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At least 1,351 records · Page 75

Commercial Cargo Derivative Study of the Advanced Hybrid Wing Body Configuration with Over-Wing Engine Nacelles

LM has leveraged our partnership with the Air Force Research Laboratory (AFRL) and NASA on the advanced hybrid wing body (HWB) concept to develop a commercial freighter which addresses the NASA Advanced Air Transport Technology (AATT) Project goals for improved efficiency beyond 2025. The current Air Force Research Laboratory (AFRL) Revolutionary Configurations for Energy Efficiency (RCEE) program established the HWB configuration and technologies needed for military transports to achieve aerodynamic and fuel efficiencies well beyond the commercial industry's most modern designs. This study builds upon that effort to develop a baseline commercial cargo aircraft and two HWB derivative commercial cargo aircraft to quanitify the benefit of the HWB and establish a technology roadmap for further development.

Hooker, John R.↗

International Space Station Evolution Data Book: Baseline Design - Volume 1

The International Space Station (ISS) will provide an Earth-orbiting facility that will accommodate engineering experiments as well as research in a microgravity environment for life and natural sciences. The ISS will distribute resource utilities and support permanent human habitation for conducting this research and experimentation in a safe and habitable environment. The objectives of the ISS program are to develop a world-class, international orbiting laboratory for conducting high-value scientific research for the benefit of humans on Earth; to provide access to the microgravity environment; to develop the ability to live and work in space for extended periods; and to provide a research test bed for developing advanced technology for human and robotic exploration of space. The current design and development of the ISS has been achieved through the outstanding efforts of many talented engineers, designers, technicians, and support personnel who have dedicated their time and hard work to producing a state-of-the-art Space Station. Despite these efforts, the current design of the ISS has limitations that have resulted from cost and technology issues. Regardless, the ISS must evolve during its operational lifetime to respond to changing user needs and long-term national and international goals. As technologies develop and user needs change, the ISS will be modified to meet these demands. The design and development of these modifications should begin now to prevent a significant lapse in time between the baseline design and the realization of future opportunities. For this effort to begin, an understanding of the baseline systems and current available opportunities for utilization needs to be achieved. Volume I of this document provides the consolidated overview of the ISS baseline systems. It also provides information on the current facilities available for pressurized and unpressurized payloads. Information on current plans for crew availability and utilization; resource timelines and margin summaries including power, thermal, and storage volumes; and an overview of the ISS cargo traffic and the vehicle traffic model is also included.

Jorgensen, Catherine A.↗

Baseline Radiological Conditions for the Transient Reactor Test (TREAT) Restart

The Transient Reactor Test (TREAT) facility, located on the Idaho National Laboratory (INL), northwest of the Materials and Fuels Complex (MFC), has been in programmatic shutdown for more than twenty-three years. Construction of TREAT by the Teller Construction Co., Portland, Oregon, was started in February, 1958, and completed in early November, 1958. The reactor first achieved criticality on February 23, 1959. Operations continued until April 28, 1994, when the reactor was shut down due to the lack of a programmatic mission. Recently, the U.S. Department of Energy (DOE) identified a need to resume transient testing of new reactor fuels. The Resumption of Transient Testing Program (RTTP) has readied the TREAT facility to resume transient testing operations. The first reactor criticality since the shut down in 1994 was achieved on November 14, 2017. This report details the radiological measurements taken in the TREAT Reactor Building and the surrounding environment prior to and just after its restart in order to characterize the radiological conditions that existed prior to and during the initial restart operations. The authors would like to acknowledge the support from RTTP Management and the TREAT Operations staff for allowing the extensive radiological surveys, as well as the health physics technicians from the INL Radiological Control organization who performed many of the measurements referenced in this report.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Space transfer vehicle concepts and requirements study. Volume 2, book 4: Integrated advanced technology development

The Space Transfer Vehicle (STV) program provides both an opportunity and a requirement to increase our upper stage capabilities with the development and applications of new technologies. Issues such as man rating, space basing, reusability, and long lunar surface storage times drive the need for new technology developments and applications. In addition, satisfaction of mission requirements such as lunar cargo delivery capability and lunar landing either require new technology development or can be achieved in a more cost-effective manner with judicious applications of advanced technology. During the STV study, advanced technology development requirements and plans have been addressed by the Technology/Advanced Development Working Group composed of NASA and contractor representatives. This report discusses the results to date of this working group. The first section gives an overview of the technologies that have potential or required applications for the STV and identifies those technologies baselined for the STV. Figures are provided that list the technology categories and show the priority placed on those technology categories for either the space-based or ground-based options. The second section covers the plans and schedules for incorporating the technologies into the STV program.

Weber, Gary A.↗

NASA's Initial Artemis Human Landing System

In April 2020, NASA announced the selection of three companies to begin the initial phase of development of human landing systems to take the first woman and the first person of color to the lunar surface through NASA’s Artemis lunar exploration program. The selected companies were a Blue Origin-led team with Lockheed Martin, Northrup Grumman, and Draper; Dynetics (a Leidos company); and SpaceX. Contracts were awarded shortly after, kicking off a ten-month base period during which NASA worked closely with each company to finalize functional and performance requirements, confirm lander development standards, and establish baseline designs, schedules, and management plans for contract execution and human spaceflight certification. At the end of the base period, in the Spring of 2021, NASA awarded a single follow-on Option A contract to SpaceX to continue their work on Human Landing System (HLS) Starship development. Currently NASA and SpaceX are working collaboratively on Option A which will ultimately culminate in one uncrewed and one crewed mission to the lunar surface under Artemis III. This paper will provide a look at the Option A phase of development for the Human Landing System Program, including publicly available information on SpaceX’s HLS Starship design as well as near-term and future milestones for HLS and the Artemis program.

Lisa Watson-Morgan↗

Solid polymer electrolyte (SPE) fuel cell technology program, phase 2/2A

Test evaluations were performed on a fabricated single solid polymer electrolyte cell unit. The cell operated at increased current density and at higher performance levels. This improved performance was obtained through a combination of increased temperature, increased reactant pressures, improved activation techniques and improved thermal control over the baseline cell configuration. The cell demonstrated a higher acid content membrane which resulted in increased performance. Reduced catalyst loading and low cost membrane development showed encouraging results.

Source record↗

M & V Shootout: Setting the Stage For Testing the Performance of New Energy Baseline

Trustworthy savings calculations are critical to convincing investors in energy efficiency projects of the benefit and cost-effectiveness of such investments and their ability to replace or defer supply-side capital investments. However, today’s methods for measurement and verification (M&V) of energy savings constitute a significant portion of the total costs of efficiency projects. They also require time-consuming data acquisition and often do not deliver results until years after the program period has ended. A spectrum of savings calculation approaches are used, with some relying more heavily on measured data and others relying more heavily on estimated or modeled data, or stipulated information. The rising availability of “smart” meters, combined with new analytical approaches to quantifying savings, has opened the door to conducting M&V more quickly and at lower cost, with comparable or improved accuracy. Energy management and information systems (EMIS) technologies, not only enable significant site energy savings, but are also beginning to offer M&V capabilities. This paper expands recent analyses of public-domain, whole-building M&V methods, focusing on more novel baseline modeling approaches that leverage interval meter data. We detail a testing procedure and metrics to assess the performance of these new approaches using a large test dataset. We also provide conclusions regarding the accuracy, cost, and time trade-offs between more traditional M&V and these emerging streamlined methods. Finally, we discuss the potential evolution of M&V to better support the energy efficiency industry through low-cost approaches, and the long-term agenda for validation of building energy analytics.

Touzani, Samir↗

Low Cerebral Blood Volume Identifies Poor Outcome in Stent Retriever Thrombectomy

BackgroundMechanical thrombectomy (MT) is an efficient treatment of acute stroke caused by large-vessel occlusion. We evaluated the factors predicting poor clinical outcome (3-month modified Rankin Scale, mRS >2) although MT performed with modern stent retrievers.MethodsWe prospectively collected the clinical and imaging data of 105 consecutive anterior circulation stroke patients who underwent MT after multimodal CT imaging. Patients with occlusion of the internal carotid artery and/or middle cerebral artery up to the M2 segment were included. We recorded baseline clinical, procedural and imaging variables, technical outcome, 24-h imaging outcome and the clinical outcome. Differences between the groups were studied with appropriate statistical tests and binary logistic regression analysis.ResultsLow cerebral blood volume Alberta stroke program early CT score (CBV-ASPECTS) was associated with poor clinical outcome (median 7 vs. 9, p = 0.01). Lower collateral score (CS) significantly predicted poor outcome in regression modelling with CS = 0 increasing the odds of poor outcome 4.4-fold compared to CS = 3 (95% CI 1.27–15.5, p = 0.02). Lower CBV-ASPECTS significantly predicted poor clinical outcome among those with moderate or severe stroke (OR 0.82, 95% CI 0.68–1, p = 0.05) or poor collateral circulation (CS 0–1, OR 0.66, 95% CI 0.48–0.90, p = 0.009) but not among those with mild strokes or good collaterals.ConclusionsCBV-ASPECTS estimating infarct core is a significant predictor of poor clinical outcome among anterior circulation stroke patients treated with MT, especially in the setting of poor collateral circulation and/or moderate or severe stroke.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Hybrid data-driven and model-informed online tool wear detection in milling machines

Precision machining tool wear is responsible for low product throughput and quality. Monitoring the tool wear online is vital to prevent degradation in machining quality. However, direct real-time tool wear measurement is not practical. This paper presents residual-based anomaly detection models, combining a hybrid model comprised of a physics-based model and a data-driven model (a decision tree or a neural network) to predict signals of interest (e.g., power or forces) under nominal conditions, followed by Page’s cumulative sum test for detecting tool wear on-line using the computer numerical control machine measurements. The most informative features are ranked using dynamic programming and its approximation variants from real-time measurements and machine settings, such as the width of cut, depth of cut, feed rate and spindle speed, that serve as inputs to the predictive models. The baseline nominal model is incrementally updated with experimental data via a gradient boosted adaptation model to generate the residuals that account for discrepancies between the actual machine data under normal conditions and the baseline nominal model predictions. The hybrid model is validated against 20 Mazak milling machine experimental tests and one Haas run-to-failure experiment. The proposed anomaly detector is applied to synthetic data from simulations of the physics-based model at different operating conditions, measurement noise levels, and tool wear levels, and the methods were able to achieve an overall 92% accuracy in data with 1% noise. The anomaly detection methods based on hybrid model reduced the false alarms of either the data-driven or physical-based models alone, and are found to be capable of good online detection of tool wear.

42 ENGINEERING↗

An Ensemble Optimization Framework for Coupled Design of Hydropower Contracts and Real-Time Reservoir Operating Rules

Often, revenues from hydropower generation depend on the operator's ability to provide firm power in the presence of uncertain inflows. The primary options available for optimizing revenue are negotiation of a firm power contract before operations begin and adjustment of the reservoir release during operations. Contract and release strategy optimization are closely coupled and most appropriately analyzed with stochastic real-time control methods. Here we use an ensemble-based approach to stochastic optimization that provides a convenient way to construct nonparametric revenue probability distributions to explore the implications of uncertainty. The firm power contract is a simplified bilateral fixed price agreement that partially insulates operator and buyer from price fluctuations. The release control laws and firm energy target are jointly optimized to maximize the operator's expected revenue. Revenue probability distributions and related spill performance statistics indicate that predictive operating strategies such as stochastic dynamic programming and model predictive control can give significantly better performance than standard deterministic operating rules. The performance obtained from batch optimization with perfect inflow information establishes a convenient upper bound on potential revenue and provides a baseline for assessing the significance of differences between real-time operating strategies. Sensitivity analysis indicates that the benefits of predictive operational strategies are greatest for reservoirs with medium nondimensional residence times and less important for reservoirs with large residence times. Overall, probabilistic analysis of the coupled hydropower contract-operations problem provides a realistic way to assess revenue and risk for reservoirs that must provide firm power when inflows are uncertain.

13 HYDRO ENERGY↗

Commercial Building Energy Baseline Modeling Software: Performance Metrics and Method Testing with Open Source Models and Implications for Proprietary Software Testing

The overarching goal of this work is to advance the capabilities of technology evaluators in evaluating the building-level baseline modeling capabilities of Energy Management and Information System (EMIS) software. Through their customer engagement platforms and products, EMIS software products have the potential to produce whole-building energy savings through multiple strategies: building system operation improvements, equipment efficiency upgrades and replacements, and inducement of behavioral change among the occupants and operations personnel. Some offerings may also automate the quantification of whole-building energy savings, relative to a baseline period, using empirical models that relate energy consumption to key influencing parameters, such as ambient weather conditions and building operation schedule. These automated baseline models can be used to streamline the whole-building measurement and verification (M&V) process, and therefore are of critical importance in the context of multi-measure whole-building focused utility efficiency programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting

The U.S. Department of Energy’s Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. The strategic targets were a 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. The baseline vehicle was an average of several available vehicles in this class. Mass and cost breakdowns from several sources were used, including original equipment manufacturers’ (OEMs’) input through U.S. Department of Energy’s Vehicle Technologies Office programs and public presentations, A2Mac1 LLC’s teardown information, Lotus Engineering Limited and FEV, Inc. breakdowns in their respective lightweighting studies, and IBIS Associates, Inc.’s decades of experience in automotive lightweighting and materials substitution analyses. Information on lightweighting strategies in this analysis came from these same sources and the ongoing U.S. Department of Energy-funded Vehma International of America, Inc. /Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, and many United States Council for Automotive Research’s/United States Automotive Materials Partnership LLC lightweight materials programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Ion-Pair Proton Exchange Membrane Fuel Cells for Heavy-duty Transportation

The purpose of this project is to build a fuel cell prototype that demonstrates high temperature proton exchange membrane fuel cell technology (HT PEMFC) commercial readiness. It advances from a technology baseline established in a prior CRADA in which these same Parties collaborated during the years 2020-2024. These efforts are aligned with the intentions of the DOE Hydrogen Fuel Cell Technology Office (HFTO) L’Innovator Pilot Program. Participant observes that its US-based competitive advantage may be improved by further optimizing Laboratory inventions. This CRADA is intended to further improve National Laboratory compositions and to develop commercial HT PEMFC membrane electrode assemblies (MEAs) that perform over a range of operating temperatures and relative humidity, that generate power from both low grade and pure hydrogen, and that are resistant to air impurities. Participant’s goal is to advance the commercial competitiveness of National Laboratory technologies in fuel cell products for heavy-duty truck integrators, for stationary power generation, marine applications, and for emerging interest from commercial aviation. The Parties will collaborate on producing a HT PEMFC MEA that integrates LANL ion pair technology and Brookhaven catalyst technology. The Laboratories plan to research and develop compositions for testing and evaluation. The participant will manufacture multiple MEAs based on the Laboratory compositions and will enable selected customers to validate performance characteristics. The Laboratories will convey to Participant the methods of making the National Laboratory compositions such that Participant may reproduce and then scale Laboratory methods into commercial production. Throughout the project, the Laboratories and Participant will iteratively test and optimize the compositions of materials of the MEAs, intending to optimize characteristics such as power density and lifecycle durability. Participant’s intended customers include fuel cells for large trucks, aviation, power back up, marine, and portable power.

99 GENERAL AND MISCELLANEOUS↗

INTERFEROMETRIC MONITORING OF GAMMA-RAY BRIGHT AGNs. I. THE RESULTS OF SINGLE-EPOCH MULTIFREQUENCY OBSERVATIONS

We present results of single-epoch very long baseline interferometry (VLBI) observations of gamma-ray bright active galactic nuclei (AGNs) using the Korean VLBI Network (KVN) at the 22, 43, 86, and 129 GHz bands, which are part of a KVN key science program, Interferometric Monitoring of Gamma-Ray Bright AGNs. We selected a total of 34 radio-loud AGNs of which 30 sources are gamma-ray bright AGNs with flux densities of >6 × 10{sup −10} ph cm{sup −2} s{sup −1}. Single-epoch multifrequency VLBI observations of the target sources were conducted during a 24 hr session on 2013 November 19 and 20. All observed sources were detected and imaged at all frequency bands, with or without a frequency phase transfer technique, which enabled the imaging of 12 faint sources at 129 GHz, except for one source. Many of the target sources are resolved on milliarcsecond scales, yielding a core-jet structure, with the VLBI core dominating the synchrotron emission on a milliarcsecond scale. CLEAN flux densities of the target sources are 0.43–28 Jy, 0.32–21 Jy, 0.18–11 Jy, and 0.35–8.0 Jy in the 22, 43, 86, and 129 GHz bands, respectively. Spectra of the target sources become steeper at higher frequency, with spectral index means of −0.40, −0.62, and −1.00 in the 22–43 GHz, 43–86 GHz and 86–129 GHz bands, respectively, implying that the target sources become optically thin at higher frequencies (e.g., 86–129 GHz).

79 ASTRONOMY AND ASTROPHYSICS↗

Planning for orbital repairs to the Space Station and equipment

This paper summarizes an extensive study that was performed to establish a baseline for tools, materials, and repair techniques that will be needed for an astronaut to repair structures in an orbital environment, with a view towards future on-orbit repairs to the Space Station. The study program confirmed the premise that repairs must and can be made by astronauts while in an orbital environment. Scenarios for both welding repair and composite repair techniques are presented, along with a discussion of human factors considerations. A Space Station maintenance work station module is described, followed by a discussion of the Neutral Buoyancy Simulator test facility used to evaluate crew work performance in zero g conditions.

Haber, Harry S.↗

The development of composite materials for spacecraft precision reflector panels

One of the critical technology needs for large precision reflectors required for future astrophysics and optical communications is in the area of structural materials. Therefore, a major area of the Precision Segmented Reflector Program at NASA is to develop lightweight composite reflector panels with durable, space environmentally stable materials which maintain both surface figure and required surface accuracy necessary for space telescope applications. Results from the materials research and development program at NASA Langley Research Center are discussed. Advanced materials that meet the reflector panel requirements are identified. Thermal, mechanical and durability properties of candidate materials after exposure to simulated space environments are compared to the baseline material.

Tompkins, Stephen S.↗

Neuropsychological Testing of Astronauts

The Spaceflight Cognitive Assessment Tool for Windows (WinSCAT) is a computer program that administers a battery of five timed neuro-cognitive tests. WinSCAT was developed to give astronauts an objective and automated means of assessing their cognitive functioning during space flight, as compared with their own baseline performances measured during similar prior testing on the ground. WinSCAT is also intended for use by flight surgeons to assess cognitive impairment after exposure of astronauts to such cognitive assaults as head trauma, decompression sickness, and exposure to toxic gas. The tests were selected from among a group of tests, denoted the Automated Neuropsychological Assessment Metrics, that were created by the United States Navy and Army for use in evaluating the cognitive impairment of military personnel who have been subjected to medication or are suspected to have sustained brain injuries. These tests have been validated in a variety of clinical settings and are now in the public domain. The tests are presented in a Microsoft Windows shell that facilitates administration and enables immediate reporting of test scores in numerical and graphical forms.

Flynn, Christopher↗

Collaborative Software Development Approach Used to Deliver the New Shuttle Telemetry Ground Station

United Space Alliance (USA) developed and used a new software development method to meet technical, schedule, and budget challenges faced during the development and delivery of the new Shuttle Telemetry Ground Station at Kennedy Space Center. This method, called Collaborative Software Development, enabled KSC to effectively leverage industrial software and build additional capabilities to meet shuttle system and operational requirements. Application of this method resulted in reduced time to market, reduced development cost, improved product quality, and improved programmer competence while developing technologies of benefit to a small company in California (AP Labs Inc.). Many modifications were made to the baseline software product (VMEwindow), which improved its quality and functionality. In addition, six new software capabilities were developed, which are the subject of this article and add useful functionality to the VMEwindow environment. These new software programs are written in C or VXWorks and are used in conjunction with other ground station software packages, such as VMEwindow, Matlab, Dataviews, and PVWave. The Space Shuttle Telemetry Ground Station receives frequency-modulation (FM) and pulse-code-modulated (PCM) signals from the shuttle and support equipment. The hardware architecture (see figure) includes Sun workstations connected to multiple PCM- and FM-processing VersaModule Eurocard (VME) chassis. A reflective memory network transports raw data from PCM Processors (PCMPs) to the programmable digital-to-analog (D/A) converters, strip chart recorders, and analysis and controller workstations.

Kirby, Randy L.↗