Geologic Mapping in the Middle Mountains, Yuma Country, Arizona, with SEBASS Hyperspectral TIR Images
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Engineering topics
Smith, M.
Publications and source records attributed to Smith, M..
Optimizing Process Parameters to Produce Single Phase YBa2Cu3O7 Powder
Process parameters such as temperature and time are varied to obtain single phase (pure) YBa2Cu307 powders. X-ray diffraction patterns of superconducting and nonsuperconducting powders are observed in situ in normal and elevated temperature environments to confirm known strong peaks that are unique to YBa2Cu307. Peaks vary in magnitude as a result of superconducting - nonsuperconducting phase transitions. Known strong peaks serve as our basis in monitoring transitional changes. Peak isotherms obtained experimentally are correlated with theoretical models to identify the weighting factor that characterizes the optimum isotherm. By isolating the parameters under which 100% peak growth occurs most rapidly, we obtain the optimum isotherm. The choices made for firing temperature and atmosphere were determined to be the primary factors necessary to ensure sample purity.
Hurley, J. S.↗
PULSAUR 2: Rocket and groundbased measurements in a pulsating aurora
The second pulsating aurora rocket (PULSAUR 2) rocket was launched into a pulsating aurora on 9 February 1994 and carried a broad range of instruments in order to perform a study of this type of aurora. The rocket measurements were complemented with a set of ground-based measurements. The particle measurements performed in the rocket are related to the ground-based optical measurements performed along the rocket trajectory. It is found that the high energy electrons are largely in phase with the measured luminosity. The EISCAT measurements carried out during the flight are reviewed. The PULSAUR 2 campaign is described. Results concerning the auroral conditions and the particle measurements are presented.
Soeraas, Finn↗
GPS Global Tracking Network Operations At JPL During the 1992 IGS Experiment and Beyond
The GPS Network Operations center at JPL Provides resources for the collection, distribution and maintenance of GPS data from global network of GPS receivers. This includes the ability to remotely diagnosis receiver problems, communicate with receivers and operators of receivers, to automatically collect, process and distribute data for 14 stations in the IGS network. This amounts to 35 megabytes of raw, finished data and products daily.
GPS receiver Global Network↗
Structure redesign for improved dynamic response
The concepts of multivariable control design are used to redesign structures represented by lumped parameter models. When the mass is held constant, the changing of passive structural members is mathematically equivalent to an output feedback decentralized control problem. When the mass is also allowed to change, a generalization of the output feedback formulation is required. The design objective is to minimize the changes in the structure required to simultaneously satisfy inequality constraints on both the root-mean-square and absolute value of the dynamic response of each output. An alternative objective treated is to minimize the root-mean-square of the dynamic response subject to inequality constraints on the changes allowed in each structural member. Examples illustrate both procedures.
Skelton, R. E.↗
Advanced Cardiac Life Support (ACLS) utilizing Man-Tended Capability (MTC) hardware onboard Space Station Freedom
Because of the time and distance involved in returning a patient from space to a definitive medical care facility, the capability for Advanced Cardiac Life Support (ACLS) exists onboard Space Station Freedom. Methods: In order to evaluate the effectiveness of terrestrial ACLS protocols in microgravity, a medical team conducted simulations during parabolic flights onboard the KC-135 aircraft. The hardware planned for use during the MTC phase of the space station was utilized to increase the fidelity of the scenario and to evaluate the prototype equipment. Based on initial KC-135 testing of CPR and ACLS, changes were made to the ventricular fibrillation algorithm in order to accommodate the space environment. Other constraints to delivery of ACLS onboard the space station include crew size, minimum training, crew deconditioning, and limited supplies and equipment. Results: The delivery of ACLS in microgravity is hindered by the environment, but should be adequate. Factors specific to microgravity were identified for inclusion in the protocol including immediate restraint of the patient and early intubation to insure airway. External cardiac compressions of adequate force and frequency were administered using various methods. The more significant limiting factors appear to be crew training, crew size, and limited supplies. Conclusions: Although ACLS is possible in the microgravity environment, future evaluations are necessary to further refine the protocols. Proper patient and medical officer restraint is crucial prior to advanced procedures. Also emphasis should be placed on early intubation for airway management and drug administration. Preliminary results and further testing will be utilized in the design of medical hardware, determination of crew training, and medical operations for space station and beyond.
Smith, M.↗
Ceramic Fabric Coated With Silicon Carbide
Material used as high-temperature shell. Ceramic fabric coated with silicon carbide (SiC) serves as tough, heat-resistant covering for other refractory materials. Developed to protect reusable insulating tiles on advanced space transportation systems. New covering makes protective glaze unnecessary. Used on furnace bricks or on insulation for engines.
Riccitiello, S. R.↗
Furnace for Tensile Testing of Flexible Ceramics
Ceramic cloth and thread tested quickly at temperatures up to 1,250 degree C. Tensile strengths of ceramic cloths and threads measured conveniently in new furnace at specified temperatures up to 1,250 degree C, using ordinary mechanical tester. Samples heated along part of their lengths in furnace slots. Interchangeable furnace chambers and matching heating elements sized to match size of tested ceramic material.
Smith, M.↗
Thermal response of integral, multicomponent composite thermal protection systems
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Stewart, D. A.↗
Insulation Blankets for High-Temperature Use
Insulating blanket resists temperatures up to 1,500 degrees F (815 degrees C). Useful where high-temperature resistance, flexibility, and ease of installation are important - for example, insulation for odd-shaped furnaces and high-temperature ducts, curtains for furnace openings and fire control, and conveyor belts in hot processes. Blanket is quilted composite consisting of two face sheets: outer one of silica, inner one of silica or other glass cloth with center filling of pure silica glass felt sewn together with silica glass threads.
Goldstein, H.↗
An evaluation of a SIRA image to determine forest density under conditions of moderate topographical variation
Many studies have shown that radar images have increased classification accuracy over spectral classifications using only LANDSAT Multispectral Band Scanner (MSS) images. It was the objective to determine if a SIRA image taken over Hayfork when used alone or inconjuction with LANDSAT MSS data would increase separation of units not identified by LANSAT spectral mixture models. Areas in the LANDSAT model of varying vegetation density (0 to 50%) that had proven to be accurate by field surveys were compared. It was found in the Hayfork area that SIRA did not increase or help delineation of vegetation or ultramific units over LANDSAT MSS.
Smith, M.↗
Options for improving rigidized ceramic heatshields
Studies regarding capabilities, tensile strength, and dimensional stability of fibrous ceramics, used in current thermal protection systems and those required for future NASA advanced transfer vehicles, are presented. It is shown that the use of smaller diameter (2-4 micron) aluminoborosilicate fibers (instead of conventional 11-micron size) in the FRCI composites improves the homogeneity and tensile strength of high-silica composite. Substitution of the smaller aluminoborosilicate fibers by 2-4-micron alumina fibers in the AETB composites improves the dimensional stability, at the expense of a substantial increase in the thermal expansion coefficient, with a potential decrease in tensile strength.
Leiser, D. B.↗
Strategies for analyzing mixed pixels in remotely sensed imagery
Two uncalibrated synthetic aperture radar (SAR) scenes from Death Valley, California, and two uncalibrated scenes from Owens Valley, California, were used to test a technique to identify and separate the primary factors associated with multipolarized radar image sets. Unique to the technique is the concept that varied types of radar polarization signatures are a result of the interaction of a few physical factors (e.g., roughness, volume scattering, and dielectric constant). Thus, the varied signatures observed in an image reflect the interaction between these factors. The objectives are to first separate the interaction of factors directly influencing the measurement and to attempt to identify these factors. Interpretation of the SAR image sets proceeds by testing models that hypothesize the cause and effect relations between those factors directly affecting the radar measurement and those features of interest to the interpreter. The results of our analysis indicated two consistent endmember types over all four image scenes. These types are defined by a high flat polarized signature near a level of 255 DN and a low level flat signature near 0 DN for all polarizations. Four other endmember types were also isolated. The spatial distribution of these endmember types indicates possible correspondence to surface volume scattering and changes in surface dielectric. However, the shapes of these endmember types were different from scene to scene.
Smith, M.↗
Thermal response of integral multicomponent composite thermal protection systems
Integral-multicomponent thermal-protection materials are discussed in terms of their thermal response to an arc-jet airstream. In-depth temperature measurements are compared with predictions from a one-dimensional, finite-difference code using calculated thermal conductivity values derived from an engineering model. The effect of composition, as well as the optical properties of the bonding material between components, on thermal response is discussed. The performance of these integral-multicomponent composite materials is compared with baseline Space Shuttle insulation.
Stewart, D. A.↗
The composition, structure, temperature and dynamics of the upper thermosphere in the polar regions during October to December 1981
Observational data obtained by the Dynamics Explorer-2 (DE-2) spacecraft were compared with global model simulations in order to study the composition, structure, temperature, and dynamics of the upper thermosphere in polar regions during the period October-December 1981. A UCL three-dimensional model was used to simulate the seasonal, diurnal, and geomagnetic response of the neutral thermosphere and to follow the major features of the solar and geomagnetic inputs during the late 1981 period. Overall agreement was obtained between the simulations and the DE-2 data for thermospheric wind structure at high latitudes, and for the combined thermal and compositional structure in both hemispheres. Computer-generated line drawings of the variations in thermospheric structure are given, as well as a series of color graphic illustrations of the DE-2 data.
Rees, D.↗
Heat-Shield Gap Filler
Ceramic cloth strips provide flexible, easily replaceable insulating filler. Filler prevents hot gas from flowing between heat-shield tiles while allowing space for thermal expansion and contraction. Strips easily replaced when necessary.
Leiser, D. B.↗
Nonradial Pulsation and Mass Loss in Early B Stars
It has been firmly established that nonradial pulsation (NRP) probably occurs in nearly all sharp-lined early B stars near the main sequence. A recent breakthrough occurred with the discovery of quasi emission/absorption bumps moving across the line profiles of the rapid rotators zeta Oph and alpha Vir. It was found that an intermediate-1 (1=8) NRP mode is responsible for these features in zeta Oph. Some 20 Be and Bn stars were monitored and convincing evidence for NRP in 13 of them was found. Line profile variations suggestive of NRP in the other 7 were also discovered. A search for line profile variables among moderate rotators has turned up NRP in epsilon and eta Lep, with v sin i's of 140 and 70 km/sec, respectively. It now seems that NRP can be present at all rotational velocities with equal frequency (near 100%! . However, at most 20% of these stars exhibit detectable photometric variations.
Penrod, G. D.↗
Thermal response of advanced high temperature ceramic-composite insulation to a convectively heated environment
The Space Shuttle uses currently fibrous high temperature, reusable surface insulation (HRSI) as a Thermal Protection System (TPS) at 1260 C for normal-design mission operation. Higher density material of a similar type extended the maximum temperature to 1480 C. However, a surface temperature capability exceeding 1540 C is desired for future space vehicles, such as the Orbital Transfer Vehicle (OTV). A TPS providing such a capability would permit future entry vehicles to enter the atmosphere at a much higher velocity than the Space Shuttle. The present investigation is concerned with arc-jet test data obtained from a family of fibrous refractory-composite insulation (FRCI) materials developed to meet the future TPS requirements. FRCI materials containing between 20 and 80 percent aluminoborosilicate fibers with the balance composed of silica fibers were studied.
Stewart, D. A.↗