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At least 577 records · Page 32

Complete Status Report Documenting Weld Development for Thin Wall Tubing of ODS Ferritic Alloys

Beginning in 2015, research in the FCRD program began the development of FSW for joining thin sections of 14YWT in the form of thin (0.5 mm) plate and ultimately thin wall tubing. In the previous fiscal year, a ~1 mm thick plate, or sheet, of 14YWT was produced by hot rolling with no edge cracking. The initial FSW experiment was performed on the 1 mm thick plate and involved a bead-on-plate weld in which the spinning pin tool is plunged into the plate surface, but does not penetrate the thickness of the plate, and then travels the length of the plate. The FSW run successfully produced a bead-on-plate stir zone on the 1 mm thick plate of 14YWT, but no characterization studies of the stir zone were performed by the end of FY15. Therefore, the results presented in this report cover the microstructural analysis of the bead-on-plate stir zone and the initial research task on obtaining tensile properties of the stir zone using the digital image correlation (DIC) approach during testing of miniature tensile specimens to assess the quality of the FSW parameters used in the initial experiment. The results of the microstructural characterization study using optical, scanning electron and scanning transmission electron microscopies showed the grain structure in the SZ to have isotropic and irregular shape but very similar size compared to the highly elongated grains oriented horizontally with the plane of the plate that were observed in the unaffected zone of 14YWT. Several cracks oriented horizontally were observed mostly on the retreating side of the SZ in both the SZ and TMAZ. These cracks may have formed due to insufficient pressure being exerted on the top surface of the plate by the shoulder and pin tool during the FSW run. High resolution STEM-EDS analysis showed the presence of the Y-Ti-O particles in the SZ, but that some particles exhibited coarsening. Overall, the FSW parameters used to produce the bead-on-plate SZ in the 0.1 cm thick plate of 14YWT were nearly optimized. The results of the digital image correlation (DIC) analysis of the two SS-Mini-2 tensile specimens fabricated from the 0.1 cm thick plate of 14YWT showed that the specimens exhibited high strength and good ductility. However, strain localization occurred in one of the specimens during the tensile test that was too close to the grips, which invalidated the data from the DIC analysis. This was surprising since the abrupt crack pop-in that occurred in the 0.1 cm thick plate of 14YWT during fabrication by wire EDM suggested that residual stresses were high. Residual stress measurements and the effects of post weld heat treatment on the FSW quality of joined 14YWT plates will be investigated in the next FW work package.

36 MATERIALS SCIENCE↗

Tuscaloosa Marine Shale Laboratory

The Tuscaloosa Marine Shale (TMS) in Louisiana and Mississippi is an Upper Cretaceous source rock formation sandwiched between the sands of the upper and lower Tuscaloosa sections. The TMS is believed to be the source rock for underlying prolific Tuscaloosa sand formation. The TMS has an unproven estimate of 7,000,000,000 bbls of recoverable oil while its current total average production is about 3,000 bbls of oil per day in 2017. In 2013 and 2014, more than 80 wells were drilled horizontally into the TMS that were fractured using multi-stage fracturing technology. The results from this have been mixed, but recent production for several wells show an appealing initial oil production rate of more than 1000 bbl/day. The preliminary core analysis by industry partners and a few literature studies shows that the TMS is one of the most clay-rich and sensitive shales to water. Due to these and other technical problems, there is high risk for the economic development of TMS compared to other shale plays. The experiences of major industrial players in the TMS show the necessity of open and collaborative efforts to better understand the critical gaps in the development of this challenging and potentially highly economic shale play to enable more cost-efficient and environmentally-sound recovery from this unconventional liquid-rich shale play. The overall objective of this project is to form a consortium of science and industry partners to address the following six major objectives using scientific and technical approaches: 1. To improve wellbore integrity by better understanding the sources of the wellbore instability issues, proposing innovative mud and cement design for the TMS. 2. To improve formation evaluation using laboratory techniques for the evaluation of mineralogical composition, organic content, and produced-water chemistry as well as well log and geophysical analysis. 3. To determine the role of geologic discontinuities on fracture growth and shale creep behavior using digital image correlation technique. 4. To investigate the application of stable CO 2 foam and super-hydrophobic proppants for improved reservoir stimulation. 5. To better understand the nature of water/hydrocarbon/CO 2 flow in clay and organic-rich formation and the role of water/fluid interaction on recovery. 6. To prepare better socio-economic environment for TMS development by community engagement. Subsequently, the TMS virtual laboratory conducted testing and analysis of various properties of rock and formation fluids from the TMS, including but not limited to the following: Analyzing reports and logs to better understand the source of wellbore instability in TMS wells; Experiments to design a customized cement based on TMS requirements; Experiments to obtain the mineralogical and geochemical composition of TMS samples; Seismic analysis of TMS geophysical data to better predict total organic carbon (TOC) content and brittleness in TMS; Well log analysis to better estimate the TOC and geo-mechanical properties of TMS; Experiments on formation water to understand the chemistry of produced water; Experiments to determine the role of lamination and natural fractures on fracture propagation or rock deformation using digital image correlation technique in in-direct tensile tests, semi-circular bend test and creep tests Experiments to determine the stability and rheological properties of nanoparticle-stabilized CO 2 foam in TMS rock samples; Experiments to determine fluid dynamics in un-propped TMS fractures and the role of nano-coating of proppants on fluid dynamics in fractures with proppants; Micro-fluidics experiments to enhance the understanding of fluid dynamics in tight liquidrich pores with high clay content; Socio-economic studies to better engage communities in TMS development.

58 GEOSCIENCES↗

Spheres of Earth: An Introduction to Making Observations of Earth Using an Earth System's Science Approach. Student Guide

Scientists from the Image Science and Analysis Laboratory (ISAL) at NASA's Johnson Space Center (JSC) work with astronauts onboard the International Space Station (ISS) who take images of Earth. Astronaut photographs, sometimes referred to as Crew Earth Observations, are taken using hand-held digital cameras onboard the ISS. These digital images allow scientists to study our Earth from the unique perspective of space. Astronauts have taken images of Earth since the 1960s. There is a database of over 900,000 astronaut photographs available at http://eol.jsc.nasa.gov . Images are requested by ISAL scientists at JSC and astronauts in space personally frame and acquire them from the Destiny Laboratory or other windows in the ISS. By having astronauts take images, they can specifically frame them according to a given request and need. For example, they can choose to use different lenses to vary the amount of area (field of view) an image will cover. Images can be taken at different times of the day which allows different lighting conditions to bring out or highlight certain features. The viewing angle at which an image is acquired can also be varied to show the same area from different perspectives. Pointing the camera straight down gives you a nadir shot. Pointing the camera at an angle to get a view across an area would be considered an oblique shot. Being able to change these variables makes astronaut photographs a unique and useful data set. Astronaut photographs are taken from the ISS from altitudes of 300 - 400 km (~185 to 250 miles). One of the current cameras being used, the Nikon D3X digital camera, can take images using a 50, 100, 250, 400 or 800mm lens. These different lenses allow for a wider or narrower field of view. The higher the focal length (800mm for example) the narrower the field of view (less area will be covered). Higher focal lengths also show greater detail of the area on the surface being imaged. Scientists from the Image Science and Analysis Laboratory (ISAL) at NASA s Johnson Space Center (JSC) work with astronauts onboard the International Space Station (ISS) who take images of Earth. Astronaut photographs, sometimes referred to as Crew Earth Observations, are taken using hand-held digital cameras onboard the ISS. These digital images allow scientists to study our Earth from the unique perspective of space. Astronauts have taken images of Earth since the 1960s. There is a database of over 900,000 astronaut photographs available at http://eol.jsc.nasa.gov . Images are requested by ISAL scientists at JSC and astronauts in space personally frame and acquire them from the Destiny Laboratory or other windows in the ISS. By having astronauts take images, they can specifically frame them according to a given request and need. For example, they can choose to use different lenses to vary the amount of area (field of view) an image will cover. Images can be taken at different times of the day which allows different lighting conditions to bring out or highlight certain features. The viewing angle at which an image is acquired can also be varied to show the same area from different perspectives. Pointing the camera straight down gives you a nadir shot. Pointing the camera at an angle to get a view across an area would be considered an oblique shot. Being able to change these variables makes astronaut photographs a unique and useful data set. Astronaut photographs are taken from the ISS from altitudes of 300 - 400 km (approx.185 to 250 miles). One of the current cameras being used, the Nikon D3X digital camera, can take images using a 50, 100, 250, 400 or 800mm lens. These different lenses allow for a wider or narrower field of view. The higher the focal length (800mm for example) the narrower the field of view (less area will be covered). Higher focal lengths also show greater detail of the area on the surface being imaged. There are four major systems or spheres of Earth. They are: Atmosphere, Biosphere, Hydrosphe, and Litho/Geosphere.

Graff, Paige Valderrama↗

Chemo-Mechanical Instabilities in Lithium Cobalt Oxide at Higher State-Of-Charge in Li-Ion Batteries

Transition metal oxide cathodes are widely used in commercial Li-ion batteries. However, their practical charge capacity is limited due to severe chemo-mechanical instabilities at higher charge voltage, and state-of-charge condition. Here, in situ stress and strain measurements were synchronized to probe mechanical deformations in the lithium cobalt oxide (LCO) cathode via a multi-beam stress sensor and digital image correlation, respectively. In situ mechanical measurements revealed how Li removal from the electrode structure induces deformations on the LCO composite cathodes during cycling. The structure and morphology of the LCO cathodes were further investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies. Two distinct electrochemical and mechanical behaviors were identified when the LCO was charged up to 4.65 V. The LCO undergoes a compressive stress generation when charged up to 4.2 V and surface fractures on the LCO particles were detected by SEM. LCO cathode experienced significantly large contractions (negative strains) when charged up to 4.65 V, where intergranular crack formation and phase transformation were detected on the LCO particles via SEM and XRD, respectively. Overall, the study bridges complicated structural deformations with in situ analysis of mechanical degradations in LCO cathodes charged at higher voltages. The correlation is vital to understanding instability mechanisms in transition metal oxides at high voltages for alkali metal ion batteries.

higher state-of-charge↗

Omniview motionless camera orientation system

An apparatus and method is provided for converting digital images for use in an imaging system. The apparatus includes a data memory which stores digital data representing an image having a circular or spherical field of view such as an image captured by a fish-eye lens, a control input for receiving a signal for selecting a portion of the image, and a converter responsive to the control input for converting digital data corresponding to the selected portion into digital data representing a planar image for subsequent display. Various methods include the steps of storing digital data representing an image having a circular or spherical field of view, selecting a portion of the image, and converting the stored digital data corresponding to the selected portion into digital data representing a planar image for subsequent display. In various embodiments, the data converter and data conversion step may use an orthogonal set of transformation algorithms.

Martin, H. Lee↗

A New Method of Creating High-Temperature Speckle Patterns and Its Application in the Determination of the High-Temperature Mechanical Properties of Metals

Speckle techniques, such as DIC (Digital Image Correlation) and DSP (Digital Speckle Photography), are frequently used to determine the high-temperature mechanical properties of materials. Speckle techniques require the creation of a random speckle pattern on the surface of the specimen. The most commonly used approach to creating a high-contrast speckle pattern is to spray a layer of black paint particles on a white background. However, in a high-temperature environment, the paint particles tend to peel off or burn off. In this paper, we present an approach that uses a novel laser-engraving technology, where the created speckles will sustain temperatures as high as the melting temperature of the specimen. The size, density, depth and distribution of the speckles can be controlled to suit a particular situation. Since the pattern is part of the specimen, it will never disappear, until the melting temperature of the metal is reached. As an application, we used the technique to determine the elastic modulus of Ti up to 600{sup °}C and tungsten up to 1000{sup °}C.

42 ENGINEERING↗

A state-of-the-art review of experimental and computational studies of granular materials: Properties, advances, challenges, and future directions

Modeling of heterogeneous materials and media is a problem of fundamental importance to a wide class of phenomena and systems, ranging from condensed matter physics, soft materials, and composite media to porous media, biological systems, geosystems, ceramic engineering, pharmaceutical science and even in space discoveries. Among the most important materials are granular systems, which have received intense interest from the engineering, physics, and mathematics communities. In this review paper, the recent developments and new advances in experimental, and computational methods on a variety of scales and physics that extend understanding to a wide range of materials and phenomena are reviewed. Experimental advances include computed neutron and nanometer-scale tomography, magnetic resonance imaging, refractive index matching, digital image correlation, acoustic emission analysis, and the most recent 4D techniques. Furthermore, a tremendous shift has occurred from the continuum scale to micro-scale and developing multiscale approaches. As such, various computational methods, including, constitutive modeling, discrete modeling, and multiscale approaches, have been developed. In conclusion, aside from all these evolutions, more complicated modeling called coupled, or multiphysics, systems representing a simultaneous presence of heat, fluid, chemical variation, and mechanical effect are also explored.

36 MATERIALS SCIENCE↗

Application of Perona Malik anisotropic diffusion on digital radiographic image

Perona Malik Anisotropic Diffusion (PMAD) is a very useful and efficient denoising technique if the parameters are properly selected. Overestimating the parameters may cause oversmoothed and underestimating it may leave unfiltered noise. This makes the selection of parameters a crucial process. In this paper the PMAD model is solved using a finite difference scheme The discretized model is evaluated using different diffusion coefficient of exponential and quadratic on defective radiographic images in terms of quality and efficiency. In the application of the PMAD model on image data, a set of defective radiographic images of welding is used as input data. Peak Signal to Noise Ratio (PSNR), Structural Similarity Measure (SSIM) and temporal time are used to evaluate the performance of the model. The implementation of the experiment has been carried out using MATLAB R2009a. In terms of quality, results show that the Quadratic Diffusion Coefficient Function (QDCF) provides better results compared with the Exponential Diffusion Coefficient Function (EDCF). In conclusion, the denoising effect using PMAD model based on finite difference scheme shows able to improve image quality by removing noise in the defective radiographic image.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Geometrical-Based Generative Adversarial Network to Enhance Digital Rock Image Quality

X-ray microcomputed tomography (micro-CT) is a common tool for the study of porous media structures and properties. High-quality micro-CT data are required to accurately capture pore structures. Acquiring high-quality micro-CT data, however, is not always possible, owing to application limitations and experimental constraints. Therefore, we propose a geometrical-based generative adversarial network (GAN) to rapidly restore noisy micro-CT images to their clean counterparts. The training data and related ground-truth (GT) data are scanned for 7 min and 9.5 h, respectively. To evaluate the performance of the geometrical-based GAN, a 6003 voxel image that has never been used for training is reconstructed and compared with the corresponding GT image. Histogram matching and linear normalization are implemented to adjust the histogram of the reconstructed image to that of the GT image. A watershed-based segmentation method is then applied to delineate pore and solid phases. Lastly, we measure the Minkowski functionals and petrophysical properties, including absolute permeability, pore size distribution, drainage capillary pressure-saturation curve, and imbibition relative permeability, to estimate the physical accuracy of the denoised image. The results show that the proposed geometrical-based GAN can accurately restore noisy micro-CT data. By reducing the scanning time from 9.5 h to 7 min, the expenditure of collecting micro-CT can be decreased significantly. This is particularly important for applications where time-lapse images of a dynamic process are required, high-throughput imaging is necessary for real-time data analysis, or where the quantification of large sample volumes is required.

58 GEOSCIENCES↗

Sights of summer from Lab’s earliest days digitization preserves images from 1940s, features early staff enjoying Los Alamos

Working at the Lab during World War II was serious business, but even these world-changing scientists and staff found time to play during the summer months. The National Security Research Center (NSRC), which is the Lab’s classified library and also houses unclassified artifacts from Los Alamos history, recently rescanned candid footage from two of contributors to the Manhattan Project.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗

Laser produces color images from digital data

Color recorder uses two lasers to generate three different-colored beams. Modulators vary intensity of each beam according to information stored on magnetic tape. Together, three beams are sufficient to reproduce virtually any colors on photographic film. Tape synchronizes motion of beam-writing carriage with modulation imposed on beams.

Shulman, A. R.↗

Assessing urbanized area expansion through the integration of Landsat and conventional data /79052/

An image base information system (IBIS) is utilized to integrate Landsat and census data for the purpose of mapping urban land and updating urbanized-area outer lines. IBIS is a subset of the video image communication and retrieval digital image processing system developed at JPL. IBIS is used to analyze three urban areas: Orlando, Florida; Seattle, Washington; and Boston, Massachusetts. In all three applications the primary objective is to map the expansion of urban land cover in the urban fringe. Pertinent tabular reports are produced.

Davis, J. B.↗

Data compression for National Oceanic and Atmospheric Administration /NOAA/ weather satellite systems

The National Oceanic and Atmospheric Administration (NOAA) receives high quality infrared weather images from each of its two geostationary weather satellites at an average data rate of 57 kilobits/second. These images are currently distributed to field stations over 3 kilohertz analog phone lines. The resulting loss in image quality renders the images unacceptable for proposed digital image processing. This paper documents the study leading to a current effort to implement a microprocessor-based universal noiseless coder/decoder to satisfy NOAA's requirements of high quality, good coverage and timely transmission of its infrared images.

Rice, R. F.↗

Earth resources observation with the Shuttle imaging radar

To fully understand the radar signature of different surface features and covers, observations must be made in a variety of sensor parameters (that is, frequency, polarization, and incidence angle). This makes it possible to choose those sensor parameters that will provide the greatest amount of information about the surface. The Shuttle Imaging Radar (SIR) will be able to obtain surface images at two frequencies (L-band and C-band), at multiple polarizations, and at all incidence angles from near vertical to near grazing. The SIR will operate in the synthetic aperture imaging mode and provide digital images of the surfaces with a resolution of approximately 20 m. As part of the SIR flights, a number of planned large-scale experiments will be carried out in the fields of geologic mapping, vegetation classification, land cover mapping, surface moisture measurements, and ocean surface observation.

Elachi, C.↗

IMAGES: A digital computer program for interactive modal analysis and gain estimation for eigensystem synthesis

An interactive digital computer program for modal analysis and gain estimation for eigensystem synthesis was written. Both mathematical and operation considerations are described; however, the mathematical presentation is limited to those concepts essential to the operational capability of the program. The program is capable of both modal and spectral synthesis of multi-input control systems. It is user friendly, has scratchpad capability and dynamic memory, and can be used to design either state or output feedback systems.

Jones, R. L.↗

Overview of the Shuttle Imaging Radar (SIR-C)

The Shuttle Imaging Radar-C (SIR-C) experiment will provide increased capability over Seasat and the two previous Shuttle Imaging Radars by acquiring digital images simultaneously at two microwave frequencies (L- and C-band) with multiple signal polarizations (HH, VV, HV, VH). The SIR-C is a dual bandwidth system so that investigators can choose a high or low resolution mode (20 and 10 MHz, respectively). An X-band SAR with VV polarization will be flown with SIR-C, resulting in a three-frequency capability. The SIR-C prototype data will be acquired using an airborne imaging radar to test designs that will be implemented on SIR-C, to develop the overall calibration strategy for SIR-C, and to develop data analysis tools for SIR-C data.

Evans, D.↗