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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including, cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, parkinson s and alzheimer s disease, cataracts, and aging

Schoenfeld, Michael P.↗
NASA NTRS2012

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases as Medical Counter Measures

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

Schoenfeld, Michael P.↗
NASA NTRS2011

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

Schoenfeld, Michael P.↗
NASA NTRS2015

Dried Plum Protects From Radiation-Induced Bone Loss by Attenuating Pro-Osteoclastic and Oxidative Stress Responses

Future space explorations beyond the earths magnetosphere will increase human exposure to space radiation and associated risks to skeletal health. We hypothesize that oxidative stress resulting from radiation exposure plays a major role in progressive bone loss and dysfunction in associated tissue. In animal studies, increased free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility. Our long-term goals are to define the mechanisms and risk of bone loss in the spaceflight environment and to facilitate the development of effective countermeasures. We had previously reported that exposure to low or high-LET radiation correlates with an acute increase in the expression of pro-osteoclastic and oxidative stress genes in bone during the early response to radiation followed by pathological changes in skeletal structure. We then conducted systematic screening for potential countermeasures against bone loss where we tested the ability of various antioxidants to mitigate the radiation-induced increase in expression of these markers. For the screen, 16-week old C57Bl6J mice were treated with a dietary antioxidant cocktail, injectable DHLA or a dried plum-enriched diet (DP). Mice were then exposed to 2Gy 137Cs radiation and one day later, marrow cells were collected and the relevant genes analyzed for expression levels. Among the candidate countermeasures tested, DP was most effective in reducing the expression of genes associated with bone loss. Furthermore, analysis of skeletal structure by microcomputed tomography (microCT) revealed that DP also prevents the radiation-induced deterioration in skeletal microarchitecture as indicated by parameters such as percent bone volume (BVTV), trabecular spacing and trabecular number. We also found that DP has similar protective effects on skeletal structure in a follow-up study using 1 Gy of sequential proton and iron, radiation species relevant to spaceflight. When cultured ex vivo under osteogenic conditions, bone marrow-derived cells from DP-fed animals exhibited increased colony numbers compared to control diet-fed animals. These findings suggest that DP exerts pro-osteogenic effects apart from its previously demonstrated anti-resorptive action, which may be one of the mechanisms underlying its radioprotective effect on bone. In conclusion, a diet enriched in certain types of antioxidants may be useful as an intervention for radiation-induced bone loss.

Bone-loss↗
NASA NTRS1998

Radiation Effects and Protection for Moon and Mars Missions

Manned and robotic missions to the Earth's moon and Mars are exposed to a continuous flux of Galactic Cosmic Rays (GCR) and occasional, but intense, fluxes of Solar Energetic Particles (SEP). These natural radiations impose hazards to manned exploration, but also present some constraints to the design of robotic missions. The hazards to interplanetary flight crews and their uncertainties have been studied recently by a National Research Council Committee (Space Studies Board 1996). Considering the present uncertainty estimates, thick spacecraft shielding would be needed for manned missions, some of which could be accomplished with onboard equipment and expendables. For manned and robotic missions, the effects of radiation on electronics, sensors, and controls require special consideration in spacecraft design. This paper describes the GCR and SEP particle fluxes, secondary particles behind shielding, uncertainties in radiobiological effects and their impact on manned spacecraft design, as well as the major effects on spacecraft equipment. The principal calculational tools and considerations to mitigate the radiation effects are discussed, and work in progress to reduce uncertainties is included.

Parnell, Thomas A.↗
NASA NTRS1994

Design considerations for a Space Station radiation shield for protection from both man-made and natural sources

This study was conducted to analyze scenarios involving the use of nuclear-power vehicles in the vicinity of a manned Space Station (SS) in low-earth-orbit (LEO) to quantify their radiological impact to the station crew. In limiting the radiant dose to crew members, mission planners may (1) shut the reactor down prior to reentry, (2) position the vehicle at a prescribed parking distance, and (3) deploy radiation shield about the shutdown reactor. The current report focuses on the third option in which point-kernel gamma-ray shielding calculations were performed for a variety of shield configurations for both nuclear electric propulsion (NEP) and nuclear thermal rocket (NTR) vehicles. For a returning NTR vehicle, calculations indicate that a 14.9 MT shield would be needed to limit the integrated crew exposure to no more than 0.05 Sv over a period of six months (25 percent of the allowable exposure to man-made radiation sources). During periods of low vehicular activity in LEO, the shield may be redeployed about the SS habitation module in order to decrease crew exposures to trapped proton radiations by approximately a factor of 10. The corresponding shield mass required for deployment at a returning NEP vehicle is 2.21 MT. Additional scenarios examined include the radioactivation of various metals as might be found in tools used in EVA activities.

Bolch, Wesley E.↗
DOE OSTI2020

PNNL Measurement Results for the 2018 FlatTop Criticality Nuclear Accident Dosimetry Exercise at the Nevada National Security Site (IER-253)

The Pacific Northwest National Laboratory (PNNL) participated in the FlatTop exercise IER-253 at the National Nuclear Security Site (NNSS) during the week of May 21, 2018. This report summarizes the measurements of the personal nuclear accident dosimeters (PNAD). Additionally, portable survey instrument readings and measurements of the simulated biological samples are included. The FlatTop exercise (IER-253) tested only PNADs and did not include fixed nuclear accident dosimeters (FNAD). Previous PNAD results obtained in 2016 at the Godiva-IV exercise IER-148 were summarized in PNNL Measurement Results for the 2016 Criticality Accident Dosimetry Exercise at the Nevada National Security Site IER-148 (PNNL-26497). The results clearly indicated that the previous dose conversions were a historical legacy of the Hanford Site and corresponded closer to kerma dose (or first collision dose, and not to Hp(10) dose). The technical basis for PNAD dose was based on the Godiva-IV exercise and documented in A New Dose Calculation Methodology for New PNAD and FNAD Designs at PNNL (PNNL-27023). The configuration of the PNAD was described in these two documents. The FlatTop exercise was the first time PNNL tested this new dose calculation methodology. Results were generally favorable with some results conservatively over reported that fell above the performance criteria. The reported gamma dose results fell non-conservatively low because only the default parameters obtained from the Godiva-IV exercise were used, and because the OSL gamma dosimeter has an energy dependency. The results from the simulated biological samples were also favorable, and in several cases conservatively over reported.

61 RADIATION PROTECTION AND DOSIMETRY↗
NASA NTRS1977

Radiative metallic thermal protection systems - A status report

During the early stages of the space shuttle program there were a number of technological uncertainties concerning the applicability of metallic thermal protection systems (TPS) to the multimission environment of the shuttle. To resolve the uncertainties and to advance the state-of-the-art, the NASA-Langley Research Center initiated a broad-based technology program to develop metallic TPS over the temperature range from 810 K to 1590 K. Wind tunnel tests conducted to assess the influence of surface/stream interaction of wavy surfaces on the design of metallic TPS indicate small increases in heat flux and surface drag for flow angles less than 20 deg. Analytical and experimental investigations, recently completed, have significantly improved prediction methods for cyclic creep behavior of TPS components repeatedly exposed to complex mission cycles. Thermal/structural concept optimization studies to minimize mass while maintaining structural integrity have led to advanced designs with unit masses which are competitive with those for shuttle RSI. In addition, the durability and reusability of metallic TPS have been repeatedly demonstrated in tests of full-scale systems. The current state-of-the-art strongly suggests that radiative metallic TPS have come of age.

Bohon, H. L.↗
DOE OSTI2022

Curcumin Nanodiscs Improve Solubility and Serve as Radiological Protectants against Ionizing Radiation Exposures in a Cell-Cycle Dependent Manner

Curcumin, a natural polyphenol derived from the spice turmeric (Curcuma longa), contains antioxidant, anti-inflammatory, and anti-cancer properties. However, curcumin bioavailability is inherently low due to poor water solubility and rapid metabolism. Here, we further refined for use curcumin incorporated into “biomimetic” nanolipoprotein particles (cNLPs) consisting of a phospholipid bilayer surrounded by apolipoprotein A1 and amphipathic polymer scaffolding moieties. Our cNLP formulation improves the water solubility of curcumin over 30-fold and produces nanoparticles with ~350 µg/mL total loading capacity for downstream in vitro and in vivo applications. We found that cNLPs were well tolerated in AG05965/MRC-5 human primary lung fibroblasts compared to cultures treated with curcumin solubilized in DMSO (curDMSO). Pre-treatment with cNLPs of quiescent G0/G1-phase MRC-5 cultures improved cell survival following 137Cs gamma ray irradiations, although this finding was reversed in asynchronously cycling log-phase cell cultures. These findings may be useful for establishing cNLPs as a method to improve curcumin bioavailability for administration as a radioprotective and/or radiomitigative agent against ionizing radiation (IR) exposures in non-cycling cells or as a radiosensitizing agent for actively dividing cell populations, such as tumors.

36 MATERIALS SCIENCE↗
NASA NTRS2015

Dietary Supplement Attenuates Radiation-Induced Osteoclastogenic and Oxidative Stress-Related Responses and Protects Adult Mice from Radiation-Induced Bone Loss

Our central hypothesis is that oxidative stress plays a key role in cell dysfunction and progressive bone loss caused by radiation exposure during spaceflight. In animal studies, excess free radical formation is associated with pathological changes in bone structure, enhanced bone resorption, reduced bone formation and decreased bone mineral density, which can lead to skeletal fragility. We previously reported that exposure to low or high-LET radiation rapidly increases expression levels of pro-osteoclastogenic and oxidative stress-related genes in bone and marrow, followed by pathological changes in skeletal structure. To screen various antioxidants for radioprotective effects on bone, 4 month old, male C57Bl6/J mice were treated with a dietary antioxidant cocktail, injectable alpha-lipoic acid, or a dried plum-enriched diet (DP). Mice were then exposed to 2Gy 137Cs total body radiation and one day later marrow cells were collected and the relevant genes analyzed for expression levels. Of the candidates tested, DP was most effective in reducing bone resorption-related gene expression. Microcomputed tomography revealed that DP also prevented the radiation-induced deterioration of skeletal microarchitecture, as indicated by percent bone volume, trabecular spacing and trabecular number. DP had similar protective effects on skeletal structure after sequential exposure to protons (0.5 Gy, 150MeV/n) and 56Fe 0.5Gy, 600 MeV/n). When cultured ex vivo under osteogenic conditions, bone marrow-derived cells from DP-fed animals exhibited increased colony numbers compared to control diet-fed animals. These findings suggest that DP exerted pro-osteogenic effects apart from previously identified anti-resorptive actions, which may contribute to radioprotection of skeletal tissue. In conclusion, a diet enriched in certain types of antioxidants and polyphenols such as DP may be useful as an intervention to protect tissues from degenerative effects of ionizing radiation.

Globus, Ruth↗
NASA NTRS2003

Biological countermeasures in space radiation health

Exposure to the types of ionizing radiation encountered during space travel may cause a number of health-related problems, but the primary concern is related to the increased risk of cancer induction in astronauts. The major types of radiation considered to be of importance during space travel are protons and particles of high atomic number and high energy (HZE particles). It is now clear that biological countermeasures can be used to prevent or reduce the levels of biological consequences resulting from exposure to protons or HZE particles, including the induction of cancer, immunosuppression and neurological defects caused by these types of ionizing radiation. Research related to the dietary additions of agents to minimize the risks of developing health-related problems which can result from exposure to space radiations is reviewed.

NASA Discipline Radiation Health↗
NASA NTRS2012

MAARSS: Magnet Architectures and Active Radiation Shielding Study

Protecting humans from space radiation is a major hurdle for human exploration of the solar system and beyond. Like on Earth, large magnetic fields surrounding a spaceship would deflect charged particles away from the habitat region and reduce the radiation dose to acceptable limits. The objective of this study is to determine the feasibility of current state of the art (SOA) high temperature superconducting (HTS) magnets as a means to protect crew from space radiation exposure on long duration missions beyond Low Earth Orbit (LEO). The study will look at architecture concepts to deflect high energy Galactic Cosmic Radiation (GCR) and Solar Proton Events (SPEs). Mass, power, and shielding efficiency will be considered and compared with current passive shielding capabilities. This report will walk the reader through several designs considered over the one year study and discuss the multiple parameters that should be evaluated for magnetic shielding. The study team eventually down-selects to a scalable light weight solenoid architecture that is launchable and then deployable using magnetic pressure to expand large diameter coils. Benefitting from the low temperature and high vacuum environment of deep space, existing high-temperature superconductors make such radiation shields realistic, near-term technical developments.

Westover, Shayne C.↗
DOE OSTI2020

MCNP calculations concerning the UW 137 Cs release event (Final Report)

This document supersedes earlier reports (LA-UR-19-32358 and LA-UR-20-22216) that discussed MCNP-calculated conversion factors (count rate per unit activity per unit area) for collimated 2”x2” NaI detectors (Ludlum model 44-10 and Thermo model SPA3) in contact with duct and plenum walls. Specifically, for duct and plenum dimensions and construction details of interest to the University of Washington ¹³⁷Cs release event. This document also corrects some of the data presented in the earlier LA-UR reports.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

RCT Continuing Training (Q2 2021) [Slides]

This quarter’s training assignment is split into two sections. Section one will review the fundamental elements of removing items from controlled areas. This section discusses each decision point and the required actions to determine if an item is suitable for release. Section two briefly reviews Area Radiation Monitors, commonly referred to as ‘ARMs’, and discusses the required actions to take in the event of an ARM alarm.” Report includes slides and transcript.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2022

RCT Continuing Training 1st Quarter 2022 Presentation Transcript

Welcome to RCT Continuing Training. This training will discuss the process for: collecting and evaluating radiological air samples and submitting samples to HPAL. This training consists of viewing the online presentation and completing its associated exercise guide, Utrain number 53850. It is recommended that you have the exercise guide with you while following along with the online training

61 RADIATION PROTECTION AND DOSIMETRY↗