The isotopic composition and concentration of water, hydrogen, and carbon in some Apollo 15 and 16 soils and in the Apollo 17 orange soil
Explore the source record for details and available documents.
Epstein, S.↗
SEARCH · Engineering Papers
Results for “concentric carbon”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Development of a six-man, self-contained carbon dioxide collection subsystem for spacecraft application
Life Systems, working with NASA, has developed an electrochemical, six-man, self-contained carbon dioxide concentrator subsystem (CX-6) designed to normally remove 13.2 lb/day of CO2 while maintaining the CO2 partial pressure (pCO2) of the cabin atmosphere at 3 mm Hg or less. The CX-6 was subjected to extensive parametric and endurance testing. The effects of operating conditions on CO2 removal and electrical efficiencies were determined, including effects of hydrogen (H2) flow rate, process airflow rate, pCO2, operating temperature and current density. A total of 209 days of operation was accumulated. The subsystem was designed with self-contained electronic control and monitoring instrumentation. The CX-6 was redesigned and repackaged into the CO2 collection subsystem for the air revitalization group of the space station prototype.
Schubert, F. H.↗
Electrochemical air revitalization system optimization investigation
A program to characterize a Breadboard of an Electrochemical Air Revitalization System (BEARS) was successfully completed. The BEARS is composed of three components: (1) a water vapor electrolysis module (WVEM) for O2 production and partial humidity control, (2) an electrochemical depolarized carbon dioxide concentrator module (EDCM) for CO2 control, and (3) a power-sharing controller, designed to utilize the power produced by the EDCM to partially offset the WVEM power requirements. It is concluded from the results of this work that the concept of electrochemical air revitalization with power-sharing is a viable solution to the problem of providing a localized topping force for O2 generation, CO2 removal and partial humidity control aboard manned spacecraft. Continued development of the EARS concept is recommended, applying the operational experience and limits identified during the BEARS program to testing of a one-man capacity system and toward the development of advanced system controls to optimize EARS operation for given interfaces and requirements. Successful completion of this development will produce timely technology necessary to plan future advanced environmental control and life support system programs and experiments.
Woods, R. R.↗
Analysis of impact of Busch Gardens expansion on air quality of surrounding area
This report is concerned primarily with the increase in carbon monoxide concentrations and hydrocarbon concentrations induced by the projected increased traffic that would be associated with the parking facilities planned to support the expansion of Busch Gardens (Virginia) planned for the summar of 1976. Of primary concern is the integrated effect of the increased traffic that will be handled by existing facilities and an enlarged parking lot across the highway from the main Busch Garden attraction.
Kindle, E. C.↗
Feasibility study of launch vehicle ground cloud neutralization
The distribution of hydrogen chloride in the cloud was analyzed as a function of launch pad geometry and rate of rise of the vehicle during the first 24 sec of burn in order to define neutralization requirements. Delivery systems of various types were developed in order to bring the proposed chemical agents in close contact with the hydrogen chloride. Approximately one-third of the total neutralizing agent required can be delivered from a ground installed system at the launch pad; concentrated sodium carbonate solution is the preferred choice of agent for this launch pad system. Two-thirds of the neutralization requirement appears to need delivery by aircraft. Only one chemical agent (ammonia) may be reasonably considered for delivery by aircraft, because weight and bulk of all other agents are too large.
Vanderarend, P. C.↗
A technique for extracting blood samples from mice in fire toxicity tests
The extraction of adequate blood samples from moribund and dead mice has been a problem because of the small quantity of blood in each animal and the short time available between the animals' death and coagulation of the blood. These difficulties are particularly critical in fire toxicity tests because removal of the test animals while observing proper safety precautions for personnel is time-consuming. Techniques for extracting blood samples from mice were evaluated, and a technique was developed to obtain up to 0.8 ml of blood from a single mouse after death. The technique involves rapid exposure and cutting of the posterior vena cava and accumulation of blood in the peritoneal space. Blood samples of 0.5 ml or more from individual mice have been consistently obtained as much as 16 minutes after apparent death. Results of carboxyhemoglobin analyses of blood appeared reproducible and consistent with carbon monoxide concentrations in the exposure chamber.
Bucci, T. J.↗
Estimation of economic losses
If the concentration of carbon fibers (CF) is high after their dispersion due to an aircraft fire, there is a significant possibility that a number of residential, commercial, and industrial establishments might be affected by electronic equipment failure. Estimating economic losses from CF release involves characterizing an entire spectrum of buildings and electronic equipment within a given community. A number of simplified assumptions were made to reduce the data collection requirements to manageable proportions. A limited number of facility categories were identified, and assumed to be relatively homogeneous. The detailed examination of potential losses on an industry-by-industry basis is an important area for future investigation.
Source record↗
Evaluation of micron size carbon fibers released from burning graphite composites
Quantitative estimates were developed of micron carbon fibers released during the burning of graphite composites. Evidence was found of fibrillated particles which were the predominant source of the micron fiber data obtained from large pool fire tests. The fibrillation phenomena were attributed to fiber oxidation effects caused by the fire environment. Analysis of propane burn test records indicated that wind sources can cause considerable carbon fiber oxidation. Criteria estimates were determined for the number of micron carbon fibers released during an aircraft accident. An extreme case analysis indicated that the upper limit of the micron carbon fiber concentration level was only about half the permissible asbestos ceiling concentration level.
Sussholz, B.↗
Some effects of gas adsorption on the high temperature volatile release behavior of a terrestrial basalt, tektite and lunar soil
Mass pyrograms obtained from high-temperature, mass psectrometric pyrolysis of a glassy theoleiitic submarine basalt and a tektite, ground in air to less than 64 microns, have shown N2 and SO release patterns very similar to those from the pyrolysis of mature lunar soil fines. The N2 and CO release behavior from the terrestrial samples reproduces the biomodal, high-temperature (approximately 700 and 1050 C) features from the lunar samples. Unground portions of the basalt and tektite show no release of N2 and CO during pyrolysis. Grinding also alters the release behavior and absolute amounts of H2O and CO2. It is suggested that adsorption of atmospheric gases in addition to solar wind implantation of ions may account for the wide range of values in previously reported concentrations of carbon and nitrogen from lunar fines.
Graham, D. G.↗
Effect of fuel nitrogen and hydrogen content on emissions in hydrocarbon combustion
How the emissions of nitrogen oxides and carbon monoxide are affected by: (1) the decreased hydrogen content and (2) the increased organic nitrogen content of coal derived fuels is investigated. Previous CRT experimental work in a two stage flame tube has shown the effectiveness of rich lean two stage combustion in reducing fuel nitrogen conversion to nitrogen oxides. Previous theoretical work gave preliminary indications that emissions trends from the flame tube experiment could be predicted by a two stage, well stirred reactor combustor model using a detailed chemical mechanism for propane oxidation and nitrogen oxide formation. Additional computations are reported and comparisons with experimental results for two additional fuels and a wide range of operating conditions are given. Fuels used in the modeling are pure propane, a propane toluene mixture and pure toluene. These give hydrogen contents 18, 11 and 9 percent by weight, respectively. Fuel bound nitrogen contents of 0.5 and 1.0 percent were used. Results are presented for oxides of nitrogen and also carbon monoxide concentrations as a function of primary equivalence ratio, hydrogen content and fuel bound nitrogen content.
Bittker, D. A.↗
Relative toxicity testing of spacecraft materials. 1: Spacecraft materials
In chamber thermodegradation procedures were used to access the lethality to rats of the pyrolysis/combustion products of three foams, an adhesive backed metallic tape and RTV silicone rubber adhesive sealant used in spacecraft construction. The role of carbon monoxide in the overall pyrolysate toxicity was also investigated. Post exposure observation of the rats, histological evaluation of selected organs, carbon monoxide concentration in the chamber atmosphere during exposure and the percent carboxyhemoglobin in the animals expiring in the chamber are discussed. Thermogravimetric analysis and dosage response results are given. The lethal effect of the RTV silicon appears to be due to physical obstruction of the respiratory system by particulate matter from pyrolysis.
Lawrence, W. H.↗
Defect structure of EFG silicon ribbon
The defect structure of EFG ribbons was studied using EBIC, TEM and HVEM. By imaging the same areas in EBIC and HVEM, a direct correlation between the crystallographic nature of defects and their electrical properties was obtained. (1) Partial dislocations at coherent twin boundaries may or may not be electrically active. Since no microprecipitates were observed at these dislocations it is likely that the different electrical activity is a consequence of the different dislocation core structures. (2) 2nd order twin joins were observed which followed the same direction as the coherent first order twins normally associated with EFG ribbons. These 2nd order twin joins are in all cases strongly electrically active. EFG ribbons contain high concentrations of carbon. Since no evidence of precipitation was found with TEM it is suggested that the carbon may be incorporated into the higher order twin boundaries now known to exist in EFG ribbons.
Strunk, H.↗
Eruption mechanics on the earth, moon and Mars
A survey is provided of recent comparative studies on the character of eruption mechanics on earth, the moon and Mars. Among the relevant determinations made are: (1) a source depth for lunar basaltic magmas deeper, at 100 km, than most terrestrial ones; (2) the rising of both lunar and terrestrial magmas to less than 2 km below the surface before gases begin to exsolve; (3) carbon monoxide concentrations in lunar basalts are an order of magnitude lower than the average volatile contents of terrestrial basalts; and (4) unequivocal proof is lacking for the existence of ignimbrites in Martian volcanic formations, which would be formed by the collapse of large eruption columns.
Wadge, G.↗
Development of advanced Czochralski growth process to produce low cost 150 kg silicon ingots from a single crucible for technology readiness
Six growth runs used the Kayex-Hameo Automatic Games Logic (AGILE) computer based system for growth from larger melts in the Mod CG2000. The implementation of the melt pyrometer sensor allowed for dip temperature monitoring and usage by the operator/AGILE system. Use of AGILE during recharge operations was successfully evaluated. The tendency of crystals to lose cylindrical shape (spiraling) continued to be a problem. The hygrometer was added to the Furnace Gas Analysis System and used on several growth runs. The gas chromatograph, including the integrator, was also used for more accurate carbon monoxide concentration measurements. Efforts continued for completing the automation of the total Gas Analysis System. An economic analysis, based on revised achievable straight growth rate, is presented.
Lane, R. L.↗
OSTA-1 - The Space Shuttle's first scientific payload
The capabilities of the first Space Shuttle scientific payload for remote sensing observations of the earth are evaluated, and the instruments used are from the Office of Space and Terrestrial Applications (OSTA-1). The payload gathered 10 million square kilometers of data over the earth's oceans, 6 million square kilometers of data over land masses, and global atmospheric data on carbon monoxide concentration. Shuttle imaging radar collected data over a 10,000 km sweep from Spain to Australia, a Shuttle multispectral infrared radiometer obtained 400,000 ten-channel spectra in clear weather conditions over four continents, and the Ocean Color Experiment detected water color for interpretation of major water constituents. The mission is considered to be a success based on the amount of data collected, and scientific and technical insight gained for the development of Shuttle flight instruments.
Moore, J. W.↗
A mathematical model of a large open fire
A mathematical model capable of predicting the detailed characteristics of large, liquid fuel, axisymmetric, pool fires is described. The predicted characteristics include spatial distributions of flame gas velocity, soot concentration and chemical specie concentrations including carbon monoxide, carbon dioxide, water, unreacted oxygen, unreacted fuel and nitrogen. Comparisons of the predictions with experimental values are also given.
Harsha, P. T.↗
The first Shuttle scientific payload /OSTA-1/
On Nov. 12, 1981, the Space Shuttle was launched for its second flight (STS-2). It carried with it the first scientific payload designed to perform remote sensing observations of the earth. During the 54 hour flight, scientific instruments from the OSTA-1 (Office of Space and Terrestrial Applications) payload gathered data over the earth's oceans and land masses, and global atmospheric data on concentrations of carbon monoxide in the atmosphere. The flight demonstrated the capability of the Shuttle to serve as an orbiting platform for scientific research. Instruments were successfully developed for spaceflight for a fraction of the costs associated with instruments flown on unmanned satellite missions. Perhaps most importantly, the instruments have been successfully returned to the investigators for the first time in the history of remote sensing from space.
Taranik, J. V.↗
Carbon monoxide mixing ratio inference from gas filter radiometer data
A new algorithm has been developed which permits, for the first time, real time data reduction of nadir measurements taken with a gas filter correlation radiometer to determine tropospheric carbon monoxide concentrations. The algorithm significantly reduces the complexity of the equations to be solved while providing accuracy comparable to line-by-line calculations. The method is based on a regression analysis technique using a truncated power series representation of the primary instrument output signals to infer directly a weighted average of trace gas concentration. The results produced by a microcomputer-based implementation of this technique are compared with those produced by the more rigorous line-by-line methods. This algorithm has been used in the reduction of Measurement of Air Pollution from Satellites, Shuttle, and aircraft data.
Wallio, H. A.↗