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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 1,513 records · Page 84
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Development of a CFD code for casting simulation

Because of high rejection rates for large structural castings (e.g., the Space Shuttle Main Engine Alternate Turbopump Design Program), a reliable casting simulation computer code is very desirable. This code would reduce both the development time and life cycle costs by allowing accurate modeling of the entire casting process. While this code could be used for other types of castings, the most significant reductions of time and cost would probably be realized in complex investment castings, where any reduction in the number of development castings would be of significant benefit. The casting process is conveniently divided into three distinct phases: (1) mold filling, where the melt is poured or forced into the mold cavity; (2) solidification, where the melt undergoes a phase change to the solid state; and (3) cool down, where the solidified part continues to cool to ambient conditions. While these phases may appear to be separate and distinct, temporal overlaps do exist between phases (e.g., local solidification occurring during mold filling), and some phenomenological events are affected by others (e.g., residual stresses depend on solidification and cooling rates). Therefore, a reliable code must accurately model all three phases and the interactions between each. While many codes have been developed (to various stages of complexity) to model the solidification and cool down phases, only a few codes have been developed to model mold filling.

Murph, Jesse E.↗
NASA NTRS1996

Momentum Transfer Studies and Studies of Linear and Nonlinear Optical Properties of Metal Colloids and Semiconductor Quantum Dots

Phase 1 of this work involved design work on a momentum transfer device. The progress on design and testing will be presented. Phase 2 involved the systematic study of the MPD thruster for dual uses. Though it was designed as a thruster for space vehicles, the characteristics of the plasma make it an excellent candidate for industrial applications. This project sought to characterize the system for use in materials processing and characterization. The surface modification on ZnCdTe, CdTe, and ZnTe will be presented. Phase 3 involved metal colloids and semiconductor quantum dots. One aspect of this project involves a collaborative effort with the Solid State Division of ORNL. The thrust behind this research is to develop ion implantation for synthesizing novel materials (quantum dots wires and wells, and metal colloids) for applications in all optical switching devices, up conversion, and the synthesis of novel refractory materials. The ions of interest are Au, Ag, Cd, Se, In, P, Sb, Ga, and As. The specific materials of interest are: CdSe, CdTe, InAs, GaAs, InP, GaP, InSb, GaSb, and InGaAs. A second aspect of this research program involves using porous glass (25-200 A) for fabricating materials of finite size. The results of some of this work will also be reported.

Collins, W. E.↗
NASA NTRS1996

Independent Verification and Validation of Complex User Interfaces: A Human Factors Approach

The Usability Testing and Analysis Facility (UTAF) at the NASA Johnson Space Center has identified and evaluated a potential automated software interface inspection tool capable of assessing the degree to which space-related critical and high-risk software system user interfaces meet objective human factors standards across each NASA program and project. Testing consisted of two distinct phases. Phase 1 compared analysis times and similarity of results for the automated tool and for human-computer interface (HCI) experts. In Phase 2, HCI experts critiqued the prototype tool's user interface. Based on this evaluation, it appears that a more fully developed version of the tool will be a promising complement to a human factors-oriented independent verification and validation (IV&V) process.

Whitmore, Mihriban↗
DOE OSTI2017

Phase 2: Updated Geothermal Play Fairway Analysis of the Tularosa Basin, New Mexico

Play fairway analysis (PFA) methodologies, both deterministic and stochastic, are being applied for medium to low enthalpy geothermal resources in the Tularosa Basin, in south-central New Mexico. These PFA methods use datasets representative of heat, groundwater and fault-fracture related permeability to locate areas with the lowest risk of geothermal energy development. Our Phase 1 PFAs predicted several plays throughout the study area, with a range of certainty and risk, based upon legacy data. In Phase 2, new data were collected for high priority plays and integrated into the PFAs to enhance certainty and further reduce risk. Field geology, gravity surveys and alluvial fan geomorphology supplemented the understanding of geologic structure and potential permeability, while additional well sampling, geothermometry and temperature logging provided valuable information about heat in the subsurface. In order to statistically compare and contrast the layers of evidence in the Tularosa Basin with the broader Great Basin, a probabilistic Weights of Evidence analysis was conducted in parallel with the inclusive and deterministic petroleum industry logic PFA. Both methods yielded 3 similar plays, while Weights of Evidence identified 2 additional plays. A sixth play was inferred around the NASA-Aerospace Data Facility Southwest site, north-east of Las Cruces, based on a promising shallow temperature survey, geothermometers, and structural interpretations of geophysical data. Here, the White Sands Missile Range main cantonment (headquarters) play is now given high priority, along with McGregor Range, Fort Bliss, due to the discovery of relatively high geothermometer values.

15 GEOTHERMAL ENERGY↗
DOE OSTI2013

An Exploration of Mercury Soils Treatment Technologies for the Y-12 Plant - 13217

There are a number of areas at the Y-12 National Security Complex (Y-12) that have been contaminated with mercury due to historical mercury use and storage. Remediation of these areas is expected to generate large volumes of waste that are Resource Conservation and Recovery Act (RCRA) characteristically hazardous. These soils will require treatment to meet RCRA Land Disposal Restrictions (LDR) prior to disposal. URS - CH2M Oak Ridge LLC (UCOR) performed a feasibility assessment to evaluate on-site and off-site options for the treatment and disposal of mercury-contaminated soil from the Y-12 Site. The focus of the feasibility assessment was on treatment for disposal at the Environmental Management Waste Management Facility (EMWMF) located on the Oak Ridge Reservation. A two-phase approach was used in the evaluation process of treatment technologies. Phase 1 involved the selection of three vendors to perform treatability studies using their stabilization treatment technology on actual Y-12 soil. Phase II involved a team of waste management specialists performing an in-depth literature review of all available treatment technologies for treating mercury contaminated soil using the following evaluation criteria: effectiveness, feasibility of implementation, and cost. The result of the treatability study and the literature review revealed several viable on-site and off-site treatment options. This paper presents the methodology used by the team in the evaluation of technologies especially as related to EMWMF waste acceptance criteria, the results of the physical treatability studies, and a regulatory analysis for obtaining regulator approval for the treatment/disposal at the EMWMF. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2017

Synthesis of Ti Oxides at Reducing Conditions: Implications for Beamline Standards and Cosmochemistry

These initial experiments demonstrate the great potential for synthesizing customized compounds for use as standards, or in buffering experiments at reducing conditions. We are also investigating Cr and V oxides, as well as compounds containing these elements such as FeV2O4 and FeCr2O4. Oxygen fugacity exerts a major control on mineral major element chemistry and elemental valence of minerals in any plane-tary compositional system [1]. For Earth, Fe is multivalent ranging from nearly Fe0 at low fO2 in the deep mantle to Fe2+ to Fe3+ at high low fO2. For solar nebular and meteoritic materials fO2 ranges from near IW to ~10 log fO2 units below the IW buffer [1]. Phases in CAIs, for example, contain no Fe2+, but may contain Ti4+, Ti3+, or Ti2+, and Cr3+ or Cr2+, and V3+ or V2+ [1,2,3]. De-tailed study of inclusions may reveal important differences in fO2 thus reflecting different environments in the solar nebula [4]. XANES, FEG-SEM, and TEM can reveal such variations in micro and nano samples such as Stardust and cosmic dust particles [5], but successful application to reduced conditions depends upon the availability of well characterized standards. Acquiring appropriate standards for reduced phases that contain Ti3+ or Ti2+, Cr3+ or Cr2+, and V3+ or V2+ can be a challenge. Here we report our preliminary results at synthesizing reduced Ti bearing standards, and focus on the preliminary characterization.

Righter, K.↗
DOE OSTI2016

Single- and Double-Site Substitutions in Mixed-Metal Oxides: Adjusting the Band Edges Toward the Water Redox Couples

New mixed-metal oxide solid solutions, i.e., the single-metal substituted Na 2 Ta 4–y Nb y O 11 (0 ≤ y ≤ 4) and the double-metal substituted Na 2–2x Sn x Ta 4–y Nb y O 11 (0 ≤ y ≤ 4; 0 ≤ x ≤ 0.35), were investigated and used to probe the impact of composition on their crystalline structures, optical band gaps, band energies, and photocatalytic properties. The Na 2 Ta 4 O 11 (y = 1) phase was prepared by flux-mediated synthesis, while the members of the Na 2 Ta 4–y Nb y O 11 solid solution (1 ≤ y ≤ 4) were prepared by traditional high-temperature reactions. The Sn(II)-containing Na 2–2x Sn x Ta 4–y Nb y O 11 (0 ≤ y ≤ 4) solid solutions were prepared by flux-mediated ion-exchange reactions of the Na 2 Ta 4–y Nb y O 11 solid solutions within a SnCl 2 flux. The crystalline structures of both solid solutions are based on the parent Na 2 B 4 O 11 (B = Nb, Ta) phases and consist of layers of edge-shared BO 7 pentagonal bipyramids that alternate with layers of isolated BO 6 octahedra surrounded by Na(I) cations. Rietveld refinements of the Na 2 Ta 4–y Nb y O 11 solid solution showed that Nb(V) cations were disordered equally over both the BO 7 and BO 6 atomic sites, with a symmetry-lowering distortion from R$\overline{3c}$ to C2/c occurring at ~67–75% Nb (y = ~2.7–3.0). A red-shift in the optical band gaps from ~4.3 to ~3.6 eV is observed owing to a new conduction band edge that arises from the introduction of the lower-energy Nb 4d-orbitals. Reactions of these phases within a SnCl 2 flux yielded the new Na 2–2x Sn x Ta 4–y Nb y O 11 solid solution with Sn-content varying from ~11% to ~21%. However, significant red-shifting of the band gap is found with increasing Nb-content, down to ~2.3 eV for Na 1.4 Sn 0.3 Nb 4 O 11 , because of the higher energy valence band edge upon incorporation of Sn(II) into the structure. Aqueous suspensions of the particles irradiated at ultraviolet–visible energies yielded the highest photocatalytic hydrogen production rates for Na 1.3 Sn 0.35 Ta 1.2 Nb 2.8 O 11 (~124 μmol H 2 ·g –1 ·h –1 ) and Na 1.4 Sn 0.3 Ta 3 NbO 11 (~105 μmol H 2 ·g –1 ·h –1 ), i.e., for the compositions with the highest Sn(II)-content. Further, polycrystalline films show n-type anodic photocurrents under ultraviolet–visible light irradiation. These results show that the valence and conduction band energies can be raised and lowered, respectively, using single-metal and double-metal substituted solid solutions. Furthermore, a novel approach is revealed for achieving smaller visible-light bandgap sizes and a closer bracketing of the water redox couples in order to drive total water splitting reactions that are critical for efficient solar energy conversion.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1991

The development of a program analysis environment for Ada: Reverse engineering tools for Ada

The Graphical Representations of Algorithms, Structures, and Processes for Ada (GRASP/Ada) has successfully created and prototyped a new algorithm level graphical representation for Ada software, the Control Structure Diagram (CSD). The primary impetus for creation of the CSD was to improve the comprehension efficiency of Ada software and thus improve reliability and reduce costs. The emphasis was on the automatic generation of the CSD from Ada source code to support reverse engineering and maintenance. The CSD has the potential to replace traditional prettyprinted Ada source code. In Phase 1 of the GRASP/Ada project, the CSD graphical constructs were created and applied manually to several small Ada programs. A prototype (Version 1) was designed and implemented using FLEX and BISON running under the Virtual Memory System (VMS) on a VAX 11-780. In Phase 2, the prototype was improved and ported to the Sun 4 platform under UNIX. A user interface was designed and partially implemented. The prototype was applied successfully to numerous Ada programs ranging in size from several hundred to several thousand lines of source code. In Phase 3 of the project, the prototype was prepared for limited distribution (GRASP/Ada Version 3.0) to facilitate evaluation. The user interface was extensively reworked. The current prototype provides the capability for the user to generate CSD from Ada source code in a reverse engineering mode with a level of flexibility suitable for practical application.

Cross, James H., II↗
NASA NTRS1990

ART/Ada and CLIPS/Ada

Although they have reached a point of commercial viability, expert systems were originally developed in artificial intelligence (AI) research environments. Many of the available tools still work best in such environments. These environments typically utilize special hardware such as LISP machines and relatively unfamiliar languages such as LISP or Prolog. Space Station applications will require deep integration of expert system technology with applications developed in conventional languages, specifically Ada. The ability to apply automation to Space Station functions could be greatly enhanced by widespread availability of state-of-the-art expert system tools based on Ada. Although there have been some efforts to examine the use of Ada for AI applications, there are few, if any, existing products which provide state-of-the-art AI capabilities in an Ada tool. The goal of the ART/Ada Design Project is to conduct research into the implementation in Ada of state-of-the-art hybrid expert systems building tools (ESBT's). This project takes the following approach: using the existing design of the ART-IM ESBT as a starting point, analyze the impact of the Ada language and Ada development methodologies on that design; redesign the system in Ada; and analyze its performance. The research project will attempt to achieve a comprehensive understanding of the potential for embedding expert systems in Ada systems for eventual application in future Space Station Freedom projects. During Phase 1 of the project, initial requirements analysis, design, and implementation of the kernel subset of ART-IM functionality was completed. During Phase 2, the effort has been focused on the implementation and performance analysis of several versions with increasing functionality. Since production quality ART/Ada tools will not be available for a considerable time, and additional subtask of this project will be the completion of an Ada version of the CLIPS expert system shell developed by NASA. This tool will provide full syntactic compatibility with any eventual products of the ART/Ada design while allowing SSFP developers early access to this technology.

Culbert, Chris↗
NASA NTRS1993

Criteria for evaluation of grid generation systems

Many CFD grid generation systems are in use nationally, but few comparative studies have been performed to quantify their relative merits. A study was undertaken to systematically evaluate and select the best CFD grid generation codes available. Detailed evaluation criteria were established as the basis for the evaluation conducted. Descriptions of thirty-four separate criteria, grouped into eight general categories are provided. Benchmark test cases, developed to test basic features of selected codes, are described in detail. Scoring guidelines were generated to establish standards for measuring code capabilities, ensuring uniformity of ratings, and minimizing personal bias among the three code evaluators. Ten candidate codes were identified from government, industry, universities, and commercial software companies. A three phase evaluation was conducted. In Phase 1, ten codes identified were screened through conversations with code authors and other industry experts. Seven codes were carried forward into a Phase 2 evaluation in which all codes were scored according to the predefined criteria. Two codes emerged as being significantly better than the others: RAGGS and GRIDGEN. Finally, these two codes were carried forward into a Phase 3 evaluation in which complex 3-D multizone grids were generated to verify capability.

Ascoli, Edward P.↗
NASA NTRS2009

Citric Acid Passivation of Stainless Steel

Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

Yasensky, David↗
DOE OSTI2012

Some Beam Dynamics and Related Studies of Possible Changes to the ILC Baseline Design

Since the completion of the ILC Reference Design Report (RDR) in 2007, global R and D has continued on all ILC systems in a coordinated program titled Technical Design Phase 1. This program, which is planned and coordinated by the Program Managers and the Technical Area Group Leaders, will transition to a Phase 2 in 2010 which has the goal of producing a more complete Technical Design Report in 2012. In this transition there will be a re-baseline process which will update and or modify the RDR baseline design taking into account progress with systems design and progress with various technologies coming from the continuing R and D programs. The RDR design was considered by some to be a conservative one and many of the topics being studied for inclusion in a new baseline are directed towards more optimum cost versus risk designs. Some of these are engineering systems design modifications, both technical and civil, while others are accelerator parameters, technical system designs and beam dynamics optimizations. A few of the latter are described here.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Reducing the Cost of Thermal Energy Storage for Parabolic Trough Solar Power Plants

Thermal energy storage systems using phase change materials were evaluated for trough systems that use oil, steam, and high temperature salts as heat transfer fluids. A variety of eutectic salts and metal alloys were considered as phase change materials in a cascaded arrangement. Literature values of specific heat, latent heat, density, and other thermophysical properties were used in initial analyses. Testing laboratories were contracted to measure properties for candidate materials for comparison to the literature and for updating the models. A TRNSYS model from Phase 1 was further developed for optimizing the system, including a novel control algorithm. A concept for increasing the bulk thermal conductivity of the phase change system was developed using expanded metal sheets. Outside companies were contracted to design and cost systems using platecoil heat exchangers immersed in the phase change material. Laboratory evaluations of the one-dimensional and three-dimensional behavior of expanded metal sheets in a low conductivity medium were used to optimize the amount of thermal conductivity enhancement. The thermal energy storage systems were compared to baseline conventional systems. The best phase change system found in this project, which was for the high temperature plant, had a projected cost of $25.2 per kWhth, The best system also had a cost that was similar to the base case, a direct two-tank molten salt system.

14 SOLAR ENERGY↗
DOE OSTI2019

TA-16-0303 Crystal Grow Lab Renovation [Slides]

The LANL High Explosives (HE) Crystal Lab at TA-40 Building 12 is a unique, and nearly the sole, national resource for the growth and sample preparation of large HE single crystals and related materials. This work has outgrown is current facility and is in dire need of both additional space and modern lab technology. The goal of this project is to renovate the 1950’s era building TA-16-303 to accommodate these operations and successfully relocate them from TA-40-12. Phase 1 of this project, completed in May of 2018, was to de-energize the facility and perform clean-up / remediation activities. Phase 2, the actual renovation of the facility, is currently underway and on track to achieve Occupancy by May of 2020.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Hydrogen Storage for Flexible Fossil Fuel Power Generation: Integration of Underground Hydrogen Storage with Gas Turbine (Final Report)

As the nation continues to encourage, through market structures and financial incentives, the proliferation of intermittent renewable electricity, how to optimize the ever-changing electric grid and identify means to retain and improve resilience, while ensuring continued reductions in GHG emissions, will be critical. According to Bloomberg, wind & solar generated 10.5% of US electricity in 2020 and that percentage continues to grow. In support of expanding renewable energy use, and to address its intermittent nature, this project will develop the Hydrogen Storage for Flexible Fossil Fuel Power Generation platform that is dispatchable, reliable, repeatable and have the ability to produce zero or negative carbon power while interfacing with geology capable of CO2 and hydrogen storage. GTI Energy (GTIE) and team members Illinois State Geological Survey (ISGS), Mitsubishi Heavy Industries America (MHIA), Ameren Illinois, Hexagon Purus, and the Low Carbon Resources Initiative (LCRI) completed a Phase I Conceptual Study under contract DE-FE0032012 for Hydrogen Storage for Flexible Fossil Fuel Power Generation: Integration of Underground Hydrogen Storage with Gas Turbine. The Hydrogen Storage for Flexible Fossil Fuel Power Generation platform addresses the intermittent nature of the expanding use of Variable Renewable Energy (VRE) generation. The low cost of the electricity (COE) generated results in greater dispatch and more operation at higher power levels (higher efficiency), fewer short intervals, and fewer start/stop cycles. The reliable, resilient system can produce zero carbon power and store hydrogen. It will demonstrate hydrogen storage in geologic formations like those used in natural gas underground storage thus enabling large scale storage of hydrogen in sedimentary strata across the United States rather than in geographically restricted salt caverns. The Phase I study confirmed the system is feasible and generates power at lower cost than other low carbon approaches. The demonstration defines the pathway for broad commercial application and will accelerate the development of larger systems suitable for centralized utility scale electricity production. The study advanced the maturity of the H 2 storage-based system with flexible power generation by completing a Pre-FEED study (Phase II). The Pre-FEED focused on the selected Energy Farm on the University of Illinois Urbana-Champaign (UIUC) site that includes above ground and underground hydrogen storage, low-carbon hydrogen production (GTI’s Compact Hydrogen Generator, CHG) with underground CO2 sequestration, and a 40-MW class gas turbine. The Pre-FEED addressed the entire system and its interconnection to the natural gas and electric grid and mitigation of key risks, such as storage behavior, load-following, and system operation. During Phase 1 of the project, the team completed key tasks, which moved the entire demonstration project, specific components and approaches closer to commercialization. These Phase I Accomplishments include: Completing System Requirements Review; Completing System Layout and Modeling - Heat & Mass Balance and Process Flow Diagram; Completing modelling of 9 turbine performance cases; Evaluating rock strata for underground storage of hydrogen and sequestration of carbon dioxide; Completing initial modelling of underground storage of hydrogen and withdrawal with evaluation of loss and water production; Identifying roadable storage for above ground hydrogen storage; Identifying existing electrical infrastructure for receiving/delivering electricity; Identifying existing gas supply infrastructure for receiving natural gas; Document concept design/development plans in required reports. Conclusions: The 12-month Feasibility study in Phase I study was completed and confirmed the system is feasible and generates power at lower cost than other low carbon approaches and even lower cost than the reference NGCC plant without carbon capture when taking advantage of 45Q carbon credits. The study enabled the fidelity of the concept to be improved and allowed identification of the requirements for the system. Defining the individual system and component requirements was performed via the system requirements review with the whole team. These requirements were then incorporated into and iterated with our Heat & Mass Balance process model and process flow diagrams were generated to reflect the overall system. This information was then used to complete the TEA and show economic feasibility. Large scale non-salt geologic storage of hydrogen is an enabling technology for a hydrogen-fired turbine that can be retrofitted into large-scale electric generating units (EGU). Our demonstration will include 428 MWh or ~4 hours full load of hydrogen storage (above and underground). Carbon capture inherent to the CHG process can capture 90% CO 2 (with upgrades to >98%). This system provides a COE of 23% savings relative to an NGCC with a post combustion amine system. Our proposed storage system decouples carbon capture and hydrogen production from power production; therefore, we expect our proposed system’s efficiency and variable COE to be superior resulting in overall higher dispatch and reduced deep cycling. Our demonstration will be full to multi-day hydrogen storage and has the potential for longer (seasonal) duration commercially. The demonstration defines the pathway for broad commercial application and will accelerate the development of larger systems suitable for centralized utility scale electricity production.

03 NATURAL GAS↗
NASA NTRS1984

Transformation toughened ceramics for the heavy duty diesel engine technology program

The objective of this program is to develop an advanced high temperature oxide structural ceramic for application to the heavy duty diesel engine. The approach is to employ transformation toughening by additions of ZrO.5HfO.5O2 solid solution to the oxide ceramics, mullite (2Al2O3S2SiO2) and alumina (Al2O3). The study is planned for three phases, each 12 months in duration. This report covers Phase 1. During this period, processing techniques were developed to incorporate the ZrO.5HfO.5O2 solid solution in the matrices while retaining the necessary metastable tetragonal phase. Modulus of rupture and of elasticity, coefficient of thermal expansion, fracture toughness by indent technique and thermal diffusivity of representative specimens were measured. In Phase 2, the process will be improved to provide higher mechanical strength and to define the techniques for scale up to component size. In Phase 3, full scale component prototypes will be fabri-]cated.

Musikant, S.↗
NASA NTRS1991

A feedback control for the advanced launch system

A robust feedback algorithm is presented for a near-minimum-fuel ascent of a two-stage launch vehicle operating in the equatorial plane. The development of the algorithm is based on the ideas of neighboring optimal control and can be derived into three phases. In phase 1, the formalism of optimal control is employed to calculate fuel-optimal ascent trajectories for a simple point-mass model. In phase 2, these trajectories are used to numerically calculate gain functions of time for the control(s), the total flight time, and possibly, for other variables of interest. In phase 3, these gains are used to determine feedback expressions for the controls associated with a more realistic model of a launch vehicle. With the Advanced Launch System in mind, all calculations are performed on a two-stage vehicle with fixed thrust history, but this restriction is by no means important for the approach taken. Performance and robustness of the algorithm is found to be excellent.

Seywald, Hans↗
DOE OSTI2021

Investigation of Rare Earth Element Extraction from North Dakota Coal-Related Feedstocks (Phase 2 Final Technical Report)

There were four major goals of this project: i) identify promising lignite or lignite-related feedstocks with total rare earth element content above 300 parts per million (ppm), ii) evaluate at the lab and bench-scale the extractability of the REE from the material, iii) determine the processing required to generate REE concentrates in excess of 2 wt%, iv) evaluate the economic feasibility of the process and develop a pathway for commercialization. In the Phase 1 study, work was primarily focused upon resource evaluation and labscale extractability of the REE, with a preliminary techno-economic assessment (TEA) conducted, whereas in the Phase 2 work, the extraction process was conducted at the bench scale, a method for cost-effective generation of higher purity mixed REE concentrates (up to 65%) was developed, and a refined TEA on the bench-scale data for a 1,000 kg coal processing test was conducted.

01 COAL, LIGNITE, AND PEAT↗