Maximizing the Spatial Resolution for Single Crystal Diffractometer Detectors
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Wang, Jun↗
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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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Maximizing Efficiency and Quality: Leveraging Automated Testing for Laboratory Commissioning
The traditional commissioning process for a building often implements sampling rates to select equipment for functional acceptance testing when large quantities of equipment are present. While this approach is generally effective in identifying wide-spread issues, it has several key shortfalls. (1) It provides a one-time validation of equipment operation in which the standard documentation is a simple checklist of pass/fail questions. (2) It fails to evaluate equipment not included in the sample rate selection. During the construction and commissioning process of the new Research and Innovation Laboratory (RAIL) in Golden, CO, the National Renewable Energy Laboratory team engaged Group14 Engineering to implement a Connected Commissioning process using fault detection and diagnostic software for automated functional acceptance testing. The goal of this presentation will be to highlight the advantages offered by automated functional testing in this critical laboratory setting. These are primarily (1) sampling 100% of BAS-connected equipment during functional testing, (2) testing results backed by data beyond the traditional pass/fail checklist, and (3) an automated test process that can be regularly executed by the building management team for ongoing commissioning throughout the life of the building. The presentation will also cover technical challenges associated with connected commissioning and the important conversations with the key stakeholders that need to occur well before functional acceptance testing in order to successfully implement the automated testing processes.
automated testing↗
Development of a low cost, low maintenance Maximal Asymmetric Drag Wave Energy Converter (MADWEC)
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clean energy↗
Maximizing Demand Flexibility with Buildings and FERC 2222
In 2020, the Federal Energy Regulatory Commission (FERC) approved a rule, Order 2222, that requires market operators to create pathways enabling distributed energy resource aggregators (DERAs) to compete in all regional organized wholesale electric markets. The goal is to encourage various forms of distributed energy resources (DERs) to participate in electricity markets in a way that would enhance competition, encourage innovation, and drive down costs for consumers. In this document, we briefly discuss how FERC Order 2222 affects the opportunities for participation in electricity markets for building owners and operators, the role of aggregators, and the involvement of buildings in the electricity market.
demand flexibility↗
Refining Absorber Shroud Geometry to Maximize Power Output and Reduce Power Peaking in ATF Test Train
In the wake of the Fukushima Daiichi nuclear power plant accident in 2011, the accident tolerant fuels (ATF) program was initiated to enhance the safety of light-water reactor fuels, placing significant emphasis on cladding. A crucial step for the broad implementation of ATF in commercial reactors involves irradiation testing of the fuel designs. ATF-2D, the latest experiment in the ATF series, is slated to undergo irradiation in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). ATF-2D is a joint effort of the INL with industry partners General Electric Global Research; Framatome; General Atomics; the Japan Atomic Energy Agency; Hitachi-GE Nuclear Energy, Ltd; Global Nuclear Fuel-Japan Co., Ltd; Nippon Nuclear Fuel Development Co., Ltd; and Mitsubishi Heavy Industries, Ltd. The ATF-2D test train design consists of four tiers, each housing six rodlets. The device will be inserted in Loop 2A within the central flux trap of the ATR, and is anticipated to undergo irradiation throughout three 60-day cycles. Typical pressurized water reactor conditions will be emulated during the irradiation. The objective of the work presented here is to dimension neutron-absorbing hafnium (Hf) components surrounding the fuel rodlets, such that the axial power profile is flattened, while simultaneously ensuring that the total fission power output of the entire test train remains below 200 kW.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Refining Absorber Shroud Geometry to Maximize Power Output and Reduce Power Peaking in ATF Test Train
In the wake of the Fukushima Daiichi nuclear power plant accident in 2011, the accident tolerant fuels (ATF) program was initiated to enhance the safety of light-water reactor fuels, placing significant emphasis on cladding. A crucial step for the broad implementation of ATF in commercial reactors involves irradiation testing of the fuel designs. ATF-2D, the latest experiment in the ATF series, is slated to undergo irradiation in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). ATF-2D is a joint effort of the INL with industry partners General Electric Global Research; Framatome; General Atomics; the Japan Atomic Energy Agency; Hitachi-GE Nuclear Energy, Ltd; Global Nuclear Fuel-Japan Co., Ltd; Nippon Nuclear Fuel Development Co., Ltd; and Mitsubishi Heavy Industries, Ltd. The ATF-2D test train design consists of four tiers, each housing six rodlets. The device will be inserted in Loop 2A within the central flux trap of the ATR, and is anticipated to undergo irradiation throughout three 60-day cycles. Typical pressurized water reactor conditions will be emulated during the irradiation. The objective of the work presented here is to dimension neutron-absorbing hafnium (Hf) components surrounding the fuel rodlets, such that the axial power profile is flattened, while simultaneously ensuring that the total fission power output of the entire test train remains below 200 kW.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Reinforcement Learning for Distance Maximization in Energy-Constrained Robots
Our goal is to teach a robot to walk in an energy efficient way. Inspired by nature [1], we create a reinforcement learning method that balances distance traveled and energy consumption, which we call “utility.” Further, each step is symmetric to ensure equal strides while walking straight. We achieve our goal by rewarding decisions that lead to the best utility over several training iterations.
Pereira, Luiz Manella↗
Maximizing Efficiency and Quality: Leveraging Automated Testing for Laboratory Commissioning
The traditional commissioning process uses sampling to select equipment for functional acceptance testing when large quantities of equipment are present. Although this approach is generally effective in identifying wide-spread issues, it has several shortcomings: it fails to evaluate equipment not included in the sample, provides only a one-time validation of equipment operation, and the standard documentation is a simple checklist of pass/fail questions. During the construction and commissioning process of the new Research and Innovation Laboratory (RAIL) in Golden, CO, the National Renewable Energy Laboratory team engaged Group14 Engineering to implement a Connected Commissioning process using fault detection and diagnostic software for automated functional acceptance testing. This presentation highlights the advantages offered by automated functional testing in this critical laboratory setting: (1) sampling 100% of BAS-connected equipment during functional testing, (2) testing results backed by data beyond the traditional pass/fail checklist, and (3) an automated test process that can be regularly executed by the building management team for ongoing commissioning throughout the life of the building. The presentation will also cover technical challenges associated with Connected Commissioning and the important conversations with key stakeholders that need to occur well before functional acceptance testing in order to successfully implement the automated testing processes.
automated testing↗
Maximizing the Benefits of On-Site Renewable Energy Generation Using On-Site Energy Storage
The commercial and industrial building sectors have a major role to play in a U.S. low-carbon future. Building owners can make a difference by deploying on-site renewable generation and storage technologies, which facilitates future-proofing their buildings as well as more effectively meeting the service requirements of the building. This resource provides an overview of common generation, storage, and load management technologies in behind-the-meter systems, and serves as a primer to demonstrate the impact on net building loads required from the grid for different sizes of renewable generation along with on-site electrical and thermal storage. These discussions can help commercial building owners communicate the value of these systems to project teams and develop innovative behind-the-meter solutions to achieve their energy goals.
ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION↗
Maximizing the Spatial Resolution for Single Crystal Diffractometer Detectors
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Wang, Jun↗
Joint Optimization of Well Completions and Controls for CO 2 Enhanced Oil Recovery and Storage
CO 2 storage through CO 2 enhanced oil recovery (EOR) is considered as one of the technologies to help promote larger scale deployment of CO 2 storage because of associated economic benefits through oil recovery, 45Q tax credits and the utilization of existing infrastructure. The objective of this study is to demonstrate how optimal reservoir management and operation strategies (including well completions and controls) can be used to optimize both CO 2 storage and oil recovery. The optimization problem was focused on jointly estimating the well completions (i.e., fraction of injection/production well perforations in each reservoir layer) and CO 2 injection/oil production controls that maximize the net present value (NPV) in a CO 2 EOR and storage operation. We utilized the newly developed StoSAG algorithm, one of the most efficient optimization algorithms in the reservoir management community, to solve the optimization problem. The performance of joint optimization approach was compared with the performance of well control only optimization approach. In addition, the performance of co-optimization of CO 2 storage and oil recovery approach was compared with the performances of maximization of only CO 2 storage and maximization of only oil recovery approaches. The optimization results showed that a joint optimization of well completions and well controls can achieve an 8.84% higher final NPV than the one obtained from the optimization of only well controls. It was observed that the NPV incremental for joint optimization is mainly due to the fact that the optimal well completions and controls approach results in efficient CO 2 storage and oil production from different reservoir layers depending on the differences in individual layer properties. Comparison of co-optimization (i.e., maximization of NPV) and maximization of only CO 2 storage or only oil recovery showed that the co-optimization and maximization of only oil recovery result in significantly higher final NPV than that obtained through maximization of only CO 2 storage approach while maximization of only CO 2 storage can achieve significantly higher CO 2 storage in the reservoir compared to the other two scenarios. The similar results for co-optimization and maximization of oil production are obtained because of the difference in oil revenue compared to CO 2 storage tax credit. To the best of our knowledge, this is the first study in oil/gas industry and CO 2 storage community to perform joint optimization of well completions and well controls in the fields. We expect that the proposed optimization framework will be a useful and efficient tool for field engineers to optimally manage CO 2 EOR projects to maximize revenue through oil recovery as well as CO 2 storage by taking advantage of the new 45Q tax law.
Artificial intelligence↗
Handgrip and general muscular strength and endurance during prolonged bedrest with isometric and isotonic leg exercise training
Measurements of maximal grip strength and endurance at 40 percent max strength were obtained for 7 men 19-21 years of age, 1-2 days before and on the first recovery day during three 2-week bedrest (BR) periods, each separated by a 3-week ambulatory recovery period. The subjects performed isometric exercise (IME) for 1 hr/day, isotonic exercise (ITE) for 1 hr/day, and no exercise (NOE) in the three BR periods. It was found that the mean maximal grip strength was unchanged after all three BR periods. Mean grip endurance was found to be unchanged after IME and ITE training, but was significantly reduced after NOE. These results indicate that IME and ITE training during BR do not increase or decrease maximal grip strength, alghough they prevent loss of grip endurance, while the maximal strength of all other major muscle groups decreases in proportion to the length of BR to 70 days. The maximal strength reduction of the large muscle groups was found to be about twice that of the small muscle groups during BR. In addition, it is shown that changes in maximal strength after spaceflight, BR, or water immersion deconditioning cannot be predicted from changes in submaximal or maximal oxygen uptake values.
Greenleaf, J. E.↗
Effect of Exercise Training and +Gz Acceleration Training on Men
Countermeasures for reduction in work capacity (maximal oxygen uptake and strength) during spaceflight and enhanced orthostatic intolerance during re-entry, landing and egress from the return vehicle are continuing problems. The purpose for this study was to test the hypothesis that passive-acceleration training; supine, interval, exercise plus acceleration training and exercise combined with acceleration training would improve orthostatic tolerance in ambulatory men; and that addition of the aerobic exercise conditioning would not alter this improved tolerance from that of passive-acceleration training. Seven men (24-38 yr) underwent "Passive" training on the Ames human-powered centrifuge (HPC) for 30 min, "Exercise" training on the cycle ergometer with constant +Gz acceleration; and "Combined" exercise training at 40% to 90% of the HPC +Gz(max) exercise level. Maximal supine exercise loads increased significant (P<0.05) by 8.3% (Passive), 12.6% (Exercise), and by 15.4% (Combined) after training, but their post-training maximal oxygen uptakes and maximal heart rates were unchanged. Maximal time to fatigue (endurance) was unchanged with Passive was increased (P<0.05) with Exercise and Combined training. Thus, the exercise in the Exercise and Combined training Phases resulted in greater maximal loads and endurance without effect on maximal oxygen uptake or heart rate. There was a 4% to 6% increase (P<0.05) in all four quadriceps muscle volumes (right and left) after post-Combined training. Resting pre-tilt heart rate was elevated by 12.9% (P<0.05) only after Passive training suggesting that the exercise training attenuated the HR response. Plasma volume (% Delta) was uniformly decreased by 8% to 14% (P<0.05) at tilt-tolerance pre- vs. post-training indicating essentially no effect of training on the level of hypovolemia. Post-training tilt-tolerance time and heart rate were increased (P<0.05) only with Passive training by 37.8% and by 29.1%, respectively. Thus, addition of exercise training appeared to attenuate the increased Passive tilt-tolerance.
Greenleaf, John E.↗
Effects of Water Limitation and Competition on Tree Carbon Allocation in an Earth System Modeling Framework
Earth system models (ESMs) have a limited capacity to represent plant functional diversity and shifts in trait distributions. Approaches to improving the representation of this complexity in ESMs include (i) optimality-based approaches that predict trait–environment responses and (ii) explicitly modelling coexistence and community assembly. These approaches are expected to converge only when optimality-based approaches identify competitively dominant strategies, which often differ from strategies that maximize ecosystem functioning or fitness components in monoculture. We used two models, LM3-PPA (a vegetation demographic model designed as an ESM component) and BiomeE (a computationally efficient analog for LM3-PPA), to explore how water limitation affects carbon allocation strategies of canopy trees. We compared competitive allocation strategies and those that maximize biomass or productivity in monoculture. We did not explicitly model coexistence or community assembly. Rather, we used model experiments to identify competitive and maximizing strategies in a two-dimensional trait space under different precipitation and mortality scenarios. At 10 eastern US locations, we simulated historical, wet and dry climate scenarios, novel drought and three different mortality scenarios (low, medium or high sensitivity to water deficit). For each site and scenario, we identified the competitive strategy and three maximizing strategies (maximum biomass, productivity or drought-tolerance). Root: leaf ratios tended to increase and leaf area tended to decrease with increasing water stress (increasing water limitation and its effects on mortality). However, relative to maximizing strategies, competitive strategies shifted towards greater allocation to roots and leaves with increasing water stress. Competitive overinvestments (greater allocation to roots and leaves by competitive strategies compared with maximizing strategies) were robust across different modelling contexts, including vegetation parameter sets (Acer vs. Populus), models (LM3-PPA vs. BiomeE) and uncalibrated vs. calibrated BiomeE versions. Synthesis: The theoretical prediction that competitive and maximizing allocation strategies differ under water limitation is confirmed for a demographic model designed as an ESM component. Optimality-based trait predictions can simplify representing trait diversity in ESMs but do not always correspond to competitive outcomes. Explicitly modelling coexistence and community assembly in ESMs is challenging but is likely the most general approach to representing trait diversity.
vegetation demographic model↗
Techno-Economic Viability of Flexible Dispatch of Unconventional Geothermal Systems
Flexible geothermal operations could boost project returns through the allocation of improved power purchase agreements and/or exploitation of power price arbitrage opportunities. In this study, we investigated the techno-economic feasibility of variable flow rate control and time-of-day pricing in closed-loop geothermal systems. We considered U-shaped multilateral system configurations and modeled a variety of technical system parameters. These designs were simulated using a slender-body theory (SBT) model for transient heat transfer and fluid flow. This subsurface model was integrated into the flexible geothermal economic model (FGEM) tool to evaluate the overall flexible geothermal system techno-economics. Future hourly ambient temperature conditions were based on the Sup3rCC dataset. Published datasets were used for future hourly wholesale electricity prices. We analyzed four operating strategies: 1) baseload operation, 2) seasonal dispatch (high flow rate during summer and nominal flow rate during the rest of the year), 3) net generation maximization by varying flow rate to maximize net power output, and 4) revenue maximization by varying flow rate to maximize revenue. We ran all four scenarios for a multiloop configuration with 12 lateral passes, 7-km vertical depth and 87-km total drilling length. Furthermore, we assumed a 60 degrees C/km geothermal gradient and ambient temperature and wholesale electricity prices for New Mexico as a typical state location. The nominal flow rate was set to 80 kg/s. When considering drilling costs of $1,000/m and a discount rate of 7%, the generation maximization scenario resulted in the lowest levelized cost of electricity (LCOE) of ~$150/MWh. When considering project return on investment (ROI), defined as lifetime net income divided by upfront capital costs, all flexible operation scenarios performed better than the base case scenario. The highest ROI of 80% was obtained with the revenue maximization scenario. With drilling costs of $200/m and a discount rate of 5%, the generation maximization scenario resulted in LCOE of $49/MWh.
flexible geothermal↗
High Resolution X-ray Imaging
NAG5-5020 covered a period of 7.5 years during which a great deal of progress was made in x-ray optical techniques under this grant. We survived peer review numerous times during the effort to keep the grant going. In 1994, when the grant started we were actively pursuing the application of spherical mirrors to improving x-ray telescopes. We had found that x-ray detectors were becoming rapidly more sophisticated and affordable, but that x-ray telescopes were only being improved through the intense application of money within the AXAF program. Clearly new techniques for the future were needed. We were successful in developing and testing at the HELSTF facility in New Mexico a four reflection coma-corrected telescope made from spheres. We were able to demonstrate 0.3 arcsecond resolution, almost to the diffraction limit of the system. The community as a whole was, at that time, not particularly interested in looking past AXAF (Chandra) and the effort needed to evolve. Since we had reached the diffraction limit using non-Wolter optics we then decided to see if we could build an x-ray interferometer in the laboratory. In the lab the potential for improved resolution was substantial. If synthetic aperture telescopes could be built in space, then orders of magnitude improvement would become feasible. In 1998 NASA, under the direction of Dr Nick White of Goddard, started a study to assess the potential and feasibility of x-ray interferometry in space. My work became of central interest to the committee because it indicated that such was possible. In early 1999 we had the breakthrough that allowed us build a practical interferometer. By using flats and hooking up with the Marshall Space Flight Center facilities we were able to demonstrate fringes at 1.25keV on a one millimeter baseline. This actual laboratory demonstration provided the solid proof of concept that NASA needed. As the year progressed the future of x-ray astronomy jelled around the Maxim program. Maxim is a set of two major x-ray astronomy missions based on the concepts I developed and demonstrated under this SR&T grant. The first Maxim is to image the sky at 100 micro-arcsecond resolution. That is one thousand times higher resolution than Hubble. The full Maxim has the ultimate goal of imaging the event horizon of a black hole in an active galactic nucleus (ALAN). This will require 0.1 micro-arcsecond resolution - one million times higher than Hubble! Nonetheless, using the techniques developed under this grant, it has become possible. Maxim Pathfinder is now in the NASA planning for a new start in approximately 20 10. The full Maxim is carried as a vision mission for the post 2015 timeframe. Finally, this grant is the evolved version of the SR&T grant we carried during the 1980s and up to 1994. At that point in time this grant was also working on x-ray optics, but concentrating on x-ray spectroscopy. The techniques developed by 1990 were not chosen for use on Chandra or XMM-Newton because they were too new. During the last year, however, the Constellation-X mission recognized the need for better spectroscopy techniques and tapped our expertise. We were able to support the initial work on Con-X through this program. It now appears that the off-plane mount will be used in Con-X, increasing performance and decreasing cost and risk.
Cash, Webster↗
Aerodynamic Rotor Design for a 25 MW Offshore Downwind Turbine
Continuously increasing offshore wind turbine scales require rotor designs that maximize power and performance. Downwind rotors offer advantages in lower mass due to reduced potential for tower strike, and is especially true at large scales, e.g., for a 25 MW turbine. In this study, three 25 MW downwind rotors, each with different prescribed lift coefficient distributions were designed (chord, geometry, and twist) and compared to maximize power production at unprecedented scales and Reynolds numbers, including a new approach to optimize rotor tilt and coning based on aeroelastic effects. To achieve this objective the design process was focused on achieving high power coefficients, while maximizing swept area and minimizing blade mass. Maximizing swept area was achieved by prescribing pre-cone and shaft tilt angles to ensure the aeroelastic orientation when the blades point upwards was nearly vertical at nearly rated conditions. Maximizing the power coefficient was achieved by prescribing axial induction factor and lift coefficient distributions which were then used as inputs for an inverse rotor design tool. The resulting rotors were then simulated to compare performance and subsequently optimized for minimum rotor mass. To achieve these goals, a high Reynolds number design space was developed using computational predictions as well as new empirical correlations for flatback airfoil drag and maximum lift. Within this design space, three rotors of small, medium and large chords were considered for clean airfoil conditions (effects of premature transition were also considered but did not significantly modify the design space). The results indicated that the medium chord design provided the best performance, producing the highest power in Region 2 from simulations while resulting in the lowest rotor mass, both of which support minimum LCOE. The methodology developed herein can be used for the design of other extreme-scale (upwind and downwind) turbines.
downwind rotors↗
Cardiorespiratory deconditioning with static and dynamic leg exercise during bed rest
Results are presented for an experimental study designed to compare the effects of heavy static and dynamic exercise training during 14 days of bed rest on the cardiorespiratory responses to submaximal and maximal exercise performed by seven healthy men aged 19-22 yr. The parameters measured were submaximal and maximal oxygen uptake, minute ventilation, heart rate, and plasma volume. The results indicate that exercise alone during bed rest reduces but does not eliminate the reduction in maximal oxygen uptake. An additional positive hydrostatic effect is therefore necessary to restore maximal oxygen uptake to ambulatory control levels. The greater protective effect of static exercise on maximal oxygen uptake is probably due to a greater hydrostatic component from the isometric muscular contraction. Neither the static nor the dynamic exercise training regimes are found to minimize the changes in all the variables studied, thereby suggesting a combination of static and dynamic exercises.
Stremel, R. W.↗