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Two nondestructive techniques were used to evaluate diffusion bond quality between a metal fail honeycomb and porous wireform substrate. The two techniques, cryographics and acousto-ultrasonics, are complementary in revealing variations of bond integrity and quality in shroud segments from an experimental aircraft turbine engine. Previously announced in STAR as N82-18612
Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data were acquired over the Goldfield Mining District, Nevada, in September 1987. Goldfield is one of the group of large epithermal precious metal deposits in Tertiary volcanic rocks, associated with silicic volcanism and caldera formation. Hydrothermal alteration consists of silicification along fractures, advanced agrillic and argillic zones further away from veins and more widespread propylitic zones. An evaluation of AVIRIS data quality was performed. Faults in the data, related to engineering problems and a different behavior of the instrument while on-board the U2, were encountered. Consequently, a decision was made to use raw data and correct them only for dark current variations and detector read-out-delays. New software was written to that effect. Atmospheric correction was performed using the flat field correction technique. Analysis of the data was then performed to extract spectral information, mainly concentrating on the 2 to 2.45 micron window, as the alteration minerals of interest have their distinctive spectral reflectance features in this region. Principally kaolinite and alunite spectra were clearly obtained. Mapping of the different minerals and alteration zones was attempted using ratios and clustering techniques. Poor signal-to-noise performance of the instrument and the lack of appropriate software prevented the production of an alteration map of the area. Spectra extracted locally from the AVIRIS data were checked in the field by collecting representative samples of the outcrops.
The success of the National Aeronautics and Space Administration's scientific and engineering projects is often based on the capability and quality of the metrology and calibration programs of its field centers and facilities. A Metrology and Calibration Working Group, having representation from each of the NASA field centers and facilities, was established to develop and implement a program to provide a centralized direction and agency wide focus. A brief history of the Group is presented. The development of the Group's operating philosophy, the long term objectives, the measurement research and development program, and review of accomplishments is discussed.
Structural optimization procedures usually start from a given design topology and vary its proportions or boundary shapes to achieve optimality under various constraints. Two different categories of structural optimization are distinguished in the literature, namely sizing and shape optimization. A major restriction in both cases is that the design topology is considered fixed and given. Questions concerning the general layout of a design (such as whether a truss or a solid structure should be used) as well as more detailed topology features (e.g., the number and connectivities of bars in a truss or the number of holes in a solid) have to be resolved by design experience before formulating the structural optimization model. Design quality of an optimized structure still depends strongly on engineering intuition. This article presents a novel approach for initiating formal structural optimization at an earlier stage, where the design topology is rigorously generated in addition to selecting shape and size dimensions. A three-phase design process is discussed: an optimal initial topology is created by a homogenization method as a gray level image, which is then transformed to a realizable design using computer vision techniques; this design is then parameterized and treated in detail by sizing and shape optimization. A fully automated process is described for trusses. Optimization of two dimensional solid structures is also discussed. Several application-oriented examples illustrate the usefulness of the proposed methodology.
Among the many problems of growing plants in completely controlled environments, such as those anticipated for the space station and the CELSS program, is the need to provide light that is both adequate for photosynthesis and of proper quality for normal growth and development. NASA scientists and engineers have recently become interested in the possibility of utilizing densely packed, solid state, light emitting diodes (LED's) as a source for this light. Unlike more conventional incandescent or electrical discharge lamps, these sources are highly monochromatic and lack energy in spectral regions thought to be important for normal plant development. In addition, a recent observation by NASA scientist has suggested that infra-red LED's, that are routinely used as photographic safelights for plants grown in darkness, may interact with the ability of plants to detect gravity. In order to establish how plants respond to light from these LED light sources we carried out a series of experiments with known pigment mutants of the model mustard plant, Arabidopsis thaliana, growing in either a gravity field or on a clinostat to simulate a micro-gravity environment. Results indicate that only red light from the 665 nm LED's disrupts the ability of normal wildtype seedlings to detect a gravity stimulus. There was no consistent effect found for the far-red (735 nm) LED's or either of the infrared (880 nm or 935 nm) LED sources but both showed some effect in one or more of the genotypes tested. Of these five members of the phytochrome multigene family in Arabidopsis, only the phytochrome B pigment mutant (hy3) lacked the ability to detect gravity under all conditions. There was no effect of either micro-gravity (clinostat) or the infra-red LED's on the light induced inhibition of hypocotyl elongation. Measurements of the pigment phytochrome in oats also showed no photoconversion by 15 min irradiations with the infra-red LED's. We conclude that phytochrome B is required for the perception of gravity and that only red light is able to disrupt this perception. The infra-red LED's also do not appear to interact with gravity perception in Arabidopsis, but caution should be exercised if infra-red LED's are to be used as photographic safelights for these types of experiments.
In-situ HO(x) (OH and HO2) measurements are an essential part of understanding the photochemistry of aircraft exhaust in the atmosphere. HO(x) affects the partitioning of nitrogen species in the NO(y) family. Its reactions are important sources and sinks for tropospheric ozone, thus providing a link between the NO(x) in aircraft exhaust and tropospheric ozone. OH mixing ratios are enhanced in aircraft wakes due to the photolysis of the HONO that is made close to the engine. Measurements of HO(x) in aircraft wakes, along with NO(x) measurements, thus provides a constraint on chemical models of the engine combustion and exhaust. The development of the Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) is reported. We designed, developed, and successfully flew this instrument. It was part of the instrument complement on board the NASA DC-8 during SUCCESS, which took place in Kansas in April and May, 1996. ATHOS has a limit-of-detection for OH (S/N = 2) of 10(exp 5) OH molecules cm(exp -3) in less than 150 seconds. While this sensitivity is about 2-3 times less than the initial projections in the proposal, it is more than adequate for good measurements of OH and HO2 from the planetary boundary layer to the stratosphere. Our participation in SUCCESS was to be engineering test flights for ATHOS; however, the high-quality measurements we obtained are being used to study HO(x) photochemistry in contrails, clouds, and the clear air.
The National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), the United States Department of Agriculture (USDA), and the United States Geological Survey (USGS), and their associates and partners, are directly responsible for establishing and leading a unique interagency team of scientists and engineers who work together to evaluate and enhance the quality remote sensing data for commercial and government use. This team is called "the Joint Agency Commercial Imagery Evaluation (JACIE) team". The team works together to define, prioritize, assign, and assess civil and commercial image quality and jointly sponsors an annual JACIE Civil Commercial Imagery Evaluation workshop with participation support from the remote sensing calibration and validation science community.
We are developing impedance controlled twisted string actuators (TSA) for use in tensegrity robots, as an alternative to traditional spooled cable actuation. Tensegrity robots are composed of continuous tension and discontinuous compression elements, with no rigid joints between elements, which give them unique force distribution properties. The use of tensegrity robots is strongly motivated by biological examples, and they are capable of locomotion and manipulation by changing lengths of their continuous network of tensional elements, which is also the primary pathways for load transfer through the structure. TSA show the potential to address some of the unique engineering challenges faced by tensegrity structures, and provide unique qualities well suited to an actively controlled tension system, such as compact, light-weight mechanical structures, inherent compliance, variable gearing'', and the ability to transmit high forces with a very low input torque. The inherent variable compliance of impedance control is essential for tensegrity robots to move through and manipulate the environment, and is a natural match to the unique qualities of TSA. This paper briefly introduces the tensegrity robots in the NASA Ames Intelligent Robotics Group and an overview of their future application to space planetary exploration. Then the effectiveness and robustness of TSA are verified through the performance of impedance control modes.
The words reliability, robustness, and resilience are often used interchangeably to describe tough and dependable systems but the distinctions between them suggest how to design more serviceable space systems. Reliability is simply the quality of consistently performing well. A system that dependably meets its design requirements in the specified environment is reliable. The designers may not consider themselves responsible for failures under unanticipated conditions. Robustness is the capability of performing without failure under a wide range of conditions, which can go beyond the expected range to include possible off-nominal conditions. Resilience is the ability to recover from or adapt to unanticipated damaging events, such as failures, accidents, external disruptions, and repurposing. Such changes can invalidate the usual operating assumptions and cause system failure. Reliability, robustness, and resilience describe dependable performance under increasingly difficult conditions, first the specified environment, then a wider possible environment, and finally unanticipated damaging conditions. These three qualities are increasingly desirable and increasingly difficult to achieve. Engineering for resilience would design systems that can ignore or repair failures, survive accidents, and recover from unanticipated disruptions. Increasing the resilience of space systems would greatly increase space crew safety. Improving reliability and robustness requires dealing with known problems, but improving resilience requires implementing a general approach to reducing the impact of unknown future events. The need for robustness and resilience has been stated for decades but little has been done. Systems designers often assume that they understand everything they need to know. The potential failures caused by changes, failures, accidents, unknown environments, and unknown unknowns can be ignored. Such overconfidence can lead to neglect of reliability, robustness, and resilience.
The words reliability, robustness, and resilience are often used interchangeably to describe tough and dependable systems but the distinctions between them suggest how to design more serviceable space systems. Reliability is simply the quality of consistently performing well. A system that dependably meets its design requirements in the specified environment is reliable. The designers may not consider themselves responsible for failures under unanticipated conditions. Robustness is the capability of performing without failure under a wide range of conditions, which can go beyond the expected range to include possible off-nominal conditions. Resilience is the ability to recover from or adapt to unanticipated damaging events, such as failures, accidents, external disruptions, and repurposing. Such changes can invalidate the usual operating assumptions and cause system failure. Reliability, robustness, and resilience describe dependable performance under increasingly difficult conditions, first the specified environment, then a wider possible environment, and finally unanticipated damaging conditions. These three qualities are increasingly desirable and increasingly difficult to achieve. Engineering for resilience would design systems that can ignore or repair failures, survive accidents, and recover from unanticipated disruptions. Increasing the resilience of space systems would greatly increase space crew safety. Improving reliability and robustness requires dealing with known problems, but improving resilience requires implementing a general approach to reducing the impact of unknown future events. The need for robustness and resilience has been stated for decades but little has been done. Systems designers often assume that they understand everything they need to know. The potential failures caused by changes, failures, accidents, unknown environments, and unknown unknowns can be ignored. Such overconfidence can lead to neglect of reliability, robustness, and resilience.
The One System Integrated Project Team (IPT) was formed in late 2011 as a way for improving the efficiency of delivery and treatment of highly radioactive waste stored in underground tanks at the U.S. Department of Energy's (DOE's) 586-square-mile Hanford Site in southeastern Washington State. The purpose of the One System IPT is to improve coordination and integration between the Hanford's Waste Treatment Plant (WTP) contractor and the Tank Operations Contractor (TOC). The vision statement is: One System is a WTP and TOC safety conscious team that, through integrated management and implementation of risk-informed decision and mission-based solutions, will enable the earliest start of safe and efficient treatment of Hanford's tank waste, to protect the Columbia River, environment and public. The IPT is a formal collaboration between Bechtel National, Inc. (BNI), which manages design and construction of the WTP for the U.S. Department of Energy's Office of River Protection (DOEORP), and Washington River Protection Solutions (WRPS), which manages the TOC for ORP. More than fifty-six (56) million gallons of highly radioactive liquid waste are stored in one hundred seventy-seven (177) aging, underground tanks. Most of Hanford's waste tanks - one hundred forty-nine (149) of them - are of an old single-shell tank (SST) design built between 1944 and 1964. More than sixty (60) of these tanks have leaked in the past, releasing an estimated one million gallons of waste into the soil and threatening the nearby Columbia River. There are another twenty-eight (28) new double-shelled tanks (DSTs), built from 1968 to 1986, that provide greater protection to the environment. In 1989, DOE, the U.S. Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) signed a landmark agreement that required Hanford to comply with federal and state environmental standards. It also paved the way for agreements that set deadlines for retrieving the tank wastes and for building and operating the WTP. The tank wastes are the result of Hanford's nearly fifty (50) years of plutonium production. In the intervening years, waste characteristics have been increasingly better understood. However, waste characteristics that are uncertain and will remain as such represent a significant technical challenge in terms of retrieval, transport, and treatment, as well as for design and construction ofWTP. What also is clear is that the longer the waste remains in the tanks, the greater the risk to the environment and the people of the Pacific Northwest. The goal of both projects - tank operations and waste treatment - is to diminish the risks posed by the waste in the tanks at the earliest possible date. About two hundred (200) WTP and TOC employees comprise the IPT. Individual work groups within One System include Technical, Project Integration & Controls, Front-End Design & Project Definition, Commissioning, Nuclear Safety & Engineering Systems Integration, and Environmental Safety and Health and Quality Assurance (ESH&QA). Additional functions and team members will be added as the WTP approaches the operational phase. The team has undertaken several initiatives since its formation to collaborate on issues: (1) alternate scenarios for delivery of wastes from the tank farms to WTP; (2) improvements in managing Interface Control Documents; (3) coordination on various technical issues, including the Defense Nuclear Facilities Nuclear Safety Board's Recommendation 2010-2; (4) deployment of the SmartPlant Foundation-configuration Management System; and (5) preparation of the joint contract deliverable of the Operational Readiness Support Plan.
This fact sheet provides a brief introduction to biodiesel, including a discussion of biodiesel blends and specifications. It also covers how biodiesel compares to diesel fuel in terms of performance (including in cold weather) and whether there are adverse effects on engines or other systems. Finally, it discusses biodiesel fuel quality and standards, and compares biodiesel emissions to those of diesel fuel.
Three post-mold operations performed in wind blade manufacturing include: trimming, to remove excess flashing; grinding, to shape the leading edge; and sanding, to prepare the are for bonding of over-lamination or paint. This work focuses on automating these three operations. Each operation scans the blade to build a point cloud, plans a tool path for the operation, and executes the toolpath using an industrial robot arm. The results are analyzed to determine the operational speed and the finish quality.
The One System Integrated Project Team (IPT) was formed in late 2011 as a way for improving the efficiency of delivery and treatment of highly radioactive waste stored in underground tanks at the U.S. Department of Energy's (DOE's) 586-square-mile Hanford Site in southeastern Washington State. The purpose of the One System IPT is to improve coordination and integration between the Hanford's Waste Treatment Plant (WTP) contractor and the Tank Operations Contractor (TOC). The vision statement is: One System is a WTP and TOC safety-conscious team that, through integrated management and implementation of risk-informed decision and mission-based solutions, will enable the earliest start of safe and efficient treatment of Hanford's tank waste, to protect the Columbia River, environment and public. The IPT is a formal collaboration between Bechtel National, Inc. (BNI), which manages design and construction of the WTP for the U.S. Department of Energy's Office of River Protection (DOEORP), and Washington River Protection Solutions (WRPS), which manages the TOC for ORP. More than fifty-six (56) million gallons of highly radioactive liquid waste are stored in one hundred seventy-seven (177) aging, underground tanks. Most of Hanford's waste tanks - one hundred forty-nine (149) of them - are of an old single-shell tank (SST) design built between 1944 and 1964. More than sixty (60) of these tanks have leaked in the past, releasing an estimated one million gallons of waste into the soil and threatening the nearby Columbia River. There are another twenty-eight (28) new double-shelled tanks (DSTs), built from 1968 to 1986, that provide greater protection to the environment. In 1989, DOE, the U.S. Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) signed a landmark agreement that required Hanford to comply with federal and state environmental standards. It also paved the way for agreements that set deadlines for retrieving the tank wastes and for building and operating the WTP. The tank wastes are the result of Hanford's nearly fifty (50) years of plutonium production. In the intervening years, waste characteristics have been increasingly better understood. However, waste characteristics that are uncertain and will remain as such represent a significant technical challenge in terms of retrieval, transport, and treatment, as well as for design and construction of WTP. What also is clear is that the longer the waste remains in the tanks, the greater the risk to the environment and the people of the Pacific Northwest. The goal of both projects - tank operations and waste treatment - is to diminish the risks posed by the waste in the tanks at the earliest possible date. About two hundred (200) WTP and TOC employees comprise the IPT. Individual work groups within One System include Technical, Project Integration and Controls, Front-End Design and Project Definition, Commissioning, Nuclear Safety and Engineering Systems Integration, and Environmental Safety and Health and Quality Assurance (ESH and QA). Additional functions and team members will be added as the WTP approaches the operational phase. The team has undertaken several initiatives since its formation to collaborate on issues: (1) alternate scenarios for delivery of wastes from the tank farms to WTP; (2) improvements in managing Interface Control Documents; (3) coordination on various technical issues, including the Defense Nuclear Facilities Nuclear Safety Board's Recommendation 2010-2; (4) deployment of the SmartPlant{sup R} Foundation-Configuration Management System; and (5) preparation of the joint contract deliverable of the Operational Readiness Support Plan. (authors)
Industries across the United States of America are competing for highly skilled talent at a time when worker retirements are increasing and fewer students are pursuing science, technology, engineering and math (STEM) related fields of study. This specialized workforce is necessary for many industries, and it is essential for the processing and management of nuclear materials and operations of the nuclear security enterprise. Competition for STEM talent impacts the region that includes the Savannah River Site (SRS), a Department of Energy complex that is responsible for environmental stewardship, environmental cleanup, waste management and disposition of nuclear materials. SRS employs nearly 11,000 people and anticipates significant workforce attrition due to retirements over the next several years. In the SRS region, nuclear industry workers are also needed for the growing nuclear power industry as construction of four new nuclear power plants is taking place within an 80-mile radius of SRS. To address growing nuclear workforce needs in this region of Georgia and South Carolina, the SRS Community Reuse Organization (SRSCRO) established the Nuclear Workforce Initiative (NWI{sup R}) during 2009. Through NWI{sup R}, the SRSCRO has developed a network of partnerships with nuclear employers and regional educators to expand nuclear workforce development capabilities. Most notably, through NWI{sup R}, the SRSCRO established a partnership with five local colleges and universities and the Department of Energy Office of Environmental Management. Together, they have produced significant results. Recently, the National Nuclear Security Administration joined the partnership to help build the future nuclear workforce that includes scientists and engineers, but also skilled technicians, production operators, welders, nuclear quality specialists and other highly skilled professionals prepared to work in a secure and procedure-oriented environment. This paper highlights results from a successful partnership between a non-profit organization, academic institutions and the United States Department of Energy designed to expand the nuclear industry talent pool. (authors)
Commercial use of thermal barrier coatings in diesel engines began in the mid 70's by Dr. Ingard Kvernes at the Central Institute for Industrial Research in Oslo, Norway. Dr. Kvernes attributed attack on diesel engine valves and piston crowns encountered in marine diesel engines in Norwegian ships as hot-corrosion attributed to a reduced quality of residual fuel. His solution was to coat these components to reduce metal temperature below the threshold of aggressive hot-corrosion and also provide protection. Roy Kamo introduced thermal barrier coatings in his 'Adiabatic Diesel Engine' in the late 70's. Kamo's concept was to eliminate the engine block water cooling system and reduce heat losses. Roy reported significant performance improvements in his thermally insulated engine at the SAE Congress in 1982. Kamo's work stimulates major programs with insulated engines, particularly in Europe. Most of the major diesel engine manufacturers conducted some level of test with insulated combustion chamber components. They initially ran into increased fuel consumption. The German engine consortium had Prof. Woschni of the Technical Institute in Munich. Woschni conducted testing with pistons with air gaps to provide the insulation effects. Woschni indicated the hot walls of the insulated engine created a major increase in heat transfer he refers to as 'convection vive.' Woschni's work was a major factor in the abrupt curtailment of insulated diesel engine work in continental Europe. Ricardo in the UK suggested that combustion should be reoptimized for the hot-wall effects of the insulated combustion chamber and showed under a narrow range of conditions fuel economy could be improved. The Department of Energy has supported thermal barrier coating development for diesel engine applications. In the Clean Diesel - 50 Percent Efficient (CD-50) engine for the year 2000, thermal barrier coatings will be used on piston crowns and possibly other components. The primary purpose of the thermal barrier coatings will be to reduce thermal fatigue as the engine peak cylinder pressure will nearly be doubled. As the coatings result in higher available energy in the exhaust gas, efficiency gains are achieved through use of this energy by turbochargers, turbocompounding or thermoelectric generators.
This is our annual presentation on the HFTO-funded MEA Manufacturing R&D project, mainly focused on development of in-line quality inspection methods for high volume fabrication of fuel cell and electrolysis MEA materials.
Modular construction can lead to additional cost overruns and delays when a defect is found on the construction site and is not easily repairable. Researchers have developed various methods that use image-based 3D reconstruction for quality assessment, but they have inherent limitations, such as inconsistency and dealing with surfaces with reflectivity and limited visual features. Therefore, this paper presents a vision-based quality assessment method using cameras for prefabricated components by addressing these limitations. Specifically, this paper proposes a novel quality inspection method with sub-millimeter accuracy using cameras focused on leveraging camera poses (as opposed to 3D point clouds that are often not consistent in quality) from the image-based 3D reconstruction. The 3D point estimation by computing triangulation was used for achieving accurate measurement. The proposed method is validated using six different variances and two case studies – an aluminum pipe with a reflective surface and a fabricated concrete column. Furthermore, the results demonstrate the accuracy and effectiveness of the proposed method.