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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 577 records · Page 32

Obscured Star-Formation in Merging Galaxies: High Resolution Radio Imaging of a Time-Ordered Sequence

We present new, deep, high resolution 6cm and 4cm radio continuum images of the central regions of a time-ordered sequence of seven large galaxy mergers. The radio observations are able to detect star-forming re- gions that are completely obscured at optical wavelengths. In all systems, we detect numerous compact radio sources embedded in more diffuse ra- dio emission, with limiting luminosities of approx. 1-5 x 10(exp l8) W Hz or approx. 1-5 times the luminosity of Cas A. Many of the compact radio sources are loosely associated with active starforming regions but not with specific optical or W emission sources. Several of the compact radio sources are coincident with Ultra-luminous X-ray objects (ULX's). In most systems, we are able to measure reliable spectral indices for the stronger sources. We find that the fraction of compact radio cources with nominally flat radio spectral indices (indicating they ae dominated by thermal radio emission from HII regions) decreases with merger age, while the fraction of sources with nonimally steep spectral indices (indicating they are dominated by nonthermal emission from supernova remnants) increases. For the flat-spectrum sources, we estimate the numbers of young massive stars, associated ionized gas masses, we estimate supernova rates and required star-formation rates, We compare these results with those from other well-studied merging galaxy systems and from other determinations of star-formation rates. We gratefully acknowledge use of the NRAO Very Large Array (VLA) and the VLA Archive. NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Neff, S. G.↗

Fiber optic smart structures and skins II; Proceedings of the Meeting, Boston, MA, Sept. 5-8, 1989

The present conference on embedded fiber-optics incorporating 'smart' structural systems and structural surfaces discusses topics in the nature and current status of university- and government-sponsored smart-structure development programs, manufacturing and cure-monitoring for composite smart structures, smart-structure damage assessment, smart-structure actuators, and smart-structure sensors and components. Attention is given to fiber-optic sensor selection, the optical properties of curing epoxies, the automated production of smart structures, damage-detection in composites with embedded fiber-optic interferometers, fiber-optic strain and impact sensors, dynamically-tunable smart composites, smart structures incorporating artificial neural networks, active structural acoustic control with smart structures, and fiber-optic shape sensing for flexible structures.

Udd, Eric↗

Distributed processing on the Space Shuttle - A case study

A Power Extension Package (PEP) has been designed to provide additional electrical power and energy during Shuttle sortie missions. The considered investigation was conducted to determine the most suitable allocation of PEP monitoring and control functions between the Orbiter's existing (centralized) Systems Management General Purpose Computer and an embedded PEP processor. PEP monitoring and control functions are examined, and a configuration definition is considered, taking into account the 'functional migration' process, function allocation criteria, and candidate functional configurations. A trade study is conducted, giving attention to an assessment of four candidate configurations. Assessment factors are related to cost, development risk, aspects of reliability and safety, PEP design complexity, PEP/STS integration complexity, flight operations, and launch/landing site operations. A thorough (subjective) assessment of the PEP system life cycle indicates substantial benefits from a distributed processing approach.

Schoonmaker, P. B.↗

A Distributed Prognostic Health Management Architecture

This paper introduces a generic distributed prognostic health management (PHM) architecture with specific application to the electrical power systems domain. Current state-of-the-art PHM systems are mostly centralized in nature, where all the processing is reliant on a single processor. This can lead to loss of functionality in case of a crash of the central processor or monitor. Furthermore, with increases in the volume of sensor data as well as the complexity of algorithms, traditional centralized systems become unsuitable for successful deployment, and efficient distributed architectures are required. A distributed architecture though, is not effective unless there is an algorithmic framework to take advantage of its unique abilities. The health management paradigm envisaged here incorporates a heterogeneous set of system components monitored by a varied suite of sensors and a particle filtering (PF) framework that has the power and the flexibility to adapt to the different diagnostic and prognostic needs. Both the diagnostic and prognostic tasks are formulated as a particle filtering problem in order to explicitly represent and manage uncertainties; however, typically the complexity of the prognostic routine is higher than the computational power of one computational element ( CE). Individual CEs run diagnostic routines until the system variable being monitored crosses beyond a nominal threshold, upon which it coordinates with other networked CEs to run the prognostic routine in a distributed fashion. Implementation results from a network of distributed embedded devices monitoring a prototypical aircraft electrical power system are presented, where the CEs are Sun Microsystems Small Programmable Object Technology (SPOT) devices.

Bhaskar, Saha↗

The use of an automated flight test management system in the development of a rapid-prototyping flight research facility

An automated flight test management system (ATMS) and its use to develop a rapid-prototyping flight research facility for artificial intelligence (AI) based flight systems concepts are described. The ATMS provides a flight test engineer with a set of tools that assist in flight planning and simulation. This system will be capable of controlling an aircraft during the flight test by performing closed-loop guidance functions, range management, and maneuver-quality monitoring. The rapid-prototyping flight research facility is being developed at the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) to provide early flight assessment of emerging AI technology. The facility is being developed as one element of the aircraft automation program which focuses on the qualification and validation of embedded real-time AI-based systems.

Duke, Eugene L.↗

Experimental testing of additively manufactured embedded fiber optic smart devices for clean energy applications

Abstract An additively manufactured prototype smart device was created to investigate in-flow temperature distributions using embedded high-definition fiber optic sensors within a component for clean energy systems. The devices were created using Ultrasonic Additive Manufacturing to create a unique embedded pathway within a flow conditioner for the high-definition fiber optic sensors to be placed within. The fibers used allowed for temperature measurements to be taken every 0.65 mm along the fiber. The high-resolution fibers were thermally calibrated enable the 2D reconstruction of the temperature profile in the flow path of the structure. This is due to the temperature-related strain response of the material and strain measurements of the fibers. Hot airflow testing of these devices showed the ability to identify localized temperature differences in the flow. The observed strain response within the smart device had higher strain concentrations in the thicker web regions than in the thinner web regions. These higher strain regions resulted in higher uncertainties for the temperature responses. Further calibration is needed to improve the accuracy of the smart devices, specifically within the inner web structures of a flow straightening component. Further investigations of the devices within flow showed the temperature sensing to be independent of the effects of flow velocity. The devices were able to distinguish temperature differences within single and two-phase flow and showed local sensitivity to the temperature changes with the identification of hot and cold spots. The presented results showed the viability of the smart device for obtaining detailed temperature distributions using common industrial components. Eventually, the goal for these smart devices will be to withstand higher temperature and pressure environments such as those experienced in nuclear, fusion, and concentrated solar energy systems.

Donlan, Connor F. (ORCID:0000000223317882)↗

Control of a Thrust Alignment Table for Modeling the Coning Dynamics of a Spinning Spacecraft with a Follower Force

This document presents a system controlling the motion of a spherical air bearing used in the modeling of spacecraft dynamics and controls in a laboratory environment. The system is part of the Spinning Rocket Simulator (SRS), used to simulate the coning of spacecraft during a thrusting stage. The reaction force at the spherical air bearing supporting the spacecraft model must coincide with the thrust axis of the model for proper simulation. Therefore, the bearing is translated in a circular path to introduce a centrifugal force. This horizontal force along with the gravitational reaction force at the bearing combines to simulate the direction of the spacecraft's thrust force. The control system receives attitude information from the spacecraft model via a laser beam embedded in the model that impinges on a photosensitive array. The non-linear system is controlled using high-speed lookup tables and digital techniques. A vector-controlled motor and a stepper motor are given the necessary signals to accurately control the turntable and platform supporting the air bearing. Preliminary performance data is presented. Mechanical elements of the table and platform are described in detail. A wireless (RF) data path for all devices on the spacecraft model to an off-table command computer is also described.

Halsmer, Dominic↗

A Temporal Differential Dynamic Logic Formal Embedding

Differential dynamic logic is a formal framework to specify and reason about hybrid programs (HPs). The core of dL is a proof calculus that contains a collection of axioms and rules for the rigorous verification of properties of HPs. Recently, dL has been embedded within the theorem prover Prototype Verification System (PVS) resulting in the tool Plaidypvs2. The integration of dL into PVS expands its expressive power; user defined functions, such as trigonometric and other transcendental functions, can be used inside the dL framework, and meta-reasoning about HPs can be performed, including reasoning about entire classes of HPs, specified using dependent types in PVS. The differential temporal dynamic logic (dTL2) extends dL with temporal logic operators to reason about all the states reachable during the execution of an HP. This paper presents a work in progress focusing on embedding dTL2 in PVS as an extension of Plaidypvs. Plaidypvs is expanded with the formalization of a trace semantics for HPs, the definition of the LTL temporal operators eventually and globally, and the implementation of the proof calculus for dTL2. This new embedding has the same capabilties as Plaidypvs, which allows user defined functions and meta-reasoning of properties of HPs. To the best of the authors’ knowledge this is the first implementation of dTL2.

differential dynamic logic↗

[The Engineering and Technical Services Directorate at the Glenn Research Center]

My name is James Moon and I am a senior at Tennessee State University where my major is Aeronautical and Industrial Technology with a concentration in industrial electronics. I am currently serving my internship in the Engineering and Technical Services Directorate at the Glenn Research Center (GRC). The Engineering and Technical Service Directorate provides the services and infrastructure for the Glenn Research Center to take research concepts to reality. They provide a full range of integrated services including engineering, advanced prototyping and testing, facility management, and information technology for NASA, industry, and academia. Engineering and Technical Services contains the core knowledge in Information Technology (IT). This includes data systems and analysis, inter and intranet based systems design and data security. Including the design and development of embedded real-time s o h a r e applications for flight and supporting ground systems, Engineering and Technical Services provide a wide range of IT services and products specific to the Glenn Research Center research and engineering community. In the 7000 Directorate I work directly in the 7611 organization. This organization is known as the Aviation Environments Technical Branch. My mentor is Vincent Satterwhite who is also the Branch Chief of the Aviation Environments Technical Branch. In this branch, I serve as the Assistant program manager of the Engineering Technology Program. The Engineering Technology Program (ETP) is one of three components of the High School L.E.R.C.I.P. This is an Agency-sponsored, eight-week research-based apprenticeship program designed to attract traditionally underrepresented high school students that demonstrate an aptitude for and interest in mathematics, science, engineering, and technology.

Moon, James↗

Smart Sensors' Role in Integrated System Health Management

During the last decade, there has been a major effort in the aerospace industry to reduce the cost per pond of payload and become competitive in the international market. Competition from Europe, Japan, and China has reduced this cost to almost a third from 1990 to 2000. This cost has leveled in recent years to an average price of around $12,000/pound of payload. One of NASA's goals is to promote the development of technologies to reduce this cost by a factor of 10 or more Exploration of space, specially manned exploration missions, involves very complex launch and flight vehicles, associated ground support systems, and extensive human support during all phases of the mission. When considering the Space Shuttle Program, we can see that vehicle and ground support systems' processing, operation, and maintenance represent a large percentage of the program cost and time. Reducing operating, processing and maintenance costs will greatly reduce the cost of Exploration programs. The Integrated System Health Management (ISHM) concept is one of the technologies that will help reduce these operating, processing and maintenance costs. ISHM is an integrated health monitoring system applicable to both flight and ground systems. It automatically and autonomously acquires information from sensors and actuators and processes that information using the ISHM-embedded knowledge. As a result, it establishes the health of the system based on the acquired information and its prior knowledge. When this concept is fully implemented, ISHM systems shall be able to perform failure prediction and remediation before actual hard failures occurs, preventing its costly consequences. Data sources, sensors, and their associated data acquisition systems, constitute the foundation of the system. A smart sensing architecture is required to support the acquisition of reliable, high quality data, required by the ISHM. A thorough definition of the smart sensor architectures, their embedded diagnostic agents, and communication protocols need to be established and standardized to allow the embedding and exchange of health information among sensors and ISHM. This workshop is aimed to foster the exchange of ideas and lessons learned between government, industry and academia to aid in the establishment of ISHM (and smart sensors) standards and guidelines as well as to identify present technology gaps that will have to be overcome to successfully achieve this goal.

Perotti, Jose M.↗

An assessment of inductive coupling roadway powered vehicles

The technical concept underlying the roadway powered vehicle system is the combination of an electrical power source embedded in the roadway and a vehicle-mounted power pickup that is inductively coupled to the roadway power source. The feasibility of such a system, implemented on a large scale was investigated. Factors considered included current and potential transportation modes and requirements, economics, energy, technology, social and institutional issues. These factors interrelate in highly complex ways, and a firm understanding of each of them does not yet exist. The study therefore was structured to manipulate known data in equally complex ways to produce a schema of options and useful questions that can form a basis for further, harder research. A dialectical inquiry technique was used in which two adversary teams, mediated by a third-party team, debated each factor and its interrelationship with the whole of the known information on the topic.

Leschly, K. O.↗

Advanced Radiation Detectors and Detector Systems Research

Real‐time awareness of space radiation is critical for missions beyond LEO. Missions to the Moon, Mars, Near‐Earth‐Objects (NEOs), inner and outer planets, as well as other destinations in space, will require embedded instrumentation to provide feedback for “smart”, adaptive control systems. Precision instrumentation will also be needed to provide improved data for space radiation modeling and space weather forecasting and awareness. Compact instrumentation on small platforms such as CubeSats and other small space‐faring vehicles will provide a better understanding of the space radiation environment by supplying data from multiple locations in space where information is yet unknown. Compact integrable solid‐state detectors with low noise and high tolerance of operation in a radiation environment are enabled by the application of Wide Band Gap semiconductors as radiation detectors. NASA Glenn Research Center (GRC) is applying its expertise and facilities in harsh environment instrumentation to develop supporting technologies that enable improved instruments for space science missions. A variety of radiation detectors are under development, such as silicon carbide semiconductor detectors, for applications to space science, lunar prospecting, and fission power systems.

Field and particle detectors↗

SpaceCube Demonstration Platform

A document discusses how the HST SM4 SpaceCube flight spare was modified to create an experiment called the Space- Cube Demonstration Platform (SC DP) for use on the MISSE7 Space Station payload (in collaboration with NRL). It is designed to serve as an on-orbit platform for demonstrating advanced fault tolerance technologies. A simple C&DH (command and data handling) system was developed for the Virtex4 FPGAs (field programmable gate arrays). Both Virtex4s on each SpaceCube run the same program, and both receive incoming telemetry. The rad-hard service FPGA performs simple error checking to verify that the incoming telemetry is valid. The SpaceCube framework was modified to allow for new program files to be sent from the ground, to be stored on the SpaceCube, and to be executed through ground commands. Each SpaceCube Virtex4 FPGA has resources set aside for experiments that are functionally isolated from the C&DH system. The experiments communicate to the C&DH system through a set of dual port memories, and this area is where the fault-tolerance experiments are executed. With the use of Xilinx commercial Virtex4 FX60 FPGAs, the fault tolerant framework allows the system to recover from radiation upsets that occur in the rad-soft parts (Virtex4 FPGA logic, embedded PPCs in Virtex4 FPGAs, SDRAM and Flash), the C&DH system that runs simultaneously on both Virtex4 FPGAs that uses a robust telemetry packet structure, checksums, and the rad-hard service FPGA to validate incoming telemetry. The ability to be reconfigured from the ground while in orbit is a novel benefit, as well as is the onboard compression capabilities that allow compressed files from the ground to be uploaded to the SpaceCube.

Espinosa, Daniel↗

Real-Time Sensor Validation System Developed

Real-time sensor validation improves process monitoring and control system dependability by ensuring data integrity through automated detection of sensor data failures. The NASA Lewis Research Center, Expert Microsystems, and Intelligent Software Associates have developed an innovative sensor validation system that can automatically detect automated sensor failures in real-time for all types of mission-critical systems. This system consists of a sensor validation network development system and a real-time kernel. The network development system provides tools that enable systems engineers to automatically generate software that can be embedded within an application. The sensor validation methodology captured by these tools can be scaled to validate any number of sensors, and permits users to specify system sensitivity. The resulting software reliably detects all types of sensor data failures.

Zakrajsek, June F.↗

Transient Thermal Analyses of Passive Systems on SCEPTOR X-57

As efficiency, emissions, and noise become increasingly prominent considerations in aircraft design, turning to an electric propulsion system is a desirable solution. Achieving the intended benefits of distributed electric propulsion (DEP) requires thermally demanding high power systems, presenting a different set of challenges compared to traditional aircraft propulsion. The embedded nature of these heat sources often preclude the use of traditional thermal management systems in order to maximize performance, with less opportunity to exhaust waste heat to the surrounding environment. This paper summarizes the thermal analyses of X-57 vehicle subsystems that don't employ externally air-cooled heat sinks. The high-power battery, wires, high-lift motors, and aircraft outer surface are subjected to heat loads with stringent thermal constraints. The temperature of these components are tracked transiently, since they never reach a steady-state equilibrium. Through analysis and testing, this report demonstrates that properly characterizing the material properties is key to accurately modeling peak temperature of these systems, with less concern for spatial thermal gradients. Experimentally validated results show the thermal profile of these systems can be sufficiently estimated using reduced order approximations.

Thermal Analyses↗

Ab Initio Many Body Quantum Embedding and Local Correlation in Crystalline Materials using Interpolative Separable Density Fitting

We present an efficient implementation of ab initio many-body quantum embedding and local correlation methods for infinite periodic systems through translational symmetry adapted interpolative separable density fitting, an approach which reduces the scaling of the calculations to only linear with the number of k-points. Employing this methodology, we compute correlated ground-state coupled cluster energies within density matrix embedding and local natural orbital correlation frameworks for both weakly and strongly correlated solids, using up to 1000 k-points. By extrapolating the local correlation domains and k-point sampling we further obtain estimates of the full coupled cluster with singles, doubles, and perturbative triples ground-state energies in the thermodynamic limit.

Chemical Physics (physics.chem-ph)↗

High Resolution Radio Imaging of the Merging Galaxies NGC3256 and NGC4194

We present new 6cm and 4cm radio continuum images of the central regions of the merging galaxy systems NGC3256 and NGC4194. NGC3256 is imaged with a resolution of approx. 1 in. or approx. 190pc; NGC4194 is imaged with a resolution of approx. 0.3 in. or approx. 50pc. In both systems, we detect numerous compact radio sources embedded in more diffuse radio emission. We detect 65 compact sources in NGC3256 at 6cm and we detect 46 compact sources in NGC4194, both to a limiting luminosity of approx. 5 x 10(exp 18) W/ Hz or approx. 5 times the luminosity of Cas A. Most of the compact radio sources are loosely associated with active star forming regions but not with specific optical emission sources. Several compact radio sources in NGC3256 are near positions of compact X-ray sources detected by Lira et al.. In both NGC3256 and NGC4194, we are able to measure reliable spectral indices for the stronger sources. We find in NGC3256 approx. 20% have nominally flat radio spectral indices (indicating they are dominated by thermal radio emission from HII regions) while approx. 80% have nominally steep spectral indices (indicating they are dominated by nonthermal emission from supernova remnants). In NGC4194, half the compact radio sources have flat spectral indices and half have steep indices. For the flat-spectrum sources, we estimate the number of young massive stars and the associated ionized gas masses. For the steep-spectrum sources, we estimate supernova rates. We compare these results with those from other well-studied merging galaxy systems. We gratefully acknowledge use of the NRAO Very Large Array (VLA) and the VLA Archive. NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Neff, S. G.↗

SHINE Virtual Machine Model for In-flight Updates of Critical Mission Software

This software is a new target for the Spacecraft Health Inference Engine (SHINE) knowledge base that compiles a knowledge base to a language called Tiny C - an interpreted version of C that can be embedded on flight processors. This new target allows portions of a running SHINE knowledge base to be updated on a "live" system without needing to halt and restart the containing SHINE application. This enhancement will directly provide this capability without the risk of software validation problems and can also enable complete integration of BEAM and SHINE into a single application. This innovation enables SHINE deployment in domains where autonomy is used during flight-critical applications that require updates. This capability eliminates the need for halting the application and performing potentially serious total system uploads before resuming the application with the loss of system integrity. This software enables additional applications at JPL (microsensors, embedded mission hardware) and increases the marketability of these applications outside of JPL.

Plesea, Lucian↗