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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 325 records · Page 18

Bifunctional Heterometallic Metal-Organic Frameworks for Solvent-Free Heterogeneous Cascade Catalysis

A family of heterometallic metal-organic frameworks (MOFs) (CPM200s) harmoniously coexisting as Lewis acids and base (azo) sites were prepared. Seven CPM200s were employed as multifunctional heterogeneous cascade catalysts for the one-pot deacetalization-Knoevenagel reaction in a solvent-free system. Benefiting from the cooperation between Lewis acids from the open metal sites and base sites from the ligands, the CPM200s showed high activity and selectivity for the tandem reaction. The heterometallic 3D porous framework reported here not only offers a combination of two opposite active sites in the same framework of materials but also increases mass transfer of the substrate, thus maximizing the efficiency and substrate selectivity of the bifunctional catalysts. The CPM200s showed the highest turnover frequency (TOF), outperforming that of the reported MOFs in tandem with the deacetalization-Knoevenagel reaction. A strong correlation between the TOF and charge-to-radius ratio (z/r) of metal ions in the CPM200s was observed for the first time. The bifunctional CPM200s catalysts can be reused five times without significant loss of activity.

36 MATERIALS SCIENCE↗

System design of the Pioneer Venus spacecraft. Volume 12: International cooperation

A spectrum of plans has been prepared to illustrate the range of practical sharing possibilities available so as to assist Ames Research Center (ARC) and European Space Research Organization (ESRO) in selection of a program meeting mutual goals. Five plans are described showing increased participation by ESRO WITH ascending plan number. Each of these has sharing properties fulfilling particular requirements such as available ESRO budget level, extent of ESRO program responsibility, matching particular ESRO capability, and cost saving to ARC through sharing. All plans apply to orbiter sharing only. A sharing plan based on the model Plan 4 may offer the most attractive division of Pioneer Venus between ARC and ESRO. This plan allows ESRO to bear primary responsibility for the orbiter and to avoid an extensive financial burden. Savings to ARC are commensurate with ARC loss of program control. Duplication of effort is avoided by using orbiter subsystems that are common to the probe bus and orbiter.

Kelly, R. S.↗

Aeronautics and space report of the president, 1974 activities

The U.S. Government activities for 1974 in aeronautics and space are presented. Significant contributions toward the fulfillment of the nation's goals in space and aeronautics are covered, including application of space systems and technology to beneficial uses on earth, exploration of space and increase of scientific knowledge, development of improved space systems and technology, international cooperation, and advancement of civil and military aeronautics. Also in 1974, space activities in the private sector expanded to provide additional services to the public. The accomplishments are summarized.

Source record↗

Coal's role in California's energy needs

California's post-industrial society demands confidence in the energy supply system as an essential ingredient for social harmony and adequate job creating capital investment. Confidence requires policies which balance supply and demand using believable methods with adequate allowance for the unexpected, reliance on diverse sources and locations, respect for our environment, sustain our individual freedoms and provide opportunities for economic mobility. Coal will play only a part, but an important part, in a multifaceted energy policy using numerous energy sources and systems, conservation techniques, and cooperating societal institutions. Today's extensive and challenging research and development provides the foundation for future technologies which will further resolve the environmental effects associated with coal.

Daines, N. H.↗

World weather program

A brief description of the Global Weather Experiment is presented. The world weather watch program plan is described and includes a global observing system, a global data processing system, a global telecommunication system, and a voluntary cooperation program. A summary of Federal Agency plans and programs to meet the challenges of international meteorology for the two year period, FY 1980-1981, is presented.

Source record↗

Aircraft observations and cloud-microwave radiative model simulations of a deep convective system

A 3D cloud model is used to simulate the storm structure of the June 29, 1986 storm system observed during the Cooperative Huntsville Meteorological Experiment (Dodge et al., 1986), and the results are linked to a microwave radiative transfer model for simulating aircraft observations. The results of cloud and radiative model simulations are then compared with radar data and aircraft microwave observations, respectively. It is shown that the degree of agreement between model simulations and the aircraft microwave observations depends on the model-derived microphysics of cloud and precipitation. It is found that the calculated values of the brightness temperature (Tb) at 92 GHz are close to the observed temperatures, while the calculated Tb values at 18 and 37 GHz are lower than the observed Tb.

Yeh, H.-Y. M.↗

Advances in dynamics and control of flexible spacecraft and space-based manipulations; Proceedings of the Symposium, ASME Winter Annual Meeting, Dallas, TX, Nov. 25-30, 1990

Consideration is given to control formulations for vibration suppression of an active structure in slewing motions, the use if distributed sensing in control of large flexible spacecraft, an improved shooting method for solving minimum-time maneuver problems, and nonlinear slew maneuver dynamics of large flexible spacecrafts. Attention is also given to initial experiments in trusterless locomotion control of a free-flying robot, dynamic analysis to evaluate viscoelastic passive damping augmentation for the Space Shuttle Remote Manipulator System, initial experiments in cooperative manipulation from a moving platform, and intelligent pipelined control architecture for remote robotic applications.

Joshi, Suresh M.↗

Global change information support: A north-south coalition

On a daily basis we become more aware that our planet, earth, exists in a delicate balance; we, its inhabitants, must be informed caretakers. Global change communities have emerged around the globe to address this multidisciplinary subject. Information systems that integrate text, bibliographic, numeric and visual data are needed to support these global change communities. No one information center can hope to collect all the relevant data. Rather, we must form a coalition, North and South, to collect and provide access to disparate, multidisciplinary sources of information, and to develop standardized tools for documenting and manipulating this data and information. International resources need to be mobilized in a coordinated manner to move us towards this goal. This paper looks at emerging information technologies that can be utilized to build such a system, and outlines some cooperative North/South strategies.

Blados, Walter R.↗

Global change information support - A north/south coalition

On a daily basis we become more aware that our planet, earth, exists in a delicate balance; we, its inhabitants, must be informed caretakers. Global change communities have emerged around the globe to address this multidisciplinary subject. Information systems that integrate text, bibliographic, numeric and visual data are needed to support these global change communities. No one information center can hope to collect all the relevant data. Rather, we must form a coalition, North and South, to collect and provide access to disparate, multidisciplinary sources of information, and to develop standardized tools for documenting and manipulating this data and information. International resources need to be mobilized in a coordinated manner to move us towards this goal. This paper looks at emerging information technologies that can be utilized to build such a system, and outlines some cooperative North/South strategies.

Blados, Walter R.↗

Critically evaluated/distributed database of IRAS LRS spectra

Accomplishments under this grant effort include: successful scientific utilization of the IRAS Low Resolution Spectrometer (LRS) database of over 150,000 scans of 7-23 micron spectra for over 50,000 celestial sources; publication in refereed journal of an additional 486 critically evaluated spectra of sources brighter than 20 Jy, completing the LRS ATLAS (Olnon and Raimond 1986 A&A) uniformly to that level, and production of an additional 1,830 critically evaluated spectra of sources brighter than 10 Jy; creation and maintenance of on-line, remotely accessible LRS spectra of over 7500 sources; cooperation with Astrophysics Data System personnel for transitioning this LRS database to the ADS access system after funding for this project expires; and publication of research highlights, which include a systematic variation of the shapes of LRS silicate features among stars of differing IRAS broad-band colors, maser characteristics and light curve asymmetries, all correlated with the chemical and physical development and processing of solid phase materials, and preliminary evidence for silicate profile variations in individual stars as a function of visual light curve phase.

Stencel, R. E.↗

SCOS 2: An object oriented software development approach

The Spacecraft Control and Operations System 2 (SCOS 2), is intended to provide the generic mission control system infrastructure for future ESA missions. It represents a bold step forward in order to take advantage of state-of-the-art technology and current practices in the area of software engineering. Key features include: (1) use of object oriented analysis and design techniques; (2) use of UNIX, C++ and a distributed architecture as the enabling implementation technology; (3) goal of re-use for development, maintenance and mission specific software implementation; and (4) introduction of the concept of a spacecraft control model. This paper touches upon some of the traditional beliefs surrounding Object Oriented development and describes their relevance to SCOS 2. It gives rationale for why particular approaches were adopted and others not, and describes the impact of these decisions. The development approach followed is discussed, highlighting the evolutionary nature of the overall process and the iterative nature of the various tasks carried out. The emphasis of this paper is on the process of the development with the following being covered: (1) the three phases of the SCOS 2 project - prototyping & analysis, design & implementation and configuration / delivery of mission specific systems; (2) the close cooperation and continual interaction with the users during the development; (3) the management approach - the split between client staff, industry and some of the required project management activities; (4) the lifecycle adopted being an enhancement of the ESA PSS-05 standard with SCOS 2 specific activities and approaches defined; and (5) an examination of some of the difficulties encountered and the solutions adopted. Finally, the lessons learned from the SCOS 2 experience are highlighted, identifying those issues to be used as feedback into future developments of this nature. This paper does not intend to describe the finished product and its operation, but focusing on the journey to arrive there, concentrating therefore on the process and not the products of the SCOS 2 software development.

Symonds, Martin↗

Parallelization of Rocket Engine Simulator Software (PRESS)

Parallelization of Rocket Engine System Software (PRESS) project is part of a collaborative effort with Southern University at Baton Rouge (SUBR), University of West Florida (UWF), and Jackson State University (JSU). The second-year funding, which supports two graduate students enrolled in our new Master's program in Computer Science at Hampton University and the principal investigator, have been obtained for the period from October 19, 1996 through October 18, 1997. The key part of the interim report was new directions for the second year funding. This came about from discussions during Rocket Engine Numeric Simulator (RENS) project meeting in Pensacola on January 17-18, 1997. At that time, a software agreement between Hampton University and NASA Lewis Research Center had already been concluded. That agreement concerns off-NASA-site experimentation with PUMPDES/TURBDES software. Before this agreement, during the first year of the project, another large-scale FORTRAN-based software, Two-Dimensional Kinetics (TDK), was being used for translation to an object-oriented language and parallelization experiments. However, that package proved to be too complex and lacking sufficient documentation for effective translation effort to the object-oriented C + + source code. The focus, this time with better documented and more manageable PUMPDES/TURBDES package, was still on translation to C + + with design improvements. At the RENS Meeting, however, the new impetus for the RENS projects in general, and PRESS in particular, has shifted in two important ways. One was closer alignment with the work on Numerical Propulsion System Simulator (NPSS) through cooperation and collaboration with LERC ACLU organization. The other was to see whether and how NASA's various rocket design software can be run over local and intra nets without any radical efforts for redesign and translation into object-oriented source code. There were also suggestions that the Fortran based code be encapsulated in C + + code thereby facilitating reuse without undue development effort. The details are covered in the aforementioned section of the interim report filed on April 28, 1997.

Cezzar, Ruknet↗

Nonlinear Acoustics Used To Reduce Leakage Flow

Leakage and wear are two fundamental problems in all traditional turbine seals that contribute to an engine's inefficiency. The solutions to seal leakage and wear conflict in the conventional design space. Reducing the clearance between the seal and rotating shaft reduces leakage but increases wear because of increased contact incidents. Increasing the clearance to reduce the contact between parts reduces wear but increases parasitic leakage. The goal of this effort is to develop a seal that restricts leakage flow using acoustic pressure while operating in a noncontacting manner, thereby increasing life. In 1996, Dr. Timothy Lucas announced his discovery of a method to produce shock-free high-amplitude pressure waves. For the first time, the formation of large acoustic pressures was possible using dissonant resonators. A pre-prototype acoustic seal developed at the NASA Glenn Research Center exploits this fundamental acoustic discovery: a specially shaped cavity oscillated at the contained fluid's resonant frequency produces high-amplitude acoustic pressure waves of a magnitude approaching those required of today's seals. While the original researchers are continuing their development of acoustic pumps, refrigeration compressors, and electronic thermal management systems using this technology, the goal of researchers at Glenn is to apply these acoustic principles to a revolutionary sealing device. When the acoustic resonator shape is optimized for the sealing device, the flow from a high-pressure cavity to a low-pressure cavity will be restricted by a series of high-amplitude standing pressure waves of higher pressure than the pressure to be sealed. Since the sealing resonator cavity will not touch the adjacent sealing structures, seal wear will be eliminated, improving system life. Under a cooperative agreement between Glenn and the Ohio Aerospace Institute (OAI), an acoustic-based pre-prototype seal was demonstrated for the first time. A pressurized cavity was attached to one end of the resonator while the other end remained open to ambient pressure. Measurements were taken at several values of applied pressure with the assembly stationary, oscillated at an off-resonance frequency, and then oscillated on-resonance. The three cases show that the flow through the conical resonator can be reduced by oscillating the resonator at the resonance frequency of the air contained within the cavity. The results are currently being compared with results obtained from a commercial computational fluid dynamics code. The objective is to improve the design through numerical simulation before fabricating a next-generation prototype sealing device. Future work is aimed at implementing acoustic seal design improvements to further reduce the leakage flow rate through the device and at reducing the device's overall size.

Daniels, Christopher C.↗

Next Generation Life Support Project Status

Next Generation Life Support (NGLS) is one of over twenty technology development projects sponsored by NASA's Game Changing Development Program. The NGLS Project develops selected life support technologies needed for humans to live and work productively in space, with focus on technologies for future use in spacecraft cabin and space suit applications. Over the last three years, NGLS had five main project elements: Variable Oxygen Regulator (VOR), Rapid Cycle Amine (RCA) swing bed, High Performance (HP) Extravehicular Activity (EVA) Glove, Alternative Water Processor (AWP) and Series-Bosch Carbon Dioxide Reduction. The RCA swing bed, VOR and HP EVA Glove tasks are directed at key technology needs for the Portable Life Support System (PLSS) and pressure garment for an Advanced Extravehicular Mobility Unit (EMU). Focus is on prototyping and integrated testing in cooperation with the Advanced Exploration Systems (AES) Advanced EVA Project. The HP EVA Glove Element, new this fiscal year, includes the generation of requirements and standards to guide development and evaluation of new glove designs. The AWP and Bosch efforts focus on regenerative technologies to further close spacecraft cabin atmosphere revitalization and water recovery loops and to meet technology maturation milestones defined in NASA's Space Technology Roadmaps. These activities are aimed at increasing affordability, reliability, and vehicle self-sufficiency while decreasing mass and mission cost, supporting a capability-driven architecture for extending human presence beyond low-Earth orbit, along a human path toward Mars. This paper provides a status of current technology development activities with a brief overview of future plans.

Barta, Daniel J.↗

Handling Late Changes to Titan Science

The Cassini mission has been in orbit for eight years, returning a wealth of scientific data from Titan and the Saturnian system. The mission, a cooperative undertaking between NASA, ESA and ASI, is currently in its second extension of the prime mission. The Cassini Solstice Mission (CSM) extends the mission's lifetime until Saturn's northern summer solstice in 2017. The Titan Orbital Science Team (TOST) has the task of integrating the science observations for all 56 targeted Titan flybys in the CSM. In order to balance Titan science across the entire set of flybys during the CSM, to optimize and influence the Titan flyby altitudes, and to decrease the future workload, TOST went through a "jumpstart" process before the start of the CSM. The "jumpstart" produced Master Timelines for each flyby, identifying prime science observations and allocating control of the spacecraft attitude to specific instrument teams. Three years after completing this long-range plan, TOST now faces a new challenge: incorporating changes into the Titan Science Plan without undoing the balance achieved during the jumpstart.

Pitesky, Jo Eliza↗

Weather Guidance for UAS Urban Medical Transport Missions

Unmanned aircraft will revolutionize healthcare services by providing efficient and expeditious delivery of life-saving transplant organs and supplies to hospitals in urban environments, where road traffic and congestion can slow delivery times and endanger lives. Bell has developed the Autonomous Pod Transport (APT) vehicle to serve this market, with entry into service in mid-2020s. Adverse weather conditions can introduce risks and inefficiencies in urban environments leading to flight delays and cancellations. In 2018, National Aeronautics and Space Administration (NASA) and Bell entered into a cooperative agreement, under the Systems Integration and Operationalization (SIO) program to tackle key challenges to enable future commercial unmanned aircraft operations. The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) at the University of Massachusetts, Amherst, joined this team to demonstrate weather avoidance technologies for remotely piloted and autonomous vehicles. CASA has developed the ‘City Warn’ hazard alerting platform to gather weather information from various weather sensors and models, and based on user (or mission) preferences for alerting and on user (or unmanned aircraft) locations, the platform shares timely weather intelligence with users and the systems used by them for remote operations. This presentation discusses the weather avoidance solution developed during this project, leading up to the demonstration of the end-to-end system in Fall 2020. The presentation will cover the following topics: 1) goals related to weather avoidance 2) the design requirements process, including the results of pilot interviews, 3) weather observation and avoidance needs 4) selection of regional and national weather data sets 5) design of the weather graphical interface and 6) considerations for real-time weather alerting. The end-to-end system that was developed will be discussed, along with the results from the demonstration flight. The presentation will conclude with insights from the project team on lessons learned and best practices on weather avoidance technologies for the industry going ahead.

weather avoidance↗

Weather Guidance for UAS Urban Medical Transport Missions

Unmanned aircraft will revolutionize healthcare services by providing efficient and expeditious delivery of life-saving transplant organs and supplies to hospitals in urban environments, where road traffic and congestion can slow delivery times and endanger lives. Bell has developed the Autonomous Pod Transport (APT) vehicle to serve this market, with entry into service in mid-2020s. Adverse weather conditions can introduce risks and inefficiencies in urban environments leading to flight delays and cancellations. In 2018, National Aeronautics and Space Administration (NASA) and Bell entered into a cooperative agreement, under the Systems Integration and Operationalization (SIO) program to tackle key challenges to enable future commercial unmanned aircraft operations. The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) at the University of Massachusetts, Amherst, joined this team to demonstrate weather avoidance technologies for remotely piloted and autonomous vehicles. CASA has developed the ‘City Warn’ hazard alerting platform to gather weather information from various weather sensors and models, and based on user (or mission) preferences for alerting and on user (or unmanned aircraft) locations, the platform shares timely weather intelligence with users and the systems used by them for remote operations. This presentation discusses the weather avoidance solution developed during this project, leading up to the demonstration of the end-to-end system in Fall 2020. The presentation will cover the following topics: 1) goals related to weather avoidance 2) the design requirements process, including the results of pilot interviews, 3) weather observation and avoidance needs 4) selection of regional and national weather data sets 5) design of the weather graphical interface and 6) considerations for real-time weather alerting. The end-to-end system that was developed will be discussed, along with the results from the demonstration flight. The presentation will conclude with insights from the project team on lessons learned and best practices on weather avoidance technologies for the industry going ahead.

weather avoidance↗