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Jun 4, 2016
06/16
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Impact Journals
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In this work gold nanoparticles has been prepared via ablation of pure Au metal target in doubled distilled water was accomplished using Q-switched Nd: YAG pulse width 10 ns energy was 700 mJ number of shots was 90 shot at different laser wavelength(532 nm and 1064 nm) The effect of laser wavelength on the optical and surface morphology have been studied the result showed decrease in particle size when the wavelength of laser increase and UV-Visible result show a blue shift in the absorption...
Topics: Gold Nanoparticle, Laser Ablation, Laser Wavelength, Noble Metals Nanoparticles & Size
253
253
Jun 9, 2011
06/11
by
Abedin, M. Nurul; Refaat, Tamer F.; Bhat, Ishwara; Xiao, Ye-Gao; Bandra, Sumith; Gunapala, Sarath D
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Knowledge of the spatial and temporal distribution of atmospheric species such as CO2, O3, H2O, and CH4 is important for understanding the chemistry and physical cycles involving Earth s atmosphere. Although several remote sensing techniques are suitable for such measurements they are considered high cost techniques involving complicated instrumentation. Therefore, simultaneous measurement of atmospheric species using a single remote sensing instrument is significant for minimizing cost, size...
Topics: CERAMICS, THIN FILMS, THERMOCOUPLES, HIGH TEMPERATURE ENVIRONMENTS, ROBUSTNESS (MATHEMATICS),...
358
358
Jun 21, 2010
06/10
by
Bond, A. C.; Swanson, A. G
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No Abstract Available
Topics: CATALYTIC ACTIVITY, HYDROGEN OXYGEN ENGINES, METAL OXIDES, NOBLE METALS, CATALYSTS, IGNITION,...
Journal of Research of the National Bureau of Standards
Topics: CdCI2, density of states, HgO, noble metals, rigid band model, transition metals, x-ray...
637
637
Jun 26, 2010
06/10
by
Etheridge, O. E
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Space shuttle trajectory performance data for east and west test range launch simulations
Topics: DRIFT (INSTRUMENTATION), VACUUM, ENVIRONMENTAL TESTS, THERMOCOUPLES, AIR, ARGON, ELECTRICAL...
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223
May 31, 2011
05/11
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Smelyanskiy, Vadim N.; Toussaint, Ud
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We study both analytically and numerically the complexity of the adiabatic quantum evolution algorithm applied to random instances of combinatorial optimization problems. We use as an example the NP-complete set partition problem and obtain an asymptotic expression for the minimal gap separating the ground and exited states of a system during the execution of the algorithm. We show that for computationally hard problem instances the size of the minimal gap scales exponentially with the problem...
Topics: NOBLE METALS, TECHNOLOGY TRANSFER, CATALYSTS, CARBON MONOXIDE, LOW TEMPERATURE, OXIDATION, CARBON...
Thirty commercially produced monolith and pellet catalysts were tested as part of a screening process to select catalysts suitable for use in a gas turbine combustor. The catalysts were contained in a 1.8 centimeter diameter quartz tube and heated to temperatures varying between 300 and 1,200 K while a mixture of propane and air passed through the bed at space velocities of 44,000 to 70,000/hour. The amount of propane oxidized was measured as a function of catalyst temperature. Of the samples...
Topics: NASA Technical Reports Server (NTRS), CATALYSTS, COMBUSTION CHAMBERS, GAS TURBINES, CATALYTIC...
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278
May 23, 2011
05/11
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Jones, Henry E
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A study of the full-potential modeling of a blade-vortex interaction was made. A primary goal of this study was to investigate the effectiveness of the various methods of modeling the vortex. The model problem restricts the interaction to that of an infinite wing with an infinite line vortex moving parallel to its leading edge. This problem provides a convenient testing ground for the various methods of modeling the vortex while retaining the essential physics of the full three-dimensional...
Topics: LUNAR ROCKS, COST EFFECTIVENESS, COMPRESSIBILITY, BINDERS (MATERIALS), LUNAR SOIL, CONCRETES,...
Noble-metal braze applied to appropriately prepared zirconia parts produces a gas-tight, durable seal that can withstand temperature of 825 C for over 2000 hours without deterioration.
Topics: NASA Technical Reports Server (NTRS), BRAZING, CERAMICS, ELECTROPLATING, HIGH TEMPERATURE, METAL...
The nature of the interface, adhesion and friction properties of noble metals, platinum metals, Group IV (B) metals and transition metals were considered. The surface chemical activity of the noble and platinum metals is shown to effect metal to metal interfaces as does a valance bonding in the transition metals. With the Group IV (B) metals the degree of metallic nature of the elements is shown to effect interfacial behavior. The effect of surface segregation of alloy constituents such as...
Topics: NASA Technical Reports Server (NTRS), ADHESION, FRICTION, METAL-METAL BONDING, SOLID-SOLID...
A wet oxidation process was developed for oxidizing waste materials, comprising dissolved ruthenium salt in a reactant feed stream containing the waste materials. The feed stream is introduced into a reactor, and the reactor contents are then raised to an elevated temperature to effect deposition of a catalytic surface of ruthenium black on the interior walls of the reactor. The feed stream is then maintained in the reactor for a period of time sufficient to effect at least partial oxidation of...
Topics: NASA Technical Reports Server (NTRS), INDUSTRIAL WASTES, OXIDATION, SOLID WASTES, CATALYSTS, NOBLE...
Application of thin dielectric, base metal electrode (BME) ceramic capacitors for high-reliability applications requires development of testing procedures that can assure high quality and reliability of the parts. In this work, distributions of breakdown voltages (VBR) in variety of low-voltage BME multilayer ceramic capacitors (MLCCs) have been measured and analyzed. It has been shown that analysis of the distributions can indicate the proportion of defective parts in the lot and significance...
Topics: NASA Technical Reports Server (NTRS), CAPACITORS, QUALITY CONTROL, DIELECTRICS, ELECTRIC POTENTIAL,...
Investigation has revealed reasonably oxidation resistant thermocouple pairing suitable for use in combustor gas streams at temperatures above 1873 K and at pressures above 20 atmospheres.
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT ENGINES, COMBUSTION CHAMBERS, ENGINE DESIGN,...
An improved flow-through electrolytic hygrometer is described which utilizes a long lasting oxidation-resistant, hollow fiber formed from persulfonic acid substituted polytetrafluoroethylene having closely spaced noble metal electrodes in contact with the inner and outer surfaces of the fiber. The fiber is disposed within a chamber so that the moisture-bearing gas passes in contact with at least one surface of the fiber. The electrodes are connected in series to a dc voltage supply and an...
Topics: NASA Technical Reports Server (NTRS), ELECTROLYSIS, HYGROMETERS, SOLID ELECTRODES, SYNTHETIC...
STC Catalysts, Inc. (SCi) manufactures a noble metal reducible oxide catalyst consisting primarily of platinum and tin dioxide deposited on a ceramic substrate. It is an ambient temperature oxidation catalyst that was developed primarily for Carbon Dioxide Lasers.The catalyst was developed by the NASA Langley Research Center for the Laser Atmospheric Wind Sounder Program (LAWS) which was intended to measure wind velocity on a global basis. There are a number of NASA owned patents covering...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE, CATALYSTS, CERAMICS, DIOXIDES, PLATINUM,...
Cracks in ceramic capacitors are one of the major causes of failures during operation of electronic systems. Humidity testing has been successfully used for many years to verify the absence of cracks and assure quality of military grade capacitors. Traditionally, only precious metal electrode (PME) capacitors were used in high reliability applications and the existing requirements for humidity testing were developed for this type of parts. With the advance of base metal electrode (BME)...
Topics: NASA Technical Reports Server (NTRS), CERAMICS, METALS, ELECTRODES, NOBLE METALS, CAPACITORS,...
Silver ions in aqueous solutions (0.05 to 1 ppm) are used for microbial control in water systems. The silver ions remain in solution when stored in plastic containers, but the concentration rapidly decreases to non-biocidal levels when stored in metal containers. The silver deposits onto the surface and is reduced to non-biocidal silver metal when it contacts less noble metal surfaces, including stainless steel, titanium, and nickel-based alloys. Five methods of treatment of contact metal...
Topics: NASA Technical Reports Server (NTRS), PLATING, METAL SURFACES, SILVER, NOBLE METALS, METAL IONS,...
Oxidation of CO to CO2 is an important reaction technologically and environmentally and a complex and interesting reaction scientifically. In most cases, the reaction is carried out in order to remove CO as an environmental hazard. A major application of heterogeneous catalysts is catalytic oxidation of CO in the exhaust of combustion devices. The reaction over catalysts in exhaust gas is fast and often mass-transfer-limited since exhaust gases are hot and O2/CO ratios are high. The main...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE, CATALYSIS, CATALYSTS, EXHAUST GASES, METAL...
El Goresy et al.'s observation of Nb, Zr, and Ta in refractory platinum metal nuggets (RPMN's) from Ca-Al-rich inclusions (CAI's) in the Allende meteorite led them to propose that these lithophile elements alloyed in the metallic state with noble metals in the early solar nebula. However, Grossman pointed out that the thermodynamic stability of Zr in the oxide phase is vastly greater than metallic Zr at estimated solar nebula conditions. Jones and Burnett suggested this discrepancy may be...
Topics: NASA Technical Reports Server (NTRS), ALLENDE METEORITE, METEORITIC COMPOSITION, NOBLE METALS,...
The overall objective is to develop efficient and economical separation and recovery methods for the platinum group and other precious metals. The separation of Pd(II) from Pt(II), Ir(III), and Rh(III) with trioctylphosphine oxide (TOPO) in heptane using centrifugal partition chromatography (CPC) was investigated. Activities to achieve this objective focussed on selection and evaluation of extraction systems for the PGM and modification of selected systems for multistage operation with a view...
Topics: NASA Technical Reports Server (NTRS), CENTRIFUGAL FORCE, CHROMATOGRAPHY, EXTRATERRESTRIAL...
Hydrothermal precipitates, black smoker particulate, and massive sulphide dredge samples from the Explorer Ridge on the Juan de Fuca Plate and the TAG hydrothermal area on the Mid-Atlantic Ridge were analyzed for selected noble metals including Au, Ir and Pd by radiochemical neutron activation analysis. The preliminary results indicate that gold contents may reach the ppm range although values in the neighborhood of 100 to 200 ppb are more typical. The platinum group elements (PGE) represented...
Topics: NASA Technical Reports Server (NTRS), FRACTIONATION, GOLD, NOBLE METALS, PLATINUM, RADIOCHEMISTRY,...
In the early morning of January 15, 2006, the Stardust Sample Return Capsule (SRC) successfully delivered its precious cargo of cometary particles to the awaiting recovery team at the Utah Test and Training Range (UTTR). As the SRC entered at 12.8 km/s, the fastest manmade object to traverse the atmosphere, a team of researchers imaged the event aboard the NASA DC-8 airborne observatory. At SRC entry, the airplane was at an altitude of 11.9 km positioned within 6.4 km of the prescribed,...
Topics: NASA Technical Reports Server (NTRS), STARDUST MISSION, CARGO, NOBLE METALS, TEST RANGES,...
Three performance characteristics of noble metal thermocouples in various environments are discussed. Catalytic effects cause significant errors when noble metal thermocouple materials are exposed to air containing unburned gases in temperature ranges from 25 C to 1500 C. The thermoelectric stability of the iridium 40 rhodium to iridium thermocouple system at 2000 C in an oxidizing medium is described. The effects of large and small temperature gradients on the accuracy and stability of...
Topics: NASA Technical Reports Server (NTRS), NOBLE METALS, TEMPERATURE MEASUREMENT, THERMOCOUPLES,...
The catalytic oxidation of CO over noble metal catalysts is reviewed. Results obtained on supported noble metal catalysts and single crystals both at high pressures and under UHV conditions are compared. The underlying causes which result in surface instabilities and multiple steady-state oscillations are considered, in particular, the occurrence of hot spots. CO islands of reactivity, surface oxide formation and phase transformations under oscillatory conditions are discussed.
Topics: NASA Technical Reports Server (NTRS), CARBON MONOXIDE, CATALYTIC ACTIVITY, NOBLE METALS, OXIDATION,...
During the past year a viable procedure centered around centrifugal partition chromatography (CPC), a multistage liquid-liquid partitioning technique for the separation of precious metals (Pt, Pd, Rh, Ir, Os, Ru), was developed. Stable and inexpensive ligands that can be readily recycled to achieve the separations of the precious metals were identified. The separation methods developed so far yield three separate fractions: Pt, Pd, and Rh-Ir. The Rh-Ir pair can be separated in a subsequent run....
Topics: NASA Technical Reports Server (NTRS), DECOMPOSITION, LIGANDS, LIQUID PHASES, NOBLE METALS, PHASE...
Two investigatory studies on performance characteristics of noble-metal thermocouples are described. (1) thermoelectric stability as affected by preferential oxidation of iridium in the system iridium-40% rhodium versus iridium, and (2) the effects of temperature gradients on the emf stability of the systems platinum-13% rhodium versus platinum and iridium-40% rhodium versus iridium, operating in air. The stability investigation was carried out at three temperatures - 1700, 1850, and 2000 C -...
Topics: NASA Technical Reports Server (NTRS), HIGH TEMPERATURE TESTS, NOBLE METALS, STABILITY TESTS,...
A small, lightweight, portable apparatus based on an electrochemical sensing principle has been developed for monitoring low concentrations of ethylene in air. Ethylene has long been known to be produced by plants and to stimulate the growth and other aspects of the development of plants (including, notably, ripening of fruits and vegetables), even at concentrations as low as tens of parts per billion (ppb). The effects are magnified in plant-growth and -storage chambers wherein ethylene can...
Topics: NASA Technical Reports Server (NTRS), ETHYLENE, ELECTROCHEMICAL OXIDATION, DETECTION, NOBLE METALS,...
The preparation conditions for precious metal/tin oxide catalysts were optimized for maximum carbon monoxide/oxygen recombination efficiency. This was achieved by controlling the tin digestion, the peptization to form the sol, the calcination process and the method of adding the precious metals. Extensive studies of the tin oxide structure were carried out over the temperature range 20 to 500 C in air or hydrogen environments using Raman scattering and X ray diffraction. Adsorbed species on tin...
Topics: NASA Technical Reports Server (NTRS), CARBON MONOXIDE, CARBONATES, CATALYSTS, OXIDATION, TIN...
Electrochemical test results are presented for six noble metals evaluated in two acidic test solutions which are representative of waste liquids processed in the Environmental Control and Life Support System (ECLSS) aboard the International Space Station (ISS). The two test solutions consisted of fresh waste liquid which had been modified with a proposed or alternate pretreatment formulation and its associated brine concentrate. The six test metals included three titanium grades, (Commercially...
Topics: NASA Technical Reports Server (NTRS), METALS, COMPATIBILITY, ELECTROCHEMICAL CORROSION, CORROSION...
Base-metal-electrode (BME) ceramic capacitors are being investigated for possible use in high-reliability spacelevel applications. This paper focuses on how BME capacitors construction and microstructure affects their lifetime and reliability. Examination of the construction and microstructure of commercial off-the-shelf (COTS) BME capacitors reveals great variance in dielectric layer thickness, even among BME capacitors with the same rated voltage. Compared to PME (precious-metal-electrode)...
Topics: NASA Technical Reports Server (NTRS), CERAMICS, CAPACITORS, METALS, ELECTRODES, RELIABILITY,...
The United States has made a commitment to go back to the moon to stay in the early part of the next century. In order to achieve this objective it became evident to NASA that a Lunar Outpost will be needed to house scientists and astronauts who will be living on the moon for extended periods of time. A study has been undertaken by the authors and supported by NASA to study the feasibility of using lunar regolith with different binders such as molten sulfur, epoxy or hydraulic cement as a...
Topics: NASA Technical Reports Server (NTRS), LUNAR ROCKS, LUNAR SOIL, CONCRETES, VACUUM CHAMBERS, WATER,...
Work, during the research program, was concentrated on lubricant development, gear lubrication and evaluation, providing coated test specimens, advising NASA contractors about solid lubrication specific applications, and investigation of new method of attaching lubricating solids to bearing surfaces by sputtering technique.
Topics: NASA Technical Reports Server (NTRS), BEARINGS, BINDERS (MATERIALS), GRAPHITE, HIGH VACUUM,...
Two catalysts for the selective oxidation of trace amounts of contaminant gases in air have been developed for use aboard the International Space Station. These catalysts might also be useful for reducing concentrations of fumes in terrestrial industrial facilities especially facilities that use halocarbons as solvents, refrigerant liquids, and foaming agents, as well as facilities that generate or utilize ammonia. The first catalyst is of the supported-precious-metal type. This catalyst is...
Topics: NASA Technical Reports Server (NTRS), CATALYSTS, CONTAMINANTS, OXIDATION, TRACE CONTAMINANTS,...
A multi-layer ceramic capacitor (MLCC) is a high-temperature (1350C typical) co-fired ceramic monolithic that is composed of many layers of alternately stacked oxide-based dielectric and internal metal electrodes. To make the dielectric layers insulating and the metal electrode layers conducting, only highly oxidation-resistant precious metals, such as platinum, palladium, and silver, can be used for the co-firing of insulating MLCCs in a regular air atmosphere. MLCCs made with precious metals...
Topics: NASA Technical Reports Server (NTRS), CERAMICS, CAPACITORS, NOBLE METALS, ELECTRODES, DIELECTRICS,...
Correlations for combustion efficiency percentage drop and the minimum required adiabatic reaction temperature necessary to meet emissions goals of 13.6 g CO/kg fuel and 1.64 g HC/kg fuel are presented. Combustion efficiency was found to be a function of the cell density, cell circumference, reactor length, reference velocity, and adiabatic reaction temperature. The percentage pressure drop at an adiabatic reaction temperature of 1450 K was found to be proportional to the reference velocity to...
Topics: NASA Technical Reports Server (NTRS), AIR POLLUTION, CATALYSIS, COMBUSTION CHAMBERS, EMISSION, GAS...
393
393
May 29, 2011
05/11
by
Content, David; Sroda, Tom; Palmer, Christopher; Kuznetsov, Iva
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The program we are attempting to bring about combines 3 difficult features, in order to demonstrate accuracy of efficiency predictions: (1) Accurate groove metrology methods on surface relief gratings; (2) Rigorous and usable electromagnetic efficiency calculation codes; (3) Accurate efficiency measurements in polarized light The benefit would be an increase in yield for high-performance gratings. Many such applications suffer long lead time or serious performance loss when new gratings are...
Topics: PERFORMANCE TESTS, DIODES, METALLIZING, ADHESION TESTS, ANNEALING, HEAT TREATMENT, SUBSTRATES,...
Sliding friction experiments were conducted with the noble metals copper, silver, and gold and two binary alloys of these metals contacting iron in the presence of various adsorbates including, oxygen, methyl mercaptan, and methyl chloride. A pin on disk specimen configuration was used with a load of 100 grams, sliding velocity of 60 mm/min; at 25 C with the surfaces saturated with the adsorbates. Auger emission spectroscopy was used to monitor surface films. Results of the experiments indicate...
Topics: NASA Technical Reports Server (NTRS), ELECTRON TRANSITIONS, IRON, METAL SURFACES, NOBLE METALS,...
In the early morning of January 15, 2006, the Stardust Sample Return Capsule (SRC) successfully delivered its precious cargo of cometary particles to the awaiting recovery team at the Utah Test and Training Range (UTTR). As the SRC entered at 12.8 km/s, the fastest manmade object to traverse the atmosphere, a team of researchers imaged the event aboard the NASA DC-8 airborne observatory. At SRC entry, the airplane was at an altitude of 11.9 km positioned within 6.4 km of the prescribed,...
Topics: NASA Technical Reports Server (NTRS), STARDUST MISSION, TEST RANGES, INTERNATIONAL SPACE STATION,...
The Sensors and Electronics Technology Branch of the NASA Glenn Research Center is developing thin-film-based sensors for surface measurement in propulsion system research. Thin-film sensors do not require special machining of the components on which they are mounted, and they are considerably thinner than wire- or foil-based sensors. One type of sensor being advanced is the thin-film thermocouple, specifically for applications in high-temperature combustion environments. Ceramics are being...
Topics: NASA Technical Reports Server (NTRS), CERAMICS, THIN FILMS, THERMOCOUPLES, ELECTRIC POTENTIAL, HIGH...
An ambient temperature oxygen microsensor, based on a Nafion polymer electrolyte, has been developed and was microfabricated using thin-film technologies. A challenge in the operation of Nafion-based sensor systems is that the conductivity of Nafion film depends on the humidity in the film. Nafion film loses conductivity when the moisture content in the film is too low, which can affect sensor operation. The advancement here is the identification of a method to retain the operation of the...
Topics: NASA Technical Reports Server (NTRS), AMBIENT TEMPERATURE, ELECTROLYTES, ENVIRONMENTAL MONITORING,...
The effective investigation of space weathering demands an interdisciplinary approach that is at least as diversified as any other in planetary science. Because it is a macroscopic process affecting all bodies in the solar system, impact and its resulting shock effects must be given detailed attention in this regard. Direct observation of the effects of impact is most readily done for the Moon, but it still remains difficult for other bodies in the solar system. Analyses of meteorites and...
Topics: NASA Technical Reports Server (NTRS), SPACE WEATHERING, REAL TIME OPERATION, SPACE LABORATORIES,...
Thermal electromotive-force changes for 30 commercially available noble- and refractory-metal thermocouples have been determined in air, argon, and vacuum, at 1600 K for exposures up to 10,000 hours. Investigation techniques can serve as guidelines for future studies of other thermocouple systems.
Topics: NASA Technical Reports Server (NTRS), AIR, ALUMINUM OXIDES, ARGON, DRIFT (INSTRUMENTATION),...
Catalytic combustion of both low and medium heating value gases using actual coal derived gases obtained from operating gasifiers was demonstrated. A fixed bed gasifier with a complete product gas cleanup system was operated in an air blown mode to produce low heating value gas. A fluidized bed gasifier with a water quench product gas cleanup system was operated in both an air enriched and an oxygen blown mode to produce low and medium, heating value gas. Noble metal catalytic reactors were...
Topics: NASA Technical Reports Server (NTRS), CATALYTIC ACTIVITY, COAL DERIVED GASES, COMBUSTION, FLUIDIZED...
A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT ENGINES, CATALYTIC ACTIVITY, COMBUSTION CHAMBERS,...
PCBs are removed from contaminated media using a treatment system including zero-valent metal particles and an organic hydrogen donating solvent. The treatment system may include a weak acid in order to eliminate the need for a coating of catalytic noble metal on the zero-valent metal particles. If catalyzed zero-valent metal particles are used, the treatment system may include an organic hydrogen donating solvent that is a non-water solvent. The treatment system may be provided as a...
Topics: NASA Technical Reports Server (NTRS), HYDROGEN, METAL PARTICLES, NOBLE METALS, POLYCHLORINATED...
An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the igniter and three alternative mountings thereof within the combustion chamber are disclosed. The...
Topics: NASA Technical Reports Server (NTRS), IGNITERS, CATALYSTS, LIQUID ROCKET PROPELLANTS, GUN...
The present invention utilizes two precious metals with two to five different metal-oxides in a layered matrix to convert CO, HCs, and NOx to CO.sub.2, and N.sub.2 by oxidation of two components and reduction of the other in a moderately high temperature gaseous environment containing excess oxygen.
Topics: NASA Technical Reports Server (NTRS), COMBUSTION PRODUCTS, CARBON DIOXIDE, METAL OXIDES, NOBLE...
A very high purity (99.99+) high temperature co-fired ceramic (HTCC) alumina has recently become commercially available. The raw material of this HTCC alumina is very different from conventional HTCC alumina, and more importantly there is no glass additive in this co-fired material. Previously, selected HTCC and LTCC (low temperature co-fired ceramic) alumina materials were evaluated at high temperatures as dielectric and compared to a regularly sintered 96 polycrystalline alumina (96 Al2O3),...
Topics: NASA Technical Reports Server (NTRS), HIGH TEMPERATURE, CERAMICS, PURITY, DIELECTRIC PROPERTIES,...
After introducing the desired features in a transmitter for laser radar applications, the output characteristics of several configurations of frequency-stable TEA-CO2 lasers are reviewed. Based on work carried out at the Defence Research Establishment Valcartier (DREV), output pulses are examined from short cavity lasers, CW-TEA hybrid lasers, and amplifiers for low power pulses. It is concluded that the technique of injecting a low-power laser beam into a TEA laser resonator with Gaussian...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, FREQUENCY STABILITY, LIFE...
Near the poles of the Moon, there are permanently shadowed craters whose surface temperatures never exceed 100 K. Craters within craters, commonly referred to as double-shaded craters, have areas where even colder regions exist with, in many cases, temperatures that should never exceed 50 K. The presence of water ice possibly existing in permanently shaded areas of the moon has been hypothesized, discussed, and studied since Watson et al. [1] predicted the possibility of ice on the moon....
Topics: NASA Technical Reports Server (NTRS), THERMAL ENVIRONMENTS, LUNAR EXPLORATION, HIGH TEMPERATURE...
