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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
DOE OSTI2025

Operational Experience and Development of a Reliability Model for the ATR Demineralizer System (Slides)

The Advanced Test Reactor (ATR) is a light water reactor with aluminum clad driver fuel. Strict limits are implemented on pH, conductivity, and filterable solids to assure the performance of the driver fuel limit corrosion of the primary coolant system (PCS) pressure boundary components. A bypass demineralizer system is used to maintain PCS coolant within allowable bands for each of the aforementioned variables. Unlike many other reactors, the ATR does not have a filtration system. As such, failure of ion exchange resin in the bypass demineralizer can defeat the purpose of the system and result in high filterable solids in the PCS. Power operations with high filterable solids is prohibited by a technical safety requirement. This paper discusses recent failures of the ATR bypass demineralizer system. The testing and analysis done to deduce the cause of the failures is covered, as well as short term mitigative steps that were taken. To prevent the likelihood of future issues, historical data from the ATR and industry is used to develop a reliability model of the ATR bypass demineralizer system. Evidence of radiolytic decomposition of ion exchange resin was found in the cause investigation. As such, special attention is given to ion exchange resin failure due to high radiation environments. The reliability model is used to develop the ATR testing and maintenance program. Specifically, limits on resin service life are discussed.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗
NASA NTRS1984

Research opportunities in bone demineralization, phase 3

An overview of bone demineralization during space flight, observations in bone demineralization and experiments related to bone loss planned for Spacelab flights, and suggestions for further research are investigated. The observations of the working group focused upon the following topics: (1) pathogenesis of bone demineralization, (2) potential for occurrence of renal stones consequent to prolonged hypercalciuria, (3) development of appropriate ground based and inflight models to study bone demineralization, (4) integration of research efforts, and (5) development of effective countermeasures.

Anderson, S. A.↗
DOE OSTI2026

Biomass Demineralization: A Critical Need for Future Biorefineries

Biomass contains up to 14 essential elements that serve as nutrients for plant growth and development, including photosynthesis and enzyme functionalities. These elements in different chemical forms (e.g., minerals) constitute the inorganic fraction of biomass and can cause operational issues in thermal and biochemical biomass conversion technologies. In biomass gasification and pyrolysis processes, for instance, inorganics can cause fouling, tar formation, and corrosion. In catalytic and biochemical processes, inorganics can poison catalysts, alter biochemical pathways, and modify product yields and selectivity. This review provides an overview of the inorganic content in biomass feedstocks, the critical role inorganics play in plant biochemistry, the effect that inorganics have in various thermochemical and biochemical biomass conversion technologies, and different approaches to remove them from biomass. We provide recommendations for future research, focusing on developing technologies to effectively remove inorganics from biomass, using the inorganics to improve soil quality and for alternative applications, and designing biorefineries to convert demineralized biomass obtained from diverse sources.

09 - BIOMASS FUELS↗
DOE OSTI2021

Demineralization of Carbon Black Derived from End-of-Life Tires

The research carried out in this exploratory research demonstrates an energy and cost-efficient method to purify carbon black recovered from waste tires for recycling back into tires or rubber products. Compared to conventional methods, the methods explored demonstrate improvements in product purity by 40%-60%, a reduction in water requirements by 50%, reduction in processing costs by 80%-90%, and processing/embodied energy by 70%-95%. A techno-economic feasibility analysis of a pilot scale operation shows that these new demineralization methods explored in this work are potentially economically viable. Further development and implication of this technology would help enable cleanup of waste tires and recycling of tires. The work carried out in this study has been successful in demonstrating a new processing method to produce recycled carbon black (rCB) with drastically improved economic viability and impacts.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

From Obsolete to Optimal (ATR Demineralized Water System)

My project was migrating a Human-Machine Interface (HMI) and Programmable Logic Controller (PLC) program from legacy software to a modern platform, enhancing operational efficiency and eliminating unsupported, obsolete equipment. Initially, I used a migration tool to transfer the programs to the new software, then manually updated variables to align with the new PLC. I optimized the PLC code by leveraging new scaling features in the I/O cards, removing over 45 obsolete rungs, and enhancing clarity with functional tag aliases. Next, I modernized the HMI's visuals with an updated color scheme and 3D buttons. I developed multiple interface versions iteratively refining them based on operator feedback. I also designed and created a dedicated "Rounds" screen incorporating insights from a previous intern’s project to streamline daily rounds. To improve clarity, consistency, and efficiency I redesigned the entire interface. Adding visual indicators to enhance operational awareness: red is used for values outside normal specifications, green for normal operating modes, yellow for manual mode, and grey for offline units. Additionally, I added a dynamic visual representation of tank levels, creating PLC logic to show the level in inches as well as inches and feet. I then incorporated a navigation sidebar to facilitate efficient screen transitions. Risk of human error was mitigated by defining narrow input ranges for tank level shutoff and password protecting setpoint changes. I also fixed issues with datatypes that caused inaccuracies in the original code. Overall, this comprehensive upgrade significantly enhanced the HMI's functionality, user experience, and operational reliability.

47 - OTHER INSTRUMENTATION↗
DOE OSTI2021

Cyclic strain enhances the early stage mineral nucleation and the modulus of demineralized bone matrix

The adaptive response of bones to mechanical loading is essential for musculoskeletal development. Despite the importance of collagen in bone mineralization, little is known about how cyclic strain influences physicochemical responses of collagen, especially at the early stage of mineralization when the levels of strain are higher than those in mature bones. The findings in this study show that, without any cell-mediated activity, cyclic strain increases nucleation rates of calcium phosphate (CaP) nanocrystals in highly-organized collagen matrices. The cyclic strain enhances the transport of mineralization fluids with nucleation precursors into the matrix, thus forming more CaP nanocrystals and increasing the elastic modulus of the collagen matrix. The results also suggest that the multiscale spatial distribution of nanocrystals in the fibrous collagen network determines tissue-level mechanical properties more critically than the total mineral content. Furthermore, by linking nano- and micro-scale observations with tissue-level mechanical properties, we provide new insights into designing better biomaterials.

36 MATERIALS SCIENCE↗
NASA NTRS1971

Bone demineralization

Crew members of the Gemini 4, Gemini 5, and Gemini 7 missions were compared regarding skeletal changes in three major anatomic sites with respect to changes in skeletal density during space flight. Bone-mass changes have been found for the command pilot and the pilot of each mission in the conventional os calcis section, in the combined sections covering 60 percent of the os calcis, and in hand phalanges 5-2 and 4-2. Comparison of radiographically determined losses in X-ray absorbence with X-ray absorbence losses in healthy young men subjected to bedrest immobilization for the same length of time showed that losses for the crewmembers exceeded losses for the bedrest subjects in all cases; this was an indication that restriction of body movement did not represent the only factor involved.

Mack, P. B.↗
NASA NTRS1978

Experiment requirements: Vitamin D metabolites and bone demineralization, Spacelab 2, experiment no. 1

As a contribution toward an understanding of the molecular basis of bone loss, mineral imbalance, and increasing fecal calcium under conditions of prolonged space flight, the blood levels of biologically active vitamin D metabolites of flight crew members will be quantitatively measured. Prior to the mission, the refinement of existing and the development of new techniques for the assay of all vitamin D metabolites will provide an arsenal of methods suitable for a wide range of metabolite levels. In terms of practical application, the analysis of human and animal plasma samples, Spacelab crew plasma samples, and flight hardware are envisioned.

Schnoes, H. K.↗
NASA NTRS1980

Long-term follow-up of Skylab bone demineralization

The os calcis mineral was measured in the nine Skylab crew members and in eight control subjects, 5 years after the Skylab Program, utilizing a photon absorptiometric technique. These measurements were compared with preflight measurements in an attempt to discover any long-term effects of space flight on the skeletal system. A statistically significant loss of bone mineral was found in the crew members who flew, but caution is urged in the interpretation of this difference. A recommendation to continue studies of this type is made.

Tilton, F. E.↗
NASA NTRS1966

Experiment M-6: Bone Demineralization

Densitometric evaluations of serial radiographs of "normal" subjects have often shown rather frequent changes in bone mass within relatively short periods of time. For this reason it was decided to make two pre-flight and two post flight radiographs of the Gemini V backup crew. In comparing the changes observed preflight and post flight as the conventional os calcis scanning site between the two crews, it was found that no changes greater than 4 percent were evident in either member of the backup crew. In comparing the changes observed preflight and postflight as the conventional o calcis scanning site between the two crews, it was found that no changes greater than 4 percent were evident in either member of the backup crew. This is in contract to the 15.1 and 8.9 percent losses observed in the prime crew. It has long been known that the skeletal system experiences a general loss of mineral under immobilization or extended bed rest. However, in both Gemini IV and Gemini V studies, bone mass losses were greater in both the os calcis and phalanx than were shown by the TWU bed-rest subjects during the same period of time. Although the bone mass losses in the 8-day Gemini V flight were generally greater than in the 4-day Gemini IV flight, the information to date is still insufficient to conclude that the losses tend to progress linearly with time, or whether a form of physiological adaptation may occur in longer space flights.

Mack, Pauline B.↗