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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Super-adsorbing porous thermo-responsive desiccants

Thermo-responsive hydrogel composite (TRHC) desiccants having high adsorption capacities, fast adsorption/desorption rates, and low regeneration temperatures (Treg) compared to traditional desiccants. TRHC desiccants may be synthesized by freeze drying. The porous structures resulting from freeze drying copolymers of thermo-responsive polymers and/or hygroscopic agents may be combined with hygroscopic inorganic salts, resulting in TRHC desiccants having superior performance properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2008

Improving our Understanding of Atlantic Tropical Cyclones through Knowledge of the Saharan Air Layer: Hope or Hype?

The existence of the Saharan air layer (SAL), a layer of warm, dry, dusty air that frequently moves westward off of the Saharan desert of Africa and over the tropical Atlantic Ocean, has long been appreciated. As air moves over the desert, it is strongly heated from below, producing a very hot air mass at low levels. Because there is no moisture source over the Sahara, the rise in temperature causes a sharp drop in relative humidity, thus drying the air. In addition, the warm air produces a very strong jet of easterly flow in the middle troposphere called the African easterly jet that is thought to play a critical role in hurricane formation. In recent years, there has been an increased focus on the impact that the SAL has on the formation and evolution of hurricanes in the Atlantic. However, the nature of its impact remains unclear, with some researchers arguing that the SAL amplifies hurricane development and with others arguing that it inhibits it. The argument for positively influencing hurricane development is based upon the fact that the African easterly jet produces the waves that eventually form hurricanes and that it leads to rising motion south of the jet that favors the development of deep thunderstorm clouds. The potential negative impacts of the SAL include 1) low-level vertical wind shear associated with the African easterly jet; 2) warm SAL air aloft, which increases thermodynamic stability and suppresses cloud development; and 3) dry air, which produces cold downdrafts in precipitating regions, thereby removing energy needed for storm development. As part of this recent focus on the SAL and hurricanes (which motivated a 2006 NASA field experiment), there has been little emphasis on the SAL s potential positive influences and almost complete emphasis on its possible negative influences, almost to the point of claims that the SAL is the major suppressing influence on hurricanes in the Atlantic. Multiple NASA satellite data sets (TRMM, MODIS, and AIRS/AMSU) and National Centers for Environmental Prediction global analyses are used to characterize the SAL s properties and evolution in relation to developing hurricanes. The results show that storms generally form on the southern side of the jet, where favorable background rotation is high. The jet often helps to form the northern side of the storms and rarely moves over their inner cores, so jet-induced vertical wind shear does not appear to be a negative influence on developing storms. Warm SAL air is confined to regions north of the jet and generally does not impact the tropical cyclone precipitation south of the jet. Of the three proposed negative influences, dry air appears to be the key influence; however, the presence of dry SAL air is not a good indicator of whether a storm will weaken since many examples of intensifying storms surrounded by such dry air can be found. In addition, a global view of relative humidity shows moisture distributions in other ocean basins that are almost identical to the Atlantic. The dry zones correspond to regions of descending air on the eastern and equatorward sides of semi-permanent oceanic high pressure systems. Thus, the dry air over the Atlantic appears to be primarily a product of the large-scale flow, but with enhanced drying at low levels associated with the Sahara. As a result, we conclude that the SAL is not a major negative influence on hurricanes. It is just one of many possible influences and can be both positive and negative.

Braun, Scott A.↗
NASA NTRS2010

Reevaluating the Role of Saharan Air Layer in Atlantic Tropical Cyclogenesis and Evolution

The existence of the Saharan air layer (SAL), a layer of warm, dry, dusty air that frequently moves westward off of the Saharan desert of Africa and over the tropical Atlantic Ocean, has long been appreciated. As air moves over the desert, it is strongly heated from below, producing a very hot air mass at low levels. Because there is no moisture source over the Sahara, the rise in temperature causes a sharp drop in relative humidity, thus drying the air. In addition, the warm air produces a very strong jet of easterly flow in the middle troposphere called the African easterly jet that is thought to play a critical role in hurricane formation. In recent years, there has been an increased focus on the impact that the SAL has on the formation and evolution of hurricanes in the Atlantic. However, the nature of its impact remains unclear, with some researchers arguing that the SAL amplifies hurricane development and with others arguing that it inhibits it. The argument for positively influencing hurricane development is based upon the fact that the African easterly jet provides an energy source for the waves that eventually form hurricanes and that it leads to rising motion south of the jet that favors the development of deep thunderstorm clouds. The potential negative impacts of the SAL include 1) low-level vertical wind shear associated with the African easterly jet; 2) warm SAL air aloft, which increases thermodynamic stability and suppresses cloud development; and 3) dry air, which produces cold downdrafts in precipitating regions, thereby removing energy needed for storm development. As part of this recent focus on the SAL and hurricanes (which motivated a 2006 NASA field experiment), there has been little emphasis on the SAL s potential positive influences and almost complete emphasis on its possible negative influences, almost to the point of claims that the SAL is the major suppressing influence on hurricanes in the Atlantic. In this study, multiple NASA satellite data sets (TRMM, MODIS, CALIPSO, and AIRS/AMSU) and National Centers for Environmental Prediction global analyses are used to see if the proposed negative influences deserve all of the attention they have recently received. The results show that storms generally form on the southern side of the African jet, where favorable background rotation is high. The jet often helps to form the northern side of the storms and is typically stronger in storms that intensify than those that weaken, suggesting that jet-induced vertical wind shear is not a negative influence on developing storms. Warm SAL air is confined to regions north of the jet and generally does not impact the tropical cyclone precipitation south of the jet. A comparison of the environments of strongly strengthening storms and of weakening storms shows no differences in SAL structure, indicating that the SAL has little influence on whether storms weaken or intensify. The large-scale flow at upper levels above the SAL was found to be most important, with the environment of strengthening storms having very little vertical wind shear and also favoring more expansive outflow from the storm. The SAL is shown to occur in a large-scale environment that is already characteristically dry as a result of large-scale subsidence (sinking air motions). Strong surface heating and deep dry convective mixing enhance dryness at low levels, but moisten the air at midlevels. Therefore, mid-to-upper-level dryness is not a defining characteristic of the SAL, but is instead a signature of subsidence. As a result, we conclude that the SAL is not the major negative influence on hurricanes that recent studies have emphasized. It is just one of many possible influences and can be both positive and negative.

Braun, Scott A.↗
NASA NTRS1991

A two-dimensional numerical investigation of the interaction between sea breezes and deep convection over the Florida peninsula

The Colorado State University Regional Atmospheric Modeling System is used to investigate the interaction between sea breezes and deep convection over the Florida peninsula, and it is shown that this model can simulate the broad features of the three characteristic types of convection systems classified by Blanchard and Lopez (1985). In sensitivity tests performed for a variety of wind and thermodynamic profiles and for different soil-moisture contents, it was found that increases in the low-level temperature and in moisture content speeded up the development of convection. It was found that the dry-soil simulation produced rapidly developing sea breezes that moved inland quickly, while the moist soil case produced a much more slowly developing sea breeze. The total rainfall over the peninsula for the dry-soil case was greater than for the moist soil; it is suggested that the enhanced surface heat fluxes for the dry soil case create stronger low-level convergence over the peninsula (than in the moist-soil case) to force the convection.

Nicholls, Melville E.↗
DOE OSTI2023

Ab Initio Molecular Dynamics Study of Pd Nucleation on a γ-Al 2 O 3 Surface

We perform ab initio molecular dynamics (AIMD) free energy simulations to investigate the stability and dynamics of dispersed Pd atoms and subnanometer clusters on γ-Al 2 O 3 . We consider nucleation for varying Pd loadings on dry γ-Al 2 O 3 (100), dry γ-Al 2 O 3 (110) and wet γ-Al 2 O 3 (110) and examine temperature, entropy and water coverage effects on the stability and dynamics of Pd clusters. At low Pd loading (1.07 Pd atoms/nm 2 on the (100) and 0.75 Pd/nm 2 on the (110)), association of the Pd atoms is thermodynamically unfavorable on the dry surfaces and almost thermoneutral on the wet (110) owing to water blocking of the AlIII defect sites. In agreement with past studies, the Pd atoms are quite mobile but the diffusion free energy barriers do not increase with the water coverage, as previously suggested, but rather remain similar in magnitude owing to translational entropy at finite temperatures. At these Pd loadings, oxidized Pd(II) atoms on the wet (110) surface are dispersed and immobile. At higher Pd loading (1.12 and 1.5 Pd atoms/nm 2 ) on the (110) surface, Pd 3 and Pd 4 clusters are thermodynamically very stable and form fast. At the 1.12 Pd atoms/nm 2 loading, the formation of the Pd 3 cluster is two orders of magnitude slower when the surface is hydroxylated as the system becomes somewhat trapped before the dinuclear cluster Pd 2 collides with a Pd atom.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1973

Preliminary study of turbojets with rotary flow inductors for a low-noise supersonic transport

In a simplified airplane-mission study for a Mach 2.61 supersonic transport, dry turbojets with and without real suppressors and dry turbojets with ideal rotary flow inductors were studied for sideline noise levels as low as FAR 36-20. Compressor pressure ratio was varied from 5 to 30 and turbine temperature from 1800 to 3000 F. For no noise constraint and without a suppressor, the best dry turbojet gave a payload of 9.0 percent of gross weight and a sideline noise of 126 effective perceived noise decibels. Payload dropped rapidly for lower noise goals, becoming 6.3 percent of gross weight at FAR 36. At FAR 36, the turbojet with suppressor gave a payload of 8.3 percent and the turbojet with ideal rotary flow inductor, 7.3 percent. Below FAR 36, the ideal inductor was far superior to the real suppressor, giving payloads of 6.6 percent at FAR 36-10 and 5.7 percent at FAR 36-20.

Dugan, J. F., Jr.↗
NASA NTRS2004

Zeolite Formation and Weathering Processes in Dry Valleys of Antartica: Martian Analogs

Terrestrial weathering processes in cold-desert climates such as the Dry Valleys of Antarctica may provide an excellent analog to chemical weathering and diagenesis of soils on Mars. Detailed studies of soil development and the chemical and mineralogical alterations occurring within soil columns in Wright Valley, Antarctica show incredible complexity in the upper meter of soil. Previous workers noted the ice-free Dry Valleys are the best terrestrial approximations to contemporary Mars. Images returned from the Pathfinder and Spirit landers show similarities to surfaces observed within the Dry Valleys. Similarities to Mars that exist in these valleys are: mean temperatures always below freezing (-20 C), no rainfall, sparse snowfall-rapidly removed by sublimation, desiccating winds, diurnal freeze-thaw cycles (even during daylight hours), low humidity, oxidative environment, relatively high solar radiation and low magnetic fields . The Dry Valley soils contain irregular distributions and low abundances of soil microorganisms that are somewhat unusual on Earth. Physical processes-such as sand abrasion-are dominant mechanisms of rock weathering in Antarctica. However, chemical weathering is also an important process even in such extreme climates. For example, ionic migration occurs even in frozen soils along liquid films on individual soil particles. It has also been shown that water with liquid-like properties is present in soils at temperatures on the order of approx.-80 C and it has been observed that the percentage of oxidized iron increases with increasing soil age and enrichments in oxidized iron occurs toward the surface. The presence of evaporates is evident and appear similar to "evaporite sites" within the Pathfinder and Spirit sites. Evaporites indicate ionic migration and chemical activity even in the permanently frozen zone. The presence of evaporates indicates that chemical weathering of rocks and possibly soils has been active. Authogenic zeolites have been identified within the soil columns because they are fragile; i.e. they are euhedral, unabraded, and unfractured, strongly suggesting in situ formation. Their presence in Antarctic samples is another indication that diagenic processes are active in cold-desert environments. The presence of zeolites, and other clays along with halites, sulfates, carbonates, and hydrates are to be expected within the soil columns on Mars at the Gusev and Isidis Planitia regions. The presence of such water-bearing minerals beneath the surface supplies one of the requirements to support biological activity on Mars.

Gibson, E. K., Jr.↗
DOE OSTI2023

Anthropogenic Aerosols Contribute to the Recent Decline in Precipitation Over the U.S. Southwest

Abstract The winter‐spring precipitation over the Southwestern United States (SWUS) decreased since 1980. It is frequently attributed to Pacific internal decadal variability, but recent studies found anthropogenic aerosols (AA) can also induce a transition to a negative Pacific Decadal Variability (PDV) phase. We revisit the attribution of SWUS drying by quantifying the contributions of anthropogenically forced decadal Pacific Sea Surface Temperatures (SSTs). Applying a low‐frequency component analysis to observations, Community Earth System Model version 2 (CESM2) all‐forcings and single‐forcing large ensembles, we find up to 42% of the observed precipitation trend to be related to the AA‐induced negative PDV‐like pattern, which is driven by the emission shift from the Western to the Eastern Hemisphere. In CESM2, other radiative forcings counteract the influence of AA, but it remains unclear whether the model correctly simulates this balance. This implies that the near‐future trajectories of these forcings, in particular Asian aerosols, are important for projections of SWUS precipitation.

Geology↗
DOE OSTI2021

A Novel Platform for Algal Biomass Production Using Cellulosic Mixotrophy (CeMix) (Final Technical Report)

This novel project, branded CeMIX for cellulosic mixotrophy, targets solutions for several technological barriers limiting the deployment of algae cultivation in sunny, arid regions (specifically the southwest United States). Opening up the region for algae cultivation could increase DOE’s resource assessments and biofuel potential for the U.S. Mixotrophic metabolism in support of liquid fuel production is completely dependent on the availability of waste organic carbon in order to avoid diversion of food resources for fuel production. The use of cellulosic sugar hydrolysate (CSH) produced via the NREL process provided a standardized carbon source for study of the underlying biochemistry and metabolic adjustments to mixotrophy. Mixotrophic metabolism uses both photosynthetic CO 2 fixation and sugar oxidation to improve biomass productivity and harvest yield. The project was high-risk, high-reward in the sense that adding organic carbon to algal cultivation is an invitation for rapid-growth, heterotrophic contaminants to overtake the culture and consume mineral nutrients needed for algal growth. To help evade this outcome the project focused on acidophilic red algae that require low pH conditions with 40-48°C optimal temperature profiles that define them as low-range thermophiles. This is the only project in the BETO portfolio to utilize extreme conditions of low pH and high operating temperatures to control pathogens and competitors in mass culture. The project yielded five major outcomes. 1) Harvest densities of 5-10 g ash-free dry weight are easily achieved, providing a 10-fold reduction in water required and dewatering demand. 2) Catabolic repression of photosynthesis in G. sulphuraria is conditionally repressed by low oxygen. 3) Mixotrophic growth on cellulosic hydrolysate consumes all C6 and C5 sugars concomitant with increases in floridean starch with little change in lipid content. Protein content can be manipulated between 35 and 54 wt% by varying the C:N molar ratio from 10:1 to 20:1, respectively. 4) Mixotrophic cultures with up to 50 mM total sugar are remarkably stable at pH 2.5 and daily average reactor temperatures of 40°C. 5) Capital costs for glass tubular photobioreactors are prohibitive for liquid fuel production using a hydrothermal liquefaction processing pathway. The economic outlook for covered raceway ponds is better with a project minimum fuel selling price at $3.32 dm 3 GE -1 .

09 BIOMASS FUELS↗
NASA NTRS2002

Additive Effects on Si3n4 Oxidation/Volatilization in Water Vapor

Two commercially available additive-containing silicon nitride materials were exposed in four environments which range in severity from dry oxygen at 1 atm pressure, and low gas velocity to an actual turbine engine. Oxidation and volatilization kinetics were monitored at temperatures ranging from 1066 to 1400 C. The main purpose of this paper is to examine the surface oxide morphology resulting from the exposures. It was found that the material surface was enriched in rare earth silicate phases in combustion environments when compared to the oxides formed on materials exposed in dry oxygen. However, the in situ formation of rare earth disilicate phases offered little additional protection from the volatilization of silica observed in combustion environments. It was concluded that externally applied environmental barrier coatings are needed to protect additive-containing silicon nitride materials from volatilization reactions in combustion environments. Introduction Si3N4 is proposed for use as components, such as vanes, in turbine applications. Tens of thousands of hours of life are needed for both land-based turbines and aeropropulsion applications. Additive-containing SisN4 materials are

Opila, Elizabeth J.↗
NASA NTRS1974

Service life of metals at low temperatures

Current concepts of the nature of fatigue failure at low temperatures are presented on the basis of experimental results of various investigators. The fundamental approach to the technique for studying low-temperature fatigue is examined. The necessity for using the same medium at different fatigue test temperatures and also the necessity for taking into account the magnitude of the plastic deformation amplitude are confirmed. Experimental data from a study of the influence of low temperatures (down to liquid nitrogen temperatures) on the fatigue life of copper and armco-iron in dry air, over a wide range of deformations, are presented. These results are compared with microscopic and electron microscopic pictures of the surface of the deformed specimens.

Verkin, B. I.↗
NASA NTRS1977

Low-temperature coal desulfurization

Economical, low-temperature chlorinolysis converts sulfur to water-soluble sulfates. Sulfates are removed by washing. Subsequent steps dry coal and remove chlorine. Chlorine and solvents can be reused.

Ganguli, P. S.↗
NASA NTRS1983

Stimulation of lettuce productivity by manipulation of diurnal temperature and light

Salad Bowl and Waldmann's Green leaf lettuce (Lactuca sativa L.) were exposed to photosynthetic photon flux densities (PPFDs) of 444 or 889 micromol/s per sq m for 20 hrs/day under a diurnal temperature regime of 25-C days/15-C nights or 20-C days/15-C nights. Leaf dry weight of both cultivars was highest under the high PPFD/warm temperature regime and lowest under the low PPFD/cool temperature regime. Waldmann's Green yielded more than did Salad Bowl at 889 micromol/s per sq m and 25-C days/20-C nights. Under high PPFD, both cultivars yielded better with 25-C days/25-C nights than with 25-C days/20-C nights, although relative growth rates were the same under both temperature regimes.

Knight, Sharon L.↗
DOE OSTI2020

Progression to Compatibility Evaluations in Flowing Molten Salts

Molten salt compatibility with structural alloys has been identified as a key issue for the development of Generation 3 concentrating solar power (CSP) systems with thermal storage. To accelerate this evaluation to pumped systems, the goal of this project was to conduct thermal convection loop (TCL) experiments with a peak temperature of ≥700°C and a typical temperature gradient of ~100°C. The experiments indicated that conventional ~16wt.%Cr Ni-based alloys are compatible up to 700°C with purified (i.e. low O) or dried (low H₂O) industrial-sourced Mg-K-Na chloride salt with <10 μm/yr loss. This two-year project was conducted based on the experimental and mechanistic understanding developed more than 60 years ago at Oak Ridge National Laboratory (ORNL). The first TCL experiment met the <15 μm/yr corrosion metric for this project with specimens of Ni-based alloy 600 exposed at 580°-700°C for 1000 h and post-exposure room temperature tensile tests showed minimal degradation. The second TCL experiment successfully deployed an electrochemical sensor from Argonne National Laboratory and had a peak temperature of 750°C but only ran for ~110 h due to a furnace failure. Both experiments used highly purified industrial-sourced salt with an O content of ~3 μg O/g salt and a Mg addition of 0.04 wt.%. In the second year, the Chloride Collective developed a more economical drying procedure such that the O content was much higher (>20,000 μg O/g salt). A third TCL experiment was conducted with a sensor and a peak temperature of 700°C using dried salt from the same industrial source and increased NaCl content (~20 wt.%). In addition to a 0.05% Mg addition to the salt, a Mg coupon was added in the coldest part of the loop which dissolved during the experiment. Again, small mass changes were noted for specimens of alloys 600 and C276 but the values were slightly higher than those measured in purified salt with Mg. A thin non-continuous and non-adherent oxide layer was deposited on most specimens containing Mg, Si and Al but Cr depletion also was observed. Both years included facilities qualification crucible experiments and then capsule experiments to confirm a baseline isothermal reaction rate. The first year capsule experiment led to the conclusion that the two-stage ORNL purification process using NH₄Cl and CCl₄ left the salt with a high Cl potential and a Mg addition (~0.05wt.%) was needed to lower the potential. The second year capsule experiments at 600° and 700°C found little difference in depth of attack for 0-0.25%Mg additions. In general, the complex reactions where salt can be trapped in the porous surface layer of metal indicated that mass change is an unreliable metric and average depth of Cr depletion is a better metric for assessing the extent of attack. These results have created a new baseline that is contrary to the recent published literature for chloride salts where mass losses have been reported that can be extrapolated to very significant annual metal loss rates. Chloride salt corrosion can be controlled and the results also indicate that salt purification to low O levels may not be necessary. However, additional TCL experiments are needed at different times and temperatures to generate important engineering information such as temperature dependent corrosion rates and reaction rate laws for extrapolation to long-term behavior and isolate the effect of salt additives and impurities.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Temperature-Time Modeling of Spent Fuel Cladding in Dry Storage Casks

This report uses thermal and decay heat modeling to investigate spent fuel performance and the potential for cladding to anneal in dry storage conditions. Annealing is an important feature to investigate in SNF cladding because it has a direct relationship to cladding response in storage, transportation and disposal conditions. Annealed cladding may have lower strength than unannealed cladding, however its increased ductility would provide better protection against rupture in high strain rate situations such as severe accidents. These consequences are the driver for this work however are outside of the scope of this report. The modeling focused on three representative storage systems, the TN-32B, MAGNASTOR with TSC-37 canister, and NUHOMS AHSM with a 32PTH2 canister. This covers the vertical dual-purpose, vertical ventilated and horizontal ventilated casks respectively. Decay heat modeling using high and low enrichment assemblies was used to bound the decay heat curves that might be expected in dry storage. To bound the temperature relationship, the storage casks were modeled starting at the design basis heat loads with heat decaying through time. Although the results are bounding there is not an attempt to maximize conservatism, rather the intent to form a reasonable upper limit on temperature that will be broadly applicable to the U.S. cask fleet. This will allow materials testing to focus on relevant conditions for annealing that may affect the U.S. spent fuel inventory. The results show a clear dependence on heat load pattern in time in Figure S-1 and Figure S-2. This dependence is due to the different assembly decay heat curves for different assemblies in preferentially loaded casks. It shows the need for careful decay heat modeling when examining in service fuel temperatures that are less than the cask design basis heat load. The body of the report shows percent cladding cutoffs of 300°C and 350 °C as well. These results can be used to inform testing and conclusions about cladding performance through time and the potential for cladding annealing during dry storage.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

Project Phase 1 Report: Reducing Data Center Peak Cooling Demand and Energy Costs With Cold Underground Thermal Energy Storage (Cold UTES)

Cold Underground Thermal Energy Storage (Cold UTES) is an ultra-long duration grid energy storage technology. With Cold-UTES, low-cost grid power is converted to cold thermal energy and stored in the native subsurface rock at the point of use. Cold UTES is one approach within the general category of engineered geothermal systems. Cold UTES for peak-hour cooling of data centers (DCs) was studied for deployment in Maricopa County, Arizona and Loudoun County, Virgina using thermal storage capacities from 4 GWh-th to over 1,000 GWh-th (>1 Terawatt-hour). The two sites have different power and transmission systems, available grid energy resources, daily and seasonal load profiles, weather conditions, and grid regulatory requirements. The study results indicate high value for both locations and because of this, likely indicates value across most of the US and the world. The basis of the study was a 1,000 MW-e hourly electric use of DC computing and auxiliary loads, which was modeled as 1 GW-th of thermal load to a dry cooled heat rejection system - i.e. a cooling system that does not consume water. The electric power required for cooling the DC varies as the air temperature changes. In cold weather only the dry-coolers are used, with an electrical load for cooling load as low as 10 MW-e. In hot summer hours, chillers and dry- coolers are required, which raises the electrical load for cooling load to as much as 300 MW-e. The continuous and peak cooling electrical loads result in a grid interconnection requirement of no less than 1,300 MW-e. From both a grid and thermal design modeling perspective the 1.3 GW-e could either be a single facility or result from the total load at multiple sites.

15 GEOTHERMAL ENERGY↗
DOE OSTI2024

Relithiation process for direct regeneration of cathode materials from spent lithium-ion batteries

A method for the regeneration of cathode material from spent lithium-ion batteries is provided. The method includes dissolving a lithium precursor in a polyhydric alcohol to form a solution. Degraded cathode material containing lithium metal oxides are dispersed into the solution under mechanical stirring, forming a mixture. The mixture is heat treated within a reactor vessel or microwave oven. During this heat treatment, lithium is intercalated into the degraded cathode material. The relithiated electrode material is collected by filtration, washing with solvents, and drying. The relithiated electrode material is then ground with a lithium precursor and thermally treated at a relatively low temperature for a predetermined time period to obtain regenerated cathode material.

Belharouak, Ilias↗
NASA NTRS1976

Polyimide film wear: Effect of temperature and atmosphere

Friction and wear experiments conducted on polyimide films bonded to 440C stainless steel disks indicated that a wear transition (from high wear to low wear) accompanied a friction transition (from high friction to low friction). In dry argon or dry air (less than 20 ppm H2O), the transition was found to occur at 40 plus or minus 10 C; when H20 was present in air (10,000 ppm H2O), the transition was found to be elevated to a temperature between 100 and 200 C. Wear rate calculations made at 25, 100, and 200 C indicated that film wear was relatively constant for particular experimental conditions; however, the rate was strongly dependent on temperature and atmosphere.

Fusaro, R. L.↗