Sample records for microwear textures record
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NASA Astrophysics Data System (ADS)
Bestwick, Jordan; Unwin, David; Butler, Richard; Henderson, Don; Purnell, Mark
2017-04-01
Pterosaurs (Pterosauria) were a successful group of Mesozoic flying reptiles. For 150 million years they were integral components of terrestrial and coastal ecosystems, yet their feeding ecology remains poorly constrained. Postulated pterosaur diets include insectivory, piscivory and/or carnivory, but many dietary hypotheses are speculative and/or based on little evidence, highlighting the need for alternative approaches to provide robust data. One method involves quantitative analysis of the micron-scale 3D textures of worn pterosaur tooth surfaces - dental microwear texture analysis. Microwear is produced as scratches and chips generated by food items create characteristic tooth surface textures. Microwear analysis has never been applied to pterosaurs, but we might expect microwear textures to differ between pterosaurs with different diets. An important step in investigating pterosaur microwear is to examine microwear from extant organisms with known diets to provide a comparative data set. This has been achieved through analysis of non-occlusal microwear textures in extant bats, crocodilians and monitor lizards, clades within which species exhibit insectivorous, piscivorous and carnivorous diets. The results - the first test of the hypothesis that non-occlusal microwear textures in these extant clades vary with diet - provide the context for the first robust quantitative tests of pterosaur diets.
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Merceron, Gildas; Scott, Jessica; Scott, Robert S; Geraads, Denis; Spassov, Nikolai; Ungar, Peter S
2009-12-01
Here we compare dental microwear textures from specimens of the fossil genus Mesopithecus (Cercopithecidae, Colobinae) from the late Miocene of Eastern Europe with dental microwear textures from four extant primate species with known dietary differences. Results indicate that the dental microwear textures of Mesopithecus differ from those of extant leaf eaters Alouatta palliata and Trachypithecus cristatus and instead resemble more closely those of the occasional hard-object feeders Cebus apella and Lophocebus albigena. Microwear texture data presented here in combination with results from previous analyses suggest that Mesopithecus was a widespread, opportunistic feeder that often consumed hard seeds. These data are consistent with the hypothesis that early colobines may have preferred hard seeds to leaves.
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Can texture analysis of tooth microwear detect within guild niche partitioning in extinct species?
NASA Astrophysics Data System (ADS)
Purnell, Mark; Nedza, Christopher; Rychlik, Leszek
2017-04-01
Recent work shows that tooth microwear analysis can be applied further back in time and deeper into the phylogenetic history of vertebrate clades than previously thought (e.g. niche partitioning in early Jurassic insectivorous mammals; Gill et al., 2014, Nature). Furthermore, quantitative approaches to analysis based on parameterization of surface roughness are increasing the robustness and repeatability of this widely used dietary proxy. Discriminating between taxa within dietary guilds has the potential to significantly increase our ability to determine resource use and partitioning in fossil vertebrates, but how sensitive is the technique? To address this question we analysed tooth microwear texture in sympatric populations of shrew species (Neomys fodiens, Neomys anomalus, Sorex araneus, Sorex minutus) from BiaŁ owieza Forest, Poland. These populations are known to exhibit varying degrees of niche partitioning (Churchfield & Rychlik, 2006, J. Zool.) with greatest overlap between the Neomys species. Sorex araneus also exhibits some niche overlap with N. anomalus, while S. minutus is the most specialised. Multivariate analysis based only on tooth microwear textures recovers the same pattern of niche partitioning. Our results also suggest that tooth textures track seasonal differences in diet. Projecting data from fossils into the multivariate dietary space defined using microwear from extant taxa demonstrates that the technique is capable of subtle dietary discrimination in extinct insectivores.
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Dental microwear textures: reconstructing diets of fossil mammals
NASA Astrophysics Data System (ADS)
DeSantis, Larisa R. G.
2016-06-01
Dietary information of fossil mammals can be revealed via the analysis of tooth morphology, tooth wear, tooth geochemistry, and the microscopic wear patterns on tooth surfaces resulting from food processing. Although dental microwear has long been used by anthropologists and paleontologists to clarify diets in a diversity of mammals, until recently these methods focused on the counting of wear features (e.g., pits and scratches) from two-dimensional surfaces (typically via scanning electron microscopes or low-magnification light microscopes). The analysis of dental microwear textures can instead reveal dietary information in a broad range of herbivorous, omnivorous, and carnivorous mammals by characterizing microscopic tooth surfaces in three-dimensions, without the counting of individual surface features. To date, dental microwear textures in ungulates, xenarthrans, marsupials, carnivorans, and primates (including humans and their ancestors) are correlated with known dietary behavior in extant taxa and reconstruct ancient diets in a diversity of prehistoric mammals. For example, tough versus hard object feeding can be characterized across disparate phylogenetic groups and can distinguish grazers, folivorous, and flesh consumers (tougher food consumers) from woody browsers, frugivores, and bone consumers (harder object feeders). This paper reviews how dental microwear textures can be useful to reconstructing diets in a broad array of living and extinct mammals, with commentary on areas of future research.
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Diet of upper paleolithic modern humans: evidence from microwear texture analysis.
El Zaatari, Sireen; Hublin, Jean-Jacques
2014-04-01
This article presents the results of the occlusal molar microwear texture analysis of 32 adult Upper Paleolithic modern humans from a total of 21 European sites dating to marine isotope stages 3 and 2. The occlusal molar microwear textures of these specimens were analyzed with the aim of examining the effects of the climatic, as well as the cultural, changes on the diets of the Upper Paleolithic modern humans. The results of this analysis do not reveal any environmentally driven dietary shifts for the Upper Paleolithic hominins indicating that the climatic and their associated paleoecological changes did not force these humans to significantly alter their diets in order to survive. However, the microwear texture analysis does detect culturally related changes in the Upper Paleolithic humans' diets. Specifically, significant differences in diet were found between the earlier Upper Paleolithic individuals, i.e., those belonging to the Aurignacian and Gravettian contexts, and the later Magdalenian ones, such that the diet of the latter group was more varied and included more abrasive foods compared with those of the former. Copyright © 2014 Wiley Periodicals, Inc.
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Estalrrich, Almudena; Young, Mariel B; Teaford, Mark F; Ungar, Peter S
2015-11-01
Recent dental microwear studies have shown that fossil species differ from one another in texture attributes-both in terms of central tendency and dispersion. Most comparative studies used to interpret these results have relied on poorly provenienced museum samples that are not well-suited to consideration of within species variation in diet. Here we present a study of two species of platyrrhine monkeys, Alouatta belzebul (n = 60) and Sapajus apella (n = 28) from Pará State in the Brazilian Amazon in order to assess effects of habitat variation on microwear (each species was sampled from forests that differ in the degree of disturbance from highly disturbed to minimally disturbed). Results indicate that microwear texture values vary between habitats-more for the capuchins than the howler monkeys. This is consistent with the notion that diets of the more folivorous A. belzebul are less affected by habitat disturbance than those of the more frugivorous S. apella. It also suggests that microwear holds the potential to reflect comparatively subtle differences in within-species variation in fossil taxa if sample size and control over paleohabitat allow. © 2015 Wiley Periodicals, Inc.
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NASA Astrophysics Data System (ADS)
Williams, Frank L'Engle; Holmes, Noelle A.
2012-09-01
Late Pliocene Procynocephalus subhimalayanus from the Upper Siwaliks, India is known from only three specimens. The dietary proclivities of this taxon have implications for reconstructing the paleoecology of the Upper Siwaliks. The dental microwear texture properties of Procynocephalus are compared to those from extant tropical forest primates including Alouatta palliata (n = 11), Cebus apella (n = 13), Gorilla gorilla (n = 9), Lophocebus albigena (n = 15) and Trachypithecus cristatus (n = 12). Dental microwear textures are generated by scanning the surface enamel of Facet 9 using white-light confocal microscopy at 100x. Four variables were extracted from scale-sensitive fractal analysis, and the data were ranked before ANOVA with post-hoc tests of significance and multivariate analyses were performed. Procynocephalus clusters closest to Lophocebus, Cebus and some Gorilla specimens suggesting hard-object feeding characterized a portion of its diet. The dental microwear texture of Procynocephalus supports interpretations of widespread grasslands of the Late Pliocene Kansal Formation (Pinjor zone). The extreme enamel complexity characterizing Procynocephalus may derive from consumption of underground storage organs, or other foods with high grit loads. Foods consumed near ground level carry a heavy load of abrasive minerals possibly contributing to greater enamel surface complexity and textural fill volume.
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Purnell, Mark; Seehausen, Ole; Galis, Frietson
2012-01-01
Resource polymorphisms and competition for resources are significant factors in speciation. Many examples come from fishes, and cichlids are of particular importance because of their role as model organisms at the interface of ecology, development, genetics and evolution. However, analysis of trophic resource use in fishes can be difficult and time-consuming, and for fossil fish species it is particularly problematic. Here, we present evidence from cichlids that analysis of tooth microwear based on high-resolution (sub-micrometre scale) three-dimensional data and new ISO standards for quantification of surface textures provides a powerful tool for dietary discrimination and investigation of trophic resource exploitation. Our results suggest that three-dimensional approaches to analysis offer significant advantages over two-dimensional operator-scored methods of microwear analysis, including applicability to rough tooth surfaces that lack distinct scratches and pits. Tooth microwear textures develop over a longer period of time than is represented by stomach contents, and analyses based on textures are less prone to biases introduced by opportunistic feeding. They are more sensitive to subtle dietary differences than isotopic analysis. Quantitative textural analysis of tooth microwear has a useful role to play, complementing existing approaches, in trophic analysis of fishes—both extant and extinct. PMID:22491979
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Tooth form and function: insights into adaptation through the analysis of dental microwear.
Ungar, Peter S
2009-01-01
Mammalian molar form is clearly adapted to fracture foods with specific material properties. Studies of dental functional morphology can therefore offer important clues about the diets of fossil taxa. That said, analyses of tooth form provide insights into ability to fracture resistant foods rather than the food preferences of individuals. Recent work suggests that specialized occlusal morphology can relate to either preferred foods, or to occasionally eaten fallback items critical for survival. This paper reviews dental microwear texture analysis, a new approach that can be used to infer fracture properties of foods eaten in life. High-resolution 3D point clouds of microwear surfaces are collected and analyzed using scale-sensitive fractal analyses. Resulting data are free from operator measurement error, and allow the characterization and comparison of within-species variation in microwear texture attributes. Examples given here include four extant primate species (two folivores and two hard object fallback feeders), and two fossil hominin taxa. All groups show at least some individuals with simple microwear surfaces that suggest a lack of consumption of hard and brittle abrasive foods during the last few meals. On the other hand, some hard object fallback specimens have very complex surfaces consistent with consumption of hard, brittle foods. The latter pattern is also found in one hominin species. These results suggest that dental microwear texture analysis can help us determine whether craniodental specializations in fossil species are adaptations to preferred foods, or to less often but still critical fallback items. Copyright (c) 2009 S. Karger AG, Basel.
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3D tooth microwear texture analysis in fishes as a test of dietary hypotheses of durophagy
NASA Astrophysics Data System (ADS)
Purnell, Mark A.; Darras, Laurent P. G.
2016-03-01
An understanding of how extinct animals functioned underpins our understanding of past evolutionary events, including adaptive radiations, and the role of functional innovation and adaptation as drivers of both micro- and macroevolution. Yet analysis of function in extinct animals is fraught with difficulty. Hypotheses that interpret molariform teeth in fishes as evidence of durophagous (shell-crushing) diets provide a good example of the particular problems inherent in the methods of functional morphology. This is because the assumed close coupling of form and function upon which the approach is based is weakened by, among other things, behavioural flexibility and the absence of a clear one to one relationship between structures and functions. Here we show that ISO 25178-2 standard parameters for surface texture, derived from analysis of worn surfaces of molariform teeth of fishes, vary significantly between species that differ in the amount of hard-shelled prey they consume. Two populations of the Sheepshead Seabream (Archosargus probatocephalus) were studied. This fish is not a dietary specialist, and one of the populations is known to consume more vegetation and less hard-shelled prey than the other; this is reflected in significant differences in their microwear textures. The Archosargus populations differ significantly in their microwear from the specialist shell-crusher Anarhichas lupus (the Atlantic Wolffish). Multivariate analysis of these three groups of fishes lends further support to the relationship between diet and tooth microwear, and provides robust validation of the approach. Application of the multivariate models derived from microwear texture in Archosargus and Anarhichas to a third fish species—the cichlid Astatoreochromis alluaudi—successfully separates wild caught fish that ate hard-shelled prey from lab-raised fish that did not. This cross-taxon validation demonstrates that quantitative analysis of tooth microwear texture can differentiate between fishes with different diets even when they range widely in size, habitat, and in the structure of their trophic apparatus. The approach thus has great potential as an additional tool for dietary analysis in extant fishes, and for testing dietary hypotheses in ancient and extinct species.
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Anterior dental microwear textures show habitat-driven variability in Neandertal behavior.
Krueger, Kristin L; Ungar, Peter S; Guatelli-Steinberg, Debbie; Hublin, Jean-Jacques; Pérez-Pérez, Alejandro; Trinkaus, Erik; Willman, John C
2017-04-01
The causes of Neandertal anterior tooth wear patterns, including labial rounding, labial scratches, and differential anterior-posterior wear, have been debated for decades. The most common explanation is the "stuff-and-cut" hypothesis, which describes Neandertals clamping down on a piece of meat and slicing a portion close to their lips. "Stuff-and-cut" has been accepted as a general aspect of Neandertal behavior without fully assessing its variability. This study analyzes anterior dental microwear textures across habitats, locations, and time intervals to discern possible variation in Neandertal anterior tooth-use behavior. Forty-five Neandertals from 24 sites were analyzed, represented by high-resolution replicas of permanent anterior teeth. The labial surface was scanned for antemortem microwear using a white-light confocal profiler. The resultant 3D-point clouds, representing 204 × 276 μm for each specimen, were uploaded into SSFA software packages for texture characterization. Statistical analyses, including MANOVAs, ANOVAs, and pairwise comparisons, were completed on ranked microwear data. Neandertal descriptive statistics were also compared to 10 bioarchaeological samples of known or inferred dietary and behavioral regimes. The Neandertal sample varied significantly by habitat, suggesting this factor was a principal driving force for differences in Neandertal anterior tooth-use behaviors. The Neandertals from open habitats showed significantly lower anisotropy and higher textural fill volume than those inhabiting more closed, forested environments. The texture signature from the open-habitat Neandertals was most similar to that of the Ipiutak and Nunavut, who used their anterior teeth for intense clamping and grasping behaviors related to hide preparation. Those in more closed habitats were most similar to the Arikara, who did not participate in non-dietary behaviors. These Neandertal individuals had a broad range of texture values consistent with non-dietary and dietary behaviors, suggesting they varied more in anterior tooth-use behaviors and exploited a wider variety of plant and animal resources than did those from open habitats. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Ungar, Peter S; Abella, Elicia F; Burgman, Jenny H E; Lazagabaster, Ignacio A; Scott, Jessica R; Delezene, Lucas K; Manthi, Fredrick K; Plavcan, J Michael; Ward, Carol V
2017-05-09
Reconstructions of habitat at sites like Kanapoi are key to understanding the environmental circumstances in which hominins evolved during the early Pliocene. While Australopithecus anamensis shows evidence of terrestrial bipedality traditionally associated with a more open setting, its enamel has low δ 13 C values consistent with consumption of C 3 foods, which predominate in wooded areas of tropical Africa. Habitat proxies, ranging from paleosols and their carbonates to associated herbivore fauna and their carbon isotope ratios, suggest a heterogeneous setting with both grass and woody plant components, though the proportions of each have been difficult to pin down. Here we bring dental microwear texture analysis of herbivorous fauna to bear on the issue. We present texture data for fossil bovids, primates, rodents, and suids (n = 107 individuals in total) from the hominin bearing deposits at Kanapoi, and interpret these in the light of closely related extant mammals with known differences in diet. The Kanapoi bovid results, for example, are similar to those for extant variable grazers or graze-browse intermediate taxa. The Kanapoi suid data vary by taxon, with one similar to the pattern of extant grazers and the other more closely resembling mixed feeders. The Kanapoi primates and rodents are more difficult to associate with a specific environment, though it seems that grass was likely a component in the diets of both. All taxa evince microwear texture patterns consistent with a mosaic of discrete microhabitats or a heterogeneous setting including both tree and grass components. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Mechanisms and causes of wear in tooth enamel: implications for hominin diets.
Lucas, Peter W; Omar, Ridwaan; Al-Fadhalah, Khaled; Almusallam, Abdulwahab S; Henry, Amanda G; Michael, Shaji; Thai, Lidia Arockia; Watzke, Jörg; Strait, David S; Atkins, Anthony G
2013-03-06
The wear of teeth is a major factor limiting mammalian lifespans in the wild. One method of describing worn surfaces, dental microwear texture analysis, has proved powerful for reconstructing the diets of extinct vertebrates, but has yielded unexpected results in early hominins. In particular, although australopiths exhibit derived craniodental features interpreted as adaptations for eating hard foods, most do not exhibit microwear signals indicative of this diet. However, no experiments have yet demonstrated the fundamental mechanisms and causes of this wear. Here, we report nanowear experiments where individual dust particles, phytoliths and enamel chips were slid across a flat enamel surface. Microwear features produced were influenced strongly by interacting mechanical properties and particle geometry. Quartz dust was a rigid abrasive, capable of fracturing and removing enamel pieces. By contrast, phytoliths and enamel chips deformed during sliding, forming U-shaped grooves or flat troughs in enamel, without tissue loss. Other plant tissues seem too soft to mark enamel, acting as particle transporters. We conclude that dust has overwhelming importance as a wear agent and that dietary signals preserved in dental microwear are indirect. Nanowear studies should resolve controversies over adaptive trends in mammals like enamel thickening or hypsodonty that delay functional dental loss.
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Donohue, Shelly L.; DeSantis, Larisa R. G.; Schubert, Blaine W.; Ungar, Peter S.
2013-01-01
Dramatic environmental changes associated with global cooling since the late Miocene, and the onset of glacial-interglacial cycles in the Pleistocene served as a backdrop to the evolutionary radiation of modern bears (family Ursidae). These environmental changes likely prompted changes in food availability, and triggered dietary adaptations that served as motive forces in ursid evolution. Here, we assess correspondence of dental microwear textures of first and second lower molars with diet in extant ursids. We use the resulting baseline data to evaluate the hypothesis that the Pleistocene giant short-faced bear, Arctodus simus, was a bone consumer and hyper-scavenger at Rancho La Brea, California, USA. Significant variation along the tooth row is consistent with functional differentiation, with the second molar serving as a better dietary recorder than the first. Results evince significant variation among species: carnivorous and omnivorous ursids (Ursus maritimus, U. americanus) have significantly higher and more variable complexity (Asfc) than more herbivorous ones (Ailuropoda melanoleuca, Tremarctos ornatus, U. malayanus), and A. melanoleuca is differentiated from U. maritimus and U. americanus by significantly higher and more variable anisotropy (epLsar) values. Arctodus simus from Rancho La Brea exhibits wear attributes most comparable to its closest living relative (T. ornatus), which is inconsistent with hard-object (e.g., bone) consumption, and the hypothesis that short-faced bears were bone consuming hyper-scavengers across their range. PMID:24204860
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Mechanisms and causes of wear in tooth enamel: implications for hominin diets
Lucas, Peter W.; Omar, Ridwaan; Al-Fadhalah, Khaled; Almusallam, Abdulwahab S.; Henry, Amanda G.; Michael, Shaji; Thai, Lidia Arockia; Watzke, Jörg; Strait, David S.; Atkins, Anthony G.
2013-01-01
The wear of teeth is a major factor limiting mammalian lifespans in the wild. One method of describing worn surfaces, dental microwear texture analysis, has proved powerful for reconstructing the diets of extinct vertebrates, but has yielded unexpected results in early hominins. In particular, although australopiths exhibit derived craniodental features interpreted as adaptations for eating hard foods, most do not exhibit microwear signals indicative of this diet. However, no experiments have yet demonstrated the fundamental mechanisms and causes of this wear. Here, we report nanowear experiments where individual dust particles, phytoliths and enamel chips were slid across a flat enamel surface. Microwear features produced were influenced strongly by interacting mechanical properties and particle geometry. Quartz dust was a rigid abrasive, capable of fracturing and removing enamel pieces. By contrast, phytoliths and enamel chips deformed during sliding, forming U-shaped grooves or flat troughs in enamel, without tissue loss. Other plant tissues seem too soft to mark enamel, acting as particle transporters. We conclude that dust has overwhelming importance as a wear agent and that dietary signals preserved in dental microwear are indirect. Nanowear studies should resolve controversies over adaptive trends in mammals like enamel thickening or hypsodonty that delay functional dental loss. PMID:23303220
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NASA Astrophysics Data System (ADS)
Francisco, Arthur; Blondel, Cécile; Brunetière, Noël; Ramdarshan, Anusha; Merceron, Gildas
2018-03-01
Tooth wear and, more specifically, dental microwear texture is a dietary proxy that has been used for years in vertebrate paleoecology and ecology. DMTA, dental microwear texture analysis, relies on a few parameters related to the surface complexity, anisotropy and heterogeneity of the enamel facets at the micrometric scale. Working with few but physically meaningful parameters helps in comparing published results and in defining levels for classification purposes. Other dental microwear approaches are based on ISO parameters and coupled with statistical tests to find the more relevant ones. The present study roughly utilizes most of the aforementioned parameters in their more or less modified form. But more than parameters, we here propose a new approach: instead of a single parameter characterizing the whole surface, we sample the surface and thus generate 9 derived parameters in order to broaden the parameter set. The identification of the most discriminative parameters is performed with an automated procedure which is an extended and refined version of the workflows encountered in some studies. The procedure in its initial form includes the most common tools, like the ANOVA and the correlation analysis, along with the required mathematical tests. The discrimination results show that a simplified form of the procedure is able to more efficiently identify the desired number of discriminative parameters. Also highlighted are some trends like the relevance of working with both height and spatial parameters, as well as the potential benefits of dimensionless surfaces. On a set of 45 surfaces issued from 45 specimens of three modern ruminants with differences in feeding preferences (grazing, leaf-browsing and fruit-eating), it is clearly shown that the level of wear discrimination is improved with the new methodology compared to the other ones.
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Surface-Sensitive Microwear Texture Analysis of Attrition and Erosion.
Ranjitkar, S; Turan, A; Mann, C; Gully, G A; Marsman, M; Edwards, S; Kaidonis, J A; Hall, C; Lekkas, D; Wetselaar, P; Brook, A H; Lobbezoo, F; Townsend, G C
2017-03-01
Scale-sensitive fractal analysis of high-resolution 3-dimensional surface reconstructions of wear patterns has advanced our knowledge in evolutionary biology, and has opened up opportunities for translatory applications in clinical practice. To elucidate the microwear characteristics of attrition and erosion in worn natural teeth, we scanned 50 extracted human teeth using a confocal profiler at a high optical resolution (X-Y, 0.17 µm; Z < 3 nm). Our hypothesis was that microwear complexity would be greater in erosion and that anisotropy would be greater in attrition. The teeth were divided into 4 groups, including 2 wear types (attrition and erosion) and 2 locations (anterior and posterior teeth; n = 12 for each anterior group, n = 13 for each posterior group) for 2 tissue types (enamel and dentine). The raw 3-dimensional data cloud was subjected to a newly developed rigorous standardization technique to reduce interscanner variability as well as to filter anomalous scanning data. Linear mixed effects (regression) analyses conducted separately for the dependent variables, complexity and anisotropy, showed the following effects of the independent variables: significant interactions between wear type and tissue type ( P = 0.0157 and P = 0.0003, respectively) and significant effects of location ( P < 0.0001 and P = 0.0035, respectively). There were significant associations between complexity and anisotropy when the dependent variable was either complexity ( P = 0.0003) or anisotropy ( P = 0.0014). Our findings of greater complexity in erosion and greater anisotropy in attrition confirm our hypothesis. The greatest geometric means were noted in dentine erosion for complexity and dentine attrition for anisotropy. Dentine also exhibited microwear characteristics that were more consistent with wear types than enamel. Overall, our findings could complement macrowear assessment in dental clinical practice and research and could assist in the early detection and management of pathologic tooth wear.
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Incisor microwear and diet in three species of Colobus.
Kelley, J
1990-01-01
Examination of incisor microwear in three species of Colobus revealed that the predominantly folivorous C. badius more closely resembles C. satanas, a seed predator/folivore, than C. guereza, another predominantly folivorous species. This demonstrates that species of the same broad dietary category can have very different patterns of incisor microwear, indicative of differences in food procurement behavior and/or the physical properties of dietary items for some portion of the diet. Conversely, species of different categories can have microwear patterns that, superficially at least, are quite similar. The dissimilarity in incisor microwear between C. badius and C. guereza is mirrored to a certain extent in molar microwear, although the differences are not nearly so great on the molars. The differences between C. badius and C. guereza may involve different food items in the major, folivorous portions of their diets, or they may relate to differences in the very minor fruit and bark components. The similar microwear patterns of C. badius and C. satanas demonstrate that incisor microwear by itself is unreliable for assigning fossil species to broad dietary categories. Incisor microwear can be used to infer finer dietary distinctions in fossil species for which dietary category has been determined by other means.
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Christensen, Hilary B.
2014-01-01
Low-magnification microwear techniques have been used effectively to infer diets within many unrelated mammalian orders, but the extent to which patterns are comparable among such different groups, including long extinct mammal lineages, is unknown. Microwear patterns between ecologically equivalent placental and marsupial mammals are found to be statistically indistinguishable, indicating that microwear can be used to infer diet across the mammals. Microwear data were compared to body size and molar shearing crest length in order to develop a system to distinguish the diet of mammals. Insectivores and carnivores were difficult to distinguish from herbivores using microwear alone, but combining microwear data with body size estimates and tooth morphology provides robust dietary inferences. This approach is a powerful tool for dietary assessment of fossils from extinct lineages and from museum specimens of living species where field study would be difficult owing to the animal’s behavior, habitat, or conservation status. PMID:25099537
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Implications of Diet for the Extinction of Saber-Toothed Cats and American Lions
DeSantis, Larisa R. G.; Schubert, Blaine W.; Scott, Jessica R.; Ungar, Peter S.
2012-01-01
The saber-toothed cat, Smilodon fatalis, and American lion, Panthera atrox, were among the largest terrestrial carnivores that lived during the Pleistocene, going extinct along with other megafauna ∼12,000 years ago. Previous work suggests that times were difficult at La Brea (California) during the late Pleistocene, as nearly all carnivores have greater incidences of tooth breakage (used to infer greater carcass utilization) compared to today. As Dental Microwear Texture Analysis (DMTA) can differentiate between levels of bone consumption in extant carnivores, we use DMTA to clarify the dietary niches of extinct carnivorans from La Brea. Specifically, we test the hypothesis that times were tough at La Brea with carnivorous taxa utilizing more of the carcasses. Our results show no evidence of bone crushing by P. atrox, with DMTA attributes most similar to the extant cheetah, Acinonyx jubatus, which actively avoids bone. In contrast, S. fatalis has DMTA attributes most similar to the African lion Panthera leo, implying that S. fatalis did not avoid bone to the extent previously suggested by SEM microwear data. DMTA characters most indicative of bone consumption (i.e., complexity and textural fill volume) suggest that carcass utilization by the extinct carnivorans was not necessarily more complete during the Pleistocene at La Brea; thus, times may not have been “tougher” than the present. Additionally, minor to no significant differences in DMTA attributes from older (∼30–35 Ka) to younger (∼11.5 Ka) deposits offer little evidence that declining prey resources were a primary cause of extinction for these large cats. PMID:23300674
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Implications of diet for the extinction of saber-toothed cats and American lions.
Desantis, Larisa R G; Schubert, Blaine W; Scott, Jessica R; Ungar, Peter S
2012-01-01
The saber-toothed cat, Smilodon fatalis, and American lion, Panthera atrox, were among the largest terrestrial carnivores that lived during the Pleistocene, going extinct along with other megafauna ∼12,000 years ago. Previous work suggests that times were difficult at La Brea (California) during the late Pleistocene, as nearly all carnivores have greater incidences of tooth breakage (used to infer greater carcass utilization) compared to today. As Dental Microwear Texture Analysis (DMTA) can differentiate between levels of bone consumption in extant carnivores, we use DMTA to clarify the dietary niches of extinct carnivorans from La Brea. Specifically, we test the hypothesis that times were tough at La Brea with carnivorous taxa utilizing more of the carcasses. Our results show no evidence of bone crushing by P. atrox, with DMTA attributes most similar to the extant cheetah, Acinonyx jubatus, which actively avoids bone. In contrast, S. fatalis has DMTA attributes most similar to the African lion Panthera leo, implying that S. fatalis did not avoid bone to the extent previously suggested by SEM microwear data. DMTA characters most indicative of bone consumption (i.e., complexity and textural fill volume) suggest that carcass utilization by the extinct carnivorans was not necessarily more complete during the Pleistocene at La Brea; thus, times may not have been "tougher" than the present. Additionally, minor to no significant differences in DMTA attributes from older (∼30-35 Ka) to younger (∼11.5 Ka) deposits offer little evidence that declining prey resources were a primary cause of extinction for these large cats.
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Yamada, Eisuke; Kubo, Mugino O.
2017-01-01
Dental microwear of four postcanine teeth of Exaeretodon argentinus was analyzed using both two dimensional (2D) and three dimensional (3D) methods to infer their masticatory jaw movements. Results of both methods were congruent, showing that linear microwear features (scratches) were well aligned and mostly directed to the antero-posterior direction in all four teeth examined. These findings support the palinal masticatory jaw movement, which was inferred in previous studies based on the observation of gross morphology of wear facets. In contrast, the lack of detection of lateral scratches confirmed the absence of the lateral jaw movement that was also proposed by a previous study. Considering previous microwear studies on cynodonts, palinal jaw movements observed in Exaeretodon evolved within cynognathian cynodonts from the fully orthal jaw movement of its basal member. Although there are currently only three studies of dental microwear of non-mammalian cynodonts including the present study, microwear analysis is a useful tool for the reconstruction of masticatory jaw movement and its future application to various cynodonts will shed light on the evolutionary process of jaw movement towards the mammalian condition in more detail. PMID:29186178
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Tooth microwear formation rate in Gasterosteus aculeatus
Baines, D C; Purnell, M A; Hart, P J B
2014-01-01
Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals. PMID:24773545
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Harvati, Katerina; Darlas, Andreas; Bailey, Shara E; Rein, Thomas R; El Zaatari, Sireen; Fiorenza, Luca; Kullmer, Ottmar; Psathi, Eleni
2013-06-01
The Kalamakia cave, a Middle Paleolithic site on the western coast of the Mani peninsula, Greece, was excavated in 1993-2006 by an interdisciplinary team from the Ephoreia of Paleoanthropology and Speleology (Greek Ministry of Culture) and the Muséum national d'Histoire naturelle (Paris). The site is dated to between ca. 100,000 and >39,000 years BP (Before Present) and has yielded Mousterian lithics, a rich fauna, and human remains from several layers. The latter include 10 isolated teeth, a cranial fragment and three postcranial elements. The remains represent at least eight individuals, two of them subadults, and show both carnivore and anthropogenic modifications. They can be identified as Neanderthal on the basis of diagnostic morphology on most specimens. A diet similar to that of Neanderthals from mixed habitat is suggested by our analysis of dental wear (occlusal fingerprint analysis) and microwear (occlusal texture microwear analysis), in agreement with the faunal and palynological analyses of the site. These new fossils significantly expand the Neanderthal sample known from Greece. Together with the human specimens from Lakonis and Apidima, the Kalamakia human remains add to the growing evidence of a strong Neanderthal presence in the Mani region during the Late Pleistocene. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Percher, Alice M; Romero, Alejandro; Galbany, Jordi; Nsi Akoue, Gontran; Pérez-Pérez, Alejandro; Charpentier, Marie J E
2017-01-01
Analyses of dental micro- and macro-wear offer valuable information about dietary adaptations. The buccal surface of the teeth does not undergo attrition, indicating that dental microwear may directly inform about food properties. Only a few studies have, however, investigated the environmental and individual factors involved in the formation of such microwear in wild animals. Here, we examine variation of buccal microwear patterns of mandibular molars in a large free-ranging population of mandrills (Mandrillus sphinx). We first explore the influence of seasonality and individual's sex, age and tooth macrowear-expressed as the percent of dentine exposure (PDE)-on six microwear variables. Second, we analyze the interplay between individual's diet and PDE. In a last analysis, we revisit our results on mandrills in the light of other primate's microwear studies. We show that the average buccal scratch length and the frequency of vertical buccal scratches are both higher during the long dry season compared to the long rainy season, while we observe the inverse relationship for disto-mesial scratches. In addition, females present more disto-mesial scratches than males and older individuals present higher scratch density, a greater proportion of horizontal scratches but a lower proportion of vertical scratches than young animals. PDE yields similar results than individual's age confirming earlier results in this population on the relationship between age and tooth macrowear. Because seasonality and individual characteristics are both known to impact mandrills' diet in the study population, our results suggest that buccal microwear patterns may inform about individual feeding strategies. Furthermore, PDE increases with the consumption of potentially abrasive monocotyledonous plants, independently of the individuals' age, although it is not affected by food mechanical properties. Finally, buccal scratch densities by orientation appear as relevant proxies for discriminating between different primate taxa.
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Do mandibular cross-sectional properties and dental microwear give similar dietary signals?
Organ, Jason M; Ruff, Christopher B; Teaford, Mark F; Nisbett, Richard A
2006-08-01
Previous animal experimental work evaluating the effects of dietary consistency on mastication was generally limited to studies of either mandibular structure or rates and types of tooth wear. Control groups fed hard diets (HD) consistently exhibited increased cortical remodeling and/or bone strength when compared to groups fed soft diets (SD). Results of tooth-wear studies showed faster rates of tooth wear in HD animals. This study evaluates the effects of dietary differences on both mandibular structural morphology and postcanine dental microwear in the same animals. We examined mandibles and dentitions from eight miniature swine, raised from 4 weeks to 9 months of age on HD and SD (n = 4, each group). Mandibular structural properties were calculated from peripheral quantitative computed tomography slices at the dp3-dp4 and dp4-M1 junctions. Dental microwear analysis was performed on mandibular lingual crushing facets of dp4 and M1, using photomicrographs of high-resolution casts taken at 500x magnification in a scanning electron microscope. Our results suggest that between the dp3-dp4 contact, HD animals have mandibles that are stronger and more rigid mediolaterally than SD animals. At the dp4-M1 contact, HD animals have mandibles that are stronger and more rigid mediolaterally, dorsoventrally, and in torsion than SD animals. Dental microwear results indicate that SD pigs have higher incidences of pitting and more overall microwear features on their premolars than do HD pigs, yet there are no significant differences in molar microwear morphology between the dietary groups. Near-significant correlations exist between pit size and dorsoventral bending strength, but only for HD pigs. These results suggest that dietary consistency significantly affects both mandibular structure and dental microwear, yet direct correlations between the two are complicated by a number of factors.
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Tooth microwear formation rate in Gasterosteus aculeatus.
Baines, D C; Purnell, M A; Hart, P J B
2014-05-01
Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals. © 2014 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.
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Romero, Alejandro; Galbany, Jordi; Nsi Akoue, Gontran; Pérez-Pérez, Alejandro; Charpentier, Marie J. E.
2017-01-01
Analyses of dental micro- and macro-wear offer valuable information about dietary adaptations. The buccal surface of the teeth does not undergo attrition, indicating that dental microwear may directly inform about food properties. Only a few studies have, however, investigated the environmental and individual factors involved in the formation of such microwear in wild animals. Here, we examine variation of buccal microwear patterns of mandibular molars in a large free-ranging population of mandrills (Mandrillus sphinx). We first explore the influence of seasonality and individual’s sex, age and tooth macrowear–expressed as the percent of dentine exposure (PDE)–on six microwear variables. Second, we analyze the interplay between individual’s diet and PDE. In a last analysis, we revisit our results on mandrills in the light of other primate’s microwear studies. We show that the average buccal scratch length and the frequency of vertical buccal scratches are both higher during the long dry season compared to the long rainy season, while we observe the inverse relationship for disto-mesial scratches. In addition, females present more disto-mesial scratches than males and older individuals present higher scratch density, a greater proportion of horizontal scratches but a lower proportion of vertical scratches than young animals. PDE yields similar results than individual’s age confirming earlier results in this population on the relationship between age and tooth macrowear. Because seasonality and individual characteristics are both known to impact mandrills’ diet in the study population, our results suggest that buccal microwear patterns may inform about individual feeding strategies. Furthermore, PDE increases with the consumption of potentially abrasive monocotyledonous plants, independently of the individuals’ age, although it is not affected by food mechanical properties. Finally, buccal scratch densities by orientation appear as relevant proxies for discriminating between different primate taxa. PMID:29073184
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Peigné, Stéphane; Goillot, Cyrielle; Germonpré, Mietje; Blondel, Cécile; Bignon, Olivier; Merceron, Gildas
2009-01-01
Previous morphological and isotopic studies indicate that Late Pleistocene cave bear (Ursus spelaeus) diet ranged from mostly vegetarian to omnivory or even carnivory. However, such analyses do not provide information on seasonal diets, and only provide an average record of diet. A dental microwear analysis of 43 young and adult individuals demonstrate that, during the predormancy period, cave bears from Goyet (Late Pleistocene, Belgium) were not strictly herbivorous, but had a mixed diet composed of hard items (e.g., possibly bone), invertebrates (e.g., insects), meat (ungulates, small vertebrates), and/or plant matter (hard mast, seeds, herbaceous vegetations, and fruits). Therefore, our results indicate that cave bears at Goyet were generalist omnivores during the predormancy period, which is consistent with current data on the dietary ecology of extant bears during this season. These data also raise questions about the ecological role and causes of the extinction of cave bears. PMID:19706401
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Bodoriková, Silvia; Tibenská, Kristína Domonkosová; Katina, Stanislav; Uhrová, Petra; Dörnhöferová, Michaela; Takács, Michal; Urminský, Jozef
2013-01-01
The aim of the study was to determine the diet of an historical human population using the trace elements in dental tissues and dental buccal microwear. Although 38 individuals had been buried in the cemetery, preservation of the remains did not allow analysis of all of them. A total of 13 individuals were analysed, of which the samples for trace-element analysis consisted of 12 permanent premolars from 12 individuals. Buccal microwear was studied in a sample of nine teeth from nine individuals. Both trace-element and microwear analyses were performed on eight individuals. All analyzed teeth were intact, with fully developed roots, without dental calculus and macro-abrasion. Concentrations of Sr, Zn, and Ca, and their ratios, were used to determine the relative proportions of plant and animal protein in the diet. Samples were analyzed using optical emission spectrometry with inductively coupled plasma. The values of the Sr and Zn concentrations indicate that a diet of the investigated population was of a mixed character with approximately the same proportion of plants and meat in their food. Buccal microwear was studied in molds ofbuccal surfaces and observed at 100x magnification with a scanning electron microscope (SEM). Length and orientation of striations were determined with the SigmaScan Pro 5.0 image analysis program. The results obtained from microwear analysis correspond with those from trace-element analysis and showed that the population consumed a mixed diet. The density of the scratches indicates that the diet contained a considerable vegetable component. The high number of vertical scratches and their high average length suggest that individuals also consumed a large portion of meat. The results of both analyses showed that there were also individuals whose diet had probably been poor, i.e. richer in animal protein, which probably could be related to their health or social status in the population.
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Lozano, Marina; Bermúdez de Castro, José M; Carbonell, Eudald; Arsuaga, Juan Luis
2008-10-01
In this study we examine the labial and occlusal surfaces of incisors and canines of hominins recovered from the Sima de los Huesos (SH), middle Pleistocene site, in order to establish the possible extra-masticatory use of anterior teeth. We have compared the microwear of these fossils with microwear from the anterior teeth of Australian Aborigines, a population characterized by ethnographic evidence of the use of their teeth as a third hand. These two samples of teeth were microscopically analyzed using Scanning Electron Microscopy (SEM). Our results support the "cultural" origin of microwear observed on fossil teeth: we conclude that the SH hominins used their anterior teeth as a "third hand" for para- or extra-masticatory activities.
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Determining the direction of tooth grinding: an in vitro study.
ten Berge, F; te Poel, J; Ranjitkar, S; Kaidonis, J A; Lobbezoo, F; Hughes, T E; Townsend, G C
2012-08-01
The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on enamel, perpendicularly to the direction of grinding, could predict the grinding direction. Experimental scratches were placed using a scalpel blade on standardised wear facets that had been prepared by wearing opposing enamel surfaces in an electromechanical tooth wear machine. These control 'baseline' facets (with unworn experimental scratches) were subjected to 50 wear cycles, so that differential microwear could be observed on the leading and trailing edges of the 'final' facets. In Group 1 (n=28), the 'footprint' microwear patterns corresponding to the known grinding direction of specimens in the tooth wear machine were identified. Then, they were used to predict the direction of tooth grinding blindly in the same sample after a 2-week intermission period. To avoid overfitting the predictive model, its sensitivity was also cross-validated in a new sample (Group 2, n=14). A crescent-shaped characteristic observed in most experimental scratches matched the grinding direction on all occasions. The best predictor of the direction of grinding was a combined assessment of the leading edge microwear pattern and the crescent characteristic (82.1% in Group 1 and 92.9% in Group 2). In conclusion, a simple scratch test can determine the direction of tooth grinding with high reliability, although further improvement in sensitivity is desirable. © 2012 Blackwell Publishing Ltd.
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Surface analysis of stone and bone tools
NASA Astrophysics Data System (ADS)
Stemp, W. James; Watson, Adam S.; Evans, Adrian A.
2016-03-01
Microwear (use-wear) analysis is a powerful method for identifying tool use that archaeologists and anthropologists employ to determine the activities undertaken by both humans and their hominin ancestors. Knowledge of tool use allows for more accurate and detailed reconstructions of past behavior, particularly in relation to subsistence practices, economic activities, conflict and ritual. It can also be used to document changes in these activities over time, in different locations, and by different members of society, in terms of gender and status, for example. Both stone and bone tools have been analyzed using a variety of techniques that focus on the observation, documentation and interpretation of wear traces. Traditionally, microwear analysis relied on the qualitative assessment of wear features using microscopes and often included comparisons between replicated tools used experimentally and the recovered artifacts, as well as functional analogies dependent upon modern implements and those used by indigenous peoples from various places around the world. Determination of tool use has also relied on the recovery and analysis of both organic and inorganic residues of past worked materials that survived in and on artifact surfaces. To determine tool use and better understand the mechanics of wear formation, particularly on stone and bone, archaeologists and anthropologists have increasingly turned to surface metrology and tribology to assist them in their research. This paper provides a history of the development of traditional microwear analysis in archaeology and anthropology and also explores the introduction and adoption of more modern methods and technologies for documenting and identifying wear on stone and bone tools, specifically those developed for the engineering sciences to study surface structures on micro- and nanoscales. The current state of microwear analysis is discussed as are the future directions in the study of microwear on stone and bone tools.
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Mallon, Jordan C; Anderson, Jason S
2014-01-01
Megaherbivorous dinosaurs were exceptionally diverse on the Late Cretaceous island continent of Laramidia, and a growing body of evidence suggests that this diversity was facilitated by dietary niche partitioning. We test this hypothesis using the fossil megaherbivore assemblage from the Dinosaur Park Formation (upper Campanian) of Alberta as a model. Comparative tooth morphology and wear, including the first use of quantitative dental microwear analysis in the context of Cretaceous palaeosynecology, are used to infer the mechanical properties of the foods these dinosaurs consumed. The phylliform teeth of ankylosaurs were poorly adapted for habitually processing high-fibre plant matter. Nevertheless, ankylosaur diets were likely more varied than traditionally assumed: the relatively large, bladed teeth of nodosaurids would have been better adapted to processing a tougher, more fibrous diet than the smaller, cusp-like teeth of ankylosaurids. Ankylosaur microwear is characterized by a preponderance of pits and scratches, akin to modern mixed feeders, but offers no support for interspecific dietary differences. The shearing tooth batteries of ceratopsids are much better adapted to high-fibre herbivory, attested by their scratch-dominated microwear signature. There is tentative microwear evidence to suggest differences in the feeding habits of centrosaurines and chasmosaurines, but statistical support is not significant. The tooth batteries of hadrosaurids were capable of both shearing and crushing functions, suggestive of a broad dietary range. Their microwear signal overlaps broadly with that of ankylosaurs, and suggests possible dietary differences between hadrosaurines and lambeosaurines. Tooth wear evidence further indicates that all forms considered here exhibited some degree of masticatory propaliny. Our findings reveal that tooth morphology and wear exhibit different, but complimentary, dietary signals that combine to support the hypothesis of dietary niche partitioning. The inferred mechanical and dietary patterns appear constant over the 1.5 Myr timespan of the Dinosaur Park Formation megaherbivore chronofauna, despite continual species turnover.
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Mallon, Jordan C.; Anderson, Jason S.
2014-01-01
Megaherbivorous dinosaurs were exceptionally diverse on the Late Cretaceous island continent of Laramidia, and a growing body of evidence suggests that this diversity was facilitated by dietary niche partitioning. We test this hypothesis using the fossil megaherbivore assemblage from the Dinosaur Park Formation (upper Campanian) of Alberta as a model. Comparative tooth morphology and wear, including the first use of quantitative dental microwear analysis in the context of Cretaceous palaeosynecology, are used to infer the mechanical properties of the foods these dinosaurs consumed. The phylliform teeth of ankylosaurs were poorly adapted for habitually processing high-fibre plant matter. Nevertheless, ankylosaur diets were likely more varied than traditionally assumed: the relatively large, bladed teeth of nodosaurids would have been better adapted to processing a tougher, more fibrous diet than the smaller, cusp-like teeth of ankylosaurids. Ankylosaur microwear is characterized by a preponderance of pits and scratches, akin to modern mixed feeders, but offers no support for interspecific dietary differences. The shearing tooth batteries of ceratopsids are much better adapted to high-fibre herbivory, attested by their scratch-dominated microwear signature. There is tentative microwear evidence to suggest differences in the feeding habits of centrosaurines and chasmosaurines, but statistical support is not significant. The tooth batteries of hadrosaurids were capable of both shearing and crushing functions, suggestive of a broad dietary range. Their microwear signal overlaps broadly with that of ankylosaurs, and suggests possible dietary differences between hadrosaurines and lambeosaurines. Tooth wear evidence further indicates that all forms considered here exhibited some degree of masticatory propaliny. Our findings reveal that tooth morphology and wear exhibit different, but complimentary, dietary signals that combine to support the hypothesis of dietary niche partitioning. The inferred mechanical and dietary patterns appear constant over the 1.5 Myr timespan of the Dinosaur Park Formation megaherbivore chronofauna, despite continual species turnover. PMID:24918431
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Tibenská, Kristína Domonkosová; Bodoriková, Silvia; Katina, Stanislav; Kovácsová, Veronika; Kubová, Jana; Takács, Michal
2010-01-01
The aim of the study was to determine the diet of a historical human population. Dental microwear and trace elements were analyzed. Although 38 individuals had been buried in the cemetery, only 13 of them were suitable for the analysis of trace elements and 17 skeletal remains for microwear analysis. Buccal microwear has been studied in a sample of 17 teeth from Gán cemetery. Teeth molds of the buccal surface were obtained and observed at 120x magnification with a scanning electron microscope (SEM). Length and orientation of each striation have been determined with a SigmaScan Pro 5.0 image analysis program. The results of the analysis from Gán were compared with the previous study in a sample of 153 molar teeth from different modern hunter-gatherer, pastorals, and agriculturalist groups, with different diets (Inuit, Fueguians, Bushmen, Australian aborigines, Andaman's, Indians from Vancouver, Veddahs, Tasmanians, Lapps, and Hindus), preserved at museum collections. Buccal dental microwear density and length by orientation showed almost an inclination to hunter-gatherers from tropic and arid climates. The sample for the trace elements analysis consisted of 10 permanent molars and 3 permanent premolars. All analyzed teeth were intact, with fully developed roots, without dental caries, calculus and abrasion. Samples were analyzed using the method of optical emission spectrometry with inductively coupled plasma. Three elements: Ca, Sr, and Zn were chosen as basic diet determinants. Concentrations of these elements and their ratios were used for description of a relative proportion of plant and animal protein in a diet. The values of the Sr and Zn concentrations indicate that a diet of investigated population was rich in plant food. Higher Sr values in women can indicate lower proportion of animal protein in a diet, but significant differences have not been found. Differences between non-adult and adult individuals and between individuals with and without grave furnishings have also not been significant.
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NASA Astrophysics Data System (ADS)
Charles, Cyril; Jaeger, Jean-Jacques; Michaux, Jacques; Viriot, Laurent
2007-01-01
Observations of dental microwear are used to analyse the correlation between changes in molar tooth crown morphology and the direction of masticatory movement during the evolution of Myodonta (Rodentia, Mammalia). The studied sample includes 36 specimens representing both superfamilies of Myodonta (Muroidea and Dipodoidea) spanning 16 dipodoid and 9 muroid species. Microscopic scratches on occlusal surfaces resulting from contact between opposite teeth during mastication are analysed. Using these features, we determine the direction of masticatory movements. Microwear patterns display diverse orientations among Dipodoidea: oblique in Sicistinae, Euchoreutinae and Zapodinae, propalinal in Dipodinae and intermediary in Allactaginae. Similarly, Muroidea exhibit the following orientations: oblique in Cricetinae and propalinal in Arvicolinae, Cricetomyinae, Gerbillinae and Murinae. These various chewing types illustrate different evolutionary grades within the superfamilies. Acquisition of the antero-posterior masticatory movement in Dipodoidea is related to flattening of the molar occlusal surface. However, in some muroid subfamilies, this direction of mastication is associated with low-crowned and cuspidate molars (Cricetomyinae, Murinae).
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Testing Dietary Hypotheses of East African Hominines Using Buccal Dental Microwear Data
Martínez, Laura Mónica; Estebaranz-Sánchez, Ferran; Galbany, Jordi
2016-01-01
There is much debate on the dietary adaptations of the robust hominin lineages during the Pliocene-Pleistocene transition. It has been argued that the shift from C3 to C4 ecosystems in Africa was the main factor responsible for the robust dental and facial anatomical adaptations of Paranthropus taxa, which might be indicative of the consumption of fibrous, abrasive plant foods in open environments. However, occlusal dental microwear data fail to provide evidence of such dietary adaptations and are not consistent with isotopic evidence that supports greater C4 food intake for the robust clades than for the gracile australopithecines. We provide evidence from buccal dental microwear data that supports softer dietary habits than expected for P. aethiopicus and P. boisei based both on masticatory apomorphies and isotopic analyses. On one hand, striation densities on the buccal enamel surfaces of paranthropines teeth are low, resembling those of H. habilis and clearly differing from those observed on H. ergaster, which display higher scratch densities indicative of the consumption of a wide assortment of highly abrasive foodstuffs. Buccal dental microwear patterns are consistent with those previously described for occlusal enamel surfaces, suggesting that Paranthropus consumed much softer diets than previously presumed and thus calling into question a strict interpretation of isotopic evidence. On the other hand, the significantly high buccal scratch densities observed in the H. ergaster specimens are not consistent with a highly specialized, mostly carnivorous diet; instead, they support the consumption of a wide range of highly abrasive food items. PMID:27851745
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Merceron, Gildas; Schulz, Ellen; Kordos, László; Kaiser, Thomas M
2007-10-01
The environment of the hominoid Dryopithecus brancoi at Rudabánya (Late Miocene of Hungary) is reconstructed here using the dietary traits of fossil ruminants and equids. Two independent approaches, dental micro- and meso-wear analyses, are applied to a sample of 73 specimens representing three ruminants: Miotragocerus sp. (Bovidae), Lucentia aff. pierensis (Cervidae), Micromeryx flourensianus (Moschidae), and one equid, Hippotherium intrans (Equidae). The combination of meso- and micro-wear signatures provides both long- and short-term dietary signals, and through comparisons with extant species, the feeding styles of the fossil species are reconstructed. Both approaches categorize the cervid as an intermediate feeder engaged in both browsing and grazing. The bovid Miotragocerus sp. is depicted as a traditional browser. Although the dental meso-wear pattern of the moschid has affinities with intermediate feeders, its dental micro-wear pattern also indicates significant intake of fruits and seeds. Hippotherium intrans was not a grazer and its dental micro-wear pattern significantly differs from that of living browsers, which may suggest that the fossil equid was engaged both in grazing and browsing. However, the lack of extant equids which are pure browsers prevents any definitive judgment on the feeding habits of Hippotherium. Based on these dietary findings, the Rudabánya paleoenvironment is reconstructed as a dense forest. The presence of two intermediate feeders indicates some clearings within this forest; however the absence of grazers suggests that these clearings were most likely confined. To demonstrate the ecological diversity among the late Miocene hominoids in Europe, the diet and habitat of Dryopithecus brancoi and Ouranopithecus macedoniensis (Greece) are compared.
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Mechanical modelling of tooth wear
Kallonen, Aki
2016-01-01
Different diets wear teeth in different ways and generate distinguishable wear and microwear patterns that have long been the basis of palaeodiet reconstructions. Little experimental research has been performed to study them together. Here, we show that an artificial mechanical masticator, a chewing machine, occluding real horse teeth in continuous simulated chewing (of 100 000 chewing cycles) is capable of replicating microscopic wear features and gross wear on teeth that resemble wear in specimens collected from nature. Simulating pure attrition (chewing without food) and four plant material diets of different abrasives content (at n = 5 tooth pairs per group), we detected differences in microscopic wear features by stereomicroscopy of the chewing surface in the number and quality of pits and scratches that were not always as expected. Using computed tomography scanning in one tooth per diet, absolute wear was quantified as the mean height change after the simulated chewing. Absolute wear increased with diet abrasiveness, originating from phytoliths and grit. In combination, our findings highlight that differences in actual dental tissue loss can occur at similar microwear patterns, cautioning against a direct transformation of microwear results into predictions about diet or tooth wear rate. PMID:27411727
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Dietary flexibility and niche partitioning of large herbivores through the Pleistocene of Britain
NASA Astrophysics Data System (ADS)
Rivals, Florent; Lister, Adrian M.
2016-08-01
Tooth wear analysis techniques (mesowear and microwear) are employed to analyze dietary traits in proboscideans, perissodactyls and artiodactyls from 33 Pleistocene localities in Britain. The objectives of this study are to examine the variability in each taxon, to track dietary shifts through time, and to investigate resource partitioning among species. The integration of mesowear and microwear results first allowed us to examine dietary variability. We identified differences in variability among species, from more stenotopic species such as Capreolus capreolus to more eurytopic species such as Megaloceros giganteus and Cervus elaphus. Broad dietary shifts at the community level are seen between climatic phases, and are the result of species turnover as well as dietary shifts in the more flexible species. The species present at each locality are generally spread over a large part of the dietary spectrum, and resource partitioning was identified at most of these localities. Mixed feeders always coexist with at least one of the two strict dietary groups, grazers or browsers. Finally, for some species, a discrepancy is observed between meso- and microwear signals and may imply that individuals tended to die at a time of year when their normal food was in short supply.
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Stemp, W James; Lerner, Harry J; Kristant, Elaine H
2013-01-01
Although previous use-wear studies involving quartz and quartzite have been undertaken by archaeologists, these are comparatively few in number. Moreover, there has been relatively little effort to quantify use-wear on stone tools made from quartzite. The purpose of this article is to determine the effectiveness of a measurement system, laser scanning confocal microscopy (LSCM), to document the surface roughness or texture of experimental Mistassini quartzite scrapers used on two different contact materials (fresh and dry deer hide). As in previous studies using LSCM on chert, flint, and obsidian, this exploratory study incorporates a mathematical algorithm that permits the discrimination of surface roughness based on comparisons at multiple scales. Specifically, we employ measures of relative area (RelA) coupled with the F-test to discriminate used from unused stone tool surfaces, as well as surfaces of quartzite scrapers used on dry and fresh deer hide. Our results further demonstrate the effect of raw material variation on use-wear formation and its documentation using LSCM and RelA. © Wiley Periodicals, Inc.
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Neanderthal teeth from Moula-Guercy, Ardèche, France.
Hlusko, Leslea J; Carlson, Joshua P; Guatelli-Steinberg, Debbie; Krueger, Kristin L; Mersey, Ben; Ungar, Peter S; Defleur, Alban
2013-07-01
Here we describe dental remains from a Neanderthal fossil assemblage from Moula-Guercy, France. Our report demonstrates that the Moula-Guercy hominid remains contribute important morphological, developmental, and behavioral data to understanding Neanderthal evolutionary history. We include gross comparative morphological descriptions and enamel surface microstructure and microwear data. These teeth reveal numerous characteristics that are diagnostic of Neanderthals and provide no evidence for the presence of any other hominid taxa. Enamel growth increment data from the Moula-Guercy specimens yield evidence of a Neanderthal pattern of development, although at the lower end of the range of variation. The presence of a significant number of linear enamel hypoplasias indicates that these individuals were stressed during childhood. Molar microwear data suggest that these Neanderthals did not differ significantly from modern humans in terms of the fracture properties of the food they were consuming. The incisor microwear and macro striations provide evidence that these individuals may have been using their anterior teeth as tools, similar to the practices of several modern human populations such as the Inuit, Ipiutak, and Australian Aboriginals, and reminiscent of evidence from other Neanderthals from Krapina, Croatia, as well as the 600,000 year old hominids from Sima de los Huesos, Spain. Am J Phys Anthropol 151:477-491, 2013.© 2013 Wiley Periodicals, Inc. Copyright ©2013 Wiley Periodicals, Inc.
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The diet of the first Europeans from Atapuerca
Pérez-Pérez, Alejandro; Lozano, Marina; Romero, Alejandro; Martínez, Laura M.; Galbany, Jordi; Pinilla, Beatriz; Estebaranz-Sánchez, Ferran; Bermúdez de Castro, José María; Carbonell, Eudald; Arsuaga, Juan Luís
2017-01-01
Hominin dietary specialization is crucial to understanding the evolutionary changes of craniofacial biomechanics and the interaction of food processing methods’ effects on teeth. However, the diet-related dental wear processes of the earliest European hominins remain unknown because most of the academic attention has focused on Neandertals. Non-occlusal dental microwear provides direct evidence of the effect of chewed food particles on tooth enamel surfaces and reflects dietary signals over time. Here, we report for the first time the direct effect of dietary abrasiveness as evidenced by the buccal microwear patterns on the teeth of the Sima del Elefante-TE9 and Gran Dolina-TD6 Atapuerca hominins (1.2–0.8 million years ago − Myr) as compared with other Lower and Middle Pleistocene populations. A unique buccal microwear pattern that is found in Homo antecessor (0.96–0.8 Myr), a well-known cannibal species, indicates dietary practices that are consistent with the consumption of hard and brittle foods. Our findings confirm that the oldest European inhabitants ingested more mechanically-demanding diets than later populations because they were confronted with harsh, fluctuating environmental conditions. Furthermore, the influence of grit-laden food suggests that a high-quality meat diet from butchering processes could have fueled evolutionary changes in brain size. PMID:28240290
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Dietary specializations and diversity in feeding ecology of the earliest stem mammals.
Gill, Pamela G; Purnell, Mark A; Crumpton, Nick; Brown, Kate Robson; Gostling, Neil J; Stampanoni, M; Rayfield, Emily J
2014-08-21
The origin and radiation of mammals are key events in the history of life, with fossils placing the origin at 220 million years ago, in the Late Triassic period. The earliest mammals, representing the first 50 million years of their evolution and including the most basal taxa, are widely considered to be generalized insectivores. This implies that the first phase of the mammalian radiation--associated with the appearance in the fossil record of important innovations such as heterodont dentition, diphyodonty and the dentary-squamosal jaw joint--was decoupled from ecomorphological diversification. Finds of exceptionally complete specimens of later Mesozoic mammals have revealed greater ecomorphological diversity than previously suspected, including adaptations for swimming, burrowing, digging and even gliding, but such well-preserved fossils of earlier mammals do not exist, and robust analysis of their ecomorphological diversity has previously been lacking. Here we present the results of an integrated analysis, using synchrotron X-ray tomography and analyses of biomechanics, finite element models and tooth microwear textures. We find significant differences in function and dietary ecology between two of the earliest mammaliaform taxa, Morganucodon and Kuehneotherium--taxa that are central to the debate on mammalian evolution. Morganucodon possessed comparatively more forceful and robust jaws and consumed 'harder' prey, comparable to extant small-bodied mammals that eat considerable amounts of coleopterans. Kuehneotherium ingested a diet comparable to extant mixed feeders and specialists on 'soft' prey such as lepidopterans. Our results reveal previously hidden trophic specialization at the base of the mammalian radiation; hence even the earliest mammaliaforms were beginning to diversify--morphologically, functionally and ecologically. In contrast to the prevailing view, this pattern suggests that lineage splitting during the earliest stages of mammalian evolution was associated with ecomorphological specialization and niche partitioning.
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NASA Astrophysics Data System (ADS)
Calandra, Ivan; Göhlich, Ursula B.; Merceron, Gildas
2008-09-01
Although low in diversity, megaherbivores (mammals weighting over 103 kg) and especially proboscideans have a powerful impact on the structure and dynamics of present-day ecosystems. During the Neogene (23 to 2.6 Ma) of Europe, the diversity and geographic distribution of these megaherbivores was much greater. Nonetheless, their role in past ecosystems is unclear. Nutrition is one of the main bonds between organisms and their environment. Therefore, the ecology of organisms can be inferred from their dietary habits. The present study is aimed at characterizing the feeding habits of diverse megaherbivores through dental microwear analyses. This method was applied on cheek teeth of three sympatric species of proboscideans from the middle/late Miocene of the Molasse Basin in Southern Germany: Gomphotherium subtapiroideum, Gomphotherium steinheimense, and Deinotherium giganteum. The microwear signatures are significantly different between these taxa, suggesting differences in feeding habits and ecological niches within a woodland environment. D. giganteum probably browsed on dicotyledonous foliages whereas the two species of gomphotheres were neither strict grazers nor strict browsers and instead probably fed on a large spectrum of vegetal resources. The differences of occlusal molar morphology between the two gomphotheres are supported by the dental microwear pattern. Indeed, G. subtapiroideum probably ingested more abrasive material than G. steinheimense. Thus, our results suggest that these proboscideans did not compete for food resources.
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Viewpoints: diet and dietary adaptations in early hominins: the hard food perspective.
Strait, David S; Constantino, Paul; Lucas, Peter W; Richmond, Brian G; Spencer, Mark A; Dechow, Paul C; Ross, Callum F; Grosse, Ian R; Wright, Barth W; Wood, Bernard A; Weber, Gerhard W; Wang, Qian; Byron, Craig; Slice, Dennis E; Chalk, Janine; Smith, Amanda L; Smith, Leslie C; Wood, Sarah; Berthaume, Michael; Benazzi, Stefano; Dzialo, Christine; Tamvada, Kelli; Ledogar, Justin A
2013-07-01
Recent biomechanical analyses examining the feeding adaptations of early hominins have yielded results consistent with the hypothesis that hard foods exerted a selection pressure that influenced the evolution of australopith morphology. However, this hypothesis appears inconsistent with recent reconstructions of early hominin diet based on dental microwear and stable isotopes. Thus, it is likely that either the diets of some australopiths included a high proportion of foods these taxa were poorly adapted to consume (i.e., foods that they would not have processed efficiently), or that aspects of what we thought we knew about the functional morphology of teeth must be wrong. Evaluation of these possibilities requires a recognition that analyses based on microwear, isotopes, finite element modeling, and enamel chips and cracks each test different types of hypotheses and allow different types of inferences. Microwear and isotopic analyses are best suited to reconstructing broad dietary patterns, but are limited in their ability to falsify specific hypotheses about morphological adaptation. Conversely, finite element analysis is a tool for evaluating the mechanical basis of form-function relationships, but says little about the frequency with which specific behaviors were performed or the particular types of food that were consumed. Enamel chip and crack analyses are means of both reconstructing diet and examining biomechanics. We suggest that current evidence is consistent with the hypothesis that certain derived australopith traits are adaptations for consuming hard foods, but that australopiths had generalized diets that could include high proportions of foods that were both compliant and tough. Copyright © 2013 Wiley Periodicals, Inc.
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Introductory Archaeology: The Inexpensive Laboratory.
ERIC Educational Resources Information Center
Rice, Patricia C.
1990-01-01
Describes a number of student-focused laboratory exercises that are inexpensive, yet show the scientific character of archaeology. Describes the environmental laboratory exercise which includes the following analysis topics: (1) pollen; (2) earth core; (3) microfaunal; and (4) microwear. Describes the ceramic laboratory which involves…
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Comparing ungulate dietary proxies using discriminant function analysis.
Fraser, Danielle; Theodor, Jessica M
2011-12-01
A variety of tooth-wear and morphological dietary proxies have been proposed for ungulates. In turn, they have been applied to fossil specimens with the purpose of reconstructing the diets of extinct taxa. Although these dietary proxies have been used in isolation and in combination, a consistent set of statistical analyses has never been applied to all of the available datasets. The purpose of this study is to determine how well the most commonly used dietary proxies classify ungulates as browsers, grazers, and mixed feeders individually and in combination. Discriminant function analysis is applied to individual dietary proxies (hypsodonty, mesowear, microwear, and several cranial dietary proxies) and to combinations thereof to compare rates of successful dietary classification. In general, the tooth-wear dietary proxies (mesowear and microwear) perform better than morphological dietary proxies, though none are strong proxies in isolation. The success rates of the cranial dietary proxies are not increased substantially when ruminants and bovids are analyzed separately, and significance among the three dietary guilds is reduced when controlling for phylogenetic relatedness. The combination of hypsodonty, mesowear, and microwear is found to have a high rate of successful dietary classification, but a combination of all commonly used proxies increases the success rate to 100%. In most cases, mixed feeders bear the greatest resemblance to browsers suggesting that a morphology intermediate to browsers and grazers may represent a fitness valley resulting from the inability to exploit both browse and graze efficiently. These results are important for future paleoecological studies and should be used as a guide for determining which dietary proxies are appropriate to the research question. Copyright © 2011 Wiley-Liss, Inc.
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Rivals, Florent; Prignano, Luce; Semprebon, Gina M.; Lozano, Sergi
2015-01-01
The seasonality of human occupations in archaeological sites is highly significant for the study of hominin behavioural ecology, in particular the hunting strategies for their main prey-ungulates. We propose a new tool to quantify such seasonality from tooth microwear patterns in a dataset of ten large samples of extant ungulates resulting from well-known mass mortality events. The tool is based on the combination of two measures of variability of scratch density, namely standard deviation and coefficient of variation. The integration of these two measurements of variability permits the classification of each case into one of the following three categories: (1) short events, (2) long-continued event and (3) two separated short events. The tool is tested on a selection of eleven fossil samples from five Palaeolithic localities in Western Europe which show a consistent classification in the three categories. The tool proposed here opens new doors to investigate seasonal patterns of ungulate accumulations in archaeological sites using non-destructive sampling. PMID:26616864
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An Investigation of Dust Storms Observed with the Mars Color Imager
NASA Technical Reports Server (NTRS)
Guzewich, Scott D.; Toigo, Anthony D.; Wang, Huiqun
2017-01-01
Daily global imaging by the Mars Color Imager (MARCI) continues the record of the Mars Orbiter Camera (MOC) and has allowed creation of a long-duration record of Martian dust storms. We observe dust storms over the first two Mars years of the MARCI record, including tracking individual storms over multiple sols, as well as tracking the growth and recession of the seasonal polar caps. Using the combined 6 Mars year record of textured dust storms (storms with visible textures on the observed dust cloud tops), we study the relationship between textured dust storm activity and meteorology (as simulated by the MarsWRF general circulation model) and surface properties. We find that textured dust storms preferentially occur in places and seasons with above average surface wind stress. Textured dust storm occurrence also has a modest linear anti-correlation with surface albedo (0.43) and topography (0.40). Lastly, we perform an empirical orthogonal function (EOF) analysis on the distribution of occurrence of textured dust storms and find that over 50 of the variance in textured dust storm activity can be explained by two EOF modes. We associate the first EOF mode with cap-edge storms just before Ls = 180deg and the second EOF mode with flushing dust storms that occur from Ls = 180-210deg and again near Ls = 320deg.
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NASA Astrophysics Data System (ADS)
Rivals, Florent; Ziegler, Reinhard
2018-05-01
High-resolution paleoecological proxies, such as stable isotopes or tooth microwear in large mammals, are often used for their potential to deliver information about the paleodietary traits of individuals and populations at the time of death. Such proxies are of interest in high resolution sites because they provide accurate data regarding the diet of large herbivores as well as the habitats that were available at the time of formation of the site, and by inference can detect seasonality in the formation of the assemblages. The integration of two techniques, tooth mesowear and microwear, applied to Middle Pleistocene assemblages of large herbivores from Steinheim and Heppenloch did not indicate seasonality at any of the two sites, most likely due to low resolution and time averaging of the dietary signal. However, the combination of the two proxies was highly informative for reconstructing the paleodiets of the large herbivores. The two paleodietary proxies provided consistent results that permitted us to propose a reconstruction of the paleodiets and habitats available at each site.
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Laser Texturing of Magnetic Recording Media Final Report CRADA No. TSV-1298-96
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hackel, L.; Marshall, A.
The Commercial Laser Systems Group at LLNL developed a concept for patterning of computer magnetic recording discs. Magnetic recording media require texturing over areas designated for contact in order to minimize friction with data transducing heads. In fabricating a hard disk, an aluminum nickel-phosphorous substrate was polished to a specular finish then a mechanical means was used to roughen an annular area intended to be the head contact band. In a previous patent (US Patent 5,062,021) it was proposed that the focused output of a low power laser with short pulse length could be used to generate the textured pattern.more » However, the patterned area typically required 75,000 textured spots that needed to be rapidly (less than 10 seconds) printed with good uniformity. A means to achieve the accurate placement and uniform profile, as well as a meaningfully rapid process time, was not discussed in the referenced patent. The LLNL team devised a system that could rapidly and inexpensively accomplish the texturing.« less
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Neandertal versus Modern Human Dietary Responses to Climatic Fluctuations
El Zaatari, Sireen; Grine, Frederick E.; Ungar, Peter S.; Hublin, Jean-Jacques
2016-01-01
The Neandertal lineage developed successfully throughout western Eurasia and effectively survived the harsh and severely changing environments of the alternating glacial/interglacial cycles from the middle of the Pleistocene until Marine Isotope Stage 3. Yet, towards the end of this stage, at the time of deteriorating climatic conditions that eventually led to the Last Glacial Maximum, and soon after modern humans entered western Eurasia, the Neandertals disappeared. Western Eurasia was by then exclusively occupied by modern humans. We use occlusal molar microwear texture analysis to examine aspects of diet in western Eurasian Paleolithic hominins in relation to fluctuations in food supplies that resulted from the oscillating climatic conditions of the Pleistocene. There is demonstrable evidence for differences in behavior that distinguish Upper Paleolithic humans from members of the Neandertal lineage. Specifically, whereas the Neandertals altered their diets in response to changing paleoecological conditions, the diets of Upper Paleolithic humans seem to have been less affected by slight changes in vegetation/climatic conditions but were linked to changes in their technological complexes. The results of this study also indicate differences in resource exploitation strategies between these two hominin groups. We argue that these differences in subsistence strategies, if they had already been established at the time of the first contact between these two hominin taxa, may have given modern humans an advantage over the Neandertals, and may have contributed to the persistence of our species despite habitat-related changes in food availabilities associated with climate fluctuations. PMID:27119336
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Neandertal versus Modern Human Dietary Responses to Climatic Fluctuations.
El Zaatari, Sireen; Grine, Frederick E; Ungar, Peter S; Hublin, Jean-Jacques
2016-01-01
The Neandertal lineage developed successfully throughout western Eurasia and effectively survived the harsh and severely changing environments of the alternating glacial/interglacial cycles from the middle of the Pleistocene until Marine Isotope Stage 3. Yet, towards the end of this stage, at the time of deteriorating climatic conditions that eventually led to the Last Glacial Maximum, and soon after modern humans entered western Eurasia, the Neandertals disappeared. Western Eurasia was by then exclusively occupied by modern humans. We use occlusal molar microwear texture analysis to examine aspects of diet in western Eurasian Paleolithic hominins in relation to fluctuations in food supplies that resulted from the oscillating climatic conditions of the Pleistocene. There is demonstrable evidence for differences in behavior that distinguish Upper Paleolithic humans from members of the Neandertal lineage. Specifically, whereas the Neandertals altered their diets in response to changing paleoecological conditions, the diets of Upper Paleolithic humans seem to have been less affected by slight changes in vegetation/climatic conditions but were linked to changes in their technological complexes. The results of this study also indicate differences in resource exploitation strategies between these two hominin groups. We argue that these differences in subsistence strategies, if they had already been established at the time of the first contact between these two hominin taxa, may have given modern humans an advantage over the Neandertals, and may have contributed to the persistence of our species despite habitat-related changes in food availabilities associated with climate fluctuations.
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Horwath, B C; Waterman, A J; Lillios, K T; Irish, J D
2014-04-01
Although the social and political changes accompanying the transition from the Neolithic through Copper Age, between the 4th and 3rd millennia cal BCE, in southwestern Iberia are reasonably well understood, much less is known about whether population movements and dietary changes accompanied these transformations. To address this question, human dental remains from the Middle through Late Neolithic site of Feteira II (3600-2900 cal BCE) and the Late Neolithic site of Bolores (2800-2600 cal BCE) in the Portuguese Estremadura were used to examine diet (microwear) and affinity (dental non-metrics). Microwear features were not found to be significantly different between Feteira II and Bolores, suggesting that the emergence of social complexity during this period did not result in large-scale changes in subsistence practices during the period of use at these sites. Using the Arizona State University Dental Anthropology System and supporting statistics, no significant difference between the samples from Feteira II and Bolores was observed, suggesting that no population replacement occurred between the Middle Neolithic and Late Neolithic/Copper Age. However, at Bolores there is some indication that there may have been demographic exchanges between southern Iberian and North African populations during the Late Neolithic/Copper Age. Copyright © 2013 Elsevier GmbH. All rights reserved.
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DeMiguel, Daniel; Alba, David M.; Moyà-Solà, Salvador
2014-01-01
Given the central adaptive role of diet, paleodietary inference is essential for understanding the relationship between evolutionary and paleoenvironmental change. Here we rely on dental microwear analysis to investigate the role of dietary specialization in the diversification and extinction of Miocene hominoids from Western Eurasian between 14 and 7 Ma. New microwear results for five extinct taxa are analyzed together with previous data for other Western Eurasian genera. Except Pierolapithecus (that resembles hard-object feeders) and Oreopithecus (a soft-frugivore probably foraging opportunistically on other foods), most of the extinct taxa lack clear extant dietary analogues. They display some degee of sclerocarpy, which is most clearly expressed in Griphopithecus and Ouranopithecus (adapted to more open and arid environments), whereas Anoiapithecus, Dryopithecus and, especially, Hispanopithecus species apparently relied more strongly on soft-frugivory. Thus, contrasting with the prevailing sclerocarpic condition at the beginning of the Eurasian hominoid radiation, soft- and mixed-frugivory coexisted with hard-object feeding in the Late Miocene. Therefore, despite a climatic trend towards cooling and increased seasonality, a progressive dietary diversification would have occurred (probably due to competitive exclusion and increased environmental heterogeneity), although strict folivory did not evolve. Overall, our analyses support the view that the same dietary specializations that enabled Western Eurasian hominoids to face progressive climatic deterioration were the main factor ultimately leading to their extinction when more drastic paleoenvironmental changes took place. PMID:24848272
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Experimental Study on the Perception Characteristics of Haptic Texture by Multidimensional Scaling.
Wu, Juan; Li, Na; Liu, Wei; Song, Guangming; Zhang, Jun
2015-01-01
Recent works regarding real texture perception demonstrate that physical factors such as stiffness and spatial period play a fundamental role in texture perception. This research used a multidimensional scaling (MDS) analysis to further characterize and quantify the effects of the simulation parameters on haptic texture rendering and perception. In a pilot experiment, 12 haptic texture samples were generated by using a 3-degrees-of-freedom (3-DOF) force-feedback device with varying spatial period, height, and stiffness coefficient parameter values. The subjects' perceptions of the virtual textures indicate that roughness, denseness, flatness and hardness are distinguishing characteristics of texture. In the main experiment, 19 participants rated the dissimilarities of the textures and estimated the magnitudes of their characteristics. The MDS method was used to recover the underlying perceptual space and reveal the significance of the space from the recorded data. The physical parameters and their combinations have significant effects on the perceptual characteristics. A regression model was used to quantitatively analyze the parameters and their effects on the perceptual characteristics. This paper is to illustrate that haptic texture perception based on force feedback can be modeled in two- or three-dimensional space and provide suggestions on improving perception-based haptic texture rendering.
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Yamamoto, Kengo; Masaoka, Toshinori; Manaka, Masakazu; Oonishi, Hironobu; Clarke, Ian; Shoji, Hiromu; Kawanabe, Keiichi; Imakiire, Atsuhiro
2004-04-01
We studied the micro-wear phenomena of unique, extensively cross-linked polyethylene cups (cross-linked with 1,000 kGy-irradiation) that had been used briefly in Japan. Two retrievals (at 15 years) came from the Japanese "SOM" hip system (implanted 1971-78). These were compared to a set of 0 kGy and 500-1,500 kGy cups run in our hip simulator. The polyethylene cups that had not been cross-linked had the greatest wear. The worn areas had a burnished appearance and were clearly separated from the unworn region by a distinct ridge-line. The worn areas had lost all machine tracks, showed a large amount of UHMWPE 'flow', and long PE fibrils. The associated surface rippling was degraded. These features were considered synonymous with severe polyethylene wear. In contrast, the worn areas in the very cross-linked cups had a visibly matte surface and no ridge-line. Micro-examination showed that the machine tracks were still present. Ripple formations were less obvious than in the cups that were not cross-linked, polyethylene surface fibrils were scarcer and all the fibrils were much smaller than in the cups that were not crosslinked. Our two retrieved cups and the simulator cups confirmed the greater wear-resistance of very cross-linked polyethylene. It should also be noted that the SOM cup design and processing were unique and differed greatly from that of modern polyethylene cups.
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Puncture-and-Pull Biomechanics in the Teeth of Predatory Coelurosaurian Dinosaurs.
Torices, Angelica; Wilkinson, Ryan; Arbour, Victoria M; Ruiz-Omeñaca, Jose Ignacio; Currie, Philip J
2018-05-07
The teeth of putatively carnivorous dinosaurs are often blade-shaped with well-defined serrated cutting edges (Figure 1). These ziphodont teeth are often easily differentiated based on the morphology and density of the denticles [1, 2]. A tearing function has been proposed for theropod denticles in general [3], but the functional significance of denticle phenotypic variation has received less attention. In particular, the unusual hooked denticles found in troodontids suggest a different feeding strategy or diet compared to other small theropods. We used a two-pronged approach to investigate the function of denticle shape variation across theropods with both congruent body shapes and sizes (e.g., dromaeosaurids versus troodontids) and highly disparate body shapes and sizes (e.g., troodontids versus tyrannosaurids), using microwear and finite element analyses (Figure 1). We found that many toothed coelurosaurian theropods employed a puncture-and-pull feeding movement, in which parallel scratches form while biting down into prey and oblique scratches form as the head is pulled backward with the jaws closed. In finite element simulations, theropod teeth had the lowest stresses when bite forces were aligned with the oblique family of microwear scratches. Different denticle morphologies performed differently under a variety of simulated biting angles: Dromaeosaurus and Saurornitholestes were well-adapted for handling struggling prey, whereas troodontid teeth were more likely to fail at non-optimal bite angles. Troodontids may have favored softer, smaller, or immobile prey. Copyright © 2018 Elsevier Ltd. All rights reserved.
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McGrew, William C
2014-06-01
The role of invertebrates in the evolution of human diet has been under-studied by comparison with vertebrates and plants. This persists despite substantial knowledge of the importance of the 'other faunivory', especially insect-eating, in the daily lives of non-human primates and traditional human societies, especially hunters and gatherers. Most primates concentrate on two phyla, Mollusca and Arthropoda, but of the latter's classes, insects (especially five orders: Coleoptera, Hymenoptera, Isoptera, Lepidoptera, Orthoptera) are paramount. An insect product, bees' honey, is particularly important, and its collection shows a reversal of the usual sexual division of labor. Human entomophagy involves advanced technology (fire, containers) and sometimes domestication. Insectivory provides comparable calorific and nutritional benefits to carnivory, but with different costs. Much insectivory in hominoids entails elementary technology used in extractive foraging, such as termite fishing by chimpanzees. Elucidating insectivory in the fossil and paleontological record is challenging, but at least nine avenues are available: remains, lithics, residues, DNA, coprolites, dental microwear, stable isotopes, osteology, and depictions. All are in play, but some have been more successful so far than others. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Texture-adaptive hyperspectral video acquisition system with a spatial light modulator
NASA Astrophysics Data System (ADS)
Fang, Xiaojing; Feng, Jiao; Wang, Yongjin
2014-10-01
We present a new hybrid camera system based on spatial light modulator (SLM) to capture texture-adaptive high-resolution hyperspectral video. The hybrid camera system records a hyperspectral video with low spatial resolution using a gray camera and a high-spatial resolution video using a RGB camera. The hyperspectral video is subsampled by the SLM. The subsampled points can be adaptively selected according to the texture characteristic of the scene by combining with digital imaging analysis and computational processing. In this paper, we propose an adaptive sampling method utilizing texture segmentation and wavelet transform (WT). We also demonstrate the effectiveness of the sampled pattern on the SLM with the proposed method.
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Wu, Wei; Chen, Guiming; Fan, Boxuan; Liu, Jianyou
2016-01-01
Energy consumption and tribological properties could be improved by proper design of surface texture in friction. However, some literature focused on investigating their performance under high temperature. In the study, different groove surface textures were fabricated on steels by a laser machine, and their tribological behaviors were experimentally studied with the employment of the friction and wear tester under distinct high temperature and other working conditions. The friction coefficient was recorded, and wear performance were characterized by double light interference microscope, scanning electron microscope (SEM) and x-ray energy dispersive spectrometry (EDS). Then, the performances of energy consumptions were carefully estimated. Results showed that friction coefficient, wear, and energy consumption could almost all be reduced by most textures under high temperature conditions, but to a different extent which depends on the experimental conditions and texture parameters. The main improvement mechanisms were analyzed, such as the hardness change, wear debris storage, thermal stress release and friction induced temperature reduction by the textures. Finally, a scattergram of the relatively reduced ratio of the energy consumption was drawn for different surface textures under four distinctive experimental conditions to illustrate the comprehensive energy consumption improving ability of textures, which was of benefit for the application of texture design.
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Wu, Wei; Chen, Guiming; Fan, Boxuan; Liu, Jianyou
2016-01-01
Energy consumption and tribological properties could be improved by proper design of surface texture in friction. However, some literature focused on investigating their performance under high temperature. In the study, different groove surface textures were fabricated on steels by a laser machine, and their tribological behaviors were experimentally studied with the employment of the friction and wear tester under distinct high temperature and other working conditions. The friction coefficient was recorded, and wear performance were characterized by double light interference microscope, scanning electron microscope (SEM) and x-ray energy dispersive spectrometry (EDS). Then, the performances of energy consumptions were carefully estimated. Results showed that friction coefficient, wear, and energy consumption could almost all be reduced by most textures under high temperature conditions, but to a different extent which depends on the experimental conditions and texture parameters. The main improvement mechanisms were analyzed, such as the hardness change, wear debris storage, thermal stress release and friction induced temperature reduction by the textures. Finally, a scattergram of the relatively reduced ratio of the energy consumption was drawn for different surface textures under four distinctive experimental conditions to illustrate the comprehensive energy consumption improving ability of textures, which was of benefit for the application of texture design. PMID:27035658
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Garion, Liora; Dubin, Uri; Rubin, Yoav; Khateb, Mohamed; Schiller, Yitzhak; Azouz, Rony; Schiller, Jackie
2014-01-01
Texture discrimination is a fundamental function of somatosensory systems, yet the manner by which texture is coded and spatially represented in the barrel cortex are largely unknown. Using in vivo two-photon calcium imaging in the rat barrel cortex during artificial whisking against different surface coarseness or controlled passive whisker vibrations simulating different coarseness, we show that layer 2–3 neurons within barrel boundaries differentially respond to specific texture coarsenesses, while only a minority of neurons responded monotonically with increased or decreased surface coarseness. Neurons with similar preferred texture coarseness were spatially clustered. Multi-contact single unit recordings showed a vertical columnar organization of texture coarseness preference in layer 2–3. These findings indicate that layer 2–3 neurons perform high hierarchical processing of tactile information, with surface coarseness embodied by distinct neuronal subpopulations that are spatially mapped onto the barrel cortex. DOI: http://dx.doi.org/10.7554/eLife.03405.001 PMID:25233151
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Shedding light into the function of the earliest vertebrate skeleton
NASA Astrophysics Data System (ADS)
Martinez-Perez, Carlos; Purnell, Mark; Rayfield, Emily; Donoghue, Philip
2016-04-01
Conodonts are an extinct group of jawless vertebrates, the first in our evolutionary lineage to develop a biomineralized skeleton. As such, the conodont skeleton is of great significance because of the insights it provides concerning the biology and function of the primitive vertebrate skeleton. Conodont function has been debated for a century and a half on the basis of its paleocological importance in the Palaezoic ecosystems. However, due to the lack of extanct close representatives and the small size of the conodont element (under a milimiter in length) strongly limited their functional analysis, traditional restricted to analogy. More recently, qualitative approaches have been developed, facilitating tests of element function based on occlusal performance and analysis of microwear and microstructure. In this work we extend these approaches using novel quantitative experimental methods including Synchrotron Radiation X-ray Tomographic Microscopy or Finite Element Analysis to test hypotheses of conodont function. The development of high resolution virtual models of conodont elements, together with biomechanical approaches using Finite Element analysis, informed by occlusal and microwear analyses, provided conclusive support to test hypothesis of structural adaptation within the crown tissue microstructure, showing a close topological co-variation patterns of compressive and tensile stress distribution with different crystallite orientation. In addition, our computational analyses strongly support a tooth-like function for many conodont species. Above all, our study establishes a framework (experimental approach) in which the functional ecology of conodonts can be read from their rich taxonomy and phylogeny, representing an important attempt to understand the role of this abundant and diverse clade in the Phanerozoic marine ecosystems.
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NASA Astrophysics Data System (ADS)
Simura, Rayko; Taniuchi, Tetsuo; Sugiyama, Kazumasa; Fukuda, Tsuguo
2018-01-01
Ce-doped YAG/Al2O3 melt-growth composite (MGC) samples were grown by the micro-pulling-down (μ-PD) method, and their physical and chemical properties were investigated. The grown MGC samples exhibit fine-grained granophyric texture at the micron scale. Fluorescence spectra, excited by a blue laser diode, were recorded, and, in particular, the finely textured granophyric MGC sample doped with 0.1 at% Ce and prepared with a growth rate of 3 mm/min shows superior fluorescence properties without high-temperature deterioration of fluorescence intensity. The μ-PD method is demonstrated to be applicable for manufacturing finely textured MGC samples with improved luminous efficiency as phosphors for white LEDs.
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Fliegel, D; Wirth, R; Simonetti, A; Furnes, H; Staudigel, H; Hanski, E; Muehlenbachs, K
2010-12-01
Pillow lava rims and interpillow hyaloclastites from the upper part of the Pechenga Greenstone Belt, Kola Peninsula, N-Russia contain rare tubular textures 15-20 μm in diameter and up to several hundred μm long in prehnite-pumpellyite to lower greenschist facies meta-volcanic glass. The textures are septate with regular compartments 5-20 μm across and exhibit branching, stopping and no intersecting features. Synchrotron micro-energy dispersive X-ray was used to image elemental distributions; scanning transmission X-ray microscopy, Fe L-edge and C K-edge were used to identify iron and carbon speciation at interfaces between the tubular textures and the host rock. In situ U-Pb radiometric dating by LA-MC-ICP-MS (laser ablation multicollector inductively coupled plasma mass spectrometry) of titanite from pillow lavas yielded a metamorphic age of 1790 ± 89 Ma. Focused ion-beam milling combined with transmission electron microscopy was used to analyze the textures in three dimensions. Electron diffraction showed that the textures are mineralized by orientated pumpellyite. On the margins of the tubes, an interface between mica or chlorite and the pumpellyite shows evidence of dissolution reactions where the pumpellyite is replaced by mica/chlorite. A thin poorly crystalline Fe-phase, probably precipitated out of solution, occurs at the interface between pumpellyite and mica/chlorite. This sequence of phases leads to the hypothesis that the tubes were initially hollow, compartmentalized structures in volcanic glass that were mineralized by pumpellyite during low-grade metamorphism. Later, a Fe-bearing fluid mineralized the compartments between the pumpellyite and lastly the pumpellyite was partially dissolved and replaced by chlorite during greenschist metamorphism. The most plausible origin for a septate-tubular texture is a progressive etching of the host matrix by several generations of microbes and subsequently these tubes were filled by authigenic mineral precipitates. This preserves the textures in the rock record over geological time. The micro textures reported here thus represent a pumpellyite-mineralized trace fossil that records a Paleoproterozoic sub-seafloor biosphere. © 2010 Blackwell Publishing Ltd.
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Understanding Crystal Populations: The Role of Textural Analysis in Determining Magmatic Timescales
NASA Astrophysics Data System (ADS)
Jerram, D. A.
2006-12-01
Crystal populations in igneous rocks that erupt at the Earths surface act as records of magma chamber processes at depth, predominantly recording episodes of growth/nucleation and geochemical changes within the host body. Detailed inspection of such crystal populations, however, reveals a complex crystal cargo that comprises crystals which have grown directly from the host, crystals that have spent one or more protracted periods being isolated from the host magma and crystals that originated from a completely different magma body and/or country rock. To further interrogate this crystal cargo we can use textural analysis techniques to fully quantify the crystal population and gather important information about the population, such as crystal morphology, spatial distribution and size relationships. When quantified, such data can be used to better constrain the different components of the resultant crystal population and how they relate to each other. Additionally, by combining textural analysis information with geochemical analysis, a powerful measure of magma timescales and magma chamber processes results. In this contribution the different types of textural analysis techniques in 2D and 3D are introduced with examples from both plutonic and volcanic systems presented to highlight the roll of this approach to quantifying magma timescales.
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NASA Astrophysics Data System (ADS)
Willcock, M. A. W.; Cas, R. A. F.
2014-06-01
Exceptional exposure through a Permian intra-caldera ignimbrite fill within the 42 × 40 km Ora caldera (>1,290 km3 erupted volume) provides an opportunity to study welding textures in a thick intra-caldera ignimbrite succession. The ignimbrite succession records primary dense welding, a simple cooling unit structure, common crystallisation zones, and remarkably preserves fresh to slightly hydrated glass in local vitrophyre zones. Evidence for primary syn- and post-emplacement welding consists of (a) viscously deformed and sintered juvenile glass and relict shard textures; (b) complete deposit welding; (c) subtle internal welding intensity variations; (d) vitrophyre preserved locally at the base of the ignimbrite succession; (e) persistent fiamme juvenile clast shapes throughout the succession at the macroscopic and microscopic scales, defining a moderate to well-developed eutaxitic texture; (f) common undulating juvenile clast (pumice) margins and feathery terminations; (g) a general loss of deposit porosity; and (h) perlitic fracturing. A low collapsing or fountaining explosive eruption column model is proposed to have facilitated the ubiquitous welding of the deposit, which in turn helped preserve original textures. The ignimbrite succession preserves no evidence of a time break through the sequence and columnar joints cross-gradational ignimbrite lithofacies boundaries, so the ignimbrite is interpreted to represent a simple cooling unit. Aspect ratio and anisotropy of magnetic susceptibility (AMS) analyses through stratigraphic sections within the thick intra-caldera succession and at the caldera margin reveal variable welding compaction and strain profiles. Significantly, these data show that welding degree/intensity may vary in an apparently simple cooling unit because of variations in eruption process recorded in differing lithofacies. These data imply complex eruption, emplacement, and cooling processes. Three main crystallisation textural zones are identified in the ignimbrite succession: localised vitrophyre zones, widespread microcrystalline to sparsely spherulitic pseudomorphed vitriclastic textural zones, and thick granophyric zones. These zones record a typical spectrum from rapid to prolonged cooling. The non-uniform crystallisation patterns reflect variations in deposit thickness, the relative position of deposits within the larger ignimbrite succession, the type of substrate material, and the degree of confinement in the intra-caldera setting. We support previous work suggesting that traditional welding classifications (e.g. Smith, US Geological Survey Professional Paper 354-F 1960b) are most appropriate for use within altered and/or ancient ignimbrite successions.
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Accurate documentation in cultural heritage by merging TLS and high-resolution photogrammetric data
NASA Astrophysics Data System (ADS)
Grussenmeyer, Pierre; Alby, Emmanuel; Assali, Pierre; Poitevin, Valentin; Hullo, Jean-François; Smigiel, Eddie
2011-07-01
Several recording techniques are used together in Cultural Heritage Documentation projects. The main purpose of the documentation and conservation works is usually to generate geometric and photorealistic 3D models for both accurate reconstruction and visualization purposes. The recording approach discussed in this paper is based on the combination of photogrammetric dense matching and Terrestrial Laser Scanning (TLS) techniques. Both techniques have pros and cons, and criteria as geometry, texture, accuracy, resolution, recording and processing time are often compared. TLS techniques (time of flight or phase shift systems) are often used for the recording of large and complex objects or sites. Point cloud generation from images by dense stereo or multi-image matching can be used as an alternative or a complementary method to TLS. Compared to TLS, the photogrammetric solution is a low cost one as the acquisition system is limited to a digital camera and a few accessories only. Indeed, the stereo matching process offers a cheap, flexible and accurate solution to get 3D point clouds and textured models. The calibration of the camera allows the processing of distortion free images, accurate orientation of the images, and matching at the subpixel level. The main advantage of this photogrammetric methodology is to get at the same time a point cloud (the resolution depends on the size of the pixel on the object), and therefore an accurate meshed object with its texture. After the matching and processing steps, we can use the resulting data in much the same way as a TLS point cloud, but with really better raster information for textures. The paper will address the automation of recording and processing steps, the assessment of the results, and the deliverables (e.g. PDF-3D files). Visualization aspects of the final 3D models are presented. Two case studies with merged photogrammetric and TLS data are finally presented: - The Gallo-roman Theatre of Mandeure, France); - The Medieval Fortress of Châtel-sur-Moselle, France), where a network of underground galleries and vaults has been recorded.
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NASA Astrophysics Data System (ADS)
Manning, C. E.; Kelemen, P. B.; Michibayashi, K.; Harris, M.; Urai, J. L.; de Obeso, J. C.; Jesus, A. P. M.; Zeko, D.
2017-12-01
Oman Drilling Project Hole BT1B intersected 191 m of listvenite (magnesite + quartz rock) and serpentinite in the hanging wall of the basal thrust of the Oman ophiolite. Recovery was 100%. Listvenite is the dominant lithology in the upper plate rocks (166 m). Its shows wide color and textural variation, including pseudomorphic replacement of serpentinized peridotite. Serpentinite was encountered in two main contiguous intervals totaling 25 m. In light of the strongly metasomatic nature for the origin of listvenite, a substantial portion of the core description effort was dedicated to characterization of the complex veining history recorded in the hole. Dense veining is recorded in both lithologies. The density of <1 mm veins is >200/m. The density of veins >1 mm was 50-100/m, with somewhat higher densities recorded in serpentinite than in listvenite. In order of oldest to youngest, the main vein types in serpentinite are microscopic mesh-textured serpentine veins, macroscopic serpentine veins, carbonate-oxide veins, and carbonate veins. The vein paragenesis in listvenite is: early carbonate-oxide veins, followed by carbonate and carbonate-quartz veins, then late carbonate veins. The carbonate-oxide and carbonate veins are shared by the lithologies and hold clues to the transformation of ultramafic rocks to listvenite. Carbonate-oxide veins form a distinctive set that is interpreted to be the earliest record of carbonate formation in serpentinite. They contain Fe-oxide, usually hematite, on a medial line, with antitaxial magnesite crystals growing outward and showing terminations against wall rock minerals. Antitaxial textures may be evidence of positive reaction volumes. In serpentinite, secondary serpentine after earlier serpentine is common at vein margins. Carbonate-oxide veins are the earliest observed in listvenite, where they may form isolated veins to dense, aligned networks that impart a foliated texture. In some cases, they appear to predate replacement of serpentine by microcrystalline quartz. Both lithologies record later, coarser, through going carbonate ± quartz veins. Preliminary vein petrology in BT1B rocks indicates that fracture formation and filling by secondary minerals is integral to the metasomatic replacement of altered peridotite by listvenite.
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A. T. Hudak; C.A. Wessman
2001-01-01
Fire suppression associated with decades of cattle grazing can result in bush encroachment in savannas. Textural analyses of historical, high resolution images was used to characterize bush densities across a South African study landscape. A control site, where vegetation was assumed to have changed minimally for the duration of the image record (1955-1996), was used...
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Wu, Yan; Deng, Tao; Hu, Yaowu; Ma, Jiao; Zhou, Xinying; Mao, Limi; Zhang, Hanwen; Ye, Jie; Wang, Shi-Qi
2018-05-16
Feeding preference of fossil herbivorous mammals, concerning the coevolution of mammalian and floral ecosystems, has become of key research interest. In this paper, phytoliths in dental calculus from two gomphotheriid proboscideans of the middle Miocene Junggar Basin, Central Asia, have been identified, suggesting that Gomphotherium connexum was a mixed feeder, while the phytoliths from G. steinheimense indicates grazing preference. This is the earliest-known proboscidean with a predominantly grazing habit. These results are further confirmed by microwear and isotope analyses. Pollen record reveals an open steppic environment with few trees, indicating an early aridity phase in the Asian interior during the Mid-Miocene Climate Optimum, which might urge a diet remodeling of G. steinheimense. Morphological and cladistic analyses show that G. steinheimense comprises the sister taxon of tetralophodont gomphotheres, which were believed to be the general ancestral stock of derived "true elephantids"; whereas G. connexum represents a more conservative lineage in both feeding behavior and tooth morphology, which subsequently became completely extinct. Therefore, grazing by G. steinheimense may have acted as a behavior preadaptive for aridity, and allowing its lineage evolving new morphological features for surviving later in time. This study displays an interesting example of behavioral adaptation prior to morphological modification.
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Novel Texture-based Visualization Methods for High-dimensional Multi-field Data Sets
2013-07-06
project: In standard format showing authors, title, journal, issue, pages, and date, for each category list the following: b) papers published...visual- isation [18]. Novel image acquisition and simulation tech- niques have made is possible to record a large number of co-located data fields...function, structure, anatomical changes, metabolic activity, blood perfusion, and cellular re- modelling. In this paper we investigate texture-based
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Flavor perception and aroma release from model dairy desserts.
Lethuaut, Laurent; Weel, Koen G C; Boelrijk, Alexandra E M; Brossard, Chantal D
2004-06-02
Six model dairy desserts, with three different textures and two sucrose levels, were equally flavored with a blend of four aroma compounds [ethyl pentanoate, amyl acetate, hexanal, and (E)-2-hexenal] and evaluated by a seven person panel in order to study whether the sensory perception of the flavor and the aroma release during eating varied with the textural characteristics or the sweetness intensity of the desserts. The sensory perception was recorded by the time intensity (TI) method, while the in vivo aroma release was simultaneously measured by the MS-nose. Considering the panel as a whole, averaged flavor intensity increased with sucrose level and varied with the texture of the desserts. Depending on the aroma compound, the averaged profile of in vivo aroma release varied, but for each aroma compound, averaged aroma release showed no difference with the sucrose level and little difference with the texture of the desserts. Perceptual sweetness-aroma interactions were the main factors influencing perception whatever the texture of the desserts.
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NASA Astrophysics Data System (ADS)
Lo, Yu-Yun; Lin, Yusin; Chen, Chris C.; Wang, Chien-Min
1999-04-01
The use of NiAl seedlayer before depositing the underlayer on a (nontextured) polished substrate was studied. Same sputtering conditions were used on a (circumferentially) textured substrate for the purpose of comparison. The static magnetic properties measured by the vibrating sample magnetometer show very close Hc, Mrδ, and S* between them; and the magnetic recording performances measured by the Guzik tester show they are comparable. The "twice around modulation" verified by signal envelope test disappears on both of them. From this result, it is believed that the circumferential texturing is probably no longer needed when the NiAl seedlayer is added before depositing the underlayer.
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Whitlock, John A.
2011-01-01
Background As gigantic herbivores, sauropod dinosaurs were among the most important members of Mesozoic communities. Understanding their ecology is fundamental to developing a complete picture of Jurassic and Cretaceous food webs. One group of sauropods in particular, Diplodocoidea, has long been a source of debate with regard to what and how they ate. Because of their long lineage duration (Late Jurassic-Late Cretaceous) and cosmopolitan distribution, diplodocoids formed important parts of multiple ecosystems. Additionally, fortuitous preservation of a large proportion of cranial elements makes them an ideal clade in which to examine feeding behavior. Methodology/Principal Findings Hypotheses of various browsing behaviors (selective and nonselective browsing at ground-height, mid-height, or in the upper canopy) were examined using snout shape (square vs. round) and dental microwear. The square snouts, large proportion of pits, and fine subparallel scratches in Apatosaurus, Diplodocus, Nigersaurus, and Rebbachisaurus suggest ground-height nonselective browsing; the narrow snouts of Dicraeosaurus, Suuwassea, and Tornieria and the coarse scratches and gouges on the teeth of Dicraeosaurus suggest mid-height selective browsing in those taxa. Comparison with outgroups (Camarasaurus and Brachiosaurus) reinforces the inferences of ground- and mid-height browsing and the existence of both non-selective and selective browsing behaviors in diplodocoids. Conclusions/Significance These results reaffirm previous work suggesting the presence of diverse feeding strategies in sauropods and provide solid evidence for two different feeding behaviors in Diplodocoidea. These feeding behaviors can subsequently be tied to paleoecology, such that non-selective, ground-height behaviors are restricted to open, savanna-type environments. Selective browsing behaviors are known from multiple sauropod clades and were practiced in multiple environments. PMID:21494685
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Merceron, Gildas; Costeur, Loïc; Maridet, Olivier; Ramdarshan, Anusha; Göhlich, Ursula B
2012-07-01
The present study attempts to characterize the environmental conditions that prevailed along the western shores of the Central Paratethys and its hinterland during the early middle Miocene at the same time t primates reached their peak in species diversity in Central Europe. Based on faunal structure (using cenograms), paleotemperature reconstruction (using cricetid diversity), and dietary reconstruction of ruminants (using molar micro-wear analyses), four faunal assemblages are used to characterize the regional environmental context. The cenograms for Göriach and Devínska Novà Ves Zapfe's fissure site support the presence of mosaic environments with open areas under rather humid conditions. This is also supported by the dental micro-wear analyses of ruminants. The species of Palaeomerycidae were most probably the only predominant browsers. Surprisingly, the three cervids, Dicrocerus, Heteroprox, and Euprox, were highly involved in grazing. Pseudoeotragus seegrabensis was likely a generalist and the two specimens assigned to the second bovid, Eotragus clavatus, were browsers. The two species of tragulids plot between fruit browsers and generalists. Moreover, paleotemperatures based on cricetid diversity estimate mean annual temperature at about 18 °C with potential high seasonal variations. These data support the predominance of mosaic landscapes along the western shores of the Central Paratethys and its hinterland during the Miocene Climatic Optimum as primates reach a peak in species diversity. This result lends credence to the hypothesis that environmental heterogeneity favours radiation among mammals, and that the specific environmental context of the Central Paratethys western border might explain the high diversity of the middle Miocene primates. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Temporal resolution of orientation-defined texture segregation: a VEP study.
Lachapelle, Julie; McKerral, Michelle; Jauffret, Colin; Bach, Michael
2008-09-01
Orientation is one of the visual dimensions that subserve figure-ground discrimination. A spatial gradient in orientation leads to "texture segregation", which is thought to be concurrent parallel processing across the visual field, without scanning. In the visual-evoked potential (VEP) a component can be isolated which is related to texture segregation ("tsVEP"). Our objective was to evaluate the temporal frequency dependence of the tsVEP to compare processing speed of low-level features (e.g., orientation, using the VEP, here denoted llVEP) with texture segregation because of a recent literature controversy in that regard. Visual-evoked potentials (VEPs) were recorded in seven normal adults. Oriented line segments of 0.1 degrees x 0.8 degrees at 100% contrast were presented in four different arrangements: either oriented in parallel for two homogeneous stimuli (from which were obtained the low-level VEP (llVEP)) or with a 90 degrees orientation gradient for two textured ones (from which were obtained the texture VEP). The orientation texture condition was presented at eight different temporal frequencies ranging from 7.5 to 45 Hz. Fourier analysis was used to isolate low-level components at the pattern-change frequency and texture-segregation components at half that frequency. For all subjects, there was lower high-cutoff frequency for tsVEP than for llVEPs, on average 12 Hz vs. 17 Hz (P = 0.017). The results suggest that the processing of feature gradients to extract texture segregation requires additional processing time, resulting in a lower fusion frequency.
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Texture-dependent motion signals in primate middle temporal area
Gharaei, Saba; Tailby, Chris; Solomon, Selina S; Solomon, Samuel G
2013-01-01
Neurons in the middle temporal (MT) area of primate cortex provide an important stage in the analysis of visual motion. For simple stimuli such as bars and plaids some neurons in area MT – pattern cells – seem to signal motion independent of contour orientation, but many neurons – component cells – do not. Why area MT supports both types of receptive field is unclear. To address this we made extracellular recordings from single units in area MT of anaesthetised marmoset monkeys and examined responses to two-dimensional images with a large range of orientations and spatial frequencies. Component and pattern cell response remained distinct during presentation of these complex spatial textures. Direction tuning curves were sharpest in component cells when a texture contained a narrow range of orientations, but were similar across all neurons for textures containing all orientations. Response magnitude of pattern cells, but not component cells, increased with the spatial bandwidth of the texture. In addition, response variability in all neurons was reduced when the stimulus was rich in spatial texture. Fisher information analysis showed that component cells provide more informative responses than pattern cells when a texture contains a narrow range of orientations, but pattern cells had more informative responses for broadband textures. Component cells and pattern cells may therefore coexist because they provide complementary and parallel motion signals. PMID:24000175
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Wright, L; Cotter, D; Hickson, M; Frost, G
2005-06-01
There are very few studies looking at the energy and protein requirements of patients requiring texture modified diets. Dysphagia is the main indication for people to be recommended texture-modified diets. Older people post-stroke are the key group in the hospital setting who consume this type of diet. The diets can be of several consistencies ranging from pureed to soft textures. To compare the 24-hour dietary intake of older people consuming a texture modified diet in a clinical setting to older people consuming a normal hospital diet. Weighed food intakes and food record charts were used to quantify the patients' intakes, which were compared to their individual requirements. The oral intake of 55 patients was measured. Twenty-five of the patients surveyed were eating a normal diet and acted as controls for 30 patients who were prescribed a texture-modified diet. The results showed that the texture-modified group had significantly lower intakes of energy (3877 versus 6115 kJ, P < 0.0001) and protein (40 versus 60 g, P < 0.003) compared to consumption of the normal diet. The energy and protein deficit from estimated requirements was significantly greater in the texture-modified group (2549 versus 357 kJ, P < 0.0001; 6 versus 22 g, P = 0.013; respectively). These statistically significant results indicate that older people on texture-modified diets have a lower intake of energy and protein than those consuming a normal hospital diet and it is likely that other nutrients will be inadequate. All patients on texture-modified diets should be assessed by the dietitian for nutritional support. Evidence based strategies for improving overall nutrient intake should be identified.
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Texture discrimination and multi-unit recording in the rat vibrissal nerve
Albarracín, Ana L; Farfán, Fernando D; Felice, Carmelo J; Décima, Emilio E
2006-01-01
Background Rats distinguish objects differing in surface texture by actively moving their vibrissae. In this paper we characterized some aspects of texture sensing in anesthetized rats during active touch. We analyzed the multifiber discharge from a deep vibrissal nerve when the vibrissa sweeps materials (wood, metal, acrylic, sandpaper) having different textures. We polished these surfaces with sandpaper (P1000) to obtain close degrees of roughness and we induced vibrissal movement with two-branch facial nerve stimulation. We also consider the change in pressure against the vibrissa as a way to improve the tactile information acquisition. The signals were compared with a reference signal (control) – vibrissa sweeping the air – and were analyzed with the Root Mean Square (RMS) and the Power Spectrum Density (PSD). Results We extracted the information about texture discrimination hidden in the population activity of one vibrissa innervation, using the RMS values and the PSD. The pressure level 3 produced the best differentiation for RMS values and it could represent the "optimum" vibrissal pressure for texture discrimination. The frequency analysis (PSD) provided information only at low-pressure levels and showed that the differences are not related to the roughness of the materials but could be related to other texture parameters. Conclusion Our results suggest that the physical properties of different materials could be transduced by the trigeminal sensory system of rats, as are shown by amplitude and frequency changes. Likewise, varying the pressure could represent a behavioral strategy that improves the information acquisition for texture discrimination. PMID:16719904
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Texture discrimination and multi-unit recording in the rat vibrissal nerve.
Albarracín, Ana L; Farfán, Fernando D; Felice, Carmelo J; Décima, Emilio E
2006-05-23
Rats distinguish objects differing in surface texture by actively moving their vibrissae. In this paper we characterized some aspects of texture sensing in anesthetized rats during active touch. We analyzed the multifiber discharge from a deep vibrissal nerve when the vibrissa sweeps materials (wood, metal, acrylic, sandpaper) having different textures. We polished these surfaces with sandpaper (P1000) to obtain close degrees of roughness and we induced vibrissal movement with two-branch facial nerve stimulation. We also consider the change in pressure against the vibrissa as a way to improve the tactile information acquisition. The signals were compared with a reference signal (control)--vibrissa sweeping the air--and were analyzed with the Root Mean Square (RMS) and the Power Spectrum Density (PSD). We extracted the information about texture discrimination hidden in the population activity of one vibrissa innervation, using the RMS values and the PSD. The pressure level 3 produced the best differentiation for RMS values and it could represent the "optimum" vibrissal pressure for texture discrimination. The frequency analysis (PSD) provided information only at low-pressure levels and showed that the differences are not related to the roughness of the materials but could be related to other texture parameters. Our results suggest that the physical properties of different materials could be transduced by the trigeminal sensory system of rats, as are shown by amplitude and frequency changes. Likewise, varying the pressure could represent a behavioral strategy that improves the information acquisition for texture discrimination.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Saleh, Ahmed A., E-mail: asaleh@uow.edu.au
Even with the use of X-ray polycapillary lenses, sample tilting during pole figure measurement results in a decrease in the recorded X-ray intensity. The magnitude of this error is affected by the sample size and/or the finite detector size. These errors can be typically corrected by measuring the intensity loss as a function of the tilt angle using a texture-free reference sample (ideally made of the same alloy as the investigated material). Since texture-free reference samples are not readily available for all alloys, the present study employs an empirical procedure to estimate the correction curve for a particular experimental configuration.more » It involves the use of real texture-free reference samples that pre-exist in any X-ray diffraction laboratory to first establish the empirical correlations between X-ray intensity, sample tilt and their Bragg angles and thereafter generate correction curves for any Bragg angle. It will be shown that the empirically corrected textures are in very good agreement with the experimentally corrected ones. - Highlights: •Sample tilting during X-ray pole figure measurement leads to intensity loss errors. •Texture-free reference samples are typically used to correct the pole figures. •An empirical correction procedure is proposed in the absence of reference samples. •The procedure relies on reference samples that pre-exist in any texture laboratory. •Experimentally and empirically corrected textures are in very good agreement.« less
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NASA Astrophysics Data System (ADS)
Piasecka, Magdalena; Strąk, Kinga; Maciejewska, Beata; Grabas, Bogusław
2016-09-01
The paper presents results concerning flow boiling heat transfer in a vertical minichannel with a depth of 1.7 mm and a width of 16 mm. The element responsible for heating FC-72, which flowed laminarly in the minichannel, was a plate with an enhanced surface. Two types of surface textures were considered. Both were produced by vibration-assisted laser machining. Infrared thermography was used to record changes in the temperature on the outer smooth side of the plate. Two-phase flow patterns were observed through a glass pane. The main aim of the study was to analyze how the two types of surface textures affect the heat transfer coefficient. A two-dimensional heat transfer approach was proposed to determine the local values of the heat transfer coefficient. The inverse problem for the heated wall was solved using a semi-analytical method based on the Trefftz functions. The results are presented as relationships between the heat transfer coefficient and the distance along the minichannel length and as boiling curves. The experimental data obtained for the two types of enhanced heated surfaces was compared with the results recorded for the smooth heated surface. The highest local values of the heat transfer coefficient were reported in the saturated boiling region for the plate with the type 1 texture produced by vibration-assisted laser machining.
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Accurate 3d Textured Models of Vessels for the Improvement of the Educational Tools of a Museum
NASA Astrophysics Data System (ADS)
Soile, S.; Adam, K.; Ioannidis, C.; Georgopoulos, A.
2013-02-01
Besides the demonstration of the findings, modern museums organize educational programs which aim to experience and knowledge sharing combined with entertainment rather than to pure learning. Toward that effort, 2D and 3D digital representations are gradually replacing the traditional recording of the findings through photos or drawings. The present paper refers to a project that aims to create 3D textured models of two lekythoi that are exhibited in the National Archaeological Museum of Athens in Greece; on the surfaces of these lekythoi scenes of the adventures of Odysseus are depicted. The project is expected to support the production of an educational movie and some other relevant interactive educational programs for the museum. The creation of accurate developments of the paintings and of accurate 3D models is the basis for the visualization of the adventures of the mythical hero. The data collection was made by using a structured light scanner consisting of two machine vision cameras that are used for the determination of geometry of the object, a high resolution camera for the recording of the texture, and a DLP projector. The creation of the final accurate 3D textured model is a complicated and tiring procedure which includes the collection of geometric data, the creation of the surface, the noise filtering, the merging of individual surfaces, the creation of a c-mesh, the creation of the UV map, the provision of the texture and, finally, the general processing of the 3D textured object. For a better result a combination of commercial and in-house software made for the automation of various steps of the procedure was used. The results derived from the above procedure were especially satisfactory in terms of accuracy and quality of the model. However, the procedure was proved to be time consuming while the use of various software packages presumes the services of a specialist.
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Mosaic Convergence of Rodent Dentitions
Lazzari, Vincent; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Aguilar, Jean-Pierre; Jaeger, Jean-Jacques; Michaux, Jacques; Viriot, Laurent
2008-01-01
Background Understanding mechanisms responsible for changes in tooth morphology in the course of evolution is an area of investigation common to both paleontology and developmental biology. Detailed analyses of molar tooth crown shape have shown frequent homoplasia in mammalian evolution, which requires accurate investigation of the evolutionary pathways provided by the fossil record. The necessity of preservation of an effective occlusion has been hypothesized to functionally constrain crown morphological changes and to also facilitate convergent evolution. The Muroidea superfamily constitutes a relevant model for the study of molar crown diversification because it encompasses one third of the extant mammalian biodiversity. Methodology/Principal Findings Combined microwear and 3D-topographic analyses performed on fossil and extant muroid molars allow for a first quantification of the relationships between changes in crown morphology and functionality of occlusion. Based on an abundant fossil record and on a well resolved phylogeny, our results show that the most derived functional condition associates longitudinal chewing and non interlocking of cusps. This condition has been reached at least 7 times within muroids via two main types of evolutionary pathways each respecting functional continuity. In the first type, the flattening of tooth crown which induces the removal of cusp interlocking occurs before the rotation of the chewing movement. In the second type however, flattening is subsequent to rotation of the chewing movement which can be associated with certain changes in cusp morphology. Conclusion/Significance The reverse orders of the changes involved in these different pathways reveal a mosaic evolution of mammalian dentition in which direction of chewing and crown shape seem to be partly decoupled. Either can change in respect to strong functional constraints affecting occlusion which thereby limit the number of the possible pathways. Because convergent pathways imply distinct ontogenetic trajectories, new Evo/Devo comparative studies on cusp morphogenesis are necessary. PMID:18974837
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NASA Astrophysics Data System (ADS)
Garrido, C. J.; Padrón-Navarta, J. A.; López-Sánchez-Vizcaíno, V.; Gómez-Pugnaire, M. T.; Marchesi, C.; Tommasi, A.
2012-04-01
Our understanding of subduction zone processes is tightly connected to our knowledge of the cycling of volatiles in the Earth, namely the loci of devolatilization reactions and the fluid migration mechanism. The exact nature of fluid pathways at high-pressure conditions is poorly known and still highly speculative. Studies metamorphic terrains that record main dehydration reaction are, thus, an invaluable tool to decipher the mechanism for fluid expulsion. Among other dehydration reactions in subduction zones, the antigorite (Atg) breakdown is rather discontinuous, releases the largest amount of fluids (ca. 9 wt. %) and is considered to have important seismological implications. The antigorite dehydration front in the Cerro del Almirez (Betic Cordillera, Spain) offers, thus, an unique opportunity to investigate the dynamics of fluid expulsion through the study of micro- and macrotextures recorded in the prograde assemblage (chlorite harzburgite). Granoblastic texture are interspersed in decameter-sized domains with spinifex-like chl-harzburgite and were formed under similar P-T conditions (~1.6-1.9 GPa and 680-710°C). We ascribe these textures to shifts of the growth rate due to temporal and spatial fluctuations of the affinity of the Atg-breakdown reaction. These fluctuations are driven by cyclic variations of the excess fluid pressure which are ultimately controlled by the hydrodynamics of deserpentinization fluid expulsion. Crystallization at a low affinity of the reaction, correspondig to the granoblastic texture, may be attained if fluids are slowly drained out from the dehydration front. During the advancement of the dehydration front, overpressured domains are left behind preserving highly metastable Atg-serpentinite domains. Brittle failure results in a sudden drop of the fluid pressure, and a displacement of Atg equilibrium towards the prograde products that crystallizes at a high affinity of the reaction (spinifex-like texture). Evidences of brittle failure are found along grain-size reduction zones (GSRZ), a few mm to meters wide, which form roughly planar conjugate structures and crosscut the metamorphic texture. GSRZ are characterized by (1) sharp, irregular shapes and abrupt terminations contacts with undeformed metaperidotite, (2) an important reduction of the olivine grain size (60-250 µm), and (3) decrease in the opx modal amount. Analysis of olivine crystal-preferred orientations in GSRZ shows similar patterns, but a higher dispersion than in neighboring metaperidotite. These structures are interpreted as due to hydrofracturing allowing for the formation of high permeability channelways for overpressured fluids. This textural bimodality (granofels and Spinifex-like) and the record of brittle failure hence witnesses a unique example of the feedbacks between the cyclic dynamic of metamorphic fluid expulsion, the reaction rate and crystallisation of the Atg-dehydrating system.
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NASA Astrophysics Data System (ADS)
Allu, N. C.; Prakash, V.; Gautam, P. K.; Bera, S. K.
2014-12-01
This work explains the sedimentation history and environment and climate changes during the Holocene along the southwest coast of India. The area is characterized by various landforms such as lagoons, barrier islands, beach ridges, paleostrandlines, alluvial plains, marshy lands and flood plains. Paleodelta, located at the mouth of the modern Periyar River is an important geomorphic marker. A borehole of 40 m depth was drilled in the paleodelta and sediment samples were recovered at different depth intervals. Paleoclimate and paleo-environment were inferred based on geochronology, textural and geotechnical parameters, clay minerals, and pollen analysis results. The bottom of the borehole represents an age of ~ 12 ka BP. Sediments exhibit coarsening texture upwards of the borehole, with fine mud and peat intercalations at the bottom. Six litho facies - muddy sand, sand, sandy mud, silty sand, sandy silt, and mud - were recorded. Geotechnical properties comprising moisture content, organic carbon, plasticity index record high values, whereas low bulk density associated with a low critical shear stress, are recorded. An increase in illite and to a lesser degree smectite with concomitant decrease in kaolinite is observed. Sediment texture represents a major change of depositional environment from marine to fluvial sedimentary facies during the major sea level fall i.e., after 7 ka B.P. The present sea level attained during 4-5 ka B.P; major rise of sea level has taken place from 7-11 ka BP and regression during 7 - 5 ka B.P. These transgression and regression phases introduced the changes in the environment of deposition. The monsoon was dynamic and more intense after the major fall of sea level causing the fluctuations in the fluvial facies. Upward coarsening of grain size in the borehole indicates change in sediment deposition due to increased hydrodynamic conditions and strong fluvial action, which can be linked to marine regression. Geotechnical properties suggest textural changes and sedimentary facies. An upward increase in smectite and kaolinite and decreasing illite supports major fall in sea level and also the aridity. Pollen record of sediment strata supports the paleo-environment dominated by the presence of semi-evergreen type of mangrove plants during mid- to early-Holocene times.
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1971-12-01
1. General Principles: 'Statistical Aspect of the Correlation Between Objective and Subjective Measurements of Meat Tenderness', by M. C. Gacula, Jr., J. B. Reaume, K. J. Morgan, and R. L. Luckett 1. General Principles: 'Texture of Semi-Solid Foods: Sensory and Physical Correlates', by W. F. Henry, M. H. Katz, F. J. Pilgrim, and A. T. May 2. Instrumentation and Methodology: 'Measurement of Bread Staling', by W. Morandini and L. Wassermann 2. Instrumentation and Methodology: 'Physical Considerations of the Methods of Consistency Measurement of Butter', by E. Knoop 2. Instrumentation and Methodology: 'Electronic Recording Mixers for the Baking Test', by P. W. Voisey, V. M. Bendelow and H. Miller 2. Instrumentation and Methodology: 'Measurement of the Consistency of Reconstituted Instant Potato Flakes', by P. W. Voisey and P. R. Dean 2. Instrumentation and Methodology: 'The Ottawa Electronic Recording Farinograph', by P. W. Voisey, H. Miller and P. L. Byrne 3. Objective Measurements: A. FOODS: 'The Rheological Properties of Corn Horny Endosperm', by J. R. Hamerle*, R. K. White**, and N. N. Mohsenin*** 3. Objective Measurements: 'Evaluation of Mechanical Properties of Comminuted Sausages by Construction and Analysis of Rheological Model', by St. Tyszkiewicz 3. Objective Measurements: 'Studies on Creep Compliance of Butter', by M. Chwiej 3. Objective Measurements: 'Heat-Induced Milk Gels. II. Preparation of Gels and Measurement of Firmness', by M. Kalab, P. W. Voisey and D. B. Emmons 3. Objective Measurements: 'Rheology of Fresh, Aged and Gamma-Irradiated Egg White', by M. A. Tung, J. F. Richards, B. C. Morrison and E. L. Watson 3. Objective Measurements: 'Retardation of Bread Staling - Practical Experiences', by W. Morandini and L. Wassermann 3. Objective Measurements: B. PHARMACEUTICALS: 'Influence of HLB on Certain Physicochemical Parameters of an O/W Emulsion', by M. Schrenzel 3. Objective Measurements: 'The Rheological Evaluation of Semisolids', by L. H. Block and P. P. Lamy 4. Factors Affecting Texture: 'Effects of Physical and Mechanical Treatments on the Tenderness of the Beef Longissimus', by G. C. Smith, T. C. Arango and Z. L. Carpenter 4. Factors Affecting Texture: 'Histological and Physical Changes in Carrots as Affected by Blanching, Cooking, Freezing, Freeze Drying and Compression', by A. R. Rahman, W. L. Henning and D. E. Westcott 4. Factors Affecting Texture: 'Effects of Physiological Maturity of Beef and Marbling of Rib Steaks on Eating Quality', by H. L. Norris, D. L. Harrison, L. L. Anderson, B. Van Welck and H. J. Tuma 4. Factors Affecting Texture: 'Effect of Ultimate pH Upon the Water-Holding Capacity and Tenderness of Mutton', by P. E. Bouton, P. V. Harris and W. R. Shorthose 4. Factors Affecting Texture: 'The Dilution Coefficient of Butter Serum and the Consistency of Butter', by E. Pijanowski, M. Chwiej, H. Hernik and M. Kurtowicz 4. Factors Affecting Texture: 'Moisture and pH Changes as Criteria of Freshness in Abalone and their Relationship to Texture of the Canned Product', by D. G. James and J. Olley 4. Factors Affecting Texture: 'Effect of Sucrose on Crispness of Explosion-Puffed Apple Pieces Exposed to High Humidities', by E. O. Strolle, J. Cording, Jr., P. E. McDowell, and R. K. Eskew 4. Factors Affecting Texture: 'Effect of Heat Treatment on Viscosity of Yolk', by P. K. Chang, W. D. Powrie and O. Fennema 4. Factors Affecting Texture: 'Protein Quality and Quantity: A Rheological Assessment of the Relative Importance in Breadmaking', by T. Webb, P. W. Heaps, and J. B. M. Coppock 4. Factors Affecting Texture: 'Bread Staling. 1. Experimental Study', by E. M. A. Willhoft 4. Factors Affecting Texture: 'Bread Staling. II. Theoretical Study', by E. M. A. Willhoft.
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Global ensemble texture representations are critical to rapid scene perception.
Brady, Timothy F; Shafer-Skelton, Anna; Alvarez, George A
2017-06-01
Traditionally, recognizing the objects within a scene has been treated as a prerequisite to recognizing the scene itself. However, research now suggests that the ability to rapidly recognize visual scenes could be supported by global properties of the scene itself rather than the objects within the scene. Here, we argue for a particular instantiation of this view: That scenes are recognized by treating them as a global texture and processing the pattern of orientations and spatial frequencies across different areas of the scene without recognizing any objects. To test this model, we asked whether there is a link between how proficient individuals are at rapid scene perception and how proficiently they represent simple spatial patterns of orientation information (global ensemble texture). We find a significant and selective correlation between these tasks, suggesting a link between scene perception and spatial ensemble tasks but not nonspatial summary statistics In a second and third experiment, we additionally show that global ensemble texture information is not only associated with scene recognition, but that preserving only global ensemble texture information from scenes is sufficient to support rapid scene perception; however, preserving the same information is not sufficient for object recognition. Thus, global ensemble texture alone is sufficient to allow activation of scene representations but not object representations. Together, these results provide evidence for a view of scene recognition based on global ensemble texture rather than a view based purely on objects or on nonspatially localized global properties. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
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NASA Astrophysics Data System (ADS)
Grussenmeyer, P.; Alby, E.; Landes, T.; Koehl, M.; Guillemin, S.; Hullo, J. F.; Assali, P.; Smigiel, E.
2012-07-01
Different approaches and tools are required in Cultural Heritage Documentation to deal with the complexity of monuments and sites. The documentation process has strongly changed in the last few years, always driven by technology. Accurate documentation is closely relied to advances of technology (imaging sensors, high speed scanning, automation in recording and processing data) for the purposes of conservation works, management, appraisal, assessment of the structural condition, archiving, publication and research (Patias et al., 2008). We want to focus in this paper on the recording aspects of cultural heritage documentation, especially the generation of geometric and photorealistic 3D models for accurate reconstruction and visualization purposes. The selected approaches are based on the combination of photogrammetric dense matching and Terrestrial Laser Scanning (TLS) techniques. Both techniques have pros and cons and recent advances have changed the way of the recording approach. The choice of the best workflow relies on the site configuration, the performances of the sensors, and criteria as geometry, accuracy, resolution, georeferencing, texture, and of course processing time. TLS techniques (time of flight or phase shift systems) are widely used for recording large and complex objects and sites. Point cloud generation from images by dense stereo or multi-view matching can be used as an alternative or as a complementary method to TLS. Compared to TLS, the photogrammetric solution is a low cost one, as the acquisition system is limited to a high-performance digital camera and a few accessories only. Indeed, the stereo or multi-view matching process offers a cheap, flexible and accurate solution to get 3D point clouds. Moreover, the captured images might also be used for models texturing. Several software packages are available, whether web-based, open source or commercial. The main advantage of this photogrammetric or computer vision based technology is to get at the same time a point cloud (the resolution depends on the size of the pixel on the object), and therefore an accurate meshed object with its texture. After matching and processing steps, we can use the resulting data in much the same way as a TLS point cloud, but in addition with radiometric information for textures. The discussion in this paper reviews recording and important processing steps as geo-referencing and data merging, the essential assessment of the results, and examples of deliverables from projects of the Photogrammetry and Geomatics Group (INSA Strasbourg, France).
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Changes in the taste and textural attributes of apples in response to climate change
Sugiura, Toshihiko; Ogawa, Hidekazu; Fukuda, Noriaki; Moriguchi, Takaya
2013-01-01
The effects of climate change on the taste and textural attributes of foods remain largely unknown, despite much public interest. On the basis of 30–40 years of records, we provide evidence that the taste and textural attributes of apples have changed as a result of recent global warming. Decreases in both acid concentration, fruit firmness and watercore development were observed regardless of the maturity index used for harvest date (e.g., calendar date, number of days after full bloom, peel colour and starch concentration), whereas in some cases the soluble-solids concentration increased; all such changes may have resulted from earlier blooming and higher temperatures during the maturation period. These results suggest that the qualities of apples in the market are undergoing long-term changes. PMID:23948740
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Bayless, E. Randall; Arihood, Leslie D.; Reeves, Howard W.; Sperl, Benjamin J.S.; Qi, Sharon L.; Stipe, Valerie E.; Bunch, Aubrey R.
2017-01-18
As part of the National Water Availability and Use Program established by the U.S. Geological Survey (USGS) in 2005, this study took advantage of about 14 million records from State-managed collections of water-well drillers’ records and created a database of hydrogeologic properties for the glaciated United States. The water-well drillers’ records were standardized to be relatively complete and error-free and to provide consistent variables and naming conventions that span all State boundaries.Maps and geospatial grids were developed for (1) total thickness of glacial deposits, (2) total thickness of coarse-grained deposits, (3) specific-capacity based transmissivity and hydraulic conductivity, and (4) texture-based estimated equivalent horizontal and vertical hydraulic conductivity and transmissivity. The information included in these maps and grids is required for most assessments of groundwater availability, in addition to having applications to studies of groundwater flow and transport. The texture-based estimated equivalent horizontal and vertical hydraulic conductivity and transmissivity were based on an assumed range of hydraulic conductivity values for coarse- and fine-grained deposits and should only be used with complete awareness of the methods used to create them. However, the maps and grids of texture-based estimated equivalent hydraulic conductivity and transmissivity may be useful for application to areas where a range of measured values is available for re-scaling.Maps of hydrogeologic information for some States are presented as examples in this report but maps and grids for all States are available electronically at the project Web site (USGS Glacial Aquifer System Groundwater Availability Study, http://mi.water.usgs.gov/projects/WaterSmart/Map-SIR2015-5105.html) and the Science Base Web site, https://www.sciencebase.gov/catalog/item/58756c7ee4b0a829a3276352.
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Cortes-Rodicio, J; Sanchez-Merino, G; Garcia-Fidalgo, M A; Tobalina-Larrea, I
To identify those textural features that are insensitive to both technical and biological factors in order to standardise heterogeneity studies on 18 F-FDG PET imaging. Two different studies were performed. First, nineteen series from a cylindrical phantom filled with different 18 F-FDG activity concentration were acquired and reconstructed using three different protocols. Seventy-two texture features were calculated inside a circular region of interest. The variability of each feature was obtained. Second, the data for 15 patients showing non-pathological liver were acquired. Anatomical and physiological features such as patient's weight, height, body mass index, metabolic active volume, blood glucose level, SUV and SUV standard deviation were also recorded. A liver covering region of interest was delineated and low variability textural features calculated in each patient. Finally, a multivariate Spearman's correlation analysis between biological factors and texture features was performed. Only eight texture features analysed show small variability (<5%) with activity concentration and reconstruction protocol making them suitable for heterogeneity quantification. On the other hand, there is a high statistically significant correlation between MAV and entropy (P<0.05). Entropy feature is, indeed, correlated (P<0.05) with all patient parameters, except body mass index. The textural features that are correlated with neither technical nor biological factors are run percentage, short-zone emphasis and intensity, making them suitable for quantifying functional changes or classifying patients. Other textural features are correlated with technical and biological factors and are, therefore, a source of errors if used for this purpose. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.
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Tütken, Thomas; Kaiser, Thomas M.; Vennemann, Torsten; Merceron, Gildas
2013-01-01
Background The equid Hippotherium primigenium, with moderately hypsodont cheek teeth, rapidly dispersed through Eurasia in the early late Miocene. This dispersal of hipparions into the Old World represents a major faunal event during the Neogene. The reasons for this fast dispersal of H. primigenium within Europe are still unclear. Based on its hypsodonty, a high specialization in grazing is assumed although the feeding ecology of the earliest European hipparionines within a pure C3 plant ecosystem remains to be investigated. Methodology/Principal Findings A multi-proxy approach, combining carbon and oxygen isotopes from enamel as well as dental meso- and microwear analyses of cheek teeth, was used to characterize the diet of the earliest European H. primigenium populations from four early Late Miocene localities in Germany (Eppelsheim, Höwenegg), Switzerland (Charmoille), and France (Soblay). Enamel δ13C values indicate a pure C3 plant diet with small (<1.4‰) seasonal variations for all four H. primigenium populations. Dental wear and carbon isotope compositions are compatible with dietary differences. Except for the Höwenegg hipparionines, dental microwear data indicate a browse-dominated diet. By contrast, the tooth mesowear patterns of all populations range from low to high abrasion suggesting a wide spectrum of food resources. Conclusions/Significance Combined dental wear and stable isotope analysis enables refined palaeodietary reconstructions in C3 ecosystems. Different H. primigenium populations in Europe had a large spectrum of feeding habits with a high browsing component. The combination of specialized phenotypes such as hypsodont cheek teeth with a wide spectrum of diet illustrates a new example of the Liem’s paradox. This dietary flexibility associated with the capability to exploit abrasive food such as grasses probably contributed to the rapid dispersal of hipparionines from North America into Eurasia and the fast replacement of the brachydont equid Anchitherium by the hypsodont H. primigenium in Europe. PMID:24040254
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Depositional processes in large-scale debris-flow experiments
Major, J.J.
1997-01-01
This study examines the depositional process and characteristics of deposits of large-scale experimental debris flows (to 15 m3) composed of mixtures of gravel (to 32 mm), sand, and mud. The experiments were performed using a 95-m-long, 2-m-wide debris-flow flume that slopes 31??. Following release, experimental debris flows invariably developed numerous shallow (???10 cm deep) surges. Sediment transported by surges accumulated abruptly on a 3?? runout slope at the mouth of the flume. Deposits developed in a complex manner through a combination of shoving forward and shouldering aside previously deposited debris and through progressive vertical accretion. Progressive accretion by the experimental flows is contrary to commonly assumed en masse sedimentation by debris flows. Despite progressive sediment emplacement, deposits were composed of unstratified accumulations of generally unsorted debris; hence massively textured, poorly sorted debris-flow deposits are not emplaced uniquely en masse. The depositional process was recorded mainly by deposit morphology and surface texture and was not faithfully registered by interior sedimentary texture; homogeneous internal textures could be misinterpreted as the result of en masse emplacement by a single surge. Deposition of sediment by similar, yet separate, debris flows produced a homogenous, massively textured composite deposit having little stratigraphic distinction. Similar deposit characteristics and textures are observed in natural debris-flow deposits. Experimental production of massively textured deposits by progressive sediment accretion limits interpretations that can be drawn from deposit characteristics and casts doubt on methods of estimating flow properties from deposit thickness or from relations between particle size and bed thickness.
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Lung cancer from asbestos textured ceilings: a case study.
Dahlgren, James G; Talbott, Patrick J
2016-04-01
Asbestos was used in spray applied textured ceilings from 1945 to at least 1980. Exposure to asbestos and the probability of developing lung disease is high in individuals who lived with these types of ceilings in their home. Asbestos exposure and frequency of disease is even higher in an apartment suffering from flooding, maintenance, and/or multiple structural impacts. Our goal is to examine a case of lung cancer in a non-smoking individual exposed to asbestos from the damaged acoustic ceilings in her apartment. The subject's medical and occupational records were obtained and reviewed and a physical examination was performed. Exposure ratings were obtained from previous literature for discussion purposes. Asbestos-textured ceilings are a possible source of asbestos exposure and there may be a risk of developing cancer in individuals exposed to ceiling deterioration.
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Towards true 3D textural analysis; using your crystal mush wisely.
NASA Astrophysics Data System (ADS)
Jerram, D. A.; Morgan, D. J.; Pankhurst, M. J.
2014-12-01
The crystal cargo that is found in volcanic and plutonic rocks contains a wealth of information about magmatic mush processes, crystallisation history, crystal entrainment and recycling. Phenocryst populations predominantly record episodes of growth/nucleation and bulk geochemical changes within an evolving crystal-melt body. Ante- and xeno-crysts provide useful clues to the nature of mush interaction with wall rock and with principal magma(s). Furthermore, crystal evolutions (core to rim) record pathways through pressure, temperature and compositional space. These can often illustrate complex recycling within systems, describing the plumbing architecture. Understanding this architecture underpins our knowledge of how igneous systems can interact with the crust, grow, freeze, re-mobilise and prime for eruption. Initially, 2D studies produced corrected 3D crystal size distributions to help provide information about nucleation and residence times. It immediately became clear that crystal shape is an important factor in determining the confidence placed upon 3D reconstructions of 2D data. Additionally studies utilised serial sections of medium- to coarse-grain-size populations which allowed 3D reconstruction using modelling software to be improved, since size and shape etc. can be directly constrained. Finally the advent of textural studies using X-ray tomography has revolutionised the way in which we can inspect the crystal cargo in mushy systems, allowing us to image in great detail crystal packing arrangements, 3D CSDs, shapes and orientations etc. The latest most innovative studies use X-ray micro-computed tomography to rapidly characterise chemical populations within the crystal cargo, adding a further dimension to this approach, and implies the ability to untangle magmatic chemical components to better understand their individual and combined evolution. In this contribution key examples of the different types of textural analysis techniques in 2D and 3D, including texture movie animations, are used from both plutonic and volcanic systems to highlight the roll of this approach towards a goal of true 3D textural analysis.
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Numerosity but not texture-density discrimination correlates with math ability in children.
Anobile, Giovanni; Castaldi, Elisa; Turi, Marco; Tinelli, Francesca; Burr, David C
2016-08-01
Considerable recent work suggests that mathematical abilities in children correlate with the ability to estimate numerosity. Does math correlate only with numerosity estimation, or also with other similar tasks? We measured discrimination thresholds of school-age (6- to 12.5-years-old) children in 3 tasks: numerosity of patterns of relatively sparse, segregatable items (24 dots); numerosity of very dense textured patterns (250 dots); and discrimination of direction of motion. Thresholds in all tasks improved with age, but at different rates, implying the action of different mechanisms: In particular, in young children, thresholds were lower for sparse than textured patterns (the opposite of adults), suggesting earlier maturation of numerosity mechanisms. Importantly, numerosity thresholds for sparse stimuli correlated strongly with math skills, even after controlling for the influence of age, gender and nonverbal IQ. However, neither motion-direction discrimination nor numerosity discrimination of texture patterns showed a significant correlation with math abilities. These results provide further evidence that numerosity and texture-density are perceived by independent neural mechanisms, which develop at different rates; and importantly, only numerosity mechanisms are related to math. As developmental dyscalculia is characterized by a profound deficit in discriminating numerosity, it is fundamental to understand the mechanism behind the discrimination. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
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Size dependence of chondrule textural types
NASA Technical Reports Server (NTRS)
Goswami, J. N.
1984-01-01
Chrondrule textural types were studied for size sorted chondrules from the ordinary chondrites Dhajala, Eston and Chainpur and the CM chondrite Murchison. Aliquot samples from size sorted Dhajala chondrules were studied for their oxygen isotopic composition and chondrules from Weston were studied for their precompaction irradiation records by nuclear track technique. Correlations between chondrule textural types and oxygen isotope or track data were identified. A distinct dependence of chondrule textural type on chondrule size was evident in the data for both Dhajala and Weston chondrules. No significant deviation was noticed in the abundance pattern of nonporphyritic chondrules within individual size fractions in the 200 to 800 micron size interval. Overabundance is found of nonporphyritic chondrules in the 100 to 200 micron size fraction of Murchison chondrules, the trend is not as distinct for Chainpur chondrules. Two hundred microns is suggested as the cutoff size below which radiative cooling is extremely efficient during the chondrule forming process. It is suggested that this offers a possibility for use of physical and chemical characteristics of small chondrules to constrain the temperature history during the chondrule formation process.
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Wang, Kun-Ching
2015-01-14
The classification of emotional speech is mostly considered in speech-related research on human-computer interaction (HCI). In this paper, the purpose is to present a novel feature extraction based on multi-resolutions texture image information (MRTII). The MRTII feature set is derived from multi-resolution texture analysis for characterization and classification of different emotions in a speech signal. The motivation is that we have to consider emotions have different intensity values in different frequency bands. In terms of human visual perceptual, the texture property on multi-resolution of emotional speech spectrogram should be a good feature set for emotion classification in speech. Furthermore, the multi-resolution analysis on texture can give a clearer discrimination between each emotion than uniform-resolution analysis on texture. In order to provide high accuracy of emotional discrimination especially in real-life, an acoustic activity detection (AAD) algorithm must be applied into the MRTII-based feature extraction. Considering the presence of many blended emotions in real life, in this paper make use of two corpora of naturally-occurring dialogs recorded in real-life call centers. Compared with the traditional Mel-scale Frequency Cepstral Coefficients (MFCC) and the state-of-the-art features, the MRTII features also can improve the correct classification rates of proposed systems among different language databases. Experimental results show that the proposed MRTII-based feature information inspired by human visual perception of the spectrogram image can provide significant classification for real-life emotional recognition in speech.
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NASA Astrophysics Data System (ADS)
Isaenkova, M.; Perlovich, Yu; Fesenko, V.
2016-04-01
Currently used methods for constructing texture complete direct pole figure (CDPF) based on the results of X-ray diffractometric measurements were considered with respect to the products of Zr-based alloys and, in particular, used in a nuclear reactor cladding tubes, for which the accuracy of determination of integral texture parameters is of the especial importance. The main attention was devoted to technical issues which are solved by means of computer processing of large arrays of obtained experimental data. Among considered questions there are amendments of the defocusing, techniques for constructing of complete direct pole figures and determination of integral textural parameters. The methods of reconstruction of complete direct pole figures by partial direct pole figures recorded up to tilt angles of sample ψ=70-80°: the method of extrapolation of data to an uninvestigated region of the stereographic projection, and the method of "sewing" of partial pole figures measured for three mutually perpendicular plane sections of the product. The limits of applicability of these methods, depending on the shape of the test product and the degree of inhomogeneity of the layer-by-layer texture, were revealed. On the basis of a large number of experimental data, the accuracy of the integral parameters used for calculation of the physical and mechanical properties of metals with a hexagonal crystal structure was found to be equal to 0.02, when taking into account the texture heterogeneity of regular products from Zr-based alloys.
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Hydrodynamic implications of textural trends in sand deposits of the 2004 tsunami in Sri Lanka
Morton, R.A.; Goff, J.R.; Nichol, S.L.
2008-01-01
Field observations and sediment samples at a coastal-plain setting in southeastern Sri Lanka were used to document the erosional and depositional impacts of the 2004 Indian Ocean tsunami and to interpret the hydrodynamic processes that produced an extensive sand-sheet deposit. Tsunami deposit thicknesses ranged from 6 to 22??cm with thickness being controlled partly by antecedent topography. The deposit was composed of coarse to medium sand organized into plane-parallel laminae and a few laminasets. Vertical textural trends showed an overall but non-systematic upward fining and upward thinning of depositional units with an upward increase in heavy-mineral laminations at some locations. Repeated patterns in the vertical textural trends (upward fining, upward coarsening, uniform) were used to subdivide and correlate the deposit into five hydro-textural stratigraphic units. The depositional units were linked to hydrodynamic processes and upcurrent conditions, such as rates of sediment supply and composition of the sediment sources. Vertical changes in grain-size distributions recorded the depositional phases associated with flow acceleration, initial unsteady pulsating flow, relatively stable and uniform flow, flow deceleration, slack water, and return flow or flow redirection. Study results suggest that vertical textural trends from multiple cross-shore sections can be used to interpret complex tsunami flow histories, but at the location examined, interpretation of the lateral textural trends did not provide a basis for identifying the correct sediment transport pathways because flow near the landward boundary was multidirectional.
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Episodic fluid expulsion and fluid pathways during high-pressure dehydration of serpentinite
NASA Astrophysics Data System (ADS)
Padrón-Navarta, J.; Garrido, C. J.; López Sánchez-Vizcaíno, V.; Gómez-Pugnaire, M.; Tommasi, A.; Marchesi, C.
2011-12-01
Our understanding of subduction zone processes is tightly connected to our knowledge of the cycling of volatiles in the Earth, namely the loci of devolatilization reactions and the fluid migration mechanism. The exact nature of fluid pathways at high-pressure conditions is poorly known and still highly speculative. The study of metamorphic terrains that record main dehydration reaction are, thus, an invaluable tool to decipher the mechanism for fluid expulsion. Among other dehydration reactions in subduction zones, the antigorite (Atg) breakdown is rather discontinuous, releases the largest amount of fluids (ca. 9 wt. %) and is considered to have important seismological implications. The antigorite dehydration front in the Cerro del Almirez (Betic Cordillera, Spain) offers, thus, an unique opportunity to investigate the dynamics of fluid expulsion through the study of micro- and macrotextures recorded in the prograde assemblage (chlorite harzburgite). Chl-harzburgites show two textures interspersed in decameter-sized domains: granoblastic and spinifex-like. Both were formed under similar P-T conditions (~1.6-1.9 GPa and 680-710°C)). We ascribe the change in texture to shifts of the growth rate due to temporal and spatial fluctuations of the affinity of the Atg-breakdown reaction. These fluctuations are driven by cyclic variations of the excess fluid pressure which are ultimately controlled by the hydrodynamics of deserpentinization fluid expulsion. Crystallization at a low affinity of the reaction, correspondig to the granoblastic texture, may be attained if fluids are slowly drained out from the dehydration front. During the advancement of the dehydration front, overpressured domains are left behind preserving highly metastable Atg-serpentinite domains. Brittle failure results in a sudden drop of the fluid pressure, and a displacement of Atg equilibrium towards the prograde products that crystallizes at a high affinity of the reaction (spinifex-like texture). Evidences of brittle failure are found along grain-size reduction zones (GSRZ), a few mm to meters wide, which form roughly planar conjugate structures and crosscut the metamorphic texture. GSRZ are characterized by (1) sharp, irregular shapes and abrupt terminations contacts with undeformed metaperidotite, (2) an important reduction of the olivine grain size (60-250 μm), and (3) decrease in the opx modal amount. Analysis of olivine crystal-preferred orientations in GSRZ shows similar patterns, but a higher dispersion than in neighboring metaperidotite. These structures are interpreted as due to hydrofracturing allowing for the formation of high permeability channelways for overpressured fluids. This textural bimodality (granofels and spinifex-like) and the record of brittle failure witness a unique example of feedback between cyclic metamorphic fluid expulsion, reaction rates, and deformation in the Atg-dehydrating system.
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The Diagenesis and Replacement of Cosmic Dust in the Geological Record
NASA Astrophysics Data System (ADS)
Suttle, M. D.; Genge, M. J.
2017-07-01
We report the discovery of abundant pseudomorphic fossil cosmic spherules, preserved in 87Ma old Cretaceous chalk. These replaced micrometeorites are composed of hematite or iron silicides and identified on the basis of characteristic textures.
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King, P M
1997-01-01
The purpose of this study was to determine if a correlation exists between touch-pressure threshold testing and sensory discrimination function, specifically tactile gnosis for texture and object recognition. Twenty-nine patients diagnosed with carpal tunnel syndrome (CTS), as confirmed by electromyography or nerve conduction velocity tests, were administered three sensibility tests: the Semmes-Weinstein monofilament test, a texture discrimination test, and an object identification test. Norms were established for texture and object recognition tests using 100 subjects (50 females and 50 males) with normal touch-pressure thresholds as assessed by the Semmes-Weinstein monofilament test. The CTS patients were grouped into three categories of sensibility as determined by their performance on the Semmes-Weinstein monofilament test: normal, diminished light touch, and diminished protective sensation. Through an independent t test statistical procedure, each of the three categories mean response times for identification of textures of objects were compared with the normed response times. Accurate responses were given for identification of all textures and objects. No significant difference (p < .05) was noted in mean response times of the CTS patients with normal touch-pressure thresholds. A significant difference (p < .05) in response times by those CTS patients with diminished light touch was detected in identification in four out of six objects. Subjects with diminished protective sensation had significantly longer response times (p < .05) for identification of the textures of cork, coarse and fine sandpaper, and rubber. Significantly longer response times were recorded by the same subjects for identification of such objects as a screw and a button, and for the shapes of a square, triangle, and oval.
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The Evaluation of Basal Respiration for Various Soil Textures in Ecologically Sensitive Area
NASA Astrophysics Data System (ADS)
Huličová, P.; Kotorová, D.; Fazekašová, D.; Hynšt, J.
2017-10-01
The present contribution was focused on monitoring changes in the soil basal respiration in different textures of soil in the dry polder Beša. The research was conducted between 2012 and 2014 on soil type Fluvisol locations on three soil textures: clay - loam soil, clayey soil and clay soil in three soil depths. The basal respiration (BR) has been determine by soil CO2 production measuring from incubated soil samples in serum bottles in laboratory condition. Release Co2 has been analysed by gas chromatography. Content of clay particles were in the range 52.18 % to 81.31%, indicating the high difference between the minimum and maximum content. By using of multiple LSD-test we recorded statistically significant impact of clay on basal respiration. Results confirm the values of basal respiration with the depth of the soil profile decreased.
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Soil sedimentology at Gusev Crater from Columbia Memorial Station to Winter Haven
Cabrol, N.A.; Herkenhoff, K. E.; Greeley, R.; Grin, E.A.; Schroder, C.; d'Uston, C.; Weitz, C.; Yingst, R.A.; Cohen, B. A.; Moore, J.; Knudson, A.; Franklin, B.; Anderson, R.C.; Li, R.
2008-01-01
A total of 3140 individual particles were examined in 31 soils along Spirit's traverse. Their size, shape, and texture were quantified and classified. They represent a unique record of 3 years of sedimentologic exploration from landing to sol 1085 covering the Plains Unit to Winter Haven where Spirit spent the Martian winter of 2006. Samples in the Plains Unit and Columbia Hills appear as reflecting contrasting textural domains. One is heterogeneous, with a continuum of angular-to-round particles of fine sand to pebble sizes that are generally dust covered and locally cemented in place. The second shows the effect of a dominant and ongoing dynamic aeolian process that redistributes a uniform population of medium-size sand. The texture of particles observed in the samples at Gusev Crater results from volcanic, aeolian, impact, and water-related processes. Copyright 2008 by the American Geophysical Union.
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NASA Astrophysics Data System (ADS)
Cao, Shuyun; Neubauer, Franz; Liu, Junlai; Bernroider, Manfred; Genser, Johann
2016-04-01
The presence of deep exhumed crustal rocks with a dominant but contrasting mineralogy results in shear concentration in the rheological weakest layer, which exhibits contrasting patterns of fabrics and thermal conditions during their formation. We tested a combination of methodologies including microstructural and textural investigations, geochronology and geothermometry on deformed rocks from exhumed strike-slip fault, Ailao Shan-Red River, SE, Asian. Results indicate that the exhumed deep crustal rocks since late Oligocene (ca. 28 Ma) to Pliocene (ca. 4 Ma) typically involve dynamic microstructural, textural and thermal evolution processes, which typically record a progressive deformation and syn-kinematic reactions from ductile to semi-ductile and brittle behavior during exhumation. This transformation also resulted in dramatic strength reduction that promoted strain localization along the strike-slip and transtensional faults. Detailed analysis has revealed the co-existence of microfabrics ranging from high-temperatures (granulite facies conditions) to overprinting low-temperatures (lower greenschist facies conditions). The high-temperature microstructures and textures are in part or entirely altered by subsequent, overprinting low-temperature shearing. In quartz-rich rocks, quartz was deformed in the dislocation creep regime and records transition of microfabrics and slip systems during decreasing temperature, which lasted until retrogression related to final exhumation. As a result, grain-size reduction associated by fluids circulating within the strike-slip fault zone at brittle-ductile transition leads to rock softening, which resulted in strain localization, weak rock rheology and the overall hot thermal structure of the crust. Decompression occurred during shearing and as a result of tectonic exhumation. All these results demonstrate that the ductile to ductile-brittle transition involves a combination of different deformation mechanisms, rheological transition features and feedbacks between deformation, decreasing temperature and fluids.
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Wang, Kun-Ching
2015-01-01
The classification of emotional speech is mostly considered in speech-related research on human-computer interaction (HCI). In this paper, the purpose is to present a novel feature extraction based on multi-resolutions texture image information (MRTII). The MRTII feature set is derived from multi-resolution texture analysis for characterization and classification of different emotions in a speech signal. The motivation is that we have to consider emotions have different intensity values in different frequency bands. In terms of human visual perceptual, the texture property on multi-resolution of emotional speech spectrogram should be a good feature set for emotion classification in speech. Furthermore, the multi-resolution analysis on texture can give a clearer discrimination between each emotion than uniform-resolution analysis on texture. In order to provide high accuracy of emotional discrimination especially in real-life, an acoustic activity detection (AAD) algorithm must be applied into the MRTII-based feature extraction. Considering the presence of many blended emotions in real life, in this paper make use of two corpora of naturally-occurring dialogs recorded in real-life call centers. Compared with the traditional Mel-scale Frequency Cepstral Coefficients (MFCC) and the state-of-the-art features, the MRTII features also can improve the correct classification rates of proposed systems among different language databases. Experimental results show that the proposed MRTII-based feature information inspired by human visual perception of the spectrogram image can provide significant classification for real-life emotional recognition in speech. PMID:25594590
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Real-time photorealistic stereoscopic rendering of fire
NASA Astrophysics Data System (ADS)
Rose, Benjamin M.; McAllister, David F.
2007-02-01
We propose a method for real-time photorealistic stereo rendering of the natural phenomenon of fire. Applications include the use of virtual reality in fire fighting, military training, and entertainment. Rendering fire in real-time presents a challenge because of the transparency and non-static fluid-like behavior of fire. It is well known that, in general, methods that are effective for monoscopic rendering are not necessarily easily extended to stereo rendering because monoscopic methods often do not provide the depth information necessary to produce the parallax required for binocular disparity in stereoscopic rendering. We investigate the existing techniques used for monoscopic rendering of fire and discuss their suitability for extension to real-time stereo rendering. Methods include the use of precomputed textures, dynamic generation of textures, and rendering models resulting from the approximation of solutions of fluid dynamics equations through the use of ray-tracing algorithms. We have found that in order to attain real-time frame rates, our method based on billboarding is effective. Slicing is used to simulate depth. Texture mapping or 2D images are mapped onto polygons and alpha blending is used to treat transparency. We can use video recordings or prerendered high-quality images of fire as textures to attain photorealistic stereo.
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Lighting Up Science for the Visually Impaired.
ERIC Educational Resources Information Center
Billings, Gilbert W.; And Others
1980-01-01
Described are activities designed specifically for visually impaired students, demonstrating (1) meiosis, (2) mass, (3) enzyme-substrate reactions, (4) function and relationships of flowering parts. Employed are tactile and auditory learning aids, such as the tape recorder, electric eye, Braille typewriter, textured fabrics, and three-dimensional…
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A System Approach to Navy Medical Education and Training. Appendix 23. Urology Technician.
1974-08-31
IOBSERVE/RECORD OR DESCRIBE CHARACTERISTICS OF DRAINAGE FROM IINTERNAL BODY ORGANS 8 1OBSERVE/RECORD OR DESCRIBE CHARACTERISTICS OF DRAINAGE FROM...WHICH STAFF MEMBER IPATIENT SHOULD SEE 16 ICHECK COLOR OF SKIN, E.G. CYANOSIS, BLANCHING, JAUNDICE, IMOTTLING 17 ICHECK TEXTURE OF SKIN, E.G. DRY...POSSIBLE IPATIENT USE I 29 IDETERMINE MEDICATIONS AND SUPPLIES FOR DRUG KITS 30 ICHECK/COUNT NARCOTICS/CONTROLLED DRUGS 31 1DO AN INVENTORY OF DRUGS
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Häggman-Henrikson, Birgitta; Nordh, Erik; Eriksson, Per-Olof
2013-10-01
Previous findings, during chewing, that boluses of larger size and harder texture result in larger amplitudes of both mandibular and head-neck movements suggest a relationship between increased chewing load and incremental recruitment of jaw and neck muscles. The present report evaluated jaw (masseter and digastric) and neck [sternocleidomastoid (SCM) and trapezius] muscle activity during the chewing of test foods of different sizes and textures by 10 healthy subjects. Muscle activity was recorded by surface electromyography and simultaneous mandibular and head movements were recorded using an optoelectronic technique. Each subject performed continuous jaw-opening/jaw-closing movements whilst chewing small and large boluses of chewing gum and rubber silicone (Optosil). For jaw opening/jaw closing without a bolus, SCM activity was recorded for jaw opening concomitantly with digastric activity. During chewing, SCM activity was recorded for jaw closing concomitantly with masseter activity. Trapezius activity was present in some, but not all, cycles. For the masseter and SCM muscles, higher activity was seen with larger test foods, suggesting increased demand and recruitment of these muscles in response to an increased chewing load. This result reinforces the previous notion of a close functional connection between the jaw and the neck motor systems in jaw actions and has scientific and clinical significance for studying jaw function and dysfunction. © 2013 Eur J Oral Sci.
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Natural Models for Autonomous Control of Spatial Navigation, Sensing, and Guidance, Part 1
2011-06-16
polarization sensitivity ten times more acute than previously documented in cephalopods (cuttlefish and octopus ) and crustaceans (mantis shrimps and crabs...responded to perceived looming stimuli in a number of ways, including swimming movements , skin colour and texture changes, which were recorded using
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NASA Astrophysics Data System (ADS)
Ian Schipper, C.; Mandon, Céline; Maksimenko, Anton; Castro, Jonathan M.; Conway, Chris E.; Hauer, Peter; Kirilova, Martina; Kilgour, Geoff
2017-10-01
Vesicles in volcanic rocks are physical records of magmatic degassing; however, the interpretation of their textures is complicated by resorption, coalescence, and collapse. We discuss the textural significance of vesicle-hosted vapor-phase cristobalite (high-T, low-P SiO2 polymorph), and its utility as a complement to textural assessments of magmatic degassing, using a representative dacite bomb erupted from White Island volcano (New Zealand) in 1999. Imaging in 2D (SEM) and 3D (CT) shows the bomb to have 56% bulk porosity, almost all of which is connected ( 99%) and devoid of SiO2 phases. The remaining ( 1%) of porosity is in isolated, sub-spherical vesicles that have corroded walls and contain small (< 30 μm across) prismatic vapor-phase cristobalite crystals (98.4 ± 0.4 wt.% SiO2 with diagnostic laser Raman spectra). Halogen degassing models show vapor-phase cristobalite to be indicative of closed-system chlorine and fluorine partitioning into H2O-rich fluid in isolated pores. At White Island, this occurred during shallow (< 100s of meters) ascent and extensive ( 50%) groundmass crystallization associated with slow cooling in a volcanic plug. Pristine textures in this White Island bomb demonstrate the link between pore isolation and vapor-phase cristobalite deposition. We suggest that because these crystals have higher preservation potential than the bubbles in which they form, they can serve as durable, qualitative textural indicators of halogen degassing and pre-quench bubble morphologies in slowly cooled volcanic rocks (e.g., lava flows and domes), even where emplacement mechanisms have overprinted original bubble textures.
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Bone structure studies with holographic interferometric nondestructive testing and x-ray methods
NASA Astrophysics Data System (ADS)
Silvennoinen, Raimo; Nygren, Kaarlo; Rouvinen, Juha; Petrova, Valentina V.
1994-02-01
Changes in the biomechanics and in the molecular texture and structure of isolated radioulnar bones of subadult European moose (Alces alces L.) collected in various environmentally polluted areas of Finland were investigated by means of holographic interferometric non- destructive testing (HNDT), radiological, morphometrical, and x-ray diffraction methods. By means of small caudal-cranial bending forces, the surface movements of the lower end (distal epiphysis) of the radial bone were recorded with the HNDT method. To study bone molecular texture and structure changes under external compressing forces, the samples for x-ray diffraction analysis were taken from the upper end of the ulnar bone (olecranon tip). Results showed that the bones obtained from the Harjavalta area and those of North Karelian moose showing malnutrition and healing femoral fractures produced different HNDT pictures compared with the four normally developed North Karelian moose. In the x-ray diffraction, the Harjavalta samples showed changes in molecular texture and structure compared with the samples from the apparently normal North Karelian animals.
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Employing wavelet-based texture features in ammunition classification
NASA Astrophysics Data System (ADS)
Borzino, Ángelo M. C. R.; Maher, Robert C.; Apolinário, José A.; de Campos, Marcello L. R.
2017-05-01
Pattern recognition, a branch of machine learning, involves classification of information in images, sounds, and other digital representations. This paper uses pattern recognition to identify which kind of ammunition was used when a bullet was fired based on a carefully constructed set of gunshot sound recordings. To do this task, we show that texture features obtained from the wavelet transform of a component of the gunshot signal, treated as an image, and quantized in gray levels, are good ammunition discriminators. We test the technique with eight different calibers and achieve a classification rate better than 95%. We also compare the performance of the proposed method with results obtained by standard temporal and spectrographic techniques
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NASA Astrophysics Data System (ADS)
Sharp, T. G.; Hu, J.; Walton, E. L.
2016-08-01
Shock metamorphic effects in martian meteorites provide a record of recent impact events on Mars. We examined the textures and mineralogy associated with shock melting in three highly shocked martian basalts: NWA 8159, Tissint and EET A79001.
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The angus mammoth: A decades-old scientific controversy resolved
Holen, S.R.; May, D.W.; Mahan, S.A.
2011-01-01
The Angus Mammoth site in south-central Nebraska has been controversial since its discovery in 1931 when a fluted artifact was reported to be associated with the mammoth. For nearly 80 years it has not been known if Angus was a paleontol??gica! site predating the human occupation of North America as has been asserted by some geologists and paleontologists, or an archaeological site dating to the late Pleistocene as has been advocated by some archaeologists. Geomorphic study and luminescence dating have finally solved the problem after nearly eight decades. Although microwear and technological analyses have determined that the Angus biface is an authentic artifact, TL and IRSL dates have shown that the matrix above the mammoth is much too old for a mammoth/fluted point association to be valid. Copyright ??2011 by the Society for American Archaeology.
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1999-09-30
history. OBJECTIVES 1) Is the variability in a river’s sediment load, observed over the last 100 years or less, adequate to provide a proxy for longer-term...experiments, small basins are able to capture in terms of textural proxies , both the natural variability associated with precipitation and temperature...as well as realistic scenarios of abrupt climate change. Open ocean basins, like the Eel River, are less likely to record the proxy record of ambient
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Fagan, C C; O'Donnell, C P; O'Callaghan, D J; Downey, G; Sheehan, E M; Delahunty, C M; Everard, C; Guinee, T P; Howard, V
2007-04-01
The objective of this study was to determine the potential of mid-infrared spectroscopy in conjunction with partial least squares (PLS) regression to predict various quality parameters in cheddar cheese. Cheddar cheeses (n= 24) were manufactured and stored at 8 degrees C for 12 mo. Mid-infrared spectra (640 to 4000/cm) were recorded after 4, 6, 9, and 12 mo storage. At 4, 6, and 9 mo, the water-soluble nitrogen (WSN) content of the samples was determined and the samples were also evaluated for 11 sensory texture attributes using descriptive sensory analysis. The mid-infrared spectra were subjected to a number of pretreatments, and predictive models were developed for all parameters. Age was predicted using scatter-corrected, 1st derivative spectra with a root mean square error of cross-validation (RMSECV) of 1 mo, while WSN was predicted using 1st derivative spectra (RMSECV = 2.6%). The sensory texture attributes most successfully predicted were rubbery, crumbly, chewy, and massforming. These attributes were modeled using 2nd derivative spectra and had corresponding RMSECV values in the range of 2.5 to 4.2 on a scale of 0 to 100. It was concluded that mid-infrared spectroscopy has the potential to predict age, WSN, and several sensory texture attributes of cheddar cheese.
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Diagenetically altered fossil micrometeorites suggest cosmic dust is common in the geological record
NASA Astrophysics Data System (ADS)
Suttle, Martin D.; Genge, Matthew J.
2017-10-01
We report the discovery of fossil micrometeorites from Late Cretaceous chalk. Seventy-six cosmic spherules were recovered from Coniacian (87 ± 1 Ma) sediments of the White Chalk Supergroup. Particles vary from pristine silicate and iron-type spherules to pseudomorphic spherules consisting of either single-phase recrystallized magnetite or Fe-silicide. Pristine spherules are readily identified as micrometeorites on the basis of their characteristic mineralogies, textures and compositions. Both magnetite and silicide spherules contain dendritic crystals and spherical morphologies, testifying to rapid crystallisation of high temperature iron-rich metallic and oxide liquids. These particles also contain spherical cavities, representing weathering and removal of metal beads and irregular cavities, representing vesicles formed by trapped gas during crystallization; both features commonly found among modern Antarctic Iron-type (I-type) cosmic spherules. On the basis of textural analysis, the magnetite and Fe-silicide spherules are shown to be I-type cosmic spherules that have experienced complete secondary replacement during diagenesis (fossilization). Our results demonstrate that micrometeorites, preserved in sedimentary rocks, are affected by a suite of complex diagenetic processes, which can result in disparate replacement minerals, even within the same sequence of sedimentary beds. As a result, the identification of fossil micrometeorites requires careful observation of particle textures and comparisons with modern Antarctic collections. Replaced micrometeorites imply that geochemical signatures the extraterrestrial dust are subject to diagenetic remobilisation that limits their stratigraphic resolution. However, this study demonstrates that fossil, pseudomorphic micrometeorites can be recognised and are likely common within the geological record.
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Reading the medical record. I. Analysis of physicians' ways of reading the medical record.
Nygren, E; Henriksson, P
1992-01-01
Physicians were interviewed about their routines in everyday use of the medical record. From the interviews, we conclude that the medical record is a well functioning working instrument for the experienced physician. Using the medical record as a basis for decision making involves interpretation of format, layout and other textural features of the type-written data. Interpretation of these features provides effective guidance in the process of searching, reading and assessing the relevance of different items of information in the record. It seems that this is a skill which is an integrated part of diagnostic expertise. This skill plays an important role in decision making based on the large amount of information about a patient, which is exhibited to the reader in the medical record. This finding has implications for the design of user interfaces for reading computerized medical records.
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NASA Astrophysics Data System (ADS)
Budzyń, Bartosz; Sláma, Jiří; Kozub-Budzyń, Gabriela A.; Konečný, Patrik; Holický, Ivan; Rzepa, Grzegorz; Jastrzębski, Mirosław
2018-06-01
The application of zircon and xenotime geochronometers requires knowledge of their potential and limitations related to possible disturbance of the age record. The alteration of the intergrown zircon and xenotime in pegmatite from the Góry Sowie Block (SW Poland) was studied using the electron microprobe analysis, X-ray WDS compositional mapping, micro-Raman analysis, and LA-ICP-MS U-Pb dating of zircon and xenotime, as well as the U-Th-total Pb dating of uraninite. These microanalytical techniques were applied to understand the formation mechanisms of the secondary textures related to post-magmatic processes in the zircon and xenotime intergrowth, and to constrain their timing. Textural and compositional features combined with U-Pb data indicate that the pegmatite-related crystallization of the zircon and xenotime intergrowth occurred ca. 2.09 Ga (2086 ± 35 Ma for zircon and 2093 ± 52 Ma for xenotime), followed by the re-equilibration of zircon and xenotime ca. 370 Ma (373 ± 18 Ma and 368 ± 6 Ma, respectively) during the formation of the younger pegmatite. The zircon and xenotime were most likely derived from Precambrian basement rocks and emplaced in the pegmatite as a restite. The zircon preserved textures related to diffusion-reaction processes that affected its high-U core (up to ca. 9.6 wt% UO2), which underwent further metamictization and amorphization due to self-radiation damage. The zircon rim and xenotime were affected by coupled dissolution-reprecipitation processes that resulted in patchy zoning, age disturbance and sponge-like textures. Xenotime was also partially replaced by fluorapatite or hingganite-(Y) and Y-enriched allanite-(Ce). The termination of the low-temperature alteration was constrained by the U-Th-total Pb age of the uraninite inclusions that crystallized in zircon at 281 ± 2 Ma, which is consistent with the age of 278 ± 15 Ma obtained from the youngest cluster of U-Pb ages in the re-equilibrated high-U zircon domains. This study demonstrates the importance of the careful examination of compositional, microtextural and geochronological data obtained using microanalytical techniques to reconstruct the complex thermal histories recorded by accessory minerals.
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Barron, Andrew; Srinivasan, Mandyam V
2006-03-01
There is now increasing evidence that honey bees regulate their ground speed in flight by holding constant the speed at which the image of the environment moves across the eye (optic flow). We have investigated the extent to which ground speed is affected by headwinds. Honey bees were trained to enter a tunnel to forage at a sucrose feeder placed at its far end. Ground speeds in the tunnel were recorded while systematically varying the visual texture of the tunnel, and the strength of headwinds experienced by the flying bees. We found that in a flight tunnel bees used visual cues to maintain their ground speed, and adjusted their air speed to maintain a constant rate of optic flow, even against headwinds which were, at their strongest, 50% of a bee's maximum recorded forward velocity. Manipulation of the visual texture revealed that headwind is compensated almost fully even when the optic flow cues are very sparse and subtle, demonstrating the robustness of this visual flight control system. We discuss these findings in the context of field observations of flying bees.
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Evidence Integration in Natural Acoustic Textures during Active and Passive Listening
Rupp, Andre; Celikel, Tansu
2018-01-01
Abstract Many natural sounds can be well described on a statistical level, for example, wind, rain, or applause. Even though the spectro-temporal profile of these acoustic textures is highly dynamic, changes in their statistics are indicative of relevant changes in the environment. Here, we investigated the neural representation of change detection in natural textures in humans, and specifically addressed whether active task engagement is required for the neural representation of this change in statistics. Subjects listened to natural textures whose spectro-temporal statistics were modified at variable times by a variable amount. Subjects were instructed to either report the detection of changes (active) or to passively listen to the stimuli. A subset of passive subjects had performed the active task before (passive-aware vs passive-naive). Psychophysically, longer exposure to pre-change statistics was correlated with faster reaction times and better discrimination performance. EEG recordings revealed that the build-up rate and size of parieto-occipital (PO) potentials reflected change size and change time. Reduced effects were observed in the passive conditions. While P2 responses were comparable across conditions, slope and height of PO potentials scaled with task involvement. Neural source localization identified a parietal source as the main contributor of change-specific potentials, in addition to more limited contributions from auditory and frontal sources. In summary, the detection of statistical changes in natural acoustic textures is predominantly reflected in parietal locations both on the skull and source level. The scaling in magnitude across different levels of task involvement suggests a context-dependent degree of evidence integration. PMID:29662943
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Textural and mineral chemistry constraints on evolution of Merapi Volcano, Indonesia
NASA Astrophysics Data System (ADS)
Innocenti, Sabrina; del Marmol, Mary-Ann; Voight, Barry; Andreastuti, Supriyati; Furman, Tanya
2013-07-01
We analyze and compare the textures of Merapi lavas (basalts and basaltic andesites) ranging in age from Proto-Merapi through modern activity, with the goal of gaining insights on the temporal evolution of Merapi's magmatic system. Analysis of textural parameters, such as phenocryst and microphenocryst crystallinity, coupled with crystal size distribution theory, provides information about the storage and transport of magmas. We combine textural analyses with geochemical investigations for a comprehensive comparison of erupted lavas over time. The chemical analyses identify crystal growth processes in magma chambers and underline differences between sample groups. Our work suggests the occurrence of two distinct histories, presumably associated with (at least) two generally distinct types of rheological behaviors and storage/transport systems. These behaviors are associated with different plagioclase growth patterns, with both groups influenced by late-stage shallow decompression degassing-induced microlite crystallization. Both groups contain amphibole crystals that indicate an early period of mid-crustal to deep-crustal storage of water-rich magmas. Dome lavas from the 20th century eruptive activity indicate quasi-steady-state nucleation-and-growth evolution interspersed with episodes of reheating and textural coarsening, suggesting residence in magma storage at multiple depths, both > 10 km, and < 10 km, while samples from the older stratigraphic history of Merapi record both repeated attainment and loss of quasi-steady-state conditions. These observations, coupled with our companion study of Merapi tephra samples, suggest that the relatively benign type of activity observed in the 20th century will be interrupted from time to time in the future by more explosive eruptions, such as that of 2010.
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Evidence Integration in Natural Acoustic Textures during Active and Passive Listening.
Górska, Urszula; Rupp, Andre; Boubenec, Yves; Celikel, Tansu; Englitz, Bernhard
2018-01-01
Many natural sounds can be well described on a statistical level, for example, wind, rain, or applause. Even though the spectro-temporal profile of these acoustic textures is highly dynamic, changes in their statistics are indicative of relevant changes in the environment. Here, we investigated the neural representation of change detection in natural textures in humans, and specifically addressed whether active task engagement is required for the neural representation of this change in statistics. Subjects listened to natural textures whose spectro-temporal statistics were modified at variable times by a variable amount. Subjects were instructed to either report the detection of changes (active) or to passively listen to the stimuli. A subset of passive subjects had performed the active task before (passive-aware vs passive-naive). Psychophysically, longer exposure to pre-change statistics was correlated with faster reaction times and better discrimination performance. EEG recordings revealed that the build-up rate and size of parieto-occipital (PO) potentials reflected change size and change time. Reduced effects were observed in the passive conditions. While P2 responses were comparable across conditions, slope and height of PO potentials scaled with task involvement. Neural source localization identified a parietal source as the main contributor of change-specific potentials, in addition to more limited contributions from auditory and frontal sources. In summary, the detection of statistical changes in natural acoustic textures is predominantly reflected in parietal locations both on the skull and source level. The scaling in magnitude across different levels of task involvement suggests a context-dependent degree of evidence integration.
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NASA Astrophysics Data System (ADS)
Sai, Hitoshi; Matsui, Takuya; Koida, Takashi; Matsubara, Koji; Kondo, Michio; Sugiyama, Shuichiro; Katayama, Hirotaka; Takeuchi, Yoshiaki; Yoshida, Isao
2015-05-01
We report a high-efficiency triple-junction thin-film silicon solar cell fabricated with the so-called substrate configuration. It was verified whether the design criteria for developing single-junction microcrystalline silicon (μc-Si:H) solar cells are applicable to multijunction solar cells. Furthermore, a notably high short-circuit current density of 32.9 mA/cm2 was achieved in a single-junction μc-Si:H cell fabricated on a periodically textured substrate with a high-mobility front transparent contacting layer. These technologies were also combined into a-Si:H/μc-Si:H/μc-Si:H triple-junction cells, and a world record stabilized efficiency of 13.6% was achieved.
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Feldspar 40Ar/39Ar dating of ICDP PALEOVAN cores
NASA Astrophysics Data System (ADS)
Engelhardt, Jonathan Franz; Sudo, Masafumi; Stockhecke, Mona; Oberhänsli, Roland
2017-11-01
Volcaniclastic fall deposits in ICDP drilling cores from Lake Van, Turkey, contain sodium-rich sanidine and calcium-rich anorthoclase, which both comprise a variety of textural zoning and inclusions. An age model records the lake's history and is based on climate-stratigraphic correlations, tephrostratigraphy, paleomagnetics, and earlier 40Ar/39Ar analyses (Stockhecke et al., 2014b). Results from total fusion and stepwise heating 40Ar/39Ar analyses presented in this study allow for the comparison of radiometric constraints from texturally diversified feldspar and the multi-proxy lacustrine age model and vice versa. This study has investigated several grain-size fractions of feldspar from 13 volcaniclastic units. The feldspars show textural features that are visible in cathodoluminescence (CL) or back-scattered electron (BSE) images and can be subdivided into three dominant zoning-types: (1) compositional zoning, (2) round pseudo-oscillatory zoning and (3) resorbed and patchy zoning (Ginibre et al., 2004). Round pseudo-oscillatory zoning records a sensitive alternation of Fe and Ca that also reflects resorption processes. This is only visible in CL images. Compositional zoning reflects anticorrelated anorthite and orthoclase contents and is visible in BSE. Eleven inverse isochron ages from total fusion and three from stepwise heating analyses fit the age model. Four experiments resulted in older inverse isochron ages that do not concur with the model within 2σ uncertainties and that deviate from 1 ka to 17 ka minimum. C- and R-type zoning are interpreted as representing growth in magma chamber cupolas, as wall mushes, or in narrow conduits. Persistent compositions of PO-type crystals and abundant surfaces recording dissolution features correspond to formation within a magma chamber. C-type zoning and R-type zoning have revealed an irregular incorporation of melt and fluid inclusions. These two types of zoning in feldspar are interpreted as preferentially contributing either heterogeneously distributed excess 40Ar or inherited 40Ar to the deviating 40Ar/39Ar ages that are discussed in this study.
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Gao, Shan; Liao, Quanwen; Liu, Wei; Liu, Zhichun
2017-10-31
Recently, numerous studies focused on the wetting process of droplets on various surfaces at a microscale level. However, there are a limited number of studies about the mechanism of condensation on patterned surfaces. The present study performed the dynamic wetting behavior of water droplets and condensation process of water molecules on substrates with different pillar structure parameters, through molecular dynamic simulation. The dynamic wetting results indicated that droplets exhibit Cassie state, PW state, and Wenzel state successively on textured surfaces with decreasing solid fraction. The droplets possess a higher static contact angle and a smaller spreading exponent on textured surfaces than those on smooth surfaces. The condensation processes, including the formation, growth, and coalescence of a nanodroplet, are simulated and quantitatively recorded, which are difficult to be observed by experiments. In addition, a wetting transition and a dewetting transition were observed and analyzed in condensation on textured surfaces. Combining these simulation results with previous theoretical and experimental studies will guide us to understand the hypostasis and mechanism of the condensation more clearly.
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The Effect of Interface Texture on Exchange Biasing in Ni(80)Fe(20)/Ir(20)Mn(80) System.
Chen, Yuan-Tsung
2009-01-01
Exchange-biasing phenomenon can induce an evident unidirectional hysteresis loop shift by spin coupling effect in the ferromagnetic (FM)/antiferromagnetic (AFM) interface which can be applied in magnetoresistance random access memory (MRAM) and recording-head applications. However, magnetic properties are the most important to AFM texturing. In this work, top-configuration exchange-biasing NiFe/IrMn(x A) systems have been investigated with three different conditions. From the high-resolution cross-sectional transmission electron microscopy (HR X-TEM) and X-ray diffraction results, we conclude that the IrMn (111) texture plays an important role in exchange-biasing field (H(ex)) and interfacial exchange energy (J(k)). H(ex) and J(k) tend to saturate when the IrMn thickness increases. Moreover, the coercivity (H(c)) dependence on IrMn thickness is explained based on the coupling or decoupling effect between the spins of the NiFe and IrMn layers near the NiFe/IrMn interface. In this work, the optimal values for H(ex) and J(k) are 115 Oe and 0.062 erg/cm(2), respectively.
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NASA Astrophysics Data System (ADS)
Faryad, S. W.; Jedlicka, R.; Hauzenberger, C.; Racek, M.
2018-03-01
Mafic layers displaying transition between clinopyroxenite and eclogite within peridotite from felsic granulite in the Bohemian Massif (Lower Austria) have been investigated. The mafic-ultramafic bodies shared a common granulite facies metamorphism with its hosting felsic rocks, but they still preserve evidence of eclogite facies metamorphism. The selected mafic layer for this study is represented by garnet with omphacite in the core of coarse-grained clinopyroxene, while fine-grained clinopyroxene in the matrix is diopside. In addition, garnet contains inclusions of omphacite, alkali feldspars, hydrous and other phases with halogens and/or CO2. Textural relations along with compositional zoning in garnet from the clinopyroxenite-eclogite layers favour solid-state recrystallization of the precursor minerals in the inclusions and formation of garnet and omphacite during subduction. Textures and major and trace element distribution in garnet indicate two stages of garnet growth that record eclogite facies and subsequent granulite facies overprint. The possible model explaining the textural and compositional changes of minerals is that the granulite facies overprint occurred after formation and exhumation of the eclogite facies rocks.
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NASA Technical Reports Server (NTRS)
Simon, J. I.; Simon, S. B.; Nguyen, A. N.; Ross, D. K.; Messenger, S.
2017-01-01
We conducted NanoSIMS O-isotopic imaging of a primitive spinel-rich CAI spherule (27-2) from the MIL 090019 CO3 chondrite. Inclusions such as 27-2 are proposed to record inner nebula processes during an epoch of rapid solar nebula evolution. Mineralogical and textural analyses suggest that this CAI formed by high temperature reactions, partial melting, and condensation. This CAI exhibits radial O-isotopic heterogeneity among multiple occurrences of the same mineral, reflecting interactions with distinct nebular O-isotopic reservoirs.
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Constantino, Paul J; Borrero-Lopez, Oscar; Pajares, Antonia; Lawn, Brian R
2016-01-01
The deformation and wear events that underlie microwear and macrowear signals commonly used for dietary reconstruction in fossil animals can be replicated and quantified by controlled laboratory tests on extracted tooth specimens in conjunction with fundamental micromechanics analysis. Key variables governing wear relations include angularity, stiffness (modulus), and size of the contacting particle, along with material properties of enamel. Both axial and sliding contacts can result in the removal of tooth enamel. The degree of removal, characterized by a "wear coefficient," varies strongly with particle content at the occlusal interface. Conditions leading to a transition from mild to severe wear are discussed. Measurements of wear traces can provide information about contact force and particle shape. The potential utility of the micromechanics methodology as an adjunct for investigating tooth durability and reconstructing diet is explored. © 2015 WILEY Periodicals, Inc.
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NASA Astrophysics Data System (ADS)
Edward Anand, E.; Natarajan, S.
2015-01-01
Cobalt-Tungsten (Co-W) alloy coatings possessing high hardness and wear/corrosion resistance, due to their ecofriendly processing, have been of interest to the researchers owing to its various industrial applications in automobile, aerospace, and machine parts. This technical paper reports Co-W alloy coatings dispersed with multiwalled carbon nanotubes (MWCNTs) produced by pulse electrodeposition from aqueous bath involving cobalt sulfate, sodium tungstate, and citric acid on stainless steel substrate (SS316). Studies on surface morphology through SEM, microhardness by Vickers method, microwear by pin-on-disk method, and corrosion behavior through potentiodynamic polarization method for the Co-W-CNT coatings were reported. Characterization studies were done by SEM and EDX analysis. The results showed that the corrosion and tribological properties of the pulse-electrodeposited Co-W-CNT alloy coatings were greatly influenced by its morphology, microhardness, %W, and MWCNT content in the coatings.
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NASA Astrophysics Data System (ADS)
Mockford, T.; Zobeck, T. M.; Lee, J. A.; Gill, T. E.; Dominguez, M. A.; Peinado, P.
2012-12-01
Understanding the controls of mineral dust emissions and their particle size distributions during wind-erosion events is critical as dust particles play a significant impact in shaping the earth's climate. It has been suggested that emission rates and particle size distributions are independent of soil chemistry and soil texture. In this study, 45 samples of wind-erodible surface soils from the Southern High Plains and Chihuahuan Desert regions of Texas, New Mexico, Colorado and Chihuahua were analyzed by the Lubbock Dust Generation, Analysis and Sampling System (LDGASS) and a Beckman-Coulter particle multisizer. The LDGASS created dust emissions in a controlled laboratory setting using a rotating arm which allows particle collisions. The emitted dust was transferred to a chamber where particulate matter concentration was recorded using a DataRam and MiniVol filter and dust particle size distribution was recorded using a GRIMM particle analyzer. Particle size analysis was also determined from samples deposited on the Mini-Vol filters using a Beckman-Coulter particle multisizer. Soil textures of source samples ranged from sands and sandy loams to clays and silts. Initial results suggest that total dust emissions increased with increasing soil clay and silt content and decreased with increasing sand content. Particle size distribution analysis showed a similar relationship; soils with high silt content produced the widest range of dust particle sizes and the smallest dust particles. Sand grains seem to produce the largest dust particles. Chemical control of dust emissions by calcium carbonate content will also be discussed.
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Soil moisture data as a constraint for groundwater recharge estimation
NASA Astrophysics Data System (ADS)
Mathias, Simon A.; Sorensen, James P. R.; Butler, Adrian P.
2017-09-01
Estimating groundwater recharge rates is important for water resource management studies. Modeling approaches to forecast groundwater recharge typically require observed historic data to assist calibration. It is generally not possible to observe groundwater recharge rates directly. Therefore, in the past, much effort has been invested to record soil moisture content (SMC) data, which can be used in a water balance calculation to estimate groundwater recharge. In this context, SMC data is measured at different depths and then typically integrated with respect to depth to obtain a single set of aggregated SMC values, which are used as an estimate of the total water stored within a given soil profile. This article seeks to investigate the value of such aggregated SMC data for conditioning groundwater recharge models in this respect. A simple modeling approach is adopted, which utilizes an emulation of Richards' equation in conjunction with a soil texture pedotransfer function. The only unknown parameters are soil texture. Monte Carlo simulation is performed for four different SMC monitoring sites. The model is used to estimate both aggregated SMC and groundwater recharge. The impact of conditioning the model to the aggregated SMC data is then explored in terms of its ability to reduce the uncertainty associated with recharge estimation. Whilst uncertainty in soil texture can lead to significant uncertainty in groundwater recharge estimation, it is found that aggregated SMC is virtually insensitive to soil texture.
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Realization of memory effect in smectic X* phase
NASA Astrophysics Data System (ADS)
Kishor, Murthynedi Hari; Madhu Mohan, M. L. N.
2018-09-01
Homologous series of DTA + nBA (where n varies from 2 to 8) comprises of seven homologues, out of which DTA+4BA alone exhibits a new smectic ordering labelled as smectic X*. Hence DTA+4BA is chosen to investigate various chemical, thermal optical and electrical studies. DSC thermograms reveal the transition temperature and enthalpy values of smectic X* phase. FTIR spectroscopy confirms the formation of hydrogen bonding. Variation of tilt angle with temperature is studied and fitted to a power law confirming the Mean field theory predicted value. An interesting feature of this work is the observation of memory effect in smectic X* phase. When an external field is applied to the mesogen in smectic X* phase, the texture undergoes a change and remains invariant even after the field is removed, further the texture of the phase can be erased only by taking it to isotropic temperature. Another proof for memory effect is the dielectric hysteresis in smectic X* recorded with field. Helix in smectic X* is reported. Yet another interesting observation is the identification of parachromatism in smectic X* phase namely the textures remain the same while the colour of the textures changes completely with decrement in the temperature of the mesogen. Dielectric relaxations in Goldstone mode are studied and analyzed with Cole-Cole plots. The relaxation is suppressed on application of field indicative of Arrhenius in nature.
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The Time Course of Segmentation and Cue-Selectivity in the Human Visual Cortex
Appelbaum, Lawrence G.; Ales, Justin M.; Norcia, Anthony M.
2012-01-01
Texture discontinuities are a fundamental cue by which the visual system segments objects from their background. The neural mechanisms supporting texture-based segmentation are therefore critical to visual perception and cognition. In the present experiment we employ an EEG source-imaging approach in order to study the time course of texture-based segmentation in the human brain. Visual Evoked Potentials were recorded to four types of stimuli in which periodic temporal modulation of a central 3° figure region could either support figure-ground segmentation, or have identical local texture modulations but not produce changes in global image segmentation. The image discontinuities were defined either by orientation or phase differences across image regions. Evoked responses to these four stimuli were analyzed both at the scalp and on the cortical surface in retinotopic and functional regions-of-interest (ROIs) defined separately using fMRI on a subject-by-subject basis. Texture segmentation (tsVEP: segmenting versus non-segmenting) and cue-specific (csVEP: orientation versus phase) responses exhibited distinctive patterns of activity. Alternations between uniform and segmented images produced highly asymmetric responses that were larger after transitions from the uniform to the segmented state. Texture modulations that signaled the appearance of a figure evoked a pattern of increased activity starting at ∼143 ms that was larger in V1 and LOC ROIs, relative to identical modulations that didn't signal figure-ground segmentation. This segmentation-related activity occurred after an initial response phase that did not depend on the global segmentation structure of the image. The two cue types evoked similar tsVEPs up to 230 ms when they differed in the V4 and LOC ROIs. The evolution of the response proceeded largely in the feed-forward direction, with only weak evidence for feedback-related activity. PMID:22479566
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Clumped Isotope Records of Environmental Change and Diagenesis at the Onset of the Cryogenian
NASA Astrophysics Data System (ADS)
Mackey, T.; Bergmann, K.; Jost, A. B.; Cantine, M.; Wilcots, J.
2017-12-01
Carbonate strata from NE Spitsbergen and W Nordaustlandet, Svalbard, provide a window into changing depositional environments and sediment diagenesis through the Neoproterozoic. Our data bracket climate perturbations including the Sturtian and Marinoan Snowball Earth, and these sections have also experienced a range of burial and alteration histories. Comparison of clumped isotope values (Δ47) in specific petrographic textures and mineralogies provides a test for post-depositional alteration. Specifically, we focus on strata across globally correlated carbon isotope excursions (CIE) and within carbonate conglomerates to constrain changes in Δ47 through time. Calcites across sections from the onset of the Cryogenian typically record higher temperatures than co-occurring dolomites, consistent with calcite and dolomite reordering kinetics. In the most extreme cases, both depositional and burial calcites record equilibration above the closure temperature for calcites, but dolomite temperatures calculated from Δ47 values indicate that they have not been fully reordered. For example, stratigraphic variation in Δ47 values exceeds 40°C ( 60-100°C) from the pre-Sturtian Russøya Member of the Elbobreen Formation. Such variability could reflect preferential alteration of specific textures or changes in temperature associated with dolomite precipitation. Carbonate strata have also been resedimented as clasts in overriding Sturtian diamictites, and comparison of clasts to underlying stratigraphy and carbonate matrix provide a test for the source and timing of stratigraphic variations in Δ47 values. In a single location dolomite clasts record temperatures varying by >20°C ( 60-80°C), and clast-associated dolomicrite matrix records temperatures as low as 20-30°C. Together, these data indicate that at least some component of the Δ47 signal reflects differences in attributes of the dolomites prior to the Sturtian glaciation.
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Cheng, Nai-Ming; Fang, Yu-Hua Dean; Lee, Li-yu; Chang, Joseph Tung-Chieh; Tsan, Din-Li; Ng, Shu-Hang; Wang, Hung-Ming; Liao, Chun-Ta; Yang, Lan-Yan; Hsu, Ching-Han; Yen, Tzu-Chen
2015-03-01
The question as to whether the regional textural features extracted from PET images predict prognosis in oropharyngeal squamous cell carcinoma (OPSCC) remains open. In this study, we investigated the prognostic impact of regional heterogeneity in patients with T3/T4 OPSCC. We retrospectively reviewed the records of 88 patients with T3 or T4 OPSCC who had completed primary therapy. Progression-free survival (PFS) and disease-specific survival (DSS) were the main outcome measures. In an exploratory analysis, a standardized uptake value of 2.5 (SUV 2.5) was taken as the cut-off value for the detection of tumour boundaries. A fixed threshold at 42 % of the maximum SUV (SUVmax 42 %) and an adaptive threshold method were then used for validation. Regional textural features were extracted from pretreatment (18)F-FDG PET/CT images using the grey-level run length encoding method and grey-level size zone matrix. The prognostic significance of PET textural features was examined using receiver operating characteristic (ROC) curves and Cox regression analysis. Zone-size nonuniformity (ZSNU) was identified as an independent predictor of PFS and DSS. Its prognostic impact was confirmed using both the SUVmax 42 % and the adaptive threshold segmentation methods. Based on (1) total lesion glycolysis, (2) uniformity (a local scale texture parameter), and (3) ZSNU, we devised a prognostic stratification system that allowed the identification of four distinct risk groups. The model combining the three prognostic parameters showed a higher predictive value than each variable alone. ZSNU is an independent predictor of outcome in patients with advanced T-stage OPSCC, and may improve their prognostic stratification.
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Potter-McIntyre, Sally L; Chan, Marjorie A; McPherson, Brian J
2014-01-01
Iron (oxyhydr)oxide microbial mats in modern to ∼100 ka tufa terraces are present in a cold spring system along Ten Mile Graben, southeastern Utah, USA. Mats exhibit morphological, chemical, and textural biosignatures and show diagenetic changes that occur over millennial scales. The Jurassic Brushy Basin Member of the Morrison Formation in the Four Corners region of the USA also exhibits comparable microbial fossils and iron (oxyhydr)oxide biosignatures in the lacustrine unit. Both the modern spring system and Brushy Basin Member represent alkaline, saline, groundwater-fed systems and preserve diatoms and other similar algal forms with cellular elaboration. Two distinct suites of elements (1. C, Fe, As and 2. C, S, Se, P) are associated with microbial fossils in modern and ancient iron (oxyhydr)oxides and may be potential markers for biosignatures. The presence of ferrihydrite in ∼100 ka fossil microbial mats and Jurassic rocks suggests that this thermodynamically unstable mineral may also be a potential biomarker. One of the most extensive sedimentary records on Mars is exposed in Gale Crater and consists of non-acidic clays and sulfates possibly of lacustrine origin. These terrestrial iron (oxyhydr)oxide examples are a valuable analogue because of similar iron- and clay-rich host rock compositions and will help (1) understand diagenetic processes in a non-acidic, saline lacustrine environment such as the sedimentary rocks in Gale Crater, (2) document specific biomediated textures, (3) demonstrate how biomediated textures might persist or respond to diagenesis over time, and (4) provide a ground truth library of textures to explore and compare in extraterrestrial iron (oxyhydr)oxides, where future explorations hope to detect past evidence of life.
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NASA Astrophysics Data System (ADS)
Stefanov, W. L.; Stefanov, W. L.; Christensen, P. R.
2001-05-01
Land cover and land use changes associated with urbanization are important drivers of global ecologic and climatic change. Quantification and monitoring of these changes are part of the primary mission of the ASTER instrument, and comprise the fundamental research objective of the Urban Environmental Monitoring (UEM) Program. The UEM program will acquire day/night, visible through thermal infrared ASTER data twice per year for 100 global urban centers over the duration of the mission (6 years). Data are currently available for a number of these urban centers and allow for initial comparison of global city structure using spatial variance texture analysis of the 15 m/pixel visible to near infrared ASTER bands. Variance texture analysis highlights changes in pixel edge density as recorded by sharp transitions from bright to dark pixels. In human-dominated landscapes these brightness variations correlate well with urbanized vs. natural land cover and are useful for characterizing the geographic extent and internal structure of cities. Variance texture analysis was performed on twelve urban centers (Albuquerque, Baghdad, Baltimore, Chongqing, Istanbul, Johannesburg, Lisbon, Madrid, Phoenix, Puebla, Riyadh, Vancouver) for which cloud-free daytime ASTER data are available. Image transects through each urban center produce texture profiles that correspond to urban density. These profiles can be used to classify cities into centralized (ex. Baltimore), decentralized (ex. Phoenix), or intermediate (ex. Madrid) structural types. Image texture is one of the primary data inputs (with vegetation indices and visible to thermal infrared image spectra) to a knowledge-based land cover classifier currently under development for application to ASTER UEM data as it is acquired. Collaboration with local investigators is sought to both verify the accuracy of the knowledge-based system and to develop more sophisticated classification models.
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Shen, Wei-Chih; Chen, Shang-Wen; Liang, Ji-An; Hsieh, Te-Chun; Yen, Kuo-Yang; Kao, Chia-Hung
2017-09-01
In this study, we investigated the correlation between the lymph node (LN) status or histological types and textural features of cervical cancers on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. We retrospectively reviewed the imaging records of 170 patients with International Federation of Gynecology and Obstetrics stage IB-IVA cervical cancer. Four groups of textural features were studied in addition to the maximum standardized uptake value (SUV max ), metabolic tumor volume, and total lesion glycolysis (TLG). Moreover, we studied the associations between the indices and clinical parameters, including the LN status, clinical stage, and histology. Receiver operating characteristic curves were constructed to evaluate the optimal predictive performance among the various textural indices. Quantitative differences were determined using the Mann-Whitney U test. Multivariate logistic regression analysis was performed to determine the independent factors, among all the variables, for predicting LN metastasis. Among all the significant indices related to pelvic LN metastasis, homogeneity derived from the gray-level co-occurrence matrix (GLCM) was the sole independent predictor. By combining SUV max , the risk of pelvic LN metastasis can be scored accordingly. The TLG mean was the independent feature of positive para-aortic LNs. Quantitative differences between squamous and nonsquamous histology can be determined using short-zone emphasis (SZE) from the gray-level size zone matrix (GLSZM). This study revealed that in patients with cervical cancer, pelvic or para-aortic LN metastases can be predicted by using textural feature of homogeneity from the GLCM and TLG mean, respectively. SZE from the GLSZM is the sole feature associated with quantitative differences between squamous and nonsquamous histology.
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From Mush to Eruption in 1000 Years: Rapid Assembly of the Super-Sized Oruanui Magma Body
NASA Astrophysics Data System (ADS)
Allan, A. S.; Morgan, D. J.; Wilson, C. J.; Millet, M.
2012-12-01
The mush model is useful in explaining how large volumes of evolved silicic melt can be generated in and extracted from a crystal-rich source to form crystal-poor rhyolite magma bodies at shallow crustal levels. It is unclear, however, how processes of melt extraction and/or formation of the melt-dominant magma body might be reflected in the crystal record, and what physical and temporal constraints can be applied. Textural observations and in situ geochemical fingerprints in crystals from pumices of the ~25.4 ka Oruanui eruption (Taupo, New Zealand), offer new perspectives on the processes, physical conditions and timing of the melt extraction and accumulation. Almost all orthopyroxene (opx) and plagioclase (plag) cores have textures showing a period of disequilibrium (partial dissolution and/or resorption) followed by stable conditions (infilling of raddled cores; euhedral rim overgrowths). Trace element contents in amphibole (amph), which was stable and actively crystallizing in all but the most evolved parcels of Oruanui magma, complement textural evidence showing that Mn and Zn liberated by opx dissolution were preferentially sequestered in amph. Concentrations of these opx-loving elements show a prominent inflection when plotted against indices of melt evolution (e.g. Eu/Eu* in amph) marking a return to opx stability and subsequent crystallization. Plagioclase, the most abundant crystal phase, records a more complex history with significant inheritance, but textural and chemical evidence suggests that at least some of Oruanui plag crystals experienced the same departure from and return to stability as the opx. Amphibole trace element data are linked to in situ estimates of P-T-fO2 and melt H2O determined via the Ridolfi et al. (2010: Contrib Mineral Petrol 160, 45) thermobarometer. Textural and geochemical evidence combined with P-T-H2O model values indicate that three major Oruanui crystal phases (opx, amph, plag) record a significant decompression event (from ~250 to ~150 MPa) with associated cooling (from ~900 to 820°C) coupled with the destabilization of opx. We interpret this event to reflect the extraction of rhyolitic melt plus crystals from a mush-like reservoir to form the Oruanui melt-dominant body. This body grew within model pressures of 90-150 MPa (~4-6 km depth) held at 760-800°C, with a generally homogeneous melt composition, as reflected in the consistent rim compositions of the three mineral phases. Fe-Mg diffusion modelling of core-rim boundaries in opx implies that accumulation of the ~530 km3 melt dominant body began only ca. 1000 years before eruption. The traditionally envisaged quasi-static drivers of the mush model (crystal settling, gas sparging, etc.) are difficult to reconcile with the rapidity of this timeframe, and a more dynamic, external influence (e.g. from extensional tectonics) is implied.
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Paleoenvironmental basis of cognitive evolution in great apes.
Potts, Richard
2004-03-01
A bias favoring tree-dominated habitats and ripe-fruit frugivory has persisted in great ape evolution since the early Miocene. This bias is indicated by fossil ape paleoenvironments, molar morphology, dental microwear, the geographic pattern of extinctions, and extant apes' reliance on wooded settings. The ephemeral aspect of high-quality fruit has placed a premium on cognitive and social means of finding and defending food sources, and appears related to great apes' affinity since the Miocene for wooded, fruit-rich environments. These habitats have, however, undergone a severe withdrawal toward the low latitudes of Africa and Southeast Asia since the late Miocene, corresponding to a decline in the diversity of great apes beginning 9.5 million years ago. Plio-Pleistocene records imply that wooded settings of Africa and SE Asia were prone to substantial fragmentation and coalescence. Once apes were confined to equatorial settings, therefore, habitat instability heightened the spatial/temporal uncertainty of ripe-fruit sources. Prolonged learning, the assignment of attributes to distant places, mental representation, and reliance on fallback foods were all favored in this dynamic environmental context. These abilities helped sustain forest frugivory in most lineages. Fluid social grouping afforded the animals opportunities to locate ephemeral foods in continuous and fragmented forests. Fission-fusion grouping also magnified the problems of object impermanence (of individuals) and dispersion manifested by food sources in the ecological realm. Thus the spatial and temporal dynamics of fruit and wooded habitats since the Miocene are reflected in important components of great ape cognition, foraging, and sociality. In contrast to great apes, cercopithecoid monkeys have increased their plant dietary options and diversified in seasonal environments since the late Miocene. Early hominins eventually severed the habitat bias that characterized the evolution of great apes, and later expanded into diverse environments. Copyright 2004 Wiley-Liss, Inc.
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Merkin, Grigory V; Stien, Lars Helge; Pittman, Karin; Nortvedt, Ragnar
2014-06-01
Commercially collected records of Atlantic salmon (Salmo salar L.) muscle texture hardness were used to evaluate the effect of slaughter procedures and seasonality on texture quality. A database collected by Marine Harvest® contained flesh hardness records of Atlantic salmon slaughtered at processing plants in Norway from summer 2010 to summer 2011. The fish were slaughtered either by (1) percussion followed by automated bleeding ("Percussive") or (2) live chilling with exposure to carbon dioxide (CO2 ) followed by manual severing gill arches and bleeding ("CO2 ") or (3) live chilling with exposure to CO2 followed by percussive stunning and at the end automated bleeding ("CO2 ·percussive"). Hardness in salmon muscle cutlets was measured in Newtons (N) by Materials Testing Machine Zwick 500N. The hardness in salmon varied significantly over the study period (P < 0.05, mixed effect model) and showed the softest value of 21.2 (± 0.7) Newton (N) in summer 2011 and hardest 24.1 (± 0.2) N in autumn 2010. Slaughter procedures had a significant effect on salmon muscle hardness (P < 0.05, mixed effect model), where percussion followed by automated bleeding resulted in the hardest value (24.0 ± 0.4 N) as compared with CO2 stunning (21.8 ± 0.2 N) and combination of CO2 and percussive stunning (23.1 ± 0.15 N). CO2 is suspected as a causal factor in accelerated postmortem softening of the salmon muscle. Commercial use of CO2 in combination with live chilling results in accelerated postmortem softening of the muscle tissue in salmon and should be avoided. © 2014 Institute of Food Technologists®
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Military personnel recognition system using texture, colour, and SURF features
NASA Astrophysics Data System (ADS)
Irhebhude, Martins E.; Edirisinghe, Eran A.
2014-06-01
This paper presents an automatic, machine vision based, military personnel identification and classification system. Classification is done using a Support Vector Machine (SVM) on sets of Army, Air Force and Navy camouflage uniform personnel datasets. In the proposed system, the arm of service of personnel is recognised by the camouflage of a persons uniform, type of cap and the type of badge/logo. The detailed analysis done include; camouflage cap and plain cap differentiation using gray level co-occurrence matrix (GLCM) texture feature; classification on Army, Air Force and Navy camouflaged uniforms using GLCM texture and colour histogram bin features; plain cap badge classification into Army, Air Force and Navy using Speed Up Robust Feature (SURF). The proposed method recognised camouflage personnel arm of service on sets of data retrieved from google images and selected military websites. Correlation-based Feature Selection (CFS) was used to improve recognition and reduce dimensionality, thereby speeding the classification process. With this method success rates recorded during the analysis include 93.8% for camouflage appearance category, 100%, 90% and 100% rates of plain cap and camouflage cap categories for Army, Air Force and Navy categories, respectively. Accurate recognition was recorded using SURF for the plain cap badge category. Substantial analysis has been carried out and results prove that the proposed method can correctly classify military personnel into various arms of service. We show that the proposed method can be integrated into a face recognition system, which will recognise personnel in addition to determining the arm of service which the personnel belong. Such a system can be used to enhance the security of a military base or facility.
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Forde, C G; Leong, C; Chia-Ming, E; McCrickerd, K
2017-02-22
The structural properties of foods have a functional role to play in oral processing behaviours and sensory perception, and also impact on meal size and the experience of fullness. This study adopted a new approach by using behavioural coding analysis of eating behaviours to explore how a range of food textures manifest as the microstructural properties of eating and expectations of fullness. A selection of 47 Asian foods were served in fixed quantities to a panel of participants (N = 12) and their eating behaviours were captured via web-camera recordings. Behavioural coding analysis was completed on the recordings to extract total bites, chews and swallows and cumulative time of the food spent in the mouth. From these measurements a series of microstructural properties including average bite size (g), chews per bite, oro-sensory exposure time (seconds) and average eating rate (g min -1 ) were derived per food. The sensory and macronutrient properties of each food were correlated with the microstructure of eating to compare the differences in eating behaviour on a gram for gram basis. There were strong relationships between the perceived food textural properties and its eating behaviours and a food's total water content was the best predictor of its eating rate. Foods that were eaten at a slower eating rate, with smaller bites and more chews per bite were rated as higher in the expected fullness. These relationships are important as oral processing behaviours and beliefs about the potential satiating value of food influence portion decisions and moderate meal size. These data support the idea that naturally occurring differences in the food structure and texture could be used to design meals that slow the rate of eating and maximise fullness.
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Edinger, Janick; Pai, Dinesh K; Spering, Miriam
2017-01-01
The neural control of pursuit eye movements to visual textures that simultaneously translate and rotate has largely been neglected. Here we propose that pursuit of such targets-texture pursuit-is a fully three-dimensional task that utilizes all three degrees of freedom of the eye, including torsion. Head-fixed healthy human adults (n = 8) tracked a translating and rotating random dot pattern, shown on a computer monitor, with their eyes. Horizontal, vertical, and torsional eye positions were recorded with a head-mounted eye tracker. The torsional component of pursuit is a function of the rotation of the texture, aligned with its visual properties. We observed distinct behaviors between those trials in which stimulus rotation was in the same direction as that of a rolling ball ("natural") in comparison to those with the opposite rotation ("unnatural"): Natural rotation enhanced and unnatural rotation reversed torsional velocity during pursuit, as compared to torsion triggered by a nonrotating random dot pattern. Natural rotation also triggered pursuit with a higher horizontal velocity gain and fewer and smaller corrective saccades. Furthermore, we show that horizontal corrective saccades are synchronized with torsional corrective saccades, indicating temporal coupling of horizontal and torsional saccade control. Pursuit eye movements have a torsional component that depends on the visual stimulus. Horizontal and torsional eye movements are separated in the motor periphery. Our findings suggest that translational and rotational motion signals might be coordinated in descending pursuit pathways.
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NASA Astrophysics Data System (ADS)
Giuntoli, Francesco; Lanari, Pierre; Engi, Martin
2018-02-01
Contiguous continental high-pressure terranes in orogens offer insight into deep recycling and transformation processes that occur in subduction zones. These remain poorly understood, and currently debated ideas need testing. The approach we chose is to investigate, in detail, the record in suitable rock samples that preserve textures and robust mineral assemblages that withstood overprinting during exhumation. We document complex garnet zoning in eclogitic mica schists from the Sesia Zone (western Italian Alps). These retain evidence of two orogenic cycles and provide detailed insight into resorption, growth, and diffusion processes induced by fluid pulses in high-pressure conditions. We analysed local textures and garnet compositional patterns, which turned out remarkably complex. By combining these with thermodynamic modelling, we could unravel and quantify repeated fluid-rock interaction processes. Garnet shows low-Ca porphyroclastic cores that were stable under (Permian) granulite facies conditions. The series of rims that surround these cores provide insight into the subsequent evolution: the first garnet rim that surrounds the pre-Alpine granulite facies core in one sample indicates that pre-Alpine amphibolite facies metamorphism followed the granulite facies event. In all samples documented, cores show lobate edges and preserve inner fractures, which are sealed by high-Ca garnet that reflects high-pressure Alpine conditions. These observations suggest that during early stages of subduction, before hydration of the granulites, brittle failure of garnet occurred, indicating high strain rates that may be due to seismic failure. Several Alpine rims show conspicuous textures indicative of interaction with hydrous fluid: (a) resorption-dominated textures produced lobate edges, at the expense of the outer part of the granulite core; (b) peninsulas and atoll garnet are the result of replacement reactions; and (c) spatially limited resorption and enhanced transport of elements due to the fluid phase are evident along brittle fractures and in their immediate proximity. Thermodynamic modelling shows that all of these Alpine rims formed under eclogite facies conditions. Structurally controlled samples allow these fluid-garnet interaction phenomena to be traced across a portion of the Sesia Zone, with a general decrease in fluid-garnet interaction observed towards the external, structurally lower parts of the terrane. Replacement of the Permian HT assemblages by hydrate-rich Alpine assemblages can reach nearly 100 % of the rock volume. Since we found no clear relationship between discrete deformation structures (e.g. shear zones) observed in the field and the fluid pulses that triggered the transformation to eclogite facies assemblages, we conclude that disperse fluid flow was responsible for the hydration.
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Scholte, H Steven; Jolij, Jacob; Fahrenfort, Johannes J; Lamme, Victor A F
2008-11-01
In texture segregation, an example of scene segmentation, we can discern two different processes: texture boundary detection and subsequent surface segregation [Lamme, V. A. F., Rodriguez-Rodriguez, V., & Spekreijse, H. Separate processing dynamics for texture elements, boundaries and surfaces in primary visual cortex of the macaque monkey. Cerebral Cortex, 9, 406-413, 1999]. Neural correlates of texture boundary detection have been found in monkey V1 [Sillito, A. M., Grieve, K. L., Jones, H. E., Cudeiro, J., & Davis, J. Visual cortical mechanisms detecting focal orientation discontinuities. Nature, 378, 492-496, 1995; Grosof, D. H., Shapley, R. M., & Hawken, M. J. Macaque-V1 neurons can signal illusory contours. Nature, 365, 550-552, 1993], but whether surface segregation occurs in monkey V1 [Rossi, A. F., Desimone, R., & Ungerleider, L. G. Contextual modulation in primary visual cortex of macaques. Journal of Neuroscience, 21, 1698-1709, 2001; Lamme, V. A. F. The neurophysiology of figure ground segregation in primary visual-cortex. Journal of Neuroscience, 15, 1605-1615, 1995], and whether boundary detection or surface segregation signals can also be measured in human V1, is more controversial [Kastner, S., De Weerd, P., & Ungerleider, L. G. Texture segregation in the human visual cortex: A functional MRI study. Journal of Neurophysiology, 83, 2453-2457, 2000]. Here we present electroencephalography (EEG) and functional magnetic resonance imaging data that have been recorded with a paradigm that makes it possible to differentiate between boundary detection and scene segmentation in humans. In this way, we were able to show with EEG that neural correlates of texture boundary detection are first present in the early visual cortex around 92 msec and then spread toward the parietal and temporal lobes. Correlates of surface segregation first appear in temporal areas (around 112 msec) and from there appear to spread to parietal, and back to occipital areas. After 208 msec, correlates of surface segregation and boundary detection also appear in more frontal areas. Blood oxygenation level-dependent magnetic resonance imaging results show correlates of boundary detection and surface segregation in all early visual areas including V1. We conclude that texture boundaries are detected in a feedforward fashion and are represented at increasing latencies in higher visual areas. Surface segregation, on the other hand, is represented in "reverse hierarchical" fashion and seems to arise from feedback signals toward early visual areas such as V1.
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Millan, C.; Wilson, T.; Paulsen, T.
2007-01-01
Microstructures in natural fractures in core recovered offshore from Cape Roberts, Ross Sea, Antarctica, provide new constraints on the relative timing of faulting and sedimentation in the Victoria Land Basin along the Transantarctic Mountain rift flank. This study characterizes the textures, fabrics and grain-scale structures from thin section analysis of samples of microfaults, veins, and clastic dikes. Microfaults are abundant and display two different types of textures, interpreted to record two different deformation modes: pre-lithification shearing and brittle faulting of cohesive sediment. Both clastic dikes and calcite veins commonly follow fault planes, indicating that injections of liquefied sediment and circulating fluids used pre-existing faults as conduits. The close association of clastic injections, diagenetic mineralization, and faulting indicates that faulting was synchronous with deposition in the rift basin
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NASA Astrophysics Data System (ADS)
Dilissen, Nicole; Garrido, Carlos J.; López Sánchez-Vizcaíno, Vicente; Padrón-Navarta, José Alberto
2015-04-01
Arc volcanism, earthquakes and subduction dynamics are controlled by fluids from downgoing slabs and their effect on the melting and rheology of the overlying mantle wedge. High pressure dehydration of serpentinite in the slab and the subduction channel is considered as one of the main sources of fluids in subduction zones. Even though this metamorphic reaction is essential in subduction activities, the behavior of the fluids, the kinetics and thermodynamics during the breakdown reaction are still poorly understood. The Cerro del Almirez (Nevado-Filábride Complex, Betic Cordillera, SE Spain) uniquely preserves the dehydration front from antigorite serpentinite to chlorite-harzburgite and constitutes a unique natural laboratory to investigate high-pressure dehydration of serpentinite. This reaction occurred in a subduction setting releasing up to 13 wt% of water, contributing significantly to the supply of fluids to the overlying mantle wedge. A key to the understanding of the metamorphic conditions prevailing during serpentinite dehydration is to study the two prominent textures -granofels and spinifex-like chlorite harzburgite- occurring in this reaction product. The detailed texture differences in the Chl-harzburgite can provide insights into diverse kinetic and thermodynamic conditions of this dehydration reaction due to variations in effective pressure and drainage conditions. It has been proposed that difference in overpressure (P') and deviation from growth equilibrium, i.e. overstepping, is responsible for these two types of textures [Padrón-Navarta et al., 2011]. The magnitude and duration of P' is highly dependent on dehydration kinetics [Connolly, 1997]. The fast pressure drop, with spinifex-texture as a product, can be linked to draining events expected after hydrofracturing, which are recorded in grain size reduction zones in this massif. According to this hypothesis, mapping of textural variation in Chl-harzburgite might be used as a proxy to investigate the hydrodynamics of serpentinite dehydration reaction. During an intensive detailed field mapping of a well-exposed area of ca. 0.87 km2 in the W-SW part of the massif, we mapped textural variations of Chl-harzburgite every three to ten meters. Granofels and spinifex lenses occur within scales of decimetres to decametres. These spatial scale constrains can be linked to temporal scales of the reactions and to the spatial and temporal variation of fluid release during dehydration of serpentinite. REFERENCES Connolly, J. A. D. (1997), Devolatilization-generated fluid pressure and deformation-propagated fluid flow during prograde regional metamorphism, J. Geophys. Res.-Solid Earth, 102(B8), 18149-18173, doi:10.1029/97jb00731. Padrón-Navarta, J. A., V. López Sánchez-Vizcaíno, C. J. Garrido, and M. T. Gómez-Pugnaire (2011), Metamorphic record of high-pressure dehydration of antigorite serpentinite to chlorite harzburgite in a subduction setting (Cerro del Almirez, Nevado-Filábride Complex, southern Spain), Journal of Petrology, 52(10), 2047-2078.
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Matthew B. Russell; Christopher W. Woodall; Shawn Fraver; Anthony W. D' Amato
2013-01-01
Large-scale inventories of downed woody debris (DWD; downed dead wood of a minimum size) often record decay status by assigning pieces to classes of decay according to their visual/structural attributes (e.g., presence of branches, log shape, and texture and color of wood). DWD decay classes are not only essential for estimating current DWD biomass and carbon stocks,...
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Lunar textural analysis based on WAC-derived kilometer-scale roughness and entropy maps
NASA Astrophysics Data System (ADS)
Li, Bo; Wang, XueQiang; Zhang, Jiang; Chen, Jian; Ling, Zongcheng
2016-06-01
In general, textures are thought to be some complicated repeated patterns formed by elements, or primitives which are sorted in certain rules. Lunar surfaces record the interactions between its outside environment and itself, thus, based on high-resolution DEM model or image data, there are some topographic features which have different roughness and entropy values or signatures on lunar surfaces. Textures of lunar surfaces can help us to concentrate on typical topographic and photometric variations and reveal the relationships between obvious features (craters, impact basins, sinuous rilles (SRs) and ridges) with resurfacing processes on the Moon. In this paper, the term surface roughness is an expression of the variability of a topographic or photometric surface at kilometer scale, and the term entropy can characterize the variability inherent in a geological and topographic unit and evaluate the uncertainty of predictions made by a given geological process. We use the statistical moments of gray-level histograms in different-sized neighborhoods (e.g., 3, 5, 10, 20, 40 and 80 pixels) to compute the kilometer-scale roughness and entropy values, using the mosaic image from 70°N to 70°S obtained by Lunar Reconnaissance Orbiter (LRO) Wide Angle Camera (WAC). Large roughness and entropy signatures were only found in the larger scale maps, while the smallest 3-pixel scale map had more disorderly and unsystematic textures. According to the entropy values in 10-pixel scale entropy map, we made a frequency curve and categorized lunar surfaces into three types, shadow effects, maria and highlands. A 2D scatter plot of entropy versus roughness values was produced and we found that there were two point clusters corresponding to the highlands and maria, respectively. In the last, we compared the topographic and photometric signatures derived from Lunar Orbiter Laser Altimeter (LOLA) data and WAC mosaic image. On the lunar surfaces, the ridges have obvious multilevel topographic textures which are sensitive to the topographic changes, while the ejecta deposits of fresh craters appear obvious photometric textures which are sensitive to the brightness variations.
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NASA Astrophysics Data System (ADS)
Gall, H. D.; Cipar, J. H.; Crispin, K. L.; Kürkçüoğlu, B.; Furman, T.
2017-12-01
We elucidate crystal recycling and magma recharge processes at Hasandağ by investigating compositional zoning patterns and textural variation in plagioclase crystals from Quaternary basaltic andesite through dacite lavas. Previous work on Hasandağ intermediate compositions identified thermochemical disequilibrium features and showed abundant evidence for magma mixing1,2. We expand on this work through detailed micro-texture and mineral diffusion analysis to explore the mechanisms and timescales of crystal transport and mixing processes. Thermobarometric calculations constrain the plumbing system to 1.2-2 kbar and 850-950°C, corresponding to a felsic magma chamber at 4.5 km. Electron microprobe results reveal plagioclase phenocrysts from all lava types have common core (An33-46) and rim (An36-64) compositions, with groundmass laths (An57-67) resembling the phenocryst rims. Low An cores are ubiquitous, regardless of bulk rock chemistry, and suggest a consistent composition within the magma reservoir prior to high An rim growth. High An rims are regularly enriched in Mg, Fe, Ti and Sr, which we attribute to mafic recharge and magma mixing. We assess mixing timescales by inverse diffusion modeling of Mg profiles across the core-rim boundaries. Initial results suggest mixing to eruption processes occur on the order of days to months. Heterogeneous calculated timescales within thin sections indicate crystal populations with different growth histories. Crystals often display prominent sieve-textured zones just inside the rim, as well as other disequilibrium features such as oscillatory zoning or resorbed and patchy-zoned cores. We interpret these textures to indicate mobilization of a homogeneous dacitic reservoir with abundant An35 plagioclase crystals by frequent injection of mafic magma. Variability in observed textures and calculated timescales manifests during defrosting of a highly crystalline felsic mush, through different degrees of magma mixing. This process results in distinct crystal populations, some of which record punctuated ascent and storage, while others are erupted rapidly after the influx of new magma. Aydar, E., & Gourgaud, A. (1998). J. Volcanol. Geotherm. Res., 85(1), 129-152. Ustunisik, G., & Kilinc, A. (2011). Lithos, 125(3), 984-993.
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Late Reduction Textures in Almahata Sitta Ureilite
NASA Technical Reports Server (NTRS)
Herrin, J. S.; Le, L.; Zolensky, M. E.; Ito, M.; Jenniskens, P.; Shaddad, M. H.
2009-01-01
The Almahata Sitta ureilite, derived from asteroid 2008 TC3, consists of many individual fragments recovered from the Nubian dessert strewn field [1]. Like most ureilites, it contains abundant carbon and exhibits examples of disequilibrium textures that record a late reduction event accompanied by rapid cooling (tens of degC/h) from high temperatures (1150-1300 C). Variations in Fe/Mg of silicate minerals are accompanied by variations in Fe/Mn, indicating loss of Fe into metal [2]. In coarser-grained fragments of Almahata Sitta, olivine exhibits irregular high mg# rims in contact with networks of interstitial metal 5- 20 microns in typical thickness. This is a common ureilite texture thought to be driven by the reaction of graphite to a CO gas phase and the concurrent reduction of FeO in olivine to Fe metal, with excess silica going primarily into pyroxene (2MgFeSiO4 + C approaches MgSiO4 + MgSiO3 + 2Fe + CO) [3, see also 4,5,6]. Other fragments of Almahata Sitta exhibit anomalous textures such as fine grain size, high porosity, and abundant graphite. Within these fragments pyroxene locally exhibits high-mg# rims in contact with metal and a discreet silica phase, suggesting that the reduction mechanism MgFeSi2O6 + C approaches MgSiO3 + Fe + SiO2 + CO. Metals in Almahata Sitta are particularly unaltered in comparison to ureilite finds. Variations in minor and trace element composition of this metal might partly result from localized dilution as iron is supplied by reduction of silicates.
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A laboratory model for solidification of Earth's core
NASA Astrophysics Data System (ADS)
Bergman, Michael I.; Macleod-Silberstein, Marget; Haskel, Michael; Chandler, Benjamin; Akpan, Nsikan
2005-11-01
To better understand the influence of rotating convection in the outer core on the solidification of the inner core we have constructed a laboratory model for solidification of Earth's core. The model consists of a 15 cm radius hemispherical acrylic tank concentric with a 5 cm radius hemispherical aluminum heat exchanger that serves as the incipient inner core onto which we freeze ice from salt water. Long exposure photographs of neutrally buoyant particles in illuminated planes suggest reduction of flow parallel to the rotation axis. Thermistors in the tank near the heat exchanger show that in experiments with rotation the temperature near the pole is lower than near the equator, unlike for control experiments without rotation or with a polymer that increases the fluid viscosity. The photographs and thermistors suggest that our observation that ice grows faster near the pole than near the equator for experiments with rotation is a result of colder water not readily convecting away from the pole. Because of the reversal of the thermal gradient, we expect faster equatorial solidification in the Earth's core. Such anisotropy in solidification has been suggested as a cause of inner core elastic (and attenuation) anisotropy, though the plausibility of this suggestion will depend on the core Nusselt number and the slope of the liquidus, and the effects of post-solidification deformation. Previous experiments on hexagonal close-packed alloys such as sea ice and zinc-tin have shown that fluid flow in the melt can result in a solidification texture transverse to the solidification direction, with the texture depending on the nature of the flow. A comparison of the visualized flow and the texture of columnar ice crystals in thin sections from these experiments confirms flow-induced transverse textures. This suggests that the convective pattern at the base of the outer core is recorded in the texture of the inner core, and that outer core convection might contribute to the complexity in the seismically inferred pattern of anisotropy in the Earth's inner core.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Sorensen, J; Duran, C; Stingo, F
Purpose: To characterize the effect of virtual monochromatic reconstructions on several commonly used texture analysis features in DECT of the chest. Further, to assess the effect of monochromatic energy levels on the ability of these textural features to identify tissue types. Methods: 20 consecutive patients underwent chest CTs for evaluation of lung nodules using Siemens Somatom Definition Flash DECT. Virtual monochromatic images were constructed at 10keV intervals from 40–190keV. For each patient, an ROI delineated the lesion under investigation, and cylindrical ROI’s were placed within 5 different healthy tissues (blood, fat, muscle, lung, and liver). Several histogram- and Grey Levelmore » Cooccurrence Matrix (GLCM)-based texture features were then evaluated in each ROI at each energy level. As a means of validation, these feature values were then used in a random forest classifier to attempt to identify the tissue types present within each ROI. Their predictive accuracy at each energy level was recorded. Results: All textural features changed considerably with virtual monochromatic energy, particularly below 70keV. Most features exhibited a global minimum or maximum around 80keV, and while feature values changed with energy above this, patient ranking was generally unaffected. As expected, blood demonstrated the lowest inter-patient variability, for all features, while lung lesions (encompassing many different pathologies) exhibited the highest. The accuracy of these features in identifying tissues (76% accuracy) was highest at 80keV, but no clear relationship between energy and classification accuracy was found. Two common misclassifications (blood vs liver and muscle vs fat) accounted for the majority (24 of the 28) errors observed. Conclusion: All textural features were highly dependent on virtual monochromatic energy level, especially below 80keV, and were more stable above this energy. However, in a random forest model, these commonly used features were able to reliably differentiate between most tissues types regardless of energy level. Dr Godoy has received a dual-energy CT research grant from Siemens Healthcare. That grant did not directly fund this research.« less
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Chan, Marjorie A.; McPherson, Brian J.
2014-01-01
Abstract Iron (oxyhydr)oxide microbial mats in modern to ∼100 ka tufa terraces are present in a cold spring system along Ten Mile Graben, southeastern Utah, USA. Mats exhibit morphological, chemical, and textural biosignatures and show diagenetic changes that occur over millennial scales. The Jurassic Brushy Basin Member of the Morrison Formation in the Four Corners region of the USA also exhibits comparable microbial fossils and iron (oxyhydr)oxide biosignatures in the lacustrine unit. Both the modern spring system and Brushy Basin Member represent alkaline, saline, groundwater-fed systems and preserve diatoms and other similar algal forms with cellular elaboration. Two distinct suites of elements (1. C, Fe, As and 2. C, S, Se, P) are associated with microbial fossils in modern and ancient iron (oxyhydr)oxides and may be potential markers for biosignatures. The presence of ferrihydrite in ∼100 ka fossil microbial mats and Jurassic rocks suggests that this thermodynamically unstable mineral may also be a potential biomarker. One of the most extensive sedimentary records on Mars is exposed in Gale Crater and consists of non-acidic clays and sulfates possibly of lacustrine origin. These terrestrial iron (oxyhydr)oxide examples are a valuable analogue because of similar iron- and clay-rich host rock compositions and will help (1) understand diagenetic processes in a non-acidic, saline lacustrine environment such as the sedimentary rocks in Gale Crater, (2) document specific biomediated textures, (3) demonstrate how biomediated textures might persist or respond to diagenesis over time, and (4) provide a ground truth library of textures to explore and compare in extraterrestrial iron (oxyhydr)oxides, where future explorations hope to detect past evidence of life. Key Words: Biogeochemistry—Mars—Biosignatures—Diagenesis—Iron oxides. Astrobiology 14, 1–14. PMID:24380534
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Intraoral radiographs texture analysis for dental implant planning.
Mundim, Mayara B V; Dias, Danilo R; Costa, Ronaldo M; Leles, Cláudio R; Azevedo-Marques, Paulo M; Ribeiro-Rotta, Rejane F
2016-11-01
Computer vision extracts features or attributes from images improving diagnosis accuracy and aiding in clinical decisions. This study aims to investigate the feasibility of using texture analysis of periapical radiograph images as a tool for dental implant treatment planning. Periapical radiograph images of 127 jawbone sites were obtained before and after implant placement. From the superimposition of the pre- and post-implant images, four regions of interest (ROI) were delineated on the pre-implant images for each implant site: mesial, distal and apical peri-implant areas and a central area. Each ROI was analysed using Matlab® software and seven image attributes were extracted: mean grey level (MGL), standard deviation of grey levels (SDGL), coefficient of variation (CV), entropy (En), contrast, correlation (Cor) and angular second moment (ASM). Images were grouped by bone types-Lekholm and Zarb classification (1,2,3,4). Peak insertion torque (PIT) and resonance frequency analysis (RFA) were recorded during implant placement. Differences among groups were tested for each image attribute. Agreement between measurements of the peri-implant ROIs and overall ROI (peri-implant + central area) was tested, as well as the association between primary stability measures (PIT and RFA) and texture attributes. Differences among bone type groups were found for MGL (p = 0.035), SDGL (p = 0.024), CV (p < 0.001) and En (p < 0.001). The apical ROI showed a significant difference from the other regions for all attributes, except Cor. Concordance correlation coefficients were all almost perfect (ρ > 0.93), except for ASM (ρ = 0.62). Texture attributes were significantly associated with the implant stability measures. Texture analysis of periapical radiographs may be a reliable non-invasive quantitative method for the assessment of jawbone and prediction of implant stability, with potential clinical applications. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
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McLoughlin, Nicola; Grosch, Eugene G
2015-10-01
The low-temperature alteration of submarine volcanic glasses has been argued to involve the activity of microorganisms, and analogous fluid-rock-microbial-mediated alteration has also been postulated on Mars. However, establishing the extent to which microbes are involved in volcanic glass alteration has proven to be difficult, and the reliability of resulting textural biosignatures is debated, particularly in the early rock record. We therefore propose a hierarchical scheme to evaluate the biogenicity of candidate textural biosignatures found in altered terrestrial and extraterrestrial basaltic glasses and serpentinized ultramafic rocks. The hierarchical scheme is formulated to give increasing confidence of a biogenic origin and involves (i) investigation of the textural context and syngenicity of the candidate biosignature; (ii) characterization of the morphology and size range of the microtextures; (iii) mapping of the geological and physicochemical variables controlling the occurrence and preservation of the microtextures; (iv) in situ investigation of chemical signatures that are syngenetic to the microtexture; and (v) identification of growth patterns suggestive of biological behavior and redox variations in the host minerals. The scheme results in five categories of candidate biosignature as follows: Category 1 indicates preservation of very weak evidence for biogenicity, Categories 2 through 4 indicate evidence for increasing confidence of a biogenic origin, and Category 5 indicates that biogenic origin is most likely. We apply this hierarchical approach to examine the evidence for a biogenic origin of several examples, including candidate bacterial encrustations in altered pillow lavas, granular and tubular microtextures in volcanic glass from the subseafloor and a Phanerozoic ophiolite, mineralized microtextures in Archean metavolcanic glass, and alteration textures in olivines of the martian meteorite Yamato 000593. The aim of this hierarchical approach is to provide a framework for identifying robust biosignatures of microbial life in the altered oceanic crust on Earth, and in extraterrestrial altered mafic-ultramafic rocks, particularly on Mars.
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Arroyo, Adrián; Hirata, Satoshi; Matsuzawa, Tetsuro; de la Torre, Ignacio
2016-01-01
We present the results of a series of experiments at the Kumamoto Sanctuary in Japan, in which captive chimpanzees (Pan troglodytes) performed several nut cracking sessions using raw materials from Olduvai Gorge, Tanzania. We examined captive chimpanzee pounding tools using a combination of technological analysis, use-wear distribution, and micro-wear analysis. Our results show specific patterns of use-wear distribution across the active surfaces of pounding tools, which reveal some similarities with traces on archaeological percussive objects from the Early Stone Age, and are consistent with traces on other experimental pounding tools used by modern humans. The approach used in this study may help to stablish a framework with which to interpret archaeological assemblages and improve understanding of use-wear formation processes on pounding tools used by chimpanzees. This study represents the first direct comparison of chimpanzee pounding tools and archaeological material, and thus may contribute to a better understanding of hominin percussive activities.
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Arroyo, Adrián; Hirata, Satoshi; Matsuzawa, Tetsuro; de la Torre, Ignacio
2016-01-01
We present the results of a series of experiments at the Kumamoto Sanctuary in Japan, in which captive chimpanzees (Pan troglodytes) performed several nut cracking sessions using raw materials from Olduvai Gorge, Tanzania. We examined captive chimpanzee pounding tools using a combination of technological analysis, use-wear distribution, and micro-wear analysis. Our results show specific patterns of use-wear distribution across the active surfaces of pounding tools, which reveal some similarities with traces on archaeological percussive objects from the Early Stone Age, and are consistent with traces on other experimental pounding tools used by modern humans. The approach used in this study may help to stablish a framework with which to interpret archaeological assemblages and improve understanding of use-wear formation processes on pounding tools used by chimpanzees. This study represents the first direct comparison of chimpanzee pounding tools and archaeological material, and thus may contribute to a better understanding of hominin percussive activities. PMID:27870877
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Bridges, N.T.; Calef, F.J.; Hallett, B.W.; Herkenhoff, Kenneth E.; Lanza, N.L.; Le Mouélic, S.; Newman, C.E.; Blaney, D.L.; de Pablo, M.A.; Kocurek, G.A.; Langevin, Y.; Lewis, K.W.; Mangold, N.; Maurice, S.; Meslin, P.-Y.; Pinet, P.; Renno, N.O.; Rice, CM.S.; Richardson, M.E.; Sautter, V.; Sletten, R.S.; Wiens, R.C.; Yingst, R.A.
2014-01-01
Ventifacts, rocks abraded by wind-borne particles, are found in Gale Crater, Mars. In the eastward drive from “Bradbury Landing” to “Rocknest,” they account for about half of the float and outcrop seen by Curiosity's cameras. Many are faceted and exhibit abrasion textures found at a range of scales, from submillimeter lineations to centimeter-scale facets, scallops, flutes, and grooves. The drive path geometry in the first 100 sols of the mission emphasized the identification of abrasion facets and textures formed by westerly flow. This upwind direction is inconsistent with predictions based on models and the orientation of regional dunes, suggesting that these ventifact features formed from very rare high-speed winds. The absence of active sand and evidence for deflation in the area indicates that most of the ventifacts are fossil features experiencing little abrasion today.
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NASA Technical Reports Server (NTRS)
Ashwal, Lewis D.; Wooden, Joseph L.
1989-01-01
This paper presents Nd, Sr, and Pb isotopic data indicating a late-Archean/early-Proterozoic age for the River Valley anorthositic pluton of the southwestern Grenville Province of Sudbury, Ontario. Pb-Pb isotopic data on 10 whole-rock samples ranging in composition from anorthosite to gabbro yield an age of 2560 + or - 155 Ma. The River Valley pluton is thus the oldest anorthositic intrusive yet recognized within the Grenville Province. The Sm-Nd isotopic system records an age of 2377 + or - 68 Ma. High Pb-208/Pb-204 of deformed samples relative to igneous-textured rocks implies Th introduction and/or U loss during metamorphism in the River Valley area. Rb-Sr data from igneous-textured and deformed samples and from mineral separates give an age of 2185 + or - 105 Ma, indicating substantial disturbance of the Rb-Sr isotopic system.
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Computer vision research with new imaging technology
NASA Astrophysics Data System (ADS)
Hou, Guangqi; Liu, Fei; Sun, Zhenan
2015-12-01
Light field imaging is capable of capturing dense multi-view 2D images in one snapshot, which record both intensity values and directions of rays simultaneously. As an emerging 3D device, the light field camera has been widely used in digital refocusing, depth estimation, stereoscopic display, etc. Traditional multi-view stereo (MVS) methods only perform well on strongly texture surfaces, but the depth map contains numerous holes and large ambiguities on textureless or low-textured regions. In this paper, we exploit the light field imaging technology on 3D face modeling in computer vision. Based on a 3D morphable model, we estimate the pose parameters from facial feature points. Then the depth map is estimated through the epipolar plane images (EPIs) method. At last, the high quality 3D face model is exactly recovered via the fusing strategy. We evaluate the effectiveness and robustness on face images captured by a light field camera with different poses.
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Spatiotemporal evolution of dehydration reactions in subduction zones (Invited)
NASA Astrophysics Data System (ADS)
Padron-Navarta, J.
2013-12-01
Large-scale deep water cycling takes place through subduction zones in the Earth, making our planet unique in the solar system. This idiosyncrasy is the result of a precise but unknown balance between in-gassing and out-gassing fluxes of volatiles. Water is incorporated into hydrous minerals during seafloor alteration of the oceanic lithosphere. The cycling of volatiles is triggered by dehydration of these minerals that release fluids from the subducting slab to the mantle wedge and eventually to the crust or to the deep mantle. Whereas the loci of such reactions are reasonably well established, the mechanisms of fluid migration during dehydration reactions are still barely known. One of the challenges is that dehydration reactions are dynamic features evolving in time and space. Experimental data on low-temperature dehydration reactions (i.e. gypsum) and numerical models applied to middle-crust conditions point to a complex spatiotemporal evolution of the dehydration process. The extrapolation of these inferences to subduction settings has not yet been explored but it is essential to understand the dynamism of these settings. Here I propose an alternative approach to tackle this problem through the textural study of high-pressure terrains that experienced dehydration reactions. Spatiotemporal evolution of dehydration reactions should be recorded during mineral nucleation and growth through variations in time and space of the reaction rate. Insights on the fluid migration mechanism could be inferred therefore by noting changes in the texture of prograde assemblages. The dehydration of antigorite in serpentinite is a perfect candidate to test this approach as it releases a significant amount of fluid and produces a concomitant porosity. Unusual alternation of equilibrium and disequilibrium textures observed in Cerro del Almirez (Betic Cordillera, S Spain)[1, 2] attest for a complex fluid migration pattern for one of the most relevant reactions in subduction zones. This opens the possibility to correlate textural features recorded in high-pressure terrains with the physical fingerprint of dehydration reactions such as fluid flow rates and eventually seismicity or tremor. References [1] Padrón-Navarta, J. A., Tommasi, A., Garrido, C. J., López Sánchez-Vizcaíno, V., Gómez-Pugnaire, M. T., Jabaloy, A. & Vauchez, A. (2010). Fluid transfer into the wedge controlled by high-pressure hydrofracturing in the cold top-slab mantle. Earth and Planetary Science Letters 297, 271-286. [2] Padrón-Navarta, J. A., López Sánchez-Vizcaíno, V., Garrido, C. J. & Gómez-Pugnaire, M. T. (2011). Metamorphic Record of High-pressure Dehydration of Antigorite Serpentinite to Chlorite Harzburgite in a Subduction Setting (Cerro del Almirez, Nevado-Filábride Complex, Southern Spain). Journal of Petrology 52, 2047-2078.
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Volcanic Rocks As Targets For Astrobiology Missions
NASA Astrophysics Data System (ADS)
Banerjee, N.
2010-12-01
Almost two decades of study highlight the importance of terrestrial subaqueous volcanic rocks as microbial habitats, particularly in glass produced by the quenching of basaltic lava upon contact with water. On Earth, microbes rapidly begin colonizing glassy surfaces along fractures and cracks exposed to water. Microbial colonization of basaltic glass leads to enhanced alteration through production of characteristic granular and/or tubular bioalteration textures. Infilling of formerly hollow alteration textures by minerals enable their preservation through geologic time. Basaltic rocks are a major component of the Martian crust and are widespread on other solar system bodies. A variety of lines of evidence strongly suggest the long-term existence of abundant liquid water on ancient Mars. Recent orbiter, lander and rover missions have found evidence for the presence of transient liquid water on Mars, perhaps persisting to the present day. Many other solar system bodies, notably Europa, Enceladus and other icy satellites, may contain (or have once hosted) subaqueous basaltic glasses. The record of terrestrial glass bioalteration has been interpreted to extend back ~3.5 billion years and is widespread in modern oceanic crust and its ancient metamorphic equivalents. The terrestrial record of glass bioalteration strongly suggests that glassy or formerly glassy basaltic rocks on extraterrestrial bodies that have interacted with liquid water are high-value targets for astrobiological exploration.
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Culbertson, Heather; Kuchenbecker, Katherine J
2017-01-01
Interacting with physical objects through a tool elicits tactile and kinesthetic sensations that comprise your haptic impression of the object. These cues, however, are largely missing from interactions with virtual objects, yielding an unrealistic user experience. This article evaluates the realism of virtual surfaces rendered using haptic models constructed from data recorded during interactions with real surfaces. The models include three components: surface friction, tapping transients, and texture vibrations. We render the virtual surfaces on a SensAble Phantom Omni haptic interface augmented with a Tactile Labs Haptuator for vibration output. We conducted a human-subject study to assess the realism of these virtual surfaces and the importance of the three model components. Following a perceptual discrepancy paradigm, subjects compared each of 15 real surfaces to a full rendering of the same surface plus versions missing each model component. The realism improvement achieved by including friction, tapping, or texture in the rendering was found to directly relate to the intensity of the surface's property in that domain (slipperiness, hardness, or roughness). A subsequent analysis of forces and vibrations measured during interactions with virtual surfaces indicated that the Omni's inherent mechanical properties corrupted the user's haptic experience, decreasing realism of the virtual surface.
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The effect of texture granularity on texture synthesis quality
NASA Astrophysics Data System (ADS)
Golestaneh, S. Alireza; Subedar, Mahesh M.; Karam, Lina J.
2015-09-01
Natural and artificial textures occur frequently in images and in video sequences. Image/video coding systems based on texture synthesis can make use of a reliable texture synthesis quality assessment method in order to improve the compression performance in terms of perceived quality and bit-rate. Existing objective visual quality assessment methods do not perform satisfactorily when predicting the synthesized texture quality. In our previous work, we showed that texture regularity can be used as an attribute for estimating the quality of synthesized textures. In this paper, we study the effect of another texture attribute, namely texture granularity, on the quality of synthesized textures. For this purpose, subjective studies are conducted to assess the quality of synthesized textures with different levels (low, medium, high) of perceived texture granularity using different types of texture synthesis methods.
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NASA Astrophysics Data System (ADS)
Saubin, Elodie; Tuffen, Hugh; Gurioli, Lucia; Owen, Jacqueline; Castro, Jonathan; Berlo, Kim; McGowan, Ellen; Schipper, C.; Wehbe, Katia
2016-05-01
The mechanisms of hazardous silicic eruptions are controlled by complex, poorly-understood conduit processes. Observations of recent Chilean rhyolite eruptions have revealed the importance of hybrid activity, involving simultaneous explosive and effusive emissions from a common vent. Such behaviour hinges upon the ability of gas to decouple from magma in the shallow conduit. Tuffisite veins are increasingly suspected to be a key facilitator of outgassing, as they repeatedly provide a transient permeable escape route for volcanic gases. Intersection of foam domains by tuffisite veins appears critical to efficient outgassing. However, knowledge is currently lacking into textural heterogeneities within shallow conduits, their relationship with tuffisite vein propagation, and the implications for fragmentation and degassing processes. Similarly, the magmatic vesiculation response to upper conduit pressure perturbations, such as those related to the slip of dense magma plugs, remains largely undefined. Here we provide a detailed characterization of an exceptionally large tuffisite vein within a rhyolitic obsidian bomb ejected during transitional explosive-effusive activity at Chaitén, Chile in May 2008. Vein textures and chemistry provide a time-integrated record of the invasion of a dense upper conduit plug by deeper fragmented magma. Quantitative textural analysis reveals diverse vesiculation histories of various juvenile clast types. Using vesicle size distributions, bubble number densities, zones of diffusive water depletion, and glass H2O concentrations, we propose a multi-step degassing/fragmentation history, spanning deep degassing to explosive bomb ejection. Rapid decompression events of ~3-4 MPa are associated with fragmentation of foam and dense magma at ~200-350 metres depth in the conduit, permitting vertical gas and pyroclast mobility over hundreds of metres. Permeable pathway occlusion in the dense conduit plug by pyroclast accumulation and sintering preceded ultimate bomb ejection, which then triggered a final bubble nucleation event. Our results highlight how the vesiculation response of magma to decompression events is highly sensitive to the local melt volatile concentration, which is strongly spatially heterogeneous. Repeated opening of pervasive tuffisite vein networks promotes this heterogeneity, allowing juxtaposition of variably volatile-rich magma fragments that are derived from a wide range of depths in the conduit. This process enables efficient but explosive removal of gas from rhyolitic
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Mattonen, Sarah A.; Palma, David A.; Department of Oncology, The University of Western Ontario, London, Ontario N6A 4L6
Purpose: Benign computed tomography (CT) changes due to radiation induced lung injury (RILI) are common following stereotactic ablative radiotherapy (SABR) and can be difficult to differentiate from tumor recurrence. The authors measured the ability of CT image texture analysis, compared to more traditional measures of response, to predict eventual cancer recurrence based on CT images acquired within 5 months of treatment. Methods: A total of 24 lesions from 22 patients treated with SABR were selected for this study: 13 with moderate to severe benign RILI, and 11 with recurrence. Three-dimensional (3D) consolidative and ground-glass opacity (GGO) changes were manually delineatedmore » on all follow-up CT scans. Two size measures of the consolidation regions (longest axial diameter and 3D volume) and nine appearance features of the GGO were calculated: 2 first-order features [mean density and standard deviation of density (first-order texture)], and 7 second-order texture features [energy, entropy, correlation, inverse difference moment (IDM), inertia, cluster shade, and cluster prominence]. For comparison, the corresponding response evaluation criteria in solid tumors measures were also taken for the consolidation regions. Prediction accuracy was determined using the area under the receiver operating characteristic curve (AUC) and two-fold cross validation (CV). Results: For this analysis, 46 diagnostic CT scans scheduled for approximately 3 and 6 months post-treatment were binned based on their recorded scan dates into 2–5 month and 5–8 month follow-up time ranges. At 2–5 months post-treatment, first-order texture, energy, and entropy provided AUCs of 0.79–0.81 using a linear classifier. On two-fold CV, first-order texture yielded 73% accuracy versus 76%–77% with the second-order features. The size measures of the consolidative region, longest axial diameter and 3D volume, gave two-fold CV accuracies of 60% and 57%, and AUCs of 0.72 and 0.65, respectively. Conclusions: Texture measures of the GGO appearance following SABR demonstrated the ability to predict recurrence in individual patients within 5 months of SABR treatment. Appearance changes were also shown to be more accurately predictive of recurrence, as compared to size measures within the same time period. With further validation, these results could form the substrate for a clinically useful computer-aided diagnosis tool which could provide earlier salvage of patients with recurrence.« less
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Automatic Texture Reconstruction of 3d City Model from Oblique Images
NASA Astrophysics Data System (ADS)
Kang, Junhua; Deng, Fei; Li, Xinwei; Wan, Fang
2016-06-01
In recent years, the photorealistic 3D city models are increasingly important in various geospatial applications related to virtual city tourism, 3D GIS, urban planning, real-estate management. Besides the acquisition of high-precision 3D geometric data, texture reconstruction is also a crucial step for generating high-quality and visually realistic 3D models. However, most of the texture reconstruction approaches are probably leading to texture fragmentation and memory inefficiency. In this paper, we introduce an automatic framework of texture reconstruction to generate textures from oblique images for photorealistic visualization. Our approach include three major steps as follows: mesh parameterization, texture atlas generation and texture blending. Firstly, mesh parameterization procedure referring to mesh segmentation and mesh unfolding is performed to reduce geometric distortion in the process of mapping 2D texture to 3D model. Secondly, in the texture atlas generation step, the texture of each segmented region in texture domain is reconstructed from all visible images with exterior orientation and interior orientation parameters. Thirdly, to avoid color discontinuities at boundaries between texture regions, the final texture map is generated by blending texture maps from several corresponding images. We evaluated our texture reconstruction framework on a dataset of a city. The resulting mesh model can get textured by created texture without resampling. Experiment results show that our method can effectively mitigate the occurrence of texture fragmentation. It is demonstrated that the proposed framework is effective and useful for automatic texture reconstruction of 3D city model.
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2013-03-01
framework of orientation distribution functions and crack-induced texture o Quantify effects of temperature on damage behavior and damage monitoring...measurement model was obtained from hidden Markov modeling (HMM) of joint time-frequency (TF) features extracted from the PZT sensor signals using the...considered PZT sensor signals recorded from a bolted aluminum plate. About only 20% of the samples of a signal were first randomly selected as
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Improving Neural Recording Technology at the Nanoscale
NASA Astrophysics Data System (ADS)
Ferguson, John Eric
Neural recording electrodes are widely used to study normal brain function (e.g., learning, memory, and sensation) and abnormal brain function (e.g., epilepsy, addiction, and depression) and to interface with the nervous system for neuroprosthetics. With a deep understanding of the electrode interface at the nanoscale and the use of novel nanofabrication processes, neural recording electrodes can be designed that surpass previous limits and enable new applications. In this thesis, I will discuss three projects. In the first project, we created an ultralow-impedance electrode coating by controlling the nanoscale texture of electrode surfaces. In the second project, we developed a novel nanowire electrode for long-term intracellular recordings. In the third project, we created a means of wirelessly communicating with ultra-miniature, implantable neural recording devices. The techniques developed for these projects offer significant improvements in the quality of neural recordings. They can also open the door to new types of experiments and medical devices, which can lead to a better understanding of the brain and can enable novel and improved tools for clinical applications.
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Memory texture as a mechanism of improvement in preference by adding noise
NASA Astrophysics Data System (ADS)
Zhao, Yinzhu; Aoki, Naokazu; Kobayashi, Hiroyuki
2014-02-01
According to color research, people have memory colors for familiar objects, which correlate with high color preference. As a similar concept to this, we propose memory texture as a mechanism of texture preference by adding image noise (1/f noise or white noise) to photographs of seven familiar objects. Our results showed that (1) memory texture differed from real-life texture; (2) no consistency was found between memory texture and real-life texture; (3) correlation existed between memory texture and preferred texture; and (4) the type of image noise which is more appropriate to texture reproduction differed by object.
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NASA Astrophysics Data System (ADS)
Bach, W.; Giampouras, M.; Garcia-Ruiz, J. M.; Garrido, C. J.; Los, C.; Fussmann, D.; Monien, P.
2017-12-01
Interactions between meteoric water and ultramafic rocks within Oman ophiolite give rise to the formation of thermal spring waters of variable composition and temperature. Discharge of two different types of water forms complex hydrological networks of streams and ponds, in which the waters mix, undergo evaporation, and take up atmospheric CO2. We conducted a pond-by-pond sampling of waters and precipitates in two spring sites within the Wadi Tayin massif, Nasif and Khafifah, and examined how hydrochemistry and associated mineral saturation states affect the variations in mineral phases and textures. Three distinctive types of waters were identified in the system: a) Mg-type (7.9 < pH < 9.5); Mg-HCO3-rich waters, b) Ca-type (pH > 11.6); Ca-OH-rich waters, and c) Mix-type (9.6 < pH < 11.5); waters arising upon mixing of Mg-type and Ca-type. PHREEQC was used to evaluate the role of mixing in aqueous speciation and the evolution of the saturation index value of different mineral phases. Mineral and textural characterization by X-ray diffraction, Raman spectroscopy and scanning electron microscopy were combined with these hydrogeochemical constraints to determine the factors controlling mineralogical and textural diversity in the system. In Ca-type waters, uptake of CO2 during the exposure of the fluids to the atmosphere is the predominant precipitation mechanism of CaCO3. High Mg:Ca ratios and high supersaturation rate of CaCO3 favor the growth of aragonite over calcite in mixed fluids. Changes in morphology and texture of aragonite crystals and crystal aggregates indicate the variations in the values of supersaturation and supersaturation rate of CaCO3 in the different water types. Brucite precipitation is common and driven by fluid mixing, while interaction with air-derived CO2 causes its alteration to hydromagnesite. The proximity of gabbroic lithologies appears to affect the presence of Al-bearing layered double hydroxides (LDHs). Furthermore, transformation of nesquehonite to dypingite in Mg-type waters record a shift towards more alkaline conditions due to occasional mixing. This study demonstrates that water mixing, atmospheric CO2 up-take, and evaporation are the main drivers of precipitation and textural differentiation of minerals occurring in serpentinization-driven alkaline environments.
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Wilkinson, Michael; Ewen, Alistair; Caplan, Nicholas; O'leary, David; Smith, Neil; Stoneham, Richard; Saxby, Lee
2018-05-01
The effect of textured insoles on kinetics and kinematics of overground running was assessed. 16 male injury-free-recreational runners attended a single visit (age 23 ± 5 yrs; stature 1.78 ± 0.06 m; mass 72.6 ± 9.2 kg). Overground 15-m runs were completed in flat, canvas plimsolls both with and without textured insoles at self-selected velocity on an indoor track in an order that was balanced among participants. Average vertical loading rate and peak vertical force (F peak ) were captured by force platforms. Video footage was digitised for sagittal plane hip, knee and ankle angles at foot strike and mid stance. Velocity, stride rate and length and contact and flight time were determined. Subjectively rated plantar sensation was recorded by visual scale. 95% confidence intervals estimated mean differences. Smallest worthwhile change in loading rate was defined as standardised reduction of 0.54 from a previous comparison of injured versus non-injured runners. Loading rate decreased (-25 to -9.3 BW s -1 ; 60% likely beneficial reduction) and plantar sensation was increased (46-58 mm) with the insole. F peak (-0.1 to 0.14 BW) and velocity (-0.02 to 0.06 m s -1 ) were similar. Stride length, flight and contact time were lower (-0.13 to -0.01 m; -0.02 to-0.01 s; -0.016 to -0.006 s) and stride rate was higher (0.01-0.07 steps s -1 ) with insoles. Textured insoles elicited an acute, meaningful decrease in vertical loading rate in short distance, overground running and were associated with subjectively increased plantar sensation. Reduced vertical loading rate could be explained by altered stride characteristics.
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Diamond, James; Anderson, Neil H; Bartels, Peter H; Montironi, Rodolfo; Hamilton, Peter W
2004-09-01
Quantitative examination of prostate histology offers clues in the diagnostic classification of lesions and in the prediction of response to treatment and prognosis. To facilitate the collection of quantitative data, the development of machine vision systems is necessary. This study explored the use of imaging for identifying tissue abnormalities in prostate histology. Medium-power histological scenes were recorded from whole-mount radical prostatectomy sections at x 40 objective magnification and assessed by a pathologist as exhibiting stroma, normal tissue (nonneoplastic epithelial component), or prostatic carcinoma (PCa). A machine vision system was developed that divided the scenes into subregions of 100 x 100 pixels and subjected each to image-processing techniques. Analysis of morphological characteristics allowed the identification of normal tissue. Analysis of image texture demonstrated that Haralick feature 4 was the most suitable for discriminating stroma from PCa. Using these morphological and texture measurements, it was possible to define a classification scheme for each subregion. The machine vision system is designed to integrate these classification rules and generate digital maps of tissue composition from the classification of subregions; 79.3% of subregions were correctly classified. Established classification rates have demonstrated the validity of the methodology on small scenes; a logical extension was to apply the methodology to whole slide images via scanning technology. The machine vision system is capable of classifying these images. The machine vision system developed in this project facilitates the exploration of morphological and texture characteristics in quantifying tissue composition. It also illustrates the potential of quantitative methods to provide highly discriminatory information in the automated identification of prostatic lesions using computer vision.
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Chen, Shang-Wen; Shen, Wei-Chih; Lin, Ying-Chun; Chen, Rui-Yun; Hsieh, Te-Chun; Yen, Kuo-Yang; Kao, Chia-Hung
2017-04-01
This study investigated the correlation of the matrix heterogeneity of tumors on 18 F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) with gene-expression profiling in patients with pharyngeal cancer and determined the prognostic factors for radiotherapy-based treatment outcomes. We retrospectively reviewed the records of 57 patients with stage III-IV oropharyngeal or hypopharyngeal cancer who had completed definitive therapy. Four groups of the textural features as well as 31 indices were studied in addition to maximum standard uptake value, metastatic tumor volume, and total lesion glycolysis. Immunohistochemical data from pretreatment biopsy specimens (Glut1, CAIX, VEGF, HIF-1α, EGFR, Ki-67, Bcl-2, CLAUDIN-4, YAP-1, c-Met, and p16) were analyzed. The relationships between the indices and genomic expression were studied, and the robustness of various textural features relative to cause-specific survival and primary relapse-free survival was analyzed. The overexpression of VEGF was positively associated with the increased values of the matrix heterogeneity obtained using gray-level nonuniformity for zone (GLNUz) and run-length nonuniformity (RLNU). Advanced T stage (p = 0.01, hazard ratio [HR] = 3.38), a VEGF immunoreactive score of >2 (p = 0.03, HR = 2.79), and a higher GLNUz value (p = 0.04, HR = 2.51) were prognostic factors for low cause-specific survival, whereas advanced T stage, a HIF-1α staining percentage of ≥80%, and a higher GLNUz value were prognostic factors for low primary-relapse free survival. The overexpression of VEGF was associated with the increased matrix index of GLNUz and RLNU. For patients with pharyngeal cancer requiring radiotherapy, the treatment outcome can be stratified according to the textural features, T stage, and biomarkers.
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A Search for Impact Debris in the Pliocene Age Sirius Group, Transantarctic Mountains
NASA Technical Reports Server (NTRS)
Harvey, Ralph P.; Boyd, Hiram
2003-01-01
The Sirius Group is a mixed sequence of interbedded diamictite and mudstone of Pliocene age found at scattered locations along the length of the Transantarctic Mountains. Sirius Group rocks are usually considered tillites, but contain some very "un-tillite" elements. Within section and from site to site, Sirius Group rocks vary considerably in terms of texture and relative abundance of clast lithologies, recording a history that includes shifting influences of glacial, lacustrine, fluvial and wetland processes. The colorful heritage of the Sirius Group has generated a lot of interest due to its potential as a record of changes in the behavior of the East Antarctic icesheet during a climatologically interesting period.
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Shock-induced kelyphite formation in the core of a complex impact crater
NASA Astrophysics Data System (ADS)
Deseta, Natalie; Boonsue, Suporn; Gibson, Roger L.; Spray, John G.
2017-10-01
We present a compositional and textural analysis of shock-induced microtextures in garnet porphyroblasts in migmatitic garnet-cordierite-biotite paragneisses from the centre of the Vredefort impact structure, South Africa. Detailed imaging and major element analysis of deformation features in, and adjacent to, the garnet porphyroblasts record a complex, heterogeneous distribution of shock effects at the microscale. As the most competent silicate mineral in the assemblage, with the highest Hugoniot Elastic Limit and a wide pressure-temperature stability field, the porphyroblastic garnet preserves a more diverse shock deformation response compared to minerals such as quartz and feldspar, which underwent more comprehensive shock metamorphism and subsequent annealing. The garnet porphyroblasts display pre-impact fractures that are overprinted by later intra-granular Hertzian and distinctive planar fractures associated with the impact event. Shock-induced strain localization occurred along internal slip planes and defects, including pre-existing fractures and inclusion boundaries in the garnet. Symplectitic (kelyphitic) coronas commonly enclose the garnet porphyroblasts, and inhabit intra-granular fractures. The kelyphite assemblage in fractures with open communication beyond garnet grain boundaries is characterized by orthopyroxene—cordierite—sapphirine. Conversely, the kelyphite assemblage in closed-off intra-granular fractures is highly variable, comprising spatially restricted combinations of a secondary garnet phase with a majoritic component, Al-rich orthopyroxene, sapphirine and cordierite. The impedance contrast between garnet porphyroblasts and their inclusions further facilitated the formation of shock-induced features (Al-rich orthopyroxene coronas). Together, the textural and mineralogical data suggest that these features provide a record of oscillatory shock perturbations initiated under confining pressure beneath the transient crater floor. This occurred as the shocked rock volume underwent post-shock expansion, forming the core of the central uplift, and was followed by variable textural re-equilibration. This study thus provides a microtextural and mineralogical perspective of the shock regime within confined crust immediately prior to and during central uplift formation.
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NASA Astrophysics Data System (ADS)
Dilissen, N. M.; Garrido, C. J.; Lopez Sanchez-Vizcaino, V.; Jabaloy-Sánchez, A.; Padrón-Navarta, J. A.
2015-12-01
Subduction zones are dynamic convergent plate boundaries associated with arc volcanism and earthquakes, which are believed to be controlled by fluids released during devolatilization reactions from the downgoing slab. The high-pressure breakdown of antigorite serpentinite to prograde chlorite-harzburgite is considered to be the most significant source of water in subduction zones. The Cerro del Almirez ultramafic massif (Betic Cordillera, SE Spain) is a unique exhumed subduction terrane that preserves this dehydration reaction as a sharp front. Chl-harzburgite in this massif displays two differentiated textures-granofels and spinifex-like- indicating that antigorite breakdown occurred at different overstepping of the dehydration reaction. Detailed mapping of textural variations in chl-harzburgite unveils a network of granofels and spinifex-like lenses. These lenses have triaxial ellipsoid shapes with average axial ratios of 16:7:1 and 19:8:1, respectively, with the shorter axis nearly perpendicular to the serpentine-out isograd, and the longest axis ranging from 23 to 190 meters. We calculated the volume of water release per lens using the modal amount of olivine according to the model reaction 1Atg = 4Clin + 6Fo + 6En + 15H2O. The growth time and water flux per lens was computed using experimental olivine growth rates for granular and dendritic, spinifex-like olivine. Preliminary results show that formation of spinifex and granofels lenses imply temporal variations of the volumetric water fluxes ranging from 0.12 to 0.02 m3m-2yr-1, respectively. If the time of formation of lenses is inversely proportional to its relative distance to the dehydration front, the 52m thick, chl-harzburgite lens network in Almirez records ca. 315 yrs of antigorite dehydration. Our results show that antigorite dehydration in subduction zones occurs in a highly non-steady regime with yearly to decadal variations of water fluxes that record variations in the dynamics of slab and fluid expulsion mechanisms.
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What determines sclerobiont colonization on marine mollusk shells?
Ochi Agostini, Vanessa; Ritter, Matias do Nascimento; José Macedo, Alexandre; Muxagata, Erik; Erthal, Fernando
2017-01-01
Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts.
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What determines sclerobiont colonization on marine mollusk shells?
José Macedo, Alexandre; Muxagata, Erik; Erthal, Fernando
2017-01-01
Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts. PMID:28902894
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Adhesive behavior of micro/nano-textured surfaces
NASA Astrophysics Data System (ADS)
Zhang, Yuyan; Wang, Xiaoli; Li, Hanqing; Wang, Ben
2015-02-01
A numerical model of the adhesive contact between a rigid smooth sphere and an elastic textured surface based on the Lennard-Jones interatomic potential law and the Hamaker summation method is established. Textures are considered by introducing the texture height distribution into the gap equation. Simulation results show that the pull-off force on textured surfaces decreases compared to that on smooth surfaces. Furthermore, effects of sphere-shaped textures on reducing adhesion are more obvious than cylinder-shaped or cube-shaped textures when the coverage area ratio, maximum height and interval of textures are fixed. For surfaces with sphere-shaped textures, variation trends of the mean pull-off force with texture density are not monotonous, and there exists a certain range of texture densities in which the mean pull-off force is small and its variation is insignificant. In addition, the pull-off force depends also on the maximum height and radius of textures. On one hand, if the texture radius is fixed, larger maximum height results in smaller pull-off force, and if the maximum height is fixed, the pull-off force tends to increase almost linearly with increases in texture radius. On the other hand, if the height-diameter ratio of textures is fixed, the pull-off force reaches a minimum at an optimum texture radius or maximum height.
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A subjective study and an objective metric to quantify the granularity level of textures
NASA Astrophysics Data System (ADS)
Subedar, Mahesh M.; Karam, Lina J.
2015-03-01
Texture granularity is an important visual characteristic that is useful in a variety of applications, including analysis, recognition, and compression, to name a few. A texture granularity measure can be used to quantify the perceived level of texture granularity. The granularity level of the textures is influenced by the size of the texture primitives. A primitive is defined as the smallest recognizable repetitive object in the texture. If the texture has large primitives then the perceived granularity level tends to be lower as compared to a texture with smaller primitives. In this work we are presenting a texture granularity database referred as GranTEX which consists of 30 textures with varying levels of primitive sizes and granularity levels. The GranTEX database consists of both natural and man-made textures. A subjective study is conducted to measure the perceived granularity level of textures present in the GranTEX database. An objective metric that automatically measures the perceived granularity level of textures is also presented as part of this work. It is shown that the proposed granularity metric correlates well with the subjective granularity scores.
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NASA Astrophysics Data System (ADS)
Baker, David M. H.; Head, James W.
2015-11-01
The mid-latitudes of Mars are host to a record of recent episodes of accumulations of ice-rich materials. The record includes debris aprons, interpreted to be debris-covered glaciers, that may represent the preserved remnants of a much more extensive ice sheet. We assessed the possibility of former glacial extents by examining debris aprons and the surrounding plains in Deuteronilus Mensae. Geomorphic units and stratigraphic relationships were mapped and documented from Mars Reconnaissance Orbiter (MRO) Context (CTX) and High Resolution Imaging Science Experiment (HiRISE) camera images, and crater retention ages were estimated from crater size-frequency distributions. Three major units are observed within the study area: debris aprons, lower plains, and upper plains. Debris aprons exhibit characteristics typical for these features documented elsewhere and in previous studies, including integrated flow lineations and patterns, convex-upward profiles, and knobby and brain terrain surface textures. A lower bound on the age for debris aprons is estimated to be 0.9 Ga. Debris aprons are superposed on a lower plains unit having a lower bound age of 3.3-3.5 Ga. A 50-100 m thick upper plains unit superposes both debris apron landforms and lower plains units and has a best-fit minimum age of 0.6 Ga. The upper plains unit exhibits characteristics of atmospherically-emplaced mantle material, including fine-grained nature, sublimation textures, cyclic layering, draping character, and widespread spatial distribution. Fracturing and subsequent sublimation/erosion of upper plains on debris aprons has contributed to many of the surface textures on debris aprons. The upper plains unit has also been eroded from the lower plains and plateaus, evidenced by isolated blocks of upper plains in the interiors of craters and on the walls and tops of plateaus. While no conclusive evidence diagnostic of former cold-based ice sheets are observed in the plains within the study region, such landforms and units may have been poorly developed or absent, as is often the case on Earth, and would have been covered and reworked by later mantling episodes. These observations suggest that emplacement of thick ice-rich mantle deposits extended at least to near the Early/Middle Amazonian boundary and overlapped with the waning stages of glaciation in Deuteronilus Mensae.
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NASA Astrophysics Data System (ADS)
Miyata, Kazunori; Nakajima, Masayuki
1995-04-01
A method is given for synthesizing a texture by using the interface of a conventional drawing tool. The majority of conventional texture generation methods are based on the procedural approach, and can generate a variety of textures that are adequate for generating a realistic image. But it is hard for a user to imagine what kind of texture will be generated simply by looking at its parameters. Furthermore, it is difficult to design a new texture freely without a knowledge of all the procedures for texture generation. Our method offers a solution to these problems, and has the following four merits: First, a variety of textures can be obtained by combining a set of feature lines and attribute functions. Second, data definitions are flexible. Third, the user can preview a texture together with its feature lines. Fourth, people can design their own textures interactively and freely by using the interface of a conventional drawing tool. For users who want to build this texture generation method into their own programs, we also give the language specifications for generating a texture. This method can interactively provide a variety of textures, and can also be used for typographic design.
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Liu, Jianli; Lughofer, Edwin; Zeng, Xianyi
2015-01-01
Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design, and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective, and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and non-linear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.
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Development of iron platinum/oxide high anisotropy magnetic media
NASA Astrophysics Data System (ADS)
Yang, En
Because the size of magnetic grains is approaching the superparamagnetic limit in current perpendicular media, it is necessary to produce thin film media made with magnetic alloys with larger magneto-crystalline anisotropy energies to achieve higher recording densities. Due to its high anisotropy field and good environmental stability, FePt (L10) is the most promising media for achieving such ultra-high recording densities. However, there are several challenges associated with the development of FePt as a perpendicular media. As deposited FePt has disordered fee phase; either high deposition temperature, > 600 oC, or a high temperature post annealing process is required to obtain the ordered L10 structure, which is not desirable for manufacturing purposes. Therefore, techniques that enable ordering at significantly reduced temperatures are critically and urgently needed. Furthermore, in order to use it as a high density recording media, very small (less than 5 nm), uniform and fully-ordered, magnetically isolated FePt (L10) columnar grains with well defined grain boundaries, excellent perpendicular texture and high coercivity are desired. In this study, experiments and research have been mainly focused on the following aspects: (1) controlling of c axis orientation of FePt, (2) obtaining small columnar FePt grains, (3) improving order parameter and magnetic properties at lower ordering temperature. After a systematic experimental investigation, we have found an experimental approach for obtaining highly ordered L1 0 FePt-oxide thin film media at moderate deposition temperatures. In most previous studies, the FePt-Oxide layer is directly deposited on a textured MgO (001) layer. By introducing a double buffer layer in between the FePt-oxide layer and the MgO underlayer, we are able to substantially enhance the L1 0 ordering of the FePt-oxide layer while lowering the deposition temperature to 400oC. The buffer layers also yield a significantly enhanced (001) texture of the formed L10 FePt film. With the order parameter near unity, the coercivity of the resulting granular L10 FePt-oxide film exceeds Hc > 20 kOe with an average grain size about D = 8 nm. With the buffer layer technique, l8kOe coercivity has also been achieved for L10 FePt-oxide film at a grain size of about D = 4.5 nm, but it requires 35% of SiO2 in the magnetic layer. With 9% of Oxide in the film, excellent perpendicular texture, very high order parameter and small grain size of FePt can also be obtained by utilizing RuAl grain size defining layer along with TiN barrier layer. With the Ag buffer layer technique, the microstructure and magnetic properties of FePt films with RuAl grain size defining layer can be further improved.
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NASA Astrophysics Data System (ADS)
Bestmann, Michel; Kunze, Karsten; Matthews, Alan
2000-11-01
The deformation history of a monophase calcite marble shear zone complex on Thassos Island, Northern Greece, is reconstructed by detailed geometric studies of the textural and microstructural patterns relative to a fixed reference system (shear zone boundary, SZB). Strain localization within the massive marble complex is linked to decreasing P- T conditions during the exhumation process of the metamorphic core complex. Solvus thermometry indicates that temperatures of 300-350°C prevailed during part of the shear zone deformation history. The coarse-grained marble protolith outside the shear zone is characterized by symmetrically oriented twin sets due to early coaxial deformation. A component of heterogeneous non-coaxial deformation is first recorded within the adjacent protomylonite. Enhanced strain weakening by dynamic recrystallization promoted strong localization of plastic deformation in the ultramylonite of the calcite shear zone, where high strain was accommodated by non-coaxial flow. This study demonstrates that both a pure shear and a simple shear strain path can result in similar crystallographic preferred orientations (single c-axis maximum perpendicular to the SZB) by different dominant deformation mechanisms. Separated a-axis pole figures (+ a- and - a-axis) show different density distributions with orthorhombic texture symmetry in the protolith marble and monoclinic symmetry in the ultramylonite marble consistently with the observed grain fabric symmetry.
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Image statistics underlying natural texture selectivity of neurons in macaque V4
Okazawa, Gouki; Tajima, Satohiro; Komatsu, Hidehiko
2015-01-01
Our daily visual experiences are inevitably linked to recognizing the rich variety of textures. However, how the brain encodes and differentiates a plethora of natural textures remains poorly understood. Here, we show that many neurons in macaque V4 selectively encode sparse combinations of higher-order image statistics to represent natural textures. We systematically explored neural selectivity in a high-dimensional texture space by combining texture synthesis and efficient-sampling techniques. This yielded parameterized models for individual texture-selective neurons. The models provided parsimonious but powerful predictors for each neuron’s preferred textures using a sparse combination of image statistics. As a whole population, the neuronal tuning was distributed in a way suitable for categorizing textures and quantitatively predicts human ability to discriminate textures. Together, we suggest that the collective representation of visual image statistics in V4 plays a key role in organizing the natural texture perception. PMID:25535362
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Tepley, F. J.; Davidson, J.P.; Tilling, R.I.; Arth, Joseph G.
2000-01-01
Consistent core-to-rim decreases of 87Sr/86Sr ratios and coincident increases in Sr concentrations in plagioclase phenocrysts of varying size (~ 1 cm to 2 mm) are reported from samples of the 1982 and pre-1982 (~ 200 ka) eruptions of El Chichon Volcano. Maximum 87Sr/86Sr ratios of ~ 0.7054, significantly higher than the whole-rock isotopic ratios (~ 0.7040-0.7045), are found in the cores of plagioclase phenocrysts, and minimum 87Sr/86Sr ratios of ~ 0.7039 are found near some of the rims. Plagioclase phenocrysts commonly display abrupt fluctuations in An content (up to 25 mol %) that correspond to well-developed dissolution surfaces The isotopic, textural and compositional characteristics suggest that these plagioclase phenocrysts grew in a system that was periodically recharged by higher-temperature magma with a lower 87Sr/86Sr ratio and a higher Sr concentration. Rim 87Sr/86Sr ratios in plagioclase phenocrysts of rocks from the 200 ka eruption indicate that, at that time, the magma had already attained the lowest recorded 87Sr/86Sr value of the system (~ 0.7039). In contrast, cores from plagioclase phenocrysts of the 1982 eruption, inferred to have grown in the past few thousand years, have the highest recorded 87Sr/86Sr ratios of the system. Collectively, the Sr isotopic data (for plagioclase and whole rock), disequilibrium textural features of the phenocrysts, known eruption frequencies, and inferred crystal-residence times of the plagioclases are best interpreted in terms of an intermittent magma chamber model. Similar processes, including crustal contamination, magma mixing, periodic recharge by addition of more mafic magma to induce plagioclase disequilibrium (possibly triggering eruption) and subsequent re-equilibration, apparently were operative throughout the 200 ky history of the El Chichon magma system.
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Redox History of Early Solar System Planetismals Recorded in the D;Orbigny Angrite
DOE Office of Scientific and Technical Information (OSTI.GOV)
King, P.L.; Sutton, S.R.; Spilde, M.N.
2012-04-02
Angrites are ancient basaltic meteorites ({approx}4.56 Ga) that preserve evidence of some of the solar system's earliest melting events. The volcanic-textured angrites such as D'Orbigny were rapidly crystallized and are relatively pristine; lacking shock, brecciation, and parent-body weathering textures. Thus, these angrites provide a unique 'window' into the petrogenesis of planetary bodies in the early solar system. Angrites may be formed by partial melting of CV chondrites under relatively oxidized sources compared to the eucrites, and therefore may document variations in fO{sub 2} conditions on carbonaceous chondrite parent bodies. Thus, understanding the intrinsic fO{sub 2} conditions of the angrites ismore » needed to determine how different early Solar System basalts form, to model separation of the core, mantle and crust, and to understand magnetic fields on planetary bodies. The D'Orbigny angrite contains a range of textures: (a) crystalline texture containing interlocking crystals of fassaite (pyroxene) with Ti-rich rims, anorthite, and Mg-olivine with Fe-rich rims; (b) cavities with protruding needle-like pyroxene and anorthite dusted by Ca-(Mg)-carbonate; (c) mesostasis with kirschsteinite, ilmenite, troilite, phosphates (e.g., merrilite, whitlockite and Casilicophosphate), rhonite and minor glass; (d) glasses ({approx} angrite composition) in vesicles, as inclusions and as beads, and also cross-cutting crystal-rich portions of the rock; (e) vesicles (e.g., {approx}1.4 vol. %, 0.0219-87.7 mm{sup 3}). Analysis of the textures and Fe{sup 3+}/Fetotal of the cavity pyroxene suggests that the oxygen fugacity (fO{sub 2}) increased in the D'Orbigny angrite perhaps due to introduction of a gas phase. Here we examine the detailed fO{sub 2} history using micro-analyses that allow us to avoid inclusions that may cause spurious results. We present analyses of both S- and V- oxidation states to complement other work using Fe-oxidation state and to avoid problems related to measuring low concentrations of Fe{sup 3+} and propagating errors when calculating fO{sub 2} in samples with low Fe{sup 3+} concentrations.« less
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Krishnan, M Muthu Rama; Venkatraghavan, Vikram; Acharya, U Rajendra; Pal, Mousumi; Paul, Ranjan Rashmi; Min, Lim Choo; Ray, Ajoy Kumar; Chatterjee, Jyotirmoy; Chakraborty, Chandan
2012-02-01
Oral cancer (OC) is the sixth most common cancer in the world. In India it is the most common malignant neoplasm. Histopathological images have widely been used in the differential diagnosis of normal, oral precancerous (oral sub-mucous fibrosis (OSF)) and cancer lesions. However, this technique is limited by subjective interpretations and less accurate diagnosis. The objective of this work is to improve the classification accuracy based on textural features in the development of a computer assisted screening of OSF. The approach introduced here is to grade the histopathological tissue sections into normal, OSF without Dysplasia (OSFWD) and OSF with Dysplasia (OSFD), which would help the oral onco-pathologists to screen the subjects rapidly. The biopsy sections are stained with H&E. The optical density of the pixels in the light microscopic images is recorded and represented as matrix quantized as integers from 0 to 255 for each fundamental color (Red, Green, Blue), resulting in a M×N×3 matrix of integers. Depending on either normal or OSF condition, the image has various granular structures which are self similar patterns at different scales termed "texture". We have extracted these textural changes using Higher Order Spectra (HOS), Local Binary Pattern (LBP), and Laws Texture Energy (LTE) from the histopathological images (normal, OSFWD and OSFD). These feature vectors were fed to five different classifiers: Decision Tree (DT), Sugeno Fuzzy, Gaussian Mixture Model (GMM), K-Nearest Neighbor (K-NN), Radial Basis Probabilistic Neural Network (RBPNN) to select the best classifier. Our results show that combination of texture and HOS features coupled with Fuzzy classifier resulted in 95.7% accuracy, sensitivity and specificity of 94.5% and 98.8% respectively. Finally, we have proposed a novel integrated index called Oral Malignancy Index (OMI) using the HOS, LBP, LTE features, to diagnose benign or malignant tissues using just one number. We hope that this OMI can help the clinicians in making a faster and more objective detection of benign/malignant oral lesions. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Invasion of Hydrous Fluids Predates Kimberlite Formation
NASA Astrophysics Data System (ADS)
Kopylova, M. G.; Wang, Q.; Smith, E. M.
2017-12-01
Petrological observations on diamonds and peridotite xenoliths in kimberlites point towards an influx of hydrous metasomatic fluids shortly predating kimberlite formation. Diamonds may grow at different times within the same segment of the cratonic mantle, and diamonds that form shortly before (<5-7 My) the kimberlite entrainment host the more hydrous fluid inclusions. Younger fibrous diamonds typically contain 10-25 wt.% water in fluid inclusions, while older octahedrally-grown diamonds host "dry" N2-CO2 fluids. Our recent studies of fluids in diamond now show that many different kinds of diamonds can contain fluid inclusions. Specifically, we found a new way to observe and analyze fluids in octahedrally-grown, non-fibrous diamonds by examining healed fractures. This is a new textural context for fluid inclusions that reveals a valuable physical record of infiltrating mantle fluids, that postdate diamond growth, but equilibrate within the diamond stability field at depths beyond 150 km. Another sign of the aqueous fluids influx is the formation of distinct peridotite textures shortly predating the kimberlite. Kimberlites entrain peridotite xenoliths with several types of textures: older coarse metamorphic textures and younger, sheared textures. The preserved contrast in grain sizes between porphyroclasts and neoblasts in sheared peridotites constrain the maximum duration of annealing. Experimental estimates of the annealing time vary from 7x107 sec (2 years) to 106 years (1 My) depending on olivine hydration, strain rate, pressure, temperature and, ultimately, the annealing mechanism. Kimberlite sampling of sheared peridotites from the lithosphere- asthenosphere boundary (LAB) implies their formation no earlier than 1 My prior to the kimberlite ascent. Water contents of olivine measured by FTIR spectrometry using polarized light demonstrated contrasting hydration of coarse and sheared samples. Olivine from sheared peridotite samples has the average water content of 78±3 ppm, in contrast to the less hydrated coarse peridotites (33±6 ppm). LAB hydration results in the lower viscosity of the mantle (1-4 orders of magnitude) translating into 10-104- fold increase in strain rate if stress, its duration, pressure, temperature and the deformation mechanism are assumed constant.
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22.7% efficient PERL silicon solar cell module with a textured front surface
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhao, J.; Wang, A.; Campbell, P.
1997-12-31
This paper describes a solar cell module efficiency of 22.7% independently measured at Sandia National Laboratories. This is the highest ever confirmed efficiency for a photovoltaic module of this size achieved by cells made from any material. This 778-cm{sup 2} module used 40 large-area double layer antireflection coated PERL (passivated emitter, rear locally-diffused) silicon cells of average efficiency of 23.1%. A textured front module surface considerably improve the module efficiency. Also reported is an independently confirmed efficiency of 23.7% for a 21.6 cm{sup 2} cell of the type used in the module. Using these PERL cells in the 1996 Worldmore » Solar Challenge solar car race from Darwin to Adelaide across Australia, Honda`s Dream and Aisin Seiki`s Aisol III were placed first and third, respectively. Honda also set a new record by reaching Adelaide in four days with an average speed of 90km/h over the 3010 km course.« less
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Enhancing Motion-In-Depth Perception of Random-Dot Stereograms.
Zhang, Di; Nourrit, Vincent; De Bougrenet de la Tocnaye, Jean-Louis
2018-07-01
Random-dot stereograms have been widely used to explore the neural mechanisms underlying binocular vision. Although they are a powerful tool to stimulate motion-in-depth (MID) perception, published results report some difficulties in the capacity to perceive MID generated by random-dot stereograms. The purpose of this study was to investigate whether the performance of MID perception could be improved using an appropriate stimulus design. Sixteen inexperienced observers participated in the experiment. A training session was carried out to improve the accuracy of MID detection before the experiment. Four aspects of stimulus design were investigated: presence of a static reference, background texture, relative disparity, and stimulus contrast. Participants' performance in MID direction discrimination was recorded and compared to evaluate whether varying these factors helped MID perception. Results showed that only the presence of background texture had a significant effect on MID direction perception. This study provides suggestions for the design of 3D stimuli in order to facilitate MID perception.
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Conjoint representation of texture ensemble and location in the parahippocampal place area.
Park, Jeongho; Park, Soojin
2017-04-01
Texture provides crucial information about the category or identity of a scene. Nonetheless, not much is known about how the texture information in a scene is represented in the brain. Previous studies have shown that the parahippocampal place area (PPA), a scene-selective part of visual cortex, responds to simple patches of texture ensemble. However, in natural scenes textures exist in spatial context within a scene. Here we tested two hypotheses that make different predictions on how textures within a scene context are represented in the PPA. The Texture-Only hypothesis suggests that the PPA represents texture ensemble (i.e., the kind of texture) as is, irrespective of its location in the scene. On the other hand, the Texture and Location hypothesis suggests that the PPA represents texture and its location within a scene (e.g., ceiling or wall) conjointly. We tested these two hypotheses across two experiments, using different but complementary methods. In experiment 1 , by using multivoxel pattern analysis (MVPA) and representational similarity analysis, we found that the representational similarity of the PPA activation patterns was significantly explained by the Texture-Only hypothesis but not by the Texture and Location hypothesis. In experiment 2 , using a repetition suppression paradigm, we found no repetition suppression for scenes that had the same texture ensemble but differed in location (supporting the Texture and Location hypothesis). On the basis of these results, we propose a framework that reconciles contrasting results from MVPA and repetition suppression and draw conclusions about how texture is represented in the PPA. NEW & NOTEWORTHY This study investigates how the parahippocampal place area (PPA) represents texture information within a scene context. We claim that texture is represented in the PPA at multiple levels: the texture ensemble information at the across-voxel level and the conjoint information of texture and its location at the within-voxel level. The study proposes a working hypothesis that reconciles contrasting results from multivoxel pattern analysis and repetition suppression, suggesting that the methods are complementary to each other but not necessarily interchangeable. Copyright © 2017 the American Physiological Society.
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Rapakivi texture: An indication of the crystallization of hydrosilicates, II
NASA Astrophysics Data System (ADS)
Elliston, John N.
1985-05-01
Rapakivi granites have puzzled all who have seriously studied them. Typical rapakivi texture is a mixture of variously mantled, non-mantled or partly mantled, concentrically zoned, plastically distorted, fragmented, reaggregated, large and small ovoids. Commonly they are potash feldspar often mantled by, and having a variable content of plagioclase. Some display remarkable sphericity. In form, composition, zoning sequence, and crystallization pattern each ovoid reflects an individual development. Up to five concentric internal plagioclase rims have been observed and some ovoids may be isolated in autoliths and wall-rocks. Anomalies and contradictions arise from any assumption of genesis from a cooling melt. The recorded objective data imply that the "magma" from which rapakivi textures develop had similar diffusive and rheological properties to those of a partly dewatered macromolecular paste or a mixture of gelatinous hydrosilicates. As indicated by deep oil wells this system is found at somewhat elevated temperatures at considerable depths within accumulated sediments. In addition to the very specific diffusive and rheological properties of such partly dewatered sediments, the system has as its major components normal solvated macromolecules of mixed clays, silica gels and hydrous ferromagnesian minerals which are characterised by distinctive particle sizes and geometric shapes (platelets, spheres and rods, respectively). Thixotropic liquefaction and intrusion of such concentrated gelatinous "magma" or sediment paste introduces relative movement between the component macromolecules whereby they can reduce surface energy by interaction to assume a "close-packed" condition and aggregate during laminar flow into macro-accretions comprised essentially of their respective particle shapes. Syneresis of these precursor accretions desorbs ions, including the small montmorillonite particles behaving as a colloidal electrolyte. These diffuse from the illitic cores to form a montmorillonite-rich rim which it is suggested crystallizes together with the illitic cores to form mantled or polymantled feldspar ovoids. Crystallization of the rapakivi massif is associated with strong temperature rise stemming from exothermic crystallization of the close-packed metastable colloids. This follows the development of the characteristic texture. The rounded and rimmed precursor accretions are formed during earlier lower-temperature episodes of thixotropic liquefaction which are isothermal. The fluidity is an earlier event. There is high temperature dependent on the rate of water loss but no molten stage. Forty-six typical features of rapakivi texture are described and illustrated, each of which is directly attributable to specific interactions in an alternately dynamic and static colloidal system. Individual correlation between each observed distinctive feature of the rapakivi texture and the well-documented physico-chemical process is complete. For sediment-derived granites, therefore, the rapakivi texture can confidently be assumed to be an indication of the crystallization of their sedimentary hydrosilicate precursors.
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Textured catalysts and methods of making textured catalysts
Werpy, Todd [West Richland, WA; Frye, Jr., John G.; Wang, Yong [Richland, WA; Zacher, Alan H [Kennewick, WA
2007-03-06
A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.
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Texture control of zircaloy tubing during tube reduction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nagai, N.; Kakuma, T.; Fujita, K.
1982-01-01
Seven batches of Zircaloy-2 nuclear fuel cladding tubes with different textures were processed from tube shells of the same size, by different reduction routes, using pilger and 3-roll mills. Based on the texture data of these tubes, the texture control of Zircaloy tubing, the texture gradient across the wall, and the texture change during annealing were studied. The deformation texture of Zicaloy-2 tubing was dependent on the tool's curvature and was independent of the dimensions of the mother tubes. The different slopes of texture gradients were observed between the tubing of higher strain ration and that of lower strain ratio.
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Some distinguishing characteristics of contour and texture phenomena in images
NASA Technical Reports Server (NTRS)
Jobson, Daniel J.
1992-01-01
The development of generalized contour/texture discrimination techniques is a central element necessary for machine vision recognition and interpretation of arbitrary images. Here, the visual perception of texture, selected studies of texture analysis in machine vision, and diverse small samples of contour and texture are all used to provide insights into the fundamental characteristics of contour and texture. From these, an experimental discrimination scheme is developed and tested on a battery of natural images. The visual perception of texture defined fine texture as a subclass which is interpreted as shading and is distinct from coarse figural similarity textures. Also, perception defined the smallest scale for contour/texture discrimination as eight to nine visual acuity units. Three contour/texture discrimination parameters were found to be moderately successful for this scale discrimination: (1) lightness change in a blurred version of the image, (2) change in lightness change in the original image, and (3) percent change in edge counts relative to local maximum.
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Scharfenberger, Christian; Wong, Alexander; Clausi, David A
2015-01-01
We propose a simple yet effective structure-guided statistical textural distinctiveness approach to salient region detection. Our method uses a multilayer approach to analyze the structural and textural characteristics of natural images as important features for salient region detection from a scale point of view. To represent the structural characteristics, we abstract the image using structured image elements and extract rotational-invariant neighborhood-based textural representations to characterize each element by an individual texture pattern. We then learn a set of representative texture atoms for sparse texture modeling and construct a statistical textural distinctiveness matrix to determine the distinctiveness between all representative texture atom pairs in each layer. Finally, we determine saliency maps for each layer based on the occurrence probability of the texture atoms and their respective statistical textural distinctiveness and fuse them to compute a final saliency map. Experimental results using four public data sets and a variety of performance evaluation metrics show that our approach provides promising results when compared with existing salient region detection approaches.
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Fiber vs Rolling Texture: Stress State Dependence for Cold-Drawn Wire
NASA Astrophysics Data System (ADS)
Zorina, M. A.; Karabanalov, M. S.; Stepanov, S. I.; Demakov, S. L.; Loginov, Yu. N.; Lobanov, M. L.
2018-02-01
The texture of the cold-drawn copper wire was investigated along the radius using electron backscatter diffraction. The complex fiber texture of the central region of the wire was considered as the rolling texture consisting of a set of preferred orientations. The texture of the periphery region was revealed to be similar to the shear texture. The orientation-dependent properties of the wire were proven to be determined by the texture of the near-surface layers.
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Semantic attributes based texture generation
NASA Astrophysics Data System (ADS)
Chi, Huifang; Gan, Yanhai; Qi, Lin; Dong, Junyu; Madessa, Amanuel Hirpa
2018-04-01
Semantic attributes are commonly used for texture description. They can be used to describe the information of a texture, such as patterns, textons, distributions, brightness, and so on. Generally speaking, semantic attributes are more concrete descriptors than perceptual features. Therefore, it is practical to generate texture images from semantic attributes. In this paper, we propose to generate high-quality texture images from semantic attributes. Over the last two decades, several works have been done on texture synthesis and generation. Most of them focusing on example-based texture synthesis and procedural texture generation. Semantic attributes based texture generation still deserves more devotion. Gan et al. proposed a useful joint model for perception driven texture generation. However, perceptual features are nonobjective spatial statistics used by humans to distinguish different textures in pre-attentive situations. To give more describing information about texture appearance, semantic attributes which are more in line with human description habits are desired. In this paper, we use sigmoid cross entropy loss in an auxiliary model to provide enough information for a generator. Consequently, the discriminator is released from the relatively intractable mission of figuring out the joint distribution of condition vectors and samples. To demonstrate the validity of our method, we compare our method to Gan et al.'s method on generating textures by designing experiments on PTD and DTD. All experimental results show that our model can generate textures from semantic attributes.
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NASA Astrophysics Data System (ADS)
Yilbas, B. S.; Ali, H.; Al-Sharafi, A.; Al-Sulaiman, F.; Karatas, C.
2018-05-01
Zirconium nitride is used as a selective surface for concentrated solar heating applications and one of the methods to form a zirconium nitride is texturing of zirconia surface by a high intensity laser beam under high pressure nitrogen gas environment. Laser texturing also provides hydrophobic surface characteristics via forming micro/nano pillars at the surface; however, environmental dust settlement on textured surface influences the surface characteristics significantly. In the present study, laser texturing of zirconia surface and effects of the dust particles on the textured surface in a humid air ambient are investigated. Analytical tools are used to assess the morphological changes on the laser textured surface prior and after the dust settlement in the humid air ambient. It is found that laser textured surface has hydrophobic characteristics. The mud formed during condensate of water on the dust particles alters the characteristics of the laser textured surface. The tangential force required to remove the dry mud from the textured surface remains high; in which case, the dried liquid solution at the mud-textured surface interface is responsible for the strong adhesion of the dry mud on the textured surface. The textured surface becomes hydrophilic after the dry mud was removed from the surface by a desalinated water jet.
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Analyzing and improving surface texture by dual-rotation magnetorheological finishing
NASA Astrophysics Data System (ADS)
Wang, Yuyue; Zhang, Yun; Feng, Zhijing
2016-01-01
The main advantages of magnetorheological finishing (MRF) are its high convergence rate of surface error, the ability of polishing aspheric surfaces and nearly no subsurface damage. However, common MRF produces directional surface texture due to the constant flow direction of the magnetorheological (MR) polishing fluid. This paper studies the mechanism of surface texture formation by texture modeling. Dual-rotation magnetorheological finishing (DRMRF) is presented to suppress directional surface texture after analyzing the results of the texture model for common MRF. The results of the surface texture model for DRMRF and the proposed quantitative method based on mathematical statistics indicate the effective suppression of directional surface texture. An experimental setup is developed and experiments show directional surface texture and no directional surface texture in common MRF and DRMRF, respectively. As a result, the surface roughness of DRMRF is 0.578 nm (root-mean-square value) which is lower than 1.109 nm in common MRF.
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Structural analysis of natural textures.
Vilnrotter, F M; Nevatia, R; Price, K E
1986-01-01
Many textures can be described structurally, in terms of the individual textural elements and their spatial relationships. This paper describes a system to generate useful descriptions of natural textures in these terms. The basic approach is to determine an initial, partial description of the elements using edge features. This description controls the extraction of the texture elements. The elements are grouped by type, and spatial relationships between elements are computed. The descriptions are shown to be useful for recognition of the textures, and for reconstruction of periodic textures.
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Nanotribological response of a plasma nitrided bio-steel.
Samanta, Aniruddha; Chakraborty, Himel; Bhattacharya, Manjima; Ghosh, Jiten; Sreemany, Monjoy; Bysakh, Sandip; Rane, Ramkrishna; Joseph, Alphonsa; Jhala, Ghanshyam; Mukherjee, Subroto; Das, Mitun; Mukhopadhyay, Anoop K
2017-01-01
AISI 316L is a well known biocompatible, austenitic stainless steel (SS). It is thus a bio-steel. Considering its importance as a bio-prosthesis material here we report the plasma nitriding of AISI 316L (SS) followed by its microstructural and nanotribological characterization. Plasma nitriding of the SS samples was carried out in a plasma reactor with a hot wall vacuum chamber. For ease of comparison these plasma nitrided samples were termed as SSPN. The experimental results confirmed the formations of an embedded nitrided metal layer zone (ENMLZ) and an interface zone (IZ) between the ENMLZ and the unnitrided bulk metallic layer zone (BMLZ) in the SSPN sample. These ENMLZ and IZ in the SSPN sample were richer in iron nitride (FeN) chromium nitride (CrN) along with the austenite phase. The results from nanoindentation, microscratch, nanoscratch and sliding wear studies confirmed that the static contact deformation resistance, the microwear, nanowear and sliding wear resistance of the SSPN samples were much better than those of the SS samples. These results were explained in terms of structure-property correlations. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Neandertals made the first specialized bone tools in Europe
Soressi, Marie; McPherron, Shannon P.; Lenoir, Michel; Dogandžić, Tamara; Goldberg, Paul; Jacobs, Zenobia; Maigrot, Yolaine; Martisius, Naomi L.; Miller, Christopher E.; Rendu, William; Richards, Michael; Skinner, Matthew M.; Steele, Teresa E.; Talamo, Sahra; Texier, Jean-Pierre
2013-01-01
Modern humans replaced Neandertals ∼40,000 y ago. Close to the time of replacement, Neandertals show behaviors similar to those of the modern humans arriving into Europe, including the use of specialized bone tools, body ornaments, and small blades. It is highly debated whether these modern behaviors developed before or as a result of contact with modern humans. Here we report the identification of a type of specialized bone tool, lissoir, previously only associated with modern humans. The microwear preserved on one of these lissoir is consistent with the use of lissoir in modern times to obtain supple, lustrous, and more impermeable hides. These tools are from a Neandertal context proceeding the replacement period and are the oldest specialized bone tools in Europe. As such, they are either a demonstration of independent invention by Neandertals or an indication that modern humans started influencing European Neandertals much earlier than previously believed. Because these finds clearly predate the oldest known age for the use of similar objects in Europe by anatomically modern humans, they could also be evidence for cultural diffusion from Neandertals to modern humans. PMID:23940333
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Barium ferrite thin-film recording media
NASA Astrophysics Data System (ADS)
Sui, Xiaoyu; Scherge, Matthias; Kryder, Mark H.; Snyder, John E.; Harris, Vincent G.; Koon, Norman C.
1996-03-01
Both longitudinal and perpendicular barium ferrite thin films are being pursued as overcoatless magnetic recording media. In this paper, prior research on thin-film Ba ferrite is reviewed and the most recent results are presented. Self-textured high-coercivity longitudinal Ba ferrite thin films have been achieved using conventional rf diode sputtering. Microstructural studies show that c-axis in-plane oriented grains have a characteristic acicular shape, while c-axis perpendicularly oriented grains have a platelet shape. Extended X-ray absorption fine structure (EXAFS) measurements indicate that the crystal orientations are predetermined by the structural anisotropy in the as-sputtered 'amorphous' state. Recording tests on 1500 Oe coercivity longitudinal Ba ferrite disks show performance comparable with that of a 1900 Oe Co alloy disk. To further improve the recording performance, both grain size and aspect ratio need to be reduced. Initial tribological tests indicate high hardness of Ba ferrite thin films. However, surface roughness needs to be reduced. For future ultrahigh-density contact recording, it is believed that perpendicular recording may be used. A thin Pt underlayer has been found to be capable of producing Ba ferrite thin films with excellent c-axis perpendicular orientation.
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NASA Astrophysics Data System (ADS)
Saubin, Elodie; Tuffen, Hugh; Gurioli, Lucia; Owen, Jacqueline; Castro, Jonathan; Berlo, Kim; McGowan, Ellen; Schipper, C. Ian; Wehbe, Katia
2016-04-01
Conduit processes govern the mechanisms of hazardous silicic eruptions, but our understanding of complex conduit behaviour is far from complete. Observations of recent Chilean rhyolite eruptions have revealed the importance of hybrid activity, involving simultaneous explosive and effusive emissions from a common vent[1]. Such behaviour hinges upon the ability of gas to decouple from magma in the shallow conduit. Tuffisite veins are increasingly suspected to be a key facilitator of outgassing, as they repeatedly provide a transient permeable escape route for volcanic gases. However, we have limited insights into the interactions between tuffisites and foams that appear critical to efficient outgassing[2], and into how heterogeneous conduit magma responds to pressure perturbations related to repeated disruption or slip of dense magma plugs. Here we provide a detailed characterization of an exceptionally large tuffisite vein within a rhyolitic obsidian bomb ejected during transitional explosive-effusive activity at volcán Chaitén, Chile in May 2008. Vein textures and chemistry provide a time-integrated record of the invasion of a dense upper conduit plug by deeper fragmented magma. Quantitative textural analysis reveals diverse vesiculation histories of varied juvenile clast types. Using vesicle size distributions, bubble number densities, zones of diffusive water depletion, and glass H2O concentrations, we propose a multi-step degassing/fragmentation history, spanning deep degassing to explosive bomb ejection. Rapid decompression events of ~3-4 MPa are associated with fragmentation of foam and dense magma at ~200-300 metres depth in the conduit, permitting vertical gas and pyroclast mobility over >100-200 metres. Permeable pathway occlusion in the dense conduit plug by pyroclast accumulation and sintering preceded ultimate bomb ejection, which triggered a final bubble nucleation event. Our results highlight how the vesiculation response of magma to decompression events is highly sensitive to the local melt volatile concentration, which is strongly spatially heterogeneous. Repeated opening of pervasive tuffisite vein networks promotes this heterogeneity, allowing juxtaposition of variably volatile-rich magma fragments that are derived from a wide range of depths in the conduit. This process enables efficient but explosive removal of gas from rhyolitic magma and creates a complex textural collage within dense rhyolitic lava, in which neighbouring fused clasts may have experienced vastly different degassing histories. [1] Schipper CI et al 2013 JVGR 262, 25-37. [2] Castro JM et al 2012 EPSL 333, 63-69.
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Werpy, Todd [West Richland, WA; Wang, Yong [Richland, WA
2003-12-30
A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.
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Height perception influenced by texture gradient.
Tozawa, Junko
2012-01-01
Three experiments were carried out to examine whether a texture gradient influences perception of relative object height. Previous research implicated texture cues in judgments of object width, but similar influences have not been demonstrated for relative height. In this study, I evaluate a hypothesis that the projective ratio of the number of texture elements covered by the objects combined with the ratio of the retinal object heights determines percepts of relative object height. Density of texture background was varied: four density conditions ranged from no-texture to very dense texture. In experiments 1 and 2, participants judged the height of comparison bar compared to the standard bar positioned on no-texture or textured backgrounds. Results showed relative height judgments differed with texture manipulations, consistent with predictions from a hypothesised combination of the number of texture elements with retinal height (experiment 1), or partially consistent with this hypothesis (experiment 2). In experiment 2, variations in the position of a comparison object showed that comparisons located far from the horizon were judged more poorly than in other positions. In experiment 3 I examined distance perception; relative distance judgments were found to be also affected by textured backgrounds. Results are discussed in terms of Gibson's relational theory and distance calibration theory.
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Deep Filter Banks for Texture Recognition, Description, and Segmentation.
Cimpoi, Mircea; Maji, Subhransu; Kokkinos, Iasonas; Vedaldi, Andrea
Visual textures have played a key role in image understanding because they convey important semantics of images, and because texture representations that pool local image descriptors in an orderless manner have had a tremendous impact in diverse applications. In this paper we make several contributions to texture understanding. First, instead of focusing on texture instance and material category recognition, we propose a human-interpretable vocabulary of texture attributes to describe common texture patterns, complemented by a new describable texture dataset for benchmarking. Second, we look at the problem of recognizing materials and texture attributes in realistic imaging conditions, including when textures appear in clutter, developing corresponding benchmarks on top of the recently proposed OpenSurfaces dataset. Third, we revisit classic texture represenations, including bag-of-visual-words and the Fisher vectors, in the context of deep learning and show that these have excellent efficiency and generalization properties if the convolutional layers of a deep model are used as filter banks. We obtain in this manner state-of-the-art performance in numerous datasets well beyond textures, an efficient method to apply deep features to image regions, as well as benefit in transferring features from one domain to another.
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Reliability and dimensionality of judgments of visually textured materials.
Cho, R Y; Yang, V; Hallett, P E
2000-05-01
We extended perceptual studies of the Brodatz set of textured materials. In the experiments, texture perception for different texture sets, viewing distances, or lighting intensities was examined. Subjects compared one pair of textures at a time. The main task was to rapidly rate all of the texture pairs on a number scale for their overall dissimilarities first and then for their dissimilarities according to six specified attributes (e.g., texture contrast). The implied dimensionality of perceptual texture space was usually at least four, rather than three. All six attributes proved to be useful predictors of overall dissimilarity, especially coarseness and regularity. The novel attribute texture lightness, an assessment of mean surface reflectance, was important when viewing conditions were wide-ranging. We were impressed by the general validity of texture judgments across subject, texture set, and comfortable viewing distances or lighting intensities. The attributes are nonorthogonal directions in four-dimensional perceptual space and are probably not narrow linear axes. In a supplementary experiment, we studied a completely different task: identifying textures from a distance. The dimensionality for this more refined task is similar to that for rating judgments, so our findings may have general application.
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Interactive evolution of camouflage.
Reynolds, Craig
2011-01-01
This article presents an abstract computation model of the evolution of camouflage in nature. The 2D model uses evolved textures for prey, a background texture representing the environment, and a visual predator. A human observer, acting as the predator, is shown a cohort of 10 evolved textures overlaid on the background texture. The observer clicks on the five most conspicuous prey to remove ("eat") them. These lower-fitness textures are removed from the population and replaced with newly bred textures. Biological morphogenesis is represented in this model by procedural texture synthesis. Nested expressions of generators and operators form a texture description language. Natural evolution is represented by genetic programming (GP), a variant of the genetic algorithm. GP searches the space of texture description programs for those that appear least conspicuous to the predator.
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Low-level contrast statistics are diagnostic of invariance of natural textures
Groen, Iris I. A.; Ghebreab, Sennay; Lamme, Victor A. F.; Scholte, H. Steven
2012-01-01
Texture may provide important clues for real world object and scene perception. To be reliable, these clues should ideally be invariant to common viewing variations such as changes in illumination and orientation. In a large image database of natural materials, we found textures with low-level contrast statistics that varied substantially under viewing variations, as well as textures that remained relatively constant. This led us to ask whether textures with constant contrast statistics give rise to more invariant representations compared to other textures. To test this, we selected natural texture images with either high (HV) or low (LV) variance in contrast statistics and presented these to human observers. In two distinct behavioral categorization paradigms, participants more often judged HV textures as “different” compared to LV textures, showing that textures with constant contrast statistics are perceived as being more invariant. In a separate electroencephalogram (EEG) experiment, evoked responses to single texture images (single-image ERPs) were collected. The results show that differences in contrast statistics correlated with both early and late differences in occipital ERP amplitude between individual images. Importantly, ERP differences between images of HV textures were mainly driven by illumination angle, which was not the case for LV images: there, differences were completely driven by texture membership. These converging neural and behavioral results imply that some natural textures are surprisingly invariant to illumination changes and that low-level contrast statistics are diagnostic of the extent of this invariance. PMID:22701419
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NASA Technical Reports Server (NTRS)
Haralick, R. H. (Principal Investigator); Bosley, R. J.
1974-01-01
The author has identified the following significant results. A procedure was developed to extract cross-band textural features from ERTS MSS imagery. Evolving from a single image texture extraction procedure which uses spatial dependence matrices to measure relative co-occurrence of nearest neighbor grey tones, the cross-band texture procedure uses the distribution of neighboring grey tone N-tuple differences to measure the spatial interrelationships, or co-occurrences, of the grey tone N-tuples present in a texture pattern. In both procedures, texture is characterized in such a way as to be invariant under linear grey tone transformations. However, the cross-band procedure complements the single image procedure by extracting texture information and spectral information contained in ERTS multi-images. Classification experiments show that when used alone, without spectral processing, the cross-band texture procedure extracts more information than the single image texture analysis. Results show an improvement in average correct classification from 86.2% to 88.8% for ERTS image no. 1021-16333 with the cross-band texture procedure. However, when used together with spectral features, the single image texture plus spectral features perform better than the cross-band texture plus spectral features, with an average correct classification of 93.8% and 91.6%, respectively.
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Advecting Procedural Textures for 2D Flow Animation
NASA Technical Reports Server (NTRS)
Kao, David; Pang, Alex; Moran, Pat (Technical Monitor)
2001-01-01
This paper proposes the use of specially generated 3D procedural textures for visualizing steady state 2D flow fields. We use the flow field to advect and animate the texture over time. However, using standard texture advection techniques and arbitrary textures will introduce some undesirable effects such as: (a) expanding texture from a critical source point, (b) streaking pattern from the boundary of the flowfield, (c) crowding of advected textures near an attracting spiral or sink, and (d) absent or lack of textures in some regions of the flow. This paper proposes a number of strategies to solve these problems. We demonstrate how the technique works using both synthetic data and computational fluid dynamics data.
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Through-process modelling of texture and anisotropy in AA5182
NASA Astrophysics Data System (ADS)
Crumbach, M.; Neumann, L.; Goerdeler, M.; Aretz, H.; Gottstein, G.; Kopp, R.
2006-07-01
A through-process texture and anisotropy prediction for AA5182 sheet production from hot rolling through cold rolling and annealing is reported. Thermo-mechanical process data predicted by the finite element method (FEM) package T-Pack based on the software LARSTRAN were fed into a combination of physics based microstructure models for deformation texture (GIA), work hardening (3IVM), nucleation texture (ReNuc), and recrystallization texture (StaRT). The final simulated sheet texture was fed into a FEM simulation of cup drawing employing a new concept of interactively updated texture based yield locus predictions. The modelling results of texture development and anisotropy were compared to experimental data. The applicability to other alloys and processes is discussed.
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Inamura, T; Shimizu, R; Kim, H Y; Miyazaki, S; Hosoda, H
2016-04-01
The rolling rate (r) dependence of textures was investigated in the Ti-26Nb-3Al (mol%) alloy to reveal the conditions required to form the {001}<110> recrystallization texture, which is a desirable orientation for the β-titanium shape memory alloy. {001}<110> was the dominant cold-rolling texture when r=90% and it was transferred to the recrystallization texture without forming {112}<110>, which is detrimental for the isotropic mechanical properties of the rolled sheet. A further increase in r resulted in the formation of {112}<110> in both rolling and recrystallization textures. Therefore, r should be controlled to form only the {001}<110> rolling texture, because the {112}<110> texture can overwhelm the {001}<110> texture during recrystallization. Copyright © 2016 Elsevier B.V. All rights reserved.
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Wallis, Thomas S A; Funke, Christina M; Ecker, Alexander S; Gatys, Leon A; Wichmann, Felix A; Bethge, Matthias
2017-10-01
Our visual environment is full of texture-"stuff" like cloth, bark, or gravel as distinct from "things" like dresses, trees, or paths-and humans are adept at perceiving subtle variations in material properties. To investigate image features important for texture perception, we psychophysically compare a recent parametric model of texture appearance (convolutional neural network [CNN] model) that uses the features encoded by a deep CNN (VGG-19) with two other models: the venerable Portilla and Simoncelli model and an extension of the CNN model in which the power spectrum is additionally matched. Observers discriminated model-generated textures from original natural textures in a spatial three-alternative oddity paradigm under two viewing conditions: when test patches were briefly presented to the near-periphery ("parafoveal") and when observers were able to make eye movements to all three patches ("inspection"). Under parafoveal viewing, observers were unable to discriminate 10 of 12 original images from CNN model images, and remarkably, the simpler Portilla and Simoncelli model performed slightly better than the CNN model (11 textures). Under foveal inspection, matching CNN features captured appearance substantially better than the Portilla and Simoncelli model (nine compared to four textures), and including the power spectrum improved appearance matching for two of the three remaining textures. None of the models we test here could produce indiscriminable images for one of the 12 textures under the inspection condition. While deep CNN (VGG-19) features can often be used to synthesize textures that humans cannot discriminate from natural textures, there is currently no uniformly best model for all textures and viewing conditions.
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Methods of making textured catalysts
Werpy, Todd [West Richland, WA; Frye, Jr., John G.; Wang, Yong [Richland, WA; Zacher, Alan H [Kennewick, WA
2010-08-17
A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.
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Natural texture retrieval based on perceptual similarity measurement
NASA Astrophysics Data System (ADS)
Gao, Ying; Dong, Junyu; Lou, Jianwen; Qi, Lin; Liu, Jun
2018-04-01
A typical texture retrieval system performs feature comparison and might not be able to make human-like judgments of image similarity. Meanwhile, it is commonly known that perceptual texture similarity is difficult to be described by traditional image features. In this paper, we propose a new texture retrieval scheme based on texture perceptual similarity. The key of the proposed scheme is that prediction of perceptual similarity is performed by learning a non-linear mapping from image features space to perceptual texture space by using Random Forest. We test the method on natural texture dataset and apply it on a new wallpapers dataset. Experimental results demonstrate that the proposed texture retrieval scheme with perceptual similarity improves the retrieval performance over traditional image features.
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Wavelet-based image analysis system for soil texture analysis
NASA Astrophysics Data System (ADS)
Sun, Yun; Long, Zhiling; Jang, Ping-Rey; Plodinec, M. John
2003-05-01
Soil texture is defined as the relative proportion of clay, silt and sand found in a given soil sample. It is an important physical property of soil that affects such phenomena as plant growth and agricultural fertility. Traditional methods used to determine soil texture are either time consuming (hydrometer), or subjective and experience-demanding (field tactile evaluation). Considering that textural patterns observed at soil surfaces are uniquely associated with soil textures, we propose an innovative approach to soil texture analysis, in which wavelet frames-based features representing texture contents of soil images are extracted and categorized by applying a maximum likelihood criterion. The soil texture analysis system has been tested successfully with an accuracy of 91% in classifying soil samples into one of three general categories of soil textures. In comparison with the common methods, this wavelet-based image analysis approach is convenient, efficient, fast, and objective.
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Crystallographic texture of straight-rolled ?-uranium foils via neutron and X-ray diffraction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Einhorn, J. R.; Steiner, M. A.; Vogel, S. C.
The texture of recrystallized straight-rolled ?-uranium foils, a component in prospective irradiation target designs for medical isotope production, has been measured by neutron diffraction, as well as X-ray diffraction using both Cu and Mo sources. Variations in the penetration depth of neutron and X-ray radiation allow for determination of both the bulk and surface textures. The bulk ?-uranium foil texture is similar to the warm straight-rolled plate texture, with the addition of a notable splitting of the (001) poles along the transverse direction. The surface texture of the foils is similar to the bulk, with an additional (001) texture componentmore » that is oriented between the rolling and normal directions. Differences between the surface and bulk textures are expected to arise from shear forces during the rolling process and the influence that distinct strain histories have on subsequent texture evolution during recrystallization.« less
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Crystallographic texture of straight-rolled ?-uranium foils via neutron and X-ray diffraction
Einhorn, J. R.; Steiner, M. A.; Vogel, S. C.; ...
2017-05-25
The texture of recrystallized straight-rolled ?-uranium foils, a component in prospective irradiation target designs for medical isotope production, has been measured by neutron diffraction, as well as X-ray diffraction using both Cu and Mo sources. Variations in the penetration depth of neutron and X-ray radiation allow for determination of both the bulk and surface textures. The bulk ?-uranium foil texture is similar to the warm straight-rolled plate texture, with the addition of a notable splitting of the (001) poles along the transverse direction. The surface texture of the foils is similar to the bulk, with an additional (001) texture componentmore » that is oriented between the rolling and normal directions. Differences between the surface and bulk textures are expected to arise from shear forces during the rolling process and the influence that distinct strain histories have on subsequent texture evolution during recrystallization.« less
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NASA Technical Reports Server (NTRS)
Hudson, W. R.
1976-01-01
A microscopic surface texture is created by sputter etching a surface while simultaneously sputter depositing a lower sputter yield material onto the surface. A xenon ion beam source has been used to perform this texturing process on samples as large as three centimeters in diameter. Ion beam textured surface structures have been characterized with SEM photomicrographs for a large number of materials including Cu, Al, Si, Ti, Ni, Fe, Stainless steel, Au, and Ag. Surfaces have been textured using a variety of low sputter yield materials - Ta, Mo, Nb, and Ti. The initial stages of the texture creation have been documented, and the technique of ion beam sputter removal of any remaining deposited material has been studied. A number of other texturing parameters have been studied such as the variation of the texture with ion beam power, surface temperature, and the rate of texture growth with sputter etching time.
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Texture segmentation by genetic programming.
Song, Andy; Ciesielski, Vic
2008-01-01
This paper describes a texture segmentation method using genetic programming (GP), which is one of the most powerful evolutionary computation algorithms. By choosing an appropriate representation texture, classifiers can be evolved without computing texture features. Due to the absence of time-consuming feature extraction, the evolved classifiers enable the development of the proposed texture segmentation algorithm. This GP based method can achieve a segmentation speed that is significantly higher than that of conventional methods. This method does not require a human expert to manually construct models for texture feature extraction. In an analysis of the evolved classifiers, it can be seen that these GP classifiers are not arbitrary. Certain textural regularities are captured by these classifiers to discriminate different textures. GP has been shown in this study as a feasible and a powerful approach for texture classification and segmentation, which are generally considered as complex vision tasks.
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NASA Astrophysics Data System (ADS)
Menezes, Pradeep L.; Kishore; Kailas, Satish V.; Lovell, Michael R.
2015-01-01
Surface texture influences friction during sliding contact conditions. In the present investigation, the effect of surface texture and roughness of softer and harder counter materials on friction during sliding was analyzed using an inclined scratch testing system. In the experiments, two test configurations, namely (a) steel balls against aluminum alloy flats of different surface textures and (b) aluminum alloy pins against steel flats of different surface textures, are utilized. The surface textures were classified into unidirectionally ground, 8-ground, and randomly polished. For a given texture, the roughness of the flat surfaces was varied using grinding or polishing methods. Optical profilometer and scanning electron microscope were used to characterize the contact surfaces before and after the experiments. Experimental results showed that the surface textures of both harder and softer materials are important in controlling the frictional behavior. The softer material surface textures showed larger variations in friction between ground and polished surfaces. However, the harder material surface textures demonstrated a better control over friction among the ground surfaces. Although the effect of roughness on friction was less significant when compared to textures, the harder material roughness showed better correlations when compared to the softer material roughness.
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Control of mechanical response of freestanding PbZr0.52Ti0.48O3 films through texture
NASA Astrophysics Data System (ADS)
Das, Debashish; Sanchez, Luz; Martin, Joel; Power, Brian; Isaacson, Steven; Polcawich, Ronald G.; Chasiotis, Ioannis
2016-09-01
The texture of piezoelectric lead zirconate titanate (PZT) thin films plays a key role in their mechanical response and linearity in the stress vs. strain behavior. The open circuit mechanical properties of PZT films with controlled texture varying from 100% (001) to 100% (111) were quantified with the aid of direct strain measurements from freestanding thin film specimens. The texture was tuned using a highly {111}-textured Pt substrate and excess-Pb in the PbTiO3 seed layer. The mechanical and ferroelastic properties of 500 nm thick PZT (52/48) films were found to be strongly dependent on grain orientation: the lowest elastic modulus of 90 ± 2 GPa corresponded to pure (001) texture, and its value increased linearly with the percentage of (111) texture reaching 122 ± 3 GPa for pure (111) texture. These elastic modulus values were between those computed for transversely isotropic textured PZT films by using the soft and hard bulk PZT compliance coefficients. Pure (001) texture exhibited maximum non-linearity and ferroelastic domain switching, contrary to pure (111) texture that exhibited more linearity and the least amount of switching. A micromechanics model was employed to calculate the strain due to domain switching. The model fitted well the non-linearities in the experimental stress-strain curves of (001) and (111) textured PZT films, predicting 17% and 10% of switched 90° domains that initially were favorably aligned with the applied stress in (001) and (111) textured PZT films, respectively.
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NASA Astrophysics Data System (ADS)
Izawa, M. R. M.; Banerjee, N. R.; Flemming, R. L.; Bridge, N. J.; Schultz, C.
2010-03-01
Recent studies have demonstrated that terrestrial subaqueous basalts and hyaloclastites are suitable microbial habitats. During subaqueous basaltic volcanism, glass is produced by the quenching of basaltic magma upon contact with water. On Earth, microbes rapidly begin colonizing the glassy surfaces along fractures and cracks that have been exposed to water. Microbial colonization of basaltic glass leads to the alteration and modification of the rocks and produces characteristic granular and/or tubular bioalteration textures. Infilling of the alteration textures by minerals such as phyllosilicates, zeolites and titanite may enable their preservation through geologic time. Basaltic rocks are a major component of the Martian crust and are widespread on other solar system bodies. A variety of lines of evidence strongly suggests the long-term existence of abundant liquid water on ancient Mars. Recent orbiter, lander and rover missions have found evidence for the presence of transient liquid water on Mars, perhaps persisting to the present day. Many other solar system bodies, notably Europa, Enceladus and other icy satellites, may contain (or have once hosted) subaqueous basaltic glasses. The record of terrestrial glass bioalteration has been interpreted to extend as far back as ˜3.5 billion years ago and is widespread in oceanic crust and its metamorphic equivalents. The terrestrial record of glass bioalteration strongly suggests that glassy or formerly glassy basaltic rocks on extraterrestrial bodies that have interacted with liquid water are high-value targets for astrobiological exploration.
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Factors associated with compliance with viscosity-modified diet among dysphagic patients.
Shim, Jae Seong; Oh, Byung-Mo; Han, Tai Ryoon
2013-10-01
To investigate compliance with a viscosity-modified diet among Korean dysphagic patients and to determine which factors are associated with compliance. We retrospectively reviewed medical records of patients who had been recommended to use thickeners in the previous videofluoroscopic swallowing study (VFSS). Among 68 patients, 6 were excluded because tube feeding was required due to deterioration in their medical condition. Finally, 62 patients were included in the study. Patient compliance was assessed using their medical records by checking whether he or she had maintained thickener use until the next VFSS. To determine which factors affect compliance, the relationship between thickener use and patient characteristics, such as sex, age, inpatient/outpatient status, severity of dysphagia, aspiration symptoms, follow-up interval of VFSS, and current swallowing therapy status were assessed. For noncompliers, reasons for not using thickeners were investigated by telephone interview. Among 62 patients, 35 (56.5%) were compliers, and 27 (43.5%) were noncompliers. Eighteen (90%) of 20 inpatients had followed previous recommendations; however, only 17 (40.5%) of 42 outpatients had been using thickeners. Of patient characteristics, only admission status was significantly correlated with compliance. When asked about the reason why they had not used thickeners, noncompliers complained about dissatisfaction with texture and taste, greater difficulty in swallowing, and inconvenience of preparing meals. Among Korean dysphagic patients, compliance with a viscosity-modified liquid diet was only about 50%. Betterments of texture and taste along with patient education might be necessary to improve compliance with thickener use.
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NASA Astrophysics Data System (ADS)
Brosnan, Kristen H.
In this study, XRD and electron backscatter diffraction (EBSD) techniques were used to characterize the fiber texture in oriented PMN-28PT and the intensity data were fit with a texture model (the March-Dollase equation) that describes the texture in terms of texture fraction (f), and the width of the orientation distribution (r). EBSD analysis confirmed the <001> orientation of the microstructure, with no distinguishable randomly oriented, fine grain matrix. Although XRD rocking curve and EBSD data analysis gave similar f and r values, XRD rocking curve analysis was the most efficient and gave a complete description of texture fraction and texture orientation (f = 0.81 and r = 0.21, respectively). XRD rocking curve analysis was the preferred approach for characterization of the texture volume and the orientation distribution of texture in fiber-oriented PMN-PT. The dielectric, piezoelectric and electromechanical properties for random ceramic, 69 vol% textured, 81 vol% textured, and single crystal PMN-28PT were fully characterized and compared. The room temperature dielectric constant at 1 kHz for highly textured PMN-28PT was epsilonr ≥ 3600 with low dielectric loss (tan delta = 0.004). The temperature dependence of the dielectric constant for 81 vol% textured ceramic followed a similar trend as the single crystal PMN-28PT up to the rhombohedral to tetragonal transition temperature (TRT) at 104°C. 81 vol% textured PMN-28PT consistently displayed 60 to 65% of the single crystal PMN-28PT piezoelectric coefficient (d33) and 1.5 to 3.0 times greater than the random ceramic d33 (measured by Berlincourt meter, unipolar strain-field curves, IEEE standard resonance method, and laser vibrometry). The 81 vol% textured PMN-28PT displayed similarly low piezoelectric hysteresis as single crystal PMN-28PT measured by strain-field curves at 5 kV/cm. 81 vol% textured PMN-28PT and single crystal PMN-28PT displayed similar mechanical quality factors of QM = 74 and 76, respectively. The electromechanical coupling (k 33) of 81 vol% textured PMN-28PT (k33 = 0.79) was a significant fraction of single crystal (k33 = 0.91) and was higher than a commercial PMN-PT ceramic (k33 ˜ 0.74). The nonlinearity of the dielectric and piezoelectric response were investigated in textured ceramics and single crystal PMN-28PT using the Rayleigh approach. The reversible piezoelectric coefficient was found to increase significantly and the hysteretic contribution to the piezoelectric coefficient decreased significantly with an increase in texture volume. This indicates that increasing the texture volume decreases the non-180° domain wall contribution to the piezoelectric response in PMN-28PT. Finally, 81 vol% textured ceramics were also integrated into a Navy SONAR transducer design. In-water characterization of the transducers showed higher source levels, higher in-water coupling, higher acoustic intensity, and more bandwidth for the 81 vol% textured PMN-28PT tonpilz single elements compared to the ceramic PMN-28PT tonpilz element. In addition, an 81 vol% textured PMN-28PT tonpilz element showed large scale linearity in sound pressure levels as a function of drive level under high drive conditions (up to 2.33 kV/cm). The maximum electromechanical coupling obtained by the 81 vol% textured PMN-28PT transducer under high drive conditions was keff = 0.69. However, the resonance frequency shifted significantly during high drive tests (Deltafs = -19% at 3.7 kV/cm), evidence of a "soft" characteristic of the 81 vol% textured PMN-28PT, possibly caused by Sr2+ from the template particles. The results suggest there are limitations on the preload compressive stress (and thus drive level) for these textured ceramics, but this could be addressed with compositional modifications. The dielectric, piezoelectric and electromechanical properties have been significantly improved in textured PMN-PT ceramics of this study. Furthermore, scale-up in processing for incorporation into devices of highly textured ceramics with reproducible texture (and hence narrow properties distribution) was achieved in these materials. SONAR applications could benefit from textured ceramic parts because of their ease of processing, compositional homogeneity and potentially lower cost. (Abstract shortened by UMI.)
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Prieto, Iván; Martínez-Tillería, Karina; Martínez-Manchego, Luis; Montecinos, Sonia; Pugnaire, Francisco I; Squeo, Francisco A
2010-08-01
Hydraulic lift (HL) is the passive movement of water through the roots from deep wet to dry shallow soil layers when stomata are closed. HL has been shown in different ecosystems and species, and it depends on plant physiology and soil properties. In this study we explored HL patterns in several arid land shrubs, and developed a simple model to simulate the temporal evolution and magnitude of HL during a soil drying cycle under relatively stable climatic conditions. This model was then used to evaluate the influence of soil texture on the quantity of water lifted by shrubs in different soil types. We conducted transpiration suppression experiments during spring 2005 in Chile and spring 2008 in Spain on five shrub species that performed HL, Flourensia thurifera, Senna cumingii and Pleocarphus revolutus (Chile), Retama sphaerocarpa and Artemisia barrelieri (Spain). Shrubs were covered with a black, opaque plastic fabric for a period of 48-72 h, and soil water potential was recorded at different depths under the shrubs. While the shrubs remained covered, water potential continuously increased in shallow soil layers until the cover was removed. The model output indicated that the amount of water lifted by shrubs is heavily dependent on soil texture, as shrubs growing in loamy soils redistributed up to 3.6 times more water than shrubs growing on sandy soils. This could be an important consideration for species growing in soils with different textures, as their ability to perform HL would be context dependent.
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NASA Astrophysics Data System (ADS)
Zdanowicz, G.; Boudon, G.; Balcone-Boissard, H.; Cioni, R.; Mundula, F.; Orsi, G.; Civetta, L.; Agrinier, P.
2018-04-01
Plinian eruptions are characterized by high intensity and an overall steady character, and result in a stable convective column. The main processes controlling the dynamics of such steady and stable plume systems have been extensively investigated. Conversely, sub-Plinian eruptions are unsteady, as recorded by the large variability of the products and deposits. Our knowledge of the processes creating this unsteadiness on various timescales remains limited, and still requires more observations as well as theoretical and experimental investigation. Here, we focus on the sub-Plinian eruption of the Greenish Pumice (GP, 19,265 ± 105 BP), Mt. Somma-Vesuvius (Italy). On the basis of coupled geochemical and textural analyses of samples from the well-established stratigraphy of the GP deposits, we investigate volatiles (H2O, CO2, F, Cl) to better constrain the unsteady sub-Plinian eruptive style. This allows us to carry out a detailed study of the degassing processes in relation to the eruption dynamics. We find that degassing by open-system processes generally dominates throughout the entire eruption, but alternates with episodes of closed-system degassing. The fluctuating degassing regimes, responsible for the variable magma ascent rate within the conduit, are also responsible for the eruptive column instability. Volatile behavior is well correlated with textural heterogeneities of the eruptive products. Both reflect higher conduit heterogeneity than for Plinian eruptions, where we find a higher horizontal gradient in magma ascent velocity due to a smaller conduit diameter.
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Characterization of nuclear graphite elastic properties using laser ultrasonic methods
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zeng, Fan W; Han, Karen; Olasov, Lauren R
2015-01-01
Laser ultrasonic methods have been used to characterize the elastic behaviors of commercially-available and legacy nuclear graphites. Since ultrasonic techniques are sensitive to various aspects of graphite microstructure including preferred grain orientation, microcrack orientation and porosity, laser ultrasonics is a candidate technique for monitoring graphite degradation and structural integrity in environments expected in high-temperature, gas-cooled nuclear reactors. Aspects of materials texture can be assessed by studying ultrasonic wavespeeds as a function of propagation direction and polarization. Shear wave birefringence measurements, in particular, can be used to evaluate elastic anisotropy. In this work, laser ultrasonic measurements of graphite moduli have beenmore » made to provide insight into the relationship between the microstructures and the macroscopic stiffnesses of these materials. In particular, laser ultrasonic measurements have been made using laser line sources to produce shear waves with specific polarizations. By varying the line orientation relative to the sample, shear wave birefringence measurements have been recorded. Results from shear wave birefringence measurements show that an isostatically molded graphite, such as PCIB, behaves isotropically, while an extruded graphite, such as H-451, displays significant ultrasonic texture. Graphites have complicated microstructures that depend on the manufacturing processes used, and ultrasonic texture in these materials could originate from grain orientation and preferred microcrack alignment. Effects on material isotropy due to service related microstructural changes are possible and the ultimate aim of this work is to determine the degree to which these changes can be assessed nondestructively using laser ultrasonics measurements« less
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Texture evolution and mechanical behaviour of irradiated face-centred cubic metals
NASA Astrophysics Data System (ADS)
Chen, L. R.; Xiao, X. Z.; Yu, L.; Chu, H. J.; Duan, H. L.
2018-02-01
A physically based theoretical model is proposed to investigate the mechanical behaviour and crystallographic texture evolution of irradiated face-centred cubic metals. This model is capable of capturing the main features of irradiated polycrystalline materials including irradiation hardening, post-yield softening and plasticity localization. Numerical results show a good agreement with experimental data for both unirradiated and irradiated stress-strain relationships. The study of crystallographic texture reveals that the initial randomly distributed texture of unirradiated metals under tensile loading can evolve into a mixture of [111] and [100] textures. Regarding the irradiated case, crystallographic texture develops in a different way, and an extra part of [110] texture evolves into [100] and [111] textures. Thus, [100] and [111] textures become dominant more quickly compared with those of the unirradiated case for the reason that [100] and [111]-oriented crystals have higher strength, and their plastic deformation behaviours are more active than other oriented crystals. It can be concluded that irradiation-induced defects can affect both the mechanical behaviour and texture evolution of metals, both of which are closely related to irradiation hardening.
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Objective measurement of bread crumb texture
NASA Astrophysics Data System (ADS)
Wang, Jian; Coles, Graeme D.
1995-01-01
Evaluation of bread crumb texture plays an important role in judging bread quality. This paper discusses the application of image analysis methods to the objective measurement of the visual texture of bread crumb. The application of Fast Fourier Transform and mathematical morphology methods have been discussed by the authors in their previous work, and a commercial bread texture measurement system has been developed. Based on the nature of bread crumb texture, we compare the advantages and disadvantages of the two methods, and a third method based on features derived directly from statistics of edge density in local windows of the bread image. The analysis of various methods and experimental results provides an insight into the characteristics of the bread texture image and interconnection between texture measurement algorithms. The usefulness of the application of general stochastic process modelling of texture is thus revealed; it leads to more reliable and accurate evaluation of bread crumb texture. During the development of these methods, we also gained useful insights into how subjective judges form opinions about bread visual texture. These are discussed here.
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The neutron texture diffractometer at the China Advanced Research Reactor
NASA Astrophysics Data System (ADS)
Li, Mei-Juan; Liu, Xiao-Long; Liu, Yun-Tao; Tian, Geng-Fang; Gao, Jian-Bo; Yu, Zhou-Xiang; Li, Yu-Qing; Wu, Li-Qi; Yang, Lin-Feng; Sun, Kai; Wang, Hong-Li; Santisteban, J. r.; Chen, Dong-Feng
2016-03-01
The first neutron texture diffractometer in China has been built at the China Advanced Research Reactor, due to strong demand for texture measurement with neutrons from the domestic user community. This neutron texture diffractometer has high neutron intensity, moderate resolution and is mainly applied to study texture in commonly used industrial materials and engineering components. In this paper, the design and characteristics of this instrument are described. The results for calibration with neutrons and quantitative texture analysis of zirconium alloy plate are presented. The comparison of texture measurements with the results obtained in HIPPO at LANSCE and Kowari at ANSTO illustrates the reliability of the texture diffractometer. Supported by National Nature Science Foundation of China (11105231, 11205248, 51327902) and International Atomic Energy Agency-TC program (CPR0012)
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Tozer, Daniel J; Zeestraten, Eva; Lawrence, Andrew J; Barrick, Thomas R; Markus, Hugh S
2018-06-04
Magnetic resonance imaging may be useful to assess disease severity in cerebral small vessel disease (SVD), identify those individuals who are most likely to progress to dementia, monitor disease progression, and act as surrogate markers to test new therapies. Texture analysis extracts information on the relationship between signal intensities of neighboring voxels. A potential advantage over techniques, such as diffusion tensor imaging, is that it can be used on clinically obtained magnetic resonance sequences. We determined whether texture parameters (TP) were abnormal in SVD, correlated with cognitive impairment, predicted cognitive decline, or conversion to dementia. In the prospective SCANS study (St George's Cognition and Neuroimaging in Stroke), we assessed TP in 121 individuals with symptomatic SVD at baseline, 99 of whom attended annual cognitive testing for 5 years. Conversion to dementia was recorded for all subjects during the 5-year period. Texture analysis was performed on fluid-attenuated inversion recovery and T1-weighted images. The TP obtained from the SVD cohort were cross-sectionally compared with 54 age-matched controls scanned on the same magnetic resonance imaging system. There were highly significant differences in several TP between SVD cases and controls. Within the SVD population, TP were highly correlated to other magnetic resonance imaging parameters (brain volume, white matter lesion volume, lacune count). TP correlated with executive function and global function at baseline and predicted conversion to dementia, after controlling for age, sex, premorbid intelligence quotient, and magnetic resonance parameters. TP, which can be obtained from routine clinical images, are abnormal in SVD, and the degree of abnormality correlates with executive dysfunction and global cognition at baseline and decline during 5 years. TP may be useful to assess disease severity in clinically collected data. This needs testing in data clinically acquired across multiple sites. © 2018 The Authors.
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Proterozoic metamorphism and uplift history of the north-central Laramie Mountains, Wyoming, USA
Patel, S.C.; Frost, B.R.; Chamberlain, K.R.; Snyder, G.L.
1999-01-01
The Laramie Mountains of south-eastern Wyoming contain two metamorphic domains that are separated by the 1.76 Ga. Laramie Peak shear zone (LPSZ). South of the LPSZ lies the Palmer Canyon block, where apatite U-Pb ages are c. 1745 Ma and the rocks have undergone Proterozoic kyanite-grade Barrovian metamorphism. In contrast, in the Laramie Peak block, north of the shear zone, the U-Pb apatite ages are 2.4-2.1 Ga, the granitic rocks are unmetamorphosed and supracrustal rocks record only low-T amphibolite facies metamorphism that is Archean in age. Peak mineral assemblages in the Palmer Canyon block include (a) quartz-biotite-plagioclase-garnet-staurolite-kyanite in the pelitic schists; (b) quartz-biotite-plagioclase-low-Ca amphiboles-kyanite in Mg-Al-rich schists, and locally (c) hornblende-plagioclase-garnet in amphibolites. All rock types show abundant textural evidence of decompression and retrograde re-equilibration. Notable among the texturally late minerals are cordierite and sapphirine, which occur in coronas around kyanite in Mg-Al-rich schists. Thermobarometry from texturally early and late assemblages for samples from different areas within the Palmer Canyon block define decompression from > 7 kbar to < 3 kbar. The high-pressure regional metamorphism is interpreted to be a response to thrusting associated with the Medicine Bow orogeny at c. 1.78-1.76 Ga. At this time, the north-central Laramie Range was tectonically thickened by as much as 12 km. This crustal thickening extended for more than 60 km north of the Cheyenne belt in southern Wyoming. Late in the orogenic cycle, rocks of the Palmer Canyon block were uplifted and unroofed as the result of transpression along the Laramie Peak shear zone to produce the widespread decompression textures. The Proterozoic tectonic history of the central Laramie Range is similar to exhumation that accompanied late-orogenic oblique convergence in many Phanerozoic orogenic belts.
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Peng, Jinhua; Zhang, Zhen; Liu, Zhao; Li, Yaozu; Guo, Peng; Zhou, Wei; Wu, Yucheng
2018-03-08
Friction stir processing (FSP) was used to achieve grain refinement on Mg-Al-Zn alloys, which also brought in significant texture modification. The different micro-texture characteristics were found to cause irregular micro-hardness distribution in FSPed region. The effects of texture and grain size were investigated by comparative analyses with strongly textured rolling sheet. Grain refinement improved both strength and elongation in condition of a basal texture while such led to an increment in yield stress and a drop in elongation and ultimate stress when the basal texture was modified by FSP.
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Magma deformation and emplacement in rhyolitic dykes
NASA Astrophysics Data System (ADS)
McGowan, Ellen; Tuffen, Hugh; James, Mike; Wynn, Peter
2016-04-01
Silicic eruption mechanisms are determined by the rheological and degassing behaviour of highly-viscous magma ascending within shallow dykes and conduits. However, we have little knowledge of how magmatic behaviour shifts during eruptions as dykes and conduits evolve. To address this we have analysed the micro- to macro-scale textures in shallow, dissected rhyolitic dykes at the Tertiary Húsafell central volcano in west Iceland. Dyke intrusion at ~3 Ma was associated with the emplacement of subaerial rhyolitic pyroclastic deposits following caldera formation[1]. The dykes are dissected to ~500 m depth, 2-3 m wide, and crop out in two stream valleys with 5-30 m-long exposures. Dykes intrude diverse country rock types, including a welded ignimbrite, basaltic lavas, and glacial conglomerate. Each of the six studied dykes is broadly similar, exhibiting obsidian margins and microcrystalline cores. Dykes within pre-fractured lava are surrounded by external tuffisite vein networks, which are absent from dykes within conglomerate, whereas dykes failed to penetrate the ignimbrite. Obsidian at dyke margins comprises layers of discrete colour. These display dramatic thickness variations and collapsed bubble structures, and are locally separated by zones of welded, brecciated and flow-banded obsidian. We use textural associations to present a detailed model of dyke emplacement and evolution. Dykes initially propagated with the passage of fragmented, gas-charged magma and generation of external tuffisite veins, whose distribution was strongly influenced by pre-existing fractures in the country rock. External tuffisites retained permeability throughout dyke emplacement due to their high lithic content. The geochemically homogenous dykes then evolved via incremental magma emplacement, with shear deformation localised along emplacement boundary layers. Shear zones migrated between different boundary layers, and bubble deformation promoted magma mobility. Brittle-ductile microtextures and bubble populations point towards multi-step and multi-rate magma decompression, and we propose that gas overpressure in bubbles created tensile micro-cracks, whose coalescence culminated in macroscopic fragmentation. Finally, we infer that bubble collapse was associated with both localised brittle magma failure at shallow levels and macroscopic magma fragmentation deeper within the magmatic system. Processes recorded by the Húsafell dyke exposures appear akin to those occurring in the shallow conduits of Chaitén and Cordón Caulle during recent rhyolitic eruptions[2,3]. The field evidence presented here therefore bridges the gap between eruption observations and the deeper geological record, and so provides new insight into conduit evolution during explosive-hybrid-effusive eruptive phases[2,3] and the influence of country rock. The parallels between intrusive dyke textures and those found in extruded silicic lavas suggest that processes recorded in the dykes, including bubble collapse, volatile resorption, thermally-induced vesiculation and the formation of brittle-ductile shear zones, also occur within extrusive flows, contributing to their extreme textural heterogeneity[4]. [1] Saemundsson K & Noll H (1974) Jökull 24, 40-59. [2] Schipper CI et al. (2013) JVGR, 262, 25-37. [3] Castro JC et al. (2014) EPSL, 405, 52-61. [4] Shields JK et al. (2016) JVGR, 310, 137-158.
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NASA Astrophysics Data System (ADS)
Li, Ji-Lei; Gao, Jun; Klemd, Reiner; John, Timm; Wang, Xin-Shui
2016-09-01
The oxidized nature of the sub-arc mantle and hence arc magmas is generally interpreted as a result of the migration of subduction-related oxidizing fluids or melts from the descending slab into the mantle wedge. This is of particular importance seeing that the oxidization state of sub-arc magmas seems to play a key role in the formations of arc-related ore deposits. However, direct constraints on the redox state of subducted oceanic crust are sparse. Here, we provide a detailed petrological investigation on sulfide- and oxide-bearing eclogites, blueschists, micaschists, eclogite-facies and retrograde veins from the Akeyazi high-pressure (HP) terrane (NW China) in order to gain insight into the redox processes recorded in a subducting oceanic slab. Sulfides in these rocks are mainly pyrite and minor pyrrhotite, chalcopyrite, bornite, molybdenite, sphalerite and chalcocite, including exsolution textures of bornite-chalcopyrite intergrowth. Magnetite, ilmenite and pyrite occur as inclusions in garnet, whereas sulfides are dominant in the matrix. Large pyrite grains in the matrix contain inclusions of garnet, omphacite and other HP index minerals. However, magnetite replacing pyrite textures are commonly observed in the retrograded samples. The eclogite-facies and retrograde veins display two fluid events, which are characterized by an early sulfide-bearing and a later magnetite-bearing mineral assemblage, respectively. Textural and petrological evidences show that the sulfides were mainly formed during HP metamorphism. Mineral assemblage transitions reveal that the relative oxygen fugacity of subducted oceanic crust decreases slightly with increasing depths. However, according to oxygen mass balance calculations, based on the oxygen molar quantities ( nO2), the redox conditions remain constant during HP metamorphism. At shallow levels (<60 km) in the subduction channel, interaction with oxidized fluid seems to have caused an increase of the oxygen fugacity and the oxidation state of exhuming HP rocks. This study suggests that oxygen components are not released in significant amounts during HP metamorphism of subducted oceanic crust and, thus, cannot be responsible for oxidizing the mantle wedge and increasing the oxidation state of sub-arc mantle melts.
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NASA Astrophysics Data System (ADS)
Miyagi, L. M.; Kunz, M.; Couper, S.; Lin, F.; Yan, J.; Doran, A.; MacDowell, A. A.
2017-12-01
The rheology of rocks and minerals in the Earth's deep interior plays a primary role in controlling large scale geodynamic processes such as mantle convection and slab subduction. Plastic deformation resulting from these processes can lead to texture development and associated seismic anisotropy. If a detailed understanding of the link between deformation and seismic anisotropy is established, observations of seismic anisotropy can be used to understand the dynamic state in the deep Earth. However, performing deformation experiments at lower mantle pressure and temperature conditions are extremely challenging. Thus most deformation studies have been performed either at room temperature and high pressure or at reduced pressures and high temperature. Only a few extraordinary efforts have attained pressures and temperatures relevant to lower mantle. Therefore our ability to interpret observations of lower mantle seismic anisotropy in terms of mantle flow models remains limited. In order to expand the pressure and temperature range available for deformation of deep Earth relevant mineral phases, we have developed a laser heating system for in-situ double-sided heating in radial diffraction geometry at beamline 12.2.2 of the Advanced Light Source of Lawrence Berkeley National Laboratory. This allows texture and lattice strain measurements to be recorded at simultaneous high pressures and temperatures in the diamond anvil cell. This new system is integrated into the newly built axial laser heating system to allow for rapid and reliable transitioning between double-sided laser heating in axial and radial geometries. Transitioning to radial geometry is accomplished by redirecting the laser and imaging paths from 0° and 180° to 90° and 270°. To redirect the 90° path, a motorized periscope mirror pair with an objective lens can be inserted into the downstream axial beam path. The 270° redirection is accomplished by removing the upstream axial objective lens and manually installing a small assembly carrying 2 infrared mirrors and an objective lens. Using this system we have performed two pilot studies recording texture and lattice strain development during deformation of FeO up to 1300 K and 45 GPa and bridgmanite up to 1600 K and 80 GPa.
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Texture and anisotropy in ferroelectric lead metaniobate
NASA Astrophysics Data System (ADS)
Iverson, Benjamin John
Ferroelectric lead metaniobate, PbNb2O6, is a piezoelectric ceramic typically used because of its elevated Curie temperature and anisotropic properties. However, the piezoelectric constant, d33, is relatively low in randomly oriented ceramics when compared to other ferroelectrics. Crystallographic texturing is often employed to increase the piezoelectric constant because the spontaneous polarization axes of grains are better aligned. In this research, crystallographic textures induced through tape casting are distinguished from textures induced through electrical poling. Texture is described using multiple quantitative approaches utilizing X-ray and neutron time-of-flight diffraction. Tape casting lead metaniobate with an inclusion of acicular template particles induces an orthotropic texture distribution. Templated grain growth from seed particles oriented during casting results in anisotropic grain structures. The degree of preferred orientation is directly linked to the shear behavior of the tape cast slurry. Increases in template concentration, slurry viscosity, and casting velocity lead to larger textures by inducing more particle orientation in the tape casting plane. The maximum 010 texture distributions were two and a half multiples of a random distribution. Ferroelectric texture was induced by electrical poling. Electric poling increases the volume of material oriented with the spontaneous polarization direction in the material. Samples with an initial paraelectric texture exhibit a greater change in the domain volume fraction during electrical poling than randomly oriented ceramics. In tape cast samples, the resulting piezoelectric response is proportional to the 010 texture present prior to poling. This results in property anisotropy dependent on initial texture. Piezoelectric properties measured on the most textured ceramics were similar to those obtained with a commercial standard.
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Kontos, Despina; Bakic, Predrag R.; Carton, Ann-Katherine; Troxel, Andrea B.; Conant, Emily F.; Maidment, Andrew D.A.
2009-01-01
Rationale and Objectives Studies have demonstrated a relationship between mammographic parenchymal texture and breast cancer risk. Although promising, texture analysis in mammograms is limited by tissue superimposition. Digital breast tomosynthesis (DBT) is a novel tomographic x-ray breast imaging modality that alleviates the effect of tissue superimposition, offering superior parenchymal texture visualization compared to mammography. Our study investigates the potential advantages of DBT parenchymal texture analysis for breast cancer risk estimation. Materials and Methods DBT and digital mammography (DM) images of 39 women were analyzed. Texture features, shown in studies with mammograms to correlate with cancer risk, were computed from the retroareolar breast region. We compared the relative performance of DBT and DM texture features in correlating with two measures of breast cancer risk: (i) the Gail and Claus risk estimates, and (ii) mammographic breast density. Linear regression was performed to model the association between texture features and increasing levels of risk. Results No significant correlation was detected between parenchymal texture and the Gail and Claus risk estimates. Significant correlations were observed between texture features and breast density. Overall, the DBT texture features demonstrated stronger correlations with breast percent density (PD) than DM (p ≤0.05). When dividing our study population in groups of increasing breast PD, the DBT texture features appeared to be more discriminative, having regression lines with overall lower p-values, steeper slopes, and higher R2 estimates. Conclusion Although preliminary, our results suggest that DBT parenchymal texture analysis could provide more accurate characterization of breast density patterns, which could ultimately improve breast cancer risk estimation. PMID:19201357
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Power spectral ensity of markov texture fields
NASA Technical Reports Server (NTRS)
Shanmugan, K. S.; Holtzman, J. C.
1984-01-01
Texture is an important image characteristic. A variety of spatial domain techniques were proposed for extracting and utilizing textural features for segmenting and classifying images. for the most part, these spatial domain techniques are ad hos in nature. A markov random field model for image texture is discussed. A frequency domain description of image texture is derived in terms of the power spectral density. This model is used for designing optimum frequency domain filters for enhancing, restoring and segmenting images based on their textural properties.
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[Visual Texture Agnosia in Humans].
Suzuki, Kyoko
2015-06-01
Visual object recognition requires the processing of both geometric and surface properties. Patients with occipital lesions may have visual agnosia, which is impairment in the recognition and identification of visually presented objects primarily through their geometric features. An analogous condition involving the failure to recognize an object by its texture may exist, which can be called visual texture agnosia. Here we present two cases with visual texture agnosia. Case 1 had left homonymous hemianopia and right upper quadrantanopia, along with achromatopsia, prosopagnosia, and texture agnosia, because of damage to his left ventromedial occipitotemporal cortex and right lateral occipito-temporo-parietal cortex due to multiple cerebral embolisms. Although he showed difficulty matching and naming textures of real materials, he could readily name visually presented objects by their contours. Case 2 had right lower quadrantanopia, along with impairment in stereopsis and recognition of texture in 2D images, because of subcortical hemorrhage in the left occipitotemporal region. He failed to recognize shapes based on texture information, whereas shape recognition based on contours was well preserved. Our findings, along with those of three reported cases with texture agnosia, indicate that there are separate channels for processing texture, color, and geometric features, and that the regions around the left collateral sulcus are crucial for texture processing.
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Development of low friction snake-inspired deterministic textured surfaces
NASA Astrophysics Data System (ADS)
Cuervo, P.; López, D. A.; Cano, J. P.; Sánchez, J. C.; Rudas, S.; Estupiñán, H.; Toro, A.; Abdel-Aal, H. A.
2016-06-01
The use of surface texturization to reduce friction in sliding interfaces has proved successful in some tribological applications. However, it is still difficult to achieve robust surface texturing with controlled designer-functionalities. This is because the current existing gap between enabling texturization technologies and surface design paradigms. Surface engineering, however, is advanced in natural surface constructs especially within legless reptiles. Many intriguing features facilitate the tribology of such animals so that it is feasible to discover the essence of their surface construction. In this work, we report on the tribological behavior of a novel class of surfaces of which the spatial dimensions of the textural patterns originate from micro-scale features present within the ventral scales of pre-selected snake species. Mask lithography was used to produce implement elliptical texturizing patterns on the surface of titanium alloy (Ti6Al4V) pins. To study the tribological behavior of the texturized pins, pin-on-disc tests were carried out with the pins sliding against ultra-high molecular weight polyethylene discs with no lubrication. For comparison, two non-texturized samples were also tested under the same conditions. The results show the feasibility of the texturization technique based on the coefficient of friction of the textured surfaces to be consistently lower than that of the non-texturized samples.
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Aural analysis of image texture via cepstral filtering and sonification
NASA Astrophysics Data System (ADS)
Rangayyan, Rangaraj M.; Martins, Antonio C. G.; Ruschioni, Ruggero A.
1996-03-01
Texture plays an important role in image analysis and understanding, with many applications in medical imaging and computer vision. However, analysis of texture by image processing is a rather difficult issue, with most techniques being oriented towards statistical analysis which may not have readily comprehensible perceptual correlates. We propose new methods for auditory display (AD) and sonification of (quasi-) periodic texture (where a basic texture element or `texton' is repeated over the image field) and random texture (which could be modeled as filtered or `spot' noise). Although the AD designed is not intended to be speech- like or musical, we draw analogies between the two types of texture mentioned above and voiced/unvoiced speech, and design a sonification algorithm which incorporates physical and perceptual concepts of texture and speech. More specifically, we present a method for AD of texture where the projections of the image at various angles (Radon transforms or integrals) are mapped to audible signals and played in sequence. In the case of random texture, the spectral envelopes of the projections are related to the filter spot characteristics, and convey the essential information for texture discrimination. In the case of periodic texture, the AD provides timber and pitch related to the texton and periodicity. In another procedure for sonification of periodic texture, we propose to first deconvolve the image using cepstral analysis to extract information about the texton and horizontal and vertical periodicities. The projections of individual textons at various angles are used to create a voiced-speech-like signal with each projection mapped to a basic wavelet, the horizontal period to pitch, and the vertical period to rhythm on a longer time scale. The sound pattern then consists of a serial, melody-like sonification of the patterns for each projection. We believe that our approaches provide the much-desired `natural' connection between the image data and the sounds generated. We have evaluated the sonification techniques with a number of synthetic textures. The sound patterns created have demonstrated the potential of the methods in distinguishing between different types of texture. We are investigating the application of these techniques to auditory analysis of texture in medical images such as magnetic resonance images.
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Soil Texture Estimates: A Tool to Compare Texture-by-Feel and Lab Data
ERIC Educational Resources Information Center
Franzmeier, D.P.; Owens, P.R.
2008-01-01
Soil texture is a fundamental soil property that impacts agricultural and engineering land-use. Comparing texture estimates-by-feel to laboratory-known values to calibrate fingers is a common practice. As educators, it is difficult to assess this field skill consistently and fairly. The instructor may give full credit for the correct texture class…
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Fancher, Chris M.; Blendell, John E.; Bowman, Keith J.
2017-02-07
A method leveraging Rietveld full-pattern texture analysis to decouple induced domain texture from a preferred grain orientation is presented in this paper. The proposed method is demonstrated by determining the induced domain texture in a polar polymorph of 100 oriented 0.91Bi 1/2Na 1/2TiO 3-0.07BaTiO 3-0.02K 0.5Na 0.5NbO 3. Domain textures determined using the present method are compared with results obtained via single peak fitting. Texture determined using single peak fitting estimated more domain alignment than that determined using the Rietveld based method. These results suggest that the combination of grain texture and phase transitions can lead to single peak fittingmore » under or over estimating domain texture. Finally, while demonstrated for a bulk piezoelectric, the proposed method can be applied to quantify domain textures in multi-component systems and thin films.« less
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Visual texture perception via graph-based semi-supervised learning
NASA Astrophysics Data System (ADS)
Zhang, Qin; Dong, Junyu; Zhong, Guoqiang
2018-04-01
Perceptual features, for example direction, contrast and repetitiveness, are important visual factors for human to perceive a texture. However, it needs to perform psychophysical experiment to quantify these perceptual features' scale, which requires a large amount of human labor and time. This paper focuses on the task of obtaining perceptual features' scale of textures by small number of textures with perceptual scales through a rating psychophysical experiment (what we call labeled textures) and a mass of unlabeled textures. This is the scenario that the semi-supervised learning is naturally suitable for. This is meaningful for texture perception research, and really helpful for the perceptual texture database expansion. A graph-based semi-supervised learning method called random multi-graphs, RMG for short, is proposed to deal with this task. We evaluate different kinds of features including LBP, Gabor, and a kind of unsupervised deep features extracted by a PCA-based deep network. The experimental results show that our method can achieve satisfactory effects no matter what kind of texture features are used.
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Shape from texture: an evaluation of visual cues
NASA Astrophysics Data System (ADS)
Mueller, Wolfgang; Hildebrand, Axel
1994-05-01
In this paper an integrated approach is presented to understand and control the influence of texture on shape perception. Following Gibson's hypotheses, which states that texture is a mathematically and psychological sufficient stimulus for surface perception, we evaluate different perceptual cues. Starting out from a perception-based texture classification introduced by Tamura et al., we build up a uniform sampled parameter space. For the synthesis of some of our textures we use the texture description language HiLDTe. To acquire the desired texture specification we take advantage of a genetic algorithm. Employing these textures we practice a number of psychological tests to evaluate the significance of the different texture features. A comprehension of the results derived from the psychological tests is done to constitute new shape analyzing techniques. Since the vanishing point seems to be an important visual cue we introduce the Hough transform. A prospective of future work within the field of visual computing is provided within the final section.
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Yin, Anmin; Wang, Xiaochen; Glorieux, Christ; Yang, Quan; Dong, Feng; He, Fei; Wang, Yanlong; Sermeus, Jan; Van der Donck, Tom; Shu, Xuedao
2017-07-01
A photoacoustic, laser ultrasonics based approach in an Impulsive Stimulated Scattering (ISS) implementation was used to investigate the texture in polycrystalline metal plates. The angular dependence of the 'polycrystalline' surface acoustic wave (SAW) velocity measured along regions containing many grains was experimentally determined and compared with simulated results that were based on the angular dependence of the 'single grain' SAW velocity within single grains and the grain orientation distribution. The polycrystalline SAW velocities turn out to vary with texture. The SAW velocities and their angular variations for {110} texture were found to be larger than that the ones for {111} texture or the strong γ fiber texture. The SAW velocities for {001} texture were larger than for {111} texture, but with almost the same angular dependence. The results infer the feasibility to apply angular SAW angular dispersion measurements by laser ultrasonics for on-line texture monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.
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2014-10-07
While yesterday image showed a texture of oval depressions swiss cheese, this image from NASA 2001 Mars Odyssey spacecraft shows a linear surface texture of the south polar cap. This texture is described as looking like a thumbprint.
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Adaptive texture filtering for defect inspection in ultrasound images
NASA Astrophysics Data System (ADS)
Zmola, Carl; Segal, Andrew C.; Lovewell, Brian; Nash, Charles
1993-05-01
The use of ultrasonic imaging to analyze defects and characterize materials is critical in the development of non-destructive testing and non-destructive evaluation (NDT/NDE) tools for manufacturing. To develop better quality control and reliability in the manufacturing environment advanced image processing techniques are useful. For example, through the use of texture filtering on ultrasound images, we have been able to filter characteristic textures from highly-textured C-scan images of materials. The materials have highly regular characteristic textures which are of the same resolution and dynamic range as other important features within the image. By applying texture filters and adaptively modifying their filter response, we have examined a family of filters for removing these textures.
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Description of textures by a structural analysis.
Tomita, F; Shirai, Y; Tsuji, S
1982-02-01
A structural analysis system for describing natural textures is introduced. The analyzer automatically extracts the texture elements in an input image, measures their properties, classifies them into some distinctive classes (one ``ground'' class and some ``figure'' classes), and computes the distributions of the gray level, the shape, and the placement of the texture elements in each class. These descriptions are used for classification of texture images. An analysis-by-synthesis method for evaluating texture analyzers is also presented. We propose a synthesizer which generates a texture image based on the descriptions. By comparing the reconstructed image with the original one, we can see what information is preserved and what is lost in the descriptions.
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Ultra-High Sensitive Magnetoelectric Nanocomposite Current Sensors
2009-12-01
textured grains. In the sintered composite, PZT -PZN...constant increases by 50% for the moderate degree of texturing . Figure 8 shows the ME coefficient of trilayer with textured PZT – PZN as function of DC...1000 1100 d E /d H ( m V /c m .O e ) Field (Oe) NCZF - PZT - PZN ( textured ) - NCZF Figure 8: ME coefficient of the textured ME composite.
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Texture generation for use in synthetic infrared scenes
NASA Astrophysics Data System (ADS)
Ota, Clem Z.; Rollins, John M.; Bleiweiss, Max P.
1996-06-01
In the process of creating synthetic scenes for use in simulations/visualizations, texture is used as a surrogate to 'high' spatial definition. For example, if one were to measure the location of every blade of grass and all of the characteristics of each blade of grass in a lawn, then in the process of composing a scene of the lawn, it would be expected that the result would appear 'real;' however, because this process is excruciatingly laborious, various techniques have been devised to place the required details in the scene through the use of texturing. Experience gained during the recent Smart Weapons Operability Enhancement Joint Test and Evaluation (SWOE JT&E) has shown the need for higher fidelity texturing algorithms and a better parameterization of those that are in use. In this study, four aspects of the problem have been analyzed: texture extraction, texture insertion, texture metrics, and texture creation algorithms. The results of extracting real texture from an image, measuring it with a variety of metrics, and generating similar texture with three different algorithms is presented. These same metrics can be used to define clutter and to make comparisons between 'real' and synthetic (or artificial) scenes in an objective manner.
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NASA Astrophysics Data System (ADS)
Khan, Firoz; Baek, Seong-Ho; Kaur, Jasmeet; Fareed, Imran; Mobin, Abdul; Kim, Jae Hyun
2015-09-01
In this paper, we present an optical model that simulates the light trapping and scattering effects of a paraboloid texture surface first time. This model was experimentally verified by measuring the reflectance values of the periodically textured silicon (Si) surface with the shape of a paraboloid under different conditions. A paraboloid texture surface was obtained by electrochemical etching Si in the solution of hydrofluoric acid, dimethylsulfoxide (DMSO), and deionized (DI) water. The paraboloid texture surface has the advantage of giving a lower reflectance value than the hemispherical, random pyramidal, and regular pyramidal texture surfaces. In the case of parabola, the light can be concentrated in the direction of the Si surface compared to the hemispherical, random pyramidal, and regular pyramidal textured surfaces. Furthermore, in a paraboloid textured surface, there can be a maximum value of 4 or even more by anisotropic etching duration compared to the hemispherical or pyramidal textured surfaces which have a maximum h/ D (depth and diameter of the texture) value of 0.5. The reflectance values were found to be strongly dependent on the h/ D ratio of the texture surface. The measured reflectance values were well matched with the simulated ones. The minimum reflectance value of ~4 % was obtained at a wavelength of 600 nm for an h/ D ratio of 3.75. The simulation results showed that the reflectance value for the h/ D ratio can be reduced to ~0.5 % by reducing the separations among the textures. This periodic paraboloidal structure can be applied to the surface texturing technique by substituting with a conventional pyramid textured surface or moth-eye antireflection coating.
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Annealing texture of nanostructured IF steel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jamaati, Roohollah, E-mail: jamaati@nit.ac.ir
In the present work, the evolution of annealing texture in nanostructured interstitial free steel fabricated via accumulative roll bonding (ARB) process was investigated. Textural evolution after post-annealing of ARB-processed samples was evaluated using X-ray diffraction. There were several texture transitions in the γ-fiber and ζ-fiber during ARB and post-annealing treatment. It was found that with increasing the number of ARB cycles, the volume fraction of the low angle grain boundary decreased and the high angle grain boundary fraction increased. Also, the shear texture was dominant after the first cycle, while for other samples, the rolling texture was dominant. The one-cyclemore » sample clearly indicated a weak α-fiber and γ-fiber and a relatively strong ζ-fiber. In addition, during the recrystallization and before the grain growth, the intensity of α-fiber and γ-fiber decreased, the intensity of ζ-fiber increased, and the intensity of (011)〈100〉 orientation in the ε-fiber and η-fiber increased. Moreover, it was concluded that the transition from the rolling texture to the shear one was a sign of occurrence of the recrystallization (before the grain growth). Finally, with increasing the number of ARB cycles, the intensity of rolling and shear textures saturated and a stable texture formed. - Highlights: • There were texture transitions in the γ-fiber and ζ-fiber. • When the number of cycles increased, the low angle grain boundaries decreased. • The shear texture was dominant after the first cycle. • Transition from rolling texture to shear one was a sign of recrystallization. • With increasing the number of ARB cycles, a stable texture formed.« less
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NASA Astrophysics Data System (ADS)
Staudigel, H.; Furnes, H.; McLoughlin, N.; Banerjee, N.
2007-12-01
Fe and Mn oxidizing microbes interact with their environment through the microbially mediated formation of Fe/Mn oxides and through the corrosion textures they may leave behind in the solids they colonize and from which they extract nutrients. Understanding the geo-biology of Fe and Mn oxidation may focus on the study of the microbes themselves, the mineral products, its biocorrosion features and the relationships between these types of observations. We have reviewed our own data on glass bio-corrosion and in particular the wider literature on microbial mineral tunneling to develop a two stage biocorrosion model for volcanic glass that offers feedback for our understanding of the mechanisms and the dynamics of microbial dissolution. Traces of microbially mediated dissolution of volcanic glass are commonly observed in volcanic glass found in submarine volcanoes on the seafloor, and in uplifted submarine volcanoes of almost any geological age back to the origin of life. Two main bioalteration textures care observed, granular and tubular. Based on a comparison of these features in particular with tunneling by ectomycorrhizal fungi, we propose two distinct types of biocorrosion that affects glass: (1) Granular alteration textures, made up of colonies of microbe-sized, near spherical mineral - filled cavities that form irregular clusters ranging to a tens of micron thick bands at the glas surfaces. These granular textures are interpreted as the result of microbial colonization. accompanied by dissolution of the glass in their contact surface, deposition of authigenic minerals and the formation of a biofilm, that eventually seals the glass from easy access by seawater for hydration, or from microbes accessing Fe (II) in the glass. (2) The most spectacular bioalteration feature, repesented by the formation of tubes cannot be easily formed by the former mechanism because near spherical, individual microbes are likely not to produce the directionality that is required to produce the near linear or sometimes coiled tubes. Instead, we envision the activity of hyphae-like organelles or filaments, that may radiate out from a host body located in direct contact with circulating water, possibly penetrating a biofilm and entering/drilling into the fresh glass. Such microdrilling is well described in soils, where hyphae can slowly drill into silicates, in a process that takes about 1000 years to become visible as tunnels.
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Unravelling textural heterogeneity in obsidian: Shear-induced outgassing in the Rocche Rosse flow
NASA Astrophysics Data System (ADS)
Shields, J. K.; Mader, H. M.; Caricchi, L.; Tuffen, H.; Mueller, S.; Pistone, M.; Baumgartner, L.
2016-01-01
Obsidian flow emplacement is a complex and understudied aspect of silicic volcanism. Of particular importance is the question of how highly viscous magma can lose sufficient gas in order to erupt effusively as a lava flow. Using an array of methods we study the extreme textural heterogeneity of the Rocche Rosse obsidian flow in Lipari, a 2 km long, 100 m thick, ~ 800 year old lava flow, with respect to outgassing and emplacement mechanisms. 2D and 3D vesicle analyses and density measurements are used to classify the lava into four textural types: 'glassy' obsidian (< 15% vesicles), 'pumiceous' lava (> 40% vesicles), high aspect ratio, 'shear banded' lava (20-40% vesicles) and low aspect ratio, 'frothy' obsidian with 30-60% vesicles. Textural heterogeneity is observed on all scales (m to μm) and occurs as the result of strongly localised strain. Magnetic fabric, described by oblate and prolate susceptibility ellipsoids, records high and variable degrees of shearing throughout the flow. Total water contents are derived using both thermogravimetry and infrared spectroscopy to quantify primary (magmatic) and secondary (meteoric) water. Glass water contents are between 0.08-0.25 wt.%. Water analysis also reveals an increase in water content from glassy obsidian bands towards 'frothy' bands of 0.06-0.08 wt.%, reflecting preferential vesiculation of higher water bands and an extreme sensitivity of obsidian degassing to water content. We present an outgassing model that reconciles textural, volatile and magnetic data to indicate that obsidian is generated from multiple shear-induced outgassing cycles, whereby vesicular magma outgasses and densifies through bubble collapse and fracture healing to form obsidian, which then re-vesiculates to produce 'dry' vesicular magma. Repetition of this cycle throughout magma ascent results in the low water contents of the Rocche Rosse lavas and the final stage in the degassing cycle determines final lava porosity. Heterogeneities in lava rheology (vesicularity, water content, microlite content, viscosity) play a vital role in the structural evolution of an obsidian flow and overprint flow-scale morphology. Post-emplacement hydration also depends heavily on local strain, whereby connectivity of vesicles as a result of shear deformation governs sample rehydration by meteoric water, a process previously correlated to lava vesicularity alone.
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Ripoll, G; Albertí, P; Joy, M
2012-02-01
One hundred and twenty-seven lambs were fed as follows: lambs and dams grazing alfalfa (Gr); the same as Gr but lambs had access to concentrate (Gr + S); ewes grazed and lambs received milk and concentrate until weaning and thereafter concentrate and straw (Rat-Gr); ewes and lambs were stall-fed (Ind). Lambs were slaughtered at 22-24 kg live weight and fat and M. rectus abdominis colour was measured instrumentally and subjectively. The evolution of the instrumental colour and texture of M. longissimus lumborum was also recorded. There were significant differences in the instrumental colour of subcutaneous fat amongst feeding systems, but no differences were observed upon visual appraisal. On average, M. rectus abdominis colour in the four feeding systems was classed as pink. Differences in longissimus thoracis colour at 0 h disappeared at 24h of air exposure and there were no differences in pH or cooking losses. At no time were any differences in instrumental texture found. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Reihani, S F S; Tan, Thuan-Chew; Huda, Nurul; Easa, Azhar Mat
2014-07-15
In Malaysia, fresh ulam raja leaves (Cosmos caudatus) are eaten raw with rice. In this study, beef patties incorporated with extracts of ulam raja (UREX) and commercial green tea extract (GTE) added individually at 200 and 500 mg/kg were stored at -18°C for up to 10 weeks. Lipid oxidation, cooking yield, physicochemical properties, textural properties, proximate composition and sensory characteristics of the beef patties were compared between those incorporated with UREX, GTE and the control (pure beef patty). Incorporation of UREX or GTE at 500 mg/kg into beef patties reduced the extent of lipid oxidation significantly (P<0.05). UREX showed a strong lipid oxidation inhibitory effect, comparable with GTE. In addition, a significant improvement (P<0.05) in cooking yield and textural properties was also recorded. However, incorporation of UREX and GTE into beef patties showed no significant influence (P>0.05) on the colour, pH, proximate composition and overall sensory acceptability of the patties. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Sm-Nd, Rb-Sr, and Mn-Cr Ages of Yamato 74013
NASA Technical Reports Server (NTRS)
Nyquist, L. E.; Shih, C.- Y.; Reese, Y.D.
2009-01-01
Yamato 74013 is one of 29 paired diogenites having granoblastic textures. The Ar-39 - Ar-40 age of Y-74097 is approximately 1100 Ma. Rb-Sr and Sm-Nd analyses of Y-74013, -74037, -74097, and -74136 suggested that multiple young metamorphic events disturbed their isotopic systems. Masuda et al. reported that REE abundances were heterogeneous even within the same sample (Y-74010) for sample sizes less than approximately 2 g. Both they and Nyquist et al. reported data for some samples showing significant LREE enrichment. In addition to its granoblastic texture, Y-74013 is characterized by large, isolated clots of chromite up to 5 mm in diameter. Takeda et al. suggested that these diogenites originally represented a single or very small number of coarse orthopyroxene crystals that were recrystallized by shock processes. They further suggested that initial crystallization may have occurred very early within the deep crust of the HED parent body. Here we report the chronology of Y-74013 as recorded in chronometers based on long-lived Rb-87 and Sm-147, intermediate- lived Sm-146, and short-lived Mn-53.
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Delhaye, Benoit P; Schluter, Erik W; Bensmaia, Sliman J
2016-01-01
Efforts are underway to restore sensorimotor function in amputees and tetraplegic patients using anthropomorphic robotic hands. For this approach to be clinically viable, sensory signals from the hand must be relayed back to the patient. To convey tactile feedback necessary for object manipulation, behaviorally relevant information must be extracted in real time from the output of sensors on the prosthesis. In the present study, we recorded the sensor output from a state-of-the-art bionic finger during the presentation of different tactile stimuli, including punctate indentations and scanned textures. Furthermore, the parameters of stimulus delivery (location, speed, direction, indentation depth, and surface texture) were systematically varied. We developed simple decoders to extract behaviorally relevant variables from the sensor output and assessed the degree to which these algorithms could reliably extract these different types of sensory information across different conditions of stimulus delivery. We then compared the performance of the decoders to that of humans in analogous psychophysical experiments. We show that straightforward decoders can extract behaviorally relevant features accurately from the sensor output and most of them outperform humans.
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Long-range population dynamics of anatomically defined neocortical networks
Chen, Jerry L; Voigt, Fabian F; Javadzadeh, Mitra; Krueppel, Roland; Helmchen, Fritjof
2016-01-01
The coordination of activity across neocortical areas is essential for mammalian brain function. Understanding this process requires simultaneous functional measurements across the cortex. In order to dissociate direct cortico-cortical interactions from other sources of neuronal correlations, it is furthermore desirable to target cross-areal recordings to neuronal subpopulations that anatomically project between areas. Here, we combined anatomical tracers with a novel multi-area two-photon microscope to perform simultaneous calcium imaging across mouse primary (S1) and secondary (S2) somatosensory whisker cortex during texture discrimination behavior, specifically identifying feedforward and feedback neurons. We find that coordination of S1-S2 activity increases during motor behaviors such as goal-directed whisking and licking. This effect was not specific to identified feedforward and feedback neurons. However, these mutually projecting neurons especially participated in inter-areal coordination when motor behavior was paired with whisker-texture touches, suggesting that direct S1-S2 interactions are sensory-dependent. Our results demonstrate specific functional coordination of anatomically-identified projection neurons across sensory cortices. DOI: http://dx.doi.org/10.7554/eLife.14679.001 PMID:27218452
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Improved color matching of metal ceramic restorations. Part II: Procedures for visual communication.
Sorensen, J A; Torres, T J
1987-12-01
Most ceramic restorations are fabricated in a location remote from the dental office. Successful fabrication of matching life-like ceramic restorations necessitates a collaborative effort between the dentist and the ceramist. To meet the demands for visual communication of shade and surface texture, the following steps are recommended. 1. A means of communicating and recording surface texture that facilitates blending the restorations with the natural dentition should be used. 2. The system should use an esthetics prescription form that functions with the Shade Indicator Chart system to relate the shade of opaque, body, and incisal porcelains and their arrangement to the ceramist. 3. An easily made identification mold to form shade tabs is needed. 4. Identification shade tabs should be made to verify and document shade formulations selected with the Shade Indicator Chart system. 5. Methods for precisely mapping and reproducing individual characterization patterns are needed. This information permits the visualization of the end result, allowing the artistic expression of the ceramist to create vital-appearing restorations intrinsically and in harmony with the natural dentition.
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Mesozoic clay diagenesis in the Appalachian Plateau
NASA Astrophysics Data System (ADS)
Boles, A.; Mulch, A.; van der Pluijm, B.
2017-12-01
Integrated investigation of authigenic clays in the Appalachian Plateau of the northeastern US Midcontinent using X-ray goniometry, Rietveld-method based illite polytype analysis, and 40Ar/39Ar geochronology yields novel insights about the structural diagenetic history of the North American sedimentary cover sequence. Texture analysis by High Resolution X-ray Texture Goniometry records the presence of a bedding-parallel diagenetic fabric, corresponding to a burial depth of 2-5 km. New development of polytype modeling using BGMN®, a quantitative X-ray powder diffraction forward modeling and whole-pattern matching program matches mineralic characteristic of illite at those depths and reduces uncertainty estimates in age analysis. Based on dating size fractions, the diagenetic age is constrained to 225-250 Ma (Triassic) by four authigenic illite samples, reflecting protracted, regional diagenesis in the area. Preliminary H isotopic analysis points to a surface-derived diagenetic fluid with δD values ranging from -48 to -72‰ (in the range of predicted Pangea meteoric fluid), with a dependence on proximity to the Appalachian Mountains that may reflect a rain shadow effect.
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Rolling process for producing biaxially textured substrates
Goyal, Amit
2004-05-25
A method of preparing a biaxially textured article includes the steps of: rolling a metal preform while applying shear force thereto to form as-rolled biaxially textured substrate having an a rotated cube texture wherein a (100) cube face thereof is parallel to a surface of said substrate, and wherein a [100] direction thereof is at an angle of at least 30.degree. relative to the rolling direction; and depositing onto the surface of the biaxially textured substrate at least one epitaxial layer of another material to form a biaxially textured article.
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Hypothesized eye movements of neurolinguistic programming: a statistical artifact.
Farmer, A; Rooney, R; Cunningham, J R
1985-12-01
Neurolinguistic programming's hypothesized eye-movements were measured independently from videotapes of 30 subjects, aged 15 to 76 yr., who were asked to recall visual pictures, recorded audio sounds, and textural objects. chi 2 indicated that subjects' responses were significantly different from those predicted. When chi 2 comparisons were weighted by number of eye positions assigned to each modality (3 visual, 3 auditory, 1 kinesthetic), subjects' responses did not differ significantly from the expected pattern. These data indicate that the eye-movement hypothesis may represent randomly occurring rather than sensory-modality-related positions.
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Fossils of hydrothermal vent worms from Cretaceous sulfide ores of the Samail ophiolite, Oman
Haymon, R.M.; Koski, R.A.; Sinclair, C.
1984-01-01
Fossil worm tubes of Cretaceous age preserved in the Bayda massive sulfide deposit of the Samail ophiolite, Oman, are apparently the first documented examples of fossils embedded in massive sulfide deposits from the geologic record. The geologic setting of the Bayda deposit and the distinctive mineralogic and textural features of the fossiliferous samples suggest that the Bayda sulfide deposit and fossil fauna are remnants of a Cretaceous sea-floor hydrothermal vent similar to modern hot springs on the East Pacific Rise and the Juan de Fuca Ridge.
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Li, Zhiming; Yu, Lan; Wang, Xin; Yu, Haiyang; Gao, Yuanxiang; Ren, Yande; Wang, Gang; Zhou, Xiaoming
2017-11-09
The purpose of this study was to investigate the diagnostic performance of mammographic texture analysis in the differential diagnosis of benign and malignant breast tumors. Digital mammography images were obtained from the Picture Archiving and Communication System at our institute. Texture features of mammographic images were calculated. Mann-Whitney U test was used to identify differences between the benign and malignant group. The receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of texture features. Significant differences of texture features of histogram, gray-level co-occurrence matrix (GLCM) and run length matrix (RLM) were found between the benign and malignant breast group (P < .05). The area under the ROC (AUROC) of histogram, GLCM, and RLM were 0.800, 0.787, and 0.761, with no differences between them (P > .05). The AUROCs of imaging-based diagnosis, texture analysis, and imaging-based diagnosis combined with texture analysis were 0.873, 0.863, and 0.961, respectively. When imaging-based diagnosis was combined with texture analysis, the AUROC was higher than that of imaging-based diagnosis or texture analysis (P < .05). Mammographic texture analysis is a reliable technique for differential diagnosis of benign and malignant breast tumors. Furthermore, the combination of imaging-based diagnosis and texture analysis can significantly improve diagnostic performance. Copyright © 2017 Elsevier Inc. All rights reserved.
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Cascaded Amplitude Modulations in Sound Texture Perception.
McWalter, Richard; Dau, Torsten
2017-01-01
Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as "beating" in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures-stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches.
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Endo, Hiroshi; Ino, Shuichi; Fujisaki, Waka
2017-09-01
Because chewing sounds influence perceived food textures, unpleasant textures of texture-modified diets might be improved by chewing sound modulation. Additionally, since inhomogeneous food properties increase perceived sensory intensity, the effects of chewing sound modulation might depend on inhomogeneity. This study examined the influences of texture inhomogeneity on the effects of chewing sound modulation. Three kinds of nursing care foods in two food process types (minced-/puréed-like foods for inhomogeneous/homogeneous texture respectively) were used as sample foods. A pseudo-chewing sound presentation system, using electromyogram signals, was used to modulate chewing sounds. Thirty healthy elderly participants participated in the experiment. In two conditions with and without the pseudo-chewing sound, participants rated the taste, texture, and evoked feelings in response to sample foods. The results showed that inhomogeneity strongly influenced the perception of food texture. Regarding the effects of the pseudo-chewing sound, taste was less influenced, the perceived food texture tended to change in the minced-like foods, and evoked feelings changed in both food process types. Though there were some food-dependent differences in the effects of the pseudo-chewing sound, the presentation of the pseudo-chewing sounds was more effective in foods with an inhomogeneous texture. In addition, it was shown that the pseudo-chewing sound might have positively influenced feelings. Copyright © 2017 Elsevier Ltd. All rights reserved.
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The Wear Behavior of Textured Steel Sliding against Polymers
Wang, Meiling; Zhang, Changtao; Wang, Xiaolei
2017-01-01
Artificially fabricated surface textures can significantly improve the friction and wear resistance of a tribological contact. Recently, this surface texturing technique has been applied to polymer materials to improve their tribological performance. However, the wear behavior of textured tribo-pairs made of steel and polymer materials has been less thoroughly investigated and is not well understood; thus, it needs further research. The aim of this study is to investigate the wear properties of tribological contacts made of textured stainless steel against polymer surfaces. Three polymer materials were selected in this study, namely, ultrahigh molecular weight polyethylene (UHMWPE), polyoxymethylene (POM) and (polyetheretherketone) PEEK. Wear tests were operated through a ring-on-plane mode. The results revealed that the texture features and material properties affected the wear rates and friction coefficients of the textured tribo-pairs. In general, PEEK/textured steel achieved the lowest wear rate among the three types of tribo-pairs investigated. Energy dispersive x-ray spectroscopy (EDX) analysis revealed that the elements of C and O on the contacting counterfaces varied with texture features and indicated different wear behavior. Experimental and simulated results showed differences in the stress distribution around the dimple edge, which may influence wear performance. Wear debris with different surface morphologies were found for tribo-pairs with varying texture features. This study has increased the understanding of the wear behavior of tribo-pairs between textured stainless steel and polymer materials. PMID:28772688
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Banno, Hayaki; Koga, Hiroki; Yamamoto, Hiroki; Saiki, Jun
2017-07-01
This study was a case investigation of grapheme-texture synestheste TH, a female who subjectively reported experiencing a visual association between grapheme and colour/texture. First, we validated the existence of a synesthetic association in an objective manner. Involuntarily elicited experience is a major hallmark that is common to different types of synesthetes. Our results indicated interference between physical and synesthetic texture, suggesting the involuntary occurrence of synesthetic textural experience. We analysed the behavioural measures using the EZ diffusion model. The result suggested that TH's synesthetic experience was dissociable from that of briefly trained associative processing of non-synesthetes. Second, we investigated how the synesthetic experience of colour and texture dimensions was bound in the visual representation. We found that the interference effects of colour and texture were not independent. This suggested that in the elicited experience, the colour and texture features construct an integrated representation.
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NASA Technical Reports Server (NTRS)
Banks, Bruce; Miller, Sharon; deGroh, Kim; Chan, Amy; Sahota, Mandeep
2001-01-01
The application of a microscopic surface texture produced by ion beam sputter texturing to the surfaces of polymer implants has been shown to result in significant increases in cellular attachment compared to smooth surface implants in animal studies. A collaborative program between NASA Glenn Research Center and the Cleveland Clinic Foundation has been established to evaluate the potential for improving osteoblast attachment to surfaces that have been microscopically roughened by atomic oxygen texturing. The range of surface textures that are feasible depends upon both the texturing process and the duration of treatment. To determine whether surface texture saturates or continues to increase with treatment duration, an effort was conducted to examine the development of surface textures produced by various physical and chemical erosion processes. Both experimental tests and computational modeling were performed to explore the growth of surface texture with treatment time. Surface texturing by means of abrasive grit blasting of glass, stainless steel, and polymethylmethacry I ate surfaces was examined to measure the growth in roughness with grit blasting duration by surface profilometry measurements. Laboratory tests and computational modeling was also conducted to examine the development of texture on Aclar(R) (chlorotfifluoroethylene) and Kapton(R) polyimide, respectively. For the atomic oxygen texturing tests of Aclar(R), atomic force microscopy was used to measure the development of texture with atomic oxygen fluence. The results of all the testing and computational modeling support the premise that development of surface roughness obeys Poisson statistics. The results indicate that surface roughness does not saturate but increases as the square root of the treatment time.
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Microstructure, crystallographic texture and mechanical properties of friction stir welded AA2017A
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ahmed, M.M.Z., E-mail: mohamed_ahmed4@s-petrol.suez.edu.eg; Department of Metallurgical and Materials Engineering, Suez Canal University, Suez 43721; Wynne, B.P.
2012-02-15
In this study a thick section (20 mm) friction stir welded AA2017A-T451 has been characterized in terms of microstructure, crystallographic texture and mechanical properties. For microstructural analysis both optical and scanning electron microscopes have been used. A detailed crystallographic texture analysis has been carried out using the electron back scattering diffraction technique. Crystallographic texture has been examined in both shoulder and probe affected regions of the weld NG. An entirely weak texture is observed at the shoulder affected region which is mainly explained by the effect of the sequential multi pass deformation experienced by both tool probe and tool shoulder.more » The texture in the probe dominated region at the AS side of the weld is relatively weak but still assembles the simple shear texture of FCC metals with B/B{sup Macron} and C components existing across the whole map. However, the texture is stronger at the RS than at the AS of the weld, mainly dominated byB/B{sup Macron} components and with C component almost absent across the map. An alternating bands between (B) components and (B{sup Macron }) component are observed only at the AS side of the weld. - Highlights: Black-Right-Pointing-Pointer Detailed investigation of microstructure and crystallographic texture. Black-Right-Pointing-Pointer The grain size is varied from the top to the bottom of the NG. Black-Right-Pointing-Pointer An entirely weak texture is observed at the shoulder affected region. Black-Right-Pointing-Pointer The texture in the probe affected region is dominated by simple shear texture.« less
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NASA Astrophysics Data System (ADS)
Young, Kristina; Bowker, Matthew; Reed, Sasha; Howell, Armin
2017-04-01
Heterogeneity in the abiotic environment structures biotic communities by controlling niche space and parameters. This has been widely observed and demonstrated in vascular plant and other aboveground communities. While soil organisms are presumably also strongly influenced by the physical and chemical dimensions of the edaphic environment, there are fewer studies linking the development, structure, productivity or function of surface soil communities to specific edaphic gradients. Here, we use biological soil crusts (biocrusts) as a model system to determine mechanisms regulating community structure of soil organisms. We chose soil texture to serve as an edaphic gradient because of soil texture's influence over biocrust distribution on a landscape level. We experimentally manipulated texture in constructed soil, and simultaneously manipulated two main outcomes of texture, water and nutrient availability, to determine the mechanism underlying texture's influence on biocrust abundance and structure. We grew biocrust communities from a field-sourced inoculum on four different soil textures, sieved from the same parent soil material, manipulating watering levels and nutrient additions across soil textures in a full-factorial design over a 5-month period of time. We measured abundance and structure of biocrusts over time, and measured two metrics of function, N2 fixation rates and soil stabilization, at the conclusion of the experiment. Our results showed finer soil textures resulted in faster biocrust community development and dominance by mosses, whereas coarser textures grew more slowly and had biocrust communities dominated by cyanobacteria and lichen. Additionally, coarser textured soils contained cyanobacterial filaments significantly deeper into the soil profile than fine textured soils. N2-fixation values increased with increasing moss cover and decreased with increasing cyanobacterial cover, however, the rate of change depended on soil texture and water amount. Soil shear resistance was highest on finer textured soil with the highest watering treatment, whereas compression resistance was highest on the coarsest textured soils with the highest watering amounts. Nutrient addition did not influence total cover or biocrust function, but did decrease lichen cover. Taken together, these results suggest that interactions between soil texture, water, and to a lesser degree nutrients, create predictable patterns in biocrust assemblage and offers a mechanistic understanding of edaphic controls over biocrust abundance and structure. These insights add to our increasing understanding of how edaphic gradients structure soil communities.
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A neural network detection model of spilled oil based on the texture analysis of SAR image
NASA Astrophysics Data System (ADS)
An, Jubai; Zhu, Lisong
2006-01-01
A Radial Basis Function Neural Network (RBFNN) Model is investigated for the detection of spilled oil based on the texture analysis of SAR imagery. In this paper, to take the advantage of the abundant texture information of SAR imagery, the texture features are extracted by both wavelet transform and the Gray Level Co-occurrence matrix. The RBFNN Model is fed with a vector of these texture features. The RBFNN Model is trained and tested by the sample data set of the feature vectors. Finally, a SAR image is classified by this model. The classification results of a spilled oil SAR image show that the classification accuracy for oil spill is 86.2 by the RBFNN Model using both wavelet texture and gray texture, while the classification accuracy for oil spill is 78.0 by same RBFNN Model using only wavelet texture as the input of this RBFNN model. The model using both wavelet transform and the Gray Level Co-occurrence matrix is more effective than that only using wavelet texture. Furthermore, it keeps the complicated proximity and has a good performance of classification.
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Training Spatial Knowledge Acquisition Using Virtual Environments
2000-04-03
bands of textures and tiles them together to form long, continuous swaths of texture. This paper summarizes these tools and their function, and...which allows it to control these devices. It also includes a texture- tiling application to precisely line up frames from the camera to create wall...that textures exist a priori and has no support for cropping and tiling textures within the program, much less an interface to hardware specifically
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Relation between plastic surface microtexturation and Ag film percolation and resistivity
NASA Astrophysics Data System (ADS)
Rapeaux, Michel; Tribut, Laurent
2017-09-01
Reinforced polycarbonate samples are textured by laser to get hydrophilic or hydrophobic surface. Then, Ag films are deposited on textured and non-textured samples by magnetron sputtering. In-situ resistivity measurement has been done to determine the electrical percolation threshold according to the texturation. Results are discussed and texturation is presented as one option to improve surface insulation in circuit breaker after a short-circuit event.
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A Review of Texture Evolution Mechanisms During Deformation by Rolling in Aluminum Alloys
NASA Astrophysics Data System (ADS)
Li, Shasha; Zhao, Qi; Liu, Zhiyi; Li, Fudong
2018-06-01
The current understanding of texture evolution during deformation by rolling in aluminum alloys was summarized. This included understanding the evolution mechanisms and several key factors of initial texture, microstructure, alloy composition, deformation temperature, stress-strain condition, and rolling geometry. Related models on predicting texture evolution during rolling were also discussed. Finally, for this research field, the recommendations for controlling the formation of rolling textures were proposed.
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Goyal, Amit; Kroeger, Donald M.
2003-11-11
A method for forming an electronically active biaxially textured article includes the steps of providing a substrate having a single crystal metal or metal alloy surface, deforming the substrate to form an elongated substrate surface having biaxial texture and depositing an epitaxial electronically active layer on the biaxially textured surface. The method can include at least one annealing step after the deforming step to produce the biaxially textured substrate surface. The invention can be used to form improved biaxially textured articles, such as superconducting wire and tape articles having improved J.sub.c values.
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Electrodeposition of biaxially textured layers on a substrate
Bhattacharya, Raghu N; Phok, Sovannary; Spagnol, Priscila; Chaudhuri, Tapas
2013-11-19
Methods of producing one or more biaxially textured layer on a substrate, and articles produced by the methods, are disclosed. An exemplary method may comprise electrodepositing on the substrate a precursor material selected from the group consisting of rare earths, transition metals, actinide, lanthanides, and oxides thereof. An exemplary article (150) may comprise a biaxially textured base material (130), and at least one biaxially textured layer (110) selected from the group consisting of rare earths, transition metals, actinides, lanthanides, and oxides thereof. The at least one biaxially textured layer (110) is formed by electrodeposition on the biaxially textured base material (130).
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Peng, Lixia
Recrystallization texture evolution of rolled V-4Cr-4Ti alloy has been investigated by quasi-in-situ EBSD (electron back-scattering diffraction) method. Concurrently, the precipitates were characterized by SEM (Scanning Electron Microscopy). It was found that both the initial rolling textures and the distribution of the precipitates affected the formation of the recrystallization texture. It was revealed that the texture transformations of (558) 〈110〉 + (665) 〈110〉 to (334) 〈483〉 + (665) 〈1 1 2.4〉 were possibly attributed to the selective drag induced by the sparsely dispersed Ti-rich precipitates. While the densely distributed Ti-rich precipitates were responsible for the randomized recrystallization texture. Finally, when themore » precipitates were absent, the orientation changes from (112) 〈110〉 and (558) 〈110〉 to (111) 〈112〉 and (001) <110> to (001) <520> were observed. - Highlights: • Micro recrystallization texture evolution in V-4Cr-4Ti alloys is reported for the first time. • The volume fraction of Ti-rich precipitates has significant effect on the recrystallization texture evolution. • The dissolution of the Ti-rich precipitates above 1100 °C induces the strengthening of (111) <112> texture.« less
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Optimizing Pt/TiO2 templates for textured PZT growth and MEMS devices
NASA Astrophysics Data System (ADS)
Potrepka, Daniel; Fox, Glenn; Sanchez, Luz; Polcawich, Ronald
2013-03-01
Crystallographic texture of lead zirconate titanate (PZT) thin films strongly influences piezoelectric properties used in MEMS applications. Textured growth can be achieved by relying on crystal growth habit and can also be initiated by the use of a seed-layer heteroepitaxial template. Template choice and the process used to form it determine structural quality, ultimately influencing performance and reliability of MEMS PZT devices such as switches, filters, and actuators. This study focuses on how 111-textured PZT is generated by a combination of crystal habit and templating mechanisms that occur in the PZT/bottom-electrode stack. The sequence begins with 0001-textured Ti deposited on thermally grown SiO2 on a Si wafer. The Ti is converted to 100-textured TiO2 (rutile) through thermal oxidation. Then 111-textured Pt can be grown to act as a template for 111-textured PZT. Ti and Pt are deposited by DC magnetron sputtering. TiO2 and Pt film textures and structure were optimized by variation of sputtering deposition times, temperatures and power levels, and post-deposition anneal conditions. The relationship between Ti, TiO2, and Pt texture and their impact on PZT growth will be presented. Also affiliated with U.S. Army Research Lab, Adelphi, MD 20783, USA
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Orbital selective spin-texture in a topological insulator
DOE Office of Scientific and Technical Information (OSTI.GOV)
Singh, Bahadur, E-mail: bahadursingh24@gmail.com; Prasad, R.
Three-dimensional topological insulators support a metallic non-trivial surface state with unique spin texture, where spin and momentum are locked perpendicular to each other. In this work, we investigate the orbital selective spin-texture associated with the topological surface states in Sb2Te{sub 3}, using the first principles calculations. Sb2Te{sub 3} is a strong topological insulator with a p-p type bulk band inversion at the Γ-point and supports a single topological metallic surface state with upper (lower) Dirac-cone has left (right) handed spin-texture. Here, we show that the topological surface state has an additional locking between the spin and orbitals, leading to anmore » orbital selective spin-texture. The out-of-plane orbitals (p{sub z} orbitals) have an isotropic orbital texture for both the Dirac cones with an associated left and right handed spin-texture for the upper and lower Dirac cones, respectively. In contrast, the in-planar orbital texture (p{sub x} and p{sub y} projections) is tangential for the upper Dirac-cone and is radial for the lower Dirac-cone surface state. The dominant in-planar orbital texture in both the Dirac cones lead to a right handed orbital-selective spin-texture.« less
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NASA Astrophysics Data System (ADS)
Jeon, Jae-Yeol; Son, Hyeon-Taek; Woo, Kee-Do; Lee, Kwang-Jin
2012-04-01
The relationship between the texture and mechanical properties of 6xxx aluminum alloy sheets processed via cross rolling was investigated. The microstructures of the conventional rolled and cross rolled sheets after annealing were analyzed using optical micrographs (OM). The texture distribution across the thickness in the Al-Mg-Si-Cu alloy, conventional rolled sheets, and cross rolled sheets both before and after annealing was investigated via X-ray texture measurements. The texture was analyzed in three layers from the surface to the center of the sheet. The β-fiber texture of the conventional rolled sheet was typical of the texture obtained using aluminumoll ring. After annealing, the typical β-fiber orientations were changed to recrystallization textures: cube{001}<100> and normal direction (ND)-rotated cubes. However, the texture of the cross rolled sheet was composed of an asymmetrical, rolling direction (RD)-rotated cubes. After annealing, the asymmetrical orientations in the cross rolled sheet were changed to a randomized texture. The average R-value of the annealed cross rolled sheets was higher than that of the conventional rolled sheets. The limit dome height (LDH) test results demonstrated that cross rolling is effective in improving the formability of the Al-Mg-Si-Cu alloy sheets.
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NASA Technical Reports Server (NTRS)
Walker, D.; Powell, M. A.; Hays, J. F.; Lofgren, G. E.
1978-01-01
The textural features produced in Stannern, a non-porpyritic representative of the eucrite basaltic achondrite class of meteorite, at differing cooling rates and various degrees of initial superheating were studied. Textures produced from mildly superheated melts were found to be fasciculate rather than porphyritic as the result of the cosaturated bulk chemistry of Stannern. The qualitative type of texture apparently depends mainly on the degree of initial superheating, whereas cooling rate exerts a strong influence on the coarseness of texture. Increasing the degree of superheating produces textures from intergranular/subophitic to fasciculate/porphyritic. With initial superheating to 1200 deg C the transition to quasi-porphyritic is controlled by cooling rate, but the development of phenocrysts is merely an overprint on the fasciculate background texture of the groundmass. The suppression of fasciculate texture is completed by a decrease of the degree of initial superheating below the plagioclast entry and suppression of quasi-porphyritic texture is completed by decrease of the degree of initial superheating below pyroxene entry; these qualitative changes do not seem to be produced by changes of cooling rate. A grain size/cooling rate dependence has been used to deduce the cooling rate of fasciculate-textured Stannern clasts (10.1 to 100 deg C/hr).
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NASA Astrophysics Data System (ADS)
Alemayehu, Melesse; Zhang, Hong-Fu; Zhu, Bin; Fentie, Birhanu; Abraham, Samuel; Haji, Muhammed
2016-01-01
Detailed petrographical observations and in-situ major- and trace-element data for minerals from ten spinel peridotite xenoliths from a new locality in Gundeweyn area, East Gojam, have been examined in order to understand the composition, equilibrium temperature and pressure conditions as well as depletion and enrichment processes of continental lithospheric mantle beneath the Ethiopian plateau. The peridotite samples are very fresh and, with the exception of one spinel harzburgite, are all spinel lherzolites. Texturally, the xenoliths can be divided into two groups as primary and secondary textures. Primary textures are protogranular and porphyroclastic while secondary ones include reaction, spongy and lamellae textures. The Fo content of olivine and Cr# of spinel ranges from 86.5 to 90.5 and 7.7 to 14.1 in the lherzolites, respectively and are 89.8 and 49.8, respectively, in the harzburgite. All of the lherzolites fall into the lower Cr# and Fo region in the olivine-spinel mantle array than the harzburgite, which indicates that they are fertile peridotites that experienced low degrees of partial melting and melt extraction. Orthopyroxene and clinopyroxene show variable Cr2O3 and Al2O3 contents regardless of their lithology. The Mg# of orthopyroxene and clinopyroxene are 87.3 to 90.1 and 85.8 to 90.5 for lherzolite and 90.4 and 91.2 for harzburgite, respectively. The peridotites have been equilibrated at a temperature and pressure ranging from 850 to 1100 °C and 10.2 to 30 kbar, respectively, with the highest pressure record from the harzburgite. They record high mantle heat flow between 60 and 150 mW/m2, which is not typical for continental environments (40 mW/m2). Such a high geotherm in continental area shows the presence of active mantle upwelling beneath the Ethiopian plateau, which is consistent with the tectonic setting of nearby area of the Afar plume. Clinopyroxene of five lherzolites and one harzburgite samples have a LREE enriched pattern and the rest exhibit LREE depletion relative to HREE. These suggest that the lithospheric mantle of the Ethiopian plateau has experienced at least two major processes, specifically, partial melting and metasomatism that produce LREE-depleted and -enriched signature of continental lithospheric mantle, respectively. There is also no clear relationship between degree of LREE enrichment and petrography of the studied peridotite. Based on our data, we conclude that the lithospheric mantle beneath Gundeweyn has experienced melt extraction during and/or before pan-African orogeny and then interacted with various degrees of asthenospheric melt. The interaction is probably related to mantle upwelling, which is mainly focused beneath East Africa rift system (EARS).
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NASA Astrophysics Data System (ADS)
Wu, Huaping; Wu, Linzhi; Du, Shanyi
2008-04-01
The effective biaxial modulus (Meff) of fiber-textured hexagonal, tetragonal, and orthorhombic films is estimated by using the Voigt-Reuss-Hill and Vook-Witt grain-interaction models. The orientation distribution function with Gaussian distributions of the two Euler angles θ and ϕ is adopted to analyze the effect of texture dispersion degree on Meff. Numerical results that are based on ZnO, BaTiO3, and yttrium barium copper oxide (YBCO) materials show that the Vook-Witt average of Meff is identical to the Voigt-Reuss-Hill average of Meff for the (001) plane of ideally fiber-textured hexagonal and tetragonal films. The ϕ distribution has no influence on Meff of the (hkl)-fiber-textured hexagonal film at any θ distribution in terms of the isotropy in the plane perpendicular to the [001] direction. Comparably, tetragonal and orthorhombic films represent considerable actions of ϕ dispersion on Meff, and the effect of ϕ dispersion on Meff of a (001)-fiber-textured YBCO film is smaller than that for a (001)-fiber-textured BaTiO3 film since the shear anisotropic factor in the (001) shear plane of a YBCO film more closely approaches 1. Enhanced θ and ϕ distributions destroy the perfect fiber textures, and as a result, the films exhibit an evolution from ideal (hkl) fiber textures to random textures with varying full widths at half maximums of θ and ϕ.
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NASA Astrophysics Data System (ADS)
Journaux, Baptiste; Montagnat, Maurine; Chauve, Thomas; Ouladdiaf, Bachir; Allibon, John
2015-04-01
Dynamic recrystallization (DRX) strongly affects the evolution of microstructure (grain size and shape) and texture (crystal preferred orientation) in materials during deformation at high temperature. Since texturing leads to anisotropic physical properties, predicting the effect of DRX is essential for industrial applications, for interpreting geophysical data and modeling geodynamic flows, and predicting ice sheet flow and climate evolution. A large amount of literature is available related to metallurgy, geology or glaciology, but there remains overall fundamental questions about the relationship between nucleation, grain boundary migration and texture development at the microscopic scale. Previous measurements of DRX in ice were either conducted using 2D ex-situ techniques such as AITA [1,2] or Electron Backscattering Diffraction (EBSD) [3], or using 3D statistical ex-situ [4] or in-situ [5] techniques. Nevertheless, all these techniques failed to observe at the scale of nucleation processes during DRX in full 3D. Here we present a new approach using neutron Laue diffraction, which enable to perform 3D measurements of in-situ texture evolution of strained polycrystalline H2O ice (>2% at 266 K) during annealing at the microscopic scale. Thanks the CYCLOPS instrument [6] (Institut Laue Langevin Grenoble, France) and the intrinsic low background of this setup, preliminary observations enabled us to follow, in H2O ice, the evolution of serrated grain boundaries, and kink-band during annealing. Our observations show a significant evolution of the texture and internal misorientation over the course of few hours at an annealing temperature of 268.5 K. In the contrary, ice kink-band structures seem to be very stable over time at near melting temperatures. The same samples have been analyzed ex-situ using EBSD for comparison. These results represent a first step toward in-situ microscopic measurements of dynamic recrystallization processes in ice during strain. This experiment has been conducted in the frame of the ANR-funded DREAM project that focuses on the recrystallization processes in anisotropic materials. References [1] D. S. Russell-Head and C.J.L. Wilson., 2001, Journal of Glaciology, 24, 117-130. [2] Wilson, C.J.L., Peternell, M., Piazolo, S., Luzin, V., 2014, Journal of Structural Geology, Microdynamics of Ice, 61, 50-77. [3] M. Montagnat, T. Chauve, F. Barou, A. Tommasi, B. Beausir, C. Fressengeas., in prep. [4] T. H. Jacka and J. Li., 2000, In T. Hondoh, editor, Physics of Ice Core Records, pages 83-102. Hokkaido University Press, Sapporo. [5] S. Piazolo, C. J. L. Wilson, V. Luzin, C. Brouzet, and M. Peternell., 2013, Geochemistry, Geophysics, Geosystems, 14, 4185-4194. [6] B. Ouladdiaf et al., 2011, Journal of Applied Crystallography, 44, 392-397.
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DOT National Transportation Integrated Search
2017-07-01
Practitioners have often wondered whether, during ride measurement with inertial devices, the motion of the laser through pavement texture introduces non representative values of international roughness index (IRI), particularly in certain textures. ...
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The effect of texture on the shaft surface on the sealing performance of radial lip seals
NASA Astrophysics Data System (ADS)
Guo, Fei; Jia, XiaoHong; Gao, Zhi; Wang, YuMing
2014-07-01
On the basis of elastohydrodynamic model, the present study numerically analyzes the effect of various microdimple texture shapes, namely, circular, square, oriented isosceles triangular, on the pumping rate and the friction torque of radial lip seals, and determines the microdimple texture shape that can produce positive pumping rate. The area ratio, depth and shape dimension of a single texture are the most important geometric parameters which influence the tribological performance. According to the selected texture shape, parameter analysis is conducted to determine the optimal combination for the above three parameters. Simultaneously, the simulated performances of radial lip seal with texture on the shaft surface are compared with those of the conventional lip seal without any texture on the shaft surface.
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Early classification of Alzheimer's disease using hippocampal texture from structural MRI
NASA Astrophysics Data System (ADS)
Zhao, Kun; Ding, Yanhui; Wang, Pan; Dou, Xuejiao; Zhou, Bo; Yao, Hongxiang; An, Ningyu; Zhang, Yongxin; Zhang, Xi; Liu, Yong
2017-03-01
Convergent evidence has been collected to support that Alzheimer's disease (AD) is associated with reduction in hippocampal volume based on anatomical magnetic resonance imaging (MRI) and impaired functional connectivity based on functional MRI. Radiomics texture analysis has been previously successfully used to identify MRI biomarkers of several diseases, including AD, mild cognitive impairment and multiple sclerosis. In this study, our goal was to determine if MRI hippocampal textures, including the intensity, shape, texture and wavelet features, could be served as an MRI biomarker of AD. For this purpose, the texture marker was trained and evaluated from MRI data of 48 AD and 39 normal samples. The result highlights the presence of hippocampal texture abnormalities in AD, and the possibility that texture may serve as a neuroimaging biomarker for AD.
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NASA Astrophysics Data System (ADS)
Liu, Daiming; Wang, Qingkang; Wang, Qing
2018-05-01
Surface texturing is of great significance in light trapping for solar cells. Herein, the multiscale texture, consisting of microscale pyramids and nanoscale porous arrangement, was fabricated on crystalline Si by KOH etching and Ag-assisted HF etching processes and subsequently replicated onto glass with high fidelity by UV nanoimprint method. Light trapping of the multiscale texture was studied by spectral (reflectance, haze ratio) characterizations. Results reveal the multiscale texture provides the broadband reflection reducing, the highlighted light scattering and the additional self-cleaning behaviors. Compared with bare cell, the multiscale textured micromorph cell achieves a 4% relative increase in power conversion efficiency. This surface texturing route paves a promising way for developing low-cost, large-scale and high-efficiency solar applications.
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Efficient optical analysis of surface texture combinations for silicon solar cells
NASA Astrophysics Data System (ADS)
Tucher, Nico; Eisenlohr, Johannes; Kiefel, Peter; Gebrewold, Habtamu; Höhn, Oliver; Hauser, Hubert; Müller, Claas; Goldschmidt, Jan Christoph; Bläsi, Benedikt
2016-04-01
Surface textures can significantly improve anti-reflective and light trapping properties of silicon solar cells. Combining standard pyramidal front side textures with scattering or diffractive rear side textures has the potential to further increase the light path length inside the silicon and thereby increase the solar cell efficiency. In this work we introduce the OPTOS (Optical Properties of Textured Optical Sheets) simulation formalism and apply it to the modelling of silicon solar cells with different surface textures at front and rear side. OPTOS is a matrix-based method that allows for the computationally-efficient calculation of non-coherent light propagation within textured solar cells, featuring multiple textures that may operate in different optical regimes. After calculating redistribution matrices for each individual surface texture with the most appropriate technique, optical properties like angle dependent reflectance, transmittance or absorptance can be determined via matrix multiplications. Using OPTOS, we demonstrate for example that the integration of a diffractive grating at the rear side of solar cells with random pyramids at the front results in an absorptance gain that corresponds to a photocurrent density enhancement of 0.73 mA/cm2 for a 250 μm thick cell. The re-usability of matrices enables the investigation of different solar cell thicknesses within minutes. For thicknesses down to 50 μm the simulated gain increases up to 1.22 mA/cm2. The OPTOS formalism is furthermore not restricted with respect to the number of textured interfaces. By combining two or more textured sheets to effective interfaces, it is possible to optically model a complete photovoltaic module including EVA and potentially textured glass layers with one calculation tool.
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Impact splash chondrule formation during planetesimal recycling
NASA Astrophysics Data System (ADS)
Lichtenberg, Tim; Golabek, Gregor J.; Dullemond, Cornelis P.; Schönbächler, Maria; Gerya, Taras V.; Meyer, Michael R.
2018-03-01
Chondrules, mm-sized igneous-textured spherules, are the dominant bulk silicate constituent of chondritic meteorites and originate from highly energetic, local processes during the first million years after the birth of the Sun. So far, an astrophysically consistent chondrule formation scenario explaining major chemical, isotopic and textural features, in particular Fe,Ni metal abundances, bulk Fe/Mg ratios and intra-chondrite chemical and isotopic diversity, remains elusive. Here, we examine the prospect of forming chondrules from impact splashes among planetesimals heated by radioactive decay of short-lived radionuclides using thermomechanical models of their interior evolution. We show that intensely melted planetesimals with interior magma oceans became rapidly chemically equilibrated and physically differentiated. Therefore, collisional interactions among such bodies would have resulted in chondrule-like but basaltic spherules, which are not observed in the meteoritic record. This inconsistency with the expected dynamical interactions hints at an incomplete understanding of the planetary growth regime during the lifetime of the solar protoplanetary disk. To resolve this conundrum, we examine how the observed chemical and isotopic features of chondrules constrain the dynamical environment of accreting chondrite parent bodies by interpreting the meteoritic record as an impact-generated proxy of early solar system planetesimals that underwent repeated collision and reaccretion cycles. Using a coupled evolution-collision model we demonstrate that the vast majority of collisional debris feeding the asteroid main belt must be derived from planetesimals which were partially molten at maximum. Therefore, the precursors of chondrite parent bodies either formed primarily small, from sub-canonical aluminum-26 reservoirs, or collisional destruction mechanisms were efficient enough to shatter planetesimals before they reached the magma ocean phase. Finally, we outline the window in parameter space for which chondrule formation from planetesimal collisions can be reconciled with the meteoritic record and how our results can be used to further constrain early solar system dynamics.
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The harzburgites-lherzolite cycle: depletion and refertilization processes
NASA Astrophysics Data System (ADS)
Dijkstra, A. H.
2011-12-01
Lherzolites or clinopyroxene-rich harzburgites sampled at the ocean floor are now generally interpreted as refractory harzburgites refertilized by melt-rock reaction or melt impregnation at the spreading center, rather than as relatively undepleted bulk upper mantle. The key evidence for a melt refertilization origin is often textural. Critically, the refertilization can mask the underlying very refractory character: oceanic peridotites prior to melt refertilization at the ridge are often too refractory to be simple mantle residues of bulk upper mantle that was melted at the ridge. This suggests that the upper mantle contains large domains that record prior melting histories. This is supported by ancient rhenium-depletion ages that are common in oceanic peridotites. In this presentation, I will discuss some key examples (e.g., Macquarie Island [1], Pindos, Totalp, Lanzarote) of refertilized oceanic peridotites, which all have recorded previous, ancient depletions. I will show the textural and geochemical evidence for melt refertilization. It has often been assumed that melt refertilization occurs by interaction with mantle melts. However, there is now evidence for melt refertilization through a reaction with eclogite-derived melts, probably at the base of the melting column underneath the ridge system. These eclogitic mantle heterogeneities themselves do not normally survive the melting underneath the spreading center, but their isotopic signature can be recognized in the reacted peridotites. In summary, we have moved away from the idea that oceanic mantle rocks are simple melting residues of homogeneous bulk upper mantle. The picture that emerges is a rich and complex one, suggesting that oceanic mantle rocks record dynamic histories of melting and refertilization. In particular, the melting event in refertilized peridotites can be much older than the age of the ridge system at which they are sampled. Many oceanic peridotites contain evidence for a Mesoproterozoic melting event of perhaps global significance. Regardless of the nature of these melting events, it is now clear that in their complex overprinting history, oceanic peridotites more and more resemble polygenetic metamorphic rocks.
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Campbell, Kathleen A; Lynne, Bridget Y; Handley, Kim M; Jordan, Sacha; Farmer, Jack D; Guido, Diego M; Foucher, Frédéric; Turner, Susan; Perry, Randall S
2015-10-01
New Zealand and Argentine (Late Jurassic-Recent) siliceous hot-spring deposits (sinter) reveal preservation pathways of environmentally controlled, microbe-dominated sedimentary facies over geological time scales. Texturally distinctive, laminated to thinly layered, dense and vertically oriented, microtubular "palisade" fabric is common in low-temperature (<40°C) sinter-apron terraces. In modern hot springs, the dark green to brown, sheathed, photosynthetic cyanobacterium Calothrix spp. (family Rivulariaceae) constructs felted palisade mats in shallow terrace(tte) pools actively accreting opaline silica. The resulting stacked layers of silicified coarse filaments-a stromatolite-are highly porous and readily modified by postdepositional environmental perturbations, secondary silica infill, and diagenetic silica phase mineral transformations (opal-A to quartz). Fossil preservation quality is affected by relative timing of silicification, and later environmental and geological events. A systematic approach was used to characterize palisade fabric in sinters of different ages to refine tools for recognizing biosignatures in extreme environments and to track their long-term preservation pathways into the geological record. Molecular techniques, scanning electron microscopy, Raman spectrometry, X-ray powder diffraction, petrography, and lipid biomarker analyses were applied. Results indicate that microbial communities vary at the micron scale and that early and rapid silicification is paramount to long-term preservation, especially where minimal postdepositional disturbance follows fossilization. Overall, it appears that the most robust biomarkers of fossil microbial activity in hot-spring deposits are their characteristic macro- and microtextures and laser micro-Raman identified carbon. Studies of Phanerozoic geothermal deposits with mineralized microbial components are relevant analogs for Precambrian geobiology because early life is commonly preserved as microbial microfossils and biofilms in silica, some of it hydrothermal in origin. Yet the diagenetic "movie" has already been run. Hence, studying younger sinters of a range of ages provides an opportunity to "play it again" and follow the varied influences on biosignatures into the deep-time geological record.
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Jacobs, Richard H A H; Haak, Koen V; Thumfart, Stefan; Renken, Remco; Henson, Brian; Cornelissen, Frans W
2016-01-01
Our world is filled with texture. For the human visual system, this is an important source of information for assessing environmental and material properties. Indeed-and presumably for this reason-the human visual system has regions dedicated to processing textures. Despite their abundance and apparent relevance, only recently the relationships between texture features and high-level judgments have captured the interest of mainstream science, despite long-standing indications for such relationships. In this study, we explore such relationships, as these might be used to predict perceived texture qualities. This is relevant, not only from a psychological/neuroscience perspective, but also for more applied fields such as design, architecture, and the visual arts. In two separate experiments, observers judged various qualities of visual textures such as beauty, roughness, naturalness, elegance, and complexity. Based on factor analysis, we find that in both experiments, ~75% of the variability in the judgments could be explained by a two-dimensional space, with axes that are closely aligned to the beauty and roughness judgments. That a two-dimensional judgment space suffices to capture most of the variability in the perceived texture qualities suggests that observers use a relatively limited set of internal scales on which to base various judgments, including aesthetic ones. Finally, for both of these judgments, we determined the relationship with a large number of texture features computed for each of the texture stimuli. We find that the presence of lower spatial frequencies, oblique orientations, higher intensity variation, higher saturation, and redness correlates with higher beauty ratings. Features that captured image intensity and uniformity correlated with roughness ratings. Therefore, a number of computational texture features are predictive of these judgments. This suggests that perceived texture qualities-including the aesthetic appreciation-are sufficiently universal to be predicted-with reasonable accuracy-based on the computed feature content of the textures.
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Jacobs, Richard H. A. H.; Haak, Koen V.; Thumfart, Stefan; Renken, Remco; Henson, Brian; Cornelissen, Frans W.
2016-01-01
Our world is filled with texture. For the human visual system, this is an important source of information for assessing environmental and material properties. Indeed—and presumably for this reason—the human visual system has regions dedicated to processing textures. Despite their abundance and apparent relevance, only recently the relationships between texture features and high-level judgments have captured the interest of mainstream science, despite long-standing indications for such relationships. In this study, we explore such relationships, as these might be used to predict perceived texture qualities. This is relevant, not only from a psychological/neuroscience perspective, but also for more applied fields such as design, architecture, and the visual arts. In two separate experiments, observers judged various qualities of visual textures such as beauty, roughness, naturalness, elegance, and complexity. Based on factor analysis, we find that in both experiments, ~75% of the variability in the judgments could be explained by a two-dimensional space, with axes that are closely aligned to the beauty and roughness judgments. That a two-dimensional judgment space suffices to capture most of the variability in the perceived texture qualities suggests that observers use a relatively limited set of internal scales on which to base various judgments, including aesthetic ones. Finally, for both of these judgments, we determined the relationship with a large number of texture features computed for each of the texture stimuli. We find that the presence of lower spatial frequencies, oblique orientations, higher intensity variation, higher saturation, and redness correlates with higher beauty ratings. Features that captured image intensity and uniformity correlated with roughness ratings. Therefore, a number of computational texture features are predictive of these judgments. This suggests that perceived texture qualities—including the aesthetic appreciation—are sufficiently universal to be predicted—with reasonable accuracy—based on the computed feature content of the textures. PMID:27493628
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A common framework for the analysis of complex motion? Standstill and capture illusions
Dürsteler, Max R.
2014-01-01
A series of illusions was created by presenting stimuli, which consisted of two overlapping surfaces each defined by textures of independent visual features (i.e., modulation of luminance, color, depth, etc.). When presented concurrently with a stationary 2-D luminance texture, observers often fail to perceive the motion of an overlapping stereoscopically defined depth-texture. This illusory motion standstill arises due to a failure to represent two independent surfaces (one for luminance and one for depth textures) and motion transparency (the ability to perceive motion of both surfaces simultaneously). Instead the stimulus is represented as a single non-transparent surface taking on the stationary nature of the luminance-defined texture. By contrast, if it is the 2D-luminance defined texture that is in motion, observers often perceive the stationary depth texture as also moving. In this latter case, the failure to represent the motion transparency of the two textures gives rise to illusionary motion capture. Our past work demonstrated that the illusions of motion standstill and motion capture can occur for depth-textures that are rotating, or expanding / contracting, or else spiraling. Here I extend these findings to include stereo-shearing. More importantly, it is the motion (or lack thereof) of the luminance texture that determines how the motion of the depth will be perceived. This observation is strongly in favor of a single pathway for complex motion that operates on luminance-defines texture motion signals only. In addition, these complex motion illusions arise with chromatically-defined textures with smooth transitions between their colors. This suggests that in respect to color motion perception the complex motions' pathway is only able to accurately process signals from isoluminant colored textures with sharp transitions between colors, and/or moving at high speeds, which is conceivable if it relies on inputs from a hypothetical dual opponent color pathway. PMID:25566023
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Textured silicon nitride: processing and anisotropic properties
Zhu, Xinwen; Sakka, Yoshio
2008-01-01
Textured silicon nitride (Si3N4) has been intensively studied over the past 15 years because of its use for achieving its superthermal and mechanical properties. In this review we present the fundamental aspects of the processing and anisotropic properties of textured Si3N4, with emphasis on the anisotropic and abnormal grain growth of β-Si3N4, texture structure and texture analysis, processing methods and anisotropic properties. On the basis of the texturing mechanisms, the processing methods described in this article have been classified into two types: hot-working (HW) and templated grain growth (TGG). The HW method includes the hot-pressing, hot-forging and sinter-forging techniques, and the TGG method includes the cold-pressing, extrusion, tape-casting and strong magnetic field alignment techniques for β-Si3N4 seed crystals. Each processing technique is thoroughly discussed in terms of theoretical models and experimental data, including the texturing mechanisms and the factors affecting texture development. Also, methods of synthesizing the rodlike β-Si3N4 single crystals are presented. Various anisotropic properties of textured Si3N4 and their origins are thoroughly described and discussed, such as hardness, elastic modulus, bending strength, fracture toughness, fracture energy, creep behavior, tribological and wear behavior, erosion behavior, contact damage behavior and thermal conductivity. Models are analyzed to determine the thermal anisotropy by considering the intrinsic thermal anisotropy, degree of orientation and various microstructure factors. Textured porous Si3N4 with a unique microstructure composed of oriented elongated β-Si3N4 and anisotropic pores is also described for the first time, with emphasis on its unique mechanical and thermal-mechanical properties. Moreover, as an important related material, textured α-Sialon is also reviewed, because the presence of elongated α-Sialon grains allows the production of textured α-Sialon using the same methods as those used for textured β-Si3N4 and β-Sialon. PMID:27877995
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Biswas, Somjeet, E-mail: somjeetbiswas@gmail.com; Department of Materials Engineering, Indian Institute of Science, Bangalore 560012; Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures
Investigations on texture evolution and through-thickness texture heterogeneity during equal channel angular pressing (ECAP) of pure magnesium at 200 °C, 150 °C and room temperature (RT) was carried out by neutron, high energy synchrotron X-ray and electron back-scatter diffraction. Irrespective of the ECAP temperature, a distinctive basal (B) and pyramidal (C{sub 2}) II type of fibers forms. The texture differs in the bottom 1 mm portion, where the B-fiber is shifted ~ 55° due to negative shear attributed to friction. - Highlights: • ECAP of magnesium was carried out at 200 °C, 150 °C and room temperature. • Microstructure andmore » micro-texture evolution was examined using EBSD in FEG–SEM. • Bulk-texture was studied using neutron diffraction and compared with micro-texture. • Through thickness texture heterogeneity was observed by synchrotron radiation. • Changes in these parameters with respect to deformation temperature are discussed.« less
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Simulation study on improving efficiencies of perovskite solar cell: Introducing nano textures on it
NASA Astrophysics Data System (ADS)
Xie, Ziang; Sun, Shuren; Wang, Wei; Qin, Laixiang; Yan, Yu; Hou, Ruixiang; Qin, G. G.
2018-03-01
We report that the power conversion efficiencies (PCEs) of the planar CH3NH3PbI3 solar cells (SCs) can be largely improved by fabricating nano textures on the SC surface. With the finite difference time domain (FDTD) method, the ultimate efficiencies of the planar CH3NH3PbI3 SCs with two types of nano textures are investigated: the column-shaped nano hollow (CLNH) array and the cone-shaped nano hollow (CNNH) array. For the nano textured CH3NH3PbI3 SCs with photovoltaic layer depth in the range of 125 nm ∼ 500 nm, when the array period and filling fraction of the nano textures are optimized, in comparison with the planar ones, their PCE increased 42% ∼ 84% for the CLNH textured ones, and 52% ∼ 63% for the CNNH textured ones. As a conclusion, introduction of nano textures on the SC surface is a promising route for improving the PCEs of the perovskite SCs.
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Structural texture similarity metrics for image analysis and retrieval.
Zujovic, Jana; Pappas, Thrasyvoulos N; Neuhoff, David L
2013-07-01
We develop new metrics for texture similarity that accounts for human visual perception and the stochastic nature of textures. The metrics rely entirely on local image statistics and allow substantial point-by-point deviations between textures that according to human judgment are essentially identical. The proposed metrics extend the ideas of structural similarity and are guided by research in texture analysis-synthesis. They are implemented using a steerable filter decomposition and incorporate a concise set of subband statistics, computed globally or in sliding windows. We conduct systematic tests to investigate metric performance in the context of "known-item search," the retrieval of textures that are "identical" to the query texture. This eliminates the need for cumbersome subjective tests, thus enabling comparisons with human performance on a large database. Our experimental results indicate that the proposed metrics outperform peak signal-to-noise ratio (PSNR), structural similarity metric (SSIM) and its variations, as well as state-of-the-art texture classification metrics, using standard statistical measures.
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Chemometric approach to texture profile analysis of kombucha fermented milk products.
Malbaša, Radomir; Jevrić, Lidija; Lončar, Eva; Vitas, Jasmina; Podunavac-Kuzmanović, Sanja; Milanović, Spasenija; Kovačević, Strahinja
2015-09-01
In the present work, relationships between the textural characteristics of fermented milk products obtained by kombucha inoculums with various teas were investigated by using chemometric analysis. The presented data which describe numerically the textural characteristics (firmness, consistency, cohesiveness and index of viscosity) were analysed. The quadratic correlation was determined between the textural characteristics of fermented milk products obtained at fermentation temperatures of 40 and 43 °C, using milk with 0.8, 1.6 and 2.8% milk fat and kombucha inoculums cultivated on the extracts of peppermint, stinging nettle, wild thyme and winter savory. Hierarchical cluster analysis (HCA) was performed to identify the similarities among the fermented products. The best mathematical models predicting the textural characteristics of investigated samples were developed. The results of this study indicate that textural characteristics of sample based on winter savory have a significant effect on textural characteristics of samples based on peppermint, stinging nettle and wild thyme, which can be very useful in the determination of products texture profile.
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Preference evaluation of ground beef by untrained subjects with three levels of finely textured beef
Depue, Sandra Molly; Neilson, Morgan Marie
2018-01-01
After receiving bad publicity in 2012 and being removed from many ground beef products, finely textured beef (referred to as ‘pink slime’ by some) is making a comeback. Some of its proponents argue that consumers prefer ground beef containing finely textured beef, but no objective scientific party has tested this claim—that is the purpose of the present study. Over 200 untrained subjects participated in a sensory analysis in which they tasted one ground beef sample with no finely textured beef, another with 15% finely textured beef (by weight), and another with more than 15%. Beef with 15% finely textured beef has an improved juiciness (p < 0.01) and tenderness (p < 0.01) quality. However, subjects rate the flavor-liking and overall likeability the same regardless of the finely textured beef content. Moreover, when the three beef types are consumed as part of a slider (small hamburger), subjects are indifferent to the level of finely textured beef. PMID:29342174
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Field-Scale Evaluation of Infiltration Parameters From Soil Texture for Hydrologic Analysis
NASA Astrophysics Data System (ADS)
Springer, Everett P.; Cundy, Terrance W.
1987-02-01
Recent interest in predicting soil hydraulic properties from simple physical properties such as texture has major implications in the parameterization of physically based models of surface runoff. This study was undertaken to (1) compare, on a field scale, soil hydraulic parameters predicted from texture to those derived from field measurements and (2) compare simulated overland flow response using these two parameter sets. The parameters for the Green-Ampt infiltration equation were obtained from field measurements and using texture-based predictors for two agricultural fields, which were mapped as single soil units. Results of the analyses were that (1) the mean and variance of the field-based parameters were not preserved by the texture-based estimates, (2) spatial and cross correlations between parameters were induced by the texture-based estimation procedures, (3) the overland flow simulations using texture-based parameters were significantly different than those from field-based parameters, and (4) simulations using field-measured hydraulic conductivities and texture-based storage parameters were very close to simulations using only field-based parameters.
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Understanding Crystal Populations; Looking Towards 3D Quantitative Analysis
NASA Astrophysics Data System (ADS)
Jerram, D. A.; Morgan, D. J.
2010-12-01
In order to understand volcanic systems, the potential record held within crystal populations needs to be revealed. It is becoming increasingly clear, however, that the crystal populations that arrive at the surface in volcanic eruptions are commonly mixtures of crystals, which may be representative of simple crystallization, recycling of crystals and incorporation of alien crystals. If we can quantify the true 3D population within a sample then we will be able to separate crystals with different histories and begin to interrogate the true and complex plumbing within the volcanic system. Modeling crystal populations is one area where we can investigate the best methodologies to use when dealing with sections through 3D populations. By producing known 3D shapes and sizes with virtual textures and looking at the statistics of shape and size when such populations are sectioned, we are able to gain confidence about what our 2D information is telling us about the population. We can also use this approach to test the size of population we need to analyze. 3D imaging through serial sectioning or x-ray CT, provides a complete 3D quantification of a rocks texture. Individual phases can be identified and in principle the true 3D statistics of the population can be interrogated. In practice we need to develop strategies (as with 2D-3D transformations), that enable a true characterization of the 3D data, and an understanding of the errors and pitfalls that exist. Ultimately, the reproduction of true 3D textures and the wealth of information they hold, is now within our reach.
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NASA Astrophysics Data System (ADS)
Peterman, W. L.; Waring, R. H.
2014-12-01
Frequent outbreaks of insects and diseases have been recorded in forests of western North America during the past few decades, but the distribution of these outbreaks has not been uniform. In some cases, recent climatic variations along with the age and density of forests may explain some spatial variation. Forest managers and policy makers would benefit if areas prone to disturbance could be recognized so that mitigating actions could be taken. In this paper, we used two ponderosa pine-dominated sites in western Montana, U.S.A. to apply a modelling approach that couples information from remote sensing, soil surveys, and local weather stations to assess where bark beetle outbreaks might first occur and why. There was a slight downward trend in precipitation for both sites over the period between 1998 and 2010, and, interannual variability was high. Some years showed large increases followed by sharp decreases. Both sites had similar topography and fire histories, but bark beetle activity occurred earlier and more severely on one site than the other. The initial canopy density of the two sites was also similar, with leaf area indices derived via Landsat imagery ranging between 1.6- 2.0 m2 m-2. We wondered if the difference in bark beetle activity might be related to soils that were fine-textured at site I and coarse-textured at site II. We applied a process-based stand growth model (3-PG) to analyze the data and evaluate the hypotheses.
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Grasping and fingering (active or haptic touch) in healthy newborns.
Adamson-Macedo, Elvidina Nabuco; Barnes, Christopher R
2004-12-01
The traditional view that the activity of the baby's hands are triggered by a stimulus in an automatic, compulsory, stereotyped way and persisting view that fingering does not occur prior to 4 months of age, have led perception researchers to the assumption that the processing, encoding, and retainment of sensory information could not take place through the manual mode. This study aims to investigate whether fingering and different types of grasping occur before 3 months of age and can be modulated by surface texture of three objects. Using naturalistic observations, this small sample developmental study applied the AB experimental design to achieve aims above. Babies were video taped every week for 12 weeks. Three special manual stimuli were developed for this study. Focal sampling method with either zero-sampling or instantaneous sampling recording rules were used to analyse data with the Observer Video Pro. Each session comprising baseline and 3 experimental conditions lasted for four minutes. Fingering or 'proto fingering' as it is suggested in this article emerges as early as the first week of postnatal life; texture of a handled object modulates both 'proto-palm' and hand-grasp behaviour of healthy newborns. Results suggest that texture also modulates 'proto-fingering' and challenge persisting current assumption that fingering does not occur before four months of age, and further validates the phrase 'neo-haptic' touch to describe hands-on exploration of the newborn. The author suggests that some 'mental representation' of the stimulus is present during 'neo-haptic' recognition of the objects which is in accordance to a constructivist approach to (touch) perception.
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Why Does Some Subducted Continental Crust Escape Deformation and Transformation?
NASA Astrophysics Data System (ADS)
Garber, J. M.; Kylander-Clark, A. R.; Stearns, M.; Seward, G.; Hacker, B. R.
2016-12-01
Titanite geochemistry and geochronology from the Western Gneiss Region (WGR) of Norway shows that large portions of continental crust were deeply subducted and exhumed without significantly deforming or transforming, indicating heterogeneous mechanical behavior of crust at mantle depths. Titanite is stable in granitic rocks over a significant P-T range, and contains numerous major, minor, and trace elements that record 1) P-T conditions, 2) interactions with other major and accessory phases, and 3) information about the composition of coeval melts and fluids. A large titanite LA-ICP-MS dataset from WGR granitic gneisses and leucosomes yields a record that depends strongly on textural setting: some titanites formed after the decomposition of other phases at mantle depths, but other titanites preserve inherited isotopic dates and chemistry with variable recrystallization at grain rims. Differences in rock textures, as well as changes in volatile abundances (F and OH) among different titanite populations, suggest that the persistence of crustal minerals at mantle depths is coupled with limited prograde fluid infiltration, which restricted the efficacy of metamorphic reactions, likely increased rock strength, and caused heterogeneities in the density of the subducting slab. The observed expanses of untransformed, undeformed granitic crust may have been critical to coupling the continental crust to underlying mantle lithosphere, which prevented significant internal deformation of the slab (e.g,. Young et al., 2007; Butler et al., 2015). Finally, our statistical approach shows the utility of dimensional reduction in geochemical studies: rather than comparing individual element or isotopic abundances or ratios, principal components or discriminant analyses can condense variables and help efficiently distinguish between distinct geologic agents or geochemical reservoirs.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Teuton, Jeremy R.; Griswold, Richard L.; Mehdi, Beata L.
Precise analysis of both (S)TEM images and video are time and labor intensive processes. As an example, determining when crystal growth and shrinkage occurs during the dynamic process of Li dendrite deposition and stripping involves manually scanning through each frame in the video to extract a specific set of frames/images. For large numbers of images, this process can be very time consuming, so a fast and accurate automated method is desirable. Given this need, we developed software that uses analysis of video compression statistics for detecting and characterizing events in large data sets. This software works by converting the datamore » into a series of images which it compresses into an MPEG-2 video using the open source “avconv” utility [1]. The software does not use the video itself, but rather analyzes the video statistics from the first pass of the video encoding that avconv records in the log file. This file contains statistics for each frame of the video including the frame quality, intra-texture and predicted texture bits, forward and backward motion vector resolution, among others. In all, avconv records 15 statistics for each frame. By combining different statistics, we have been able to detect events in various types of data. We have developed an interactive tool for exploring the data and the statistics that aids the analyst in selecting useful statistics for each analysis. Going forward, an algorithm for detecting and possibly describing events automatically can be written based on statistic(s) for each data type.« less
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Emotional effects of dynamic textures
Toet, Alexander; Henselmans, Menno; Lucassen, Marcel P; Gevers, Theo
2011-01-01
This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music) and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely unknown, despite their natural ubiquity and increasing use in digital media. Participants watched a set of dynamic textures, representing either water or various different media, and self-reported their emotional experience. Motion complexity was found to have mildly relaxing and nondominant effects. In contrast, motion change complexity was found to be arousing and dominant. The speed of dynamics had arousing, dominant, and unpleasant effects. The amplitude of dynamics was also regarded as unpleasant. The regularity of the dynamics over the textures' area was found to be uninteresting, nondominant, mildly relaxing, and mildly pleasant. The spatial scale of the dynamics had an unpleasant, arousing, and dominant effect, which was larger for textures with diverse content than for water textures. For water textures, the effects of spatial contrast were arousing, dominant, interesting, and mildly unpleasant. None of these effects were observed for textures of diverse content. The current findings are relevant for the design and synthesis of affective multimedia content and for affective scene indexing and retrieval. PMID:23145257
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Surface texture can bias tactile form perception.
Nakatani, Masashi; Howe, Robert D; Tachi, Susumu
2011-01-01
The sense of touch is believed to provide a reliable perception of the object's properties; however, our tactile perceptions could be illusory at times. A recently reported tactile illusion shows that a raised form can be perceived as indented when it is surrounded by textured areas. This phenomenon suggests that the form perception can be influenced by the surface textures in its adjacent areas. As perception of texture and that of form have been studied independently of each other, the present study examined whether textures, in addition to the geometric edges, contribute to the tactile form perception. We examined the perception of the flat and raised contact surface (3.0 mm width) with various heights (0.1, 0.2, 0.3 mm), which had either textured or non-textured adjacent areas, under the static, passive and active touch conditions. Our results showed that texture decreased the raised perception of the surface with a small height (0.1 mm) and decreased the flat perception of the physically flat surface under the passive and active touch conditions. We discuss a possible mechanism underlying the effect of the textures on the form perception based on previous neurophysiological findings.
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NASA Astrophysics Data System (ADS)
Key, Thomas Stallings
The development of ferroelastic (90°) texture in addition to ferroelectric (180°) texture is essential to maximizing the piezoelectric properties of many hard tetragonal PZTs, including Piezoetechnologies K270. Ferroelastic texture results from motion of domain walls that is dependent on an individual crystals orientation. Increases in ferroelastic texture raises the maximum net polarization that can be achieved by changes in ferroelectric texture. By studying a hard PZT poled under various temperature conditions, insight was gained into factors affecting the development of ferroelastic texture and how ferroelastic texture contributes to piezoelectric properties. Depinning proved to be the major barrier to preventing ferroelastic domain wall motion where strain based domain interactions and polar defect complexes on the domain level appear to be the dominant factors. Insight into the affect of increased domain texture on the relationship between the increasing magnitude of the remnant polarization (|Pr|) and the magnitude of the coercive field (|EC|) was gained by plotting |EC| vs. |Pr| as a function of poling time for a variety of poling temperatures. At low |Pr| values, |EC| increased rapidly as a function of increases in |Pr| regardless of the poling temperature. This relationship was characteristic of samples poled at 25 °C where increases in ferroelastic texture were largely suppressed. Because increases in polarization were still observable changes in ferroelectric texture most responsible for the polarization increase and like play a strong role in the initial |EC| vs. |Pr| relationship. As |Pr| increased beyond 5 to 8 iC/cm2, the slope of |EC| vs. |Pr| decreased where the reduction in slope increased with poling temperature. This only occurred in samples poled at elevated temperatures where ferroelastic texture was know to ultimately develop during the poling process, leading to the suggestion that the change in slope was due to increases in combined ferroelectric and ferroelastic texture. Lastly, it was found that electric field induced increases in ferroelectric texture by poling at 25 °C occurs while ferroelastic domain wall motion is largely suppressed. This change in ferroelectric texture severely hinders the rate at which subsequent ferroelastic domain wall motion can be induced during poling at elevated temperatures below TC, suggesting that hard PZT samples should be preheated to the poling temperature before poling begins.
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Theory of Image Analysis and Recognition.
1983-01-24
Stanley M. Dunn, "Texture Classification with Change Point Statistics," TR- 1082 , July 1981. 97. R. Chellappa, "Synthesis of Textures Using Simultane...July 1981. 96. Stanley M. Dunn, "Texture Classification with Change Point Statistics," TR- 1082 , July 1981. * 97. R. Chellappa, "Synthesis of Textures
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Instrumental texture characteristics of broiler pectoralis major with the woody breast condition
USDA-ARS?s Scientific Manuscript database
The objective was to characterize texture properties of raw and cooked broiler fillets (pectoralis major) with the woody breast condition (WBC) using instrumental texture techniques Meullenet-Owens Razor Shear (MORS) and texture profile analysis (TPA). Deboned (3 h postmortem) broiler fillets were c...
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Occurrence of 'super soft' wheat kernel texture in hexaploid and tetraploid wheats
USDA-ARS?s Scientific Manuscript database
Wheat kernel texture is a key trait that governs milling performance, flour starch damage, flour particle size, flour hydration properties, and baking quality. Kernel texture is commonly measured using the Perten Single Kernel Characterization System (SKCS). The SKCS returns texture values (Hardness...
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Textural states of a hot-worked MA2-1 magnesium alloy
NASA Astrophysics Data System (ADS)
Serebryany, V. N.; Kochubei, A. Ya.; Kurtasov, S. F.; Mel'Nikov, K. E.
2007-02-01
Quantitative texture analysis is used to study texture formation in an MA2-1 magnesium alloy subjected to axisymmetric upsetting at temperatures of 250-450°C and strain rates of 10-4-100 -1. The deformed structure is examined by optical microscopy, and the results obtained are used to plot the structural-state diagram of the alloy after 50% upsetting. The experimental textures are compared with the textures calculated in terms of a thermoactivation model.
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Functional surfaces for tribological applications: inspiration and design
NASA Astrophysics Data System (ADS)
Abdel-Aal, Hisham A.
2016-12-01
Surface texturing has been recognized as a method for enhancing the tribological properties of surfaces for many years. Adding a controlled texture to one of two faces in relative motion can have many positive effects, such as reduction of friction and wear and increase in load capacity. To date, the true potential of texturing has not been realized not because of the lack of enabling texturing technologies but because of the severe lack of detailed information about the mechanistic functional details of texturing in a tribological situation. Experimental as well as theoretical analysis of textured surfaces define important metrics for performance evaluation. These metrics represent the interaction between geometry of the texturing element and surface topology. To date, there is no agreement on the optimal values that should be implemented given a particular surface. More importantly, a well-defined methodology for the generation of deterministic textures of optimized designs virtually does not exist. Nature, on the other hand, offers many examples of efficient texturing strategies (geometries and topologies) specifically applied to mitigate frictional effects in a variety of situations. Studying these examples may advance the technology of surface engineering. This paper therefore, provides a comparative review of surface texturing that manifest viable synergy between tribology and biology. We attempt to provide successful emerging examples where borrowing from nature has inspired viable surface solutions that address difficult tribological problems both in dry and lubricated contact situations.
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Multi Texture Analysis of Colorectal Cancer Continuum Using Multispectral Imagery
Chaddad, Ahmad; Desrosiers, Christian; Bouridane, Ahmed; Toews, Matthew; Hassan, Lama; Tanougast, Camel
2016-01-01
Purpose This paper proposes to characterize the continuum of colorectal cancer (CRC) using multiple texture features extracted from multispectral optical microscopy images. Three types of pathological tissues (PT) are considered: benign hyperplasia, intraepithelial neoplasia and carcinoma. Materials and Methods In the proposed approach, the region of interest containing PT is first extracted from multispectral images using active contour segmentation. This region is then encoded using texture features based on the Laplacian-of-Gaussian (LoG) filter, discrete wavelets (DW) and gray level co-occurrence matrices (GLCM). To assess the significance of textural differences between PT types, a statistical analysis based on the Kruskal-Wallis test is performed. The usefulness of texture features is then evaluated quantitatively in terms of their ability to predict PT types using various classifier models. Results Preliminary results show significant texture differences between PT types, for all texture features (p-value < 0.01). Individually, GLCM texture features outperform LoG and DW features in terms of PT type prediction. However, a higher performance can be achieved by combining all texture features, resulting in a mean classification accuracy of 98.92%, sensitivity of 98.12%, and specificity of 99.67%. Conclusions These results demonstrate the efficiency and effectiveness of combining multiple texture features for characterizing the continuum of CRC and discriminating between pathological tissues in multispectral images. PMID:26901134
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Cascaded Amplitude Modulations in Sound Texture Perception
McWalter, Richard; Dau, Torsten
2017-01-01
Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as “beating” in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures—stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches. PMID:28955191
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Prediction of textural attributes using color values of banana (Musa sapientum) during ripening.
Jaiswal, Pranita; Jha, Shyam Narayan; Kaur, Poonam Preet; Bhardwaj, Rishi; Singh, Ashish Kumar; Wadhawan, Vishakha
2014-06-01
Banana is an important sub-tropical fruit in international trade. It undergoes significant textural and color transformations during ripening process, which in turn influence the eating quality of the fruit. In present study, color ('L', 'a' and 'b' value) and textural attributes of bananas (peel, fruit and pulp firmness; pulp toughness; stickiness) were studied simultaneously using Hunter Color Lab and Texture Analyser, respectively, during ripening period of 10 days at ambient atmosphere. There was significant effect of ripening period on all the considered textural characteristics and color properties of bananas except color value 'b'. In general, textural descriptors (peel, fruit and pulp firmness; and pulp toughness) decreased during ripening except stickiness, while color values viz 'a' and 'b' increased with ripening barring 'L' value. Among various textural attributes, peel toughness and pulp firmness showed highest correlation (r) with 'a' value of banana peel. In order to predict textural properties using color values of banana, five types of equations (linear/polynomial/exponential/logarithmic/power) were fitted. Among them, polynomial equation was found to be the best fit (highest coefficient of determination, R(2)) for prediction of texture using color properties for bananas. The pulp firmness, peel toughness and pulp toughness showed R(2) above 0.84 with indicating its potentiality of the fitted equations for prediction of textural profile of bananas non-destructively using 'a' value.
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Fabrication and properties of radially <001>C textured PMN-PT cylinders for transducer applications
NASA Astrophysics Data System (ADS)
Poterala, Stephen F.; Meyer, Richard J.; Messing, Gary L.
2012-07-01
<001>C Textured PMN-PT ceramics have electromechanical properties (d33 = 850-1050 pm/V, k33 = 0.79-0.83) between those of conventional PZT ceramics and relaxor PMN-PT crystals. In this work, we tailor crystallographic orientation in textured PMN-PT ceramics for transducer designs with non-planar poling surfaces. Specifically, omni-directional cylindrical transducer elements were fabricated using monolithic, radially <001>C textured and poled PMN-PT ceramic. Texture was produced by templated grain growth using NBT-PT templates, which were oriented radially by wrapping green ceramic tapes around a cylindrical mandrel. Finished transducer elements measure ˜5 cm in diameter by ˜2.5 cm in height and demonstrate scalability of textured ceramic fabrication techniques. The fabricated cylinders are ˜50 vol. % textured and show high 31-mode electromechanical properties compared to PZT ceramics (d31 = -259 pm/V, k31 = 0.43, ɛT33 = 3000, and Qm = 350). Frequency bandwidth is related to the square of the hoop mode coupling coefficient kh2, which is ˜60% higher in textured PMN-PT cylinders compared to PZT 5H. Finite element simulations show that this parameter may be further increased by improving texture quality to ≥90 vol. %. Radially textured PMN-PT may thus improve performance in omni-directional cylindrical transducers while avoiding the need for segmented single crystal designs.
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Wendin, Karin; Ekman, Susanne; Bülow, Margareta; Ekberg, Olle; Johansson, Daniel; Rothenberg, Elisabet; Stading, Mats
2010-06-28
Patients who suffer from chewing and swallowing disorders, i.e. dysphagia, may have difficulties ingesting normal food and liquids. In these patients a texture modified diet may enable that the patient maintain adequate nutrition. However, there is no generally accepted definition of 'texture' that includes measurements describing different food textures. Objectively define and quantify categories of texture-modified food by conducting rheological measurements and sensory analyses. A further objective was to facilitate the communication and recommendations of appropriate food textures for patients with dysphagia. About 15 food samples varying in texture qualities were characterized by descriptive sensory and rheological measurements. Soups were perceived as homogenous; thickened soups were perceived as being easier to swallow, more melting and creamy compared with soups without thickener. Viscosity differed between the two types of soups. Texture descriptors for pâtés were characterized by high chewing resistance, firmness, and having larger particles compared with timbales and jellied products. Jellied products were perceived as wobbly, creamy, and easier to swallow. Concerning the rheological measurements, all solid products were more elastic than viscous (G'>G''), belonging to different G' intervals: jellied products (low G') and timbales together with pâtés (higher G'). By combining sensory and rheological measurements, a system of objective, quantitative, and well-defined food textures was developed that characterizes the different texture categories.
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Cube-textured nickel substrates for high-temperature superconductors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Specht, E.D.; Goyal, A.; Lee, D.F.
1998-02-01
The biaxial textures created in metals by rolling and annealing make them useful substrates for the growth of long lengths of biaxially textured material. The growth of overlayers such as high-temperature superconductors (HTS) require flat substrates with a single, sharp texture. A sharp cube texture is produced in high-purity Ni by rolling and annealing. The authors report the effect of rolling reduction and annealing conditions on the sharpness of the cube texture, the incidence of other orientations, the grain size, and the surface topography. A combination of high reduction, and high temperature annealing in a reducing atmosphere leads to >more » 99% cube texture, with mosaic of 9.0{degree} about the rolling direction (RD), 6.5{degree} about the transverse direction (TD), and 5.0{degree} about the normal direction (ND).« less
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NASA Astrophysics Data System (ADS)
Eldosouky, Ahmed M.; Elkhateeb, Sayed O.
2018-06-01
Enhancement of aeromagnetic data for qualitative purposes depends on the variations of texture and amplitude to outline various geologic features within the data. The texture of aeromagnetic data consists continuity of adjacent anomalies, size, and pattern. Variations in geology, or particularly rock magnetization, in a study area cause fluctuations in texture. In the present study, the anomalous features of Elallaqi area were extracted from aeromagnetic data. In order to delineate textures from the aeromagnetic data, the Red, Green, and Blue Co-occurrence Matrices (RGBCM) were applied to the reduced to the pole (RTP) grid of Elallaqi district in the South Eastern Desert of Egypt. The RGBCM are fashioned of sets of spatial analytical parameters that transform magnetic data into texture forms. Six texture features (parameters), i.e. Correlation, Contrast, Entropy, Homogeneity, Second Moment, and Variance, of RGB Co-occurrence Matrices (RGBCM) are used for analyzing the texture of the RTP grid in this study. These six RGBCM texture characteristics were mixed into a single image using principal component analysis. The calculated texture images present geologic characteristics and structures with much greater sidelong resolution than the original RTP grid. The estimated texture images enabled us to distinguish multiple geologic regions and structures within Elallaqi area including geologic terranes, lithologic boundaries, cracks, and faults. The faults of RGBCM maps were more represented than those of magnetic derivatives providing enhancement of the fine structures of Elallaqi area like the NE direction which scattered WNW metavolcanics and metasediments trending in the northwestern division of Elallaqi area.
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Doped LZO buffer layers for laminated conductors
Paranthaman, Mariappan Parans [Knoxville, TN; Schoop, Urs [Westborough, MA; Goyal, Amit [Knoxville, TN; Thieme, Cornelis Leo Hans [Westborough, MA; Verebelyi, Darren T [Oxford, MA; Rupich, Martin W [Framingham, MA
2010-03-23
A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the substrate, the biaxially textured buffer layer comprising LZO and a dopant for mitigating metal diffusion through the LZO, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.
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Comparison of objective texture measurements in raw and cooked wooden breast meat.
USDA-ARS?s Scientific Manuscript database
Broiler breast meat exhibiting the wooden breast condition is characterized as having an abnormally hard or rigid texture. The efficacy of using objective texture measurements to characterize the texture attributes of breast meat exhibiting this condition before and after cooking are not well under...
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ERIC Educational Resources Information Center
Stone, Julie
2007-01-01
In an effort to provide an opportunity for her first graders to explore texture through an engaging subject, the author developed a three-part lesson that features fish in a mixed-media artwork: (1) Exploring Textured Paint; (2) Creating the Fish; and (3) Role Playing. In this lesson, students effectively explore texture through painting, drawing,…
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7 CFR 58.317 - Bulk butter trucks, boats, texturizers, and packers.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 3 2013-01-01 2013-01-01 false Bulk butter trucks, boats, texturizers, and packers... and Grading Service 1 Equipment and Utensils § 58.317 Bulk butter trucks, boats, texturizers, and packers. Bulk butter trucks, boats, texturizers, and packers shall be constructed of aluminum, stainless...
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7 CFR 58.317 - Bulk butter trucks, boats, texturizers, and packers.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 3 2014-01-01 2014-01-01 false Bulk butter trucks, boats, texturizers, and packers... and Grading Service 1 Equipment and Utensils § 58.317 Bulk butter trucks, boats, texturizers, and packers. Bulk butter trucks, boats, texturizers, and packers shall be constructed of aluminum, stainless...
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7 CFR 58.317 - Bulk butter trucks, boats, texturizers, and packers.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 3 2011-01-01 2011-01-01 false Bulk butter trucks, boats, texturizers, and packers... and Grading Service 1 Equipment and Utensils § 58.317 Bulk butter trucks, boats, texturizers, and packers. Bulk butter trucks, boats, texturizers, and packers shall be constructed of aluminum, stainless...
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7 CFR 58.317 - Bulk butter trucks, boats, texturizers, and packers.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 3 2012-01-01 2012-01-01 false Bulk butter trucks, boats, texturizers, and packers... and Grading Service 1 Equipment and Utensils § 58.317 Bulk butter trucks, boats, texturizers, and packers. Bulk butter trucks, boats, texturizers, and packers shall be constructed of aluminum, stainless...
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7 CFR 58.317 - Bulk butter trucks, boats, texturizers, and packers.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 3 2010-01-01 2010-01-01 false Bulk butter trucks, boats, texturizers, and packers... and Grading Service 1 Equipment and Utensils § 58.317 Bulk butter trucks, boats, texturizers, and packers. Bulk butter trucks, boats, texturizers, and packers shall be constructed of aluminum, stainless...
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The use of an ion-beam source to alter the surface morphology of biological implant materials
NASA Technical Reports Server (NTRS)
Weigand, A. J.
1978-01-01
An electron bombardment, ion thruster was used as a neutralized-ion beam sputtering source to texture the surfaces of biological implant materials. Scanning electron microscopy was used to determine surface morphology changes of all materials after ion-texturing. Electron spectroscopy for chemical analysis was used to determine the effects of ion texturing on the surface chemical composition of some polymers. Liquid contact angle data were obtained for ion textured and untextured polymer samples. Results of tensile and fatigue tests of ion-textured metal alloys are presented. Preliminary data of tissue response to ion textured surfaces of some metals, polytetrafluoroethylene, alumina, and segmented polyurethane were obtained.
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Material characterization and defect inspection in ultrasound images
NASA Astrophysics Data System (ADS)
Zmola, Carl; Segal, Andrew C.; Lovewell, Brian; Mahdavieh, Jacob; Ross, Joseph; Nash, Charles
1992-08-01
The use of ultrasonic imaging to analyze defects and characterize materials is critical in the development of non-destructive testing and non-destructive evaluation (NDT/NDE) tools for manufacturing. To develop better quality control and reliability in the manufacturing environment advanced image processing techniques are useful. For example, through the use of texture filtering on ultrasound images, we have been able to filter characteristic textures from highly textured C-scan images of materials. The materials have highly regular characteristic textures which are of the same resolution and dynamic range as other important features within the image. By applying texture filters and adaptively modifying their filter response, we have examined a family of filters for removing these textures.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Kuru, Yener; Welzel, Udo; Mittemeijer, Eric J.
2014-12-01
This paper demonstrates experimentally that ultra-thin, nanocrystalline films can exhibit coexisting colossal stress and texture depth gradients. Their quantitative determination is possible by X-ray diffraction experiments. Whereas a uniform texture by itself is known to generally cause curvature in so-called sin{sup 2}ψ plots, it is shown that the combined action of texture and stress gradients provides a separate source of curvature in sin{sup 2}ψ plots (i.e., even in cases where a uniform texture does not induce such curvature). On this basis, the texture and stress depth profiles of a nanocrystalline, ultra-thin (50 nm) tungsten film could be determined.
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Method of forming biaxially textured alloy substrates and devices thereon
Goyal, Amit; Specht, Eliot D.; Kroeger, Donald M.; Paranthaman, Mariappan
2000-01-01
Specific alloys, in particular Ni-based alloys, that can be biaxially textured, with a well-developed, single component texture are disclosed. These alloys have a significantly reduced Curie point, which is very desirable from the point of view of superconductivity applications. The biaxially textured alloy substrates also possess greatly enhanced mechanical properties (yield strength, ultimate tensile strength) which are essential for most applications, in particular, superconductors. A method is disclosed for producing complex multicomponent alloys which have the ideal physical properties for specific applications, such as lattice parameter, degree of magnetism and mechanical strength, and which cannot be in textured form. In addition, a method for making ultra thin biaxially textured substrates with complex compositions is disclosed.
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Modulating Thin Film Transistor Characteristics by Texturing the Gate Metal.
Nair, Aswathi; Bhattacharya, Prasenjit; Sambandan, Sanjiv
2017-12-20
The development of reliable, high performance integrated circuits based on thin film transistors (TFTs) is of interest for the development of flexible electronic circuits. In this work we illustrate the modulation of TFT transconductance via the texturing of the gate metal created by the addition of a conductive pattern on top of a planar gate. Texturing results in the semiconductor-insulator interface acquiring a non-planar geometry with local variations in the radius of curvature. This influences various TFT parameters such as the subthreshold slope, gate voltage at the onset of conduction, contact resistance and gate capacitance. Specific studies are performed on textures based on periodic striations oriented along different directions. Textured TFTs showed upto ±40% variation in transconductance depending on the texture orientation as compared to conventional planar gate TFTs. Analytical models are developed and compared with experiments. Gain boosting in common source amplifiers based on textured TFTs as compared to conventional TFTs is demonstrated.
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Cloud and surface textural features in polar regions
NASA Technical Reports Server (NTRS)
Welch, Ronald M.; Kuo, Kwo-Sen; Sengupta, Sailes K.
1990-01-01
The study examines the textural signatures of clouds, ice-covered mountains, solid and broken sea ice and floes, and open water. The textural features are computed from sum and difference histogram and gray-level difference vector statistics defined at various pixel displacement distances derived from Landsat multispectral scanner data. Polar cloudiness, snow-covered mountainous regions, solid sea ice, glaciers, and open water have distinguishable texture features. This suggests that textural measures can be successfully applied to the detection of clouds over snow-covered mountains, an ability of considerable importance for the modeling of snow-melt runoff. However, broken stratocumulus cloud decks and thin cirrus over broken sea ice remain difficult to distinguish texturally. It is concluded that even with high spatial resolution imagery, it may not be possible to distinguish broken stratocumulus and thin clouds from sea ice in the marginal ice zone using the visible channel textural features alone.
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Utilizing Antecedent Manipulations and Reinforcement in the Treatment of Food Selectivity by Texture
ERIC Educational Resources Information Center
Najdowski, Adel C.; Tarbox, Jonathan; Wilke, Arthur E.
2012-01-01
Food selectivity by texture is relatively common in children. Treatments for food selectivity by texture have included components such as stimulus fading, reinforcement, and escape extinction. The purpose of the current study was to attempt to treat food selectivity by texture utilizing antecedent manipulations and reinforcement in the absence of…
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Modified centroid for estimating sand, silt, and clay from soil texture class
USDA-ARS?s Scientific Manuscript database
Models that require inputs of soil particle size commonly use soil texture class for input; however, texture classes do not represent the continuum of soil size fractions. Soil texture class and clay percentage are collected as a standard practice for many land management agencies (e.g., NRCS, BLM, ...
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A procedure for classifying textural facies in gravel-bed rivers
John M. Buffington; David R. Montgomery
1999-01-01
Textural patches (i.e., grain-size facies) are commonly observed in gravel-bed channels and are of significance for both physical and biological processes at subreach scales. We present a general framework for classifying textural patches that allows modification for particular study goals, while maintaining a basic degree of standardization. Textures are classified...
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NASA Astrophysics Data System (ADS)
Rajab, Fatema H.; Whitehead, David; Liu, Zhu; Li, Lin
2017-12-01
Laser surface texturing or micro/nano surface structuring in the air has been extensively studied. However, until now, there are very few studies on the characteristics of laser-textured surfaces in water, and there was no reported work on picosecond laser surface micro/nano-structuring in water. In this work, the surface properties of picosecond laser surface texturing in water and air were analysed and compared. 316L stainless steel substrates were textured using a picosecond laser. The surface morphology and the chemical composition were characterised using Philips XL30 FEG-SEM, EDX and confocal laser microscopy. The wettability of the textured surfaces was determined using a contact angle analyser FTA 188. Results showed that a variety of hierarchical micro/nano surface patterns could be controlled by a suitable adjustment of laser parameters. Not only surface morphology but also remarkable differences in wettability, optical reflectivity and surface oxygen content were observed for different types of surface textures produced by laser surface texture in water and air. The possible mechanisms of the changes in the behaviour of laser-textured surfaces are discussed.
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Epitaxial hexagonal materials on IBAD-textured substrates
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matias, Vladimir; Yung, Christopher
2017-08-15
A multilayer structure including a hexagonal epitaxial layer, such as GaN or other group III-nitride (III-N) semiconductors, a <111> oriented textured layer, and a non-single crystal substrate, and methods for making the same. The textured layer has a crystalline alignment preferably formed by the ion-beam assisted deposition (IBAD) texturing process and can be biaxially aligned. The in-plane crystalline texture of the textured layer is sufficiently low to allow growth of high quality hexagonal material, but can still be significantly greater than the required in-plane crystalline texture of the hexagonal material. The IBAD process enables low-cost, large-area, flexible metal foil substratesmore » to be used as potential alternatives to single-crystal sapphire and silicon for manufacture of electronic devices, enabling scaled-up roll-to-roll, sheet-to-sheet, or similar fabrication processes to be used. The user is able to choose a substrate for its mechanical and thermal properties, such as how well its coefficient of thermal expansion matches that of the hexagonal epitaxial layer, while choosing a textured layer that more closely lattice matches that layer.« less
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NASA Astrophysics Data System (ADS)
Benschop, H. O. G.; Breugem, W.-P.
2017-08-01
A bird-feather-inspired herringbone riblet texture was investigated for turbulent drag reduction. The texture consists of blade riblets in a converging/diverging or herringbone pattern with spanwise wavelength Λf. The aim is to quantify the drag change for this texture as compared to a smooth wall and to study the underlying mechanisms. To that purpose, direct numerical simulations of turbulent flow in a channel with height Lz were performed. The Fukagata-Iwamoto-Kasagi identity for drag decomposition was extended to textured walls and was used to study the drag change mechanisms. For Λf/Lz ≳ O(10), the herringbone texture behaves similarly to a conventional parallel-riblet texture in yaw: the suppression of turbulent advective transport results in a slight drag reduction of 2%. For Λf/Lz ≲ O(1), the drag increases strongly with a maximum of 73%. This is attributed to enhanced mean and turbulent advection, which results from the strong secondary flow that forms over regions of riblet convergence/divergence. Hence, the employment of convergent/divergent riblets in the texture seems to be detrimental to turbulent drag reduction.
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NASA Astrophysics Data System (ADS)
Yilbas, B. S.; Ali, H.; Al-Sharafi, A.; Al-Aqeeli, N.
2018-03-01
Laser gas assisted texturing of alumina surface is carried out, and formation of nitride and oxynitride compounds in the surface vicinity is examined. The laser parameters are selected to create the surface topology consisting of micro/nano pillars with minimum defect sites including micro-cracks, voids and large size cavities. Morphological and hydrophobic characteristics of the textured surface are examined using the analytical tools. The characteristics of the environmental dust and its influence on the laser textured surface are studied while mimicking the local humid air ambient. Adhesion of the dry mud on the laser textured surface is assessed through the measurement of the tangential force, which is required to remove the dry mud from the surface. It is found that laser texturing gives rise to micro/nano pillars topology and the formation of AlN and AlON compounds in the surface vicinity. This, in turn, lowers the free energy of the textured surface and enhances the hydrophobicity of the surface. The liquid solution resulted from the dissolution of alkaline and alkaline earth metals of the dust particles in water condensate forms locally scattered liquid islands at the interface of mud and textured surface. The dried liquid solution at the interface increases the dry mud adhesion on the textured surface. Some dry mud residues remain on the textured surface after the dry mud is removed by a pressurized desalinated water jet.
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Texture analysis based on the Hermite transform for image classification and segmentation
NASA Astrophysics Data System (ADS)
Estudillo-Romero, Alfonso; Escalante-Ramirez, Boris; Savage-Carmona, Jesus
2012-06-01
Texture analysis has become an important task in image processing because it is used as a preprocessing stage in different research areas including medical image analysis, industrial inspection, segmentation of remote sensed imaginary, multimedia indexing and retrieval. In order to extract visual texture features a texture image analysis technique is presented based on the Hermite transform. Psychovisual evidence suggests that the Gaussian derivatives fit the receptive field profiles of mammalian visual systems. The Hermite transform describes locally basic texture features in terms of Gaussian derivatives. Multiresolution combined with several analysis orders provides detection of patterns that characterizes every texture class. The analysis of the local maximum energy direction and steering of the transformation coefficients increase the method robustness against the texture orientation. This method presents an advantage over classical filter bank design because in the latter a fixed number of orientations for the analysis has to be selected. During the training stage, a subset of the Hermite analysis filters is chosen in order to improve the inter-class separability, reduce dimensionality of the feature vectors and computational cost during the classification stage. We exhaustively evaluated the correct classification rate of real randomly selected training and testing texture subsets using several kinds of common used texture features. A comparison between different distance measurements is also presented. Results of the unsupervised real texture segmentation using this approach and comparison with previous approaches showed the benefits of our proposal.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Nezakat, Majid, E-mail: majid.nezakat@usask.ca
We studied the texture evolution of thermo-mechanically processed austenitic stainless steel 310S. This alloy was cold rolled up to 90% reduction in thickness and subsequently annealed at 1050 °C. At the early stages of deformation, strain-induced martensite was formed from deformed austenite. By increasing the deformation level, slip mechanism was found to be insufficient to accommodate higher deformation strains. Our results demonstrated that twinning is the dominant deformation mechanism at higher deformation levels. Results also showed that cold rolling in unidirectional and cross rolling modes results in Goss/Brass and Brass dominant textures in deformed samples, respectively. Similar texture components aremore » observed after annealing. Thus, the annealing texture was greatly affected by texture of the deformed parent phase and martensite did not contribute as it showed an athermal reversion during annealing. Results also showed that when the fraction of martensite exceeds a critical point, its grain boundaries impeded the movement of austenite grain boundaries during annealing. As a result, recrystallization incubation time would increase. This caused an incomplete recrystallization of highly deformed samples, which led to a rational drop in the intensity of the texture components. - Highlights: •Thermo-mechanical processing through different cold rolling modes can induce different textures. •Martensite reversion is athermal during annealing. •Higher fraction of deformation-induced martensite can increase the annealing time required for complete recrystallization. •Annealing texture is mainly influenced by the deformation texture of austenite.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Blau, Peter Julian
If properly employed, the placement of three-dimensional feature patterns, also referred to as textures, on relatively-moving, load-bearing surfaces can be beneficial to their friction and wear characteristics. For example, geometric patterns can function as lubricant supply channels or depressions in which to trap debris. They can also alter lubricant flow in a manner that produces thicker load-bearing films locally. Considering the area occupied by solid areas and spaces, textures also change the load distribution on surfaces. At least ten different attributes of textures can be specified, and their combinations offer wide latitude in surface engineering. By employing directional machining andmore » grinding procedures, texturing has been used on bearings and seals for well over a half century, and the size scales of texturing vary widely. This report summarizes past work on the texturing of load-bearing surfaces, including past research on laser surface dimpling of ceramics done at ORNL. Textured surfaces generally show most pronounced effects when they are used in conformal or nearly conformal contacts, like that in face seals. Combining textures with other forms of surface modification and lubrication methods can offer additional benefits in surface engineering for tribology. As the literature and past work at ORNL shows, texturing does not always provide benefits. Rather, the selected pattern and arrangement of features must be matched to characteristics of the proposed application, bearing materials, and lubricants.« less
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NASA Astrophysics Data System (ADS)
Xu, H. J.; Xu, Y. B.; Jiao, H. T.; Cheng, S. F.; Misra, R. D. K.; Li, J. P.
2018-05-01
Fe-6.5 wt% Si steel hot bands with different initial grain size and texture were obtained through different annealing treatment. These bands were then warm rolled and annealed. An analysis on the evolution of microstructure and texture, particularly the formation of recrystallization texture was studied. The results indicated that initial grain size and texture had a significant effect on texture evolution and magnetic properties. Large initial grains led to coarse deformed grains with dense and long shear bands after warm rolling. Such long shear bands resulted in growth advantage for {1 1 3} 〈3 6 1〉 oriented grains during recrystallization. On the other hand, sharp {11 h} 〈1, 2, 1/h〉 (α∗-fiber) texture in the coarse-grained sample led to dominant {1 1 2} 〈1 1 0〉 texture after warm rolling. Such {1 1 2} 〈1 1 0〉 deformed grains provided massive nucleation sites for {1 1 3} 〈3 6 1〉 oriented grains during subsequent recrystallization. These {1 1 3} 〈3 6 1〉 grains were confirmed to exhibit an advantage on grain growth compared to γ-fiber grains. As a result, significant {1 1 3} 〈3 6 1〉 texture was developed and unfavorable γ-fiber texture was inhibited in the final annealed sheet. Both these aspects led to superior magnetic properties in the sample with largest initial grain size. The magnetic induction B8 was 1.36 T and the high frequency core loss P10/400 was 17.07 W/kg.
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Al Ajmi, Eiman; Forghani, Behzad; Reinhold, Caroline; Bayat, Maryam; Forghani, Reza
2018-06-01
There is a rich amount of quantitative information in spectral datasets generated from dual-energy CT (DECT). In this study, we compare the performance of texture analysis performed on multi-energy datasets to that of virtual monochromatic images (VMIs) at 65 keV only, using classification of the two most common benign parotid neoplasms as a testing paradigm. Forty-two patients with pathologically proven Warthin tumour (n = 25) or pleomorphic adenoma (n = 17) were evaluated. Texture analysis was performed on VMIs ranging from 40 to 140 keV in 5-keV increments (multi-energy analysis) or 65-keV VMIs only, which is typically considered equivalent to single-energy CT. Random forest (RF) models were constructed for outcome prediction using separate randomly selected training and testing sets or the entire patient set. Using multi-energy texture analysis, tumour classification in the independent testing set had accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 92%, 86%, 100%, 100%, and 83%, compared to 75%, 57%, 100%, 100%, and 63%, respectively, for single-energy analysis. Multi-energy texture analysis demonstrates superior performance compared to single-energy texture analysis of VMIs at 65 keV for classification of benign parotid tumours. • We present and validate a paradigm for texture analysis of DECT scans. • Multi-energy dataset texture analysis is superior to single-energy dataset texture analysis. • DECT texture analysis has high accura\\cy for diagnosis of benign parotid tumours. • DECT texture analysis with machine learning can enhance non-invasive diagnostic tumour evaluation.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Hiscocks, J., E-mail: j.hiscocks@queensu.ca
Many studies of friction stir welding have shown that periodicity of metal flow around the tool pin may result in the formation of periodic differences in microstructure and texture in the weld nugget area correlated with the weld pitch. The current work investigates the periodicity of magnesium weld microtexture in the nugget region and its association with material flow using optical and electron microscopy. Two welds created in AZ80 at different processing conditions are presented in detail, one illustrating periodic longitudinal texture change, and one showing for the first time that periodic variations in texture, grain size, or composition aremore » not defining features of periodic nugget flow. While nugget texture is dominated by shear deformation, it was found here to be affected to a lesser degree by compaction of material behind the welding tool, which led to reduction in intensity of the shear texture fiber. The decreased tendency for magnesium based alloys to form periodic patterns as compared to aluminum based alloys is explained with reference to the shear textures. - Highlights: •It is shown here that periodic material flow in the nugget does not necessitate longitudinal texture patterns. •Longitudinal texture patterns are shown to be present or absent in Mg AZ80 based on processing conditions. •Texture in the nugget is mainly dictated by shear deformation, but has measurable effects from other deformation modes. •Explanation of why longitudinal texture change is frequently reported in aluminum but not magnesium alloys is provided. •A new vector visualization of material flow based on EBSD data analysis is shown.« less
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Bayesian exploration for intelligent identification of textures.
Fishel, Jeremy A; Loeb, Gerald E
2012-01-01
In order to endow robots with human-like abilities to characterize and identify objects, they must be provided with tactile sensors and intelligent algorithms to select, control, and interpret data from useful exploratory movements. Humans make informed decisions on the sequence of exploratory movements that would yield the most information for the task, depending on what the object may be and prior knowledge of what to expect from possible exploratory movements. This study is focused on texture discrimination, a subset of a much larger group of exploratory movements and percepts that humans use to discriminate, characterize, and identify objects. Using a testbed equipped with a biologically inspired tactile sensor (the BioTac), we produced sliding movements similar to those that humans make when exploring textures. Measurement of tactile vibrations and reaction forces when exploring textures were used to extract measures of textural properties inspired from psychophysical literature (traction, roughness, and fineness). Different combinations of normal force and velocity were identified to be useful for each of these three properties. A total of 117 textures were explored with these three movements to create a database of prior experience to use for identifying these same textures in future encounters. When exploring a texture, the discrimination algorithm adaptively selects the optimal movement to make and property to measure based on previous experience to differentiate the texture from a set of plausible candidates, a process we call Bayesian exploration. Performance of 99.6% in correctly discriminating pairs of similar textures was found to exceed human capabilities. Absolute classification from the entire set of 117 textures generally required a small number of well-chosen exploratory movements (median = 5) and yielded a 95.4% success rate. The method of Bayesian exploration developed and tested in this paper may generalize well to other cognitive problems.
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Bayesian Exploration for Intelligent Identification of Textures
Fishel, Jeremy A.; Loeb, Gerald E.
2012-01-01
In order to endow robots with human-like abilities to characterize and identify objects, they must be provided with tactile sensors and intelligent algorithms to select, control, and interpret data from useful exploratory movements. Humans make informed decisions on the sequence of exploratory movements that would yield the most information for the task, depending on what the object may be and prior knowledge of what to expect from possible exploratory movements. This study is focused on texture discrimination, a subset of a much larger group of exploratory movements and percepts that humans use to discriminate, characterize, and identify objects. Using a testbed equipped with a biologically inspired tactile sensor (the BioTac), we produced sliding movements similar to those that humans make when exploring textures. Measurement of tactile vibrations and reaction forces when exploring textures were used to extract measures of textural properties inspired from psychophysical literature (traction, roughness, and fineness). Different combinations of normal force and velocity were identified to be useful for each of these three properties. A total of 117 textures were explored with these three movements to create a database of prior experience to use for identifying these same textures in future encounters. When exploring a texture, the discrimination algorithm adaptively selects the optimal movement to make and property to measure based on previous experience to differentiate the texture from a set of plausible candidates, a process we call Bayesian exploration. Performance of 99.6% in correctly discriminating pairs of similar textures was found to exceed human capabilities. Absolute classification from the entire set of 117 textures generally required a small number of well-chosen exploratory movements (median = 5) and yielded a 95.4% success rate. The method of Bayesian exploration developed and tested in this paper may generalize well to other cognitive problems. PMID:22783186
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Extraction of texture features with a multiresolution neural network
NASA Astrophysics Data System (ADS)
Lepage, Richard; Laurendeau, Denis; Gagnon, Roger A.
1992-09-01
Texture is an important surface characteristic. Many industrial materials such as wood, textile, or paper are best characterized by their texture. Detection of defaults occurring on such materials or classification for quality control anD matching can be carried out through careful texture analysis. A system for the classification of pieces of wood used in the furniture industry is proposed. This paper is concerned with a neural network implementation of the features extraction and classification components of the proposed system. Texture appears differently depending at which spatial scale it is observed. A complete description of a texture thus implies an analysis at several spatial scales. We propose a compact pyramidal representation of the input image for multiresolution analysis. The feature extraction system is implemented on a multilayer artificial neural network. Each level of the pyramid, which is a representation of the input image at a given spatial resolution scale, is mapped into a layer of the neural network. A full resolution texture image is input at the base of the pyramid and a representation of the texture image at multiple resolutions is generated by the feedforward pyramid structure of the neural network. The receptive field of each neuron at a given pyramid level is preprogrammed as a discrete Gaussian low-pass filter. Meaningful characteristics of the textured image must be extracted if a good resolving power of the classifier must be achieved. Local dominant orientation is the principal feature which is extracted from the textured image. Local edge orientation is computed with a Sobel mask at four orientation angles (multiple of (pi) /4). The resulting intrinsic image, that is, the local dominant orientation image, is fed to the texture classification neural network. The classification network is a three-layer feedforward back-propagation neural network.
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A Community Database of Quartz Microstructures: Can we make measurements that constrain rheology?
NASA Astrophysics Data System (ADS)
Toy, Virginia; Peternell, Mark; Morales, Luiz; Kilian, Ruediger
2014-05-01
Rheology can be explored by performing deformation experiments, and by examining resultant microstructures and textures as links to naturally deformed rocks. Certain deformation processes are assumed to result in certain microstructures or textures, of which some might be uniquely indicative, while most cannot be unequivocally used to interpret the deformation mechanism and hence rheology. Despite our lack of a sufficient understanding of microstructure and texture forming processes, huge advances in texture measurements and quantification of microstructural parameters have been made. Unfortunately, there are neither standard procedures nor a common consensus on interpretation of many parameters (e.g. texture, grain size, shape preferred orientation). Textures (crystallographic preferred orientations) have been extensively correlated to the interpretation of deformation mechanisms. For example the strength of textures can be measured either from the orientation distribution function (e.g. the J-index (Bunge, 1983) or texture entropy (Hielscher et al., 2007) or via the intensity of polefigures. However, there are various ways to identify a representative volume, to measure, to process the data and to calculate an odf and texture descriptors, which restricts their use as a comparative and diagnostic measurement. Microstructural parameters such as grain size, grain shape descriptors and fabric descriptors are similarly used to deduce and quantify deformation mechanisms. However there is very little consensus on how to measure and calculate some of these very important parameters, e.g. grain size which makes comparison of a vast amount of precious data in the literature very difficult. We propose establishing a community database of a standard set of such measurements, made using typical samples of different types of quartz rocks through standard methods of microstructural and texture quantification. We invite suggestions and discussion from the community about the worth of proposed parameters, methodology and usefulness and willingness to contribute to a database with free access of the community. We further invite institutions to participate on a benchmark analysis of a set of 'standard' thin sections. Bunge, H.J. 1983, Texture Analysis in Materials Science: mathematical methods. Butterworth-Heinemann, 593pp. Hielscher, R., Schaeben, H., Chateigner, D., 2007, On the entropy to texture index relationship in quantitative texture analysis: Journal of Applied Crystallography 40, 371-375.
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Record of Hybridization Preserved in Zircon, Aztec Wash Pluton, NV
NASA Astrophysics Data System (ADS)
Bromley, S. A.; Miller, C. F.; Claiborne, L. L.; Wooden, J. L.; Mazdab, F. K.
2007-12-01
The mid-Miocene Aztec Wash pluton comprises a smaller granite zone and a larger, highly heterogeneous zone in which evidence for interaction between basaltic and granitic magmas is ubiquitous. Granitic rocks in both zones show textural and compositional evidence for crystal accumulation and melt fractionation. In the heterogeneous zone, basalts have chilled, crenulate margins against granitic rocks, and there is widespread evidence for mechanical contamination of each lithology (coarse resorbed alkali feldspar in fine-grained mafic rock; mafic enclaves in granite). "Grey rocks" of intermediate composition are exposed on dm to 100's of m-scale as enclaves, pods, and initially subhorizontal sheets. They are variable texturally, but most are dominantly fine- grained and equigranular. Textures of grey rocks are consistent with rapid solidification from melt-rich magma, and, in combination with isotopic compositions intermediate between felsic and mafic rocks of the pluton, suggest an origin by near-complete homogenization of a hybrid melt (Bleick et al. 2005; Ericksen 2005). The elemental chemistry of zircon preserves information about the evolving magmatic environment in which it was hosted (Claiborne et al., 2006). Owing to its slow dissolution rate, it has the potential to survive periods of undersaturation with only partial resorption. Thus, it may record drastic shifts in T and melt chemistry that would accompany mafic-felsic hybridization. We are investigating zircon zoning patterns by cathodoluminescence (CL) and elemental compositions by SHRIMP-RG to evaluate the record of processes that they preserve. Temperatures of zircon growth are estimated using Ti-in-zircon thermometry (Watson et al. 2006), assuming a(TiO2) of ca. 0.7 (sphene +/-ilmenite are ubiquitous). Zircons from the granite zone yield estimated T's of 700-860 C, whereas those from grey rocks range from 710- 910 C. While both granite and grey zircon populations show dramatic T variations among and within grains, fluctuation tends to be more common and extreme in grains from the grey rocks, where variations exceed 100°C. Such grains appear to have both survived and recorded a substantial heating event, as would be expected if either mixing or thorough mingling occurred. Zircons from the granitic samples almost invariably have euhedral, concentric, oscillatory zoning; some have truncations in zoning indicating resorption, and many have thin, CL-dark rims. Grey rock zircons typically display thick, concentric zoning or, less commonly, banding, are rarely oscillatory zoned, and many exhibit indistinct or anhedral internal zoning (corresponding to high calculated T). Many have thick CL-bright rims and resorbed surfaces. These rims apparently represent relatively cool (less than 800 C) late stage growth following the heating event recorded in grain interiors. In both granitic and grey samples, Hf (6500-13000 ppm) shows a strong negative correlation with calculated T. In all granite samples, U (100-3000 ppm) & Th (150-3500 ppm) concentrations likewise show a strong negative correlation with calculated T, indicating that both acted as incompatible elements in these magmas. U (50-2000 ppm) & Th (50-2000 ppm) compositions show equally dramatic, but far less systematic, variation in grey samples, with high concentrations at elevated T. Growth of "hot" U, Th-rich zircon at Aztec Wash appears to be limited to the mixing environment.
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Ten Years of MISR Observations from Terra: Looking Back, Ahead, and in Between
NASA Technical Reports Server (NTRS)
Diner, David J.; Ackerman, Thomas P.; Braverman, Amy J.; Bruegge, Carol J.; Chopping, Mark J.; Clothiaux, Eugene E.; Davies, Roger; Di Girolamo, Larry; Kahn, Ralph A.; Knyazikhin, Yuri;
2010-01-01
The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global Earth data from NASA's Terra satellite since February 2000. With its nine along-track view angles, four visible/near-infrared spectral bands, intrinsic spatial resolution of 275 m, and stable radiometric and geometric calibration, no instrument that combines MISR's attributes has previously flown in space. The more than 10-year (and counting) MISR data record provides unprecedented opportunities for characterizing long-term trends in aerosol, cloud, and surface properties, and includes 3-D textural information conventionally thought to be accessible only to active sensors.
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Soil management and green water in sloping rainfed vineyards
NASA Astrophysics Data System (ADS)
José Marqués Pérez, María; Ruíz-Colmenero, Marta; García-Díaz, Andrés; Bienes Allas, Ramón
2017-04-01
Improved crop production in areas with restricted water availability is of particular interest. Farmers need to maximize the water use efficiency when the possibilities of further extension of irrigation are limited and water is becoming scarce and expensive. Water in rainfed crops depends on rainfall depth and soil characteristics such as texture and structure, water holding capacity, previous moisture, infiltration, soil surface conditions, steepness and slope length. Land management practices can be used to maximise water availability. In previous studies the unwillingness of farmers to change their practices towards more sustainable use was mainly due to the worry about water competition. This work is aimed at understanding the influence of management practices in the water partitioning of this land use. This study was conducted in a sloping vineyard in the centre of Spain. A rain gauge recorded rainfall depth and intensity in the area. Three different soil management practices were considered: 1) traditional tillage, 2) permanent cover and 3) mowed cover of cereals, both sown in the strips between vines. Two moisture sensors were buried at 10 and 35 cm depths. Three replicates per management practice were performed. It is expected that the lack of tillage increase the potential for litter to protect the soil surface against raindrop impact and to contribute to increasing soil organic carbon, and the corresponding increase in infiltration and water holding capacity. The analysis of two years of daily records of rainfall, runoff and soil moisture are intended to establish any influence of management practices on the partitioning of water. Particularly, the so-called "green water" was estimated, i.e. the fraction of rainfall that infiltrates into the soil and will be further available to plants. Soil characteristics such as texture, structure, moisture, infiltration were established. In addition simulated rainfalls carried out in summer and winter over bounded plots having different management practices allowed the record of runoff per minute and further influence in soil moisture. After rainfalls soils were at field capacity and progressively dried in undisturbed conditions. Particle size analysis shows that this soil has 58 % sand, 18% silt and 24% clay, corresponding to a Sandy Clay Loam texture. Total porosity in the topsoil ranges from 49 to 51%, although according to previous studies only the 28% is effective to stock water in their micro and mesopores. In the upper 35 cm these soils are able to store from 0.05 to 0.25 m3 of water per m3 of soil depending on the seasons. At the same time, variations of runoff / infiltration were also noticed depending on the seasons and treatments.
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USDA-ARS?s Scientific Manuscript database
The objective was to characterize texture properties of raw and cooked broiler fillets (Pectoralis major) with the wooden breast condition (WBC) using the instrumental texture techniques of Meullenet-Owens Razor Shear (MORS) and Texture Profile Analysis (TPA). Deboned (3 h post-mortem) broiler fille...
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Music Structure Analysis from Acoustic Signals
NASA Astrophysics Data System (ADS)
Dannenberg, Roger B.; Goto, Masataka
Music is full of structure, including sections, sequences of distinct musical textures, and the repetition of phrases or entire sections. The analysis of music audio relies upon feature vectors that convey information about music texture or pitch content. Texture generally refers to the average spectral shape and statistical fluctuation, often reflecting the set of sounding instruments, e.g., strings, vocal, or drums. Pitch content reflects melody and harmony, which is often independent of texture. Structure is found in several ways. Segment boundaries can be detected by observing marked changes in locally averaged texture.
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Lee, Dominic F.; Kroeger, Donald M.; Goyal, Amit
2000-01-01
The present invention provides methods and biaxially textured articles having a deformed epitaxial layer formed therefrom for use with high temperature superconductors, photovoltaic, ferroelectric, or optical devices. A buffer layer is epitaxially deposited onto biaxially-textured substrates and then mechanically deformed. The deformation process minimizes or eliminates grooves, or other irregularities, formed on the buffer layer while maintaining the biaxial texture of the buffer layer. Advantageously, the biaxial texture of the buffer layer is not altered during subsequent heat treatments of the deformed buffer. The present invention provides mechanical densification procedures which can be incorporated into the processing of superconducting films through the powder deposit or precursor approaches without incurring unfavorable high-angle grain boundaries.
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NASA Astrophysics Data System (ADS)
Ivanova, T. M.; Serebryany, V. N.
2017-12-01
The component fit method in quantitative texture analysis assumes that the texture of the polycrystalline sample can be represented by a superposition of weighted standard distributions those are characterized by position in the orientation space, shape and sharpness of the scattering. The components of the peak and axial shapes are usually used. It is known that an axial texture develops in materials subjected to direct pressing. In this paper we considered the possibility of modelling a texture of a magnesium sample subjected to equal-channel angular pressing with axial components only. The results obtained make it possible to conclude that ECAP is also a process leading to the appearance of an axial texture in magnesium alloys.
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Optimal frequency domain textural edge detection filter
NASA Technical Reports Server (NTRS)
Townsend, J. K.; Shanmugan, K. S.; Frost, V. S.
1985-01-01
An optimal frequency domain textural edge detection filter is developed and its performance evaluated. For the given model and filter bandwidth, the filter maximizes the amount of output image energy placed within a specified resolution interval centered on the textural edge. Filter derivation is based on relating textural edge detection to tonal edge detection via the complex low-pass equivalent representation of narrowband bandpass signals and systems. The filter is specified in terms of the prolate spheroidal wave functions translated in frequency. Performance is evaluated using the asymptotic approximation version of the filter. This evaluation demonstrates satisfactory filter performance for ideal and nonideal textures. In addition, the filter can be adjusted to detect textural edges in noisy images at the expense of edge resolution.
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Perceptual asymmetry in texture perception.
Williams, D; Julesz, B
1992-07-15
A fundamental property of human visual perception is our ability to distinguish between textures. A concerted effort has been made to account for texture segregation in terms of linear spatial filter models and their nonlinear extensions. However, for certain texture pairs the ease of discrimination changes when the role of figure and ground are reversed. This asymmetry poses a problem for both linear and nonlinear models. We have isolated a property of texture perception that can account for this asymmetry in discrimination: subjective closure. This property, which is also responsible for visual illusions, appears to be explainable by early visual processes alone. Our results force a reexamination of the process of human texture segregation and of some recent models that were introduced to explain it.
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Modulation of dry tribological property of stainless steel by femtosecond laser surface texturing
NASA Astrophysics Data System (ADS)
Wang, Zhuo; Zhao, Quanzhong; Wang, Chengwei; Zhang, Yang
2015-06-01
We reported on the modification of tribological properties of stainless steel by femtosecond laser surface microstructuring. Regular arranged micro-grooved textures with different spacing were produced on the AISI 304L steel surfaces by an 800-nm femtosecond laser. The tribological properties of smooth surface and textured surface were investigated by carrying out reciprocating ball-on-flat tests against Al2O3 ceramic balls under dry friction. Results show that the spacing of micro-grooves had a significant impact on friction coefficient of textured surfaces. Furthermore, the wear behaviors of smooth and textured surface were also investigated. Femtosecond laser surface texturing had a marked potential for modulating friction and wear properties if the micro-grooves were distributed in an appropriate manner.
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Method of forming biaxially textured alloy substrates and devices thereon
Goyal, Amit; Specht, Eliot D.; Kroeger, Donald M.; Paranthaman, Mariappan
1999-01-01
Specific alloys, in particular Ni-based alloys, that can be biaxially textured, with a well-developed, single component texture are disclosed. These alloys have a significantly reduced Curie point, which is very desirable from the point of view of superconductivity applications. The biaxially textured alloy substrates also possess greatly enhanced mechanical properties (yield strength, ultimate tensile strength) which are essential for most applications, in particular, superconductors. A method is disclosed for producing complex multicomponent alloys which have the ideal physical properties for specific applications, such as lattice parameter, degree of magnetism and mechanical strength, and which cannot be fabricated in textured form. In addition, a method for making ultra thin biaxially textured substrates with complex compositions is disclosed.
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NASA Astrophysics Data System (ADS)
Lee, R.; Graettinger, A. H.; Weinell, M.; Hughes, C. G.
2016-12-01
Basaltic maar-diatreme volcanoes are produced when rising magma interacts with groundwater and produces a maar crater at the ground surface. This crater is underlain by a diatreme, a downward-tapering conical structure filled with a mixture of fragments of intruded magma, fractured host rock, and clasts recycled through repeated discrete subsurface explosions. The debris of the diatreme records the mixing processes caused by subsurface explosions and is the source for ejected material that forms maar tephra rings. Determining the variable depths and lateral locations of these explosions and how energy is dissipated in the subsurface is critical to understanding how maar-diatreme eruptions progress. The Hopi Buttes Volcanic Field (HBVF) in the Navajo Nation, Arizona, USA, contains several diatremes and incised tephra rings with heterolithic clasts 10 mm - 10 m in size, and are well-exposed near-vertical to vertical outcrops. Our ability to measure the length scales and distribution of textures produced by subsurface explosions in these diatremes is limited by the physical accessibility of the exposures, due to both the verticality of the outcrops and the cultural sensitivity of the site. Quantifying the number and locations of explosions is dependent on our ability to investigate the full diatreme outcrop, and not just what can be accessed through traditional field observations. We present a novel field and computer-based technique for both quantitatively and qualitatively characterizing the composition and texture of maar-diatreme deposits in vertical outcrops. This technique uses a combination of field-collected multispectral thermal infrared (TIR) image data and visible wavelength GigaPan imagery to characterize the compositional and textural variations over a whole outcrop. To increase the spatial and spectral resolution of the TIR data, a super-resolution technique will be applied. The technique provides a simple and efficient method to augment the study of the maar-diatreme deposits at HBVF. In addition to contributing to a better understanding of the formation processes of maar-diatreme deposits around the world, the technique also shows great promise for studies involving other types of large outcrops and geologic structures.
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NASA Astrophysics Data System (ADS)
Kovaleva, Elizaveta; Harlov, Daniel; Klötzli, Urs
2017-07-01
Samples of metamorphosed and deformed granitic rocks were collected from two Alpine complexes with well-constrained metamorphic history: Western Tauern Window and Ötztal-Stubai Crystalline Complex. Zircon grains from these samples were investigated in situ by a combination of scanning electron microscope techniques, cathodoluminescence (CL) imaging and Raman spectroscopy. The aims were: to describe and interpret complicated secondary textures and microstructures in zircon; based on cross-cutting relationships between secondary microstructures, reconstruct the sequence of processes, affecting zircon crystals; link the evolution of zircon with the history of the host rocks. The results indicate that zircon in the sampled granitic rocks forms growth twins and multi-grain aggregates, which are unusual for this mineral. Moreover, various secondary textures have been found in the sampled zircon, often cross-cutting each other in a single crystal. These include: distorted oscillatory CL zoning with inner zones forming inward-penetrating, CL-bright embayments, which are the evidence of dry recrystallization via annealing/lattice recovery; CL mosaicism with no preservation of growth zoning, but abundant nano- and micro-scale pores and mineral inclusions, which are the evidence of recrystallization by coupled dissolution-reprecipitation and/or leaching; embayed zircon boundaries filled with apatite, monazite, epidote and mylonitic matrix, indicating mineral-fluid reactions resulting in zircon dissolution and fragmentation; overgrowth CL-dark rims, which contain nano-pores and point to transport and precipitation of dissolved zircon matter. We conclude that zircon in our meta-granites is sensitive to metamorphism/deformation events, and was reactive with metamorphic fluids. Additionally, we have found evidence of crystal-plastic deformation in the form of low angle boundaries and bent grain tips, which is a result of shearing and ductile deformation of the host rock. We suggest that the observed complicated secondary textures in zircon can be linked to the evolutionary stages of the host rocks such as magmatic crystallization, prograde metamorphism, peak of amphibolite-facies metamorphism, post-peak cooling and exhumation, formation of ductile shear zones and final cooling to 250 °C.
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NASA Astrophysics Data System (ADS)
Basch, V.; Rampone, E.; Crispini, L.; Ferrando, C.; Ildefonse, B.; Godard, M.
2017-12-01
Recent studies investigate the replacive formation of hybrid troctolites from mantle peridotites after multiple stages of melt-rock reactions. However, none of these studies are conducted in a field-controlled geological setting displaying the clear evolution from peridotite to dunite to troctolite. We investigated the Mt.Maggiore and Erro Tobbio ophiolitic peridotites. They both preserve structural and chemical records of two distinct melt-rock interaction stages, from a reactive melt percolation at spinel facies to plagioclase-bearing melt impregnation at shallower lithospheric depths. We performed EBSD and in situ geochemical analyses to document the textural, structural and geochemical variations of the olivine matrix during melt-rock interactions and the associated evolution from peridotite to dunite to troctolite. The olivine-saturated reactive melt percolation leads to the dissolution of mantle pyroxenes in peridotite, and to the formation of replacive dunite. At shallower level, melt impregnation leads to the crystallization of plagioclase in the dunite, and to the formation of hybrid troctolite. The latter is characterized by textural, structural and geochemical features acquired during dunitization and impregnation processes. We documented a textural evolution of the olivine matrix (decrease in grain area, tortuosity and aspect ratio) during impregnation, with a progressive corrosion of mantle olivines by a reactive melt. As a result, olivine in the hybrid troctolites occurs both as coarse deformed relicts and disrupted undeformed grains. During melt-rock interactions, the variation in olivine Crystallographic Preferred Orientation is related to the local melt/rock ratio involved in the percolation process. At high melt/rock ratio, a change from axial-[100] to axial-[010] is observed, with the disaggregation of the solid matrix. REE-enriched compositions are observed in olivine of dunites and troctolites. A geochemical modeling of melt-rock interactions (Plate Model) fits the observed evolution of modal composition with the measured trace element composition variability. The combined field, structural, and geochemical investigation of the evolution from a mantle protolith to the product of the reactions truly supports the hybrid origin of an olivine-rich troctolite.
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Quantitative Mapping of Surface Texture on the Northern Polar Residual Cap of Mars
NASA Astrophysics Data System (ADS)
Milkovich, S. M.; Byrne, S.; Russell, P. S.
2010-12-01
The northern polar residual cap (NPRC) of Mars is a water ice deposit with a rough surface made up of pits, knobs, and linear depressions on scales of tens of meters [1]. This roughness manifests as a series of bright and dark patches in visible images. Spectral data indicate that the surface of the NPRC is composed of large-grained (and therefore old) water ice. Due to the presence of this old ice, it is thought that the NPRC is in a current state of net loss of material [2]. The NPRC provides a link between the current martian climate and the historical climate recorded within the layers of the underlying north polar layered deposits. By characterizing and mapping the variations in surface texture of the NPRC, we seek to understand what factors (distance from the pole, GCM and mesoscale wind direction predictions, etc) are currently at work in resurfacing the deposit, and may have been at work in shaping the layers below. Maps of NPRC texture wavelength and orientation are being produced from HiRISE images. Two-dimensional Fourier analysis is performed upon a 256 meter x 256 meter region (corresponding to 512 x 512 pixels in 0.5 cm/pxl images, or 1024 x 1024 pixels in 0.25 cm/pxl images) within each image analyzed. The dominant wavelength of the resulting peak power spectrum corresponds to the average size of a pit-knob pair in the image, and so is a proxy for the scale of the surface roughness. The orientation of the surface roughness (i.e., the orientation of a chain of pits and mounds) is measured from a narrow range of wavelengths encompassing the dominant wavelength. We will report on how the dominant wavelengths and orientations of this surface texture vary with location and what that implies for the processes currently shaping this landscape. [1] P. C. Thomas et al, Nature 404, 161-164, 2000 [2]Y. Langevin et al, Science 307, 5715, 1581-1584, 2005.
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NASA Astrophysics Data System (ADS)
Li, Jiheng; Liu, Yangyang; Li, Xiaojuan; Mu, Xing; Bao, Xiaoqian; Gao, Xuexu
2018-07-01
The effects of different rolling conditions on the microstructure and texture of primary and secondary recrystallization in magnetostrictive Fe82Ga9Al9+0.1at%NbC alloy sheets were investigated. After the primary recrystallization annealing at 850 °C for 5 min, the as-rolled sheets prepared by warm-cold rolling with an intermediate annealing, can be fully recrystallized, and obtain the homogeneous matrix in which the fine dispersed NbC precipitate particles are distributed. The primary recrystallization textures of sheets with different rolling conditions consist mostly of strong {1 0 0} textures, γ-fiber textures, {4 1 1}〈1 4 8〉 texture and weak Goss texture. In the primary recrystallized sheets prepared by warm-cold rolling with an intermediate annealing, the high energy grain boundaries and ∑9 boundaries have the highest proportion. After high temperature annealing, the secondary recrystallizations of Goss grains in these sheets are more complete, and the size of abnormal grown Goss grain is up to several centimeters, which results in the strongest Goss texture. Correspondingly, the largest magnetostriction of 183 ppm is observed. The sample prepared by warm-cold rolling with an intermediate annealing, has homogeneous primary matrix, special texture components and grain boundary distribution, all of which provide a better surrounding for the abnormal growth of Goss grains. This work indicates that the control of rolling conditions of Fe-Ga-Al alloy sheets is necessary to achieve the strong Goss texture and obtain a possible high magnetostriction if other appropriate conditions (stress, domain structure) are achieved.
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NASA Astrophysics Data System (ADS)
Chen, Ping; Xiang, Xin; Shao, Tianmin; La, Yingqian; Li, Junling
2016-12-01
The friction and wear of stamping die surface can affect the service life of stamping die and the quality of stamping products. Surface texturing and surface coating have been widely used to improve the tribological performance of mechanical components. This study experimentally investigated the effect of triangular surface texture on the friction and wear properties of the die steel substrate with TiN coatings under oil lubrication. TiN coatings were deposited on a die steel (50Cr) substrate through a multi-arc ion deposition system, and then triangular surface texturing was fabricated by a laser surface texturing. The friction and wear test was conducted by a UMT-3 pin-on-disk tribometer under different sliding speeds and different applied loads, respectively. The adhesion test was performed to evaluate the effectiveness of triangular texturing on the interfacial bonding strength between the TiN coating and the die steel substrate. Results show that the combination method of surface texturing process and surface coating process has excellent tribological properties (the lowest frictional coefficient and wear volume), compared with the single texturing process or the single coating process. The tribological performance is improved resulting from the high hardness and low elastic modulus of TiN coatings, and the generation of hydrodynamic pressure, function of micro-trap for wear debris and micro-reservoirs for lubricating oil of the triangular surface texture. In addition, the coating bonding strength of the texturing sample is 3.63 MPa, higher than that of the single coating sample (3.48 MPa), but the mechanisms remain to be further researched.
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Texture-based segmentation and analysis of emphysema depicted on CT images
NASA Astrophysics Data System (ADS)
Tan, Jun; Zheng, Bin; Wang, Xingwei; Lederman, Dror; Pu, Jiantao; Sciurba, Frank C.; Gur, David; Leader, J. Ken
2011-03-01
In this study we present a texture-based method of emphysema segmentation depicted on CT examination consisting of two steps. Step 1, a fractal dimension based texture feature extraction is used to initially detect base regions of emphysema. A threshold is applied to the texture result image to obtain initial base regions. Step 2, the base regions are evaluated pixel-by-pixel using a method that considers the variance change incurred by adding a pixel to the base in an effort to refine the boundary of the base regions. Visual inspection revealed a reasonable segmentation of the emphysema regions. There was a strong correlation between lung function (FEV1%, FEV1/FVC, and DLCO%) and fraction of emphysema computed using the texture based method, which were -0.433, -.629, and -0.527, respectively. The texture-based method produced more homogeneous emphysematous regions compared to simple thresholding, especially for large bulla, which can appear as speckled regions in the threshold approach. In the texture-based method, single isolated pixels may be considered as emphysema only if neighboring pixels meet certain criteria, which support the idea that single isolated pixels may not be sufficient evidence that emphysema is present. One of the strength of our complex texture-based approach to emphysema segmentation is that it goes beyond existing approaches that typically extract a single or groups texture features and individually analyze the features. We focus on first identifying potential regions of emphysema and then refining the boundary of the detected regions based on texture patterns.
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Reischauer, Carolin; Patzwahl, René; Koh, Dow-Mu; Froehlich, Johannes M; Gutzeit, Andreas
2018-04-01
To evaluate whole-lesion volumetric texture analysis of apparent diffusion coefficient (ADC) maps for assessing treatment response in prostate cancer bone metastases. Texture analysis is performed in 12 treatment-naïve patients with 34 metastases before treatment and at one, two, and three months after the initiation of androgen deprivation therapy. Four first-order and 19 second-order statistical texture features are computed on the ADC maps in each lesion at every time point. Repeatability, inter-patient variability, and changes in the feature values under therapy are investigated. Spearman rank's correlation coefficients are calculated across time to demonstrate the relationship between the texture features and the serum prostate specific antigen (PSA) levels. With few exceptions, the texture features exhibited moderate to high precision. At the same time, Friedman's tests revealed that all first-order and second-order statistical texture features changed significantly in response to therapy. Thereby, the majority of texture features showed significant changes in their values at all post-treatment time points relative to baseline. Bivariate analysis detected significant correlations between the great majority of texture features and the serum PSA levels. Thereby, three first-order and six second-order statistical features showed strong correlations with the serum PSA levels across time. The findings in the present work indicate that whole-tumor volumetric texture analysis may be utilized for response assessment in prostate cancer bone metastases. The approach may be used as a complementary measure for treatment monitoring in conjunction with averaged ADC values. Copyright © 2018 Elsevier B.V. All rights reserved.
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Bates, Anthony; Miles, Kenneth
2017-12-01
To validate MR textural analysis (MRTA) for detection of transition zone (TZ) prostate cancer through comparison with co-registered prostate-specific membrane antigen (PSMA) PET-MR. Retrospective analysis was performed for 30 men who underwent simultaneous PSMA PET-MR imaging for staging of prostate cancer. Thirty texture features were derived from each manually contoured T2-weighted, transaxial, prostatic TZ using texture analysis software that applies a spatial band-pass filter and quantifies texture through histogram analysis. Texture features of the TZ were compared to PSMA expression on the corresponding PET images. The Benjamini-Hochberg correction controlled the false discovery rate at <5%. Eighty-eight T2-weighted images in 18 patients demonstrated abnormal PSMA expression within the TZ on PET-MR. 123 images were PSMA negative. Based on the corrected p-value of 0.005, significant differences between PSMA positive and negative slices were found for 16 texture parameters: Standard deviation and mean of positive pixels for all spatial filters (p = <0.0001 for both at all spatial scaling factor (SSF) values) and mean intensity following filtration for SSF 3-6 mm (p = 0.0002-0.0018). Abnormal expression of PSMA within the TZ is associated with altered texture on T2-weighted MR, providing validation of MRTA for the detection of TZ prostate cancer. • Prostate transition zone (TZ) MR texture analysis may assist in prostate cancer detection. • Abnormal transition zone PSMA expression correlates with altered texture on T2-weighted MR. • TZ with abnormal PSMA expression demonstrates significantly reduced MI, SD and MPP.
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NASA Astrophysics Data System (ADS)
Bangs, Corey F.; Kruse, Fred A.; Olsen, Chris R.
2013-05-01
Hyperspectral data were assessed to determine the effect of integrating spectral data and extracted texture feature data on classification accuracy. Four separate spectral ranges (hundreds of spectral bands total) were used from the Visible and Near Infrared (VNIR) and Shortwave Infrared (SWIR) portions of the electromagnetic spectrum. Haralick texture features (contrast, entropy, and correlation) were extracted from the average gray-level image for each of the four spectral ranges studied. A maximum likelihood classifier was trained using a set of ground truth regions of interest (ROIs) and applied separately to the spectral data, texture data, and a fused dataset containing both. Classification accuracy was measured by comparison of results to a separate verification set of test ROIs. Analysis indicates that the spectral range (source of the gray-level image) used to extract the texture feature data has a significant effect on the classification accuracy. This result applies to texture-only classifications as well as the classification of integrated spectral data and texture feature data sets. Overall classification improvement for the integrated data sets was near 1%. Individual improvement for integrated spectral and texture classification of the "Urban" class showed approximately 9% accuracy increase over spectral-only classification. Texture-only classification accuracy was highest for the "Dirt Path" class at approximately 92% for the spectral range from 947 to 1343nm. This research demonstrates the effectiveness of texture feature data for more accurate analysis of hyperspectral data and the importance of selecting the correct spectral range to be used for the gray-level image source to extract these features.
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Nketiah, Gabriel; Elschot, Mattijs; Kim, Eugene; Teruel, Jose R; Scheenen, Tom W; Bathen, Tone F; Selnæs, Kirsten M
2017-07-01
To evaluate the diagnostic relevance of T2-weighted (T2W) MRI-derived textural features relative to quantitative physiological parameters derived from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in Gleason score (GS) 3+4 and 4+3 prostate cancers. 3T multiparametric-MRI was performed on 23 prostate cancer patients prior to prostatectomy. Textural features [angular second moment (ASM), contrast, correlation, entropy], apparent diffusion coefficient (ADC), and DCE pharmacokinetic parameters (K trans and V e ) were calculated from index tumours delineated on the T2W, DW, and DCE images, respectively. The association between the textural features and prostatectomy GS and the MRI-derived parameters, and the utility of the parameters in differentiating between GS 3+4 and 4+3 prostate cancers were assessed statistically. ASM and entropy correlated significantly (p < 0.05) with both GS and median ADC. Contrast correlated moderately with median ADC. The textural features correlated insignificantly with K trans and V e . GS 4+3 cancers had significantly lower ASM and higher entropy than 3+4 cancers, but insignificant differences in median ADC, K trans , and V e . The combined texture-MRI parameters yielded higher classification accuracy (91%) than the individual parameter sets. T2W MRI-derived textural features could serve as potential diagnostic markers, sensitive to the pathological differences in prostate cancers. • T2W MRI-derived textural features correlate significantly with Gleason score and ADC. • T2W MRI-derived textural features differentiate Gleason score 3+4 from 4+3 cancers. • T2W image textural features could augment tumour characterization.
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Cortical mechanisms for the segregation and representation of acoustic textures.
Overath, Tobias; Kumar, Sukhbinder; Stewart, Lauren; von Kriegstein, Katharina; Cusack, Rhodri; Rees, Adrian; Griffiths, Timothy D
2010-02-10
Auditory object analysis requires two fundamental perceptual processes: the definition of the boundaries between objects, and the abstraction and maintenance of an object's characteristic features. Although it is intuitive to assume that the detection of the discontinuities at an object's boundaries precedes the subsequent precise representation of the object, the specific underlying cortical mechanisms for segregating and representing auditory objects within the auditory scene are unknown. We investigated the cortical bases of these two processes for one type of auditory object, an "acoustic texture," composed of multiple frequency-modulated ramps. In these stimuli, we independently manipulated the statistical rules governing (1) the frequency-time space within individual textures (comprising ramps with a given spectrotemporal coherence) and (2) the boundaries between textures (adjacent textures with different spectrotemporal coherences). Using functional magnetic resonance imaging, we show mechanisms defining boundaries between textures with different coherences in primary and association auditory cortices, whereas texture coherence is represented only in association cortex. Furthermore, participants' superior detection of boundaries across which texture coherence increased (as opposed to decreased) was reflected in a greater neural response in auditory association cortex at these boundaries. The results suggest a hierarchical mechanism for processing acoustic textures that is relevant to auditory object analysis: boundaries between objects are first detected as a change in statistical rules over frequency-time space, before a representation that corresponds to the characteristics of the perceived object is formed.
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NASA Astrophysics Data System (ADS)
Nadammal, Naresh; Kailas, Satish V.; Szpunar, Jerzy; Suwas, Satyam
2015-05-01
Friction-stir processing (FSP) has been proven as a successful method for the grain refinement of high-strength aluminum alloys. The most important attributes of this process are the fine-grain microstructure and characteristic texture, which impart suitable properties in the as-processed material. In the current work, FSP of the precipitation-hardenable aluminum alloy 2219 has been carried out and the consequent evolution of microstructure and texture has been studied. The as-processed materials were characterized using electron back-scattered diffraction, x-ray diffraction, and electron probe microanalysis. Onion-ring formation was observed in the nugget zone, which has been found to be related to the precipitation response and crystallographic texture of the alloy. Texture development in the alloy has been attributed to the combined effect of shear deformation and dynamic recrystallization. The texture was found heterogeneous even within the nugget zone. A microtexture analysis revealed the dominance of shear texture components, with C component at the top of nugget zone and the B and A2* components in the middle and bottom. The bulk texture measurement in the nugget zone revealed a dominant C component. The development of a weaker texture along with the presence of some large particles in the nugget zone indicates particle-stimulated nucleation as the dominant nucleation mechanism during FSP. Grain growth follows the Burke and Turnbull mechanism and geometrical coalescence.
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Molina, David; Pérez-Beteta, Julián; Martínez-González, Alicia; Martino, Juan; Velasquez, Carlos; Arana, Estanislao; Pérez-García, Víctor M
2017-01-01
Textural measures have been widely explored as imaging biomarkers in cancer. However, their robustness under dynamic range and spatial resolution changes in brain 3D magnetic resonance images (MRI) has not been assessed. The aim of this work was to study potential variations of textural measures due to changes in MRI protocols. Twenty patients harboring glioblastoma with pretreatment 3D T1-weighted MRIs were included in the study. Four different spatial resolution combinations and three dynamic ranges were studied for each patient. Sixteen three-dimensional textural heterogeneity measures were computed for each patient and configuration including co-occurrence matrices (CM) features and run-length matrices (RLM) features. The coefficient of variation was used to assess the robustness of the measures in two series of experiments corresponding to (i) changing the dynamic range and (ii) changing the matrix size. No textural measures were robust under dynamic range changes. Entropy was the only textural feature robust under spatial resolution changes (coefficient of variation under 10% in all cases). Textural measures of three-dimensional brain tumor images are not robust neither under dynamic range nor under matrix size changes. Standards should be harmonized to use textural features as imaging biomarkers in radiomic-based studies. The implications of this work go beyond the specific tumor type studied here and pose the need for standardization in textural feature calculation of oncological images.
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Wendin, Karin; Ekman, Susanne; Bülow, Margareta; Ekberg, Olle; Johansson, Daniel; Rothenberg, Elisabet; Stading, Mats
2010-01-01
Introduction Patients who suffer from chewing and swallowing disorders, i.e. dysphagia, may have difficulties ingesting normal food and liquids. In these patients a texture modified diet may enable that the patient maintain adequate nutrition. However, there is no generally accepted definition of ‘texture’ that includes measurements describing different food textures. Objective Objectively define and quantify categories of texture-modified food by conducting rheological measurements and sensory analyses. A further objective was to facilitate the communication and recommendations of appropriate food textures for patients with dysphagia. Design About 15 food samples varying in texture qualities were characterized by descriptive sensory and rheological measurements. Results Soups were perceived as homogenous; thickened soups were perceived as being easier to swallow, more melting and creamy compared with soups without thickener. Viscosity differed between the two types of soups. Texture descriptors for pâtés were characterized by high chewing resistance, firmness, and having larger particles compared with timbales and jellied products. Jellied products were perceived as wobbly, creamy, and easier to swallow. Concerning the rheological measurements, all solid products were more elastic than viscous (G′>G″), belonging to different G′ intervals: jellied products (low G′) and timbales together with pâtés (higher G′). Conclusion By combining sensory and rheological measurements, a system of objective, quantitative, and well-defined food textures was developed that characterizes the different texture categories. PMID:20592965
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Shu, Ting; Zhang, Bob; Yan Tang, Yuan
2017-04-01
Researchers have recently discovered that Diabetes Mellitus can be detected through non-invasive computerized method. However, the focus has been on facial block color features. In this paper, we extensively study the effects of texture features extracted from facial specific regions at detecting Diabetes Mellitus using eight texture extractors. The eight methods are from four texture feature families: (1) statistical texture feature family: Image Gray-scale Histogram, Gray-level Co-occurance Matrix, and Local Binary Pattern, (2) structural texture feature family: Voronoi Tessellation, (3) signal processing based texture feature family: Gaussian, Steerable, and Gabor filters, and (4) model based texture feature family: Markov Random Field. In order to determine the most appropriate extractor with optimal parameter(s), various parameter(s) of each extractor are experimented. For each extractor, the same dataset (284 Diabetes Mellitus and 231 Healthy samples), classifiers (k-Nearest Neighbors and Support Vector Machines), and validation method (10-fold cross validation) are used. According to the experiments, the first and third families achieved a better outcome at detecting Diabetes Mellitus than the other two. The best texture feature extractor for Diabetes Mellitus detection is the Image Gray-scale Histogram with bin number=256, obtaining an accuracy of 99.02%, a sensitivity of 99.64%, and a specificity of 98.26% by using SVM. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Muscle Protein Profiles Used for Prediction of Texture of Farmed Salmon (Salmo salar L.).
Ørnholt-Johansson, Gine; Frosch, Stina; Gudjónsdóttir, María; Wulff, Tune; Jessen, Flemming
2017-04-26
A soft texture is undesired in Atlantic salmon as it leads to downgrading and reduced yield, yet it is a factor for which the cause is not fully understood. This lack of understanding highlights the need for identifying the cause of the soft texture and developing solutions by which the processing industry can improve the yield. Changes in muscle protein profiles can occur both pre- and postharvest and constitute an overall characterization of the muscle properties including texture. The aim of this study was to investigate this relationship between specific muscle proteins and the texture of the salmon fillet. Samples for 2D-gel-based proteomics were taken from the fillet above the lateral line at the same position as where the texture had been measured. The resulting protein profiles were analyzed using multivariate data analysis. Sixteen proteins were found to correlate to the measured texture, showing that it is possible to predict peak force based on a small subset of proteins. Additionally, eight of the 16 proteins were identified by tandem mass spectrometry including serum albumin, dipeptidyl peptidase 3, heat shock protein 70, annexins, and a protein presumed to be a titin fragment. It is contemplated that the identification of these proteins and their significance for the measured texture will contribute to further understanding of the Atlantic salmon muscle texture.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Goyal, Amit; Shin, Junsoo
A polycrystalline ferroelectric and/or multiferroic oxide article includes a substrate having a biaxially textured surface; at least one biaxially textured buffer layer supported by the substrate; and a biaxially textured ferroelectric or multiferroic oxide layer supported by the buffer layer. Methods for making polycrystalline ferroelectric and/or multiferroic oxide articles are also disclosed.
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USDA-ARS?s Scientific Manuscript database
Wheat kernel texture dictates U.S. wheat market class. Durum wheat has limited demand and culinary end-uses compared to bread wheat because of its extremely hard kernel texture which precludes conventional milling. ‘Soft Svevo’, a new durum cultivar with soft kernel texture comparable to a soft whit...
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Mechanical properties of ion-beam-textured surgical implant alloys
NASA Technical Reports Server (NTRS)
Weigand, A. J.
1977-01-01
An electron-bombardment Hg ion thruster was used as an ion source to texture surfaces of materials used to make orthopedic and/or dental prostheses or implants. The materials textured include 316 stainless steel, titanium-6% aluminum, 4% vanadium, and cobalt-20% chromium, 15% tungsten. To determine the effect of ion texturing on the ultimate strength and yield strength, stainless steel and Co-Cr-W alloy samples were tensile tested to failure. Three types of samples of both materials were tested. One type was ion-textured (the process also heats each sample to 300 C), another type was simply heated to 300 C in an oven, and the third type was untreated. Stress-strain diagrams, 0.2% offset yield strength data, total elongation data, and area reduction data are presented. Fatigue specimens of ion textured and untextured 316 stainless steel and Ti-6% Al-4% V were tested. Included as an ion textured sample is a Ti-6% Al-4% V sample which was ion machined by means of Ni screen mask so as to produce an array of 140 mu m x 140 mu m x 60 mu m deep pits. Scanning electron microscopy was used to characterize the ion textured surfaces.
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Texture analysis at neutron diffractometer STRESS-SPEC
NASA Astrophysics Data System (ADS)
Brokmeier, H.-G.; Gan, W. M.; Randau, C.; Völler, M.; Rebelo-Kornmeier, J.; Hofmann, M.
2011-06-01
In response to the development of new materials and the application of materials and components in advanced technologies, non-destructive measurement methods of textures and residual stresses have gained worldwide significance in recent years. The materials science neutron diffractometer STRESS-SPEC at FRM II (Garching, Germany) is designed to be applied equally to texture and residual stress analyses by virtue of its very flexible configuration. Due to the high penetration capabilities of neutrons and the high neutron flux of STRESS-SPEC it allows a combined analysis of global texture, local texture, strain pole figure and FWHM pole figure in a wide variety of materials including metals, alloys, composites, ceramics and geological materials. Especially, the analysis of texture gradients in bulk materials using neutron diffraction has advantages over laboratory X-rays and EBSD for many scientific cases. Moreover, neutron diffraction is favourable for coarse-grained materials, where bulk information averaged over texture inhomogeneities is needed, and also stands out due to easy sample preparation. In future, the newly developed robot system for STRESS-SPEC will allow much more flexibility than an Eulerian cradle as on standard instruments. Five recent measurements are shown to demonstrate the wide range of possible texture applications at STRESS-SPEC diffractometer.
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Temperature dependence of piezoelectric properties for textured SBN ceramics.
Kimura, Masahiko; Ogawa, Hirozumi; Kuroda, Daisuke; Sawada, Takuya; Higuchi, Yukio; Takagi, Hiroshi; Sakabe, Yukio
2007-12-01
Temperature dependences of piezoelectric properties were studied for h001i textured ceramics of bismuth layer-structured ferroelectrics, SrBi(2)Nb(2)O(9) (SBN). The textured ceramics with varied orientation degrees were fabricated by templated, grain-growth method, and the temperature dependences of resonance frequency were estimated. Excellent temperature stability of resonance frequency was obtained for the 76% textured ceramics. The resonance frequency of the 76% textured specimens varied almost linearly over a wide temperature range. Therefore, the variation was slight, even in a high temperature region above 150 degrees C. Temperature stability of a quartz crystal oscillator is generally higher than that of a ceramic resonator around room temperature. The variation of resonance frequency for the 76% textured SrBi(2)Nb(2)O(9) was larger than that of oscillation frequency for a typical quartz oscillator below 150 degrees C also in this study. However, the variation of the textured SrBi(2)Nb(2)O(9) was smaller than that of the quartz oscillator over a wide temperature range from -50 to 250 degrees C. Therefore, textured SrBi(2)Nb(2)O(9) ceramics is a major candidate material for the resonators used within a wide temperature range.
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NASA Astrophysics Data System (ADS)
Khatri, Chandra B.; Sharma, Satish C.
2018-02-01
Textured surface in journal bearings is becoming an important area of investigation during the last few years. Surface textures have the shapes of micro-dimple with a small diameter and depth having order of magnitude of bearing clearance. This paper presents the influence of couple stress lubricant on the circular and non-circular hole-entry hybrid journal bearing system and reports the comparative study between the textured and non-textured circular/non-circular hybrid journal bearing system. The governing Reynolds equation has been modified for the couple stress lubricant flow in the clearance of bearing and journal. The FEM technique has been applied to solve the modified Reynolds equation together with restrictor flow equation. The numerically simulated results indicate that the influence of couple stress lubricant is significantly more in textured journal bearing than that of non-textured journal bearing. Further, it has been observed that the textured two-lobe (δ = 1.1) hybrid journal bearing lubricated with couple stress lubricant provides larger values of fluid film stiffness coefficients and stability threshold speed against other bearings studied in the present paper.
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Cooling of hot bubbles by surface texture during the boiling crisis
NASA Astrophysics Data System (ADS)
Dhillon, Navdeep; Buongiorno, Jacopo; Varanasi, Kripa
2015-11-01
We report the existence of maxima in critical heat flux (CHF) enhancement for pool boiling on textured hydrophilic surfaces and reveal the interaction mechanism between bubbles and surface texture that governs the boiling crisis phenomenon. Boiling is a process of fundamental importance in many engineering and industrial applications but the maximum heat flux that can be absorbed by the boiling liquid (or CHF) is limited by the boiling crisis. Enhancing the CHF of industrial boilers by surface texturing can lead to substantial energy savings and reduction in greenhouse gas emissions on a global scale. However, the fundamental mechanisms behind this enhancement are not well understood, with some previous studies indicating that CHF should increase monotonically with increasing texture density. However, using pool boiling experiments on a parametrically designed set of plain and nano-textured micropillar surfaces, we show that there is an optimum intermediate texture density that maximizes CHF and further that the length scale of this texture is of fundamental significance. Using imbibition experiments and high-speed optical and infrared imaging, we reveal the fundamental mechanisms governing the CHF enhancement maxima in boiling crisis. We acknowledge funding from the Chevron corporation.
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NASA Astrophysics Data System (ADS)
Yang, Lijun; Ding, Ye; Cheng, Bai; He, Jiangtao; Wang, Genwang; Wang, Yang
2018-03-01
This work puts forward femtosecond laser modification of micro-textured surface on bearing steel GCr15 in order to reduce frictional wear and enhance load capacity during its application. Multi pulses femtosecond laser ablation experiments are established for the confirmation of laser spot radius as well as single pulse threshold fluence and pulse incubation coefficient of bulk material. Analytical models are set up in combination with hydrodynamics lubrication theory. Corresponding simulations are carried out on to explore influences of surface and cross sectional morphology of textures on hydrodynamics lubrication effect based on Navier-Stokes (N-S) equation. Technological experiments focus on the impacts of femtosecond laser machining variables, like scanning times, scanning velocity, pulse frequency and scanning gap on morphology of grooves as well as realization of optimized textures proposed by simulations, mechanisms of which are analyzed from multiple perspectives. Results of unidirectional rotating friction tests suggest that spherical texture with depth-to-width ratio of 0.2 can significantly improve tribological properties at low loading and velocity condition comparing with un-textured and other textured surfaces, which also verifies the accuracy of simulations and feasibility of femtosecond laser in modification of micro-textured surface.
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Two-dimensional numerical simulation of boron diffusion for pyramidally textured silicon
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ma, Fa-Jun, E-mail: Fajun.Ma@nus.edu.sg; Duttagupta, Shubham; Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117576
2014-11-14
Multidimensional numerical simulation of boron diffusion is of great relevance for the improvement of industrial n-type crystalline silicon wafer solar cells. However, surface passivation of boron diffused area is typically studied in one dimension on planar lifetime samples. This approach neglects the effects of the solar cell pyramidal texture on the boron doping process and resulting doping profile. In this work, we present a theoretical study using a two-dimensional surface morphology for pyramidally textured samples. The boron diffusivity and segregation coefficient between oxide and silicon in simulation are determined by reproducing measured one-dimensional boron depth profiles prepared using different boronmore » diffusion recipes on planar samples. The established parameters are subsequently used to simulate the boron diffusion process on textured samples. The simulated junction depth is found to agree quantitatively well with electron beam induced current measurements. Finally, chemical passivation on planar and textured samples is compared in device simulation. Particularly, a two-dimensional approach is adopted for textured samples to evaluate chemical passivation. The intrinsic emitter saturation current density, which is only related to Auger and radiative recombination, is also simulated for both planar and textured samples. The differences between planar and textured samples are discussed.« less
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Enhancement of Stereo Imagery by Artificial Texture Projection Generated Using a LIDAR
NASA Astrophysics Data System (ADS)
Veitch-Michaelis, Joshua; Muller, Jan-Peter; Walton, David; Storey, Jonathan; Foster, Michael; Crutchley, Benjamin
2016-06-01
Passive stereo imaging is capable of producing dense 3D data, but image matching algorithms generally perform poorly on images with large regions of homogenous texture due to ambiguous match costs. Stereo systems can be augmented with an additional light source that can project some form of unique texture onto surfaces in the scene. Methods include structured light, laser projection through diffractive optical elements, data projectors and laser speckle. Pattern projection using lasers has the advantage of producing images with a high signal to noise ratio. We have investigated the use of a scanning visible-beam LIDAR to simultaneously provide enhanced texture within the scene and to provide additional opportunities for data fusion in unmatched regions. The use of a LIDAR rather than a laser alone allows us to generate highly accurate ground truth data sets by scanning the scene at high resolution. This is necessary for evaluating different pattern projection schemes. Results from LIDAR generated random dots are presented and compared to other texture projection techniques. Finally, we investigate the use of image texture analysis to intelligently project texture where it is required while exploiting the texture available in the ambient light image.
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Textural constraints on the dynamics of the 2000 Miyakejima eruption
NASA Astrophysics Data System (ADS)
Garozzo, Ileana; Romano, Claudia; Giordano, Guido; Geshi, Nobuo; Vona, Alessandro
2016-04-01
Miyakejima Volcano is a basaltic-andesite stratovolcano active from ~10.000 years, located on the north of the Izu-Bonin arc. During the last 600 years the volcano has been characterized mainly by flank fissure activity, with explosive phreatomagmatic eruptions on the coastal areas. In the last century, the activity became more frequent and regular with intervals of 20 to 70 years (1940, 1962, 1983 and 2000). The last activity started on 27 June 2000, with a minor submarine eruption on the west coast of the volcano, and proceeded with six major summit eruptions from July 8 to August 29. The eruptions led to the formation of a collapse caldera ~1.6 km across. The total erupted tephra represents only 1.7% in volume of the caldera, the high fragmentation of magma produced mainly fine-grained volcanic ash. In order to improve the understanding on the triggering and dynamics of this explosive eruption, we carried out a detailed investigation of the erupted materials with particular attention to the textural features of juvenile pyroclasts (Vesicle and Crystal Size Distributions). The stratigraphic record can be divided into six fall units, corresponding to the six summit eruptions, although juvenile materials were identified only in 4 units (unit 2, 4, 5, 6). We selected about 100 juvenile grains sampled from the bottom to the top of each level, to be analyzed by scanning electron microscopy. The study of juvenile morphological features allowed us to recognize the existence of three characteristic morphotypes, showing marked differences in their external morphologies and internal textures (from poorly to highly crystallized and vesiculated clasts). The distribution of these morphotypes is non-homogeneous along the eruptive sequence indicating changes of dynamics during magma ascent. Juveniles do not show features inherited from the interaction with external water. Vesicle Volume Distributions of the selected ash grains show that the three types of pyroclasts experienced different nucleation and growth processes. Also the Vesicles Number Densities (VNDs) vary of about one order of magnitude in the different populations (from 107 to 108 cm-3), with values comparable with those commonly related to sub-Plinian and Plinian eruptions. Data from the CSD analysis show perfect agreement with the measured VNDs (crystal population densities increasing with VNDs), suggesting a link between the degassing history and the syn-eruptive crystallization. The results of the textural analysis are used to produce a conduit model for the 2000 Miyakejima eruption. Textural analysis and modeling data are presented to reconstruct the eruptive dynamics leading to this high - energetic eruption.
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Ice/water Classification of Sentinel-1 Images
NASA Astrophysics Data System (ADS)
Korosov, Anton; Zakhvatkina, Natalia; Muckenhuber, Stefan
2015-04-01
Sea Ice monitoring and classification relies heavily on synthetic aperture radar (SAR) imagery. These sensors record data either only at horizontal polarization (RADARSAT-1) or vertically polarized (ERS-1 and ERS-2) or at dual polarization (Radarsat-2, Sentinel-1). Many algorithms have been developed to discriminate sea ice types and open water using single polarization images. Ice type classification, however, is still ambiguous in some cases. Sea ice classification in single polarization SAR images has been attempted using various methods since the beginning of the ERS programme. The robust classification using only SAR images that can provide useful results under varying sea ice types and open water tend to be not generally applicable in operational regime. The new generation SAR satellites have capability to deliver images in several polarizations. This gives improved possibility to develop sea ice classification algorithms. In this study we use data from Sentinel-1 at dual-polarization, i.e. HH (horizontally transmitted and horizontally received) and HV (horizontally transmitted, vertically received). This mode assembles wide SAR image from several narrower SAR beams, resulting to an image of 500 x 500 km with 50 m resolution. A non-linear scheme for classification of Sentinel-1 data has been developed. The processing allows to identify three classes: ice, calm water and rough water at 1 km spatial resolution. The raw sigma0 data in HH and HV polarization are first corrected for thermal and random noise by extracting the background thermal noise level and smoothing the image with several filters. At the next step texture characteristics are computed in a moving window using a Gray Level Co-occurence Matrix (GLCM). A neural network is applied at the last step for processing array of the most informative texture characteristics and ice/water classification. The main results are: * the most informative texture characteristics to be used for sea ice classification were revealed; * the best set of parameters including the window size, number of levels of quantization of sigma0 values and co-occurence distance was found; * a support vector machine (SVM) was trained on results of visual classification of 30 Sentinel-1 images. Despite the general high accuracy of the neural network (95% of true positive classification) problems with classification of young newly formed ice and rough water arise due to the similar average backscatter and texture. Other methods of smoothing and computation of texture characteristics (e.g. computation of GLCM from a variable size window) is assessed. The developed scheme will be utilized in NRT processing of Sentinel-1 data at NERSC within the MyOcean2 project.
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Monnet, Joëlle
2014-01-01
Objective: The primary objective was to assess the warming sensation caused by flavor 316282 in a cold and cough product in the target population. Methods: A single-cohort, single-treatment arm, open-label study. Subjects received one 30-mL dose of syrup containing flavor 316282, paracetamol, phenylephrine hydrochloride, and guaifenesin and recorded onset and disappearance of any warming sensation in the mouth/throat. Subjects’ assessment of strength and appeal of the sensation, taste, texture, and acceptability of the product as a cold and cough remedy was investigated using questionnaires. Results: A total of 51 subjects were included; 47 (92.1%) experienced a warming sensation. The median duration of the warming sensation was 100 s (95% confidence interval = 82 s, 112 s). The majority of subjects rated the syrup as excellent, good, or fair for treatment of cough and cold symptoms (96.1%), taste (80.4%), and texture (98.0%). There were no safety concerns, and the syrup was well tolerated. Most subjects liked the warming sensation. Conclusions: Flavor 316282 in a cold and cough syrup is associated with a warming sensation. The syrup is well tolerated, safe, and palatable. PMID:26770699
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Antarctic polymict eucrite Yamato 792769 and the cratering record on the HED parent body
NASA Technical Reports Server (NTRS)
Bogard, D.; Nyquist, L.; Takeda, H.; Mori, H.; Aoyama, T.; Bansal, B.; Wiesemann, H.; Shih, C.-Y.
1993-01-01
Compared to most other Yamato polymict eucrites, Yamato Y792769 eucrite includes fewer and smaller eucritic clasts with homogenized pyroxenes, and its fine-grained matrix is shock-compacted and sintered. In this work, the relationships between the Antarctic eucrite Y792769, monomict eucrites, polymict eucrites, and isotopic ages are investigated, using results of Ar-39/Ar-40 method to date the time of the major thermal event on the Y792769 body and the Rb-Sr and Sm-Nd methods to determine whether relict older ages might have been preserved in some of the breccia materials. The Ar-39/Ar-40 time of the last thermal event which produced the Y792769 texture is 3.99 +/- 0.04 Ga. The complete resetting of the Ar-39/Ar-40 age is consistent with the texture of Y792769 observed in TEM, suggesting that shock compaction converted part of the matrix plagioclase to maskelynite. The Sm-Nd data give an age of 4.23 +/- 0.12 Ga, reflecting partial resetting of the Sm-Nd system during breccia formation. The 3.9 Ga Ar-39/Ar-40 age probably reflects a period of intense meteoroid bompardment which affected the entire inner solar system.
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Sculpting 3D worlds with music: advanced texturing techniques
NASA Astrophysics Data System (ADS)
Greuel, Christian; Bolas, Mark T.; Bolas, Niko; McDowall, Ian E.
1996-04-01
Sound within the virtual environment is often considered to be secondary to the graphics. In a typical scenario, either audio cues are locally associated with specific 3D objects or a general aural ambiance is supplied in order to alleviate the sterility of an artificial experience. This paper discusses a completely different approach, in which cues are extracted from live or recorded music in order to create geometry and control object behaviors within a computer- generated environment. Advanced texturing techniques used to generate complex stereoscopic images are also discussed. By analyzing music for standard audio characteristics such as rhythm and frequency, information is extracted and repackaged for processing. With the Soundsculpt Toolkit, this data is mapped onto individual objects within the virtual environment, along with one or more predetermined behaviors. Mapping decisions are implemented with a user definable schedule and are based on the aesthetic requirements of directors and designers. This provides for visually active, immersive environments in which virtual objects behave in real-time correlation with the music. The resulting music-driven virtual reality opens up several possibilities for new types of artistic and entertainment experiences, such as fully immersive 3D `music videos' and interactive landscapes for live performance.
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Aeolian Abrasion at the Curiosity Landing Site: Clues to the Role of Wind in Landscape Modification
NASA Astrophysics Data System (ADS)
Bridges, N. T.; Le Mouélic, S.; Hallet, B.; Newman, C. E.; Rice, M. S.; Blaney, D. L.; Calef, F. J.; Herkenhoff, K. E.; Langevin, Y.; Lewis, K. W.; Maurice, S.; Pinet, P. C.; Wiens, R. C.; de Pablo, M.; Renno, N. O.
2013-12-01
The broad scale geomorphology of Gale Crater reflects diverse aeolian processes, from airfall settling that likely deposited much of the upper and some of the lower units of Mt. Sharp, to evidence of extensive wind exhumation and removal of material exterior to the mound, to active dunes on the crater floor. The integrated effect of aeolian sand transport can also be examined on a much smaller scale by the study of ventifacts, rocks that have been abraded by windborne particles. A diversity of ventifacts are found along Curiosity's traverse through the upper 'hummocky' (HY) geomorphic unit and the lower Yellowknife Bay (YKB) sedimentary rocks. The textures are analogous to abrasion features found on Earth and include cm-scale facets, keels, elongated pits, grooves, flutes, and basal sills. High-resolution images from ChemCam's Remote Micro-Imager also show mm-scale lineations. Evidence of differential erosion is common, with HY conglomerates (e.g., Hottah, Link) and the YKB Sheepbed mudstone unit containing distinct wind tails in the lee of resistant pebbles, and bedding features within Rocknest 3, the YKB Shaler sandstone unit, and other layered rocks displaying prominent ridge-groove topography. ChemCam LIBS depth profile data so far show no strong evidence for chemical differences in the elemental composition between abraded and non-abraded surfaces (as determined from qualitative assessment), as might be expected if there were rock coatings or weathering rinds undergoing active abrasion. Preliminary measurements of ventifact texture and wind tail orientations indicate sandblasting in HY and YKB from predominantly southwesterly and northerly directions, respectively. Based on meso-scale models of current winds and REMS results, SW flow is uncommon whereas N winds are frequent. Compositional and textural information from the suite of MSL instruments indicate that HY rocks are dominated by various types of basalt (either as whole rocks or the resistant clasts in conglomerates), whereas YKB are basaltic clastic rocks, with the lower members impregnated with sulfate veins, and were easily drilled. The HY rocks are therefore likely more resistant to abrasion than those of YKB. Combined, these results indicate that ventifacts so far investigated by MSL record two wind regimes, one a long-term integrated record of rare, yet strong winds and the other more reflective of typical conditions.
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Gharat, Amol; Baker, Curtis L
2017-01-25
Many of the neurons in early visual cortex are selective for the orientation of boundaries defined by first-order cues (luminance) as well as second-order cues (contrast, texture). The neural circuit mechanism underlying this selectivity is still unclear, but some studies have proposed that it emerges from spatial nonlinearities of subcortical Y cells. To understand how inputs from the Y-cell pathway might be pooled to generate cue-invariant receptive fields, we recorded visual responses from single neurons in cat Area 18 using linear multielectrode arrays. We measured responses to drifting and contrast-reversing luminance gratings as well as contrast modulation gratings. We found that a large fraction of these neurons have nonoriented responses to gratings, similar to those of subcortical Y cells: they respond at the second harmonic (F2) to high-spatial frequency contrast-reversing gratings and at the first harmonic (F1) to low-spatial frequency drifting gratings ("Y-cell signature"). For a given neuron, spatial frequency tuning for linear (F1) and nonlinear (F2) responses is quite distinct, similar to orientation-selective cue-invariant neurons. Also, these neurons respond to contrast modulation gratings with selectivity for the carrier (texture) spatial frequency and, in some cases, orientation. Their receptive field properties suggest that they could serve as building blocks for orientation-selective cue-invariant neurons. We propose a circuit model that combines ON- and OFF-center cortical Y-like cells in an unbalanced push-pull manner to generate orientation-selective, cue-invariant receptive fields. A significant fraction of neurons in early visual cortex have specialized receptive fields that allow them to selectively respond to the orientation of boundaries that are invariant to the cue (luminance, contrast, texture, motion) that defines them. However, the neural mechanism to construct such versatile receptive fields remains unclear. Using multielectrode recording, we found a large fraction of neurons in early visual cortex with receptive fields not selective for orientation that have spatial nonlinearities like those of subcortical Y cells. These are strong candidates for building cue-invariant orientation-selective neurons; we present a neural circuit model that pools such neurons in an imbalanced "push-pull" manner, to generate orientation-selective cue-invariant receptive fields. Copyright © 2017 the authors 0270-6474/17/370998-16$15.00/0.
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Radiocarbon constraints on fossil thinolite tufa formation in the Mono Basin, CA, USA
NASA Astrophysics Data System (ADS)
Leroy, S. L.; Zimmerman, S. R.; Hemming, S. R.; Stine, S.; Guilderson, T. P.
2009-12-01
Mono Lake is a terminal lake located at the western edge of the Great Basin, and is famous for its tufa towers. Thinolite, which is thought to be a CaCO3 pseudomorph of ikaite, is found around the Mono Basin in many fossil tufa towers, particularly at elevations above 2000 meters. The subaqueous parent mineral ikaite forms at low temperatures (< 6 °C) (Bischoff et al., 1993) and requires specific water chemistry. Previous radiocarbon dating of fossil tufa towers around the Mono Basin has yielded a rather small range of ages for the highest elevation towers, between 11.8 and 14.1 14C kyr BP (no corrections for reservoir effects have been made). A thinolite fan collected from outcrops in Mill Creek, just north of the current Mono Lake yielded an age of 10,690 ± 45 14C yr BP (12,750 ± 80 cal yr BP), consistent with a ca. 1000 year reservoir age and coincidence with thinolite crystals found in a core from the northwestern embayment of Mono Lake (Davis, 1999, QR), and thus correlating with the Younger Dryas cooling event as exhibited in the GISP2 δ18O record. While most of the thinolite textures are found at high elevations, we sampled a mound at 1955 meters (near the current shoreline, north of the lake and just east of Black Point) that has many concentric layers, some containing thinolite textures. Although tufa mounds can form very rapidly, the location at low elevation and the presence of at least 19 distinct layers led us to consider that this mound might represent a long term record of Mono Lake’s chemistry. The new data confirm that the mound formed over a long period within the last glacial cycle, with ages ranging beyond the current limits of measurement (>34 kyr) to as young as 15.5 14C kyr BP. In general there is a consistent stratigraphic trend of ages within the mound, but the thinolite ages are anomalously young and one thinolite sample shows a large age reversal. The best estimate of the age of the precipitation of this tufa mound is given by the non-thinolite textures. More work is needed to determine the best sampling and sample preparation strategies in order to get a reliable age model for this mound.
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Three-Dimensional Spin Texture in Hybrid Perovskites and Its Impact on Optical Transitions
Zhang, Xie; Shen, Jimmy -Xuan; Van de Walle, Chris G.
2018-05-15
Hybrid perovskites such as MAPbI 3 (MA = CH 3NH 3) exhibit a unique spin texture. The spin texture (as calculated within the Rashba model) has been suggested to be responsible for a suppression of radiative recombination due to a mismatch of spins at the band edges. Here we compute the spin texture from first principles and demonstrate that it does not suppress recombination. The exact spin texture is dominated by the inversion asymmetry of the local electrostatic potential, which is determined by the structural distortion induced by the MA molecule. In addition, the rotation of the MA molecule atmore » room temperature leads to a dynamic spin texture in MAPbI 3. Furthermore these insights call for a reconsideration of the scenario that radiative recombination is suppressed and provide an in-depth understanding of the origin of the spin texture in hybrid perovskites, which is crucial for designing spintronic devices.« less
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NASA Technical Reports Server (NTRS)
Gibbons, D. F.
1977-01-01
The objectives in this report were to use the ion beam sputtering technique to produce surface textures on polymers, metals, and ceramics. The morphology of the texture was altered by varying both the width and depth of the square pits which were formed by ion beam erosion. The width of the ribs separating the pits were defined by the mask used to produce the texture. The area of the surface containing pits varies as the width was changed. The biological parameters used to evaluate the biological response to the texture were: (1) fibrous capsule and inflammatory response in subcutaneous soft tissue; (2) strength of the mechanical attachment of the textured surface by the soft tissue; and (3) morphology of the epidermal layer interfacing the textured surface of percutaneous connectors. Because the sputter yield on teflon ribs was approximately an order of magnitude larger than any other material the majority of the measurements presented in the report were obtained with teflon.
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On soil textural classifications and soil-texture-based estimations
NASA Astrophysics Data System (ADS)
Ángel Martín, Miguel; Pachepsky, Yakov A.; García-Gutiérrez, Carlos; Reyes, Miguel
2018-02-01
The soil texture representation with the standard textural fraction triplet
sand-silt-clay
is commonly used to estimate soil properties. The objective of this work was to test the hypothesis that other fraction sizes in the triplets may provide a better representation of soil texture for estimating some soil parameters. We estimated the cumulative particle size distribution and bulk density from an entropy-based representation of the textural triplet with experimental data for 6240 soil samples. The results supported the hypothesis. For example, simulated distributions were not significantly different from the original ones in 25 and 85 % of cases when the sand-silt-clay andvery coarse+coarse + medium sand - fine + very fine sand - silt+clay
were used, respectively. When the same standard and modified triplets were used to estimate the average bulk density, the coefficients of determination were 0.001 and 0.967, respectively. Overall, the textural triplet selection appears to be application and data specific. -
Three-Dimensional Spin Texture in Hybrid Perovskites and Its Impact on Optical Transitions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Xie; Shen, Jimmy -Xuan; Van de Walle, Chris G.
Hybrid perovskites such as MAPbI 3 (MA = CH 3NH 3) exhibit a unique spin texture. The spin texture (as calculated within the Rashba model) has been suggested to be responsible for a suppression of radiative recombination due to a mismatch of spins at the band edges. Here we compute the spin texture from first principles and demonstrate that it does not suppress recombination. The exact spin texture is dominated by the inversion asymmetry of the local electrostatic potential, which is determined by the structural distortion induced by the MA molecule. In addition, the rotation of the MA molecule atmore » room temperature leads to a dynamic spin texture in MAPbI 3. Furthermore these insights call for a reconsideration of the scenario that radiative recombination is suppressed and provide an in-depth understanding of the origin of the spin texture in hybrid perovskites, which is crucial for designing spintronic devices.« less
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NASA Astrophysics Data System (ADS)
Williams, Bruce W.; Agnew, Sean R.; Klein, Robert W.; McKinley, Jonathan
Recent investigations suggest that it is possible to achieve dramatic modifications to both strength and ductility of magnesium alloys through a combination of alloying, grain refinement, and texture control. The current work explores the possibility of altering the texture in extruded thin-walled magnesium alloy tubes for improved ductility during axial crush in which energy is absorbed through progressive buckling. The texture evolution was predicted using the viscoplastic self-consistent (VPSC) crystal plasticity model, with strain path input from continuum-based finite element simulations of extrusion. A limited diversity of textures can be induced by altering the strain path through the extrusion die design. In some cases, such as for simple bar extrusion, the textures predicted can be connected with simple shape change. In other cases, a subtle influence of strain path involving shear-reverse-shear is predicted. The most promising textures predicted for a variety of strain paths are selected for subsequent experimental study.
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Effect of Thermomechanical Processing on Texture and Superelasticity in Fe-Ni-Co-Al-Ti-B Alloy
NASA Astrophysics Data System (ADS)
Lee, Doyup; Omori, Toshihiro; Han, Kwangsik; Hayakawa, Yasuyuki; Kainuma, Ryosuke
2018-03-01
The texture and superelasticity were investigated in austenitic Fe-Ni-Co-Al-Ti-B alloy with various reduction ratios of cold rolling and heating ratios in annealing. The rolled sheets show the {110} <112> deformation texture at a reduction ratio higher than 80%, while the texture hardly changes in the primary recrystallization at 1000 °C. The β (B2) precipitates inhibit the grain growth at this temperature, but they dissolve during heating, and secondary recrystallization occurs due to decreased pinning force at temperatures higher than 1100 °C, resulting in texture change to {210} <001> . The recrystallization texture is more strongly developed when the reduction ratio and heating rate are high and slow, respectively. The 90% cold-rolled and slowly heated sheet shows the recrystallization texture and high fraction of low-angle boundaries. As a result, ductility and superelasticity can be drastically improved in the 90% cold-rolled sheet, although superelasticity was previously obtained only in thin sheets with 98.5% reduction.
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NASA Astrophysics Data System (ADS)
Lockman, Z.; Goldacker, W.; Nast, R.; deBoer, B.; MacManus-Driscoll, J. L.
2002-08-01
Thermal oxidation of cube textured, pure Ni and Ni-Cr tapes was undertaken under different oxidation conditions to form cube textured NiO for the use as a first component of buffer layer for the coated conductor. Cube textured NiO was formed on pure Ni after oxidising for more than 130 min in O 2 at 1250 °C. The oxide thickness was >30 μm. Much shorter oxidation times (20-40 min, NiO thickness of ∼5 μm) and lower temperature (1050 °C) were required to form a similar texture on Ni-Cr foils. In addition, NiO formed on Ni-13%Cr was more highly textured than Ni-10%Cr. A Cr 2O 3 inner layer and NiO outer layer was formed on the Ni-Cr alloys.
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Sun, X; Chen, K J; Berg, E P; Newman, D J; Schwartz, C A; Keller, W L; Maddock Carlin, K R
2014-02-01
The objective was to use digital color image texture features to predict troponin-T degradation in beef. Image texture features, including 88 gray level co-occurrence texture features, 81 two-dimension fast Fourier transformation texture features, and 48 Gabor wavelet filter texture features, were extracted from color images of beef strip steaks (longissimus dorsi, n = 102) aged for 10d obtained using a digital camera and additional lighting. Steaks were designated degraded or not-degraded based on troponin-T degradation determined on d 3 and d 10 postmortem by immunoblotting. Statistical analysis (STEPWISE regression model) and artificial neural network (support vector machine model, SVM) methods were designed to classify protein degradation. The d 3 and d 10 STEPWISE models were 94% and 86% accurate, respectively, while the d 3 and d 10 SVM models were 63% and 71%, respectively, in predicting protein degradation in aged meat. STEPWISE and SVM models based on image texture features show potential to predict troponin-T degradation in meat. © 2013.
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Texture and Elastic Anisotropy of Mantle Olivine
NASA Astrophysics Data System (ADS)
Nikitin, A. N.; Ivankina, T. I.; Bourilitchev, D. E.; Klima, K.; Locajicek, T.; Pros, Z.
Eight olivine rock samples from different European regions were collected for neu- tron texture analyses and for P-wave velocity measurements by means of ultrasonic sounding at various confining pressures. The orientation distribution functions (ODFs) of olivine were determined and pole figures of the main crystallographic planes were calculated. The spatial P-wave velocity distributions were determined at confining pressures from 0.1 to 400 MPa and modelled from the olivine textures. In dependence upon the type of rock (xenolith or dunite) different behavior of both the P-wave veloc- ity distributions and the anisotropy coefficients with various confining pressures was observed. In order to explain the interdependence of elastic anisotropy and hydrostatic pressure, a model for polycrystalline olivine rocks was suggested, which considers the influence of the crystallographic and the mechanical textures on the elastic behaviour of the polycrystal. Since the olivine texture depends upon the active slip systems and the deformation temperature, neutron texture analyses enable us to estimate depth and thermodynamical conditions during texture formation.
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Highly alloyed Ni-W substrates for low AC loss applications
NASA Astrophysics Data System (ADS)
Gaitzsch, Uwe; Hänisch, Jens; Hühne, Ruben; Rodig, Christian; Freudenberger, Jens; Holzapfel, Bernhard; Schultz, Ludwig
2013-08-01
Cube texture formation has been studied in Ni-W alloys with a W content of 9 at.% and above. These alloys show a low magnetization at 77 K and below, and are therefore excellent candidates for use as substrates of coated conductors in AC applications. The application of a modified deformation and annealing sequence leads to a highly textured surface of Ni9W and Ni9.5W tapes with cube texture fractions above 96%. YBCO (YBa2Cu3O7-δ) layers obtained on these substrates using a standard buffer architecture showed a critical current density exceeding 1.5 MA cm-2 at 77 K, similar to those for films on commercial Ni5W tapes. In contrast, only a weak cube texture was achieved in Ni10W tapes. The rolling texture of this alloy showed a significantly increased Goss component, which could not be reduced by applying intermediate annealing treatments. The influence of this texture on the cube texture formation will be discussed in detail.
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Microstructure Characterization of Weakly Textured and Fine Grained AZ61 Sheet
NASA Astrophysics Data System (ADS)
Berman, T. D.; Donlon, W.; Hung, C. K.; Milligan, P.; Decker, R.; Pollock, T. M.; Jones, J. W.
Formability in magnesium alloy sheet is strongly limited by a strong basal texture in the as-rolled material, which is difficulty to remove by thermal processing. We introduce a new process to the control of texture by combining Thixomolding and Thermomechanical Processing (TTMP). Plates of AZ61L with a divorced β-Mg17Al12 eutectic are produced by Thixomolding, resulting in a non-textured, fine grained (2.8 µm) precursor. Sheet produced from the plate by single pass warm-rolling exhibits a weaker texture, and more isotropic tensile deformation than generally observed in AZ-series alloy sheet. Recrystallization annealing produces a further reduction in texture and average grain size (2.3 µm) and results in nearly isotropic room temperature deformation, a yield strength of 220 MPa, and an elongation of 23%. Particle stimulated nucleation of new grains by the β-phase during both dynamic and static recrystallization, is critical for achieving the low levels of texture. The influence of β-phase distribution in microstructure development is discussed.
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The Sines industrial complex monitoring programme: A preliminary report.
Jones, M P; Catarino, F M; Sérgio, C; Bento-Pereira, F
1981-06-01
It is anticipated that the establishment of the industrial complex at Sines, Alentejo, Portugal, will have some impact on the environment. Details of the methods used in the monitoring programme are provided. Records of the epiphytic lichen vegetation in permanent quadrats have been made and changes shown in selected sites over a three year period are discussed. Material has been collected for analysis for heavy metals and the results discussed. There is considerable variation in replicates and in interspecies values. The problem of age and bio-accumulation is mentioned. Scanning electron microscopy has shown the accumulation of particulates, as yet unidentified, the quantity varying with increase in age and surface texture. A broadly based study of the local epiphytic flora is being carried out to record the present day diversity. There appears, as yet, to be no detectable influence of the industrial complex on the epiphytic flora of the permanent quadrats.
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Multi-year encoding of daily rainfall and streamflow via the fractal-multifractal method
NASA Astrophysics Data System (ADS)
Puente, C. E.; Maskey, M.; Sivakumar, B.
2017-12-01
A deterministic geometric approach, the fractal-multifractal (FM) method, which has been proven to be faithful in encoding daily geophysical sets over a year, is used to describe records over multiple years at a time. Looking for FM parameter trends over longer periods, the present study shows FM descriptions of daily rainfall and streamflow gathered over five consecutive years optimizing deviations on accumulated sets. The results for 100 and 60 sets of five years for rainfall streamflow, respectively, near Sacramento, California illustrate that: (a) encoding of both types of data sets may be accomplished with relatively small errors; and (b) predicting the geometry of both variables appears to be possible, even five years ahead, training neural networks on the respective FM parameters. It is emphasized that the FM approach not only captures the accumulated sets over successive pentades but also preserves other statistical attributes including the overall "texture" of the records.
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Wearable Eating Habit Sensing System Using Internal Body Sound
NASA Astrophysics Data System (ADS)
Shuzo, Masaki; Komori, Shintaro; Takashima, Tomoko; Lopez, Guillaume; Tatsuta, Seiji; Yanagimoto, Shintaro; Warisawa, Shin'ichi; Delaunay, Jean-Jacques; Yamada, Ichiro
Continuous monitoring of eating habits could be useful in preventing lifestyle diseases such as metabolic syndrome. Conventional methods consist of self-reporting and calculating mastication frequency based on the myoelectric potential of the masseter muscle. Both these methods are significant burdens for the user. We developed a non-invasive, wearable sensing system that can record eating habits over a long period of time in daily life. Our sensing system is composed of two bone conduction microphones placed in the ears that send internal body sound data to a portable IC recorder. Applying frequency spectrum analysis on the collected sound data, we could not only count the number of mastications during eating, but also accurately differentiate between eating, drinking, and speaking activities. This information can be used to evaluate the regularity of meals. Moreover, we were able to analyze sound features to classify the types of foods eaten by food texture.
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NASA Technical Reports Server (NTRS)
Weigand, A. J.; Meyer, M. L.; Ling, J. S.
1977-01-01
An electron bombardment ion thruster was used as an ion source to sputter the surfaces of orthopedic prosthetic metals. Scanning electron microscopy photomicrographs were made of each ion beam textured surface. The effect of ion texturing an implant surface on its bond to bone cement was investigated. A Co-Cr-W alloy and surgical stainless steel were used as representative hard tissue implant materials to determine effects of ion texturing on bulk mechanical properties. Work was done to determine the effect of substrate temperature on the development of an ion textured surface microstructure. Results indicate that the ultimate strength of the bulk materials is unchanged by ion texturing and that the microstructure will develop more rapidly if the substrate is heated prior to ion texturing.
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Image segmentation using association rule features.
Rushing, John A; Ranganath, Heggere; Hinke, Thomas H; Graves, Sara J
2002-01-01
A new type of texture feature based on association rules is described. Association rules have been used in applications such as market basket analysis to capture relationships present among items in large data sets. It is shown that association rules can be adapted to capture frequently occurring local structures in images. The frequency of occurrence of these structures can be used to characterize texture. Methods for segmentation of textured images based on association rule features are described. Simulation results using images consisting of man made and natural textures show that association rule features perform well compared to other widely used texture features. Association rule features are used to detect cumulus cloud fields in GOES satellite images and are found to achieve higher accuracy than other statistical texture features for this problem.
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NASA Astrophysics Data System (ADS)
Sierra, Heidy; Brooks, Dana; Dimarzio, Charles
2010-07-01
The extraction of 3-D morphological information about thick objects is explored in this work. We extract this information from 3-D differential interference contrast (DIC) images by applying a texture detection method. Texture extraction methods have been successfully used in different applications to study biological samples. A 3-D texture image is obtained by applying a local entropy-based texture extraction method. The use of this method to detect regions of blastocyst mouse embryos that are used in assisted reproduction techniques such as in vitro fertilization is presented as an example. Results demonstrate the potential of using texture detection methods to improve morphological analysis of thick samples, which is relevant to many biomedical and biological studies. Fluorescence and optical quadrature microscope phase images are used for validation.
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Influence of Nd and Y on texture of as-extruded Mg-5Li-3Al-2Zn alloy
NASA Astrophysics Data System (ADS)
Wu, Liqun; Zhang, Tianlong; Cui, Chongliang; Wu, Ruizhi; Zhang, Milin; Hou, Legan
2016-07-01
Mg-5Li-3Al-2Zn alloys with the additions of Y and Nd were prepared using induction melting furnace under the atmosphere of pure argon; then they were extruded. The textures of the as-extruded alloys were analyzed by pole figures and electron backscatter diffraction. Results show that the addition of a small amount of Nd can weaken the basal texture. The further increase of Nd content has no corresponding further influence on texture. When a small amount of Y is used to replace Nd, the basal texture can be further weakened and the prismatic slip system can be further activated. In the alloy of Mg-5Li-3Al-2Zn-1.2Y-0.8Nd, the basal textures almost vanish.
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Robust constraint on cosmic textures from the cosmic microwave background.
Feeney, Stephen M; Johnson, Matthew C; Mortlock, Daniel J; Peiris, Hiranya V
2012-06-15
Fluctuations in the cosmic microwave background (CMB) contain information which has been pivotal in establishing the current cosmological model. These data can also be used to test well-motivated additions to this model, such as cosmic textures. Textures are a type of topological defect that can be produced during a cosmological phase transition in the early Universe, and which leave characteristic hot and cold spots in the CMB. We apply bayesian methods to carry out a rigorous test of the texture hypothesis, using full-sky data from the Wilkinson Microwave Anisotropy Probe. We conclude that current data do not warrant augmenting the standard cosmological model with textures. We rule out at 95% confidence models that predict more than 6 detectable cosmic textures on the full sky.
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Independent Component Analysis of Textures
NASA Technical Reports Server (NTRS)
Manduchi, Roberto; Portilla, Javier
2000-01-01
A common method for texture representation is to use the marginal probability densities over the outputs of a set of multi-orientation, multi-scale filters as a description of the texture. We propose a technique, based on Independent Components Analysis, for choosing the set of filters that yield the most informative marginals, meaning that the product over the marginals most closely approximates the joint probability density function of the filter outputs. The algorithm is implemented using a steerable filter space. Experiments involving both texture classification and synthesis show that compared to Principal Components Analysis, ICA provides superior performance for modeling of natural and synthetic textures.
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NASA Astrophysics Data System (ADS)
T, Morimoto; F, Yoshida; A, Yanagida; J, Yanagimoto
2015-04-01
First, hardening model in f.c.c. metals was formulated with collinear interactions slips, Hirth slips and Lomer-Cottrell slips. Using the Taylor and the Sachs rolling texture prediction model, the residual dislocation densities of cold-rolled commercial pure aluminum were estimated. Then, coincidence site lattice grains were investigated from observed cold rolling texture. Finally, on the basis of oriented nucleation theory and coincidence site lattice theory, the recrystallization texture of commercial pure aluminum after low-temperature annealing was predicted.
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Constraints on texture zero and cofactor zero models for neutrino mass
DOE Office of Scientific and Technical Information (OSTI.GOV)
Whisnant, K.; Liao, Jiajun; Marfatia, D.
2014-06-24
Imposing a texture or cofactor zero on the neutrino mass matrix reduces the number of independent parameters from nine to seven. Since five parameters have been measured, only two independent parameters would remain in such models. We find the allowed regions for single texture zero and single cofactor zero models. We also find strong similarities between single texture zero models with one mass hierarchy and single cofactor zero models with the opposite mass hierarchy. We show that this correspondence can be generalized to texture-zero and cofactor-zero models with the same homogeneous costraints on the elements and cofactors.
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Textural signatures for wetland vegetation
NASA Technical Reports Server (NTRS)
Whitman, R. I.; Marcellus, K. L.
1973-01-01
This investigation indicates that unique textural signatures do exist for specific wetland communities at certain times in the growing season. When photographs with the proper resolution are obtained, the textural features can identify the spectral features of the vegetation community seen with lower resolution mapping data. The development of a matrix of optimum textural signatures is the goal of this research. Seasonal variations of spectral and textural features are particularly important when performing a vegetations analysis of fresh water marshes. This matrix will aid in flight planning, since expected seasonal variations and resolution requirements can be established prior to a given flight mission.
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NASA Astrophysics Data System (ADS)
Taylor, Faith E.; Malamud, Bruce D.; Millington, James D. A.
2016-04-01
The configuration of infrastructure networks such as roads, drainage and power lines can both affect and be affected by natural hazards such as earthquakes, intense rain, wildfires and extreme temperatures. In this paper, we present and compare two methods to quantify urban topology on approximate scales of 0.0005 km2 to 10 km2 and create classifications of different 'urban textures' that relate to risk of natural hazard impact in an area. The methods we use focus on applicability in urban developing country settings, where access to high resolution and high quality data may be difficult. We use the city of Nairobi, Kenya to trial these methods. Nairobi has a population >3 million, and is a mix of informal settlements, residential and commercial development. The city and its immediate surroundings are subject to a variety of natural hazards such as floods, landslides, fires, drought, hail, heavy wind and extreme temperatures; all of these hazards can occur singly, but also have the potential for one to trigger another, thus providing a 'cascade' of hazards, or for two of the hazards to occur spatially and temporally near each other and interact. We use two measures of urban texture: (i) Street block textures, (ii) Google Earth land cover textures. Street block textures builds on the methodology of Louf and Barthelemy (2014) and uses Open Street Map data to analyse the shape, size, complexity and pattern of individual blocks of land created by fully enclosed loops of the major and minor road network of Nairobi. We find >4000 of these blocks ranging in size from approximately 0.0005 km2 to 10 km2, with approximately 5 classifications of urban texture. Google Earth land cover texture is a visual classification of homogeneous parcels of land performed in Google Earth using high-resolution airborne imagery and a qualitative criteria for each land cover type. Using the Google Earth land cover texture method, we identify >40 'urban textures' based on visual characteristics such as colour, texture, shadow and setting and have created a clear criteria for classifying an area based on its visual characteristics. These two methods for classifying urban texture in Nairobi are compared in a GIS and in the field to investigate whether there is a link between the visual appearance of an area and its network topology. From these urban textures, we may start to identify areas where (a) urban texture types may indicate a relative propensity to certain hazards and their interactions and (b) urban texture types that may increase or decrease the impact of a hazard that occurs in that area.
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Texturing new concrete pavements.
DOT National Transportation Integrated Search
1977-01-01
Several texturing experiments on heavily traveled portland cement concrete pavements in Virginia are described. Included in the experiments were textures imparted by a heavy burlap drag, metal tines (transverse and longitudinal striations), sprinkled...
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NASA Astrophysics Data System (ADS)
Vogel, M. B.; Des Marais, D. J.; Jahnke, L. L.; Turk, K.; Kubo, M.
2007-12-01
Gypsum (CaSO4·H2O) is an important phase in biogeochemistry and sedimentology as a mineral sink for sulfur, a paleoclimatic indicator, and an endolithic niche for phototrophic and chemotrophic bacteria. Sulfate deposits are also important targets of exploration for evidence of habitable environments and life on Mars. Gypsum deposits from a range of sedimentary environments at the Guerrero Negro crystallizer ponds and sabkha settings were investigated for microscale structure and composition to differentiate fabrics formed under microbial influence from those formed under abiogenic conditions. Sub-sedimentary gypsum forms in sabkha environments as mm to cm scale selenite discs (termed bird beak gypsum; Warren, 2006) and selenite disc aggregates. Selenite discs and other sub-sedimentary gypsum are characterized by a sinuous axial microtexture and poikilitically enclosed detrital particles. Sub-aqueous gypsum forms as cements, granules (termed gypsooids), and massive botryoidal crusts that line the sediment water interface and margins of managed crystallizer ponds and natural anchialine pools. Sub-aqueous gypsum exhibits a wide range of textures and mineral/biofilm associations that include amorphous to euhedral, tabular, needle and lensoidal morphologies. Elemental sulfur forms rinds on prismatic, growth aligned gypsum twins and reticulate magnesian carbonate is interspersed with both twinned crystals and rosette aggregates in stratified sub-aqueous environments. Intracrystalline biofilms and cell material was observed in association with nearly all sub-aqueous morphologies but only scarce evidence has been found for intercrystalline microbial communities. Columnar microbial communities living in anchialine pools were found to host precipitation of mm scale gypsum granules in their EPS matrix. Fine scale gypsum textures are unlikely to persist through diagenetic alteration, but understanding their primary associations with sulfur and carbonates is necessary for interpreting sulfates or their replacement phases in the ancient record.
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NASA Technical Reports Server (NTRS)
Ehlmann, Bethany L.; Viles, Heather A.; Bourke, Mary C.
2008-01-01
Boulder morphology reflects both lithology and climate and is dictated by the combined effects of erosion, transport, and weathering. At present, morphologic information at the boulder scale is underutilized as a recorder of environmental processes, partly because of the lack of a systematic quantitative parameter set for reporting and comparing data sets. We develop such a parameter set, incorporating a range of measures of boulder form and surface texture. We use standard shape metrics measured in the field and fractal and morphometric classification methods borrowed from landscape analysis and applied to laser-scanned molds. The parameter set was pilot tested on three populations of basalt boulders with distinct breakdown histories in the Channeled Scabland, Washington: (1) basalt outcrop talus; (2) flood-transported boulders recently excavated from a quarry; and (3) flood-transported boulders, extensively weathered in situ on the Ephrata Fan surface. Size and shape data were found to distinguish between flood-transported and untransported boulders. Size and edge angles (approximately 120 degrees) of flood-transported boulders suggest removal by preferential fracturing along preexisting columnar joints, and curvature data indicate rounding relative to outcrop boulders. Surface textural data show that boulders which have been exposed at the surface are significantly rougher than those buried by fan sediments. Past signatures diagnostic of flood transport still persist on surface boulders, despite ongoing overprinting by processes in the present breakdown environment through roughening and fracturing in situ. Further use of this quantitative boulder parameter set at other terrestrial and planetary sites will aid in cataloging and understanding morphologic signatures of environmental processes.
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The stimulus integration area for horizontal vergence.
Allison, Robert S; Howard, Ian P; Fang, Xueping
2004-06-01
Over what region of space are horizontal disparities integrated to form the stimulus for vergence? The vergence system might be expected to respond to disparities within a small area of interest to bring them into the range of precise stereoscopic processing. However, the literature suggests that disparities are integrated over a fairly large parafoveal area. We report the results of six experiments designed to explore the spatial characteristics of the stimulus for vergence. Binocular eye movements were recorded using magnetic search coils. Each dichoptic display consisted of a central target stimulus that the subject attempted to fuse, and a competing stimulus with conflicting disparity. In some conditions the target was stationary, providing a fixation stimulus. In other conditions, the disparity of the target changed to provide a vergence-tracking stimulus. The target and competing stimulus were combined in a variety of conditions including those in which (1) a transparent textured-disc target was superimposed on a competing textured background, (2) a textured-disc target filled the centre of a competing annular background, and (3) a small target was presented within the centre of a competing annular background of various inner diameters. In some conditions the target and competing stimulus were separated in stereoscopic depth. The results are consistent with a disparity integration area with a diameter of about 5 degrees. Stimuli beyond this integration area can drive vergence in their own right, but they do not appear to be summed or averaged with a central stimulus to form a combined disparity signal. A competing stimulus had less effect on vergence when separated from the target by a disparity pedestal. As a result, we propose that it may be more useful to think in terms of an integration volume for vergence rather than a two-dimensional retinal integration area.
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The Voltage Boost Enabled by Luminescence Extraction in Solar Cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ganapati, Vidya; Steiner, Myles A.; Yablonovitch, Eli
Over the past few years, the application of the physical principle, i.e., 'luminescence extraction,' has produced record voltages and efficiencies in photovoltaic cells. Luminescence extraction is the use of optical design, such as a back mirror or textured surfaces, to help internal photons escape out of the front surface of a solar cell. The principle of luminescence extraction is exemplified by the mantra 'a good solar cell should also be a good LED.' Basic thermodynamics says that the voltage boost should be related to concentration ratio C of a resource by ΔV = (kT/q) ln{C}. In light trapping (i.e., when the solar cell is textured and has a perfect back mirror), the concentration ratio of photons C = {4n 2}; therefore, one would expect a voltage boost of ΔV = (kT/q) ln{4n 2} over a solar cell with no texture and zero back reflectivity, where n is the refractive index. Nevertheless, there has been ambiguity over the voltage benefit to be expected from perfect luminescence extraction. Do we gain an open-circuit voltage boost of ΔV = (kT/q) ln{n 2}, ΔV = (kT/q) ln{2 n 2}, or ΔV = (kT/q) ln{4 n 2}? What is responsible for this voltage ambiguity ΔV = (kT/q) ln{4}more » $${\\asymp}$$ 36 mV? Finally, we show that different results come about, depending on whether the photovoltaic cell is optically thin or thick to its internal luminescence. In realistic intermediate cases of optical thickness, the voltage boost falls in between: ln{n 2} < (qΔV/kT) < ln{4n 2}.« less
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The Voltage Boost Enabled by Luminescence Extraction in Solar Cells
Ganapati, Vidya; Steiner, Myles A.; Yablonovitch, Eli
2016-07-01
Over the past few years, the application of the physical principle, i.e., 'luminescence extraction,' has produced record voltages and efficiencies in photovoltaic cells. Luminescence extraction is the use of optical design, such as a back mirror or textured surfaces, to help internal photons escape out of the front surface of a solar cell. The principle of luminescence extraction is exemplified by the mantra 'a good solar cell should also be a good LED.' Basic thermodynamics says that the voltage boost should be related to concentration ratio C of a resource by ΔV = (kT/q) ln{C}. In light trapping (i.e., when the solar cell is textured and has a perfect back mirror), the concentration ratio of photons C = {4n 2}; therefore, one would expect a voltage boost of ΔV = (kT/q) ln{4n 2} over a solar cell with no texture and zero back reflectivity, where n is the refractive index. Nevertheless, there has been ambiguity over the voltage benefit to be expected from perfect luminescence extraction. Do we gain an open-circuit voltage boost of ΔV = (kT/q) ln{n 2}, ΔV = (kT/q) ln{2 n 2}, or ΔV = (kT/q) ln{4 n 2}? What is responsible for this voltage ambiguity ΔV = (kT/q) ln{4}more » $${\\asymp}$$ 36 mV? Finally, we show that different results come about, depending on whether the photovoltaic cell is optically thin or thick to its internal luminescence. In realistic intermediate cases of optical thickness, the voltage boost falls in between: ln{n 2} < (qΔV/kT) < ln{4n 2}.« less
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T2 values of articular cartilage in clinically relevant subregions of the asymptomatic knee.
Surowiec, Rachel K; Lucas, Erin P; Fitzcharles, Eric K; Petre, Benjamin M; Dornan, Grant J; Giphart, J Erik; LaPrade, Robert F; Ho, Charles P
2014-06-01
In order for T2 mapping to become more clinically applicable, reproducible subregions and standardized T2 parameters must be defined. This study sought to: (1) define clinically relevant subregions of knee cartilage using bone landmarks identifiable on both MR images and during arthroscopy and (2) determine healthy T2 values and T2 texture parameters within these subregions. Twenty-five asymptomatic volunteers (age 18-35) were evaluated with a sagittal T2 mapping sequence. Manual segmentation was performed by three raters, and cartilage was divided into twenty-one subregions modified from the International Cartilage Repair Society Articular Cartilage Mapping System. Mean T2 values and texture parameters (entropy, variance, contrast, homogeneity) were recorded for each subregion, and inter-rater and intra-rater reliability was assessed. The central regions of the condyles had significantly higher T2 values than the posterior regions (P < 0.05) and higher variance than the posterior region on the medial side (P < 0.001). The central trochlea had significantly greater T2 values than the anterior and posterior condyles. The central lateral plateau had lower T2 values, lower variance, higher homogeneity, and lower contrast than nearly all subregions in the tibia. The central patellar regions had higher entropy than the superior and inferior regions (each P ≤ 0.001). Repeatability was good to excellent for all subregions. Significant differences in mean T2 values and texture parameters were found between subregions in this carefully selected asymptomatic population, which suggest that there is normal variation of T2 values within the knee joint. The clinically relevant subregions were found to be robust as demonstrated by the overall high repeatability.
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Reconstruction of a digital core containing clay minerals based on a clustering algorithm.
He, Yanlong; Pu, Chunsheng; Jing, Cheng; Gu, Xiaoyu; Chen, Qingdong; Liu, Hongzhi; Khan, Nasir; Dong, Qiaoling
2017-10-01
It is difficult to obtain a core sample and information for digital core reconstruction of mature sandstone reservoirs around the world, especially for an unconsolidated sandstone reservoir. Meanwhile, reconstruction and division of clay minerals play a vital role in the reconstruction of the digital cores, although the two-dimensional data-based reconstruction methods are specifically applicable as the microstructure reservoir simulation methods for the sandstone reservoir. However, reconstruction of clay minerals is still challenging from a research viewpoint for the better reconstruction of various clay minerals in the digital cores. In the present work, the content of clay minerals was considered on the basis of two-dimensional information about the reservoir. After application of the hybrid method, and compared with the model reconstructed by the process-based method, the digital core containing clay clusters without the labels of the clusters' number, size, and texture were the output. The statistics and geometry of the reconstruction model were similar to the reference model. In addition, the Hoshen-Kopelman algorithm was used to label various connected unclassified clay clusters in the initial model and then the number and size of clay clusters were recorded. At the same time, the K-means clustering algorithm was applied to divide the labeled, large connecting clusters into smaller clusters on the basis of difference in the clusters' characteristics. According to the clay minerals' characteristics, such as types, textures, and distributions, the digital core containing clay minerals was reconstructed by means of the clustering algorithm and the clay clusters' structure judgment. The distributions and textures of the clay minerals of the digital core were reasonable. The clustering algorithm improved the digital core reconstruction and provided an alternative method for the simulation of different clay minerals in the digital cores.
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NASA Astrophysics Data System (ADS)
Itagaki, Norikazu; Saito, Shin; Takahashi, Migaku
2009-04-01
Through analyzing the growth mechanism of the Ru layer in a nonmagnetic intermediate layer (NMIL) for perpendicular magnetic recording media, a concept for the NMIL is proposed in order to realize a recording layer of small, highly c-plane oriented grains with no intergranular exchange coupling. It was found that (1) fast Fourier transform analysis of plan-view transmission electron microscopy lattice images of Ru layers revealed that hexagonal close packed Ru grains in a c-plane oriented film readily coalesce with each other due to the disappearance of low-angle tilt boundaries. (2) A promising candidate for a NMIL consists of three individual epitaxially grown functional layers: a large-grain seed layer with a highly oriented sheet texture, a first interlayer of small grains, and a second interlayer of nonmagnetic grains isolated by a segregated oxide. (3) The Ru-SiO2/Ru/Mg NMIL based on the proposed concept exhibited small (diameter: 4.8 nm) Ru grains while retaining a narrow orientation distribution of 4.1°.
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Texture classification using autoregressive filtering
NASA Technical Reports Server (NTRS)
Lawton, W. M.; Lee, M.
1984-01-01
A general theory of image texture models is proposed and its applicability to the problem of scene segmentation using texture classification is discussed. An algorithm, based on half-plane autoregressive filtering, which optimally utilizes second order statistics to discriminate between texture classes represented by arbitrary wide sense stationary random fields is described. Empirical results of applying this algorithm to natural and sysnthesized scenes are presented and future research is outlined.
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Structures having enhanced biaxial texture
Goyal, Amit; Budai, John D.; Kroeger, Donald M.; Norton, David P.; Specht, Eliot D.; Christen, David K.
1999-01-01
A biaxially textured alloy article includes a rolled and annealed biaxially textured base metal substrate characterized by an x-ray diffraction phi scan peak of no more than 20.degree. FWHM; and a biaxially textured layer of an alloy or another material on a surface thereof. The article further includes at least one of an electromagnetic device or an electro-optical device epitaxially joined to the alloy.
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Doped Y.sub.2O.sub.3 buffer layers for laminated conductors
Paranthaman, Mariappan Parans [Knoxville, TN; Schoop, Urs [Westborough, MA; Goyal, Amit [Knoxville, TN; Thieme, Cornelis Leo Hans [Westborough, MA; Verebelyi, Darren T [Oxford, MA; Rupich, Martin W [Framingham, MA
2007-08-21
A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the metallic substrate, the biaxially textured buffer layer comprising Y.sub.2O.sub.3 and a dopant for blocking cation diffusion through the Y.sub.2O.sub.3, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.
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ERIC Educational Resources Information Center
Patel, Meeta R.; Piazza, Cathleen C.; Layer, Stacy A.; Coleman, Russell; Swartzwelder, Dana M.
2005-01-01
This study examined packing (pocketing or holding accepted food in the mouth) in 3 children who were failing to thrive or had inadequate weight gain due to insufficient caloric intake. The results of an analysis of texture indicated that total grams consumed were higher when lower textured foods were presented than when higher textured foods were…
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USDA-ARS?s Scientific Manuscript database
Wheat kernel texture dictates U.S. wheat market class. Durum wheat has limited demand and culinary end-uses compared to bread wheat because of its extremely hard kernel texture which preclude conventional milling. ‘Soft Svevo’, a new durum cultivar with soft kernel texture comparable to a soft white...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Nawrocki, J; Chino, J; Das, S
Purpose: This study examines the effect on texture analysis due to variable reconstruction of PET images in the context of an adaptive FDG PET protocol for node positive gynecologic cancer patients. By measuring variability in texture features from baseline and intra-treatment PET-CT, we can isolate unreliable texture features due to large variation. Methods: A subset of seven patients with node positive gynecological cancers visible on PET was selected for this study. Prescribed dose varied between 45–50.4Gy, with a 55–70Gy boost to the PET positive nodes. A baseline and intratreatment (between 30–36Gy) PET-CT were obtained on a Siemens Biograph mCT. Eachmore » clinical PET image set was reconstructed 6 times using a TrueX+TOF algorithm with varying iterations and Gaussian filter. Baseline and intra-treatment primary GTVs were segmented using PET Edge (MIM Software Inc., Cleveland, OH), a semi-automatic gradient-based algorithm, on the clinical PET and transferred to the other reconstructed sets. Using an in-house MATLAB program, four 3D texture matrices describing relationships between voxel intensities in the GTV were generated: co-occurrence, run length, size zone, and neighborhood difference. From these, 39 textural features characterizing texture were calculated in addition to SUV histogram features. The percent variability among parameters was first calculated. Each reconstructed texture feature from baseline and intra-treatment per patient was normalized to the clinical baseline scan and compared using the Wilcoxon signed-rank test in order to isolate variations due to reconstruction parameters. Results: For the baseline scans, 13 texture features showed a mean range greater than 10%. For the intra scans, 28 texture features showed a mean range greater than 10%. Comparing baseline to intra scans, 25 texture features showed p <0.05. Conclusion: Variability due to different reconstruction parameters increased with treatment, however, the majority of texture features showed significant changes during treatment independent of reconstruction effects.« less
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Mapping lava flow textures using three-dimensional measures of surface roughness
NASA Astrophysics Data System (ADS)
Mallonee, H. C.; Kobs-Nawotniak, S. E.; McGregor, M.; Hughes, S. S.; Neish, C.; Downs, M.; Delparte, D.; Lim, D. S. S.; Heldmann, J. L.
2016-12-01
Lava flow emplacement conditions are reflected in the surface textures of a lava flow; unravelling these conditions is crucial to understanding the eruptive history and characteristics of basaltic volcanoes. Mapping lava flow textures using visual imagery alone is an inherently subjective process, as these images generally lack the resolution needed to make these determinations. Our team has begun mapping lava flow textures using visual spectrum imagery, which is an inherently subjective process involving the challenge of identifying transitional textures such as rubbly and slabby pāhoehoe, as these textures are similar in appearance and defined qualitatively. This is particularly problematic for interpreting planetary lava flow textures, where we have more limited data. We present a tool to objectively classify lava flow textures based on quantitative measures of roughness, including the 2D Hurst exponent, RMS height, and 2D:3D surface area ratio. We collected aerial images at Craters of the Moon National Monument (COTM) using Unmanned Aerial Vehicles (UAVs) in 2015 and 2016 as part of the FINESSE (Field Investigations to Enable Solar System Science and Exploration) and BASALT (Biologic Analog Science Associated with Lava Terrains) research projects. The aerial images were stitched together to create Digital Terrain Models (DTMs) with resolutions on the order of centimeters. The DTMs were evaluated by the classification tool described above, with output compared against field assessment of the texture. Further, the DTMs were downsampled and reevaluated to assess the efficacy of the classification tool at data resolutions similar to current datasets from other planetary bodies. This tool allows objective classification of lava flow texture, which enables more accurate interpretations of flow characteristics. This work also gives context for interpretations of flows with comparatively low data resolutions, such as those on the Moon and Mars. Textural maps based on quantitative measures of roughness are a valuable asset for studies of lava flows on Earth and other planetary bodies.
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SU-F-R-18: Updates to the Computational Environment for Radiological Research for Image Analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Apte, Aditya P.; Deasy, Joseph O.
2016-06-15
Purpose: To present new tools in CERR for Texture Analysis and Visualization. Method: (1) Quantitative Image Analysis: We added the ability to compute Haralick texture features based on local neighbourhood. The Texture features depend on many parameters used in their derivation. For example: (a) directionality, (b) quantization of image, (c) patch-size for the neighborhood, (d) handling of the edge voxels within the region of interest, (e) Averaging co-occurance matrix vs texture features for different directions etc. A graphical user interface was built to set these parameters and then visualize their impact on the resulting texture maps. The entire functionality wasmore » written in Matlab. Array indexing was used to speed up the texture calculation. The computation speed is very competitive with the ITK library. Moreover, our implementation works with multiple CPUs and the computation time can be further reduced by using multiple processor threads. In order to reduce the Haralick texture maps into scalar features, we propose the use of Texture Volume Histograms. This lets users make use of the entire distribution of texture values within the region of interest rather than using just the mean and the standard deviations. (2) Qualitative/Visualization tools: The derived texture maps are stored as a new scan (derived) within CERR’s planC data structure. A display that compares various scans was built to show the raw image and the derived texture maps side-by-side. These images are positionally linked and can be navigated together. CERR’s graphics handling was updated and sped-up to be compatible with the newer Matlab versions. As a result, the users can use (a) different window levels and colormaps for different viewports, (b) click-and-drag or use mouse scroll-wheel to navigate slices. Results: The new features and updates are available via https://www.github.com/adityaapte/cerr . Conclusion: Features added to CERR increase its utility in Radiomics and Outcomes modeling.« less
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Correlations Between Textures and Infrared Spectra of the Martian Surface in Valles Marineris
NASA Astrophysics Data System (ADS)
Ralston, S. J.; Wray, J. J.
2013-12-01
RALSTON, S. J., School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, sralston3@gatech.edu, WRAY, James, School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, jwray@eas.gatech.edu In the past few decades, a wealth of information has become available on the appearance and composition of the Martian surface. While some previous research has examined possible correlations between certain surface features and mineralogy (such as the hypothesized connection between Recurring Slope Lineae and perchlorate salts), little has yet been done to determine possible correlations between mineralogy and texture in less extraordinary circumstances. In this project, one hundred images taken from across the Valles Marineris region were examined both in infrared (obtained from the CRISM instrument aboard the Mars Reconnaissance Orbiter) and in visible-light images from the HiRISE camera. Spectra were obtained from regions of interest, focusing mainly on the identification of monohydrated and polyhydrated sulfates. Other materials were included in the imaging, including phyllosilicate clays, gypsum, and jarosite, although those materials proved less abundant than the sulfates. The areas from which the spectra were taken were then examined in visible-light wavelengths using HiRISE images to determine textural qualities. The focus of this research was on two particular textures, a 'reticulated' texture and a 'stepped texture,' hypothesized to correlate to monohydrated and polyhydrated sulfates, respectively. Results showed that over 55% of areas containing monohydrated sulfates also contained reticulate texture, whereas areas that contained other materials, such as polyhydrated sulfates and clays, had only a 2-8% correlation with reticulate texture. The stepped texture was shown to have no significant correlation to any one material, although other texture/mineral pairs did show some correlation. This presentation will cover the range of textures and mineralogy found throughout Valles Marineris.
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Khoje, Suchitra
2018-02-01
Images of four qualities of mangoes and guavas are evaluated for color and textural features to characterize and classify them, and to model the fruit appearance grading. The paper discusses three approaches to identify most discriminating texture features of both the fruits. In the first approach, fruit's color and texture features are selected using Mahalanobis distance. A total of 20 color features and 40 textural features are extracted for analysis. Using Mahalanobis distance and feature intercorrelation analyses, one best color feature (mean of a* [L*a*b* color space]) and two textural features (energy a*, contrast of H*) are selected as features for Guava while two best color features (R std, H std) and one textural features (energy b*) are selected as features for mangoes with the highest discriminate power. The second approach studies some common wavelet families for searching the best classification model for fruit quality grading. The wavelet features extracted from five basic mother wavelets (db, bior, rbior, Coif, Sym) are explored to characterize fruits texture appearance. In third approach, genetic algorithm is used to select only those color and wavelet texture features that are relevant to the separation of the class, from a large universe of features. The study shows that image color and texture features which were identified using a genetic algorithm can distinguish between various qualities classes of fruits. The experimental results showed that support vector machine classifier is elected for Guava grading with an accuracy of 97.61% and artificial neural network is elected from Mango grading with an accuracy of 95.65%. The proposed method is nondestructive fruit quality assessment method. The experimental results has proven that Genetic algorithm along with wavelet textures feature has potential to discriminate fruit quality. Finally, it can be concluded that discussed method is an accurate, reliable, and objective tool to determine fruit quality namely Mango and Guava, and might be applicable to in-line sorting systems. © 2017 Wiley Periodicals, Inc.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, B; Yu, H; Jara, H
Purpose: To compare enhanced Laws texture derived from parametric proton density (PD) maps to other MRI-based surrogate markers (T2, PD, ADC) in assessing degrees of liver fibrosis in a murine model of hepatic fibrosis using 11.7T scanner. Methods: This animal study was IACUC approved. Fourteen mice were divided into control (n=1) and experimental (n=13). The latter were fed a DDC-supplemented diet to induce hepatic fibrosis. Liver specimens were imaged using an 11.7T scanner; the parametric PD, T2, and ADC maps were generated from spin-echo pulsed field gradient and multi-echo spin-echo acquisitions. Enhanced Laws texture analysis was applied to the PDmore » maps: first, hepatic blood vessels and liver margins were segmented/removed using an automated dual-clustering algorithm; secondly, an optimal thresholding algorithm was applied to reduce the partial volume artifact; next, mean and stdev were corrected to minimize grayscale variation across images; finally, Laws texture was extracted. Degrees of fibrosis was assessed by an experienced pathologist and digital image analysis (%Area Fibrosis). Scatterplots comparing enhanced Laws texture, T2, PD, and ADC values to degrees of fibrosis were generated and correlation coefficients were calculated. Unenhanced Laws texture was also compared to assess the effectiveness of the proposed enhancements. Results: Hepatic fibrosis and the enhanced Laws texture were strongly correlated with higher %Area Fibrosis associated with higher Laws texture (r=0.89). Only a moderate correlation was detected between %Area Fibrosis and unenhanced Laws texture (r=0.70). Strong correlation also existed between ADC and %Area Fibrosis (r=0.86). Moderate correlations were seen between %Area Fibrosis and PD (r=0.65) and T2 (r=0.66). Conclusions: Higher degrees of hepatic fibrosis are associated with increased Laws texture. The proposed enhancements improve the accuracy of Laws texture. Enhanced Laws texture features are more accurate than PD and T2 in assessing fibrosis, and can potentially serve as an accurate surrogate marker for hepatic fibrosis.« less
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PREFACE: 17th International Conference on Textures of Materials (ICOTOM 17)
NASA Astrophysics Data System (ADS)
Skrotzki, Werner; Oertel, Carl-Georg
2015-04-01
The 17th International Conference on Textures of Materials (ICOTOM 17) took place in Dresden, Germany, August 24-29, 2014. It belongs to the "triennial" series of ICOTOM meetings with a long tradition, starting in 1969 - Clausthal, 1971 - Cracow, 1973 - Pont-à-Mousson, 1975 - Cambridge, 1978 - Aachen, 1981 - Tokyo, 1984 - Noordwijkerhout, 1987 - Santa Fe, 1990 - Avignon, 1993 - Clausthal, 1996 - Xian, 1999 - Montreal, 2002 - Seoul, 2005 - Leuven, 2008 - Pittsburgh, 2011 - Mumbai, 2014 - Dresden. ICOTOM 17 was hosted by the Dresden University of Technology, Institute of Structural Physics. Following the tradition of the ICOTOM conferences, the main focus of ICOTOM-17 was to promote and strengthen the fundamental understanding of the basic processes that govern the formation of texture and its relation to the properties of polycrystalline materials. Nonetheless, it was the aim to forge links between basic research on model materials and applied research on engineering materials of technical importance. Thus, ICOTOM 17 provided a forum for the presentation and discussion of recent progress in research of texture and related anisotropy of mechanical and functional properties of all kinds of polycrystalline materials including natural materials like rocks. Particular attention was paid to recent advances in texture measurement and analysis as well as modeling of texture development for all kinds of processes like solidification, plastic deformation, recrystallization and grain growth, phase transformations, thin film deposition, etc. Hence, ICOTOM 17 was of great interest to materials scientists, engineers from many different areas and geoscientists. The topics covered by ICOTOM 17 were: 1. Mathematical, numerical and statistical methods of texture analysis 2. Deformation textures 3. Crystallization, recrystallization and growth textures 4. Transformation textures 5. Textures in functional materials 6. Textures in advanced materials 7. Textures in rocks 8. Texture related research on microstructures 9. Texture-induced anisotropy 10. Insight through new experimental methods 11. Technological applications of texture studies 12. Other new developments and future trends related to the field While there was large interest in the topics 2, 3 and 8, contributions to topic 7 were much less than expected. ICOTOM 17 attracted 266 scientists from 34 countries with about one third of the participants being students. This is a very good ratio showing that we could attract the young generation. There have been 216 oral and 76 poster presentations, three of which received a poster award. It is our pleasure to thank the members of the International ICOTOM Committee for their valuable help, especially for proposing and choosing the 15 plenary speakers as well as the distinguished scientist of the texture community for the "Bunge Award". 130 papers were submitted for publication in the proceedings, 116 were accepted after reviewing. We would like to express our thanks to all referees for their efficient and prompt efforts. We acknowledge particularly support from the German Research Society (DFG) and the City of Dresden. We are also grateful for industrial support from Bruker Nano GmbH, Oxford Instruments GmbH, Ametek GmbH / EDAX, Labosoft S.C., PANalytical GmbH and IOP Publishing. Finally we thank all members of the National Organizing Committee, Intercom Dresden and Conwerk / Laboratory Ten for the excellent organization of ICOTOM 17 and the very pleasant collaboration. On the first day of the conference three tutorials have been offered. Each of them has been attended by about 30 participants. 1. Texture-aided residual stress identification system (TARSIuS) (organized by Prof. Dr. J. Bonarski and Mr. B. Kania) 2. MTEX - MATLAB toolbox for quantitative texture analysis (organized by Dr. R. Hielscher and Mr. F. Bachmann) 3. Grain boundary engineering (organized by Prof. N. Bozzolo and Prof. Dr. A.D. Rollett) A highlight of ICOTOM 17 was the ceremony honoring Prof. Dr. Claude Esling with the Bunge Award for his distinguished contributions to the field of Textures of Materials and his continuous effort to pass on his knowledge to future generations of texture experts. The Bunge Award is named after Professor Hans Bunge († 2004), to whom the world's texture community is very much indebted not only for his magisterial work on the Mathematical Theory of Texture, but also for his lifelong promotion of the field of Textures of Materials. To the great delight of all participants, Helga Bunge and her son Prof. Hans-Peter Bunge, to whom many of the older generation have a personal relationship, attended the ceremony (see Fig. 1 in the PDF). Following the award ceremony Prof. Dr. Claude Esling gave an in memoriam tribute to Prof. Dr. Richard Penelle, who was an internationally recognized texture specialist. Details can be found in the proceedings paper by Esling et al. [this issue]. During the conference the International ICSMA Committee decided to convene the next conference in St. George, USA, in 2017. We wish the organizers of ICOTOM 18 great success and look forward to meeting you in St. George. Werner Skrotzki* (Chairman of ICOTOM 17, Dresden University of Technology) Carl-Georg Oertel (Dresden University of Technology) Guest Editors Dresden, March, 2015 (* Corresponding author; e-mail address: werner.skrotzki@tu-dresden.de)
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NASA Astrophysics Data System (ADS)
Daye, Dania; Bobo, Ezra; Baumann, Bethany; Ioannou, Antonios; Conant, Emily F.; Maidment, Andrew D. A.; Kontos, Despina
2011-03-01
Mammographic parenchymal texture patterns have been shown to be related to breast cancer risk. Yet, little is known about the biological basis underlying this association. Here, we investigate the potential of mammographic parenchymal texture patterns as an inherent phenotypic imaging marker of endogenous hormonal exposure of the breast tissue. Digital mammographic (DM) images in the cranio-caudal (CC) view of the unaffected breast from 138 women diagnosed with unilateral breast cancer were retrospectively analyzed. Menopause status was used as a surrogate marker of endogenous hormonal activity. Retroareolar 2.5cm2 ROIs were segmented from the post-processed DM images using an automated algorithm. Parenchymal texture features of skewness, coarseness, contrast, energy, homogeneity, grey-level spatial correlation, and fractal dimension were computed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate feature classification performance in distinguishing between 72 pre- and 66 post-menopausal women. Logistic regression was performed to assess the independent effect of each texture feature in predicting menopause status. ROC analysis showed that texture features have inherent capacity to distinguish between pre- and post-menopausal statuses (AUC>0.5, p<0.05). Logistic regression including all texture features yielded an ROC curve with an AUC of 0.76. Addition of age at menarche, ethnicity, contraception use and hormonal replacement therapy (HRT) use lead to a modest model improvement (AUC=0.78) while texture features maintained significant contribution (p<0.05). The observed differences in parenchymal texture features between pre- and post- menopausal women suggest that mammographic texture can potentially serve as a surrogate imaging marker of endogenous hormonal activity.
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Modelling patterns of pollinator species richness and diversity using satellite image texture.
Hofmann, Sylvia; Everaars, Jeroen; Schweiger, Oliver; Frenzel, Mark; Bannehr, Lutz; Cord, Anna F
2017-01-01
Assessing species richness and diversity on the basis of standardised field sampling effort represents a cost- and time-consuming method. Satellite remote sensing (RS) can help overcome these limitations because it facilitates the collection of larger amounts of spatial data using cost-effective techniques. RS information is hence increasingly analysed to model biodiversity across space and time. Here, we focus on image texture measures as a proxy for spatial habitat heterogeneity, which has been recognized as an important determinant of species distributions and diversity. Using bee monitoring data of four years (2010-2013) from six 4 × 4 km field sites across Central Germany and a multimodel inference approach we test the ability of texture features derived from Landsat-TM imagery to model local pollinator biodiversity. Textures were shown to reflect patterns of bee diversity and species richness to some extent, with the first-order entropy texture and terrain roughness being the most relevant indicators. However, the texture measurements accounted for only 3-5% of up to 60% of the variability that was explained by our final models, although the results are largely consistent across different species groups (bumble bees, solitary bees). While our findings provide indications in support of the applicability of satellite imagery textures for modeling patterns of bee biodiversity, they are inconsistent with the high predictive power of texture metrics reported in previous studies for avian biodiversity. We assume that our texture data captured mainly heterogeneity resulting from landscape configuration, which might be functionally less important for wild bees than compositional diversity of plant communities. Our study also highlights the substantial variability among taxa in the applicability of texture metrics for modelling biodiversity.
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Can we trust the calculation of texture indices of CT images? A phantom study.
Caramella, Caroline; Allorant, Adrien; Orlhac, Fanny; Bidault, Francois; Asselain, Bernard; Ammari, Samy; Jaranowski, Patricia; Moussier, Aurelie; Balleyguier, Corinne; Lassau, Nathalie; Pitre-Champagnat, Stephanie
2018-04-01
Texture analysis is an emerging tool in the field of medical imaging analysis. However, many issues have been raised in terms of its use in assessing patient images and it is crucial to harmonize and standardize this new imaging measurement tool. This study was designed to evaluate the reliability of texture indices of CT images on a phantom including a reproducibility study, to assess the discriminatory capacity of indices potentially relevant in CT medical images and to determine their redundancy. For the reproducibility and discriminatory analysis, eight identical CT acquisitions were performed on a phantom including one homogeneous insert and two close heterogeneous inserts. Texture indices were selected for their high reproducibility and capability of discriminating different textures. For the redundancy analysis, 39 acquisitions of the same phantom were performed using varying acquisition parameters and a correlation matrix was used to explore the 2 × 2 relationships. LIFEx software was used to explore 34 different parameters including first order and texture indices. Only eight indices of 34 exhibited high reproducibility and discriminated textures from each other. Skewness and kurtosis from histogram were independent from the six other indices but were intercorrelated, the other six indices correlated in diverse degrees (entropy, dissimilarity, and contrast of the co-occurrence matrix, contrast of the Neighborhood Gray Level difference matrix, SZE, ZLNU of the Gray-Level Size Zone Matrix). Care should be taken when using texture analysis as a tool to characterize CT images because changes in quantitation may be primarily due to internal variability rather than from real physio-pathological effects. Some textural indices appear to be sufficiently reliable and capable to discriminate close textures on CT images. © 2018 American Association of Physicists in Medicine.
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Modelling patterns of pollinator species richness and diversity using satellite image texture
Everaars, Jeroen; Schweiger, Oliver; Frenzel, Mark; Bannehr, Lutz; Cord, Anna F.
2017-01-01
Assessing species richness and diversity on the basis of standardised field sampling effort represents a cost- and time-consuming method. Satellite remote sensing (RS) can help overcome these limitations because it facilitates the collection of larger amounts of spatial data using cost-effective techniques. RS information is hence increasingly analysed to model biodiversity across space and time. Here, we focus on image texture measures as a proxy for spatial habitat heterogeneity, which has been recognized as an important determinant of species distributions and diversity. Using bee monitoring data of four years (2010–2013) from six 4 × 4 km field sites across Central Germany and a multimodel inference approach we test the ability of texture features derived from Landsat-TM imagery to model local pollinator biodiversity. Textures were shown to reflect patterns of bee diversity and species richness to some extent, with the first-order entropy texture and terrain roughness being the most relevant indicators. However, the texture measurements accounted for only 3–5% of up to 60% of the variability that was explained by our final models, although the results are largely consistent across different species groups (bumble bees, solitary bees). While our findings provide indications in support of the applicability of satellite imagery textures for modeling patterns of bee biodiversity, they are inconsistent with the high predictive power of texture metrics reported in previous studies for avian biodiversity. We assume that our texture data captured mainly heterogeneity resulting from landscape configuration, which might be functionally less important for wild bees than compositional diversity of plant communities. Our study also highlights the substantial variability among taxa in the applicability of texture metrics for modelling biodiversity. PMID:28973006
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Mammographic phenotypes of breast cancer risk driven by breast anatomy
NASA Astrophysics Data System (ADS)
Gastounioti, Aimilia; Oustimov, Andrew; Hsieh, Meng-Kang; Pantalone, Lauren; Conant, Emily F.; Kontos, Despina
2017-03-01
Image-derived features of breast parenchymal texture patterns have emerged as promising risk factors for breast cancer, paving the way towards personalized recommendations regarding women's cancer risk evaluation and screening. The main steps to extract texture features of the breast parenchyma are the selection of regions of interest (ROIs) where texture analysis is performed, the texture feature calculation and the texture feature summarization in case of multiple ROIs. In this study, we incorporate breast anatomy in these three key steps by (a) introducing breast anatomical sampling for the definition of ROIs, (b) texture feature calculation aligned with the structure of the breast and (c) weighted texture feature summarization considering the spatial position and the underlying tissue composition of each ROI. We systematically optimize this novel framework for parenchymal tissue characterization in a case-control study with digital mammograms from 424 women. We also compare the proposed approach with a conventional methodology, not considering breast anatomy, recently shown to enhance the case-control discriminatory capacity of parenchymal texture analysis. The case-control classification performance is assessed using elastic-net regression with 5-fold cross validation, where the evaluation measure is the area under the curve (AUC) of the receiver operating characteristic. Upon optimization, the proposed breast-anatomy-driven approach demonstrated a promising case-control classification performance (AUC=0.87). In the same dataset, the performance of conventional texture characterization was found to be significantly lower (AUC=0.80, DeLong's test p-value<0.05). Our results suggest that breast anatomy may further leverage the associations of parenchymal texture features with breast cancer, and may therefore be a valuable addition in pipelines aiming to elucidate quantitative mammographic phenotypes of breast cancer risk.
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Yoon, Hai-Jeon; Kim, Yemi; Chung, Jin; Kim, Bom Sahn
2018-03-30
Predicting response to neo-adjuvant chemotherapy (NAC) and survival in locally advanced breast cancer (LABC) is important. This study investigated the prognostic value of tumor heterogeneity evaluated with textural analysis through F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and diffusion-weighted imaging (DWI). We enrolled 83 patients with LABC who had completed NAC and curative surgery. Tumor texture indices from pretreatment FDG PET and DWI were extracted from histogram analysis and 7 different parent matrices: co-occurrence matrix, the voxel-alignment matrix, neighborhood intensity difference matrix, intensity size-zone matrix (ISZM), normalized gray-level co-occurrence matrix (NGLCM), neighboring gray-level dependence matrix (NGLDM), and texture spectrum matrix. The predictive values of textural features were tested regarding both pathologic NAC response and progression-free survival. Among 83 patients, 46 were pathologic responders, while 37 were nonresponders. The PET texture indices from 7 parent matrices, DWI texture indices from histogram, and 1 parent matrix (NGLCM) showed significant differences according to NAC response. On multivariable analysis, number nonuniformity of PET extracted from the NGLDM was an independent predictor of pathologic response (P = .009). During a median follow-up period of 17.3 months, 14 patients experienced recurrence. High-intensity zone emphasis (HIZE) and high-intensity short-zone emphasis (HISZE) from PET extracted from ISZM were significant textural predictors (P = .011 and P = .033). On Cox regression analysis, only HIZE was a significant predictor of recurrence (P = .027), while HISZE showed borderline significance (P = .107). Tumor texture indices are useful for NAC response prediction in LABC. Moreover, PET texture indices can help to predict disease recurrence. © 2018 Wiley Periodicals, Inc.
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Shaler: in situ analysis of a fluvial sedimentary deposit on Mars
DOE Office of Scientific and Technical Information (OSTI.GOV)
Edgar, Lauren A.; Gupta, Sanjeev; Rubin, David M.
This article characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground-based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars Science Laboratory Curiosity rover provide an opportunity to reconstruct at fine scale the sedimentary architecture and palaeomorphology of a fluvial environment on Mars. This work describes the grain size, texture and sedimentary facies of the Shaler outcrop, reconstructs the bedding architecture, and analyses cross-stratification tomore » determine palaeocurrents. On the basis of bedset geometry and inclination, grain-size distribution and bedform migration direction, this study concludes that the Shaler outcrop probably records the accretion of a fluvial barform. The majority of the outcrop consists of large-scale trough cross-bedding of coarse sand and granules. Palaeocurrent analyses and bedform reconstruction indicate that the beds were deposited by bedforms that migrated towards the north-east, across the surface of a bar that migrated south-east. Stacked cosets of dune cross-bedding suggest aggradation of multiple bedforms, which provides evidence for short periods of sustained flow during Shaler deposition. However, local evidence for aeolian reworking and the presence of potential desiccation cracks within the outcrop suggest that fluvial deposition may have been intermittent. The uppermost strata at Shaler are distinct in terms of texture and chemistry and are inferred to record deposition from a different sediment dispersal system with a contrasting provenance. The outcrop as a whole is a testament to the availability of liquid water on the surface of Mars in its early history.« less
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NASA Astrophysics Data System (ADS)
Cottle, John M.; Larson, Kyle P.; Yakymchuk, Chris
2018-07-01
Medium-grained leucogranite in the Tama Kosi region of the Nepalese Himalayan Metamorphic Core yields a relatively narrow range of monazite 208Pb/232Th dates with a dominant population at 21.0 Ma inferred to represent crystallization of an early plutonic phase. In contrast, the pegmatitic portion of the same intrusive complex, that cross-cuts the medium-grained leucogranite, contains zircon, monazite and xenotime that each display near-identical age spectra, recording semi-continuous (re-)crystallization from 27.5 Ma to 21.0 Ma, followed by a 2 m.y. hiatus then further (re-)crystallization between 19.4 and 18.6 Ma. The "gap" in pegmatite dates corresponds well to the crystallization age of the older leucogranite, whereas the end of accessory phase growth in the pegmatite coincides with the onset of regional-scale cooling. Detailed textural, trace element and thermochronologic data indicate that the range of zircon, monazite and xenotime dates recorded in the pegmatite reflect inherited components that underwent semi-continuous (re-)crystallization during metamorphism and/or anatexis in the source region(s), whereas dates younger than the hiatus indicate accessory phase recrystallization, related to both fluid influx and a concomitant increase in temperature. In contrast, the lack of an inherited component(s) in the medium-grained leucogranite phase is inferred to be a result of complete dissolution during partial melting. A model is proposed in which influx of heat and H2O-rich fluids associated with early leucogranite emplacement temporarily delayed zircon and monazite and xenotime crystallization, respectively. These data highlight the importance of measuring spatially resolved dates, trace elements and textural patterns from multiple accessory minerals combined with model constraints to better understand the often-complex crystallization history of anatectic melts in collisional orogens.
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Shaler: in situ analysis of a fluvial sedimentary deposit on Mars
Edgar, Lauren; Gupta, Sanjeev; Rubin, David M.; Lewis, Kevin W.; Kocurek, Gary A.; Anderson, Ryan; Bell, James F.; Dromart, Gilles; Edgett, Kenneth S.; Grotzinger, John P.; Hardgrove, Craig; Kah, Linda C.; LeVeille, Richard A.; Malin, Michael C.; Mangold, Nicholas; Milliken, Ralph E.; Minitti, Michelle; Palucis, Marisa C.; Rice, Melissa; Rowland, Scott K.; Schieber, Juergen; Stack, Kathryn M.; Sumner, Dawn Y.; Wiens, Roger C.; Williams, Rebecca M.E.; Williams, Amy J.
2018-01-01
This paper characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time, and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground-based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars Science Laboratory Curiosity rover provide an opportunity to reconstruct at fine scale the sedimentary architecture and palaeomorphology of a fluvial environment on Mars. This work describes the grain size, texture, and sedimentary facies of the Shaler outcrop, reconstructs the bedding architecture, and analyses cross-stratification to determine palaeocurrents. On the basis of bedset geometry and inclination, grain-size distribution, and bedform migration direction, this study concludes that the Shaler outcrop likely records the accretion of a fluvial barform. The majority of the outcrop consists of large-scale trough cross-bedding of coarse sand and granules. Palaeocurrent analyses and bedform reconstruction indicate that the beds were deposited by bedforms that migrated towards the northeast, across the surface of a bar that migrated southeast. Stacked cosets of dune cross-bedding suggest aggradation of multiple bedforms, which provides evidence for short periods of sustained flow during Shaler deposition. However, local evidence for aeolian reworking and the presence of potential desiccation cracks within the outcrop suggests that fluvial deposition may have been intermittent. The uppermost strata at Shaler are distinct in terms of texture and chemistry, and are inferred to record deposition from a different sediment dispersal system with a contrasting provenance. The outcrop as a whole is a testament to the availability of liquid water on the surface of Mars in its early history.
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Shaler: in situ analysis of a fluvial sedimentary deposit on Mars
Edgar, Lauren A.; Gupta, Sanjeev; Rubin, David M.; ...
2017-03-09
This article characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground-based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars Science Laboratory Curiosity rover provide an opportunity to reconstruct at fine scale the sedimentary architecture and palaeomorphology of a fluvial environment on Mars. This work describes the grain size, texture and sedimentary facies of the Shaler outcrop, reconstructs the bedding architecture, and analyses cross-stratification tomore » determine palaeocurrents. On the basis of bedset geometry and inclination, grain-size distribution and bedform migration direction, this study concludes that the Shaler outcrop probably records the accretion of a fluvial barform. The majority of the outcrop consists of large-scale trough cross-bedding of coarse sand and granules. Palaeocurrent analyses and bedform reconstruction indicate that the beds were deposited by bedforms that migrated towards the north-east, across the surface of a bar that migrated south-east. Stacked cosets of dune cross-bedding suggest aggradation of multiple bedforms, which provides evidence for short periods of sustained flow during Shaler deposition. However, local evidence for aeolian reworking and the presence of potential desiccation cracks within the outcrop suggest that fluvial deposition may have been intermittent. The uppermost strata at Shaler are distinct in terms of texture and chemistry and are inferred to record deposition from a different sediment dispersal system with a contrasting provenance. The outcrop as a whole is a testament to the availability of liquid water on the surface of Mars in its early history.« less
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Salinas-Hernández, Rosa María; González-Aguilar, Gustavo A; Tiznado-Hernández, Martín Ernesto
2015-01-01
Sensory evaluation is the ideal tool for shelf-life determination. With the objective to develop an easy shelf-life indicator, color (L*, a*, b*, chroma and hue angle), total soluble solids (TSS), firmness (F), pH, acidity, and the sensory attributes of appearance, brightness, browning, odor, flavor, texture, color, acidity and sweetness were evaluated in fresh cut mangoes (FCM) stored at 5, 10, 15 and 20 °C. Overall acceptability was evaluated by consumers. Correlation analysis between sensory attributes and physicochemical variables was carried out. Physicochemical cut-off points based on sensory attributes and consumer acceptability was obtained by regression analysis and utilized to estimate FCM shelf-life by kinetic models fitted to each variable. The validation of the model was done by comparing the shelf life estimated by kinetic models and consumers. It was recorded large correlations between appearance, brightness, and color with L*; appearance and color with chroma and hue angle; sweetness and flavor with TSS, and between F and texture. The shelf life estimated based on consumer using a 9 point hedonic scale was in the range of 10-12, 2.3-2.6, 1.3-1.5 and 1.0-1.1 days for 5, 10, 15 and 20 °C. It was recorded large correlation coefficients between the shelf life estimated by consumer acceptability scores and physicochemical variables. Kinetic models based on physicochemical variables showed a tendency to overestimate the shelf life as compared with the models bases on the sensory attributes. It was concluded that physicochemical variables can be used as a tool to estimate the FCM shelf life.
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7 CFR 51.636 - Smooth texture.
Code of Federal Regulations, 2010 CFR
2010-01-01
... FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States...) Definitions § 51.636 Smooth texture. Smooth texture means that the skin is thin and smooth for the variety and...
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7 CFR 51.1162 - Fairly smooth texture.
Code of Federal Regulations, 2010 CFR
2010-01-01
... MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND... smooth texture. Fairly smooth texture means that the skin is fairly thin and not coarse for the variety...
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7 CFR 51.698 - Smooth texture.
Code of Federal Regulations, 2010 CFR
2010-01-01
... FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States... § 51.698 Smooth texture. Smooth texture means that the skin is thin and smooth for the variety and size...
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7 CFR 51.776 - Slightly rough texture.
Code of Federal Regulations, 2014 CFR
2014-01-01
... Definitions § 51.776 Slightly rough texture. Slightly rough texture means that the skin may be slightly thick but not excessively thick, materially ridged or grooved. “Slightly thick” means that the skin...
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7 CFR 51.776 - Slightly rough texture.
Code of Federal Regulations, 2013 CFR
2013-01-01
... Definitions § 51.776 Slightly rough texture. Slightly rough texture means that the skin may be slightly thick but not excessively thick, materially ridged or grooved. “Slightly thick” means that the skin...
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Optical and electrical properties of ion beam textured Kapton and Teflon
NASA Technical Reports Server (NTRS)
Mirtich, M. J.; Sovey, J. S.
1977-01-01
Results are given for ion beam texturing of polyimide (Kapton) and fluorinated ethylene propylene (Teflon) by means of a 30-cm diam electron bombardment argon ion source. Ion beam-textured Kapton and Teflon surfaces are evaluated for various beam energies, current densities, and exposure times. The optical properties and sheet resistance are measured after each exposure. Provided in the paper are optical spectral data, resistivity measurements, calculated absorptance and emittance measurements, and surface structure SEM micrographs for various exposures to argon ions. It is found that Kapton becomes conducting and Teflon nonconducting when ion beam-textured. Textured Kapton exhibits large changes in the transmittance and solar absorptance, but only slight changes in reflectance. Surface texturing of Teflon may allow better adherence of subsequent sputtered metallic films for a high absorptance value. The results are valuable in spacecraft charging applications.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, T. K.; Wu, Z.; Stoica, A. D.
The cryogenic plastic deformation of CrCoFeMnNi high entropy alloy is characterized by three distinct stages based on the change of the work hardening rate. Microstructure and bulk texture at different strain levels were studied by electron backscatter diffraction (EBSD) and neutron diffraction. Our findings indicate that the deformation twins led to the constant work hardening rate at Stage II and resulted in the appearance of <115 >//TA texture component, while the dislocation slip was involved all though the entire plastic deformation. As a result, the twinning-mediated tensile plastic deformation at cryogenic temperature finally induced the strong {111}- < 112 >more » texture component and minor {001} < 110 > texture component accompanied with twinning-induced {115}< 552 > texture component.« less
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Liu, T. K.; Wu, Z.; Stoica, A. D.; ...
2017-06-17
The cryogenic plastic deformation of CrCoFeMnNi high entropy alloy is characterized by three distinct stages based on the change of the work hardening rate. Microstructure and bulk texture at different strain levels were studied by electron backscatter diffraction (EBSD) and neutron diffraction. Our findings indicate that the deformation twins led to the constant work hardening rate at Stage II and resulted in the appearance of <115 >//TA texture component, while the dislocation slip was involved all though the entire plastic deformation. As a result, the twinning-mediated tensile plastic deformation at cryogenic temperature finally induced the strong {111}- < 112 >more » texture component and minor {001} < 110 > texture component accompanied with twinning-induced {115}< 552 > texture component.« less
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Visualization and Quantitative Analysis of Crack-Tip Plastic Zone in Pure Nickel
NASA Astrophysics Data System (ADS)
Kelton, Randall; Sola, Jalal Fathi; Meletis, Efstathios I.; Huang, Haiying
2018-05-01
Changes in surface morphology have long been thought to be associated with crack propagation in metallic materials. We have studied areal surface texture changes around crack tips in an attempt to understand the correlations between surface texture changes and crack growth behavior. Detailed profiling of the fatigue sample surface was carried out at short fatigue intervals. An image processing algorithm was developed to calculate the surface texture changes. Quantitative analysis of the crack-tip plastic zone, crack-arrested sites near triple points, and large surface texture changes associated with crack release from arrested locations was carried out. The results indicate that surface texture imaging enables visualization of the development of plastic deformation around a crack tip. Quantitative analysis of the surface texture changes reveals the effects of local microstructures on the crack growth behavior.
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Adaptive Texture Synthesis for Large Scale City Modeling
NASA Astrophysics Data System (ADS)
Despine, G.; Colleu, T.
2015-02-01
Large scale city models textured with aerial images are well suited for bird-eye navigation but generally the image resolution does not allow pedestrian navigation. One solution to face this problem is to use high resolution terrestrial photos but it requires huge amount of manual work to remove occlusions. Another solution is to synthesize generic textures with a set of procedural rules and elementary patterns like bricks, roof tiles, doors and windows. This solution may give realistic textures but with no correlation to the ground truth. Instead of using pure procedural modelling we present a method to extract information from aerial images and adapt the texture synthesis to each building. We describe a workflow allowing the user to drive the information extraction and to select the appropriate texture patterns. We also emphasize the importance to organize the knowledge about elementary pattern in a texture catalogue allowing attaching physical information, semantic attributes and to execute selection requests. Roofs are processed according to the detected building material. Façades are first described in terms of principal colours, then opening positions are detected and some window features are computed. These features allow selecting the most appropriate patterns from the texture catalogue. We experimented this workflow on two samples with 20 cm and 5 cm resolution images. The roof texture synthesis and opening detection were successfully conducted on hundreds of buildings. The window characterization is still sensitive to the distortions inherent to the projection of aerial images onto the facades.
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Efficient rolling texture predictions and texture-sensitive properties of α-uranium foils
Steiner, Matthew A.; Klein, Robert W.; Calhoun, Christopher A.; ...
2017-01-01
Here, finite element (FE) analysis was used to simulate the strain history of an α-uranium foil during cold-rolling, with the sheet modeled as an isotropic elastoplastic continuum. The resulting strain history was then used as input for a viscoplastic self-consistent (VPSC) polycrystal plasticity model to simulate crystallographic texture evolution. Mid-plane textures predicted via the combined FE→VPSC approach show alignment of the (010) poles along the rolling direction (RD), and the (001) poles along the normal direction (ND) with a symmetric splitting along RD. The surface texture is similar to that of the mid-plane, but with a shear-induced asymmetry that favorsmore » one of the RD split features of the (001) pole figure. Both the mid-plane and surface textures predicted by the FE→VPSC approach agree with published experimental results for cold-rolled α-uranium plates, as well as predictions made by a more computationally intensive full-field crystal plasticity based finite element model. α-uranium foils produced by cold-rolling must typically undergo a final recrystallization anneal to restore ductility prior to their final application, resulting in significant texture evolution from the cold-rolled plate deformation texture. Using the texture measured from a foil in the final recrystallized state, coefficients of the thermal expansion and elastic stiffness tensors were calculated using a thermo-elastic self-consistent model, and the anisotropic yield loci and flow curves along the RD, TD, and ND were predicted using the VPSC code.« less
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Efficient rolling texture predictions and texture-sensitive properties of α-uranium foils
DOE Office of Scientific and Technical Information (OSTI.GOV)
Steiner, Matthew A.; Klein, Robert W.; Calhoun, Christopher A.
Here, finite element (FE) analysis was used to simulate the strain history of an α-uranium foil during cold-rolling, with the sheet modeled as an isotropic elastoplastic continuum. The resulting strain history was then used as input for a viscoplastic self-consistent (VPSC) polycrystal plasticity model to simulate crystallographic texture evolution. Mid-plane textures predicted via the combined FE→VPSC approach show alignment of the (010) poles along the rolling direction (RD), and the (001) poles along the normal direction (ND) with a symmetric splitting along RD. The surface texture is similar to that of the mid-plane, but with a shear-induced asymmetry that favorsmore » one of the RD split features of the (001) pole figure. Both the mid-plane and surface textures predicted by the FE→VPSC approach agree with published experimental results for cold-rolled α-uranium plates, as well as predictions made by a more computationally intensive full-field crystal plasticity based finite element model. α-uranium foils produced by cold-rolling must typically undergo a final recrystallization anneal to restore ductility prior to their final application, resulting in significant texture evolution from the cold-rolled plate deformation texture. Using the texture measured from a foil in the final recrystallized state, coefficients of the thermal expansion and elastic stiffness tensors were calculated using a thermo-elastic self-consistent model, and the anisotropic yield loci and flow curves along the RD, TD, and ND were predicted using the VPSC code.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Feng, Yan, E-mail: yanfeng@nwpu.edu.cn
Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} magnetic shape memory alloy was successfully produced as preferentially textured ribbon by melting spinning with different wheel speed. X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) were used to study structure and texture evolution of these melt-spun ribbons. The thickness of melt-spun ribbon is 42 μm, 65 μm and 30 μm depending on wheel speed of 1 0 m/s, 15 m/s and 20 m/s, respectively. Density of α fiber texture (〈100〉//ND) vary with wheel speed changes, and is most intensive in the ribbon with wheel speed of 15 m/s. Grains of the ribbons growmore » after being annealed at 873 K, 973 K, 1073 K and 1173 K, recrystallization was not observed in ribbons after being annealed at 873 K but occurred in ribbons after being annealed at higher temperatures. The α fiber texture becomes weaker to some extent after annealing at different temperatures, due to new recrystallization texture formed at the process of annealing. - Highlights: •Sectional part of shape memory ribbon is firstly investigated by EBSD method. •Thickness and texture of ribbons vary with wheel speed. •Annealing temperature affect texture and microstructure evolution greatly. •Recrystallization textures were observed in ribbons after being annealed.« less
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NASA Astrophysics Data System (ADS)
Mariethoz, Gregoire; Lefebvre, Sylvain
2014-05-01
Multiple-Point Simulations (MPS) is a family of geostatistical tools that has received a lot of attention in recent years for the characterization of spatial phenomena in geosciences. It relies on the definition of training images to represent a given type of spatial variability, or texture. We show that the algorithmic tools used are similar in many ways to techniques developed in computer graphics, where there is a need to generate large amounts of realistic textures for applications such as video games and animated movies. Similarly to MPS, these texture synthesis methods use training images, or exemplars, to generate realistic-looking graphical textures. Both domains of multiple-point geostatistics and example-based texture synthesis present similarities in their historic development and share similar concepts. These disciplines have however remained separated, and as a result significant algorithmic innovations in each discipline have not been universally adopted. Texture synthesis algorithms present drastically increased computational efficiency, patterns reproduction and user control. At the same time, MPS developed ways to condition models to spatial data and to produce 3D stochastic realizations, which have not been thoroughly investigated in the field of texture synthesis. In this paper we review the possible links between these disciplines and show the potential and limitations of using concepts and approaches from texture synthesis in MPS. We also provide guidelines on how recent developments could benefit both fields of research, and what challenges remain open.
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Pérez-Beteta, Julián; Martínez-González, Alicia; Martino, Juan; Velasquez, Carlos; Arana, Estanislao; Pérez-García, Víctor M.
2017-01-01
Purpose Textural measures have been widely explored as imaging biomarkers in cancer. However, their robustness under dynamic range and spatial resolution changes in brain 3D magnetic resonance images (MRI) has not been assessed. The aim of this work was to study potential variations of textural measures due to changes in MRI protocols. Materials and methods Twenty patients harboring glioblastoma with pretreatment 3D T1-weighted MRIs were included in the study. Four different spatial resolution combinations and three dynamic ranges were studied for each patient. Sixteen three-dimensional textural heterogeneity measures were computed for each patient and configuration including co-occurrence matrices (CM) features and run-length matrices (RLM) features. The coefficient of variation was used to assess the robustness of the measures in two series of experiments corresponding to (i) changing the dynamic range and (ii) changing the matrix size. Results No textural measures were robust under dynamic range changes. Entropy was the only textural feature robust under spatial resolution changes (coefficient of variation under 10% in all cases). Conclusion Textural measures of three-dimensional brain tumor images are not robust neither under dynamic range nor under matrix size changes. Standards should be harmonized to use textural features as imaging biomarkers in radiomic-based studies. The implications of this work go beyond the specific tumor type studied here and pose the need for standardization in textural feature calculation of oncological images. PMID:28586353
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Karacavus, Seyhan; Yılmaz, Bülent; Tasdemir, Arzu; Kayaaltı, Ömer; Kaya, Eser; İçer, Semra; Ayyıldız, Oguzhan
2018-04-01
We investigated the association between the textural features obtained from 18 F-FDG images, metabolic parameters (SUVmax , SUVmean, MTV, TLG), and tumor histopathological characteristics (stage and Ki-67 proliferation index) in non-small cell lung cancer (NSCLC). The FDG-PET images of 67 patients with NSCLC were evaluated. MATLAB technical computing language was employed in the extraction of 137 features by using first order statistics (FOS), gray-level co-occurrence matrix (GLCM), gray-level run length matrix (GLRLM), and Laws' texture filters. Textural features and metabolic parameters were statistically analyzed in terms of good discrimination power between tumor stages, and selected features/parameters were used in the automatic classification by k-nearest neighbors (k-NN) and support vector machines (SVM). We showed that one textural feature (gray-level nonuniformity, GLN) obtained using GLRLM approach and nine textural features using Laws' approach were successful in discriminating all tumor stages, unlike metabolic parameters. There were significant correlations between Ki-67 index and some of the textural features computed using Laws' method (r = 0.6, p = 0.013). In terms of automatic classification of tumor stage, the accuracy was approximately 84% with k-NN classifier (k = 3) and SVM, using selected five features. Texture analysis of FDG-PET images has a potential to be an objective tool to assess tumor histopathological characteristics. The textural features obtained using Laws' approach could be useful in the discrimination of tumor stage.
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Cooking Methods for a Soft Diet Using Chicken Based on Food Texture Analysis.
Watanabe, Emi; Maeno, Masami; Kayashita, Jun; Miyamoto, Ken-Ichi; Kogirima, Miho
2017-01-01
Undernutrition caused by difficulties in masticating is of growing concern among the elderly. Soft diets are often served at nursing homes; however, the styles differ with nursing homes. Improperly modified food texture and consistency may lead to further loss of nutritive value. Therefore, we developed a method to produce a soft diet using chicken. The texture-modified chicken was prepared by boiling a mixture of minced chicken and additive foodstuff that softened the meat. The best food additive was determined through testing cooking process, size after modification and texture. The optimum proportions of each component in the mixture were determined measuring food texture using a creep meter. Teriyaki chicken was cooked using the texture-modified chicken, and provided to a nursing home. The amount of food intake by elderly residents was subsequently surveyed. This study involved 22 residents (1 man and 21 women; mean age 91.4±5.3 y). Consequently, yakifu, which was made from wheat gluten, was the most suitable additive foodstuff. The hardness of the texture-modified chicken, with proportions of minced chicken, yakifu, and water being 50%, 10%, and 40% respectively, was under 40,000 N/m 2 . The intake amount of the texture-modified chicken of subjects whose intake amount of conventional chicken using chicken thigh was not 100% was significantly higher. These findings suggest that properly modified food textures could contribute to improve the quality of meals by preventing undernutrition among the elderly with mastication difficulties.
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Lee, Scott J; Zea, Ryan; Kim, David H; Lubner, Meghan G; Deming, Dustin A; Pickhardt, Perry J
2018-04-01
To determine if identifiable hepatic textural features are present at abdominal CT in patients with colorectal cancer (CRC) prior to the development of CT-detectable hepatic metastases. Four filtration-histogram texture features (standard deviation, skewness, entropy and kurtosis) were extracted from the liver parenchyma on portal venous phase CT images at staging and post-treatment surveillance. Surveillance scans corresponded to the last scan prior to the development of CT-detectable CRC liver metastases in 29 patients (median time interval, 6 months), and these were compared with interval-matched surveillance scans in 60 CRC patients who did not develop liver metastases. Predictive models of liver metastasis-free survival and overall survival were built using regularised Cox proportional hazards regression. Texture features did not significantly differ between cases and controls. For Cox models using all features as predictors, all coefficients were shrunk to zero, suggesting no association between any CT texture features and outcomes. Prognostic indices derived from entropy features at surveillance CT incorrectly classified patients into risk groups for future liver metastases (p < 0.001). On surveillance CT scans immediately prior to the development of CRC liver metastases, we found no evidence suggesting that changes in identifiable hepatic texture features were predictive of their development. • No correlation between liver texture features and metastasis-free survival was observed. • Liver texture features incorrectly classified patients into risk groups for liver metastases. • Standardised texture analysis workflows need to be developed to improve research reproducibility.
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NASA Astrophysics Data System (ADS)
Steiner, Matthew A.; Klein, Robert W.; Calhoun, Christopher A.; Knezevic, Marko; Garlea, Elena; Agnew, Sean R.
2017-11-01
Finite element (FE) analysis was used to simulate the strain history of an α-uranium foil during cold straight-rolling, with the sheet modeled as an isotropic elastoplastic continuum. The resulting strain history was then used as input for a viscoplastic self-consistent (VPSC) polycrystal plasticity model to simulate crystallographic texture evolution. Mid-plane textures predicted via the combined FE→VPSC approach show alignment of the (010) poles along the rolling direction (RD), and the (001) poles along the normal direction (ND) with a symmetric splitting along RD. The surface texture is similar to that of the mid-plane, but with a shear-induced asymmetry that favors one of the RD split features of the (001) pole figure. Both the mid-plane and surface textures predicted by the FE→VPSC approach agree with published experimental results for cold straight-rolled α-uranium plates, as well as predictions made by a more computationally intensive full-field crystal plasticity based finite element model. α-uranium foils produced by cold-rolling must typically undergo a recrystallization anneal to restore ductility prior to their final application, resulting in significant texture evolution from the cold-rolled plate deformation texture. Using the texture measured from a foil in the final recrystallized state, coefficients of thermal expansion and the elastic stiffness tensors were calculated using a thermo-elastic self-consistent model, and the anisotropic yield loci and flow curves along the RD, TD, and ND were predicted using the VPSC code.
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Agner, Shannon C; Soman, Salil; Libfeld, Edward; McDonald, Margie; Thomas, Kathleen; Englander, Sarah; Rosen, Mark A; Chin, Deanna; Nosher, John; Madabhushi, Anant
2011-06-01
Dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) of the breast has emerged as an adjunct imaging tool to conventional X-ray mammography due to its high detection sensitivity. Despite the increasing use of breast DCE-MRI, specificity in distinguishing malignant from benign breast lesions is low, and interobserver variability in lesion classification is high. The novel contribution of this paper is in the definition of a new DCE-MRI descriptor that we call textural kinetics, which attempts to capture spatiotemporal changes in breast lesion texture in order to distinguish malignant from benign lesions. We qualitatively and quantitatively demonstrated on 41 breast DCE-MRI studies that textural kinetic features outperform signal intensity kinetics and lesion morphology features in distinguishing benign from malignant lesions. A probabilistic boosting tree (PBT) classifier in conjunction with textural kinetic descriptors yielded an accuracy of 90%, sensitivity of 95%, specificity of 82%, and an area under the curve (AUC) of 0.92. Graph embedding, used for qualitative visualization of a low-dimensional representation of the data, showed the best separation between benign and malignant lesions when using textural kinetic features. The PBT classifier results and trends were also corroborated via a support vector machine classifier which showed that textural kinetic features outperformed the morphological, static texture, and signal intensity kinetics descriptors. When textural kinetic attributes were combined with morphologic descriptors, the resulting PBT classifier yielded 89% accuracy, 99% sensitivity, 76% specificity, and an AUC of 0.91.
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White and gray pumice in pyroclastic deposits. (Invited)
NASA Astrophysics Data System (ADS)
Wright, H. M.; Cashman, K. V.
2013-12-01
Many primary pyroclastic deposits contain at least two different colors of pumice, including volumetrically dominant white and subordinate gray. White pumice is vesicular, microlite-free, and in most cases represents direct samples of the principal magma reservoir. In contrast, subordinate gray pumice with lower vesicularity and/or more abundant microlites may sample either deep recharge OR shallow vanguard magma, where both may record information on eruption triggers. Pumice may appear gray for several reasons: 1. Gray pumice has a less-evolved bulk composition than white pumice. Presence of less-evolved (generally deep-derived) magma provides information about possible recharge magma and/or pre-eruptive compositional variation in the magma storage region. A well-known example of this difference is the 1912 eruption of Novarupta [Hildreth & Fierstein, 2012], which includes white (rhyolite) and gray (andesite and dacite) pumice. 2. Gray pumice contains elevated microlite number densities and/or microlite crystallinities and is compositionally similar to white pumice. a. Gray pumice contains abundant broken crystal fragments and lithic fragments. Broken crystals and incorporated white pumice indicate passage through the primary magma reservoir. Incorporated lithic fragments indicate breakage of wall rock and creation of new transport pathways. Microlites and breadcrusted surfaces indicate slow and/or episodic ascent at shallow levels. This textural association indicates that proto-gray pumice magma played an active role in creating a conduit to the surface. In some cases, small differences in chemistry may further indicate differences in magma batches (recharge pulses). This textural variation is found in the products of high-crystallinity large-volume (Plinian or boil-over style) eruptions, as in the Cerro Galan Ignimbrite, Argentina [Wright et al., 2011]. b. Gray pumice contains abundant microlites due to differences in decompression and/or cooling history. In this case, microlites indicate shallow degassing-induced crystallization, where proto-gray pumice forms vanguard magma or a shallow conduit plug. Gray pumice originating in a shallow conduit plug is common in Vulcanian and subPlinian silicic eruptions and is seen in the 1980 Plinian and subPlinian eruptions of Mount St. Helens [Klug & Cashman, 1994; Cashman & McConnell, 2005]. c. Gray pumice may record syn-eruptive changes in the magmatic system, often manifested as crystallization caused by either decompression or cooling [cf., Gurioli et al., 2005; Andrews & Gardner, 2010]. In summary, the compositional and textural complexities of gray pumice provide detail on pre- and syn-eruptive magmatic processes that may be impossible to obtain from (dominant) white pumice alone. Subtle compositional variations may characterize melts available to recharge and destabilize the upper magma reservoir, whereas crystal textures and compositions can be compared with experimental data to infer shallow magma ascent associated with conduit formation prior to climatic activity. Thus, analysis of gray pumice in pyroclastic deposits can yield new insight into the dynamics of eruptive processes.
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Biaxially textured articles formed by plastic deformation
Goyal, Amit
2001-01-01
A method of preparing a biaxially textured article comprises the steps of providing a metal preform, coating or laminating the preform with a metal layer, deforming the layer to a sufficient degree, and rapidly recrystallizing the layer to produce a biaxial texture. A superconducting epitaxial layer may then be deposited on the biaxial texture. In some embodiments the article further comprises buffer layers, electromagnetic devices or electro-optical devices.