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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Microscale Particulate Classifiers (MiPAC) Being Developed

The NASA Glenn Research Center is developing microscale sensors to characterize atmospheric-borne particulates. The devices are fabricated using MEMS (microelectromechanical systems) technologies. These technologies are derived from those originally developed in support of the semiconductor processing industry. The resulting microsensors can characterize a wide range of particles and are, therefore, suitable to a broad range of applications. This project is supported under a collaborative program called the Glennan Microsystems Initiative. The initiative comprises members of NASA Glenn Research Center, various university affiliates from the State of Ohio, and a number of participating industrial partners. Funding is jointly provided by NASA, the State of Ohio, and industrial members. The work described here is a collaborative arrangement between researchers at Glenn, the University of Minnesota, The National Institute of Standards and Technology (NIST), and the Cleveland State University. Actual device fabrication is conducted at Glenn and at the laboratories of Case Western Reserve University. Case Western is also located in Cleveland, Ohio, and is a participating member of the initiative. The principal investigator for this project is Paul S. Greenberg of Glenn. Two basic types of devices are being developed, and target different ranges of particle sizes. The first class of devices, which is used to measure nanoparticles (i.e., particles in the range of 0.002 to 1 mm), is based on the technique of Electrical Mobility Classification. This technique also affords the valuable ability of measuring the electrical charge state of the particles. Such information is important in the understanding of agglomeration mechanisms and is useful in the development of methods for particle repulsion. The second type of device being developed, which utilizes optical scattering, is suitable for particles larger than 1 mm. This technique also provides information on particle shape and composition. Applications for these sensors include fundamental planetary climatology, monitoring and filtration in spacecraft, human habitation modules and related systems, characterization of particulate emissions from propulsion and power systems, and as early warning sensors for both space-based and ter-restrial fire detection. These devices are also suitable for characterizing biological compounds such as allergens, infectious agents, and biotoxic agents.

Greenberg, Paul S.↗
NASA NTRS2001

Computer Model Used to Help Customize Medicine

Dr. Radhakrishnan, a researcher at the NASA Glenn Research Center, in collaboration with biomedical researchers at the Case Western Reserve University School of Medicine and Rainbow Babies and Children's Hospital, is developing computational models of human physiology that quantitate metabolism and its regulation, in both healthy and pathological states. These models can help predict the effects of stresses or interventions, such as drug therapies, and contribute to the development of customized medicine. Customized medical treatment protocols can give more comprehensive evaluations and lead to more specific and effective treatments for patients, reducing treatment time and cost. Commercial applications of this research may help the pharmaceutical industry identify therapeutic needs and predict drug-drug interactions. Researchers will be able to study human metabolic reactions to particular treatments while in different environments as well as establish more definite blood metabolite concentration ranges in normal and pathological states. These computational models may help NASA provide the background for developing strategies to monitor and safeguard the health of astronauts and civilians in space stations and colonies. They may also help to develop countermeasures that ameliorate the effects of both acute and chronic space exposure.

Stauber, Laurel J.↗
NASA NTRS2002

Ceramic Propellant Injectors Designed and Fabricated

Ceramic propellant injectors offer the potential for order-of-magnitude weight reductions in comparison to conventional metallic injectors and may enable some NASA missions. Injectors constructed of ceramic materials have the inherent advantages of being lighter weight, more erosion resistant, and capable of higher temperature operation than current metallic designs. The use of ceramics may facilitate new designs for a broad range of combustion devices in aero and space applications. In a joint project involving NASA Glenn Research Center's Ceramics and Combustion branches and Case Western Reserve University, a rocket propellant injector faceplate was designed and fabricated using laminated object manufacturing and standard ceramic processing. A number of faceplates have been successfully hot-fire bench tested.

Eckel, Andrew J.↗
NASA NTRS2002

Oxidation Behavior of GRCop-84 Copper Alloy Assessed

NASA's goal of safe, affordable space transportation calls for increased reliability and lifetimes of launch vehicles, and significant reductions of launch costs. The areas targeted for enhanced performance in the next generation of reusable launch vehicles include combustion chambers and nozzle ramps; therefore, the search is on for suitable liner materials for these components. GRCop-84 (Cu-8Cr-4Nb), an advanced copper alloy developed at the NASA Glenn Research Center in conjunction with Case Western Reserve University, is a candidate. The current liner of the Space Shuttle Main Engine is another copper alloy, NARloy-Z (Cu-3Ag-0.1Zr). It provides a benchmark against which to compare the properties of candidate successors. The thermomechanical properties of GRCop-84 have been shown to be superior, and its physical properties comparable, to those of NARloy-Z. However, environmental durability issues control longevity in this application: because copper oxide scales are not highly protective, most copper alloys are quickly consumed in oxygen environments at elevated temperatures. In consequence, NARloy-Z and most other copper alloys are prone to blanching, a degradation process that occurs through cycles of oxidation-reduction as the oxide is repeatedly formed and removed because of microscale fluctuations in the oxygen-hydrogen fuel systems of rocket engines. The Space Shuttle Main Engine lining typically degraded by blanching-induced hot spots that lead to surface roughening, pore formation, and coolant leakage. Therefore, resistance to oxidation and blanching are key requirements for second-generation reusable launch vehicle liners. The rocket engine ambient includes H2 (fuel) and H2O (combustion product) and is, hence, under reduced oxygen partial pressures. Accordingly, our studies were expanded to include oxygen partial pressures as low as 322 parts per million (ppm) at the temperatures likely to be experienced in service. A comparison of 10-hr weight gains of GRCop-84, NARloy-Z, and pure copper in 0.032, 2.2, and 100 percent oxygen from 550 to 750 C is shown. In 2.2 vol% and higher oxygen content, GRCop-84 oxidation was slower than that of NARloy-Z or Cu, but that advantage was lost or diminished in 322-ppm O2. Over longer (50-hr) exposures in 1.0 atm O2, however, the advantage of GRCop-84 increased significantly, its oxidation rate becoming approximately 10 times slower than those of Cu and NARloy-Z from 500 to 700 C. Weight gains were moderate and the kinetics parabolic for all three materials in 2.2 vol% and higher oxygen content; however, in 322-ppm O2, the scales were nonprotective below about 650 C, as reflected in linear kinetics and large weight gains. The superior oxidation resistance of GRCop-84 is likely related to the kinetics of extra oxygen consumption to form the additional oxides of Cr and Nb detected beneath the GRCop-84 oxide layer. While we continue to evaluate the blanching resistance of GRCop-84 in other tests, these oxidation results indicate that GRCop-84 is suitable as a reusable launch vehicle liner, and in applications where it is desired to use a copper alloy but without the risk of oxidative failure. Three bar charts comparing overall specific weight gains by each of the three materials studied. The top chart is for oxidation in 1.0 atm of oxygen, the middle is for 2.2% oxygen (balance argon), and the bottom is for 0.0322% oxygen. GRCop-84 outperforms the other two materials, showing the least weight gain in nearly all cases.

Thomas-Ogbuji, Linus U.↗
NASA NTRS2002

High-Temperature Gas Sensor Array (Electronic Nose) Demonstrated

The ability to measure emissions from aeronautic engines and in commercial applications such as automotive emission control and chemical process monitoring is a necessary first step if one is going to actively control those emissions. One single sensor will not give all the information necessary to determine the chemical composition of a high-temperature, harsh environment. Rather, an array of gas sensor arrays--in effect, a high-temperature electronic "nose"--is necessary to characterize the chemical constituents of a diverse, high-temperature environment, such as an emissions stream. The signals produced by this nose could be analyzed to determine the constituents of the emission stream. Although commercial electronic noses for near-room temperature applications exist, they often depend significantly on lower temperature materials or only one sensor type. A separate development effort necessary for a high-temperature electronic nose is being undertaken by the NASA Glenn Research Center, Case Western Reserve University, Ohio State University, and Makel Engineering, Inc. The sensors are specially designed for hightemperature environments. A first-generation high-temperature electronic nose has been demonstrated on a modified automotive engine. This nose sensor array was composed of sensors designed for hightemperature environments fabricated using microelectromechanical-systems- (MEMS-) based technology. The array included a tin-oxide-based sensor doped for nitrogen oxide (NOx) sensitivity, a SiC-based hydrocarbon (CxHy) sensor, and an oxygen sensor (O2). These sensors operate on different principles--resistor, diode, and electrochemical cell, respectively--and each sensor has very different responses to the individual gases in the environment. A picture showing the sensor head for the array is shown in the photograph on the left and the sensors installed in the engine are shown in the photograph on the right. Electronics are interfaced with the sensors for temperature control and signal conditioning, and packaging designed for high temperatures is necessary for the array to survive the engine environment.

Hunter, Gary W.↗
NASA NTRS2005

Structural and Acoustic Damping Characteristics of Polyimide Microspheres

A broad range of tests have been performed to evaluate the capability of tiny lightweight polyimide spheres to reduce sound and vibration. The types of testing includes impedance tube measurement of propagation constant, sound power insertion loss for single and double wall systems, particle frame wave characterization and beam vibration reduction. The tests were performed using spheres made of two types of polyimide and with varying diameter. Baseline results were established using common noise reduction treatment materials such as fiberglass and foam. The spheres were difficult to test due to their inherent mobility. Most tests required some adaptation to contain the spheres. One test returned obvious non-linear behavior, a result which has come to be expected for treatments of this type. The polyimide spheres are found to be a competent treatment for both sound and vibration energy with the reservation that more work needs to be done to better characterize the non-linear behavior.

Palumbo, Daniel L.↗
NASA NTRS2005

Free Re-boost Electrodynamic Tether on the International Space Station

The International Space Station (ISS) currently experiences significant orbital drag that requires constant make up propulsion or the Station will quickly reenter the Earth's Atmosphere. The reboost propulsion is presently achieved through the firing of hydrazine rockets at the cost of considerable propellant mass. The problem will inevitably grow much worse as station components continue to be assembled, particularly when the full solar panel arrays are deployed. This paper discusses many long established themes on electrodynamic propulsion in the context of Exploration relevance, shows how to couple unique ISS electrical power system characteristics and suggests a way to tremendously impact ISS's sustainability. Besides allowing launch mass and volume presently reserved for reboost propellant to be reallocated for science experiments and other critically needed supplies, there are a series of technology hardware demonstrations steps that can be accomplished on ISS, which are helpful to NASA s Exploration mission. The suggested ElectroDynamic (ED) tether and flywheel approach is distinctive in its use of free energy currently unusable, yet presently available from the existing solar array panels on ISS. The ideas presented are intended to maximize the utility of Station and radically increase orbital safety.

Bonometti, Joseph A.↗
NASA NTRS2002

CARES/Life Used for Probabilistic Characterization of MEMS Pressure Sensor Membranes

Microelectromechanical systems (MEMS) devices are typically made from brittle materials such as silicon using traditional semiconductor manufacturing techniques. They can be etched (or micromachined) from larger structures or can be built up with material deposition processes. Maintaining dimensional control and consistent mechanical properties is considerably more difficult for MEMS because feature size is on the micrometer scale. Therefore, the application of probabilistic design methodology becomes necessary for MEMS. This was demonstrated at the NASA Glenn Research Center and Case Western Reserve University in an investigation that used the NASA-developed CARES/Life brittle material design program to study the probabilistic fracture strength behavior of single-crystal SiC, polycrystalline SiC, and amorphous Si3N4 pressurized 1-mm-square thin-film diaphragms. These materials are of interest because of their superior high-temperature characteristics, which are desirable for harsh environment applications such as turbine engine and rocket propulsion system hot sections.

Nemeth, Noel N.↗
NASA NTRS2005

Marshall Space Flight Center Test Capabilities

The Test Laboratory at NASA's Marshall Space Flight Center has over 50 facilities across 400+ acres inside a secure, fenced facility. The entire Center is located inside the boundaries of Redstone Arsenal, a 40,000 acre military reservation. About 150 Government and 250 contractor personnel operate facilities capable of all types of propulsion and structural testing, from small components to engine systems and structural strength, structural dynamic and environmental testing. We have tremendous engineering expertise in research, evaluation, analysis, design and development, and test of space transportation systems, subsystems, and components.

Hamilton, Jeffrey T.↗
NASA NTRS2005

UltraSail - Ultra-Lightweight Solar Sail Concept

UltraSail is a next-generation high-risk, high-payoff sail system for the launch, deployment, stabilization and control of very large (sq km class) solar sails enabling high payload mass fractions for high (Delta)V. Ultrasail is an innovative, non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation-flying micro-satellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 sq km, sail subsystem area densities approaching 1 g/sq m, and thrust levels many times those of ion thrusters used for comparable deep space missions. Ultrasail can achieve outer planetary rendezvous, a deep space capability now reserved for high-mass nuclear and chemical systems. One of the primary innovations is the near-elimination of sail supporting structures by attaching each blade tip to a formation-flying micro-satellite which deploys the sail, and then articulates the sail to provide attitude control, including spin stabilization and precession of the spin axis. These tip micro-satellites are controlled by 3-axis micro-thruster propulsion and an on-board metrology system. It is shown that an optimum spin rate exists which maximizes payload mass.

Burton, Rodney L.↗
NASA NTRS2003

Strength Differential Measured in Inconel 718: Effects of Hydrostatic Pressure Studied

Aeropropulsion components, such as disks, blades, and shafts, are commonly subjected to multiaxial stress states at elevated temperatures. Experimental results from loadings as complex as those experienced in service are needed to help guide the development of accurate viscoplastic, multiaxial deformation models that can be used to improve the design of these components. During a recent study on multiaxial deformation (ref. 1) on a common aerospace material, Inconel 718, it was shown that the material in the aged state exhibits a strength differential effect (SDE), whereby the uniaxial compressive yield and subsequent flow behavior are significantly higher than those in uniaxial tension. Thus, this material cannot be described by a standard von Mises yield formulation. There have been other formulations postulated (ref. 2) that involve other combinations of the stress invariants, including the effect of hydrostatic stress. The question remained as to which invariants are necessary in the flow model. To capture the physical mechanisms occurring during deformation and reflect them in the plasticity formulation, researchers examined the flow of Inconel 718 under various amounts of hydrostatic stress to determine whether or not hydrostatic stress is needed in the formulation. Under NASA Grant NCC3-464, monitored by the NASA Glenn Research Center, a series of tensile tests were conducted at Case Western Reserve University on aged (precipitation hardened) Inconel 718 at 650 C and with superimposed hydrostatic pressure. Dogbone shaped tensile specimens (3-mm-diameter gauge by 16-mm gauge length) and cylindrical compression specimens (3-mm-diameter gauge by 6-mm gauge length) were strain gauged and loaded in a high-pressure testing apparatus. Hydrostatic pressures were obtained with argon and ranged from 210 to 630 MPa. The aged Inconel 718 showed a pronounced difference in the tension and compression yield strength (i.e., an SDE), as previously observed. Also, there were no significant effects of hydrostatic pressure on either the tensile and compressive yield strength (see the graph) or on the magnitude of the SDE. This behavior is not consistent with the pressure-dependent theory of the SDE, which postulates that the SDE is associated with pressure-dependent and/or internal friction dependent deformation associated with non-Schmid effects at the crystal level (refs. 3 and 4). Flow in Inconel 718 appears to be independent of hydrostatic pressure, suggesting that this invariant may be removed from the phenomenological constitutive model. As part of an ongoing effort to develop advanced constitutive models, Glenn s Life Prediction Branch coordinated this work with that of research on the multiaxial deformation behavior of Inconel 718 being conducted at Pennsylvania State University under NASA Grant NCC597.

Lewandowski, John J.↗
NASA NTRS2005

Computational Material Processing in Microgravity

Working with Professor David Matthiesen at Case Western Reserve University (CWRU) a computer model of the DPIMS (Diffusion Processes in Molten Semiconductors) space experiment was developed that is able to predict the thermal field, flow field and concentration profile within a molten germanium capillary under both ground-based and microgravity conditions as illustrated. These models are coupled with a novel nonlinear statistical methodology for estimating the diffusion coefficient from measured concentration values after a given time that yields a more accurate estimate than traditional methods. This code was integrated into a web-based application that has become a standard tool used by engineers in the Materials Science Department at CWRU.

Source record↗
NASA NTRS2003

Microfabricated Gas Sensors Demonstrated in Fire and Emission Applications

A range of microfabricated chemical sensors are being developed to meet the needs of fire detection and emission monitoring in aerospace applications. These sensors have the advantages over traditional technology of minimal size, weight, and power consumption as well as the ability to be placed closer to where the measurements need to be made. Sensor arrays are being developed to address detection needs in environments where multiple species need to be measured. For example, the monitoring of chemical species such as carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons, and other species is important in the detection of fires on airplanes and spacecraft. In contrast, different sensors are necessary for characterizing some aircraft engine designs where the monitoring of nitrogen oxides (NO(x)) and CO is of high interest. Demonstration of both fire and emission microsensor technology was achieved this year in a collaborative effort undertaken by the NASA Glenn Research Center, Case Western Reserve University, and Makel Engineering, Inc.

Hunter, Gary W.↗
NASA NTRS2004

Compact Microscope Imaging System With Intelligent Controls Improved

The Compact Microscope Imaging System (CMIS) with intelligent controls is a diagnostic microscope analysis tool with intelligent controls for use in space, industrial, medical, and security applications. This compact miniature microscope, which can perform tasks usually reserved for conventional microscopes, has unique advantages in the fields of microscopy, biomedical research, inline process inspection, and space science. Its unique approach integrates a machine vision technique with an instrumentation and control technique that provides intelligence via the use of adaptive neural networks. The CMIS system was developed at the NASA Glenn Research Center specifically for interface detection used for colloid hard spheres experiments; biological cell detection for patch clamping, cell movement, and tracking; and detection of anode and cathode defects for laboratory samples using microscope technology.

McDowell, Mark↗
NASA NTRS2005

SIAM-SERVIR: An Environmental Monitoring and Decision Support System for Mesoamerica

In 2002/2003 NASA, the World Bank and the United States Agency for International Development (USAID) joined with the Central American Commission for Environment and Development (CCAD) to develop an advanced decision support system for Mesoamerica (named SERVIR) as part of the Mesoamerican Environmental Information System (SIAM). Mesoamerica - composed of the seven Central American countries and the five southernmost states of Mexico - make up only a small fraction of the world s land surface. However, the region is home to seven to eight percent of the planet s biodiversity (14 biosphere reserves, 31 Ramsar sites, 8 world heritage sites, 589 protected areas) and 45 million people including more than 50 different ethnic groups. Today Mesoamerica s biological and cultural diversity is severely threatened by extensive deforestation, illegal logging, water pollution, and uncontrolled slash and burn agriculture. Additionally, Mesoamerica's distinct geology and geography result in disproportionate vulnerability to natural disasters such as earthquakes, hurricanes, drought, and volcanic eruptions. NASA Marshall Space Flight Center, together with the University of Alabama in Huntsville (UAH) and the SIAM-SERVIR partners are developing state-of-the-art decision support tools for environmental monitoring as well as disaster prevention and mitigation in Mesoamerica. These partners are contributing expertise in space-based observation with information management technologies and intimate knowledge of local ecosystems to create a system that is being used by scientists, educators, and policy makers to monitor and forecast ecological changes, respond to natural disasters and better understand both natural and human induced effects. In its first year of development and operation, the SIAM-SERVIR project has already yielded valuable information on Central American fires, weather conditions, and the first ever real-time data on red tides. This paper presents the progress thus far in the development of SIAM-SERVIR and the plans for the future.

Irwin, Daniel E.↗
NASA NTRS2005

High-Temperature, Thin-Film Ceramic Thermocouples Developed

To enable long-duration, more distant human and robotic missions for the Vision for Space Exploration, as well as safer, lighter, quieter, and more fuel efficient vehicles for aeronautics and space transportation, NASA is developing instrumentation and material technologies. The high-temperature capabilities of thin-film ceramic thermocouples are being explored at the NASA Glenn Research Center by the Sensors and Electronics Branch and the Ceramics Branch in partnership with Case Western Reserve University (CWRU). Glenn s Sensors and Electronics Branch is developing thin-film sensors for surface measurement of strain, temperature, heat flux, and surface flow in propulsion system research. Glenn s Ceramics Branch, in conjunction with CWRU, is developing structural and functional ceramic technology for aeropropulsion and space propulsion.

Sayir, Ali↗
NASA NTRS2005

Chemical evolution of RNA under hydrothermal conditions and the role of thermal copolymers of amino acids for the prebiotic degradation and formation of RNA

The roles of thermal copolymers of amino acids (TCAA) were studied for the prebiotic degradation of RNA. A weak catalytic ability of TCAA consisted of Glu, L-Ala, L-Val, L-Glu, L-Asp, and optionally L-His was detected for the cleavage of the ribose phosphodiester bond of a tetranucleotide (5'-dCrCdGdG) in aqueous solution at 80 degees C. The rate constants of the disappearance of 5'-dCrCdGdG were determined in aqueous solutions using different pH buffer and TCAA. The degradation rates were enhanced 1.3-3.0 times in the presence of TCAA at pH 7.5 and 8.0 at 80 degrees C, while the hydrolysis of oligoguanylate (oligo(G)) was accelerated about 1.6 times at pH 8.0. A weak inhibitory activity for the cleavage of oligo(G) was detected in the presence of 0.055 M TCAA-Std. On the other hand, our recent study on the influences of TCAA for the template-directed reaction of oligo(G) on a polycytidylic acid template showed that TCAA has an acceleration activity for the degradation of the activated nucleotide monomer and an acceleration activity for the formation of G5' ppG capped oligo(G). This series of studies suggest that efficient and selective catalytic or inhibitory activities for either the degradation or formation of RNA under hydrothermal conditions could have hardly emerged from the simple thermal condensation products of amino acids. A scenario is going to be deduced on the chemical evolution of enzymatic activities and RNA molecules concerning hydrothermal earth conditions. c2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

Amino Acids/chemistry↗
NASA NTRS2005

Population dynamics of transgenic strain Escherichia coli Z905/pPHL7 in freshwater and saline lake water microcosms with differing microbial community structures

Populations of Escherichia coli Z905/pPHL7, a transgenic microorganism, were heterogenic in the expression of plasmid genes when adapting to the conditions of water microcosms of various mineralization levels and structure of microbial community. This TM has formed two subpopulations (ampicillin-resistant and ampicillin-sensitive) in every microcosm. Irrespective of mineralization level of a microcosm, when E. coli Z905/pPHL7 alone was introduced, the ampicillin-resistant subpopulation prevailed, while introduction of the TM together with indigenous bacteria led to the dominance of the ampicillin-sensitive subpopulation. A high level of lux gene expression maintained longer in the freshwater microcosms than in sterile saline lake water microcosms. A horizontal gene transfer has been revealed between the jointly introduced TM and Micrococcus sp. 9/pSH1 in microcosms with the Lake Shira sterile water. c2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

Ecosystem↗