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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.

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At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Space Station Freedom viewed as a 'tight building'

The Space Station Freedom (SSF), with a 30-year projected lifetime and a completely closed-loop Environmental Control and Life Support System (ECLSS), is perhaps the ultimate 'tight building'. Recognizing the potential for the development of 'tight building syndrome' (TBS), and initiating actions to minimize possible TBS occurrences on SSF, requires a multidisciplinary approach that begins with appropriate design concerns and ends with detection and control measures on board SSF. This paper presents a brief summary of current experience with TBS on earth. Air contamination, including volatile organic compounds and microorganisms, is the focus of the discussion. Preventive steps to avoid TBS, control of environmental factors that may lead to TBS, and use of real-time instrumentation for the detection of potential causes of TBS are also outlined.

Limero, Thomas F.↗
NASA NTRS1990

Discourse for slide presentation: An overview of chemical detection systems

A brief overview of some of the analytical techniques currently used in monitoring and analyzing permanent gases and selected volatile organic compound in air are presented. Some of the analytical considerations in developing a specific method are discussed. Four broad groups of hardware are discussed: compound class specific personal monitors, gas chromatographic systems, infrared spectroscopic systems, and mass spectrometric residual gas analyzer systems. Three types of detectors are also discussed: catalytic sensor based systems, photoionization detectors, and wet or dry chemical reagent systems. Under gas chromatograph based systems five detector systems used in combination with a GC are covered: thermal conductivity detectors, photoionization detectors, Fourier transform infrared spectrophotometric systems, quadrapole mass spectrometric systems, and a relatively recent development, a surface acoustic wave vapor detector.

Peters, Randy Alan↗
NASA NTRS1991

New research on bioregenerative air/water purification systems

For the past several years, air and water purification systems have been developed and used. This technology is based on the combined activities of plants and microorganisms as they function in a natural environment. More recently, researchers have begun to address the problems associated with indoor air pollution. Various common houseplants are currently being evaluated for their abilities to reduce concentrations of volatile organic compounds (VOCS) such as formaldehyde and benzene. With development of the Space Exploration Initiative, missions will increase in duration, and problems with resupply necessitates implementation of regenerative technology. Aspects of bioregenerative technology have been included in a habitat known as the BioHome. The ultimate goal is to use this technology in conjunction with physicochemical systems for air and water purification within closed systems. This study continued the risk assessment of bioregenerative technology with emphasis on biological hazards. In an effort to evaluate the risk for human infection, analyses were directed at enumeration of fecal streptococci and enteric viruses with the BioHome waste water treatment system.

Johnson, Anne H.↗
NASA NTRS1990

Degradation mechanisms of selected hydrochlorofluorocarbons in the atmosphere: An assessment of the current knowledge

Volatile organic compounds are mainly degraded in the troposphere by attack of OH with abstraction of H atoms or addition to unsaturated linkages. The chlorofluorocarbons (CFC's) do not contain these reactive sites and consequently cannot be degraded in this way in the lower atmosphere. This results in pollution of the stratosphere by these molecules and attendant problems for ozone. The proposed replacements for CFC's, the hydrochlorofluorocarbons (HCFC's), and hydrofluorocarbons (HFC's), contain at least one hydrogen atom in the molecule, which confers on these compounds a greater sensitivity toward oxidation by OH in the troposphere and in the lower stratosphere, resulting in much shorter atmospheric lifetimes than the CFC's. Consequently, the Ozone Depletion Potential and the Atmospheric Warming Potential are reduced substantially compared to the CFC's. All the possible degradation processes of the HCFC's and HFC's proposed to replace the CFC's are examined with the principal aim of identifying chlorine- and fluorine-containing products which are stable under tropospheric conditions.

Cox, Richard A.↗
NASA NTRS1993

Comprehensive analysis of airborne contaminants from recent Spacelab missions

The Shuttle experiences unique air contamination problems because of microgravity and the closed environment. Contaminant build-up in the closed atmosphere and the lack of a gravitational settling mechanism have produced some concern in previous missions about the amount of solid and volatile airborne contaminants in the Orbiter and Spacelab. Degradation of air quality in the Orbiter/Spacelab environment, through processes such as chemical contamination, high solid-particulate levels, and high microbial levels, may affect crew performance and health. A comprehensive assessment of the Shuttle air quality was undertaken during STS-40 and STS-42 missions, in which a variety of air sampling and monitoring techniques were employed to determine the contaminant load by characterizing and quantitating airborne contaminants. Data were collected on the airborne concentrations of volatile organic compounds, microorganisms, and particulate matter collected on Orbiter/Spacelab air filters. The results showed that STS-40/42 Orbiter/Spacelab air was toxicologically safe to breathe, except during STS-40 when the Orbiter Refrigerator/Freezer unit was releasing noxious gases in the middeck. On STS-40, the levels of airborne bacteria appeared to increase as the mission progressed; however, this trend was not observed for the STS-42 mission. Particulate matter in the Orbiter/Spacelab air filters was chemically analyzed in order to determine the source of particles. Only small amounts of rat hair and food bar (STS-40) and traces of soiless medium (STS-42) were detected in the Spacelab air filters, indicating that containment for Spacelab experiments was effective.

Matney, M. L.↗
NASA NTRS1993

Biomass production chamber air analysis of wheat study (BWT931)

NASA's Controlled Ecological Life Support System (CELSS) biomass production chamber at John F. Kennedy Space Center provides a test bed for bioregenerative studies using plants to provide food, oxygen, carbon dioxide removal, and potable water to humans during long term space travel. Growing plants in enclosed environments has brought about concerns regarding the level of volatile organic compounds (VOC's) emitted from plants and the construction materials that make up the plant growth chambers. In such closed systems, the potential exists for some VOC's to reach toxic levels and lead to poor plant growth, plant death, or health problems for human inhabitants. This study characterized the air in an enclosed environment in which wheat cv. Yocora Rojo was grown. Ninty-four whole air samples were analyzed by gas chromatography/mass spectrometry throughout the eighty-four day planting. VOC emissions from plants and materials were characterized and quantified.

Batten, J. H.↗
NASA NTRS1994

Using spacecraft trace contaminant control systems to cure sick building syndrome

Many residential and commercial buildings with centralized, recirculating, heating ventilation and air conditioning systems suffer from 'Sick Building Syndrome.' Ventilation rates are reduced to save energy costs, synthetic building materials off-gas contaminants, and unsafe levels of volatile organic compounds (VOC's) accumulate. These unsafe levels of contaminants can cause irritation of eyes and throat, fatigue and dizziness to building occupants. Increased ventilation, the primary method of treating Sick Building Syndrome is expensive (due to increased energy costs) and recently, the effectiveness of increased ventilation has been questioned. On spacecraft venting is not allowed, so the primary methods of air quality control are; source control, active filtering, and destruction of VOC's. Four non-venting contaminant removal technologies; strict material selection to provide source control, ambient temperature catalytic oxidation, photocatalytic oxidation, and uptake by higher plants, may have potential application for indoor air quality control.

Graf, John C.↗
NASA NTRS1994

Development of a unique polyurethane primer/topcoat

USBI Company, a Division of Pratt & Whitney Government Engines and Space Propulsion, is involved in corrosion and environmental research and development activities both at their headquarters in Huntsville, Alabama and their Florida Operations at Kennedy Space Center, Florida. The programs involve the development of environmentally compatible materials that improve the corrosion protection of expensive Solid Rocket Boosters (SRB) that are part of the Space Shuttle systems developed and managed by Marshall Space Flight Center in Huntsville, Alabama. Coatings For Industry, a paint manufacturer in Souderton, PA helped formulate and produce the first lot of BOOSTERCOAT paint. High strength aluminum aerospace flight hardware exposed to harsh seacoast environments and seawater immersion presently uses high volatile organic compound (VOC) chromated and lead bearing primers and epoxy topcoats for corrosion protection. Epoxy paint tends to be brittle and has relatively low ultraviolet (UV) exposure resistance. A unique, environmentally compatible, non-leaded/non-chromated, low VOC polyurethane single coat (primer/topcoat) trade named BOOSTERCOAT has been developed for excellent corrosion protection, flexibility, adhesion, chemical and solvent resistance properties. This report will discuss the development of BOOSTERCOAT and the potential opportunities for commercial use in the energy, transportation, chemical, maritime, structural fields.

Novak, Howard L.↗
NASA NTRS1994

A volatile organic analyzer for Space Station: Description and evaluation of a gas chromatography/ ion mobility

A Volatile Organic Analyzer (VOA) is being developed as an essential component of the Space Station's Environmental Health System (EHS) air quality monitoring strategy to provide warning to the crew and ground personnel if volatile organic compounds exceed established exposure limits. The short duration of most Shuttle flights and the relative simplicity of the contaminant removal mechanism have lessened the concern about crew exposure to air contaminants on the Shuttle. However, the longer missions associated with the Space Station, the complex air revitalization system and the proposed number of experiments have led to a desire for real-time monitoring of the contaminants in the Space Station atmosphere. Achieving the performance requirements established for the VOA within the Space Station resource (e.g., power, weight) allocations led to a novel approach that joined a gas chromatograph (GC) to an ion mobility spectrometer (IMS). The authors of this paper will discuss the rational for selecting the GC/IMS technology as opposed to the more established gas chromatography/mass spectrometry (GC/MS) for the foundation of the VOA. The data presented from preliminary evaluations will demonstrate the versatile capability of the GC/IMS to analyze the major contaminants expected in the Space Station atmosphere. The favorable GC/IMS characteristics illustrated in this paper included excellent sensitivity, dual-mode operation for selective detection, and mobility drift times to distinguish co-eluting GC peaks. Preliminary studies have shown that the GC/IMS technology can meet surpass the performance requirements of the Space Station VOA.

Limero, Thomas F.↗
NASA NTRS1994

Estimates of ozone response to various combinations of NO(x) and VOC emission reductions in the eastern United States

There is increasing recognition that controls on NO(x) emissions may be necessary, in addition to existing and future Volatile Organic Compounds (VOC) controls, for the abatement of ozone (O3) over portions of the United States. This study compares various combinations of anthropogenic NO(x) and VOC emission reductions through a series of model simulations. A total of 6 simulations were performed with the Regional Oxidant Model (ROM) for a 9-day period in July 1988. Each simulation reduced anthropogenic NO(x) and VOC emissions across-the-board by different amounts. Maximum O3 concentrations for the period were compared between the simulations. Comparison of the simulations suggests that: (1) NO(x) controls may be more effective than VOC controls in reducing peak O3 over most of the eastern United States; (2) VOC controls are most effective in urban areas having large sources of emissions; (3) NO(x) controls may increase O3 near large point sources; and (4) the benefit gained from increasing the amount of VOC controls may lessen as the amount of NO(x) control is increased. This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Roselle, Shawn J.↗
NASA NTRS1994

Analysis of trace halocarbon contaminants in ultra high purity helium

This study describes the analysis of ultra high purity helium. Purification studies were conducted and containment removal was effected by the utilization of solid adsorbent purge-trap systems at cryogenic temperatures. Volatile organic compounds in ultra high purity helium were adsorbed on a solid adsorbent-cryogenic trap, and thermally desorbed trace halocarbon and other contaminants were analyzed by combined gas chromatography-mass spectrometry.

Fewell, Larry L.↗
NASA NTRS1994

Aqueous alternatives for metal and composite cleaning

For many years the metalworking industry has cleaned metal and composite substrates with chlorinated solvents. Recently, however, health and disposal related environmental concerns have increased regarding chlorinated solvents, including 1,1,1-trichloroethane, trichloroethylene, methylene chloride, or Freon'. World leaders have instituted a production ban of certain ozone depleting chlorofluorocarbons (CFC's) by 1996. The Occupational Safety and Health Administration (OSHA) has instituted worker vapor exposure limitations for virtually all of the solvents used in solvent-based cleaners. In addition, the United States Environmental Protection Agency (EPA) has defined nearly all solvent-based cleaners as 'hazardous'. Cradle to grave waste responsibility is another reason manufacturers are trying to replace chlorinated solvents in their cleaning processes. Because of these factors, there now is a world wide effort to reduce and/or eliminate the use of chlorinated solvents for industrial cleaning. Waterbased cleaners are among the alternatives being offered to the industry. New technology alkaline cleaners are now available that can be used instead of chlorinated solvents in many cleaning processes. These waterbased cleaners reduce the release of volatile organic compounds (VOC's) by as much as 99 percent. (The definition and method of calculation of VOC's now varies from region to region.) Hazardous waste generation can also be significantly reduced or eliminated with new aqueous technology. This in turn can ease worker exposure restrictions and positively impact the environment. This paper compares the chemical and physical properties of this aqueous cleaners versus chlorinated solvents.

Quitmeyer, Joann↗
NASA NTRS1995

Air pollution control system research: An iterative approach to developing affordable systems

This paper describes a Strategic Environmental Research and Development Program (SERDP) funded project led jointly by the Marine Corps Multi-Commodity Maintenance Centers, and the Air and Energy Engineering Research Laboratory (AEERL) of the USEPA. The research focuses on paint booth exhaust minimization using recirculation, and on volatile organic compound (VOC) oxidation by the modules of a hybrid air pollution control system. The research team is applying bench, pilot and full scale systems to accomplish the goals of reduced cost and improved effectiveness of air treatment systems for paint booth exhaust.

Watt, Lewis C.↗
NASA NTRS1995

Replacement of corrosion protection chromate primers and paints used in cryogenic applications on the Space Shuttle with wire arc sprayed aluminum coatings

With the advent of new environmental laws restricting volatile organic compounds and hexavalent chrome emissions, 'environmentally safe' thermal spray coatings are being developed to replace the traditional corrosion protection chromate primers. A wire arc sprayed aluminum coating is being developed for corrosion protection of low pressure liquid hydrogen carrying ducts on the Space Shuttle Main Engine. Currently, this hardware utilizes a chromate primer to provide protection against corrosion pitting and stress corrosion cracking induced by the cryogenic operating environment. The wire are sprayed aluminum coating has been found to have good potential to provide corrosion protection for flight hardware in cryogenic applications. The coating development, adhesion test, corrosion test and cryogenic flexibility test results will be presented.

Daniel, R. L.↗
NASA NTRS1995

Wire-Arc-Sprayed Aluminum Protects Steel Against Corrosion

Aluminum coatings wire-arc sprayed onto steel substrates found effective in protecting substrates against corrosion. Coatings also satisfy stringent requirements for adhesion and flexibility, both at room temperature and at temperatures as low as liquid hydrogen. Developed as alternatives to corrosion-inhibiting primers and paints required by law to be phased out because they contain and emit such toxic substances as chromium and volatile organic compounds.

Zimmerman, Frank R.↗
NASA NTRS1996

Cleaning Spectralon(TM) To Maintain Reflectance Properties

Hydrocarbon impurities removed and stability of Spectralon(TM) towards ultraviolet and vacuum-ultraviolet radiation greatly enhanced by baking material at 90 degrees C for 24 h in vacuum of 10 to negative 5th power torr. After vacuum bake, material handled with white cotton, lint-free gloves in clean environment (preferably cleanroom). As material has tendency to reabsorb volatile organic compounds, stored and transported only in clean, air-tight (preferably glass or oil-free metal) containers.

Stiegman, Albert↗
NASA NTRS1999

The Successful Transfer of Space Derived Convergent Spray Technology(TM): An Application for Industrial Roof Coatings and Interstate Bridge Repair

Although the levels of volatile organic compound (VOC) emissions from industrial roof coatings and paint operations have been reduced in recent years, the roof coating partnership was an effort to further reduce VOC emission levels and to also demonstrate the use of reclaimed automobile tire rubber as a filler material in roof coating systems. Different materials and coatings were evaluated and tested before the final selection was used to coat the roofs of two small buildings at NASA's MSFC (Marshall Space Flight Center) during fiscal year 1997. The primary objective of the Bridge repair partnership was to strategically leverage public and private sector funds for the purpose of developing a bridge repair process that was cheaper, better, and faster than conventional methods. It was also, imperative that this process be environmentally friendly and capable of performing under extreme conditions for a period of not less than 2 years.

McMillan, Vernotto↗
NASA NTRS1998

The Successful Transfer of Space Derived Convergent Spray: An Application for Industrial Roof Coatings and Interstate Bridge Repair

A partnership was formed between the National Aeronautics and Space Administration (NASA), the Environmental Protection Agency (EPA), and United Technologies USBI Company to develop, demonstrate, and evaluate a technology that uses a solventless spray process for depositing a lightweight, highly filled roof coating on low-sloped commercial roofs. Although the levels of volatile organic compound (VOC) emissions from industrial roof coating's and paint operations have been reduced in recent years, this partnership,was an effort to further reduce VOC emission levels and to also demonstrate the use of reclaimed automobile tire rubber as a filler material in roof coating systems. Different materials and coatings were evaluated and tested before the final selection used to coat the roofs of two small buildings at NASA's Marshall Space Flight Center during fiscal year 1997. The project successfully leveraged the investment of EPA, NASA and private sector resources to demonstrate a pre-commercial roofing coating process. This process utilizes the Convergent Spray Technologies process, which was initially developed by USBI to apply highly-filled, thermal protection coatings to the Space Shuttle Solid Rocket Boosters. A second partnership between the NASA, Federal Highway Administration, Alabama Department of Transportation and USBI Company was formed to develop and demonstrate the Convergent Spray Technology as a method of applying a skid resistant coating to interstate roads and concrete bridge decking's. Again, different materials and coatings were evaluated and tested before the final selection of ground flint and resin. Two field demonstrations were performed during fiscal year 1997 for the purpose of evaluating the coating system under actual highway conditions. These coatings were applied on Interstate 65 near Huntsville Alabama, and in the Mobile Bankhead tunnel. The system performed this task without the use of harmful solvents, and accomplished the process in a single application. This project successfully leveraged the investment of NASA, Federal Highway Administration, the Alabama Department of Transportation, and private sector funding.

McMillan, Vernotto C.↗