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Articles 9691 - 9720 of 13060
Full-Text Articles in Entire DC Network
Random Image Models For Microstructure Analysis And Simulation, Dominique Jeulin
Random Image Models For Microstructure Analysis And Simulation, Dominique Jeulin
Scanning Microscopy
A wide spectrum of Random Function models, based on the theory of Random sets, are introduced to simulate single or multivariate signals as encountered in the common practice of electron probe microscopy.
These models are built in three steps, combining the choice of a family of primary random functions and of Poisson varieties in the n-dimensional space for their implantation. For electron microscopy images, they can describe the following situations:
- topography (as obtained from stereo pair images in fractography) simulated by Boolean and by alternate sequential random functions;
- thick slices (as in the case of Transmission Electron Microscope …
Some Applications Of Image Analysis To Materials Science, François Grillon
Some Applications Of Image Analysis To Materials Science, François Grillon
Scanning Microscopy
We have presented four applications of Image Analysis to material science. The first one is on a yarn composite SiC where we want to know the relative proportion of matrix, fibers, porosity and the size of the fibers. The results are used to estimate mechanical properties of the composite.
The second one is to measure the residual porosity after a laser shock on powder metallurgy steel. The knowledge of the depth of the affected zone is necessary to optimise the laser treatment.
The third one uses Fourier transformation to analyse plastic deformation on grains. Values are obtained from Fourier transform …
Analysis Of Experiments In Helium Microbeam Mixing, J B. Davis, R E. Benenson, David Peak
Analysis Of Experiments In Helium Microbeam Mixing, J B. Davis, R E. Benenson, David Peak
All Physics Faculty Publications
We have continued to investigate ion-beam mixing in bilay-er targets irradiated by 2-MeV He+ microbeams at room temperature. Although we have previously reported a linear dependence of interface width on dose for Cu/Al targets 1, more extensive results have not supported this conclusion, within statistical uncertainty, it appears that the interface width in Cu/Al (1) is proportional to the square root of dose, at constant dose rate, (2) is larger in Al than in Cu, for the same dose, (3) is proportional to the 1/4 power of dose rate, and (4) is absent at liquid nitrogen temperature. Calculations …
Final Environmental Impact Statement Stanley Basin C & H Allotment Management Plan Sawtooth National Recreation Area, United States Forest Service
Final Environmental Impact Statement Stanley Basin C & H Allotment Management Plan Sawtooth National Recreation Area, United States Forest Service
Final Environmental Impact Statements (ID)
This Final Environmental Impact Statement (FEIS) documents the analysis conducted for the Stanley Basin Cattle and Horse Allotment Management Plan. The allotment management plan involves National Forest System lands within the Sawtooth and Challis National Forests. The analysis of the current condition of the Stanley Basin Allotment has found that the existing grazing system does not comply with the direction, standards and guidelines of the Sawtooth and Challis Forest Land and Resource Management Plans (FLRMP). The proposed action of this Final Environmental Impact Statement is to bring management of the allotment into compliance with the FLRMPs. The FEIS describes five …
Environmental Assessment, Carter Mountain-Thermopolis 230-Kv Transmission Line Project, Hot Springs County, Wyoming, U.S. Department Of Energy
Environmental Assessment, Carter Mountain-Thermopolis 230-Kv Transmission Line Project, Hot Springs County, Wyoming, U.S. Department Of Energy
Environmental Assessments (WY)
The Western Area Power Administration (Western) is proposing to construct, operate, and maintain a new 230-kV transmission line between the Carter Mountain and Thermopolis Substations in northcentral Wyoming (Hot Springs County). The project area is shown on Map 2-1. This environmental assessment was prepared in compliance with the National Environmental Policy Act (NEPA) and the regulations of the Council on Environmental Quality and the Department of Energy, which is responsible for approval of the proposed action. The Bureau of Land Management (BLM) is a cooperating agency on the project and is also the Federal review agency responsible for granting rights-of-way …
Oil And Gas Leasing On The Thunder Basin National Grassland Final Environmental Impact Statement, United States Forest Service
Oil And Gas Leasing On The Thunder Basin National Grassland Final Environmental Impact Statement, United States Forest Service
Final Environmental Impact Statements (WY)
This Final Environmental Impact Statement was conducted to analyze what lands on the Medicine Bow National Forest, Thunder Basin National Grassland in northeast Wyoming could be available for leasing and what conditions could be attached to future leases. Seven alternatives are described, and potential effects are disclosed and evaluated. These alternatives represent possible ways to manage oil and gas leasing on 520,000 acres that are available for leasing. The alternatives are: ALTERNATIVE 1, Leasing consistent with the Forest Plan (No Action); ALTERNATIVE 2, Leasing with standard and special stipulations, consistent with the Forest Plan; ALTERNATIVE 3, Leasing with standard and …
A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart
A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart
Scanning Microscopy
A common problem with electron micrographs of biological objects is that fine details are usually faint and, moreover, tend to be obscured by background noise from stain and support film. Filtering is a useful way to improve the signal-to-noise ratio and is particularly important when trying to detect small changes (conformational or due to labelling) or when examining frozen hydrated objects, where the statistical definition of the image has been reduced because of the low-dose conditions needed to prevent radiation damage. Filtering can also be used to address the superposition effects that result from the large depth of focus of …
Three-Dimensional Crystallographic Reconstruction For Atomic Resolution, Kenneth H. Downing
Three-Dimensional Crystallographic Reconstruction For Atomic Resolution, Kenneth H. Downing
Scanning Microscopy
Three-dimensional structures have recently been determined by electron crystallography at a resolution high enough to determine atomic arrangements in both protein and mineral specimens. The different nature of these two types of specimens produces some very significant differences in the way data is obtained and processed, although the principles are the same. The sensitivity of proteins to damage by the electron beam limits the signal-to-noise ratio in the image and the resolution to which data can be extracted from the image. A number of constraints, such as the amino acid sequence and the connectivity of atoms within amino acids, can …
Alignment, Classification, And Three-Dimensional Reconstruction Of Single Particles Embedded In Ice, Joachim Frank, Pawel Penczek, Weiping Liu
Alignment, Classification, And Three-Dimensional Reconstruction Of Single Particles Embedded In Ice, Joachim Frank, Pawel Penczek, Weiping Liu
Scanning Microscopy
Cryo-electron microscopy of single biological particles poses new challenges to digital image processing due to the low signal-to-noise ratio of the data. New tools have been devised to deal with important aspects of 3-D reconstruction following the random-conical data collection scheme: (a) a new shift-invariant function has been derived, which promises to facilitate alignment and classification of single particle projections; (b) a new method of orientation search is proposed, which makes it possible to relate random-conical data sets to one another prior to reconstruction; and (c) the foundation is laid for a 3-D variance estimation which utilizes the oversampling of …
Structure Analysis Of Ice-Embedded Single Particles, M. Van Heel, H. Winkler, E. Orlova, M. Schatz
Structure Analysis Of Ice-Embedded Single Particles, M. Van Heel, H. Winkler, E. Orlova, M. Schatz
Scanning Microscopy
The conventional negative-stain preparation method for electron microscopy, in which biological macromolecules are contrasted using heavy metal salts (such as uranyl-acetate), is a simple and fast technique which has helped visualize hundreds of different molecular structures. Computer analysis of such negatively stained images of individual (i.e., non-crystalline) macromolecules using statistical pattern-recognition techniques has revealed considerable new structural information. Negative staining, however, has some disadvantages: the specimens are often severely flattened (as much as 25%-75%), they often exhibit strong preferential attachment of the molecules to the supporting carbon foil, and the molecular images may be difficult to interpret due to the …
Morphological Filtering And Granulometric Analysis On Scanning Electron Micrographs: Applications In Materials Science, Murielle Prod'homme, Michel Coster, Liliane Chermant, Jean-Louis Chermant
Morphological Filtering And Granulometric Analysis On Scanning Electron Micrographs: Applications In Materials Science, Murielle Prod'homme, Michel Coster, Liliane Chermant, Jean-Louis Chermant
Scanning Microscopy
For many applications, scanning electron microscopy (SEM) images reflect the granular texture of analysed objects. So it is important to characterise the morphology of this texture and also to filter these images. Because the size of the texture is the main criterion to be studied, we have focused our paper on granulometric analysis.
We present basic parameters, morphological filtering and granulometry for Rn•R functions and their properties with local knowledge and anamorphosis.
Some applications in the domain of materials science illustrate these methods and present their suitable possibilities.
Image Algebra And Restoration, P. W. Hawkes
Image Algebra And Restoration, P. W. Hawkes
Scanning Microscopy
The arrival of image algebras has made it possible to express a vast amount of the heterogeneous material in the image processing literature in a convenient and consistent manner. Furthermore, this type of formulation has proved very fertile and many new ideas have emerged. Image restoration has, however, been studied very much less than enhancement and analysis. We explain briefly the use of one such algebra in this field and show that such tasks as reconstruction from focal series and three-dimensional reconstruction can easily be incorporated.
Multi-Dimensional Data Analysis And Processing In Electron-Induced Microanalysis, N. Bonnet, P. Trebbia
Multi-Dimensional Data Analysis And Processing In Electron-Induced Microanalysis, N. Bonnet, P. Trebbia
Scanning Microscopy
The new facilities offered by computer controlled data capturing devices allow one to open the field of data acquisition from one or two-dimensional spaces to multi-dimensional ones. The methods used for analysing and processing such data sets have to move in parallel towards multi-dimensionality. Multivariate Statistical Analysis is one of the tools which appear to be promising in : data analysis, data reduction, data processing (multivariate noise filtering), data interpolation and extrapolation. Illustrations of these different possibilities are given in the fields of spatially resolved spectroscopy, time-dependent spectroscopy and elemental mapping from Electron Energy Loss Spectroscopy.
Processing Multi-Spectral Scanning Electron Microscopy Images For Quantitative Microfabric Analysis, N. K. Tovey, D. L. Dent, W. M. Corbett, D. H. Krinsley
Processing Multi-Spectral Scanning Electron Microscopy Images For Quantitative Microfabric Analysis, N. K. Tovey, D. L. Dent, W. M. Corbett, D. H. Krinsley
Scanning Microscopy
Multi-spectral image analysis is a powerful method to characterise quantitatively the mineralogy and microfabric of soils, sediments, and other particulate materials. Backscattered scanning electron microscope (SEM) images of polished, resin-impregnated samples are grouped with the corresponding X-ray elemental maps using classification methods commonly used in remote sensing. However, the resulting mineral-segmented images require processing to render them suitable for quantification. In the past, this has been done subjectively and interactively, but the new objective methods described in this paper largely eliminate this subjectivity. An intensity gradient magnitude image of the original backscattered electron image is used as the basis of …
Image Segmentation Applied To Scanning Electron Microscopy Multi-Images Of Weathered Stones Of Monuments, M. Rautureau, R. Harba, G. Jacquet
Image Segmentation Applied To Scanning Electron Microscopy Multi-Images Of Weathered Stones Of Monuments, M. Rautureau, R. Harba, G. Jacquet
Scanning Microscopy
This paper describes a three complementary images processing method. The three images are coming from a scanning electron microscope (SEM) during the analysis of a particular stone: the Tuffeau used in most monuments of the Loire valley (France). The goal is to separate two classes of particles (calcareous and siliceous) from the porosity to give more information to experts who evaluate the damage of weathering on monuments. A specific process is developed: a first threshold on the good quality image allows separation of particles from porosity. Then, the complementarity of the three images gives the two other thresholds. Granulometry, percentages …
The Law Firm As An Economic Organization, L. Dwight Israelsen
The Law Firm As An Economic Organization, L. Dwight Israelsen
Economic Research Institute Study Papers
No abstract provided.
Final Environmental Impact Statement For Salt Lake City International Airport Expansion, Salt Lake City, Utah, United States Department Of Transportation Federal Aviation Administration
Final Environmental Impact Statement For Salt Lake City International Airport Expansion, Salt Lake City, Utah, United States Department Of Transportation Federal Aviation Administration
All U.S. Government Documents (Utah Regional Depository)
Expansion of the Salt Lake City International Airport is proposed to meet the existing and future travel demands of the public and air carriers using the airport. Specifically, it is proposed to increase the safety and efficiency of the airport by reducing congestion and delays. The expansion of the airport has been planned for over 12 years including 2 Master Planning efforts, a FAR Part 150 document (an airport noise compatability planning study), a Capacity Task Force Document, and the Draft Environmental Assessment and Expanded Environmental Assessment efforts in addition to numerous smaller studies and documents.
Relating Spectral Observations Of The Agricultural Landscape To Crop Yield, Craig L. Wiegand, Arthur J. Richardson
Relating Spectral Observations Of The Agricultural Landscape To Crop Yield, Craig L. Wiegand, Arthur J. Richardson
Food Structure
Remote sensing and microscopy share several common concerns including wavelength and sensor selection, signal processing, and image analysis. For crop yield assessments, multispectral observations are acquired photographically, videographically, or with opticalmechanical scanners from aircraft and spacecraft. Sensors are chosen at wavelengths of high atmospheric transmission and maximum contrast between the soil background and the vegetation growing out of it. Vegetation indices have been developed that maximize the information about the photosynthetic size of the vegetation in the landscape and, hence, about crop stresses and yield . Three such indices that reduce the multispectral observations to a single numerical index are …
Covariant Phase Space Formulation Of Parametrized Field Theories, Charles G. Torre
Covariant Phase Space Formulation Of Parametrized Field Theories, Charles G. Torre
All Physics Faculty Publications
Parametrized field theories, which are generally covariant versions of ordinary field theories, are studied from the point of view of the covariant phase space: the space of solutions of the field equations equipped with a canonical (pre)symplectic structure. Motivated by issues arising in general relativity, we focus on phase space representations of the space‐time diffeomorphism group, construction of observables, and the relationship between the canonical and covariant phase spaces.
Is General Relativity An "Already Parametrized" Theory?, Charles G. Torre
Is General Relativity An "Already Parametrized" Theory?, Charles G. Torre
All Physics Faculty Publications
Beginning with the work of Dirac and of Arnowitt, Deser, and Misner in the late 1950s and early 1960s, and then after subsequent development by Kuchař, the canonical dynamical structure of general relativity has often been viewed as that of a parametrized field theory in which the many-fingered spacetime variables are hidden among the geometrodynamical field variables. This paradigm of general relativity as an "already parametrized" theory forms the basis for one of the most satisfactory resolutions of the problems of time and observables in classical and quantum gravity. However, despite decades of effort, no identification of many-fingered spacetime variables …
Fragmentation Of Percolation Clusters At The Percolation Threshold, M. F. Gyure, Boyd F. Edwards
Fragmentation Of Percolation Clusters At The Percolation Threshold, M. F. Gyure, Boyd F. Edwards
All Physics Faculty Publications
A scaling theory and simulation results are presented for fragmentation of percolation clusters by random bond dilution. At the percolation threshold, scaling forms describe the average number of fragmenting bonds and the distribution of cluster masses produced by fragmentation. A relationship between the scaling exponents and standard percolation exponents is verified in one dimension, on the Bethe lattice, and for Monte Carlo simulations on a square lattice. These results further describe the structure of percolation clusters and provide kernels relevant to rate equations for fragmentation.
Ionospheric Simulation Compared With Dynamics Explorer Observations For November 22, 1981, Jan Josef Sojka, M. D. Bowline, Robert W. Schunk, J. D. Craven, L. A. Frank, J. R. Sharber, J. D. Winningham, L. H. Brace
Ionospheric Simulation Compared With Dynamics Explorer Observations For November 22, 1981, Jan Josef Sojka, M. D. Bowline, Robert W. Schunk, J. D. Craven, L. A. Frank, J. R. Sharber, J. D. Winningham, L. H. Brace
All Physics Faculty Publications
Dynamics Explorer (DE) 2 electric field and particle data have been used to constrain the inputs of a time-dependent ionospheric model (TDIM) for a simulation of the ionosphere on November 22, 1981. The simulated densities have then been critically compared with the DE 2 electron density observations. This comparison uncovers a model-data disagreement in the morning sector trough, generally good agreement of the background density in the polar cap and evening sector trough, and a difficulty in modelling the observed polar F layer patches. From this comparison, the consequences of structure in the electric field and precipitation inputs can be …
Solar Cycle Dependence Of Spacecraft Charging In Low Earth Orbit, T. B. Frooninckx, Jan Josef Sojka
Solar Cycle Dependence Of Spacecraft Charging In Low Earth Orbit, T. B. Frooninckx, Jan Josef Sojka
All Physics Faculty Publications
Recent experimental evidence has shown that Defense Meteorological Satellite Program (DMSP) polar orbiting spacecraft at 840 km can develop electric potentials as severe as −1430 V while at high magnetic latitudes. To explore this charging region, an analysis of DMSP F6, F7, F8, and F9 satellite precipitating particle and ambient plasma measurements taken during periods of high, medium, and low solar flux is performed. One hundred eighty-four charging events ranging from −46 to −1430 V are identified, and an extreme solar cycle dependence is found as charging is most frequent and severe during solar minimum. Satellite measurements and time-dependent ionospheric …
Nonlinear Statistical Filtering And Applications To Segregation In Steels From Microprobe Images, C. Daly, D. Jeulin, D. Benoît
Nonlinear Statistical Filtering And Applications To Segregation In Steels From Microprobe Images, C. Daly, D. Jeulin, D. Benoît
Scanning Microscopy
Microprobe images of solidification studies are well known to be subject to a Poisson noise. That is, the radiation count at a pixel x for a certain element may be considered to be an observation of a Poisson random variable whose parameter is equal to the true chemical concentration of the element at x. By modeling the image as a random function, we are able to use geostatistical techniques to perform various filtering operations. This filtering of the image itself may be done using linear kriging. For explicitely nonlinear problems such as the estimation of the underlying histogram of the …
Automatic Orientation Analysis Of Microfabric, N. K. Tovey, P. Smart, M. W. Hounslow, J. P. Desty
Automatic Orientation Analysis Of Microfabric, N. K. Tovey, P. Smart, M. W. Hounslow, J. P. Desty
Scanning Microscopy
The orientation of features in digitized scanning electron micrographs may be estimated using a technique which examines the changes in intensity in two orthogonal directions about each pixel. Typically, over 250, 000 estimates of orientation may be made generating an output image where the pixel value relates to the orientation direction of the feature at the corresponding pixel in the original image. At the same time, a rosette histogram may be generated to give a visual impression of any preferred alignment. These data may be reduced to two parameters specifying the direction and degree of orientation.
A new algorithm involving …
Visual Feeding By Juvenile Bear Lake Sculpin, D. Neverman, Wayne A. Wurtsbaugh
Visual Feeding By Juvenile Bear Lake Sculpin, D. Neverman, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
Young-of-the-year Bear Lake sculpin Cottus extensus feed throughout the day on benthic invertebrates and cease feeding at night when they migrate to the metalimnion. We investigated their reliance on vision by conducting feeding trials at different light levels in the laboratory. Feeding rate reached a maximum at intermediate light levels (near 10^16 photons sm^–2 ss^–1; approximately 1 lux) but decreased as light intensity increased beyond this range. At this maximum rate, the fish fed nine times faster than they were able to feed in the dark, showing that young Bear Lake sculpin rely heavily upon vision to feed. The light …
Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe
Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe
Watershed Sciences Faculty Publications
This report outlines long-term planning and monitoring activities that occurred in 1991 and 1992 in the Stanley Basin Lakes of the upper Salmon River, Idaho for the purpose of sockeye salmon (Oncorhynchus nerka) recovery. Limnological monitoring and experimental sampling protocol, designed to establish a limnological baseline and to evaluate sockeye salmon production capability of the lakes, are present:ed. Also presented are recommended passage improvements for current fish passage barriers/impediments on migratory routes to the lakes. We initiated O. Nerka population evaluations for Redfish and Alturas lakes; this included population estimates of emerging kokanee fry entering each lake in the spring …
A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp
A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp
Watershed Sciences Faculty Publications
Between 26 April and 2 May 1992, students in a utah state university aquatic ecology class visited Lake Powell to do a study of trophic gradients of the reservoir. The main axis of the reservoir was surveyed, as well as less detailed analyses of Moki and Escalante Canyons. The work was conducted in collaboration with personnel from the u.s. Bureau of Reclamation headed by Bill Vernieu, and from the u.s. Geological Survey (Dick Marzolf). Some of their data appear in the physical-chemical section of this report.
Each student was responsible for compiling a report on one of the following specific …
Lake Trout Spawning In Lake Tahoe: Egg Incubation In Deepwater Macrophyte Beds, D. A. Beauchamp, B. C. Allen, R. C. Richards, Wayne A. Wurtsbaugh, C. R. Goldman
Lake Trout Spawning In Lake Tahoe: Egg Incubation In Deepwater Macrophyte Beds, D. A. Beauchamp, B. C. Allen, R. C. Richards, Wayne A. Wurtsbaugh, C. R. Goldman
Watershed Sciences Faculty Publications
Although most populations of lake trout Salvelinus namaycush spawn over rocky shoals, use of these substrates by lake trout has not yet been found in Lake Tahoe. Large cobble substrate exists at depths less than 20 m, and steep, fractured, rocky substrate can be found in isolated areas from the surface down to at least 100 m, but no evidence of spawning activity in these areas has been found. Instead, at least a portion of the population spawns on deepwater mounds (40–60 m deep) over beds of the macrophyte Chara delicatula. This is the first known report of lake trout …
Soil Chemistry And Nutrition Of North American Red Spruce-Fir Stands: Evidence For Recent Change, J. D. Joslin, J. M. Kelly, H. Van Miegroet
Soil Chemistry And Nutrition Of North American Red Spruce-Fir Stands: Evidence For Recent Change, J. D. Joslin, J. M. Kelly, H. Van Miegroet
Watershed Sciences Faculty Publications
One set of hypotheses offered to explain the decline of red spruce (Picea rubens Sarg.) in eastern North America focuses on the effect of acidic deposition on soil chemistry changes that may affect nutrient availability and root function. Long-term soils data suggest that soil acidification has occurred in some spruce stands over the past 50 yr, with plant uptake and cation leaching both contributing to the loss of cations. Studies of tree ring chemistry also have indicated changes in Ca/Al and Mg/Al ratios in red spruce wood, suggesting increases in the ionic strength of soil solution. Irrigation studies using strong …