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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 1,045 records · Page 58

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NASA NTRS2002

STS-109 Crew Interviews - Altman

STS-109 crew Commander Scott D. Altman is seen during a prelaunch interview. He answers questions about his inspiration to become an astronaut and his career path. He gives details on the mission's goals and significance, which are all related to maintenance of the Hubble Space Telescope (HST). After the Columbia Orbiter's rendezvous with the HST, extravehicular activities (EVA) will be focused on several important tasks which include: (1) installing the Advanced Camera for Surveys; (2) installing a cooling system on NICMOS (Near Infrared Camera Multi-Object Spectrometer); (3) repairing the reaction wheel assembly; (4) installing additional solar arrays; (5) augmenting the power control unit; (6) working on the HST's gyros. The reaction wheel assembly task, a late addition to the mission, may necessitate the abandonment of one or more of the other tasks, such as the gyro work.

Source record↗

NASA NTRSDate not supplied

Orion Artemis I Descent and Landing Performance

The Artemis I mission successfully demonstrated the Orion Multi-Purpose Crew Module ability to trigger parachute deployment, control angular rate and touch-down heading using reaction control jets while under parachutes, and automatically detect splashdown. Guidance and control logic is implemented to initiate para-chute events in a favorable dynamic state and select a touchdown heading direction that will minimize impact loads at splashdown. Detection of splashdown inhibits control to prevent firing reaction control jets under water and begin the transition into post-landing activities that cut parachutes and deploy the Crew Module Up-righting System (CMUS). This paper presents analysis of Orion descent and landing guidance and control performance for the Artemis I mission utilizing imagery taken from the vehicle, recorded flight data, and results from high fidelity simulations.

Artemis 1↗

DOE OSTI2019

Formed-in-place Ceramic Systems for Sealing and Flow Control in Geothermal Applications

Conventional oil and gas tools are frequently unsuitable for downhole applications in geothermal wells, largely due to uncased well configurations and their extreme thermal/chemical fluid conditions. Consequently, relatively common O&G tools like bridge plugs and sand control screens are difficult or at times impossible to implement in geothermal wells. In commercial oil and gas, thermite-based tools are being developed for intervention and decommissioning applications, and gaining field experience and credibility. We are developing and testing such systems for geothermal applications, with the objective of forming ceramic sealing and flow control features in-situ. The process uses self-propagating thermite reactions, in which a metal is combined with an oxidizer to release significant amounts of energy in a controlled, non-explosive manner. These solid phase reactions can be engineered to generate ceramic products with specific physical and flow characteristics. We are developing and testing formulations and wireline deployment tools which yield low to high permeability as needed, and preferentially expand to fill boreholes in both large diameter and slimhole wells. Near term applications are bridge plugs for P&A operations, screens for sand control and borehole stabilization, and lost circulation control during drilling. Laboratory tests have demonstrated the ability to form these products under high temperature and pressure conditions. Field tests are in planning to demonstrate the full-scale performance of these tools. This paper will present the status and results of this demonstration project, in its first year of advanced development for the DOE geothermal technologies program. New developments utilizing thermite tools in the HP/HT oil and gas domain will also be highlighted, particularly those which may have utility in geothermal applications.

02 PETROLEUM↗

DOE OSTI2024

Experimental investigation into coal wettability changes caused by reactions with scCO 2 -H 2 O

Geological CO 2 sequestration (GCS) can help mitigate global warming and enhance methane recovery from coal beds. However, few studies have linked the effects of CO 2 to surface chemistry changes controlling wetting behavior in deep coal beds. Contact angles (CAs) of CO 2 /N 2 -high volatile bituminous coal-water systems were measured under different temperatures and pressures. The surface chemistry and physical structure of coals were characterized to investigate changes in physicochemical properties and their relations with wettability after reactions. For N 2 treatment, the time-dependence of static and dynamic CAs were insignificant, ranging within 4°. For gaseous CO 2 treatment, the static CAs and the average advancing angles increased slightly. With supercritical (sc) CO 2 , both the static and dynamic CAs increased significantly, and θ adv changed to intermediate-wet (92°). Reactions with minerals exposed to scCO 2 resulted in greater surface roughness and heterogeneity, greater contact angle hysteresis and more surface sites occupied by scCO 2 rather than H 2 O. Increases in hydrophobic functional groups and decreases in hydrophilicity were shown by FTIR spectra, reflecting the shedding of polar oxygen-containing functional groups, reduction of hydrogen bonds, and increasing percentage of hydrocarbons. XRD patterns obtained following scCO 2 -treatment showed that crystallite growth and molecular polymerization were higher toward graphite-like. The calculated structural parameters of functional groups and crystallites both showed elevated coal rank. Changes in crystallite structure, notably higher carbon content and decreased negative surface charge, are unfavorable for water-wetting. Finally, this study contributes to understanding surface chemistry changes responsible for decreased wettability during CO 2 -enhanced coal bed methane recovery and GCS in coal reservoirs.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2019

Enhanced Corrosion of Magnesium as a Treatment for Legacy SNF - 19369

The ability of high concentrations of MgCl{sub 2} to induce activity-controlled dissolution of magnesium has been investigated in the context of providing a means of stabilising reactive metal fuel wastes, as oxide/hydroxide corrosion products, to enhance the resilience of the waste form following disposal. Kinetic parameters were measured using a novel immersion testing method that utilise the gravimetric measurement of evolving hydrogen produced by the oxidation of the metal. This method demonstrates extremely high precision relative to a traditional volumetric approach and appears to be relatively robust in its accuracy despite its sensitivity to changing temperature. An effective activation energy of 10.2 kJmoL{sup -1} was measured for the reaction using the Arrhenius equation over a temperature range of 30-70 deg. C. This implies that the reaction remains controlled by the diffusion of reactants to the metal surface and fails to corroborate the effect previously observed by Casey and Bergeron. This may be explained by differences in initial conditions, or it could be that the system transitions into the previously observed state as it reaches equilibrium, a possibility that was not accounted for in this study as the experiments focussed on measuring the initial rate of reaction. Repeat testing and further study is warranted given that enhanced corrosion could offer a means to produce a self-immobilising waste form with minimal intrusion, offering both improved safety tolerances and cost savings for the decommissioning and waste disposal efforts ongoing at the Sellafield site. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2021

The scaling of kinetic and transport behaviors in the solution-phase chemistry of a plasma–liquid interface

The reactions at a plasma–liquid interface often involve species such as the solvated electron or the hydroxyl radical, which initiate the reduction or oxidation of solution-phase reactants (so-called scavengers) or are consumed by their own second-order recombination. Here, the mathematical scaling of the reaction–diffusion equations at the interface is used to obtain a characteristic time that can be used to determine the transition from highly efficient scavenger reduction or oxidation to lower efficiencies due to transport limitations. The characteristic time (tc) is validated using numerical solutions of the reaction–diffusion equations. When the scavenger kinetics are faster than second-order recombination, this characteristic transition time scales proportionally with the scavenger diffusivity (Ds) and the square of the scavenger bulk concentration (SB) and inversely proportional to the electron flux (J) squared; that is, t c = D s S B 2 F 2 /J 2 , where F is Faraday’s constant. However, when the scavenger kinetics are comparable or slower than second-order recombination, this scaling does not hold. Extending this analysis to three-dimensional systems shows that the profile of the electron flux on the surface affects the spatial location where reactions are most effective. Finally, the assessment of the implications of these behaviors for the reactor design highlights how effectively controlling the electron flux and solution transport may be necessary to improve the efficiency of scavenger reactions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

NASA NTRS2006

Ignition Characterization Test Results for the LO2/Ethanol Propellant Combination

A series of contracts were issued by the Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration (NASA) under the auspices of the Exploration Systems Mission Directorate to develop and expand the maturity of candidate technologies considered to be important for future space exploration. One such technology was to determine the viability of incorporating non-toxic propellants for Reaction Control Subsystems (RCS). Contract NAS8-01109 was issued to Aerojet to develop a dual thrust Reaction Control Engine (RCE) that utilized liquid oxygen and ethanol as the propellants. The dual thrust RCE incorporated a primary thrust level of 870 lbf, and a vernier thrust level of 10 - 30 lbf. The preferred RCS approach for the dual thrust RCE was to utilize pressure-fed liquid oxygen (LOX) and ethanol propellants; however, previous dual thrust feasibility testing incorporated GOX/Ethanol igniters as opposed to LOX/Ethanol igniters in the design. GOX/Ethanol was easier to ignite, but this combination had system design implications of providing GOX for the igniters. A LOX/Ethanol igniter was desired; however, extensive LOX/Ethanol ignition data over the anticipated operating range for the dual thrust RCE did not exist. Therefore, Aerojet designed and tested a workhorse LOX igniter to determine LOX/Ethanol ignition characteristics as part of a risk mitigation effort for the dual thrust RCE design. LOX, encompassing potential two-phase flow conditions anticipated being present in real mission applications. A workhorse igniter was designed to accommodate the hll LOX design flowrate, as well as a reduced GOX flowrate. It was reasoned that the initial LOX flow through the igniter would flash to GOX due to the latent heat stored in the hardware, causing a reduced oxygen flowrate because of a choked, or sonic, flow condition through the injection elements. As LOX flow continued, the hardware would chill-in, with the injected oxygen flow transitioning from cold GOX through two-phase flow to subcooled LOX. permitted oxygen state points to be determined in the igniter oxidizer manifold, and gas-side igniter chamber thermocouples provided chamber thermal profile characteristics. The cold flow chamber pressure (P(sub c)) for each test was determined and coupled with the igniter chamber diameter (D(sub c)) to calculate the characteristic quench parameter (P(sub c) x D(sub c)), which was plotted as a function of core mixture ratio, m. Ignition limits were determined over a broad range of valve inlet conditions, and ignition was demonstrated with oxygen inlet conditions that ranged from subcooled 210 R LOX to 486 R GOX. Once ignited at cold GOX conditions, combustion was continuous as the hardware chilled in and the core mixture ratio transitioned from values near 1.0 to over 12.5. Pulsing is required in typical RCS engines; therefore, the workhorse igniter was pulse tested to verify the ability to provide the required ignition for a pulsing RCE. The minimum electrical pulse width (EPW) of the dual thrust RCE was 0.080 seconds.

Popp, Christopher G.↗

DOE OSTI2019

Joint charge storage for high-rate aqueous zinc-manganese dioxide batteries

Aqueous rechargeable zinc-manganese dioxide batteries have great promise for large-scale energy storage due to the use of environmental friendly, abundant, and rechargeable Zn metal anode and MnO2 cathode. In the literature various intercalation and conversion reaction mechanisms have been reported depending on the origin of the starting materials, but it is not clear how these mechanisms can be simultaneously manipulated to improve the charge storage and transport properties. Here, we report a systematical study to understand the electrolyte controlled charge-storage mechanisms in layered d-MnO2. A joint Zn2+ intercalation pseudocapacitance in bulky d-MnO2 and H+ conversion reaction pathway in a wide C-rate charge-discharge range facilitates the high rate performance of high capacity d-MnO2 cathodes. The Zn-d-MnO2 system delivers discharge capacity of 136.9 mAh g-1 at 20 C and capacity retention of 92% over 4,000 cycles with joint charge storage mechanisms.

Jin, Yan↗

DOE OSTI2021

Tunable Photocatalytic Production of Syngas Using Co@C 3 N 4 and Black Phosphorus

Photocatalytic syngas production is an attractive option to efficiently generate a feedstock for the Fischer-Tropsch processes that can produce liquid fuels and other chemicals. Here, one-pot photocatalytic production of syngas (H 2 +CO) with specific and controllable ratios of H 2 /CO has proven to be a significant challenge to date. In this work, single Co 2+ sites loaded onto carbon nitride (Co@C 3 N 4 ) is combined with black phosphorus (BP) to form a hybrid material, which is capable of simultaneous photocatalytic evolution of H 2 and CO. H 2 /CO syngas ratios can be controlled in the range from 0.30 to 5.16 by changing the % weight of BP in this system or by the addition of CoCl 2 in the reaction solution. Maximum total gas evolution of 70 μmol g –1 h –1 was achieved with 20 wt % BP (BP 20% /Co@C 3 N 4 ) at a H 2 /CO ratio of 2.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2026

Ozonolysis of selenium: an alternative oxidation method for radiochemical separations of arsenic and selenium

Many arsenic and selenium radiochemical separation methods use hydrogen peroxide (H 2 O 2 ) to oxidize selenite (Se(IV)) to selenate (Se(VI)), but this reaction is challenging to control and replicate. Here, this study introduces a simple ozonolysis apparatus with an in-line oxygen-ozone generator and impinger system for rapid selenium oxidation in aqueous samples as an alternative to H 2 O 2 . The system quickly converts Se(IV) to Se(VI), enabling successful separations of arsenic-73 and selenium-75 with high recoveries using ion-exchange chromatography (1-X8). Compared to traditional H 2 O2 treatment, ozone oxidation is a faster and more easily controlled method for selenium redox chemistry.

and nuclear chemistry↗

DOE OSTI2025

Chaotrope-Based Approach for Rapid In Vitro Assembly and Loading of Bacterial Microcompartment Shells

Bacterial microcompartments (BMCs) are proteinaceous organelles that self-assemble into selectively permeable shells that encapsulate enzymatic cargo. BMCs enhance catalytic pathways by reducing crosstalk among metabolites, preventing harmful intermediates from leaking into the cytosol and increasing reaction efficiency via enzyme colocalization. The intrinsic properties of BMCs make them attractive for biotechnological engineering. However, in vivo expression methods for shell synthesis have significant drawbacks that limit the potential design space for these nanocompartments. Here, we describe the development of an efficient and rapid method for the in vitro assembly of BMC shells from their protein building blocks. Our method enables large-scale construction of BMC shells by utilizing urea as a chaotropic agent to control self-assembly and provides an approach for encapsulation of both biotic and abiotic cargo under a broad range of reaction conditions. We demonstrate an enhanced level of control over the assembly of BMC shells in vitro and expand the design parameter space for engineering BMC systems with specialized and enhanced catalytic properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2020

Catalytic bias in oxidation–reduction catalysis

Cataytic bias refers to the propensity of a reaction catalyst to effect a different rate acceleration in one direction versus the other in a chemical reaction under non-equilibrium conditions. In biocatalysis, the inherent bias of an enzyme is often advantagous to augment the innate thermodynamics of a reaction to promote efficiency and fidelity in the coordination of catabolic and anabolic pathways. In industrial chemical catalysis a directional cataltyic bias is a sought after property in facilitating the engineering of systems that couple catalysis with harvest and storage of for example fine chemicals or energy compounds. Interestingly, there is little information about catalytic bias in biocatalysis likely in large part due to difficulties in developing tractible assays sensitive enough to study detailed kinetics. For oxidation–reduction reactions, colorimetric redox indicators exist in a range of reduction potentials to provide a mechanism to study both directions of reactions in a fairly facile manner. The current short review attempts to define catalytic bias conceptually and to develop model systems for defining the parameters that control catalytic bias in enzyme catalyzed oxidation–reduction catalysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1977

A failure effects simulation of a low authority flight control augmentation system on a UH-1H helicopter

A two-pilot moving base simulator experiment was conducted to assess the effects of servo failures of a flight control system on the transient dynamics of a Bell UH-1H helicopter. The flight control hardware considered was part of the V/STOLAND system built with control authorities of from 20-40%. Servo hardover and oscillatory failures were simulated in each control axis. Measurements were made to determine the adequacy of the failure monitoring system time delay and the servo center and lock time constant, the pilot reaction times, and the altitude and attitude excursions of the helicopter at hover and 60 knots. Safe recoveries were made from all failures under VFR conditions. Pilot reaction times were from 0.5 to 0.75 sec. Reduction of monitor delay times below these values resulted in significantly reduced excursion envelopes. A subsequent flight test was conducted on a UH-1H helicopter with the V/STOLAND system installed. Series servo hardovers were introduced in hover and at 60 knots straight and level. Data from these tests are included for comparison.

Corliss, L. D.↗

NASA NTRS1978

The 200-kilowatt wind turbine project

The three 200 kilowatt wind turbines described, compose the first of three separate systems. Proposed wind turbines of the two other systems, although similar in design, are larger in both physical size and rated power generation. The overall objective of the project is to obtain early operation and performance data while gaining initial experience in the operation of large, horizontal-axis wind turbines in typical utility environments. Several of the key issues addressed include the following: (1) impact of the variable power output (due to varying wind speeds) on the utility grid (2) compatibility with utility requirements (voltage and frequency control of generated power) (3) demonstration of unattended, fail-safe operation (4) reliability of the wind turbine system (5) required maintenance and (6) initial public reaction and acceptance.

Source record↗

NASA NTRS1982

Aerodynamic comparisons of STS-1 Space Shuttle entry vehicle

A conventional flight-test program, which slowly and cautiously approaches more severe flight conditions, was not possible with the Orbiter. On the first flight, the Orbiter entered the atmosphere at Mach 28 and decelerated through the Mach range. (The subsonic portion of flight was also flown by another orbiter vehicle during the Approach and Landing Test Program.) Certification for the first flight was achieved by an extensive wind-tunnel test and analysis program and by restricting the flight maneuvers severely. The initial flights of the orbiter were heavily instrumented for the purpose of obtaining accurate aerodynamic data. Even without maneuvers to excite the system, the first flight provided comparisons between flight and wind-tunnel-derived predicted data in the areas of aerodynamic performance, longitudinal trim, and reaction-control jet interaction. The aerodynamic performance comparisons are presented.

Young, J. C.↗

NASA NTRS1987

Temperature variable long path cell for absorption measurements

The design and construction of a long path cell for absorption measurements at temperatures ranging from 215-470 K and at pressures from vacuum to 10 atm are described. The cell consists of three concentric stainless-steel tubes; the innermost tube is 6.5-in. in internal diameter, has a volume of about 47 l, and contains White-type optics, six thermocouples, and a gas input tube; and the outermost tube provides a vacuum Dewar around the inner assembly. The optical design and temperature control system for the long path temperature variable cell are examined. The long path cell is applicable for analyzing temperature and pressure dependence of spectra and reaction rates of gases, and the cell has flow and photolysis capabilities for studying transient species and photochemically initiated reactions. A diagram of the cell is provided.

Shetter, R. E.↗

NASA NTRS1988

Spacecraft redesign to reduce microphonic response of a VCO component

Reaction wheel vibration was found to induce out of specification sidebands on the carrier frequencies of some spacecraft components containing mechanical voltage control oscillators (VCOs). Concurrent investigations were performed to redesign the VCOs to reduce their response to the wheel vibration, and to design a reaction wheel isolation system to reduce the vibration input to the affected components. Component level tests indicated that both efforts provided viable solutions. The redesigned VCO will be incorporated into future spacecraft in the series, while affected spacecraft already in production will be retrofitted with the reaction wheel isolation system.

Strain, J. C.↗

NASA NTRS1987

Attitude control of a three rotor gyrostat in the presence of uncertainty

A nonlinear control law for large angle rotational maneuvers of spacecraft using reaction wheels in the presence of uncertainty is presented. The derivation of this suboptimal control law does not require any information on the values of the system parameters and the disturbance torques acting on the spacecraft. The controller includes a dynamic system in the feedback path. The control law is a nonlinear function of the attitude error, the rate of the attitude error and the compensator state. Simulation results are presented to show that large angle rotational maneuvers can be performed in spite of the uncertainty in the system.

Singh, Sahjendra N.↗