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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Evolution of bidirectional costly mutualism from byproduct consumption

Mutualisms are essential for life, yet it is unclear how they arise. A two-stage process has been proposed for the evolution of mutualisms that involve exchanges of two costly resources. First, costly provisioning by one species may be selected for if that species gains a benefit from costless byproducts generated by a second species, and cooperators get disproportionate access to byproducts. Selection could then drive the second species to provide costly resources in return. Previously, a synthetic consortium evolved the first stage of this scenario: Salmonella enterica evolved costly production of methionine in exchange for costless carbon byproducts generated by an auxotrophic Escherichia coli . Growth on agar plates localized the benefits of cooperation around methionine-secreting S. enterica . Here, we report that further evolution of these partners on plates led to hypercooperative E. coli that secrete the sugar galactose. Sugar secretion arose repeatedly across replicate communities and is costly to E. coli producers, but enhances the growth of S. enterica . The tradeoff between individual costs and group benefits led to maintenance of both cooperative and efficient E. coli genotypes in this spatially structured environment. This study provides an experimental example of de novo, bidirectional costly mutualism evolving from byproduct consumption. The results validate the plausibility of costly cooperation emerging from initially costless exchange, a scenario widely used to explain the origin of the mutualistic species interactions that are central to life on Earth.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Investigating Wireless Quantum Key Distribution for Advanced Reactor Communications

Remote operation of small modular reactor (SMR) facilities is an appealing prospect for streamlined operation costs, safety concerns, and user convenience. The ability to guarantee security of communication channels between offsite users and nuclear reactor facilities is critical to enabling remote operations, given the sensitive nature of reactor state data. This report proposes a configuration implementing quantum key distribution (QKD) and advanced encryption standard (AES) protocols to establish secure reactor data feeds. The model outlined, which utilizes the Argonne-developed SeQUeNCe software package and custom MATLAB code, determines free-space channel losses for microwave-band communications in a variety of weather conditions and simulates QKD via ground-satellite links. This report demonstrates the feasibility of repeatable, real-time key generation and distribution for this configuration towards enabling secure wireless reactor communications.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2022

Delineating Variabilities of Groundwater Level Prediction Across the Agriculturally Intensive Transboundary Aquifers of South Asia

We report the groundwater depletion in South Asia’s Himalayan, transboundary Indus-Ganges-Brahmaputra-Meghna (IGBM) rivers basin is among the highest globally. Given the high irrigation demand and population, groundwater sustainability requires an improved understanding of groundwater systems for the accurate prediction of groundwater levels (GWLs). However, the prediction of groundwater system behaviors is a significant challenge since it is dominated by spatiotemporal and subsurface depth-dependent drivers. Earlier studies that address the challenges are mainly based on the short spatial and temporal extent and/or do not separate the renewable (i.e., shallow) vs nonrenewable (i.e., deeper) groundwater signals. Here, we first identified the variable importance of spatial and depth-dependent drivers on GWL in the IGBM basin. Our results indicate a greater influence of anthropogenic factors (i.e., widespread pumping and increased population) in most parts of the IGBM basin, except in the precipitation-dominated basin of the Brahmaputra. Our next purpose was to delineate a multifactorial approach for GWL prediction using the two most used machine learning models (i.e., support vector machine and feed-forward neural network) in the literature. In general, the machine learning model outputs show a good match in comparison to the GWL from the observation wells (n = 2303 distributed across India and Bangladesh) with some limitations in areas with increased groundwater irrigation. We separately compared the results from shallow (<35 m) and deep (>35 m) observation wells, emphasizing the significance of deep groundwater pumping. Our approach highlights the importance of spatiotemporal to multidepth factors in GWL prediction and can be adopted in other parts of the globe to predict GWLs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Interim glycol flowsheet reduction/oxidation (redox) model for the Defense Waste Processing Facility (DWPF)

Control of the REDuction/OXidation (REDOX) state of glasses containing high concentrations of transition metals, such as High Level Waste (HLW) glasses, is critical in order to eliminate processing difficulties caused by overly reduced or overly oxidized melts. Operation of a HLW melter at Fe +2 /ΣFe ratios of between 0.09 and 0.33, a range which is not overly oxidizing or overly reducing, helps retain radionuclides in the melt, i.e. long-lived radioactive 99 Tc species in the less volatile reduced Tc 4+ state, 104 Ru in the melt as reduced Ru +4 state as insoluble RuO 2 , and hazardous volatile Cr 6+ in the less soluble and less volatile Cr +3 state in the glass. The melter REDOX control balances the oxidants and reductants from the feed and from processing additives such as antifoam. Currently, the Defense Waste Processing Facility (DWPF) is running a formic acid-nitric acid (FN) flowsheet where formic acid is the main reductant and nitric acid is the main oxidant. During decomposition formate and formic acid releases H 2 gas which requires close control of the melter vapor space flammability. A switch to a nitric acid-glycolic acid (GN) flowsheet is desired as the glycolic acid flowsheet releases considerably less H 2 gas upon decomposition. This would greatly simplify DWPF processing. Development of an EE term for glycolic acid in the GN flowsheet is documented in this study.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

A Realistic Full-Scale 3D Modeling of Turning Using Coupled Smoothed Particle Hydrodynamics and Finite Element Method for Predicting Cutting Forces

Computational modelling is an effective technique for understanding the complex physics of machining. Large deformations, material separation, and high computational requirements are the key challenges faced while simulating machining. This work introduces a full-scale three-dimensional model of turning operations using a combined approach based on the Smoothed Particle Hydrodynamics (SPH) and Finite Element (FE) methods. By exploiting the advantages of each method, this approach leads to high-fidelity coupled SPH-FE machining models. Cutting forces and chip morphology are the primary results of interest. The machining models are validated with the results of turning experiments. Two-dimensional machining model underpredicts the cutting force and feed force by approximately 49% and 70%, respectively. Moreover, passive force cannot be predicted using the two-dimensional model. On the other hand, with the three-dimensional models developed in this manuscript, the difference between the total simulated force and experimentally measured force is ∼17%. The chip morphologies correlate with experiments in terms of the direction of the chip movement and the “long” continuous chips observed while turning Al 6061. This work expands the realm of machining simulations from two-dimensional orthogonal machining or sectional three-dimensional model to a full-scale realistic simulation. The encouraging simulation results show the potential to study more complex phenomena, such as machining stability and tool path modulation.

42 ENGINEERING↗
NASA NTRS1995

VRA Modeling, phase 1

The destruction of organic contaminants in waste water for closed systems, such as that of Space Station, is crucial due to the need for recycling the waste water. A co-current upflow bubble column using oxygen as the gas phase oxidant and packed with catalyst particles consisting of a noble metal on an alumina substrate is being developed for this process. The objective of this study is to develop a plug-flow model that will predict the performance of this three phase reactor system in destroying a multicomponent mixture of organic contaminants in water. Mass balances on a series of contaminants and oxygen in both the liquid and gas phases are used to develop this model. These mass balances incorporate the gas-to-liquid and liquid-to-particle mass transfer coefficients, the catalyst effectiveness factor, and intrinsic reaction rate. To validate this model, a bench scale reactor has been tested at Michigan Technological University at elevated pressures (50-83 psig,) and a temperature range of 200 to 290 F. Feeds consisting of five dilute solutions of ethanol (approx. 10 ppm), chlorobenzene (approx. 20 ppb), formaldehyde (approx. 100 ppb), dimethyl sulfoxide (DMSO approx. 300 ppb), and urea (approx. 20 ppm) in water were tested individually with an oxygen mass flow rate of 0.009 lb/h. The results from these individual tests were used to develop the kinetic parameter inputs necessary for the computer model. The computer simulated results are compared to the experimental data obtained for all 5 components run in a mixture on the differential test column for a range of reactor contact times.

Kindt, Louis M.↗
DOE OSTI2018

Consumption of terrestrial organic matter in the rocky intertidal zone along the central Oregon coast

Abstract Terrestrial organic matter ( TOM ) constitutes an important source of energy in many aquatic environments. This is the first study to compare the consumption of terrestrial leaves ( Alnus rubra ) to high‐quality ( Nereocystis luetkeana ) and low‐quality ( Fucus gardneri ) sources of drift kelp and low‐quality seagrass ( Phyllospadix spp.) in pools of the rocky intertidal zone on Cape Arago, Oregon, USA . On average, 1.02 kg ash‐free dry mass ( AFDM ) per day of TOM was transported by small forested streams during fall leaf abscission to the rocky intertidal zone in small pocket bays. Leaves of A. rubra (red alder) varied in wrack from negligible (12 g AFDM /m 2 ) on some beaches to the primary source of detritus on others (256 g AFDM /m 2 ). Long‐term feeding experiments (months) showed that consumption rates of A. rubra in the spring (19.7% of the initial pack biomass) and in the fall (52% of the initial pack biomass) were intermediate between those of N. luetkeana (fully consumed) and Phyllospadix spp. (never >10% consumed of the initial pack biomass). Long‐term experiments also showed that conditioned fall‐shed leaves of A. rubra were consumed at a faster rate (52.3% of initial pack biomass) than spring‐shed leaves of A. rubra (16.8% of initial pack biomass). Short‐term feeding experiments again showed that consumption of A. rubra in the spring (18.6% of initial pack biomass over 3 d) and fall (16.7% over 7 d) was intermediate between N. luetkeana (57.3% consumed over 3 d in the spring and 60.7% over 7 d in the fall) and Phyllospadix spp. (<1% consumed in the spring). Except for Phyllospadix spp., consumption rates followed polyphenolic concentrations in that, N. luetkeana (418 mg/mL) > A. rubra (3415 mg/mL) > F. gardneri (8098 mg/mL). Phyllospadix spp. was rarely consumed despite a fairly low concentration of phenolics (800 mg/mL). In the temperate zone, leaves of A . rubra may constitute an important source of energy during the fall and winter when more nutritious marine resources dieback, such as single‐celled algae and kelp (e.g., N. luetkeana ).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Powerloads on the front end components and the duct of the heating and diagnostic neutral beam lines at ITER

The heating and current drive beam lines (HNB) at ITER are expected to deliver ∼16.7 MW power per beam line for H beams at 870 keV and D beams at 1 MeV during the H-He and the DD/DT phases of ITER operation respectively. On the other hand the diagnostic neutral beam (DNB) line shall deliver ∼2 MW power for H beams at 100 keV during both the phases. The path lengths over which the beams from the HNB and DNB beam lines need to be transported are 25.6 m and 20.7 m respectively. The transport of the beams over these path lengths results in beam losses, mainly by the direct interception of the beam with the beam line components and reionisation. The lost power is deposited on the surfaces of the various components of the beam line. In order to ensure the survival of these components over the operational life time of ITER, it is important to determine to the best possible extent the operational power loads and power densities on the various surfaces which are impacted by the beam in one way or the other during its transport. The main factors contributing to these are the divergence of the beamlets and the halo fraction in the beam, the beam aiming, the horizontal and vertical misalignment of the beam, and the gas profile along the beam path, which determines the re-ionisation loss, and the re-ionisation cross sections. The estimations have been made using a combination of the modified version of the Monte Carlo Gas Flow code (MCGF) and the BTR code. The MCGF is used to determine the gas profile in the beam line and takes into account the active gas feed into the ion source and neutraliser, the HNB-DNB cross over, the gas entering the beamline from the ITER machine, the additional gas atoms generated in the beam line due to impacting ions and the pumping speed of the cryopumps. The BTR code has been used to obtain the power loads and the power densities on the various surfaces of the front end components and the duct modules for different scenarios of ITER operation. The gas profile and the magnetic field distribution for each scenario has been considered in these evaluations. The worst case power loads and power densities for each surface have been used to study their thermo-mechanical behaviour and manufacturing feasibility. The details of these calculations and results obtained are presented and discussed.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Process assessment of small scale low temperature methanol synthesis

Biomass is a renewable energy resource and has the potential to make a significant impact on domestic fuel supplies. Biomass can be converted to fuel like methanol via several step process. The process can be split into following main steps: biomass preparation, gasification, gas cooling and cleaning, gas shift and methanol synthesis. Untill now these configuration still has a problem like high production cost, catalyst deactivation, economy of scale and a huge energy requirements. These problems become the leading inhibition for biomass conversion to methanol, which should be resolved to move towards the economical. To address these issues, we developed various process and new configurations for methanol synthesis via methyl formate. This configuration combining two reactors: the one reactor for the carbonylation of methanol and CO to form methyl formate, and the second for the hydrogenolysis of methyl formate and H{sub 2} to form two molecule of methanol. Four plant process configurations were compared with the biomass basis is 300 ton/day. The first configuration (A) is equipped with a steam reforming process for converting methane to CO and H{sub 2} for increasing H{sub 2}/CO ratio. CO{sub 2} removal is necessary to avoid poisoning the catalyst. COSORB process used for the purpose of increasing the partial pressure of CO in the feed gas. The steam reforming process in B configuration is not used with the aim of reducing the number of process equipment, so expect lower investment costs. For C configuration, the steam reforming process and COSORB are not used with the aim of reducing the number of process equipment, so expect lower investment costs. D configuration is almost similar to the configuration A. This configuration difference is in the synthesis of methanol which was held in a single reactor. Carbonylation and hydrogenolysis reactions carried out in the same reactor one. These processes were analyzed in term of technical process, material and energy balance and economic analysis. The presented study is an attempt to compile most of these efforts in order to guide future work to get cheaper low cost investment. From our study the interesting configuration to the next development is D configuration with methanol yield 112 ton/day and capital cost with 526.4 10{sup 6} IDR. The configuration of D with non-discounted and discounted rate had the break-even point approximately six and eight years.

09 BIOMASS FUELS↗
DOE OSTI2023

Integrating biomechanics in evolutionary studies, with examples from the amphidromous goby model system

The functional capacities of animals are a primary factor determining survival in nature. In this context, understanding the biomechanical performance of animals can provide insight into diverse aspects of their biology, ranging from ecological distributions across habitat gradients to the evolutionary diversification of lineages. To survive and reproduce in the face of environmental pressures, animals must perform a wide range of tasks, some of which entail tradeoffs between competing demands. Moreover, the demands encountered by animals can change through ontogeny as they grow, sexually mature or migrate across environmental gradients. To understand how mechanisms that underlie functional performance contribute to survival and diversification across challenging and variable habitats, we have pursued diverse studies of the comparative biomechanics of amphidromous goby fishes across functional requirements ranging from prey capture and fast-start swimming to adhesion and waterfall climbing. The pan-tropical distribution of these fishes has provided opportunities for repeated testing of evolutionary hypotheses. By synthesizing data from the lab and field, across approaches spanning high-speed kinematics, selection trials, suction pressure recordings, mechanical property testing, muscle fiber-type measurements and physical modeling of bioinspired designs, we have clarified how multiple axes of variation in biomechanical performance associate with the ecological and evolutionary diversity of these fishes. Here our studies of how these fishes meet both common and extreme functional demands add new, complementary perspectives to frameworks developed from other systems, and illustrate how integrating knowledge of the mechanical underpinnings of diverse aspects of performance can give critical insights into ecological and evolutionary questions.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2003

Branched-chain amino acid supplementation during bed rest: effect on recovery

Bed rest is associated with a loss of protein from the weight-bearing muscle. The objectives of this study are to determine whether increasing dietary branched-chain amino acids (BCAAs) during bed rest improves the anabolic response after bed rest. The study consisted of a 1-day ambulatory period, 14 days of bed rest, and a 4-day recovery period. During bed rest, dietary intake was supplemented with either 30 mmol/day each of glycine, serine, and alanine (group 1) or with 30 mmol/day each of the three BCAAs (group 2). Whole body protein synthesis was determined with U-(15)N-labeled amino acids, muscle, and selected plasma protein synthesis with l-[(2)H(5)]phenylalanine. Total glucose production and gluconeogenesis from alanine were determined with l-[U-(13)C(3)]alanine and [6,6-(2)H(2)]glucose. During bed rest, nitrogen (N) retention was greater with BCAA feeding (56 +/- 6 vs. 26 +/- 12 mg N. kg(-1). day(-1), P < 0.05). There was no effect of BCAA supplementation on either whole body, muscle, or plasma protein synthesis or the rate of 3-MeH excretion. Muscle tissue free amino acid concentrations were increased during bed rest with BCAA (0.214 +/- 0.066 vs. 0.088 +/- 0.12 nmol/mg protein, P < 0.05). Total glucose production and gluconeogenesis from alanine were unchanged with bed rest but were significantly reduced (P < 0.05) with the BCAA group in the recovery phase. In conclusion, the improved N retention during bed rest is due, at least in part, to accretion of amino acids in the tissue free amino acid pools. The amount accreted is not enough to impact protein kinetics in the recovery phase but does improve N retention by providing additional essential amino acids in the early recovery phase.

Non-NASA Center↗
NASA NTRS2012

Investigation of Supercritical Water Phenomena for Space and Extraterrestrial Application

The cost of carrying or resupplying life support resources for long duration manned space exploration missions such as a mission to Mars is prohibitive and requires the development of suitable recycling technologies. Supercritical Water Oxidation (SCWO) has been identified as an attractive candidate for these extended missions because (i) pre-drying of wet waste streams is not required, (ii) product streams are relatively benign, microbially inert, and easily reclaimed, (iii) waste conversion is complete and relatively fast, and (iv) with proper design and operation, reactions can be self-sustaining. Initial work in this area at NASA was carried out at the Ames Research Center in the 1990 s with a focus on understanding the linkages between feed stock preparation (i.e., particle size and distribution) of cellulosic based waste streams and destruction rates under a range of operating temperatures and pressures. More recently, work in SCWO research for space and extra-terrestrial application has been performed at NASA s Glenn Research Center where various investigations, with a particular focus in the gravitational effects on the thermo-physical processes occurring in the bulk medium, have been pursued. In 2010 a collaborative NASA/CNES (the French Space Agency) experiment on the critical transition of pure water was conducted in the long duration microgravity environment on the International Space Station (ISS). A follow-on experiment, to study the precipitation of salt in sub-critical, trans-critical and supercritical water is scheduled to be conducted on the ISS in 2013. This paper provides a brief history of NASA s earlier work in SCWO, discusses the potential for application of SCWO technology in extended space and extraterrestrial missions, describes related research conducted on the ISS, and provides a list of future research activities to advance this technology in both terrestrial and extra-terrestrial applications.

Hicks, Michael C.↗
NASA NTRS2018

The Effect of Forward-Facing Steps on Stationary Crossflow Instability Growth and Breakdown

The effect of a forward-facing step on stationary crossflow transition was studied using standard stereo particle image velocimetry (PIV) and time-resolved PIV. Step heights ranging from 53 to 71% of the boundary-layer thickness were studied in detail. The steps above a critical step height of approximately 60% of the boundary-layer thickness had a significant impact on the stationary crossflow growth downstream of the step. For the critical cases, the stationary crossflow amplitude grew suddenly downstream of the step, decayed for a short region, then grew again. The adverse pressure gradient upstream of the step resulted in a region of crossflow reversal. A secondary set of vortices, rotating in the opposite direction to the primary vortices, developed underneath the uplifted primary vortices. The wall-normal velocity disturbance (V' ) created by these secondary vortices impacted the step, and is believed to feed into the strong vortex that developed downstream of the step. A large but very short negative crossflow region formed for a short region downstream of the step due to a sharp inboard curvature of the streamlines near the wall. For the larger step height cases, a crossflow-reversal region formed just downstream of the strong negative crossflow region. This crossflow reversal region is believed to play an important role in the growth of the stationary crossflow vortices downstream of the step, and may be a good indication of the critical forward-facing step height.

Eppink, Jenna L.↗
DOE OSTI2021

Treatment of brackish water reverse osmosis brine using only solar energy

Post-treatment of brine produced by reverse osmosis (RO) is a great challenge as it often requires high energy input and works under extreme operating conditions. In this study, brine from a RO plant in El Paso, TX USA was successfully treated using a pilot-scale nanophotonics enhanced solar membrane distillation (NESMD) system. The novel NESMD reactor has a nanophotonic membrane surface area of 0.2 m 2 and an internal heat recovery system to recover the latent heat released during vapor condensation. By utilizing a sweeping gas operational mode under real solar irradiation (585–827 W m -2 ), the NESMD realized successful desalination of RO brine with the membrane flux reaching 0.45–0.65 kg m -2 h -1 and total dissolved solids (TDS) removal greater than 99.5% without an external heat condenser. The decrease in the feed flow rate to the evaporation channel of the NESMD system led to an increase in the gained output ratio (GOR) from 0.35 to 0.62. We report to the best of our knowledge, this is the largest photothermal reactor utilized for the desalination of real RO brine under practical solar irradiation. Compared with conventional brine treatment processes that require high temperature or pressure, the NESMD desalinates RO brine at near-ambient temperature and pressure with free solar energy, providing a promising approach for water desalination, and RO brine post treatment.

42 ENGINEERING↗
DOE OSTI2022

Outdoor Test Bed Performance of a Power Line Sensor Using a Real-Time Event Simulator

This report summarizes the design and application of an outdoor power line sensor testbed (OPLST) with a real-time simulator and power meter to compare a potential transformer (PT) and current transformer (CT) versus an advanced line-post sensor. The OPLST was created to validate advanced medium-voltage (20/34.5 kV) outdoor power line sensors used in electrical distribution systems. Electrical utilities have installed metering and relay-protection transformers like PTs and CTs for several decades. The PTs/CTs are iron core measurement transformers based on the electromagnetic induction principle and provide reliable data in normal grid operation. However, new outdoor power line sensors (OPLS) using other technologies like voltage divider, Rogowski coil and optical principles have become available and may have favorable performance and costs compared to PTs/CTs. Therefore, the importance of testing these technologies with the PT/CT, to compare the measured phase voltage/current at different power grid scenarios is crucial to understand the performance of these new OPLS. For this study a G&W Electric Model CVS-36-O power line sensor was chosen as the OPLS to test with voltage/current signals. An OPAL-RT Technologies Model OP4510 real-time simulator and Schweitzer Engineering Laboratories Model SEL-735 power meter were installed with the 20/34.5 kV OPLST to compare the measured transient events collected from an advanced OPLS and the PT/CT. This system is installed at the Distributed Energy Communications and Control (DECC) lab, Oak Ridge National Laboratory (ORNL). The simulator generated different power grid scenarios (electrical faults, capacitor bank operation, service restoration, etc.), and its analog-output signals were connected to the voltage/current amplifiers that feed the 20/34.5 kV aerial cable loop through the PT/CT devices. Additional PT/CT devices were also wired with the medium voltage aerial cable loop to measure the phase current/voltage signals and server as references. After each test, common format for transient data exchange (COMTRADE) files were collected from the SEL-735 power meter and used to compare the performance of the OPLS with the PT/CT. The behavior of analog signals, harmonic components, total harmonic distortion and crest factors were assessed and found favorable for the G&W sensor as compared to the reference PT/CT.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2016

Effect of Form of Chromium on Spinel Formation

A number of Hanford high level waste (HLW) streams contain sufficiently high concentrations of chromium for it to become the waste loading limiting component in the waste. Chromium has relatively low solubility in borosilicate glasses and leads to the formation of various crystal phases including spinels. The extent of crystal formation must be managed during melter processing to prevent operational issues and potential premature melter failure that can result from excessive accumulation of crystals in the melter. In previous work for the Department of Energy (DOE) Office of River Protection (ORP), high-waste loading glass formulations were developed for representative HLW streams that are high in chromium. Results from those studies suggested that there may be differences in the crystallization behavior between glasses prepared in crucible melts and those prepared in DuraMelter 100 (DM100) joule heated melter runs. Understanding the cause of those differences has the potential to lead to the development of methods to further increase waste loadings for high chromium HLW streams through control of the formation of chromium-bearing crystals. As noted previously, the potential causes include differences in the form of components in the batch, including the form of chromium, as well as redox effects. This report describes the results from work to elucidate the origins of the observed differences and to identify melter feed composition modifications to control the formation of chromium-bearing crystal phases. The work focused on determining the effects of the form of chromium and the concentrations of oxidants in feed batches on spinel crystallization. Also evaluated was the use of potential melter feed additives to influence the redox state of chromium in the melt and its effect on spinel crystallization. As described in the Test Plan for this work, the objectives were accomplished through a combination of crucible-scale tests, small-scale tests with additives to influence redox state, and melter tests. This work builds on previous work performed at the Vitreous State Laboratory (VSL) of The Catholic University of America (CUA) for ORP to increase the waste loadings and processing rates of HLW glass formulations.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1986

A design study for the use of a multiple aperture deployable antenna for soil moisture remote sensing satellite applications

The instrumentation problems associated with the measurement of soil moisture with a meaningful spatial and temperature resolution at a global scale are addressed. For this goal only medium term available affordable technology will be considered. The study while limited in scope, will utilize a large scale antenna structure, which is being developed presently as an experimental model. The interface constraints presented by a singel Space Transportation System (STS) flight will be assumed. Methodology consists of the following steps: review of science requirements; analyze effects of these requirements; present basic system engineering considerations and trade-offs related to orbit parameters, number of spacecraft and their lifetime, observation angles, beamwidth, crossover and swath, coverage percentage, beam quality and resolution, instrument quantities, and integration time; bracket the key system characteristics and develop an electromagnetic design of the antenna-passive radiometer system. Several aperture division combinations and feed array concepts are investigated to achieve maximum feasible performacne within the stated STS constraints.

Foldes, P.↗
NASA NTRS2014

Ground Testing of the EMCS Seed Cassette for Biocompatibility with the Tardigrade, Hypsibius dujardini

The European Modular Cultivation System, EMCS, was developed by ESA for plant experiments. We performed ground testing to determine whether ARC EMCS seed cassettes could be adapted for use with tardigrades for future spaceflight experiments. Tardigrades (water bears) are small invertebrates that enter the tun state in response to desiccation or other environmental stresses. Tardigrade tuns have suspended metabolism and have been shown to be survive exposure to space vacuum, high pressure, temperature and other stresses. For spaceflight experiments using the EMCS, the organisms ideally must be able to survive desiccation and storage in the cassette at ambient temperature for several weeks prior to the initiation of the experiment by the infusion of water to the cassette during spaceflight. The ability of tardigrades to survive extremes by entering the tun state make them ideal candidates for growth experiments in the EMCS cassettes. The growth substratum in the cassettes is a gridded polyether sulfone (PES) membrane. A blotter beneath the PES membrane contains dried growth medium. The goals of our study were to (1) determine whether tardigrades survive and reproduce on PES membranes, (2) develop a consistent method for dehydration of the tardigrades with high recovery rates upon rehydration, (3) to determine an appropriate food source for the tardigrades that can also be dehydrated/rehydrated and (4) successful mock rehydration experiment in cassettes with appropriate food source. We present results that show successful multigenerational growth of tardigrades on PES membranes with a variety of wet food sources. We have successfully performed a mock rehydration with tardigrades and at least one candidate food, protonema of the moss Polytrichum, that supports multigenerational growth and whose spores germinate quickly enough to match tardigrade feeding patterns post rehydration. Our results indicate that experiments on the ISS using the tardigrade, Hypsibius dujardini and other similar species could successfully be performed in the flight verified hardware of the EMCS seed cassettes.

EMCS s↗

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