Search NASA⌕ Search

SEARCH · Search NASA

Results for “Aging effect”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Intergranular corrosion resistance of Zn modified 5××× series Al alloy during retrogression and re-aging treatment

Highlights: • Increase the strength due to precipitation hardening of T-Mg{sub 32}(AlZn){sub 49} phase in the Zn modified Al-Mg alloy. • Both high corrosion resistance and high strength are achieved by retrogression and re-aging treatment in Al-5Mg-3Zn alloy. • Large Mg and Zn content difference between GBP and PFZ results in relatively high IGC susceptibility. • The intergranular corrosion mechanism of Zn modified Al-Mg alloy during retrogression and re-aging treatment is clarified. - Abstract: The effects of retrogression and re-aging treatment on the intergranular corrosion behavior of Al-5.0Mg-3.0Zn alloys are systematically studied. The alloy's strength increases when retrogression temperature increases from 390 °C to 420 °C. Samples retrogressed at 390 °C then re-aged are very susceptible to intergranular corrosion and those retrogressed at 405 °C and 420 °C express good corrosion resistance. Then the alloy's corrosion susceptibility rises with increasing retrogression temperature. Grain boundary precipitates are coarsened and distributed discontinuously with decreasing retrogression temperature. Higher retrogression temperature results in higher Mg and Zn content difference and intergranular corrosion susceptibility.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. - Highlights: • Utilized a graded CR model in male mice • The mRNA profiles of xenobiotic processing genes (XPGs) in liver were investigated. • CR up-regulates many phase-II enzymes. • CR tends to feminize the mRNA profiles of XPGs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Short term treatment with a cocktail of rapamycin, acarbose and phenylbutyrate delays aging phenotypes in mice

Pharmaceutical intervention of aging requires targeting multiple pathways, thus there is rationale to test combinations of drugs targeting different but overlapping processes. In order to determine if combining drugs shown to extend lifespan and healthy aging in mice would have greater impact than any individual drug, a cocktail diet containing 14 ppm rapamycin, 1000 ppm acarbose, and 1000 ppm phenylbutyrate was fed to 20-month-old C57BL/6 and HET3 4-way cross mice of both sexes for three months. Mice treated with the cocktail showed a sex and strain-dependent phenotype consistent with healthy aging including decreased body fat, improved cognition, increased strength and endurance, and decreased age-related pathology compared to mice treated with individual drugs or control. The severity of age-related lesions in heart, lungs, liver, and kidney was consistently decreased in mice treated with the cocktail compared to mice treated with individual drugs or control, suggesting an interactive advantage of the three drugs. This study shows that a combination of three drugs, each previously shown to enhance lifespan and health span in mice, is able to delay aging phenotypes in middle-aged mice more effectively than any individual drug in the cocktail over a 3-month treatment period.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Constraints on core-collapse supernova progenitors from explosion site integral field spectroscopy

Observationally, supernovae (SNe) are divided into subclasses according to their distinct characteristics. This diversity naturally reflects the diversity in the progenitor stars. It is not entirely clear, however, how different evolutionary paths leading massive stars to become an SN are governed by fundamental parameters such as progenitor initial mass and metallicity. Furthermore, this paper places constraints on progenitor initial mass and metallicity in distinct core-collapse SN subclasses through a study of the parent stellar populations at the explosion sites. Integral field spectroscopy (IFS) of 83 nearby SN explosion sites with a median distance of 18 Mpc has been collected and analysed, enabling detection and spectral extraction of the parent stellar population of SN progenitors. From the parent stellar population spectrum, the initial mass and metallicity of the coeval progenitor are derived by means of comparison to simple stellar population models and strong-line methods. Additionally, near-infrared IFS was employed to characterise the star formation history at the explosion sites. No significant metallicity differences are observed among distinct SN types. The typical progenitor mass is found to be highest for SN type Ic, followed by type Ib, then types IIb and II. Type IIn is the least associated with young stellar populations and thus massive progenitors. However, statistically significant differences in progenitor initial mass are observed only when comparing SNe IIn with other subclasses. Stripped-envelope SN progenitors with initial mass estimates lower than 25 M ⊙ are found; they are thought to be the result of binary progenitors. Confirming previous studies, these results support the notion that core-collapse SN progenitors cannot arise from single-star channels only, and both single and binary channels are at play in the production of core-collapse SNe. Near-infrared IFS suggests that multiple stellar populations with different ages may be present in some of the SN sites. As a consequence, there could be a non-negligible amount of contamination from old populations, and therefore the individual age estimates are effectively lower limits.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Large-scale replicated field study of maize rhizosphere identifies heritable microbes

Up until now, soil microbes that colonize plant roots and are responsive to differences in plant genotype remain to be ascertained for agronomically important crops. From a very large-scale longitudinal field study of 27 maize inbred lines planted in three fields, with partial replication 5 y later, we identify root-associated microbiota exhibiting reproducible associations with plant genotype. Analysis of 4,866 samples identified 143 operational taxonomic units (OTUs) whose variation in relative abundances across the samples was significantly regulated by plant genotype, and included five of seven core OTUs present in all samples. Plant genetic effects were significant amid the large effects of plant age on the rhizosphere microbiome, regardless of the specific community of each field, and despite microbiome responses to climate events. Seasonal patterns showed that the plant root microbiome is locally seeded, changes with plant growth, and responds to weather events. However, against this background of variation, specific taxa responded to differences in host genotype. If shown to have beneficial functions, microbes may be considered candidate traits for selective breeding.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Status of Alloy 800H in Considerations for the Gen IV Nuclear Energy Systems

Alloy 800 H is currently under consideration for applications in the next generation nuclear plant (NGNP) at operational temperatures above 750°C. This paper first describes service requirements of the nuclear system for structural materials; and then an extensive review of Alloy 800 H is given on its codification with respect to development and research history, mechanical behavior and design allowables, metallurgical aging resistance, environmental effect considerations, data requirements and availability, weldments, as well as many other aspects relevant to the intended nuclear application. Finally, further research and development activities to support the materials qualification are suggested.

36 MATERIALS SCIENCE↗
DOE OSTI2016

FRACTURE RESISTANCE OF CAST AUSTENITIC STAINLESS STEELS

Cast austenitic stainless steels (CASS) possess excellent corrosion resistance and mechanical properties and are used alongside with wrought stainless steels (SS) in light water reactors for primary pressure boundaries and reactor core internal components. In contrast to an austenitic microstructure of wrought SS, CASS alloys consist of a dual-phase microstructure of delta ferrite and austenite. While the delta ferrite is critical for the service performance of CASS alloys, it is also vulnerable to embrittlement when exposed to reactor service temperatures and fast neutron irradiations. In this study, the combined effect of thermal aging and neutron irradiation on the degradation of CASS alloys was investigated. Static casts of CF-3 and CF-8 grades with > 23% delta ferrite were selected for the study, and specimens with and without prior thermal aging were irradiated at ~320°C to about 0.08 dpa. Crack growth rate and fracture toughness J-integral resistance curve tests were performed in simulated light water reactor environments with low corrosion potential. While no elevated crack propagation rates were detected, significant reductions in fracture toughness were observed after either thermal aging or neutron irradiation. The loss of fracture toughness due to neutron irradiation seemed more evident in the samples without prior thermal aging. Transmission electron microscope (TEM) examination showed that both neutron irradiation and thermal aging affect the microstructural evolution of delta ferrite. A high density of G-phase precipitates was observed in both thermally aged and irradiated specimens The evolution of the precipitate microstructure is more extensive in the samples subjected to both thermal aging and neutron irradiation. The similarity of precipitate microstructures resulting from thermal aging and neutron irradiation are consistent with the fracture toughness results, suggesting a common microstructural origin of the observed embrittlement among the tested specimens.

cast austenitic stainless steels↗
DOE OSTI2018

Neutron and Thermal Embrittlement of RPV Steels: An Overview

Because the reactor pressure vessel (RPV) represents the first structural line of defense against the release of radiation to the public, the design and fabrication of the RPV for any nuclear reactor facility is performed at very high standards in accordance with consensus codes that are based on mechanical and physical properties of the steels used to construct the vessel. Nuclear RPVs may weigh up to 800 tons with wall thicknesses up to approximately 330 mm and are clad on the inside with stainless-steel weld metal and given a final post-weld heat treatment. The RPV is a unique structural component in that it operates under high pressures and temperatures and is exposed to relatively high neutron radiation. Although typical RPV steels and welds have excellent fracture toughness at room temperature and above when put into service, the degrading effects of high-energy neutron irradiation can cause levels of irradiation-induced embrittlement in radiation-sensitive materials of concern for the structural integrity of the RPV. In recent decades, remarkable progress has been made in developing a mechanistic understanding of irradiation embrittlement. This progress includes developing physically based and statistically calibrated models of Charpy V-notch-indexed transition temperature shifts based on results from RPV surveillance programs complemented by significant results from comprehensive research experiments performed in test reactors. In addition, advances in elastic-plastic fracture mechanics allow for a relatively small number of relatively small specimens to characterize the fracture toughness of RPV steels with statistical confidence. This paper presents a review of the primary mechanical properties, test procedures, examples of applicable codes and standards, and specimen types used to characterize RPV steels and welds, the effects of neutron irradiation on those most relevant mechanical properties, and a brief review of the effects of thermal aging on RPV materials. The paper closes with a summary.

Nanstad, Randy K.↗
DOE OSTI2015

Thermal Battery Degradation Mechanisms

Diffuse reflectance IR spectroscopy (DRIFTS) was used to investigate the effect of accelerated aging on LiSi based anodes in simulated MC3816 batteries. DRIFTS spectra showed that the oxygen, carbonate, hydroxide and sulfur content of the anodes changes with aging times and temperatures, but not in a monotonic fashion that could be correlated to phase evolution. Bands associated with sulfur species were only observed in anodes taken from batteries aged in wet environments, providing further evidence for a reaction pathway facilitated by H 2 S transport from the cathode, through the separator, to the anode. Loss of battery capacity with accelerated aging in wet environments was correlated to loss of FeS 2 in the catholyte pellets, suggesting that the major contribution to battery performance degradation results from loss of active cathode material.

25 ENERGY STORAGE↗
DOE OSTI2016

Organic Iodine Adsorption by AgZ under Prototypical Vessel Off-Gas Conditions

U.S. regulations will require the removal of 129 I from the off-gas streams of any used nuclear fuel (UNF) reprocessing plant prior to discharge of the off-gas to the environment. Multiple off-gas streams within a UNF reprocessing plant combine prior to release, and each of these streams contains some amount of iodine. For an aqueous UNF reprocessing plant, these streams include the dissolver off-gas, the cell off-gas, the vessel off-gas (VOG), the waste off-gas and the shear off-gas. To achieve regulatory compliance, treatment of multiple off-gas streams within the plant must be performed. Preliminary studies have been completed on the adsorption of I 2 onto silver mordenite (AgZ) from prototypical VOG streams. The study reported that AgZ did adsorb I 2 from a prototypical VOG stream, but process upsets resulted in an uneven feed stream concentration. The experiments described in this document both improve the characterization of I 2 adsorption by AgZ from dilute gas streams and further extend it to include characterization of the adsorption of organic iodides (in the form of CH 3 I) onto AgZ under prototypical VOG conditions. The design of this extended duration testing was such that information about the rate of adsorption, the penetration of the iodine species, and the effect of sorbent aging on iodine removal in VOG conditions could be inferred.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Standard High Solids Vessel Design Non-Newtonian Simulant Qualification

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is working to develop a Standard High Solids Vessel Design process vessel. To support testing of this new design, WTP engineering staff requested that a non-Newtonian simulant be developed that would represent the Most Adverse Design Condition (MADC), denoted as MADC-4, with respect to mixing performance as specified by WTP. The majority of the simulant requirements are specified in 24590-PTF-RPT-PE-16-001, Rev. 0, and a discussion of suggested non-Newtonian rheological parameters for the simulant was provided in WTP RPT-241, Rev. 0. This document describes the simulant composition that will satisfy the basis requirement along with ancillary testing to assess the rheological behavior of the simulant depending on the formulation approach used, simulant aging, and the effects of dilution. From this data, a simulant recipe to meet the basis is recommended. The simulant recipe was designed to meet a target rheology (as expressed by Bingham model parameters) of 34.5 ± 1.5 Pa [yield stress] and 33.5 ±1.5 cP [consistency] at 25 °C.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Multi-Gas Sensors for Enhanced Reliability of SOFC Operation

GE Research, in partnership with SUNY Polytechnic Institute (SUNY Poly), designed, built, and tested gas sensors for in situ monitoring of H 2 and CO anode tail gases produced with on-site steam reforming in solid oxide fuel cell (SOFC) systems. The knowledge of the H 2 /CO ratio of these anode tail gases should allow accurate determination and control of the efficiency of the reforming process in the SOFC system and should deliver a lower operating cost for SOFC customers. The project objectives were to achieve multi-gas monitoring capability with a single multivariable sensor, and to sustain this performance in the presence of gaseous interferences and a potential poison for the sensor. The duration of the project was 24 months with the project structure that included three technical tasks such as (1) development of design rules of photonic nanostructures for H 2 and CO gas detection, (2) laboratory validation of photonic nanostructures for selective H 2 and CO gas detection, and (3) validation of photonic nanostructures for initial stability and poison-resistance against H 2 S. To build multivariable sensors for selective H 2 and CO gas detection in the presence of interferences, we expanded our earlier knowledge of multi-gas sensors into new fabrication and functionalization methodologies as well as into new methodologies for the spectral data analysis of multi-gas responses. We have advanced our design rules of the three-dimensional (3D) photonic nanostructures that allowed detection of H 2 and CO at high temperatures as individual gases and as their mixtures and rejection of interferences such as CO 2 , H 2 O, CH 4 , and other hydrocarbons for SOFC applications. Our advanced design rules should be attractive for building the new generation of cost-effective industrial sensors. Stability and poison resistance of our 3D photonic nanostructures was tested in the laboratory conditions. While initially we utilized conventional machine learning data analysis tools, we have found that they were unable to correct for the sensor drift. Thus, we have implemented new methods of machine learning for the analysis of our spectral data. These learnings pave the way to move the future studies into advanced testing of effects of interferences, aging and field tests. In future, our work will continue to advance our sensing designs to operate in conditions with known and unknown interferences by implementing nanostructures with enhanced spectral diversity of responses to gaseous species of interest and interferences. Our systematic reduction of technical risks in this completed project and in future studies will ensure transition of this sensing technology to commercialization.

03 NATURAL GAS↗
DOE OSTI2015

II.B.3 Battery Safety Testing (SNL)

Objectives are: Serve as an independent abuse test laboratory for DOE and USABC; Abuse testing in accordance with the USABC abuse testing manual; Successful testing of all deliverables from developers under USABC contracts; Revise the USABC abuse testing manual; Test the propensity towards propagation of cell failure through multiple cell batteries; Provide mechanical testing support to develop and validate mechanical models for EV batteries; and, Evaluate the effect of cell age on abuse response.

25 ENERGY STORAGE↗
DOE OSTI2021

Body Mass Variation in an Introduced Wild Pig Population with Changing Ancestry

Total body mass variation was studied in a single wild pig (Sus scrofa) population that originated from three introductions of varying ancestry. Body mass data from 12,257 wild pigs collected over more than five decades were analyzed for differences due to the effects of sex, age class, reproductive status, season, and historic subpopulation groupings. Total body mass data from this population averaged 38 kg and ranged from 0.511 to 189 kg. The overall observed range of body mass data was consistent with previous studies. Very heavy individuals (i.e., >150 kg) made up only a small percentage of the overall population. Males were significantly larger than females, being on average 1.09 times heavier. This significant sexual dimorphic difference was seen in all but the piglet age class. This percent dimorphic difference increased with age. Body mass variation and overlap between the age classes also increased with age. Males were more variable than females within the same age class. The study area’s wild pigs were on average born at slightly less than one percent of their adult body mass. Percent weight gain toward the adult body mass increased with age and was slightly greater in females than in males. In contrast, absolute weight gain between age classes was greater in males. Pregnant sows were significantly heavier than non-pregnant females in all age class comparisons; however, this difference decreased with age. There was a seasonal shift in body mass with age, with younger age classes being heaviest in the fall-winter period and the older age classes being heaviest in spring-summer. Having originated from different ancestral stocks, two major subpopulations of wild pigs on the study area differed significantly in body mass in all sex and age class comparisons. The SRS wild pig population showed a decrease in body mass during the 1990s that was significant. This change may have been the result of both ancestral and population density variation, as well as unspecified environmental factors

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Findings during Incorporation of the Federal Guidance Report No. 15 External Dose Coefficients into the RESRAD Family of Codes

Argonne National Laboratory was tasked by the U.S. Department of Energy (DOE) to incorporate the recently published Federal Guidance Report No. 15 (FGR 15) (EPA 2019) external dose rate coefficients into the database of the RESRAD family of codes. FGR 15 is one of two publications that contain age-specific external effective dose rate coefficients that are based on the International Commission on Radiological Protection (ICRP) Publication 103 (ICRP-103) methodology (ICRP 2007) and the ICRP-107 (ICRP 2008) nuclear decay data; ICRP-144 (ICRP 2020) is the other publication.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2026

Sodium Chemistry Assessment and Initiation of Sodium Exposure Experiment on A709 Commercial Heats and LPBF 316H SS

This report documents sodium chemistry characterization and the initiation of forced‑convection sodium exposure experiments for two structural materials for sodium‑cooled fast reactors (SFRs): Alloy 709 (solution‑annealed and with an additional 775 °C/10 h precipitation treatment) and laser powder bed fusion (LPBF) 316H stainless steel tensile specimens printed with an as‑built surface condition. The sodium exposure experiment was conducted in a forced‑convection sodium loop with two vessels operated at 550 °C and 600 °C, and a cold trap maintained at <130 °C. Carbon activity in sodium was quantified using a nickel‑foil equilibration method. Initial post‑exposure evaluation after ~1,000 h indicates negligible thickness change for Alloy 709 and a small but measurable mass decrease. To isolate thermal effects from sodium effects, parallel thermal‑aging experiments were performed on Alloy 709 at 550 °C and 600 °C. Baseline tensile tests at room temperature, 550 °C, and 600 °C show expected reduction in strength with increasing temperature and serration tensile curves at elevated temperatures, consistent with dynamic strain aging. After 3,000 h thermal aging, Alloy 709 exhibits modest strengthening and reduced ductility at 550 °C. Together, these results establish the loop chemistry conditions and provide the initial corrosion and mechanical property results for ongoing long‑duration sodium exposure of Alloy 709 and LPBF 316H stainless steel.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2016

Greater sage-grouse apparent nest productivity and chick survival in Carbon County, Wyoming

Greater sage-grouse Centrocercus urophasianus populations across North America have been declining due to degradation and fragmentation of sagebrush habitat. As part of a study quantifying greater sage-grouse demographics prior to construction of a wind energy facility, we estimated apparent net nest productivity and survival rate of chicks associated with radio-equipped female sage-grouse in Carbon County, Wyoming, USA. We estimated apparent net nest productivity using a weighted mean of the average brood size and used a modified logistic-exposure method to estimate daily chick survival over a 70-day time period. Apparent nest productivity was 2.79 chicks per female (95% CI: 1.46–4.12) in 2011, 2.00 chicks per female (95% CI: 1.00–3.00) in 2012, and 1.54 chick per female (95% CI: 0.62–2.46) in 2013. Chick survival to 70 days post-hatch was 19.10% (95% CI: 6.22–37.42%) in 2011, 4.20% (95% CI: 0.84–12.31%) in 2012, and 16.05% (95% CI: 7.67–27.22%) in 2013. These estimates were low, yet within the range of other published survival rates. Chick survival was primarily associated with year and chick age, with minor effects of average temperature between surveys and hatch date. The variability in chick survival rates across years of our study suggests annual weather patterns may have large impacts on chick survival. Thus, management actions that increase the availability of food and cover for chicks may be necessary, especially during years with drought and above-average spring temperatures.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Neonatal respiratory support strategies—short and long-term respiratory outcomes

Mechanical ventilation (MV), although life-saving, is associated with chronic respiratory morbidity in both preterm and term born infants. New ventilation modes have been developed with the aim of minimising lung injury. These include invasive and non-invasive respiratory support strategies, techniques for less invasive surfactant administration (LISA) and closed-loop automated oxygen control (CLAC) systems. Increasingly, newborn infants with signs of respiratory distress are stabilised on continuous positive airway pressure (CPAP) and receive LISA. Early CPAP when compared to mechanical ventilation reduced the incidence of BPD and respiratory morbidity at 18 to 22 months corrected age. Nasal intermittent positive pressure ventilation reduced treatment failure rates compared to CPAP, but not bronchopulmonary dysplasia (BPD). LISA compared with intubation and surfactant delivery reduced BPD, but there is no evidence from randomised trials regarding long-term respiratory and neurodevelopmental outcomes. Synchronisation of positive pressure inflations with the infant's respiratory efforts used with volume targeting should be applied for infants requiring intubation as this strategy reduces BPD. A large RCT with long term follow up data demonstrated that prophylactic high frequency oscillatory ventilation (HFOV) improved respiratory and functional outcomes at school age, but those effects were not maintained after puberty. CLAC systems appear promising, but their effect on long term clinical outcomes has not yet been explored in randomised trials. Further studies are required to determine the role of newer ventilation modes such as neurally adjusted ventilator assist (NAVA). All such respiratory support strategies should be tested in randomised controlled trials powered to assess long-term outcomes.

Kaltsogianni, Ourania↗