maximum surface temperature is below 811 K is demonstrated
1-D Transient Thermal Modeling of an Ablative Material (MCC-1) Exposed to a Simulated Convective Titan 4 Launch Environment
The purpose of the work is to demonstrate that the flat test panel substrate temperatures are consistent with analysis predictions for MCC-1 applied to a aluminum substrate. The testing was performed in an aerothermal facility on samples of three different thicknesses of MCC-1 on an aluminum substrate. The results of the test were compared with a Transient Thermal model. The key assumptions of the Transient Thermal model were: (1) a one-dimensional heat transfer; (2) a constant ablation recession rate (determined from pre and post-test measurements); (3) ablation temperature of 540 degrees F; (4) Char left behind the ablation front; and (5) temperature jump correction for incident heat transfer coefficient. Two methods were used to model the heating of bare MCC-1: (1) Directly input surface temperature as a function of time; and (2) Aerothermal heating using calibration plate data and subtracting the radiation losses to tunnel walls. The results are presented as graphs. This article is presented in Viewgraph format
Working group written presentation: Trapped radiation effects
The results of the Trapped Radiation Effects Panel for the Space Environmental Effects on Materials Workshop are presented. The needs of the space community for new data regarding effects of the space environment on materials, including electronics are listed. A series of questions asked of each of the panels at the workshop are addressed. Areas of research which should be pursued to satisfy the requirements for better knowledge of the environment and better understanding of the effects of the energetic charged particle environment on new materials and advanced electronics technology are suggested
Spacecraft materials studies on the Aerospace Corporation tray on EOIM-3
A passive tray was flown on the Effects of Oxygen Interaction with Materials experiment on STS-46 (EOIM-3) with 82 samples from The Aerospace Corporation. A variety of advanced materials related to potential uses on future spacecraft were included for evaluation representing optical coatings, lubricants, polymers, composites, carbon-carbon composite protective coatings, graphite protective coatings, thermal-control materials, and some samples of current materials. An overview of the available results from the investigations of these materials is presented
Improvements in pain, medication use and quality of life in onabotulinumtoxinA-resistant chronic migraine patients following erenumab treatment – real world outcomes
Abstract Background The CGRP antagonists offer a novel therapeutic approach in migraine. Their utility in patients with severe forms of chronic migraine is a subject of particular interest. We present outcomes of 9 months of erenumab treatment in a cohort of patients with difficult-to-control chronic migraine, all of whom had prior unsatisfactory response to onabotulinumtoxinA. Methods We offered erenumab to 98 patients with a prior unsatisfactory response to onabotulinumtoxinA. Eighty of 98 had trialled greater occipital nerve injections (82%), 32/98 peripheral neurostimulation (33%) and 18/98 intravenous dihydroergotamine (18%). Thirty eight of 98 (39%) met the definition of triptan overuse and 43/98 (44%) analgesic overuse. All patients met the EHF criteria for ‘resistant migraine’. Outcome measures (recorded monthly) included days with headache limiting activities of daily living (“red”), not limiting (“amber”), headache free (“green”), and requiring triptans or other analgesics. Quality of life scores - headache impact test 6 (HIT-6), patient health questionnaire 9 (PHQ-9) and pain disability index (PDI) - were also measured. Results Mean number of red days improved by − 6.4 days (SE 0.67, 95%CI − 7.7 to − 5.1, p=0.001) at 3 months; − 6.8 days (SE 0.96, 95%CI − 8.80 to − 4.9, p=0.001) at 6 months and − 6.5 days (SE 0.86, 95%CI − 8.3 to − 4.8, p=0.001) at 9 months. Repeated measures ANOVA confirmed improvements in the number of red (p=0.001), green (p=0.001), triptan (p=0.001) and painkiller days (p=0.001) as well as scores of the HIT-6 (p=0.001), PHQ-9 (p=0.001), and PDI (p=0.001) across the duration of study. Conclusion We observed improvements in pain, medication use and quality of life in onabotulinumtoxinA-resistant chronic migraine patients following erenumab treatment. </jats:sec
- …