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At least 199 records · Page 11

NASA Ares I Crew Launch Vehicle Upper Stage Overview

By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA's Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program's transportation system. Constellation's exploration missions will include Ares I and Ares V launch vehicles required to place crew and cargo in low-Earth orbit (LEO), crew and cargo transportation systems required for human space travel, and transportation systems and scientific equipment required for human exploration of the Moon and Mars. Early Ares I configurations will support ISS re-supply missions. A self-supporting cylindrical structure, the Ares I Upper Stage will be approximately 84' long and 18' in diameter. The Upper Stage Element is being designed for increased supportability and increased reliability to meet human-rating requirements imposed by NASA standards. The design also incorporates state-of-the-art materials, hardware, design, and integrated logistics planning, thus facilitating a supportable, reliable, and operable system. With NASA retiring the Space Shuttle fleet in 2010, the success of the Ares I Project is essential to America's continued leadership in space. The first Ares I test flight, called Ares I-X, is scheduled for 2009. Subsequent test flights will continue thereafter, with the first crewed flight of the Crew Exploration Vehicle (CEV), "Orion," planned for no later than 2015. Crew transportation to the ISS will follow within the same decade, and the first Lunar excursion is scheduled for the 2020 timeframe.

McArthur, J. Craig↗

Precession model for the nucleus of periodic comet Giacobini-Zinner

The comet Giacobini-Zinner, which was discovered in 1900, is a short-period comet of the Jupiter family. It will become the first comet ever to be investigated by a spacecraft in situ, because the International Comet Explorer (ICE) is scheduled to fly through the plasma tail of this comet on September 11, 1985. For this project, it is useful to have as complete a model of the comet as can be deduced from available ground-based observations. The present paper represents, in this connection, an attempt to fill some of the many gaps with respect to an understanding of this particular comet. One of the major results of Yeomans' studies (1971, 1983, 1984) was the detection of a 'discontinuity' in the orbital motion, which qualifies P/Giacobini-Zinner as an 'erratic' comet. One objective of the paper is the formulation of a self-consistent working model of the cometary nucleus, taking into account questions regarding the applicability of the nucleus-precession model of Sekanina (1984) to the dynamically 'erratic' comets.

Sekanina, Z.↗

NASA Tech Briefs, May 2013

Topics include: Test Waveform Applications for JPL STRS Operating Environment; Pneumatic Proboscis Heat-Flow Probe; Method to Measure Total Noise Temperature of a Wireless Receiver During Operation; Cursor Control Device Test Battery; Functional Near-Infrared Spectroscopy Signals Measure Neuronal Activity in the Cortex; ESD Test Apparatus for Soldering Irons; FPGA-Based X-Ray Detection and Measurement for an X-Ray Polarimeter; Sequential Probability Ratio Test for Spacecraft Collision Avoidance Maneuver Decisions; Silicon/Carbon Nanotube Photocathode for Splitting Water; Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor; Flight Hardware Packaging Design for Stringent EMC Radiated Emission Requirements; RF Reference Switch for Spaceflight Radiometer Calibration; An Offload NIC for NASA, NLR, and Grid Computing; Multi-Scale CNT-Based Reinforcing Polymer Matrix Composites for Lightweight Structures; Ceramic Adhesive and Methods for On-Orbit Repair of Re-Entry Vehicles; Self-Healing Nanocomposites for Reusable Composite Cryotanks; Pt-Ni and Pt-Co Catalyst Synthesis Route for Fuel Cell Applications; Aerogel-Based Multilayer Insulation with Micrometeoroid Protection; Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders; Optimized Radiator Geometries for Hot Lunar Thermal Environments; A Mission Concept: Re-Entry Hopper-Aero-Space-Craft System on-Mars (REARM-Mars); New Class of Flow Batteries for Terrestrial and Aerospace Energy Storage Applications; Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments; Using a Blender to Assess the Microbial Density of Encapsulated Organisms; Mixed Integer Programming and Heuristic Scheduling for Space Communication; Video Altimeter and Obstruction Detector for an Aircraft; Control Software for Piezo Stepping Actuators; Galactic Cosmic Ray Event-Based Risk Model (GERM) Code; Sasquatch Footprint Tool; and Multi-User Space Link Extension (SLE) System.

Source record↗

Encouraging Combined Heat and Power in California Buildings

Governor Brown’s research priorities include an additional 6.5 GW of combined heat and power (CHP) by 2030. As of 2009, roughly 0.25 GW of small natural gas and biogas fired CHP is documented by the Self-Generation Incentive Program (SGIP) database. The SGIP is set to expire, and the anticipated grid de-carbonization based on the development of 20 GW of renewable energy will influence the CHP adoption. Thus, an integrated optimization approach for this analysis was chosen that allows optimizing the adoption of distributed energy resources (DER) such as photovoltaics (PV), CHP, storage technologies, etc. in the California commercial sector from the building owners’ perspective. To solve this DER adoption problem the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed by the Lawrence Berkeley National Laboratory and used extensively to address the problem of optimally investing and scheduling DER under multiple settings, has been used. The application of CHP at large industrial sites is well known, and much of its potential is already being realized. Conversely, commercial sector CHP, especially those above 50 to 100 kW peak electricity load, is widely overlooked. In order to analyze the role of DER in CO 2 reduction, 147 representative sites in different climate zones were selected from the California Commercial End Use Survey (CEUS). About 8000 individual optimization runs, with different assumptions for the electric tariffs, natural gas costs, marginal grid CO 2 emissions, and nitrogen oxide treatment costs, SGIP, fuel cell lifetime, fuel cell efficiency, PV installation costs, and payback periods for investments have been performed. The most optimistic CHP potential contribution in this sector in 2020 will be 2.7 GW. However, this result requires a SGIP in 2020, 46% average electric efficiency for fuel cells, a payback period for investments of 10 years, and a CO 2 focused approach of the building owners. In 2030 it will be only 2.5 GW due to the anticipated grid decarbonization. The 2030 result requires a 60% electric efficiency and 20 year life time for fuel cells, a payback period of 10 years, and a CO 2 minimization strategy of building owners. Finally, the possible CHP potential in 2030 shows a significant variance between 0.2 GW and 2.5 GW, demonstrating the complex interactions between technologies, policies, and customer objectives.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Implementation and Operation of Power Flow Control Solutions for Transmission Systems

Power-flow controls (PFCs) technologies provide a suite of alternatives to more-efficiently direct the flow of power on the grid, improving flexibility and enabling the grid to be more responsive and resilient. PFCs can be used in many cases to mitigate overloads and consequently defer the installation of grid-expansion projects. They can also be suitable options in situations where new transmission lines cannot be built because of environmental constraints, land use, or other types of restrictions. Other uses include mitigation of loop or unintended flows, forcing of contractual or scheduled flows, reduction of congestion, and mitigation solutions during large maintenance or construction projects. While many studies have demonstrated the potential economic benefits of PFC for different types of applications, the implementation implications of using multiple PFCs for system operation and reliability have not been analyzed in detail. The lack of information and practical experience on these aspects hinders adoption of this technology. One use case would be that multiple PFCs are required to coordinate congestion management. In such cases, multiple PFCs are deployed in a meshed power system to control power flows across a wide area. The challenges are associated with PFC interaction—namely, the self and mutual power-flow sensitivity of each PFC, which must be accounted for in the calculation of the respective operating setpoints. This report analyzes implementation and operation that must be considered in evaluating transmission solutions using PFCs. The report first analyzes attributes with which PFC-based solutions should comply, based on the objective and characteristics of each particular use case. It then describes different approaches for coordinated control of multiple PFC devices for different applications, including options to avoid adverse interactions and reduce risks due to inappropriate coordination. Control and operation are illustrated through case studies performed on both generic and actual power system models. This report provides insights for transmission planners and operation engineers about the implementation of PFC-based transmission solutions; consequently, it will help them make informed decisions about the adoption of the technology.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Nuclear Energy Advanced Modeling and Simulation (NEAMS) Accident Tolerant Fuels High Impact Problem: Coordinate Multiscale FeCrAl Modeling

Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced ac- cident tolerance when compared to traditional UO2 fuel zircaloy clad fuel rods. One of the potential replacement claddings are iron-chromium-alunimum (FeCrAl) alloys due to their increased oxidation resistance [1–4] and higher strength [1, 2]. While the oxidation characteristics of FeCrAl are a benefit for accident tolerance, the thermal neu- tron absorption cross section of FeCrAl is about ten times that of Zircaloy. This neutronic penalty necessitates thinner cladding. This allows for slightly larger pellets to give the same cold gap width in the rod. However, the slight increase in pellet diameter is not sufficient to compensate for the neutronic penalty and enriching the fuel beyond the current 5% limit appears to be necessary [5]. Current estimates indicate that this neutronic penalty will impose an increase in fuel cost of 15-35% [1, 2]. In addition to the neutronic disadvantage, it is anticipated that tritium release to the coolant will be larger because the permeability of hydrogen in FeCrAl is about 100 times higher than in Zircaloy [6]. Also, radiation-induced hardening and embrittlement of FeCrAl need to be fully characterized experimentally [7]. Due to the aggressive development schedule for inserting some of the potential materials into lead test assemblies or rods by 2022 [8] multiscale multiphysics modeling approaches have been used to provide insight into these the use of FeCrAl as a cladding material. The purpose of this letter report is to highlight the multiscale modeling effort for iron-chromium-alunimum (FeCrAl) cladding alloys as part of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program through its Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The approach taken throughout the HIP is to utilize lower length scale approaches (e.g., density functional theory, cluster dynamics, rate theory, phase field, and Visco-Plastic- Self-Consistent (VPSC)) to develop more physically informed models at the engineering scale for use in the BISON [9] fuel performance code.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

AHTR Mechanical, Structural, And Neutronic Preconceptual Design

This report provides an overview of the mechanical, structural, and neutronic aspects of the Advanced High Temperature Reactor (AHTR) design concept. The AHTR is a design concept for a large output Fluoride salt cooled High-temperature Reactor (FHR) that is being developed to enable evaluation of the technology hurdles remaining to be overcome prior to FHRs becoming a commercial reactor class. This report documents the incremental AHTR design maturation performed over the past year and is focused on advancing the design concept to a level of a functional, self-consistent system. The AHTR employs plate type coated particle fuel assemblies with rapid, off-line refueling. Neutronic analysis of the core has confirmed the viability of a 6-month 2-batch cycle with 9 weight-percent enriched uranium fuel. Refueling is intended to be performed automatically under visual guidance using dedicated robotic manipulators. The present design intent is for used fuel to be stored inside of containment for at least 6 months and then transferred to local dry wells for intermediate term, on-site storage. The mechanical and structural concept development effort has included an emphasis on transportation and constructability to minimize construction costs and schedule. The design intent is that all components be factory fabricated into rail transportable modules that are assembled into subsystems at an on-site workshop prior to being lifted into position using a heavy-lift crane in an open-top style construction. While detailed accident identification and response sequence analysis has yet to be performed, the design concept incorporates multiple levels of radioactive material containment including fully passive responses to all identified design basis or non-very-low frequency beyond design basis accidents. Key building design elements include: 1) below grade siting to minimize vulnerability to aircraft impact, 2) multiple natural circulation decay heat rejection chimneys, 3) seismic base isolation, and 4) decay heat powered back-up electricity generation. The report provides a preconceptual design of the manipulators, the fuel transfer system, and the salt transfer loops. The mechanical handling of the fuel and how it is accomplished without instrumentation inside the salt is described within the report. All drives for the manipulators reside outside the reactor top flange. The design has also taken into account the transportability of major components and how they will be assembled on site

Varma, Venugopal Koikal↗

Managing Through Continuous Improvement: If it doesn’t challenge you, it won’t change you

The past 24 months has been one of non-stop continuous improvement – every month, every week, every day, and every hour. It has been filled with continuously re-examining and challenging business systems, work processes, and legacy culture. The journey was difficult, but well worth it. It began by examining the existing conditions in each organization and building the case for change. When we stepped back and looked at our processes, systems, tools, and performance objectively, we realized we were struggling with frequent organizational, resource, and schedule conflicts, work processes that were not well-defined or expert based, project delays were common, management methods were predominantly reactive, advanced planning was limited to the near-term, no integration in scheduling across organizations, limited to no performance metrics to measure and manage performance, and internal and external customers did not feel like we were meeting their quality and performance expectations. It was a wake-up call. Change began at the top with a change leadership with where a new vision, expectations, and commitment were established. Leaving no stone left unturned, every aspect of the business was challenged which opened up communication and exposed the gaps. This was done in a ‘safe’ environment allowing for honest and solution-oriented discussion and action. The leadership team committed to managing through continuous improvement. The organizational structure was realigned to better align scope, responsibilities, execution, and customer focus. Visibility and transparency became the norm as higher levels of leadership and supporting organizations were invited to be part of regular strategy meetings and partnership discussion, effectively opening up the dialogue. This required a tremendous amount of trust and faith in a short period of time. Health assessments were conducted on each organization with specific lines of inquiry. These self-assessments helped to identify better define the scope of the organization and where targeted improvements were needed. Frequent organizational reviews were implemented to answer three fundamental questions: 1) What is your organization paid to do (scope)?, 2) How does your organization, or you, demonstrate that you are doing the job effectively?, and 3) What are you doing to improve your performance? To answer the first question, leaders defined the scope of the organization. Leaders were required to provide a path forward, with specific actions, where performance was not at expected levels internally at first and then from the stakeholders. Where business processes were not clearly understood, process maps were developed to provide this clarity for both those performing the work and those utilizing the process – the customers. To help answer the second question, numerous automated or semi-automated real-time, dynamic performance metrics were developed and implement to help leaders gain the visibility and demonstrate performance in six areas of operational excellence: safety, security, quality, effectiveness, productivity, and sustainability. Analysis of the performance provided windows of transparency and trends of work performance, work delays, cycle times, utilization, and much more that revealed many areas of improvement that were either not visible or desired to be visible. At the same time, they provided real-time progress which generated initial performance improvements by just beginning to measure. To address the third question, where systems did not support effectiveness of an existing or new process, then systems and tools were developed and implemented to drive the right behaviors and reinforce the processes. Tools and metrics were one of the major catalysts for culture shift and change. Risk assessments were leveraged into continuous improvement strategies, plans, and schedules. Targeted initiatives were identified and performed. Change and improvement was not, and is not, without significant and common challenges including limited/fixed budgets, resource availability, data access, natural resistance to change, and numerous other reasons or excuses – we called them ‘off-ramps’ and began to close them one-by-one. The results and outputs were significant and impactful in each organization and across the business with increased productivity, efficiency, visibility, accountability, management, and performance. Stakeholder satisfaction also increased. Cost and time savings allowed to more continuous improvement efforts to be performed. The effort clearly provided clear and measurable return on investment and value. Efforts that once seemed impossible, not feasible, or not achievable were performed. Decades-long issues were solved. ‘Impossible things are simply those which so far have never been done’ said Elbert Hubbard. So what will the next year be for you and your organization? Are you satisfied with the ‘same ‘ol, same ‘ol?’ Will you fall into the complacency trap and believe that change is too difficult, too expensive, and not necessary (or any number of possible excuses) or will you make this year your year or continuous improvement (and every year thereafter…)? Remember – what you do today can improve all your tomorrows’ (Ralph Marston).

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗

Comparison of Airborne and Ground-Based Function Allocation Concepts for NextGen Using Human-In-The-Loop Simulations

This paper presents an air/ground functional allocation experiment conducted by the National Aeronautics and Space Administration (NASA) using two human-in-the-Loop simulations to compare airborne and ground-based approaches to NextGen separation assurance. The approaches under investigation are two trajectory-based four-dimensional (4D) concepts; one referred to as "airborne trajectory management with self-separation" (airborne) the other as "ground-based automated separation assurance" (ground-based). In coordinated simulations at NASA's Ames and Langley Research Centers, the primary operational participants -controllers for the ground-based concept and pilots for the airborne concept - manage the same traffic scenario using the two different 4D concepts. The common scenarios are anchored in traffic problems that require a significant increase in airspace capacity - on average, double, and in some local areas, close to 250% over current day levels - in order to enable aircraft to safely and efficiently traverse the test airspace. The simulations vary common independent variables such as traffic density, sequencing and scheduling constraints, and timing of trajectory change events. A set of common metrics is collected to enable a direct comparison of relevant results. The simulations will be conducted in spring 2010. If accepted, this paper will be the first publication of the experimental approach and early results. An initial comparison of safety and efficiency as well as operator acceptability under the two concepts is expected.

Wing, David J.↗

Model-Based Control of an Aircraft Engine using an Optimal Tuner Approach

This paper covers the development of a model-based engine control (MBEC) method- ology applied to an aircraft turbofan engine. Here, a linear model extracted from the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) at a cruise operating point serves as the engine and the on-board model. The on-board model is up- dated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. MBEC provides the ability for a tighter control bound of thrust over the entire life cycle of the engine that is not achievable using traditional control feedback, which uses engine pressure ratio or fan speed. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC tighter thrust control. In addition, investigations of using the MBEC to provide a surge limit for the controller limit logic are presented that could provide benefits over a simple acceleration schedule that is currently used in engine control architectures.

Connolly, Joseph W.↗

Demographics, sleep, and daily patterns of caffeine intake of shift workers in a nationally representative sample of the US adult population

Abstract Study Objective Caffeine is the most widely consumed stimulant in the world, and sociodemographic factors including occupation are associated with intake. Shift work, required in various occupations, is associated with poor sleep, inadequate diet, and adverse health effects. Using a large nationally representative database, demographics, sleep, and caffeine intake of US adults working various shifts were assessed. Methods The 24-hour dietary recall data from NHANES 2005–2010 (N = 8,500) were used to estimate caffeine intake from foods and beverages. Work shifts were self-reported as follows: regular day shift; evening shift; night shift; rotating shift; or other shift. Regression analyses assessed associations of shift work with caffeine intake after adjustment for sociodemographic factors. Results Approximately 74% of employed adults were day-shift workers and 26% were nonday-shift workers. Night-shift workers slept for 6.25 ± 0.09 hours per day, somewhat less than day-shift workers who only slept 6.83 ± 0.02 hours (p < .0001). Mean 24-hour weekday caffeine intake of evening-, night-, and rotating-shift workers (217 ± 23, 184 ± 19, and 206 ± 15 mg, respectively) was similar (p > .3) to day-shift workers (203 ± 5 mg). Regardless of work schedule, individuals consumed the most caffeine during morning hours. Evening- and night-shift workers reported consuming 36%–46% less caffeine during their work hours and 72%–169% more during nonwork hours than day-shift workers (p < .01). Conclusions Total daily caffeine intake of shift workers is similar to nonshift workers; most caffeine is consumed in the morning regardless of shift. Because shift workers consume less caffeine during regular work hours and more during nonwork hours than day workers, they may be using caffeine to, in part, optimize off-duty alertness.

Lieberman, Harris R.↗

Distribution System State Estimation With High Penetration of Demand Response Enabled Loads

Demand-side operations incentivize utility customers to take part in various grid services. A demand response enabled load (DREL) is a flexible grid asset that schedules electricity consumption in response to a time-of-use (TOU) energy price. Consequently, its energy profile differs from that of a conventional load that is insensitive to price. This difference may cause new challenges for distribution system state estimation (DSSE). It is well known that DSSE often needs to use pseudo-measurements based on historic load profiles to increase system observability. However, historic profiles of conventional loads are not representative of DREL behaviors. Additionally, the inaccuracy impacts DSSE results and other DSSE-dependent operations. In this paper, we propose an online pseudo-measurement generation approach for DSSE with DRELs. We formulate an optimization model to represent DRELs self-adjusting actions. Sampling-based stochastic optimization techniques are proposed to account for uncertainties in DRELs. A set of representative DREL behavior data corresponding to the samples are used to characterize DREL pseudo-measurements. Case studies with modified IEEE 123-bus test system verify the validity of the proposed work.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Novel Radiometry for In-Pipe Robotic Inspection of Holdup Deposits in Gaseous Diffusion Piping - 19503

This paper details the first complete, DOE approved, deployed and operational radiometry for robotic nondestructive assay (NDA) of holdup deposits in gaseous diffusion piping. Some features, like peak-finding, Compton correction, detector efficiency, and material properties are characteristic of typical manual methods. Most features are specific to in-pipe robotic deployment. These include in-motion radiometry, self-determined location, geometric modeling of thick deposits, bounding of self-attenuation thickness and auto-checking of replicate measurements. Significant are the means for determining all the properties, equations, and constants for automatically computing and displaying all the quantities, uncertainties and information needed for NDA reporting, analysis, and review. Earlier work by this team demonstrated rudimentary but convincing robotic in-pipe NDA of holdup deposits in pipes. Cold testing with high-enrichment mat sources and hot tests with low U-235 loadings together succeeded to exhibit convincing proof-of-principle. This research-grade radiometry implementation lacked accurate odometry, efficiency calibration, high-fidelity detector modeling, attenuation modeling, forward geometric modeling, auto-segmenting, uncertainty modeling, replicate checking, deconvolution and much more. This work explains the technical basis behind robotic in-pipe NDA. It includes discussion of a new method for modeling of self-attenuation using in-pipe deposit geometry information, detail of the method's total measurement uncertainty, and explanation of calibration methods and results. Beyond development of automation-specific radiometric elements, the paper highlights analyses, testing, and technical bases specific to and supportive of the methodology. Examples include collimation characterization, detector efficiency determination, auto-calibration methodology, and odometric replicate-checking. Results of this methodology are formalized in a DOE EM Technical Basis Document, implemented in software, formally verified in review and acceptance testing and proceduralized as a means for D and D NDA at the Portsmouth enrichment facility. Measurement of U-235 quantity is a well-known cost and schedule driver in D and D of every defunct gaseous diffusion enrichment facility in the world. The radiometry methodologies and results detailed in this paper were the high hurdles. Having established the technical basis for this automated NDA, the opportunity is to apply this to many sizes and robot forms for addressing holdup deposit NDA throughout the D and D community. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Human Adaptation to Isolated and Confined Environments

A study was conducted over seven months in a winter Antarctic isolated and confined environment (ICE). Physiological and psychological data was collected several times a week. Information was collected on a monthly basis on behavior and the use of physical facilities. Adaptation and information indicated that there was a significant decrease in epinephrine and norepinephrine during the middle trimester of the winter. No vital changes were found for blood pressure. Self reports of hostility and anxiety show a linear increase. There were no significant changes in depression during ICE. The physiological and psychological data do not move in a synchronous fashion over time. The data also suggest that both ambient qualities of an ICE and discrete social environmental events, such as the arrival of the summer crew, have an impact on the outcome measures used. It may be most appropiate to develop a model for ICE's that incorporates not only global chronic stressors common to all ICE's but also the role of discrete environmental effects which can minimize or enhance the influence of more chronic stressors. Behavioral adjustment information highlight the importance of developing schedules which balance work and recreational activities.

Evans, Gary W.↗

A Linear Programming Approach to Backtracking for Single-Axis Trackers on Rolling Terrain

In this article, we present a computationally efficient method for determining optimal backtracking rotations for single-axis solar trackers on nonuniform terrain. The method allows for ganged tracking, mechanical rotation constraints, uneven row spacing, and arbitrary maximum allowable shaded fractions (to enable “fractional backtracking”). As with previous 2-D approaches, the method is suitable for terrain that varies in the transverse direction with respect to the rotation axis of the trackers. The novelty of the method lies in formulating the problem of shade avoidance as a linear problem, which is achieved by using the row interception width as the optimization variable instead of rotation angles. Formulating backtracking as a linear problem enables the use of extremely efficient linear programming algorithms, making the method highly scalable, requiring less than 1 min to compute optimal rotation schedules for hundreds of trackers. It also produces more effective backtracking rotations, reducing the frequency of shading by 4× and improving system energy output by 1%–2%.

Optimization↗

SR19007 - Future TCAP Implementation Issues

This project demonstrates the success of the PDRD program in bringing a concept from the R&D phase to direct plant funding. Although Mini-TCAP technology is overall at a TRL of ~6.5, the specific questions addressed in this project were brought from a low (2-3 TRL) to a TRL 5 over the course of the project. This project successfully completed all initial goals ahead of schedule (inventory control, guard bed, ammonia impact, and cycle time) and furthermore addressed additional scope (continued TCAP evaluation, ion chamber) in FY20. First, this project resolved minor inventory control issues by introducing a new parameter tracking and correcting for inventory changes over multiple cycles. This project also involved modification of the previously constructed plant-configured Mini-TCAP in order to allow ammonia impurity studies. TCAP was tested with ammonia in the feed stream both with and without a guard bed present to determine guard bed efficacy and the effect of ammonia if it enters TCAP. The TCAP columns were then replaced with brazed columns, where the LN2 cooling coil is brazed to the column and the column is self-brazed along the coils. This drastically improved heat transfer and consequently reduced cycle time compared to the previous columns, in which the coils were mechanically held in place. Finally, additional scopes were taken on in FY20, including evaluation of TCAP with faster cycle time and procurement of ion chambers for future TCAP integration.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Electromagnetic Pain Relief/Blocking: Feasibility Assessment

Context/Background: Astronauts use pharmaceuticals during spaceflight to manage acute and chronic pain, but use of analgesics will have drawbacks for exploration-class missions because the shelf life of these medications is limited, resupply will be curtailed, astronauts may develop tolerance and/or addiction to these medications, and side effects can include impairment of cognitive abilities. Electromagnetic devices have been developed that treat pain terrestrially by affecting neuromodulation–dubbed “electroceuticals”, these devices have varied mechanisms of action that either stimulate or suppress neural activity in the central nervous system or peripheral nerves. Objective/Purpose: The available literature was reviewed and FDA-approved pain treatments (both pharmacological and non-pharmacological), as well as those currently under development, were assessed for their suitability for use in exploration class spaceflight missions. Data Sources: Due to the COVID-19 pandemic and the resulting closure of libraries, data sources were restricted to those available digitally. Online database searches included PubMed, U.S. Patent and Trademark Office, federal grant award databases (National Aeronautics and Space Administration (NASA), Department of Defense (DoD), National Institutes of Health (NIH)), and general internet searches. More than 1,600 records were reviewed in this effort. Study Selection/Eligibility Criteria: Targeted searches included different aspects of pain management. Priority was given to review studies, to cover as much of the available literature as possible in this limited effort. Study Appraisal and Synthesis Methods/Data Extraction and Data Synthesis: The titles of the studies and the awards that were obtained by searching online databases were reviewed and further information was sought for the relevant titles. Abstracts or award summaries were generally available online; for journal abstracts, full text articles were either available online or were requested via interlibrary loan. Results: An overwhelming majority of the literature focuses on the treatment of chronic rather than acute pain because it is assumed that acute pain only rarely fails to resolve and instead transitions into chronic pain when the central nervous system becomes hypersensitized. The available electromagnetic devices marketed for pain treatment have varying levels of invasiveness, use different mechanisms of action, and have demonstrated varying efficacy when evaluated scientifically. A truly noninvasive, highly efficient device is desired for use during spaceflight. One portable, self-contained, FDA-approved device was identified that, from preliminarily assessment, best met these criteria; the device noninvasively applies pulsed shortwave therapy (PSWT) to modify pain signals from peripheral nerves, however, the device has limited battery life and the effects are relatively non-selective in type of neural signal modified. Limitations: This current effort, although extensive, did not identify a comprehensive list of all alternatives for pain treatment. Once the pandemic limitations are lifted, a longer, more thorough effort may find additional options. Conclusions/Implications: The ideal electromagnetic pain treatment device for use on exploration-class spaceflight missions does not yet exist, but it may be available soon. It is not feasible for NASA to develop medical devices due to the schedule constraints for pending exploration-class missions, but adapting a promising device that is already FDA-approved might be an option. Monitoring research that is ongoing at other federal agencies is recommended, and further review of the candidate PSWT device identified in this current effort may be warranted.

Carol Mullenax↗

Electromagnetic Pain Relief/Blocking: Feasibility Assessment

CONTEXT/BACKGROUND Astronauts use pharmaceuticals during spaceflight to manage acute and chronic pain, but use of analgesics will have drawbacks for exploration-class missions because the shelf life of these medications is limited, resupply will be curtailed, astronauts may develop tolerance and/or addiction to these medications, and side effects can include impairment of cognitive abilities. Electromagnetic devices have been developed that treat pain terrestrially by affecting neuromodulation–dubbed “electroceuticals”, these devices have varied mechanisms of action that either stimulate or suppress neural activity in the central nervous system or peripheral nerves. OBJECTIVE/PURPOSE The available literature was reviewed and FDA-approved pain treatments (both pharmacological and non-pharmacological), as well as those currently under development, were assessed for their suitability for use in exploration class spaceflight missions. DATA SOURCES Due to the COVID-19 pandemic and the resulting closure of libraries, data sources were restricted to those available digitally. Online database searches included PubMed, U.S. Patent and Trademark Office, federal grant award databases (National Aeronautics and Space Administration (NASA), Department of Defense (DoD), National Institutes of Health (NIH)), and general internet searches. More than 1,600 records were reviewed in this effort. STUDY SELECTION/ELIGIBILITY CRITERIA Targeted searches included different aspects of pain management. Priority was given to review studies, to cover as much of the available literature as possible in this limited effort. STUDY APPRAISAL AND SYNTHESIS METHODS/DATA EXTRACTION AND DATA SYNTHESIS The titles of the studies and the awards that were obtained by searching online databases were reviewed and further information was sought for the relevant titles. Abstracts or award summaries were generally available online; for journal abstracts, full text articles were either available online or were requested via interlibrary loan. RESULTS An overwhelming majority of the literature focuses on the treatment of chronic rather than acute pain because it is assumed that acute pain only rarely fails to resolve and instead transitions into chronic pain when the central nervous system becomes hypersensitized. The available electromagnetic devices marketed for pain treatment have varying levels of invasiveness, use different mechanisms of action, and have demonstrated varying efficacy when evaluated scientifically. A truly noninvasive, highly efficient device is desired for use during spaceflight. One portable, self-contained, FDA-approved device was identified that, from preliminarily assessment, best met these criteria; the device noninvasively applies pulsed shortwave therapy (PSWT) to modify pain signals from peripheral nerves, however, the device has limited battery life and the effects are relatively non-selective in type of neural signal modified. LIMITATIONS This current effort, although extensive, did not identify a comprehensive list of all alternatives for pain treatment. Once the pandemic limitations are lifted, a longer, more thorough effort may find additional options. CONCLUSIONS/IMPLICATIONS The ideal electromagnetic pain treatment device for use on exploration-class spaceflight missions does not yet exist, but it may be available soon. It is not feasible for NASA to develop medical devices due to the schedule constraints for pending exploration-class missions, but adapting a promising device that is already FDA-approved might be an option. Monitoring research that is ongoing at other federal agencies is recommended, and further review of the candidate PSWT device identified in this current effort may be warranted.

C A Mullenax↗