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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Lunar and Planetary Science XXXV: Mars: Surface Coatings, Mineralogy, and Surface Properties

The session "Mars: Surface Coatings, Mineralogy, and Surface Properties" contained the following reports:High-Silica Rock Coatings: TES Surface-Type 2 and Chemical Weathering on Mars; Old Desert Varnish-like Coatings and Young Breccias at the Mars Pathfinder Landing Site; Analyses of IR-Stealthy and Coated Surface Materials: A Comparison of LIBS and Reflectance Spectra and Their Application to Mars Surface Exploration; Contrasting Interpretations of TES Spectra of the 2003 Rover:Opportunity-Landing Site: Hematite Coatings and Gray Hematite; A New Hematite Formation Mechanism for Mars; Geomorphic and Diagenetic Analogs to Hematite Regions on Mars: Examples from Jurassic Sandstones of Southern Utah, USA; The Geologic Record of Early Mars: A Layered, Cratered, and "Valley-"ed: Volume; A Simple Approach to Estimating Surface Emissivity with THEMIS; A Large Scale Topographic Correction for THEMIS Data; Thermophysical Properties of Meridiani Planum, Mars; Thermophysical and Spectral Properties of Gusev, the MER-Spirit Landing Site on Mars; Determining Water Content of Geologic Materials Using Reflectance Spectroscopy; and Global Mapping of Martian Bound Water at 6.1 Microns Based on TES Data: Seasonal Hydration.

Source record↗
NASA NTRS1999

Migration of lymphocytes on fibronectin-coated surfaces: temporal evolution of migratory parameters

Lymphocytes typically interact with implanted biomaterials through adsorbed exogenous proteins. To provide a more complete characterization of these interactions, analysis of lymphocyte migration on adsorbed extracellular matrix proteins must accompany the commonly performed adhesion studies. We report here a comparison of the migratory and adhesion behavior of Jurkat cells (a T lymphoblastoid cell line) on tissue culture treated and untreated polystyrene surfaces coated with various concentrations of fibronectin. The average speed of cell locomotion showed a biphasic response to substrate adhesiveness for cells migrating on untreated polystyrene and a monotonic decrease for cells migrating on tissue culture-treated polystyrene. A modified approach to the persistent random walk model was implemented to determine the time dependence of cell migration parameters. The random motility coefficient showed significant increases with time when cells migrated on tissue culture-treated polystyrene surfaces, while it remained relatively constant for experiments with untreated polystyrene plates. Finally, a cell migration computer model was developed to verify our modified persistent random walk analysis. Simulation results suggest that our experimental data were consistent with temporally increasing random motility coefficients.

NASA Program Fundamental Space Biology↗
NASA NTRS1993

Thermal-infrared emission spectroscopy of natural surfaces: Application to coated surfaces

Thermal-infrared vibrational spectroscopy has great potential for remotely determining the composition of planetary surface materials by taking advantage of fundamental molecular vibrational modes that produce spectral features in the range from approximately 3 to greater than 50 microns. Much of the current interest in the thermal infrared wavelength region stems from the deployment of multispectral scanners, such as the Thermal Infrared Multispectral Scanner (TIMS) and the Mars Observer Thermal Emission Spectrometer (TES). In order to support these missions, it is necessary to develop an appropriate library of laboratory measurements. The purpose of this work was to develop a technique which, with a very limited set of assumptions, can be used to determine the emissivity of natural surfaces directly by using emitted energy.

Christensen, Philip R.↗
DOE OSTI2021

Valuation of Surface Coatings in High-Energy Density Lithium-ion Battery Cathode Materials

Artificial barriers, usually with either electrochemically active or inactive coating materials, are deployed on cathode material surfaces to mitigate detrimental side reactions by suppressing direct contact of cathode and electrolyte called surface coatings. These surface coatings are commonly known to increase the wettability of liquid electrolyte and reduce the interfacial charge transfer resistance. An important caveat is the selection of appropriate coating material with appropriate thickness for achieving enhanced electrochemical performance. As modern battery materials are increasingly developed with some type of surface coating, a careful and thorough examination of their role in mitigating the cycle life issues of cathode materials is paramount. Here, this comprehensive review article extensively covers the selection criteria of coating materials based on their chemical and physical properties and electrochemical functionalities. Additionally, the article discusses the concept of critical coating thickness and methods of achieving homogeneous coating architectures that deliver desired performance benefits. Furthermore, this comprehensive article summarizes the recent advancements, effectiveness, necessity of cathode surface coatings and identifies the key aspect of structure-property correlation between coating type/thickness and lithium-ion diffusion through coating layers as the linchpin that validates surface coating approaches especially for high capacity nickel-rich cathodes.

25 ENERGY STORAGE↗
NASA NTRS1984

Antisoiling technology: Theories of surface soiling and performance of antisoiling surface coatings

Physical examination of surfaces undergoing natural outdoor soiling suggests that soil matter accumulates in up to three distinct layers. The first layer involves strong chemical attachment or strong chemisorption of soil matter on the primary surface. The second layer is physical, consisting of a highly organized arrangement of soil creating a gradation in surface energy from a high associated with the energetic first layer to the lowest possible state on the outer surfce of the second layer. The lowest possible energy state is dictated by the physical nature of the regional atmospheric soiling materials. These first two layers are resistant to removal by rain. The third layer constitutes a settling of loose soil matter, accumulating in dry periods and being removed during rainy periods. Theories and evidence suggest that surfaces that should be naturally resistant to the formation of the first two-resistant layers should be hard, smooth, hydrophobic, free of first-period elements, and have the lowest possible surface energy. These characteristics, evolving as requirements for low-soiling surfaces, suggest that surfaces or surface coatings should be of fluorocarbon chemistry. Evidence for the three-soil-layer concept, and data on the positive performance of candidate fluorocarbon coatings on glass and transparent plastic films after 28 months of outdoor exposure, are presented.

Cuddihy, E. F.↗
DOE OSTI2021

The Role of Titania Surface Coating by Atomic Layer Deposition in Improving Osteogenic Differentiation and Hard Tissue Formation of Dental Pulp Stem Cells

Recent studies have focused on modifying implant surface properties to improve bone regeneration and osseointegration. Herein, the role of titania surface coating in enabling dental pulp stem cells (DPSCs) differentiation and hard tissue formation is studied. Atomic layer deposition is applied at lower temperature to coat a nanolayer of titania onto hard and soft polybutadiene substrates without altering their moduli, to probe the effects of surface chemistry and substrate modulus. In the absence of titania, DPSCs prefer to attach and proliferate on the hard substrate, where particle-like biomineralization is present after 28 days in culture, whereas no biomineralization is observed on the soft substrate. Applying titania surface coating results in the improvement of adhesion and proliferation, regardless of substrate modulus, whereas cell and substrate moduli remain the same as control without titania coating. Furthermore, templated biomineralization is observed given the bone-like tissue composition by Raman analysis, in consistent with real time-polymerase chain reaction (RT-PCR) results showing upregulation of osteopontin (OPN) and bone sialoprotein (BSP), representing osteogenic differentiation. Furthermore, the results indicate that titania surface coating improved the ability to nucleate banded collagen fibers which in turn templated mineral deposits, and further induced the osteogenesis of DPSCs, regardless of its substrate modulus.

36 MATERIALS SCIENCE↗
NASA NTRS1979

Aircraft surface coatings study: Energy efficient transport program

Surface coating materials for application on transport type aircraft to reduce drag, were investigated. The investigation included two basic types of materials: spray on coatings and adhesively bonded films. A cost/benefits analysis was performed, and recommendations were made for future work toward the application of this technology.

Source record↗
NASA NTRS1980

A dry-surface coating method for visualization of separation

A relatively simple and reasonably accurate dry-surface coating method for visualization of the separation line on a bluff body was devised and successfully tested. This technique is based on the color reaction of a dry film containing a pH indicator with an appropriate gas released in the body wake. The dry-surface coating method is effective at any Reynolds number and for both incident laminar and turbulent flows. It further supplies a colorful permanent of consistently good photographic quality of the separation line. The effectiveness and accuracy of this technique were tested in visualizing the separation angle on a circular cylinder in both laminar and turbulent crossflows at subcritical Reynolds numbers. Separation angles revealed by the visualization were within + or - 4 percent of their counterparts deduced from the mean wall pressure distribution.

Sadeh, W. Z.↗
NASA NTRS1981

Flight test evaluation of drag effects on surface coatings on the NASA Boeing 737 TCV airplane

A flight test program was conducted in which the effects of various surface coatings on aerodynamic drag were investigated; results of this program are described in this report. The tests were conducted at NASA-Langley Research Center on the terminal configured vehicle (TCV) Boeing 737 research airplane. The Boeing Company, as contractor with NASA under the Energy Efficient Transport (EET) program, planned and evaluated the experiment. The NASA-TCV Program Office coordinated the experiment and performed the flight tests. The principal objective of the test was to evaluate the drag reduction potential of an elastomeric polyurethane surface coating, CAAPCO B-274, which also has been considered for application on transport airplanes to protect leading edges from erosion. The smooth surface achievable with this type of coating held some promise of reducing the skin friction drag as compared to conventional production type aircraft surfaces, which are usually anodized bare metal or coated with corrosion protective paint. Requirements for high precision measurements were the principal considerations in the experiment.

George-Falvy, D.↗
NASA NTRS2004

Analyses of IR-Stealthy and Coated Surface Materials: A Comparison of LIBS and Reflectance Spectra and Their Application to Mars Surface Exploration

Identification of non-silicate samples on Mars, such as carbonates, sulfates, nitrates, or evaporites in general, is important because of their association with aqueous processes and their potential as exobiology sites. Infrared (IR) and thermal emission (TE) spectroscopy have been considered the primary tools for remote identification of these minerals. This includes current and future orbital assets such as TES on MGS, THEMIS on Mars Odyssey, OMEGA on Mars Express, CRISM on MRO, and now the Mini-TES on the MER rovers. While reflectance and emission spectroscopy have clearly been the method of choice for these missions, the technique is not always successful in mineral identifications due to dust, surface weathering chemistry, coatings, or surface texture. Here we describe and show IR spectra of several such samples, and then report on the relative success of LIBS analyses in determining the rock type.

Wiens, R. C.↗
NASA NTRS1993

Method and apparatus for measuring the strain developed in a coated surface

A method and apparatus are provided for determining the strain developed in a coated surface. A beam with a coating on a surface thereof is mounted as a cantilever and a force is applied to the free end of the beam to cause deflection of the beam until the coating on the beam fails. The strain in the beam, and hence in the coating at the point of failure, is determined based on the dimensions of the beam, the point along the beam where failure of the coating occurs and the amount of deflection of the beam, and this determination is made independently of the temperature of the beam and the material from which the beam is made. The determination is made based on the equation E= 1.5hdx/l(exp 3), where E is strain, h is the beam thickness, d is the beam deflection, x is the distance from the free end of the beam to the point where failure of the coating occurred, and l is the length of the beam.

Smith, Sheldon M.↗
NASA NTRS1989

Electromagnetic properties of material coated surfaces

The electromagnetic properties of material coated conducting surfaces were investigated. The coating geometries consist of uniform layers over a planar surface, irregularly shaped formations near edges and randomly positioned, electrically small, irregularly shaped formations over a surface. Techniques to measure the scattered field and constitutive parameters from these geometries were studied. The significance of the scattered field from these geometries warrants further study.

Beard, L.↗
NASA NTRS2017

Parabolic Flight Testing of Aeroponic Plant Growth Systems and Super Omniphobic Surface Coatings

The purpose of this project is to gain valuable data from three separate experiments. One being an aeroponics watering system, another being a PONDS passive watering system, and the last a super omniphobic surface coating apparatus.There are two aeroponics watering systems that feed water and nutrients to "plant roots" inside of a contained box. The walls inside of the contained boxes have different surface textures and shapes but each contain the same nozzle and compressor set up as a control.There is one PONDS passive watering system that feeds water from a reservoir to a porous substrate utilizing wicking materials. There is one super omniphobic surface coating apparatus that feeds water into an apparatus allowing the water to make contact with three individual compartments in which glass beads with different coatings are carefully placed between two glass slides. The outcome will contribute to the advancement in self sustainment for space exploration. The status of the project when I started was to get the system built and ready for flight come November. My intended contributions are to assist with the build of the system.

Blockey, Jamie Lynn↗
NASA NTRS1978

Development of surface coatings for air-lubricated, compliant journal bearings to 650 C

Surface coatings for an air-lubricated, compliant journal for an automotive gas turbine engine were tested to find those capable of withstanding temperatures of either 540 C (1000 F) or 650 C (1200 F). Also, the coatings have to be capable of surviving the start-stop sliding contact cycles prior to rotor lift-off and at touchdown. Selected coating combinations were tested in start-stop tests at 14 kPa (2 psi) loading for 2000 cycles at room and maximum temperatures. Specific coating recommendations are: Cdo and graphite on foil versus chrome carbide on journal up to 370 C (700 F); NASA PS-120 (Tribaloy 400, silver, and CaF2) on journal versus uncoated foil up to 540 C (1000 F); and chemically adherent Cr2O3 on journal and foil up to 650 C (1200 F). The chemically adherent Cr2O3 coating system was further tested successfully at 35 kPa (5 psi) loading for 2000 start-stop cycles.

Bhushan, B.↗