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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Practices Implemented by DOE Better Plants Program Partners to Mitigate COVID-19

Screening for symptoms, maintaining physical distance, sanitizing surfaces, wearing appropriate face masks, maintaining good personal hygiene, and reconfiguring HVAC air management are the major activities that the DOE BP partners have implemented to mitigate COVID-19. This article shares some specific practices that BP program partners have implemented for these activities. The energy impact of some practices has also been discussed and some rules of thumb have been provided to estimate energy penalties.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1980

Natural modes of helicopter rotor blades

Computer program based on Holzer-Myklestad approach calculates coupled vertical, horizontal, and torsional characteristics of wide variety of hub and blade configurations of practical interest. Program is written in FORTRAN IV.

Mineck, R. E.↗
NASA NTRS1981

Contractor point of view for system development and test program

Industry's practice of testing space qualified hardware is examined. An overview of the Global Positioning System (GPS) Test Program is discussed from the component level to the sub-system compatibility tests with the space vehicle and finally to the launch site tests, all related to the Rubidium clock.

Koide, F. K.↗
DOE OSTI2024

Demystifying Solar in WAP

Over the last two years, the National Renewable Energy Laboratory has identified the pathways for implementing solar in the Weatherization Assistance Program and Low Income Home Energy Assistance Program and practices for successful implementation. Learn about successful implementation models from around the network and the new resources that can give you a head start in planning solar into your program, including a demonstration of tools to help evaluate solar potential and cost-effectiveness at the household level, as well as a new tool from the U.S. Department of Energy National Community Solar Partnership to help connect households receiving LIHEAP assistance to community solar subscriptions that guarantee energy bill savings.

ENERGY PLANNING, POLICY, AND ECONOMY,SOLAR ENERGY↗
DOE OSTI2019

Field-to-farm gate greenhouse gas emissions from corn stover production in the Midwestern U.S.

Measured field data were used to compare two allocation methods on life cycle greenhouse gas emissions from corn (Zea mays L.) stover production in the Midwest U.S. We used publicly-available crop yield, nitrogen fertilizer, and direct soil nitrous oxide emissions data from the USDA-ARS Resilient Economic Agricultural Practices research program. Field data were aggregated from 9 locations across 26 site-years for 3 stover harvest rates (no removal; moderate removal – 3.1 Mg ha –1 ; high removal – 7.2 Mg ha –1 ) and 2 tillage practices (conventional; reduced/no-till). Net carbon uptake by crops was computed from measured plant carbon content. Monte Carlo simulations sampled input distributions to assess variability in farm-to-gate GHG emissions. The base analysis assumed no change in soil organic carbon stocks. In all cases, net CO 2 uptake during crop growth and soil-respired CO 2 dominated system emissions. Emissions were most sensitive to co-product accounting method, with system expansion emissions ~15% lower than mass allocation. Regardless of accounting method, lowest emissions occurred for a moderate removal rate under reduced/no-till management. The absence of correlations between N fertilization rate and stover removal rate or soil N 2 O emissions in this study challenges the use of such assumptions typically employed in life cycle assessments Storage of all carbon retained on the field as SOC could reduce emissions by an additional 15%. Furthermore, our results highlight how variability in GHG emissions due to location and weather can overshadow the impact of farm management practices on field-to-farm gate emissions. Graphical abstract

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1992

Conjunctive programming: An interactive approach to software system synthesis

This report introduces a technique of software documentation called conjunctive programming and discusses its role in the development and maintenance of software systems. The report also describes the conjoin tool, an adjunct to assist practitioners. Aimed at supporting software reuse while conforming with conventional development practices, conjunctive programming is defined as the extraction, integration, and embellishment of pertinent information obtained directly from an existing database of software artifacts, such as specifications, source code, configuration data, link-edit scripts, utility files, and other relevant information, into a product that achieves desired levels of detail, content, and production quality. Conjunctive programs typically include automatically generated tables of contents, indexes, cross references, bibliographic citations, tables, and figures (including graphics and illustrations). This report presents an example of conjunctive programming by documenting the use and implementation of the conjoin program.

Tausworthe, Robert C.↗
NASA NTRS2009

Extreme Programming: Maestro Style

"Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme-programming practices. The single most influential of these factors is that continuous interaction between customers and programmers is not feasible.

Norris, Jeffrey↗
NASA NTRS1983

Accommodation of practical constraints by a linear programming jet select

An experimental spacecraft control system will be incorporated into the Space Shuttle flight software and exercised during a forthcoming mission to evaluate its performance and handling qualities. The control system incorporates a 'phase space' control law to generate rate change requests and a linear programming jet select to compute jet firings. Posed as a linear programming problem, jet selection must represent the rate change request as a linear combination of jet acceleration vectors where the coefficients are the jet firing times, while minimizing the fuel expended in satisfying that request. This problem is solved in real time using a revised Simplex algorithm. In order to implement the jet selection algorithm in the Shuttle flight control computer, it was modified to accommodate certain practical features of the Shuttle such as limited computer throughput, lengthy firing times, and a large number of control jets. To the authors' knowledge, this is the first such application of linear programming. It was made possible by careful consideration of the jet selection problem in terms of the properties of linear programming and the Simplex algorithm. These modifications to the jet select algorithm may by useful for the design of reaction controlled spacecraft.

Bergmann, E.↗
NASA NTRS2001

Coverage Metrics for Model Checking

When using model checking to verify programs in practice, it is not usually possible to achieve complete coverage of the system. In this position paper we describe ongoing research within the Automated Software Engineering group at NASA Ames on the use of test coverage metrics to measure partial coverage and provide heuristic guidance for program model checking. We are specifically interested in applying and developing coverage metrics for concurrent programs that might be used to support certification of next generation avionics software.

Penix, John↗
DOE OSTI2019

Effect of doping some lanthanide oxides on optical and radiation shielding properties of cadmium borate glasses

Ce{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Nd{sub 2}O{sub 3} and Sm{sub 2}O{sub 3} doped in the cadmium borate host glass were prepared. Some optical and physical properties such as density, molar volume, optical band gap energy, the width of the band tails (Urbach energy) and radiation shielding properties were measured. In addition, the attenuation parameters, are calculated at different photon energies using the XCOM program and practical before and after irradiation. A correlation between the results from density, UV–Vis and FTIR measurements indicates that CdO plays a role as a network modifier and alter within the atomic structure is attributable to the formation of BO{sub 4} units. The attenuation parameters are calculated at different photon energies using the XCOM program and measured in experiments. These values show that there is a correlation between theoretical and experimental values. Hence, these results indicate that the samples have gamma-ray shielding in this energy range.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1987

Aircrew cooperation in the Royal Air Force

The progressive introduction of modern, high performance aircraft, coupled with a significant increase in the complexity of the operational environment, has highlighted crew co-operation as a critical factor in aircraft safety. Investigation into recent MAC aircraft accidents supports the conclusion reached by NASA and other U.S. research institutions that a positive training program is required to improve resource management in the cockpit and prevent a breakdown under stress of the crew process. Past training and regulation has concentrated on the attainment of individual flying skills, but group skills have been neglected through lack of knowledge and understanding of the group process. This long-standing deficiency is now being addressed in the U.S. by the progressive and widespread introduction of theoretical and practical training programs to improve crew co-operation. The RAF should provide similar training for its aircrews through the adaptation and development of existing training resources. Better crew co-operation would not only reduce the number of RAF aircraft accidents but also improve the morale of the Service.

Adcock, C. B.↗
DOE OSTI2021

Interdisciplinary Research Collaborative Trains Students to See Through Turbulent Systems

Despite the availability of interdisciplinary academic training programs, the practice of environmental science is often hampered by a lack of convergence across diverse disciplines. This gap is particularly salient in settings characterized by complex environmental issues, such as multiple-use coastal ecosystems. In response, we developed and implemented a training, research, and communication framework to provide undergraduates with an authentic operative experience working at the interface of interdisciplinary science and public decision-making within a case study of marine renewable energy. In our program, students gained hands-on experience with the scientific process and learned how to make information relevant, useful, and accessible to diverse stakeholder groups. Application of this framework demonstrates that the process of integrating data from biological (visual and acoustic monitoring of fish and marine mammals), physical (hydrodynamics), and social (local ecological knowledge) sciences can provide a more complete understanding of complex and turbulent ecosystems for better informed decision-making. We offer several recommendations to facilitate the adaptation and implementation of our interdisciplinary framework to diverse research contexts, with a focus on interdisciplinary training for the next generation of marine scientists.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Guide for Joint Participation in a DOE Complex Wide SAVY-4000 Surveillance Program

This document describes LANL Storage Program best practices when working with other User Sites to implement DOE M441.1-1 Manual requirements through the use of the SAVY nuclear material packaging system. It is a Manual directive for Field Element Managers to review and approve the SAVY-4000 container series design (with supporting technical basis) as a packaging system for use at their respective sites. This review and approval incorporates an evaluation of the User Site methodology for SAVY surveillance and the process for documenting its nuclear materials storage program. This document aims to assist the Field Element Mangers and User Sites in the processes necessary to credit LANL SAVY surveillance for key elements of the User Site surveillance plan.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRSDate not supplied

Conducting Feasibility Studies in a Virtual World: Lessons Learned and Emerging Best Practices from the NASA DEVELOP Program

In response to new workplace realities, the NASA DEVELOP National Program pivoted from co-locating students, emerging professionals, and science advisors to bringing together virtual teams from across the United States. In its spring 2020 term, rapidly evolving circumstances required an ad-hoc roll-out of a virtual approach to complete the spring projects. Based on the experience from the spring term and a few weeks of planning, DEVELOP then conducted a fully virtual summer term with features such as 1) online collaboration tools, 2) virtual machines for analysis, and 3) streamed training offerings, including DEVELOP’s first ever program-wide Software Carpentry workshop. This full term of bringing together remote actors to select, build, and manage teams brought many challenges. Summer feedback has influenced planning for the fall 2020 term and process improvement is ongoing. This presentation will highlight lessons learned throughout this period of rapid change. Feedback from spring and summer terms and the Software Carpentry workshop will be summarized. Beyond participant impacts, there will also be discussion of effects on project results and partner experience. Final takeaways will focus on best practices that have been distilled for virtually-conducted feasibility studies.

NASA DEVELOP↗
DOE OSTI2023

Women as a Force Multiplier for Bringing Nuclear Forensic Capabilities to the International Stage

In 2009, the US Department of Energy National Nuclear Security Administration’s (NNSA’s) Defense Nuclear Nonproliferation Program initiated a new nuclear forensics outreach effort under its Confidence Building Measures Program. Little did they know that the timing could not have been better. This article focuses on the early years (2009–2015) of the NNSA’s international nuclear forensics outreach, specifically the efforts and experiences of the women who helped establish this program, building it from a fledgling, bilateral effort into an enduring technical capacity provider engaging with dozens of countries and multilateral organizations. At the onset of the program, nuclear forensics was an emerging priority within the US Government and receiving increased focus from international organizations through high-level diplomatic efforts such as the Nuclear Security Summit and Global Initiative to Combat Nuclear Terrorism. Additionally, working-level initiatives were gaining traction through the International Atomic Energy Agency and the Nuclear Forensics International Technical Working Group. Over the next 6 years, a small team comprising a uniquely large number of women NNSA federal, contract, and national laboratory staff served as key leaders engaging with the international community to strengthen global technical nuclear forensics capacity and best practices. The program continues today under the Nuclear Smuggling Detection and Deterrence Program as Investigation Support. The experiences shared here detail a unique time period when the new technical discipline of nuclear forensics was beginning to mature and gain international traction. The authors have made every effort to remember history correctly and be as inclusive as possible. A wealth of training, guidance, and exercise documentation was developed in the 2009–2015 time frame, much of which still serves as the foundation for today’s even more extensive program and community of dedicated technical and diplomatic practitioners.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2024

Women as a force multiplier for bringing nuclear forensic capabilities to the international stage

In 2009, the U.S. Department of Energy / National Nuclear Security Administration’s (DOE/NNSA) Defense Nuclear Nonproliferation (DNN) Program initiated a new nuclear forensics outreach effort under its Confidence Building Measures Program. Little did they know that the timing could not have been better. This article focuses on the early years (2009-2015) of the NNSA’s international nuclear forensics outreach, specifically the efforts and experiences of the women who helped establish this program, building it from a fledgling bilateral effort into an enduring technical capacity provider engaging with dozens of countries and multilateral organizations. At the onset of the program, nuclear forensics was an emerging priority within the U.S. Government and receiving increased focus from international organizations through high-level diplomatic efforts such as the Nuclear Security Summit and Global Initiative to Combat Nuclear Terrorism. Additionally, working-level initiatives were gaining traction through the International Atomic Energy Agency and the Nuclear Forensics International Technical Working Group. Over the next six years, a small team comprised of a uniquely large number of women NNSA federal, contract, and national laboratory staff served as key leaders engaging with the international community to strengthen global technical nuclear forensics capacity and best practices. The program continues today under the Nuclear Smuggling Detection and Deterrence Program as Investigation Support. The experiences shared here detail a unique time period when the new technical discipline of nuclear forensics was beginning to mature and gain international traction. The authors have made every effort to remember history correctly and be as inclusive as possible. A wealth of training, guidance, and exercises documentation was developed in the 2009-2015 timeframe, much of which still serves as the foundation for today’s even more extensive program and community of dedicated technical and diplomatic practitioners.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
NASA NTRS2012

Simulation Tools Model Icing for Aircraft Design

Here s a simple science experiment to try: Place an unopened bottle of distilled water in your freezer. After 2-3 hours, if the water is pure enough, you will notice that it has not frozen. Carefully pour the water into a bowl with a piece of ice in it. When it strikes the ice, the water will instantly freeze. One of the most basic and commonly known scientific facts is that water freezes at around 32 F. But this is not always the case. Water lacking any impurities for ice crystals to form around can be supercooled to even lower temperatures without freezing. High in the atmosphere, water droplets can achieve this delicate, supercooled state. When a plane flies through clouds containing these droplets, the water can strike the airframe and, like the supercooled water hitting the ice in the experiment above, freeze instantly. The ice buildup alters the aerodynamics of the plane - reducing lift and increasing drag - affecting its performance and presenting a safety issue if the plane can no longer fly effectively. In certain circumstances, ice can form inside aircraft engines, another potential hazard. NASA has long studied ways of detecting and countering atmospheric icing conditions as part of the Agency s efforts to enhance aviation safety. To do this, the Icing Branch at Glenn Research Center utilizes a number of world-class tools, including the Center s Icing Research Tunnel and the NASA 607 icing research aircraft, a "flying laboratory" for studying icing conditions. The branch has also developed a suite of software programs to help aircraft and icing protection system designers understand the behavior of ice accumulation on various surfaces and in various conditions. One of these innovations is the LEWICE ice accretion simulation software. Initially developed in the 1980s (when Glenn was known as Lewis Research Center), LEWICE has become one of the most widely used tools in icing research and aircraft design and certification. LEWICE has been transformed over the years from strictly a research tool to one used routinely by industry and other government agencies. Glenn contractor William Wright has been the architect of this development, supported by a team of researchers investigating icing physics, creating validation data, and ensuring development according to standard software engineering practices. The program provides a virtual simulation environment for determining where water droplets strike an airfoil in flight, what kind of ice would result, and what shape that ice would take. Users can enter geometries for specific, two-dimensional cross sections of an airfoil or other airframe surface and then apply a range of inputs - different droplet sizes, temperatures, airspeeds, and more - to model how ice would build up on the surface in various conditions. The program s versatility, ease of use, and speed - LEWICE can run through complex icing simulations in only a few minutes - have contributed to it becoming a popular resource in the aviation industry.

Source record↗
NASA NTRS1989

An algorithm for the solution of dynamic linear programs

The algorithm's objective is to efficiently solve Dynamic Linear Programs (DLP) by taking advantage of their special staircase structure. This algorithm constitutes a stepping stone to an improved algorithm for solving Dynamic Quadratic Programs, which, in turn, would make the nonlinear programming method of Successive Quadratic Programs more practical for solving trajectory optimization problems. The ultimate goal is to being trajectory optimization solution speeds into the realm of real-time control. The algorithm exploits the staircase nature of the large constraint matrix of the equality-constrained DLPs encountered when solving inequality-constrained DLPs by an active set approach. A numerically-stable, staircase QL factorization of the staircase constraint matrix is carried out starting from its last rows and columns. The resulting recursion is like the time-varying Riccati equation from multi-stage LQR theory. The resulting factorization increases the efficiency of all of the typical LP solution operations over that of a dense matrix LP code. At the same time numerical stability is ensured. The algorithm also takes advantage of dynamic programming ideas about the cost-to-go by relaxing active pseudo constraints in a backwards sweeping process. This further decreases the cost per update of the LP rank-1 updating procedure, although it may result in more changes of the active set that if pseudo constraints were relaxed in a non-stagewise fashion. The usual stability of closed-loop Linear/Quadratic optimally-controlled systems, if it carries over to strictly linear cost functions, implies that the saving due to reduced factor update effort may outweigh the cost of an increased number of updates. An aerospace example is presented in which a ground-to-ground rocket's distance is maximized. This example demonstrates the applicability of this class of algorithms to aerospace guidance. It also sheds light on the efficacy of the proposed pseudo constraint relaxation scheme.

Psiaki, Mark L.↗