Arcjet Testing and Thermal Model Development for Multilayer Felt Reusable Surface Insulation
NASA Technical Reports Server (NTRS)
Milos, Frank S.; Scott, Carl Douglas; Papa, Steven V.
2012-01-01
Felt Reusable Surface Insulation was used extensively on leeward external surfaces of the Shuttle Orbiter, where the material is reusable for temperatures up to 670 K. For application on leeward surfaces of the Orion Multi-Purpose Crew Vehicle, where predicted temperatures reach 1620 K, the material functions as a pyrolyzing conformal ablator. An arcjet test series was conducted to assess the performance of multilayer Felt Reusable Surface Insulation at high temperatures, and a thermal-response, pyrolysis, and ablation model was developed. Model predictions compare favorably with the arcjet test data
Sound absorption of low-temperature reusable surface insulation candidate materials
NASA Technical Reports Server (NTRS)
Johnston, J. D.
1974-01-01
Sound absorption data from tests of four candidate low-temperature reusable surface insulation materials are presented. Limitations on the use of the data are discussed, conclusions concerning the effective absorption of the materials are drawn, and the relative significance to Vibration and Acoustic Test Facility test planning of the absorption of each material is assessed.
Heat Transfer Measurement and Modeling in Rigid High-Temperature Reusable Surface Insulation Tiles
NASA Technical Reports Server (NTRS)
Daryabeigi, Kamran; Knutson, Jeffrey R.; Cunnington, George R.
2011-01-01
Heat transfer in rigid reusable surface insulations was investigated. Steady-state thermal conductivity measurements in a vacuum were used to determine the combined contribution of radiation and solid conduction components of heat transfer. Thermal conductivity measurements at higher pressures were then used to estimate the effective insulation characteristic length for gas conduction modeling. The thermal conductivity of the insulation can then be estimated at any temperature and pressure in any gaseous media. The methodology was validated by comparing estimated thermal conductivities with published data on a rigid high-temperature silica reusable surface insulation tile. The methodology was also applied to the alumina enhanced thermal barrier tiles. Thermal contact resistance for thermal conductivity measurements on rigid tiles was also investigated. A technique was developed to effectively eliminate thermal contact resistance on the rigid tile s cold-side surface for the thermal conductivity measurements.
NASA Technical Reports Server (NTRS)
Chapman, A. J.
1973-01-01
Reusable surface insulation materials, which were developed as heat shields for the space shuttle, were tested over a range of conditions including heat-transfer rates between 160 and 620 kW/sq m. The lowest of these heating rates was in a range predicted for the space shuttle during reentry, and the highest was more than twice the predicted entry heating on shuttle areas where reusable surface insulation would be used. Individual specimens were tested repeatedly at increasingly severe conditions to determine the maximum heating rate and temperature capability. A silica-base material experienced only minimal degradation during repeated tests which included conditions twice as severe as predicted shuttle entry and withstood cumulative exposures three times longer than the best mullite material. Mullite-base materials cracked and experienced incipient melting at conditions within the range predicted for shuttle entry. Neither silica nor mullite materials consistently survived the test series with unbroken waterproof surfaces. Surface temperatures for a silica and a mullite material followed a trend expected for noncatalytic surfaces, whereas surface temperatures for a second mullite material appeared to follow a trend expected for a catalytic surface.
Closeup view of the exterior of the starboard side of ...
Close-up view of the exterior of the starboard side of the forward fuselage of the Orbiter Discovery looking at the forward facing observation windows of the flight deck. Note the High-temperature Reusable Surface Insulation (HRSI) surrounding the window openings, the Low-temperature Reusable Surface Insulation (LRSI) immediately beyond the HRSI tiles and the Advanced Flexible Reusable Surface Insulation blankets just beyond the LRSI tiles. The holes in the tiles are injection points for the application of waterproofing material. The windows are composed of redundant pressure window panes of thermal glass. This image was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Development of design allowables data for adhesives for attaching reusable surface insulation
NASA Technical Reports Server (NTRS)
Owen, H. P.; Carroll, M. T.
1972-01-01
Results are presented from tests to establish design allowables data for the following room temperature vulcanizing (RTV) silicone rubber based adhesives: (1) General Electric's RTV-560; (2) Dow Corning's 93-046; and (3) Martin Marietta's SLA-561. These adhesives are being evaluated for attaching reusable surface insulation to space shuttle structure.
NASA Technical Reports Server (NTRS)
Forgsberg, K.
1979-01-01
The primary insulation system used to protect the space shuttle orbiter on reentry is an externally attached, rigidized, fibrous silica which has been machined into tiles. The tiles constitute the temperature reusable surface insulation system and are used on over 70 percent of the vehicle exterior surface where peak temperatures range from 400 to 1260 C. Cargon-carbon leading edges are used in areas where peak temperatures exceed 1650 C and a felt flexible insulation is used in regions below 400 C. Approximately 32,000 tiles are used in the HRST system and because of vehicle configuration, aerodynamic requirements, and weight considerations no two tiles are alike. Fabrication and quality control procedures are described.
NASA Technical Reports Server (NTRS)
Owen, H. P.; Carroll, M. T.
1973-01-01
The task consisted of conducting mechanical and thermal tests to establish design allowables data on a new room temperature vulcanizing (RTV) silicone adhesive, X3-6004. Low modulus, coupled with relatively low density and good low-temperature properties of this adhesive, places it in contention as a candidate for attaching reusable surface insulation on the space shuttle. Data obtained show that the modulus values of X3-6004 are significantly lower than those of RTV-560 and the other three adhesives characterized at test temperatures from 550 to -175 F. At -175, -200 and -270 F, the modulus of X3-6004 is approximately the same as GE RTV-560 and the other three silicone adhesives. The X3-6004 adhesive exhibits good processing properties. It has a 12 percent lower density than RTV-560. Although lower in overall strength properties as compared to the other adhesives in the program, X3-6004 has adequate adhesion to 2024T81 aluminum to compete as an adhesive for attaching reusable surface insulation. It does exhibit some tendency to revert and soften at temperatures above 350 F when in a confined area.
Bonding of reusable surface insulation with low density silicone foams
NASA Technical Reports Server (NTRS)
Hiltz, A. A.; Hockridge, R. R.; Curtis, F. P.
1972-01-01
The development and evaluation of a reduced density, high reliable foamed bond strain isolation system for attaching reusable surface insulation to the space shuttle structure are reported. Included are data on virgin materials as well as on materials that received 100 cycles of exposure to 650 F for approximately 20 minutes per cycle. Room temperature vulcanizing silicon elastomers meet all the requirments for an adhesive bonding system.
NASA Technical Reports Server (NTRS)
Banas, R. P.; Elgin, D. R.; Cordia, E. R.; Nickel, K. N.; Gzowski, E. R.; Aguiler, L.
1983-01-01
Three ceramic, reusable surface insulation materials and two borosilicate glass coatings were used in the fabrication of tiles for the Space Shuttle orbiters. Approximately 77,000 tiles were made from these materials for the first three orbiters, Columbia, Challenger, and Discovery. Lessons learned in the development, scale up to production and manufacturing phases of these materials will benefit future production of ceramic reusable surface insulation materials. Processing of raw materials into tile blanks and coating slurries; programming and machining of tiles using numerical controlled milling machines; preparing and spraying tiles with the two coatings; and controlling material shrinkage during the high temperature (2100-2275 F) coating glazing cycles are among the topics discussed.
1998-08-10
In the Tile Fabrication Shop, Tony Rollins, with United Space Alliance, holds down a curtain while making a test sample of tile on a block 5-axis computerized numerical control milling machine. About 70 percent of a Space Shuttle orbiter’s external surface is shielded from heat by a network of more than 24,000 tiles formed from a silica fiber compound. They are known as High-Temperature Reusable Surface Insulation (HRSI) tiles and Low-Temperature Reusable Surface Insulation (LRSI) tiles. Most HRSI tiles are 6 inches square, but may be as large as 12 inches in some areas, and 1 to 5 inches thick. LRSI tiles are generally 8 inches square, ranging from 0.2to 1-inch thick. More advanced materials such as Flexible Insulation Blankets have replaced tiles on some upper surfaces of the orbiter
Kampf, Günter; Degenhardt, Stina; Lackner, Sibylle; Ostermeyer, Christiane
2014-01-01
Background: It has recently been reported that reusable dispensers for surface disinfection tissues may be contaminated, especially with adapted Achromobacter species 3, when products based on surface-active ingredients are used. Fresh solution may quickly become recontaminated if dispensers are not processed adequately. Methods: We evaluated the abilities of six manual and three automatic processes for processing contaminated dispensers to prevent recolonisation of a freshly-prepared disinfectant solution (Mikrobac forte 0.5%). Dispensers were left at room temperature for 28 days. Samples of the disinfectant solution were taken every 7 days and assessed quantitatively for bacterial contamination. Results: All automatic procedures prevented recolonisation of the disinfectant solution when a temperature of 60–70°C was ensured for at least 5 min, with or without the addition of chemical cleaning agents. Manual procedures prevented recontamination of the disinfectant solution when rinsing with hot water or a thorough cleaning step was performed before treating all surfaces with an alcohol-based disinfectant or an oxygen-releaser. Other cleaning and disinfection procedures, including the use of an alcohol-based disinfectant, did not prevent recolonisation. Conclusions: These results indicate that not all processes are effective for processing reusable dispensers for surface-disinfectant tissues, and that a high temperature during the cleaning step or use of a biofilm-active cleaning agent are essential. PMID:24653973
NASA Technical Reports Server (NTRS)
Throckmorton, D. A.
1976-01-01
An experimental investigation is presented that was performed to determine the effect of a surface-to-gap wall temperature discontinuity on the heat transfer within space shuttle, reusable surface insulation, tile gaps submerged in a thick turbulent boundary layer. Heat-transfer measurements were obtained on a flat-plate, single-gap model submerged in a turbulent tunnel wall boundary layer at a nominal free-stream Mach number of 10.3 and free-stream Reynolds numbers per meter of 1.5 million, 3.3 million and 7.8 million. Surface-to-gap wall temperature discontinuities of varying degree were created by heating the surface of the model upstream of the instrumented gap. The sweep angle of the gap was varied between 0 deg and 60 deg; gap width and depth were held constant. A surface-to-gap wall temperature discontinuity (surface temperature greater than gap wall temperature) results in increased heat transfer to the near-surface portion of the gap, as compared with the heat transfer under isothermal conditions, while decreasing the heat transfer to the deeper portions of the gap. The nondimensionalized heat transfer to the near-surface portion of the gap is shown to decrease with increasing Reynolds number; in the deeper portion of the gap, the heat transfer increases with Reynolds number.
Catalytic recombination of nitrogen and oxygen on high-temperature reusable surface insulation
NASA Technical Reports Server (NTRS)
Scott, C. D.
1980-01-01
The energy transfer catalytic recombination coefficient for nitrogen and oxygen recombination on the surface coating of high-temperature reusable surface insulation (HRSI) is inferred from stagnation point heat flux measurements in a high-temperature dissociated arc jet flow. The resulting catalytic recombination coefficients are correlated with an Arrhenius model for convenience, and these expressions may be used to account for catalytic recombination effects in predictions of the heat flux on the HRSI thermal protection system of the Space Shuttle Orbiter during reentry flight. Analysis of stagnation point pressure and total heat balance enthalpy measurements indicates that the arc heater reservoir conditions are not in chemical equilibrium. This is contrary to what is usually assumed for arc jet analysis and indicates the need for suitable diagnostics and analyses, especially when dealing with chemical reaction phenomena such as catalytic recombination heat transfer effects.
Tony Rollins fashions a new tile for the Space Shuttle orbiter
NASA Technical Reports Server (NTRS)
1998-01-01
In the Tile Fabrication Shop, Tony Rollins, with United Space Alliance, holds down a curtain while making a test sample of tile on a block 5-axis computerized numerical control milling machine. About 70 percent of a Space Shuttle orbiter's external surface is shielded from heat by a network of more than 24,000 tiles formed from a silica fiber compound. They are known as High-Temperature Reusable Surface Insulation (HRSI) tiles and Low-Temperature Reusable Surface Insulation (LRSI) tiles. Most HRSI tiles are 6 inches square, but may be as large as 12 inches in some areas, and 1 to 5 inches thick. LRSI tiles are generally 8 inches square, ranging from 0.2- to 1-inch thick. More advanced materials such as Flexible Insulation Blankets have replaced tiles on some upper surfaces of the orbiter.
Performance of LI-1542 reusable surface insulation system in a hypersonic stream
NASA Technical Reports Server (NTRS)
Hunt, L. R.; Bohon, H. L.
1974-01-01
The thermal and structural performance of a large panel of LI-1542 reusable surface insulation tiles was determined by a series of cyclic heating tests using radiant lamps and aerothemal tests in the Langley 8-foot high-temperature structures tunnel. Aerothermal tests were conducted at a free-stream Mach number of 6.6, a total temperature of 1830 K, Reynolds numbers of 2.0 and 4,900,000 per meter, and dynamic pressures of 29 and 65 kPa. The results suggest that pressure gradients in gaps and flow impingement on the header walls at the end of longitudinal gaps are sources for increased gap heating. Temperatures higher than surface radiation equilibrium temperature were measured deep in gaps and at the header walls. Also, the damage tolerance of the LI-1542 tiles appears to be very high. Tile edge erosion rate was slow; could not be tolerated in a shuttle application. Tiles soaked with water and subjected to rapid depressurization and aerodynamic heating showed no visible evidence of damage.
Comparison of kinetic models for atom recombination on high-temperature reusable surface insulation
NASA Technical Reports Server (NTRS)
Willey, Ronald J.
1993-01-01
Five kinetic models are compared for their ability to predict recombination coefficients for oxygen and nitrogen atoms over high-temperature reusable surface insulation (HRSI). Four of the models are derived using Rideal-Eley or Langmuir-Hinshelwood catalytic mechanisms to describe the reaction sequence. The fifth model is an empirical expression that offers certain features unattainable through mechanistic description. The results showed that a four-parameter model, with temperature as the only variable, works best with data currently available. The model describes recombination coefficients for oxygen and nitrogen atoms for temperatures from 300 to 1800 K. Kinetic models, with atom concentrations, demonstrate the influence of atom concentration on recombination coefficients. These models can be used for the prediction of heating rates due to catalytic recombination during re-entry or aerobraking maneuvers. The work further demonstrates a requirement for more recombination experiments in the temperature ranges of 300-1000 K, and 1500-1850 K, with deliberate concentration variation to verify model requirements.
Poorly processed reusable surface disinfection tissue dispensers may be a source of infection.
Kampf, Günter; Degenhardt, Stina; Lackner, Sibylle; Jesse, Katrin; von Baum, Heike; Ostermeyer, Christiane
2014-01-21
Reusable surface disinfectant tissue dispensers are used in hospitals in many countries because they allow immediate access to pre-soaked tissues for targeted surface decontamination. On the other hand disinfectant solutions with some active ingredients may get contaminated and cause outbreaks. We determined the frequency of contaminated surface disinfectant solutions in reusable dispensers and the ability of isolates to multiply in different formulations. Reusable tissue dispensers with different surface disinfectants were randomly collected from healthcare facilities. Solutions were investigated for bacterial contamination. The efficacy of two surface disinfectants was determined in suspension tests against two isolated species directly from a contaminated solution or after 5 passages without selection pressure in triplicate. Freshly prepared use solutions were contaminated to determine survival of isolates. 66 dispensers containing disinfectant solutions with surface-active ingredients were collected in 15 healthcare facilities. 28 dispensers from nine healthcare facilities were contaminated with approximately 107 cells per mL of Achromobacter species 3 (9 hospitals), Achromobacter xylosoxidans or Serratia marcescens (1 hospital each). In none of the hospitals dispenser processing had been adequately performed. Isolates regained susceptibility to the disinfectants after five passages without selection pressure but were still able to multiply in different formulations from different manufacturers at room temperature within 7 days. Neglecting adequate processing of surface disinfectant dispensers has contributed to frequent and heavy contamination of use-solutions based on surface active ingredients. Tissue dispenser processing should be taken seriously in clinical practice.
Poorly processed reusable surface disinfection tissue dispensers may be a source of infection
2014-01-01
Background Reusable surface disinfectant tissue dispensers are used in hospitals in many countries because they allow immediate access to pre-soaked tissues for targeted surface decontamination. On the other hand disinfectant solutions with some active ingredients may get contaminated and cause outbreaks. We determined the frequency of contaminated surface disinfectant solutions in reusable dispensers and the ability of isolates to multiply in different formulations. Methods Reusable tissue dispensers with different surface disinfectants were randomly collected from healthcare facilities. Solutions were investigated for bacterial contamination. The efficacy of two surface disinfectants was determined in suspension tests against two isolated species directly from a contaminated solution or after 5 passages without selection pressure in triplicate. Freshly prepared use solutions were contaminated to determine survival of isolates. Results 66 dispensers containing disinfectant solutions with surface-active ingredients were collected in 15 healthcare facilities. 28 dispensers from nine healthcare facilities were contaminated with approximately 107 cells per mL of Achromobacter species 3 (9 hospitals), Achromobacter xylosoxidans or Serratia marcescens (1 hospital each). In none of the hospitals dispenser processing had been adequately performed. Isolates regained susceptibility to the disinfectants after five passages without selection pressure but were still able to multiply in different formulations from different manufacturers at room temperature within 7 days. Conclusions Neglecting adequate processing of surface disinfectant dispensers has contributed to frequent and heavy contamination of use-solutions based on surface active ingredients. Tissue dispenser processing should be taken seriously in clinical practice. PMID:24447780
NASA Technical Reports Server (NTRS)
Galanter, S. A.
1975-01-01
A space shuttle high temperature reusable surface insulation (HRSI) tile array with a single missing or lost tile was exposed to a hot gas simulated reentry environment to investigate the heating conditions in and around the vicinity of the missing HRSI tile. Heat flux and pressure data for the lost tile condition were obtained by the use of a water cooled lost tile calibration model. The maximum aluminum substrate temperature obtained during the simulated reentry was 128 C (263 F). The lost tile calibration data indicated a maximum heat flux in the lost tile cavity region of 63 percent of the upstream reference value. This test was conducted at the Ames Research Center in the 20 MW semielliptical thermal protection system (TPS) pilot plasma arc test facility.
Xu, Yan; Wu, Qian; Shimatani, Yuji; Yamaguchi, Koji
2015-10-07
Due to the lack of regeneration methods, the reusability of nanofluidic chips is a significant technical challenge impeding the efficient and economic promotion of both fundamental research and practical applications on nanofluidics. Herein, a simple method for the total regeneration of glass nanofluidic chips was described. The method consists of sequential thermal treatment with six well-designed steps, which correspond to four sequential thermal and thermochemical decomposition processes, namely, dehydration, high-temperature redox chemical reaction, high-temperature gasification, and cooling. The method enabled the total regeneration of typical 'dead' glass nanofluidic chips by eliminating physically clogged nanoparticles in the nanochannels, removing chemically reacted organic matter on the glass surface and regenerating permanent functional surfaces of dissimilar materials localized in the nanochannels. The method provides a technical solution to significantly improve the reusability of glass nanofluidic chips and will be useful for the promotion and acceleration of research and applications on nanofluidics.
Detail view of the leading and top edge of the ...
Detail view of the leading and top edge of the vertical stabilizer of the Orbiter Discovery showing the thermal protection system components with the white Advanced Flexible Reusable Surface Insulation (AFRSI) blanket and the black High-temperature Reusable Surface Insulation (HRSI) tiles along the outer edges. The marks seen on the HRSI tiles are injection point marks and holes for the application of waterproofing material. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
SSME main combustion chamber life prediction
NASA Technical Reports Server (NTRS)
Cook, R. T.; Fryk, E. E.; Newell, J. F.
1983-01-01
Typically, low cycle fatigue life is a function of the cyclic strain range, the material properties, and the operating temperature. The reusable life is normally defined by the number of strain cycles that can be accrued before severe material degradation occurs. Reusable life is normally signified by the initiation or propagation of surface cracks. Hot-fire testing of channel wall combustors has shown significant mid-channel wall thinning or deformation during accrued cyclic testing. This phenomenon is termed cyclic-creep and appears to be significantly accelerated at elevated surface temperatures. This failure mode was analytically modelled. The cyclic life of the baseline SSME-MCC based on measured calorimeter heat transfer data, and the life sensitivity of local hot spots caused by injector effects were determined. Four life enhanced designs were assessed.
NASA Technical Reports Server (NTRS)
Viger, Brent J.; Logan, Robert F.; Fink, Jeffrey E.
1992-01-01
Specially designed bag maintains helium atmosphere around large, low-temperature duct. Easy to install, durable, and reusable. Intended to prevent cryopumping occurring if air or nitrogen allowed to make contact with cold surface of duct.
NASA Technical Reports Server (NTRS)
Taylor, A. H.; Jackson, L. R.; Weinstein, I.
1977-01-01
Three thermal protection systems proposed for a hypersonic research airplane were subjected to high heating rates in the Langley 8 foot, high temperature structures tunnel. Metallic heat sink (Lockalloy), reusable surface insulation, and insulator-ablator materials were each tested under similar conditions. The specimens were tested for a 10 second exposure on the windward side of an elevon deflected 30 deg. The metallic heat sink panel exhibited no damage; whereas the reusable surface insulation tiles were debonded from the panel and the insulator-ablator panel eroded through its thickness, thus exposing the aluminum structure to the Mach 7 environment.
Performance of a mullite reusable surface insulation system in a hypersonic stream
NASA Technical Reports Server (NTRS)
Hunt, L. R.
1976-01-01
The thermal and structural performance of a large panel of mullite reusable surface insulation (RSI) tiles was determined by a series of aerothermal tests in the Langley 8-foot high-temperature structures tunnel. The test panel was designed to represent a portion of the surface structure on a space shuttle orbiter fuselage along a 1,150 K isotherm with the mullite tile system bonded directly to the primary structure. Aerothermal tests were conducted at a free-stream Mach number of 6.7, a total temperature of 1,880 K, a unit Reynolds number of 4.6 million per meter, and dynamic pressure of 62 kPa. The thermal response of the mullite tile was as predicted, and the bond-line temperature did not exceed the design level of 570 K during a typical entry-heat cycle. Geometric irregularities of the tile gaps affected the tile edge temperatures when exposed to hypersonic flow. The tile coating demonstrated good toughness to particle impacts, but the coating cracked and flaked with thermal cycles. The gap filler of woven silica fibers appeared to hinder flow penetration into the gaps and withstood the flow shear of the present tests.
Reusable crucible for containing corrosive liquids
de Pruneda, Jean A. H.
1995-01-01
A reusable, non-wetting, corrosion-resistant material suitable for containment of corrosive liquids is formed of a tantalum or tantalum alloy substrate that is permeated with carbon atoms. The substrate is carburized to form surface layers of TaC and Ta.sub.2 C, and then is heated at high temperature under vacuum until the carbon atoms in the carbide layers diffuse throughout the substrate to form a solid solution of carbon atoms randomly interspersed in the tantalum or tantalum alloy lattice.
Reusable crucible for containing corrosive liquids
Pruneda, J.A.H. de.
1995-01-24
A reusable, non-wetting, corrosion-resistant material suitable for containment of corrosive liquids is formed of a tantalum or tantalum alloy substrate that is permeated with carbon atoms. The substrate is carburized to form surface layers of TaC and Ta[sub 2]C, and then is heated at high temperature under vacuum until the carbon atoms in the carbide layers diffuse throughout the substrate to form a solid solution of carbon atoms randomly interspersed in the tantalum or tantalum alloy lattice. 10 figures.
Advanced High Temperature Structural Seals
NASA Astrophysics Data System (ADS)
Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark
2002-10-01
This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.
Advanced High Temperature Structural Seals
NASA Technical Reports Server (NTRS)
Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark
2002-01-01
This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.
Performance of LI-1542 reusable surface insulation system in a hypersonic stream
NASA Technical Reports Server (NTRS)
Hunt, L. R.; Shideler, J. L.; Weinstein, I.
1976-01-01
The thermal and structural performance LI-1542 reusable surface insulation (RSI) tiles was investigated. The test panel was designed to represent part of the surface structure on a space shuttle orbiter fuselage along a 1250 K isotherm. Aerothermal tests were conducted at a free-stream Mach number of 6.6, a total temperature of 1820 K, Reynolds numbers of 2 millon and 5 million per meter, and dynamic pressures of 26 and 65 kPa. The RSI tiles demonstrated good thermal protection and structural integrity. High temperatures were caused by misalinement in tile height, offset the tile longitudinal alinement, and leakage around thermal seals when differential pressure existed across the panel. The damage tolerance of LI-1542 RSI appeared high. The tile coating crazed early in the test program, but this did not effect the tile integrity. Erosion of the tile edges occurred at forward-facing steps and at the ends of longitudinal gaps because of particle impacts and flow shear.
NASA Technical Reports Server (NTRS)
Milhoan, James D.; Pham, Vuong T.; Sherborne, William D.
1993-01-01
Thermal tests of Orbiter thermal protection system (TPS) tiles, which were coated with borosilicate glass slurries fabricated at Kennedy Space Center (KSC), were performed in the Radiant Heat Test Facility and the Atmospheric Reentry Materials & Structures Evaluation Facility at Johnson Space Center to verify tile coating integrity after exposure to multiple entry simulation cycles in both radiant and convective heating environments. Eight high temperature reusable surface insulation (HRSI) tiles and six low temperature reusable surface insulation (LRSI) tiles were subjected to 25 cycles of radiant heat at peaked surface temperatures of 2300 F and 1200 F, respectively. For the LRSI tiles, an additional cycle at peaked surface temperature of 2100 F was performed. There was no coating crack on any of the HRSI specimens. However, there were eight small coating cracks (less than 2 inches long) on two of the six LRSI tiles on the 26th cycle. There was practically no change on the surface reflectivity, physical dimensions, or weight of any of the test specimens. There was no observable thermal-chemical degradation of the coating either. For the convective heat test, eight HRSI tiles were tested for five cycles at a surface temperature of 2300 F. There was no thermal-induced coating crack on any of the test specimens, almost no change on the surface reflectivity, and no observable thermal-chemical degradation with an exception of minor slumping of the coating under painted TPS identification numbers. The tests demonstrated that KSC's TPS slurries and coating processes meet the Orbiter's thermal specification requirements.
NASA Technical Reports Server (NTRS)
DelPapa, Steven V.
2005-01-01
Arc jet tests of candidate tile repair materials and baseline Orbiter uncoated reusable surface insulation (RSI) were performed in the Johnson Space Center's (JSC) Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF) from June 23, 2003, through August 19, 2003. These tests were performed to screen candidate tile repair materials by verifying the high temperature performance and determining the thermal stability. In addition, tests to determine the surface emissivity at high temperatures and the geometric shrinkage of bare RSI were performed. In addition, tests were performed to determine the surface emissivity at high temperatures and the geometric shrinkage of uncoated RSI.
NASA Technical Reports Server (NTRS)
Norman, I.; Rochelle, W. C.; Kimbrough, B. S.; Ritrivi, C. A.; Ting, P. C.; Dotts, R. L.
1982-01-01
Thermal performance verification of Reusable Surface Insulation (RSI) has been accomplished by comparisons of STS-2 Orbiter Flight Test (OFT) data with Thermal Math Model (TMM) predictions. The OFT data was obtained from Development Flight Instrumentation RSI plug and gap thermocouples. Quartertile RSI TMMs were developed using measured flight data for surface temperature and pressure environments. Reference surface heating rates, derived from surface temperature data, were multiplied by gap heating ratios to obtain tile sidewall heating rates. This TMM analysis resulted in good agreement of predicted temperatures with flight data for thermocouples located in the RSI, Strain Isolation Pad, filler bar and structure.
Simultaneous Luminescence Pressure and Temperature Mapping
NASA Technical Reports Server (NTRS)
Buck, Gregory M. (Inventor)
1998-01-01
A simultaneous luminescence pressure and temperature mapping system is developed including improved dye application techniques for surface temperature and pressure measurements from 5 torr to 1000 torr with possible upgrade to from 0.5 torr to several atmospheres with improved camera resolution. Adsorbed perylene dye on slip-cast silica is pressure (oxygen) sensitive and reusable to relatively high temperatures (-150 C). Adsorbed luminescence has an approximately linear color shift with temperature, which can be used for independent temperature mapping and brightness pressure calibration with temperature.
Simultaneous Luminescence Pressure and Temperature Mapping System
NASA Technical Reports Server (NTRS)
Buck, Gregory M. (Inventor)
1995-01-01
A simultaneous luminescence pressure and temperature mapping system is developed including improved dye application techniques for surface temperature and pressure measurements from 5 torr to 1000 torr with possible upgrade to from 0.5 torr to several atmospheres with improved camera resolution. Adsorbed perylene dye on slip-cast silica is pressure (oxygen) sensitive and reusable to relatively high temperatures (approximately 150 C). Adsorbed luminescence has an approximately linear color shift with temperature, which can be used for independent temperature mapping and brightness pressure calibration with temperature.
Magnetic Carbon Microspheres as a Reusable Adsorbent for Sulfonamide Removal from Water
NASA Astrophysics Data System (ADS)
Dai, Kewei; Wang, Fenghe; Jiang, Wei; Chen, Yajun; Mao, Jing; Bao, Jian
2017-09-01
Novel reusable magnetic carbon microspheres (MCMs) were prepared by hydrothermal method with glucose as carbon source and Fe3O4 nanoparticles as magnetic raw materials. And adsorption performance of MCMs for sulfonamide removal from water was investigated in detail. The results indicated that the calcination temperature and calcination time had significant effects on the surface area and its volume porous of MCMs. When MCMs were calcined in 600 °C for 1 h, the surface area and volume porous of MCMs were 1228 m2/g and 0.448 m3/g, respectively. The adsorption results showed that the adsorption data fitted well with the Langmuir isotherm model and followed pseudo-second-order kinetics. When the pH value was changed from 4.0 to 10.0, the adsorption capacity of MCMs for sulfonamide was decreased from 24.6 to 19.2 mg/g. The adsorption capacity of as-synthesized MCMs achieved 18.31 mg/g after it was reused four times, which exhibited a desirable adsorption capacity and reusability.
Reusable high-temperature heat pipes and heat pipe panels
NASA Technical Reports Server (NTRS)
Camarda, Charles J. (Inventor); Ransone, Philip O. (Inventor)
1989-01-01
A reusable, durable heat pipe which is capable of operating at temperatures up to about 3000 F in an oxidizing environment and at temperatures above 3000 F in an inert or vacuum environment is produced by embedding a refractory metal pipe within a carbon-carbon composite structure. A reusable, durable heat pipe panel is made from an array of refractory-metal pipes spaced from each other. The reusable, durable, heat-pipe is employed to fabricate a hypersonic vehicle leading edge and nose cap.
Structures and materials technology issues for reusable launch vehicles
NASA Technical Reports Server (NTRS)
Dixon, S. C.; Tenney, D. R.; Rummler, D. R.; Wieting, A. R.; Bader, R. M.
1985-01-01
Projected space missions for both civil and defense needs require significant improvements in structures and materials technology for reusable launch vehicles: reductions in structural weight compared to the Space Shuttle Orbiter of up to 25% or more, a possible factor of 5 or more increase in mission life, increases in maximum use temperature of the external surface, reusable containment of cryogenic hydrogen and oxygen, significant reductions in operational costs, and possibly less lead time between technology readiness and initial operational capability. In addition, there is increasing interest in hypersonic airbreathing propulsion for launch and transmospheric vehicles, and such systems require regeneratively cooled structure. The technology issues are addressed, giving brief assessments of the state-of-the-art and proposed activities to meet the technology requirements in a timely manner.
A ceramic matrix composite thermal protection system for hypersonic vehicles
NASA Technical Reports Server (NTRS)
Riccitiello, Salvatore R.; Love, Wendell L.; Pitts, William C.
1993-01-01
The next generation of hypersonic vehicles (NASP, SSTO) that require reusable thermal protection systems will experience acreage surface temperatures in excess of 1100 C. More important, they will experience a more severe physical environment than the Space Shuttle due to non-pristine launching and landing conditions. As a result, maintenance, inspection, and replacement factors must be more thoroughly incorporated into the design of the TPS. To meet these requirements, an advanced thermal protection system was conceived, designated 'TOPHAT'. This system consists of a toughened outer ceramic matrix composite (CMC) attached to a rigid reusable surface insulator (RSI) which is directly bonded to the surface. The objective of this effort was to evaluate this concept in an aeroconvective environment, to determine the effect of impacts to the CMC material, and to compare the results with existing thermal protection systems.
NASA Astrophysics Data System (ADS)
Mahulikar, Shripad P.; Khurana, Shashank; Dungarwal, Ritesh; Shevakari, Sushil G.; Subramanian, Jayakumar; Gujarathi, Amit V.
2008-12-01
The temperature field history of passive Thermal Protection System (TPS) material at the nose-cap (forward stagnation region) of a Reusable Hypersonic Vehicle (RHV) is generated. The 3-D unsteady heat transfer model couples conduction in the solid with external convection and radiation that are modeled as time-varying boundary conditions on the surface. Results are presented for the following two cases: (1) nose-cap comprised of ablative TPS material only (SIRCA/PICA), and (2) nose-cap comprised of a combination of ablative TPS material with moderate thermal conductivity and insulative TPS material. Comparison of the temperature fields of SIRCA and PICA [Case (1)] indicates lowering of the peak stagnation region temperatures for PICA, due to its higher thermal conductivity. Also, the use of PICA and insulative TPS [Case (2)] for the nose-cap has higher potential for weight reduction than the use of ablative TPS alone.
Advanced High Temperature Structural Seals
NASA Technical Reports Server (NTRS)
Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Shorey, Mark W.; Steinetz, Bruce (Technical Monitor)
2000-01-01
This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 lb payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs. During the first phase of this program the existing launch vehicle control surface sealing concepts were reviewed, the aerothermal environment for a high temperature seal design was analyzed and a mock up of an arc-jet test fixture for evaluating seal concepts was fabricated.
A ceramic matrix composite thermal protection system for hypersonic vehicles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Riccitiello, S.R.; Love, W.L.; Pitts, W.C.
1993-07-01
The next generation of hypersonic vehicles (NASP, SSTO) that require reusable thermal protection systems will experience acreage surface temperatures in excess of 1100 C. More important, they will experience a more severe physical environment than the Space Shuttle due to non-pristine launching and landing conditions. As a result, maintenance, inspection, and replacement factors must be more thoroughly incorporated into the design of the TPS. To meet these requirements, an advanced thermal protection system was conceived, designated 'TOPHAT'. This system consists of a toughened outer ceramic matrix composite (CMC) attached to a rigid reusable surface insulator (RSI) which is directly bondedmore » to the surface. The objective of this effort was to evaluate this concept in an aeroconvective environment, to determine the effect of impacts to the CMC material, and to compare the results with existing thermal protection systems. 10 refs.« less
Stability and reactivity of dimethylethoxysilane
NASA Technical Reports Server (NTRS)
Johnson, Richard E.; Ford, Douglas I.
1992-01-01
Dimethylethoxysilane (DMES) is currently used to treat the High-temperature Reusable Surface Insulation (HRSI) shuttle tiles in order to provide a hydrophobic surface on the silica. DMES is a volatile, reactive silane that incorporates two reactive sites, the ethoxy group and the silica-hydride group. The work reported in this paper focused on the reactivity of these two groups with silica, water, quantitative reagents, and within DMES itself.
Development of a Pressure Box to Evaluate Reusable-Launch-Vehicle Cryogenic-Tank Panels
NASA Technical Reports Server (NTRS)
Ambur, Damodar R.; Sikora, Joseph; Maguire, James F.; Winn, Peter M.
1996-01-01
A cryogenic pressure-box test machine has been designed and is being developed to test full-scale reusable-launch-vehicle cryogenic-tank panels. This machine is equipped with an internal pressurization system, a cryogenic cooling system, and a heating system to simulate the mechanical and thermal loading conditions that are representative of a reusable-launch-vehicle mission profile. The cryogenic cooling system uses liquid helium and liquid nitrogen to simulate liquid hydrogen and liquid oxygen tank internal temperatures. A quartz lamp heating system is used for heating the external surface of the test panels to simulate cryogenic-tank external surface temperatures during re-entry of the launch vehicle. The pressurization system uses gaseous helium and is designed to be controlled independently of the cooling system. The tensile loads in the axial direction of the test panel are simulated by means of hydraulic actuators and a load control system. The hoop loads in the test panel are reacted by load-calibrated turnbuckles attached to the skin and frame elements of the test panel. The load distribution in the skin and frames can be adjusted to correspond to the tank structure by using these turnbuckles. The seal between the test panel and the cryogenic pressure box is made from a reinforced Teflon material which can withstand pressures greater than 52 psig at cryogenic temperatures. Analytical results and tests on prototype test components indicate that most of the cryogenic-tank loading conditions that occur in flight can be simulated in the cryogenic pressure-box test machine.
Cryopumping in Cryogenic Insulations for a Reusable Launch Vehicle
NASA Technical Reports Server (NTRS)
Johnson, Theodore F.; Weiser, Erik S.; Grimsley, Brian W.; Jensen, Brian J.
2003-01-01
Testing at cryogenic temperatures was performed to verify the material characteristics and manufacturing processes of reusable propellant tank cryogenic insulations for a Reusable Launch Vehicle (RLV). The unique test apparatus and test methods developed for the investigation of cryopumping in cryogenic insulations are described. Panel level test specimens with various types of cryogenic insulations were subjected to a specific thermal profile where the temperature varied from -262 C to 21 C. Cryopumping occurred if the interior temperature of the specimen exhibited abnormal temperature fluctuations, such as a sudden decrease in temperature during the heating phase.
Testing the Shuttle heat-protection armor
NASA Technical Reports Server (NTRS)
Strouhal, G.; Tillian, D. J.
1976-01-01
The article deals with the thermal protection system (TPS) designed to keep Space Shuttle structures at 350 F ratings over a wide range of temperatures encountered in orbit, but also during prelaunch, launch, deorbit and re-entry, landing and turnaround. The structure, function, fabrication, and bonding of various types of reusable surface insulation and composite materials are described. Test programs are developed for insulation, seals, and adhesion bonds; leak tests and acoustic fatigue tests are mentioned. Test facilities include arc jets, radiant heaters, furnaces, and heated tunnels. The certification tests to demonstrate TPS reusability, structural integrity, thermal performance, and endurance will include full-scale assembly tests and initial orbital flight tests.
NASA Astrophysics Data System (ADS)
Stickler, Patrick B.; Keller, Peter C.
1998-01-01
Reusable Launch Vehicles (RLV's) utilizing LOX\\LH2 as the propellant require lightweight durable structural systems to meet mass fraction goals and to reduce overall systems operating costs. Titanium honeycomb sandwich with flexible blanket TPS on the windward surface is potentially the lightest-weight and most operable option. Light weight is achieved in part because the honeycomb sandwich tank provides insulation to its liquid hydrogen contents, with no need for separate cryogenic insulation, and in part because the high use temperature of titanium honeycomb reduces the required surface area of re-entry thermal protection systems. System operability is increased because TPS needs to be applied only to surfaces where temperatures exceed approximately 650 K. In order to demonstrate the viability of a titanium sandwich constructed propellant tank, a technology demonstration program was conducted including the design, fabrication and testing of a propellant tank-TPS system. The tank was tested in controlled as well as ambient environments representing ground hold conditions for a RLV main propellant tank. Data collected during each test run was used to validate predictions for air liquefaction, outside wall temperature, boil-off rates, frost buildup and its insulation effects, and the effects of placing a thermal protection system blanket on the external surface. Test results indicated that titanium honeycomb, when used as a RLV propellant tank material, has great promise as a light-weight structural system.
Improvements to the Whoosh Bottle Rocket Car Demonstration
ERIC Educational Resources Information Center
Campbell, Dean J.; Staiger, Felicia A.; Jujjavarapu, Chaitanya N.
2015-01-01
The whoosh bottle rocket car has been redesigned to be more reusable and more robust, making it even easier to use as a demonstration. Enhancements of this demonstration, including the use of heat sensitive ink and electronic temperature probes, enable users to find warmer and cooler regions on the surface of the whoosh bottle.
NASA Technical Reports Server (NTRS)
Stewart, D. A.; Goldstein, H. E.; Leiser, D. B. (Inventor)
1983-01-01
A high temperature stable and solar radiation stable thermal control coating is described which is useful either as such, applied directly to a member to be protected, or applied as a coating on a re-usable surface insulation (RSI). It has a base coat layer and an overlay glass layer. The base coat layer has a high emittance, and the overlay layer is formed from discrete, but sintered together glass particles to give the overlay layer a high scattering coefficient. The resulting two-layer space and thermal control coating has an absorptivity-to-emissivity ratio of less than or equal to 0.4 at room temperature, with an emittance of 0.8 at 1200 F. It is capable of exposure to either solar radiation or temperatures as high as 2000 F without significant degradation. When used as a coating on a silica substrate to give an RSI structure, the coatings of this invention show significantly less reduction in emittance after long term convective heating and less residual strain than prior art coatings for RSI structures.
Aeroheating Predictions for X-34 Using an Inviscid-Boundary Layer Method
NASA Technical Reports Server (NTRS)
Riley, Christopher J.; Kleb, William L.; Alter, Steven J.
1998-01-01
Radiative equilibrium surface temperatures and surface heating rates from a combined inviscid-boundary layer method are presented for the X-34 Reusable Launch Vehicle for several points along the hypersonic descent portion of its trajectory. Inviscid, perfect-gas solutions are generated with the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and the Data-Parallel Lower-Upper Relaxation (DPLUR) code. Surface temperatures and heating rates are then computed using the Langley Approximate Three-Dimensional Convective Heating (LATCH) engineering code employing both laminar and turbulent flow models. The combined inviscid-boundary layer method provides accurate predictions of surface temperatures over most of the vehicle and requires much less computational effort than a Navier-Stokes code. This enables the generation of a more thorough aerothermal database which is necessary to design the thermal protection system and specify the vehicle's flight limits.
Mechanistic model for catalytic recombination during aerobraking maneuvers
NASA Technical Reports Server (NTRS)
Willey, Ronald J.
1989-01-01
Several mechanistic models are developed to predict recombination coefficients for use in heat shield design for reusable surface insulation (RSI) on aerobraking vehicles such as space shuttles. The models are applied over a temperature range of 300 to 1800 K and a stagnation pressure range of 0 to 3,000 Pa. A four parameter model in temperature was found to work best; however, several models (including those with atom concentrations at the surface) were also investigated. Mechanistic models developed with atom concentration terms may be applicable when sufficient data becomes available. The requirement is shown for recombination experiments in the 300 to 1000 K and 1500 to 1850 K temperature range, with deliberate concentration variations.
Detail view of the vertical stabilizer of the Orbiter Discovery ...
Detail view of the vertical stabilizer of the Orbiter Discovery looking at the two-piece rudder which is used to control the yaw position of orbiter on approach and landing in earth's atmosphere and upon landing the two-piece rudder splays open to both sides of the stabilizer to act as an air brake to help slow the craft to a stop. Note the thermal protection system components with the white Advanced Flexible Reusable Surface Insulation Blanket and the black High-temperature Reusable Surface Insulation tiles along the outer edges (HRSI tiles). The marks seen on the HRSI tiles are injection point marks and holes for the application of waterproofing material. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Detail view of the vertical stabilizer of the Orbiter Discovery ...
Detail view of the vertical stabilizer of the Orbiter Discovery Discovery showing the thermal protection system components with the white Advanced Flexible Reusable Surface Insulation (AFSI) Blanket and the black High-temperature Reusable Surface Insulation (HRSI) tiles along the outer edges . The marks seen on the HRSI tiles are injection point marks and holes for the application of waterproofing material. This view also a good detailed view of the two-piece rudder which is used to control the yaw position of orbiter on approach and landing in earth's atmosphere and upon landing the two-piece rudder splays open to both sides of the stabilizer to act as an air brake to help slow the craft to a stop. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
NASA Technical Reports Server (NTRS)
Lin, Yi; Bunker, Christopher E.; Fernandos, K. A. Shiral; Connell, John W.
2012-01-01
The impurity-free aqueous dispersions of boron nitride nanosheets (BNNS) allowed the facile preparation of silver (Ag) nanoparticle-decorated BNNS by chemical reduction of an Ag salt with hydrazine in the presence of BNNS. The resultant Ag-BNNS nanohybrids remained dispersed in water, allowing convenient subsequent solution processing. By using substrate transfer techniques, Ag-BNNS nanohybrid thin film coatings on quartz substrates were prepared and evaluated as reusable surface enhanced Raman spectroscopy (SERS) sensors that were robust against repeated solvent washing. In addition, because of the unique thermal oxidation-resistant properties of the BNNS, the sensor devices may be readily recycled by short-duration high temperature air oxidation to remove residual analyte molecules in repeated runs. The limiting factor associated with the thermal oxidation recycling process was the Ostwald ripening effect of Ag nanostructures.
Estimates Of The Orbiter RSI Thermal Protection System Thermal Reliability
NASA Technical Reports Server (NTRS)
Kolodziej, P.; Rasky, D. J.
2002-01-01
In support of the Space Shuttle Orbiter post-flight inspection, structure temperatures are recorded at selected positions on the windward, leeward, starboard and port surfaces. Statistical analysis of this flight data and a non-dimensional load interference (NDLI) method are used to estimate the thermal reliability at positions were reusable surface insulation (RSI) is installed. In this analysis, structure temperatures that exceed the design limit define the critical failure mode. At thirty-three positions the RSI thermal reliability is greater than 0.999999 for the missions studied. This is not the overall system level reliability of the thermal protection system installed on an Orbiter. The results from two Orbiters, OV-102 and OV-105, are in good agreement. The original RSI designs on the OV-102 Orbital Maneuvering System pods, which had low reliability, were significantly improved on OV-105. The NDLI method was also used to estimate thermal reliability from an assessment of TPS uncertainties that was completed shortly before the first Orbiter flight. Results fiom the flight data analysis and the pre-flight assessment agree at several positions near each other. The NDLI method is also effective for optimizing RSI designs to provide uniform thermal reliability on the acreage surface of reusable launch vehicles.
Structural active cooling applications for the Space Shuttle.
NASA Technical Reports Server (NTRS)
Masek, R. V.; Niblock, G. A.; Huneidi, F.
1972-01-01
Analytic and experimental studies have been conducted to evaluate a number of active cooling approaches to structural thermal protection for the Space Shuttle. The primary emphasis was directed toward the thermal protection system. Trade study results are presented for various heat shield material and TPS arrangements. Both metallic and reusable surface insulation (RSI) concepts were considered. Active systems heat sinks consisted of hydrogen, phase change materials, and expendable water. If consideration is given only to controlling the surface temperature, passive TPS was found to provide the most efficient system. Use of active cooling which incorporates some interior temperature control made the thermally less efficient RSI system more attractive.
Improvement of Reusable Surface Insulation (RSI) materials
NASA Technical Reports Server (NTRS)
Blome, J. C.
1972-01-01
The mullite fiber based hardened compacted fibers (HCF) type of reusable surface insulation was further developed for use in the Space Shuttle Program. Two hundred fifty formulations of fiber mixtures, fillers, binders, and organic processing aids were made using mullite fibers as the basic ingredient. Most of the work was accomplished on 15-lb/cu ft material. It was established that higher density materials are stronger with strength values as high as 250 lb/sq in. in tension. New measurement techniques and equipment were developed for accurate determination of strength and strain to failure. Room temperature to 2300 F stress-strain relationships were made. The room temperature tensile modulus of elasticity is 61,700 lb/sq in. and the strain at failure is 0.165 percent, typically, when measured longitudinally parallel to the long axes of the fibers. Thermal insulating effectiveness was increased 20 percent by reducing the diameter of some of the fibers in the material. Improvements were made in density uniformity and strength uniformity in a block of HCF by mixing improvements and by the use of organic additives. Specifications were established on the materials and processes used in making the insulation.
Reusable Cryogenic Tank VHM Using Fiber Optic Distributed Sensing Technology
NASA Technical Reports Server (NTRS)
Bodan-Sanders, Patricia; Bouvier, Carl
1998-01-01
The reusable oxygen and hydrogen tanks are key systems for both the X-33 (sub-scale, sub-orbital technology demonstrator) and the commercial Reusable Launch Vehicle (RLV). The backbone of the X-33 Reusable Cryogenic Tank Vehicle Health Management (VHM) system lies in the optical network of distributed strain temperature and hydrogen sensors. This network of fiber sensors will create a global strain and temperature map for monitoring the health of the tank structure, cryogenic insulation, and Thermal Protection System. Lockheed Martin (Sanders and LMMSS) and NASA Langley have developed this sensor technology for the X-33 and have addressed several technical issues such as fiber bonding and laser performance in this harsh environment.
Thermal and aerothermal performance of a titanium multiwall thermal protection system
NASA Technical Reports Server (NTRS)
Avery, D. E.; Shideler, J. L.; Stuckey, R. N.
1981-01-01
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.
NASA Technical Reports Server (NTRS)
Taylor, Shawn C.; DeMange, Jeffrey J.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.
2006-01-01
Knitted metallic spring tubes are the structural backbones that provide resiliency in control surface seals for use on current and future reusable space launch vehicles. Control surface seals fill the space between movable control surfaces such as body flaps, rudders and elevons, and the static body structures to which they are attached. These seals must remain in continuous contact with opposing surfaces to prevent the ingestion of damaging hot gases encountered during atmospheric re-entry. The Inconel X-750 (Special Metals Corporation) spring tube utilized in the baseline control surface seal shows significant resiliency loss when compressed at temperatures as low as 1200 F. High temperature compression testing and microstructural analysis show that creep is the dominant deformation mechanism leading to permanent set and resiliency loss in tested spring tube samples. Additional evaluation using a structured design of experiments approach shows that spring tube performance, primarily high temperature resiliency, can be enhanced through material substitution of Rene 41 (Allvac) alloy (for the baseline Inconel X-750 material) when coupled with specialized thermal processing.
Orbital Debris Impact Damage to Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Robinson, Jennifer H.
1998-01-01
In an effort by the National Aeronautics and Space Administration (NASA), hypervelocity impact tests were performed on thermal protection systems (TPS) applied on the external surfaces of reusable launch vehicles (RLV) to determine the potential damage from orbital debris impacts. Three TPS types were tested, bonded to composite structures representing RLV fuel tank walls. The three heat shield materials tested were Alumina-Enhanced Thermal Barrier-12 (AETB-12), Flexible Reusable Surface Insulation (FRSI), and Advanced Flexible Reusable Surface Insulation (AFRSI). Using this test data, predictor equations were developed for the entry hole diameters in the three TPS materials, with correlation coefficients ranging from 0.69 to 0.86. Possible methods are proposed for approximating damage occurring at expected orbital impact velocities higher than tested, with references to other published work.
Analysis of the Shuttle Orbiter reinforced carbon-carbon oxidation protection system
NASA Technical Reports Server (NTRS)
Williams, S. D.; Curry, Donald M.; Chao, Dennis; Pham, Vuong T.
1994-01-01
Reusable, oxidation-protected reinforced carbon-carbon (RCC) has been successfully flown on all Shuttle Orbiter flights. Thermal testing of the silicon carbide-coated RCC to determine its oxidation characteristics has been performed in convective (plasma Arc-Jet) heating facilities. Surface sealant mass loss was characterized as a function of temperature and pressure. High-temperature testing was performed to develop coating recession correlations for predicting performance at the over-temperature flight conditions associated with abort trajectories. Methods for using these test data to establish multi-mission re-use (i.e., mission life) and single mission limits are presented.
Coatings and Surface Treatments for Reusable Entry Systems
NASA Technical Reports Server (NTRS)
Johnson, Sylvia M.
2016-01-01
This talk outlines work in coatings for TPS done at NASA Ames. coatings and surface treatments on reusable TPS are critical for controlling the behavior of the materials. coatings discussed include RCG, TUFI and HETC. TUFROc is also discussed.
Detail view of the underside of a elevon on the ...
Detail view of the underside of a elevon on the port side wing of the Orbiter Discovery. Note the wear and replacement patterns of the High-temperature Reusable Surface Insulation tiles. This image was taken inside of the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Evaluation of Thermal Control Coatings for Flexible Ceramic Thermal Protection Systems
NASA Technical Reports Server (NTRS)
Kourtides, Demetrius; Carroll, Carol; Smith, Dane; Guzinski, Mike; Marschall, Jochen; Pallix, Joan; Ridge, Jerry; Tran, Duoc
1997-01-01
This report summarizes the evaluation and testing of high emissivity protective coatings applied to flexible insulations for the Reusable Launch Vehicle technology program. Ceramic coatings were evaluated for their thermal properties, durability, and potential for reuse. One of the major goals was to determine the mechanism by which these coated blanket surfaces become brittle and try to modify the coatings to reduce or eliminate embrittlement. Coatings were prepared from colloidal silica with a small percentage of either SiC or SiB6 as the emissivity agent. These coatings are referred to as gray C-9 and protective ceramic coating (PCC), respectively. The colloidal solutions were either brushed or sprayed onto advanced flexible reusable surface insulation blankets. The blankets were instrumented with thermocouples and exposed to reentry heating conditions in the Ames Aeroheating Arc Jet Facility. Post-test samples were then characterized through impact testing, emissivity measurements, chemical analysis, and observation of changes in surface morphology. The results show that both coatings performed well in arc jet tests with backface temperatures slightly lower for the PCC coating than with gray C-9. Impact testing showed that the least extensive surface destruction was experienced on blankets with lower areal density coatings.
Spacecraft thermal energy accommodation from atomic recombination
NASA Technical Reports Server (NTRS)
Carleton, Karen L.; Marinelli, William J.
1991-01-01
Measurements of atomic recombination probabilities important in determining energy release to reusable spacecraft thermal protection surfaces during reentry are presented. An experimental apparatus constructed to examine recombination of atomic oxygen from thermal protection and reference materials at reentry temperatures is described. The materials are examined under ultrahigh vacuum conditions to develop and maintain well characterized surface conditions that are free of contamination. When compared with stagnation point heat transfer measurements performed in arc jet facilities, these measurements indicate that a significant fraction of the excess energy available from atom recombination is removed from the surface as metastable O2.
NASA Astrophysics Data System (ADS)
Sabet Divsholi, Bahador; Yang, Yaowen
2011-04-01
Piezoelectric lead zirconate titanate (PZT) transducers have been used for health monitoring of various structures over the last two decades. There are three methods to install the PZT transducers to structures, namely, surface bonded, reusable setup and embedded PZTs. The embedded PZTs and reusable PZT setups can be used for concrete structures during construction. On the other hand, the surface bonded PZTs can be installed on the existing structures. In this study, the applicability and limitations of each installation method are experimentally studied. A real size concrete structure is cast, where the surface bonded, reusable setup and embedded PZTs are installed. Monitoring of concrete hydration and structural damage is conducted by the electromechanical impedance (EMI), wave propagation and wave transmission techniques. It is observed that embedded PZTs are suitable for monitoring the hydration of concrete by using both the EMI and the wave transmission techniques. For damage detection in concrete structures, the embedded PZTs can be employed using the wave transmission technique, but they are not suitable for the EMI technique. It is also found that the surface bonded PZTs are sensitive to damage when using both the EMI and wave propagation techniques. The reusable PZT setups are able to monitor the hydration of concrete. However they are less sensitive in damage detection in comparison to the surface bonded PZTs.
Metal-wool heat shields for space shuttle. [design, fabrication, and attachment to structure
NASA Technical Reports Server (NTRS)
Miller, R. C.; Clure, J. L.
1974-01-01
The packaging of metal wool for reusable thermal heat shields applied to aerodynamic and other surfaces for the space shuttle was analyzed and designed, and samples were fabricated and experimentally studied. Parametric trends were prepared for selected configurations. An all-metal thermally efficient, reliable, reusable and producible heat shield system was designed and structurally tested for use on spacecraft aerodynamic surfaces where temperatures do not exceed 810 K. Stainless steel sheet, primarily for structure and secondarily in the transverse plane for thermal expansion, was shown to accommodate thermal expansion in all directions when restrained at the edges and heated to 1360 K. Aerodynamic loads of 0.35 x 1000,000 newtons/sq meter, and higher, may be easily accepted by structures of this design. Seven all-metal thermal protection specimens, 12.7 cm square and 2.5 cm thick were fabricated and are being experimentally evaluated at simulated shuttle entry conditions in an arc jet facility.
NASA Astrophysics Data System (ADS)
Nagihara, S.; Zacny, K.; Chu, P.; Kiefer, W. S.
2018-02-01
We propose to equip the Deep Space Gateway spacecraft with a reusable lander that can shuttle to and from the lunar surface, and use it for collecting heat flow measurements globally on the lunar surface.
Bräuer, A; English, M J M; Steinmetz, N; Lorenz, N; Perl, T; Braun, U; Weyland, W
2002-09-01
Forced-air warming with upper body blankets has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with upper body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of eight complete upper body warming systems and to gain more insight into the principles of forced-air warming. Heat transfer of forced-air warmers can be described as follows: Qdot;=h. DeltaT. A, where Qdot;= heat flux [W], h=heat exchange coefficient [W m-2 degrees C-1], DeltaT=temperature gradient between the blanket and surface [ degrees C], and A=covered area [m2]. We tested eight different forced-air warming systems: (1) Bair Hugger and upper body blanket (Augustine Medical Inc. Eden Prairie, MN); (2) Thermacare and upper body blanket (Gaymar Industries, Orchard Park, NY); (3) Thermacare (Gaymar Industries) with reusable Optisan upper body blanket (Willy Rüsch AG, Kernen, Germany); (4) WarmAir and upper body blanket (Cincinnati Sub-Zero Products, Cincinnati, OH); (5) Warm-Gard and single use upper body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); (6) Warm-Gard and reusable upper body blanket (Luis Gibeck AB); (7) WarmTouch and CareDrape upper body blanket (Mallinckrodt Medical Inc., St. Luis, MO); and (8) WarmTouch and reusable MultiCover trade mark upper body blanket (Mallinckrodt Medical Inc.) on a previously validated copper manikin of the human body. Heat flux and surface temperature were measured with 11 calibrated heat flux transducers. Blanket temperature was measured using 11 thermocouples. The temperature gradient between the blanket and surface (DeltaT) was varied between -8 and +8 degrees C, and h was determined by linear regression analysis as the slope of DeltaT vs. heat flux. Mean DeltaT was determined for surface temperatures between 36 and 38 degrees C, as similar mean skin surface temperatures have been found in volunteers. The covered area was estimated to be 0.35 m2. Total heat flow from the blanket to the manikin was different for surface temperatures between 36 and 38 degrees C. At a surface temperature of 36 degrees C the heat flows were higher (4-26.6 W) than at surface temperatures of 38 degrees C (2.6-18.1 W). The highest total heat flow was delivered by the WarmTouch trade mark system with the CareDrape trade mark upper body blanket (18.1-26.6 W). The lowest total heat flow was delivered by the Warm-Gard system with the single use upper body blanket (2.6-4 W). The heat exchange coefficient varied between 15.1 and 36.2 W m-2 degrees C-1, and mean DeltaT varied between 0.5 and 3.3 degrees C. We found total heat flows of 2.6-26.6 W by forced-air warming systems with upper body blankets. However, the changes in heat balance by forced-air warming systems with upper body blankets are larger, as these systems are not only transferring heat to the body but are also reducing heat losses from the covered area to zero. Converting heat losses of approximately 37.8 W to heat gain, results in a 40.4-64.4 W change in heat balance. The differences between the systems result from different heat exchange coefficients and different mean temperature gradients. However, the combination of a high heat exchange coefficient with a high mean temperature gradient is rare. This fact offers some possibility to improve these systems.
Closeup view of the aft fuselage looking forward along the ...
Close-up view of the aft fuselage looking forward along the approximate centerline of the Orbiter Discovery looking at the expansion nozzles of the Space Shuttle Main Engines (SSME) and the Orbiter Maneuvering System. Also in the view is the orbiter's body flap with a protective covering over the High-temperature Reusable Surface Insulation tiles on the surface facing the SSMEs. This image was taken inside the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Reusable cryogenic foam insulation for advanced aerospace vehicles
NASA Technical Reports Server (NTRS)
Mcauliffe, Patrick S.; Taylor, Allan H.; Sparks, Larry L.; Dube, William P.
1991-01-01
Future high-speed aircraft and aerospace vehicles using cryogenic propellants will require an advanced reusable insulation system for the propellant tank structure. This cryogenic insulation system must be lightweight, structurally and thermally efficient, and capable of multiple reuse without cracking or degraded performance. This paper presents recent progress in the development of a reusable cryogenic foam insulation system having a maximum service temperature of 400 F. The system consists of preshaped, precut blocks of rigid polymethacrylimide foam insulation, wrapped with a high-temperature Kapton and aluminum foil vapor barrier which is adhesively bonded to the propellant tank wall.
Magnetically-refreshable receptor platform structures for reusable nano-biosensor chips
NASA Astrophysics Data System (ADS)
Yoo, Haneul; Lee, Dong Jun; Cho, Dong-guk; Park, Juhun; Nam, Ki Wan; Tak Cho, Young; Park, Jae Yeol; Chen, Xing; Hong, Seunghun
2016-01-01
We developed a magnetically-refreshable receptor platform structure which can be integrated with quite versatile nano-biosensor structures to build reusable nano-biosensor chips. This structure allows one to easily remove used receptor molecules from a biosensor surface and reuse the biosensor for repeated sensing operations. Using this structure, we demonstrated reusable immunofluorescence biosensors. Significantly, since our method allows one to place receptor molecules very close to a nano-biosensor surface, it can be utilized to build reusable carbon nanotube transistor-based biosensors which require receptor molecules within a Debye length from the sensor surface. Furthermore, we also show that a single sensor chip can be utilized to detect two different target molecules simply by replacing receptor molecules using our method. Since this method does not rely on any chemical reaction to refresh sensor chips, it can be utilized for versatile biosensor structures and virtually-general receptor molecular species.
Cyclic arc plasma tests of RSI materials using a preheater
NASA Technical Reports Server (NTRS)
Stewart, D. A.
1973-01-01
The results of a test program are reported in which a preheater was used with an arc plasma stream to study the thermal response of samples of candidate reusable surface insulation materials for the space shuttle. The preheater simulated the shuttle temperature history during the first and last portions of the test cycle, which could not be simulated by the air arc plasma flow. Pre- and post-test data taken for each of the materials included magnified views, optical properties, and chemical analyses. The test results indicate that the mullite base samples experience higher surface temperatures than the other materials at heating rates greater than 225 kw/sq m. The ceramic fibrous mullite and silica coatings show noncatalytic wall behavior. Internal temperature response data for the materials are compared and correlated with analytical predictions.
Improvement of reusable surface insulation material
NASA Technical Reports Server (NTRS)
1972-01-01
The results are presented of a program to improve the reusable surface insulation (RSI) system through the improvement of the LI-1500 material properties and the simplification of the RSI system. The improvements made include: 2500 F-capability RSI systems, water-impervious surface coatings, establishment of a high-emittance coating constituent, development of a secondary water-reduction system, and achievement of a lower density (9 pcf) RSI material.
Aerothermal Test of Thermal Protection Systems for X-33 Reusable Launch Vehicle
NASA Technical Reports Server (NTRS)
Sawyer, James Wayne; Hodge, Jefferson; Moore, Brad; Snyder, Kevin
1999-01-01
An array of metallic Thermal Protection System (TPS) panels developed for the windward surface of the X-33 vehicle was tested in the 8-Foot High Temperature Tunnel at the NASA Langley Research Center. These tests were the first aerothermal tests of an X-33 TPS array and the test results will be used to validate the TPS for the X-33 flight program. Specifically, the tests evaluated the structural and thermal performance of the TPS, the effectiveness of the high temperature seals between adjacent panels and the durability of the TPS under realistic aerothermal flight conditions. The effect of varying panel-to-panel step heights, intentional damage to the seals between adjacent panels, and the use of secondary seals were also investigated during the test program. The metallic TPS developed for the windward surface of the X-33, the blanket TPS developed to protect the leeward surfaces of the X-33, and the test program in the 8-Foot High Temperature Tunnel are presented and discussed.
Fundamental studies on the nature and properties of ceramic fiber insulation
NASA Technical Reports Server (NTRS)
Mueller, J. I.; Whittemore, O. J., Jr.; Scott, W. D.; Miller, A. D.; Smiser, L. W.; Leiser, D. B.
1975-01-01
Silica and mullite fibers used to fabricate reusable surface insulation (RSI) for the space shuttle orbiter may devitrify/recrystallize within the temperature range anticipated upon reentry. This is shown to be dependent upon impurity level, temperature, and time at temperature. It is determined that the effects of the material improvement and optimization program are positive. The degree of crystallinity is shown to have a predominant effect upon the strength of fabricated RSI tile, and limits are determined. Models are developed to predict tensile strengths and shrinkage rates of silica tile based upon readily measurable parameters. Thermal cycling which simulates reentry results in an increase in the crystallinity and in the porosity of tile coatings.
Close up view under the Orbiter Discovery in the Vehicle ...
Close up view under the Orbiter Discovery in the Vehicle Assembly Building at NASA's Kennedy Space Center. The view is under the port wing looking forward toward the main fuselage showing a detail of the landing gear and landing gear door. This view also shows the patterns of worn and replaced High-temperature Reusable Surface Insulation tiles. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
The FEI-TPS on the Upper Surface of the X-38
NASA Astrophysics Data System (ADS)
Antonenko, Johann; Kowal, John
2002-01-01
The X-38 is being developed by NASA-JSC as a technology demonstrator of a future Crew Rescue Vehicle. The size of the vehicle is limited to fit into the cargo bay of the shuttle. Due to its small size and shuttle-like trajectory all surfaces will receive comparably high heat rates leading to high surface temperatures. Temperatures on the nose are calculated to reach 1750°C, which is significantly higher than on the shuttle. Due to the lifting body shape, large areas of the central fuselage will be exposed to flow of hot gases around the vehicle. Here temperatures of the upper surface are calculated to reach up to 1000°C and the application of a high temperature blanket thermal protection system (TPS) becomes mandatory. Consecutively, the temperature level of the upper surface and the base area will be significantly high. Unlike on the shuttle, where large areas of the surface are covered by flexible reusable surface insulation (FRSI), locations with temperatures below 400°C will be scarce on the X-38. During development of the European shuttle HERMES the Flexible External Insulation (FEI) was developed for the upper surface TPS. This development was continued by ESA and DLR funded programs and currently a product family is available for temperatures ranging from 450°C to 1100°C for re-usable application. For a single re- entry under ultimate conditions temperatures may reach up to 1400°C. Under funding of DLR and ESA, the FEI assembly is one of the European contributions to the X-38. Three subassemblies have been chosen: the FEI-450, FEI-650 and FEI- 1000, capable of limit temperatures of 450°C, 650°C and 1000°C, respectively. The FEI-650 and FEI-1000 were already developed in the HERMES program. The FEI- 450 was developed in the German TETRA program. The qualification for X-38 application was performed for temperatures up to 510°C for the FEI-450 and up to 1130°C for the FEI-1000. Acoustic noise loads of up to 160dB have been endured, far beyond what X-38 will ever experience. The paper presents the design of the flexible blanket TPS in a joint effort by NASA-JSC and Astrium. The design process at NASA had to consider aerothermal loads and constraints of the structure and parachute subsystems. It provided the configuration of the FEI assembly and the requirements design of the FEI blankets. Astrium first designed the concept and lay-out of the FEI-assembly. Proceeding from NASA furnished model files, the design to manufacturing of the FEI-blankets was established. In addition, Astrium qualified the FEI for X-38 application. The FEI design is constrained by the aeroshell concept that distinguishes acreage panels, carrier panels and close-out areas, with dedicated blankets for each. Close out areas cover the locations of the parafoil system and create an uneven surface requiring vaulted blankets. The total of these requirements leads to an assembly of a large number of blankets, several of which have a complex shape.
Radiant Heat Transfer in Reusable Surface Insulation
NASA Technical Reports Server (NTRS)
Hughes, T. A.; Linford, R. M. F.; Chmitt, R. J.; Christensen, H. E.
1973-01-01
During radiant testing of mullite panels, temperatures in the insulation and support structure exceeded those predicted on the basis of guarded hot plate thermal conductivity tests. Similar results were obtained during arc tunnel tests of mullite specimens. The differences between effective conductivity and guarded hot plate values suggested that radiant transfer through the mullite was occurring. To study the radiant transport, measurements were made of the infrared transmission through various insulating materials and fibers of interest to the shuttle program, using black body sources over the range of 780 to 2000 K. Experimental data were analyzed and scattering coefficients were derived for a variety of materials, fiber diameters, and source temperature.
Evaluation of low cost/high temperature insulation, July 1974 - June 1975
NASA Technical Reports Server (NTRS)
Strauss, E. L.
1975-01-01
Six fiber products and six insulation blankets comprising silica, alumina, zirconia, mullite, and mixed ceramic systems were subjected to furnace exposures up to 500 hours at temperatures of 1000 to 1600 C and evaluated for chemical and dimensional stability and for changes in thermal conductivity. Alumina, zirconia, and mullite fibers were fabricated into reusable surface insulation (RSI) tile by water-felting and reimpregnation with ethyl silicate. Specimens were exposed to 25 thermal cycles at 1200 C and 1400 C and a pressure of 10 and 32 torr, respectively. Production costs for 930 sq m (10,000 sq ft) of blanket insulation and of alumina RSI tile were developed.
2011-12-01
of residuals versus iteration number. “ Intermit ” and “retheta” are turbulence parameters for turbulence intermittency and . 42 ix Figure 4-7 – Wall...is based on the fact that “the flow‐field adapts at a very fast rate to changes in the free stream conditions as the vehicle is accelerating. This...4‐6 – Example of residuals versus iteration number. “ Intermit ” and “retheta” are turbulence parameters for turbulence intermittency and
Performance of LI-1542 Reusable Surface Insulation System in a Hypersonic Stream
1974-04-01
differential pressure loading across the panel. Facility The tests were conducted in the Langley 8-foot high-temperature "’!structures tunnel ( HTST ...is too long to be simulated in the relatively short test time of the 8-foot HTST ; therefore, the radiant-heat apparatus is used in sequence with the... HTST . Impact of these minute particles caused extensive crater damage to the tiles. A series of photos is shown in figure 20 to illustrate the
Nonlinear Transient Thermal Analysis by the Force-Derivative Method
NASA Technical Reports Server (NTRS)
Balakrishnan, Narayani V.; Hou, Gene
1997-01-01
High-speed vehicles such as the Space Shuttle Orbiter must withstand severe aerodynamic heating during reentry through the atmosphere. The Shuttle skin and substructure are constructed primarily of aluminum, which must be protected during reentry with a thermal protection system (TPS) from being overheated beyond the allowable temperature limit, so that the structural integrity is maintained for subsequent flights. High-temperature reusable surface insulation (HRSI), a popular choice of passive insulation system, typically absorbs the incoming radiative or convective heat at its surface and then re-radiates most of it to the atmosphere while conducting the smallest amount possible to the structure by virtue of its low diffusivity. In order to ensure a successful thermal performance of the Shuttle under a prescribed reentry flight profile, a preflight reentry heating thermal analysis of the Shuttle must be done. The surface temperature profile, the transient response of the HRSI interior, and the structural temperatures are all required to evaluate the functioning of the HRSI. Transient temperature distributions which identify the regions of high temperature gradients, are also required to compute the thermal loads for a structural thermal stress analysis. Furthermore, a nonlinear analysis is necessary to account for the temperature-dependent thermal properties of the HRSI as well as to model radiation losses.
Aerodynamic heat transfer to RSI tile surfaces and gap intersections. [Reusable Surface Insulation
NASA Technical Reports Server (NTRS)
Dunavant, J. C.; Throckmorton, D. A.
1974-01-01
Review of the results of aerothermal heating tests of a simulated reusable surface insulation (RSI) tile array, performed on the sidewall of a Mach-10 hypersonic tunnel. In particular, the heating characteristics of the tile array, such as they result from heating inside the tile-expansion-space providing gaps between individual tiles, are investigated. The results include the finding that heating on the upstream face of a tile is strongly affected by the interacting longitudinal gap flow.
Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan
2016-02-02
A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4-9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness. © 2016 Authors.
Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan
2016-01-01
A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4–9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness. PMID:26839417
Bertrand, Brandt; Trejo-Hernández, María R; Morales-Guzmán, Daniel; Caspeta, Luis; Suárez Rodríguez, Ramón; Martínez-Morales, Fernando
2016-12-01
A Trametes versicolor laccase was functionally expressed on the membrane surface of Saccharomyces cerevisiae EBY100. Laccase expression was increased 6.57-fold by medium optimization and surpassed production by the native strain. Maximal laccase and biomass production reached 19 735 ± 1719 Ug -1 and 6.22 ± 0.53 gL -1 respectively, after 2 d of culture. Optimum oxidization of all substrates by laccase was observed at pH 3. Laccase showed high affinity towards substrates used with Km (mM) and Vmax (μmol min -1 ) values of 0.57 ± 0.0047 and 24.55 ± 0.64, 1.52 ± 0.52 and 9.25 ± 1.78, and 2.67 ± 0.12 and 11.26 ± 0.75, were reported for ABTS, 2, 6-DMP and GUA, respectively. EDTA and NaN 3 displayed none competitive inhibition towards laccase activity. The optimum temperature for activity was 50 °C; however, the enzyme was stable over a wide range of temperatures (25-70 °C). The biologically immobilized laccase showed high reusability towards phenolic substrates and low reusability with non-phenolic substrates. High affinity for a diversity phenolic compounds and great ethanol tolerance substantiates this laccase/yeast biocatalyst potential for application in the production of bioethanol. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.
Yoon, Jai Hoon; Yoon, Byung Chul; Lee, Hang Lak; Lee, Jun Kyu; Kim, Yong-Tae; Lee, Dong Ho; Choi, Il Ju; Lee, Don Haeng; Kim, Dong Hee
2012-02-01
Every country has standardized reprocessing guidelines for reducing the risk of microorganism transmission via reusable biopsy forceps. Sterilization is performed either by autoclaving or with the use of ethylene oxide (EO) gas. However, there are no clear standard global recommendations. The aim of this study was to determine whether EO gas or autoclaving is a safer and more effective method for the sterilization of reusable forceps. This was a prospective study conducted at multiple tertiary referral centers. Seventy reusable biopsy forceps that had been reused at least 20 times each were collected from six endoscopy centers. In all, 61 forceps from five centers were sterilized using EO gas, and the nine forceps from the remaining center were placed in an autoclave. We performed real-time polymerase chain reaction (RT-PCR) for Mycobacterium tuberculosis and hepatitis B virus and performed bacterial cultures on the reusable forceps, which were cut into 2- to 3-cm sections. The forceps were also scanned with an electron microscope (EM) to detect surface damage and contamination. Escherichia coli bacteria were cultured from 2 of the 61 (3.3%) reusable biopsy forceps sterilized with EO gas. On EM scanning, abundant debris and tissue materials remained on the cup surfaces of the reused biopsy forceps and on their inner wires. No microorganisms were found on the autoclaved forceps. Sterilization with EO gas may be inadequate because the complicated structure of the forceps may interfere with sterilization. Therefore, for optimum safety, reusable biopsy forceps should be sterilized by autoclaving.
High-Temperature Coatings Offer Energy Savings
NASA Technical Reports Server (NTRS)
2012-01-01
The U.S. X-Plane Program included the first-of-its-kind research in aerodynamics and astronautics with experimental vehicles, including the first aircraft to break the sound barrier; the first aircraft to fly in excess of 100,000, then 200,000, and then 300,000 feet; and the first aircraft to fly at three, four, five, and then six times the speed of sound. During the 1990s, NASA started developing a new thermal protection material to test on the X-33 and X-34 supersonic aircraft. The X-33 was intended to demonstrate the technologies needed for a new reusable launch vehicle and was projected to reach an altitude of approximately 50 miles and speeds of more than Mach 11. The X-34, a small, reusable technology demonstrator for a launch vehicle, was intended to reach an altitude of 250,000 feet and fly at speeds of Mach 8. As a result of its research and development efforts, NASA s Ames Research Center invented the Protective Ceramic Coating Material (PCCM). Applied to a surface, the thin, lightweight coating could protect the material underneath from extreme temperatures. The capability of the technology came from its emissivity, which radiated heat away from the surface it covered, thereby decreasing the amount of heat transferred to the underlying material. PCCM not only increased the capability of materials to withstand higher temperatures, it also exhibited impressive thermal shock, vibration, and acoustic performance. In addition, it proved to be resistant to abrasion and mechanical damage and was also environmentally safe, due to it being water-based and containing no solvents. Even though funding for the X-33 and X-34 ended in 2001, PCCM continued on a path of innovation.
Modal analysis and dynamic stresses for acoustically excited shuttle insulation tiles
NASA Technical Reports Server (NTRS)
Ojalvo, I. U.; Ogilvie, P. L.
1975-01-01
Improvements and extensions to the RESIST computer program developed for determining the normalized modal stress response of shuttle insulation tiles are described. The new version of RESIST can accommodate primary structure panels with closed-cell stringers, in addition to the capability for treating open-cell stringers. In addition, the present version of RESIST numerically solves vibration problems several times faster than its predecessor. A new digital computer program, titled ARREST (Acoustic Response of Reusable Shuttle Tiles) is also described. Starting with modal information contained on output tapes from RESIST computer runs, ARREST determines RMS stresses, deflections and accelerations of shuttle panels with reusable surface insulation tiles. Both programs are applicable to stringer stiffened structural panels with or without reusable surface insulation titles.
Characterization of Adhesives for Attaching Reusable Surface Insulation on Space Shuttle Vehicles
NASA Technical Reports Server (NTRS)
Owen, H. P.; Carroll, M. T.
1973-01-01
An extensive development and testing program on adhesive systems shows that: (1) A closed cell silicone rubber sponge bonded to substrates with thin bond lines of glass filled adhesive exhibits density and modulus values approximately one third that of solid silicone adhesives; (2) utilization of glass or phenolic microballoons as fillers in silicone adhesives reduces density but increases moduli of the vulcanized materials; (3) the silicone elastomer based adhesives appear to be complex systems rather than homogeneous, isotropic materials. Tensile, shear, and compression properties plotted versus temperature verify this conjecture; and (4) constant strain-stress relaxation tests on glass-filled adhesive show that stress relaxation is most pronounced near the glass transition temperature.
Measuring Permeability of Composite Cryotank Laminants
NASA Technical Reports Server (NTRS)
Oliver, Stanley T.; Selvidge, Shawn; Watwood, Michael C.
2004-01-01
This paper describes a test method developed to identify whether certain materials and material systems are suitable candidates for large pressurized reusable cryogenic tanks intended for use in current and future manned launch systems. It provides a quick way to screen numerous candidate materials for permeability under anticipated loading environments consistent with flight conditions, as well as addressing reusability issues. cryogenic tank, where the major design issue was hydrogen permeability. It was successfully used to evaluate samples subjected to biaxial loading while maintaining test temperatures near liquid hydrogen. After each sample was thermally preconditioned, a cyclic pressure load was applied to simulate the in-plane strain. First permeability was measured while a sample was under load. Then the sample was unloaded and allowed to return to ambient temperature. The test was repeated to simulate reusability, in order to evaluate its effects on material permeability.
NASA Technical Reports Server (NTRS)
Kull, F. R.
1975-01-01
The results of a program to develop a lightweight high temperature reusable fastening system for aerospace vehicle thermal protection system applications are documented. This feasibility program resulted in several fastener innovations which will meet the specific needs of the heat shield application. Three systems were designed from Hayes 188 alloy and tested by environmental exposure and residual mechanical properties. The designs include a clinch stud with a collar retainer, a weld stud with a split ring retainer, and a caged stud with a collar retainer. The results indicated that a lightweight, reusable, high temperature fastening system can be developed for aerospace vehicle application.
Near-Optimal Re-Entry Trajectories for Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Chou, H.-C.; Ardema, M. D.; Bowles, J. V.
1997-01-01
A near-optimal guidance law for the descent trajectory for earth orbit re-entry of a fully reusable single-stage-to-orbit pure rocket launch vehicle is derived. A methodology is developed to investigate using both bank angle and altitude as control variables and selecting parameters that maximize various performance functions. The method is based on the energy-state model of the aircraft equations of motion. The major task of this paper is to obtain optimal re-entry trajectories under a variety of performance goals: minimum time, minimum surface temperature, minimum heating, and maximum heading change; four classes of trajectories were investigated: no banking, optimal left turn banking, optimal right turn banking, and optimal bank chattering. The cost function is in general a weighted sum of all performance goals. In particular, the trade-off between minimizing heat load into the vehicle and maximizing cross range distance is investigated. The results show that the optimization methodology can be used to derive a wide variety of near-optimal trajectories.
NASA Technical Reports Server (NTRS)
Ransone, P. O.; Morrison, J. D.; Minster, J. E.
1979-01-01
Tiles of space shuttle reusable surface insulation coated with reaction cured glass were subjected to 25 cycles of launch pad exposure and simulated mission heating. The coating could not withstand the environment without cracking. Water absorption after cracking reached as high as 150 weight percent. Exposure of insulation fibers beneath the coating to contaminants dissolved in absorbed water initiated fiber degradation.
NASA Technical Reports Server (NTRS)
Edwards, S. F.; Kantsios, A. G.; Voros, J. P.; Stewart, W. F.
1975-01-01
The development of a radiometric technique for determining the spectral and total normal emittance of materials heated to temperatures of 800, 1100, and 1300 K by direct comparison with National Bureau of Standards (NBS) reference specimens is discussed. Emittances are measured over the spectral range of 1 to 15 microns and are statistically compared with NBS reference specimens. Results are included for NBS reference specimens, Rene 41, alundum, zirconia, AISI type 321 stainless steel, nickel 201, and a space-shuttle reusable surface insulation.
System specification for the reusable reentry satellite
NASA Technical Reports Server (NTRS)
1991-01-01
The RRS design shall provide a relatively inexpensive method of access to micro and fractional gravity space environments for an extended period of time, with eventual intact recovery on the surface of the Earth. This specification establishes the performance, design, development, and test requirements for the Reusable Reentry Satellite (RRS) system.
Reusable Reentry Satellite (RRS): Thermal control trade study
NASA Technical Reports Server (NTRS)
Wallace, Clark
1990-01-01
The design and assessment work performed in defining the on-orbit Thermal Control Subsystem (TCS) requirements for the Reusable Reentry Satellite (RRS) is discussed. Specifically, it describes the hardware and design measures necessary for maintaining the Payload Module (PM) Environmental Control Life Support System (ECLSS) heat exchanger, the hydrazine propellant, and PM water supply within their required temperature limits.
A Non Rigid Reusable Surface Insulation Concept for the Space Shuttle Thermal Protection System
NASA Technical Reports Server (NTRS)
Alexander, J. G.
1973-01-01
A reusable thermal protection system concept was developed for the space shuttle that utilizes a flexible, woven ceramic mat insulation beneath an aerodynamic skin and moisture barrier consisting of either a dense ceramic coating or a super alloy metallic foil. The resulting heat shield material has unique structural characteristics. The shear modulus of the woven mat is very low such that bending and membrane loads introduced into the underlying structural panel remain isolated from the surface skin.
High-Glass-Transition-Temperature Polyimides Developed for Reusable Launch Vehicle Applications
NASA Technical Reports Server (NTRS)
Chuang, Kathy; Ardent, Cory P.
2002-01-01
Polyimide composites have been traditionally used for high-temperature applications in aircraft engines at temperatures up to 550 F (288 C) for thousands of hours. However, as NASA shifts its focus toward the development of advanced reusable launch vehicles, there is an urgent need for lightweight polymer composites that can sustain 600 to 800 F (315 to 427 C) for short excursions (hundreds of hours). To meet critical vehicle weight targets, it is essential that one use lightweight, high-temperature polymer matrix composites in propulsion components such as turbopump housings, ducts, engine supports, and struts. Composite materials in reusable launch vehicle components will heat quickly during launch and reentry. Conventional composites, consisting of layers of fabric or fiber-reinforced lamina, would either blister or encounter catastrophic delamination under high heating rates above 300 C. This blistering and delamination are the result of a sudden volume expansion within the composite due to the release of absorbed moisture and gases generated by the degradation of the polymer matrix. Researchers at the NASA Glenn Research Center and the Boeing Company (Long Beach, CA) recently demonstrated a successful approach for preventing this delamination--the use of three-dimensional stitched composites fabricated by resin infusion.
Merits of full flow vs. conventional staged combustion cycles for reusable launch vehicle propulsion
NASA Astrophysics Data System (ADS)
Peery, Steven D.; Parsley, Randy C.
1996-03-01
This paper provides a comparison between full-flow and conventional staged combustion thermodynamic O2/H2 rocket engine cycles for Reusable Launch Vehicle, RLV, single-stage-to-orbit applications. The impact of the cycle thermodynamics, component configuration, and component operating parameters on engine performance and weight for the two approaches is presented. Both cycles were modeled with equivalent technology turbomachinery and chamber/nozzle RLV life requirements. The first order impact of cycle selection, pump exit pressure, and turbine temperature on the empty weight of an SSTO Reusable Launch Vehicle is presented.
Van Devender, J.P.; Emin, D.
1983-12-21
A reusable fast opening switch for transferring energy, in the form of a high power pulse, from an electromagnetic storage device such as an inductor into a load. The switch is efficient, compact, fast and reusable. The switch comprises a ferromagnetic semiconductor which undergoes a fast transition between conductive and metallic states at a critical temperature and which undergoes the transition without a phase change in its crystal structure. A semiconductor such as europium rich europhous oxide, which undergoes a conductor to insulator transition when it is joule heated from its conductor state, can be used to form the switch.
Van Devender, John P.; Emin, David
1986-01-01
A reusable fast opening switch for transferring energy, in the form of a high power pulse, from an electromagnetic storage device such as an inductor into a load. The switch is efficient, compact, fast and reusable. The switch comprises a ferromagnetic semiconductor which undergoes a fast transition between conductive and insulating states at a critical temperature and which undergoes the transition without a phase change in its crystal structure. A semiconductor such as europium rich europhous oxide, which undergoes a conductor to insulator transition when it is joule heated from its conductor state, can be used to form the switch.
NASA Technical Reports Server (NTRS)
Kourtides, Demetrius A.; Pitts, William C.; Araujo, Myrian; Zimmerman, R. S.
1988-01-01
Multilayer insulations (MIs) which will operate in the 500 to 1000 C temperature range are being considered for possible applications on aerospace vehicles subject to convective and radiative heating during atmospheric entry. The insulations described consist of ceramic fibers, insulations, and metal foils quilted together with ceramic thread. As these types of insulations have highly anisotropic properties, the total heat transfer characteristics must be determined. Data are presented on the thermal diffusivity and thermal conductivity of four types of MIs and are compared to the baseline Advanced Flexible Reusable Surface Insulation currently used on the Space Shuttle Orbiter. In addition, the high temperature properties of the fibers used in these MIs are discussed. The fibers investigated included silica and three types of aluminoborosilicate (ABS). Static tension tests were performed at temperatures up to 1200 C and the ultimate strain, tensile strength, and tensile modulus of single fibers were determined.
NASA Technical Reports Server (NTRS)
Kourtides, Demetrius A.; Pitts, William C.; Araujo, Myrian; Zimmerman, R. S.
1988-01-01
Multilayer insulations (MIs) which will operate in the 500 to 1000 C temperature range are being considered for possible applications on aerospace vehicles subject to convective and radiative heating during atmospheric entry. The insulations described consist of ceramic fibers, insulations, and metal foils quilted together with ceramic thread. As these types of insulations have highly anisotropic properties, the total heat transfer characteristics must be determined. Data are presented on the thermal diffusivity and thermal conductivity of four types of MIs and are compared to the baseline Advanced Flexible Reusable Surface Insulation currently used on the Space Shuttle Orbiter. In addition, the high temperature properties of the fibers used in these MIs are discussed. The fibers investigated included silica and three types of aluminoborosilicate (ABS). Static tension tests were performed at temperatures up to 1200 C and the ultimate strain, tensile strength, and tensile modulus of single fibers were determined.
NASA Technical Reports Server (NTRS)
Olds, John R.; Cowart, Kris
2001-01-01
A method for integrating Aeroheating analysis into conceptual reusable launch vehicle (RLV) design is presented in this thesis. This process allows for faster turn-around time to converge a RLV design through the advent of designing an optimized thermal protection system (TPS). It consists of the coupling and automation of four computer software packages: MINIVER, TPSX, TCAT, and ADS. MINIVER is an Aeroheating code that produces centerline radiation equilibrium temperatures, convective heating rates, and heat loads over simplified vehicle geometries. These include flat plates and swept cylinders that model wings and leading edges, respectively. TPSX is a NASA Ames material properties database that is available on the World Wide Web. The newly developed Thermal Calculation Analysis Tool (TCAT) uses finite difference methods to carry out a transient in-depth 1-D conduction analysis over the center mold line of the vehicle. This is used along with the Automated Design Synthesis (ADS) code to correctly size the vehicle's thermal protection system (TPS). The numerical optimizer ADS uses algorithms that solve constrained and unconstrained design problems. The resulting outputs for this process are TPS material types, unit thicknesses, and acreage percentages. TCAT was developed for several purposes. First, it provides a means to calculate the transient in-depth conduction seen by the surface of the TPS material that protects a vehicle during ascent and reentry. Along with the in-depth conduction, radiation from the surface of the material is calculated along with the temperatures at the backface and interior parts of the TPS material. Secondly, TCAT contributes added speed and automation to the overall design process. Another motivation in the development of TCAT is optimization. In some vehicles, the TPS accounts for a high percentage of the overall vehicle dry weight. Optimizing the weight of the TPS will thereby lower the percentage of the dry weight accounted for by the TPS. Also, this will lower the cost of the TPS and the overall cost of the vehicle.
Mechanical analysis of confectioning flaw of refractory alloy honeycomb sandwich structure
NASA Astrophysics Data System (ADS)
He, Xiaodong; Kong, Xianghao; Shi, Liping; Li, Mingwei
2009-03-01
Thermal protection system is one of the key technology of reusable launch vehicle (RLV). After C/C and ceramic-matrix composite used in space orbiter, one new-typed thermal protection systems (TPS)-ARMOR TPS is coming forth. ARMOR TPS is means adaptable, robust, metallic, operable, reusable TPS. The ARMOR TPS has many advantages, for example: fixing easily, longer life, good properties, short time of maintenance and service. The ARMOR TPS is one of important candidate structure of RLV. ARMOR thermal protection system in foreign countries for reusable launch vehicle is used instead of the traditional ceramic-matrix composite thermal protection system and C/C thermal protection system. Also the constituent feature of ARMOR thermal protection system is much better than the traditional TPS. In comparison with traditional TPS, the ARMOR TPS will be the best selection for all kinds of RLV. So the ARMOR thermal protection system will be used in aviation and spaceflight field more and more widely because of its much better performance. ARMOR TPS panel is above the whole ARMOR TPS, and the metal honeycomb sandwich structure is the surface of the ARMOR TPS panel. So the metal honeycomb sandwich structure plays an important role in the ARMOR TPS, while it bears the flight dynamic pressure and stands against the flight dynamic calefaction. The metal honeycomb sandwich structure is made using the technique of the whole braze welding. In the course of the vacuum high temperature braze welding, its surface will appear concave. The reasons which lead to the shortage are summarized and discussed. The difference of thermal expansion coefficient and pressure between the core and the panels may be the chief reasons. This paper will analyze the mechanics behavior of metal honeycomb sandwich structure in the course of the vacuum high temperature braze welding, then make sure the reasons and get a way to solve it. Haynes214 is a good material of face sheet at present. γ - TiAl and microlaminate materials are the candidate materials in the future.
High temperature seal for large structural movements
NASA Technical Reports Server (NTRS)
Steinetz, Bruce M. (Inventor); Dunlap, Jr., Patrick H. (Inventor)
2004-01-01
A high temperature sealing system is operative to seal an interface between adjacent hot structures and to minimize parasitic flow between such structures that move relative to one another in-plane or out-of-plane. The sealing system may be used to seal thrust-directing ramp structures of a reusable launch vehicle and includes a channel and a plurality of movable segmented sealing elements. Adjacent ramp structures include edge walls which extend within the channel. The sealing elements are positioned along the sides of the channel and are biased to engage with the inner surfaces of the ramp structures. The segmented sealing elements are movable to correspond to the contour of the thrust-directing ramp structures. The sealing system is operative to prevent high temperature thrust gases that flow along the ramp structures from infiltrating into the interior of the vehicle.
Active Wireless Temperature Sensors for Aerospace Thermal Protection Systems
NASA Technical Reports Server (NTRS)
Milos, Frank S.; Karunaratne, K.; Arnold, Jim (Technical Monitor)
2002-01-01
Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life-cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to advance inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and Korteks to develop active wireless sensors that can be embedded in the thermal protection system to monitor sub-surface temperature histories. These devices are thermocouples integrated with radio-frequency identification circuitry to enable acquisition and non-contact communication of temperature data through aerospace thermal protection materials. Two generations of prototype sensors are discussed. The advanced prototype collects data from three type-k thermocouples attached to a 2.54-cm square integrated circuit.
A study on metallic thermal protection system panel for Reusable Launch Vehicle
NASA Astrophysics Data System (ADS)
Caogen, Yao; Hongjun, Lü; Zhonghua, Jia; Xinchao, Jia; Yan, Lu; Haigang, Li
2008-07-01
A Ni-based superalloy honeycomb thermal protection system (TPS) panel has been fabricated. And a curved Ni-based superalloy honeycomb sandwich has also been fabricated. The preliminary thermal insulation results of a fabricated Ni-based superalloy honeycomb TPS panel (the areal density of this panel is 6.7 kg /m2 and total height is 32 mm) indicate that the maximum temperature of the lower surfaces of the panel is lower than 150∘ C when the temperature of outer surface is held at 650∘ C for 30 min. The flatwise tensile strength and compressive properties of a fabricated Ni-based superalloy honeycomb sandwich coupon was studied at room temperature. A multilayered coating has been developed on the surface of the superalloy honeycomb TPS panel for environmental protection and thermal control. The oxidation weight-change results show that the weight change of the Ni-based superalloy honeycomb sandwich with the oxidation resistant coating is extremely small at 1100∘ C in air for 10 h. The emittance layer of the multilayered coating imparts an emittance in excess of 0.85 during exposure at 850∘ C, which was at least 14% greater than that of the substrate with oxidation resistant alone.
Nasrollahzadeh, Mahmoud; Ehsani, Ali; Rostami-Vartouni, Akbar
2014-01-01
Natural Natrolite nanozeolite has been investigated as an efficient and reusable catalyst for the N-sulfonylation of amines under ultrasound irradiation at room temperature. Compared with traditional methods, the significant advantages for method are green solvent, milder and cleaner conditions, higher purity and yields, shorter reaction time, easier work-up procedure and the lower generation of waste or pollutions. The catalyst can be recovered and reused several times without significant loss of its catalytic activity. Copyright © 2013 Elsevier B.V. All rights reserved.
Raman spectra of adsorbed layers on space shuttle and AOTV thermal protection system surface
NASA Technical Reports Server (NTRS)
Willey, Ronald J.
1987-01-01
Surfaces of interest to space vehicle heat shield design were struck by a 2 W argon ion laser line while subjected to supersonic arc jet flow conditions. Emission spectra were taken at 90 deg to the angle of laser incidence on the test object. Results showed possible weak Raman shifts which could not be directly tied to any particular parameter such as surface temperature or gas composition. The investigation must be considered exploratory in terms of findings. Many undesirable effects were found and corrected as the project progressed. For instance, initial spectra settings led to ghosts which were eliminated by closing the intermediate of filter slit of the Spex from 8 to 3 mm. Further, under certain conditions, plasma lines from the laser were observed. Several materials were also investigated at room temperature for Raman shifts. Results showed Raman shifts for RCC and TEOS coated materials. The HRSI materials showed only weak Raman shifts, however, substantial efforts were made in studying these materials. Baseline materials showed the technique to be sound. The original goal was to find a Raman shift for the High-temperature Reusable Surface Insulation (HRSI) Reaction Cured borosilicate Glass (RCG) coated material and tie the amplitude of this peak to Arc jet conditions. Weak Raman shifts may be present, however, time limitations prevented confirmation.
1998-08-10
In the Tile Fabrication Shop, Tony Rollins, with United Space Alliance, cuts a High-Temperature Reusable Surface Insulation (HRSI) tile on a gun stock contour milling machine. About 70 percent of a Space Shuttle orbiter’s external surface is shielded from heat by a network of more than 24,000 tiles formed from a silica fiber compound. HRSI tiles cover the lower surface of the orbiter, areas around the forward windows, upper body flap, the base heat shield, the "eyeballs" on the front of the Orbital Maneuvering System (OMS) pods, and the leading and trailing edges of the vertical stabilizer and the rudder speed brake. They are generally 6 inches square, but may also be as large as 12 inches square in some areas, and 1 to 5 inches thick. More advanced materials such as Flexible Insulation Blankets have replaced tiles on some upper surfaces of the orbiter
Tony Rollins prepares a new tile for the Space Shuttle orbiter
NASA Technical Reports Server (NTRS)
1998-01-01
In the Tile Fabrication Shop, Tony Rollins, with United Space Alliance, cuts a High-Temperature Reusable Surface Insulation (HRSI) tile on a gun stock contour milling machine. About 70 percent of a Space Shuttle orbiter's external surface is shielded from heat by a network of more than 24,000 tiles formed from a silica fiber compound. HRSI tiles cover the lower surface of the orbiter, areas around the forward windows, upper body flap, the base heat shield, the 'eyeballs' on the front of the Orbital Maneuvering System (OMS) pods, and the leading and trailing edges of the vertical stabilizer and the rudder speed brake. They are generally 6 inches square, but may also be as large as 12 inches square in some areas, and 1 to 5 inches thick. More advanced materials such as Flexible Insulation Blankets have replaced tiles on some upper surfaces of the orbiter.
Reusable Surface Insulation Tile Thermal Protection Materials: Past, Present and the Future
NASA Technical Reports Server (NTRS)
Leiser, Daniel B.; Stewart, David A.; Venkatapathy, Ethiras (Technical Monitor)
2002-01-01
Silica (LI-900) Reusable Surface Insulation (RSI) tile have been used on the majority of the Shuttle since its initial flight. Its overall performance with Reaction Cured Glass (RCG) coating applied will be reviewed. Improvements in insulations, Fibrous Refractory Composite Insulation (FRCI-12) and Alumina Enhanced Thermal Barrier (AETB-8) and coatings/surface treatments such as Toughened Uni-Piece Fibrous Insulation (TUFI) have been developed and successfully applied. The performance of these enhancements on the Shuttle Orbiters over the past few years along with the next version of tile materials, High Efficiency Tantalum-based Ceramic (HETC) with even broader applicability will also be discussed.
Global Exploration Roadmap Derived Concept for Human Exploration of the Moon
NASA Technical Reports Server (NTRS)
Whitley, Ryan; Landgraf, Markus; Sato, Naoki; Picard, Martin; Goodliff, Kandyce; Stephenson, Keith; Narita, Shinichiro; Gonthier, Yves; Cowley, Aiden; Hosseini, Shahrzad;
2017-01-01
Taking advantage of the development of Mars-forward assets in cislunar space, a human lunar surface concept is proposed to maximize value for both lunar exploration and future deep space missions. The human lunar surface missions will be designed to build upon the cislunar activities that precede them, providing experience in planetary surface operations that cannot be obtained in cislunar space. To enable a five-mission limited campaign to the surface of the Moon, two new elements are required: a human lunar lander and a mobile surface habitat. The human lunar lander will have been developed throughout the cislunar phase from a subscale demonstrator and will consist of a descent module alongside a reusable ascent module. The reusable ascent module will be used for all five human lunar surface missions. Surface habitation, in the form of two small pressurized rovers, will enable 4 crew to spend up to 42 days on the lunar surface.
Design, Analysis and Qualification of Elevon for Reusable Launch Vehicle
NASA Astrophysics Data System (ADS)
Tiwari, S. B.; Suresh, R.; Krishnadasan, C. K.
2017-12-01
Reusable launch vehicle technology demonstrator is configured as a winged body vehicle, designed to fly in hypersonic, supersonic and subsonic regimes. The vehicle will be boosted to hypersonic speeds after which the winged body separates and descends using aerodynamic control. The aerodynamic control is achieved using the control surfaces mainly the rudder and the elevon. Elevons are deflected for pitch and roll control of the vehicle at various flight conditions. Elevons are subjected to aerodynamic, thermal and inertial loads during the flight. This paper gives details about the configuration, design, qualification and flight validation of elevon for Reusable Launch Vehicle.
Ablative heat shield design for space shuttle
NASA Technical Reports Server (NTRS)
Seiferth, R. W.
1973-01-01
Ablator heat shield configuration optimization studies were conducted for the orbiter. Ablator and reusable surface insulation (RSI) trajectories for design studies were shaped to take advantage of the low conductance of ceramic RSI and high temperature capability of ablators. Comparative weights were established for the RSI system and for direct bond and mechanically attached ablator systems. Ablator system costs were determined for fabrication, installation and refurbishment. Cost penalties were assigned for payload weight penalties, if any. The direct bond ablator is lowest in weight and cost. A mechanically attached ablator using a magnesium subpanel is highly competitive for both weight and cost.
Close up detail of the underside of the Orbiter Discovery ...
Close up detail of the underside of the Orbiter Discovery in the Vehicle Assembly Building at NASA's Kennedy Space Center. This view is from underneath the aft section looking forward. It is a close-up view of the High-temperature Reusable Surface Insulation tiles showing the wear patterns from the heat of reentry, consequential replacement of worn and damaged tiles. The wear and replacement patters are unique to each Orbiter which can serve as their particular "fingerprint". - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Sadeghi, Saman; Liang, Vincent; Cheung, Shilin; Woo, Suh; Wu, Curtis; Ly, Jimmy; Deng, Yuliang; Eddings, Mark; van Dam, R. Michael
2015-01-01
A brass-platinum electrochemical micro flow cell was developed to extract [18F]fluoride from an aqueous solution and release it into an organic based solution, suitable for subsequent radio-synthesis, in a fast and reliable manner. This cell does not suffer electrode erosion and is thus reusable while operating faster by enabling increased voltages. By optimizing temperature, trapping and release potentials, flow rates, and electrode materials, an overall [18F]fluoride trapping and release efficiency of 84±5% (n=7) was achieved. X-ray photoelectron spectroscopy (XPS) was used to analyze electrode surfaces of various metal-metal systems and the findings were correlated with the performance of the electrochemical cell. To demonstrate the reactivity of the released [18F]fluoride, the cell was coupled to a flow-through reactor and automated synthesis of [18F]FDG with a repeatable decay-corrected yield of 56±4% (n=4) was completed in <15 min. A multi-human dose of 5.92 GBq [18F]FDG was also demonstrated. PMID:23474380
Ammonia and Carbon Dioxide Concentrations in Disposable and Reusable Ventilated Mouse Cages
Silverman, Jerald; Bays, David W; Cooper, Sheldon F; Baker, Stephen P
2008-01-01
This study compares resuable and disposable individually ventilated mouse cages in terms of the formation of intracage CO2 and NH3. Crl:CD-1(ICR) female mice were placed in either disposable or reusable ventilated cages in a positive pressure animal rack. Intracage CO2 and NH3 were measured once daily for 9 d; temperature and relative humidity were monitored for the first 7 d. Results indicated higher CO2 levels in the rear of the disposable cages and in the front of the reusable cages. This pattern corresponded to where the mice tended to congregate. However, CO2 concentrations did not differ significantly between the 2 cage types. Average CO2 levels in both cage types never exceeded approximately 3000 ppm. Intracage NH3 began to rise in the reusable cages on day 4, reached approximately 50 ppm by day 5 and by day 9 was greater than 150 ppm at the cages' rear sampling port while remaining at approximately 70 ppm at the front sampling port. Intracage NH3 levels in the disposable cages remained less than or equal to 3.2 ppm. Intracage temperature and relative humidity were approximately the same in both cage types. We concluded that the disposable ventilated cage performed satisfactorily under the conditions of the study. PMID:18351723
Thermal Structures Technology Development for Reusable Launch Vehicle Cryogenic Propellant Tanks
NASA Technical Reports Server (NTRS)
Johnson, Theodore F.; Natividad, Roderick; Rivers, H. Kevin; Smith, Russell
1998-01-01
Analytical and experimental studies conducted at the NASA Langley Research Center for investigating integrated cryogenic propellant tank systems for a Reusable Launch Vehicle are described. The cryogenic tanks are investigated as an integrated tank system. An integrated tank system includes the tank wall, cryogenic insulation, Thermal Protection System (TPS) attachment sub-structure, and TPS. Analysis codes are used to size the thicknesses of cryogenic insulation and TPS insulation for thermal loads, and to predict tank buckling strengths at various ring frame spacings. The unique test facilities developed for the testing of cryogenic tank components are described. Testing at cryogenic and high-temperatures verifies the integrity of materials, design concepts, manufacturing processes, and thermal/structural analyses. Test specimens ranging from the element level to the subcomponent level are subjected to projected vehicle operational mechanical loads and temperatures. The analytical and experimental studies described in this paper provide a portion of the basic information required for the development of light-weight reusable cryogenic propellant tanks.
Thermal Structures Technology Development for Reusable Launch Vehicle Cryogenic Propellant Tanks
NASA Technical Reports Server (NTRS)
Johnson, Theodore F.; Natividad, Roderick; Rivers, H. Kevin; Smith, Russell W.
2005-01-01
Analytical and experimental studies conducted at the NASA, Langley Research Center (LaRC) for investigating integrated cryogenic propellant tank systems for a reusable launch vehicle (RLV) are described. The cryogenic tanks are investigated as an integrated tank system. An integrated tank system includes the tank wall, cryogenic insulation, thermal protection system (TPS) attachment sub-structure, and TPS. Analysis codes are used to size the thicknesses of cryogenic insulation and TPS insulation for thermal loads, and to predict tank buckling strengths at various ring frame spacings. The unique test facilities developed for the testing of cryogenic tank components are described. Testing at cryogenic and high-temperatures verifies the integrity of materials, design concepts, manufacturing processes, and thermal/structural analyses. Test specimens ranging from the element level to the subcomponent level are subjected to projected vehicle operational mechanical loads and temperatures. The analytical and experimental studies described in this paper provide a portion of the basic information required for the development of light-weight reusable cryogenic propellant tanks.
Systems integration and demonstration of advanced reusable structure for ALS
NASA Technical Reports Server (NTRS)
Gibbins, Martin N.
1991-01-01
The objective was to investigate the potential of advanced material to achieve life cycle cost (LCC) benefits for reusable structure on the advanced launch system. Three structural elements were investigated - all components of an Advanced Launch System reusable propulsion/avionics module. Leading aeroshell configurations included sandwich structure using titanium, graphite/polyimide (Gr/PI), or high-temperature aluminum (HTA) face sheets. Thrust structure truss concepts used titanium, graphite/epoxy, or silicon carbide/aluminum struts. Leading aft bulkhead concepts employed graphite epoxy and aluminum. The technical effort focused on the aeroshell because the greatest benefits were expected there. Thermal analyses show the structural temperature profiles during operation. Finite element analyses show stresses during splash-down. Weight statements and manufacturing cost estimates were prepared for calculation of LCC for each design. The Gr/PI aeroshell showed the lowest potential LCC, but the HTA aeroshell was judged to be lower risk. A technology development plan was prepared to validate the applicable structural technology.
Thermocouple design for measuring temperatures of small insects.
Hanson, A A; Venette, R C
2013-01-01
Contact thermocouples often are used to measure surface body temperature changes of insects during cold exposure. However, small temperature changes of minute insects can be difficult to detect, particularly during the measurement of supercooling points. We developed two thermocouple designs, which use 0.51 mm diameter or 0.127 mm diameter copper-constantan wires, to improve our ability to resolve insect exotherms. We tested the designs with adults from three parasitoid species: Tetrastichus planipennisi, Spathius agrili, and S. floridanus. These species are <3 mm long and <0.1 mg. Mean exotherms were greater for fine-gauge thermocouples than thick-gauge thermocouples for the smallest species tested, T. planipennisi. This difference was not apparent for larger species S. agrili and S. floridanus. Thermocouple design did not affect the mean supercooling point for any of the species. The cradle thermocouple design developed with the fine gauge wire was reusable and allowed for easy insect recovery after cold exposure.
Methane heat transfer investigation
NASA Technical Reports Server (NTRS)
1984-01-01
Future high chamber pressure LOX/hydrocarbon booster engines require copper base alloy main combustion chamber coolant channels similar to the SSME to provide adequate cooling and reusable engine life. Therefore, it is of vital importance to evaluate the heat transfer characteristics and coking thresholds for LNG (94% methane) cooling, with a copper base alloy material adjacent to he fuel coolant. High pressure methane cooling and coking characteristics recently evaluated at Rocketdyne using stainless steel heated tubes at methane bulk temperatures and coolant wall temperatures typical of advanced engine operation except at lower heat fluxes as limited by the tube material. As expected, there was no coking observed. However, coking evaluations need be conducted with a copper base surface exposed to the methane coolant at higher heat fluxes approaching those of future high chamber pressure engines.
Evaluation of Advanced Thermal Protection Techniques for Future Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Olds, John R.; Cowart, Kris
2001-01-01
A method for integrating Aeroheating analysis into conceptual reusable launch vehicle RLV design is presented in this thesis. This process allows for faster turn-around time to converge a RLV design through the advent of designing an optimized thermal protection system (TPS). It consists of the coupling and automation of four computer software packages: MINIVER, TPSX, TCAT and ADS. MINIVER is an Aeroheating code that produces centerline radiation equilibrium temperatures, convective heating rates, and heat loads over simplified vehicle geometries. These include flat plates and swept cylinders that model wings and leading edges, respectively. TPSX is a NASA Ames material properties database that is available on the World Wide Web. The newly developed Thermal Calculation Analysis Tool (TCAT) uses finite difference methods to carry out a transient in-depth I-D conduction analysis over the center mold line of the vehicle. This is used along with the Automated Design Synthesis (ADS) code to correctly size the vehicle's thermal protection system JPS). The numerical optimizer ADS uses algorithms that solve constrained and unconstrained design problems. The resulting outputs for this process are TPS material types, unit thicknesses, and acreage percentages. TCAT was developed for several purposes. First, it provides a means to calculate the transient in-depth conduction seen by the surface of the TPS material that protects a vehicle during ascent and reentry. Along with the in-depth conduction, radiation from the surface of the material is calculated along with the temperatures at the backface and interior parts of the TPS material. Secondly, TCAT contributes added speed and automation to the overall design process. Another motivation in the development of TCAT is optimization.
Manna, Joydev; Akbayrak, Serdar; Özkar, Saim
2017-12-15
Nickel(0) nanoparticles supported on cobalt ferrite (Ni 0 /CoFe 2 O 4 ), polydopamine coated cobalt ferrite (Ni 0 /PDA-CoFe 2 O 4 ) or silica coated cobalt ferrite (Ni 0 /SiO 2 -CoFe 2 O 4 ) are prepared and used as catalysts in hydrogen generation from the hydrolysis of ammonia borane at room temperature. Ni 0 /CoFe 2 O 4 (4.0% wt. Ni) shows the highest catalytic activity with a TOF value of 38.3min -1 in hydrogen generation from the hydrolysis of ammonia borane at 25.0±0.1°C. However, the initial catalytic activity of Ni 0 /CoFe 2 O 4 catalyst is not preserved in subsequent runs of hydrolysis. Coating the surface of cobalt ferrite support with polydopamine or silica leads to a significant improvement in the stability of catalysts. The TOF values of Ni 0 /PDA-CoFe 2 O 4 and Ni 0 /SiO 2 -CoFe 2 O 4 are found to be 7.6 and 5.3min -1 , respectively, at 25.0±0.1°C. Ni 0 /PDA-CoFe 2 O 4 catalyst shows high reusability as compared to the Ni 0 /CoFe 2 O 4 and Ni 0 /SiO 2 -CoFe 2 O 4 catalysts in hydrolytic dehydrogenation of ammonia borane at room temperature. All the catalysts are characterized by using a combination of various advanced analytical techniques. The results reveal that nickel nanoparticles with an average size of 12.3±0.7nm are well dispersed on the surface of PDA-CoFe 2 O 4 . . Copyright © 2017 Elsevier Inc. All rights reserved.
Application of reusable PZT sensors for monitoring initial hydration of concrete
NASA Astrophysics Data System (ADS)
Sabet Divsholi, Bahador; Yang, Yaowen
2009-03-01
To increase the efficiency of in-situ casting or precast of concrete, determining the optimal time of demolding is very important for concrete suppliers. In the first few hours after mixing, the fresh concrete gradually achieves solid properties with reasonable compressive strength. Due to different type and amount of cementitious materials, concrete additives (e.g. retarders) and curing temperature, different rates of hardening are expected. In addition, some other factors like the quality of the cementitious materials further increase the uncertainty in determining appropriate time for demolding of concrete. Electro-mechanical impedance (EMI) based lead zirconate titanate (PZT) sensors have been used for damage detection and structural identification for various engineering structures. In this work, a reusable PZT sensor for monitoring initial hydration of concrete is developed, where a piece of PZT is bonded to a piece of metal with two bolts tightened inside of the holes drilled in the metal. An impedance analyzer is used to acquire the signature of this reusable sensor. During the concrete casting, the bolts and the bottom surface of the metal is set to penetrate part of the fresh concrete. At different stages of the first 48 hours after casting, the PZT signatures are acquired. A statistical analysis technique is employed to associate the change in concrete strength with the changes in the PZT admittance signatures. The results show that the developed sensor is able to effectively monitor the initial hydration of concrete, and can be detached from the concrete for future use.
NASA Astrophysics Data System (ADS)
Pečová, M.; Šebela, M.; Marková, Z.; Poláková, K.; Čuda, J.; Šafářová, K.; Zbořil, R.
2013-03-01
In this work, magnetosomes produced by microorganisms were chosen as a suitable magnetic carrier for covalent immobilization of thermostable trypsin conjugates with an expected applicability for efficient and rapid digestion of proteins at elevated temperatures. First, a biogenic magnetite was isolated from Magnetospirillum gryphiswaldense and its free surface was coated with the natural polysaccharide chitosan containing free amino and hydroxy groups. Prior to covalent immobilization, bovine trypsin was modified by conjugating with α-, β- and γ-cyclodextrin. Modified trypsin was bound to the magnetic carriers via amino groups using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling reagents. The magnetic biomaterial was characterized by magnetometric analysis and electron microscopy. With regard to their biochemical properties, the immobilized trypsin conjugates showed an increased resistance to elevated temperatures, eliminated autolysis, had an unchanged pH optimum and a significant storage stability and reusability. Considering these parameters, the presented enzymatic system exhibits properties that are superior to those of trypsin forms obtained by other frequently used approaches. The proteolytic performance was demonstrated during in-solution digestion of model proteins (horseradish peroxidase, bovine serum albumin and hen egg white lysozyme) followed by mass spectrometry. It is shown that both magnetic immobilization and chemical modification enhance the characteristics of trypsin making it a promising tool for protein digestion.
Viability of a Reusable In-Space Transportation System
NASA Technical Reports Server (NTRS)
Jefferies, Sharon A.; McCleskey, Carey M.; Nufer, Brian M.; Lepsch, Roger A.; Merrill, Raymond G.; North, David D.; Martin, John G.; Komar, David R.
2015-01-01
The National Aeronautics and Space Administration (NASA) is currently developing options for an Evolvable Mars Campaign (EMC) that expands human presence from Low Earth Orbit (LEO) into the solar system and to the surface of Mars. The Hybrid in-space transportation architecture is one option being investigated within the EMC. The architecture enables return of the entire in-space propulsion stage and habitat to cis-lunar space after a round trip to Mars. This concept of operations opens the door for a fully reusable Mars transportation system from cis-lunar space to a Mars parking orbit and back. This paper explores the reuse of in-space transportation systems, with a focus on the propulsion systems. It begins by examining why reusability should be pursued and defines reusability in space-flight context. A range of functions and enablers associated with preparing a system for reuse are identified and a vision for reusability is proposed that can be advanced and implemented as new capabilities are developed. Following this, past reusable spacecraft and servicing capabilities, as well as those currently in development are discussed. Using the Hybrid transportation architecture as an example, an assessment of the degree of reusability that can be incorporated into the architecture with current capabilities is provided and areas for development are identified that will enable greater levels of reuse in the future. Implications and implementation challenges specific to the architecture are also presented.
NASA Technical Reports Server (NTRS)
Keen, Jill M.; DeWeese, Darrell C.; Key, Leigh W.
1997-01-01
At Kennedy Space Center (KSC), Thiokol Corporation provides the engineering to assemble and prepare the Space Shuttle Reusable Solid Rocket Motor (RSRM) for launch. This requires hand cleaning over 86 surfaces including metals, adhesives, rubber and electrical insulations, various painted surfaces and thermal protective materials. Due to the phase-out of certain ozone depleting chemical (ODC) solvents, all RSRM hand wipe operations being performed at KSC using l,l,1-trichloroethane (TCA) were eliminated. This presentation summarizes the approach used and the data gathered in the effort to eliminate TCA from KSC hand wipe operations.
NASA Technical Reports Server (NTRS)
Gallegos, J. J.
1978-01-01
A multi-objective test program was conducted at the NASA/JSC Radiant Heat Test Facility in which an aluminum skin/stringer test panel insulated with FRSI (Flexible Reusable Surface Insulation) was subjected to 24 simulated Space Shuttle Orbiter ascent/entry heating cycles with a cold soak in between in the 10th and 20th cycles. A two-dimensional thermal math model was developed and utilized to predict the thermal performance of the FRSI. Results are presented which indicate that the modeling techniques and property values have been proven adequate in predicting peak structure temperatures and entry thermal responses from both an ambient and cold soak condition of an FRSI covered aluminum structure.
NASA Astrophysics Data System (ADS)
Li, Hui; Li, Gui; Li, Zhiping; Lu, Cuimei; Li, Yanan; Tan, Xianzhou
2013-01-01
Surface imprinting chlorogenic acid (CGA) on nano-TiO2 particles as sacrificial support material was successfully performed by using 4-vinylpyridine (4-VP) as functional monomer to obtain a hollow CGA-imprinted polymer (H-MIP1). Fourier transmission infrared spectrometry (FTIR) and scanning electron microscopy (SEM) were utilized for structurally characterizing the polymers obtained and adsorption dynamics and thermodynamic behavior investigated according to different models. Binding selectivity, adsorption capacity and the reusability for this H-MIP1 were also evaluated. This hollow CGA imprinted polymer shows rapid binding dynamics and higher binding capability toward the template molecules. The pseudo first-order kinetic model was shown best to describe the binding process of CGA on the H-MIP1 and Langmuir isotherm model best to fit the experimental adsorption isotherm data. Through adsorption isotherms at different temperatures, thermodynamic parameter values were obtained. Selectivity coefficients for the H-MIP1 toward the template were 2.209, 3.213, 1.746 and 2.353 relative to CA, VA, PCA and GA, respectively. This H-MIP1 was also indicated with a good imprint effect and a high capability to capture CGA from methanol extract of Eucommia ulmoides (E. ulmoides) leaves. Additionally, a good reusability for this imprinted polymer was exhibited during repeated adsorption-desorption use.
Saxena, Shivalika; Shukla, Surendra; Thakur, Akhilesh; Gupta, Reena
2008-03-01
The present work is focused on efficient immobilization of polygalacturonase on polyethylene matrix, followed by its application in apple juice clarification. Immobilization of polygalacturonase on activated polyethylene and its use in apple juice clarification was not reported so far. Aspergillus niger Van Tieghem (MTCC 3323) produced polygalacturonase when grown in modified Riviere's medium containing pectin as single carbon source by fed-batch culture. The enzyme was precipitated with ethanol and purified by gel filtration chromatography (Sephacryl S-100) and immobilized onto glutaraldehyde-activated polyethylene. The method is very simple and time saving for enzyme immobilization. Various characteristics of immobilized enzyme such as optimum reaction temperature and pH, temperature and pH stability, binding kinetics, efficiency of binding, reusability and metal ion effect on immobilized enzymes were evaluated in comparison to the free enzyme. Both the free and immobilized enzyme showed maximum activity at a temperature of 45 degrees C and pH 4.8. Maximum binding efficiency was 38%. The immobilized enzyme was reusable for 3 cycles with 50% loss of activity after the third cycle. Twenty-four U of immobilized enzyme at 45 degrees C and 1 h incubation time increased the transmittance of the apple juice by about 55% at 650 nm. The immobilized enzyme can be of industrial advantage in terms of sturdiness, availability, inertness, low price, reusability and temperature stability.
2007-06-13
KENNEDY SPACE CENTER, FLA. -- United Space Alliance employees prepared three test articles that will be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles were flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Photo credit: NASA/Kim Shiflett
Martinez-Solorio, Dionicio; Melillo, Bruno; Sanchez, Luis; Liang, Yong; Lam, Erwin; Houk, K. N.; Smith, Amos B.
2016-01-01
A reusable silicon-based transfer agent (1) has been designed, synthesized, and validated for effective room-temperature palladium-catalyzed cross-coupling reactions (CCRs) of aryl and heteroaryl chlorides with readily accessible aryl lithium reagents. The crystalline, bench-stable siloxane transfer agent (1) is easily prepared via a one-step protocol. Importantly, this “green” CCR protocol circumvents prefunctionalization, isolation of organometallic cross-coupling partners, and/or stoichiometric waste aside from LiCl. DFT calculations support a σ-bond metathesis mechanism during transmetalation and lead to insights on the importance of the CF3 groups. PMID:26835838
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tian, Chengcheng; Bao, Chunhui; Binder, Andrew
We employed poly(4-styrenesulfonic acid) brush-grafted silica particles, synthesized by surface-initiated atom transfer radical polymerization, as a reusable acid catalyst for dehydration of fructose to 5-hydroxymethylfurfural (HMF) in water. Furthermore, the particles exhibited a high activity with the HMF yield of up to 31%, in contrast to 26% from the corresponding free homopolymer catalyst.
Self-unloading, reusable, lunar lander project
NASA Technical Reports Server (NTRS)
Arseculeratne, Ruwan; Cavazos, Melissa; Euker, John; Ghavidel, Fred; Hinkel, Todd J.; Hitzfelder, John; Leitner, Jesse; Nevik, James; Paynter, Scott; Zolondek, Allen
1990-01-01
In the early 21st century, NASA will return to the Moon and establish a permanent base. To achieve this goal safely and economically, B&T Engineering has designed an unmanned, reusable, self-unloading lunar lander. The lander is designed to deliver 15,000 kg payloads from an orbit transfer vehicle (OTV) in a low lunar polar orbit and an altitude of 200 km to any location on the lunar surface.
Thermal Protection Materials for Reentry Applications
NASA Technical Reports Server (NTRS)
Johnson, Sylvia M.; Stackpoole, Mairead; Gusman, Mike; Loehman, Ron; Kotula, Paul; Ellerby, Donald; Arnold, James; Wercinski, Paul; Reuthers, James; Kontinos, Dean
2001-01-01
Thermal protection materials and systems (IRS) are used to protect spacecraft during reentry into Earth's atmosphere or entry into planetary atmospheres. As such, these materials are subject to severe environments with high heat fluxes and rapid heating. Catalytic effects can increase the temperatures substantially. These materials are also subject to impact damage from micrometeorites or other debris during ascent, orbit, and descent, and thus must be able to withstand damage and to function following damage. Thermal protection materials and coatings used in reusable launch vehicles will be reviewed, including the needs and directions for new materials to enable new missions that require faster turnaround and much greater reusability. The role of ablative materials for use in high heat flux environments, especially for non-reusable applications and upcoming planetary missions, will be discussed. New thermal protection system materials may enable the use of sharp nose caps and leading edges on future reusable space transportation vehicles. Vehicles employing this new technology would have significant increases in maneuverability and out-of-orbit cross range compared to current vehicles, leading to increased mission safety in the event of the need to abort during ascent or from orbit. Ultrahigh temperature ceramics, a family of materials based on HfB2 and ZrB2 with SiC, will be discussed. The development, mechanical and thermal properties, and uses of these materials will be reviewed.
Akhmal Saadon, Syaiful; Sathishkumar, Palanivel; Mohd Yusoff, Abdull Rahim; Hakim Wirzal, Mohd Dzul; Rahmalan, Muhammad Taufiq; Nur, Hadi
2016-08-01
In this study, the zinc oxide (ZnO) layer was synthesised on the surface of Zn plates by three different techniques, i.e. electrolysis, hydrogen peroxide and heat treatment. The synthesised ZnO layers were characterised using scanning electron microscopy, X-ray diffraction, UV-visible diffuse reflectance and photoluminescence spectroscopy. The photocatalytic activity of the ZnO layer was further assessed against methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB was achieved up to 84%, 79% and 65% within 1 h for ZnO layers synthesised by electrolysis, heat and hydrogen peroxide treatment, respectively. The reusability results show that electrolysis and heat-treated ZnO layers have considerable photocatalytic stability. Furthermore, the results confirmed that the photocatalytic efficiency of ZnO was directly associated with the thickness and enlarged surface area of the layer. Finally, this study proved that the ZnO layers synthesised by electrolysis and heat treatment had shown better operational stability and reusability.
Addressing surface-induced loss and decoherence in superconducting quantum circuits
NASA Astrophysics Data System (ADS)
Fuhrer, Andreas; Mueller, Peter; Kuhlmann, Andreas; Filipp, Stefan; Deshpande, Veeresh; Drechsler, Ute
Many of the advances in coherence and fidelity of superconducting qubits have been made possible by clever engineering of the coupling to the environment and operation at noise-insensitive sweet spots. However, this leads to a compromise in experimental flexibility and device tunability, which can become inhibitive as the system size is scaled up. Material and interface related degrees of freedoms are harder to mitigate and are expected to become increasingly important in more complex systems. They impose limits both on coherence (flux-noise) and lifetimes (surface loss) of superconducting qubits. To study and eliminate these effects we have constructed a reusable UHV-compatible sample enclosure that enables us to perform various surface passivation steps before cooling superconducting devices to cryogenic temperatures. The enclosure can accommodate large chips with up to 18 microwave ports and can be vacuum sealed at pressures below 8e-10 mbar. We discuss its operation principle and present first measurement results of superconducting CPW resonators and qubit devices with and without prior surface treatments.
X-34 Experimental Aeroheating at Mach 6 and 10
NASA Technical Reports Server (NTRS)
Berry, Scott A.; Horvath, Thomas J.; DiFulvio, Michael; Glass, Christopher; Merski, N. Ronald
1998-01-01
Critical technologies are being developed to support the goals of the NASA Office of Aeronautics and Space Transportation Technology Access to Space initiative for next-generation reusable space transportation systems. From the perspective of aerothermodynamic performance throughout the flight trajectory, the Reusable Launch Vehicle program incorporates conceptual analysis, ground-based testing, and computational fluid dynamics to provide flyable suborbital flight demonstrator vehicles. This report provides an overview of the hypersonic aeroheating wind tunnel test program conducted at the NASA Langley Research Center in support of one of these vehicles, the X-34 small reusable technology demonstrator program. Global surface heat transfer images, surface streamline patterns, and shock shapes were measured on 0.0153- and 0.0183-scale models of proposed X-34 flight vehicles at Mach 6 and 10 in air. The primary parametrics that were investigated include angles-of-attack from 0 to 35 deg. and freestream unit Reynolds numbers from 0.5 to 8 million per foot (which was sufficient to produce laminar, transitional, and turbulent heating data), both with and without control surface deflections. Comparisons of the experimental data to computational predictions are included, along with a discussion of the implications of some of the experimental flow features for the flight vehicle.
Wang, Jianfeng; Liu, Zhongmei; Zhou, Zhemin
2017-06-01
Chelating of pullulanases onto nickel (II)-modified magnetic nanoparticles results in one-step purification and immobilization of pullulanase, and facilitates the commercial application of pullulanase in industrial scale. To improve the catalytic behavior, especially the operational stability, of the nanocatalyst in consecutive batch reactions, we prepared various iminodiacetic acid-modified magnetic nanoparticles differed in surface polarity and spacer length, on which the His6-tagged pullulanases were chelated via nickel ions, and then studied the correlation between the MNPs surface property and the corresponding catalyst behavior. When pullulanases were chelated onto the surface-modified MNPs, the thermostability of all pullulanase derivatives were lower than that of free counterpart, being not relevant to the protein orientation guided by the locality of the His6-tag, but related to the MNPs basal surface polarity and the grafted spacer length. After chelating of pullulanases onto MNPs, there were changes observed in the pH-activity profile and the apparent Michaelis constant toward pullulan. The changing tendencies were mainly dependent on the His6-tagged pullulanase orientation, and the changing extents were tuned by the spacer length. The reusability of pullulanase immobilized by N-terminal His6-tag was higher than that of pullulanase immobilized by C-terminal His6-tag. Moreover, the reusability of the immobilized pullulanase tested increased till grafting polyether amine-400 as spacer-arm, therefore the N-terminal His6-tagged pullulanase chelating MNPs grafted polyether amine-400 gave the best reusability, which retained 60% of initial activity after 18 consecutive cycles with a total reaction time of 9h. Additionally, the correlation analysis of the catalyst behaviors indicated that the reusability was independent from other catalytic properties such as thermostability and substrate affinity. All the results revealed that the catalyst behavior can be mainly controlled by the His6-tagged pullulanase orientation than by the MNPs surface property which can tune the catalyst function. Copyright © 2017. Published by Elsevier Inc.
SU-E-T-353: Effects of Time and Temperature On a Potential Reusable 3D Dosimeter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Juang, T; Miles, D; Crockett, E
Purpose: Preliminary studies of a novel, optically-clearing PRESAGE 3D dosimeter formulation (Presage-RU) demonstrated potential reusability. This study investigates the effects of time and temperature on the accuracy and reusability of Presage-RU, and reports on progress toward developing a reusable 3D dosimeter. Methods: Presage-RU was cast as small volume samples (1×1×4.5cm). The effect of dose response sensitivity with reirradiation and time was evaluated by irradiating samples from 0–10Gy, measuring change in optical density (ΔOD), clearing at room temperature (RT) (5–7 days to fully clear), and then repeating for a total of 5 irradiations. Effects of heating on clearing rate were investigatedmore » by irradiating samples to 8Gy, then tracking measurements with samples held at RT, 35°C, and 45°C. Two cylindrical dosimeters (11cm diameter, 9.5cm length) were evaluated for dosimetric accuracy when stored at RT and −3°C prior to irradiation. Plans delivered were 2 overlapping AP fields (RT) and VMAT (-3°C). Results: Heating the dosimeters reduced the clearing half-life from 16.3h at RT to 5.8h (35°C) and 5.1h (45°C), but also increased background ΔOD by 1.7x (35°C) and 2.3x (45°C). Reductions in dose response were more closely linked to age than reirradiation, and storage at RT showed pronounced desensitization from dosimeter edges. These results suggest desensitization from oxygen diffusion. It should be noted that atmospheric diffusion into the dosimeter is not seen in standard, single-use PRESAGE, and is likely caused by differences in the Presage-RU polyurethane matrix. The dosimeter kept in cold storage, however, showed no evidence of desensitization and exhibited accuracy on par with standard PRESAGE with a 3%/3mm 3D gamma passing rate of 98.1%. Conclusions: Presage-RU is sensitive to storage temperatures and time, both of which affect oxygen diffusion and subsequent desensitization. Development shows promising progress with further formulation optimization as the next step toward achieving a successful reusable 3D dosimeter. This work was supported by NIH R01CA100835. John Adamovics is the president of Heuris Inc., which commercializes PRESAGE.« less
Static and aerothermal tests of a superalloy honeycomb prepackaged thermal protection system
NASA Technical Reports Server (NTRS)
Gorton, Mark P.; Shideler, John L.; Webb, Granville L.
1993-01-01
A reusable metallic thermal protection system has been developed for vehicles with maximum surface temperatures of up to 2000 F. An array of two 12- by 12-in. panels was subjected to radiant heating tests that simulated Space Shuttle entry temperature and pressure histories. Results indicate that this thermal protection system, with a mass of 2.201 lbm/ft(exp 2), can successfully prevent typical aluminum primary structure of an entry vehicle like the Space Shuttle from exceeding temperatures greater than 350 F at a location on the vehicle where the maximum surface temperature is 1900 F. A flat array of 20 panels was exposed to aerothermal flow conditions, at a Mach number of 6.75. The panels were installed in a worst-case orientation with the gaps between panels parallel to the flow. Results from the aerothermal tests indicated that convective heating occurred from hot gas flow in the gaps between the panels. Proposed design changes to prevent gap heating occurred from hot gas flow in the gaps between the panels. Proposed design changes to prevent gap heating include orienting panels so that gaps are not parallel to the flow and using a packaged, compressible gap-filler material between panels to block hot gas flow in the gaps.
Transonic aerodynamic characteristics of a proposed wing-body reusable launch vehicle concept
NASA Technical Reports Server (NTRS)
Springer, A. M.
1995-01-01
A proposed wing-body reusable launch vehicle was tested in the NASA Marshall Space Flight Center's 14 x 14-inch trisonic wind tunnel during the winter of 1994. This test resulted in the vehicle's subsonic and transonic, Mach 0.3 to 1.96, longitudinal and lateral aerodynamic characteristics. The effects of control surface deflections on the basic vehicle's aerodynamics, including a body flap, elevons, ailerons, and tip fins, are presented.
NASA Technical Reports Server (NTRS)
Nordine, Paul C.; Fujimoto, Gordon T.; Greene, Frank T.
1987-01-01
The detection of excited oxygen and ozone molecules formed by surface catalyzed oxygen atom recombination and reaction was investigated by laser induced fluorescence (LIF), molecular beam mass spectrometric (MBMS), and field ionization (FI) techniques. The experiment used partially dissociated oxygen flows from a microwave discharge at pressures in the range from 60 to 400 Pa or from an inductively coupled RF discharge at atmospheric pressure. The catalyst materials investigated were nickel and the reaction cured glass coating used for Space Shuttle reusable surface insulation tiles. Nonradiative loss processes for the laser excited states makes LIF detection of O2 difficult such that formation of excited oxygen molecules could not be detected in the flow from the microwave discharge or in the gaseous products of atom loss on nickel. MBMS experiments showed that ozone was a product of heterogeneous O atom loss on nickel and tile surfaces at low temperatures and that ozone is lost on these materials at elevated temperatures. FI was separately investigated as a method by which excited oxygen molecules may be conveniently detected. Partial O2 dissociation decreases the current produced by FI of the gas.
Selective and reusable iron(II)-based molecular sensor for the vapor-phase detection of alcohols.
Naik, Anil D; Robeyns, Koen; Meunier, Christophe F; Léonard, Alexandre F; Rotaru, Aurelian; Tinant, Bernard; Filinchuk, Yaroslav; Su, Bao Lian; Garcia, Yann
2014-02-03
A mononuclear iron(II) neutral complex (1) is screened for sensing abilities for a wide spectrum of chemicals and to evaluate the response function toward physical perturbation like temperature and mechanical stress. Interestingly, 1 precisely detects methanol among an alcohol series. The sensing process is visually detectable, fatigue-resistant, highly selective, and reusable. The sensing ability is attributed to molecular sieving and subsequent spin-state change of iron centers, after a crystal-to-crystal transformation.
NASA Technical Reports Server (NTRS)
Willden, Kurtis S. (Inventor)
1995-01-01
A reusable laminate mandrel which is unaffected by extreme temperature changes. The flexible laminate mandrel is comprised of sheets stacked to produce the required configuration, a cover wrap that applies pressure to the mandrel laminate, maintaining the stack cross-section. Then after use, the mandrels can be removed, disassembled, and reused. In the method of extracting the flexible mandrel from one end of a composite stiffener, individual ones of the laminae of the flexible mandrel or all are extracted at the same time, depending on severity of the contour.
Biodiesel production from castor oil using heterogeneous Ni doped ZnO nanocatalyst.
Baskar, G; Aberna Ebenezer Selvakumari, I; Aiswarya, R
2018-02-01
In the present study, castor oil with high free fatty acid was used for biodiesel production using heterogeneous Ni doped ZnO nanocatalyst. Ni doped ZnO nanocomposite calcinated at 800 °C has shown better catalytic activity. Process parameters on heterogeneous catalysis of castor oil into biodiesel were optimized using conventional and Response Surface Methodology (RSM). RSM was found more accurate in estimating the optimum conditions with higher biodiesel yield (95.20%). The optimum conditions for transesterification was found to be oil to methanol molar ratio of 1:8, catalyst loading 11% (w/w), reaction temperature of 55 °C for 60 min of reaction time by response surface method. The reusability studies showed that the nanocatalyst can be reused efficiently for 3 cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.
Tebbutt, G. M.
1988-01-01
A comparison of five methods of cleaning Formica surfaces contaminated with bacteria dried in milk has been carried out. A standardized procedure was developed, and impression plates were found to be at least as sensitive as a swab-rinse method for detecting bacteria on the surfaces. The most satisfactory results were obtained with one type of disposable alcohol-impregnated wipe and with a detergent/hypochlorite solution applied with paper. A reusable cloth impregnated with disinfectant initially performed well against all test organisms, but was less reliable against Staphylococcus aureus and Streptococcus faecalis, after the cloth had been used and rinsed several times. The importance of introducing methods to reduce the high risk of cross-contamination presently associated with the use of wiping cloths in catering premises is stressed. PMID:3141202
NASA Astrophysics Data System (ADS)
Rafiee, Ezzat; Mirnezami, Fakhrosadat
2017-02-01
By combining phosphotungstic acid (PW) and SO3H- functioned zwitterion, heteropoly anion-based Brønsted acidic ionic liquids (HPA-ILs) were successfully obtained. Scanning electron microscopy and energy dispersive X-ray spectroscopy were provided the morphology and composition of the prepared material. Catalytic performance and reusability of the catalysts were evaluated through an esterification reaction between oleic acid and methanol for production of biodiesel. Relationship between catalytic activities and acidity of the catalysts have been discussed by potentiometric titration. The results showed that HPA-ILs had good activity and reusability. HPA-ILs dissolved in the reaction mixture during the reaction process and could be precipitated and separated from products at lower temperature.
Wei, Zuojun; Lou, Jiongtao; Su, Chuanmin; Guo, Dechao; Liu, Yingxin; Deng, Shuguang
2017-04-22
To achieve a higher activity and reusability of a Ru-based catalyst, Ru nanoparticles were embedded in N-doped mesoporous carbon through a hard-template method. The catalyst showed excellent catalytic performance (314 h -1 turnover frequency) and recyclability (reusable five times with 3 % activity loss) for the hydrogenolysis of levulinic acid to γ-valerolactone. Compared with the mesoporous carbon without N-doping and conventional activated carbon, the introduction of N-dopant effectively improved the dispersion of Ru nanoparticles, decreased the average size of Ru nanoparticles to as small as 1.32 nm, and improved the adsorption of levulinic acid, which contributed to the increase in the activity of the catalyst. Additionally, the embedding method increased the interaction between Ru nanoparticles and carbon support in contrast with the conventional impregnation method, thus preventing the Ru nanoparticles from migration, aggregation, and leaching from the carbon surface and therefore increasing the reusability of the catalyst. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Self-unloading, unmanned, reusable lunar lander project
NASA Technical Reports Server (NTRS)
Cowan, Kevin; Lewis, Ron; Mislinski, Philip; Rivers, Donna; Smith, Solar; Vasicek, Clifford; Verona, Matt
1991-01-01
A payload delivery system will be required to support the buildup and operation of a manned lunar base. In response, a self-unloading, unmanned, reusable lunar lander was conceptually designed. The lander will deliver a 7000 kg payload, with the same dimensions as a space station logistics module, from low lunar orbit to any location on the surface of the moon. The technical aspects of the design is introduced as well as the management structure and project cost.
NASA Astrophysics Data System (ADS)
Bhaumik, Ria; Mondal, Naba Kumar
2016-06-01
The present work highlighted the effective application of banana peel dust (BPD) for removal of fluoride (F-) from aqueous solution. The effects of operating parameters such as pH, initial concentration, adsorbent dose, contact time, agitation speed and temperature were analysed using response surface methodology. The significance of independent variables and their interactions were tested by the analysis of variance and t test statistics. Experimental results revealed that BPD has higher F- adsorption capacity (17.43, 26.31 and 39.5 mg/g). Fluoride adsorption kinetics followed pseudo-second-order model with high correlation of coefficient value (0.998). On the other hand, thermodynamic data suggest that adsorption is favoured at lower temperature, exothermic in nature and enthalpy driven. The adsorbents were characterised through scanning electron microscope, Fourier transform infrared spectroscopy and point of zero charges (pHZPC) ranges from pH 6.2-8.2. Finally, error analysis clearly demonstrates that all three adsorbents are well fitted with Langmuir isotherm compared to the other isotherm models. The reusable properties of the material support further development for commercial application purpose.
Health Monitoring Technology for Thermal Protection Systems on Reusable Hypersonic Vehicles
NASA Technical Reports Server (NTRS)
Milos, Frank S.; Watters, D. G.; Heinemann, J. M.; Karunaratne, K. S.; Arnold, Jim (Technical Monitor)
2001-01-01
Integrated subsystem health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles (RLVs) in order to reduce life cycle costs, to increase safety margins, and to improve mission reliability. This talk summarizes a joint effort between NASA Ames and industry partners to develop rapid non-contact diagnostic tools for health and performance monitoring of thermal protection systems (TPS) on future RLVs. The specific goals for TPS health monitoring are to increase the speed and reliability of TPS inspections for improved operability at lower cost. The technology being developed includes a 3-D laser scanner for examining the exterior surface of the TPS, and a subsurface microsensor suite for monitoring the health and performance of the TPS. The sensor suite consists of passive overlimit sensors and sensors for continuous parameter monitoring in flight. The sensors are integrated with radio-frequency identification (RFID) microchips to enable wireless communication of-the sensor data to an external reader that may be a hand-held scanner or a large portal. Prototypes of the laser system and both types of subsurface sensors have been developed. The laser scanner was tested on Shuttle Orbiter Columbia and was able to dimension surface chips and holes on a variety of TPS materials. The temperature-overlimit microsensor has a diameter under 0.05 inch (suitable for placement in gaps between ceramic TPS tiles) and can withstand 700 F for 15 minutes.
Carbon Nanotubes Blended Hydroxyapatite Ethanol Sensor
NASA Astrophysics Data System (ADS)
Anjum, S. R.; Khairnar, R. S.
2016-12-01
Nano crystals of Hydroxyapatite (HAp) were synthesized by a wet chemical precipitation method. The nano composite materials were developed by doping various weight concentrations of carbon nanotubes in HAp, followed by characterization using scanning electron microscopy, and X-ray diffraction. Thick films of these materials were prepared by using screen printing technique. The ethanol sensing properties of these nano crystals and nano composite films were investigated by two probe electrical method. The gas sensing features such as operating temperature, response and recovery time, maximum gas detection limit, etc. were studied, since these parameters are of prime importance for sensor. The results revealed that at room temperature, the composite materials exhibited improved sensing performance towards 100 ppm ethanol with fast response times. It also showed shorter recovery time with higher vapor uptake capacity. The ethanol adsorption processes on doped and undoped substrates can be explained by surface chemical reactions as well as providing the possible adsorption models. The novelty of this work lies in developing reusable sensor substrates for room temperature sensing.
BLIMPK/Streamline Surface Catalytic Heating Predictions on the Space Shuttle Orbiter
NASA Technical Reports Server (NTRS)
Marichalar, Jeremiah J.; Rochelle, William C.; Kirk, Benjamin S.; Campbell, Charles H.
2006-01-01
This paper describes the results of an analysis of localized catalytic heating effects to the U.S. Space Shuttle Orbiter Thermal Protection System (TPS). The analysis applies to the High-temperature Reusable Surface Insulation (HRSI) on the lower fuselage and wing acreage, as well as the critical Reinforced Carbon-Carbon on the nose cap, chin panel and the wing leading edge. The object of the analysis was to use a modified two-layer approach to predict the catalytic heating effects on the Orbiter windward HRSI tile acreage, nose cap, and wing leading edge assuming localized highly catalytic or fully catalytic surfaces. The method incorporated the Boundary Layer Integral Matrix Procedure Kinetic (BLIMPK) code with streamline inputs from viscous Navier-Stokes solutions to produce heating rates for localized fully catalytic and highly catalytic surfaces as well as for nominal partially catalytic surfaces (either Reinforced Carbon-Carbon or Reaction Cured Glass) with temperature-dependent recombination coefficients. The highly catalytic heating results showed very good correlation with Orbiter Experiments STS-2, -3, and -5 centerline and STS-5 wing flight data for the HRSI tiles. Recommended catalytic heating factors were generated for use in future Shuttle missions in the event of quick-time analysis of damaged or repaired TPS areas during atmospheric reentry. The catalytic factors are presented along the streamlines as well as a function of stagnation enthalpy so they can be used for arbitrary trajectories.
2007-06-13
KENNEDY SPACE CENTER, FLA. -- Another view of the area of orbiter Endeavour's orbital maneuvering system, or OMS, pod where the tear occurred on Atlantis during launch of mission STS-117 on June 8, 2007. Repair is under consideration following testing at KSC and Houston. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles were flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Photo credit: NASA/Kim Shiflett
2007-06-13
KENNEDY SPACE CENTER, FLA. -- Another view of the area of orbiter Endeavour's orbital maneuvering system, or OMS, pod where the tear occurred on Atlantis during launch of mission STS-117 on June 8, 2007. Repair is under consideration following testing at KSC and Houston. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles were flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Photo credit: NASA/Kim Shiflett
Closeup oblique view of the aft fuselage of the Orbiter ...
Close-up oblique view of the aft fuselage of the Orbiter Discovery looking forward and port as the last Space Shuttle Main Engine is being removed, it can be seen on the left side of the image frame. Note that one of the Orbiter Maneuvering System/ Reaction Control System has been removed while one of them remains. Also note that the body flap, below the engine positions has a protective covering to prevent damage to the High-temperature Reusable Surface Insulation tiles. This image was taken inside the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Closeup oblique view of the aft fuselage of the Orbiter ...
Close-up oblique view of the aft fuselage of the Orbiter Discovery looking forward and starboard as the last Space Shuttle Main Engine is being removed, it can be seen on the right side of the image frame. Note that one of the Orbiter Maneuvering System/ Reaction Control System has been removed while one of them remains. Also note that the body flap, below the engine positions has a protective covering to prevent damage to the High-temperature Reusable Surface Insulation tiles. This image was taken inside the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
NASA Astrophysics Data System (ADS)
Park, J.-S.; Park, J.-H.; Lee, D.-W.
2018-02-01
In this paper, we describe a simple manufacturing method for producing an optically transparent super-hydrophobic polymer thin film using a reusable photo-curable polymer mold. Soluble photoresist (PR) molds were prepared with under-exposed and under-baked processes, which created unique hierarchical micro/nano structures. The reverse phase of the PR mold was replicated on the surface of polydimethylsiloxane (PDMS) substrates. The unique patterns on the replicated PDMS molds were successfully transferred back to the UV curable polyurethane-acrylate (PUA) using a laboratory-made UV exposure system. Continuous production of the super-hydrophobic PDMS thin film was demonstrated using the reusable PUA mold. In addition, hydrophobic nano-silica powder was sprayed onto the micro/nano structured PDMS surfaces to further improve hydrophobicity. The fabricated PDMS thin films with hierarchical surface texturing showed a water contact angle ⩾150°. Excellent optical transmittance within the range of visible light of wavelengths between 400-800 nm was experimentally confirmed using a spectrophotometer. High efficiency of the super-hydrophobic PDMS film in optical transparency was also confirmed using solar panels. The fabricated PUA molds are very suitable for use in roll-to-roll or roll-to-plate systems which allow continuous production of super-hydrophobic thin films with an excellent optical transparency.
NASA Technical Reports Server (NTRS)
Bradley, P. F.; Throckmorton, D. A.
1981-01-01
A study was completed to determine the sensitivity of computed convective heating rates to uncertainties in the thermal protection system thermal model. Those parameters considered were: density, thermal conductivity, and specific heat of both the reusable surface insulation and its coating; coating thickness and emittance; and temperature measurement uncertainty. The assessment used a modified version of the computer program to calculate heating rates from temperature time histories. The original version of the program solves the direct one dimensional heating problem and this modified version of The program is set up to solve the inverse problem. The modified program was used in thermocouple data reduction for shuttle flight data. Both nominal thermal models and altered thermal models were used to determine the necessity for accurate knowledge of thermal protection system's material thermal properties. For many thermal properties, the sensitivity (inaccuracies created in the calculation of convective heating rate by an altered property) was very low.
NASA Technical Reports Server (NTRS)
Unal, Resit; Morris, W. Douglas; White, Nancy H.; Lepsch, Roger A.; Brown, Richard W.
2000-01-01
This paper describes the development of parametric models for estimating operational reliability and maintainability (R&M) characteristics for reusable vehicle concepts, based on vehicle size and technology support level. A R&M analysis tool (RMAT) and response surface methods are utilized to build parametric approximation models for rapidly estimating operational R&M characteristics such as mission completion reliability. These models that approximate RMAT, can then be utilized for fast analysis of operational requirements, for lifecycle cost estimating and for multidisciplinary sign optimization.
Assessment of Alternate Thermal Protection Systems for the Space Shuttle Orbiter
NASA Technical Reports Server (NTRS)
Kelly, H. N.; Webb, G. L.
1982-01-01
Candidate concepts are identified. The impact on the Shuttle Orbiter performance life cycle cost, and risk was assessed and technology advances required to bring the selected TPS to operational readiness are defined. The best system is shown to be a hybrid blend of metallic and carbon-carbon TPS concepts. These alternate concepts offer significant improvements in reusability and are mass competitive with the current ceramic tile reusable surface insulation. Programmatic analysis indicates approximately five years are required to bring the concepts to operational readiness.
Venkatesan, Shanmuganathan; Kumar, Annamalai Senthil; Lee, Jyh-Fu; Chan, Ting-Shan; Zen, Jyh-Myng
2012-05-14
The aerobic oxidation of primary amines to their respective nitriles has been carried out at room temperature using a highly reusable nanocrystalline ruthenium oxide pyrochlore Nafion composite catalyst (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Enhancement of solar water pasteurization with reflectors.
Safapour, N; Metcalf, R H
1999-02-01
A simple and reliable method that could be used in developing countries to pasteurize milk and water with solar energy is described. A cardboard reflector directs sunshine onto a black jar, heating water to pasteurizing temperatures in several hours. A reusable water pasteurization indicator verifies that pasteurization temperatures have been reached.
Analysis and Testing of High Temperature Fibrous Insulation for Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Daryabeigi, Kamran
1999-01-01
Analytical models were developed to model the heat transfer through high-temperature fibrous insulation used in metallic thermal protection systems on reusable launch vehicles. The optically thick approximation was used to simulate radiation heat transfer through the insulation. Different models for gaseous conduction and solid conduction in the fibers, and for combining the various modes of heat transfer into a local, volume-averaged, thermal conductivity were considered. The governing heat transfer equations were solved numerically, and effective thermal conductivities were calculated from the steady-state results. An experimental apparatus was developed to measure the apparent thermal conductivity of insulation subjected to pressures, temperatures and temperature gradients representative of re-entry conditions for launch vehicles. The apparent thermal conductivity of an alumina fiber insulation was measured at nominal densities of 24, 48 and 96 kg/cu m. Data were obtained at environmental pressures from 10(exp 4) to 760 torr, with the insulation cold side maintained at room temperature and its hot side temperature varying up to 1000 C. The experimental results were used to evaluate the analytical models. The best analytical model resulted in effective thermal conductivity predictions that were within 8% of experimental results.
Self-Healing Nanocomposites for Reusable Composite Cryotanks
NASA Technical Reports Server (NTRS)
Eberly, Daniel; Ou, Runqing; Karcz, Adam; Skandan, Ganesh
2013-01-01
Composite cryotanks, or composite overwrapped pressure vessels (COPVs), offer advantages over currently used aluminum-lithium cryotanks, particularly with respect to weight savings. Future NASA missions are expected to use COPVs in spaceflight propellant tanks to store fuels, oxidizers, and other liquids for launch and space exploration vehicles. However, reliability, reparability, and reusability of the COPVs are still being addressed, especially in cryogenic temperature applications; this has limited the adoption of COPVs in reusable vehicle designs. The major problem with composites is the inherent brittleness of the epoxy matrix, which is prone to microcrack formation, either from exposure to cryogenic conditions or from impact from different sources. If not prevented, the microcracks increase gas permeation and leakage. Accordingly, materials innovations are needed to mitigate microcrack damage, and prevent damage in the first place, in composite cryotanks. The self-healing technology being developed is capable of healing the microcracks through the use of a novel engineered nanocomposite, where a uniquely designed nanoparticle additive is incorporated into the epoxy matrix. In particular, this results in an enhancement in the burst pressure after cryogenic cycling of the nanocomposite COPVs, relative to the control COPVs. Incorporating a novel, self-healing, epoxy-based resin into the manufacture of COPVs allows repeatable self-healing of microcracks to be performed through the simple application of a low-temperature heat source. This permits COPVs to be reparable and reusable with a high degree of reliability, as microcracks will be remediated. The unique phase-separated morphology that was imparted during COPV manufacture allows for multiple self-healing cycles. Unlike single-target approaches where one material property is often improved at the expense of another, robustness has been introduced to a COPV by a combination of a modified resin and nanoparticle additives. Unique nanoparticles were used that have been surface-functionalized to be compatible with the resin. Both organic and inorganic components toughen the matrix and result in a more impact-resistant COPV. In one resin system containing an inorganic nanomaterial additive, a significant improvement in burst performance was observed after the COPV was cryo-impact-damaged and then self-healed, with a greater than 10% improvement in burst pressure after the self-healing process was performed. Initial cross-sectional analysis via microscopy showed good resin infiltration of the carbon fibers and without voids. To further enhance the capability between the nanomaterial additives and the resin, a surface modification was successfully performed. A second specialty epoxy resin was prepared using a surface modified nanomaterial additive, and COPVs were fabricated. Steps were taken to improve the mechanical properties of the COPVs by using a low-viscosity resin system that contained a different curing agent. This lower viscosity improves the processing of the COPV, and preliminary results show that the burst pressure of these new vessels is 20 to 25% higher than that of the original. The self-healing concept demonstrated in this research and development effort represents a platform technology, and the self-healing property is neither restricted to the particular epoxy system used here, nor to the COPV application. Self-healing is a direct result of a unique phase separated morphology created via the resin and is aided by the nanoparticles. The self-healing function can be introduced to other customer-specific resin systems in coating, bulk, or composite applications provided that the unique phase separated morphology can be enabled in those systems.
Characterization of cement-based materials using a reusable piezoelectric impedance-based sensor
NASA Astrophysics Data System (ADS)
Tawie, R.; Lee, H. K.
2011-08-01
This paper proposes a reusable sensor, which employs a piezoceramic (PZT) plate as an active sensing transducer, for non-destructive monitoring of cement-based materials based on the electromechanical impedance (EMI) sensing technique. The advantage of the sensor design is that the PZT can be easily removed from the set-up and re-used for repetitive tests. The applicability of the sensor was demonstrated for monitoring of the setting of cement mortar. EMI measurements were performed using an impedance analyzer and the transformation of the specimen from the plastic to solid state was monitored by automatically measuring the changes in the PZT conductance spectra with respect to curing time using the root mean square deviation (RMSD) algorithm. In another experiment, drying-induced moisture loss of a hardened mortar specimen at saturated surface dry (SSD) condition was measured, and monitored using the reusable sensor to establish a correlation between the RMSD values and moisture loss rate. The reusable sensor was also demonstrated for detecting progressive damages imparted on a mortar specimen attached with the sensor under several loading levels before allowing it to load to failure. Overall, the reusable sensor is an effective and efficient monitoring device that could possibly be used for field application in characterization of cement-based materials.
Wang, Tao; Zhu, Chengzhu; Liu, Haibo; Xu, Yongpeng; Zou, Xuehua; Xu, Bin; Chen, Tianhu
2018-02-01
Natural manganese ore catalysts for selective catalytic reduction (SCR) of NO with NH 3 at low temperature in the presence and absence of SO 2 and H 2 O were systematically investigated. The physical and chemical properties of catalysts were characterized by X-ray diffraction, Brunauer-Emmett-Teller (BET) specific surface area, NH 3 temperature-programmed desorption (NH 3 -TPD) and NO-TPD methods. The results showed that natural manganese ore from Qingyang of Anhui Province had a good low-temperature activity and N 2 selectivity, and it could be a novel catalyst in terms of stability, good efficiency, good reusability and lower cost. The NO conversion exceeded 85% between 150°C and 300°C when the initial NO concentration was 1000 ppm. The activity was suppressed by adding H 2 O (10%) or SO 2 (100 or 200 ppm), respectively, and its activity could recover while the SO 2 supply is cut off. The simultaneous addition of H 2 O and SO 2 led to the increase of about 100% in SCR activity than bare addition of SO 2 . The formation of the amorphous MnO x , high concentration of lattice oxygen and surface-adsorbed oxygen groups and a lot of reducible species as well as adsorption of the reactants brought about excellent SCR performance and exhibited good SO 2 and H 2 O resistance.
Hercules Single-Stage Reusable Vehicle (HSRV) Operating Base
NASA Technical Reports Server (NTRS)
Moon, Michael J.; McCleskey, Carey M.
2017-01-01
Conceptual design for the layout of lunar-planetary surface support systems remains an important area needing further master planning. This paper explores a structured approach to organize the layout of a Mars-based site equipped for routinely flying a human-scale reusable taxi system. The proposed Hercules Transportation System requires a surface support capability to sustain its routine, affordable, and dependable operation. The approach organizes a conceptual Hercules operating base through functional station sets. The station set approach will allow follow-on work to trade design approaches and consider technologies for more efficient flow of material, energy, and information at future Mars bases and settlements. The station set requirements at a Mars site point to specific capabilities needed. By drawing from specific Hercules design characteristics, the technology requirements for surface-based systems will come into greater focus. This paper begins a comprehensive process for documenting functional needs, architectural design methods, and analysis techniques necessary for follow-on concept studies.
Sustaining Human Presence on Mars Using ISRU and a Reusable Lander
NASA Technical Reports Server (NTRS)
Arney, Dale C.; Jones, Christopher A.; Klovstad, Jordan J.; Komar, D.R.; Earle, Kevin; Moses, Robert; Shyface, Hilary R.
2015-01-01
This paper presents an analysis of the impact of ISRU (In-Site Resource Utilization), reusability, and automation on sustaining a human presence on Mars, requiring a transition from Earth dependence to Earth independence. The study analyzes the surface and transportation architectures and compared campaigns that revealed the importance of ISRU and reusability. A reusable Mars lander, Hercules, eliminates the need to deliver a new descent and ascent stage with each cargo and crew delivery to Mars, reducing the mass delivered from Earth. As part of an evolvable transportation architecture, this investment is key to enabling continuous human presence on Mars. The extensive use of ISRU reduces the logistics supply chain from Earth in order to support population growth at Mars. Reliable and autonomous systems, in conjunction with robotics, are required to enable ISRU architectures as systems must operate and maintain themselves while the crew is not present. A comparison of Mars campaigns is presented to show the impact of adding these investments and their ability to contribute to sustaining a human presence on Mars.
Response Surface Model Building Using Orthogonal Arrays for Computer Experiments
NASA Technical Reports Server (NTRS)
Unal, Resit; Braun, Robert D.; Moore, Arlene A.; Lepsch, Roger A.
1997-01-01
This study investigates response surface methods for computer experiments and discusses some of the approaches available. Orthogonal arrays constructed for computer experiments are studied and an example application to a technology selection and optimization study for a reusable launch vehicle is presented.
NASA Technical Reports Server (NTRS)
Gille, J. P.
1972-01-01
A program is described that was conducted to develop an internal insulation system for potential application to the liquid hydrogen tanks of a reusable booster, where the tanks would be subjected to repeated high temperatures. The design of the internal insulation is based on a unique gas layer concept, in which capillary or surface tension effects are used to maintain a stable gas layer, within a cellular core structure, between the tank wall and the contained liquid hydrogen. Specific objectives were to select materials for insulation systems that would be compatible with wall temperatures of 350 F and 650 F during reentry into the earth's atmosphere, and to fabricate and test insulation systems under conditions simulating the operating environment. A materials test program was conducted to evaluate the properties of candidate materials at elevated temperatures and at the temperature of liquid hydrogen, and to determine the compatibility of the materials with a hydrogen atmosphere at the appropriate elevated temperature. The materials that were finally selected included Kapton polyimide films, silicone adhesives, fiber glass batting, and in the case of the 350 F system, Teflon film.
Enhancement of Solar Water Pasteurization with Reflectors
Safapour, Negar; Metcalf, Robert H.
1999-01-01
A simple and reliable method that could be used in developing countries to pasteurize milk and water with solar energy is described. A cardboard reflector directs sunshine onto a black jar, heating water to pasteurizing temperatures in several hours. A reusable water pasteurization indicator verifies that pasteurization temperatures have been reached. PMID:9925631
NASA Technical Reports Server (NTRS)
Johnson, Sylvia M.
2011-01-01
For enhanced aerodynamic performance. Materials for sharp leading edges can be reusable but need different properties because of geometry and very high temperatures. Require materials with significantly higher temperature capabilities, but for short duration. Current shuttle RCC leading edge materials: T approx. 1650 C. Materials for vehicles with sharp leading edges: T>2000 C. >% Figure depicts: High Temperature at Tip and Steep Temperature Gradient. Passive cooling is simplest option to manage the intense heating on sharp leading edges.
2012-04-05
CAPE CANAVERAL, Fla. – Kennedy Space Center Director Bob Cabana, right, shows a space shuttle low-temperature reusable surface insulation LRSI tile to Florida’s Lt. Gov. Jennifer Carroll during a tour of Kennedy’s Orbiter Processing Facility-1. The tile is part of the shuttle’s thermal protection system which covers the shuttle’s exterior and protects it from the heat of re-entry. The tour coincided with Carroll’s visit to Kennedy for a meeting with Cabana. Atlantis is being prepared for public display at the Kennedy Space Center Visitor Complex in 2013. The groundbreaking for Atlantis’ exhibit hall took place in January Atlantis is scheduled to be moved to the visitor complex in November. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Jim Grossmann
2012-04-05
CAPE CANAVERAL, Fla. – Kennedy Space Center Director Bob Cabana, right, shows a space shuttle high-temperature reusable surface insulation HRSI tile to Florida’s Lt. Gov. Jennifer Carroll during a tour of Kennedy’s Orbiter Processing Facility-1. The tile is part of the shuttle’s thermal protection system which covers the shuttle’s exterior and protects it from the heat of re-entry. The tour coincided with Carroll’s visit to Kennedy for a meeting with Cabana. Atlantis is being prepared for public display at the Kennedy Space Center Visitor Complex in 2013. The groundbreaking for Atlantis’ exhibit hall took place in January Atlantis is scheduled to be moved to the visitor complex in November. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Jim Grossmann
Singh, Siddhartha; Singh, Amit Kumar; Singh, M Chandrakumar; Pandey, Pramod Kumar
2017-02-01
Immobilization of enzymes is valuably important as it improves the stability and hence increases the reusability of enzymes. The present investigation is an attempt for immobilization of purified glucose-6-phosphate dehydrogenase from pigeon pea on different matrix. Maximum immobilization was achieved when alginate was used as immobilization matrix. As compared to soluble enzyme the alginate immobilized enzyme exhibited enhanced optimum pH and temperature. The alginate immobilized enzyme displayed more than 80% activity up to 7 continuous reactions and more than 50% activity up to 11 continuous reactions.
NASA Technical Reports Server (NTRS)
Nurick, W. H.
1974-01-01
An evaluation of reusable thrust chambers for the space shuttle orbit maneuvering engine was conducted. Tests were conducted using subscale injector hot-fire procedures for the injector configurations designed for a regenerative cooled engine. The effect of operating conditions and fuel temperature on combustion chamber performance was determined. Specific objectives of the evaluation were to examine the optimum like-doublet element geometry for operation at conditions consistent with a fuel regeneratively cooled engine (hot fuel, 200 to 250 F) and the sensitivity of the triplet injector element to hot fuels.
Development and flight test of metal-lined CFRP cryogenic tank for reusable rocket
NASA Astrophysics Data System (ADS)
Higuchi, Ken; Takeuchi, Shinsuke; Sato, Eiichi; Naruo, Yoshihiro; Inatani, Yoshifumi; Namiki, Fumiharu; Tanaka, Kohtaro; Watabe, Yoko
2005-07-01
A cryogenic tank made of carbon fiber reinforced plastic (CFRP) shell with aluminum thin liner has been designed as a liquid hydrogen (LH2) tank for an ISAS reusable launch vehicle, and the function of it has been proven by repeated flights onboard the test vehicle called reusable vehicle testing (RVT) in October 2003. The liquid hydrogen tank has to be a pressure vessel, because the fuel of the engine of the test vehicle is supplied by fuel pressure. The pressure vessel of a combination of the outer shell of CFRP for strength element at a cryogenic temperature and the inner liner of aluminum for gas barrier has shown excellent weight merit for this purpose. Interfaces such as tank outline shape, bulk capacity, maximum expected operating pressure (MEOP), thermal insulation, pipe arrangement, and measurement of data are also designed to be ready onboard. This research has many aims, not only development of reusable cryogenic composite tank but also the demonstration of repeated operation including thermal cycle and stress cycle, familiarization with test techniques of operation of cryogenic composite tanks, and the accumulation of data for future design of tanks, vehicle structures, safety evaluation, and total operation systems.
NASA Astrophysics Data System (ADS)
Lai, Yi-Chen; Ho, Hsin-Chia; Shih, Bo-Wei; Tsai, Feng-Yu; Hsueh, Chun-Hway
2018-05-01
Surface-enhanced Raman scattering (SERS) substrate with a higher surface area, enhanced light harvesting, multiple hot spots and strong electromagnetic field enhancements would exhibit enhanced Raman signals. Herein, the Ag nanoparticle/ZnO nanowire heterostructure decorated periodic silicon nanotube (Ag@ZnO@SiNT) substrate was proposed and fabricated. The proposed structure employed as SERS-active substrate was examined, and the results showed both the high performance in terms of high sensitivity and good reproducibility. Furthermore, the Ag@ZnO@SiNT substrate demonstrated the self-cleaning performance through the photocatalytic degradation of probed molecules upon UV-irradiation. The results showed that the proposed nanostructure had high performance, good reproducibility and reusability, and it is a promising SERS-active substrate for molecular sensing and cleaning.
NASA Technical Reports Server (NTRS)
1997-01-01
Advanced Flexible Reusable Surface Insulation, developed by Ames Research Center, protects the Space Shuttle from the searing heat that engulfs it on reentry into the Earth's atmosphere. Initially integrated into the Space Shuttle by Rockwell International, production was transferred to Hi-Temp Insulation Inc. in 1974. Over the years, Hi-Temp has created many new technologies to meet the requirements of the Space Shuttle program. This expertise is also used commercially, including insulation blankets to cover aircrafts parts, fire barrier material to protect aircraft engine cowlings and aircraft rescue fire fighter suits. A Fire Protection Division has also been established, offering the first suit designed exclusively by and for aircraft rescue fire fighters. Hi-Temp is a supplier to the Los Angeles City Fire Department as well as other major U.S. civil and military fire departments.
Atomic oxygen recombination on the ODS PM 1000 at high temperature under air plasma
NASA Astrophysics Data System (ADS)
Balat-Pichelin, M.; Bêche, E.
2010-06-01
High temperature materials are necessary for the design of primary heat shields for future reusable space vehicles re-entering atmospheric planet at hypersonic velocity. During the re-entry phase on earth, one of the most important phenomena occurring on the heat shield is the recombination of atomic oxygen and this phenomenon is more or less catalyzed by the material of the heat shield. PM 1000 is planned to be use on the EXPERT capsule to study in real conditions its catalycity. Before the flight, it is necessary to perform measurements on ground test facility. Experimental data of the recombination coefficient of atomic oxygen under air plasma flow were obtained in the diffusion reactor MESOX on pre-oxidized PM 1000, for two total pressures 300 and 1000 Pa in the temperature range (850-1650 K) using actinometry and optical emission spectroscopy. In this investigation, the evolution of the recombination coefficient is dependent of temperature, pressure level and also of the chemical composition of the surface leading to one order of magnitude for a given temperature. The recombination coefficient is increasing with temperature and also dependent on the static pressure. The surface change due to the plasma exposure is inspected with SEM, XRD and XPS. As chromium oxide is the main part of the oxide layer formed during the oxidation in air plasma conditions, a sintered Cr 2O 3 sample was elaborated from powders to compare the data of the recombination coefficient obtained on PM 1000. Pre- and post-test analyses on the several materials were carried out using SEM, WDS, XRD and XPS.
Airframe integration trade studies for a reusable launch vehicle
NASA Astrophysics Data System (ADS)
Dorsey, John T.; Wu, Chauncey; Rivers, Kevin; Martin, Carl; Smith, Russell
1999-01-01
Future launch vehicles must be lightweight, fully reusable and easily maintained if low-cost access to space is to be achieved. The goal of achieving an economically viable Single-Stage-to-Orbit (SSTO) Reusable Launch Vehicle (RLV) is not easily achieved and success will depend to a large extent on having an integrated and optimized total system. A series of trade studies were performed to meet three objectives. First, to provide structural weights and parametric weight equations as inputs to configuration-level trade studies. Second, to identify, assess and quantify major weight drivers for the RLV airframe. Third, using information on major weight drivers, and considering the RLV as an integrated thermal structure (composed of thrust structures, tanks, thermal protection system, insulation and control surfaces), identify and assess new and innovative approaches or concepts that have the potential for either reducing airframe weight, improving operability, and/or reducing cost.
A green, reusable SERS film with high sensitivity for in-situ detection of thiram in apple juice
NASA Astrophysics Data System (ADS)
Sun, Hongbao; Liu, Hai; Wu, Yiyong
2017-09-01
We report a green and reusable surface-enhanced Raman scattering (SERS) film based on PMMA/Ag NPs/graphene. By using this Raman substrate, the SERS signals of R6G were significantly enhanced reaching a minimum detectable concentration of 5 × 10-8 M, due to having lots of hot spots adhered backside to the exposed graphene. The SERS film can be used for in-situ monitoring of trace thiram in apple juice with a detection limit of 1 × 10-6 M (0.24 ppm), which is below the maximal residue limit (MRL) of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Furthermore, reusability studies show that the SERS film can be used repeatedly. In addition, the graphene-enhanced SERS technique shows great potential applications for the in-situ detection and identification of pesticide residues in environmental water, fruits and vegetables.
Airframe Integration Trade Studies for a Reusable Launch Vehicle
NASA Technical Reports Server (NTRS)
Dorsey, John T.; Wu, Chauncey; Rivers, Kevin; Martin, Carl; Smith, Russell
1999-01-01
Future launch vehicles must be lightweight, fully reusable and easily maintained if low-cost access to space is to be achieved. The goal of achieving an economically viable Single-Stage-to-Orbit (SSTO) Reusable Launch Vehicle (RLV) is not easily achieved and success will depend to a large extent on having an integrated and optimized total system. A series of trade studies were performed to meet three objectives. First, to provide structural weights and parametric weight equations as inputs to configuration-level trade studies. Second, to identify, assess and quantify major weight drivers for the RLV airframe. Third, using information on major weight drivers, and considering the RLV as an integrated thermal structure (composed of thrust structures, tanks, thermal protection system, insulation and control surfaces), identify and assess new and innovative approaches or concepts that have the potential for either reducing airframe weight, improving operability, and/or reducing cost.
Toward mass producible ordered bulk heterojunction organic photovoltaic devices.
Kim, Taeyong; Yoon, Hyunsik; Song, Hyung-Jun; Haberkorn, Niko; Cho, Younghyun; Sung, Seung Hyun; Lee, Chang Hee; Char, Kookheon; Theato, Patrick
2012-12-13
A strategy to fabricate nanostructured poly(3-hexylthiophene) (P3HT) films for organic photovoltaic (OPV) cells by a direct transfer method from a reusable soft replica mold is presented. The flexible polyfluoropolyether (PFPE) replica mold allows low-pressure and low- temperature process condition for the successful transfer of nanostructured P3HT films onto PEDOT/PSS-coated ITO substrates. To reduce the fabrication cost of masters in large area, we employed well-ordered anodic aluminum oxide (AAO) as a template. Also, we provide a method to fabricate reversed nanostructures by exploiting the self-replication of replica molds. The concept of the transfer method in low temperature with a flexible and reusable replica mold obtained from an AAO template will be a firm foundation for a low-cost fabrication process of ordered OPVs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Transient Analysis of Thermal Protection System for X-33 Aircraft using MSC/NASTRAN
NASA Technical Reports Server (NTRS)
Miura, Hirokazu; Chargin, M. K.; Bowles, J.; Tam, T.; Chu, D.; Chainyk, M.; Green, Michael J. (Technical Monitor)
1997-01-01
X-33 is an advanced technology demonstrator vehicle for the Reusable Launch Vehicle (RLV) program. The thermal protection system (TPS) for the X-33 is composed of complex layers of materials to protect internal components, while withstanding severe external temperatures induced by aerodynamic heating during high speed flight. It also serves as the vehicle aeroshell in some regions using a stand-off design. MSC/NASTRAN thermal analysis capability was used to predict transient temperature distribution (within the TPS) throughout a mission, from launch through the cool-off period after landing. In this paper, a typical analysis model, representing a point on the vehicle where the liquid oxygen tank is closest to the outer mold line, is described. The maximum temperature difference between the outer mold line and the internal surface of the liquid oxygen tank can exceed 1500 F. One dimensional thermal models are used to select the materials and determine the thickness of each layer for minimum weight while insuring that all materials remain within the allowable temperature range. The purpose of working with three dimensional (3D) comprehensive models using MSC/NASTRAN is to assess the 3D radiation effects and the thermal conduction heat shorts of the support fixtures.
NASA Technical Reports Server (NTRS)
Riccitiello, S. R.; Figueroa, H.; Coe, C. F.; Kuo, C. P.
1984-01-01
An advanced leading-edge concept was analyzed using the space shuttle leading edge system as a reference model. The comparison indicates that a direct-bond system utilizing a high temperature (2700 F) fibrous refractory composite insulation tile bonded to a high temperature (PI/graphite) composite structure can result in a weight savings of up to 800 lb. The concern that tile damage or loss during ascent would result in adverse entry aerodynamics if a leading edge tile system were used is addressed. It was found from experiment that missing tiles (as many as 22) on the leading edge would not significantly affect the basic force-and-moment aerodynamic coefficients. Additionally, this concept affords a degree of redundancy to a thermal protection system in that the base structure (being a composite material) ablates and neither melts nor burns through when subjected to entry heating in the event tiles are actually lost or damaged during ascent.
NASA Technical Reports Server (NTRS)
Gnoffo, Peter A.; Inger, George R.
1999-01-01
The local viscous-inviscid interaction field generated by a wall temperature jump on a flat plate in supersonic flow and on the windside of a Reusable Launch Vehicle in hypersonic flow is studied in detail by both a Navier-Stokes numerical code and an analytical triple-deck model. Treatment of the rapid heat transfer changes both upstream and downstream of the jump is included. Closed form relationships derived from the triple-deck theory are presented. The analytically predicted pressure and heating variations including upstream influence are found to be in generally good agreement with the Computational Fluid Dynamic (CFD) predictions. These analyses not only clarify the interactive physics involved but also are useful in preliminary design of thermal protection systems and as an insertable module to improve CFD code efficiency when applied to such small-scale interaction problems. The analyses only require conditions at the wall and boundary-layer edge which are easily extracted from a baseline, constant wall temperature, CFD solution.
Performance of an ablator for Space Shuttle inorbit repair in an arc-plasma airstream
NASA Technical Reports Server (NTRS)
Stewart, D. A.; Cuellar, M.; Flowers, O.
1983-01-01
An ablator patch material performed well in an arc plasma environment simulating nominal Earth entry conditions for the Space Shuttle. Ablation tests using vacuum molded cones provided data to optimize the formulation of a two part polymer system for application under space conditions. The blunt cones were made using a Teflon mold and a state of the art caulking gun. Char stability of formulations with various amounts of catalyst and diluent were investigated. The char was found to be unstable in formulations with low amounts of catalyst and high amounts of diluent. The best polymer system determined by these tests was evaluated using a half tile patch in a multiple High Temperature Reusable surface Insulation tile model. It was demonstrated that this ablator could be applied in a space environment using a state of the art caulking gun, would maintain the outer mold line of the thermal protection system during entry, and would keep the bond line temperature at the aluminum tile interface below the design limit.
Improved Thermal-Switch Disks Protect Batteries
NASA Technical Reports Server (NTRS)
Darcy, Eric; Bragg, Bobby
1990-01-01
Improved thermal-switch disks help protect electrical batteries against high currents like those due to short circuits or high demands for power in circuits supplied by batteries. Protects batteries against excessive temperatures. Centered by insulating fiberglass washer. Contains conductive polymer that undergoes abrupt increase in electrical resistance when excessive current raises its temperature above specific point. After cooling, polymer reverts to low resistance. Disks reusable.
Programmers manual for static and dynamic reusable surface insulation stresses (resist)
NASA Technical Reports Server (NTRS)
Ogilvie, P. L.; Levy, A.; Austin, F.; Ojalvo, I. U.
1974-01-01
Programming information for the RESIST program for the dynamic and thermal stress analysis of the space shuttle surface insulation is presented. The overall flow chart of the program, overlay chart, data set allocation, and subprogram calling sequence are given along with a brief description of the individual subprograms and typical subprogram output.
Immobilization of enzyme using natural feldspar for use in the synthesis of oleyl oleate
NASA Astrophysics Data System (ADS)
Ali, Balqish Juliana; Othman, Siti Salhah; Harun, Farah Wahida; Jumal, Juliana; Rahman, Mohd Basyaruddin Abdul
2018-06-01
Natural feldspar from Tanah Putih, Gua Musang, Kelantan (Malaysia) was physico-chemically characterized using X-ray Diffraction (XRD), Surface Area and Porosity Analysis (ASAP) and Energy Dispersive X-ray (EDX) techniques. The feldspar was found to be of the potassium (K) type, with major components containing aluminum (Al), and silicon (Si). The feldspar also possesses 38.307 nm mean pore diameter and 18.717 m2/g surface area. Candida rugosa (CRL) was then immobilized onto natural feldspar by physical adsorption method. About 49.96% of protein content was immobilized onto the support. The catalytic activity of the immobilized lipase was determined by the esterification reaction using oleic acid and oleyl alcohol. The effects of various reaction temperatures, stability in organic solvent, and lipase recyclability on the esterification reaction for the native and immobilized lipase were investigated. Feldspar-immobilized lipase exhibited higher activity than that of the native lipase. Immobilized lipase retained its activity ca. 50% even after incubation at high temperature (70°C) with the optimum reaction temperature of 40°C, long incubation in hexane up to 10 days and after ten repeated cycles used. Feldspar-immobilized lipase also showed considerably efficient reusability where it was not easily leached even after being washed with large amount of hexane (20 mL). These results showed that physical adsorption method is suitable for the immobilization of lipase onto feldspar.
Modeling and Evaluation of Canted Coil Springs as High Temperature Seal Preloading Devices
NASA Technical Reports Server (NTRS)
Oswald, Jay J.; Mullen, Robert L.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.
2004-01-01
Future reusable launch vehicles will require advanced structural seals. This includes propulsion seals along edges and hinge lines in hypersonic engines, and control surface seals for movable flaps and elevons on proposed reentry vehicles. Seals must remain in sealing engagement with opposing surfaces, for multiple missions, even though the seal gap may be opening and closing due to thermal and structural loads. To meet this requirement either the seals themselves must be resilient or there must be a resilient structural element behind the seals. Case Western Reserve University is working with NASA s Glenn Research Center to develop more resilient high temperature seal components and preloading devices. Results are presented for a finite element analysis of a canted coil spring that is being considered as a high temperature seal preloading device. This type of spring is a leading candidate due to its ability to provide nearly constant force over a large deflection. The finite element analyses were verified by comparing them to experimental results of canted coil springs of three different stiffnesses, measured at Glenn Research Center. Once validated the parameterized model was combined with a scripting algorithm to assess the effects of key spring design variables (wire diameter, coils per inch, cant amplitude, eccentricity, and spring width) on spring stiffness and maximum Von Mises stress to aid in subsequent design.
Cyclic hot firing results of tungsten-wire-reinforced, copper-lined thrust chambers
NASA Technical Reports Server (NTRS)
Kazaroff, John M.; Jankovsky, Robert S.
1990-01-01
An advanced thrust liner material for potential long life reusable rocket engines is described. This liner material was produced with the intent of improving the reusable life of high pressure thrust chambers by strengthening the chamber in the hoop direction, thus avoiding the longitudinal cracking due to low cycle fatigue that is observed in conventional homogeneous copper chambers, but yet not reducing the high thermal conductivity that is essential when operating with high heat fluxes. The liner material produced was a tungsten wire reinforced copper composite. Incorporating this composite into two hydrogen-oxygen test rocket chambers was done so that its performance as a reusable liner material could be evaluated. Testing results showed that both chambers failed prematurely, but the crack sites were perpendicular to the normal direction of cracking indicating a degree of success in containing the tremendous thermal strain associated with high temperature rocket engines. The failures, in all cases, were associated with drilled instrumentation ports and no other damages or deformations were found elsewhere in the composite liners.
Pressure gradient effects on heat transfer to reusable surface insulation tile-array gaps
NASA Technical Reports Server (NTRS)
Throckmorton, D. A.
1975-01-01
An experimental investigation was performed to determine the effect of pressure gradient on the heat transfer within space shuttle reusable surface insulation (RSI) tile-array gaps under thick, turbulent boundary-layer conditions. Heat-transfer and pressure measurements were obtained on a curved array of full-scale simulated RSI tiles in a tunnel-wall boundary layer at a nominal free-stream Mach number and free-stream Reynolds numbers. Transverse pressure gradients of varying degree were induced over the model surface by rotating the curved array with respect to the flow. Definition of the tunnel-wall boundary-layer flow was obtained by measurement of boundary-layer pitot pressure profiles, wall pressure, and heat transfer. Flat-plate heat-transfer data were correlated and a method was derived for prediction of heat transfer to a smooth curved surface in the highly three-dimensional tunnel-wall boundary-layer flow. Pressure on the floor of the RSI tile-array gap followed the trends of the external surface pressure. Heat transfer to the surface immediately downstream of a transverse gap is higher than that for a smooth surface at the same location. Heating to the wall of a transverse gap, and immediately downstream of it, at its intersection with a longitudinal gap is significantly greater than that for the simple transverse gap.
Future Launch Vehicle Structures - Expendable and Reusable Elements
NASA Astrophysics Data System (ADS)
Obersteiner, M. H.; Borriello, G.
2002-01-01
Further evolution of existing expendable launch vehicles will be an obvious element influencing the future of space transportation. Besides this reusability might be the change with highest potential for essential improvement. The expected cost reduction and finally contributing to this, the improvement of reliability including safe mission abort capability are driving this idea. Although there are ideas of semi-reusable launch vehicles, typically two stages vehicles - reusable first stage or booster(s) and expendable second or upper stage - it should be kept in mind that the benefit of reusability will only overwhelm if there is a big enough share influencing the cost calculation. Today there is the understanding that additional technology preparation and verification will be necessary to master reusability and get enough benefits compared with existing launch vehicles. This understanding is based on several technology and system concepts preparation and verification programmes mainly done in the US but partially also in Europe and Japan. The major areas of necessary further activities are: - System concepts including business plan considerations - Sub-system or component technologies refinement - System design and operation know-how and capabilities - Verification and demonstration oriented towards future mission mastering: One of the most important aspects for the creation of those coming programmes and activities will be the iterative process of requirements definition derived from concepts analyses including economical considerations and the results achieved and verified within technology and verification programmes. It is the intention of this paper to provide major trends for those requirements focused on future launch vehicles structures. This will include the aspects of requirements only valid for reusable launch vehicles and those common for expendable, semi-reusable and reusable launch vehicles. Structures and materials is and will be one of the important technology areas to be improved. This includes: - Primary structures - Thermal protection systems (for high and low temperatures) - Hot structures (leading edges, engine cowling, ...) - Tanks (for various propellants and fluids, cryo, ...) Requirements to be considered are including materials properties and a variety of loads definition - static and dynamic. Based on existing knowledge and experience for expendable LV (Ariane, ...) and aircraft there is the need to established a combined understanding to provide the basis for an efficient RLV design. Health monitoring will support the cost efficient operation of future reusable structures, but will also need a sound understanding of loads and failure mechanisms as basis. Risk mitigation will ask for several steps of demonstration towards a cost efficient RLV (structures) operation. Typically this has or will start with basic technology, to be evolved to components demonstration (TPS, tanks, ...) and finally to result in the demonstration of the cost efficient reuse operation. This paper will also include a programmatic logic concerning future LV structures demonstration.
Re-usable electrochemical glucose sensors integrated into a smartphone platform.
Bandodkar, Amay J; Imani, Somayeh; Nuñez-Flores, Rogelio; Kumar, Rajan; Wang, Chiyi; Mohan, A M Vinu; Wang, Joseph; Mercier, Patrick P
2018-03-15
This article demonstrates a new smartphone-based reusable glucose meter. The glucose meter includes a custom-built smartphone case that houses a permanent bare sensor strip, a stylus that is loaded with enzyme-carbon composite pellets, and sensor instrumentation circuits. A custom-designed Android-based software application was developed to enable easy and clear display of measured glucose concentration. A typical test involves the user loading the software, using the stylus to dispense an enzymatic pellet on top of the bare sensor strip affixed to the case, and then introducing the sample. The electronic module then acquires and wirelessly transmits the data to the application software to be displayed on the screen. The deployed pellet is then discarded to regain the fresh bare sensor surface. Such a unique working principle allows the system to overcome challenges faced by previously reported reusable sensors, such as enzyme degradation, leaching, and hysteresis effects. Studies reveal that the enzyme loaded in the pellets are stable for up to 8 months at ambient conditions, and generate reproducible sensor signals. The work illustrates the significance of the pellet-based sensing system towards realizing a reusable, point-of-care sensor that snugly fits around a smartphone and which does not face issues usually common to reusable sensors. The versatility of this system allows it to be easily modified to detect other analytes for application in a wide range of healthcare, environmental and defense domains. Copyright © 2017 Elsevier B.V. All rights reserved.
2009-12-14
CAPE CANAVERAL, Fla. - In Orbiter Processing Facility Bay 1 at NASA's Kennedy Space Center in Florida, United Space Alliance technician Jeff Holmes uses heat lamps in a putty repair on some of the high-temperature reusable surface insulation tiles, or HRSI tiles, on the lower forward fuselage of space shuttle Atlantis. An average of 125 tiles are replaced after each mission either due to handling damage or accumulated repairs. These black tiles are optimized for maximum emissivity, which means they lose heat faster than white tiles. This property is required to maximize heat rejection during the hot phase of reentry. Atlantis next is slated to deliver an Integrated Cargo Carrier and Russian-built Mini Research Module to the International Space Station on the STS-132 mission. Launch is targeted for May 14, 2010. Photo credit: NASA/Jack Pfaller
2009-12-14
CAPE CANAVERAL, Fla. - In Orbiter Processing Facility Bay 1 at NASA's Kennedy Space Center in Florida, heat lamps assist United Space Alliance technician Jeff Holmes in a putty repair on some of the high-temperature reusable surface insulation tiles, or HRSI tiles, on the lower forward fuselage of space shuttle Atlantis. An average of 125 tiles are replaced after each mission either due to handling damage or accumulated repairs. These black tiles are optimized for maximum emissivity, which means they lose heat faster than white tiles. This property is required to maximize heat rejection during the hot phase of reentry. Atlantis next is slated to deliver an Integrated Cargo Carrier and Russian-built Mini Research Module to the International Space Station on the STS-132 mission. Launch is targeted for May 14, 2010. Photo credit: NASA/Jack Pfaller
2009-12-14
CAPE CANAVERAL, Fla. - In Orbiter Processing Facility Bay 1 at NASA's Kennedy Space Center in Florida, United Space Alliance technician Jeff Holmes makes a putty repair on some of the high-temperature reusable surface insulation tiles, or HRSI tiles, on the lower forward fuselage of space shuttle Atlantis. An average of 125 tiles are replaced after each mission either due to handling damage or accumulated repairs. These black tiles are optimized for maximum emissivity, which means they lose heat faster than white tiles. This property is required to maximize heat rejection during the hot phase of reentry. Atlantis next is slated to deliver an Integrated Cargo Carrier and Russian-built Mini Research Module to the International Space Station on the STS-132 mission. Launch is targeted for May 14, 2010. Photo credit: NASA/Jack Pfaller
2012-04-05
CAPE CANAVERAL, Fla. – Kennedy Space Center Director Bob Cabana, left, explains the placement of high-temperature reusable surface insulation HRSI tile on the underbelly of space shuttle Atlantis to Florida’s Lt. Gov. Jennifer Carroll during a tour of Kennedy’s Orbiter Processing Facility-1. The tile is part of the shuttle’s thermal protection system which covers the shuttle’s exterior and protects it from the heat of re-entry. The tour coincided with Carroll’s visit to Kennedy for a meeting with Cabana. Atlantis is being prepared for public display at the Kennedy Space Center Visitor Complex in 2013. The groundbreaking for Atlantis’ exhibit hall took place in January Atlantis is scheduled to be moved to the visitor complex in November. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Jim Grossmann
General view of the underside of the Orbiter Discovery on ...
General view of the underside of the Orbiter Discovery on the port side looking toward the starboard side and slightly forward. Note the landing gear assemblies, the jack stands attached to the External Tank (ET) attach points in on the Orbiter/ET propellant interface plate and the black High-Temperature Reusable Surface Insulation. The varying degrees of darkness of the tiles is due to the age of the tiles, the more recently replaced tiles are darker than the older tiles. The pattern created by the tile replacement is unique to each orbiter and becomes their "fingerprint". This view was taken in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX
Vibrational Properties of Zr(Hf)B2-SiC UHTC Composites by Micro-Raman Spectroscopy
NASA Astrophysics Data System (ADS)
Donohue, M.; Carpenter, C.; Orlovskaya, N.
Development and characterization of novel materials that are lightweight, possess high mechanical properties, can withstand high temperatures, and provide superior thermal properties are crucial to meet the future demands of Air Force, Army, Navy, Missile Defense Agency (MDA), and other military and space agencies. Materials for such applications (hypersonic air-breathing vehicles, including Single-To-Orbit vehicles and Two-Stage-To-Orbit aerospace planes, fully reusable space transport vehicles, hypersonic cruise missiles) experience severe aero-thermal loads with nose-cone and nozzle temperatures in excess of 2,000°F and 4,000°F, respectively. High G acceleration is also a problem. Even the most advanced materials, such as Ti, Inconel X, carbon-carbon, and silicon carbide based composites cannot withstand the excessive heat generated, especially during re-entry, and they cannot meet the guidelines for future high performance aircrafts, kinetic energy interceptors and reusable space planes. Thus, the demand for low-cost, light weight high temperature materials for thermal protection systems (TPS) is expected to be on the significant rise in the near future.
Antony, R; Suja Pon Mini, P S; Theodore David Manickam, S; Sanjeev, Ganesh; Mitu, Liviu; Balakumar, S
2015-01-01
Chitosan (a biopolymer) anchored Cu(II) and Ni(II) Schiff base complexes, [M(OIAC)Cl2] (M: Cu/Ni and OIAC: ([2-oxo-1H-indol-3-ylidene]amino)chitosan) were electron beam irradiated by different doses (100 Gy, 1 kGy and 10 kGy). The electron beam has shown potential impact on biopolymer's support, in detail chain linking and chain scissoring, as evidenced by viscosity studies, FT-IR and X-ray diffraction spectroscopic techniques. Due to these structural changes, thermal properties of the complexes were found to be changed. The surface of these heterogeneous complexes was also effectually altered by electron beam. As a consequence, pores and holes were created as probed by SEM technique. The catalytic activity of both non-irradiated and irradiated complexes was investigated in the aerobic oxidation of cyclohexane using hydrogen peroxide oxidant. The catalytic ability of the complexes was enhanced significantly after irradiation as the result of surface changes. The reusability of the complexes was also greatly affected because of the structural variations in polymeric support. In terms of both better catalytic activity along with the reusability, 1 kGy is suggested as the best dose to attain adequate increase in catalytic activity and good reusability. Copyright © 2015 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fu, Zhifeng; Shao, Guocheng; Wang, Jun
2011-04-01
A filter pillar-array microstructure was coupled with a pneumatic micro-valve to fabricate a reusable miniaturized beads-trapping/releasing flow cell, in which trapping and releasing beads can be conveniently realized by switching the micro-valve. This miniaturized device was suitable to construct automatic fluidic system for “renewable surface analysis”. The renewable surface strategy based on pneumatic micro-valve enabled capture of beads in beads chamber prior to each assay, and release of the used beads after the assay. Chemiluminescent competitive immunoassay of 3,5,6-trichloropyridinol (TCP) was performed as a model to demonstrate the application potential of this reusable miniaturized flow cell. The whole fluidic assaymore » process including beads trapping, immuno-binding, beads washing, beads releasing and signal collection could be completed in 10 min. Immunoassay of TCP using this miniaturized device showed a linear range of 0.20-70 ng/mL with a limit of detection of 0.080 ng/mL. The device had been successfully used for detection of TCP spiked in rat serum with average recovery of 97%. This investigation provides a rapid, sensitive, reusable, low-cost and automatic miniaturized device for solid-phase biochemical analysis for various purposes.« less
NASA Astrophysics Data System (ADS)
Kongor, Anita; Panchal, Manthan; Athar, Mohd; Mehta, Viren; Bhatt, Keyur; Jha, P. C.; Jain, Vinod
2018-04-01
Novel calix[4]pyrrole encapsulated platinum nanoparticles (PtNPs) have been prepared in the aqueous medium using meso-tetra(methoxy) meso-tetra (4-phenoxy acetohydrazide) calix[4]pyrrole (MCPTH) as both reducing as well as the capping agent. The developed MCPTH-PtNPs nano-assembly has been characterized by HRTEM, XRD, XPS, TGA and FTIR methods. Grafting capability of MCPTH on PtNPs was envisaged by molecular dynamics simulations that renders towards the complemented role of ligand in capping the surface via metal-acceptor interactions. These nanoparticles have been exploited for chemoselective hydrogenation of nitroarenes using molecular hydrogen at room temperature. Supplemented computational and experimental apprehension clearly corroborates that hydrazide group remains in close contact with the surface and provides adequate coordination sites for the adsorption of nitrenes; required for hydrogenation. This catalytic approach can be conceived as an important tool for determining the electronic and structural influence on the catalytic activity which may open new vistas pertaining to the use of calix functionalized nanocatalyst.
Akbayrak, Serdar; Tonbul, Yalçın; Özkar, Saim
2016-07-05
Ruthenium(0) nanoparticles supported on ceria (Ru(0)/CeO2) were in situ generated from the reduction of ruthenium(iii) ions impregnated on ceria during the hydrolysis of ammonia borane. Ru(0)/CeO2 was isolated from the reaction solution by centrifugation and characterized by ICP-OES, BET, XRD, TEM, SEM-EDS and XPS techniques. All the results reveal that ruthenium(0) nanoparticles were successfully supported on ceria and the resulting Ru(0)/CeO2 is a highly active, reusable and long-lived catalyst for hydrogen generation from the hydrolysis of ammonia borane with a turnover frequency value of 361 min(-1). The reusability tests reveal that Ru(0)/CeO2 is still active in the subsequent runs of hydrolysis of ammonia borane preserving 60% of the initial catalytic activity even after the fifth run. Ru(0)/CeO2 provides a superior catalytic lifetime (TTO = 135 100) in hydrogen generation from the hydrolysis of ammonia borane at 25.0 ± 0.1 °C before deactivation. The work reported here includes the formation kinetics of ruthenium(0) nanoparticles. The rate constants for the slow nucleation and autocatalytic surface growth of ruthenium(0) nanoparticles were obtained using hydrogen evolution as a reporter reaction. An evaluation of rate constants at various temperatures enabled the estimation of activation energies for both the reactions, Ea = 60 ± 7 kJ mol(-1) for the nucleation and Ea = 47 ± 2 kJ mol(-1) for the autocatalytic surface growth of ruthenium(0) nanoparticles, as well as the activation energy of Ea = 51 ± 2 kJ mol(-1) for the catalytic hydrolysis of ammonia borane.
NASA Astrophysics Data System (ADS)
Ross, M.
2011-12-01
Reusable Suborbital Launch Vehicles (RSLVs) are expected to play a large role in the space transport sector in coming decades, opening a new chapter in middle and upper atmospheric flight. RSLV flight rates of up to 1000 per year are forecast as early as 2025. While combustion emissions from each RSLV launch are small, less than 10 metric tons or less, the cumulative stratospheric emissions loading from RSLV flights could significantly exceed the loading from present day orbital launches. Recent GCM results suggest that black carbon (BC) emissions from hydrocarbon fueled rocket engines - including engine types planned for some RSLVs - are of particular interest because BC emitted by rockets could affect global direct radiative forcing and composition in the middle atmosphere to a much greater extent than other rocket emissions such as carbon dioxide and water. We present arguments and model results indicating that 1000 RSLV launches per year could regionally increase stratospheric BC by at least tens of percent over the background and change surface temperatures by over one degree. We also show how the new middle atmospheric measurement capabilities offered by RSLVs permit heretofore unavailable measurements of background stratospheric and mesospheric particle populations and an assessment of the buildup of RSLV exhaust particles during the time that RSLV flight rates are expected to surge (2015-2025).
Scalable and reusable micro-bubble removal method to flatten large-area 2D materials
NASA Astrophysics Data System (ADS)
Pham, Phi H. Q.; Quach, Nhi V.; Li, Jinfeng; Burke, Peter J.
2018-04-01
Bubbles generated during electro-delamination and chemical etch during large-area two-dimensional (2D) material transfer has been shown to cause rippling, and consequently, results in tears and wrinkles in the transferred film. Here, we demonstrate a scalable and reusable method to remove surface adhered micro-bubbles by using hydrophobic surfaces modified by self-assembled monolayers (SAMs). Bubble removal allows the 2D film to flatten out and prevents the formation of defects. Electrical characterization was used to verify improved transfer quality and was confirmed by increased field-effect mobility and decreased sheet resistance. Raman spectroscopy was also used to validate enhanced electrical quality following transfer. The bubble removal method can be applied to an assortment of 2D materials using diverse hydrophobic SAM variants. Our studies can be integrated into large scale applications and will lead to improved large-area 2D electronics in general.
NASA Astrophysics Data System (ADS)
Huang, Da; Freeley, Mark; Palma, Matteo
2017-03-01
We present a facile strategy of general applicability for the assembly of individual nanoscale moieties in array configurations with single-molecule control. Combining the programming ability of DNA as a scaffolding material with a one-step lithographic process, we demonstrate the patterning of single quantum dots (QDs) at predefined locations on silicon and transparent glass surfaces: as proof of concept, clusters of either one, two, or three QDs were assembled in highly uniform arrays with a 60 nm interdot spacing within each cluster. Notably, the platform developed is reusable after a simple cleaning process and can be designed to exhibit different geometrical arrangements.
Reusable Metallic Thermal Protection Systems Development
NASA Technical Reports Server (NTRS)
Blosser, Max L.; Martin, Carl J.; Daryabeigi, Kamran; Poteet, Carl C.
1998-01-01
Metallic thermal protection systems (TPS) are being developed to help meet the ambitious goals of future reusable launch vehicles. Recent metallic TPS development efforts at NASA Langley Research Center are described. Foil-gage metallic honeycomb coupons, representative of the outer surface of metallic TPS were subjected to low speed impact, hypervelocity impact, rain erosion, and subsequent arcjet exposure. TPS panels were subjected to thermal vacuum, acoustic, and hot gas flow testing. Results of the coupon and panel tests are presented. Experimental and analytical tools are being developed to characterize and improve internal insulations. Masses of metallic TPS and advanced ceramic tile and blanket TPS concepts are compared for a wide range of parameters.
Gao, Shan; Luo, Tiantian; Zhou, Qi; Luo, Wenjun; Li, Haifeng; Jing, Luru
2018-05-01
In this work, the soluble sodium lignosulphonate (LS Na ) molecules were successfully grafted onto the surface of pine sawdust (PSD) particles to obtain an efficient adsorbent (PSD-LS) for removing Hg 2+ from wastewater. In advance, the surface of sawdust particles were carboxymethylated by chloroacetic acid, the LS Na would be anchored on the surface by a heterogeneous esterification reaction occurred between the hydroxyl of LS Na and carboxyl on PSD surface. The resultant product (PSD-LS) exhibited a good adsorption performance for Hg 2+ with adsorption capacity up to 164.77 mg/g and it was characterized by scanning electron microscope (SEM), energy dispersive X-ray diffraction (EDX), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The effects of pH, contact time, adsorption temperature and initial concentration on the adsorption of Hg 2+ were investigated. Results showed that the pseudo-second-order kinetics and Langmuir isotherm model could describe the adsorption process better. In addition, the composite adsorbent has outstanding reusability with high and stable desorption rates under several continuous cycle. These findings suggested that PSD-LS was a potential adsorbent to remove hazardous metal ions from wastewater. Copyright © 2018 Elsevier Inc. All rights reserved.
Evaluation by Rocket Combustor of C/C Composite Cooled Structure Using Metallic Cooling Tubes
NASA Astrophysics Data System (ADS)
Takegoshi, Masao; Ono, Fumiei; Ueda, Shuichi; Saito, Toshihito; Hayasaka, Osamu
In this study, the cooling performance of a C/C composite material structure with metallic cooling tubes fixed by elastic force without chemical bonding was evaluated experimentally using combustion gas in a rocket combustor. The C/C composite chamber was covered by a stainless steel outer shell to maintain its airtightness. Gaseous hydrogen as a fuel and gaseous oxygen as an oxidizer were used for the heating test. The surface of these C/C composites was maintained below 1500 K when the combustion gas temperature was about 2800 K and the heat flux to the combustion chamber wall was about 9 MW/m2. No thermal damage was observed on the stainless steel tubes that were in contact with the C/C composite materials. The results of the heating test showed that such a metallic tube-cooled C/C composite structure is able to control the surface temperature as a cooling structure (also as a heat exchanger) as well as indicated the possibility of reducing the amount of coolant even if the thermal load to the engine is high. Thus, application of this metallic tube-cooled C/C composite structure to reusable engines such as a rocket-ramjet combined-cycle engine is expected.
NASA Astrophysics Data System (ADS)
Crosbie, A. L.
Aspects of aerothermodynamics are considered, taking into account aerodynamic heating for gaps in laminar and transitional boundary layers, the correlation of convection heat transfer for open cavities in supersonic flow, the heat transfer and pressure on a flat plate downstream of heated square jet in a Mach 0.4 to 0.8 crossflow, the effect of surface roughness character on turbulent reentry heating, three-dimensional protuberance interference heating in high-speed flow, and hypersonic flow over small span flaps in a thick turbulent boundary layer. Questions of thermal protection are investigated, giving attention to thermochemical ablation of tantalum carbide loaded carbon-carbons, the catalytic recombination of nitrogen and oxygen on high-temperature reusable surface insulation, particle acceleration using a helium arc heater, a temperature and ablation optical sensor, a wind-tunnel study of ascent heating of multiple reentry vehicle configurations, and reentry vehicle soft-recovery techniques. Subjects examined in connection with a discussion of planetary entry are related to a thermal protection system for the Galileo mission atmospheric entry probe, the viscosity of multicomponent partially ionized gas mixtures associated with Jovian entry, coupled laminar and turbulent flow solutions for Jovian entry, and a preliminary aerothermal analysis for Saturn entry.
Reuter, R R; Carroll, J A; Hulbert, L E; Dailey, J W; Galyean, M L
2010-10-01
A device was developed to monitor rectal temperature automatically in cattle for application in research settings. Compared with manual measurement of rectal temperature, this device decreases labor and time requirements and allows data collection without the influence of animal handling or restraint. The device consists of a custom-fabricated aluminum tail harness that supports an indwelling rectal temperature data logger. Materials cost approximately US $300 per unit, and units are completely reusable. Use of this device would increase the conditions under which accurate rectal temperature measurements can be obtained in experiments with cattle.
Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Daryabeigi, Kamran
1999-01-01
An experimental apparatus was designed to measure the effective thermal conductivity of various high temperature insulations subject to large temperature gradients representative of typical launch vehicle re-entry aerodynamic heating conditions. The insulation sample cold side was maintained around room temperature, while the hot side was heated to temperatures as high as 1800 degrees Fahrenheit. The environmental pressure was varied from 0.0001 to 760 torr. All the measurements were performed in a dry gaseous nitrogen environment. The effective thermal conductivity of Saffil, Q-Fiber felt, Cerachrome, and three multi-layer insulation configurations were measured.
Aerojet advanced engine concept
NASA Technical Reports Server (NTRS)
Schoenman, L.
1984-01-01
The future orbit transfer vehicle (OTV) requirements which dictate the need for a highly versatile, highly reliable, reusable propulsion module are discussed. To attain maximum operational economy, space-basing is essential. This requires a reusable, maintenance free engine. The design features of this space based engine are defined. A new engine cycle and its advantages allow all the maintenance goals to be attained. Rubbing contact and interpropellant seals and purges are eliminated when GO2 is used to drive the LO2 pump. The TPA design has only one moving part. The use of both GH2 and GO2 to drive the turbines lowers the turbine temperatures in addition lower GH2 temperatures and pressures improve chamber cooling and longer life. The use of GO2 as a turbine drive fluid is addressed. Space based engines require an integrated control and health monitoring system to improve system reliability and eliminate all scheduled maintenance. It is concluded that all OTV propulsion requirements can be fulfilled with a single engine. The technological developments required to demonstrate that engine are outlined.
Thermal Protection and Control
NASA Technical Reports Server (NTRS)
Greene, Effie E.
2013-01-01
During all phases of a spacecraft's mission, a Thermal Protection System (TPS) is needed to protect the vehicle and structure from extreme temperatures and heating. When designing TPS, low weight and cost while ensuring the protection of the vehicle is highly desired. There are two main types of TPS, ablative and reusable. The Apollo missions needed ablators due to the high heat loads from lunar reentry. However, when the desire for a reusable space vehicle emerged, the resultant_ Space Shuttle program propelled a push for the development of reusable TPS. With the growth of reqsable TPS, the need for ablators declined, triggering a drop off of the ablator industry. As a result, the expertise was not heavily maintained within NASA or the industry. When the Orion Program initiated a few years back, a need. for an ablator reemerged. Yet, due to of the lack of industry capability, redeveloping the ablator material took several years and came at a high cost. As NASA looks towards the future with both the Orion and Commercial Crew Programs, a need to preserve reusable, ablative, and other TPS technologies is essential. Research of the different TPS materials alongside their properties, capabilities, and manufacturing process was performed, and the benefits of the materials were analyzed alongside the future of TPS. Knowledge of the different technologies has the ability to help us know what expertise to maintain and ensure a lack in the industry does not occur again.
Fault-Tolerant and Reconfigurable Control of Unmanned Aerial Vehicles (UAVs)
2008-02-29
forces and moments are expressed as functions of angle of attack, sideslip angle, angular rates, and control surface deflection. L, M, and N are...invertible. As for matrix B, the control surfaces of the reusable launch vehicle are designed to control each axes angular rate of aircraft...literature as being invertible. As for matrix B, the control surfaces of the UAV are designed to control angular rate along each axis of the aircraft
Alhassan, Fatah H; Rashid, Umer; Taufiq-Yap, Yun Hin
2015-01-01
The utilization of ferric-manganese promoted molybdenum oxide/zirconia (Fe-Mn- MoO3/ZrO2) (FMMZ) solid acid catalyst for production of biodiesel was demonstrated. FMMZ is produced through impregnation reaction followed by calcination at 600°C for 3 h. The characterization of FMMZ had been done using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), temperature programmed desorption of NH3 (TPD-NH3), transmission electron microscopy(TEM) and Brunner-Emmett-Teller (BET) surface area measurement. The effect of waste cooking oil methyl esters (WCOME's) yield on the reactions variables such as reaction temperature, catalyst loading, molar ratio of methanol/oil and reusability were also assessed. The catalyst was used to convert the waste cooking oil into corresponding methyl esters (95.6%±0.15) within 5 h at 200℃ reaction temperature, 600 rpm stirring speed, 1:25 molar ratio of oil to alcohol and 4% w/w catalyst loading. The reported catalyst was successfully recycled in six connective experiments without loss in activity. Moreover, the fuel properties of WCOME's were also reported using ASTM D 6751 methods.
CFD-Based Design Optimization for Single Element Rocket Injector
NASA Technical Reports Server (NTRS)
Vaidyanathan, Rajkumar; Tucker, Kevin; Papila, Nilay; Shyy, Wei
2003-01-01
To develop future Reusable Launch Vehicle concepts, we have conducted design optimization for a single element rocket injector, with overall goals of improving reliability and performance while reducing cost. Computational solutions based on the Navier-Stokes equations, finite rate chemistry, and the k-E turbulence closure are generated with design of experiment techniques, and the response surface method is employed as the optimization tool. The design considerations are guided by four design objectives motivated by the consideration in both performance and life, namely, the maximum temperature on the oxidizer post tip, the maximum temperature on the injector face, the adiabatic wall temperature, and the length of the combustion zone. Four design variables are selected, namely, H2 flow angle, H2 and O2 flow areas with fixed flow rates, and O2 post tip thickness. In addition to establishing optimum designs by varying emphasis on the individual objectives, better insight into the interplay between design variables and their impact on the design objectives is gained. The investigation indicates that improvement in performance or life comes at the cost of the other. Best compromise is obtained when improvements in both performance and life are given equal importance.
2007-06-13
KENNEDY SPACE CENTER, FLA. -- United Space Alliance employees prepare test articles to be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. A tear occurred in an area of the OMS pod on Atlantis during launch of mission STS-117 on June 8, 2007. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles will be flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Repair is under consideration following testing at KSC and Houston. Photo credit: NASA/Amanda Diller
2007-06-13
KENNEDY SPACE CENTER, FLA. -- United Space Alliance employees prepare test articles to be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. A tear occurred in an area of the OMS pod on Atlantis during launch of mission STS-117 on June 8, 2007. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles will be flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Repair is under consideration following testing at KSC and Houston. Photo credit: NASA/Amanda Diller
2007-06-13
KENNEDY SPACE CENTER, FLA. -- United Space Alliance employees prepare test articles to be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. A tear occurred in an area of the OMS pod on Atlantis during launch of mission STS-117 on June 8, 2007. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles will be flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Repair is under consideration following testing at KSC and Houston. Photo credit: NASA/Amanda Diller
2007-06-13
KENNEDY SPACE CENTER, FLA. -- United Space Alliance employees prepare test articles to be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. A tear occurred in an area of the OMS pod on Atlantis during launch of mission STS-117 on June 8, 2007. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles will be flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Repair is under consideration following testing at KSC and Houston. Photo credit: NASA/Amanda Diller
2007-06-13
KENNEDY SPACE CENTER, FLA. -- A United Space Alliance employee prepares a test article that will be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. A tear occurred in an area of the OMS pod on Atlantis during launch of mission STS-117 on June 8, 2007. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles will be flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Repair is under consideration following testing at KSC and Houston. Photo credit: NASA/Amanda Diller
2007-06-13
KENNEDY SPACE CENTER, FLA. -- United Space Alliance employees prepare test articles to be used in wind tunnel testing by NASA to collect data for analysis of the detached Flexible Insulation Blanket, or FIB, on Atlantis. A tear occurred in an area of the OMS pod on Atlantis during launch of mission STS-117 on June 8, 2007. The test articles each feature three tiles (Low Temperature Reusable Surface Insulation, or LRSI) affixed next to two FIB blankets, simulating the thermal protection system set-up on Atlantis' OMS pod in the vicinity of the in-flight anomaly. These test articles will be flown to Texas the morning of June 14. The TPS team at KSC has also provided a total of 22 FIB samples for other testing and analysis. Repair is under consideration following testing at KSC and Houston. Photo credit: NASA/Amanda Diller
Crew Launch Vehicle Mobile Launcher Solid Rocket Motor Plume Induced Environment
NASA Technical Reports Server (NTRS)
Vu, Bruce T.; Sulyma, Peter
2008-01-01
The plume-induced environment created by the Ares 1 first stage, five-segment reusable solid rocket motor (RSRMV) will impose high heating rates and impact pressures on Launch Complex 39. The extremes of these environments pose a potential threat to weaken or even cause structural components to fail if insufficiently designed. Therefore the ability to accurately predict these environments is critical to assist in specifying structural design requirements to insure overall structural integrity and flight safety. This paper presents the predicted thermal and pressure environments induced by the launch of the Crew Launch Vehicle (CLV) from Launch Complex (LC) 39. Once the environments are predicted, a follow-on thermal analysis is required to determine the surface temperature response and the degradation rate of the materials. An example of structures responding to the plume-induced environment will be provided.
NASA Technical Reports Server (NTRS)
Throckmorton, D. A.
1975-01-01
An experimental investigation was performed to determine the effect of pressure gradient on the heat transfer to space shuttle reusable surface insulation (RSI) tile array gaps under thick, turbulent boundary layer conditions. Heat transfer and pressure measurements were obtained on a curved array of full-scale simulated RSI tiles in a tunnel wall boundary layer at a nominal freestream Mach number of 10.3 and freestream unit Reynolds numbers of 1.6, 3.3, and and 6.1 million per meter. Transverse pressure gradients were induced over the model surface by rotating the curved array with respect to the flow. Definition of the tunnel wall boundary layer flow was obtained by measurement of boundary layer pitot pressure profiles, and flat plate wall pressure and heat transfer. Flat plate wall heat transfer data were correlated and a method was derived for prediction of smooth, curved array heat transfer in the highly three-dimensional tunnel wall boundary layer flow and simulation of full-scale space shuttle vehicle pressure gradient levels was assessed.
Low Temperature Regolith Bricks for In-Situ Structural Material
NASA Technical Reports Server (NTRS)
Grossman, Kevin; Sakthivel, Tamil S.; Mantovani, James; Seal, Sudipta
2016-01-01
Current technology for producing in-situ structural materials on future missions to Mars or the moon relies heavily on energy-intensive sintering processes to produce solid bricks from regolith. This process requires heating the material up to temperatures in excess of 1000 C and results in solid regolith pieces with compressive strengths in the range of 14000 to 28000 psi, but are heavily dependent on the porosity of the final material and are brittle. This method is currently preferred over a low temperature cementation process to prevent consumption of precious water and other non-renewable materials. A high strength structural material with low energy requirements is still needed for future colonization of other planets. To fulfill these requirements, a nano-functionalization process has been developed to produce structural bricks from regolith simulant and shows promising mechanical strength results. Functionalization of granular silicate particles into alkoxides using a simple low temperature chemical process produces a high surface area zeolite particles that are held together via inter-particle oxygen bonding. Addition of water in the resulting zeolite particles produces a sol-gel reaction called "inorganic polymerization" which gives a strong solid material after a curing process at 60 C. The aqueous solution by-product of the reaction is currently being investigated for its reusability; an essential component of any ISRU technology. For this study, two batches of regolith bricks are synthesized from JSC-1A; the first batch from fresh solvents and chemicals, the second batch made from the water solution by-product of the first batch. This is done to determine the feasibility of recycling necessary components of the synthesis process, mainly water. Characterization including BET surface area, SEM, and EDS has been done on the regolith bricks as well as the constituent particles,. The specific surface area of 17.53 sq m/g (average) of the granular regolith material was obtained from nitrogen adsorption isotherm measurement. The size, shape and textures of regolith from SEM shows that the particles are 25-50 micrometers in size and mostly irregular in shape (Figure 1a). The elemental composition of regolith was identified from EDS analysis showed the presence of Si, Al, Fe, Na, Mg, Ca, Ti, O and C (see figure 1b). Each set of cylindrical brick samples were prepared by low energy process, and cured for 21 and 28 days, respectively to compare their compressive strength. Figure 1c, and d shows the JSC-1A brick and the compressive strength measurements. The results from the 21 day cured bricks (2 bricks) have been done and yielded an aver-age strength of 3050 psi, considerably higher than Portland cement mortars (Type IV and V). This promising technology provides the benefits of construction material similar to concrete, with a low complexity, low energy synthesis process and the likelihood of complete reusability of precious resources. Compressive strength using this method can be improved by increasing the surface area of the particles, using bi-modal particle size distribution, and adding certain additives to increase inter-particle forces.
Disposable biomedical electrode
NASA Technical Reports Server (NTRS)
Frost, J. D., Jr.; Hillman, C. E., Jr.
1977-01-01
Reusable recording cap equipped with compressible snap-on bioelectronic electrodes is worn by patient to allow remote monitoring of electroencephalogram and electro-oculogram waveforms. Electrodes can be attached to inside surface of stretch-textile cap at twelve monitoring positions and at one or two ground positions.
Energy-reduction concept for incandescent lamps
NASA Technical Reports Server (NTRS)
Vorhaben, K. H.
1981-01-01
Reusable infrared reflector maintains filament temperature and reduces power requirements. Fixed installed over light bulb directs energy formerly lost back to lamp filament. This energy aids electric current in heating filament, allowing lower-wattage bulb to produce same amount of light as higher-wattage bulb in ordinary fixture.
NASA Technical Reports Server (NTRS)
Jackson, L. R.; Dixon, S. C.
1980-01-01
The design and assessment of reusable surface insulation (RSI), metallic stand off and multiwall thermal protection systems (TPS) is discussed. Multiwall TPS is described in some detail, and analyses useful for design of multiwall are included. Results indicate that multiwall has the potential to satisfy the TPS design goals better than the other systems. The total mass of the stand-off TPS and of the metallic systems require less primary structure mass than the RSI system, since the nonbuckling skin criteria required for RSI may be removed. Continued development of multiwall TPS is required to verify its potential and to provide the necessary data base for design.
Effect of silicon carbide on devitrification of a glass coating for reusable surface insulation
NASA Technical Reports Server (NTRS)
Ransone, P. O.
1978-01-01
Devitrification (nucleation and growth of cristobalite) were investigated in the LI-0042 coating used for the space shuttle surface insulation. Excessive devitrification was found to be associated with the silicon carbide (SiC) constituent in the coating. Test results show that significant devitrification occurred only when SiC was present in the coating and when the thermal-exposure atmosphere was oxidizing.
Ansar, Siyam M.; Chakraborty, Saptarshi
2018-01-01
Mercaptoundecanoic acid (MUA) functionalized gold nanoparticles (AuNP-MUA) were synthesized and demonstrated to possess pH-triggered aggregation and re-dispersion, as well as the capability of phase transfer between aqueous and organic phases in response to changes in pH. The pH of aggregation for AuNP-MUA is consistent with the pKa of MUA (pH ~4) in solution, while AuNP-MUA phase transition between aqueous and organic phases occurs at pH ~9. The ion pair formation between the amine group in octadecylamine (ODA), the carboxylate group in MUA, and the hydrophobic alkyl chain of ODA facilitates the phase transfer of AuNP-MUA into an organic medium. The AuNP-MUA were investigated as a reusable catalyst in the catalytic reduction of 4-nitrophenol by borohydride—a model reaction for AuNPs. It was determined that 100% MUA surface coverage completely inhibits the catalytic activity of AuNPs. Decreasing the surface coverage was shown to increase catalytic activity, but this decrease also leads to decreased colloidal stability, recoverability, and reusability in subsequent reactions. At 60% MUA surface coverage, colloidal stability and catalytic activity were achieved, but the surface coverage was insufficient to enable redispersion following pH-induced recovery. A balance between AuNP colloidal stability, recoverability, and catalytic activity with reusability was achieved at 90% MUA surface coverage. The AuNP-MUA catalyst can also be recovered at different pH ranges depending on the recovery method employed. At pH ~4, protonation of the MUA results in reduced surface charge and aggregation. At pH ~9, ODA will form an ion-pair with the MUA and induce phase transfer into an immiscible organic phase. Both the pH-triggered aggregation/re-dispersion and aqueous/organic phase transfer methods were employed for catalyst recovery and reuse in subsequent reactions. The ability to recover and reuse the AuNP-MUA catalyst by two different methods and different pH regimes is significant, based on the fact that nanoparticle-catalyzed reactions may occur under different pH conditions. PMID:29772775
Locking Nut with Stress-Distributing Insert
NASA Technical Reports Server (NTRS)
Daniels, Christopher C.
2010-01-01
Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.
Fiber reinforced superalloys for rocket engines
NASA Technical Reports Server (NTRS)
Petrasek, Donald W.; Stephens, Joseph R.
1989-01-01
High pressure turbopumps for advanced reusable liquid propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several fold increase in life and over a 200 C increase in temperature capability over the current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.
NASA Technical Reports Server (NTRS)
Pearson, A.
1975-01-01
The objective of this program was to establish feasibility of a process to produce low cost aluminum oxide fibers having sufficient strength, flexibility, and thermal stability for multiple re-use at temperatures to 1480 C in advanced RSI type heat shields for reentry vehicles. Using bench-scale processing apparatus, the Alcoa 'Saphiber' process was successfully modified to produce nominally 8 microns diameter polycrystalline alpha-alumina fiber. Thermal stability was demonstrated in vacuum reheating tests to 1371 C and in atmospheric reheating to 1483 C. Individual fiber properties of strength, modulus, and flexibility were not determined because of friability and short length of the fiber. Rigidized tile produced from fiber of nominally 8, 20 and 40 micron diameter had thermal conductivities significantly higher than those of RSI SiO2 or mullite at relatively low temperature but became comparable above about 1000 C. Tile densities were high due to short fiber length, especially in the coarser diameter fiber. No significant effect of fiber diameter on thermal properties could be determined form the data. Mechanical properties of tiles deteriorated as fiber diameter increased.
Fiber reinforced superalloys for rocket engines
NASA Technical Reports Server (NTRS)
Petrasek, Donald W.; Stephens, Joseph R.
1988-01-01
High-pressure turbopumps for advanced reusable liquid-propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several-fold increase in life and over a 200C increase in temperature capability over current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.
Bhattacharyya, Amartya; Banerjee, Bhaskar; Ghorai, Soumitra; Rana, Dipak; Roy, Indranil; Sarkar, Gunjan; Saha, Nayan Ranjan; De, Sriparna; Ghosh, Tapas Kumar; Sadhukhan, Sourav; Chattopadhyay, Dipankar
2018-05-15
In this work, we report the development of a cross-linked bio-composite consisting of graphene oxide, potato starch, cross-linker glutaraldehyde and its application to adsorption of the industrial dye, methylene blue, from aqueous solution. The inexpensiveness, non-hazardous nature and easy bio-degradability are the major reasons for the selection of starch material as one of the components of the bio-composite. The bio-composite has been characterized by FTIR, SEM, XRD, particle size and zeta potential analysis. The FTIR analysis reveals the nature of the binding sites and surface morphology of the bio-composite can be understood through SEM. The auto-phase separability of the adsorbent i.e., the precipitation of the adsorbent without any mechanical means is another factor which makes this particular material very attractive as an adsorbent. Parameters like adsorbent dosage, pH, temperature, rotation speed and salt concentration have been varied to find out the suitable dye adsorption conditions. Furthermore, the time dependence of adsorption process has been analyzed using pseudo-first and pseudo-second order kinetics. The adsorption isotherms have been constructed to suggest convincing mechanistic pathway for this adsorption process. Finally, desorption studies have been successfully performed in 3 cycles, establishing the reusability of the material, which should allow the adsorbent to be economically promising for practical application in wastewater treatment. Copyright © 2018 Elsevier B.V. All rights reserved.
Polyimide Boosts High-Temperature Performance
NASA Technical Reports Server (NTRS)
2008-01-01
Maverick Corporation, of Blue Ash, Ohio, licensed DMBZ-15 polyimide technology from Glenn Research Center. This ultrahigh-temperature material provides substantial weight savings and reduced machining costs compared to the same component made with more traditional metallic materials. DMBZ-15 has a wide range of applications from aerospace (aircraft engine and airframe components, space transportation systems, and missiles) to non-aerospace (oil drilling, rolling mill), and is particularly well-suited to use as face sheets with honey cones or thermal protection systems for reusable launch vehicles, which encounter elevated temperatures during launch and re-entry.
TPS Materials and Costs for Future Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Rasky, Dan J.; Milos, Frank S.; Squire, Tom H.; Arnold, James O. (Technical Monitor)
2000-01-01
There is considerable interest in developing new reusable launch vehicles (RLVs) for reducing the cost of transporting payload to and from orbit. This work reviews thirteen candidate thermal protection system (TPS) options currently available for RLVs. It is useful to begin with the current Shuttle TPS layout as a reference. The nose cap and wing leading edge , which reach the highest temperatures, are made of reinforced carbon-carbon (RCC) that is protected from oxidation by an external coating (about 0.020" thick) of silicon-carbide. Most of the windward surface is 9 lb/cubic ft ceramic tiles (LI-900) with a thin (about 0.012") coating of Reaction Cured Glass (RCG). The leeward side of the vehicle is covered largely by AFRSI, a quilted ceramic blanket, and FRSI, a polyamide felt. These four materials can be considered first generation reusable TPS. Since the time of the Shuttle design, considerable progress has been made advancing TPS technologies in terms of thermal performance, robustness, and cost. For each of the major systems, a second generation ceramic TPS has been developed, tested, and characterized. Metallic-based systems have also been developed. For applications requiring RCC in the past, advanced carbon-carbon (ACC) is now available. This material has better mechanical properties, somewhat higher temperature capability to 2900F and greatly increased oxidation resistance. New carbon fiber reinforced silicon-carbide matrix composites (C/SiCs) have shown additional improvement in properties over ACC with use temperatures to 3000F and above. For rigid tiles, NASA Ames has made two significant advancements. The first is a tile substrate called Alumina Enhanced Thermal Barrier, or AETB, that incorporates alumina fibers for improved dimensional stability at high temperatures, to 2600F and above. This material can be made to densities as low as 8 lb/cubic ft. The second is a coating preparation called Toughened Uni-piece Fibrous Insulation, or TUFT, that penetrates about 0.1 in. into the tile substrate. The resulting composite, with a functionally gradient density near the surface, provides orders of magnitude increased damage resistance compared with RCG coated LI-900, with only a small weight increase. The TPS that combines these two developments is called AETB-8/TUFI and has been adopted for high damage areas on the Shuttles. Two notable developments have occur-red in flexible ceramic blanket technology. The first is aluminoborosilicate-based fibers with use temperatures of 2200F and above," in comparison to quartz and silica fiber used in AFRSI which have multi-use temperature limits of 1200 to 1400F. Blankets incorporating these new high temperature fibers are referred to as AFRSI-HT. The second is an integral weaving techniques that produces a fluted core blanket with a smoother surface and greater resistance to aero-acoustic noise, to levels as high as 170 dB. This Ames innovation is called Tailorable Advanced Blanket Insulation, or TABI. Finally, for felt-based TPS, Boeing is developing Polybenzimidazole Blanket Insulation, or PBI, with a multi-use temperature limit of 1000F and above, in contrast to Shuttle FRSI which has a multi-use temperature limit of about 700F. 1.6 NASA Langley and BF Goodrich (formerly Rohr Corp.) have led the development of metallic-based TPS. This activity uses essentially three approaches: metallic tiles which encase a fibrous ceramic batting in a box fabricated largely from metallic honeycombs, typically Nickel based alloys; metallic honeycomb sheets, made of Nickel-based alloys, incorporating a fibrous back-side insulation encapsulated in a metallic foil bag, providing reduced weight; and metallic multi-wall, which is comprised of dimpled Titanium metal sheets, which are stacked and then diffusion bonded at contact points to form the TPS. The Nickel-based systems can be used up to temperatures of about 1800F, and the Titanium system to about 100F. These thirteen TPS materials have pros and cons to their usage in terms of temperature capability, weight, initial cost, and maintenance. Carbon-carbon and C/SiC systems have the highest temperature capability but are relatively expensive and heavy, requiring significant time, expertise, and costly facilities and tools for design and fabrication. Second generation ceramic tiles are relatively light, durable, simple to fabricate and easy to install; however, waterproofing is a concern. Blankets and felts are light, simple, inexpensive, and easy to install over curved vehicle surfaces, but durability and waterproofing are concerns. Metallics are robust and appear to have eliminated waterproofing, but they tend to be heavy and relatively expensive, requiring costly facilities and tools. If thin metal sheets are used to reduce weights, then issues arise from possible metal fatigue and corrosion caused by thermal cycling, pressure oscillations, and environmental exposure. For application to future RLVs, system analyses show that a significant component of the vehicle life cycle cost is from the TPS; however, it is difficult to quantify and to compare the potential savings of advanced systems without performing full vehicle designs using each of the different options. Because this entails a considerable effort and also tends to submerge TPS cost impacts under unrelated vehicle design assumptions, there is a clear need for a simpler quantitative method to evaluate the cost impact of different TPS options. To this end, this work introduces a TPS life-cycle cost parameter which is easily computed and applicable to generic RLVs.
Bräuer, A; English, M J M; Lorenz, N; Steinmetz, N; Perl, T; Braun, U; Weyland, W
2003-01-01
Forced-air warming has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with lower body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of six complete lower body warming systems. Heat transfer of forced-air warmers can be described as follows:[1]Qdot;=h.DeltaT.A where Qdot; = heat transfer [W], h = heat exchange coefficient [W m-2 degrees C-1], DeltaT = temperature gradient between blanket and surface [ degrees C], A = covered area [m2]. We tested the following forced-air warmers in a previously validated copper manikin of the human body: (1) Bair Hugger and lower body blanket (Augustine Medical Inc., Eden Prairie, MN); (2) Thermacare and lower body blanket (Gaymar Industries, Orchard Park, NY); (3) WarmAir and lower body blanket (Cincinnati Sub-Zero Products, Cincinnati, OH); (4) Warm-Gard(R) and lower body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); (5) Warm-Gard and reusable lower body blanket (Luis Gibeck AB); and (6) WarmTouch and lower body blanket (Mallinckrodt Medical Inc., St. Luis, MO). Heat flux and surface temperature were measured with 16 calibrated heat flux transducers. Blanket temperature was measured using 16 thermocouples. DeltaT was varied between -10 and +10 degrees C and h was determined by a linear regression analysis as the slope of DeltaT vs. heat flux. Mean DeltaT was determined for surface temperatures between 36 and 38 degrees C, because similar mean skin temperatures have been found in volunteers. The area covered by the blankets was estimated to be 0.54 m2. Heat transfer from the blanket to the manikin was different for surface temperatures between 36 degrees C and 38 degrees C. At a surface temperature of 36 degrees C the heat transfer was higher (between 13.4 W to 18.3 W) than at surface temperatures of 38 degrees C (8-11.5 W). The highest heat transfer was delivered by the Thermacare system (8.3-18.3 W), the lowest heat transfer was delivered by the Warm-Gard system with the single use blanket (8-13.4 W). The heat exchange coefficient varied between 12.5 W m-2 degrees C-1 and 30.8 W m-2 degrees C-1, mean DeltaT varied between 1.04 degrees C and 2.48 degrees C for surface temperatures of 36 degrees C and between 0.50 degrees C and 1.63 degrees C for surface temperatures of 38 degrees C. No relevant differences in heat transfer of lower body blankets were found between the different forced-air warming systems tested. Heat transfer was lower than heat transfer by upper body blankets tested in a previous study. However, forced-air warming systems with lower body blankets are still more effective than forced-air warming systems with upper body blankets in the prevention of perioperative hypothermia, because they cover a larger area of the body surface.
A reusable PZT transducer for monitoring initial hydration and structural health of concrete.
Yang, Yaowen; Divsholi, Bahador Sabet; Soh, Chee Kiong
2010-01-01
During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection and parameter identification for various engineering structures over the last two decades. In this work, a reusable PZT transducer setup for monitoring initial hydration of concrete and structural health is developed, where a piece of PZT is bonded to an enclosure with two bolts tightened inside the holes drilled in the enclosure. An impedance analyzer is used to acquire the admittance signatures of the PZT. Root mean square deviation (RMSD) is employed to associate the change in concrete strength with changes in the PZT admittance signatures. The results show that the reusable setup is able to effectively monitor the initial hydration of concrete and the structural health. It can also be detached from the concrete for future re-use.
A Reusable PZT Transducer for Monitoring Initial Hydration and Structural Health of Concrete
Yang, Yaowen; Divsholi, Bahador Sabet; Soh, Chee Kiong
2010-01-01
During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection and parameter identification for various engineering structures over the last two decades. In this work, a reusable PZT transducer setup for monitoring initial hydration of concrete and structural health is developed, where a piece of PZT is bonded to an enclosure with two bolts tightened inside the holes drilled in the enclosure. An impedance analyzer is used to acquire the admittance signatures of the PZT. Root mean square deviation (RMSD) is employed to associate the change in concrete strength with changes in the PZT admittance signatures. The results show that the reusable setup is able to effectively monitor the initial hydration of concrete and the structural health. It can also be detached from the concrete for future re-use. PMID:22399929
24 Inch Reusable Solid Rocket Motor Test
NASA Technical Reports Server (NTRS)
2002-01-01
A scaled-down 24-inch version of the Space Shuttle's Reusable Solid Rocket Motor was successfully fired for 21 seconds at a Marshall Space Flight Center (MSFC) Test Stand. The motor was tested to ensure a replacement material called Lycocel would meet the criteria set by the Shuttle's Solid Motor Project Office. The current material is a heat-resistant, rayon-based, carbon-cloth phenolic used as an insulating material for the motor's nozzle. Lycocel, a brand name for Tencel, is a cousin to rayon and is an exceptionally strong fiber made of wood pulp produced by a special 'solvent-spirning' process using a nontoxic solvent. It will also be impregnated with a phenolic resin. This new material is expected to perform better under the high temperatures experienced during launch. The next step will be to test the material on a 48-inch solid rocket motor. The test, which replicates launch conditions, is part of Shuttle's ongoing verification of components, materials, and manufacturing processes required by MSFC, which oversees the Reusable Solid Rocket Motor project. Manufactured by the ATK Thiokol Propulsion Division in Promontory, California, the Reusable Solid Rocket Motor measures 126 feet (38.4 meters) long and 12 feet (3.6 meters) in diameter. It is the largest solid rocket motor ever flown and the first designed for reuse. During its two-minute burn at liftoff, each motor generates an average thrust of 2.6 million pounds (1.2 million kilograms).
Lee, Hae Won; Kang, Dong-Ho; Cho, Jeong Ho; Lee, Sungjoo; Jun, Dong-Hwan; Park, Jin-Hong
2018-05-30
In recent years when the demand for high-performance biosensors has been aroused, a field-effect transistor (FET)-type biosensor (BioFET) has attracted great interest because of its high sensitivity, label-free detection, fast detection speed, and miniaturization. However, the insulating membrane in the conventional BioFET, which is essential in preventing the surface dangling bonds of typical semiconductors from nonspecific bindings, has limited the sensitivity of biosensors. Here, we present a highly sensitive and reusable membraneless BioFET based on a defect-free van der Waals material, tungsten diselenide (WSe 2 ). We intentionally generated a few surface defects that serve as extra binding sites for the bioreceptor immobilization through weak oxygen plasma treatment, consequently magnifying the sensitivity values to 2.87 × 10 5 A/A for 10 mM glucose. The WSe 2 BioFET also maintained its high sensitivity even after several cycles of rinsing and glucose application were repeated.
NASA Technical Reports Server (NTRS)
Smitherman, David; Woodcock, Gordon
2012-01-01
A space transportation infrastructure is described that utilizes the Space Launch System (SLS), the Mulit-Purpose Crew Vehicle (MPCV), the International Space Station (ISS), and propellant depot servicing platforms to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicle (ELV) systems such as the Delta IV Heavy, Atlas V, and Falcon 9, for commercial crew, cargo, and propellant launches to a Low-Earth-Orbit (LEO) Depot and/or the ISS. The SLS provides all payload and propellant launches to the Earth-Moon Langrange Point 1 (EML1) Depot to support new reusable in-space transportation vehicles. The ISS or follow-on LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing and to Earth-Moon L1 for EML1 Depot missions. The EML1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid, and Mars missions. New vehicle design concepts are presented that can be launched utilizing the SLS and current ELV systems. These new reusable vehicle concepts include a Crew Transfer Vehicle (CTV) derived from the MPCV and a reusable Cryogenic Propulsion Stage (CPS) for crew transportation between the LEO Depot, EML1 Depot and missions beyond the Earth-Moon vicinity; a new reusable Lunar Lander for crew transportation between the EML1 Depot and the lunar surface; and a new reusable Deep Space Habitat (DSH) with a CTV to support crew missions from the EML1 Depot to ESL2, Asteroids, and a Mars Orbital Depot. The LEO Depot, EML1 Depot, and Mars Orbital Depot are based on International Space Station (ISS) heritage hardware. Data provided includes the number of launches required for each mission utilizing SLS and current ELV systems (Delta IV Heavy or equivalent) and the approximate vehicle masses and propellant requirements. Also included is a discussion on affordability with ideas on technologies that could reduce the number of launches required and thoughts on how this infrastructure might be implemented incrementally over the next few decades. The potential benefits of this infrastructure include competitive bidding for ELV flights and propellant services, development of new reusable in-space vehicles, and development of a robust multiuse infrastructure that can support many government and commercial missions simultaneously.
Mechanical Attachment of Reusable Surface Insulation to Space Shuttle Primary Structure
NASA Technical Reports Server (NTRS)
Fleck, R. W.; Lehman, J. K.
1973-01-01
Three methods of attaching surface insulation tiles to shuttle primary structure have been proposed: direct bond, mechanical attachment, and subpanels with standoffs. The direct bond approach is lightweight but is difficult to refurbish and inspect. The subpanel approach is heavier but allows for easy refurbishment since subpanels are easily removed and replaced. The mechanical attachment approach allows easy refurbishment and inspection and is lightweight when an efficient insulator is used between surface insulation tiles and primary structure.
NASA Technical Reports Server (NTRS)
Johnson, W. S.; Pavlick, M. M.; Oliver, M. S.
2005-01-01
Composite materials are being used in the aerospace industry as a means of reducing vehicle weight. In particular, polymer matrix composites (PMC) are good candidates due to their high strength-to-weight and high stiffness-to-weight ratios. Future reusable space launch vehicles and space exploration structures will need advanced light weight composites in order to minimize vehicle weight while demonstrating robustness and durability, guaranteeing high factors of safety. In particular, the implementation of composite cryogenic propellant fuel tanks (cryotanks) for future reusable launch vehicles (RLVs) could greatly reduce the vehicle's weight versus identically sized cryotanks constructed of metallic materials. One candidate composite material for future cryotank designs is IM7/977-2, which is a graphite/epoxy system. A successful candidate must demonstrate reasonable structural properties over a wide range of temperatures. Since the matrix material is normally the weak link in the composite, tests that emphasize matrix-dominated behavior need to be conducted. Therefore, the objective of this work is to determine the mode I interlaminar fracture toughness of "unidirectional" 8-ply and 16-ply IM7/977-2 through experimental testing. Tests were performed at -196 degrees Celsius (-320 degrees Fahrenheit), 22 degrees Celsius (72 degrees Fahrenheit), 93 degrees Celsius (200 degrees Fahrenheit) and 160 degrees C (320 degrees Fahrenheit). Low temperature testing was completed while the specimen was submerged in a liquid nitrogen bath. High temperature testing was completed in a temperature-controlled oven.
NASA Technical Reports Server (NTRS)
Brazel, J. P.; Kennedy, B. S.
1974-01-01
The materials studied are described along with the apparatus and the experimental techniques employed. The results of the measurements involving two REI Silica materials and a Mod 1 B REI Mullite are listed in a table. Measurements were conducted at unusually high temperature differences to detect 'shine-through' radiation transparency. Photographs are presented of the high-temperature guarded hot plate assembly.
Biodiesel production from used cooking oil by two-step heterogeneous catalyzed process.
Srilatha, K; Prabhavathi Devi, B L A; Lingaiah, N; Prasad, R B N; Sai Prasad, P S
2012-09-01
The present study demonstrates the production of biodiesel from used cooking oil containing high free fatty acid by a two-step heterogeneously catalyzed process. The free fatty acids were first esterified with methanol using a 25 wt.% TPA/Nb(2)O(5) catalyst followed by transesterification of the oil with methanol over ZnO/Na-Y zeolite catalyst. The catalysts were characterized by XRD, FT-IR, BET surface area and CO(2)-TPD. In the case of transesterification the effect of reaction parameters, such as catalyst concentration, methanol to oil molar ratio and reaction temperature, on the yield of ester were investigated. The catalyst with 20 wt.% ZnO loading on Na-Y exhibited the highest activity among the others. Both the solid acid and base catalysts were found to be reusable for several times indicating their efficacy in the two-step process. Copyright © 2012 Elsevier Ltd. All rights reserved.
Srivastava, Garima; Singh, Kritika; Talat, Mahe; Srivastava, Onkar Nath; Kayastha, Arvind M.
2014-01-01
β-Amylase finds application in food and pharmaceutical industries. Functionalized graphene sheets were customised as a matrix for covalent immobilization of Fenugreek β-amylase using glutaraldehyde as a cross-linker. The factors affecting the process were optimized using Response Surface Methodology based Box-Behnken design of experiment which resulted in 84% immobilization efficiency. Scanning and Transmission Electron Microscopy (SEM, TEM) and Fourier Tansform Infrared (FTIR) spectroscopy were employed for the purpose of characterization of attachment of enzyme on the graphene. The enzyme kinetic studies were carried out for obtaining best catalytic performance and enhanced reusability. Optimum temperature remained unchanged, whereas optimum pH showed shift towards acidic range for immobilized enzyme. Increase in thermal stability of immobilized enzyme and non-toxic nature of functionalized graphene can be exploited for production of maltose in food and pharmaceutical industries. PMID:25412079
Fracture behavior of the Space Shuttle thermal protection system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Komine, A.; Kobayashi, A.S.
1983-09-01
Stable crack-growth and fracture-toughness experiments were conducted using precracked specimens machined from LI-900 reusable surface insulation (RSI) tiles of the Space Shuttle thermal protection system (TPS) at room temperature. Similar fracture experiments were conducted on fracture specimens with preexisting cracks at the interface of the tile and the strain isolation pad (SIP). Stable crack growth was not observed in the LI-900 tile fracture specimens which had a fracture toughness of 12.0 kPa sq rt of m. The intermittent subcritical crack growth at the tile-pad interface of the fracture specimens was attributed to successive local pull-outs due to tensile overload inmore » the LI-900 tile and cannot be characterized by linear elastic fracture mechanics. No subcritical interfacial crack growth was observed in the fracture specimens with densified LI-900 tiles where brittle fracture initiated at an interior point away from the densification. 11 references.« less
Cellulase immobilization on magnetic nanoparticles encapsulated in polymer nanospheres.
Lima, Janaina S; Araújo, Pedro H H; Sayer, Claudia; Souza, Antonio A U; Viegas, Alexandre C; de Oliveira, Débora
2017-04-01
Immobilization of cellulases on magnetic nanoparticles, especially magnetite nanoparticles, has been the main approach studied to make this enzyme, economically and industrially, more attractive. However, magnetite nanoparticles tend to agglomerate, are very reactive and easily oxidized in air, which has strong impact on their useful life. Thus, it is very important to provide proper surface coating to avoid the mentioned problems. This study aimed to investigate the immobilization of cellulase on magnetic nanoparticles encapsulated in polymeric nanospheres. The support was characterized in terms of morphology, average diameter, magnetic behavior and thermal decomposition analyses. The polymer nanospheres containing encapsulated magnetic nanoparticles showed superparamagnetic behavior and intensity average diameter about 150 nm. Immobilized cellulase exhibited broader temperature stability than in the free form and great reusability capacity, 69% of the initial enzyme activity was maintained after eight cycles of use. The magnetic support showed potential for cellulase immobilization and allowed fast and easy biocatalyst recovery through a single magnet.
Oxidation of Ultra-High Temperature Ceramics in Water Vapor
NASA Technical Reports Server (NTRS)
Nguyen, QuynhGiao N.; Opila, Elizabeth J.; Robinson, Raymond C.
2003-01-01
Ultra high temperature ceramics (UHTCs) including HfB2 + SiC (20% by volume), ZrB2 + SiC (20% by volume) and ZrB2 + SiC (14% by volume) + C (30% by volume) have historically been evaluated as reusable thermal protection systems for hypersonic vehicles. This study investigates UHTCs for use as potential combustion and aeropropulsion engine materials. These materials were oxidized in water vapor (90%) using a cyclic vertical furnace at 1 atm. The total exposure time was 10 hours at temperatures of 1200, 1300, and 1400 C. CVD SiC was also evaluated as a baseline comparison. Weight change measurements, X-ray diffraction analyses, surface and cross-sectional SEM and EDS were performed. These results will be compared with tests ran in static air at temperatures of 1327, 1627, and 1927 C. Oxidation comparisons will also be made to the study by Tripp. A small number of high pressure burner rig (HPBR) results at 1100 and 1300 C will also be discussed. Specific weight changes at all three temperatures along with the SIC results are shown. SiC weight change is negligible at such short duration times. HB2 + SiC (HS) performed the best out of all the tested UHTCS for all exposure temperatures. ZrB2 + Sic (ZS) results indicate a slightly lower oxidation rate than that of ZrBl + SiC + C (ZCS) at 1200 and 1400 C, but a clear distinction can not be made based on the limited number of tested samples. Scanning electron micrographs of the cross-sections of all the UHTCs were evaluated. A representative area for HS is presented at 1400 C for 26 hours which was the composition with the least amount of oxidation. A continuous SiO2 scale is present in the outer most edge of the surface. An image of ZCS is presented at 1400 C for 10 hours, which shows the most degradation of all the compositions studied. Here, the oxide surface is a mixture of ZrSiO4, ZrO2 and SO2.
Thermal Exposure Effects on Properties of Al-Li Alloy Plate Products
NASA Technical Reports Server (NTRS)
Shah, Sandeep; Wells, Douglas; Wagner, John; Babel, Henry
2002-01-01
Aluminum-Lithium (AL-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional aluminum alloys. For example, the application of an Al-Li alloy to the space shuttle external cryogenic fuel tank contributed to the weight savings that enabled successful deployment of International Space Station components. The composition and heat treatment of this alloy were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. As most aerospace structural hardware is weight sensitive, a reusable cryotank will be designed to the limits of the materials mechanical properties. Therefore, this effort was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of one relatively production mature alloy and two developmental alloys C458 and L277. Tensile and fracture toughness behavior was evaluated after exposure to temperatures as high as 3oooF for up to IO00 hrs. Microstructural changes were also evaluated to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Characterizing the effect of thermal exposure on the properties of Al-Li alloys is important to defining a service limiting temperature, exposure time, and end-of-life properties.
Adaptable Holders for Arc-Jet Screening Candidate Thermal Protection System Repair Materials
NASA Technical Reports Server (NTRS)
Riccio, Joe; Milhoan, Jim D.
2010-01-01
Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.
Vertical Landing Aerodynamics of Reusable Rocket Vehicle
NASA Astrophysics Data System (ADS)
Nonaka, Satoshi; Nishida, Hiroyuki; Kato, Hiroyuki; Ogawa, Hiroyuki; Inatani, Yoshifumi
The aerodynamic characteristics of a vertical landing rocket are affected by its engine plume in the landing phase. The influences of interaction of the engine plume with the freestream around the vehicle on the aerodynamic characteristics are studied experimentally aiming to realize safe landing of the vertical landing rocket. The aerodynamic forces and surface pressure distributions are measured using a scaled model of a reusable rocket vehicle in low-speed wind tunnels. The flow field around the vehicle model is visualized using the particle image velocimetry (PIV) method. Results show that the aerodynamic characteristics, such as the drag force and pitching moment, are strongly affected by the change in the base pressure distributions and reattachment of a separation flow around the vehicle.
Optimization and Immobilization of Purified Labeo rohita Visceral Protease by Entrapment Method
Geethanjali, S.; Subash, Anitha
2013-01-01
The purified fish visceral protease enzyme was immobilized by using various concentrations of sodium alginate and calcium chloride to optimize the best concentration for the formation of the beads. Then it was characterized by assaying the optimal pH, temperature, storage stability and reusability. The results on immobilization with sodium alginate and calcium chloride showed that a combination of 2% sodium alginate and 0.3 M calcium chloride weas found to be the optimum concentration for the formation of spherical and stable beads, this gave a maximal entrapped activity of 48.31%, and there was no change in the optimum pH 8.0 and temperature 40°C of protease before and after entrapment. The results on stability and reusability indicated that it was stable at 4°C retaining 100% residual activity after 5 days of storage and 67% loss of activity after ten days of storage and it retained 100% residual activity on the first reuse, 75% residual activity on the second reuse, 25% residual activity on the third use and complete loss in the activity on the fourth reuse. PMID:23533718
Comparison of reusable insulation systems for cryogenically-tanked earth-based space vehicles
NASA Technical Reports Server (NTRS)
Sumner, I. E.; Barber, J. R.
1978-01-01
Three reusable insulation systems concepts have been developed for use with cryogenic tanks of earth-based space vehicles. Two concepts utilized double-goldized Kapton (DGK) or double-aluminized Mylar (DAM) multilayer insulation (MLI), while the third utilized a hollow-glass-microsphere, load-bearing insulation (LBI). All three insulation systems have recently undergone experimental testing and evaluation under NASA-sponsored programs. Thermal performance measurements were made under space-hold (vacuum) conditions for insulation warm boundary temperatures of approximately 291 K. The resulting effective thermal conductivity was approximately .00008 W/m-K for the MLI systems (liquid hydrogen test results) and .00054 W/m-K for the LBI system (liquid nitrogen test results corrected to liquid hydrogen temperature). The DGK MLI system experienced a maximum thermal degradation of 38 percent, the DAM MLI system 14 percent, and the LBI system 6.7 percent due to repeated thermal cycling representing typical space flight conditions. Repeated exposure of the DAM MLI system to a high humidity environment for periods as long as 8 weeks provided a maximum degradation of only 24 percent.
NASA Astrophysics Data System (ADS)
Gahlout, Mayur; Rudakiya, Darshan M.; Gupte, Shilpa; Gupte, Akshaya
2017-08-01
Immobilization of enzyme with nanostructures enhances its ideal characteristics, which may allow the enzyme to become more stable and resistant. The present investigation deals with the formulation of laccase nanosilica conjugates to overcome the problems associated with its stability and reusability. Synthesized nanosilica and laccase nanoparticles were spherical shaped, with the mean size of 220 and 615 nm, respectively. Laccase nanoparticles had an optimum temperature of 55 °C and pH 4.0 for the oxidation of ABTS. Laccase nanoparticle retained 79% of residual activity till 20th cycle. It also showed 91% of its initial activity at lower temperatures even after 60 days. Laccase nanoparticles were applied for Reactive Violet 1 degradation wherein 96.76% of decolourization was obtained at pH 5.0 and 30 °C within 12 h. Toxicity studies on microbes and plants suggested that the degraded metabolites were less toxic than control dye. Thus, the method applied for immobilization increased storage stability and reusability of laccase, and therefore, it can be utilized for efficient degradation of azo dyes.
NASA Astrophysics Data System (ADS)
Liu, Ying; Zhang, Kun; Yin, Xiaoshuang; Yang, Wenzhong; Zhu, Hongjun
2016-04-01
The metal-deposited magnetic catalyst microspheres (MCM-MPs) were successfully synthesized by one facile, high yield and controllable approach. Here, the bare magnetic microspheres were firstly synthesized according to the solvothermal method. Then silica shell were coated on the surface of the magnetic microspheres via sol-gel method, and subsequently with surface modifying with amino in the purpose to form SiO2-NH2 shell. Thus, metal particles were easily adsorbed into the SiO2-NH2 shell and in-situ reduced by NaBH4 solution. All the obtained products (MCM-Cu, MCM-Ag, MCM-Pd) which were monodisperse and constitutionally stable were exhibited high magnetization and excellent catalytic activity towards dyes solution reduction. The catalytic rate ratio of MCM-Pd: MCM-Cu: MCM-Ag could be 10:3:1. Besides, some special coordination compound Cu2(OH)3Br had been generated in the in-situ reduced process of MCM-Cu, which produced superior cyclical stability (>20 times) than that of MCM-Ag and MCM-Pd. In all, those highly reusability and great catalytic efficiency of MCM-MPs show promising and great potential for treatment of dye-contaminated water.
A Framework for Assessing the Reusability of Hardware (Reusable Rocket Engines)
NASA Technical Reports Server (NTRS)
Childress-Thompson, Rhonda; Thomas, Dale; Farrington, Philip
2016-01-01
Within the past few years, there has been a renewed interest in reusability as it applies to space flight hardware. Commercial companies such as Space Exploration Technologies Corporation (SpaceX), Blue Origin, and United Launch Alliance (ULA) are pursuing reusable hardware. Even foreign companies are pursuing this option. The Indian Space Research Organization (ISRO) launched a reusable space plane technology demonstrator and Airbus Defense and Space is planning to recover the main engines and avionics from its Advanced Expendable Launcher with Innovative engine Economy [1] [2]. To date, the Space Shuttle remains as the only Reusable Launch (RLV) to have flown repeated missions and the Space Shutte Main Engine (SSME) is the only demonstrated reusable engine. Whether the hardware being considered for reuse is a launch vehicle (fully reusable), a first stage (partially reusable), or a booster engine (single component), the overall governing process is the same; it must be recovered and recertified for flight. Therefore, there is a need to identify the key factors in determining the reusability of flight hardware. This paper begins with defining reusability to set the context, addresses the significance of reuse, and discusses areas that limit successful implementation. Finally, this research identifies the factors that should be considered when incorporating reuse.
Reusable Solid Rocket Motor Nozzle Joint-4 Thermal Analysis
NASA Technical Reports Server (NTRS)
Clayton, J. Louie
2001-01-01
This study provides for development and test verification of a thermal model used for prediction of joint heating environments, structural temperatures and seal erosions in the Space Shuttle Reusable Solid Rocket Motor (RSRM) Nozzle Joint-4. The heating environments are a result of rapid pressurization of the joint free volume assuming a leak path has occurred in the filler material used for assembly gap close out. Combustion gases flow along the leak path from nozzle environment to joint O-ring gland resulting in local heating to the metal housing and erosion of seal materials. Analysis of this condition was based on usage of the NASA Joint Pressurization Routine (JPR) for environment determination and the Systems Improved Numerical Differencing Analyzer (SINDA) for structural temperature prediction. Model generated temperatures, pressures and seal erosions are compared to hot fire test data for several different leak path situations. Investigated in the hot fire test program were nozzle joint-4 O-ring erosion sensitivities to leak path width in both open and confined joint geometries. Model predictions were in generally good agreement with the test data for the confined leak path cases. Worst case flight predictions are provided using the test-calibrated model. Analysis issues are discussed based on model calibration procedures.
Feng, Quan; Hou, Dayin; Zhao, Yong; Xu, Tao; Menkhaus, Todd J; Fong, Hao
2014-12-10
In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane with fiber diameters of ∼200-400 nm was prepared first; subsequently, 2-hydroxyethyl methacrylate (HEMA), 2-dimethylaminoethyl methacrylate (DMAEMA), and acrylic acid (AA) were selected as the monomers for surface grafting of polymer chains/brushes via the atom transfer radical polymerization (ATRP) method. Thereafter, four nanofibrous membranes (i.e., RC, RC-poly(HEMA), RC-poly(DMAEMA), and RC-poly(AA)) were explored as innovative supports for immobilization of an enzyme of bovine liver catalase (CAT). The amount/capacity, activity, stability, and reusability of immobilized catalase were evaluated, and the kinetic parameters (Vmax and Km) for immobilized and free catalase were determined. The results indicated that the respective amounts/capacities of immobilized catalase on RC-poly(HEMA) and RC-poly(DMAEMA) nanofibrous membranes reached 78 ± 3.5 and 67 ± 2.7 mg g(-1), which were considerably higher than the previously reported values. Meanwhile, compared to that of free CAT (i.e., 18 days), the half-life periods of RC-CAT, RC-poly(HEMA)-CAT, RC-poly(DMAEMA)-CAT, and RC-poly(AA)-CAT were 49, 58, 56, and 60 days, respectively, indicating that the storage stability of immobilized catalase was also significantly improved. Furthermore, the immobilized catalase exhibited substantially higher resistance to temperature variation (tested from 5 to 70 °C) and lower degree of sensitivity to pH value (tested from 4.0 and 10.0) than the free catalase. In particular, according to the kinetic parameters of Vmax and Km, the nanofibrous membranes of RC-poly(HEMA) (i.e., 5102 μmol mg(-1) min(-1) and 44.89 mM) and RC-poly(DMAEMA) (i.e., 4651 μmol mg(-1) min(-1) and 46.98 mM) had the most satisfactory biocompatibility with immobilized catalase. It was therefore concluded that the electrospun RC nanofibrous membranes surface-grafted with 3-dimensional nanolayers of polymer chains/brushes would be suitable/ideal as efficient supports for high-density and reusable enzyme immobilization.
NASA Technical Reports Server (NTRS)
Milos, Frank S.; Arnold, Jim (Technical Monitor)
2001-01-01
Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles (RLVs) in order to reduce life cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to develop inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and industry partners to develop "wireless" devices that can be embedded in the thermal protection system to monitor temperature or other quantities of interest. These devices are sensors integrated with radio-frequency identification (RFID) microchips to enable non-contact communication of sensor data to an external reader that may be a hand-held scanner or a large portal. Both passive and active prototype devices have been developed. The passive device uses a thermal fuse to indicate the occurrence of excessive temperature. This device has a diameter under 0.13 cm. (suitable for placement in gaps between ceramic TPS tiles on an RLV) and can withstand 370 C for 15 minutes. The active device contains a small battery to provide power to a thermocouple for recording a temperature history during flight. The bulk of the device must be placed beneath the TPS for protection from high temperature, but the thermocouple can be placed in a hot location such as near the external surface.
NASA Technical Reports Server (NTRS)
Johnson, Sylvia M.
2000-01-01
The objectives of the project summarized in this viewgraph presentation are the following: (1) Develop a lightweight and low cost durable Thermal Protection System (TPS) for easy application to reusable launch vehicle payload launchers; (2) Develop quickly processed composite TPS processing and repair techniques; and (3) Develop higher temperature capability tile TPS. The benefits of this technology include reduced installation and operations cost, enhanced payload capability resulting from TPS weight reduction, and enhanced flight envelope and performance resulting from higher temperature capability TPS which can result in improved safety.
NASA Technical Reports Server (NTRS)
Gusman, Michael I.; Stackpoole, Mairead; Ellerby, Donald T.; Johnson, Sylvia M.; Arnold, Jim (Technical Monitor)
2001-01-01
Previous work on refractory diboride composites has shown these systems to have potential for use in high temperature leading edge applications for reusable reentry vehicles. These composites, based on compositions of HfB2 or ZrB2 with SiC particulate reinforcements, have shown good oxidation resistance in reentry environments. In this work we are investigating the effects of composition and microstructure on properties. Preliminary studies of composite mechanical properties and oxidation behavior will be discussed.
Evolution of technologies applied to space and aeronautic structures
NASA Astrophysics Data System (ADS)
Abiven, H.
Advanced materials in aerospace structures and their use in reusable launch vehicles are discussed. It is found that composite materials can be used for structures with temperatures up to 400 C, and for most structures with heat shielding. For structures with temperatures up to 1000 C, metals such as Norsial, based on rene alloys could be used. It is concluded that a combination of silicon and carbon composites with Aerocoat/TH hydrotranspiration heat shielding give a heat flux resistant structure with no thermal dilation problems.
Adhesive Bonding Characterization of Composite Joints for Cryogenic Usage
NASA Technical Reports Server (NTRS)
Graf, Neil A.; Schieleit, Gregory F.; Biggs, Robert
2000-01-01
The development of polymer composite cryogenic tanks is a critical step in creating the next generation of launch vehicles. Future reusable launch vehicles need to minimize the gross liftoff weight (GLOW). This weight reduction is possible due to the large reduction in weight that composite materials can provide over current aluminum technology. In addition to composite technology, adhesively bonded joints potentially have several benefits over mechanically fastened joints, such as weight savings and cryogenic fluid containment. Adhesively bonded joints may be used in several areas of these cryogenic tanks, such as in lobe-to-lobe joints (in a multi-lobe concept), skirt-to-tank joint, strut-to-tank joint, and for attaching stringers and ring frames. The bonds, and the tanks themselves, must be able to withstand liquid cryogenic fuel temperatures that they contain. However, the use of adhesively bonded composite joints at liquid oxygen and hydrogen temperatures is largely unknown and must be characterized. Lockheed Martin Space Systems Company, Michoud Operations performed coupon-level tests to determine effects of material selection, cure process parameters, substrate surface preparation, and other factors on the strength of these composite joints at cryogenic temperatures. This led to the selection of a material and process that would be suitable for a cryogenic tank. KEY WORDS: Composites, Adhesive Bonding, Cryogenics
Liu, Yong-Bo; Qu, Dan; Wen, Yu-Juan; Ren, He-Jun
2015-06-01
Aniline is of great environmental concern with regards to widespread occurrence in water and soil and increasing threat into the life forms. Bioremediation involving the use of degrading bacterium in the removal of aniline is the most promising process, yet inhibited under low temperature usually. In the present study, a new psychrotrophic bacterial strain isolated from groundwater, designated AN-1, was shown to be capable of aniline degradation in a concentration range of 135-2202 mg L(-1) within 72 h at 10 °C. Strain AN-1 was proposed to be a Pseudomonas migulae group of bacteria based on the evolutionary relationship and the morphological and biochemical characteristics. The pH, NaH2PO4, and aniline concentration were used as independent variables to optimize the aniline removal by AN-1 at 10 °C, and a statistically significant (R (2) = 0.9230, p < 0.005) quadratic polynomial mathematical model was suggested. Moreover, an efficient biocomposite by assembling Fe3O4 nanoparticles onto the surface of AN-1 cells was constructed. Compared with free cells, the microbial cell/Fe3O4 biocomposite had the same biodegradation activity but exhibited remarkable reusability. This study highlights AN-1 might be a promising candidate for aniline removal from wastewater at low temperatures.
Code of Federal Regulations, 2010 CFR
2010-07-01
... content of less than 19.5 percent or greater than 23 percent. Intermodal container means a reusable cargo... does not include ship shaped or deep draft barges. Bulling means the horizontal dragging of cargo across a surface with none of the weight of the cargo supported by the fall. Danger zone means any place...
Code of Federal Regulations, 2013 CFR
2013-07-01
... content of less than 19.5 percent or greater than 23 percent. Intermodal container means a reusable cargo... does not include ship shaped or deep draft barges. Bulling means the horizontal dragging of cargo across a surface with none of the weight of the cargo supported by the fall. Danger zone means any place...
Code of Federal Regulations, 2014 CFR
2014-07-01
... content of less than 19.5 percent or greater than 23 percent. Intermodal container means a reusable cargo... does not include ship shaped or deep draft barges. Bulling means the horizontal dragging of cargo across a surface with none of the weight of the cargo supported by the fall. Danger zone means any place...
2013-03-31
found to not thermally accommodate to the surface, rather they leave in excited vibrational levels. The new finite-rate model and thermal accommodation...vehicle’s thermal protection system (TPS). Many TPS materials act as a catalyst for the heterogeneous recombination of dissociated species back into...it is a significant component in both reusable (LI900, LI2200, FRSI) and ablative (SIRCA) thermal protection systems [24]. In addition, studies have
Pilot cryo tunnel: Attachments, seals, and insulation
NASA Technical Reports Server (NTRS)
Wilson, J. F.; Ware, G. D.; Ramsey, J. W., Jr.
1974-01-01
Several different tests are described which simulated the actual configuration of a cryogenic wind tunnel operating at pressures up to 5 atmospheres (507 kPa) and temperatures from -320 F (78K) to 120 F (322K) in order to determine compatible bolting, adequate sealing, and effective insulating materials. The evaluation of flange attachments (continuous threaded studs) considered bolting based on compatible flanges, attachment materials, and prescribed bolt elongations. Various types of seals and seal configurations were studied to determine suitability and reusability under the imposed pressure and temperature loadings. The temperature profile was established for several materials used for structural supports.
Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.
2015-10-06
Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.
Self-cleaning poly(dimethylsiloxane) film with functional micro/nano hierarchical structures.
Zhang, Xiao-Sheng; Zhu, Fu-Yun; Han, Meng-Di; Sun, Xu-Ming; Peng, Xu-Hua; Zhang, Hai-Xia
2013-08-27
This paper reports a novel single-step wafer-level fabrication of superhydrophobic micro/nano dual-scale (MNDS) poly(dimethylsiloxane) (PDMS) films. The MNDS PDMS films were replicated directly from an ultralow-surface-energy silicon substrate at high temperature without any surfactant coating, achieving high precision. An improved deep reactive ion etching (DRIE) process with enhanced passivation steps was proposed to easily realize the ultralow-surface-energy MNDS silicon substrate and also utilized as a post-treatment process to strengthen the hydrophobicity of the MNDS PDMS film. The chemical modification of this enhanced passivation step to the surface energy has been studied by density functional theory, which is also the first investigation of C4F8 plasma treatment at molecular level by using first-principle calculations. From the results of a systematic study on the effect of key process parameters (i.e., baking temperature and time) on PDMS replication, insight into the interaction of hierarchical multiscale structures of polymeric materials during the micro/nano integrated fabrication process is experimentally obtained for the first time. Finite element simulation has been employed to illustrate this new phenomenon. Additionally, hierarchical PDMS pyramid arrays and V-shaped grooves have been developed and are intended for applications as functional structures for a light-absorption coating layer and directional transport of liquid droplets, respectively. This stable, self-cleaning PDMS film with functional micro/nano hierarchical structures, which is fabricated through a wafer-level single-step fabrication process using a reusable silicon mold, shows attractive potential for future applications in micro/nanodevices, especially in micro/nanofluidics.
Cooper, James E; Kendig, Eric L; Belcher, Scott M
2011-10-01
Bisphenol A (BPA) is a ubiquitous high volume industrial chemical that is an estrogen and an environmental endocrine disrupting chemical. Bisphenol A is used extensively in the production of consumer goods, polycarbonate plastics, epoxy resins and coatings used to line metallic food and beverage cans. There is great concern regarding the possible harmful effects from exposures that result from BPA leaching into foods and beverages from packaging or storage containers. The objective of this study was to independently assess whether BPA contamination of water was occurring from different types of reusable drinking bottles marketed as alternatives to BPA-containing polycarbonate plastics. Using a sensitive and quantitative BPA-specific competitive enzyme-linked immunosorbent assay we evaluated whether BPA migrated into water stored in polycarbonate or copolyester plastic bottles, and different lined or unlined metallic reusable water bottles. At room temperature the concentration of BPA migrating from polycarbonate bottles ranged from 0.2 to 0.3 mg L⁻¹. Under identical conditions BPA migration from aluminium bottles lined with epoxy-based resins was variable depending on manufacturer ranging from 0.08 to 1.9 mg L⁻¹. Boiling water significantly increased migration of BPA from the epoxy lined bottles. No detectable BPA contamination was observed in water stored in bottles made from Tritan™ copolyester plastic, uncoated stainless steel, or aluminium lined with EcoCare™. The results from this study demonstrate that when used according to manufacturers' recommendations reusable water bottles constructed from "BPA-free" alternative materials are suitable for consumption of beverages free of BPA contamination. Copyright © 2011 Elsevier Ltd. All rights reserved.
Cooper, James E.; Kendig, Eric L.; Belcher, Scott M.
2011-01-01
Bisphenol A(BPA) is a ubiquitous high volume industrial chemical that is an estrogen and an environmental endocrine disrupting chemical. Bisphenol A is used extensively in the production of consumer goods, polycarbonate plastics, epoxy resins, coating used to line metallic food and beverage cans, and other products.There is great concern regarding the possible harmful effects from exposures that result from BPAleaching into foods and beverages from packaging or storage containers. The objective of this study was to independently assesswhether BPA contamination of water was occurring from different types of reusable drinking bottlesmarketed as alternatives to BPA-containing polycarbonate plastics. Using a sensitive and quantitative BPA-specific competitive enzyme-linked immunosorbent assaywe evaluated whether BPA migrated into water stored inpolycarbonateor copolyester plastic bottles, and different lined or unlined metallic reusable water bottles. At room temperature the concentration of BPA migrating from polycarbonate bottles ranged from 0.2–0.3 mg/L. Under identical conditions BPA migration from aluminium bottles lined with epoxy-based resins was variable depending on manufacturer ranging from 0.08 to 1.9 mg/L.Boiling water significantly increased migration of BPA from the epoxy lined bottles. No detectable BPA contamination was observed in water stored in bottles made from Tritan™ copolyester plastic, uncoated stainless steel, or aluminium lined with EcoCare™. The results from this study demonstrate that when used according to manufactures’ recommendations reusable water bottles constructed from “BPA-free” alternative materials are suitable for consumption of beverages free of BPA contamination. PMID:21741673
Chen, Hsiao Wei; Murugadoss, Arumugam; Hor, T S Andy; Sakurai, Hidehiro
2010-12-29
Fe(3)O(4):PVP/Au nanocomposite synthesized via a two-step procedure was tested as a quasi-homogenous alcohol oxidation catalyst. It was found that the nanocomposite was able to carry out aerobic oxidation of alcohols in water at room temperature. Studies show rapid magnetic recoverability and reusability characteristics.
NASA Astrophysics Data System (ADS)
Shao, Gaofeng; Lu, Yucao; Wu, Xiaodong; Wu, Jun; Cui, Sheng; Jiao, Jian; Shen, Xiaodong
2017-09-01
To develop a flexible reusable surface insulation for thermal protection system, MoSi2-aluminoborosilicate glass hybrid coatings have been prepared on Al2O3 fiber reinforced Al2O3-SiO2 aerogel composite by slurry dipping and rapid sintering method. The effect of MoSi2 content on radiative property and thermal shock behavior was investigated. The total emissivity values of all the coatings exceeded 0.85 in the wavelength of 0.8-2.5 μm. The M10 and M50 coatings were up to 0.9, which was due to the highest amorphous glass content of the M10 coating and the largest surface roughness of the M50 coating. The M30 coated composite showed the best thermal shock resistance with only 0.023% weight loss after 20 thermal shock cycles between 1473 K and room temperature, which was attributed to the similar thermal expansion coefficients between the coating and the substrate and the appropriate viscosity of aluminoborosilicate glass at 1473 K. The cracks resulted from CTE mismatch stress with different sizes formed and grew on the surface of M10, M40 and M50 coated samples, leading to the failure of the composites.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kulkarni, Suresh D., E-mail: suresh.dk@manipal.edu; Kumbar, Sagar; Menon, Samvit G.
Highlights: • Phase pure, magnetic ZnFe{sub 2}O{sub 4}@ZnO nanoparticles synthesized with excellent yield. • ZnFe{sub 2}O{sub 4}@ZnO displayed higher UV photocatalytic efficiency than ZnO nanoparticles. • First report on visible light photodegradation of methyl orange by ZnFe{sub 2}O{sub 4}@ZnO. • Excellent reusability of ZnFe{sub 2}O{sub 4}@ZnO nanoparticles observed for azo dye removal. - Abstract: Visible light photodegradation of aqueous methyl orange using magnetically separable core–shell ZnFe{sub 2}O{sub 4}@ZnO nanoparticles is reported. A combination of low temperature (190 °C) microwave synthesis and hydrothermal method were used to prepare phase pure material with excellent yield (95%). The magnetic separability, surface area ofmore » 41 m{sup 2}/g and visible light absorption make ZnFe{sub 2}O{sub 4}@ZnO nanoparticles a good solar photocatalyst. ZnFe{sub 2}O{sub 4}@ZnO displayed greater UV photocatalytic efficiency than ZnO owing to the generation of large number of electron-hole pairs. Visible light photodegradation of MO using ZnFe{sub 2}O{sub 4}@ZnO nanoparticles is reported for the first time. Higher first order rate constants under both UV and visible light for core-shell nanoparticles suggested their superiority over its individual oxides. The ZnFe{sub 2}O{sub 4}@ZnO showed excellent reusability with high photocatalytic efficiencies suggesting its suitability for solar photocatalytic applications.« less
NASA Technical Reports Server (NTRS)
Davis, Randall C. (Inventor); Taylor, Allan H. (Inventor); Jackson, L. Robert (Inventor); Mcauliffe, Patrick S. (Inventor)
1988-01-01
This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system.
NASA Technical Reports Server (NTRS)
Manderscheid, J. M.; Kaufman, A.
1985-01-01
Turbine blades for reusable space propulsion systems are subject to severe thermomechanical loading cycles that result in large inelastic strains and very short lives. These components require the use of anisotropic high-temperature alloys to meet the safety and durability requirements of such systems. To assess the effects on blade life of material anisotropy, cyclic structural analyses are being performed for the first stage high-pressure fuel turbopump blade of the space shuttle main engine. The blade alloy is directionally solidified MAR-M 246 alloy. The analyses are based on a typical test stand engine cycle. Stress-strain histories at the airfoil critical location are computed using the MARC nonlinear finite-element computer code. The MARC solutions are compared to cyclic response predictions from a simplified structural analysis procedure developed at the NASA Lewis Research Center.
Study of structural active cooling and heat sink systems for space shuttle
NASA Technical Reports Server (NTRS)
1972-01-01
This technology investigation was conducted to evaluate the feasibility of a number of thermal protection systems (TPS) concepts which are alternate candidates to the space shuttle baseline TPS. Four independent tasks were performed. Task 1 consisted of an in-depth evaluation of active structural cooling of the space shuttle orbiter. In Task 2, heat sink concepts for the booster were studied to identify and postulate solutions for design problems unique to heat sink TPS. Task 3 consisted of a feasibility demonstration test of a phase change material (PCM) incorporated into a reusable surface insulation (RSI) thermal protection system for the shuttle orbiter. In Task 4 the feasibility of heat pipes for stagnation region cooling was studied for the booster and the orbiter. Designs were developed for the orbiter leading edge and used in trade studies of leading edge concepts. At the time this program was initiated, a 2-stage fully reusable shuttle system was envisioned; therefore, the majority of the tasks were focused on the fully reusable system environments. Subsequently, a number of alternate shuttle system approaches, with potential for reduced shuttle system development funding requirements, were proposed. Where practicable, appropriate shifts in emphasis and task scoping were made to reflect these changes.
Development of Metallic Thermal Protection Systems for the Reusable Launch Vehicle
NASA Technical Reports Server (NTRS)
Blosser, Max L.
1996-01-01
A reusable Thermal Protection System (TPS) that is not only lightweight, but durable, operable and cost effective is one of the technologies required by the Reusable Launch Vehicle (RLV) to achieve the goal of drastically reducing the cost of delivering payload to orbit. Metallic TPS is one of the systems being developed to meet this challenge. Current efforts involve improving the superalloy honeycomb TPS concept, which consists of a foil-gage metallic box encapsulating a low density fibrous insulation, and evaluating it for RLV requirements. The superalloy honeycomb TPS concept is mechanically attached to the vehicle structure. Improvements include more efficient internal insulation, a simpler, lighter weight configuration, and a quick-release fastener system for easier installation and removal. Evaluation includes thermal and structural analysis, fabrication and testing of both coupons and TPS panels under conditions simulating RLV environments. Coupons of metallic honeycomb sandwich, representative of the outer TPS surface, were subjected to low speed impact, hypervelocity impact, and rain erosion testing as well as subsequent arcjet exposure. Arrays of TPS panels have been subjected to radiant heating in a thermal/vacuum facility, aerodynamic heating in an arcjet facility and acoustic loading.
Parameter Validation for Evaluation of Spaceflight Hardware Reusability
NASA Technical Reports Server (NTRS)
Childress-Thompson, Rhonda; Dale, Thomas L.; Farrington, Phillip
2017-01-01
Within recent years, there has been an influx of companies around the world pursuing reusable systems for space flight. Much like NASA, many of these new entrants are learning that reusable systems are complex and difficult to acheive. For instance, in its first attempts to retrieve spaceflight hardware for future reuse, SpaceX unsuccessfully tried to land on a barge at sea, resulting in a crash-landing. As this new generation of launch developers continues to develop concepts for reusable systems, having a systematic approach for determining the most effective systems for reuse is paramount. Three factors that influence the effective implementation of reusability are cost, operability and reliability. Therefore, a method that integrates these factors into the decision-making process must be utilized to adequately determine whether hardware used in space flight should be reused or discarded. Previous research has identified seven features that contribute to the successful implementation of reusability for space flight applications, defined reusability for space flight applications, highlighted the importance of reusability, and presented areas that hinder successful implementation of reusability. The next step is to ensure that the list of reusability parameters previously identified is comprehensive, and any duplication is either removed or consolidated. The characteristics to judge the seven features as good indicators for successful reuse are identified and then assessed using multiattribute decision making. Next, discriminators in the form of metrics or descriptors are assigned to each parameter. This paper explains the approach used to evaluate these parameters, define the Measures of Effectiveness (MOE) for reusability, and quantify these parameters. Using the MOEs, each parameter is assessed for its contribution to the reusability of the hardware. Potential data sources needed to validate the approach will be identified.
Effects of Thermal Exposure on Properties of Al-Li Alloys
NASA Technical Reports Server (NTRS)
Shah, Sandeep; Wells, Douglas; Stanton, William; Lawless, Kirby; Russell, Carolyn; Wagner, John; Domack, Marcia; Babel, Henry; Farahmand, Bahram; Schwab, David;
2002-01-01
Aluminum-Lithium (Al-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional Al alloys. For example, the application of Al-Li alloy 2195 to the space shuffle external cryogenic fuel tank resulted in weight savings of over 7,000 lb, enabling successful deployment of International Space Station components. The composition and heat treatment of 2195 were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time-dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. Literature surveys have indicated that there is limited thermal exposure data on Al-Li alloys. The effort reported here was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of Al-Li alloys C458, L277, and 2195 in plate gages. Tensile, fracture toughness, and corrosion resistance were evaluated for both parent metal and friction stir welds (FSW) after exposure to temperatures as high as 300 F for up to 1000 hrs. Microstructural changes were evaluated with thermal exposure in order to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Friction stir welds of all alloys showed a drop in elongation with increased length of exposure. Understanding the effect of thermal exposure on the properties and microstructure of Al-Li alloys must be considered in defining service limiting temperatures and exposure times for a reusable cryotank structure.
14 CFR 437.23 - Program description.
Code of Federal Regulations, 2013 CFR
2013-01-01
... photographs of the reusable suborbital rocket; and (2) Gross liftoff weight and thrust profile of the reusable suborbital rocket. (b) An applicant must describe— (1) All reusable suborbital rocket systems, including any..., software and computing systems, avionics, and guidance systems used in the reusable suborbital rocket; (2...
14 CFR 437.23 - Program description.
Code of Federal Regulations, 2011 CFR
2011-01-01
... photographs of the reusable suborbital rocket; and (2) Gross liftoff weight and thrust profile of the reusable suborbital rocket. (b) An applicant must describe— (1) All reusable suborbital rocket systems, including any..., software and computing systems, avionics, and guidance systems used in the reusable suborbital rocket; (2...
14 CFR 437.23 - Program description.
Code of Federal Regulations, 2014 CFR
2014-01-01
... photographs of the reusable suborbital rocket; and (2) Gross liftoff weight and thrust profile of the reusable suborbital rocket. (b) An applicant must describe— (1) All reusable suborbital rocket systems, including any..., software and computing systems, avionics, and guidance systems used in the reusable suborbital rocket; (2...
14 CFR 437.23 - Program description.
Code of Federal Regulations, 2010 CFR
2010-01-01
... photographs of the reusable suborbital rocket; and (2) Gross liftoff weight and thrust profile of the reusable suborbital rocket. (b) An applicant must describe— (1) All reusable suborbital rocket systems, including any..., software and computing systems, avionics, and guidance systems used in the reusable suborbital rocket; (2...
14 CFR 437.23 - Program description.
Code of Federal Regulations, 2012 CFR
2012-01-01
... photographs of the reusable suborbital rocket; and (2) Gross liftoff weight and thrust profile of the reusable suborbital rocket. (b) An applicant must describe— (1) All reusable suborbital rocket systems, including any..., software and computing systems, avionics, and guidance systems used in the reusable suborbital rocket; (2...
2003-10-01
In the Orbiter Processing Facility, Harrell Watts (left), with United Space Alliance, removes a tile from the thermal barrier around the umbilical areas, the external tank attach points, on the underside of Atlantis. The umbilical areas are closed off after ET separation by a door, seen here. The exposed area of each closed door is covered with reusable surface insulation.
A semiconductor titania (TiO2) surface was modified by surfactant adsorption to make it more hydrophobic and to increase the adsorption of hydrophobic organic compounds (HOCs) and their photodegradation rates under UV irradiation. Photocatalytic experiments using Ti...
NASA Technical Reports Server (NTRS)
1991-01-01
Project UM-Haul is the preliminary design of a reusable lunar transportation vehicle that travels between a lunar parking orbit and the lunar surface. This vehicle is an indispensible link in the overall task of establishing a lunar base as defined by the NASA Space Exploration Initiative. The response to this need consists of two independent vehicles: a lander and an unloader. The system can navigate and unload itself with a minimum amount of human intervention. The design addresses structural analysis, propulsion, power, controls, communications, payload handling and orbital operations. The Lander has the capacity to decend from low lunar orbit (LLO) to the lunar surface carrying a 7000 kg payload, plus the unloader, plus propellant for ascent to LLO. The Lander employs the Unloader by way of a motorized ramp. The Unloader is a terrain vehicle capable of carrying cargoes of 8,500 kg mass and employs a lift system to lower payloads to the ground. The system can perform ten missions before requiring major servicing.
NASA Astrophysics Data System (ADS)
Li, Hui; Li, Yuzhuo; Li, Zhiping; Peng, Xiyang; Li, Yanan; Li, Gui; Tan, Xianzhou; Chen, Gongxi
2012-03-01
Preparation of berberine hydrochloride (B-Cl) imprinted polymers (MIPs) based on surface imprinting technique with silica gel as sacrificial support material was performed successfully by using B-Cl as template, methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) as functional monomer and cross-linker, respectively. The prepared polymers were characterized by Fourier transmission infrared spectrometry (FTIR) and scanning electron microscopy (SEM). Adsorption behavior of the MIPs for the template and its structural analogues was investigated. Sites distribution on the surface of MIPs was explored by using different isotherm adsorption models and thermodynamic parameters for the adsorption of B-Cl on the MIPs determined. Sample application and reusability for the MIPs was also evaluated. Results indicated the strong adsorption and high selectivity of the MIPs for B-Cl. Saturated adsorption capacity reached 27.2 μmol g-1 and the selectivity coefficient of the MIPs for B-Cl relative to jatrorrhizine hydrochloride (J-Cl) and palmatine palmatus hydrochloride (P-Cl) are 3.70 and 6.03, respectively. In addition, the MIPs were shown with good reusability and selectively retention ability in sample application.
Reusable software parts and the semi-abstract data type
NASA Technical Reports Server (NTRS)
Cohen, Sanford G.
1986-01-01
The development of reuable software parts has been an area of intense discussion within the software community for many years. An approach is described for developing reusable parts for the applications of missile guidance, navigation and control which meet the following criteria: (1) Reusable; (2) Tailorable; (3) Efficient; (4) Simple to use; and (5) Protected against misuse. Validating the feasibility of developing reusable parts which possess these characteristics is the basis of the Common Ada Missile Packages Program (CAMP). Under CAMP, over 200 reusable software parts were developed, including part for navigation, Kalman filter, signal processing and autopilot. Six different methods are presented for designing reusable software parts.
Mechanical attachments for flexible blanket TPS
NASA Astrophysics Data System (ADS)
Newquist, Charles W.; Anderson, David M.; Shorey, Mark W.; Preedy, Kristina S.
1998-01-01
The operability of a flexible blanket thermal protection system for a reusable launch vehicle can be improved by using mechanical attachments instead of adhesive bonding to fasten the thermal protection system to the vehicle structure. Mechanical attachments offer specific benefits by (1) permitting the use of composite or metal structures at or near their maximum temperatures (above the adhesive temperature limit) thereby reducing the required TPS thickness and weight, (2) significantly reducing both the frequency and time for TPS replacement, (3) providing easy access to hatches and the underlying structure, and (4) allowing the attachment of flexible TPS to integral cryotanks, where the TPS/structure interface temperature may fall below the lower temperature of the silicone adhesives.
Characterisation of electrical resistance for CMC Materials up to 1200 °C
NASA Astrophysics Data System (ADS)
Stäbler, T.; Böhrk, H.; Voggenreiter, H.
2017-12-01
Damage to thermal protection systems (TPS) during atmospheric re-entry is a severe safety issue, especially when considering re-usability of space transportation systems. There is a need for structural health monitoring systems and non-destructive inspection methods. However, damages are hard to detect. When ceramic matrix composites, in this case carbon fibre reinforced silicon carbide (C/C-SiC), are used as a TPS, the electrical properties of the present semiconductor material can be used for health monitoring, since the resistivity changes with damage, strain and temperature. In this work the electrical resistivity as a function of the material temperature is analysed eliminating effects of thermal electricity and the thermal coefficient of electrical resistance is determined. A sensor network is applied for locally and time resolved monitoring of the 300 mm x 120 mm x 3 mm panel shaped samples. Since the material is used for atmospheric re-entry it needs to be characterised for a wide range of temperatures, in this case as high as 1200 °C. Therefore, experiments in an inductively heated test bench were conducted. Firstly, a reference sample was used with thermocouples for characterising the temperature distribution across the sample surface. Secondly, electrical resistance under heat load was measured, time and spatially resolved. Results will be shown and discussed in terms of resistance dependence on temperature, thermal coefficient of electrical resistance, thermal electricity and electrical path orientation including an analysis on effective conducting cross section. Conversely, the thermal coefficient can also be used to determine the material temperature as a function of electrical resistance.
NASA Astrophysics Data System (ADS)
Zhao, Linyan; Li, Lian; Wang, Yixi; Wu, Jianning; Meng, Guihua; Liu, Zhiyong; Guo, Xuhong
2018-01-01
Oily wastewater caused by industrial production and crude oil leakage has attracted worldwide attention. Here, a thermo- and pH dual-responsive biodegradable cellulose-based aerogel for oil-water separation was designed and prepared via surface-initiated atom transfer radical polymerization (ATRP) of non-fluorine-containing 2-dimethylaminoethyl methacrylate (DMAEMA). The cellulose-based aerogel exhibit switchable superhydrophilicity with a water contact angle (WCA) of 0° and hydrophobicity (WCA 130°) by modulating pH or temperature. The functionalized cellulose-based aerogels could be used to absorb the water under 60 °C (pH 7.0) and pH is 1.0 (T = 25 °C), while absorb oil underwater when the temperature is above 60 °C (pH 7.0) or pH is 13.0 (T = 25 °C). So this adsorbent were suitable for the separation of water-rich or oil-rich oil/water mixtures, and it could adsorb oil over ten times its own weight, and had a good reusability. What's more, the cellulose-based aerogel is green, low cost, and environmental friendly, which makes it a promising candidate to be used for oil-water separation.
14 CFR 431.79 - Reusable launch vehicle mission reporting requirements.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Reusable launch vehicle mission reporting requirements. 431.79 Section 431.79 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...-Licensing Requirements-Reusable Launch Vehicle Mission License Terms and Conditions § 431.79 Reusable launch...
14 CFR 431.79 - Reusable launch vehicle mission reporting requirements.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Reusable launch vehicle mission reporting requirements. 431.79 Section 431.79 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...-Licensing Requirements-Reusable Launch Vehicle Mission License Terms and Conditions § 431.79 Reusable launch...
14 CFR 431.79 - Reusable launch vehicle mission reporting requirements.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Reusable launch vehicle mission reporting requirements. 431.79 Section 431.79 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...-Licensing Requirements-Reusable Launch Vehicle Mission License Terms and Conditions § 431.79 Reusable launch...
14 CFR 431.79 - Reusable launch vehicle mission reporting requirements.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Reusable launch vehicle mission reporting requirements. 431.79 Section 431.79 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...-Licensing Requirements-Reusable Launch Vehicle Mission License Terms and Conditions § 431.79 Reusable launch...
14 CFR 437.67 - Tracking a reusable suborbital rocket.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Tracking a reusable suborbital rocket. 437... a reusable suborbital rocket. A permittee must— (a) During permitted flight, measure in real time the position and velocity of its reusable suborbital rocket; and (b) Provide position and velocity...
14 CFR 437.67 - Tracking a reusable suborbital rocket.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Tracking a reusable suborbital rocket. 437... a reusable suborbital rocket. A permittee must— (a) During permitted flight, measure in real time the position and velocity of its reusable suborbital rocket; and (b) Provide position and velocity...
14 CFR 437.67 - Tracking a reusable suborbital rocket.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Tracking a reusable suborbital rocket. 437... a reusable suborbital rocket. A permittee must— (a) During permitted flight, measure in real time the position and velocity of its reusable suborbital rocket; and (b) Provide position and velocity...
14 CFR 437.67 - Tracking a reusable suborbital rocket.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Tracking a reusable suborbital rocket. 437... a reusable suborbital rocket. A permittee must— (a) During permitted flight, measure in real time the position and velocity of its reusable suborbital rocket; and (b) Provide position and velocity...
14 CFR 437.67 - Tracking a reusable suborbital rocket.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Tracking a reusable suborbital rocket. 437... a reusable suborbital rocket. A permittee must— (a) During permitted flight, measure in real time the position and velocity of its reusable suborbital rocket; and (b) Provide position and velocity...
Habiba, Umma; Joo, Tan Chin; Siddique, Tawsif A; Salleh, Areisman; Ang, Bee Chin; Afifi, Amalina M
2017-11-01
The chitosan/polyvinyl alcohol/TiO 2 composite was synthesized. Two different degrees of deacetylation of chitosan were prepared by hydrolysis to compare the effectiveness of them. The composite was analyzed via field emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction, thermal gravimetric analysis, weight loss test and adsorption study. The FTIR and XRD results proved the interaction among chitosan, PVA and TiO 2 without any chemical reaction. It was found that, chitosan with higher degree of deacetylation has better stability. Furthermore, it also showed that higher DD of chitosan required less time to reach equilibrium for methyl orange. The adsorption followed the pseudo-second-order kinetic model. The Langmuir and Freundlich isotherm models were fitted well for isotherm study. Adsorption capacity was higher for the composite containing chitosan with higher DD. The dye removal rate was independent of the dye's initial concentration. The adsorption capacity was increased with temperature and it was found from reusability test that the composite containing chitosan with higher DD is more reusable. It was notable that adsorption capacity was even after 15 runs. Therefore, chitosan/PVA/TiO 2 composite can be a very useful material for dye removal. Copyright © 2017 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zadehahmadi, Farnaz; Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir; Moghadam, Majid, E-mail: moghadamm@sci.ui.ac.ir
2014-10-15
In the present work, chloromethylated MIL-101(Cr) modified with imidazole, Im-MIL-101, was applied as a support for immobilizing of tetraphenylporphyrinatomangenese(III) chloride. The imidazole-bound MIL-101, Im-MIL-101, not only used as support for immobilization of manganese porphyrin but also applied as a heterogeneous axial base. The Mn(TPP)Cl@Im-MIL-101 catalyst was characterized by UV–vis, FT-IR, X-ray diffraction (XRD), N{sub 2} adsorption, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), elemental analysis and inductively coupled plasma (ICP) methods. The catalytic activity of this new catalytic system was investigated in the alkene epoxidation and alkane hydroxylation using NaIO{sub 4} as an oxidant in CH{sub 3}CN/H{submore » 2}O at room temperature. This heterogeneous catalyst is highly efficient, stable and reusable in the oxidation of hydrocarbons. - Highlights: • MIL-101 was modified by covalent post synthetic modification. • Mn(TPP)Cl was anchored to imidazole modified MIL-101 by covalent attachment. • A heterogeneous catalyst was prepared. • The catalyst was used for epoxidation of alkenes and hydroxylation of alkanes. • The catalyst was reusable.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Dongyan, E-mail: xdy0156@sina.com; Ma, Hong; Cheng, Fei
2014-05-01
Graphical abstract: - Highlights: • SAPO-34 supported zirconium sulfate solid acid catalyst was prepared. • Esterification of acetic acid with ethanol can be catalyzed by ZS/SAPO-34. • The hydration of ZS is vital to the acidic property and catalytic performance. • The ZS/SAPO-34 catalyst treated at 200 °C shows good reusability. - Abstract: Zirconium sulfate (ZS) was supported on SAPO-34 molecular sieve by using an incipient wetness impregnation method with zirconium sulfate as the precursor. The as-prepared catalysts were used as solid acid catalyst for esterification reaction of acetic acid with ethanol. The influence of calcination temperature on the acidicmore » property, catalytic activity, and reusability of ZS/SAPO-34 catalysts were mainly investigated. FT-IR, SEM, EDS and TG analysis have been carried out to demonstrate the characteristics of ZS/SAPO-34 catalysts. It was found that the 30 wt%ZS/SAPO-34 catalysts display the property of superacid irrespective of calcination temperature. The ZS/SAPO-34 catalyst treated at 200 °C can enhance the interaction between the supported ZS and SAPO-34 and keep the catalyst remaining substantially active after several reaction cycles. However, further increasing calcination temperature will cause the transfer of ZS from hydrate to anhydrous phase, and thus the decrease of activity.« less
Cooling Duct Analysis for Transpiration/Film Cooled Liquid Propellant Rocket Engines
NASA Technical Reports Server (NTRS)
Micklow, Gerald J.
1996-01-01
The development of a low cost space transportation system requires that the propulsion system be reusable, have long life, with good performance and use low cost propellants. Improved performance can be achieved by operating the engine at higher pressure and temperature levels than previous designs. Increasing the chamber pressure and temperature, however, will increase wall heating rates. This necessitates the need for active cooling methods such as film cooling or transpiration cooling. But active cooling can reduce the net thrust of the engine and add considerably to the design complexity. Recently, a metal drawing process has been patented where it is possible to fabricate plates with very small holes with high uniformity with a closely specified porosity. Such a metal plate could be used for an inexpensive transpiration/film cooled liner to meet the demands of advanced reusable rocket engines, if coolant mass flow rates could be controlled to satisfy wall cooling requirements and performance. The present study investigates the possibility of controlling the coolant mass flow rate through the porous material by simple non-active fluid dynamic means. The coolant will be supplied to the porous material by series of constant geometry slots machined on the exterior of the engine.
High-Temperature Polymer Composites Tested for Hypersonic Rocket Combustor Backup Structure
NASA Technical Reports Server (NTRS)
Sutter, James K.; Shin, E. Eugene; Thesken, John C.; Fink, Jeffrey E.
2005-01-01
Significant component weight reductions are required to achieve the aggressive thrust-toweight goals for the Rocket Based Combined Cycle (RBCC) third-generation, reusable liquid propellant rocket engine, which is one possible engine for a future single-stage-toorbit vehicle. A collaboration between the NASA Glenn Research Center and Boeing Rocketdyne was formed under the Higher Operating Temperature Propulsion Components (HOTPC) program and, currently, the Ultra-Efficient Engine Technology (UEET) Project to develop carbon-fiber-reinforced high-temperature polymer matrix composites (HTPMCs). This program focused primarily on the combustor backup structure to replace all metallic support components with a much lighter polymer-matrixcomposite- (PMC-) titanium honeycomb sandwich structure.
A new support material for IgG adsorption: Syntrichia papillosissima (Copp.) Loeske.
Demir, Mithat Evrim; Aktaş Uygun, Deniz; Erdağ, Adnan; Akgöl, Sinan
2017-11-01
In this presented work, Syntrichia papillosissima (Copp.) Loeske (S. papillosissima) was used as a natural phytosorbent for IgG purification. These moss species were collected for the natural habitat and prepared for IgG adsorption studies by cleaning, drying, and grinding to uniform size. Syntrichia papillosissima samples were characterized by using FTIR and SEM studies. Functional groups of S. papillosissima were identified by FTIR analysis, while surface characteristics were determined by SEM studies. A batch system was used for the adsorption of IgG onto S. papillosissima surface and physical conditions of the IgG adsorption medium were investigated by modifying the pH, IgG concentration and temperature. Maximum IgG adsorption onto S. papillosissima was found to be 68.01 mg/g moss by using pH 5.0 buffer system. Adsorption kinetic isotherms were also studied and it was found that, Langmuir adsorption model was appropriate for this adsorption study. Reusability profile of S. papillosissima was also investigated and IgG adsorption capacity did not decrease significantly after 5 reuse studies. Results indicated that S. papillosissima species have the capacity to be used as biosorbent for IgG purification, with its low cost, natural and biodegradable structure.
Turbojet-type engines for the airbreathing propulsion of reusable winged launchers
NASA Astrophysics Data System (ADS)
Duparcq, J. L.; Hermant, E.; Scherrer, D.
Combined propulsion systems for hypersonic application have become new challenges for industrial and research organizations. In France, SNECMA and SEP, which have just joined together for a common effort on hypersonics within Hyperspace, and ONERA have been involved, under CNES (French space agency) contracts, in the assessment of new propulsion concepts for reusable winged launchers (SSTO or TSTO). As potential solutions for the airbreathing propulsion, some turbojet-type engines are presented: —the twin spool turbojet or turbofan with reheat —the turbojet with reheat —the twin-duct turbojet ramjet —the precooled turbojet with reheat. All these engines have been sized for a flight Mach number under seven with a cryogenic fuel (liquid hydrogen). Mainly due to total temperature and pressure encountered along the trajectory, the systems will have to withstand severe physical constraints. Coupled with performance and size requirements, like specific thrust and maximum air capture area, these operating conditions have been taken into account in order to select each engine cycle and technical arrangement. Performance and mass criteria make it possible to compare these systems and to emphasize their distinctive features among the propulsion concepts envisioned for the future reusable winged launchers (including airbreathing combined engines under study in France). The first step of the final selection, leading to the best adaptation between the engine and the vehicle, will then be tackled. This will be particularly enhanced by the analysis of potential advantages or technical difficulties, like thrust-to-weight ratio or needs of variable geometry and heat exchangers. The twin-duct turbojet ramjet, for example, is probably one of the best candidates for the first stages of propulsion of a reusable winged launcher.
Chaiyut, Nattawut; Worawanitchaphong, Phatsakon
2013-01-01
The waste shell was utilized as a bioresource of calcium oxide (CaO) in catalyzing a transesterification to produce biodiesel (methyl ester). The economic and environmen-friendly catalysts were prepared by a calcination method at 700–1,000°C for 4 h. The heterogeneous catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller (BET) method. The effects of reaction variables such as reaction time, reaction temperature, methanol/oil molar ratio, and catalyst loading on the yield of biodiesel were investigated. Reusability of waste shell catalyst was also examined. The results indicated that the CaO catalysts derived from waste shell showed good reusability and had high potential to be used as biodiesel production catalysts in transesterification of palm oil with methanol. PMID:24453854
1998-01-01
Engineers at Marshall Space Flight Center (MSFC) in Huntsville, Alabama, are working with industry partners to develop a new generation of more cost-efficient space vehicles. Lightweight fuel tanks and components under development will be the critical elements in tomorrow's reusable launch vehicles and will tremendously curb the costs of getting to space. In this photo, Tom DeLay, a materials processes engineer for MSFC, uses a new graphite epoxy technology to create lightweight cryogenic fuel lines for futuristic reusable launch vehicles. He is wrapping a water-soluble mandrel, or mold, with a graphite fabric coated with an epoxy resin. Once wrapped, the pipe will be vacuum-bagged and autoclave-cured. The disposable mold will be removed to reveal a thin-walled fuel line. In addition to being much lighter and stronger than metal, this material won't expand or contract as much in the extreme temperatures encountered by launch vehicles.
Liu, Wanting; Su, Qing; Ju, Pengyao; Guo, Bixuan; Zhou, Hui; Li, Guanghua; Wu, Qiaolin
2017-02-22
A hydrazone-based covalent organic framework (COF) was synthesized by condensation of 2,5-dimethoxyterephthalohydrazide with 1,3,5-triformylbenzene under solvothermal conditions. The COF material exhibits excellent porosity with a BET surface area of up to 1501 m 2 g -1 , high crystallinity, and good thermal and chemical stability. Moreover, it showed efficient photocatalytic activity towards cross-dehydrogenative coupling (CDC) reactions between tetrahydroisoquinolines and nucleophiles such as nitromethane, acetone, and phenylethyl ketone. The metal-free catalytic system also offers attractive advantages including simplicity of operation, wide substrate adaptability, ambient reaction conditions, and robust recycling capability of the catalyst, thus providing a promising platform for highly efficient and reusable photocatalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Microwave Extraction of Lunar Water for Rocket Fuel
NASA Technical Reports Server (NTRS)
Ethridge, Edwin C.; Donahue, Benjamin; Kaukler, William
2008-01-01
Nearly 50% of the lunar surface is oxygen, present as oxides in silicate rocks and soil. Methods for reduction of these oxides could liberate the oxygen. Remote sensing has provided evidence of significant quantities of hydrogen possibly indicating hundreds of millions of metric tons, MT, of water at the lunar poles. If the presence of lunar water is verified, water is likely to be the first in situ resource exploited for human exploration and for LOX-H2 rocket fuel. In-Situ lunar resources offer unique advantages for space operations. Each unit of product produced on the lunar surface represents 6 units that need not to be launched into LEO. Previous studies have indicated the economic advantage of LOX for space tugs from LEO to GEO. Use of lunar derived LOX in a reusable lunar lander would greatly reduce the LEO mass required for a given payload to the moon. And Lunar LOX transported to L2 has unique advantages for a Mars mission. Several methods exist for extraction of oxygen from the soil. But, extraction of lunar water has several significant advantages. Microwave heating of lunar permafrost has additional important advantages for water extraction. Microwaves penetrate and heat from within not just at the surface and excavation is not required. Proof of concept experiments using a moon in a bottle concept have demonstrated that microwave processing of cryogenic lunar permafrost simulant in a vacuum rapidly and efficiently extracts water by sublimation. A prototype lunar water extraction rover was built and tested for heating of simulant. Microwave power was very efficiently delivered into a simulated lunar soil. Microwave dielectric properties (complex electric permittivity and magnetic permeability) of lunar regolith simulant, JSC-1A, were measured down to cryogenic temperatures and above room temperature. The microwave penetration has been correlated with the measured dielectric properties. Since the microwave penetration depth is a function of temperature and frequency, an extraction system can be designed for water removal from different depths.
Novel dry cryotherapy system for cooling the equine digit
Stefanovski, Darko; Lenfest, Margret; Chatterjee, Sraboni; Orsini, James
2018-01-01
Objectives Digital cryotherapy is commonly used for laminitis prophylaxis and treatment. Currently validated methods for distal limb cryotherapy involve wet application or compression technology. There is a need for a practical, affordable, dry cryotherapy method that effectively cools the digit. The objective of this study was to evaluate the hoof wall surface temperatures (HWSTs) achieved with a novel dry cryotherapy technology. Design Repeated-measures in vivo experimental study. Setting Experimental intervention at a single site. Participants 6 systemically healthy horses (3 mares, 3 geldings). Interventions Cryotherapy was applied to six horses for eight hours with a commercially available rubber and rubber and welded fabricice boot, which extended proximally to include the foot and pastern. Reusable malleable cold therapy packs were secured against the foot and pastern with the three built-in hook-and-loop fastener panels. Primary and secondary outcome measures HWST and pastern surface temperature of the cryotherapy-treated limb, HWST of the control limb and ambient temperature were recorded every five minutes throughout the study period. Results Results were analysed with mixed-effects multivariable regression analysis. The HWST (median 11.1°C, interquartile range 8.6°C–14.7°C) in the cryotherapy-treated limb was significantly decreased compared with the control limb (median 29.7°C, interquartile range 28.9°C–30.4°C) (P≤0.001). Cryotherapy limb HWST reached a minimum of 6.75°C (median) with an interquartile range of 4.1°C–9.3°C. Minimum HWST was achieved 68 minutes after cryotherapy pack application. Conclusions Dry application of cryotherapy significantly reduced HWST and reached minimums below the therapeutic target of 10°C. This cryotherapy method might offer an effective alternative for digital cooling. PMID:29344364
Reusable biocompatible interface for immobilization of materials on a solid support
Salamon, Zdzislaw; Schmidt, Richard A.; Tollin, Gordon; Macleod, H. Angus
1996-01-01
A method for the formation of a biocompatible film composed of a self-assembled bilayer membrane deposited on a planar surface. This bilayer membrane is capable of immobilizing materials to be analyzed in an environment very similar to their native state. Materials so immobilized may be subject to any of a number of analytical techniques.
Contracting/expanding self-sealing cryogenic tube seals
NASA Technical Reports Server (NTRS)
Jia, Lin X. (Inventor)
1997-01-01
Contracting/expanding self-sealing cryogenic tube seals are disclosed which use the different properties of thermal contraction and expansion of selected dissimilar materials in accord with certain design criteria to yield self-tightening seals via sloped-surface sealing. The seals of the subject invention are reusable, simple to assemble, and adaptable to a wide variety of cryogenic applications.
NASA Technical Reports Server (NTRS)
Ormiston, T.; Tanzilli, R. A.
1973-01-01
The development of reusable surface insulation materials that are thermal shock resistant and highly refractory is discussed. A stabilized, high-cristobalite, aluminum orthophosphate fiber was developed and found to possess the desired qualities. The application of such a material to heat shielding for space shuttles is examined.
Contracting/expanding self-sealing cryogenic tube seals
NASA Technical Reports Server (NTRS)
Jia, Lin X. (Inventor)
1997-01-01
Contracting/expanding self-sealing cryogenic tube seals are disclosed which use the different properties of thermal contraction and expansion of selected dissimilar materials in accord with certain design criteria to yield self-tightening seals via sloped-surface sealing. The seals of the subject invention are reusable, simple to assemble, adaptable to a wide variety of cryogenic applications.
NASA Technical Reports Server (NTRS)
Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.
2012-01-01
The nuclear thermal rocket (NTR) is a proven, high thrust propulsion technology that has twice the specific impulse (I(sub sp) approx.900 s) of today's best chemical rockets. During the Rover and NERVA (Nuclear Engine for Rocket Vehicle Applications) programs, twenty rocket reactors were designed, built and ground tested. These tests demonstrated: (1) a wide range of thrust; (2) high temperature carbide-based nuclear fuel; (3) sustained engine operation; (4) accumulated lifetime; and (5) restart capability - everything required for affordable human missions beyond LEO. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, the NTR was selected as the preferred propulsion option because of its proven technology, higher performance, lower IMLEO, versatile vehicle design, and growth potential. Furthermore, the NTR requires no large technology scale-ups since the smallest engine tested during the Rover program - the 25 klb(sub f) "Pewee" engine is sufficient for human Mars missions when used in a clustered engine configuration. The "Copernicus" crewed Mars transfer vehicle developed for DRA 5.0 was an expendable design sized for fast-conjunction, long surface stay Mars missions. It therefore has significant propellant capacity allowing a reusable "1-year" round trip human mission to a large, high energy near Earth asteroid (NEA) like Apophis in 2028. Using a "split mission" approach, Copernicus and its two key elements - a common propulsion stage and integrated "saddle truss" and LH2 drop tank assembly - configured as an Earth Return Vehicle / propellant tanker, can also support a short round trip (approx.18 month) / short orbital stay (60 days) Mars reconnaissance mission in the early 2030's before a landing is attempted. The same short stay orbital mission can be performed with an "all-up" vehicle by adding an "in-line" LH2 tank to Copernicus to supply the extra propellant needed for this higher energy, opposition-class mission. To transition to a reusable Mars architecture, Copernicus' saddle truss / drop tank assembly is replaced by an in-line tank and "star truss" assembly with paired modular drop tanks to further increase the vehicle's propellant capacity. Shorter "1-way" transit time fast-conjunction Mars missions are another possibility using this vehicle configuration but, as with reusability, increased launch mass is required. "Scaled down" versions of Copernicus (sized to a SLS lift capability of approx.70 t - 100 t) can be developed initially allowing reusable lunar cargo delivery and crewed landing missions, easy NEA missions (e.g., 2000 SG344 also in 2028) or an expendable mission to Apophis. Mission scenario descriptions, key vehicle features and operational characteristics are provided along with a brief discussion of NASA's current activities and its "pre-decisional" plans for future NTR development.
Lim, Chul-Hyun; Kim, Won Chul; Kim, Jin Soo; Cho, Yu Kyung; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Kyu Yong; Chung, In-Sik
2012-01-01
Background/Aims It is believed that disposable biopsy forceps are more costly than reusable biopsy forceps. In this study, we evaluated performance and cost of disposable forceps versus reusable forceps in esophagogastroduodenoscopic biopsy. Methods Between October 2009 and July 2010, we enrolled 200 patients undergoing esophagogastroduodenoscopic biopsy at Seoul St. Mary's Hospital. Biopsies were performed with 100 disposable or 5 reusable forceps by random assignment. Seventy-five additional patients were studied to estimate durability of reusable forceps. The assisting nurses estimated the performance of the forceps. The evaluation of costs included purchase prices and reprocessing costs. The adequacy of the sample was estimated according to the diameter of the obtained tissue. Results Performance of disposable forceps was estimated as excellent in 97.0%, good in 2.0% and adequate in 1.0%. Reusable forceps were estimated as excellent in 36.0%, good in 36.0%, adequate in 25.1% and inadequate in 2.9%. The performance of reusable forceps declined with the number of uses. The reprocessing cost of reusable forceps for one biopsy session was calculated as ₩8,021. The adequacy of the sample was excellent for both forceps. Conclusions Disposable forceps showed excellent performance. Considering the reprocessing costs of reusable forceps, usage of disposable forceps with a low price should be considered. PMID:22741133
Knowledge-based reusable software synthesis system
NASA Technical Reports Server (NTRS)
Donaldson, Cammie
1989-01-01
The Eli system, a knowledge-based reusable software synthesis system, is being developed for NASA Langley under a Phase 2 SBIR contract. Named after Eli Whitney, the inventor of interchangeable parts, Eli assists engineers of large-scale software systems in reusing components while they are composing their software specifications or designs. Eli will identify reuse potential, search for components, select component variants, and synthesize components into the developer's specifications. The Eli project began as a Phase 1 SBIR to define a reusable software synthesis methodology that integrates reusabilityinto the top-down development process and to develop an approach for an expert system to promote and accomplish reuse. The objectives of the Eli Phase 2 work are to integrate advanced technologies to automate the development of reusable components within the context of large system developments, to integrate with user development methodologies without significant changes in method or learning of special languages, and to make reuse the easiest operation to perform. Eli will try to address a number of reuse problems including developing software with reusable components, managing reusable components, identifying reusable components, and transitioning reuse technology. Eli is both a library facility for classifying, storing, and retrieving reusable components and a design environment that emphasizes, encourages, and supports reuse.
Adler, S; Scherrer, M; Rückauer, K D; Daschner, F D
2005-02-01
The economic and environmental effects were compared between disposable and reusable instruments used for laparoscopic cholecystectomy. Special consideration was given to the processing of reusable instruments in the Miele G 7736 CD MCU washer disinfector and the resultant cost of sterilization. The instruments frequently used in their disposable form were identified with the help of surgeons. Thus, of all the instruments used for laparoscopic cholecystectomy, the disposable and reusable versions of trocars, scissors, and Veress cannula were compared. For the case examined in this study, the performance of laparoscopic cholecystectomy with disposable instruments was 19 times more expensive that for reusable instruments. The higher cost of using disposable instruments is primarily attributable to the purchase price of the instruments. The processing of reusable instruments has little significance in terms of cost, whereas the cost for disposing of disposable instruments is the least significant factor. The number of laparoscopic cholecystectomies performed per year does not substantially influence cost. In the authors' opinion, assessment of the environmental consequences shows that reusable instruments are environmentally advantageous. Considering the upward pressure of costs in hospitals, disposable instruments should be used for laparoscopic cholecystectomy only if they offer clear advantages over reusable instruments.
Characterization of Thin Film Polymers Through Dynamic Mechanical Analysis and Permeation
NASA Technical Reports Server (NTRS)
Herring, Helen
2003-01-01
Thin polymer films are being considered, as candidate materials to augment the permeation resistance of cryogenic hydrogen fuel tanks such as would be required for future reusable launch vehicles. To evaluate performance of candidate films after environmental exposure, an experimental study was performed to measure the thermal/mechanical and permeation performance of six, commercial-grade materials. Dynamic storage modulus, as measured by Dynamic Mechanical Analysis, was found over a range of temperatures. Permeability, as measured by helium gas diffusion, was found at room temperature. Test data was correlated with respect to film type and pre-test exposure to moisture, elevated temperature, and cryogenic temperature. Results indicated that the six films were comparable in performance and their resistance to environmental degradation.
Ishihara, Shinsuke; Labuta, Jan; Nakanishi, Takashi; Tanaka, Takeshi; Kataura, Hiromichi
2017-10-27
We report amperometric detection of formaldehyde (HCHO) using hydroxylamine hydrochloride and single-walled carbon nanotubes (SWCNTs). Hydroxylamine hydrochloride reacts with HCHO to emit HCl vapor, which injects a hole carrier into semiconducting SWCNTs. The increase of conductivity in SWCNTs is easily monitored using an ohmmeter. The debundling of SWCNTs with a metallo-supramolecular polymer (MSP) increased the active surface area in the SWCNTs network, leading to excellent sensitivity to HCHO with a limit of detection (LoD) of 0.016 ppm. The response of sensor is reversible, and the sensor is reusable. The selectivity to HCHO is 10 5 -10 6 times higher than interferences with other volatiles such as water, methanol, and toluene. Moreover, false-positive responses caused by a significant variation of humidity and/or temperature are successfully discriminated from true-positive responses by using two sensors, one with and the other without hydroxylamine hydrochloride, in a referenced system.
Ma, Xiaobin; Wang, Danli; Yin, Michelle; Lucente, Juliet; Wang, Wenjun; Ding, Tian; Ye, Xingqian; Liu, Donghong
2017-05-01
In this study, ultrasound was applied both during and after the immobilization process and characteristics of different immobilized pectinase samples were studied. When introduced during the immobilization process, ultrasound at an intensity of 9WmL -1 for 20min increased the immobilization yield 92.28% more than the control. When introduced to the already immobilized pectinase, ultrasound at an intensity of 4.5WmL -1 for 10min increased the pectinase activity by 30.05%. Results of scanning electron microscope demonstrated that ultrasound increased surface area and loosened structures of immobilized enzymes. Higher V max and lower K m were obtained after ultrasound treatment, indicating the increased catalytic efficiency and enhanced affinity of immobilized pectinase. Furthermore, the optimum temperature and pH for free and immobilized pectinase remained unchanged at 50°C and pH 4. Thermostability, reaction stability and reusability of two ultrasound-treated pectinase enzymes slightly decreased due to structural matrix changes. Copyright © 2016 Elsevier B.V. All rights reserved.
Fabrication, characterization and application of pectin degrading Fe3O4-SiO2 nanobiocatalyst.
Seenuvasan, Muthulingam; Malar, Carlin Geor; Preethi, Sridhar; Balaji, Nagarajan; Iyyappan, Jeyaraj; Kumar, Madhava Anil; Kumar, Kannaiyan Sathish
2013-05-01
The covalent binding of pectinase onto amino functionalized silica-coated magnetic nanoparticles (CSMNPs) through glutaraldehyde activation was investigated for nanobiocatalyst fabrication. The average particle size and morphology of the nanoparticles were characterized using transmission electron microscopy (TEM). The statistical analysis for TEM image suggests that the coating and binding process did not cause any significant change in size of MNPs. The morphological and phase change of the magnetic nanoparticles (MNPs) after various coatings and immobilization were characterized by X-ray diffraction (XRD) studies. The various surface modifications and pectinase binding onto nanoparticles were confirmed by Fourier transform infrared (FT-IR) spectroscopy. The maximum activity of immobilized pectinase was obtained at its weight ratio of 19.0×10(-3) mg bound pectinase/mg CSMNPs. The pH, temperature, reusability, storage ability and kinetic studies were established to monitor their improved stability and activity of the fabricated nanobiocatalyst. Furthermore, the application was extended in the clarification of Malus domestica juice. Copyright © 2013 Elsevier B.V. All rights reserved.
Tamura, Masazumi; Ishikawa, Susumu; Betchaku, Mii; Nakagawa, Yoshinao; Tomishige, Keiichi
2018-06-20
CeO2-supported Ru (Ru/CeO2) worked as an effective and reusable heterogeneous catalyst for the selective dissociation of the C-N bond in amides, particularly primary amides, with H2 in water solvent at low reaction temperature of 333 K, and high yields of the corresponding alcohols were obtained from primary amides.
Optimization of covalent immobilization of pectinase on sodium alginate support.
Li, Tuoping; Wang, Na; Li, Suhong; Zhao, Qiancheng; Guo, Mei; Zhang, Cheyun
2007-09-01
Pectinase was immobilized on a sodium alginate support using glutaraldehyde and retained 66% activity. The optimal pH for activity shifted from 3.0 to 3.5 after immobilization; however, the optimum temperature remained unchanged at 40 degrees C. The immobilized enzyme also had a higher thermal stability and reusability than the free enzyme, and retained 80% of initial activity after 11 batch reactions.
Methodology for Assessing Reusability of Spaceflight Hardware
NASA Technical Reports Server (NTRS)
Childress-Thompson, Rhonda; Thomas, L. Dale; Farrington, Phillip
2017-01-01
In 2011 the Space Shuttle, the only Reusable Launch Vehicle (RLV) in the world, returned to earth for the final time. Upon retirement of the Space Shuttle, the United States (U.S.) no longer possessed a reusable vehicle or the capability to send American astronauts to space. With the National Aeronautics and Space Administration (NASA) out of the RLV business and now only pursuing Expendable Launch Vehicles (ELV), not only did companies within the U.S. start to actively pursue the development of either RLVs or reusable components, but entities around the world began to venture into the reusable market. For example, SpaceX and Blue Origin are developing reusable vehicles and engines. The Indian Space Research Organization is developing a reusable space plane and Airbus is exploring the possibility of reusing its first stage engines and avionics housed in the flyback propulsion unit referred to as the Advanced Expendable Launcher with Innovative engine Economy (Adeline). Even United Launch Alliance (ULA) has announced plans for eventually replacing the Atlas and Delta expendable rockets with a family of RLVs called Vulcan. Reuse can be categorized as either fully reusable, the situation in which the entire vehicle is recovered, or partially reusable such as the National Space Transportation System (NSTS) where only the Space Shuttle, Space Shuttle Main Engines (SSME), and Solid Rocket Boosters (SRB) are reused. With this influx of renewed interest in reusability for space applications, it is imperative that a systematic approach be developed for assessing the reusability of spaceflight hardware. The partially reusable NSTS offered many opportunities to glean lessons learned; however, when it came to efficient operability for reuse the Space Shuttle and its associated hardware fell short primarily because of its two to four-month turnaround time. Although there have been several attempts at designing RLVs in the past with the X-33, Venture Star and Delta Clipper Experimental (DC-X), reusability within the spaceflight arena is still in its infancy. With unlimited resources (namely, time and money), almost any launch vehicle and its associated hardware can be made reusable. However, an endless supply of funds for space exploration is not the case in today's economy for neither government agencies nor their commercial counterparts. Therefore, any organization wanting to be a leader in space exploration and remain competitive in this unforgiving space faring industry must confront shrinking budgets with more cost conscious and efficient designs. Therefore, standards for developing reusable spaceflight hardware need to be established. By having standards available to existing and emerging companies, some of the potential roadblocks and limitations that plagued previous attempts at reuse may be minimized or completely avoided.
Reusable rocket engine optical condition monitoring
NASA Technical Reports Server (NTRS)
Wyett, L.; Maram, J.; Barkhoudarian, S.; Reinert, J.
1987-01-01
Plume emission spectrometry and optical leak detection are described as two new applications of optical techniques to reusable rocket engine condition monitoring. Plume spectrometry has been used with laboratory flames and reusable rocket engines to characterize both the nominal combustion spectra and anomalous spectra of contaminants burning in these plumes. Holographic interferometry has been used to identify leaks and quantify leak rates from reusable rocket engine joints and welds.
Toward Reusable Graphics Components in Ada
1993-03-01
Then alternatives for obtaining well- engineered reusable software components were examined. Finally, the alternatives were analyzed, and the most...reusable software components. Chapter 4 describes detailed design and implementation strategies in building a well- engineered reusable set of components in...study. 2.2 The Object-Oriented Paradigm 2.2.1 The Need for Object-Oriented Techniques. Among software engineers the software crisis is a well known
Space Transportation Infrastructure Supported By Propellant Depots
NASA Technical Reports Server (NTRS)
Smitherman, David; Woodcock, Gordon
2012-01-01
A space transportation infrastructure is described that utilizes propellant depot servicing platforms to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicle (ELV) systems such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support a new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid and Mars Missions. New vehicle design concepts are presented that can be launched on current 5 meter diameter ELV systems. These new reusable vehicle concepts include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot, L1 Depot and missions beyond L1; a new reusable lunar lander for crew transportation between the L1 Depot and the lunar surface; and Mars orbital Depot are based on International Space Station (ISS) heritage hardware. Data provided includes the number of launches required for each mission utilizing current ELV systems (Delta IV Heavy or equivalent) and the approximate vehicle masses and propellant requirements. Also included is a discussion on affordability with ideas on technologies that could reduce the number of launches required and thoughts on how this infrastructure include competitive bidding for ELV flights and propellant services, developments of new reusable in-space vehicles and development of a multiuse infrastructure that can support many government and commercial missions simultaneously.
Cost analysis of single-use (Ambu® aScope™) and reusable bronchoscopes in the ICU.
Perbet, S; Blanquet, M; Mourgues, C; Delmas, J; Bertran, S; Longère, B; Boïko-Alaux, V; Chennell, P; Bazin, J-E; Constantin, J-M
2017-12-01
Flexible optical bronchoscopes are essential for management of airways in ICU, but the conventional reusable flexible scopes have three major drawbacks: high cost of repairs, need for decontamination, and possible transmission of infectious agents. The main objective of this study was to measure the cost of bronchoalveolar lavage (BAL) and percutaneous tracheostomy (PT) using reusable bronchoscopes and single-use bronchoscopes in an ICU of an university hospital. The secondary objective was to compare the satisfaction of healthcare professionals with reusable and single-use bronchoscopes. The study was performed between August 2009 and July 2014 in a 16-bed ICU. All BAL and PT procedures were performed by experienced healthcare professionals. Cost analysis was performed considering ICU and hospital organization. Healthcare professional satisfaction with single-use and reusable scopes was determined based on eight factors. Sensitivity analysis was performed by applying discount rates (0, 3, and 5%) and by simulation of six situations based on different assumptions. At a discount rate of 3%, the costs per BAL for the two reusable scopes were 188.86€ (scope 1) and 185.94€ (scope 2), and the costs per PT for the reusable scope 1 and scope 2 and single-use scopes were 1613.84€, 410.24€, and 204.49€, respectively. The cost per procedure for the reusable scopes depended on the number of procedures performed, maintenance costs, and decontamination costs. Healthcare professionals were more satisfied with the third-generation single-use Ambu ® aScope™. The cost per procedure for the single-use scope was not superior to that for reusable scopes. The choice of single-use or reusable bronchoscopes in an ICU should consider the frequency of procedures and the number of bronchoscopes needed.
2003-10-01
KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Ryan Levann, with United Space Alliance, checks data on the tile removed from the thermal barrier around the umbilical areas, the external tank attach points, on the underside of Atlantis. The umbilical areas are closed off after ET separation by a door, seen here. The exposed area of each closed door is covered with reusable surface insulation.
Reusable biocompatible interface for immobilization of materials on a solid support
Salamon, Z.; Schmidt, R.A.; Tollin, G.; Macleod, H.A.
1996-05-28
A method is presented for the formation of a biocompatible film composed of a self-assembled bilayer membrane deposited on a planar surface. This bilayer membrane is capable of immobilizing materials to be analyzed in an environment very similar to their native state. Materials so immobilized may be subject to any of a number of analytical techniques. 3 figs.
Supercavitating Projectile Tracking System and Method
2009-12-30
Distribution is unlimited 20100104106 Attorney Docket No. 96681 SUPERCAVITATING PROJECTILE TRACKING SYSTEM AND METHOD STATEMENT OF GOVERNMENT...underwater track or path 14 of a supercavitating vehicle under surface 16 of a body of water. In this embodiment, passive acoustic or pressure...transducers 12 are utilized to measure a pressure field produced by a moving supercavitating vehicle. The present invention provides a low-cost, reusable
NASA Technical Reports Server (NTRS)
Shtessel, Yuri B.
2002-01-01
In this report we present a time-varying sliding mode control (TV-SMC) technique for reusable launch vehicle (RLV) attitude control in ascent and entry flight phases. In ascent flight the guidance commands Euler roll, pitch and yaw angles, and in entry flight it commands the aerodynamic angles of bank, attack and sideslip. The controller employs a body rate inner loop and the attitude outer loop, which are separated in time-scale by the singular perturbation principle. The novelty of the TVSMC is that both the sliding surface and the boundary layer dynamics can be varied in real time using the PD-eigenvalue assignment technique. This salient feature is used to cope with control command saturation and integrator windup in the presence of severe disturbance or control effector failure, which enhances the robustness and fault tolerance of the controller. The TV-SMC is developed and tuned up for the X-33 sub-orbital technology demonstration vehicle in launch and re-entry modes. A variety of nominal, dispersion and failure scenarios have tested via high fidelity 6DOF simulations using MAVERIC/SLIM simulation software.
NASA Technical Reports Server (NTRS)
Ojalvo, I. U.; Austin, F.; Levy, A.
1974-01-01
An efficient iterative procedure is described for the vibration and modal stress analysis of reusable surface insulation (RSI) of multi-tiled space shuttle panels. The method, which is quite general, is rapidly convergent and highly useful for this application. A user-oriented computer program based upon this procedure and titled RESIST (REusable Surface Insulation Stresses) has been prepared for the analysis of compact, widely spaced, stringer-stiffened panels. RESIST, which uses finite element methods, obtains three dimensional tile stresses in the isolator, arrestor (if any) and RSI materials. Two dimensional stresses are obtained in the tile coating and the stringer-stiffened primary structure plate. A special feature of the program is that all the usual detailed finite element grid data is generated internally from a minimum of input data. The program can accommodate tile idealizations with up to 850 nodes (2550 degrees-of-freedom) and primary structure idealizations with a maximum of 10,000 degrees-of-freedom. The primary structure vibration capability is achieved through the development of a new rapid eigenvalue program named ALARM (Automatic LArge Reduction of Matrices to tridiagonal form).
Hu, Zunfang; Xu, Longqian; Wen, Xianghua
2013-01-01
Immobilization of enzymes on mesoporous silicas (MS) allows for good reusability. MS with two-dimensional hexagonal pores in diameter up to 14.13 nm were synthesized using Pluronic P123 as template and 1,3,5-triisopropylbenzene as a swelling agent in acetate buffer. The surface of MS was modified by the silanization reagents 3-aminopropyltriethoxysilane. Lignin peroxidase (LiP) was successfully immobilized on the modified MS through covalent binding method by four agents: glutaraldehyde, 1,4-phenylene diisothiocyanate, cyanotic chloride and water-soluble carbodiimide. Results showed that cyanotic chloride provided the best performance for LIP immobilization. The loaded protein concentration was 12.15 mg/g and the immobilized LiP activity was 812.9 U/L. Immobilized LiP had better pH stability. Acid Orange II was used to examine the reusability of immobilized LiP, showing more than 50% of the dye was decolorized at the fifth cycle.
Lunar lander conceptual design
NASA Technical Reports Server (NTRS)
Stecklein, J. M.; Petro, A. J.; Stump, W. R.; Adorjan, A. S.; Chambers, T. V.; Donofrio, M.; Hirasaki, J. K.; Morris, O. G.; Nudd, G.; Rawlings, R. P.
1992-01-01
This paper is a first look at the problems of building a lunar lander to support a small lunar surface base. A series of trade studies was performed to define the lander. The initial trades concerned choosing number of stages, payload mass, parking orbit altitude, and propellant type. Other important trades and issues included plane change capability, propellant loading and maintenance location, and reusability considerations. Given a rough baseline, the systems were then reviewed. A conceptual design was then produced. The process was carried through only one iteration. Many more iterations are needed. A transportation system using reusable, aerobraked orbital transfer vehicles (OTV's) is assumed. These OTV's are assumed to be based and maintained at a low Earth orbit (LEO) space station, optimized for transportation functions. Single- and two-stage OTV stacks are considered. The OTV's make the translunar injection (TLI), lunar orbit insertion (LOI), and trans-Earth injection (TEI) burns, as well as midcourse and perigee raise maneuvers.
2002-08-01
A scaled-down 24-inch version of the Space Shuttle's Reusable Solid Rocket Motor was successfully fired for 21 seconds at a Marshall Space Flight Center (MSFC) Test Stand. The motor was tested to ensure a replacement material called Lycocel would meet the criteria set by the Shuttle's Solid Motor Project Office. The current material is a heat-resistant, rayon-based, carbon-cloth phenolic used as an insulating material for the motor's nozzle. Lycocel, a brand name for Tencel, is a cousin to rayon and is an exceptionally strong fiber made of wood pulp produced by a special "solvent-spirning" process using a nontoxic solvent. It will also be impregnated with a phenolic resin. This new material is expected to perform better under the high temperatures experienced during launch. The next step will be to test the material on a 48-inch solid rocket motor. The test, which replicates launch conditions, is part of Shuttle's ongoing verification of components, materials, and manufacturing processes required by MSFC, which oversees the Reusable Solid Rocket Motor project. Manufactured by the ATK Thiokol Propulsion Division in Promontory, California, the Reusable Solid Rocket Motor measures 126 feet (38.4 meters) long and 12 feet (3.6 meters) in diameter. It is the largest solid rocket motor ever flown and the first designed for reuse. During its two-minute burn at liftoff, each motor generates an average thrust of 2.6 million pounds (1.2 million kilograms).
Resin Transfer Moldable Polyimides Developed for High-Temperature Applications
NASA Technical Reports Server (NTRS)
Meador, Mary Ann
2000-01-01
High-temperature polyimides, such as PMR 15 (which was developed at the NASA Glenn Research Center at Lewis Field), are becoming an increasingly important class of materials for a variety of aerospace applications, such as aircraft engine components and propulsion and airframe components for reusable launch vehicles (RLV s). Because of their high specific strength and low density, use of these materials in place of more traditional aerospace materials, such as titanium, can significantly reduce component and vehicle weight, leading to reductions in fuel consumption (and pollutants), increases in payload and passenger capacity, and improvements in vehicle performance.
Thin-film sensors for reusable space propulsion systems
NASA Technical Reports Server (NTRS)
Hepp, Aloysius F.; Kim, Walter S.
1989-01-01
Thin-film thermocouples (TFTCs) were developed for aircraft gas turbine engines and are in use for temperature measurement on turbine blades up to 1800 F. Established aircraft engine gas turbine technology is currently being adapted to turbine engine blade materials and the environment encountered in the Space Shuttle Main Engine (SSME)-severe thermal shock from cryogenic fuel to combustion temperatures. Initial results with coupons of MAR M-246 (+Hf) and PWA 1480 were followed by fabrication of TFTC on SSME turbine blades. Current efforts are focused on preparation for testing in the Turbine Blade Tester at NASA Marshall Space Flight Center.
Safe Life Propulsion Design Technologies (3rd Generation Propulsion Research and Technology)
NASA Technical Reports Server (NTRS)
Ellis, Rod
2000-01-01
The tasks outlined in this viewgraph presentation on safe life propulsion design technologies (third generation propulsion research and technology) include the following: (1) Ceramic matrix composite (CMC) life prediction methods; (2) Life prediction methods for ultra high temperature polymer matrix composites for reusable launch vehicle (RLV) airframe and engine application; (3) Enabling design and life prediction technology for cost effective large-scale utilization of MMCs and innovative metallic material concepts; (4) Probabilistic analysis methods for brittle materials and structures; (5) Damage assessment in CMC propulsion components using nondestructive characterization techniques; and (6) High temperature structural seals for RLV applications.
Chang, Yuanyuan; Zhuo, Ying; Chai, Yaqin; Yuan, Ruo
2017-08-15
In this work, an elegantly designed host-guest recognition-assisted electrochemical release was established and applied in a reusable electrochemical biosensor for the detection of microRNA-182-5p (miRNA-182-5p), a prostate cancer biomarker in prostate cancer, based on the DNA cross configuration-fueled target cycling and strand displacement reaction (SDR) amplification. With such a design, the single target miRNA input could be converted to large numbers of single-stranded DNA (S1-Trp and S2-Trp) output, which could be trapped by cucurbit[8]uril methyl viologen (CB-8-MV 2+ ) based on the host-guest recognition, significantly enhancing the sensitivity for miRNA detection. Moreover, the nucleic acids products obtained from the process of cycling amplification could be utilized sufficiently, avoiding the waste and saving the experiment cost. Impressively, by resetting a settled voltage, the proposed biosensor could release S1-Trp and S2-Trp from the electrode surface, attributing that the guest ion methyl viologen (MV 2+ ) was reduced to MV +· under this settled voltage and formed a more-stable CB-8-MV +· -MV +· complex. Once O 2 was introduced in this system, MV +· could be oxidized to MV 2+ , generating the complex of CB-8-MV 2+ for capturing S1-Trp and S2-Trp again in only 5 min. As a result, the simple and fast regeneration of biosensor for target detection was realized on the base of electrochemical redox-driven assembly and release, overcoming the challenges of time-consuming, burdensome operations and expensive experimental cost in traditional reusable biosensors and updating the construction method for a reusable bisensor. Furthermore, the biosensor could be reused for more than 10 times with a regeneration rate of 93.20%-102.24%. After all, the conception of this work provides a novel thought for the construction of effective reusable biosensor to detect miRNA and other biomarkers and has great potential application in the area requiring the release of nucleic acids or proteins.
Validation of a new device to quantify groundwater-surface water exchange
NASA Astrophysics Data System (ADS)
Cremeans, Mackenzie M.; Devlin, J. F.
2017-11-01
Distributions of flow across the groundwater-surface water interface should be expected to be as complex as the geologic deposits associated with stream or lake beds and their underlying aquifers. In these environments, the conventional Darcy-based method of characterizing flow systems (near streams) has significant limitations, including reliance on parameters with high uncertainties (e.g., hydraulic conductivity), the common use of drilled wells in the case of streambank investigations, and potentially lengthy measurement times for aquifer characterization and water level measurements. Less logistically demanding tools for quantifying exchanges across streambeds have been developed and include drive-point mini-piezometers, seepage meters, and temperature profiling tools. This project adds to that toolbox by introducing the Streambed Point Velocity Probe (SBPVP), a reusable tool designed to quantify groundwater-surface water interactions (GWSWI) at the interface with high density sampling, which can effectively, rapidly, and accurately complement conventional methods. The SBPVP is a direct push device that measures in situ water velocities at the GWSWI with a small-scale tracer test on the probe surface. Tracer tests do not rely on hydraulic conductivity or gradient information, nor do they require long equilibration times. Laboratory testing indicated that the SBPVP has an average accuracy of ± 3% and an average precision of ± 2%. Preliminary field testing, conducted in the Grindsted Å in Jutland, Denmark, yielded promising agreement between groundwater fluxes determined by conventional methods and those estimated from the SBPVP tests executed at similar scales. These results suggest the SBPVP is a viable tool to quantify groundwater-surface water interactions in high definition in sandy streambeds.
Replication of patterned thin-film structures for use in plasmonics and metamaterials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Norris, David J; Han, Sang Eon; Bhan, Aditya
The present invention provides templating methods for replicating patterned metal films from a template substrate such as for use in plasmonic devices and metamaterials. Advantageously, the template substrate is reusable and can provide plural copies of the structure of the template substrate. Because high-quality substrates that are inherently smooth and flat are available, patterned metal films in accordance with the present invention can advantageously provide surfaces that replicate the surface characteristics of the template substrate both in the patterned regions and in the unpatterned regions.
NASA Technical Reports Server (NTRS)
Wang, Q.; Ewing, M. E.; Mathias, E. C.; Heman, J.; Smith, C.; McCool, Alex (Technical Monitor)
2001-01-01
Methodologies have been developed for modeling both gas dynamics and heat transfer inside the carbon fiber rope (CFR) for applications in the space shuttle reusable solid rocket motor joints. Specifically, the CFR is modeled using an equivalent rectangular duct with a cross-section area, friction factor and heat transfer coefficient such that this duct has the same amount of mass flow rate, pressure drop, and heat transfer rate as the CFR. An equation for the friction factor is derived based on the Darcy-Forschheimer law and the heat transfer coefficient is obtained from pipe flow correlations. The pressure, temperature and velocity of the gas inside the CFR are calculated using the one-dimensional Navier-Stokes equations. Various subscale tests, both cold flow and hot flow, have been carried out to validate and refine this CFR model. In particular, the following three types of testing were used: (1) cold flow in a RSRM nozzle-to-case joint geometry, (2) cold flow in a RSRM nozzle joint No. 2 geometry, and (3) hot flow in a RSRM nozzle joint environment simulator. The predicted pressure and temperature history are compared with experimental measurements. The effects of various input parameters for the model are discussed in detail.
Mechanically expandable annular seal
Gilmore, R.F.
1983-07-19
A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.
Cartwright, J A; Hill, T L; Smith, S; Shaw, D
2016-07-01
Sample quality of gastrointestinal endoscopic biopsies is of paramount importance for accurate histological diagnosis. Many veterinary practices use reusable forceps as a result of perceived decreased cost. With reusable forceps, it remains unknown whether sample quality declines with repeated use and becomes inferior to single-use forceps and is therefore more or less cost effective than single-use forceps. The study hypothesis was that reusable forceps sample quality would deteriorate after repeated use as compared to single-use forceps. Sixty-five dogs undergoing gastrointestinal endoscopy for diagnostic investigations at the Hospital for Small Animals, Edinburgh University. A prospective, pathologist-blinded study comparing single-use and reusable alligator standard cup biopsy forceps (Olympus 2.0 mm 1550 mm) with 5 randomized reusable forceps. Sample quality (stomach, duodenum, ileum, and colon) was assessed by a single pathologist using the WSAVA guidelines. There was no difference in the adequacy, depth, villi number, or crush artifact in the 4 intestinal areas between forceps type with at least 10, and up to 15, repeated uses of the reusable forceps. This study demonstrates that reusable cup biopsy forceps provide equivalent biopsy quality after repeated uses to single-use forceps and are cost effective at 10-case use. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
KASCADE2017 - An experimental study of thermal circulations and turbulence in complex terrain
NASA Astrophysics Data System (ADS)
Pardyjak, Eric; Dupuy, Florian; Durand, Pierre; Gunawardena, Nipun; Hedde, Thierry; Rubin, Pierre
2017-04-01
The KASCADE (KAtabatic winds and Stability over CAdarache for Dispersion of Effluents) 2017 experiment was conducted during winter 2017 with the overarching objective of improving prediction of dispersion in complex terrain during stable atmospheric conditions. The experiment builds on knowledge gathered during the first KASCADE experiment conducted in 2013 (Duine et al., 2016), which provided detailed observations of the vertical structure of the atmosphere during stable conditions. In spite of this improved understanding, considerable uncertainty remains regarding the near-surface horizontal spatial and temporal variability of winds and thermodynamic variables. For this specific campaign, the general aim has been to use a large number of sensors to improve our understanding of the spatial and temporal development, evolution and breakdown of topographically driven flows. KASCADE 2017 consisted of continuous observations, which were broadened during ten Intensive Observation Periods (IOPs) conducted in the Cadarache Valley located in south-eastern France from January through March 2017. The Cadarache Valley is a relatively small valley (6 km x 1 km) with modest slopes and elevation differences between the valley floor and nearby peaks ( 100 m). The valley is embedded in the larger Durance Valley drainage system leading to multi-scale flow interactions. During the winter, winds are light and stably stratified leading to thermal circulations as well as complex near-surface atmospheric layering that impacts dispersion of contaminants. The continuously operating instrumentation deployed included mean near surface (2-m) and sub-surface observations from 12 low-cost Local Energy-budget Measurement Stations (LEMS), four sonic anemometer masts, one full surface flux station, sodar measurements at two locations, wind and temperature measurements from a tall 110 m tower, and two additional met stations. During IOPs, additional deployments included a low-cost tethered balloon temperature profiler as well as regular (every 3 hours) radiosoundings (including recoverable and reusable probes). The presentation will provide an overview of the experiment and several interesting "first-results." First results will include data characterizing highly-regular nocturnal horizontal wind meandering and associated turbulence statistics. In addition, we present data on the development of strong near surface stable stratification hours before sunset.
Effect of Environment on the Stress- Rupture Behavior of a C/SiC Composite Studied
NASA Technical Reports Server (NTRS)
Verrilli, Michael J.; Kiser, J. Douglas; Opila, Elizabeth J.; Calomino, Anthony M.
2002-01-01
Advanced reusable launch vehicles will likely incorporate fiber-reinforced ceramic matrix composites (CMC's) in critical propulsion and airframe components. The use of CMC's is highly desirable to save weight, improve reuse capability, and increase performance. One of the candidate CMC materials is carbon-fiber-reinforced silicon carbide (C/SiC). In potential propulsion applications, such as turbopump rotors and nozzle exit ramps, C/SiC components will be subjected to a service cycle that includes mechanical loading under complex, high-pressure environments containing hydrogen, oxygen, and steam. Degradation of both the C fibers and the SiC matrix are possible in these environments. The objective of this effort was to evaluate the mechanical behavior of C/SiC in various environments relevant to reusable launch vehicle applications. Stress-rupture testing was conducted at the NASA Glenn Research Center on C/SiC specimens in air and steam-containing environments. Also, the oxidation kinetics of the carbon fibers that reinforce the composite were monitored by thermogravimetric analysis in the same environments and temperatures used for the stress-rupture tests of the C/SiC composite specimens. The stress-rupture lives obtained for C/SiC tested in air and in steam/argon mixtures are shown in the following bar chart. As is typical for most materials, lives obtained at the lower temperature (600 C) are longer than for the higher temperature (1200 C). The effect of environment was most pronounced at the lower temperature, where the average test duration in steam at 600 C was at least 30 times longer than the lives obtained in air. The 1200 C data revealed little difference between the lives of specimens tested in air and steam at atmospheric pressure.
Improved coating for silica fiber based ceramic Reusable Surface Insulation (CRSI)
NASA Technical Reports Server (NTRS)
Ormiston, T. J.
1974-01-01
A series of coatings was developed for the space shuttle type silica fiber insulation system and characterized for optical and physical properties. Reentry simulation tests were run using a radiant panel and also using a hypersonic plasma arc. The coatings produced had improved physical and optical properties as well as greater reuse capability over the GE version of the JSC-0042 coating.
Thermal stress analysis of reusable surface insulation for shuttle
NASA Technical Reports Server (NTRS)
Ojalvo, I. U.; Levy, A.; Austin, F.
1974-01-01
An iterative procedure for accurately determining tile stresses associated with static mechanical and thermally induced internal loads is presented. The necessary conditions for convergence of the method are derived. An user-oriented computer program based upon the present method of analysis was developed. The program is capable of analyzing multi-tiled panels and determining the associated stresses. Typical numerical results from this computer program are presented.
Structural Integrity and Durability of Reusable Space Propulsion Systems
NASA Technical Reports Server (NTRS)
1985-01-01
The space shuttle main engine (SSME), a reusable space propulsion system, is discussed. The advances in high pressure oxygen hydrogen rocket technology are reported to establish the basic technology and to develop new analytical tools for the evaluation in reusable rocket systems.
Air Force Reusable Booster System A Quick-look, Design Focused Modeling and Cost Analysis Study
NASA Technical Reports Server (NTRS)
Zapata, Edgar
2011-01-01
Presents work supporting the Air force Reusable Booster System (RBS) - A Cost Study with Goals as follows: Support US launch systems decision makers, esp. in regards to the research, technology and demonstration investments required for reusable systems to succeed. Encourage operable directions in Reusable Booster / Launch Vehicle Systems technology choices, system design and product and process developments. Perform a quick-look cost study, while developing a cost model for more refined future analysis.
A Framework for Assessing the Reusability of Hardware (Reusable Rocket Engines)
NASA Technical Reports Server (NTRS)
Childress-Thompson, Rhonda; Farrington, Philip; Thomas, Dale
2016-01-01
Within the space flight community, reusability has taken center stage as the new buzzword. In order for reusable hardware to be competitive with its expendable counterpart, two major elements must be closely scrutinized. First, recovery and refurbishment costs must be lower than the development and acquisition costs. Additionally, the reliability for reused hardware must remain the same (or nearly the same) as "first use" hardware. Therefore, it is imperative that a systematic approach be established to enhance the development of reusable systems. However, before the decision can be made on whether it is more beneficial to reuse hardware or to replace it, the parameters that are needed to deem hardware worthy of reuse must be identified. For reusable hardware to be successful, the factors that must be considered are reliability (integrity, life, number of uses), operability (maintenance, accessibility), and cost (procurement, retrieval, refurbishment). These three factors are essential to the successful implementation of reusability while enabling the ability to meet performance goals. Past and present strategies and attempts at reuse within the space industry will be examined to identify important attributes of reusability that can be used to evaluate hardware when contemplating reusable versus expendable options. This paper will examine why reuse must be stated as an initial requirement rather than included as an afterthought in the final design. Late in the process, changes in the overall objective/purpose of components typically have adverse effects that potentially negate the benefits. A methodology for assessing the viability of reusing hardware will be presented by using the Space Shuttle Main Engine (SSME) to validate the approach. Because reliability, operability, and costs are key drivers in making this critical decision, they will be used to assess requirements for reuse as applied to components of the SSME.
Long, Yang; Wang, Yi; Zhang, Dun; Ju, Peng; Sun, Yan
2016-11-01
Novel BiOI hierarchical nanostructures with porous architecture was prepared at room temperature by an economical, facile and rapid route. The coupling adsorption and degradation efficiency of rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) could achieve 98.7%, 43.2%, 76.9% within 180min in the presence of BiOI, respectively. BiOI hierarchical nanostructures also exhibit excellent effective biocidal performances, and the disinfection rate of the typical biofouling bacteria Bacillus sp. and Pseudoalteromonas sp. could reach 99.9% and 99.8% in 60min, respectively. The circulate photocatalytic degradation of RhB experiment verified the good stability and reusability of BiOI hierarchical nanostructures. Based on active specie trapping experiments, the superoxide radicals (O2(-)) and holes (h(+)) were proved to be the main reactive species in the BiOI-based system. The obviously enhanced coupling adsorption and photocatalytic degradation performance of BiOI hierarchical nanostructures could be mainly attributed to the large surface area (64.5m(2)/g), negatively charged surface and the intrinsic electron structure. This study provides a new strategy to develop novel photocatalysts for water treatment and marine antifouling. Copyright © 2016 Elsevier Inc. All rights reserved.
Space shuttle orbit maneuvering engine reusable thrust chamber program
NASA Technical Reports Server (NTRS)
Senneff, J. M.
1975-01-01
Reusable thrust chamber and injector concepts were evaluated for the space shuttle orbit maneuvering engine (OME). Parametric engine calculations were carried out by computer program for N2O4/amine, LOX/amine and LOX/hydrocarbon propellant combinations for engines incorporating regenerative cooled and insulated columbium thrust chambers. The calculation methods are described including the fuel vortex film cooling method of combustion gas temperature control, and performance prediction. A method of acceptance of a regeneratively cooled heat rejection reduction using a silicone oil additive was also demonstrated by heated tube heat transfer testing. Regeneratively cooled thrust chamber operation was also demonstrated where the injector was characterized for the OME application with a channel wall regenerative thrust chamber. Bomb stability testing of the demonstration chambers/injectors demonstrated recovery for the nominal design of acoustic cavities. Cavity geometry changes were also evaluated to assess their damping margin. Performance and combustion stability was demonstrated of the originally developed 10 inch diameter combustion pattern operating in an 8 inch diameter thrust chamber.
Reusable bi-directional 3ω sensor to measure thermal conductivity of 100-μm thick biological tissues
NASA Astrophysics Data System (ADS)
Lubner, Sean D.; Choi, Jeunghwan; Wehmeyer, Geoff; Waag, Bastian; Mishra, Vivek; Natesan, Harishankar; Bischof, John C.; Dames, Chris
2015-01-01
Accurate knowledge of the thermal conductivity (k) of biological tissues is important for cryopreservation, thermal ablation, and cryosurgery. Here, we adapt the 3ω method—widely used for rigid, inorganic solids—as a reusable sensor to measure k of soft biological samples two orders of magnitude thinner than conventional tissue characterization methods. Analytical and numerical studies quantify the error of the commonly used "boundary mismatch approximation" of the bi-directional 3ω geometry, confirm that the generalized slope method is exact in the low-frequency limit, and bound its error for finite frequencies. The bi-directional 3ω measurement device is validated using control experiments to within ±2% (liquid water, standard deviation) and ±5% (ice). Measurements of mouse liver cover a temperature ranging from -69 °C to +33 °C. The liver results are independent of sample thicknesses from 3 mm down to 100 μm and agree with available literature for non-mouse liver to within the measurement scatter.
Cyclic Cryogenic Thermal-Mechanical Testing of an X-33/RLV Liquid Oxygen Tank Concept
NASA Technical Reports Server (NTRS)
Rivers, H. Kevin
1999-01-01
An important step in developing a cost-effective, reusable, launch vehicle is the development of durable, lightweight, insulated, cryogenic propellant tanks. Current cryogenic tanks are expendable so most of the existing technology is not directly applicable to future launch vehicles. As part of the X-33/Reusable Launch Vehicle (RLV) Program, an experimental apparatus developed at the NASA Langley Research Center for evaluating the effects of combined, cyclic, thermal and mechanical loading on cryogenic tank concepts was used to evaluate cryogenic propellant tank concepts for Lockheed-Martin Michoud Space Systems. An aluminum-lithium (Al 2195) liquid oxygen tank concept, insulated with SS-1171 and PDL-1034 cryogenic insulation, is tested under simulated mission conditions, and the results of those tests are reported. The tests consists of twenty-five simulated Launch/Abort missions and twenty-five simulated flight missions with temperatures ranging from -320 F to 350 F and a maximum mechanical load of 71,300 lb. in tension.
Wang, Ximing; Chen, Zhangjing
2017-01-01
A lignocellulose/montmorillonite (LMT) nanocomposite was prepared as a reusable adsorbent for cobalt(II) ions, and characterized by nitrogen (N2) adsorption/desorption isotherm, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR). LMT exhibited efficient adsorption of cobalt ions (Co(II)), and the adsorbed Co(II) was readily desorbed by nitric acid (HNO3). All parameters affecting the adsorption and/or desorption of Co(II), including initial Co(II) concentration, pH value, temperature, HNO3 concentration, and time, were optimized. The kinetic data analysis showed that the adsorption followed the pseudo-second-order kinetic model and fit well into the Langmuir isotherm equation. Notably, the nanocomposite can be used four times without significantly losing adsorbent capability. The Energy-Dispersive X-ray (EDX) and FTIR spectra analysis also revealed that the adsorption mechanism may be mainly a chemical adsorption dominated process. PMID:29186794
Note: reliable and reusable ultrahigh vacuum optical viewports.
Arora, P; Sen Gupta, A
2012-04-01
We report a simple technique for the realization of ultrahigh vacuum optical viewports. The technique relies on using specially designed thin copper knife-edges and using a thin layer of Vacseal(®) on tip of the knife-edges between the optical flat and the ConFlat(®) (CF) flange. The design of the windows is such that it gives uniform pressure on the flat without breaking it. The assembled window is a complete unit, which can be mounted directly onto a CF flange of the vacuum chamber. It can be removed and reused without breaking the window seal. The design is reliable as more than a dozen such windows have survived several bake out and cooling cycles and have been leak tested up to 10(-11) Torr l/s level with a commercial Helium leak detector. The advantages of this technique are ease of assembly and leak proof sealing that survives multiple temperature cycling making the windows reliable and reusable. © 2012 American Institute of Physics
Lubner, Sean D; Choi, Jeunghwan; Wehmeyer, Geoff; Waag, Bastian; Mishra, Vivek; Natesan, Harishankar; Bischof, John C; Dames, Chris
2015-01-01
Accurate knowledge of the thermal conductivity (k) of biological tissues is important for cryopreservation, thermal ablation, and cryosurgery. Here, we adapt the 3ω method-widely used for rigid, inorganic solids-as a reusable sensor to measure k of soft biological samples two orders of magnitude thinner than conventional tissue characterization methods. Analytical and numerical studies quantify the error of the commonly used "boundary mismatch approximation" of the bi-directional 3ω geometry, confirm that the generalized slope method is exact in the low-frequency limit, and bound its error for finite frequencies. The bi-directional 3ω measurement device is validated using control experiments to within ±2% (liquid water, standard deviation) and ±5% (ice). Measurements of mouse liver cover a temperature ranging from -69 °C to +33 °C. The liver results are independent of sample thicknesses from 3 mm down to 100 μm and agree with available literature for non-mouse liver to within the measurement scatter.
Lightweight Thermal Insulation for a Liquid-Oxygen Tank
NASA Technical Reports Server (NTRS)
Willen, G. Scott; Lock, Jennifer; Nieczkoski, Steve
2005-01-01
A proposed lightweight, reusable thermal-insulation blanket has been designed for application to a tank containing liquid oxygen, in place of a non-reusable spray-on insulating foam. The blanket would be of the multilayer-insulation (MLI) type and equipped with a pressure-regulated nitrogen purge system. The blanket would contain 16 layers in two 8-layer sub-blankets. Double-aluminized polyimide 0.3 mil (.0.008 mm) thick was selected as a reflective shield material because of its compatibility with oxygen and its ability to withstand ionizing radiation and high temperature. The inner and outer sub-blanket layers, 1 mil (approximately equals 0.025 mm) and 3 mils (approximately equals 0.076 mm) thick, respectively, would be made of the double-aluminized polyimide reinforced with aramid. The inner and outer layers would provide structural support for the more fragile layers between them and would bear the insulation-to-tank attachment loads. The layers would be spaced apart by lightweight, low-thermal-conductance netting made from polyethylene terephthalate.
Characterization of Cold Sprayed CuCrAl Coated GRCop-84 Substrates for Reusable Launch Vehicles
NASA Technical Reports Server (NTRS)
Raj, S . V.; Barrett, C. A.; Lerch, B. A.; Karthikeyan, J.; Ghosn, L. J.; Haynes, J.
2005-01-01
An advanced Cu-8(at.%)Cr-4%Nb alloy developed at NASA's Glenn Research Center, and designated as GRCop-84, is currently being considered for use as combustor liners and nozzles in NASA's future generations of reusable launch vehicles (RLVs). Despite the fact that this alloy has superior mechanical and oxidation properties compared to many commercially available copper alloys, it is felt that its high temperature and environmental resistance capabilities can be further enhanced with the development and use of suitable coatings. Several coatings and processes are currently being evaluated for their suitability and future down selection. A newly developed CuCrAl has shown excellent oxidation resistance compared to current generation Cu-Cr coating alloys. Cold spray technology for depositing the CuCrAl coating on a GRCop-84 substrate is currently being developed under NASA's Next Generation Launch Technology (NGLT) Propulsion Research and Technology (PR&T) project. The microstructures, mechanical and thermophysical properties of overlay coated GRCop-84 substrates are discussed.
NASA Astrophysics Data System (ADS)
Zadehahmadi, Farnaz; Tangestaninejad, Shahram; Moghadam, Majid; Mirkhani, Valiollah; Mohammadpoor-Baltork, Iraj; Khosropour, Ahmad R.; Kardanpour, Reihaneh
2014-10-01
In the present work, chloromethylated MIL-101(Cr) modified with imidazole, Im-MIL-101, was applied as a support for immobilizing of tetraphenylporphyrinatomangenese(III) chloride. The imidazole-bound MIL-101, Im-MIL-101, not only used as support for immobilization of manganese porphyrin but also applied as a heterogeneous axial base. The Mn(TPP)Cl@Im-MIL-101 catalyst was characterized by UV-vis, FT-IR, X-ray diffraction (XRD), N2 adsorption, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), elemental analysis and inductively coupled plasma (ICP) methods. The catalytic activity of this new catalytic system was investigated in the alkene epoxidation and alkane hydroxylation using NaIO4 as an oxidant in CH3CN/H2O at room temperature. This heterogeneous catalyst is highly efficient, stable and reusable in the oxidation of hydrocarbons.
14 CFR 437.95 - Inspection of additional reusable suborbital rockets.
Code of Federal Regulations, 2010 CFR
2010-01-01
... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Terms and Conditions of an Experimental Permit § 437.95 Inspection of additional reusable suborbital rockets. A permittee may launch or reenter additional reusable suborbital rockets of the same design under the permit after...
14 CFR 437.95 - Inspection of additional reusable suborbital rockets.
Code of Federal Regulations, 2012 CFR
2012-01-01
... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Terms and Conditions of an Experimental Permit § 437.95 Inspection of additional reusable suborbital rockets. A permittee may launch or reenter additional reusable suborbital rockets of the same design under the permit after...
14 CFR 437.95 - Inspection of additional reusable suborbital rockets.
Code of Federal Regulations, 2014 CFR
2014-01-01
... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Terms and Conditions of an Experimental Permit § 437.95 Inspection of additional reusable suborbital rockets. A permittee may launch or reenter additional reusable suborbital rockets of the same design under the permit after...
14 CFR 437.95 - Inspection of additional reusable suborbital rockets.
Code of Federal Regulations, 2013 CFR
2013-01-01
... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Terms and Conditions of an Experimental Permit § 437.95 Inspection of additional reusable suborbital rockets. A permittee may launch or reenter additional reusable suborbital rockets of the same design under the permit after...
14 CFR 437.95 - Inspection of additional reusable suborbital rockets.
Code of Federal Regulations, 2011 CFR
2011-01-01
... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Terms and Conditions of an Experimental Permit § 437.95 Inspection of additional reusable suborbital rockets. A permittee may launch or reenter additional reusable suborbital rockets of the same design under the permit after...
Sherman, Jodi D; Raibley, Lewis A; Eckelman, Matthew J
2018-01-09
Traditional medical device procurement criteria include efficacy and safety, ease of use and handling, and procurement costs. However, little information is available about life cycle environmental impacts of the production, use, and disposal of medical devices, or about costs incurred after purchase. Reusable and disposable laryngoscopes are of current interest to anesthesiologists. Facing mounting pressure to quickly meet or exceed conflicting infection prevention guidelines and oversight body recommendations, many institutions may be electively switching to single-use disposable (SUD) rigid laryngoscopes or overcleaning reusables, potentially increasing both costs and waste generation. This study provides quantitative comparisons of environmental impacts and total cost of ownership among laryngoscope options, which can aid procurement decision making to benefit facilities and public health. We describe cradle-to-grave life cycle assessment (LCA) and life cycle costing (LCC) methods and apply these to reusable and SUD metal and plastic laryngoscope handles and tongue blade alternatives at Yale-New Haven Hospital (YNHH). The US Environmental Protection Agency's Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI) life cycle impact assessment method was used to model environmental impacts of greenhouse gases and other pollutant emissions. The SUD plastic handle generates an estimated 16-18 times more life cycle carbon dioxide equivalents (CO2-eq) than traditional low-level disinfection of the reusable steel handle. The SUD plastic tongue blade generates an estimated 5-6 times more CO2-eq than the reusable steel blade treated with high-level disinfection. SUD metal components generated much higher emissions than all alternatives. Both the SUD handle and SUD blade increased life cycle costs compared to the various reusable cleaning scenarios at YNHH. When extrapolated over 1 year (60,000 intubations), estimated costs increased between $495,000 and $604,000 for SUD handles and between $180,000 and $265,000 for SUD blades, compared to reusables, depending on cleaning scenario and assuming 4000 (rated) uses. Considering device attrition, reusable handles would be more economical than SUDs if they last through 4-5 uses, and reusable blades 5-7 uses, before loss. LCA and LCC are feasible methods to ease interpretation of environmental impacts and facility costs when weighing device procurement options. While management practices vary between institutions, all standard methods of cleaning were evaluated and sensitivity analyses performed so that results are widely applicable. For YNHH, the reusable options presented a considerable cost advantage, in addition to offering a better option environmentally. Avoiding overcleaning reusable laryngoscope handles and blades is desirable from an environmental perspective. Costs may vary between facilities, and LCC methodology demonstrates the importance of time-motion labor analysis when comparing reusable and disposable device options.
Reusable Launch Vehicle Technology Program
NASA Technical Reports Server (NTRS)
Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, R. Eugene
1996-01-01
Industry/NASA Reusable Launch Vehicle (RLV) Technology Program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low-cost program. This paper reviews the current status of the Reusable Launch Vehicle Technology Program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion, and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight tests. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost-effective, reusable launch vehicle systems.
On/off-switchable LSPR nano-immunoassay for troponin-T
Ashaduzzaman, Md.; Deshpande, Swapneel R.; Murugan, N. Arul; Mishra, Yogendra Kumar; Turner, Anthony P. F.; Tiwari, Ashutosh
2017-01-01
Regeneration of immunosensors is a longstanding challenge. We have developed a re-usable troponin-T (TnT) immunoassay based on localised surface plasmon resonance (LSPR) at gold nanorods (GNR). Thermosensitive poly(N-isopropylacrylamide) (PNIPAAM) was functionalised with anti-TnT to control the affinity interaction with TnT. The LSPR was extremely sensitive to the dielectric constant of the surrounding medium as modulated by antigen binding after 20 min incubation at 37 °C. Computational modelling incorporating molecular docking, molecular dynamics and free energy calculations was used to elucidate the interactions between the various subsystems namely, IgG-antibody (c.f., anti-TnT), PNIPAAM and/or TnT. This study demonstrates a remarkable temperature dependent immuno-interaction due to changes in the PNIPAAM secondary structures, i.e., globular and coil, at above or below the lower critical solution temperature (LCST). A series of concentrations of TnT were measured by correlating the λLSPR shift with relative changes in extinction intensity at the distinct plasmonic maximum (i.e., 832 nm). The magnitude of the red shift in λLSPR was nearly linear with increasing concentration of TnT, over the range 7.6 × 10−15 to 9.1 × 10−4 g/mL. The LSPR based nano-immunoassay could be simply regenerated by switching the polymer conformation and creating a gradient of microenvironments between the two states with a modest change in temperature. PMID:28382946
Production of Biodiesel by Esterification of Free Fatty Acid over Solid Catalyst from Biomass Waste
NASA Astrophysics Data System (ADS)
Mukti, N. I. F.; Sutrisno, B.; Hidayat, A.
2018-05-01
Recently, low cost feedstocks have been utilized to replace vegetable oils in order to improve the economic feasibility of biodiesel. The esterification of free fatty acid (FFA) on Palm Fatty Acid Distillate (PFAD) with methanol using solid catalyst generated from bagasse fly ash is a promising method to convert FFA into biodiesel. In this research, the esterification of FFA on PFAD using the sulfonated bagasse fly ash catalyst was studied. The performances of the catalysts were evaluated in terms of the reaction temperatures, the molar ratios of methanol to PFAD, and the catalyst loading. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimum conditions were methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%wt. of PFAD, and reaction temperature of 6°C. The reusability of the solid acid carbon catalysts was also studied in this work. The catalytic activity decreased up to 38% after third cycle. The significant decline in catalyst esterification activity was due to acid site leaching. The physico-characteristics and acid site densities were analyzed by Nitrogen gas adsorption, surface functional groups by Fourier transform infrared spectroscopy (FT-IR), elemental analysis using X-ray fluorescent (XRF), and acid-base back titration methods for determination of acid density.
Shell tile thermal protection system
NASA Technical Reports Server (NTRS)
Macconochie, I. O.; Lawson, A. G.; Kelly, H. N. (Inventor)
1984-01-01
A reusable, externally applied thermal protection system for use on aerospace vehicles subject to high thermal and mechanical stresses utilizes a shell tile structure which effectively separates its primary functions as an insulator and load absorber. The tile consists of structurally strong upper and lower metallic shells manufactured from materials meeting the thermal and structural requirements incident to tile placement on the spacecraft. A lightweight, high temperature package of insulation is utilized in the upper shell while a lightweight, low temperature insulation is utilized in the lower shell. Assembly of the tile which is facilitated by a self-locking mechanism, may occur subsequent to installation of the lower shell on the spacecraft structural skin.
Feasibility study of polyurethane shape-memory polymer actuators for pressure bandage application.
Ahmad, Manzoor; Luo, Jikui; Miraftab, Mohsen
2012-02-01
The feasibility of laboratory-synthesized polyurethane-based shape-memory polymer (SMPU) actuators has been investigated for possible application in medical pressure bandages where gradient pressure is required between the ankle and the knee for treatment of leg ulcers. In this study, using heat as the stimulant, SMPU strip actuators have been subjected to gradual and cyclic stresses; their recovery force, reproducibility and reusability have been monitored with respect to changes in temperature and circumference of a model leg, and the stress relaxation at various temperatures has been investigated. The findings suggest that SMPU actuators can be used for the development of the next generation of pressure bandages.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-20
... Permits for Reusable Suborbital Rockets AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... Number: 2120-0722. Title: Experimental Permits for Reusable Suborbital Rockets. Form Numbers: There are... experimental permits for reusable suborbital rockets to authorize launches for the purpose of research and...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-21
... Permits for Reusable Suborbital Rockets AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... INFORMATION: OMB Control Number: 2120-0722. Title: Experimental Permits for Reusable Suborbital Rockets. Form... experimental permits for reusable suborbital rockets to authorize launches for the purpose of research and...
Sterilization of reusable implant components: a pilot study.
Cain, J R; Mitchell, D L; Gillespie, J C
2000-12-01
The placement and restoration of dental implants require the use of numerous reusable instruments and components. The adequate sterilization of reusable instruments and components is essential to prevent cross contamination between patients. Sterilization usually is accomplished with single-use sterilization envelopes. A reusable sterilization vehicle would reduce costs as well as the waste generated in patient care. This study was designed to determine the efficacy of a 10-cc Pyrex test tube as a sterilization vehicle for reusable dental implant instruments and components. In this study, a reusable dental implant component was placed in a Pyrex test tube, along with a biologic test strip. A control biologic test strip was kept for each test tube. The test tube was closed with a cotton roll folded in half and placed in the opening. Twenty test tubes were prepared. five sets of 4 test tubes were placed in an autoclave in different locations with varying orientations. The autoclave completed a standard sterilization cycle. The biological monitoring service indicated that the biologic test strips in 100% of the test tubes were sterile, whereas the control strips were 100% nonsterile. A Pyrex test tube sealed with a cotton roll can serve as a sterilization vehicle for reusable dental implant instruments and components.
Is It Worth It? - the Economics of Reusable Space Transportation
NASA Technical Reports Server (NTRS)
Webb, Richard
2016-01-01
Over the past several decades billions of dollars have been invested by governments and private companies in the pursuit of lower cost access to space through earth-to-orbit (ETO) space transportation systems. Much of that investment has been focused on the development and operation of various forms of reusable transportation systems. From the Space Shuttle to current efforts by private commercial companies, the overarching belief of those making such investments has been that reusing system elements will be cheaper than utilizing expendable systems that involve throwing away costly engines, avionics, and other hardware with each flight. However, the view that reusable systems are ultimately a "better" approach to providing ETO transportation is not held universally by major stakeholders within the space transportation industry. While the technical feasibility of at least some degree of reusability has been demonstrated, there continues to be a sometimes lively debate over the merits and drawbacks of reusable versus expendable systems from an economic perspective. In summary, is it worth it? Based on our many years of direct involvement with the business aspects of several expendable and reusable transportation systems, it appears to us that much of the discussion surrounding reusability is hindered by a failure to clearly define and understand the financial and other metrics by which the financial "goodness" of a reusable or expandable approach is measured. As stakeholders, the different users and suppliers of space transportation have a varied set of criteria for determining the relative economic viability of alternative strategies, including reusability. Many different metrics have been used to measure the affordability of space transportation, such as dollars per payload pound (kilogram) to orbit, cost per flight, life cycle cost, net present value/internal rate of return, and many others. This paper will examine the key considerations that influence stakeholders as they make space transportation investment decisions, including primary metrics by which various stakeholders measure financial goodness and other factors that significantly shape decisions to invest in reusable or expendable systems. It must be noted at the outset that reusable systems take many forms and perform different transportation functions including, but not limited to, ETO payload delivery. The discussion in this paper is limited to the economics of ETO transportation systems.
Wahba, Marwa I
2018-03-01
The poor mechanical stability of chitosan has long impeded its industrial utilization as an immobilization carrier. In this study, the mechanical properties of chitosan beads were greatly improved through utilizing the slow rate of the sodium bicarbonate-induced chitosan gelation and combining it with the chemical cross-linking action of glutaraldehyde (GA). The GA-treated sodium bicarbonate-gelled chitosan beads exhibited much better mechanical properties and up to 2.45-fold higher observed activity of the immobilized enzyme (β-D-galactosidase (β-gal)) when compared to the GA-treated sodium tripolyphosphate (TPP)-gelled chitosan beads. The differences between the sodium bicarbonate-gelled and the TPP-gelled chitosan beads were proven visually and also via scanning electron microscopy, elemental analysis, and differential scanning calorimetry. Moreover, the optimum pH, the optimum temperature, the apparent K m , and the apparent V max of the β-gals immobilized onto the two aforementioned types of chitosan beads were determined and compared. A reusability study was also performed. This study proved the superiority of the sodium bicarbonate-gelled chitosan beads as they retained 72.22 ± 4.57% of their initial observed activity during the 13 th reusability cycle whereas the TPP-gelled beads lost their activity during the first four reusability cycles, owing to their fragmentation. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:347-361, 2018. © 2017 American Institute of Chemical Engineers.
Liu, Xiong; Zhou, Wenqi; Xu, Longqi
2017-09-01
A type of resin-anchored CuPF 6 -(S)-BINAP was synthesized and identified. The PS-CuPF 6 -(S)-BINAP resin was used to adsorb the phenylalanine enantiomers. The results showed that the adsorption capacity of PS-CuPF 6 -(S)-BINAP resin toward L-phenylalanine was higher than that of resin toward D-phenylalanine. PS-CuPF 6 -(S)-BINAP resin exhibited good enantioselectivity toward L-phenylalanine and D-phenylalanine. The influence of phenylalanine concentration, pH, adsorption time, and temperature on the enantioselectivity of the resin were investigated. The results showed that the enantioselectivity of the resin increased with increasing the phenylalanine concentration, pH, and adsorption time, while it decreased with an increase in temperature. The causes for these influences are discussed. The highest enantioselectivity (α = 2.81) was obtained when the condition of phenylalanine concentration was 0.05 mmol/mL, pH was 8, adsorption time was 12 h, and temperature 5°C. The desorption test for removing D/L-phenylalanine on PS-CuPF 6 -(S)-BINAP resin was also investigated. The desorption ratios of D-phenylalanine and L-phenylalanine at pH of 1 were 95.7% and 94.3%, respectively. This result indicated that the PS-CuPF 6 -(S)-BINAP resin could be regenerated by shaking with an acidic solution. The reusability of the PS-CuPF 6 -(S)-BINAP resin was also assessed and the resin exhibited considerable reusability. © 2017 Wiley Periodicals, Inc.
NASA Technical Reports Server (NTRS)
Olds, John R.; Izon, Stephen James
2002-01-01
The Thermal Calculation Analysis Tool (TCAT), originally developed for the Space Systems Design Lab at the Georgia Institute of Technology, is a conceptual design tool capable of integrating aeroheating analysis into conceptual reusable launch vehicle design. It provides Thermal Protection System (TPS) unit thicknesses and acreage percentages based on the geometry of the vehicle and a reference trajectory to be used in calculation of the total cost and weight of the vehicle design. TCAT has proven to be reasonably accurate at calculating the TPS unit weights for in-flight trajectories; however, it does not have the capability of sizing TPS materials above cryogenic fuel tanks for ground hold operations. During ground hold operations, the vehicle is held for a brief period (generally about two hours) during which heat transfer from the TPS materials to the cryogenic fuel occurs. If too much heat is extracted from the TPS material, the surface temperature may fall below the freezing point of water, thereby freezing any condensation that may be present at the surface of the TPS. Condensation or ice on the surface of the vehicle is potentially hazardous to the mission and can also damage the TPS. It is questionable whether or not the TPS thicknesses provided by the aeroheating analysis would be sufficiently thick to insulate the surface of the TPS from the heat transfer to the fuel. Therefore, a design tool has been developed that is capable of sizing TPS materials at these cryogenic fuel tank locations to augment TCAT's TPS sizing capabilities.
Comparative life cycle assessment of disposable and reusable laryngeal mask airways.
Eckelman, Matthew; Mosher, Margo; Gonzalez, Andres; Sherman, Jodi
2012-05-01
Growing awareness of the negative impacts from the practice of health care on the environment and public health calls for the routine inclusion of life cycle criteria into the decision-making process of device selection. Here we present a life cycle assessment of 2 laryngeal mask airways (LMAs), a one-time-use disposable Unique™ LMA and a 40-time-use reusable Classic™ LMA. In life cycle assessment, the basis of comparison is called the "functional unit." For this report, the functional unit of the disposable and reusable LMAs was taken to be maintenance of airway patency by 40 disposable LMAs or 40 uses of 1 reusable LMA. This was a cradle-to-grave study that included inputs and outputs for the manufacture, transport, use, and waste phases of the LMAs. The environmental impacts of the 2 LMAs were estimated using SimaPro life cycle assessment software and the Building for Environmental and Economic Sustainability impact assessment method. Sensitivity and simple life cycle cost analyses were conducted to aid in interpretation of the results. The reusable LMA was found to have a more favorable environmental profile than the disposable LMA as used at Yale New Haven Hospital. The most important sources of impacts for the disposable LMA were the production of polymers, packaging, and waste management, whereas for the reusable LMA, washing and sterilization dominated for most impact categories. The differences in environmental impacts between these devices strongly favor reusable devices. These benefits must be weighed against concerns regarding transmission of infection. Health care facilities can decrease their environmental impacts by using reusable LMAs, to a lesser extent by selecting disposable LMA models that are not made of certain plastics, and by ordering in bulk from local distributors. Certain practices would further reduce the environmental impacts of reusable LMAs, such as increasing the number of devices autoclaved in a single cycle to 10 (-25% GHG emissions) and improving the energy efficiency of the autoclaving machines by 10% (-8% GHG emissions). For both environmental and cost considerations, management and operating procedures should be put in place to ensure that reusable LMAs are not discarded prematurely.
Low-Cost, High Glass-Transition Temperature, Thermosetting Polyimide Developed
NASA Technical Reports Server (NTRS)
Chuang, Kathy C.
1999-01-01
PMR-15 polyimide, developed in the mid-1970's at the NASA Lewis Research Center, is recognized as a state-of-the-art high-temperature resin for composite applications in the temperature range of 500 to 550 F (260 to 288 C). PMR-15 offers easy processing and good property retention at a reasonable cost. For these reasons, it is widely used in both military and commercial aircraft engine components. Traditionally, polyimide composites have been designed for long-term use at 500 to 600 F over thousands of hours. However, new applications in reusable launch vehicles (RLV's) require lightweight materials that can perform for short times (tens of hours) at temperatures between 800 and 1000 F (425 and 538 C). Current efforts at Lewis are focused on raising the use temperature of polyimide composites by increasing the glass-transition temperature of the matrix resins. Achieving this dramatic increase in the upper use temperature without sacrificing polymer and composite processability is a major technical challenge.
14 CFR 431.3 - Types of reusable launch vehicle mission licenses.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Types of reusable launch vehicle mission licenses. 431.3 Section 431.3 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...) General § 431.3 Types of reusable launch vehicle mission licenses. (a) Mission-specific license. A mission...
14 CFR 431.9 - Issuance of a reusable launch vehicle mission license.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Issuance of a reusable launch vehicle mission license. 431.9 Section 431.9 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.9 Issuance of a reusable launch vehicle mission license. (a) The FAA issues...
14 CFR 431.3 - Types of reusable launch vehicle mission licenses.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Types of reusable launch vehicle mission licenses. 431.3 Section 431.3 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...) General § 431.3 Types of reusable launch vehicle mission licenses. (a) Mission-specific license. A mission...
14 CFR 431.9 - Issuance of a reusable launch vehicle mission license.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Issuance of a reusable launch vehicle mission license. 431.9 Section 431.9 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.9 Issuance of a reusable launch vehicle mission license. (a) The FAA issues...
14 CFR 431.13 - Transfer of a reusable launch vehicle mission license.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Transfer of a reusable launch vehicle mission license. 431.13 Section 431.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.13 Transfer of a reusable launch vehicle mission license. (a) Only the FAA may...
14 CFR 431.13 - Transfer of a reusable launch vehicle mission license.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Transfer of a reusable launch vehicle mission license. 431.13 Section 431.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.13 Transfer of a reusable launch vehicle mission license. (a) Only the FAA may...
14 CFR 431.9 - Issuance of a reusable launch vehicle mission license.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Issuance of a reusable launch vehicle mission license. 431.9 Section 431.9 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.9 Issuance of a reusable launch vehicle mission license. (a) The FAA issues...
14 CFR 431.3 - Types of reusable launch vehicle mission licenses.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Types of reusable launch vehicle mission licenses. 431.3 Section 431.3 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...) General § 431.3 Types of reusable launch vehicle mission licenses. (a) Mission-specific license. A mission...
14 CFR 431.13 - Transfer of a reusable launch vehicle mission license.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Transfer of a reusable launch vehicle mission license. 431.13 Section 431.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.13 Transfer of a reusable launch vehicle mission license. (a) Only the FAA may...
14 CFR 431.13 - Transfer of a reusable launch vehicle mission license.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Transfer of a reusable launch vehicle mission license. 431.13 Section 431.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.13 Transfer of a reusable launch vehicle mission license. (a) Only the FAA may...
14 CFR 431.3 - Types of reusable launch vehicle mission licenses.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Types of reusable launch vehicle mission licenses. 431.3 Section 431.3 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...) General § 431.3 Types of reusable launch vehicle mission licenses. (a) Mission-specific license. A mission...
14 CFR 431.3 - Types of reusable launch vehicle mission licenses.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Types of reusable launch vehicle mission licenses. 431.3 Section 431.3 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...) General § 431.3 Types of reusable launch vehicle mission licenses. (a) Mission-specific license. A mission...
14 CFR 431.13 - Transfer of a reusable launch vehicle mission license.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Transfer of a reusable launch vehicle mission license. 431.13 Section 431.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.13 Transfer of a reusable launch vehicle mission license. (a) Only the FAA may...
14 CFR 431.9 - Issuance of a reusable launch vehicle mission license.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Issuance of a reusable launch vehicle mission license. 431.9 Section 431.9 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.9 Issuance of a reusable launch vehicle mission license. (a) The FAA issues...
14 CFR 431.9 - Issuance of a reusable launch vehicle mission license.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Issuance of a reusable launch vehicle mission license. 431.9 Section 431.9 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) General § 431.9 Issuance of a reusable launch vehicle mission license. (a) The FAA issues...
How dirty are your reusable water bottles?
NASA Astrophysics Data System (ADS)
Williams, S.
2017-12-01
Reusable water bottles are an environment-friendly option but may grow harmful bacteria if not washed regularly. To test whether washing habits affect bacterial growth, I swabbed 10 different plastic reusable bottles and counted colony growth after laboratory incubation. My results did not show a clear relationship between days since last wash and colony growth.
Support for life-cycle product reuse in NASA's SSE
NASA Technical Reports Server (NTRS)
Shotton, Charles
1989-01-01
The Software Support Environment (SSE) is a software factory for the production of Space Station Freedom Program operational software. The SSE is to be centrally developed and maintained and used to configure software production facilities in the field. The PRC product TTCQF provides for an automated qualification process and analysis of existing code that can be used for software reuse. The interrogation subsystem permits user queries of the reusable data and components which have been identified by an analyzer and qualified with associated metrics. The concept includes reuse of non-code life-cycle components such as requirements and designs. Possible types of reusable life-cycle components include templates, generics, and as-is items. Qualification of reusable elements requires analysis (separation of candidate components into primitives), qualification (evaluation of primitives for reusability according to reusability criteria) and loading (placing qualified elements into appropriate libraries). There can be different qualifications for different installations, methodologies, applications and components. Identifying reusable software and related components is labor-intensive and is best carried out as an integrated function of an SSE.
NASA Technical Reports Server (NTRS)
Pauckert, R. P.
1974-01-01
The stability characteristics of the like-doublet injector were defined over the range of OME chamber pressures and mixture ratios. This was accomplished by bomb testing the injector and cavity configurations in solid wall thrust chamber hardware typical of a flight contour with fuel heated to regenerative chamber outlet temperatures. It was found that stability in the 2600-2800 Hz region depends upon injector hydraulics and on chamber acoustics.
2001-03-01
tungsten thin wall nozzle liner removed from reusable mandrel. b) W and Re rocket, nozzle inserts (2 inserts per mandrel) for Air Force. Rhenium PPI...compares the fabrication time for the VPS nozzles with equivalent carbon / carbon composite (C/C) and forged tungsten materials. Table 5: Comparison of...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO1 1181 TITLE: Low Cost, Net Shape Fabrication of Rhenium and High
Rocket Motor Microphone Investigation
NASA Technical Reports Server (NTRS)
Pilkey, Debbie; Herrera, Eric; Gee, Kent L.; Giraud, Jerom H.; Young, Devin J.
2010-01-01
At ATK's facility in Utah, large full-scale solid rocket motors are tested. The largest is a five-segment version of the reusable solid rocket motor, which is for use on the Ares I launch vehicle. As a continuous improvement project, ATK and BYU investigated the use of microphones on these static tests, the vibration and temperature to which the instruments are subjected, and in particular the use of vent tubes and the effects these vents have at low frequencies.
NASA Technical Reports Server (NTRS)
Johnson, Theodore F.; Waters, W. Allen; Singer, Thomas N.; Haftka, Raphael T.
2004-01-01
A next generation reusable launch vehicle (RLV) will require thermally efficient and light-weight cryogenic propellant tank structures. Since these tanks will be weight-critical, analytical tools must be developed to aid in sizing the thickness of insulation layers and structural geometry for optimal performance. Finite element method (FEM) models of the tank and insulation layers were created to analyze the thermal performance of the cryogenic insulation layer and thermal protection system (TPS) of the tanks. The thermal conditions of ground-hold and re-entry/soak-through for a typical RLV mission were used in the thermal sizing study. A general-purpose nonlinear FEM analysis code, capable of using temperature and pressure dependent material properties, was used as the thermal analysis code. Mechanical loads from ground handling and proof-pressure testing were used to size the structural geometry of an aluminum cryogenic tank wall. Nonlinear deterministic optimization and reliability optimization techniques were the analytical tools used to size the geometry of the isogrid stiffeners and thickness of the skin. The results from the sizing study indicate that a commercial FEM code can be used for thermal analyses to size the insulation thicknesses where the temperature and pressure were varied. The results from the structural sizing study show that using combined deterministic and reliability optimization techniques can obtain alternate and lighter designs than the designs obtained from deterministic optimization methods alone.
Evaluating the Ergonomics of Flexible Ureteroscopy.
Ludwig, Wesley W; Lee, Gyusung; Ziemba, Justin B; Ko, Joan S; Matlaga, Brian R
2017-10-01
To date, the ergonomics of flexible ureteroscopy (URS) have not been well described. We performed a study to assess the biomechanical stresses on urologists performing URS and to investigate the effect of ureteroscope type on these parameters. Electromyography (EMG) was used to quantify the activation level of muscle groups involved in URS. Surface EMG electrodes (Delsys, Boston, MA) were placed on the right and left thenar, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), biceps, triceps, and deltoid. Three endoscopes were studied: single-use digital (Boston Scientific LithoVue), reusable digital (Karl Storz Flex-X c ), and reusable fiber-optic (Karl Storz Flex-X 2 ). Each ureteroscope was used to perform a set sequence of navigation and procedural tasks in a training model. EMG data were processed and normalized to compare the maximum voluntary contractions between muscle groups. Cumulative muscular workload (CMW) and average muscular work per second (AWS) were used for comparative analysis. For navigational tasks, CMW and AWS were greatest for the ECU, followed in descending order by right and left thenar, FCU, biceps, deltoid, and triceps. For procedural tasks, CMW and AWS were greatest for the right thenar, followed in descending order by the left thenar, ECU, FCU, triceps, biceps, and deltoid. During navigational tasks, both LithoVue and Flex-X c had lower CMWs for every muscle group than Flex-X 2 (p < 0.05). LithoVue and Flex-X c had similar AWS and both were lower than Flex-X 2 for the right thenar, ECU, biceps, and deltoid activation (p < 0.05). During procedural tasks, both LithoVue and Flex-X c had lower CMWs and AWS for right and left thenar, ECU, and biceps than Flex-X 2 (p < 0.05). This study provides the first description of EMG-measured ergonomics of URS. Both the single-use and reusable digital ureteroscopes have similar profiles, and both have significantly better ergonomic metrics than the reusable fiber-optic ureteroscope.
Space Transportation Infrastructure Supported By Propellant Depots
NASA Technical Reports Server (NTRS)
Smitherman, David; Woodcock, Gordon
2011-01-01
A space transportation infrastructure is described that utilizes propellant depots to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicles such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to a Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing, and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid, and Mars missions. A Mars Orbital Depot is also described to support ongoing Mars missions. New concepts for vehicle designs are presented that can be launched on current 5-meter diameter expendable launch vehicles. These new reusable vehicle concepts include a LEO Depot, L1 Depot, and Mars Orbital Depot based on International Space Station (ISS) heritage hardware. The high-energy depots at L1 and Mars orbit are compatible with, but do not require, electric propulsion tug use for propellant and/or cargo delivery. New reusable in-space crew transportation vehicles include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot and the L1 Depot, a new reusable Lunar Lander for crew transportation between the L1 Depot and the lunar surface, and a Deep Space Habitat (DSH) to support crew missions from the L1 Depot to ESL2, Asteroid, and Mars destinations. A 6 meter diameter Mars lander concept is presented that can be launched without a fairing based on the Delta IV heavy Payload Planners Guide, which indicates feasibility of a 6.5 meter fairing. This lander would evolve to re-usable operations when propellant production is established on Mars. Figure 1 provides a summary of the possible missions this infrastructure can support. Summary mission profiles are presented for each primary mission capability. These profiles are the basis for propellant loads, numbers of vehicles/stages and launches for each mission capability. Data includes the number of launches required for each mission utilizing current expendable launch vehicle systems, and concluding remarks include ideas for reducing the number of launches through incorporation of heavy-lift launch vehicles, solar electric propulsion, and other transportation support concepts.
NASA Astrophysics Data System (ADS)
Pranav Nithin, R.; Gopikrishnan, S.; Sumesh, A.
2018-02-01
Cooling towers are the heat transfer devices commonly found in industries which are used to extract the high temperature from the coolants and make it reusable in various plants. Basically, the cooling towers has Fills made of PVC sheets stacked together to increase the surface area exposure of the cooling liquid flowing through it. This paper focuses on the study in such a manufacturing plant where fills are being manufactured. The productivity using the current manufacturing method was only 6 to 8 fills per day, where the ideal capacity was of 14 fills per day. In this plant manual labor was employed in the manufacturing process. A change in the process modification designed and implemented will help the industry to increase the productivity to 14. In this paper, initially the simulation study was done using ARENA the simulation package and later the new design was done using CAD Package and validated using Ansys Mechanical APDL. It’s found that, by the implementation of the safe design the productivity can be increased to 196 Units.
Dai, Xiao-Yan; Kong, Li-Min; Wang, Xiao-Ling; Zhu, Qing; Chen, Kai; Zhou, Tao
2018-07-01
Pectinase was immobilized onto sodium alginate/graphene oxide beads via amide bonds by using N,N'-dicyclohexylcarbodiimide/N-hydroxysuccinimide as the activating agent. The immobilized pectinase was characterized by Fourier transform infrared spectra and scanning electron microscopy analyses. Immobilization conditions were optimized by Box-Behnken design and the response surface method. The activity of the immobilized pectinase prepared under optimal conditions reached 1236.86 ± 40.21 U/g, with an enzyme activity recovery of 83.5%. The optimal pH of free pectinase was 4.5, while that of immobilized pectinase was shifted to 4.0. The optimal temperature of immobilized pectinase was increased to 60 °C, which was 10 °C higher than that of free form. Furthermore, the immobilized pectinase possessed a superior thermal stability and storage stability to those of free pectinase. Reusability studies indicated that the immobilized pectinase retained 73% of initial activity after six times cycles. Due to these good properties, such immobilized pectinase may find application in food industry. Copyright © 2018 Elsevier Ltd. All rights reserved.
Reusable Launch Vehicle Attitude Control Using a Time-Varying Sliding Mode Control Technique
NASA Technical Reports Server (NTRS)
Shtessel, Yuri B.; Zhu, J. Jim; Daniels, Dan; Jackson, Scott (Technical Monitor)
2002-01-01
In this paper we present a time-varying sliding mode control (TVSMC) technique for reusable launch vehicle (RLV) attitude control in ascent and entry flight phases. In ascent flight the guidance commands Euler roll, pitch and yaw angles, and in entry flight it commands the aerodynamic angles of bank, attack and sideslip. The controller employs a body rate inner loop and the attitude outer loop, which are separated in time-scale by the singular perturbation principle. The novelty of the TVSMC is that both the sliding surface and the boundary layer dynamics can be varied in real time using the PD-eigenvalue assignment technique. This salient feature is used to cope with control command saturation and integrator windup in the presence of severe disturbance or control effector failure, which enhances the robustness and fault tolerance of the controller. The TV-SMC ascent and descent designs are currently being tested with high fidelity, 6-DOF dispersion simulations. The test results will be presented in the final version of this paper.
Universal and reusable virus deactivation system for respiratory protection
NASA Astrophysics Data System (ADS)
Quan, Fu-Shi; Rubino, Ilaria; Lee, Su-Hwa; Koch, Brendan; Choi, Hyo-Jick
2017-01-01
Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary/secondary infection and transmission. Here, we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt. The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases.
Universal and reusable virus deactivation system for respiratory protection
Quan, Fu-Shi; Rubino, Ilaria; Lee, Su-Hwa; Koch, Brendan; Choi, Hyo-Jick
2017-01-01
Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary/secondary infection and transmission. Here, we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt. The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases. PMID:28051158
14 CFR 431.15 - Rights not conferred by a reusable launch vehicle mission license.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Rights not conferred by a reusable launch vehicle mission license. 431.15 Section 431.15 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION... LAUNCH VEHICLE (RLV) General § 431.15 Rights not conferred by a reusable launch vehicle mission license...
14 CFR 431.15 - Rights not conferred by a reusable launch vehicle mission license.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Rights not conferred by a reusable launch vehicle mission license. 431.15 Section 431.15 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION... LAUNCH VEHICLE (RLV) General § 431.15 Rights not conferred by a reusable launch vehicle mission license...
14 CFR 431.15 - Rights not conferred by a reusable launch vehicle mission license.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Rights not conferred by a reusable launch vehicle mission license. 431.15 Section 431.15 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION... LAUNCH VEHICLE (RLV) General § 431.15 Rights not conferred by a reusable launch vehicle mission license...
14 CFR 431.15 - Rights not conferred by a reusable launch vehicle mission license.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Rights not conferred by a reusable launch vehicle mission license. 431.15 Section 431.15 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION... LAUNCH VEHICLE (RLV) General § 431.15 Rights not conferred by a reusable launch vehicle mission license...
14 CFR 431.15 - Rights not conferred by a reusable launch vehicle mission license.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Rights not conferred by a reusable launch vehicle mission license. 431.15 Section 431.15 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION... LAUNCH VEHICLE (RLV) General § 431.15 Rights not conferred by a reusable launch vehicle mission license...
Methodology for Evaluating Quality and Reusability of Learning Objects
ERIC Educational Resources Information Center
Kurilovas, Eugenijus; Bireniene, Virginija; Serikoviene, Silvija
2011-01-01
The aim of the paper is to present the scientific model and several methods for the expert evaluation of quality of learning objects (LOs) paying especial attention to LOs reusability level. The activities of eQNet Quality Network for a European Learning Resource Exchange (LRE) aimed to improve reusability of LOs of European Schoolnet's LRE…
14 CFR 437.31 - Verification of operating area containment and key flight-safety event limitations.
Code of Federal Regulations, 2010 CFR
2010-01-01
...(a) to contain its reusable suborbital rocket's instantaneous impact point within an operating area... limits on the ability of the reusable suborbital rocket to leave the operating area; or (2) Abort... requirements of § 437.59 to conduct any key flight-safety event so that the reusable suborbital rocket's...
14 CFR 437.31 - Verification of operating area containment and key flight-safety event limitations.
Code of Federal Regulations, 2013 CFR
2013-01-01
...(a) to contain its reusable suborbital rocket's instantaneous impact point within an operating area... limits on the ability of the reusable suborbital rocket to leave the operating area; or (2) Abort... requirements of § 437.59 to conduct any key flight-safety event so that the reusable suborbital rocket's...
14 CFR 437.31 - Verification of operating area containment and key flight-safety event limitations.
Code of Federal Regulations, 2012 CFR
2012-01-01
...(a) to contain its reusable suborbital rocket's instantaneous impact point within an operating area... limits on the ability of the reusable suborbital rocket to leave the operating area; or (2) Abort... requirements of § 437.59 to conduct any key flight-safety event so that the reusable suborbital rocket's...
14 CFR 437.31 - Verification of operating area containment and key flight-safety event limitations.
Code of Federal Regulations, 2011 CFR
2011-01-01
...(a) to contain its reusable suborbital rocket's instantaneous impact point within an operating area... limits on the ability of the reusable suborbital rocket to leave the operating area; or (2) Abort... requirements of § 437.59 to conduct any key flight-safety event so that the reusable suborbital rocket's...
14 CFR 437.31 - Verification of operating area containment and key flight-safety event limitations.
Code of Federal Regulations, 2014 CFR
2014-01-01
...(a) to contain its reusable suborbital rocket's instantaneous impact point within an operating area... limits on the ability of the reusable suborbital rocket to leave the operating area; or (2) Abort... requirements of § 437.59 to conduct any key flight-safety event so that the reusable suborbital rocket's...
NASA Technical Reports Server (NTRS)
Morgan, Timothy E.
1995-01-01
The objective of the Reusable Software System (RSS) is to provide NASA Langley Research Center and its contractor personnel with a reusable software technology through the Internet. The RSS is easily accessible, provides information that is extractable, and the capability to submit information or data for the purpose of scientific research at NASA Langley Research Center within the Atmospheric Science Division.
NASA Technical Reports Server (NTRS)
Esposito, J. J.; Zabora, R. F.
1975-01-01
Pertinent mechanical and physical properties of six high conductivity metals were determined. The metals included Amzirc, NARloy Z, oxygen free pure copper, electroformed copper, fine silver, and electroformed nickel. Selection of these materials was based on their possible use in high performance reusable rocket nozzles. The typical room temperature properties determined for each material included tensile ultimate strength, tensile yield strength, elongation, reduction of area, modulus of elasticity, Poisson's ratio, density, specific heat, thermal conductivity, and coefficient of thermal expansion. Typical static tensile stress-strain curves, cyclic stress-strain curves, and low-cycle fatigue life curves are shown. Properties versus temperature are presented in graphical form for temperatures from 27.6K (-410 F) to 810.9K (1000 F).
Improved Multi-Axial, Temperature and Time Dependent (MATT) Failure Model
NASA Technical Reports Server (NTRS)
Richardson, D. E.; Anderson, G. L.; Macon, D. J.
2002-01-01
An extensive effort has recently been completed by the Space Shuttle's Reusable Solid Rocket Motor (RSRM) nozzle program to completely characterize the effects of multi-axial loading, temperature and time on the failure characteristics of three filled epoxy adhesives (TIGA 321, EA913NA, EA946). As part of this effort, a single general failure criterion was developed that accounted for these effects simultaneously. This model was named the Multi- Axial, Temperature, and Time Dependent or MATT failure criterion. Due to the intricate nature of the failure criterion, some parameters were required to be calculated using complex equations or numerical methods. This paper documents some simple but accurate modifications to the failure criterion to allow for calculations of failure conditions without complex equations or numerical techniques.
Chen, Bingan; Zhong, Guofang; Oppenheimer, Pola Goldberg; Zhang, Can; Tornatzky, Hans; Esconjauregui, Santiago; Hofmann, Stephan; Robertson, John
2015-02-18
We have systematically studied the macroscopic adhesive properties of vertically aligned nanotube arrays with various packing density and roughness. Using a tensile setup in shear and normal adhesion, we find that there exists a maximum packing density for nanotube arrays to have adhesive properties. Too highly packed tubes do not offer intertube space for tube bending and side-wall contact to surfaces, thus exhibiting no adhesive properties. Likewise, we also show that the surface roughness of the arrays strongly influences the adhesion properties and the reusability of the tubes. Increasing the surface roughness of the array strengthens the adhesion in the normal direction, but weakens it in the shear direction. Altogether, these results allow progress toward mimicking the gecko's vertical mobility.
Differences in alarm events between disposable and reusable electrocardiography lead wires.
Albert, Nancy M; Murray, Terri; Bena, James F; Slifcak, Ellen; Roach, Joel D; Spence, Jackie; Burkle, Alicia
2015-01-01
Disposable electrocardiographic lead wires (ECG-LWs) may not be as durable as reusable ones. To examine differences in alarm events between disposable and reusable ECG-LWs. Two cardiac telemetry units were randomized to reusable ECG-LWs, and 2 units alternated between disposable and reusable ECG-LWs for 4 months. A remote monitoring team, blinded to ECG-LW type, assessed frequency and type of alarm events by using total counts and rates per 100 patient days. Event rates were compared by using generalized linear mixed-effect models for differences and noninferiority between wire types. In 1611 patients and 9385.5 patient days of ECG monitoring, patient characteristics were similar between groups. Rates of alarms for no telemetry, leads fail, or leads off were lower in disposable ECG-LWs (adjusted relative risk [95% CI], 0.71 [0.53-0.96]; noninferiority P < .001; superiority P = .03) and monitoring (artifact) alarms were significantly noninferior (adjusted relative risk [95% CI]: 0.88, [0.62-1.24], P = .02; superiority P = .44). No between-group differences existed in false or true crisis alarms. Disposable ECG-LWs were noninferior to reusable ECG-LWs for all false-alarm events (N [rate per 100 patient days], disposable 2029 [79.1] vs reusable 6673 [97.9]; adjusted relative risk [95% CI]: 0.81 [0.63-1.06], P = .002; superiority P = .12.) Disposable ECG-LWs with patented push-button design had superior performance in reducing alarms created by no telemetry, leads fail, or leads off and significant noninferiority in all false-alarm rates compared with reusable ECG-LWs. Fewer ECG alarms may save nurses time, decrease alarm fatigue, and improve patient safety. ©2015 American Association of Critical-Care Nurses.
Rollnick, M
1991-05-01
Both re-usable and disposable systems have their merits and problems. The disposable system, being fully integrated, appears to be steadily gaining market share compared with the re-usable system. Since its introduction, the success of the re-usable system has been limited by the use of pans not designed for automatic processing. Where the 'perfection' pan has been superseded by 'open' shaped receptacles and those used in commode chairs, cleaning effectiveness can be improved by a factor of 10. For this and other reasons, nursing involvement in the re-usable system can be high while the 'perfection' pan is in use. A work study exercise to compare nursing involvement in re-usable and disposable systems is under way. When selecting a human waste disposal system for any site, it is vital that all disciplines discuss and decide objectives. The equipment usage, space, site conditions, availability and quality of supplies (eg water, electricity), the costs of maintenance, nursing time and other expenditure must be considered. The disposable system is capable of high process rates (more than double that of the fastest re-usable system). Its capital cost is currently about 1,000 pounds less than an average re-usable system, but in the busiest wards, revenue costs may be higher. In such wards the space for disposable receptacle storage can be as much as five to ten times machine volume. The design of macerators is generally simpler (having less components) than washer-disinfectors. Monitoring and maintenance involvement are likewise expected to be lower, particularly in hospitals with modern drainage systems.(ABSTRACT TRUNCATED AT 250 WORDS)
Production Planning and Simulation for Reverse Supply Chain
NASA Astrophysics Data System (ADS)
Murayama, Takeshi; Yoda, Mitsunobu; Eguchi, Toru; Oba, Fuminori
This paper describes a production planning method for a reverse supply chain, in which a disassembly company takes reusable components from returned used products and supplies the reusable components for a product manufacturer. This method addresses the issue that the timings and quantities of returned products and reusable components obtained from them are unknown. This method first predicts the quantities of returned products and reusable components at each time period by using reliability models. Using the prediction result, the method performs production planning based on Material Requirements Planning (MRP). This method enables us to plan at each time period: the quantity of the products to be disassembled; the quantity of the reusable components to be used; and the quantity of the new components to be produced. The flow of the components and products through a forward and reverse supply chain is simulated to show the effectiveness of the method.
Reusable Component Model Development Approach for Parallel and Distributed Simulation
Zhu, Feng; Yao, Yiping; Chen, Huilong; Yao, Feng
2014-01-01
Model reuse is a key issue to be resolved in parallel and distributed simulation at present. However, component models built by different domain experts usually have diversiform interfaces, couple tightly, and bind with simulation platforms closely. As a result, they are difficult to be reused across different simulation platforms and applications. To address the problem, this paper first proposed a reusable component model framework. Based on this framework, then our reusable model development approach is elaborated, which contains two phases: (1) domain experts create simulation computational modules observing three principles to achieve their independence; (2) model developer encapsulates these simulation computational modules with six standard service interfaces to improve their reusability. The case study of a radar model indicates that the model developed using our approach has good reusability and it is easy to be used in different simulation platforms and applications. PMID:24729751
High efficiency replicated x-ray optics and fabrication method
Barbee, Jr., Troy W.; Lane, Stephen M.; Hoffman, Donald E.
2001-01-01
Replicated x-ray optics are fabricated by sputter deposition of reflecting layers on a super-polished reusable mandrel. The reflecting layers are strengthened by a supporting multilayer that results in stronger stress-relieved reflecting surfaces that do not deform during separation from the mandrel. The supporting multilayer enhances the ability to part the replica from the mandrel without degradation in surface roughness. The reflecting surfaces are comparable in smoothness to the mandrel surface. An outer layer is electrodeposited on the supporting multilayer. A parting layer may be deposited directly on the mandrel before the reflecting surface to facilitate removal of the layered, tubular optic device from the mandrel without deformation. The inner reflecting surface of the shell can be a single layer grazing reflection mirror or a resonant multilayer mirror. The resulting optics can be used in a wide variety of applications, including lithography, microscopy, radiography, tomography, and crystallography.
Advanced Key Technologies for Hot Control Surfaces in Space Re- Entry Vehicles
NASA Astrophysics Data System (ADS)
Dogigli, Michael; Pradier, Alain; Tumino, Giorgio
2002-01-01
(1)MAN Technologie AG, D- 86153 Augsburg, Germany (2,3) ESA, 2200 Noordwijk ZH, The Netherlands Current space re-entry vehicles (e.g. X-38 vehicle 201, the prototype of the International Space Station's Crew Return Vehicle (CRV)) require advanced control surfaces (so called body flaps). Such control surfaces allow the design of smaller and lighter vehicles as well as faster re-entries (compared to the US Shuttle). They are designed as light-weight structures that need no metallic parts, need no mass or volume consuming heat sinks to protect critical components (e.g. bearings) and that can be operated at temperatures of more than 1600 "C in air transferring high mechanical loads (dynamic 40 kN, static 70 kN) at the same time. Because there is a need for CRV and also for Reusable Launch Vehicles (RLV) in future, the European Space Agency (ESA) felt compelled to establish a "Future European Space Transportation and Investigation Program,, (FESTIP) and a "General Support for Technology Program,, (GSTP). One of the main goals of these programs was to develop and qualify key-technologies that are able to master the above mentioned challenging requirements for advanced hot control surfaces and that can be applied for different vehicles. In 1996 MAN Technologie has started the development of hot control surfaces for small lifting bodies in the national program "Heiü Strukturen,,. One of the main results of this program was that especially the following CMC (Ceramic Matrix Composite) key technologies need to be brought up to space flight standard: Complex CMC Structures, CMC Bearings, Metal-to-CMC Joining Technologies, CMC Fasteners, Oxidation Protection Systems and Static and Dynamic Seals. MAN Technologie was contracted by ESA to continue the development and qualification of these key technologies in the frame of the FESTIP and the GSTP program. Development and qualification have successfully been carried out. The key technologies have been applied for the X-38 vehicle 201 body flaps that have been designed, manufactured and qualified also by MAN Technologie in the frame of the national TETRA program ("Technologien fu zuku ftige Raum-Transportsysteme,,). A set of two body flaps will be delivered to NASA at the beginning of 2002 to be integrated into the vehicle 201. Based on development- and qualification tests, the paper describes main technical properties and features of these key technologies that at the same time represent the status of the art. In a qualification test (simultaneous application of thermal and mechanical loads with bearing movements in oxidising atmosphere) of a full scaled CMC bearing, five complete re-entries have been simulated successfully. The paper informs about applied mechanical load and temperature histories as well as about the number of intermittent bearing movements. The paper further informs about the complex CMC attachment structures (attachment of bearing into the body flap and load introduction) that have been qualified together with the CMC bearing. The attachment of the body flap to the vehicle's aft structure has also been qualified by tests in which also four re- entries have been simulated successfully. The attachment in principle is an interfacing structure between the "hot" (1600 "C) CMC body flap and the "cold,, (175 "C) metallic vehicle's aft structure that is able to transfer high me- chanical loads at high temperatures and minimise the heat flux through interfacing components in such way that the temperature difference of 1600 "C 175 "C = 1425 "C is brought down over a structure-length of only 200 mm. The paper informs about applied mechanical load and temperature histories and about the safety margins that have been demonstrated by rupture tests. Mechanical load carrying capacity and thermal resistance of ceramic fasteners have been demonstrated in several development tests which cover tension-, shear-, fatigue- and self locking-tests as well as tests with fastener assemblies representative for the body flaps. The reliability of these fasteners has also been demonstrated in the bearing and body flap qualification tests. In a comprehensive development test campaign, oxidation protection systems as well as repair methods have been developed and successfully applied for the body flap structure and components that reliably can be protected at least for four re-entries. The development of key technologies is continued in the national ASTRA program ("Basistechnologien fu keramische Hochtemperatur-Komponenten,,) and in international programs that among others focus on to improve the reusability of high temperature CMC components for RLVs.
Liu, Lanhua; Zhou, Xiaohong; Lu, Yun; Shan, Didi; Xu, Bi; He, Miao; Shi, Hanchang; Qian, Yi
2017-11-15
The apparent increase in hormone-induced cancers and disorders of the reproductive tract has led to a growing demand for new technologies capable of screening xenoestrogens. We reported an estrogen receptor (ER)-based reusable fiber biosensor for facile screening estrogenic compounds in environment. The bioassay is based on the competition of xenoestrogens with 17β-estradiol (E 2 ) for binding to the recombinant receptor of human estrogen receptor α (hERα) protein, leaving E 2 free to bind to fluorophore-labeled anti-E 2 monoclonal antibody. Unbound anti-E 2 antibody then binds to the immobilized E 2 -protein conjugate on the fiber surface, and is detected by fluorescence emission induced by evanescent field. As expected, the stronger estrogenic activity of xenoestrogen would result in the weaker fluorescent signal. Three estrogen-agonist compounds, diethylstilbestrol (DES), 4-n-nonylphenol (NP) and 4-n-octylphenol (OP), were chosen as a paradigm for validation of this assay. The rank order of estrogenic potency determined by this biosensor was DES>OP>NP, which were consistent with the published results in numerous studies. Moreover, the E 2 -protein conjugate modified optical fiber was robust enough for over 300 sensing cycles with the signal recoveries ranging from 90% to 100%. In conclusion, the biosensor is reusable, reliable, portable and amenable to on-line operation, providing a facile, efficient and economical alternative to screen potential xenoestrogens in environment. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Marshall, B. A.; Marroquin, J.
1984-01-01
In order to support analysis of the STS-6 advanced flexible reusable surface insulation (AFRSI) anomaly, data were obtained for aerodynamic and aeroacoustic environments in affected areas of the orbiter. Data are presented in tabular form.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-13
... Reusable Suborbital Rockets at the Mojave Air and Space Port AGENCY: Federal Aviation Administration (FAA... of SpaceShipTwo Reusable Suborbital Rockets at the Mojave Air and Space Port. The Draft EA was... licenses to operate SpaceShipTwo Reusable Suborbital Rockets and WhiteKnightTwo carrier aircraft at the...
Long-term/strategic scenario for reusable booster stages
NASA Astrophysics Data System (ADS)
Sippel, Martin; Manfletti, Chiara; Burkhardt, Holger
2006-02-01
This paper describes the final design status of a partially reusable space transportation system which has been under study for five years within the German future launcher technology research program ASTRA. It consists of dual booster stages, which are attached to an advanced expendable core. The design of the reference liquid fly-back boosters (LFBB) is focused on LOX/LH2 propellant and a future advanced gas-generator cycle rocket motor. The preliminary design study was performed in close cooperation between DLR and the German space industry. The paper's first part describes recent progress in the design of this reusable booster stage. The second part of the paper assesses a long-term, strategic scenario of the reusable stage's operation. The general idea is the gradual evolution of the above mentioned basic fly-back booster vehicle into three space transportation systems performing different tasks: Reusable First Stage for a small launcher application, successive development to a fully reusable TSTO, and booster for a super-heavy-lift rocket to support an ambitious space flight program like manned Mars missions. The assessment addresses questions of technical sanity, preliminary sizing and performance issues and, where applicable, examines alternative options.
2000 NASA Seal/Secondary Air System Workshop. Volume 1
NASA Technical Reports Server (NTRS)
Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)
2001-01-01
The 2000 NASA Seal/Secondary Air System Workshop covered four main areas: (1) overviews of NASA-sponsored Ultra-Efficient Engine Technology (UEET) and Access to Space Programs, with emphasis on program goals and seal needs; (2) review of turbine engine seal issues from the perspective of end users such as United Airlines; (3) reviews of sealing concepts, test results, experimental facilities, and numerical predictions; and (4) reviews of material development programs relevant to advanced seals development. The NASA UEET overview illustrates for the reader the importance of advanced technologies, including seals, in meeting future engine system efficiency and emission goals. GE, Pratt & Whitney, and Honeywell presented advanced seal development work being performed within their organizations. The NASA-funded GE/Stein Seal team has successfully demonstrated a large (3-ft. diam) aspirating seal that can withstand all anticipated pressures, speeds, and rotor runouts anticipated for a GE90 L.P. turbine balance piston location. GE/Stein Seal are fabricating a full-scale seal to be tested in a GE-90 ground test engine in early 2002. Pratt & Whitney and Stein Seal are investigating carbon seals to accommodate large radial movements anticipated in future geared-fan gearbox locations. Honeywell presented a finger seal design being considered for a high-temperature static combustor location incorporating ceramic finger elements. Successful demonstration of the braided carbon rope thermal barriers to extreme temperatures (5500 F) for short durations provide a new form of very high temperature thermal barrier for future Shuttle solid rocket motor nozzle joints. The X-37, X-38, and future highly reusable launch vehicles pose challenging control surface seal demands that require new seal concepts made from emerging high temperature ceramics and other materials.
NASA Astrophysics Data System (ADS)
Cho, Yuichiro; Kameda, Shingo; Okuno, Mamoru; Horiuchi, Misa; Shibasaki, Kazuo; Wagatsuma, Ryo; Aida, Yusuke; Miura, Yayoi N.; Yoshioka, Kazuo; Okazaki, Ryuji; Sugita, Seiji
2017-10-01
Mass spectrometry has been widely used in lander missions to characterize the volatiles in rocks and soils on planetary surfaces. A good vacuum seal is very important for introducing such solid samples to a vacuum chamber and ejecting them. However, multiple measurements require many metal gaskets, leading to extra weight and complexity for the instruments. In this study, we investigate the capability of three kinds of elastomeric O-rings (Viton, Nexus-SLT, and Nexus-FV) as vacuum seals for mass spectrometric measurements, particularly for in situ K-Ar dating on Mars. First, thermal cycle tests revealed that low-temperature-resistant O-rings can maintain pressure <10-5 Pa at -60 °C under 1 bar ambient pressure, whereas Viton O-rings leaked at -25 °C. Then, the amount of 40Ar due to outgassing from the O-rings and permeation under the ambient pressure of 650 Pa or 3 Pa was measured and compared with the amounts of 40Ar that a flight-equivalent laser would liberate from potential target Martian rocks. The measured amounts were <1% of that a target rock with 5000 ppm K2O and an age of 4.2 Ga would yield. These results suggest that a Viton O-ring can maintain the Ar blank low under the Mars atmospheric pressure when temperatures are higher than -25 °C. A double O-ring seal using the low-temperature-resistant elastomers would be an alternative approach at lower temperatures. The elastomeric O-rings would be useful for constructing a small and light-weighted mass spectrometric instrument for in situ K-Ar dating on Mars.
Refractory Ceramic Foams for Novel Applications
NASA Technical Reports Server (NTRS)
Stackpoole, M.
2008-01-01
Workers at NASA Ames Research center are endeavoring to develop durable, oxidation-resistant, foam thermal protection systems (TPSs) that would be suitable for covering large exterior spacecraft surfaces, would have low to moderate densities, and would have temperature capabilities comparable to those of carbon-based TPSs [reusable at 3,000 F (.1,650 C)] with application of suitable coatings. These foams may also be useful for repairing TPSs while in orbit. Moreover, on Earth as well as in outer space, these foams might be useful as catalyst supports and filters. Preceramic polymers are obvious candidates for use in making the foams in question. The use of these polymers offers advantages over processing routes followed in making conventional ceramics. Among the advantages are the ability to plastically form parts, the ability to form pyrolized ceramic materials at lower temperatures, and the ability to form high-purity microstructures having properties that can be tailored to satisfy requirements. Heretofore, preceramic polymers have been used mostly in the production of such low-dimensional products as fibers because the loss of volatiles during pyrolysis of the polymers leads to porosity and large shrinkage (in excess of 30 percent). In addition, efforts to form bulk structures from preceramic polymers have resulted in severe cracking during pyrolysis. However, because the foams in question would consist of networks of thin struts (in contradistinction to nonporous dense solids), these foams are ideal candidates for processing along a preceramic-polymer route.
Application of fiber Bragg grating sensors to real-time strain measurement of cryogenic tanks
NASA Astrophysics Data System (ADS)
Takeda, Nobuo; Mizutani, Tadahito; Hayashi, Kentaro; Okabe, Yoji
2003-08-01
Although many researches of strain measurement using fiber Bragg grating (FBG) sensors were conducted, there were few applications of FBG sensors to spacecraft in operation. It is very significant to develop an onboard system for the real-time strain measurement during the flight operation. In the present research, the real-time strain measurement of a composite liquid hydrogen (LH2) tank, which consisted of CFRP and aluminum liner, was attempted. Adhesive property of the FBG sensors was investigated first of all. As a result, UV coated FBG sensors and polyurethane adhesive were adopted. Then, reflection spectra from FBG sensors were measured through the tensile test at liquid helium (LHe) temperature. Since the center wavelength shifted in proportion to the applied strain, the FBG sensor was suitable as a precise strain sensor even at LHe temperature. Next, the development of an onboard FBG demodulator was discussed. This onboard demodulator was designed for weight saving to be mounted on a reusable rocket vehicle test (RVT) operated by the Institute of Space and Astronautical Science (ISAS). FBG sensors were bonded on the surface of the composite LH2 tank for the RVT. Then, strain measurement using the onboard demodulator was conducted through the cryogenic pressure test of the tank and compared with the result measured using the optical spectrum analyzer (OSA).
Synthesis of cerium and nickel doped titanium nanofibers for hydrolysis of sodium borohydride.
Tamboli, Ashif H; Gosavi, S W; Terashima, Chiaki; Fujishima, Akira; Pawar, Atul A; Kim, Hern
2018-07-01
A recyclable titanium nanofibers, doped with cerium and nickel doped was successfully synthesized by using sol-gel and electrospinning method for hydrogen generation from alkali free hydrolysis of NaBH 4 . The resultant nanocomposite was characterized to find out the structural and physical-chemical properties by a series of analytical techniques such as FT-IR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), SEM (scanning electron microscope), EDX (energy-dispersive X-ray spectroscopy),N 2 adsorption-desorption and BET (Brunauer-Emmett-Teller), etc. The results revealed that cerium and nickel nanoparticles were homogeneously distributed on the surface of the TiO 2 nanofibers due to having similar oxidation state and atomic radium of TiO 2 nanofibers with CeO 2 and NiO for the effective immobilization of metal ions. The NiO doped catalyst showed superior catalytic performance towards the hydrolysis reaction of NaBH 4 at room temperature. These catalysts have ability to produce 305 mL of H 2 within the time of 160 min at room temperature. Additionally, reusability test revealed that the catalyst is active even after five runs of hydrolytic reaction, implying the as-prepared NiO doped TiO 2 nanofibers could be considered as a potential candidate catalyst for portable hydrogen fuel system such as PEMFC (proton exchange membrane fuel cells). Copyright © 2018 Elsevier Ltd. All rights reserved.
Kinetic and catalytic analysis of mesoporous Co3O4 on the oxidation of morin
NASA Astrophysics Data System (ADS)
Xaba, Morena. S.; Meijboom, Reinout
2017-11-01
Herein we report on the synthesis, characterization and catalytic evaluation of mesoporous cobalt oxides on the oxidation of morin. These mesoporous cobalt oxides were synthesized using an inverse surfactant micelle method, they are connected, well-defined with intra-particle voids. These materials were calcined to different final heating temperatures of 150, 250, 350, 450 and 550 °C, and each mesoporous cobalt oxide catalyst showed unique physical properties and catalytic behavior. Morin oxidation was used as a model reaction in the presence of hydrogen peroxide to evaluate the kinetic and catalytic activity of calcined mesoporous cobalt oxides. The adsorption-desorption equilibrium rate constants of morin and hydrogen peroxide were found to be inversely proportional to the crystallite size of the mesoporous cobalt oxide, and the characteristic path length in which the mass transfer takes place was found to be directly proportional to the crystallite size. The materials were characterized using powder X-Ray Diffraction (p-XRD), N2-sorption isotherms (BET), hydrogen temperature programmed reduction (H2-TPR) and High Resolution-Transmission Electron Microscopy (HR-TEM). UV-vis spectrophotometry was used to monitor the time-resolved absorbance of morin at λmax = 410 nm. The surface reaction in this system is described in terms of the well-established Langmuir-Hinshelwood model. The thermodynamic parameters, EA, ΔH#, ΔS# and ΔG# were calculated and catalyst recycling and reusability is demonstrated.
Sun, Huaiyan; Jin, Xinyu; Long, Nengbing; Zhang, Ruifeng
2017-02-01
A ZnO nanowires/macroporous SiO 2 composite was used as support to immobilize horseradish peroxidase (HRP) by in-situ cross-linking method. Using diethylene glycol diglycidyl ether (DDE) as a long-chained cross-linker, it was adsorbed on the surface of ZnO nanowires before reaction with HRPs, the resulted composite was quite different from the traditional cross-linking enzyme aggregates (CLEAs) on both structure and catalytic performance. The immobilized HRP showed high activity in the decolorization of azo dyes. The effect of various conditions such as the loading amount of HRP, solution pH, temperature, contact time and concentration of dye were optimized on the decolorization. The decolorization percentage of Acid Blue 113 and Acid black 10 BX reached as high as 95.4% and 90.3%, respectively. The immobilized HRP gave the highest decolorization rate under dye concentration as 50mg/L and reaction time of 35min. The immobilized HRP exhibited much better resistance to temperature and pH inactivation than free HRP. The storage stability and reusability were greatly improved through the immobilization, from the decolorization of Acid blue 113 it was found that 80.4% of initial efficiency retained after incubation at 4°C for 60 days, and that 79.4% of decolorization efficiency retained after 12 cycles reuse. Copyright © 2016 Elsevier B.V. All rights reserved.
Anuar, Sabiqah Tuan; Villegas, Carla; Mugo, Samuel M; Curtis, Jonathan M
2011-06-01
This study demonstrates the utility of a flow-through enzyme immobilized silica microreactor for lipid transformations. A silica micro structured fiber (MSF) consisting of 168 channels of internal diameter 4-5 μm provided a large surface area for the covalent immobilization of Candida antartica lipase. The specific activity of the immobilized lipase was determined by hydrolysis of p-nitrophenyl butyrate and calculated to be 0.81 U/mg. The catalytic performance of the lipase microreactor was demonstrated by the efficient ethanolysis of canola oil. The parameters affecting the performance of the MSF microreactor, including temperature and reaction flow rate, were investigated. Characterization of the lipid products exiting the microreactor was performed by non-aqueous reversed-phased liquid chromatography (NARP-LC) with evaporative light scattering detector (ELSD) and by comprehensive two-dimensional gas chromatography (GC x GC). Under optimized conditions of 1 μL/min flow rate of 5 mg/mL trioleoylglycerol (TO) in ethanol and 50 °C reaction temperature, 2-monooleoylglycerol was the main product at > 90% reaction yield. The regioselectivity of the Candida antartica lipase immobilized MSF microreactor in the presence of ethanol was found to be comparable to that obtained under conventional conditions. The ability of these reusable flow-through microreactors to regioselectively form monoacylglycerides in high yield from triacylglycerides demonstrate their potential use in small-scale lipid transformations or analytical lipids profiling.
Characterization of Damage Accumulation in a C/SiC Composite at Elevated Temperatures
NASA Technical Reports Server (NTRS)
Telesman, Jack; Verrilli, Mike; Ghosn, Louis; Kantzos, Pete
1997-01-01
This research is part of a program aimed to evaluate and demonstrate the ability of candidate CMC materials for a variety of applications in reusable launch vehicles. The life and durability of these materials in rocket and engine applications are of major concern and there is a need to develop and validate life prediction methodology. In this study, material characterization and mechanical testing was performed in order to identify the failure modes, degradation mechanisms, and progression of damage in a C/SiC composite at elevated temperatures. The motivation for this work is to provide the relevant damage information that will form the basis for the development of a physically based life prediction methodology.
Başak, Esra; Aydemir, Tülin; Dinçer, Ayşe; Becerik, Seda Çınar
2013-12-01
Catalase was immobilized on chitosan and modified chitosan. Studies were carried out on free-immobilized catalase concerning the determination of optimum temperature, pH, thermal, storage stability, reusability, and kinetic parameters. Optimum temperature and pH for free catalase and catalase immobilized were found as 35°C and 7.0, respectively. After 100 times of repeated tests, the immobilized catalases on chitosan-clay and magnetic chitosan maintain over 50% and 60% of the original activity, respectively. The ease of catalase immobilization on low-cost matrices and good stability upon immobilization in the present study make it a suitable product for further use in the food industry.
Reusable vibration resistant integrated circuit mounting socket
Evans, Craig N.
1995-01-01
This invention discloses a novel form of socket for integrated circuits to be mounted on printed circuit boards. The socket uses a novel contact which is fabricated out of a bimetallic strip with a shape which makes the end of the strip move laterally as temperature changes. The end of the strip forms a barb which digs into an integrated circuit lead at normal temperatures and holds it firmly in the contact, preventing loosening and open circuits from vibration. By cooling the contact containing the bimetallic strip the barb end can be made to release so that the integrated circuit lead can be removed from the socket without damage either to the lead or to the socket components.
Feasibility study of polyurethane shape-memory polymer actuators for pressure bandage application
Ahmad, Manzoor; Luo, Jikui; Miraftab, Mohsen
2012-01-01
The feasibility of laboratory-synthesized polyurethane-based shape-memory polymer (SMPU) actuators has been investigated for possible application in medical pressure bandages where gradient pressure is required between the ankle and the knee for treatment of leg ulcers. In this study, using heat as the stimulant, SMPU strip actuators have been subjected to gradual and cyclic stresses; their recovery force, reproducibility and reusability have been monitored with respect to changes in temperature and circumference of a model leg, and the stress relaxation at various temperatures has been investigated. The findings suggest that SMPU actuators can be used for the development of the next generation of pressure bandages. PMID:27877473
NASA Technical Reports Server (NTRS)
Milos, Frank S.; Watters, David G.; Pallix, Joan B.; Bahr, Alfred J.; Huestis, David L.; Arnold, Jim (Technical Monitor)
2001-01-01
Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to develop inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and SRI International to develop 'SensorTags,' radio frequency identification devices coupled with event-recording sensors, that can be embedded in the thermal protection system to monitor temperature or other quantities of interest. Two prototype SensorTag designs containing thermal fuses to indicate a temperature overlimit are presented and discussed.
Insulating Material for Next-Generation Spacecraft
NASA Technical Reports Server (NTRS)
White, Susan; Johnson, Sylvia; Salerno, Louis; Kittel, Peter; Roach, Pat; Helvensteijn, Ben; Kashani, Ali
2006-01-01
A report discusses the development of a flexible thermal-insulation material for cryogenic tanks in next-generation spacecraft. This material is denoted Advanced Reusable All-temperature Multimode Insulation System (ARAMIS). The report begins by describing the need for ARAMIS and the technological challenges of developing a single material that is useable throughout the temperature range from storage of liquid hydrogen (20 K) to atmospheric-reentry heating (>2,000 K), has the requisite low thermal conductivity, resists condensation of moisture without need for a gas purge, and withstands reentry heating for a 400-mission lifetime. The report then discusses laboratory apparatuses for testing materials that have been and will be considered as candidates for the development of ARAMIS.
Measuring Thermal Conductivity and Moisture Absorption of Cryo-Insulation Materials
NASA Technical Reports Server (NTRS)
Lambert, Michael A.
1998-01-01
NASA is seeking to develop thermal insulation material systems suitable for withstanding both extremely high temperatures encountered during atmospheric re-entry heating and aero- braking maneuvers, as well as extremely low temperatures existing in liquid fuel storage tanks. Currently, materials used for the high temperature insulation or Thermal Protection System (TPS) are different from the low temperature, or cryogenic insulation. Dual purpose materials are necessary to the development of reusable launch vehicles (RLV). The present Space Shuttle (or Space Transportation System, STS) employs TPS materials on the orbiter and cryo-insulation materials on the large fuel tank slung under the orbiter. The expensive fuel tank is jettisoned just before orbit is achieved and it burns up while re-entering over the Indian Ocean. A truly completely reusable launch vehicle must store aR cryogenic fuel internally. The fuel tanks will be located close to the outer surface. In fact the outer skin of the craft will probably also serve as the fuel tank enclosure, as in jet airliners. During a normal launch the combined TPS/cryo-insulation system will serve only as a low temperature insulator, since aerodynamic heating is relatively minimal during ascent to orbit. During re-entry, the combined TPS/cryo-insulation system will serve only as a high temperature insulator, since all the cryogenic fuel will have been expended in orbit. However, in the event of an.aborted launch or a forced/emergency early re-entry, the tanks will still contain fuel, and the TPS/cryo-insulation will have to serve as both low and high temperature insulation. Also, on long duration missions, such as to Mars, very effective cryo-insulation materials are needed to reduce bod off of liquid propellants, thereby reducing necessary tankage volume, weight, and cost. The conventional approach to obtaining both low and high temperature insulation, such as is employed for the X-33 and X-34 spacecraft, is to use separate TPS and cryo-insulation materials, which are connected by means of adhesives or stand-offs (spacers). Three concepts are being considered: (1) the TPS is bonded directly to the cryo-insulation which, in turn, is bonded to the exterior of the tank, (2) stand-offs are used to make a gap between the TPS and the cryo-insulation, which is bonded externally to the tank, (3) TPS is applied directly or with stand-offs to the exterior so the tank, and cryo-insulation is applied directly to the interior of the tank. Many potential problems are inherent in these approaches. For example, mismatch between coefficients of thermal expansion of the TPS and cryo-insulation, as well as aerodynamic loads, could lead to failure of the bond. Internal cryo-insulation must be prevent from entering the sump of the fuel turbo-pump. The mechanical integrity of the stand-off structure (if used) must withstand multiple missions. During ground hold (i.e., prior to launch) moisture condensation must be minimized in the gap between the cryo-insulation and the TPS. The longer term solution requires the development of a single material to act as cryo- insulation during ground hold and as TPS during re-entry. Such a material minimizes complexity and weight while improving reliability and reducing cost.
Conductive heat exchange with a gel-coated circulating water mattress.
Bräuer, Anselm; Pacholik, Larissa; Perl, Thorsten; English, Michael John Murray; Weyland, Wolfgang; Braun, Ulrich
2004-12-01
The use of forced-air warming is associated with costs for the disposable blankets. As an alternative method, we studied heat transfer with a reusable gel-coated circulating water mattress placed under the back in eight healthy volunteers. Heat flux was measured with six calibrated heat flux transducers. Additionally, mattress temperature, skin temperature, and core temperature were measured. Water temperature was set to 25 degrees C, 30 degrees C, 35 degrees C, and 41 degrees C. Heat transfer was calculated by multiplying heat flux by contact area. Mattress temperature, skin temperature, and heat flux were used to determine the heat exchange coefficient for conduction. Heat flux and water temperature were related by the following equation: heat flux = 10.3 x water temperature - 374 (r(2) = 0.98). The heat exchange coefficient for conduction was 121 W . m(-2) . degrees C(-1). The maximal heat transfer with the gel-coated circulating water mattress was 18.4 +/- 3.3 W. Because of the small effect on the heat balance of the body, a gel-coated circulating water mattress placed only on the back cannot replace a forced-air warming system.
Integrated circuits, and design and manufacture thereof
Auracher, Stefan; Pribbernow, Claus; Hils, Andreas
2006-04-18
A representation of a macro for an integrated circuit layout. The representation may define sub-circuit cells of a module. The module may have a predefined functionality. The sub-circuit cells may include at least one reusable circuit cell. The reusable circuit cell may be configured such that when the predefined functionality of the module is not used, the reusable circuit cell is available for re-use.
A Prospective Randomized Study Comparing Disposable with Reusable Blades for a Morcellator Device.
Becker, Benedikt; Orywal, Ann Katrin; Hausmann, Teresa; Gross, Andreas J; Netsch, Christopher
2017-03-01
Transurethral enucleation of the prostate for the management of benign prostatic obstruction (BPO) involves two steps: the enucleation and morcellation procedure. The aim of our study was to assess the efficacy of a morcellator device using disposable and reusable blades with different settings of morcellation speed. A prospective randomized study was initiated for patients with symptomatic BPO undergoing Thulium laser enucleation of the prostate. Mechanical tissue morcellation was performed using the Piranha™ morcellator (R. Wolf, Knittlingen, Germany) with disposable or reusable blades at 850 (n = 24) or 1500 revolutions per minute (rpm) (n = 24). Patient characteristics, intraoperative complications, and the morcellation rate (g/min) were recorded. Data are expressed as median and interquartile range (IQR). Forty-eight patients were randomized using disposable (n = 24) or reusable blades (n = 24). For reusable blades, the morcellation rate did not increase when changing the morcellation speed from 850 to 1500 rpm (5 vs 4.53 g/min, p = 0.843). The morcellation rate increased significantly when changing the morcellation speed from 850 to 1500 rpm using single-use blades (4.77 vs 10 g/min, p ≤ 0.014). The morcellation rate was not different at 850 rpm between reusable and single-use blades (5 vs 4.77 g/min, p = 0.671). Conversely, the morcellation rate was significantly different at 1500 rpm between reusable and single-use blades (4.53 vs 10 g/min, p ≤ 0.017). The total morcellation rate (at 850 and 1500 rpm) was significantly increased using single-use blades compared to reusable blades (7.67 vs 4.8 g/min, p ≤ 0.026). Interestingly, enucleated weight (g) and the morcellation rate (g/min) correlated inversely using single-use blades at 1500 rpm (r = -0.742, p ≤ 0.004). Only one superficial bladder injury occurred at 1500 rpm, which needed no further interventions. The Piranha morcellator facilitates efficient tissue removal with single-use and reusable blades. Disposable morcellator blades increase tissue removal significantly at 1500 rpm.
NASA Technical Reports Server (NTRS)
2004-01-01
KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, workers remove the Rudder Speed Brake panel on the vertical tail of the orbiter Atlantis. The Rudder Speed Brake is being removed for inspection and maintenance prior to Return to Flight. The vertical tail consists of a structural fin surface made of aluminum, the Rudder Speed Brake surface, a tip and a lower trailing edge. The rudder splits into two halves to serve as a speed brake. The vertical tail and Rudder Speed Brake are covered with a reusable thermal protection system. The Rudder Speed Brake is used to guide and slow the Shuttle as it comes in for a landing.
Closeup of F-15B Flight Test Fixture (FTF) with X-33 Thermal Protection Systems (TPS)
NASA Technical Reports Server (NTRS)
1998-01-01
A close up of the Flight Test Fixture II, mounted on the underside of the F-15B Aerodynamic Flight Facility aircraft. The Thermal Protection System (TPS)samples, which included metallic Inconel tiles, soft Advanced Flexible Reusable Surface Insulation tiles, and sealing materials, were attached to the forward-left side position of the test fixture. In-flight video from the aircraft's on-board video system, as well as chase aircraft photos and video footage, documented the condition of the TPS during flights. Surface pressures over the TPS was measured by thermocouples contained in instrumentation 'islands,' to document shear and shock loads.
NASA Technical Reports Server (NTRS)
Houser, J. F.; Runciman, W. H.
1971-01-01
Experimental aerodynamic investigations were made in the Grumman 36-inch hypersonic wind tunnel on a .00435 scale model of the H-32 reusable space shuttle booster. The objectives of the test were to determine the static stability characteristics and control surface effectiveness at hypersonic speeds. Data were taken at M = 8.12 over a range of angles of attack between -5 and 85 deg at beta = 0 deg and over a range of side slip angles between -10 and 10 deg at alpha = 0 and 70 deg. Six component balance data and base-cavity pressure data were recorded.
Closeup of F-15B Flight Test Fixture (FTF) with X-33 Thermal Protection Systems (TPS)
1998-05-14
A close up of the Flight Test Fixture II, mounted on the underside of the F-15B Aerodynamic Flight Facility aircraft. The Thermal Protection System (TPS) samples, which included metallic Inconel tiles, soft Advanced Flexible Reusable Surface Insulation tiles, and sealing materials, were attached to the forward-left side position of the test fixture. In-flight video from the aircraft's on-board video system, as well as chase aircraft photos and video footage, documented the condition of the TPS during flights. Surface pressures over the TPS was measured by thermocouples contained in instrumentation "islands," to document shear and shock loads.
Experimental evaluation of joint designs for a space-shuttle orbiter ablative leading edge
NASA Technical Reports Server (NTRS)
Tompkins, S. S.; Kabana, W. P.
1975-01-01
The thermal performance of two types of ablative leading-edge joints for a space-shuttle orbiter were tested and evaluated. Chordwise joints between ablative leading-edge segments, and spanwise joints between ablative leading-edge segments and reusable surface insulation tiles were exposed to simulated shuttle heating environments. The data show that the thermal performance of models with chordwise joints to be as good as jointless models in simulated ascent-heating and orbital cold-soak environments. The suggestion is made for additional work on the joint seals, and, in particular, on the effects of heat-induced seal-material surface irregularities on the local flow.
NASA Technical Reports Server (NTRS)
2004-01-01
KENNEDY SPACE CENTER, FLA. -- A Rudder Speed Brake Actuator is being removed from the orbiter Atlantis for shipment to the vendor for inspection. An actuator is a motor that moves the tail rudder back and forth to help steer it during landing and brake its speed. The vertical tail consists of a structural fin surface made of aluminum, the Rudder Speed Brake surface, a tip and a lower trailing edge. The rudder splits into two halves to serve as a speed brake. The vertical tail and Rudder Speed Brake are covered with a reusable thermal protection system. Atlantis is undergoing maintenance and inspection in the Orbiter Processing Facility for a future mission.
NASA Technical Reports Server (NTRS)
2004-01-01
KENNEDY SPACE CENTER, FLA. -- A Rudder Speed Brake Actuator is being removed from the orbiter Atlantis for shipment to the vendor for inspection. An actuator is a motor that moves the tail rudder back and forth to help steer it during landing and brake its speed. The vertical tail consists of a structural fin surface made of aluminum, the Rudder Speed Brake surface, a tip and a lower trailing edge. The rudder splits into two halves to serve as a speed brake. The vertical tail and Rudder Speed Brake are covered with a reusable thermal protection system. Atlantis is undergoing maintenance and inspection in the Orbiter Processing Facility for a future mission.
Ma, Fang; Du, Hongtao; Li, Ronghua; Zhang, Zengqiang
In this work, pyridinium-functionalized silica nanoparticles adsorbent (PC/SiO2/Fe3O4) was synthesized for phosphate removal from aqueous solutions. The removal efficiency of phosphate on the PC/SiO2/Fe3O4 was carried out and investigated under various conditions such as pH, contact temperature and initial concentration. The results showed that the adsorption equilibrium could be reached within 10 min, which fitted a Langmuir isotherm model, with maximum adsorption capacity of 94.16 mg/g, and the kinetic data were fitted well by pseudo-second-order and intra-particle diffusion models. Phosphate loaded on the adsorbents could be easily desorbed with 0.2 mol/L of NaOH, and the adsorbents showed good reusability. The adsorption capacity was still around 50 mg/g after 10 times of reuse. All the results demonstrated that this pyridinium-functionalized mesoporous material could be used for the phosphate removal from aqueous solution and it was easy to collect due to its magnetic properties.
Catalytic Palladium Film Deposited by Scalable Low-Temperature Aqueous Combustion.
Voskanyan, Albert A; Li, Chi-Ying Vanessa; Chan, Kwong-Yu
2017-09-27
This article describes a novel method for depositing a dense, high quality palladium thin film via a one-step aqueous combustion process which can be easily scaled up. Film deposition of Pd from aqueous solutions by conventional chemical or electrochemical methods is inhibited by hydrogen embrittlement, thus resulting in a brittle palladium film. The method outlined in this work allows a direct aqueous solution deposition of a mirror-bright, durable Pd film on substrates including glass and glassy carbon. This simple procedure has many advantages including a very high deposition rate (>10 cm 2 min -1 ) and a relatively low deposition temperature (250 °C), which makes it suitable for large-scale industrial applications. Although preparation of various high-quality oxide films has been successfully accomplished via solution combustion synthesis (SCS) before, this article presents the first report on direct SCS production of a metallic film. The mechanism of Pd film formation is discussed with the identification of a complex formed between palladium nitrate and glycine at low temperature. The catalytic properties and stability of films are successfully tested in alcohol electrooxidation and electrochemical oxygen reduction reaction. It was observed that combustion deposited Pd film on a glassy carbon electrode showed excellent catalytic activity in ethanol oxidation without using any binder or additive. We also report for the first time the concept of a reusable "catalytic flask" as illustrated by the Suzuki-Miyaura cross-coupling reaction. The Pd film uniformly covers the inner walls of the flask and eliminates the catalyst separation step. We believe the innovative concept of a reusable catalytic flask is very promising and has the required features to become a commercial product in the future.
NASA Astrophysics Data System (ADS)
Barrocas, B.; Nunes, C. D.; Carvalho, M. L.; Monteiro, O. C.
2016-11-01
In this work, titanate nanotubes were modified with silver nanoparticles to produce new nanocomposite materials with enhanced photocatalytic activity for phenol removal. The TNTs were produced using a hydrothermal approach and, after being submitted to an Ag+ exchange process, metallic Ag nanoparticles were obtained over the nanotubes surface. The prepared materials were structural, morphological and optical characterized by X-ray powder diffraction, micro X-ray fluorescence, transmission electron microscopy, diffused reflectance spectroscopy and X-ray photoelectron spectroscopy. The characterization results indicate that Ag+ was immobilized not only in the nanotubes external surface but mainly in the TiO6 interlayers space. The application of this new nanocomposite material on photocatalytic degradation of pollutants was investigated. First, the evaluation of hydroxyl radical formation, using the terephthalic acid as a probe was studied. The photocatalytic activity of the sensitized materials for phenol degradation was afterwards evaluated. The results show that the nanocomposite sample is the best catalyst, achieving 98.0% photodegradation efficiency of a 0.2 mM phenol solution within 20 min under UV-vis radiation. The reusability of the prepared samples as photocatalysts was evaluated in four successive degradation assays, using fresh phenol solutions. The sensitized sample demonstrated excellent catalytic reusability ability, without loss of photochemical stability. The structural and morphological characterization during these experiments revealed no modifications on the nanotubes morphology but a continuous increase on the Ag nanoparticles, in number and size, with the irradiation time. A mechanism for this continuous growth of the Ag nanoparticles, together with the phenol catalytic photodegradation, over the nanotubes surface, is proposed and discussed.
Wang, Jhe-Yi; Su, Ya-Ling; Wu, Bo-Hao; Cheng, Shu-Hua
2016-01-15
The toxicity of bisphenol A (BPA) has attracted considerable attention, and the reported electrochemical sensors for BPA need further improvement in reusability due to serious surface fouling. In this study, a composite film is designed aiming to provide both an accurate and repeatable platform for BPA determination. The conducting poly(3,4-ethylenedioxythiophene) film (PEDOT) and ionic liquid 1-butyl-3-methylimidazolium bromide (BMIMBr) were modified onto screen-printed carbon electrodes (SPCE) by electropolymerization and drop/spin methods, respectively. The surface characteristics of the composite film were characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and surface water contact angle experiments. The composite film-modified electrodes exhibited a linear response to BPA in the range of 0.1-500µM in pH 7.0 phosphate buffer solution (PBS) under optimized flow-injection amperometry. The method sensitivity and detection limit (S/N=3) were 0.2661μA μM(-1) (2.419μA μM(-1)cm(-2)) and 0.02µM, respectively. A relative standard deviation of 1.95% was obtained for 77 successive measurements of 10µM BPA, and the repeatability outperformed previously reported work. The proposed method was applied to detect BPA released from plastic water bottles using the standard addition method, and satisfactory recoveries were obtained. The electrochemical assay was validated by comparison with the chromatographic method, and the results showed good agreement between the two methods. Copyright © 2015 Elsevier B.V. All rights reserved.
Darvishi Cheshmeh Soltani, Reza; Safari, Mahdi
2016-09-01
The improvement of sonocatalytic treatment of real textile wastewater in the presence of MgO nanoparticles was the main goal of the present study. According to our preliminary results, the application of pulse mode of sonication, together with the addition of periodate ions, produced the greatest sonocatalytic activity and consequently, the highest chemical oxygen demand (COD) removal efficiency (73.95%) among all the assessed options. In the following, pulsed sonocatalysis of real textile wastewater in the presence of periodate ions was evaluated response surface methodologically on the basis of central composite design. Accordingly, a high correlation coefficient of 0.95 was attained for the applied statistical strategy to optimize the process. As results, a pulsed sonication time of 141min, MgO dosage of 2.4g/L, solution temperature of 314K and periodate concentration of 0.11M gave the maximum COD removal of about 85%. Under aforementioned operational conditions, the removal of total organic carbon (TOC) was obtained to be 63.34% with the reaction rate constant of 7.1×10(-3)min(-1) based on the pseudo-first order kinetic model (R(2)=0.99). Overall, periodate-assisted pulsed sonocatalysis over MgO nanoparticles can be applied as an efficient alternative process for treating and mineralizing real textile wastewater with good reusability potential. Copyright © 2016 Elsevier B.V. All rights reserved.
Elias, Nursyafiqah; Chandren, Sheela; Razak, Fazira Ilyana Abdul; Jamalis, Joazaizulfazli; Widodo, Nashi; Wahab, Roswanira Abdul
2018-07-15
The contribution of chitosan/nanocellulose (CS-NC) to the enzymatic activity of Candida rugosa lipase covalently bound on the surface of CS-NC (CRL/CS-NC) was investigated. Cellulosic material from oil palm frond leaves (OPFL) were bleached, alkaline treated and acid hydrolyzed to obtain the purified NC and used as nano-fillers in CS. XRD, Raman spectroscopy and optical fluorescence microscopic analyses revealed existence of strong hydrogen bonds between CS and the NC nanofillers. The CRLs were successfully conjugated to the surface of the CS-NC supports via imine bonds that occurred through a Schiff's based mechanism. Process parameters for the immobilization of CRL were assessed for factors temperature, concentration of glutaraldehyde and pH, to afford the highest enzyme activity to achieve maximum conversion of butyl butyrate within 3h of incubation. Conversion as high as 88% was reached under an optimized condition of 25°C, 0.3% glutaraldehyde concentration and buffer at pH7. Thermal stability of CRL/CS-NCs was 1.5-fold greater than that of free CRL, with biocatalysts reusability for up to 8 successive esterification cycles. This research provides a promising approach for expanding the use of NC from OPFL for enhancing enzyme activity in favour of an alternative eco-friendly means to synthesize butyl butyrate. Copyright © 2018 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Jianqiang, Tu; Jinlong, Peng; Xianning, Yang; Lianzhong, Chen
2016-10-01
The active cooling thermal protection technology is the efficient method to resolve the long-duration work and reusable problems of hydrocarbon-fueled scramjet combustor, where worst thermo-mechanical loads occur. The fuel is passed through coolant channels adjacent to the heated surfaces to absorb heat from the heating exchanger panels, prior to injection into the combustor. The heating exchanger both cooled down the wall temperature of the combustor wall and heats and cracks the hydrocarbon fuel inside the panel to permit an easier combustion and satisfying combustion efficiency. The subscale active cooling metallic panels, with dimensions of 100×100 mm and different coolant channel sizes, have been tested under typical combustion thermal environment produced by arc heated Turbulent Flow Duct (TFD). The heat exchange ability of different coolant channel sizes has been obtained. The big-scale active cooling metallic panel, with dimensions of 100 × 750 mm and the coolant channel sizes of better heating exchange performance, has been made and tested in the big-scale arc heated TFD facility. The test results show that the local superheated ablation is easy to happen for the cooling fuel assigned asymmetrically in the bigscale active cooling metallic panel, and the cooling fuel rate can reduce 8%˜10% after spraying the Thermal Barrier Coating (TBC) in the heating surface.
Immobilization of pectinase onto Fe3O4@SiO2-NH2 and its activity and stability.
Fang, Gang; Chen, Honggao; Zhang, Yunpeng; Chen, Anqing
2016-07-01
Fe3O4 magnetic nanometer particles (MNPS) with a diameter of 30-40nm and coated by ammoniated silicon dioxides were developed by sol-gel method. The X-ray diffraction (XRD) pattern indicates that the Fe3O4 is wrapped in the amorphous SiO2, and the Fourier-transform infrared spectroscopy (FT-IR) analysis confirmed the NH2 group had been successfully introduced onto the surface of Fe3O4@SiO2 nanoparticles. The main factors related to the immobilization process of pectinase onto the magnetic support were optimized by multi-factor orthogonal experiments, and the recommended combination is that 3% glutaraldehyde (coupling agent), pH=8.0, 50°C, and cross-linking time 8h. Scanning electron microscope (SEM) and FT-IR analyses confirmed that the pectinase had been immobilized onto the surface of the amino modified nanoparticles. The storage stability and reusability of the pectinase were enhanced by the immobilization that 64.4% of the total starting activity was retrieved after 7 recycling batches and only about 21.1% of the total activity was lost after 30-day storage. For the application of the immobilized pectinase, the optimal pH and temperature were 8.5 and 55°C, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.
Bedogni, Gabriel A; Acevedo, Mauro D; Aguzín, Federico; Okulik, Nora B; Padró, Cristina L
2017-07-07
In this paper, glycerol esterification with acetic acid (AA) was studied on several solid acid catalysts: Al 2 O 3 , Al-MCM-41, HPA/SiO 2 , HBEA, Amberlyst 15 and Amberlyst 36 with the aim of determining the reaction conditions and the nature of the surface acid sites required to produce selectively triacetylglycerol (triacetin). The acidity of the catalysts (nature, density and strength of acid sites) was characterized by temperature-programmed desorption of NH 3 and FTIR of adsorbed pyridine. Al 2 O 3 (Lewis acidity) did not show any activity in the reaction. In contrast, highest activity and selectivity to the triacetylated product (triacetin) were obtained on catalysts with Brønsted acidity: Amberlyst 15 and Amberlyst 36. The effect of temperature and molar ratio of AA to glycerol was studied, and the results showed that both parameters have a significant impact on the production of the desired product. Glycerol conversion rate and selectivity to triacetin increased when temperature or AA to glycerol molar ratio were increased, reaching a triacetin yield on Amberlyst 36 of 44% at 393 K and AA to glycerol molar ratio of 6. Deactivation and reusability of Amberlyst 36 were evaluated by performing consecutive catalytic tests. The presence of some irreversible deactivation due to sulfur loss was observed. In addition, the feasibility of using crude glycerol from biodiesel production as reactant was also investigated. Conversion of crude pretreated glycerol yielded values of triacetin and diacetin similar to those obtained with the commercial pure glycerol although at a lower rate.
International aerospaceplane efforts
NASA Technical Reports Server (NTRS)
Lindley, Charles A.
1992-01-01
Although the U.S. began the first reusable space booster effort in the late 1950's, it is no longer an exclusive field. All of the technologically advanced nations, and several groups of nations, have one or more reusable booster efforts in progress. A listing of the entries in the field is presented. The list is somewhat misleading, because it includes both fully reusable and partially reusable boosters, both manned and unmanned, and both flight test and operational proposals. Additionally, not all of the projects are funded, and only a few of the projects will survive. The most likely candidates are the following: France/ESA, Germany/ESA, Great Britain/ESA/(USSR), USSR(past), and Japan. A discussion of the preceding projects is provided.
2nd Generation Reusable Launch Vehicle Potential Commercial Development Scenarios
NASA Technical Reports Server (NTRS)
Creech, Stephen D.; Rogacki, John R. (Technical Monitor)
2001-01-01
The presentation will discuss potential commercial development scenarios for a Second Generation Reusable Launch Vehicle. The analysis of potential scenarios will include commercial rates of return, government return on investment, and market considerations. The presentation will include policy considerations in addition to analysis of Second Generation Reusable Launch Vehicle economics. The data discussed is being developed as a part of NASA's Second Generation Reusable Launch Vehicle Program, for consideration as potential scenarios for enabling a next generation system. Material will include potential scenarios not previously considered by NASA or presented at other conferences. Candidate paper has not been presented at a previous meeting, and conference attendance of the author has been approved by NASA.
Surface dose measurement for helical tomotherapy.
Snir, Jonatan A; Mosalaei, Homeira; Jordan, Kevin; Yartsev, Slav
2011-06-01
To compare the surface dose measurements made by different dosimeters for the helical tomotherapy (HT) plan in the case of the target close to the surface. Surface dose measurements in different points for the HT plan to deliver 2 Gy to the planning target volume (PTV) at 5 mm below the surface of the cylindrical phantom were performed by radiochromic films, single use metal oxide semiconductor field-effect transistor (MOSFET) dosimeters, silicon IVD QED diode, and optically stimulated luminescence (OSL) dosimeters. The measured doses by all dosimeters were within 12 +/- 8% difference of each other. Radiochromic films, EBT, and EBT2, provide high spatial resolution, although it is difficult to get accurate measurements of dose. Both the OSL and QED measured similar dose to that of the MOSFET detectors. The QED dosimeter is promising as a reusable on-line wireless dosimeter, while the OSL dosimeters are easier to use, require minimum setup time and are very precise.
Hospital information system: reusability, designing, modelling, recommendations for implementing.
Huet, B
1998-01-01
The aims of this paper are to precise some essential conditions for building reuse models for hospital information systems (HIS) and to present an application for hospital clinical laboratories. Reusability is a general trend in software, however reuse can involve a more or less part of design, classes, programs; consequently, a project involving reusability must be precisely defined. In the introduction it is seen trends in software, the stakes of reuse models for HIS and the special use case constituted with a HIS. The main three parts of this paper are: 1) Designing a reuse model (which objects are common to several information systems?) 2) A reuse model for hospital clinical laboratories (a genspec object model is presented for all laboratories: biochemistry, bacteriology, parasitology, pharmacology, ...) 3) Recommendations for generating plug-compatible software components (a reuse model can be implemented as a framework, concrete factors that increase reusability are presented). In conclusion reusability is a subtle exercise of which project must be previously and carefully defined.
Ascent Aerodynamic Pressure Distributions on WB001
NASA Technical Reports Server (NTRS)
Vu, B.; Ruf, J.; Canabal, F.; Brunty, J.
1996-01-01
To support the reusable launch vehicle concept study, the aerodynamic data and surface pressure for WB001 were predicted using three computational fluid dynamic (CFD) codes at several flow conditions between code to code and code to aerodynamic database as well as available experimental data. A set of particular solutions have been selected and recommended for use in preliminary conceptual designs. These computational fluid dynamic (CFD) results have also been provided to the structure group for wing loading analysis.
PRE_X Programme: Aerothermodynamic Objectives and Aeroshape Definition for in Flight Experiments
NASA Astrophysics Data System (ADS)
Lambert, O.; Tribot, J.-P.; Saint-Cloud, F.
2002-01-01
As the expendable launch vehicles (ELV) are limited in their trend to lower costs, the reusability (Reusable Launch Vehicle, RLV) could be the way to make drastic step. By the year 2001, CNES proposed through the ANGEL phase 1 programme to preprare the required technical maturity before that RLV's become alternatives to ELV's. In such way, system ,propulsion, ground based demonstrations, aero-thermo-dynamics as well as in flight experimentation are planned. This paper is focused on the aero-thermo-dynamics (ATD) and in flight demonstration activities with emphasis on the better understanding of ATD problems emerging from past programmes among them shock wave transitionnal boundary layer interaction on surface control, boundary layer transition, local aerothermodynamic effects, gas- surface interaction, catalycity, base flow prediction,...In order to minimize as small as possible the management risk a first generation of vehicle dubbed Pre_X is designed to validate technological choices and to have as soon as possible re-entry data to calibrate the various tools involved in the future RLV definition. In addition, the main requirement for PRE_X aeroshape definition and the two different design approaches considered by Dassault Aviation and EADS-LV are discussed. Then, the more promising concept for the PRE_X application is presented. Finally, the current status of the ATD activities is given as well as the perspectives.
Behnajady, Mohammad A; Dadkhah, Hojjat; Eskandarloo, Hamed
2018-04-01
In this study, a horizontally rotating disc recirculated (HRDR) photoreactor equipped with two UV lamps (6 W) was designed and fabricated for photocatalytic removal of p-nitrophenol (PNP). Photocatalyst (TiO 2 ) nanoparticles were immobilized onto a high-density polyethylene (HDPE) disc, and PNP containing solution was allowed to flow (flow rate of 310 mL min -1 ) in radial direction along the surface of the rotating disc illuminated with UV light. The efficiency of direct photolysis and photocatalysis and the effect of rotating speed on the removal of PNP were studied in the HRDR photoreactor. It was found that TiO 2 -P25 nanoparticles are needed for the effective removal of PNP and there was an optimum rotating speed (450 rpm) for the efficient performance of the HRDR photoreactor. Then effects of operational variables on the removal efficiency were optimized using response surface methodology. The results showed that the predicted values of removal efficiency are consistent with experimental results with an R 2 of 0.9656. Optimization results showed that maximum removal percent (82.6%) was achieved in the HRDR photoreactor at the optimum operational conditions. Finally, the reusability of the HRDR photoreactor was evaluated and the results showed high reusability and stability without any significant decrease in the photocatalytic removal efficiency.
Yuan, Bo; Yin, Xiao-Qian; Liu, Xiao-Qin; Li, Xing-Yang; Sun, Lin-Bing
2016-06-29
Much attention has been paid to metal-organic frameworks (MOFs) due to their large surface areas, tunable functionality, and diverse structure. Nevertheless, most reported MOFs show poor hydrothermal stability, which seriously hinders their applications. Here a strategy is adopted to tailor the properties of MOFs by means of incorporating carboxyl-functionalized natural clay attapulgite (ATP) into HKUST-1, a well-known MOF. A new type of hybrid material was thus fabricated from the hybridization of HKUST-1 and ATP. Our results indicated that the hydrothermal stability of the MOFs as well as the catalytic performance was apparently improved. The frameworks of HKUST-1 were severely destroyed after hydrothermal treatment (hot water vapor, 60 °C), while that of the hybrid materials was maintained. For the hybrid materials containing 8.4 wt % of ATP, the surface area reached 1302 m(2)·g(-1) and was even higher than that of pristine HKUST-1 (1245 m(2)·g(-1)). In the ring-opening of styrene oxide, the conversion reached 98.9% at only 20 min under catalysis from the hybrid material, which was obviously higher than that over pristine HKUST-1 (80.9%). Moreover, the hybrid materials showed excellent reusability and the catalytic activity was recoverable without loss after six cycles. Our materials provide promising candidates for heterogeneous catalysis owing to the good catalytic activity and reusability.