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Sample records for selective sweep consistent

  1. Soft shoulders ahead: spurious signatures of soft and partial selective sweeps result from linked hard sweeps.

    Science.gov (United States)

    Schrider, Daniel R; Mendes, Fábio K; Hahn, Matthew W; Kern, Andrew D

    2015-05-01

    Characterizing the nature of the adaptive process at the genetic level is a central goal for population genetics. In particular, we know little about the sources of adaptive substitution or about the number of adaptive variants currently segregating in nature. Historically, population geneticists have focused attention on the hard-sweep model of adaptation in which a de novo beneficial mutation arises and rapidly fixes in a population. Recently more attention has been given to soft-sweep models, in which alleles that were previously neutral, or nearly so, drift until such a time as the environment shifts and their selection coefficient changes to become beneficial. It remains an active and difficult problem, however, to tease apart the telltale signatures of hard vs. soft sweeps in genomic polymorphism data. Through extensive simulations of hard- and soft-sweep models, here we show that indeed the two might not be separable through the use of simple summary statistics. In particular, it seems that recombination in regions linked to, but distant from, sites of hard sweeps can create patterns of polymorphism that closely mirror what is expected to be found near soft sweeps. We find that a very similar situation arises when using haplotype-based statistics that are aimed at detecting partial or ongoing selective sweeps, such that it is difficult to distinguish the shoulder of a hard sweep from the center of a partial sweep. While knowing the location of the selected site mitigates this problem slightly, we show that stochasticity in signatures of natural selection will frequently cause the signal to reach its zenith far from this site and that this effect is more severe for soft sweeps; thus inferences of the target as well as the mode of positive selection may be inaccurate. In addition, both the time since a sweep ends and biologically realistic levels of allelic gene conversion lead to errors in the classification and identification of selective sweeps. This

  2. Selective sweeps in growing microbial colonies

    International Nuclear Information System (INIS)

    Korolev, Kirill S; Müller, Melanie J I; Murray, Andrew W; Nelson, David R; Karahan, Nilay; Hallatschek, Oskar

    2012-01-01

    Evolutionary experiments with microbes are a powerful tool to study mutations and natural selection. These experiments, however, are often limited to the well-mixed environments of a test tube or a chemostat. Since spatial organization can significantly affect evolutionary dynamics, the need is growing for evolutionary experiments in spatially structured environments. The surface of a Petri dish provides such an environment, but a more detailed understanding of microbial growth on Petri dishes is necessary to interpret such experiments. We formulate a simple deterministic reaction–diffusion model, which successfully predicts the spatial patterns created by two competing species during colony expansion. We also derive the shape of these patterns analytically without relying on microscopic details of the model. In particular, we find that the relative fitness of two microbial strains can be estimated from the logarithmic spirals created by selective sweeps. The theory is tested with strains of the budding yeast Saccharomyces cerevisiae for spatial competitions with different initial conditions and for a range of relative fitnesses. The reaction–diffusion model also connects the microscopic parameters like growth rates and diffusion constants with macroscopic spatial patterns and predicts the relationship between fitness in liquid cultures and on Petri dishes, which we confirmed experimentally. Spatial sector patterns therefore provide an alternative fitness assay to the commonly used liquid culture fitness assays. (paper)

  3. Selective sweeps in growing microbial colonies

    Science.gov (United States)

    Korolev, Kirill S.; Müller, Melanie J. I.; Karahan, Nilay; Murray, Andrew W.; Hallatschek, Oskar; Nelson, David R.

    2012-04-01

    Evolutionary experiments with microbes are a powerful tool to study mutations and natural selection. These experiments, however, are often limited to the well-mixed environments of a test tube or a chemostat. Since spatial organization can significantly affect evolutionary dynamics, the need is growing for evolutionary experiments in spatially structured environments. The surface of a Petri dish provides such an environment, but a more detailed understanding of microbial growth on Petri dishes is necessary to interpret such experiments. We formulate a simple deterministic reaction-diffusion model, which successfully predicts the spatial patterns created by two competing species during colony expansion. We also derive the shape of these patterns analytically without relying on microscopic details of the model. In particular, we find that the relative fitness of two microbial strains can be estimated from the logarithmic spirals created by selective sweeps. The theory is tested with strains of the budding yeast Saccharomyces cerevisiae for spatial competitions with different initial conditions and for a range of relative fitnesses. The reaction-diffusion model also connects the microscopic parameters like growth rates and diffusion constants with macroscopic spatial patterns and predicts the relationship between fitness in liquid cultures and on Petri dishes, which we confirmed experimentally. Spatial sector patterns therefore provide an alternative fitness assay to the commonly used liquid culture fitness assays.

  4. Enhancing the mathematical properties of new haplotype homozygosity statistics for the detection of selective sweeps.

    Science.gov (United States)

    Garud, Nandita R; Rosenberg, Noah A

    2015-06-01

    Soft selective sweeps represent an important form of adaptation in which multiple haplotypes bearing adaptive alleles rise to high frequency. Most statistical methods for detecting selective sweeps from genetic polymorphism data, however, have focused on identifying hard selective sweeps in which a favored allele appears on a single haplotypic background; these methods might be underpowered to detect soft sweeps. Among exceptions is the set of haplotype homozygosity statistics introduced for the detection of soft sweeps by Garud et al. (2015). These statistics, examining frequencies of multiple haplotypes in relation to each other, include H12, a statistic designed to identify both hard and soft selective sweeps, and H2/H1, a statistic that conditional on high H12 values seeks to distinguish between hard and soft sweeps. A challenge in the use of H2/H1 is that its range depends on the associated value of H12, so that equal H2/H1 values might provide different levels of support for a soft sweep model at different values of H12. Here, we enhance the H12 and H2/H1 haplotype homozygosity statistics for selective sweep detection by deriving the upper bound on H2/H1 as a function of H12, thereby generating a statistic that normalizes H2/H1 to lie between 0 and 1. Through a reanalysis of resequencing data from inbred lines of Drosophila, we show that the enhanced statistic both strengthens interpretations obtained with the unnormalized statistic and leads to empirical insights that are less readily apparent without the normalization. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMcahon, Katherine D.; Mamlstrom, Rex R.

    2014-05-12

    Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ecotype model? of diversification, but not previously observed in natural populations.

  6. Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMahon, Katherine D.; Malmstrom, Rex R.

    2014-06-18

    Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ‘ecotype model’ of diversification, but not previously observed in natural populations.

  7. Selective sweeps of mitochondrial DNA can drive the evolution of uniparental inheritance.

    Science.gov (United States)

    Christie, Joshua R; Beekman, Madeleine

    2017-08-01

    Although the uniparental (or maternal) inheritance of mitochondrial DNA (mtDNA) is widespread, the reasons for its evolution remain unclear. Two main hypotheses have been proposed: selection against individuals containing different mtDNAs (heteroplasmy) and selection against "selfish" mtDNA mutations. Recently, uniparental inheritance was shown to promote adaptive evolution in mtDNA, potentially providing a third hypothesis for its evolution. Here, we explore this hypothesis theoretically and ask if the accumulation of beneficial mutations provides a sufficient fitness advantage for uniparental inheritance to invade a population in which mtDNA is inherited biparentally. In a deterministic model, uniparental inheritance increases in frequency but cannot replace biparental inheritance if only a single beneficial mtDNA mutation sweeps through the population. When we allow successive selective sweeps of mtDNA, however, uniparental inheritance can replace biparental inheritance. Using a stochastic model, we show that a combination of selection and drift facilitates the fixation of uniparental inheritance (compared to a neutral trait) when there is only a single selective mtDNA sweep. When we consider multiple mtDNA sweeps in a stochastic model, uniparental inheritance becomes even more likely to replace biparental inheritance. Our findings thus suggest that selective sweeps of beneficial mtDNA haplotypes can drive the evolution of uniparental inheritance. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  8. Genomic scans for selective sweeps using SNP data

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Williamson, Scott; Kim, Yuseob

    2005-01-01

    of the selection coefficient. To illustrate the method, we apply our approach to data from the Seattle SNP project and to Chromosome 2 data from the HapMap project. In Chromosome 2, the most extreme signal is found in the lactase gene, which previously has been shown to be undergoing positive selection. Evidence...

  9. Classic selective sweeps revealed by massive sequencing in cattle.

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    Saber Qanbari

    2014-02-01

    Full Text Available Human driven selection during domestication and subsequent breed formation has likely left detectable signatures within the genome of modern cattle. The elucidation of these signatures of selection is of interest from the perspective of evolutionary biology, and for identifying domestication-related genes that ultimately may help to further genetically improve this economically important animal. To this end, we employed a panel of more than 15 million autosomal SNPs identified from re-sequencing of 43 Fleckvieh animals. We mainly applied two somewhat complementary statistics, the integrated Haplotype Homozygosity Score (iHS reflecting primarily ongoing selection, and the Composite of Likelihood Ratio (CLR having the most power to detect completed selection after fixation of the advantageous allele. We find 106 candidate selection regions, many of which are harboring genes related to phenotypes relevant in domestication, such as coat coloring pattern, neurobehavioral functioning and sensory perception including KIT, MITF, MC1R, NRG4, Erbb4, TMEM132D and TAS2R16, among others. To further investigate the relationship between genes with signatures of selection and genes identified in QTL mapping studies, we use a sample of 3062 animals to perform four genome-wide association analyses using appearance traits, body size and somatic cell count. We show that regions associated with coat coloring significantly (P<0.0001 overlap with the candidate selection regions, suggesting that the selection signals we identify are associated with traits known to be affected by selection during domestication. Results also provide further evidence regarding the complexity of the genetics underlying coat coloring in cattle. This study illustrates the potential of population genetic approaches for identifying genomic regions affecting domestication-related phenotypes and further helps to identify specific regions targeted by selection during speciation, domestication and

  10. On detecting incomplete soft or hard selective sweeps using haplotype structure

    DEFF Research Database (Denmark)

    Ferrer-Admetlla, Anna; Liang, Mason; Korneliussen, Thorfinn Sand

    2014-01-01

    We present a new haplotype-based statistic (nSL) for detecting both soft and hard sweeps in population genomic data from a single population. We compare our new method with classic single-population haplotype and site frequency spectrum (SFS)-based methods and show that it is more robust, particu......We present a new haplotype-based statistic (nSL) for detecting both soft and hard sweeps in population genomic data from a single population. We compare our new method with classic single-population haplotype and site frequency spectrum (SFS)-based methods and show that it is more robust......, particularly to recombination rate variation. However, all statistics show some sensitivity to the assumptions of the demographic model. Additionally, we show that nSL has at least as much power as other methods under a number of different selection scenarios, most notably in the cases of sweeps from standing...

  11. Distinguishing between Selective Sweeps from Standing Variation and from a De Novo Mutation

    Science.gov (United States)

    Peter, Benjamin M.; Huerta-Sanchez, Emilia; Nielsen, Rasmus

    2012-01-01

    An outstanding question in human genetics has been the degree to which adaptation occurs from standing genetic variation or from de novo mutations. Here, we combine several common statistics used to detect selection in an Approximate Bayesian Computation (ABC) framework, with the goal of discriminating between models of selection and providing estimates of the age of selected alleles and the selection coefficients acting on them. We use simulations to assess the power and accuracy of our method and apply it to seven of the strongest sweeps currently known in humans. We identify two genes, ASPM and PSCA, that are most likely affected by selection on standing variation; and we find three genes, ADH1B, LCT, and EDAR, in which the adaptive alleles seem to have swept from a new mutation. We also confirm evidence of selection for one further gene, TRPV6. In one gene, G6PD, neither neutral models nor models of selective sweeps fit the data, presumably because this locus has been subject to balancing selection. PMID:23071458

  12. Distinguishing between selective sweeps from standing variation and from a de novo mutation.

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    Benjamin M Peter

    Full Text Available An outstanding question in human genetics has been the degree to which adaptation occurs from standing genetic variation or from de novo mutations. Here, we combine several common statistics used to detect selection in an Approximate Bayesian Computation (ABC framework, with the goal of discriminating between models of selection and providing estimates of the age of selected alleles and the selection coefficients acting on them. We use simulations to assess the power and accuracy of our method and apply it to seven of the strongest sweeps currently known in humans. We identify two genes, ASPM and PSCA, that are most likely affected by selection on standing variation; and we find three genes, ADH1B, LCT, and EDAR, in which the adaptive alleles seem to have swept from a new mutation. We also confirm evidence of selection for one further gene, TRPV6. In one gene, G6PD, neither neutral models nor models of selective sweeps fit the data, presumably because this locus has been subject to balancing selection.

  13. Signatures of positive selection: from selective sweeps at individual loci to subtle allele frequency changes in polygenic adaptation.

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    Stephan, Wolfgang

    2016-01-01

    In the past 15 years, numerous methods have been developed to detect selective sweeps underlying adaptations. These methods are based on relatively simple population genetic models, including one or two loci at which positive directional selection occurs, and one or two marker loci at which the impact of selection on linked neutral variation is quantified. Information about the phenotype under selection is not included in these models (except for fitness). In contrast, in the quantitative genetic models of adaptation, selection acts on one or more phenotypic traits, such that a genotype-phenotype map is required to bridge the gap to population genetics theory. Here I describe the range of population genetic models from selective sweeps in a panmictic population of constant size to evolutionary traffic when simultaneous sweeps at multiple loci interfere, and I also consider the case of polygenic selection characterized by subtle allele frequency shifts at many loci. Furthermore, I present an overview of the statistical tests that have been proposed based on these population genetics models to detect evidence for positive selection in the genome. © 2015 John Wiley & Sons Ltd.

  14. A selective sweep on a deleterious mutation in CPT1A in Arctic populations

    KAUST Repository

    Clemente, Florian J.

    2014-11-01

    Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype data from native Siberians have previously highlighted a 3 Mb chromosome 11 region containing 79 protein-coding genes as the strongest candidates for positive selection in Northeast Siberians. However, it was not possible to determine which of the genes might be driving the selection signal. Here, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele is associated with hypoketotic hypoglycemia and high infant mortality yet occurs at high frequency in Canadian and Greenland Inuits and was also found at 68% frequency in our Northeast Siberian sample. We provide evidence of one of the strongest selective sweeps reported in humans; this sweep has driven this variant to high frequency in circum-Arctic populations within the last 6-23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment.

  15. A selective sweep on a deleterious mutation in CPT1A in Arctic populations

    KAUST Repository

    Clemente, Florian J.; Cardona, Alexia; Inchley, Charlotte E.; Peter, Benjamin M.; Jacobs, Guy; Pagani, Luca; Lawson, Daniel John; Antã o, Tiago; Vicente, Má rio; Mitt, Mario; Degiorgio, Michael; Faltyskova, Zuzana; Xue, Yali; Ayub, Qasim; Szpak, Michal; Mä gi, Reedik; Eriksson, Anders; Manica, Andrea; Raghavan, Maanasa; Rasmussen, Morten Arendt Rendt; Rasmussen, Simon B.; Willerslev, Eske; Vidal-Puig, Antonio J.; Tyler-Smith, Chris; Villems, Richard; Nielsen, Rasmus Wedel; Metspalu, Mait; Malyarchuk, Boris A.; Derenko, Miroslava V.; Kivisild, Toomas

    2014-01-01

    Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype data from native Siberians have previously highlighted a 3 Mb chromosome 11 region containing 79 protein-coding genes as the strongest candidates for positive selection in Northeast Siberians. However, it was not possible to determine which of the genes might be driving the selection signal. Here, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele is associated with hypoketotic hypoglycemia and high infant mortality yet occurs at high frequency in Canadian and Greenland Inuits and was also found at 68% frequency in our Northeast Siberian sample. We provide evidence of one of the strongest selective sweeps reported in humans; this sweep has driven this variant to high frequency in circum-Arctic populations within the last 6-23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment.

  16. Soft sweeps III: the signature of positive selection from recurrent mutation.

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    Pleuni S Pennings

    2006-12-01

    Full Text Available Polymorphism data can be used to identify loci at which a beneficial allele has recently gone to fixation, given that an accurate description of the signature of selection is available. In the classical model that is used, a favored allele derives from a single mutational origin. This ignores the fact that beneficial alleles can enter a population recurrently by mutation during the selective phase. In this study, we present a combination of analytical and simulation results to demonstrate the effect of adaptation from recurrent mutation on summary statistics for polymorphism data from a linked neutral locus. We also analyze the power of standard neutrality tests based on the frequency spectrum or on linkage disequilibrium (LD under this scenario. For recurrent beneficial mutation at biologically realistic rates, we find substantial deviations from the classical pattern of a selective sweep from a single new mutation. Deviations from neutrality in the level of polymorphism and in the frequency spectrum are much less pronounced than in the classical sweep pattern. In contrast, for levels of LD, the signature is even stronger if recurrent beneficial mutation plays a role. We suggest a variant of existing LD tests that increases their power to detect this signature.

  17. Selective sweep on human amylase genes postdates the split with Neanderthals

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    Inchley, Charlotte E.; Larbey, Cynthia D. A.; Shwan, Nzar A. A.; Pagani, Luca; Saag, Lauri; Antão, Tiago; Jacobs, Guy; Hudjashov, Georgi; Metspalu, Ene; Mitt, Mario; Eichstaedt, Christina A.; Malyarchuk, Boris; Derenko, Miroslava; Wee, Joseph; Abdullah, Syafiq; Ricaut, François-Xavier; Mormina, Maru; Mägi, Reedik; Villems, Richard; Metspalu, Mait; Jones, Martin K.; Armour, John A. L.; Kivisild, Toomas

    2016-01-01

    Humans have more copies of amylase genes than other primates. It is still poorly understood, however, when the copy number expansion occurred and whether its spread was enhanced by selection. Here we assess amylase copy numbers in a global sample of 480 high coverage genomes and find that regions flanking the amylase locus show notable depression of genetic diversity both in African and non-African populations. Analysis of genetic variation in these regions supports the model of an early selective sweep in the human lineage after the split of humans from Neanderthals which led to the fixation of multiple copies of AMY1 in place of a single copy. We find evidence of multiple secondary losses of copy number with the highest frequency (52%) of a deletion of AMY2A and associated low copy number of AMY1 in Northeast Siberian populations whose diet has been low in starch content. PMID:27853181

  18. The yule approximation for the site frequency spectrum after a selective sweep.

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    Sebastian Bossert

    Full Text Available In the area of evolutionary theory, a key question is which portions of the genome of a species are targets of natural selection. Genetic hitchhiking is a theoretical concept that has helped to identify various such targets in natural populations. In the presence of recombination, a severe reduction in sequence diversity is expected around a strongly beneficial allele. The site frequency spectrum is an important tool in genome scans for selection and is composed of the numbers S(1,...,S(n-1, where S(k is the number of single nucleotide polymorphisms (SNPs present in k from n individuals. Previous work has shown that both the number of low- and high-frequency variants are elevated relative to neutral evolution when a strongly beneficial allele fixes. Here, we follow a recent investigation of genetic hitchhiking using a marked Yule process to obtain an analytical prediction of the site frequency spectrum in a panmictic population at the time of fixation of a highly beneficial mutation. We combine standard results from the neutral case with the effects of a selective sweep. As simulations show, the resulting formula produces predictions that are more accurate than previous approaches for the whole frequency spectrum. In particular, the formula correctly predicts the elevation of low- and high-frequency variants and is significantly more accurate than previously derived formulas for intermediate frequency variants.

  19. A selective sweep in a Varroa destructor resistant honeybee (Apis mellifera) population.

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    Lattorff, H Michael G; Buchholz, Josephine; Fries, Ingemar; Moritz, Robin F A

    2015-04-01

    The mite Varroa destructor is one of the most dangerous parasites of the Western honeybee (Apis mellifera) causing enormous colony losses worldwide. Various chemical treatments for the control of the Varroa mite are currently in use, which, however, lead to residues in bee products and often to resistance in mites. This facilitated the exploration of alternative treatment methods and breeding for mite resistant honeybees has been in focus for breeders in many parts of the world with variable results. Another approach has been applied to a honeybee population on Gotland (Sweden) that was exposed to natural selection and survived Varroa-infestation for more than 10years without treatment. Eventually this population became resistant to the parasite by suppressing the reproduction of the mite. A previous QTL mapping study had identified a region on chromosome 7 with major loci contributing to the mite resistance. Here, a microsatellite scan of the significant candidate QTL regions was used to investigate potential footprints of selection in the original population by comparing the study population on Gotland before (2000) and after selection (2007). Genetic drift had caused an extreme loss of genetic diversity in the 2007 population for all genetic markers tested. In addition to this overall reduction of heterozygosity, two loci on chromosome 7 showed an even stronger and significant reduction in diversity than expected from genetic drift alone. Within the selective sweep eleven genes are annotated, one of them being a putative candidate to interfere with reduced mite reproduction. A glucose-methanol-choline oxidoreductase (GMCOX18) might be involved in changing volatiles emitted by bee larvae that might be essential to trigger oogenesis in Varroa. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Topography of sound level representation in the FM sweep selective region of the pallid bat auditory cortex.

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    Measor, Kevin; Yarrow, Stuart; Razak, Khaleel A

    2018-05-26

    Sound level processing is a fundamental function of the auditory system. To determine how the cortex represents sound level, it is important to quantify how changes in level alter the spatiotemporal structure of cortical ensemble activity. This is particularly true for echolocating bats that have control over, and often rapidly adjust, call level to actively change echo level. To understand how cortical activity may change with sound level, here we mapped response rate and latency changes with sound level in the auditory cortex of the pallid bat. The pallid bat uses a 60-30 kHz downward frequency modulated (FM) sweep for echolocation. Neurons tuned to frequencies between 30 and 70 kHz in the auditory cortex are selective for the properties of FM sweeps used in echolocation forming the FM sweep selective region (FMSR). The FMSR is strongly selective for sound level between 30 and 50 dB SPL. Here we mapped the topography of level selectivity in the FMSR using downward FM sweeps and show that neurons with more monotonic rate level functions are located in caudomedial regions of the FMSR overlapping with high frequency (50-60 kHz) neurons. Non-monotonic neurons dominate the FMSR, and are distributed across the entire region, but there is no evidence for amplitopy. We also examined how first spike latency of FMSR neurons change with sound level. The majority of FMSR neurons exhibit paradoxical latency shift wherein the latency increases with sound level. Moreover, neurons with paradoxical latency shifts are more strongly level selective and are tuned to lower sound level than neurons in which latencies decrease with level. These data indicate a clustered arrangement of neurons according to monotonicity, with no strong evidence for finer scale topography, in the FMSR. The latency analysis suggests mechanisms for strong level selectivity that is based on relative timing of excitatory and inhibitory inputs. Taken together, these data suggest how the spatiotemporal

  1. Hitchhiking and Selective Sweeps of Plasmodium falciparum Sulfadoxine and Pyrimethamine Resistance Alleles in a Population from Central Africa▿ †

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    McCollum, Andrea M.; Basco, Leonardo K.; Tahar, Rachida; Udhayakumar, Venkatachalam; Escalante, Ananias A.

    2008-01-01

    Sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum is encoded by a number of mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes. Here, we have characterized point mutations in dhfr and dhps and microsatellite loci around dhfr on chromosome 4 and dhps on chromosome 8 as well as neutral markers on chromosomes 2 and 3 in 332 samples from Yaoundé, Cameroon. The triple mutant dhfr haplotype that originated in Southeast Asia is the most predominant in this sample set, but we also find additional independent haplotypes at low frequency and an incipient process of genetic differentiation among alleles of Southeast Asian origin. As reported for other African populations, we find evidence of a selective sweep for resistant dhfr mutants in this Cameroonian population due to drug selection. Although we find evidence for a selective sweep in dhps mutants associated with SP resistance, the dynamics of dhps mutants appear different than those observed for dhfr mutants. Overall, our results yield support for the use of microsatellite markers to track resistant parasites; however, the detection of resistant dhfr alleles in low frequency, the evidence of divergence among dhfr alleles that share a common evolutionary origin, and the distinct dynamics of resistant dhps alleles emphasize the importance of comprehensive, population-based investigations to evaluate the effects of drug selection on parasite populations. PMID:18765692

  2. Private selective sweeps identified from next-generation pool-sequencing reveal convergent pathways under selection in two inbred Schistosoma mansoni strains.

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    Julie A J Clément

    Full Text Available BACKGROUND: The trematode flatworms of the genus Schistosoma, the causative agents of schistosomiasis, are among the most prevalent parasites in humans, affecting more than 200 million people worldwide. In this study, we focused on two well-characterized strains of S. mansoni, to explore signatures of selection. Both strains are highly inbred and exhibit differences in life history traits, in particular in their compatibility with the intermediate host Biomphalaria glabrata. METHODOLOGY/PRINCIPAL FINDINGS: We performed high throughput sequencing of DNA from pools of individuals of each strain using Illumina technology and identified single nucleotide polymorphisms (SNP and copy number variations (CNV. In total, 708,898 SNPs were identified and roughly 2,000 CNVs. The SNPs revealed low nucleotide diversity (π = 2 × 10(-4 within each strain and a high differentiation level (Fst = 0.73 between them. Based on a recently developed in-silico approach, we further detected 12 and 19 private (i.e. specific non-overlapping selective sweeps among the 121 and 151 sweeps found in total for each strain. CONCLUSIONS/SIGNIFICANCE: Functional annotation of transcripts lying in the private selective sweeps revealed specific selection for functions related to parasitic interaction (e.g. cell-cell adhesion or redox reactions. Despite high differentiation between strains, we identified evolutionary convergence of genes related to proteolysis, known as a key virulence factor and a potential target of drug and vaccine development. Our data show that pool-sequencing can be used for the detection of selective sweeps in parasite populations and enables one to identify biological functions under selection.

  3. Cooperative Research Twin Trawl Sweep Comparison Study

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    National Oceanic and Atmospheric Administration, Department of Commerce — The "Twin-Trawl Sweep Efficiency Study" was intended to compare the sweep efficiency and selectivity of the NEFSC standardized bottom trawl to that of a standardized...

  4. A selective sweep in a microsporidian parasite Nosema-tolerant honeybee population, Apis mellifera

    DEFF Research Database (Denmark)

    Huang, Q.; Lattorff, H. M. G.; Kryger, P.

    2014-01-01

    Nosema is a microsporidian parasite of the honeybee, which infects the epithelial cells of the gut. In Denmark, honeybee colonies have been selectively bred for the absence of Nosema over decades, resulting in a breeding line that is tolerant toward Nosema infections. As the tolerance toward the ...

  5. A Selective Sweep on a Deleterious Mutation in CPT1A in Arctic Populations

    DEFF Research Database (Denmark)

    Clemente, Florian J.; Cardona, Alexia; Inchley, Charlotte E.

    2014-01-01

    Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype......, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele...... this variant to high frequency in circum-Arctic populations within the last 6–23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment....

  6. Strong selective sweeps associated with ampliconic regions in great ape X chromosomes

    DEFF Research Database (Denmark)

    Nam, Kiwoong; Munch, Kasper; Hobolth, Asger

    2014-01-01

    The unique inheritance pattern of X chromosomes makes them preferential targets of adaptive evolution. We here investigate natural selection on the X chromosome in all species of great apes. We find that diversity is more strongly reduced around genes on the X compared with autosomes...... with ampliconic sequences we propose that intra-genomic conflict between the X and the Y chromosomes is a major driver of X chromosome evolution....

  7. Selective sweep on human amylase genes postdates the split with Neanderthals

    OpenAIRE

    Inchley, Charlotte E.; Larbey, Cynthia D. A.; Shwan, Nzar A. A.; Pagani, Luca; Saag, Lauri; Antão, Tiago; Jacobs, Guy; Hudjashov, Georgi; Metspalu, Ene; Mitt, Mario; Eichstaedt, Christina A.; Malyarchuk, Boris; Derenko, Miroslava; Wee, Joseph; Abdullah, Syafiq

    2016-01-01

    Humans have more copies of amylase genes than other primates. It is still poorly understood, however, when the copy number expansion occurred and whether its spread was enhanced by selection. Here we assess amylase copy numbers in a global sample of 480 high coverage genomes and find that regions flanking the amylase locus show notable depression of genetic diversity both in African and non-African populations. Analysis of genetic variation in these regions supports the model of an early sele...

  8. Single feature polymorphism (SFP-based selective sweep identification and association mapping of growth-related metabolic traits in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Stitt Mark

    2010-03-01

    Full Text Available Abstract Background Natural accessions of Arabidopsis thaliana are characterized by a high level of phenotypic variation that can be used to investigate the extent and mode of selection on the primary metabolic traits. A collection of 54 A. thaliana natural accession-derived lines were subjected to deep genotyping through Single Feature Polymorphism (SFP detection via genomic DNA hybridization to Arabidopsis Tiling 1.0 Arrays for the detection of selective sweeps, and identification of associations between sweep regions and growth-related metabolic traits. Results A total of 1,072,557 high-quality SFPs were detected and indications for 3,943 deletions and 1,007 duplications were obtained. A significantly lower than expected SFP frequency was observed in protein-, rRNA-, and tRNA-coding regions and in non-repetitive intergenic regions, while pseudogenes, transposons, and non-coding RNA genes are enriched with SFPs. Gene families involved in plant defence or in signalling were identified as highly polymorphic, while several other families including transcription factors are depleted of SFPs. 198 significant associations between metabolic genes and 9 metabolic and growth-related phenotypic traits were detected with annotation hinting at the nature of the relationship. Five significant selective sweep regions were also detected of which one associated significantly with a metabolic trait. Conclusions We generated a high density polymorphism map for 54 A. thaliana accessions that highlights the variability of resistance genes across geographic ranges and used it to identify selective sweeps and associations between metabolic genes and metabolic phenotypes. Several associations show a clear biological relationship, while many remain requiring further investigation.

  9. Incomplete Selective Sweeps of Microcystis Population Detected by the Leader-End CRISPR Fragment Analysis in a Natural Pond

    Directory of Open Access Journals (Sweden)

    Shigeko Kimura

    2018-03-01

    Full Text Available The freshwater cyanobacterium Microcystis aeruginosa frequently forms toxic massive blooms and exists in an arms race with its infectious phages in aquatic natural environments, and as a result, has evolved extremely diverse and elaborate antiviral defense systems, including the clustered regularly interspaced short palindromic repeats (CRISPR-CRISPR-associated genes (Cas system. Here, to assess Microcystis population dynamics associated with exogenous mobile genetic elements such as phages and plasmids, we examined the temporal variation in CRISPR genotypes (CTs by analyzing spacer sequences detected in a natural pond between June and October 2013 when a cyanobacterial bloom occurred. A total of 463,954 high-quality leader-end CRISPR sequences were obtained and the sequences containing spacers were classified into 31 previously reported CTs and 68 new CTs based on the shared order of the leader-end spacers. CT19 was the most dominant genotype (32% among the 16 most common CTs, followed by CT52 (14% and CT58 (9%. Spacer repertoires of CT19 showed mainly two different types; CT19origin, which was identical to the CT19 spacer repertoire of previously isolated strains, and CT19new+, which contained a new spacer at the leader-end of the CRISPR region of CT19origin, which were present in almost equal abundance, accounting for up to 99.94% of CT19 sequences. Surprisingly, we observed the spacer repertoires of the second to tenth spacers of CT19origin at the most leader-end of proto-genotype sequences of CT19origin. These were observed during the sampling in this study and our previous study at the same ecosystem in 2010 and 2011, suggesting these CTs persisted from 2011 to 2013 in spite of phage pressure. The leader-end variants were observed in other CT genotypes. These findings indicated an incomplete selective sweep of Microcystis populations. We explained the phenomenon as follow; the abundance of Microcystis varied seasonally and drastically

  10. The strong selective sweep candidate gene ADRA2C does not explain domestication related changes in the stress response of chickens.

    Directory of Open Access Journals (Sweden)

    Magnus Elfwing

    Full Text Available Analysis of selective sweeps to pinpoint causative genomic regions involved in chicken domestication has revealed a strong selective sweep on chromosome 4 in layer chickens. The autoregulatory α-adrenergic receptor 2C (ADRA2C gene is the closest to the selective sweep and was proposed as an important gene in the domestication of layer chickens. The ADRA2C promoter region was also hypermethylated in comparison to the non-selected ancestor of all domesticated chicken breeds, the Red Junglefowl, further supporting its relevance. In mice the receptor is involved in the fight-or-flight response as it modulates epinephrine release from the adrenals. To investigate the involvement of ADRA2C in chicken domestication, we measured gene expression in the adrenals and radiolabeled receptor ligand in three brain regions comparing the domestic White Leghorn strain with the wild ancestor Red Junglefowl. In adrenals ADRA2C was twofold greater expressed than the related receptor gene ADRA2A, indicating that ADRA2C is the predominant modulator of epinephrine release but no strain differences were measured. In hypothalamus and amygdala, regions associated with the stress response, and in striatum, receptor binding pIC50 values ranged between 8.1-8.4, and the level was not influenced by the genotyped allele. Because chicken strains differ in morphology, physiology and behavior, differences attributed to a single gene may be lost in the noise caused by the heterogeneous genetic background. Therefore an F10 advanced intercross strain between White Leghorn and Red Junglefowl was used to investigate effects of ADRA2C alleles on fear related behaviors and fecundity. We did not find compelling genotype effects in open field, tonic immobility, aerial predator, associative learning or fecundity. Therefore we conclude that ADRA2C is probably not involved in the domestication of the stress response in chicken, and the strong selective sweep is probably caused by selection

  11. Sweeping the State Space

    DEFF Research Database (Denmark)

    Mailund, Thomas

    The thesis describes the sweep-line method, a newly developed reduction method for alleviating the state explosion problem inherent in explicit-state state space exploration. The basic idea underlying the sweep-line method is, when calculating the state space, to recognise and delete states...... that are not reachable from the currently unprocessed states. Intuitively we drag a sweep-line through the state space with the invariant that all states behind the sweep-line have been processed and are unreachable from the states in front of the sweep-line. When calculating the state space of a system we iteratively...

  12. Effects of asymmetric nuclear introgression, introgressive mitochondrial sweep, and purifying selection on phylogenetic reconstruction and divergence estimates in the Pacific clade of Locustella warblers.

    Science.gov (United States)

    Drovetski, Sergei V; Semenov, Georgy; Red'kin, Yaroslav A; Sotnikov, Vladimir N; Fadeev, Igor V; Koblik, Evgeniy A

    2015-01-01

    When isolated but reproductively compatible populations expand geographically and meet, simulations predict asymmetric introgression of neutral loci from a local to invading taxon. Genetic introgression may affect phylogenetic reconstruction by obscuring topology and divergence estimates. We combined phylogenetic analysis of sequences from one mtDNA and 12 nuDNA loci with analysis of gene flow among 5 species of Pacific Locustella warblers to test for presence of genetic introgression and its effects on tree topology and divergence estimates. Our data showed that nuDNA introgression was substantial and asymmetrical among all members of superspecies groups whereas mtDNA showed no introgression except a single species pair where the invader's mtDNA was swept by mtDNA of the local species. This introgressive sweep of mtDNA had the opposite direction of the nuDNA introgression and resulted in the paraphyly of the local species' mtDNA haplotypes with respect to those of the invader. Тhe multilocus nuDNA species tree resolved all inter- and intraspecific relationships despite substantial introgression. However, the node ages on the species tree may be underestimated as suggested by the differences in node age estimates based on non-introgressing mtDNA and introgressing nuDNA. In turn, the introgressive sweep and strong purifying selection appear to elongate internal branches in the mtDNA gene tree.

  13. Genomic Footprints of Selective Sweeps from Metabolic Resistance to Pyrethroids in African Malaria Vectors Are Driven by Scale up of Insecticide-Based Vector Control.

    Science.gov (United States)

    Barnes, Kayla G; Weedall, Gareth D; Ndula, Miranda; Irving, Helen; Mzihalowa, Themba; Hemingway, Janet; Wondji, Charles S

    2017-02-01

    Insecticide resistance in mosquito populations threatens recent successes in malaria prevention. Elucidating patterns of genetic structure in malaria vectors to predict the speed and direction of the spread of resistance is essential to get ahead of the 'resistance curve' and to avert a public health catastrophe. Here, applying a combination of microsatellite analysis, whole genome sequencing and targeted sequencing of a resistance locus, we elucidated the continent-wide population structure of a major African malaria vector, Anopheles funestus. We identified a major selective sweep in a genomic region controlling cytochrome P450-based metabolic resistance conferring high resistance to pyrethroids. This selective sweep occurred since 2002, likely as a direct consequence of scaled up vector control as revealed by whole genome and fine-scale sequencing of pre- and post-intervention populations. Fine-scaled analysis of the pyrethroid resistance locus revealed that a resistance-associated allele of the cytochrome P450 monooxygenase CYP6P9a has swept through southern Africa to near fixation, in contrast to high polymorphism levels before interventions, conferring high levels of pyrethroid resistance linked to control failure. Population structure analysis revealed a barrier to gene flow between southern Africa and other areas, which may prevent or slow the spread of the southern mechanism of pyrethroid resistance to other regions. By identifying a genetic signature of pyrethroid-based interventions, we have demonstrated the intense selective pressure that control interventions exert on mosquito populations. If this level of selection and spread of resistance continues unabated, our ability to control malaria with current interventions will be compromised.

  14. Genomic Footprints of Selective Sweeps from Metabolic Resistance to Pyrethroids in African Malaria Vectors Are Driven by Scale up of Insecticide-Based Vector Control.

    Directory of Open Access Journals (Sweden)

    Kayla G Barnes

    2017-02-01

    Full Text Available Insecticide resistance in mosquito populations threatens recent successes in malaria prevention. Elucidating patterns of genetic structure in malaria vectors to predict the speed and direction of the spread of resistance is essential to get ahead of the 'resistance curve' and to avert a public health catastrophe. Here, applying a combination of microsatellite analysis, whole genome sequencing and targeted sequencing of a resistance locus, we elucidated the continent-wide population structure of a major African malaria vector, Anopheles funestus. We identified a major selective sweep in a genomic region controlling cytochrome P450-based metabolic resistance conferring high resistance to pyrethroids. This selective sweep occurred since 2002, likely as a direct consequence of scaled up vector control as revealed by whole genome and fine-scale sequencing of pre- and post-intervention populations. Fine-scaled analysis of the pyrethroid resistance locus revealed that a resistance-associated allele of the cytochrome P450 monooxygenase CYP6P9a has swept through southern Africa to near fixation, in contrast to high polymorphism levels before interventions, conferring high levels of pyrethroid resistance linked to control failure. Population structure analysis revealed a barrier to gene flow between southern Africa and other areas, which may prevent or slow the spread of the southern mechanism of pyrethroid resistance to other regions. By identifying a genetic signature of pyrethroid-based interventions, we have demonstrated the intense selective pressure that control interventions exert on mosquito populations. If this level of selection and spread of resistance continues unabated, our ability to control malaria with current interventions will be compromised.

  15. Directional selection in temporally replicated studies is remarkably consistent.

    Science.gov (United States)

    Morrissey, Michael B; Hadfield, Jarrod D

    2012-02-01

    Temporal variation in selection is a fundamental determinant of evolutionary outcomes. A recent paper presented a synthetic analysis of temporal variation in selection in natural populations. The authors concluded that there is substantial variation in the strength and direction of selection over time, but acknowledged that sampling error would result in estimates of selection that were more variable than the true values. We reanalyze their dataset using techniques that account for the necessary effect of sampling error to inflate apparent levels of variation and show that directional selection is remarkably constant over time, both in magnitude and direction. Thus we cannot claim that the available data support the existence of substantial temporal heterogeneity in selection. Nonetheless, we conject that temporal variation in selection could be important, but that there are good reasons why it may not appear in the available data. These new analyses highlight the importance of applying techniques that estimate parameters of the distribution of selection, rather than parameters of the distribution of estimated selection (which will reflect both sampling error and "real" variation in selection); indeed, despite availability of methods for the former, focus on the latter has been common in synthetic reviews of the aspects of selection in nature, and can lead to serious misinterpretations. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  16. Cache Oblivious Distribution Sweeping

    DEFF Research Database (Denmark)

    Brodal, G.S.; Fagerberg, R.

    2002-01-01

    We adapt the distribution sweeping method to the cache oblivious model. Distribution sweeping is the name used for a general approach for divide-and-conquer algorithms where the combination of solved subproblems can be viewed as a merging process of streams. We demonstrate by a series of algorith...

  17. Identification of X-linked quantitative trait loci affecting cold tolerance in Drosophila melanogaster and fine mapping by selective sweep analysis.

    Science.gov (United States)

    Svetec, Nicolas; Werzner, Annegret; Wilches, Ricardo; Pavlidis, Pavlos; Alvarez-Castro, José M; Broman, Karl W; Metzler, Dirk; Stephan, Wolfgang

    2011-02-01

    Drosophila melanogaster is a cosmopolitan species that colonizes a great variety of environments. One trait that shows abundant evidence for naturally segregating genetic variance in different populations of D. melanogaster is cold tolerance. Previous work has found quantitative trait loci (QTL) exclusively on the second and the third chromosomes. To gain insight into the genetic architecture of cold tolerance on the X chromosome and to compare the results with our analyses of selective sweeps, a mapping population was derived from a cross between substitution lines that solely differed in the origin of their X chromosome: one originates from a European inbred line and the other one from an African inbred line. We found a total of six QTL for cold tolerance factors on the X chromosome of D. melanogaster. Although the composite interval mapping revealed slightly different QTL profiles between sexes, a coherent model suggests that most QTL overlapped between sexes, and each explained around 5-14% of the genetic variance (which may be slightly overestimated). The allelic effects were largely additive, but we also detected two significant interactions. Taken together, this provides evidence for multiple QTL that are spread along the entire X chromosome and whose effects range from low to intermediate. One detected transgressive QTL influences cold tolerance in different ways for the two sexes. While females benefit from the European allele increasing their cold tolerance, males tend to do better with the African allele. Finally, using selective sweep mapping, the candidate gene CG16700 for cold tolerance colocalizing with a QTL was identified. © 2010 Blackwell Publishing Ltd.

  18. Consistent sensor, relay, and link selection in wireless sensor networks

    NARCIS (Netherlands)

    Arroyo Valles, M.D.R.; Simonetto, A.; Leus, G.J.T.

    2017-01-01

    In wireless sensor networks, where energy is scarce, it is inefficient to have all nodes active because they consume a non-negligible amount of battery. In this paper we consider the problem of jointly selecting sensors, relays and links in a wireless sensor network where the active sensors need

  19. Genome-wide candidate regions for selective sweeps revealed through massive parallel sequencing of DNA across ten turkey populations

    NARCIS (Netherlands)

    Aslam, M.L.; Bastiaansen, J.W.M.; Megens, H.J.W.C.; Crooijmans, R.P.M.A.; Blomberg, L.; Groenen, M.

    2014-01-01

    Background The domestic turkey (Meleagris gallopavo) is an important agricultural species that is largely used as a meat-type bird. Characterizing genetic variation in populations of domesticated species and associating these variation patterns with the evolution, domestication, and selective

  20. Genomic and Transcriptomic Associations Identify a New Insecticide Resistance Phenotype for the Selective Sweep at the Cyp6g1 Locus of Drosophila melanogaster.

    Science.gov (United States)

    Battlay, Paul; Schmidt, Joshua M; Fournier-Level, Alexandre; Robin, Charles

    2016-08-09

    Scans of the Drosophila melanogaster genome have identified organophosphate resistance loci among those with the most pronounced signature of positive selection. In this study, the molecular basis of resistance to the organophosphate insecticide azinphos-methyl was investigated using the Drosophila Genetic Reference Panel, and genome-wide association. Recently released full transcriptome data were used to extend the utility of the Drosophila Genetic Reference Panel resource beyond traditional genome-wide association studies to allow systems genetics analyses of phenotypes. We found that both genomic and transcriptomic associations independently identified Cyp6g1, a gene involved in resistance to DDT and neonicotinoid insecticides, as the top candidate for azinphos-methyl resistance. This was verified by transgenically overexpressing Cyp6g1 using natural regulatory elements from a resistant allele, resulting in a 6.5-fold increase in resistance. We also identified four novel candidate genes associated with azinphos-methyl resistance, all of which are involved in either regulation of fat storage, or nervous system development. In Cyp6g1, we find a demonstrable resistance locus, a verification that transcriptome data can be used to identify variants associated with insecticide resistance, and an overlap between peaks of a genome-wide association study, and a genome-wide selective sweep analysis. Copyright © 2016 Battlay et al.

  1. Selective Sweep Analysis in the Genomes of the 91-R and 91-C Drosophila melanogaster Strains Reveals Few of the ‘Usual Suspects’ in Dichlorodiphenyltrichloroethane (DDT) Resistance

    Science.gov (United States)

    Steele, Laura D.; Coates, Brad; Valero, M. Carmen; Sun, Weilin; Seong, Keon Mook; Muir, William M.; Clark, John M.; Pittendrigh, Barry R.

    2015-01-01

    Adaptation of insect phenotypes for survival after exposure to xenobiotics can result from selection at multiple loci with additive genetic effects. To the authors’ knowledge, no selective sweep analysis has been performed to identify such loci in highly dichlorodiphenyltrichloroethane (DDT) resistant insects. Here we compared a highly DDT resistant phenotype in the Drosophila melanogaster (Drosophila) 91-R strain to the DDT susceptible 91-C strain, both of common origin. Whole genome re-sequencing data from pools of individuals was generated separately for 91-R and 91-C, and mapped to the reference Drosophila genome assembly (v. 5.72). Thirteen major and three minor effect chromosome intervals with reduced nucleotide diversity (π) were identified only in the 91-R population. Estimates of Tajima's D (D) showed corresponding evidence of directional selection in these same genome regions of 91-R, however, no similar reductions in π or D estimates were detected in 91-C. An overabundance of non-synonymous proteins coding to synonymous changes were identified in putative open reading frames associated with 91-R. Except for NinaC and Cyp4g1, none of the identified genes were the ‘usual suspects’ previously observed to be associated with DDT resistance. Additionally, up-regulated ATP-binding cassette transporters have been previously associated with DDT resistance; however, here we identified a structurally altered MDR49 candidate resistance gene. The remaining fourteen genes have not previously been shown to be associated with DDT resistance. These results suggest hitherto unknown mechanisms of DDT resistance, most of which have been overlooked in previous transcriptional studies, with some genes having orthologs in mammals. PMID:25826265

  2. Automatic sweep circuit

    International Nuclear Information System (INIS)

    Keefe, D.J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input is described. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found

  3. Automatic sweep circuit

    Science.gov (United States)

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  4. The sweep-line state space exploration method

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars M.; Mailund, Thomas

    2012-01-01

    . The contribution of this paper is twofold. First, we provide a coherent presentation of the sweep-line theory and the many variants of the method that have been developed over the past 10 years since the basic idea of the method was conceived. Second, we survey a selection of case studies where the sweep...

  5. R2d2 Drives Selfish Sweeps in the House Mouse.

    Science.gov (United States)

    Didion, John P; Morgan, Andrew P; Yadgary, Liran; Bell, Timothy A; McMullan, Rachel C; Ortiz de Solorzano, Lydia; Britton-Davidian, Janice; Bult, Carol J; Campbell, Karl J; Castiglia, Riccardo; Ching, Yung-Hao; Chunco, Amanda J; Crowley, James J; Chesler, Elissa J; Förster, Daniel W; French, John E; Gabriel, Sofia I; Gatti, Daniel M; Garland, Theodore; Giagia-Athanasopoulou, Eva B; Giménez, Mabel D; Grize, Sofia A; Gündüz, İslam; Holmes, Andrew; Hauffe, Heidi C; Herman, Jeremy S; Holt, James M; Hua, Kunjie; Jolley, Wesley J; Lindholm, Anna K; López-Fuster, María J; Mitsainas, George; da Luz Mathias, Maria; McMillan, Leonard; Ramalhinho, Maria da Graça Morgado; Rehermann, Barbara; Rosshart, Stephan P; Searle, Jeremy B; Shiao, Meng-Shin; Solano, Emanuela; Svenson, Karen L; Thomas-Laemont, Patricia; Threadgill, David W; Ventura, Jacint; Weinstock, George M; Pomp, Daniel; Churchill, Gary A; Pardo-Manuel de Villena, Fernando

    2016-06-01

    A selective sweep is the result of strong positive selection driving newly occurring or standing genetic variants to fixation, and can dramatically alter the pattern and distribution of allelic diversity in a population. Population-level sequencing data have enabled discoveries of selective sweeps associated with genes involved in recent adaptations in many species. In contrast, much debate but little evidence addresses whether "selfish" genes are capable of fixation-thereby leaving signatures identical to classical selective sweeps-despite being neutral or deleterious to organismal fitness. We previously described R2d2, a large copy-number variant that causes nonrandom segregation of mouse Chromosome 2 in females due to meiotic drive. Here we show population-genetic data consistent with a selfish sweep driven by alleles of R2d2 with high copy number (R2d2(HC)) in natural populations. We replicate this finding in multiple closed breeding populations from six outbred backgrounds segregating for R2d2 alleles. We find that R2d2(HC) rapidly increases in frequency, and in most cases becomes fixed in significantly fewer generations than can be explained by genetic drift. R2d2(HC) is also associated with significantly reduced litter sizes in heterozygous mothers, making it a true selfish allele. Our data provide direct evidence of populations actively undergoing selfish sweeps, and demonstrate that meiotic drive can rapidly alter the genomic landscape in favor of mutations with neutral or even negative effects on overall Darwinian fitness. Further study will reveal the incidence of selfish sweeps, and will elucidate the relative contributions of selfish genes, adaptation and genetic drift to evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Consistent and Conservative Model Selection with the Adaptive LASSO in Stationary and Nonstationary Autoregressions

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl

    2016-01-01

    We show that the adaptive Lasso is oracle efficient in stationary and nonstationary autoregressions. This means that it estimates parameters consistently, selects the correct sparsity pattern, and estimates the coefficients belonging to the relevant variables at the same asymptotic efficiency...

  7. Hyperspectral band selection based on consistency-measure of neighborhood rough set theory

    International Nuclear Information System (INIS)

    Liu, Yao; Xie, Hong; Wang, Liguo; Tan, Kezhu; Chen, Yuehua; Xu, Zhen

    2016-01-01

    Band selection is a well-known approach for reducing dimensionality in hyperspectral imaging. In this paper, a band selection method based on consistency-measure of neighborhood rough set theory (CMNRS) was proposed to select informative bands from hyperspectral images. A decision-making information system was established by the reflection spectrum of soybeans’ hyperspectral data between 400 nm and 1000 nm wavelengths. The neighborhood consistency-measure, which reflects not only the size of the decision positive region, but also the sample distribution in the boundary region, was used as the evaluation function of band significance. The optimal band subset was selected by a forward greedy search algorithm. A post-pruning strategy was employed to overcome the over-fitting problem and find the minimum subset. To assess the effectiveness of the proposed band selection technique, two classification models (extreme learning machine (ELM) and random forests (RF)) were built. The experimental results showed that the proposed algorithm can effectively select key bands and obtain satisfactory classification accuracy. (paper)

  8. Consistent selection towards low activity phenotypes when catchability depends on encounters among human predators and fish.

    Directory of Open Access Journals (Sweden)

    Josep Alós

    Full Text Available Together with life-history and underlying physiology, the behavioural variability among fish is one of the three main trait axes that determines the vulnerability to fishing. However, there are only a few studies that have systematically investigated the strength and direction of selection acting on behavioural traits. Using in situ fish behaviour revealed by telemetry techniques as input, we developed an individual-based model (IBM that simulated the Lagrangian trajectory of prey (fish moving within a confined home range (HR. Fishers exhibiting various prototypical fishing styles targeted these fish in the model. We initially hypothesised that more active and more explorative individuals would be systematically removed under all fished conditions, in turn creating negative selection differentials on low activity phenotypes and maybe on small HR. Our results partly supported these general predictions. Standardised selection differentials were, on average, more negative on HR than on activity. However, in many simulation runs, positive selection pressures on HR were also identified, which resulted from the stochastic properties of the fishes' movement and its interaction with the human predator. In contrast, there was a consistent negative selection on activity under all types of fishing styles. Therefore, in situations where catchability depends on spatial encounters between human predators and fish, we would predict a consistent selection towards low activity phenotypes and have less faith in the direction of the selection on HR size. Our study is the first theoretical investigation on the direction of fishery-induced selection of behaviour using passive fishing gears. The few empirical studies where catchability of fish was measured in relation to passive fishing techniques, such as gill-nets, traps or recreational fishing, support our predictions that fish in highly exploited situations are, on average, characterised by low swimming activity

  9. Time-Consistent Strategies for a Multiperiod Mean-Variance Portfolio Selection Problem

    Directory of Open Access Journals (Sweden)

    Huiling Wu

    2013-01-01

    Full Text Available It remained prevalent in the past years to obtain the precommitment strategies for Markowitz's mean-variance portfolio optimization problems, but not much is known about their time-consistent strategies. This paper takes a step to investigate the time-consistent Nash equilibrium strategies for a multiperiod mean-variance portfolio selection problem. Under the assumption that the risk aversion is, respectively, a constant and a function of current wealth level, we obtain the explicit expressions for the time-consistent Nash equilibrium strategy and the equilibrium value function. Many interesting properties of the time-consistent results are identified through numerical sensitivity analysis and by comparing them with the classical pre-commitment solutions.

  10. Detecting consistent patterns of directional adaptation using differential selection codon models.

    Science.gov (United States)

    Parto, Sahar; Lartillot, Nicolas

    2017-06-23

    Phylogenetic codon models are often used to characterize the selective regimes acting on protein-coding sequences. Recent methodological developments have led to models explicitly accounting for the interplay between mutation and selection, by modeling the amino acid fitness landscape along the sequence. However, thus far, most of these models have assumed that the fitness landscape is constant over time. Fluctuations of the fitness landscape may often be random or depend on complex and unknown factors. However, some organisms may be subject to systematic changes in selective pressure, resulting in reproducible molecular adaptations across independent lineages subject to similar conditions. Here, we introduce a codon-based differential selection model, which aims to detect and quantify the fine-grained consistent patterns of adaptation at the protein-coding level, as a function of external conditions experienced by the organism under investigation. The model parameterizes the global mutational pressure, as well as the site- and condition-specific amino acid selective preferences. This phylogenetic model is implemented in a Bayesian MCMC framework. After validation with simulations, we applied our method to a dataset of HIV sequences from patients with known HLA genetic background. Our differential selection model detects and characterizes differentially selected coding positions specifically associated with two different HLA alleles. Our differential selection model is able to identify consistent molecular adaptations as a function of repeated changes in the environment of the organism. These models can be applied to many other problems, ranging from viral adaptation to evolution of life-history strategies in plants or animals.

  11. Consistency in Estimation and Model Selection of Dynamic Panel Data Models with Fixed Effects

    Directory of Open Access Journals (Sweden)

    Guangjie Li

    2015-07-01

    Full Text Available We examine the relationship between consistent parameter estimation and model selection for autoregressive panel data models with fixed effects. We find that the transformation of fixed effects proposed by Lancaster (2002 does not necessarily lead to consistent estimation of common parameters when some true exogenous regressors are excluded. We propose a data dependent way to specify the prior of the autoregressive coefficient and argue for comparing different model specifications before parameter estimation. Model selection properties of Bayes factors and Bayesian information criterion (BIC are investigated. When model uncertainty is substantial, we recommend the use of Bayesian Model Averaging to obtain point estimators with lower root mean squared errors (RMSE. We also study the implications of different levels of inclusion probabilities by simulations.

  12. A semi-nonparametric mixture model for selecting functionally consistent proteins.

    Science.gov (United States)

    Yu, Lianbo; Doerge, Rw

    2010-09-28

    High-throughput technologies have led to a new era of proteomics. Although protein microarray experiments are becoming more common place there are a variety of experimental and statistical issues that have yet to be addressed, and that will carry over to new high-throughput technologies unless they are investigated. One of the largest of these challenges is the selection of functionally consistent proteins. We present a novel semi-nonparametric mixture model for classifying proteins as consistent or inconsistent while controlling the false discovery rate and the false non-discovery rate. The performance of the proposed approach is compared to current methods via simulation under a variety of experimental conditions. We provide a statistical method for selecting functionally consistent proteins in the context of protein microarray experiments, but the proposed semi-nonparametric mixture model method can certainly be generalized to solve other mixture data problems. The main advantage of this approach is that it provides the posterior probability of consistency for each protein.

  13. Analyser of sweeping electron beam

    International Nuclear Information System (INIS)

    Strasser, A.

    1993-01-01

    The electron beam analyser has an array of conductors that can be positioned in the field of the sweeping beam, an electronic signal treatment system for the analysis of the signals generated in the conductors by the incident electrons and a display for the different characteristics of the electron beam

  14. Selective sweep analysis in the genomes of the 91-R and 91-C Drosophila melanogaster strains reveals few of the ‘usual suspects’ in Dichlorodiphenyltrichloroethane (DDT) resistance

    Science.gov (United States)

    Adaptation of insect phenotypes for survival after exposure to xenobiotics can result from selection at multiple loci with additive genetic effects. A high level dichlorodiphenyltrichloroethane (DDT) resistance phenotype in the Drosophila melanogaster strain 91-R has resulted due to continuous labo...

  15. Reward speeds up and increases consistency of visual selective attention: a lifespan comparison.

    Science.gov (United States)

    Störmer, Viola; Eppinger, Ben; Li, Shu-Chen

    2014-06-01

    Children and older adults often show less favorable reward-based learning and decision making, relative to younger adults. It is unknown, however, whether reward-based processes that influence relatively early perceptual and attentional processes show similar lifespan differences. In this study, we investigated whether stimulus-reward associations affect selective visual attention differently across the human lifespan. Children, adolescents, younger adults, and older adults performed a visual search task in which the target colors were associated with either high or low monetary rewards. We discovered that high reward value speeded up response times across all four age groups, indicating that reward modulates attentional selection across the lifespan. This speed-up in response time was largest in younger adults, relative to the other three age groups. Furthermore, only younger adults benefited from high reward value in increasing response consistency (i.e., reduction of trial-by-trial reaction time variability). Our findings suggest that reward-based modulations of relatively early and implicit perceptual and attentional processes are operative across the lifespan, and the effects appear to be greater in adulthood. The age-specific effect of reward on reducing intraindividual response variability in younger adults likely reflects mechanisms underlying the development and aging of reward processing, such as lifespan age differences in the efficacy of dopaminergic modulation. Overall, the present results indicate that reward shapes visual perception across different age groups by biasing attention to motivationally salient events.

  16. Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity.

    Directory of Open Access Journals (Sweden)

    Stephen R Doyle

    2017-07-01

    Full Text Available Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread.Pooled next generation sequencing (Pool-seq was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR and sub-optimal responder (SOR parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs, with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure had a significantly greater role in shaping genetic diversity than the evolution of SOR.This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic

  17. Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

    Science.gov (United States)

    Nana-Djeunga, Hugues C.; Kengne-Ouafo, Jonas A.; Pion, Sébastien D. S.; Bopda, Jean; Kamgno, Joseph; Wanji, Samuel; Che, Hua; Kuesel, Annette C.; Walker, Martin; Basáñez, Maria-Gloria; Boakye, Daniel A.; Osei-Atweneboana, Mike Y.; Boussinesq, Michel; Prichard, Roger K.; Grant, Warwick N.

    2017-01-01

    Background Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana—exposed to more than a decade of regular ivermectin treatment—have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread. Methodology/Principal findings Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR. Conclusions/Significance This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different

  18. Variants of Moreau's sweeping process

    International Nuclear Information System (INIS)

    Siddiqi, A.H.; Manchanda, P.

    2001-07-01

    In this paper we prove the existence and uniqueness of two variants of Moreau's sweeping process -u'(t) is an element of Nc (t) (u(t)), where in one variant we replace u(t) by u'(t) in the right-hand side of the inclusion and in the second variant u'(t) and u(t) are respectively replaced by u''(t) and u'(t). (author)

  19. A Consistent Fuzzy Preference Relations Based ANP Model for R&D Project Selection

    Directory of Open Access Journals (Sweden)

    Chia-Hua Cheng

    2017-08-01

    Full Text Available In today’s rapidly changing economy, technology companies have to make decisions on research and development (R&D projects investment on a routine bases with such decisions having a direct impact on that company’s profitability, sustainability and future growth. Companies seeking profitable opportunities for investment and project selection must consider many factors such as resource limitations and differences in assessment, with consideration of both qualitative and quantitative criteria. Often, differences in perception by the various stakeholders hinder the attainment of a consensus of opinion and coordination efforts. Thus, in this study, a hybrid model is developed for the consideration of the complex criteria taking into account the different opinions of the various stakeholders who often come from different departments within the company and have different opinions about which direction to take. The decision-making trial and evaluation laboratory (DEMATEL approach is used to convert the cause and effect relations representing the criteria into a visual network structure. A consistent fuzzy preference relations based analytic network process (CFPR-ANP method is developed to calculate the preference-weights of the criteria based on the derived network structure. The CFPR-ANP is an improvement over the original analytic network process (ANP method in that it reduces the problem of inconsistency as well as the number of pairwise comparisons. The combined complex proportional assessment (COPRAS-G method is applied with fuzzy grey relations to resolve conflicts arising from differences in information and opinions provided by the different stakeholders about the selection of the most suitable R&D projects. This novel combination approach is then used to assist an international brand-name company to prioritize projects and make project decisions that will maximize returns and ensure sustainability for the company.

  20. Sweep time performance of optic streak camera

    International Nuclear Information System (INIS)

    Wang Zhebin; Yang Dong; Zhang Huige

    2012-01-01

    The sweep time performance of the optic streak camera (OSC) is of critical importance to its application. The systematic analysis of full-screen sweep velocity shows that the traditional method based on the averaged velocity and its nonlinearity would increase the uncertainty of sweep time and can not reflect the influence of the spatial distortion of OSC. A elaborate method for sweep time has been developed with the aid of full-screen sweep velocity and its uncertainty. It is proved by the theoretical analysis and experimental study that the method would decrease the uncertainty of sweep time within 1%, which would improve the accuracy of sweep time and the reliability of OSC application. (authors)

  1. 3D flow visualizations by means of laser beam sweeps

    International Nuclear Information System (INIS)

    Prenel, J.P.; Porcar, R.; Diemunsch, G.

    1987-01-01

    A method in which two-dimensional aperiodic or periodic sweeps are used to produce three-dimensional light sweeps makes possible the quasi-simultaneous recording of different specific planes of a flow, or the characterization of a fluid without revolution symmetry. The optical device consists of two scanners (whose axes are orthogonal) set into a telescope, allowing fine focusing of the light sheets in the study zone. The method also allows visualizations on skewed surfaces, particularly those of flows without a cylindrical geometry; it is applicable from low velocity, as in heat convection, to supersonic velocity, as in the analysis of a nonaxisymmetric ejector. 8 references

  2. Mental health courts and their selection processes: modeling variation for consistency.

    Science.gov (United States)

    Wolff, Nancy; Fabrikant, Nicole; Belenko, Steven

    2011-10-01

    Admission into mental health courts is based on a complicated and often variable decision-making process that involves multiple parties representing different expertise and interests. To the extent that eligibility criteria of mental health courts are more suggestive than deterministic, selection bias can be expected. Very little research has focused on the selection processes underpinning problem-solving courts even though such processes may dominate the performance of these interventions. This article describes a qualitative study designed to deconstruct the selection and admission processes of mental health courts. In this article, we describe a multi-stage, complex process for screening and admitting clients into mental health courts. The selection filtering model that is described has three eligibility screening stages: initial, assessment, and evaluation. The results of this study suggest that clients selected by mental health courts are shaped by the formal and informal selection criteria, as well as by the local treatment system.

  3. Combined Influence of Selective Focus and Decision Involvement on Attitude-Decision Consistency in a Memory-based Decision Context

    OpenAIRE

    A. VAN KERCKHOVE; I. VERMEIR; M. GEUENS

    2009-01-01

    Marketers often use salient stimuli to draw consumers’ attention to a specific brand in the hope that a selective focus on the own brand increases the sales of this brand. However, previous studies are inconsistent concerning the impact that selectively focusing on a specific brand has on final brand choice. To offer an explanation for these inconsistent results, this paper introduces decision involvement as a moderator of the relation between selective focus and attitude-decision consistency...

  4. TIME CALIBRATED OSCILLOSCOPE SWEEP CIRCUIT

    Science.gov (United States)

    Smith, V.L.; Carstensen, H.K.

    1959-11-24

    An improved time calibrated sweep circuit is presented, which extends the range of usefulness of conventional oscilloscopes as utilized for time calibrated display applications in accordance with U. S. Patent No. 2,832,002. Principal novelty resides in the provision of a pair of separate signal paths, each of which is phase and amplitude adjustable, to connect a high-frequency calibration oscillator to the output of a sawtooth generator also connected to the respective horizontal deflection plates of an oscilloscope cathode ray tube. The amplitude and phase of the calibration oscillator signals in the two signal paths are adjusted to balance out feedthrough currents capacitively coupled at high frequencies of the calibration oscillator from each horizontal deflection plate to the vertical plates of the cathode ray tube.

  5. A study of Consistency in the Selection of Search Terms and Search Concepts: A Case Study in National Taiwan University

    Directory of Open Access Journals (Sweden)

    Mu-hsuan Huang

    2001-12-01

    Full Text Available This article analyzes the consistency in the selection of search terms and search contents of college and graduate students in National Taiwan University when they are using PsycLIT CD-ROM database. 31 students conducted pre-assigned searches, doing 59 searches generating 609 search terms. The study finds the consistency in selection of search terms of first level is 22.14% and second level is 35%. These results are similar with others’ researches. About the consistency in search concepts, no matter the overlaps of searched articles or judge relevant articles are lower than other researches. [Article content in Chinese

  6. Strongyle egg shedding consistency in horses on farms using selective therapy in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Martin Krarup; Haaning, Niels; Olsen, Susanne Nautrup

    2006-01-01

    Knowledge of horses that shed the same number of strongyle eggs over time can lead to the optimization of parasite control strategies. This study evaluated shedding of strongyle eggs in 424 horses on 10 farms whan a selective anthelmintic treatment regime was used over a 3-year period....

  7. Strong and consistent natural selection associated with armour reduction in sticklebacks.

    Science.gov (United States)

    LE Rouzic, Arnaud; Østbye, Kjartan; Klepaker, Tom O; Hansen, Thomas F; Bernatchez, Louis; Schluter, Dolph; Vøllestad, L Asbjørn

    2011-06-01

    Measuring the strength of natural selection is tremendously important in evolutionary biology, but remains a challenging task. In this work, we analyse the characteristics of selection for a morphological change (lateral-plate reduction) in the threespine stickleback Gasterosteus aculeatus. Adaptation to freshwater, leading with the reduction or loss of the bony lateral armour, has occurred in parallel on numerous occasions in this species. Completely-plated and low-plated sticklebacks were introduced into a pond, and the phenotypic changes were tracked for 20 years. Fish from the last generation were genotyped for the Ectodysplasin-A (Eda) locus, the major gene involved in armour development. We found a strong fitness advantage for the freshwater-type fish (on average, 20% fitness advantage for the freshwater morph, and 92% for the freshwater genotype). The trend is best explained by assuming that this fitness advantage is maximum at the beginning of the invasion and decreases with time. Such fitness differences provide a quantifiable example of rapid selection-driven phenotypic evolution associated with environmental change in a natural population. © 2011 Blackwell Publishing Ltd.

  8. Alternating direction transport sweeps for linear discontinuous SN method

    International Nuclear Information System (INIS)

    Yavuz, M.; Aykanat, C.

    1993-01-01

    The performance of Alternating Direction Transport Sweep (ADTS) method is investigated for spatially differenced Linear Discontinuous S N (LD-S N ) problems on a MIMD multicomputer, Intel IPSC/2. The method consists of dividing a transport problem spatially into sub-problems, assigning each sub-problem to a separate processor. Then, the problem is solved by performing transport sweeps iterating on the scattering source and interface fluxes between the sub-problems. In each processor, the order of transport sweeps is scheduled such that a processor completing its computation in a quadrant of a transport sweep is able to use the most recent information (exiting fluxes of neighboring processor) as its incoming fluxes to start the next quadrant calculation. Implementation of this method on the Intel IPSC/2 multicomputer displays significant speedups over the one-processor method. Also, the performance of the method is compared with those reported previously for the Diamond Differenced S N (DD-S N ) method. Our experimental experience illustrates that the parallel performance of both the ADTS LD- and DD-S N methods is the same. (orig.)

  9. A consistent reaction scheme for the selective catalytic reduction of nitrogen oxides with ammonia

    DEFF Research Database (Denmark)

    Janssens, Ton V.W.; Falsig, Hanne; Lundegaard, Lars Fahl

    2015-01-01

    For the first time, the standard and fast selective catalytic reduction of NO by NH3 are described in a complete catalytic cycle, that is able to produce the correct stoichiometry, while only allowing adsorption and desorption of stable molecules. The standard SCR reaction is a coupling of the ac...... for standard SCR. Finally, the role of a nitrate/nitrite equilibrium and the possible in uence of Cu dimers and Brønsted sites are discussed, and an explanation is offered as to how a catalyst can be effective for SCR, while being a poor catalyst for NO oxidation to NO2....... spectroscopy (FTIR). A consequence of the reaction scheme is that all intermediates in fast SCR are also part of the standard SCR cycle. The calculated activation energy by density functional theory (DFT) indicates that the oxidation of an NO molecule by O2 to a bidentate nitrate ligand is rate determining...

  10. Thermal effects of divertor sweeping in ITER

    International Nuclear Information System (INIS)

    Wesley, J.C.

    1992-01-01

    In this paper, thermal effects of magnetically sweeping the separatrix strike point on the outer divertor target of the International Thermonuclear Fusion Reactor (ITER) are calculated. For the 0. 2 Hz x ± 12 cm sweep scenario proposed for ITER operations, the thermal capability of a generic target design is found to be slightly inadequate (by ∼ 5%) to accommodate the full degree of plasma scrape-off peaking postulated as a design basis. The principal problem identified is that the 5 s sweep period is long relative to the 1. 4 s thermal time constant of the divertor target. An increase of the sweep frequency to ∼ 1 Hz is suggested: this increase would provide a power handling margin of ∼ 25% relative to present operational criteria

  11. Southwest Energy Efficiency Project (SWEEP) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Howard [Southwest Energy Efficiency Project (SWEEP), Boulder, CO (United States); Meyers, Jim [Southwest Energy Efficiency Project (SWEEP), Boulder, CO (United States)

    2018-01-29

    SWEEP worked with Energy Efficiency and Renewable Energy (EERE) programs to foster greater energy efficiency throughout the Southwest. SWEEP accomplished this through a combination of analysis and support; preparation and distribution of materials on best practice technologies, policies and programs; and technical assistance and information dissemination to states and municipalities in the southwest supporting BTO, AMO, OWIP for advancement of efficiency in products and practices. These efforts were accomplished during the period 2012 through 2017.

  12. Feeling conflicted and seeking information: when ambivalence enhances and diminishes selective exposure to attitude-consistent information.

    Science.gov (United States)

    Sawicki, Vanessa; Wegener, Duane T; Clark, Jason K; Fabrigar, Leandre R; Smith, Steven M; Durso, Geoffrey R O

    2013-06-01

    To date, little research has examined the impact of attitudinal ambivalence on attitude-congruent selective exposure. Past research would suggest that strong/univalent rather than weak/ambivalent attitudes should be more predictive of proattitudinal information seeking. Although ambivalent attitude structure might weaken the attitude's effect on seeking proattitudinal information, we believe that conflicted attitudes might also motivate attitude-congruent selective exposure because proattitudinal information should be effective in reducing ambivalence. Two studies provide evidence that the effects of ambivalence on information choices depend on amount of issue knowledge. That is, ambivalence motivates attitude-consistent exposure when issue knowledge is relatively low because less familiar information is perceived to be effective at reducing ambivalence. Conversely, when knowledge is relatively high, more unambivalent (univalent) attitudes predicted attitude-consistent information seeking.

  13. Investigation of Spiral and Sweeping Holes

    Science.gov (United States)

    Thurman, Douglas; Poinsatte, Philip; Ameri, Ali; Culley, Dennis; Raghu, Surya; Shyam, Vikram

    2015-01-01

    Surface infrared thermography, hotwire anemometry, and thermocouple surveys were performed on two new film cooling hole geometries: spiral/rifled holes and fluidic sweeping holes. The spiral holes attempt to induce large-scale vorticity to the film cooling jet as it exits the hole to prevent the formation of the kidney shaped vortices commonly associated with film cooling jets. The fluidic sweeping hole uses a passive in-hole geometry to induce jet sweeping at frequencies that scale with blowing ratios. The spiral hole performance is compared to that of round holes with and without compound angles. The fluidic hole is of the diffusion class of holes and is therefore compared to a 777 hole and Square holes. A patent-pending spiral hole design showed the highest potential of the non-diffusion type hole configurations. Velocity contours and flow temperature were acquired at discreet cross-sections of the downstream flow field. The passive fluidic sweeping hole shows the most uniform cooling distribution but suffers from low span-averaged effectiveness levels due to enhanced mixing. The data was taken at a Reynolds number of 11,000 based on hole diameter and freestream velocity. Infrared thermography was taken for blowing rations of 1.0, 1.5, 2.0, and 2.5 at a density ration of 1.05. The flow inside the fluidic sweeping hole was studied using 3D unsteady RANS.

  14. A consistency-based feature selection method allied with linear SVMs for HIV-1 protease cleavage site prediction.

    Directory of Open Access Journals (Sweden)

    Orkun Oztürk

    Full Text Available BACKGROUND: Predicting type-1 Human Immunodeficiency Virus (HIV-1 protease cleavage site in protein molecules and determining its specificity is an important task which has attracted considerable attention in the research community. Achievements in this area are expected to result in effective drug design (especially for HIV-1 protease inhibitors against this life-threatening virus. However, some drawbacks (like the shortage of the available training data and the high dimensionality of the feature space turn this task into a difficult classification problem. Thus, various machine learning techniques, and specifically several classification methods have been proposed in order to increase the accuracy of the classification model. In addition, for several classification problems, which are characterized by having few samples and many features, selecting the most relevant features is a major factor for increasing classification accuracy. RESULTS: We propose for HIV-1 data a consistency-based feature selection approach in conjunction with recursive feature elimination of support vector machines (SVMs. We used various classifiers for evaluating the results obtained from the feature selection process. We further demonstrated the effectiveness of our proposed method by comparing it with a state-of-the-art feature selection method applied on HIV-1 data, and we evaluated the reported results based on attributes which have been selected from different combinations. CONCLUSION: Applying feature selection on training data before realizing the classification task seems to be a reasonable data-mining process when working with types of data similar to HIV-1. On HIV-1 data, some feature selection or extraction operations in conjunction with different classifiers have been tested and noteworthy outcomes have been reported. These facts motivate for the work presented in this paper. SOFTWARE AVAILABILITY: The software is available at http

  15. Selecting the best bank that offered Islamic personal loan package by using consistent fuzzy preference relations (CFPR)

    Science.gov (United States)

    Kadir, Norhidayah A.; Sarudin, Ezzah Suraya; Hamid, Fairus; Shamsuddin, Nor Diyana Ahmad

    2014-10-01

    There are various thoughts and opinions when it comes to how people think of their selected banks. Therefore, to choose the best bank with a good personal loan package can be a bit tricky especially for first time customer. This research offers a guide in choosing the right bank for applying personal loan package by highlighting the important criteria that applicants should take into consideration. In order to cater the problem above, we used Consistent Fuzzy Preference Relations (CFPR). Based on expert and public opinions, the important criteria in selecting an Islamic personal loan package are interest rate, tenure of loan, processing period and security of the loan. We developed questionnaire with the criteria mention earlier and distributed it among academic staffs and non academic staffs at Faculty of Computer and Mathematical Sciences (FSKM), UiTM Shah Alam. Based on the questionnaire, we found that four banks have been selected for multiple reasons. Before we could determine the best bank, calculations are divided into 2 phases which are criteria weights determination and ranking of alternatives. We implemented these phases to get the aggregation result and to obtain the ranking in descending order. As a result, our objectives have been achieved. As a conclusion, CFPR can help others in the decision making process.

  16. Soft Sweeps Are the Dominant Mode of Adaptation in the Human Genome.

    Science.gov (United States)

    Schrider, Daniel R; Kern, Andrew D

    2017-08-01

    The degree to which adaptation in recent human evolution shapes genetic variation remains controversial. This is in part due to the limited evidence in humans for classic "hard selective sweeps", wherein a novel beneficial mutation rapidly sweeps through a population to fixation. However, positive selection may often proceed via "soft sweeps" acting on mutations already present within a population. Here, we examine recent positive selection across six human populations using a powerful machine learning approach that is sensitive to both hard and soft sweeps. We found evidence that soft sweeps are widespread and account for the vast majority of recent human adaptation. Surprisingly, our results also suggest that linked positive selection affects patterns of variation across much of the genome, and may increase the frequencies of deleterious mutations. Our results also reveal insights into the role of sexual selection, cancer risk, and central nervous system development in recent human evolution. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. Nonadiabatic exchange dynamics during adiabatic frequency sweeps.

    Science.gov (United States)

    Barbara, Thomas M

    2016-04-01

    A Bloch equation analysis that includes relaxation and exchange effects during an adiabatic frequency swept pulse is presented. For a large class of sweeps, relaxation can be incorporated using simple first order perturbation theory. For anisochronous exchange, new expressions are derived for exchange augmented rotating frame relaxation. For isochronous exchange between sites with distinct relaxation rate constants outside the extreme narrowing limit, simple criteria for adiabatic exchange are derived and demonstrate that frequency sweeps commonly in use may not be adiabatic with regard to exchange unless the exchange rates are much larger than the relaxation rates. Otherwise, accurate assessment of the sensitivity to exchange dynamics will require numerical integration of the rate equations. Examples of this situation are given for experimentally relevant parameters believed to hold for in-vivo tissue. These results are of significance in the study of exchange induced contrast in magnetic resonance imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Solar Wind Earth Exchange Project (SWEEP)

    Science.gov (United States)

    2016-10-28

    highly charged ions of the solar wind. The main challenge in predicting the resultant photon flux in the X-ray energy bands is due to the...Newton, an X-ray astronomical observatory. We use OMNI solar wind conditions, heavy ion composition data from ACE, the Hodges neutral hydrogen model...of SWEEP was to compare theoretical models of X-ray emission in the terrestrial magnetosphere caused by the Solar Wind Charge Exchange

  19. Automatically sweeping dual-channel boxcar integrator

    International Nuclear Information System (INIS)

    Keefe, D.J.; Patterson, D.R.

    1978-01-01

    An automatically sweeping dual-channel boxcar integrator has been developed to automate the search for a signal that repeatedly follows a trigger pulse by a constant or slowly varying time delay when that signal is completely hidden in random electrical noise and dc-offset drifts. The automatically sweeping dual-channel boxcar integrator improves the signal-to-noise ratio and eliminates dc-drift errors in the same way that a conventional dual-channel boxcar integrator does, but, in addition, automatically locates the hidden signal. When the signal is found, its time delay is displayed with 100-ns resolution, and its peak value is automatically measured and displayed. This relieves the operator of the tedious, time-consuming, and error-prone search for the signal whenever the time delay changes. The automatically sweeping boxcar integrator can also be used as a conventional dual-channel boxcar integrator. In either mode, it can repeatedly integrate a signal up to 990 times and thus make accurate measurements of the signal pulse height in the presence of random noise, dc offsets, and unsynchronized interfering signals

  20. Strategy for a consistent selection of radionuclide migration parameters for the Belgian safety and feasibility case-1

    International Nuclear Information System (INIS)

    Bruggeman, C.; Maes, N.; Salah, S.; Brassinnes, S.; Van Geet, M.

    2010-01-01

    ;best estimates'. The 'source range' is the range outside of which the involved parameter is almost certainly not expected to lay, while the 'expert range' is the range inside of which the involved parameter is judged to lay by experts. The expert range is therefore by definition more narrow than the source range, and represents the most 'realistically foreseeable' parameter set based on current knowledge. The source range on the other hand, represents a more 'pessimistic' or 'conservative' parameter set. Given the complexity of the geochemical environment, and the sheer multitude of different well- and ill-defined geochemical processes taking place under such conditions, a complete thermodynamic understanding and description is in reality impossible to achieve. Moreover, the currently considered PA conceptual models are very simple from a geochemical point-of-view, and are not capable to account for this multitude of processes. Therefore, the translation of all these processes to a limited, but relevant, parameter database, is not straightforward. The above observations and limitations make it necessary to derive a sound methodology that can be used for the selection of retention and migration parameters for safety-relevant nuclides. This methodology will strive for thermodynamic consistency, but will take into account practical limitations with regard to the understanding of geochemical processes, the ability to describe them, and the simplifications needed to describe these processes with parameters used for PA. The cornerstone of this methodology involves the drafting of so-called 'phenomenological models'. These models are based on the combined insights gained from: 1) experimental observations of the geochemical behaviour of the different considered radionuclides, 2) thermodynamical reflections with regard to their general geochemical characteristics, 3) geochemical modelling which is used to predict the major

  1. HB-Line Dissolution of Glovebox Floor Sweepings

    International Nuclear Information System (INIS)

    Gray, J.H.

    1998-02-01

    Two candidate flowsheets for dissolving glovebox floor sweepings in the HB-Line Phase I geometrically favorable dissolver have been developed.Dissolving conditions tested and modified during the laboratory program were based on the current processing scheme for dissolving high-fired Pu-238 oxide in HB-Line. Subsequent adjustments made to the HB-Line flowsheet reflected differences in the dissolution behavior between high-fired Pu-238 oxide and the MgO sand/PuF 4 /PuO 2 mixture in glovebox floor sweepings. Although both candidate flowsheets involved two separate dissolving steps and resulted incomplete dissolution of all solids, the one selected for use in HB-Line will require fewer processing operations and resembles the initial flowsheet proposed for dissolving sand, slag, and crucible material in F-Canyon dissolvers. Complete dissolution of glovebox floor sweepings was accomplished in the laboratory by initially dissolving between 55 and 65 degree in a 14 molar nitric acid solution. Under these conditions, partial dissolution of PuF 4 and complete dissolution of PuO 2 and MgO sand were achieved in less than one hour. The presence of free fluoride in solution,uncomplexed by aluminum, was necessary for complete dissolution of the PuO 2 .The remaining PuF 4 dissolved following addition of aluminum nitrate nonahydrate (ANN) to complex the fluoride and heating between 75 and 85 degree C for an additional hour. Precipitation of magnesium and/or aluminum nitrates could occur before, during, and after transfer of product solutions. Both dilution and/or product solution temperature controls may be necessary to prevent precipitation of these salts. Corrosion of the dissolver should not be an issue during these dissolving operations. Corrosion is minimized when dissolving at 55-65 degree C for one to three hours at a maximum uncomplexed free fluoride concentration of 0.07 molar and by dissolving at 75-85 degree C at a one to one aluminum to fluoride mole ratio for another

  2. NOFI oil Vee-Sweep and extension boom test at OHMSETT

    International Nuclear Information System (INIS)

    Bitting, K.R.; Vicedomine, J.

    1993-01-01

    The NOFI Vee-Sweep is an inflatable oil collection boom held in a V configuration by cross netting attached to the skirt of the boom. The NOFI 600S is an inflatable oil boom used to divert oil into the Vee-Sweep. The lower section of the 600S skirt consists of a feather net and a ballast chain. The booms are designed for open-ocean skimming where a skimmer is placed in the Vee-Sweep apex to remove the collected oil. During testing, the booms were preloaded with oil and towed in the OHMSETT tank at various speeds and wave conditions. Each boom was tested for its first and gross (continuous) oil loss speeds. The Vee-Sweep was also evaluated for wave performance, oil thickness vs tow speed, oil loss rate, and critical tow speed. Finally, a DESMI-250 oil skimmer was placed in the Vee-Sweep apex and oil loss tests were run while the skimmer was operating. During the critical tow speed testing, failures occurred due to apex submergence at ca 3.5 knots in calm water and short-crested waves, and 2.4 knots in harbor chop. The oil loss tests showed that the Vee-Sweep retains oil at speeds significantly higher than conventional booms. First oil loss speeds ranged from 1.3 knots in calm water to 1.0 knot in regular waves. The Vee-Sweep's high buoyancy/weight ratio gave it good wave performance in all conditions tested. The 600S oil loss speeds were higher than those of most conventional booms, and performance was better when the feather net was attached. 1 ref., 4 figs., 4 tabs

  3. S/HIC: Robust Identification of Soft and Hard Sweeps Using Machine Learning.

    Directory of Open Access Journals (Sweden)

    Daniel R Schrider

    2016-03-01

    Full Text Available Detecting the targets of adaptive natural selection from whole genome sequencing data is a central problem for population genetics. However, to date most methods have shown sub-optimal performance under realistic demographic scenarios. Moreover, over the past decade there has been a renewed interest in determining the importance of selection from standing variation in adaptation of natural populations, yet very few methods for inferring this model of adaptation at the genome scale have been introduced. Here we introduce a new method, S/HIC, which uses supervised machine learning to precisely infer the location of both hard and soft selective sweeps. We show that S/HIC has unrivaled accuracy for detecting sweeps under demographic histories that are relevant to human populations, and distinguishing sweeps from linked as well as neutrally evolving regions. Moreover, we show that S/HIC is uniquely robust among its competitors to model misspecification. Thus, even if the true demographic model of a population differs catastrophically from that specified by the user, S/HIC still retains impressive discriminatory power. Finally, we apply S/HIC to the case of resequencing data from human chromosome 18 in a European population sample, and demonstrate that we can reliably recover selective sweeps that have been identified earlier using less specific and sensitive methods.

  4. Detection and reconstruction of freeform sweeps

    KAUST Repository

    Barton, Michael

    2014-05-01

    We study the difficult problem of deciding if parts of a freeform surface can be generated, or approximately generated, by the motion of a planar profile through space. While this task is basic for understanding the geometry of shapes as well as highly relevant for manufacturing and building construction, previous approaches were confined to special cases like kinematic surfaces or "moulding" surfaces. The general case remained unsolved so far. We approach this problem by a combination of local and global methods: curve analysis with regard to "movability", curve comparison by common substring search in curvature plots, an exhaustive search through all planar cuts enhanced by quick rejection procedures, the ordering of candidate profiles and finally, global optimization. The main applications of our method are digital reconstruction of CAD models exhibiting sweep patches, and aiding in manufacturing freeform surfaces by pointing out those parts which can be approximated by sweeps. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  5. Sweeping at the Martin boundary of a fine domain

    DEFF Research Database (Denmark)

    El Kadiri, Mohamed; Fuglede, Bent

    2016-01-01

    We study sweeping on a subset of the Riesz-Martin space of a fine domain in R n   (n≥2), both with respect to the natural topology and the minimal-fine topology, and show that the two notions of sweeping are identical.......We study sweeping on a subset of the Riesz-Martin space of a fine domain in R n   (n≥2), both with respect to the natural topology and the minimal-fine topology, and show that the two notions of sweeping are identical....

  6. Application of the WEPS and SWEEP models to non-agricultural disturbed lands

    Directory of Open Access Journals (Sweden)

    J. Tatarko

    2016-12-01

    Full Text Available Wind erosion not only affects agricultural productivity but also soil, air, and water quality. Dust and specifically particulate matter ≤10 μm (PM-10 has adverse effects on respiratory health and also reduces visibility along roadways, resulting in auto accidents. The Wind Erosion Prediction System (WEPS was developed by the USDA-Agricultural Research Service to simulate wind erosion and provide for conservation planning on cultivated agricultural lands. A companion product, known as the Single-Event Wind Erosion Evaluation Program (SWEEP, has also been developed which consists of the stand-alone WEPS erosion submodel combined with a graphical interface to simulate soil loss from single (i.e., daily wind storm events. In addition to agricultural lands, wind driven dust emissions also occur from other anthropogenic sources such as construction sites, mined and reclaimed areas, landfills, and other disturbed lands. Although developed for agricultural fields, WEPS and SWEEP are useful tools for simulating erosion by wind for non-agricultural lands where typical agricultural practices are not employed. On disturbed lands, WEPS can be applied for simulating long-term (i.e., multi-year erosion control strategies. SWEEP on the other hand was developed specifically for disturbed lands and can simulate potential soil loss for site- and date-specific planned surface conditions and control practices. This paper presents novel applications of WEPS and SWEEP for developing erosion control strategies on non-agricultural disturbed lands. Erosion control planning with WEPS and SWEEP using water and other dust suppressants, wind barriers, straw mulch, re-vegetation, and other management practices is demonstrated herein through the use of comparative simulation scenarios. The scenarios confirm the efficacy of the WEPS and SWEEP models as valuable tools for supporting the design of erosion control plans for disturbed lands that are not only cost-effective but

  7. Application of the WEPS and SWEEP models to non-agricultural disturbed lands.

    Science.gov (United States)

    Tatarko, J; van Donk, S J; Ascough, J C; Walker, D G

    2016-12-01

    Wind erosion not only affects agricultural productivity but also soil, air, and water quality. Dust and specifically particulate matter ≤10 μm (PM-10) has adverse effects on respiratory health and also reduces visibility along roadways, resulting in auto accidents. The Wind Erosion Prediction System (WEPS) was developed by the USDA-Agricultural Research Service to simulate wind erosion and provide for conservation planning on cultivated agricultural lands. A companion product, known as the Single-Event Wind Erosion Evaluation Program (SWEEP), has also been developed which consists of the stand-alone WEPS erosion submodel combined with a graphical interface to simulate soil loss from single (i.e., daily) wind storm events. In addition to agricultural lands, wind driven dust emissions also occur from other anthropogenic sources such as construction sites, mined and reclaimed areas, landfills, and other disturbed lands. Although developed for agricultural fields, WEPS and SWEEP are useful tools for simulating erosion by wind for non-agricultural lands where typical agricultural practices are not employed. On disturbed lands, WEPS can be applied for simulating long-term (i.e., multi-year) erosion control strategies. SWEEP on the other hand was developed specifically for disturbed lands and can simulate potential soil loss for site- and date-specific planned surface conditions and control practices. This paper presents novel applications of WEPS and SWEEP for developing erosion control strategies on non-agricultural disturbed lands. Erosion control planning with WEPS and SWEEP using water and other dust suppressants, wind barriers, straw mulch, re-vegetation, and other management practices is demonstrated herein through the use of comparative simulation scenarios. The scenarios confirm the efficacy of the WEPS and SWEEP models as valuable tools for supporting the design of erosion control plans for disturbed lands that are not only cost-effective but also incorporate

  8. A Generalised Sweep-Line Method for Safety Properties

    DEFF Research Database (Denmark)

    Mailund; Kristensen, Lars Michael

    2002-01-01

    The recently developed sweep-line method exploits progress present in many concurrent systems to explore the full state space of the system while storing only small fragments of the state space in memory at a time. A disadvantage of the sweep-line method is that it relies on a monotone and global...

  9. A Compositional Sweep-Line State Space Exploration Method

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Mailund, Thomas

    2002-01-01

    State space exploration is a main approach to verification of finite-state systems. The sweep-line method exploits a certain kind of progress present in many systems to reduce peak memory usage during state space exploration. We present a new sweep-line algorithm for a compositional setting where...

  10. Effect of blade sweep on inlet flow in axial compressor cascades

    Directory of Open Access Journals (Sweden)

    Hao Chang

    2015-02-01

    Full Text Available This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep. A computational fluid dynamics (CFD package was used to simulate the cascades and obtain the required three-dimensional (3D flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation (CF terms in the momentum equation. A program for data reduction was conducted to obtain a circumferentially averaged flow field. The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed.

  11. Planetesimal formation by sweep-up coagulation

    Science.gov (United States)

    Windmark, Fredrik; Birnstiel, Til; Ormel, Chris W.; Dullemond, Cornelis P.

    2013-07-01

    The formation of planetesimals is often accredited to collisional sticking of dust grains in the protoplanetary disk. The exact process is however unknown, as collisions between larger aggregates tend to lead to fragmentation or bouncing rather than sticking. These growth barriers tend to halt the dust growth already at millimeters or centimeters in size, which is far below the kilometer-sizes that are needed for gravity to aid in the accretion. To study how far dust coagulation can proceed, we have developed a new collision model based on the latest laboratory experiments, and have used it together with a dust-size evolution code capable of resolving all grain interactions in the protoplanetary disk. We find that for the general dust population, bouncing and fragmenting collisions prevent the growth above millimeter-sizes. However, a small number of lucky particles can grow larger than the rest by only interacting at low, sticky velocities. As they grow, they become increasingly resilient to fragmentation caused by the small grains. In this way, two populations are formed: One which remains small due to the collisional barriers, and one that continues to grow by sweeping up the smaller grains around them.

  12. A selective sweep in chimpanzees : is SIV the culprit?

    NARCIS (Netherlands)

    Groot, N.G. de

    2010-01-01

    The human immunodeficiency virus type 1 (HIV-1) is a major threat to mankind, as most infected individuals develop a lethal disease called acquired immunodeficiency syndrome (AIDS). However, a minority group of individuals are long-term non-progressors (LTNP), and resistance to AIDS is strongly

  13. Sweeping a persisting superconducting magnet with a transformer

    International Nuclear Information System (INIS)

    Spencer, G.F.; Alexander, P.W.; Ihas, G.G.

    1982-01-01

    A method for sweeping a persisting superconducting magnet is described. The field sweep is achieved by including in the superconducting loop of the magnet a coil which acts as the secondary coil of a transformer. Variation of the current in the primary coil of the transformer, controlled from outside the cryostat, causes the field-sweeping action through flux-linking with the superconducting loop. Compared to directly changing the current in a magnet, this technique improves control by the ratio of the magnet's inductance to the transformer's inductance. The advantages of using an all-metal vacuum-tight superconducting feedthrough are discussed. (author)

  14. An Algorithm for Parallel Sn Sweeps on Unstructured Meshes

    International Nuclear Information System (INIS)

    Pautz, Shawn D.

    2002-01-01

    A new algorithm for performing parallel S n sweeps on unstructured meshes is developed. The algorithm uses a low-complexity list ordering heuristic to determine a sweep ordering on any partitioned mesh. For typical problems and with 'normal' mesh partitionings, nearly linear speedups on up to 126 processors are observed. This is an important and desirable result, since although analyses of structured meshes indicate that parallel sweeps will not scale with normal partitioning approaches, no severe asymptotic degradation in the parallel efficiency is observed with modest (≤100) levels of parallelism. This result is a fundamental step in the development of efficient parallel S n methods

  15. Suppression of nonlinear frequency-sweeping of resonant interchange modes in a magnetic dipole with applied radio frequency fields

    International Nuclear Information System (INIS)

    Maslovsky, D.; Levitt, B.; Mauel, M. E.

    2003-01-01

    Interchange instabilities excited by energetic electrons trapped by a magnetic dipole nonlinearly saturate and exhibit complex, coherent spectral characteristics and frequency sweeping [H. P. Warren and M. E. Mauel, Phys. Plasmas 2, 4185 (1995)]. When monochromatic radio frequency (rf) fields are applied in the range of 100-1000 MHz, the saturation behavior of the interchange instability changes dramatically. For applied fields of sufficient intensity and pulse-length, coherent interchange fluctuations are suppressed and frequency sweeping is eliminated. When rf fields are switched off, coherent frequency sweeping reappears. Since low frequency interchange instabilities preserve the electron's first and second adiabatic invariants, these observations can be interpreted as resulting from nonlinear resonant wave-particle interactions described within a particle phase-space, (ψ,φ), comprised of the third adiabatic invariant and the azimuthal angle. Self-consistent numerical simulation is used to study (1) the nonlinear development of the instability, (2) the radial mode structure of the interchange instability, and (3) the suppression of frequency sweeping. When the applied rf heating is modeled as an 'rf collisionality', the simulation reproduces frequency sweeping suppression and suggests an explanation for the observations that is consistent with Berk and co-workers [H. L. Berk et al., Phys. Plasmas 6, 3102 (1999)

  16. Signatures of soft sweeps across the Dt1 locus underlying determinate growth habit in soya bean [Glycine max (L.) Merr.].

    Science.gov (United States)

    Zhong, Limei; Yang, Qiaomei; Yan, Xin; Yu, Chao; Su, Liu; Zhang, Xifeng; Zhu, Youlin

    2017-09-01

    Determinate growth habit is an agronomically important trait associated with domestication in soya bean. Previous studies have demonstrated that the emergence of determinacy is correlated with artificial selection on four nonsynonymous mutations in the Dt1 gene. To better understand the signatures of the soft sweeps across the Dt1 locus and track the origins of the determinate alleles, we examined patterns of nucleotide variation in Dt1 and the surrounding genomic region of approximately 800 kb. Four local, asymmetrical hard sweeps on four determinate alleles, sized approximately 660, 120, 220 and 150 kb, were identified, which constitute the soft sweeps for the adaptation. These variable-sized sweeps substantially reflected the strength and timing of selection and indicated that the selection on the alleles had been completed rapidly within half a century. Statistics of EHH, iHS, H12 and H2/H1 based on haplotype data had the power to detect the soft sweeps, revealing distinct signatures of extensive long-range LD and haplotype homozygosity, and multiple frequent adaptive haplotypes. A haplotype network constructed for Dt1 and a phylogenetic tree based on its extended haplotype block implied independent sources of the adaptive alleles through de novo mutations or rare standing variation in quick succession during the selective phase, strongly supporting multiple origins of the determinacy. We propose that the adaptation of soya bean determinacy is guided by a model of soft sweeps and that this model might be indispensable during crop domestication or evolution. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  17. Procedures for waste management from street sweeping and stormwater systems.

    Science.gov (United States)

    2016-05-01

    Street sweeping and storm water system cleaning activities are conducted regularly by ODOT to comply with NPDES permit requirements and to ensure roadway safety. Once collected, these materials are classified as solid waste and require cost-effective...

  18. Characterization of Residuals Collected from Street Sweeping Operations

    Science.gov (United States)

    2018-02-01

    Street sweeping is a routine roadway maintenance activity conducted by the Virginia Department of Transportation (VDOT). It also provides an added benefit as a non-structural stormwater best management practice implemented by VDOT to meet total maxim...

  19. A beam sweeping system for the Fermilab antiproton production target

    International Nuclear Information System (INIS)

    Bieniosek, F.M.

    1993-08-01

    In the Main Injector era beam intensities high enough to damage the antiproton production target will be available. In order to continue to operate with a tightly-focused primary beam spot on the target, and thus maintain yield, it will be necessary to spread the hot spot on the target by use of a beam sweeping system. This report summarizes the requirements for such a system, and addresses the issues involved in the design of a sweeping system

  20. Interface Consistency

    DEFF Research Database (Denmark)

    Staunstrup, Jørgen

    1998-01-01

    This paper proposes that Interface Consistency is an important issue for the development of modular designs. Byproviding a precise specification of component interfaces it becomes possible to check that separately developedcomponents use a common interface in a coherent matter thus avoiding a very...... significant source of design errors. Awide range of interface specifications are possible, the simplest form is a syntactical check of parameter types.However, today it is possible to do more sophisticated forms involving semantic checks....

  1. The Effects of Sweeping Jet Actuator Parameters on Flow Separation Control

    Science.gov (United States)

    Koklu, Mehti

    2015-01-01

    A parametric experimental study was performed with sweeping jet actuators (fluidic oscillators) to determine their effectiveness in controlling flow separation on an adverse pressure gradient ramp. Actuator parameters that were investigated include blowing coefficients, operation mode, pitch and spreading angles, streamwise location, aspect ratio, and scale. Surface pressure measurements and surface oil flow visualization were used to characterize the effects of these parameters on the actuator performance. 2D Particle Image Velocimetry measurements of the flow field over the ramp and hot-wire measurements of the actuator's jet flow were also obtained for selective cases. In addition, the sweeping jet actuators were compared to other well-known flow control techniques such as micro-vortex generators, steady blowing, and steady vortex-generating jets. The results confirm that the sweeping jet actuators are more effective than steady blowing and steady vortex-generating jets. The results also suggest that an actuator with a larger spreading angle placed closer to the location where the flow separates provides better performance. For the cases tested, an actuator with an aspect ratio, which is the width/depth of the actuator throat, of 2 was found to be optimal. For a fixed momentum coefficient, decreasing the aspect ratio to 1 produced weaker vortices while increasing the aspect ratio to 4 reduced coverage area. Although scaling down the actuator (based on the throat dimensions) from 0.25 inch x 0.125 inch to 0.15 inch x 0.075 inch resulted in similar flow control performance, scaling down the actuator further to 0.075 inch x 0.0375 inch reduced the actuator efficiency by reducing the coverage area and the amount of mixing in the near-wall region. The results of this study provide insight that can be used to design and select the optimal sweeping jet actuator configuration for flow control applications.

  2. Modelling for near-surface interaction of lithium ceramics and sweep-gas by use of cellular automation

    International Nuclear Information System (INIS)

    Shimura, K.; Terai, T.; Yamawaki, M.; Yamaguchi, K.

    2003-01-01

    Tritium release from the lithium ceramics as a fusion reactor breeder material is strongly affected by the composition of the sweep-gas as result of its influences with the material's surface. The typical surface processes which play important roles are adsorption, desorption and interaction between vacancy site and the constituents of the sweep-gas. Among a large number of studies and models, yet it seems to be difficult to model the overall behaviour of those processes due to its complex time-transient nature. In the present work the coarse grained atomic simulation based on the Cellular Automaton (CA) is used to model the dynamics of near-surface interaction between Li 2 O surface and sweep-gas that is consisting of a noble gas, hydrogen gas and water vapour. (author)

  3. Sweep devices for picosecond image-converter streak cameras

    International Nuclear Information System (INIS)

    Cunin, B.; Miehe, J.A.; Sipp, B.; Schelev, M.Ya.; Serduchenko, J.N.; Thebault, J.

    1979-01-01

    Four different sweep devices based on microwave tubes, avalanche transistors, krytrons, and laser-triggered spark gaps are treated in detail. These control circuits are developed for picosecond image-converter cameras and generate sweep pulses providing streak speeds in the range of 10 7 to 5x10 10 cm/sec with maximum time resolution better than 10 -12 sec. Special low-jitter triggering schemes reduce the jitter to less than 5x10 -11 sec. Some problems arising in the construction and matching of the sweep devices and image-streak tube are discussed. Comparative parameters of nanosecond switching elements are presented. The results described can be used by other authors involved in streak camera development

  4. Development of sealing plug for sweep gas line

    International Nuclear Information System (INIS)

    Kikuchi, Taiji; Yamada, Hirokazu; Saitoh, Takashi; Nakamichi, Masaru; Tsuchiya, Kunihiko; Kawamura, Hiroshi

    2004-03-01

    On the irradiation capsule for neutron irradiation test of the tritium breeder, the sealing plug is necessary to prevent a leak of tritium gas when the tritium breeder is picked up from the irradiation capsule after irradiation test. However, the general valve and plug cannot apply to sealing of the sweep gas line because of the following factors, the neutron irradiation effect, limited space in the irradiation capsule, high sealing efficiency, simple method and operation for control. Therefore, the sealing plug for sweep gas line has to be developed. This paper reports the development of the sealing plug for sweep gas line and the operating procedure of the sealing plug in the irradiation capsule. (author)

  5. Single-sweep spectral analysis of contact heat evoked potentials

    DEFF Research Database (Denmark)

    Hansen, Tine M; Graversen, Carina; Frøkjaer, Jens B

    2015-01-01

    AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single-sweep ch......AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single...... by 13% (P = 0.04) and 9% (P = 0.007), while the beta and gamma bands were increased by 10% (P = 0.006) and 24% (P = 0.04). CONCLUSION: The decreases in the delta and theta band are suggested to represent a decrease in the pain specific morphology of the CHEPs, which indicates a diminished pain response...

  6. Determination of lysergic acid diethylamide (LSD) in mouse blood by capillary electrophoresis/ fluorescence spectroscopy with sweeping techniques in micellar electrokinetic chromatography.

    Science.gov (United States)

    Fang, Ching; Liu, Ju-Tsung; Chou, Shiu-Huey; Lin, Cheng-Huang

    2003-03-01

    The separation and on-line concentration of lysergic acid diethylamide (LSD) in mouse blood was achieved by means of capillary electrophoresis/fluorescence spectroscopy using sodium dodecyl sulfate (SDS) as the surfactant. Techniques involving on-line sample concentration, including sweeping micellar electrokinetic chromatography (sweeping-MEKC) and cation-selective exhaustive injection-sweep-micellar electrokinetic chromatography (CSEI-sweep-MEKC) were applied; the optimum on-line concentration and separation conditions were determined. In the analysis of an actual sample, LSD was found in a blood sample from a test mouse (0.1 mg LSD fed to a 20 g mouse; approximately 1/10 to the value of LD(50)). As a result, 120 and 30 ng/mL of LSD was detected at 20 and 60 min, respectively, after ingestion of the doses.

  7. NGC 3312: A victim of ram pressure sweeping

    International Nuclear Information System (INIS)

    Mcmahon, P.M.; Richter, O.G.; Vangorkom, J.H.; Ferguson, H.C.

    1990-01-01

    Researchers are undertaking a volume limited survey of the Hydra I cluster in neutral hydrogen using the National Radio Astronomy Observatory's Very Large Array (VLA). The main purpose is to study the effects of a dense environment on the gaseous component of the galaxies. Observational evidence has been accumulating recently that ram pressure sweeping does occur in the centers of clusters, but it is possible that tidal interactions play a role as well. Results of high resolution HI imaging of NGC 3312, the large peculiar spiral near the cluster center are presented. Hydra I (= A1060) is the nearest rich cluster beyond Virgo and, as such, presents a unique opportunity to do a complete survey of a cluster. It is similar to the Virgo cluster in many of its general physical characteristics, such as size, x ray luminosity, velocity dispersion, and galaxy content (high spiral fraction). However, Hydra I appears to be more regular and relaxed. This is evident in the x ray distribution in its central region, which is radially symmetric and centered on the dominant galaxy, NGC 3311, a cD-like elliptical. The observed x ray luminosity implies a central gas density of 4.5 x 10 to the 3rd power cm(-3). Gallagher (1978) argued from optical images of NGC 3312 that this galaxy might be an ideal candidate to directly study effects of the ram pressure process; it might currently be undergoing stripping of its interstellar medium. The researchers' data are consistent with this suggestion, but other origins of the peculiar appearance cannot yet be ruled out

  8. Achieving consistent image quality and overall radiation dose reduction for coronary CT angiography with body mass index-dependent tube voltage and tube current selection

    International Nuclear Information System (INIS)

    Wang, G.; Gao, J.; Zhao, S.; Sun, X.; Chen, X.; Cui, X.

    2014-01-01

    Aim: To develop a quantitative body mass index (BMI)-dependent tube voltage and tube current selection method for obtaining consistent image quality and overall dose reduction in computed tomography coronary angiography (CTCA). Methods and materials: The images of 190 consecutive patients (group A) who underwent CTCA with fixed protocols (100 kV/193 mAs for 100 patients with a BMI of <27 and 120 kV/175 mAs for 90 patients with a BMI of >27) were retrospectively analysed and reconstructed with an adaptive statistical iterative reconstruction (ASIR) algorithm at 50% blending. Image noise was measured and the relationship to BMI was studied to establish BMI-dependent tube current for obtaining CTCA images with user-specified image noise. One hundred additional cardiac patients (group B) were examined using prospective triggering with the BMI-dependent tube voltage/current. CTCA image-quality score, image noise, and effective dose from groups B and C (subgroup of A of 100 patients examined with prospective triggering only) were obtained and compared. Results: There was a linear relationship between image noise and BMI in group A. Using a BMI-dependent tube current in group B, an average CTCA image noise of 27.7 HU (target 28 HU) and 31.7 HU (target 33 HU) was obtained for the subgroups of patients with BMIs of >27 and of <27, respectively, and was independent of patient BMI. There was no difference between image-quality scores between groups B and C (4.52 versus 4.60, p > 0.05). The average effective dose for group B (2.56 mSv) was 42% lower than group C (4.38 mSv; p < 0.01). Conclusion: BMI-dependent tube voltage/current selection in CTCA provides an individualized protocol that generates consistent image quality and helps to reduce overall patient radiation dose. - Highlights: • BMI-dependent kVp and mA selection method may be established in CCTA. • BMI-dependent kVp and mA enables consistent CCTA image quality. • Overall dose reduction of 40% can

  9. Plasma turbulence measured by fast sweep reflectometry on Tore Supra

    International Nuclear Information System (INIS)

    Clairet, F.; Vermare, L.; Leclert, G.

    2004-01-01

    Traditionally devoted to electron density profile measurement we show that fast frequency sweeping reflectometry technique can bring valuable and innovative measurements onto plasma turbulence. While fast frequency sweeping technique is traditionally devoted to electron density radial profile measurements we show in this paper how we can handle the fluctuations of the reflected signal to recover plasma density fluctuation measurements with a high spatial and temporal resolution. Large size turbulence related to magneto-hydrodynamic (MHD) activity and the associated magnetic islands can be detected. The radial profile of the micro-turbulence, which is responsible for plasma anomalous transport processes, is experimentally determined through the fluctuation of the reflected phase signal. (authors)

  10. Plasma turbulence measured by fast sweep reflectometry on Tore Supra

    International Nuclear Information System (INIS)

    Clairet, F.; Vermare, L.; Heuraux, S.; Leclert, G.

    2004-01-01

    Traditionally devoted to electron density profile measurement we show that fast frequency sweeping reflectometry technique can bring valuable and innovative measurements onto plasma turbulence. While fast frequency sweeping technique is traditionally devoted to electron density radial profile measurements we show in this paper how we can handle the fluctuations of the reflected signal to recover plasma density fluctuation measurements with a high spatial and temporal resolution. Large size turbulence related to magneto-hydrodynamic (MHD) activity and the associated magnetic islands can be detected. The radial profile of the micro-turbulence, which is responsible for plasma anomalous transport processes, is experimentally determined through the fluctuation of the reflected phase signal

  11. Towards the harmonization between National Forest Inventory and Forest Condition Monitoring. Consistency of plot allocation and effect of tree selection methods on sample statistics in Italy.

    Science.gov (United States)

    Gasparini, Patrizia; Di Cosmo, Lucio; Cenni, Enrico; Pompei, Enrico; Ferretti, Marco

    2013-07-01

    In the frame of a process aiming at harmonizing National Forest Inventory (NFI) and ICP Forests Level I Forest Condition Monitoring (FCM) in Italy, we investigated (a) the long-term consistency between FCM sample points (a subsample of the first NFI, 1985, NFI_1) and recent forest area estimates (after the second NFI, 2005, NFI_2) and (b) the effect of tree selection method (tree-based or plot-based) on sample composition and defoliation statistics. The two investigations were carried out on 261 and 252 FCM sites, respectively. Results show that some individual forest categories (larch and stone pine, Norway spruce, other coniferous, beech, temperate oaks and cork oak forests) are over-represented and others (hornbeam and hophornbeam, other deciduous broadleaved and holm oak forests) are under-represented in the FCM sample. This is probably due to a change in forest cover, which has increased by 1,559,200 ha from 1985 to 2005. In case of shift from a tree-based to a plot-based selection method, 3,130 (46.7%) of the original 6,703 sample trees will be abandoned, and 1,473 new trees will be selected. The balance between exclusion of former sample trees and inclusion of new ones will be particularly unfavourable for conifers (with only 16.4% of excluded trees replaced by new ones) and less for deciduous broadleaves (with 63.5% of excluded trees replaced). The total number of tree species surveyed will not be impacted, while the number of trees per species will, and the resulting (plot-based) sample composition will have a much larger frequency of deciduous broadleaved trees. The newly selected trees have-in general-smaller diameter at breast height (DBH) and defoliation scores. Given the larger rate of turnover, the deciduous broadleaved part of the sample will be more impacted. Our results suggest that both a revision of FCM network to account for forest area change and a plot-based approach to permit statistical inference and avoid bias in the tree sample

  12. Sex ratios in the most-selective elite US undergraduate colleges and universities are consistent with the hypothesis that modern educational systems increasingly select for conscientious personality compared with intelligence.

    Science.gov (United States)

    Charlton, Bruce G

    2009-08-01

    The main predictors of examination results and educational achievement in modern societies are intelligence (IQ - or general factor 'g' intelligence) and the personality trait termed 'Conscientiousness' (C). I have previously argued that increased use of continuous assessment (e.g. course work rather than timed and supervised examinations) and increased duration of the educational process implies that modern educational systems have become increasingly selective for the personality trait of Conscientiousness and consequently less selective for IQ. I have tested this prediction (in a preliminary fashion) by looking at the sex ratios in the most selective elite US universities. My two main assumptions are: (1) that a greater proportion of individuals with very high intelligence are men than women, and (2) that women are more conscientious than men. To estimate the proportion of men and women expected at highly-selective schools, I performed demonstration calculations based on three plausible estimates of male and female IQ averages and standard deviations. The expected percentage of men at elite undergraduate colleges (selecting students with IQ above 130 - i.e. in the top 2% of the population) were 66%, 61% and 74%. When these estimates were compared with the sex ratios at 33 elite colleges and universities, only two technical institutes had more than 60% men. Elite US colleges and universities therefore seem to be selecting primarily on the basis of something other than IQ - probably conscientiousness. There is a 'missing population' of very high IQ men who are not being admitted to the most selective and prestigious undergraduate schools, probably because their high school educational qualifications and evaluations are too low. This analysis is therefore consistent with the hypothesis that modern educational systems tend to select more strongly for Conscientiousness than for IQ. The implication is that modern undergraduates at the most-selective US schools are not

  13. Selective Synthesis of Gasoline-Ranged Hydrocarbons from Syngas over Hybrid Catalyst Consisting of Metal-Loaded ZSM-5 Coupled with Copper-Zinc Oxide

    Directory of Open Access Journals (Sweden)

    Ting Ma

    2014-04-01

    Full Text Available The conversion of syngas (CO + H2 to gasoline-ranged hydrocarbons was carried out using a hybrid catalyst consisting of metal-loaded ZSM-5 coupled with Cu-ZnO in a near-critical n-hexane solvent. Methanol was synthesized from syngas over Cu-ZnO; subsequently, was converted to hydrocarbons through the formation of dimethyl ether (DME over the metal-loaded ZSM-5. When 0.5 wt% Pd/ZSM-5 and 5 wt% Cu/ZSM-5 among the metal-loaded ZSM-5 catalysts with Pd, Co, Fe or Cu were employed as a portion of the hybrid catalyst, the gasoline-ranged hydrocarbons were selectively produced (the gasoline-ranged hydrocarbons in all hydrocarbons: 59% for the hybrid catalyst with Pd/ZSM-5 and 64% for that with Cu/ZSM-5 with a similar CO conversion during the reaction. An increase in the Cu loading on ZSM-5 resulted in increasing the yield of the gasoline-ranged hydrocarbons, and in decreasing the yield of DME. Furthermore, the hybrid catalyst with Cu/ZSM-5 exhibited no deactivation for 30 h of the reaction. It was revealed that a hybrid catalyst containing Cu/ZSM-5 was efficient in the selective synthesis of gasoline-ranged hydrocarbons from syngas via methanol in the near-critical n-hexane fluid.

  14. Provably optimal parallel transport sweeps on regular grids

    Energy Technology Data Exchange (ETDEWEB)

    Adams, M. P.; Adams, M. L.; Hawkins, W. D. [Dept. of Nuclear Engineering, Texas A and M University, 3133 TAMU, College Station, TX 77843-3133 (United States); Smith, T.; Rauchwerger, L.; Amato, N. M. [Dept. of Computer Science and Engineering, Texas A and M University, 3133 TAMU, College Station, TX 77843-3133 (United States); Bailey, T. S.; Falgout, R. D. [Lawrence Livermore National Laboratory (United States)

    2013-07-01

    We have found provably optimal algorithms for full-domain discrete-ordinate transport sweeps on regular grids in 3D Cartesian geometry. We describe these algorithms and sketch a 'proof that they always execute the full eight-octant sweep in the minimum possible number of stages for a given P{sub x} x P{sub y} x P{sub z} partitioning. Computational results demonstrate that our optimal scheduling algorithms execute sweeps in the minimum possible stage count. Observed parallel efficiencies agree well with our performance model. An older version of our PDT transport code achieves almost 80% parallel efficiency on 131,072 cores, on a weak-scaling problem with only one energy group, 80 directions, and 4096 cells/core. A newer version is less efficient at present-we are still improving its implementation - but achieves almost 60% parallel efficiency on 393,216 cores. These results conclusively demonstrate that sweeps can perform with high efficiency on core counts approaching 10{sup 6}. (authors)

  15. Provably optimal parallel transport sweeps on regular grids

    International Nuclear Information System (INIS)

    Adams, M. P.; Adams, M. L.; Hawkins, W. D.; Smith, T.; Rauchwerger, L.; Amato, N. M.; Bailey, T. S.; Falgout, R. D.

    2013-01-01

    We have found provably optimal algorithms for full-domain discrete-ordinate transport sweeps on regular grids in 3D Cartesian geometry. We describe these algorithms and sketch a 'proof that they always execute the full eight-octant sweep in the minimum possible number of stages for a given P x x P y x P z partitioning. Computational results demonstrate that our optimal scheduling algorithms execute sweeps in the minimum possible stage count. Observed parallel efficiencies agree well with our performance model. An older version of our PDT transport code achieves almost 80% parallel efficiency on 131,072 cores, on a weak-scaling problem with only one energy group, 80 directions, and 4096 cells/core. A newer version is less efficient at present-we are still improving its implementation - but achieves almost 60% parallel efficiency on 393,216 cores. These results conclusively demonstrate that sweeps can perform with high efficiency on core counts approaching 10 6 . (authors)

  16. A new interpretation of distortion artifacts in sweep measurements

    DEFF Research Database (Denmark)

    Torras Rosell, Antoni; Jacobsen, Finn

    2011-01-01

    The characterization of acoustical spaces by means of impulse response measurements is often biased by the nonlinear behavior of the loudspeaker used to excite the system under test. In this context the distortion immunity provided by the sweep technique has been investigated. The results show...

  17. Using temperature sweeps to investigate rheology of bioplastics

    Science.gov (United States)

    As part of research toward production of protein-based bioplastics, small amplitude oscillatory shear analyses were performed in the temperature sweep mode to examine protein blends in the presence of wheat flour and glycerol. The elastic modulus (G') of these samples was much higher than the visco...

  18. Experimental transonic flutter characteristics of two 72 deg-sweep delta-wing models

    Science.gov (United States)

    Doggett, Robert V., Jr.; Soistmann, David L.; Spain, Charles V.; Parker, Ellen C.; Silva, Walter A.

    1989-01-01

    Transonic flutter boundaries are presented for two simple, 72 deg. sweep, low-aspect-ratio wing models. One model was an aspect-ratio 0.65 delta wing; the other model was an aspect-ratio 0.54 clipped-delta wing. Flutter boundaries for the delta wing are presented for the Mach number range of 0.56 to 1.22. Flutter boundaries for the clipped-delta wing are presented for the Mach number range of 0.72 to 0.95. Selected vibration characteristics of the models are also presented.

  19. Acupuncture and/or sweeping of the fetal membranes before induction of labor

    DEFF Research Database (Denmark)

    Andersen, Bodil Birgitte; Knudsen, Birthe; Lyndrup, Jens

    2013-01-01

    To evaluate the efficacy of acupuncture, and sweeping of the fetal membranes, as methods for induction of labor.......To evaluate the efficacy of acupuncture, and sweeping of the fetal membranes, as methods for induction of labor....

  20. A Parallel Sweeping Preconditioner for Heterogeneous 3D Helmholtz Equations

    KAUST Repository

    Poulson, Jack

    2013-05-02

    A parallelization of a sweeping preconditioner for three-dimensional Helmholtz equations without large cavities is introduced and benchmarked for several challenging velocity models. The setup and application costs of the sequential preconditioner are shown to be O(γ2N4/3) and O(γN logN), where γ(ω) denotes the modestly frequency-dependent number of grid points per perfectly matched layer. Several computational and memory improvements are introduced relative to using black-box sparse-direct solvers for the auxiliary problems, and competitive runtimes and iteration counts are reported for high-frequency problems distributed over thousands of cores. Two open-source packages are released along with this paper: Parallel Sweeping Preconditioner (PSP) and the underlying distributed multifrontal solver, Clique. © 2013 Society for Industrial and Applied Mathematics.

  1. Sweep-twist adaptive rotor blade : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Ashwill, Thomas D.

    2010-02-01

    Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercial development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.

  2. The frequency and level of sweep in mixed hardwood saw logs in the eastern United States

    Science.gov (United States)

    Peter Hamner; Marshall S. White; Philip A. Araman

    2007-01-01

    Hardwood sawmills traditionally saw logs in a manner that either orients sawlines parallel to the log central axis (straight sawing) or the log surface (allowing for taper). Sweep is characterized as uniform curvature along the entire length of a log. For logs with sweep, lumber yield losses from straight and taper sawing increase with increasing levels of sweep. Curve...

  3. Surfaces Relief Profilometry of Solid Objects by Sweeping of a Laser Line

    Science.gov (United States)

    Salas-Peimbert, Didia P.; Trujillo-Schiaffino, Gerardo; Mendoza-Villegas, Paloma G.; Ojeda-González, Daniel; Almazán-Cuellar, Saúl; Corral-Martínez, Luis F.

    2008-04-01

    This paper describes the development of a laser system for the digitalization and three-dimensional reconstruction of solid objects. The first step consists of applying on the object a linear sweeping of a thin laser line using a laser diode with 635 nm and 5 mW, a motorized stage for linear displacement of 138 mm, and a controller with RS232 interface. The next step consists of capturing and transmitting the image of the deformed line on the object to a computer. For this step was used a monochrome camera CCD, and an image acquisition board. The last step consists of the three-dimensional reconstruction of the solid object. All the corresponding algorithms were implemented using the programming language LabVIEW.

  4. Lipschitz continuous data dependence of sweeping processes in BV spaces

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Roche, T.

    2011-01-01

    Roč. 15, č. 3 (2011), s. 637-650 ISSN 1531-3492 R&D Projects: GA ČR GAP201/10/2315; GA MŠk LC06052 Institutional research plan: CEZ:AV0Z10190503 Keywords : rate independence * discontinuous sweeping process * Kurzweil integral Subject RIV: BA - General Mathematics Impact factor: 0.921, year: 2011 http://aimsciences.org/journals/pdfs.jsp?paperID=5943&mode=full

  5. Fast sweeping method for the factored eikonal equation

    Science.gov (United States)

    Fomel, Sergey; Luo, Songting; Zhao, Hongkai

    2009-09-01

    We develop a fast sweeping method for the factored eikonal equation. By decomposing the solution of a general eikonal equation as the product of two factors: the first factor is the solution to a simple eikonal equation (such as distance) or a previously computed solution to an approximate eikonal equation. The second factor is a necessary modification/correction. Appropriate discretization and a fast sweeping strategy are designed for the equation of the correction part. The key idea is to enforce the causality of the original eikonal equation during the Gauss-Seidel iterations. Using extensive numerical examples we demonstrate that (1) the convergence behavior of the fast sweeping method for the factored eikonal equation is the same as for the original eikonal equation, i.e., the number of iterations for the Gauss-Seidel iterations is independent of the mesh size, (2) the numerical solution from the factored eikonal equation is more accurate than the numerical solution directly computed from the original eikonal equation, especially for point sources.

  6. Analysis of sweeping heat loads on divertor plate materials

    International Nuclear Information System (INIS)

    Hassanein, A.

    1991-01-01

    The heat flux on the divertor plate of a fusion reactor is probably one of the most limiting constraints on its lifetime. The current heat flux profile on the outer divertor plate of a device like ITER is highly peaked with narrow profile. The peak heat flux can be as high as 30--40 MW/m 2 with full width at half maximum (FWHM) is in the order of a few centimeters. Sweeping the separatrix along the divertor plate is one of the options proposed to reduce the thermomechanical effects of this highly peaked narrow profile distribution. The effectiveness of the sweeping process is investigated parametrically for various design values. The optimum sweeping parameters of a particular heat load will depend on the design of the divertor plate as well as on the profile of such a heat load. In general, moving a highly peaked heat load results in substantial reduction of the thermomechanical effects on the divertor plate. 3 refs., 8 figs

  7. Performance Comparison of Sweeping/Steady Jet Actuators

    Science.gov (United States)

    Hirsch, Damian; Mercier, Justin; Noca, Flavio; Gharib, Morteza

    2015-11-01

    Flow control through the use of steady jet actuators has been used on various aircraft models since the late 1950's. However, the focus of recent studies has shifted towards the use of sweeping jets (fluidic oscillators) rather than steady jet actuators. In this work, experiments using various jet actuator designs were conducted at GALCIT's Lucas Wind Tunnel on a NACA 0012 vertical tail model similar to that of the Boeing 767 vertical stabilizer at Reynolds numbers ranging from 0.5 to 1.2 million. The rudder angle was fixed at 20 degrees. A total of 32 jet actuators were installed along the wingspan perpendicular to the trailing edge and the rudder shoulder of the vertical stabilizer. It is known that these types of flow control prevent separation. However, the goal of this work is to compare different jet designs and evaluate their performance. Parameters such as the number of actuators, their volumetric flow, and the wind tunnel speed were varied. The lift generation capabilities of steady and sweeping jet actuators were then compared. Another set of experiments was conducted to compare a new sweeping jet actuator design with one of the standard versions. Supported by Boeing.

  8. Thermal transients due to sweeping of the separatrix on the monoblock divertor concept for ITER

    International Nuclear Information System (INIS)

    Renda, V.; Papa, L.; Soria, A.

    1991-01-01

    The ITER divertor plate considered in the present study is the monoblock design option, consisting of an armour of CFC-SEP-Carb graphite tiles, crossed by the tubes of the water cooling system made in Mo-Re alloy. Preliminary steady-state calculations for a peak flux of 15 MW/m 2 showed that the allowable thickness to limit the maximum temperature to 1273 K (1000degC) is about 5 mm. This small value reduces the lifetime of the plate, due to the expected erosion rate, to an unacceptable value from the engineering standpoint. A sweeping of the separatrix has been proposed to reduce the erosion of the protective armour and to lessen the thermomechanical effects of the localized peak surface heat flux. A rotation of the null points of the separatrix of 30 mm radius with a frequency of 0.3 Hz for a surface heat flux of 15 MW/m 2 was assumed as nominal working condition. Several scenarios were considered as off-normal conditions: the loss of sweeping accident, the change in frequency from 0.3 to 0.1 Hz and the change of the peak of the surface heat flux from 15 to 30 MW/m 2 . The results related to the nominal condition show that a 16 mm thick armour could be allowed; this value should ensure an acceptable lifetime for the divertor plate. The loss of sweeping accident leads the surface temperature to reach about 2273 K in few seconds; the change in frequency raises the maximum temperature of 423 K, but its range doubles; the change in peak flux leads to a maximum temperature of about 2373 K. (author)

  9. Linear sweep polarographic determination of nucleic acids using acridine orange as a bioprobe

    Directory of Open Access Journals (Sweden)

    WEI SUN

    2007-11-01

    Full Text Available The interaction of acridine orange (AO with double-stranded (ds DNA in aqueous solution was investigated by linear sweep polarography (LSP on a dropping mercury working electrode (DME. In pH 2.5 Britton–Robinson (B–R buffer solution, AO had a sensitive linear sweep polarographic reductive peak at –0.89 V (vs. SCE, which could be greatly inhibited by the addition of dsDNA, with a positive shift of the peak potential. Based on the decrease of the reductive peak current, a new quantitative electrochemical determination method for dsDNA was developed with a linear range of 2.0−20.0 mg l-1 and the linear regression equation: ΔIp” (nA = 111.90 C (mg l-1+125.32 (n = 9, γ = 0.997. The influences of commonly co-existing substances, such as metal ions, amino acid, etc., on the determination were also investigated. The method is sensitive, rapid and simple with good selectivity. The new proposed method was further applied to the detection of RNA and three synthetic samples containing dsDNA with satisfactory results. The binding number and the equilibrium constant between dsDNA and AO were calculated by an electrochemical method.

  10. Cross-polarization phenomena in the NMR of fast spinning solids subject to adiabatic sweeps

    Energy Technology Data Exchange (ETDEWEB)

    Wi, Sungsool, E-mail: sungsool@magnet.fsu.edu, E-mail: lucio.frydman@weizmann.ac.il; Gan, Zhehong [National High Magnetic Field Laboratory, Tallahassee, Florida 32304 (United States); Schurko, Robert [Department of Chemistry and Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor N9B 3P4, Ontario (Canada); Frydman, Lucio, E-mail: sungsool@magnet.fsu.edu, E-mail: lucio.frydman@weizmann.ac.il [National High Magnetic Field Laboratory, Tallahassee, Florida 32304 (United States); Department of Chemical Physics, Weizmann Institute of Sciences, 76100 Rehovot (Israel)

    2015-02-14

    Cross-polarization magic-angle spinning (CPMAS) experiments employing frequency-swept pulses are explored within the context of obtaining broadband signal enhancements for rare spin S = 1/2 nuclei at very high magnetic fields. These experiments employ adiabatic inversion pulses on the S-channel ({sup 13}C) to cover a wide frequency offset range, while simultaneously applying conventional spin-locking pulse on the I-channel ({sup 1}H). Conditions are explored where the adiabatic frequency sweep width, Δν, is changed from selectively irradiating a single magic-angle-spinning (MAS) spinning centerband or sideband, to sweeping over multiple sidebands. A number of new physical features emerge upon assessing the swept-CP method under these conditions, including multiple zero- and double-quantum CP transfers happening in unison with MAS-driven rotary resonance phenomena. These were examined using an average Hamiltonian theory specifically designed to tackle these experiments, with extensive numerical simulations, and with experiments on model compounds. Ultrawide CP profiles spanning frequency ranges of nearly 6⋅γB{sub 1}{sup s} were predicted and observed utilizing this new approach. Potential extensions and applications of this extremely broadband transfer conditions are briefly discussed.

  11. Study of plasma turbulence by ultrafast sweeping reflectometry on the Tore Supra Tokamak

    International Nuclear Information System (INIS)

    Hornung, Gregoire

    2013-01-01

    The performance of a fusion reactor is closely related to the turbulence present in the plasma. The latter is responsible for anomalous transport of heat and particles that degrades the confinement. The measure and characterization of turbulence in tokamak plasma is therefore essential to the understanding and control of this phenomenon. Among the available diagnostics, the sweeping reflectometer installed on Tore Supra allows to access the plasma density fluctuations from the edge to the centre of the plasma discharge with a fine spatial (mm) and temporal resolution (μs), that is of the order of the characteristic turbulence scales.This thesis consisted in the characterization of plasma turbulence in Tore Supra by ultrafast sweeping reflectometry measurements. Correlation analyses are used to quantify the spatial and temporal scales of turbulence as well as their radial velocity. In the first part, the characterization of turbulence properties from the reconstructed plasma density profiles is discussed, in particular through a comparative study with Langmuir probe data. Then, a parametric study is presented, highlighting the effect of collisionality on turbulence, an interpretation of which is proposed in terms of the stabilization of trapped electron turbulence in the confined plasma. Finally, it is shown how additional heating at ion cyclotron frequency produces a significant though local modification of the turbulence in the plasma near the walls, resulting in a strong increase of the structure velocity and a decrease of the correlation time. The supposed effect of rectified potentials generated by the antenna is investigated via numerical simulations. (author) [fr

  12. Reverse spontaneous laser line sweeping in ytterbium fiber laser

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Petr; Peterka, Pavel; Honzátko, Pavel; Kubeček, V.

    2017-01-01

    Roč. 14, č. 3 (2017), č. článku 035102. ISSN 1612-2011 R&D Projects: GA ČR(CZ) GA16-13306S Institutional support: RVO:67985882 ; RVO:68378271 Keywords : laser line sweeping * ytterbium * fiber lasers Subject RIV: BH - Optics, Masers, Lasers; BH - Optics, Masers, Lasers (FZU-D) OBOR OECD: Optics (including laser optics and quantum optics); Optics (including laser optics and quantum optics) (FZU-D) Impact factor: 2.537, year: 2016

  13. Vertical-horizontal wells for depletion and sweep

    Energy Technology Data Exchange (ETDEWEB)

    Muraikhi, A. J.; Pham, T. R.; Liu, J. S.; Khatib, M. R.; Muhaish, A. S. [Saudi Aramco (Saudi Arabia)

    1998-12-31

    A well completion scheme currently in use in a thick, large, elongated carbonate anticline Middle-East oil reservoir is described. This method of well completion calls for a combination of an open hole horizontal section penetrating the top 10 feet of the reservoir and a cased or undisturbed vertical segment through the thick formation. The horizontal section is used for producing and the vertical segment is used for monitoring purposes. Field experience and supported reservoir simulation exercises have shown that the horizontal application is superior to conventional vertical completion both from the economic and from the sweep point of view. 4 refs., 12 figs.

  14. Simulation and theory of spontaneous TAE frequency sweeping

    International Nuclear Information System (INIS)

    Wang Ge; Berk, H.L.

    2012-01-01

    A simulation model, based on the linear tip model of Rosenbluth, Berk and Van Dam (RBV), is developed to study frequency sweeping of toroidal Alfvén eigenmodes (TAEs). The time response of the background wave in the RBV model is given by a Volterra integral equation. This model captures the properties of TAE waves both in the gap and in the continuum. The simulation shows that phase space structures form spontaneously at frequencies close to the linearly predicted frequency, due to resonant particle–wave interactions and background dissipation. The frequency sweeping signals are found to chirp towards the upper and lower continua. However, the chirping signals penetrate only the lower continuum, whereupon the frequency chirps and mode amplitude increases in synchronism to produce an explosive solution. An adiabatic theory describing the evolution of a chirping signal is developed which replicates the chirping dynamics of the simulation in the lower continuum. This theory predicts that a decaying chirping signal will terminate at the upper continuum though in the numerical simulation the hole disintegrates before the upper continuum is reached. (paper)

  15. Simulation and theory of spontaneous TAE frequency sweeping

    Science.gov (United States)

    Wang, Ge; Berk, H. L.

    2012-09-01

    A simulation model, based on the linear tip model of Rosenbluth, Berk and Van Dam (RBV), is developed to study frequency sweeping of toroidal Alfvén eigenmodes (TAEs). The time response of the background wave in the RBV model is given by a Volterra integral equation. This model captures the properties of TAE waves both in the gap and in the continuum. The simulation shows that phase space structures form spontaneously at frequencies close to the linearly predicted frequency, due to resonant particle-wave interactions and background dissipation. The frequency sweeping signals are found to chirp towards the upper and lower continua. However, the chirping signals penetrate only the lower continuum, whereupon the frequency chirps and mode amplitude increases in synchronism to produce an explosive solution. An adiabatic theory describing the evolution of a chirping signal is developed which replicates the chirping dynamics of the simulation in the lower continuum. This theory predicts that a decaying chirping signal will terminate at the upper continuum though in the numerical simulation the hole disintegrates before the upper continuum is reached.

  16. Spall behaviors of high purity copper under sweeping detonation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang, E-mail: yangyanggroup@163.com [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Zhi-qiang, Peng; Xing-zhi, Chen [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Zhao-liang, Guo; Tie-gang, Tang; Hai-bo, Hu [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); Qing-ming, Zhang [National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2016-01-10

    Suites of sweeping detonation experiments were conducted to assess the spall behavior of high purity copper samples with different heat treatment histories. Incipient spall samples were obtained at different sweeping detonation condition. Metallographic and Electron Backscattered Diffraction (EBSD) analyses were performed on the soft-recovered samples. The effects of grain boundaries, grain size, crystal orientation and loading direction on the spall behaviors were discussed. Spall plane branching was found in the main spall plane of the damage samples. For similar microstructure, the area of voids increase with the increase of shock stress, and the coalescence of voids also become more obvious. Results from EBSD analysis show that the grain sizes were decreased and the grains were elongated along the direction of the plate width. Triple junctions composed of two or more general high angle boundaries are the preferred locations for intergranular damage. Voids prefer to nucleate in the grain boundaries composed of grain with high Taylor Factor (TF) than other grains. The damage areas in the grains with high TF are more severe. Boundaries close to perpendicular to the loading direction are more susceptible to void nucleation than the boundaries close to parallel to the loading direction, but the difference of voids nucleated in these two boundaries is less significant than the results obtained by plate impact experiment. It would be caused by the obliquity between the shock loading direction and the plate normal.

  17. Adiabatic sweep pulses for earth's field NMR with a surface coil

    Science.gov (United States)

    Conradi, Mark S.; Altobelli, Stephen A.; Sowko, Nicholas J.; Conradi, Susan H.; Fukushima, Eiichi

    2018-03-01

    Adiabatic NMR sweep pulses are described for inversion and excitation in very low magnetic fields B0 and with broad distribution of excitation field amplitude B1. Two aspects distinguish the low field case: (1) when B1 is comparable to or greater than B0, the rotating field approximation fails and (2) inversion sweeps cannot extend to values well below the Larmor frequency because they would approach or pass through zero frequency. Three approaches to inversion are described. The first is a conventional tangent frequency sweep down to the Larmor frequency, a 180° phase shift, and a sweep back up to the starting frequency. The other two are combined frequency and amplitude sweeps covering a narrower frequency range; one is a symmetric sweep from above to below the Larmor frequency and the other uses a smooth decrease of B1 immediately before and after the 180° phase shift. These two AM/FM sweeps show excellent inversion efficiencies over a wide range of B1, a factor of 30 or more. We also demonstrate an excitation sweep that works well in the presence of the same wide range of B1. We show that the primary effect of the counter-rotating field (i.e., at low B0) is that the magnetization suffers large, periodic deviations from where it would be at large B0. Thus, successful sweep pulses must avoid any sharp features in the amplitude, phase, or frequency.

  18. HUBBLE CLICKS IMAGES OF IO SWEEPING ACROSS JUPITER

    Science.gov (United States)

    2002-01-01

    While hunting for volcanic plumes on Io, NASA's Hubble Space Telescope captured these images of the volatile moon sweeping across the giant face of Jupiter. Only a few weeks before these dramatic images were taken, the orbiting telescope snapped a portrait of one of Io's volcanoes spewing sulfur dioxide 'snow.' These stunning images of the planetary duo are being released to commemorate the ninth anniversary of the Hubble telescope's launch on April 24, 1990. All of these images were taken with the Wide Field and Planetary Camera 2. The three overlapping snapshots show in crisp detail Io passing above Jupiter's turbulent clouds. The close-up picture of Io (bottom right) reveal a 120-mile-high (200-kilometer) plume of sulfur dioxide 'snow' emanating from Pillan, one of the moon's active volcanoes. 'Other observations have inferred sulfur dioxide 'snow' in Io's plumes, but this image offers direct observational evidence for sulfur dioxide 'snow' in an Io plume,' explains John R. Spencer of Lowell Observatory in Flagstaff, Ariz. A Trip Around Jupiter The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. In two of the images, Io appears to be skimming Jupiter's cloud tops, but it's actually 310,000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas the moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut. These images were further sharpened through image reconstruction techniques. The view is so crisp that one would have to stand on Io to see this much detail on Jupiter with the naked eye. The bright patches on Io

  19. Structural Consistency, Consistency, and Sequential Rationality.

    OpenAIRE

    Kreps, David M; Ramey, Garey

    1987-01-01

    Sequential equilibria comprise consistent beliefs and a sequentially ra tional strategy profile. Consistent beliefs are limits of Bayes ratio nal beliefs for sequences of strategies that approach the equilibrium strategy. Beliefs are structurally consistent if they are rationaliz ed by some single conjecture concerning opponents' strategies. Consis tent beliefs are not necessarily structurally consistent, notwithstan ding a claim by Kreps and Robert Wilson (1982). Moreover, the spirit of stru...

  20. Mitigation of divertor heat loads by strike point sweeping in high power JET discharges

    Science.gov (United States)

    Silburn, S. A.; Matthews, G. F.; Challis, C. D.; Frigione, D.; Graves, J. P.; Mantsinen, M. J.; Belonohy, E.; Hobirk, J.; Iglesias, D.; Keeling, D. L.; King, D.; Kirov, K.; Lennholm, M.; Lomas, P. J.; Moradi, S.; Sips, A. C. C.; Tsalas, M.; Contributors, JET

    2017-12-01

    Deliberate periodic movement (sweeping) of the high heat flux divertor strike lines in tokamak plasmas can be used to manage the heat fluxes experienced by exhaust handling plasma facing components, by spreading the heat loads over a larger surface area. Sweeping has recently been adopted as a routine part of the main high performance plasma configurations used on JET, and has enabled pulses with 30 MW plasma heating power and 10 MW radiation to run for 5 s without overheating the divertor tiles. We present analysis of the effectiveness of sweeping for divertor temperature control on JET, using infrared camera data and comparison with a simple 2D heat diffusion model. Around 50% reduction in tile temperature rise is obtained with 5.4 cm sweeping compared to the un-swept case, and the temperature reduction is found to scale slower than linearly with sweeping amplitude in both experiments and modelling. Compatibility of sweeping with high fusion performance is demonstrated, and effects of sweeping on the edge-localised mode behaviour of the plasma are reported and discussed. The prospects of using sweeping in future JET experiments with up to 40 MW heating power are investigated using a model validated against existing experimental data.

  1. Mitigation of divertor heat loads by strike point sweeping in high power JET discharges

    International Nuclear Information System (INIS)

    Silburn, S A; Matthews, G F; Challis, C D; Belonohy, E; Iglesias, D; Keeling, D L; King, D; Kirov, K; Lomas, P J; Frigione, D; Graves, J P; Mantsinen, M J; Hobirk, J; Lennholm, M; Moradi, S; Sips, A C C; Tsalas, M

    2017-01-01

    Deliberate periodic movement (sweeping) of the high heat flux divertor strike lines in tokamak plasmas can be used to manage the heat fluxes experienced by exhaust handling plasma facing components, by spreading the heat loads over a larger surface area. Sweeping has recently been adopted as a routine part of the main high performance plasma configurations used on JET, and has enabled pulses with 30 MW plasma heating power and 10 MW radiation to run for 5 s without overheating the divertor tiles. We present analysis of the effectiveness of sweeping for divertor temperature control on JET, using infrared camera data and comparison with a simple 2D heat diffusion model. Around 50% reduction in tile temperature rise is obtained with 5.4 cm sweeping compared to the un-swept case, and the temperature reduction is found to scale slower than linearly with sweeping amplitude in both experiments and modelling. Compatibility of sweeping with high fusion performance is demonstrated, and effects of sweeping on the edge-localised mode behaviour of the plasma are reported and discussed. The prospects of using sweeping in future JET experiments with up to 40 MW heating power are investigated using a model validated against existing experimental data. (paper)

  2. Simulation of Sweep-Jet Flow Control, Single Jet and Full Vertical Tail

    Science.gov (United States)

    Childs, Robert E.; Stremel, Paul M.; Garcia, Joseph A.; Heineck, James T.; Kushner, Laura K.; Storms, Bruce L.

    2016-01-01

    This work is a simulation technology demonstrator, of sweep jet flow control used to suppress boundary layer separation and increase the maximum achievable load coefficients. A sweep jet is a discrete Coanda jet that oscillates in the plane parallel to an aerodynamic surface. It injects mass and momentum in the approximate streamwise direction. It also generates turbulent eddies at the oscillation frequency, which are typically large relative to the scales of boundary layer turbulence, and which augment mixing across the boundary layer to attack flow separation. Simulations of a fluidic oscillator, the sweep jet emerging from a nozzle downstream of the oscillator, and an array of sweep jets which suppresses boundary layer separation are performed. Simulation results are compared to data from a dedicated validation experiment of a single oscillator and its sweep jet, and from a wind tunnel test of a full-scale Boeing 757 vertical tail augmented with an array of sweep jets. A critical step in the work is the development of realistic time-dependent sweep jet inflow boundary conditions, derived from the results of the single-oscillator simulations, which create the sweep jets in the full-tail simulations. Simulations were performed using the computational fluid dynamics (CFD) solver Overow, with high-order spatial discretization and a range of turbulence modeling. Good results were obtained for all flows simulated, when suitable turbulence modeling was used.

  3. Second order evolution inclusions governed by sweeping process in Banach spaces

    Directory of Open Access Journals (Sweden)

    A. G. Ibrahim

    2009-11-01

    Full Text Available In this paper we prove two existence theorems concerning the existence of solutions for second order evolution inclusions governed by sweeping process with closed convex sets depending on time and state in Banach spaces. This work extends some recent existence theorems cncerning sweeping process from Hilbert spaces to Banach spaces.

  4. Analysis of Massively Parallel Discrete-Ordinates Transport Sweep Algorithms with Collisions

    International Nuclear Information System (INIS)

    Bailey, T.S.; Falgout, R.D.

    2008-01-01

    We present theoretical scaling models for a variety of discrete-ordinates sweep algorithms. In these models, we pay particular attention to the way each algorithm handles collisions. A collision is defined as a processor having multiple angles with ready to be swept during one stage of the sweep. The models also take into account how subdomains are assigned to processors and how angles are grouped during the sweep. We describe a data driven algorithm that resolves collisions efficiently during the sweep as well as other algorithms that have been designed to avoid collisions completely. Our models are validated using the ARGES and AMTRAN transport codes. We then use the models to study and predict scaling trends in all of the sweep algorithms

  5. Examination of Signatures of Recent Positive Selection on Genes Involved in Human Sialic Acid Biology.

    Science.gov (United States)

    Moon, Jiyun M; Aronoff, David M; Capra, John A; Abbot, Patrick; Rokas, Antonis

    2018-03-28

    Sialic acids are nine carbon sugars ubiquitously found on the surfaces of vertebrate cells and are involved in various immune response-related processes. In humans, at least 58 genes spanning diverse functions, from biosynthesis and activation to recycling and degradation, are involved in sialic acid biology. Because of their role in immunity, sialic acid biology genes have been hypothesized to exhibit elevated rates of evolutionary change. Consistent with this hypothesis, several genes involved in sialic acid biology have experienced higher rates of non-synonymous substitutions in the human lineage than their counterparts in other great apes, perhaps in response to ancient pathogens that infected hominins millions of years ago (paleopathogens). To test whether sialic acid biology genes have also experienced more recent positive selection during the evolution of the modern human lineage, reflecting adaptation to contemporary cosmopolitan or geographically-restricted pathogens, we examined whether their protein-coding regions showed evidence of recent hard and soft selective sweeps. This examination involved the calculation of four measures that quantify changes in allele frequency spectra, extent of population differentiation, and haplotype homozygosity caused by recent hard and soft selective sweeps for 55 sialic acid biology genes using publicly available whole genome sequencing data from 1,668 humans from three ethnic groups. To disentangle evidence for selection from confounding demographic effects, we compared the observed patterns in sialic acid biology genes to simulated sequences of the same length under a model of neutral evolution that takes into account human demographic history. We found that the patterns of genetic variation of most sialic acid biology genes did not significantly deviate from neutral expectations and were not significantly different among genes belonging to different functional categories. Those few sialic acid biology genes that

  6. Enhancement of the conductivity detection signal in capillary electrophoresis systems using neutral cyclodextrins as sweeping agents.

    Science.gov (United States)

    Boublík, Milan; Riesová, Martina; Dubský, Pavel; Gaš, Bohuslav

    2018-06-01

    Conductivity detection is a universal detection technique often encountered in electrophoretic separation systems, especially in modern chip-electrophoresis based devices. On the other hand, it is sparsely combined with another contemporary trend of enhancing limits of detection by means of various preconcentration strategies. This can be attributed to the fact that a preconcentration experimental setup usually brings about disturbances in a conductivity baseline. Sweeping with a neutral sweeping agent seems a good candidate for overcoming this problem. A neutral sweeping agent does not hinder the conductivity detection while a charged analyte may preconcentrate on its boundary due to a decrease in its effective mobility. This study investigates such sweeping systems theoretically, by means of computer simulations, and experimentally. A formula is provided for the reliable estimation of the preconcentration factor. Additionally, it is demonstrated that the conductivity signal can significantly benefit from slowing down the analyte and thus the overall signal enhancement can easily overweight amplification caused solely by the sweeping process. The overall enhancement factor can be deduced a priori from the linearized theory of electrophoresis implemented in the PeakMaster freeware. Sweeping by neutral cyclodextrin is demonstrated on an amplification of a conductivity signal of flurbiprofen in a real drug sample. Finally, a possible formation of unexpected system peaks in systems with a neutral sweeping agent is revealed by the computer simulation and confirmed experimentally. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Load consequences when sweeping blades - A case study of a 5 MW pitch controlled wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Verelst, D.R.S.; Larsen, Torben J.

    2010-08-15

    The generic 5 MW NREL wind turbine model is used in Risoe's aeroelastic simulator HAWC2 to investigate 120 different swept blade configurations (forward and backward sweep). Sensitivity for 2 different controllers is considered as well. Backward sweep results in a pitch to feather torsional moment of the blade, effectively reducing blade twist angles under increased loading. This behaviour results in decreased flap-wise fatigue and extreme loads, an increase for edge-wise fatigue loading and status quo or slight decrease in extreme loads (depending on the controller). Tower base and shaft-end bending moments are reduced as well. Forward sweep leads to an increase in angle of attack under loading. For a pitch controlled turbine this leads to an increase in fatigue and extreme loading in all cases. A controller inflicted instability is present for the more extreme forward swept cases. Due to the shape of considered sweep curves, an inherent and significant increase in torsional blade root bending moment is noted. A boomerang shaped sweep curve is proposed to counteract this problematic increased loading. Controller sensitivity shows that adding sweep affects some loadings differently. Power output is reduced for backward sweep since the blade twist is optimized as a rigid structure, ignoring the torsional deformations which for a swept blade can be significant. (author)

  8. Measurements of the eigenfunction of reversed shear Alfvén eigenmodes that sweep downward in frequency

    International Nuclear Information System (INIS)

    Heidbrink, W. W.; Austin, M. E.; Spong, D. A.; Tobias, B. J.; Van Zeeland, M. A.

    2013-01-01

    Reversed shear Alfvén eigenmodes (RSAEs) usually sweep upward in frequency when the minimum value of the safety factor q min decreases in time. On rare occasions, RSAEs sweep downward prior to the upward sweep. Electron cyclotron emission measurements show that the radial eigenfunction during the downsweeping phase is similar to the eigenfunction of normal, upsweeping RSAEs

  9. Autonomous Planning and Replanning for Mine-Sweeping Unmanned Underwater Vehicles

    Science.gov (United States)

    Gaines, Daniel M.

    2010-01-01

    This software generates high-quality plans for carrying out mine-sweeping activities under resource constraints. The autonomous planning and replanning system for unmanned underwater vehicles (UUVs) takes as input a set of prioritized mine-sweep regions, and a specification of available UUV resources including available battery energy, data storage, and time available for accomplishing the mission. Mine-sweep areas vary in location, size of area to be swept, and importance of the region. The planner also works with a model of the UUV, as well as a model of the power consumption of the vehicle when idle and when moving.

  10. Fast grid layout algorithm for biological networks with sweep calculation.

    Science.gov (United States)

    Kojima, Kaname; Nagasaki, Masao; Miyano, Satoru

    2008-06-15

    Properly drawn biological networks are of great help in the comprehension of their characteristics. The quality of the layouts for retrieved biological networks is critical for pathway databases. However, since it is unrealistic to manually draw biological networks for every retrieval, automatic drawing algorithms are essential. Grid layout algorithms handle various biological properties such as aligning vertices having the same attributes and complicated positional constraints according to their subcellular localizations; thus, they succeed in providing biologically comprehensible layouts. However, existing grid layout algorithms are not suitable for real-time drawing, which is one of requisites for applications to pathway databases, due to their high-computational cost. In addition, they do not consider edge directions and their resulting layouts lack traceability for biochemical reactions and gene regulations, which are the most important features in biological networks. We devise a new calculation method termed sweep calculation and reduce the time complexity of the current grid layout algorithms through its encoding and decoding processes. We conduct practical experiments by using 95 pathway models of various sizes from TRANSPATH and show that our new grid layout algorithm is much faster than existing grid layout algorithms. For the cost function, we introduce a new component that penalizes undesirable edge directions to avoid the lack of traceability in pathways due to the differences in direction between in-edges and out-edges of each vertex. Java implementations of our layout algorithms are available in Cell Illustrator. masao@ims.u-tokyo.ac.jp Supplementary data are available at Bioinformatics online.

  11. Mechanistic Understanding of Microbial Plugging for Improved Sweep Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Steven Bryant; Larry Britton

    2008-09-30

    Microbial plugging has been proposed as an effective low cost method of permeability reduction. Yet there is a dearth of information on the fundamental processes of microbial growth in porous media, and there are no suitable data to model the process of microbial plugging as it relates to sweep efficiency. To optimize the field implementation, better mechanistic and volumetric understanding of biofilm growth within a porous medium is needed. In particular, the engineering design hinges upon a quantitative relationship between amount of nutrient consumption, amount of growth, and degree of permeability reduction. In this project experiments were conducted to obtain new data to elucidate this relationship. Experiments in heterogeneous (layered) beadpacks showed that microbes could grow preferentially in the high permeability layer. Ultimately this caused flow to be equally divided between high and low permeability layers, precisely the behavior needed for MEOR. Remarkably, classical models of microbial nutrient uptake in batch experiments do not explain the nutrient consumption by the same microbes in flow experiments. We propose a simple extension of classical kinetics to account for the self-limiting consumption of nutrient observed in our experiments, and we outline a modeling approach based on architecture and behavior of biofilms. Such a model would account for the changing trend of nutrient consumption by bacteria with the increasing biomass and the onset of biofilm formation. However no existing model can explain the microbial preference for growth in high permeability regions, nor is there any obvious extension of the model for this observation. An attractive conjecture is that quorum sensing is involved in the heterogeneous bead packs.

  12. Laminar/transition sweeping flow-mixing model for wire-wrapped LMFBR assemblies

    International Nuclear Information System (INIS)

    Burns, K.F.; Rohsenow, W.M.; Todreas, N.E.

    1980-07-01

    Recent interest in analyzing the thermal hydraulic characteristics of LMFBR assemblies operating in the mixed convection regime motivates the extension of the aforementioned turbulent sweeping flow model to low Reynolds number flows. The accuracy to which knowledge of the mixing parameters is required has not been well determined, due to the increased influence of conduction and buoyancy effects with respect to energy transport at low Reynolds numbers. This study represents a best estimate attempt to correlate the existing low Reynolds number sweeping flow data. The laminar/transition model which is presented is expected to be useful in anayzing mixed convection conditions. However, the justification for making additional improvemements is contingent upon two factors. First, the ability of the proposed laminar/transition model to predict additional low Reynolds number sweeping flow data for other geometries needs to be investigated. Secondly, the sensitivity of temperature predictions to uncertainties in the values of the sweeping flow parameters should be quantified

  13. Evaluation of two sweeping methods for estimating the number of immature Aedes aegypti (Diptera: Culicidae in large containers

    Directory of Open Access Journals (Sweden)

    Margareth Regina Dibo

    2013-07-01

    Full Text Available Introduction Here, we evaluated sweeping methods used to estimate the number of immature Aedes aegypti in large containers. Methods III/IV instars and pupae at a 9:1 ratio were placed in three types of containers with, each one with three different water levels. Two sweeping methods were tested: water-surface sweeping and five-sweep netting. The data were analyzed using linear regression. Results The five-sweep netting technique was more suitable for drums and water-tanks, while the water-surface sweeping method provided the best results for swimming pools. Conclusions Both sweeping methods are useful tools in epidemiological surveillance programs for the control of Aedes aegypti.

  14. Numerical investigation of collector cooling for a 1 MW ITER gyrotron operated with vertical sweeping

    Energy Technology Data Exchange (ETDEWEB)

    Savoldi, Laura; Bertani, Cristina [Dipartimento Energia, Politecnico di Torino (Italy); Cau, Francesca; Cismondi, Fabio [Fusion for Energy, Barcelona (Spain); Gantenbein, Gerd; Illy, Stefan [KIT, Karlsruhe (Germany); Monni, Grazia [Dipartimento Energia, Politecnico di Torino (Italy); Zanino, Roberto, E-mail: roberto.zanino@polito.it [Dipartimento Energia, Politecnico di Torino (Italy)

    2015-11-15

    The present gyrotron designs for EC plasma heating in nuclear fusion reactors require the safe exhaust of a power comparable to that injected into the plasma, in order to keep the maximum temperature below the acceptable value of 300 °C. In this paper, the commercial computational fluid dynamics (CFD) software STAR-CCM+{sup ®} is used to analyze the thermal performance of the annular copper collector of a 1 MW ITER gyrotron, equipped with a hypervapotron structure made of annular fins with rectangular cavities of aspect ratio (depth/width) = 3, cooled by highly subcooled (90–100 °C) pressurized water flowing at ∼4 m/s. It is assumed that the simple vertical sweeping strategy is used to reduce the very high peak heat flux on the collector (up to 30 MW/m{sup 2} transient, 5 MW/m{sup 2} time average), due to the spent electron beam. The 2D steady-state conjugate heat transfer problem is solved assuming azimuthal symmetry and accounting for 2-phase flow. The single-cavity flow and heat transfer problem is considered first, to optimize the mesh and the selection of the turbulence model. For the operating conditions considered in this paper, the full collector (100+ cavities) solution shows that boiling occurs only in a limited number of cavities close to the peaks of the heat flux, with the vapor remaining trapped in the bottom of the cavities, i.e. no full hypervapotron regime should be achieved in these operating conditions. The steady-state analysis allows the numerical evaluation of the heat transfer coefficients between Cu and water; these are then used as input for the simplified, purely thermal (solid only) analysis of the actual transient problem for the full collector. The results of the simplified model, which allows a huge reduction of the computational effort, are successfully benchmarked against those of a comprehensive thermal–hydraulic simulation. The computed peak Cu temperature is below the acceptable limit under the steady-state (time averaged

  15. A new method for calculating volumetric sweeps efficiency using streamline simulation concepts

    International Nuclear Information System (INIS)

    Hidrobo, E A

    2000-01-01

    One of the purposes of reservoir engineering is to quantify the volumetric sweep efficiency for optimizing reservoir management decisions. The estimation of this parameter has always been a difficult task. Until now, sweep efficiency correlations and calculations have been limited to mostly homogeneous 2-D cases. Calculating volumetric sweep efficiency in a 3-D heterogeneous reservoir becomes difficult due to inherent complexity of multiple layers and arbitrary well configurations. In this paper, a new method for computing volumetric sweep efficiency for any arbitrary heterogeneity and well configuration is presented. The proposed method is based on Datta-Gupta and King's formulation of streamline time-of-flight (1995). Given the fact that the time-of-flight reflects the fluid front propagation at various times, then the connectivity in the time-of-flight represents a direct measure of the volumetric sweep efficiency. The proposed approach has been applied to synthetic as well as field examples. Synthetic examples are used to validate the volumetric sweep efficiency calculations using the streamline time-of-flight connectivity criterion by comparison with analytic solutions and published correlations. The field example, which illustrates the feasibility of the approach for large-scale field applications, is from the north Robertson unit, a low permeability carbonate reservoir in west Texas

  16. A Sweeping Jet Application on a High Reynolds Number Semispan Supercritical Wing Configuration

    Science.gov (United States)

    Jones, Gregory S.; Milholen, William E., II; Chan, David T.; Melton, Latunia; Goodliff, Scott L.; Cagle, C. Mark

    2017-01-01

    The FAST-MAC circulation control model was modified to test an array of unsteady sweeping-jet actuators at realistic flight Reynolds numbers in the National Transonic Facility at the NASA Langley Research Center. Two types of sweeping jet actuators were fabricated using rapid prototype techniques, and directed over a 15% chord simple-hinged flap. The model was configured for low-speed high-lift testing with flap deflections of 30 deg and 60 deg, and a transonic cruise configuration having a 0 deg flap deflection. For the 30 deg flap high-lift configuration, the sweeping jets achieved comparable lift performance in the separation control regime, while reducing the mass flow by 54% as compared to steady blowing. The sweeping jets however were not effective for the 60 deg flap. For the transonic cruise configuration, the sweeping jets reduced the drag by 3.3% at an off-design condition. The drag reduction for the design lift coefficient for the sweeping jets offer is only half the drag reduction shown for the steady blowing case (6.5%), but accomplished this with a 74% reduction in mass flow.

  17. Using Computational Fluid Dynamics and Experiments to Design Sweeping Jets for High Reynolds Number Cruise Configurations

    Science.gov (United States)

    Jones, Gregory S.; Milholen, William E., II; Fell, Jared S.; Webb, Sandy R.; Cagle, C. Mark

    2016-01-01

    The application of a sweeping jet actuator to a circulation control system was initiated by a risk reduction series of experiments to optimize the authority of a single sweeping jet actuator. The sweeping jet design was integrated into the existing Fundamental Aerodynamic Subsonic Transonic- Modular Active Control (FAST-MAC) model by replacing the steady blowing system with an array of thirty-nine sweeping jet cartridges. A constant slot height to wing chord ratio was similar to the steady blowing configuration resulting in each actuator having a unique in size for the sweeping jet configuration. While this paper will describe the scaling and optimization of the actuators for future high Reynolds number applications, the major focus of this effort was to target the transonic flight regime by increasing the amplitude authority of the actuator. This was accomplished by modifying the diffuser of the sweeping jet actuator, and this paper highlights twelve different diffuser designs. The experimental portion of this work was completed in the NASA Langley National Transonic Facility.

  18. A sweep plate emittance scanner for high-power CW ion beams

    International Nuclear Information System (INIS)

    Debiak, T.W.; Ng, Y.; Sredniawski, J.; Stasi, W.

    1996-01-01

    Sweep plate scanners are preferred for emittance measurement due to their versatility, simplicity, and precision. At the Advanced Technology and Development Center of Northrop Grumman, we have routinely used these devices for characterization of injector beams with less than 20 W/cm 2 average power density. To characterize higher power beams, like those required for production of tritium or for radioactive waste transmutation, the scanner pod and data collection algorithm must be redesigned due to the possibility of melting the scanner's protective front face or distorting the precision entrance knife edges. Among the methods we have used to mitigate these effects, one consists of drastically reducing the amount of time required for data collection. In this method, the emittance scanner pod traverses the beam in two passes, each requiring less than 0.5 second. In the first pass, the phase space limits of the beam are determined. In the second pass, data is collected primarily within the phase space region limits determined in the first pass. In this way, enough points are collected to assure that the precision of the measurement is high, even though the data collection time for each scan is less than 0.5 second. This paper will describe the layout of the scanner components, the data collection electronics and algorithm, and the data analysis. (author)

  19. Determination of strobilurin fungicide residues in fruits and vegetables by micellar electrokinetic capillary chromatography with sweeping.

    Science.gov (United States)

    Wang, Kun; Chen, Guan-hua; Wu, Xian; Shi, Jie; Guo, Dong-shan

    2014-02-01

    A new assay of micellar electrokinetic capillary chromatography with sweeping was developed to determine azoxystrobin, kresoxim-methyl and pyraclostrobin in fruits and vegetables. The key factors affecting resolution and peak height were studied and the optimum conditions were obtained for separation and enrichment. The running buffer consisted of 40 mM borate, 25 mM sodium dodecyl sulfate and 15% acetonitrile, and its pH was adjusted to 8.4. The sample was injected for 677 nL and the separation voltage was 25 kV. Under the optimum conditions, the enrichment factors of azoxystrobin, kresoxim-methyl and pyraclostrobin were 861, 550 and 403; the linear dynamic ranges were all 0.01-5.0 mg/L; the limits of detection were 0.002, 0.001 and 0.002 mg/kg; the recoveries of spiked samples were 85.1-98.5%, 87.5-97.0% and 89.1-99.1%, respectively. The assay can meet the requirement of maximum residue limits for these three strobilurin fungicides, and has been applied for determining their residues in fruits and vegetables.

  20. Dynamic control of low-Z material deposition and tungsten erosion by strike point sweeping on DIII-D

    Directory of Open Access Journals (Sweden)

    J. Guterl

    2017-08-01

    Full Text Available Carbon deposition on tungsten between ELMs was investigated in DIII-D in semi-attached/detached H-mode plasma conditions using fixed outer strike point (OSP positions. Carbon deposition during plasma exposure of tungsten was monitored in-situ by measuring the reflectivity of the tungsten sample surface. No significant carbon deposition, i.e., without strong variations of the reflectivity, was observed during these experiments including discharges at high densities. In contrast, ERO modeling predicts a significant carbon deposition on the tungsten surface for those high density plasma conditions. The surface reflectivity decreases with methane injection, consistent with increased carbon coverage, as expected. The sweeping of OSP leads to a pronounced increase of the surface reflectivity, suggesting that the strike point sweeping may provide an effective means to remove carbon coating from tungsten surface. The ERO modeling however predicts again a regime of carbon deposition for these experiments. The discrepancies between carbon deposition regime predicted by the ERO model and the experimental observations suggest that carbon erosion during ELMs may significantly affect carbon deposition on tungsten.

  1. Design and optimization of a bend-and-sweep compliant mechanism

    International Nuclear Information System (INIS)

    Tummala, Y; Frecker, M I; Wissa, A A; Hubbard Jr, J E

    2013-01-01

    A novel contact aided compliant mechanism called bend-and-sweep compliant mechanism is presented in this paper. This mechanism has nonlinear stiffness properties in two orthogonal directions. An angled compliant joint (ACJ) is the fundamental element of this mechanism. Geometric parameters of ACJs determine the stiffness of the compliant mechanism. This paper presents the design and optimization of bend-and-sweep compliant mechanism. A multi-objective optimization problem was formulated for design optimization of the bend-and-sweep compliant mechanism. The objectives of the optimization problem were to maximize or minimize the bending and sweep displacements, depending on the situation, while minimizing the von Mises stress and mass of each mechanism. This optimization problem was solved using NSGA-II (a genetic algorithm). The results of this optimization for a single ACJ during upstroke and downstroke are presented in this paper. Results of two different loading conditions used during optimization of a single ACJ for upstroke are presented. Finally, optimization results comparing the performance of compliant mechanisms with one and two ACJs are also presented. It can be inferred from these results that the number of ACJs and the design of each ACJ determines the stiffness of the bend-and-sweep compliant mechanism. These mechanisms can be used in various applications. The goal of this research is to improve the performance of ornithopters by passively morphing their wings. In order to achieve a bio-inspired wing gait called continuous vortex gait, the wings of the ornithopter need to bend, and sweep simultaneously. This can be achieved by inserting the bend-and-sweep compliant mechanism into the leading edge wing spar of the ornithopters. (paper)

  2. Consistent model driven architecture

    Science.gov (United States)

    Niepostyn, Stanisław J.

    2015-09-01

    The goal of the MDA is to produce software systems from abstract models in a way where human interaction is restricted to a minimum. These abstract models are based on the UML language. However, the semantics of UML models is defined in a natural language. Subsequently the verification of consistency of these diagrams is needed in order to identify errors in requirements at the early stage of the development process. The verification of consistency is difficult due to a semi-formal nature of UML diagrams. We propose automatic verification of consistency of the series of UML diagrams originating from abstract models implemented with our consistency rules. This Consistent Model Driven Architecture approach enables us to generate automatically complete workflow applications from consistent and complete models developed from abstract models (e.g. Business Context Diagram). Therefore, our method can be used to check practicability (feasibility) of software architecture models.

  3. Bitcoin Meets Strong Consistency

    OpenAIRE

    Decker, Christian; Seidel, Jochen; Wattenhofer, Roger

    2014-01-01

    The Bitcoin system only provides eventual consistency. For everyday life, the time to confirm a Bitcoin transaction is prohibitively slow. In this paper we propose a new system, built on the Bitcoin blockchain, which enables strong consistency. Our system, PeerCensus, acts as a certification authority, manages peer identities in a peer-to-peer network, and ultimately enhances Bitcoin and similar systems with strong consistency. Our extensive analysis shows that PeerCensus is in a secure state...

  4. Consistent classical supergravity theories

    International Nuclear Information System (INIS)

    Muller, M.

    1989-01-01

    This book offers a presentation of both conformal and Poincare supergravity. The consistent four-dimensional supergravity theories are classified. The formulae needed for further modelling are included

  5. Maximum power point tracking for PV systems under partial shading conditions using current sweeping

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2015-01-01

    Highlights: • A novel approach for tracking the maximum power point of photovoltaic systems. • Able to handle both the uniform insolation and partial shading conditions. • Maximum power point tracking based on current sweeping. - Abstract: Partial shading on photovoltaic (PV) arrays causes multiple peaks on the output power–voltage characteristic curve and local searching technique such as perturb and observe (P&O) method could easily fail in searching for the global maximum. Moreover, existing global searching techniques are still not very satisfactory in terms of speed and implementation complexity. In this paper, a fast global maximum power point (MPPT) tracking method which is using current sweeping for photovoltaic arrays under partial shading conditions is proposed. Unlike conventional approach, the proposed method is current based rather than voltage based. The initial maximum power point will be derived based on a current sweeping test and the maximum power point can be enhanced by a finer local search. The speed of the global search is mainly governed by the apparent time constant of the PV array and the generation of a fast current sweeping test. The fast current sweeping test can easily be realized by a DC/DC boost converter with a very fast current control loop. Experimental results are included to demonstrate the effectiveness of the proposed global searching scheme

  6. Investigation of the Hydrodynamics of Sweep Blade in Hi-Speed Axial Fuel Pump Impeller

    Directory of Open Access Journals (Sweden)

    Ran Tao

    2013-01-01

    Full Text Available Fuel pump is a crucial component in aircraft engine ignition system. For the hi-speed axial fuel pumps, rotating stall triggers vortex and affects the operation stability and security. Sweep blade is widely used to solve the stability problems in aerodynamics field. Investigation on the hydrodynamics was conducted in this study. Based on the typical straight blade pump, positive and negative sweep blade pumps were modeled. With the large eddy simulation method, CFD simulations were conducted to calculate and analyze the flow characteristics in the pump models. To verify the simulation, experiments were also launched on the hydraulic test rig. Results show that the vortex occurs at the suction surface of blade and gathers near the blade tip region. Positive sweep blade is effective to reduce the hydraulic losses by driving the stalled fluid into the mid-part of blade. By applying the positive sweep blade on the axial fuel pump, the instability operating region will be diminished. Adopting sweep blade provides an effective means for stability and security of axial fuel pumps.

  7. EFFECT OF SWEEP ANGLE ON THE VORTICAL FLOW OVER DELTA WINGS AT AN ANGLE OF ATTACK OF 10°

    Directory of Open Access Journals (Sweden)

    JAMES BRETT

    2014-12-01

    Full Text Available CFD simulations have been used to analyse the vortical flows over sharp edged delta wings with differing sweep angles under subsonic conditions at an angle of attack of 10°. RANS simulations were validated against experimental data for a 65° sweep wing, with a flat cross-section, and the steadiness of the flow field was assessed by comparing the results against unsteady URANS and DES simulations. To assess the effect of sweep angle on the flow field, a range of sweep angles from 65° to 43° were simulated. For moderate sweep wings the primary vortex was observed to detach from the leading edge, undergoing vortex breakdown, and a weaker, replacement, "shadow" vortex was formed. The shadow vortex was observed for sweep angles of 50° and less, and resulted in reduced lift production near the wing tips loss of the stronger primary vortex.

  8. Detection of undistorted continuous wave (CW) electron paramagnetic resonance (EPR) spectra with non-adiabatic rapid sweep (NARS) of the magnetic field

    Science.gov (United States)

    Kittell, Aaron W.; Camenisch, Theodore G.; Ratke, Joseph J.; Sidabras, Jason W.; Hyde, James S.

    2011-01-01

    A continuous wave (CW) electron paramagnetic resonance (EPR) spectrum is typically displayed as the first harmonic response to the application of 100 kHz magnetic field modulation, which is used to enhance sensitivity by reducing the level of 1/f noise. However, magnetic field modulation of any amplitude causes spectral broadening and sacrifices EPR spectral intensity by at least a factor of two. In the work presented here, a CW rapid-scan spectroscopic technique that avoids these compromises and also provides a means of avoiding 1/f noise is developed. This technique, termed non-adiabatic rapid sweep (NARS) EPR, consists of repetitively sweeping the polarizing magnetic field in a linear manner over a spectral fragment with a small coil at a repetition rate that is sufficiently high that receiver noise, microwave phase noise, and environmental microphonics, each of which has 1/f characteristics, are overcome. Nevertheless, the rate of sweep is sufficiently slow that adiabatic responses are avoided and the spin system is always close to thermal equilibrium. The repetitively acquired spectra from the spectral fragment are averaged. Under these conditions, undistorted pure absorption spectra are obtained without broadening or loss of signal intensity. A digital filter such as a moving average is applied to remove high frequency noise, which is approximately equivalent in bandwidth to use of an integrating time constant in conventional field modulation with lock-in detection. Nitroxide spectra at L- and X-band are presented. PMID:21741868

  9. Consistency of orthodox gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, S. [INFN, Frascati (Italy). Laboratori Nazionali di Frascati; Shiekh, A. [International Centre for Theoretical Physics, Trieste (Italy)

    1997-01-01

    A recent proposal for quantizing gravity is investigated for self consistency. The existence of a fixed-point all-order solution is found, corresponding to a consistent quantum gravity. A criterion to unify couplings is suggested, by invoking an application of their argument to more complex systems.

  10. Quasiparticles and thermodynamical consistency

    International Nuclear Information System (INIS)

    Shanenko, A.A.; Biro, T.S.; Toneev, V.D.

    2003-01-01

    A brief and simple introduction into the problem of the thermodynamical consistency is given. The thermodynamical consistency relations, which should be taken into account under constructing a quasiparticle model, are found in a general manner from the finite-temperature extension of the Hellmann-Feynman theorem. Restrictions following from these relations are illustrated by simple physical examples. (author)

  11. Ka-Band Digital Beamforming and SweepSAR Demonstration for Ice and Solid Earth Topography

    Science.gov (United States)

    Sadowy, Gregory; Ghaemi, Hirad; Heavy, Brandon; Perkovic, Dragana; Quddus, Momin; Zawadzki, Mark; Moller, Delwyn

    2010-01-01

    GLISTIN is an instrument concept for a single-pass interferometric SAR operating at 35.6 GHz. To achieve large swath widths using practical levels of transmitter power, a digitally-beamformed planar waveguide array is used. This paper describes results from a ground-based demonstration of a 16-receiver prototype. Furthermore, SweepSAR is emerging as promising technique for achieving very wide swaths for surface change detection. NASA and DLR are studying this approach for the DESDynI and Tandem-L missions. SweepSAR employs a reflector with a digitally-beamformed array feed. We will describe development of an airborne demonstration of SweepSAR using the GLISTIN receiver array and a reflector.

  12. Sweep excitation with order tracking: A new tactic for beam crack analysis

    Science.gov (United States)

    Wei, Dongdong; Wang, KeSheng; Zhang, Mian; Zuo, Ming J.

    2018-04-01

    Crack detection in beams and beam-like structures is an important issue in industry and has attracted numerous investigations. A local crack leads to global system dynamics changes and produce non-linear vibration responses. Many researchers have studied these non-linearities for beam crack diagnosis. However, most reported methods are based on impact excitation and constant frequency excitation. Few studies have focused on crack detection through external sweep excitation which unleashes abundant dynamic characteristics of the system. Together with a signal resampling technique inspired by Computed Order Tracking, this paper utilize vibration responses under sweep excitations to diagnose crack status of beams. A data driven method for crack depth evaluation is proposed and window based harmonics extracting approaches are studied. The effectiveness of sweep excitation and the proposed method is experimentally validated.

  13. Hybrid massively parallel fast sweeping method for static Hamilton–Jacobi equations

    Energy Technology Data Exchange (ETDEWEB)

    Detrixhe, Miles, E-mail: mdetrixhe@engineering.ucsb.edu [Department of Mechanical Engineering (United States); University of California Santa Barbara, Santa Barbara, CA, 93106 (United States); Gibou, Frédéric, E-mail: fgibou@engineering.ucsb.edu [Department of Mechanical Engineering (United States); University of California Santa Barbara, Santa Barbara, CA, 93106 (United States); Department of Computer Science (United States); Department of Mathematics (United States)

    2016-10-01

    The fast sweeping method is a popular algorithm for solving a variety of static Hamilton–Jacobi equations. Fast sweeping algorithms for parallel computing have been developed, but are severely limited. In this work, we present a multilevel, hybrid parallel algorithm that combines the desirable traits of two distinct parallel methods. The fine and coarse grained components of the algorithm take advantage of heterogeneous computer architecture common in high performance computing facilities. We present the algorithm and demonstrate its effectiveness on a set of example problems including optimal control, dynamic games, and seismic wave propagation. We give results for convergence, parallel scaling, and show state-of-the-art speedup values for the fast sweeping method.

  14. Sweeping total reflection X-ray fluorescence optimisation to monitor the metallic contamination into IC manufacturing

    International Nuclear Information System (INIS)

    Borde, Yannick; Danel, Adrien; Roche, Agnes; Veillerot, Marc

    2008-01-01

    Among the methods available on the market today to control as metallic contamination in integrated circuit manufacturing, Sweeping Total reflection X-ray Fluorescence mode appears a very good method, providing fast and entire wafer mapping. With the goal of a pertinent use of Sweeping Total reflection X-ray Fluorescence in advanced Integrated Circuit manufacturing this work discusses how acceptable levels of contamination specified by the production (low levels to be detected) can be taken into account. The relation between measurement results (surface coverage, throughput, low limit of detection, limit of quantification, quantification of localized contamination) and Sweeping Total reflection X-ray Fluorescence parameters (number of measurement points and integration time per point) is presented in details. In particular, a model is proposed to explain the mismatch between actual surface contamination in a localized spot on wafer and Total reflection X-ray Fluorescence reading. Both calibration and geometric issues have been taken into account

  15. Hybrid massively parallel fast sweeping method for static Hamilton–Jacobi equations

    International Nuclear Information System (INIS)

    Detrixhe, Miles; Gibou, Frédéric

    2016-01-01

    The fast sweeping method is a popular algorithm for solving a variety of static Hamilton–Jacobi equations. Fast sweeping algorithms for parallel computing have been developed, but are severely limited. In this work, we present a multilevel, hybrid parallel algorithm that combines the desirable traits of two distinct parallel methods. The fine and coarse grained components of the algorithm take advantage of heterogeneous computer architecture common in high performance computing facilities. We present the algorithm and demonstrate its effectiveness on a set of example problems including optimal control, dynamic games, and seismic wave propagation. We give results for convergence, parallel scaling, and show state-of-the-art speedup values for the fast sweeping method.

  16. Michelson mode selector for spectral range stabilization in a self-sweeping fiber laser.

    Science.gov (United States)

    Tkachenko, A Yu; Vladimirskaya, A D; Lobach, I A; Kablukov, S I

    2018-04-01

    We report on spectral range stabilization in a self-sweeping laser by adding a narrowband fiber Bragg grating (FBG) to the output mirror in the Michelson configuration. The effects of FBG reflectivity and optical path difference in the Michelson interferometer on the laser spectral dynamics are investigated. Optimization of the interferometer allows us to demonstrate broadband (over 16 nm) self-sweeping operation and reduction of the start and stop wavelength fluctuations by two orders and one order of magnitude (∼100 and 15 times) for start and stop bounds, respectively (down to several picometers). The proposed approaches significantly improve quality of the spectral dynamics and facilitate application of the self-sweeping lasers.

  17. Exact solutions for oscillatory shear sweep behaviors of complex fluids from the Oldroyd 8-constant framework

    Science.gov (United States)

    Saengow, Chaimongkol; Giacomin, A. Jeffrey

    2018-03-01

    In this paper, we provide a new exact framework for analyzing the most commonly measured behaviors in large-amplitude oscillatory shear flow (LAOS), a popular flow for studying the nonlinear physics of complex fluids. Specifically, the strain rate sweep (also called the strain sweep) is used routinely to identify the onset of nonlinearity. By the strain rate sweep, we mean a sequence of LAOS experiments conducted at the same frequency, performed one after another, with increasing shear rate amplitude. In this paper, we give exact expressions for the nonlinear complex viscosity and the corresponding nonlinear complex normal stress coefficients, for the Oldroyd 8-constant framework for oscillatory shear sweeps. We choose the Oldroyd 8-constant framework for its rich diversity of popular special cases (we list 18 of these). We evaluate the Fourier integrals of our previous exact solution to get exact expressions for the real and imaginary parts of the complex viscosity, and for the complex normal stress coefficients, as functions of both test frequency and shear rate amplitude. We explore the role of infinite shear rate viscosity on strain rate sweep responses for the special case of the corotational Jeffreys fluid. We find that raising η∞ raises the real part of the complex viscosity and lowers the imaginary. In our worked examples, we thus first use the corotational Jeffreys fluid, and then, for greater accuracy, we use the Johnson-Segalman fluid, to describe the strain rate sweep response of molten atactic polystyrene. For our comparisons with data, we use the Spriggs relations to generalize the Oldroyd 8-constant framework to multimode. Our generalization yields unequivocally, a longest fluid relaxation time, used to assign Weissenberg and Deborah numbers to each oscillatory shear flow experiment. We then locate each experiment in the Pipkin space.

  18. Reduction of non-point source contaminants associated with road-deposited sediments by sweeping.

    Science.gov (United States)

    Kim, Do-Gun; Kang, Hee-Man; Ko, Seok-Oh

    2017-09-19

    Road-deposited sediments (RDS) on an expressway, residual RDS collected after sweeping, and RDS removed by means of sweeping were analyzed to evaluate the degree to which sweeping removed various non-point source contaminants. The total RDS load was 393.1 ± 80.3 kg/km and the RDS, residual RDS, and swept RDS were all highly polluted with organics, nutrients, and metals. Among the metals studied, Cu, Zn, Pb, Ni, Ca, and Fe were significantly enriched, and most of the contaminants were associated with particles within the size range from 63 μm to 2 mm. Sweeping reduced RDS and its associated contaminants by 33.3-49.1% on average. We also measured the biological oxygen demand (BOD) of RDS in the present work, representing to our knowledge the first time that this has been done; we found that RDS contains a significant amount of biodegradable organics and that the reduction of BOD by sweeping was higher than that of other contaminants. Significant correlations were found between the contaminants measured, indicating that the organics and the metals originated from both exhaust and non-exhaust particles. Meanwhile, the concentrations of Cu and Ni were higher in 63 μm-2 mm particles than in smaller particles, suggesting that some metals in RDS likely exist intrinsically in particles, rather than only as adsorbates on particle surfaces. Overall, the results in this study showed that sweeping to collect RDS can be a good alternative for reduction of contaminants in runoff.

  19. Comparison of least squares and exponential sine sweep methods for Parallel Hammerstein Models estimation

    Science.gov (United States)

    Rebillat, Marc; Schoukens, Maarten

    2018-05-01

    Linearity is a common assumption for many real-life systems, but in many cases the nonlinear behavior of systems cannot be ignored and must be modeled and estimated. Among the various existing classes of nonlinear models, Parallel Hammerstein Models (PHM) are interesting as they are at the same time easy to interpret as well as to estimate. One way to estimate PHM relies on the fact that the estimation problem is linear in the parameters and thus that classical least squares (LS) estimation algorithms can be used. In that area, this article introduces a regularized LS estimation algorithm inspired on some of the recently developed regularized impulse response estimation techniques. Another mean to estimate PHM consists in using parametric or non-parametric exponential sine sweeps (ESS) based methods. These methods (LS and ESS) are founded on radically different mathematical backgrounds but are expected to tackle the same issue. A methodology is proposed here to compare them with respect to (i) their accuracy, (ii) their computational cost, and (iii) their robustness to noise. Tests are performed on simulated systems for several values of methods respective parameters and of signal to noise ratio. Results show that, for a given set of data points, the ESS method is less demanding in computational resources than the LS method but that it is also less accurate. Furthermore, the LS method needs parameters to be set in advance whereas the ESS method is not subject to conditioning issues and can be fully non-parametric. In summary, for a given set of data points, ESS method can provide a first, automatic, and quick overview of a nonlinear system than can guide more computationally demanding and precise methods, such as the regularized LS one proposed here.

  20. A convergence analysis for a sweeping preconditioner for block tridiagonal systems of linear equations

    KAUST Repository

    Bagci, Hakan

    2014-11-11

    We study sweeping preconditioners for symmetric and positive definite block tridiagonal systems of linear equations. The algorithm provides an approximate inverse that can be used directly or in a preconditioned iterative scheme. These algorithms are based on replacing the Schur complements appearing in a block Gaussian elimination direct solve by hierarchical matrix approximations with reduced off-diagonal ranks. This involves developing low rank hierarchical approximations to inverses. We first provide a convergence analysis for the algorithm for reduced rank hierarchical inverse approximation. These results are then used to prove convergence and preconditioning estimates for the resulting sweeping preconditioner.

  1. Scaling of the susceptibility vs. magnetic-field sweep rate in Fe8 molecular magnet

    Science.gov (United States)

    Jordi, M.; Hernandez-Mínguez, A.; Hernandez, J. M.; Tejada, J.; Stroobants, S.; Vanacken, J.; Moshchalkov, V. V.

    2004-12-01

    The dependence of the magnetization reversal on the sweep rate of the applied magnetic field has been studied for single crystals of Fe8 magnetic molecules. Our experiments have been conducted at temperatures below 1 K and sweep rates of the magnetic field between 103 T/s to 104 T/s. The systematic shift of the values of the magnetic field at which the magnetization reversal occurs, indicates that this reversal process is not governed by the Landau-Zener transition model. Our data can be explained in terms of the superradiance emission model proposed by Chudnovsky and Garanin (Phys. Rev. Lett. 89 (2002) 157201).

  2. A discrete element model for soil-sweep interaction in three different soils

    DEFF Research Database (Denmark)

    Chen, Y; Munkholm, Lars Juhl; Nyord, Tavs

    2013-01-01

    . To serve the model development, the sweep was tested in three different soils (coarse sand, loamy sand, and sandy loam). In the tests, soil cutting forces (draught and vertical forces) and soil disturbance characteristics (soil cross-section disturbance and surface deformation) resulting from the sweep...... were measured. The measured draught and vertical forces were used in calibrations of the most sensitive model parameter, particle stiffness. The calibrated particle stiffness was 0.75 × 103 N m−1 for the coarse sand, 2.75 × 103 N m−1 for the loamy sand, and 6 × 103 N m−1 for the sandy loam...

  3. A convergence analysis for a sweeping preconditioner for block tridiagonal systems of linear equations

    KAUST Repository

    Bagci, Hakan; Pasciak, Joseph E.; Sirenko, Kostyantyn

    2014-01-01

    We study sweeping preconditioners for symmetric and positive definite block tridiagonal systems of linear equations. The algorithm provides an approximate inverse that can be used directly or in a preconditioned iterative scheme. These algorithms are based on replacing the Schur complements appearing in a block Gaussian elimination direct solve by hierarchical matrix approximations with reduced off-diagonal ranks. This involves developing low rank hierarchical approximations to inverses. We first provide a convergence analysis for the algorithm for reduced rank hierarchical inverse approximation. These results are then used to prove convergence and preconditioning estimates for the resulting sweeping preconditioner.

  4. Fast sweeping methods for hyperbolic systems of conservation laws at steady state II

    Science.gov (United States)

    Engquist, Björn; Froese, Brittany D.; Tsai, Yen-Hsi Richard

    2015-04-01

    The idea of using fast sweeping methods for solving stationary systems of conservation laws has previously been proposed for efficiently computing solutions with sharp shocks. We further develop these methods to allow for a more challenging class of problems including problems with sonic points, shocks originating in the interior of the domain, rarefaction waves, and two-dimensional systems. We show that fast sweeping methods can produce higher-order accuracy. Computational results validate the claims of accuracy, sharp shock curves, and optimal computational efficiency.

  5. Threshold received sound pressure levels of single 1-2 kHz and 6-7 kHz up-sweeps and down-sweeps causing startle responses in a harbor porpoise (Phocoena phocoena)

    NARCIS (Netherlands)

    Kastelein, R.A.; Steen, N.; Gransier, R.; Wensveen, P.J.; Jong, C.A.F. de

    2012-01-01

    Mid-frequency and low-frequency sonar systems produce frequency-modulated sweeps which may affect harbor porpoises. To study the effect of sweeps on behavioral responses (specifically startle responses, which we define as sudden changes in swimming speed and/or direction), a harbor porpoise in a

  6. Consistency in PERT problems

    OpenAIRE

    Bergantiños, Gustavo; Valencia-Toledo, Alfredo; Vidal-Puga, Juan

    2016-01-01

    The program evaluation review technique (PERT) is a tool used to schedule and coordinate activities in a complex project. In assigning the cost of a potential delay, we characterize the Shapley rule as the only rule that satisfies consistency and other desirable properties.

  7. Determining Plane-Sweep Sampling Points in Image Space Using the Cross-Ratio for Image-Based Depth Estimation

    Science.gov (United States)

    Ruf, B.; Erdnuess, B.; Weinmann, M.

    2017-08-01

    With the emergence of small consumer Unmanned Aerial Vehicles (UAVs), the importance and interest of image-based depth estimation and model generation from aerial images has greatly increased in the photogrammetric society. In our work, we focus on algorithms that allow an online image-based dense depth estimation from video sequences, which enables the direct and live structural analysis of the depicted scene. Therefore, we use a multi-view plane-sweep algorithm with a semi-global matching (SGM) optimization which is parallelized for general purpose computation on a GPU (GPGPU), reaching sufficient performance to keep up with the key-frames of input sequences. One important aspect to reach good performance is the way to sample the scene space, creating plane hypotheses. A small step size between consecutive planes, which is needed to reconstruct details in the near vicinity of the camera may lead to ambiguities in distant regions, due to the perspective projection of the camera. Furthermore, an equidistant sampling with a small step size produces a large number of plane hypotheses, leading to high computational effort. To overcome these problems, we present a novel methodology to directly determine the sampling points of plane-sweep algorithms in image space. The use of the perspective invariant cross-ratio allows us to derive the location of the sampling planes directly from the image data. With this, we efficiently sample the scene space, achieving higher sampling density in areas which are close to the camera and a lower density in distant regions. We evaluate our approach on a synthetic benchmark dataset for quantitative evaluation and on a real-image dataset consisting of aerial imagery. The experiments reveal that an inverse sampling achieves equal and better results than a linear sampling, with less sampling points and thus less runtime. Our algorithm allows an online computation of depth maps for subsequences of five frames, provided that the relative

  8. DETERMINING PLANE-SWEEP SAMPLING POINTS IN IMAGE SPACE USING THE CROSS-RATIO FOR IMAGE-BASED DEPTH ESTIMATION

    Directory of Open Access Journals (Sweden)

    B. Ruf

    2017-08-01

    Full Text Available With the emergence of small consumer Unmanned Aerial Vehicles (UAVs, the importance and interest of image-based depth estimation and model generation from aerial images has greatly increased in the photogrammetric society. In our work, we focus on algorithms that allow an online image-based dense depth estimation from video sequences, which enables the direct and live structural analysis of the depicted scene. Therefore, we use a multi-view plane-sweep algorithm with a semi-global matching (SGM optimization which is parallelized for general purpose computation on a GPU (GPGPU, reaching sufficient performance to keep up with the key-frames of input sequences. One important aspect to reach good performance is the way to sample the scene space, creating plane hypotheses. A small step size between consecutive planes, which is needed to reconstruct details in the near vicinity of the camera may lead to ambiguities in distant regions, due to the perspective projection of the camera. Furthermore, an equidistant sampling with a small step size produces a large number of plane hypotheses, leading to high computational effort. To overcome these problems, we present a novel methodology to directly determine the sampling points of plane-sweep algorithms in image space. The use of the perspective invariant cross-ratio allows us to derive the location of the sampling planes directly from the image data. With this, we efficiently sample the scene space, achieving higher sampling density in areas which are close to the camera and a lower density in distant regions. We evaluate our approach on a synthetic benchmark dataset for quantitative evaluation and on a real-image dataset consisting of aerial imagery. The experiments reveal that an inverse sampling achieves equal and better results than a linear sampling, with less sampling points and thus less runtime. Our algorithm allows an online computation of depth maps for subsequences of five frames, provided that

  9. Performance of the SWEEP model affected by estimates of threshold friction velocity

    Science.gov (United States)

    The Wind Erosion Prediction System (WEPS) is a process-based model and needs to be verified under a broad range of climatic, soil, and management conditions. Occasional failure of the WEPS erosion submodel (Single-event Wind Erosion Evaluation Program or SWEEP) to simulate erosion in the Columbia Pl...

  10. Comparison of measured and simulated friction velocity and threshold friction velocity using SWEEP

    Science.gov (United States)

    The Wind Erosion Prediction System (WEPS) was developed by the USDA Agricultural Research Service as a tool to predict wind erosion and assess the influence of control practices on windblown soil loss. Occasional failure of the WEPS erosion submodel (SWEEP) to simulate erosion in the Columbia Platea...

  11. Lock-free parallel and concurrent garbage collection by mark&sweep

    NARCIS (Netherlands)

    Gao, H.; Groote, J. F.; Hesselink, W. H.

    2007-01-01

    This paper presents a lock-free algorithm for mark&sweep garbage collection (GC) in a realistic model using synchronization primitives load-linked/store-conditional (LL/SC) or compare-and-swap (CAS) offered by machine arch i lectures. The algorithm is concurrent in the sense that garbage collection

  12. Use of exhaust gas as sweep flow to enhance air separation membrane performance

    Science.gov (United States)

    Dutart, Charles H.; Choi, Cathy Y.

    2003-01-01

    An intake air separation system for an internal combustion engine is provided with purge gas or sweep flow on the permeate side of separation membranes in the air separation device. Exhaust gas from the engine is used as a purge gas flow, to increase oxygen flux in the separation device without increasing the nitrogen flux.

  13. Phylogeography of Nasonia vitripennis (Hymenoptera) indicates a mitochondrial-Wolbachia sweep in North America

    NARCIS (Netherlands)

    Raychoudhury, R.; Grillenberger, B. K.; Gadau, J.; Bijlsma, R.; van de Zande, L.; Werren, J. H.; Beukeboom, L. W.

    Here we report evidence of a mitochondrial-Wolbachia sweep in North American populations of the parasitoid wasp Nasonia vitripennis, a cosmopolitan species and emerging model organism for evolutionary and genetic studies. Analysis of the genetic variation of 89 N. vitripennis specimens from Europe

  14. Oxide vapor distribution from a high-frequency sweep e-beam system

    Science.gov (United States)

    Chow, R.; Tassano, P. L.; Tsujimoto, N.

    1995-03-01

    Oxide vapor distributions have been determined as a function of operating parameters of a high frequency sweep e-beam source combined with a programmable sweep controller. We will show which parameters are significant, the parameters that yield the broadest oxide deposition distribution, and the procedure used to arrive at these conclusions. A design-of-experimental strategy was used with five operating parameters: evaporation rate, sweep speed, sweep pattern (pre-programmed), phase speed (azimuthal rotation of the pattern), profile (dwell time as a function of radial position). A design was chosen that would show which of the parameters and parameter pairs have a statistically significant effect on the vapor distribution. Witness flats were placed symmetrically across a 25 inches diameter platen. The stationary platen was centered 24 inches above the e-gun crucible. An oxide material was evaporated under 27 different conditions. Thickness measurements were made with a stylus profilometer. The information will enable users of the high frequency e-gun systems to optimally locate the source in a vacuum system and understand which parameters have a major effect on the vapor distribution.

  15. Wingbeat frequency-sweep and visual stimuli for trapping male Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    Combinations of female wingbeat acoustic cues and visual cues were evaluated to determine their potential for use in male Aedes aegypti (L.) traps in peridomestic environments. A modified Centers for Disease control (CDC) light trap using a 350-500 Hz frequency-sweep broadcast from a speaker as an a...

  16. Numerical simulation of incidence and sweep effects on delta wing vortex breakdown

    Science.gov (United States)

    Ekaterinaris, J. A.; Schiff, Lewis B.

    1994-01-01

    The structure of the vortical flowfield over delta wings at high angles of attack was investigated. Three-dimensional Navier-Stokes numerical simulations were carried out to predict the complex leeward-side flowfield characteristics, including leading-edge separation, secondary separation, and vortex breakdown. Flows over a 75- and a 63-deg sweep delta wing with sharp leading edges were investigated and compared with available experimental data. The effect of variation of circumferential grid resolution grid resolution in the vicinity of the wing leading edge on the accuracy of the solutions was addressed. Furthermore, the effect of turbulence modeling on the solutions was investigated. The effects of variation of angle of attack on the computed vortical flow structure for the 75-deg sweep delta wing were examined. At moderate angles of attack no vortex breakdown was observed. When a critical angle of attack was reached, bubble-type vortex breakdown was found. With further increase in angle of attack, a change from bubble-type breakdown to spiral-type vortex breakdown was predicted by the numerical solution. The effects of variation of sweep angle and freestream Mach number were addressed with the solutions on a 63-deg sweep delta wing.

  17. Acetate and phosphate anion adsorption linear sweep voltammograms simulated using density functional theory

    KAUST Repository

    Savizi, Iman Shahidi Pour; Janik, Michael J.

    2011-01-01

    ) electrode potential. Four models of the electrode potential are used including a simple vacuum slab model, an applied electric field model with and without the inclusion of a solvating water bi-layer, and the double reference model. The linear sweep

  18. Variation sweep rate cyclic voltammetry on the capacitance electrode activated carbon/PVDF with polymer electrolyte

    Science.gov (United States)

    Rohmawati, L.; Setyarsih, W.; Nurjannah, T.

    2018-03-01

    Sweep rate of the process voltammetry cyclic characterization is very influential towards the electrode capacitance value, especially on activated carbon electrodes/PVDF. A simple method of this research by use a mixing for electrode activated carbon/10 wt. % PVDF and the separator is made of a polymer electrolyte (PVA/H3PO4) by a sol gel method. The prototype supercapacitor is made in the form of a sandwich with a separator placed between two electrodes. Electrodes and separators are arranged in layers at a pressure of 1500 psi, then heated at 50°C for 10 minutes. Next done cyclic voltammetry in a potential range of -1 V to 1 V with a sweep rate of 5 mV/s, 10 mV/s, 20 mV/s, 25 mV/s and 50 mV/s. This results of curves voltammogram is reversible, the most wide curve on the sweep rate of 5 mV/s and most narrow curve on a sweep rate of 50 mV/s. Supercapacitor capacitance values obtained by 86 F/g, 43 F/g, 21 F/g, 16 F/g, and 8 F/g.

  19. Effect of elasticity during viscoelastic polymer flooding : a possible mechanism of increasing the sweep efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Urbissinova, T.S.; Trivedi, J.J.; Kuru, E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2010-12-15

    This paper discussed a laboratory experiment undertaken to study how the elasticity of polymer-based fluids affects microscopic sweep efficiency, which has implications for enhanced oil recovery processes. In a series of experiments, polymer solutions with the same shear viscosity but notably different elastic characteristics were injected through a mineral-oil-saturated sandpack. The experiments involved a special core holder that was designed to simulate radial flow. The solution was injected via a perforated injection line located in the centre of the cell, and fluids were produced by way of 2 production lines located at the periphery. The shear rate used in the experiments was within the range of field applications. Using polymer solutions with similar shear viscosity behaviour and different elasticity allowed the effect of elasticity on sweep efficiency to be singled out. It was concluded that adjusting the molecular weight distribution of the solution at a constant shear viscosity and polymer concentration could improve the sweep efficiency of a polymeric fluid. The higher-elasticity polymer solution had a higher resistance to flow through porous media, resulting in better sweep efficiency and lower residual oil saturation. The objective of the study was to isolate elasticity from the other parameters that affect displacement efficiency to show the individual effect of elasticity on oil recovery. 20 refs., 5 tabs., 14 figs.

  20. ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel

    Science.gov (United States)

    Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil; Drnevich, Raymond Francis

    2013-04-02

    The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

  1. On the effects of nonlinearities in room impulse response measurements with exponential sweeps

    DEFF Research Database (Denmark)

    Ciric, Dejan; Markovic, Milos; Mijic, Miomir

    2013-01-01

    In room impulse response measurements, there are some common disturbances that affect the measured results. These disturbances include nonlinearity, noise and time variance. In this paper, the effects of nonlinearities in the measurements with exponential sweep-sine signals are analyzed from diff...

  2. Wind turbine rotor blade with in-plane sweep and devices using the same, and methods for making the same

    Science.gov (United States)

    Wetzel, Kyle Kristopher

    2014-06-24

    A wind turbine includes a rotor having a hub and at least one blade having a torsionally rigid root, an inboard section, and an outboard section. The inboard section has a forward sweep relative to an elastic axis of the blade and the outboard section has an aft sweep.

  3. Reporting consistently on CSR

    DEFF Research Database (Denmark)

    Thomsen, Christa; Nielsen, Anne Ellerup

    2006-01-01

    This chapter first outlines theory and literature on CSR and Stakeholder Relations focusing on the different perspectives and the contextual and dynamic character of the CSR concept. CSR reporting challenges are discussed and a model of analysis is proposed. Next, our paper presents the results...... of a case study showing that companies use different and not necessarily consistent strategies for reporting on CSR. Finally, the implications for managerial practice are discussed. The chapter concludes by highlighting the value and awareness of the discourse and the discourse types adopted...... in the reporting material. By implementing consistent discourse strategies that interact according to a well-defined pattern or order, it is possible to communicate a strong social commitment on the one hand, and to take into consideration the expectations of the shareholders and the other stakeholders...

  4. Geometrically Consistent Mesh Modification

    KAUST Repository

    Bonito, A.

    2010-01-01

    A new paradigm of adaptivity is to execute refinement, coarsening, and smoothing of meshes on manifolds with incomplete information about their geometry and yet preserve position and curvature accuracy. We refer to this collectively as geometrically consistent (GC) mesh modification. We discuss the concept of discrete GC, show the failure of naive approaches, and propose and analyze a simple algorithm that is GC and accuracy preserving. © 2010 Society for Industrial and Applied Mathematics.

  5. Toward Cooling Uniformity: Investigation of Spiral, Sweeping Holes, and Unconventional Cooling Paradigms

    Science.gov (United States)

    Shyam, Vikram; Thurman, Douglas R.; Poinsatte, Philip E.; Ameri, Ali A.; Culley, Dennis E.

    2018-01-01

    Surface infrared thermography, hotwire anemometry, and thermocouple surveys were performed on two new film cooling hole geometries: spiral/rifled holes and fluidic sweeping holes. Ways to quantify the efficacy of novel cooling holes that are asymmetric, not uniformly spaced or that show variation from hole to hole are presented. The spiral holes attempt to induce large-scale vorticity to the film cooling jet as it exits the hole to prevent the formation of the kidney shaped vortices commonly associated with film cooling jets. The fluidic sweeping hole uses a passive in-hole geometry to induce jet sweeping at frequencies that scale with blowing ratios. The spiral hole performance is compared to that of round holes with and without compound angles. The fluidic hole is of the diffusion class of holes and is therefore compared to a 777 hole and square holes. A patent-pending spiral hole design showed the highest potential of the nondiffusion type hole configurations. Velocity contours and flow temperature were acquired at discreet cross-sections of the downstream flow field. The passive fluidic sweeping hole shows the most uniform cooling distribution but suffers from low span-averaged effectiveness levels due to enhanced mixing. The data was taken at a Reynolds number of 11,000 based on hole diameter and freestream velocity. Infrared thermography was taken for blowing ratios of 1.0, 1.5, 2.0, and 2.5 at a density ratio of 1.05. The flow inside the fluidic sweeping hole was studied using 3D unsteady RANS. A section on ideas for future work is included that addresses issues of quantifying cooling uniformity and provides some ideas for changing the way we think about cooling such as changing the direction of cooling or coupling acoustic devices to cooling holes to regulate frequency.

  6. The Rucio Consistency Service

    CERN Document Server

    Serfon, Cedric; The ATLAS collaboration

    2016-01-01

    One of the biggest challenge with Large scale data management system is to ensure the consistency between the global file catalog and what is physically on all storage elements. To tackle this issue, the Rucio software which is used by the ATLAS Distributed Data Management system has been extended to automatically handle lost or unregistered files (aka Dark Data). This system automatically detects these inconsistencies and take actions like recovery or deletion of unneeded files in a central manner. In this talk, we will present this system, explain the internals and give some results.

  7. The signature of positive selection at randomly chosen loci.

    OpenAIRE

    Przeworski, Molly

    2002-01-01

    In Drosophila and humans, there are accumulating examples of loci with a significant excess of high-frequency-derived alleles or high levels of linkage disequilibrium, relative to a neutral model of a random-mating population of constant size. These are features expected after a recent selective sweep. Their prevalence suggests that positive directional selection may be widespread in both species. However, as I show here, these features do not persist long after the sweep ends: The high-frequ...

  8. Is cosmology consistent?

    International Nuclear Information System (INIS)

    Wang Xiaomin; Tegmark, Max; Zaldarriaga, Matias

    2002-01-01

    We perform a detailed analysis of the latest cosmic microwave background (CMB) measurements (including BOOMERaNG, DASI, Maxima and CBI), both alone and jointly with other cosmological data sets involving, e.g., galaxy clustering and the Lyman Alpha Forest. We first address the question of whether the CMB data are internally consistent once calibration and beam uncertainties are taken into account, performing a series of statistical tests. With a few minor caveats, our answer is yes, and we compress all data into a single set of 24 bandpowers with associated covariance matrix and window functions. We then compute joint constraints on the 11 parameters of the 'standard' adiabatic inflationary cosmological model. Our best fit model passes a series of physical consistency checks and agrees with essentially all currently available cosmological data. In addition to sharp constraints on the cosmic matter budget in good agreement with those of the BOOMERaNG, DASI and Maxima teams, we obtain a heaviest neutrino mass range 0.04-4.2 eV and the sharpest constraints to date on gravity waves which (together with preference for a slight red-tilt) favor 'small-field' inflation models

  9. Consistent Quantum Theory

    Science.gov (United States)

    Griffiths, Robert B.

    2001-11-01

    Quantum mechanics is one of the most fundamental yet difficult subjects in physics. Nonrelativistic quantum theory is presented here in a clear and systematic fashion, integrating Born's probabilistic interpretation with Schrödinger dynamics. Basic quantum principles are illustrated with simple examples requiring no mathematics beyond linear algebra and elementary probability theory. The quantum measurement process is consistently analyzed using fundamental quantum principles without referring to measurement. These same principles are used to resolve several of the paradoxes that have long perplexed physicists, including the double slit and Schrödinger's cat. The consistent histories formalism used here was first introduced by the author, and extended by M. Gell-Mann, J. Hartle and R. Omnès. Essential for researchers yet accessible to advanced undergraduate students in physics, chemistry, mathematics, and computer science, this book is supplementary to standard textbooks. It will also be of interest to physicists and philosophers working on the foundations of quantum mechanics. Comprehensive account Written by one of the main figures in the field Paperback edition of successful work on philosophy of quantum mechanics

  10. Beam pinging, sweeping, shaking, and electron/ion collecting, at the Proton Storage Ring

    International Nuclear Information System (INIS)

    Hardek, T.W.; Macek, R.J.; Plum, M.A.; Wang, T.S.F.

    1993-01-01

    We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results

  11. Sweeping-window arc therapy: an implementation of rotational IMRT with automatic beam-weight calculation

    International Nuclear Information System (INIS)

    Cameron, C

    2005-01-01

    Sweeping-window arc therapy (SWAT) is a variation of intensity-modulated radiation therapy (IMRT) with direct aperture optimization (DAO) that is initialized with a leaf sequence of sweeping windows that move back and forth periodically across the target as the gantry rotates. This initial sequence induces modulation in the dose and is assumed to be near enough to a minimum to allow successful optimization, done with simulated annealing, without requiring excessive leaf speeds. Optimal beam weights are calculated analytically, with easy extension to allow for variable beam weights. In this paper SWAT is tested on a phantom model and clinical prostate case. For the phantom, constant and variable beam weights are used. Although further work (in particular, improving the dose model) is required, the results show SWAT to be a feasible approach to generating deliverable dynamic arc treatments that are optimized

  12. Sweeping Jet Actuators - A New Design Tool for High Lift Generation

    Science.gov (United States)

    Graff, Emilio; Seele, Roman; Lin, John C.; Wygnanski, Israel

    2013-01-01

    Active Flow Control (AFC) experiments performed at the Caltech Lucas Wind Tunnel on a generic airplane vertical tail model proved the effectiveness of sweeping jets in improving the control authority of a rudder. The results indicated that a momentum coefficient (C(sub u)) of approximately 2% increased the side force in excess of 50% at the maximum conventional rudder deflection angle in the absence of yaw. However, sparsely distributed actuators providing a collective C(sub u) approx. = 0.1% were able to increase the side force in excess of 20%. This result is achieved by reducing the spanwise flow along the swept back rudder and its success is attributed to the large sweep back angle of the vertical tail. This current effort was sponsored by the NASA Environmentally Responsible Aviation (ERA) project.

  13. A second order discontinuous Galerkin fast sweeping method for Eikonal equations

    Science.gov (United States)

    Li, Fengyan; Shu, Chi-Wang; Zhang, Yong-Tao; Zhao, Hongkai

    2008-09-01

    In this paper, we construct a second order fast sweeping method with a discontinuous Galerkin (DG) local solver for computing viscosity solutions of a class of static Hamilton-Jacobi equations, namely the Eikonal equations. Our piecewise linear DG local solver is built on a DG method developed recently [Y. Cheng, C.-W. Shu, A discontinuous Galerkin finite element method for directly solving the Hamilton-Jacobi equations, Journal of Computational Physics 223 (2007) 398-415] for the time-dependent Hamilton-Jacobi equations. The causality property of Eikonal equations is incorporated into the design of this solver. The resulting local nonlinear system in the Gauss-Seidel iterations is a simple quadratic system and can be solved explicitly. The compactness of the DG method and the fast sweeping strategy lead to fast convergence of the new scheme for Eikonal equations. Extensive numerical examples verify efficiency, convergence and second order accuracy of the proposed method.

  14. Sweeping-window arc therapy: an implementation of rotational IMRT with automatic beam-weight calculation

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, C [Division of Radiation Physics, Department of Radiation Oncology, Stanford Cancer Center, 875 Blake Wilbur Drive, Rm G-233, Stanford, CA 94305-5847 (United States)

    2005-09-21

    Sweeping-window arc therapy (SWAT) is a variation of intensity-modulated radiation therapy (IMRT) with direct aperture optimization (DAO) that is initialized with a leaf sequence of sweeping windows that move back and forth periodically across the target as the gantry rotates. This initial sequence induces modulation in the dose and is assumed to be near enough to a minimum to allow successful optimization, done with simulated annealing, without requiring excessive leaf speeds. Optimal beam weights are calculated analytically, with easy extension to allow for variable beam weights. In this paper SWAT is tested on a phantom model and clinical prostate case. For the phantom, constant and variable beam weights are used. Although further work (in particular, improving the dose model) is required, the results show SWAT to be a feasible approach to generating deliverable dynamic arc treatments that are optimized.

  15. 1 μs broadband frequency sweeping reflectometry for plasma density and fluctuation profile measurements

    Science.gov (United States)

    Clairet, F.; Bottereau, C.; Medvedeva, A.; Molina, D.; Conway, G. D.; Silva, A.; Stroth, U.; ASDEX Upgrade Team; Tore Supra Team; Eurofusion Mst1 Team

    2017-11-01

    Frequency swept reflectometry has reached the symbolic value of 1 μs sweeping time; this performance has been made possible, thanks to an improved control of the ramp voltage driving the frequency source. In parallel, the memory depth of the acquisition system has been upgraded and can provide up to 200 000 signals during a plasma discharge. Additional improvements regarding the trigger delay determination of the acquisition and the voltage ramp linearity required by this ultra-fast technique have been set. While this diagnostic is traditionally dedicated to the plasma electron density profile measurement, such a fast sweeping rate can provide the study of fast plasma events and turbulence with unprecedented time and radial resolution from the edge to the core. Experimental results obtained on ASDEX Upgrade plasmas are presented to demonstrate the performances of the diagnostic.

  16. Flow field characteristics of impinging sweeping jets: TR-PIV measurement

    Science.gov (United States)

    Wen, Xin; Peng, Di; Liu, Yingzheng; Tang, Hui

    2017-11-01

    Influence of Reynolds number of sweeping jets on its impinging flow fields was extensively investigated in a water tank. Toward this end, a fluidic oscillator was specially designed to produce spatially sweeping jets which imping on a flat plate. Six Reynolds numbers were tested by controlling the supply flow rate of the fluidic oscillator. Impinging flow fields were captured by time-resolved Particle Image Velocimetry (TR-PIV) measurement. Reference signals were extracted from the flow fields for phase reconstruction. The oscillating flow fields with super-harmonic frequency at different regions were discussed in term of the phase-averaged velocity, vorticity and turbulent velocity. Dynamic mode decomposition (DMD) was used to capture the most-energetic flow patterns with distinct frequencies. By projecting the phase-averaged flow fields onto a reduced basis of DMD modes, the phase correlation between the distinct flow patterns were analyzed under different Reynolds numbers.

  17. Grain boundary sweeping and dissolution effects on fission product behaviour under severe fuel damage accident conditions

    International Nuclear Information System (INIS)

    Rest, J.

    1986-01-01

    The theoretical FASTGRASS-VFP model has been used in the interpretation of fission gas, iodine, tellurium, and cesium release from severe-fuel-damage (SFD) tests performed in the PBF reactor in Idaho. A theory of grain boundary sweeping of gas bubbles, gas bubble behavior during fuel liquefaction (destruction of grain boundaries due to formation of a U-rich melt phase), and during U-Zr eutectic melting has been included within the FASTGRASS-VFP formalism. The grain-boundary-sweeping theory considers the interaction between the moving grain boundary and two distinct size classes of bubbles, those on grain faces and on grain edges. The theory of the effects of fuel liquefaction and U-Zr eutectic melting on fission product behaviour considers the migration and coalescence of fission gas bubbles in either molten uranium, or a Zircaloy-Uranium eutectic melt. Results of the analyses demonstrate that intragranular fission product behavior during the tests can be interpreted in terms of a grain-growth/grain-boundary-sweeping mechanism that enhances the flow of fission products from within the grains to the grain boundaries. Whereas fuel liquefaction leads to an enhanced release of fission products in trace-irradiated fuel, the occurrence of fuel liquefaction in normally-irradiated fuel can degrade fission product release. This phenomenon is due in part to reduced gas-bubble mobilities in a viscous medium as compared to vapor transport, and in part to a degradation of grain growth rates and the subsequent decrease in grain-boundary sweeping of intragranular fission products into the liquified lamina. The analysis shows that total UO 2 dissolution due to eutectic melting leads to increased release for both trace-irradiated and normally-irradiated fuel. The FASTGRASS-VFP predictions, measured release rates from the above tests, and previously published release rates are compared and differences between fission product behavior in trace-irradiated and in normally

  18. Field Experience with Sweep Frequency Response Analysis for Power Transformer Diagnosis

    OpenAIRE

    Ambuj Kumar; Sunil Kumar Singh; Shrikant Singh

    2015-01-01

    Sweep frequency response analysis has been turning out a powerful tool for investigation of mechanical as well as electrical integration of transformers. In this paper various aspect of practical application of SFRA has been studied. Open circuit and short circuit measurement were done on different phases of high voltage and low voltage winding. A case study was presented for the transformer of rating 31.5 MVA for various frequency ranges. A clear picture was presented fo...

  19. Study of Near-Stall Flow Behavior in a Modern Transonic Fan with Composite Sweep

    Science.gov (United States)

    Hah, Chunill; Shin, Hyoun-Woo

    2011-01-01

    Detailed flow behavior in a modern transonic fan with a composite sweep is investigated in this paper. Both unsteady Reynolds-averaged Navier-Stokes (URANS) and Large Eddy Simulation (LES) methods are applied to investigate the flow field over a wide operating range. The calculated flow fields are compared with the data from an array of high-frequency response pressure transducers embedded in the fan casing. The current study shows that a relatively fine computational grid is required to resolve the flow field adequately and to calculate the pressure rise across the fan correctly. The calculated flow field shows detailed flow structure near the fan rotor tip region. Due to the introduction of composite sweep toward the rotor tip, the flow structure at the rotor tip is much more stable compared to that of the conventional blade design. The passage shock stays very close to the leading edge at the rotor tip even at the throttle limit. On the other hand, the passage shock becomes stronger and detaches earlier from the blade passage at the radius where the blade sweep is in the opposite direction. The interaction between the tip clearance vortex and the passage shock becomes intense as the fan operates toward the stall limit, and tip clearance vortex breakdown occurs at near-stall operation. URANS calculates the time-averaged flow field fairly well. Details of measured RMS static pressure are not calculated with sufficient accuracy with URANS. On the other hand, LES calculates details of the measured unsteady flow features in the current transonic fan with composite sweep fairly well and reveals the flow mechanism behind the measured unsteady flow field.

  20. Outcome of Membrane Sweeping in Reducing Induction Rates in Post-Date Pregnancies

    International Nuclear Information System (INIS)

    Saleem, U.; Mustafa, N.; Akhtar, S.

    2013-01-01

    Objectives: To determine the effectiveness of membrane sweeping in reducing need for induction of labour in post-date pregnancies and to enlist types and frequencies of complications experienced with membrane sweeping. Study Design: Randomized Control trial. Setting and Duration of Study: The study was carried out at Department of Obstetrics and Gynaecology, Combined Military Hospital, Lahore from February 2007 to April 2008. Patients and Methods: One hundred primi or second gravidas with uncomplicated singleton pregnancies having cephalic presentation at 40+1-5 weeks of gestation were enrolled after informed consent, and divided randomly into two groups of fifty each. Biophysical profile of 8/8 for each case was ensured. Group A underwent membrane sweeping while group B did not. All patients not having spontaneous labour were induced at 40+5 weeks. Data regarding number of patients having spontaneous labour or induction of labour was recorded. Mode of delivery either vaginal or cesarean birth was also recorded. In group A occurence of complications i.e vaginal bleeding or leaking, discomfort, irregular pains, fever and neonatal sepsis was recorded. Results: The difference in rate of spontaneous labor, induction rate and mode of delivery was insignificant between both the groups (p>0.05). In group A, 44% felt discomfort, 4% had bleeding per vaginum, 2% had leaking per vaginum and 28% had more than one complication. There were no cases of maternal or neonatal sepsis. Twenty percent did not have any side effects. Conclusion: Sweeping of membranes is not effective in reducing induction rates in post dates pregnancies. It does not improve the spontaneous labour rate and there is no effect on the mode of delivery. Therefore, any potential benefits of this intervention must be balanced against risk of maternal discomfort and other adverse effects. (author)

  1. On gas sweeping from central regions of galaxies with active nuclei

    International Nuclear Information System (INIS)

    Silich, S.A.; Fomin, P.I.

    1980-01-01

    A mechanism of gas sweeping by shock waves from central regions of plane galaxies with active nuclei which is connected with the angular moment transfer from a stellar-cloud component to a gas one is considered. It is shown that shock waves are capable to form the observable density profile with the maximum at a distance of some kpc from galaxy centre for the time of the order of 10 9 years

  2. Residual sweeping errors in turbulent particle pair diffusion in a Lagrangian diffusion model.

    Science.gov (United States)

    Malik, Nadeem A

    2017-01-01

    Thomson, D. J. & Devenish, B. J. [J. Fluid Mech. 526, 277 (2005)] and others have suggested that sweeping effects make Lagrangian properties in Kinematic Simulations (KS), Fung et al [Fung J. C. H., Hunt J. C. R., Malik N. A. & Perkins R. J. J. Fluid Mech. 236, 281 (1992)], unreliable. However, such a conclusion can only be drawn under the assumption of locality. The major aim here is to quantify the sweeping errors in KS without assuming locality. Through a novel analysis based upon analysing pairs of particle trajectories in a frame of reference moving with the large energy containing scales of motion it is shown that the normalized integrated error [Formula: see text] in the turbulent pair diffusivity (K) due to the sweeping effect decreases with increasing pair separation (σl), such that [Formula: see text] as σl/η → ∞; and [Formula: see text] as σl/η → 0. η is the Kolmogorov turbulence microscale. There is an intermediate range of separations 1 < σl/η < ∞ in which the error [Formula: see text] remains negligible. Simulations using KS shows that in the swept frame of reference, this intermediate range is large covering almost the entire inertial subrange simulated, 1 < σl/η < 105, implying that the deviation from locality observed in KS cannot be atributed to sweeping errors. This is important for pair diffusion theory and modeling. PACS numbers: 47.27.E?, 47.27.Gs, 47.27.jv, 47.27.Ak, 47.27.tb, 47.27.eb, 47.11.-j.

  3. Effect of Sweep on Cavity Flow Fields at Subsonic and Transonic Speeds

    Science.gov (United States)

    Tracy, Maureen B.; Plentovich, Elizabeth B.; Hemsch, Michael J.; Wilcox, Floyd J.

    2012-01-01

    An experimental investigation was conducted in the NASA Langley 7 x 10-Foot High Speed Tunnel (HST) to study the effect of leading- and trailing-edge sweep on cavity flow fields for a range of cavity length-to-height (l/h) ratios. The free-stream Mach number was varied from 0.2 to 0.8. The cavity had a depth of 0.5 inches, a width of 2.5 inches, and a maximum length of 12.0 inches. The leading- and trailing-edge sweep was adjusted using block inserts to achieve leading edge sweep angles of 65 deg, 55 deg, 45 deg, 35 deg, and 0 deg. The fore and aft cavity walls were always parallel. The aft wall of the cavity was remotely positioned to achieve a range of length-to-depth ratios. Fluctuating- and static-pressure data were obtained on the floor of the cavity. The fluctuating pressure data were used to determine whether or not resonance occurred in the cavity rather than to provide a characterization of the fluctuating pressure field. Qualitative surface flow visualization was obtained using a technique in which colored water was introduced into the model through static-pressure orifices. A complete tabulation of the mean static-pressure data for the swept leading edge cavities is included.

  4. Parallel Sn Sweeps on Unstructured Grids: Algorithms for Prioritization, Grid Partitioning, and Cycle Detection

    International Nuclear Information System (INIS)

    Plimpton, Steven J.; Hendrickson, Bruce; Burns, Shawn P.; McLendon, William III; Rauchwerger, Lawrence

    2005-01-01

    The method of discrete ordinates is commonly used to solve the Boltzmann transport equation. The solution in each ordinate direction is most efficiently computed by sweeping the radiation flux across the computational grid. For unstructured grids this poses many challenges, particularly when implemented on distributed-memory parallel machines where the grid geometry is spread across processors. We present several algorithms relevant to this approach: (a) an asynchronous message-passing algorithm that performs sweeps simultaneously in multiple ordinate directions, (b) a simple geometric heuristic to prioritize the computational tasks that a processor works on, (c) a partitioning algorithm that creates columnar-style decompositions for unstructured grids, and (d) an algorithm for detecting and eliminating cycles that sometimes exist in unstructured grids and can prevent sweeps from successfully completing. Algorithms (a) and (d) are fully parallel; algorithms (b) and (c) can be used in conjunction with (a) to achieve higher parallel efficiencies. We describe our message-passing implementations of these algorithms within a radiation transport package. Performance and scalability results are given for unstructured grids with up to 3 million elements (500 million unknowns) running on thousands of processors of Sandia National Laboratories' Intel Tflops machine and DEC-Alpha CPlant cluster

  5. SWEEP, a computer program for the analysis of CDA energetics in liquid metal reactors

    International Nuclear Information System (INIS)

    Suk, Soo Dong; Lee, Yong Bum; Hahn, Do Hee

    2003-12-01

    The SWEEP computer code was developed in this study to evaluate the work energy arising from two-phase expansion of fuel or sodium during core disruptive accidents in KALIMER. In the SWEEP program, scoping calculations with a modified Bethe-Tait method is first carried out using SCHAMBETA module to provide the initial thermodynamic conditions for the subsequent analyses to estimate the mechanical work energy generated in the reactor system. To estimate the work energy due to fuel-vapor expansion, a bounding approach is adopted to calculate the work potential assuming isentropic expansion to atmospheric pressure during super-prompt critical power excursions. Work potentials are also calculated in the SWEEP code for sodium expansion using the simple thermodynamic models including the infinite heat transfer model during expansion(Hicks and Menzies method) or more realistic zero heat transfer model for a typical initial condition of core disruptive accident. Core disruptive accidents have been investigated at Korea Atomic Energy Research Institute(KAERI) as part of the work to demonstrate the inherent and ultimate safety of conceptual design of the Korea Advanced Liquid Metal Reactor(KALIMER), a 150 MWe pool-type sodium cooled prototype fast reactor that uses U-TRU-Zr metallic fuel

  6. Analysing Infinite-State Systems by Combining Equivalence Reduction and the Sweep-Line Method

    DEFF Research Database (Denmark)

    Mailund, Thomas

    2002-01-01

    The sweep-line method is a state space exploration method for on-the-fly verification aimed at systems exhibiting progress. Presence of progress in the system makes it possible to delete certain states during state space generation, which reduces the memory used for storing the states. Unfortunat......The sweep-line method is a state space exploration method for on-the-fly verification aimed at systems exhibiting progress. Presence of progress in the system makes it possible to delete certain states during state space generation, which reduces the memory used for storing the states....... Unfortunately, the same progress that is used to improve memory performance in state space exploration often leads to an infinite state space: The progress in the system is carried over to the states resulting in infinitely many states only distinguished through the progress. A finite state space can...... property essential for the sweep-line method. We evaluate the new method on two case studies, showing significant improvements in performance, and we briefly discuss the new method in the context of Timed Coloured Petri Nets, where the “increasing global time” semantics can be exploited for more efficient...

  7. Sweeping Gas Membrane Desalination Using Commercial Hydrophobic Hollow Fiber Membranes; TOPICAL

    International Nuclear Information System (INIS)

    EVANS, LINDSEY; MILLER, JAMES E.

    2002-01-01

    Water shortages affect 88 developing countries that are home to half of the world's population. In these places, 80-90% of all diseases and 30% of all deaths result from poor water quality. Furthermore, over the next 25 years, the number of people affected by severe water shortages is expected to increase fourfold. Low cost methods of purifying freshwater, and desalting seawater are required to contend with this destabilizing trend. Membrane distillation (MD) is an emerging technology for separations that are traditionally accomplished via conventional distillation or reverse osmosis. As applied to desalination, MD involves the transport of water vapor from a saline solution through the pores of a hydrophobic membrane. In sweeping gas MD, a flowing gas stream is used to flush the water vapor from the permeate side of the membrane, thereby maintaining the vapor pressure gradient necessary for mass transfer. Since liquid does not penetrate the hydrophobic membrane, dissolved ions are completely rejected by the membrane. MD has a number of potential advantages over conventional desalination including low temperature and pressure operation, reduced membrane strength requirements, compact size, and 100% rejection of non-volatiles. The present work evaluated the suitability of commercially available technology for sweeping gas membrane desalination. Evaluations were conducted with Celgard Liqui-Cel(reg s ign) Extra-Flow 2.5X8 membrane contactors with X-30 and X-40 hydrophobic hollow fiber membranes. Our results show that sweeping gas membrane desalination systems are capable of producing low total dissolved solids (TDS) water, typically 10 ppm or less, from seawater, using low grade heat. However, there are several barriers that currently prevent sweeping gas MD from being a viable desalination technology. The primary problem is that large air flows are required to achieve significant water yields, and the costs associated with transporting this air are prohibitive. To

  8. Influence of additives and impurities in sweep gas and solid tritium release behaviour from lithium ceramics (review)

    International Nuclear Information System (INIS)

    Tanaka, Satoru

    1991-01-01

    Tritium release from solid breeding material is affected by small amounts of additives or impurities in the sweep gas or solid itself. Addition of hydrogen or water vapor to the sweep gas is reported to enhance the surface reaction of tritium release. Doping to solid breeder with elements of different valence from lithium has a possibility to improve tritium diffusion in the solid. Surface reaction and migration behavior in bulk are believed to be also affected by impurities in the sweep gas and in the solid. In order to model tritium release behavior in the blanket of fusion reactor, the mechanism of interaction with these additives or impurities must be quantitatively formulated. However, the mechanism of these remains to be elucidated. In this paper effects of these additives and impurities on tritium migration are reviewed. The mechanism of surface reaction for He+H 2 sweep gas is also discussed. (orig.)

  9. [Relation between frequency modulation direction selectivity and forward masking of inferior collicular neurons: a study on in vivo intracellular recording in mice].

    Science.gov (United States)

    Fu, Zi-Ying; Zeng, Hong; Tang, Jia; Li, Jie; Li, Juan; Chen, Qi-Cai

    2013-06-25

    It has been reported that the frequency modulation (FM) or FM direction sensitivity and forward masking of central auditory neurons are related with the neural inhibition, but there are some arguments, because no direct evidence of inhibitory synaptic input was obtained in previous studies using extracellular recording. In the present study, we studied the relation between FM direction sensitivity and forward masking of the inferior collicular (IC) neurons using in vivo intracellular recordings in 20 Mus musculus Km mice. Thirty seven with complete data among 93 neurons were analyzed and discussed. There was an inhibitory area which consisted of inhibitory postsynaptic potentials (IPSP) at high frequency side of frequency tuning of up-sweep FM (FMU) sensitive neurons (n = 12) and at low frequency side of frequency tuning of down-sweep FM (FMD) selective neurons (n = 8), while there was no any inhibitory area at both sides of frequency tuning of non-FM sweep direction (FMN) sensitive neurons (n = 17). Therefore, these results show that the inhibitory area at low or high frequency side of frequency tuning is one of the mechanisms for forming FM sweep direction sensitivity of IC neurons. By comparison of forward masking produced by FMU and FMD sound stimuli in FMU, FMD and FMN neurons, the selective FM sounds could produce stronger forward masking than the non-selective in FMU and FMD neurons, while there was no forward masking difference between FMU and FMD stimuli in the FMN neurons. We suggest that the post-action potential IPSP is a potential mechanism for producing stronger forward masking in FMU and FMD neurons.

  10. Genomic consequences of selection and genome-wide association mapping in soybean.

    Science.gov (United States)

    Wen, Zixiang; Boyse, John F; Song, Qijian; Cregan, Perry B; Wang, Dechun

    2015-09-03

    Crop improvement always involves selection of specific alleles at genes controlling traits of agronomic importance, likely resulting in detectable signatures of selection within the genome of modern soybean (Glycine max L. Merr.). The identification of these signatures of selection is meaningful from the perspective of evolutionary biology and for uncovering the genetic architecture of agronomic traits. To this end, two populations of soybean, consisting of 342 landraces and 1062 improved lines, were genotyped with the SoySNP50K Illumina BeadChip containing 52,041 single nucleotide polymorphisms (SNPs), and systematically phenotyped for 9 agronomic traits. A cross-population composite likelihood ratio (XP-CLR) method was used to screen the signals of selective sweeps. A total of 125 candidate selection regions were identified, many of which harbored genes potentially involved in crop improvement. To further investigate whether these candidate regions were in fact enriched for genes affected by selection, genome-wide association studies (GWAS) were conducted on 7 selection traits targeted in soybean breeding (grain yield, plant height, lodging, maturity date, seed coat color, seed protein and oil content) and 2 non-selection traits (pubescence and flower color). Major genomic regions associated with selection traits overlapped with candidate selection regions, whereas no overlap of this kind occurred for the non-selection traits, suggesting that the selection sweeps identified are associated with traits of agronomic importance. Multiple novel loci and refined map locations of known loci related to these traits were also identified. These findings illustrate that comparative genomic analyses, especially when combined with GWAS, are a promising approach to dissect the genetic architecture of complex traits.

  11. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  12. Robust analysis of the hydrophobic basic analytes loratadine and desloratadine in pharmaceutical preparations and biological fluids by sweeping-cyclodextrin-modified micellar electrokinetic chromatography.

    Science.gov (United States)

    El-Awady, Mohamed; Belal, Fathalla; Pyell, Ute

    2013-09-27

    The analysis of hydrophobic basic analytes by micellar electrokinetic chromatography (MEKC) is usually challenging because of the tendency of these analytes to be adsorbed onto the inner capillary wall in addition to the difficulty to separate these compounds as they exhibit extremely high retention factors. A robust and reliable method for the simultaneous determination of loratadine (LOR) and its major metabolite desloratadine (DSL) is developed based on cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) with acidic sample matrix and basic background electrolyte (BGE). The influence of the sample matrix on the reachable focusing efficiency is studied. It is shown that the application of a low pH sample solution mitigates problems associated with the low solubility of the hydrophobic basic analytes in aqueous solution while having advantages with regard to on-line focusing. Moreover, the use of a basic BGE reduces the adsorption of these analytes in the separation compartment. The separation of the studied analytes is achieved in less than 7min using a BGE consisting of 10mmolL(-1) disodium tetraborate buffer, pH 9.30 containing 40mmolL(-1) SDS and 20mmolL(-1) hydroxypropyl-β-CD while the sample solution is composed of 10mmolL(-1) phosphoric acid, pH 2.15. A full validation study of the developed method based on the pharmacopeial guidelines is performed. The method is successfully applied to the analysis of the studied drugs in tablets without interference of tablet additives as well as the analysis of spiked human urine without any sample pretreatment. Furthermore, DSL can be detected as an impurity in LOR bulk powder at the stated pharmacopeial limit (0.1%, w/w). The selectivity of the developed method allows the analysis of LOR and DSL in combination with the co-formulated drug pseudoephedrine. It is shown that in CD-MEKC with basic BGE, solute-wall interactions are effectively suppressed allowing the development of efficient and precise

  13. Sweep visually evoked potentials and visual findings in children with West syndrome.

    Science.gov (United States)

    de Freitas Dotto, Patrícia; Cavascan, Nívea Nunes; Berezovsky, Adriana; Sacai, Paula Yuri; Rocha, Daniel Martins; Pereira, Josenilson Martins; Salomão, Solange Rios

    2014-03-01

    West syndrome (WS) is a type of early childhood epilepsy characterized by progressive neurological development deterioration that includes vision. To demonstrate the clinical importance of grating visual acuity thresholds (GVA) measurement by sweep visually evoked potentials technique (sweep-VEP) as a reliable tool for evaluation of the visual cortex status in WS children. This is a retrospective study of the best-corrected binocular GVA and ophthalmological features of WS children referred for the Laboratory of Clinical Electrophysiology of Vision of UNIFESP from 1998 to 2012 (Committee on Ethics in Research of UNIFESP n° 0349/08). The GVA deficit was calculated by subtracting binocular GVA score (logMAR units) of each patient from the median values of age norms from our own lab and classified as mild (0.1-0.39 logMAR), moderate (0.40-0.80 logMAR) or severe (>0.81 logMAR). Associated ophthalmological features were also described. Data from 30 WS children (age from 6 to 108 months, median = 14.5 months, mean ± SD = 22.0 ± 22.1 months; 19 male) were analyzed. The majority presented severe GVA deficit (0.15-1.44 logMAR; mean ± SD = 0.82 ± 0.32 logMAR; median = 0.82 logMAR), poor visual behavior, high prevalence of strabismus and great variability in ocular positioning. The GVA deficit did not vary according to gender (P = .8022), WS type (P = .908), birth age (P = .2881), perinatal oxygenation (P = .7692), visual behavior (P = .8789), ocular motility (P = .1821), nystagmus (P = .2868), risk of drug-induced retinopathy (P = .4632) and participation in early visual stimulation therapy (P = .9010). The sweep-VEP technique is a reliable tool to classify visual system impairment in WS children, in agreement with the poor visual behavior exhibited by them. Copyright © 2013 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  14. The Grid[Way] Job Template Manager, a tool for parameter sweeping

    Science.gov (United States)

    Lorca, Alejandro; Huedo, Eduardo; Llorente, Ignacio M.

    2011-04-01

    Parameter sweeping is a widely used algorithmic technique in computational science. It is specially suited for high-throughput computing since the jobs evaluating the parameter space are loosely coupled or independent. A tool that integrates the modeling of a parameter study with the control of jobs in a distributed architecture is presented. The main task is to facilitate the creation and deletion of job templates, which are the elements describing the jobs to be run. Extra functionality relies upon the GridWay Metascheduler, acting as the middleware layer for job submission and control. It supports interesting features like multi-dimensional sweeping space, wildcarding of parameters, functional evaluation of ranges, value-skipping and job template automatic indexation. The use of this tool increases the reliability of the parameter sweep study thanks to the systematic bookkeeping of job templates and respective job statuses. Furthermore, it simplifies the porting of the target application to the grid reducing the required amount of time and effort. Program summaryProgram title: Grid[Way] Job Template Manager (version 1.0) Catalogue identifier: AEIE_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIE_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Apache license 2.0 No. of lines in distributed program, including test data, etc.: 3545 No. of bytes in distributed program, including test data, etc.: 126 879 Distribution format: tar.gz Programming language: Perl 5.8.5 and above Computer: Any (tested on PC x86 and x86_64) Operating system: Unix, GNU/Linux (tested on Ubuntu 9.04, Scientific Linux 4.7, centOS 5.4), Mac OS X (tested on Snow Leopard 10.6) RAM: 10 MB Classification: 6.5 External routines: The GridWay Metascheduler [1]. Nature of problem: To parameterize and manage an application running on a grid or cluster. Solution method: Generation of job templates as a cross product of

  15. Ion source plasma parameters measurement based on Langmuir probe with commercial frequency sweep

    International Nuclear Information System (INIS)

    Xie, Y.H.; Hu, C.D.; Liu, S.; Shong, S.H.; Jiang, C.C.; Liu, Z.M.

    2010-01-01

    Langmuir probe is one of the main diagnostic tools to measure the plasma parameters in the ion source. In this article, the commercial frequency power, which is sine wave of 50 Hz, was supplied on the Langmuir probe to measure the plasma parameters. The best feature of this probe sweep voltage is that it does not need extra design. The probe I-V characteristic curve can be got in less than 5 ms and the plasma parameters, the electron temperature and the electron density, varying with the time can be got in one plasma discharge of 400 ms.

  16. Consistent reconstruction of 4D fetal heart ultrasound images to cope with fetal motion.

    Science.gov (United States)

    Tanner, Christine; Flach, Barbara; Eggenberger, Céline; Mattausch, Oliver; Bajka, Michael; Goksel, Orcun

    2017-08-01

    4D ultrasound imaging of the fetal heart relies on reconstructions from B-mode images. In the presence of fetal motion, current approaches suffer from artifacts, which are unrecoverable for single sweeps. We propose to use many sweeps and exploit the resulting redundancy to automatically recover from motion by reconstructing a 4D image which is consistent in phase, space, and time. An interactive visualization framework to view animated ultrasound slices from 4D reconstructions on arbitrary planes was developed using a magnetically tracked mock probe. We first quantified the performance of 10 4D reconstruction formulations on simulated data. Reconstructions of 14 in vivo sequences by a baseline, the current state-of-the-art, and the proposed approach were then visually ranked with respect to temporal quality on orthogonal views. Rankings from 5 observers showed that the proposed 4D reconstruction approach significantly improves temporal image quality in comparison with the baseline. The 4D reconstructions of the baseline and the proposed methods were then inspected interactively for accessibility to clinically important views and rated for their clinical usefulness by an ultrasound specialist in obstetrics and gynecology. The reconstructions by the proposed method were rated as 'very useful' in 71% and were statistically significantly more useful than the baseline reconstructions. Multi-sweep fetal heart ultrasound acquisitions in combination with consistent 4D image reconstruction improves quality as well as clinical usefulness of the resulting 4D images in the presence of fetal motion.

  17. Ultrasonic flow-through filtration of microparticles in a microfluidic channel using frequency sweep technique

    International Nuclear Information System (INIS)

    Seo, Dae Cheol; Ahn, Bong Young; Cho, Seung Hyun; Siddique, A. K. M. Ariful Haque; Kim, Cheol Gi

    2013-01-01

    Many studies have been conducted on the filtration of microparticles using the acoustic radiation force of ultrasonic standing wave. The present work concerns a flow-through particle filtration method by utilizing frequency varying ultrasound. The periodical frequency sweep of the ultrasonic standing wave translocates particles across a microchannel, where particles in fluid flow are filtrated without barriers. The present filtration technique in a microfluidic channel was proposed conceptually in the 1990s. However, its experimental realization on actual particles in a microfluidic channel has not been carried out in a notable way. Several sizes of polystyrene microspheres (10 µm to 90 µm) and silicon carbide (SiC) particles (37 µm) suspended in water were applied as a test sample. For filtration of those particles, a Y-branched microfluidic channel with one inlet and two outlets was made out of steel and acrylic as a form of modulized device. Ultrasound of a few MHz in band frequency (1.75 MHz to 3.05 MHz) was transmitted into one side of the channel wall to generate a standing wave field in fluid flow. The periodical frequency sweep operation showed successful filtration performance, whereby particles in water flowed into one outlet and purified water flowed into the other outlet of the Y branch of the channel.

  18. Solving the Capacitive Effect in the High-Frequency sweep for Langmuir Probe in SYMPLE

    International Nuclear Information System (INIS)

    Pramila; Patel, J J; Rajpal, R; Hansalia, C J; Anitha, V P; Sathyanarayana, K

    2017-01-01

    Langmuir Probe based measurements need to be routinely carried out to measure various plasma parameters such as the electron density (n e ), the electron temperature (T e ), the floating potential (V f ), and the plasma potential (V p ). For this, the diagnostic electronics along with the biasing power supplies is installed in standard industrial racks with a 2KV isolation transformer. The Signal Conditioning Electronics (SCE) system is populated inside the 4U-chassis based system with the front-end electronics, designed using high common mode differential amplifiers which can measure small differential signal in presence of high common mode dc- bias or ac ramp voltage used for biasing the probes. DC-biasing of the probe is most common method for getting its I-V characteristic but method of biasing the probe with a sweep at high frequency encounters the problem of corruption of signal due to capacitive effect specially when the sweep period and the discharge time is very fast and die down in the order of μs or lesser. This paper presents and summarises the method of removing such effects encountered while measuring the probe current. (paper)

  19. Lax-Friedrichs sweeping scheme for static Hamilton-Jacobi equations

    International Nuclear Information System (INIS)

    Kao, C.Y.; Osher, Stanley; Qian Jianliang

    2004-01-01

    We propose a simple, fast sweeping method based on the Lax-Friedrichs monotone numerical Hamiltonian to approximate viscosity solutions of arbitrary static Hamilton-Jacobi equations in any number of spatial dimensions. By using the Lax-Friedrichs numerical Hamiltonian, we can easily obtain the solution at a specific grid point in terms of its neighbors, so that a Gauss-Seidel type nonlinear iterative method can be utilized. Furthermore, by incorporating a group-wise causality principle into the Gauss-Seidel iteration by following a finite group of characteristics, we have an easy-to-implement, sweeping-type, and fast convergent numerical method. However, unlike other methods based on the Godunov numerical Hamiltonian, some computational boundary conditions are needed in the implementation. We give a simple recipe which enforces a version of discrete min-max principle. Some convergence analysis is done for the one-dimensional eikonal equation. Extensive 2-D and 3-D numerical examples illustrate the efficiency and accuracy of the new approach. To our knowledge, this is the first fast numerical method based on discretizing the Hamilton-Jacobi equation directly without assuming convexity and/or homogeneity of the Hamiltonian

  20. Lax-Friedrichs sweeping scheme for static Hamilton-Jacobi equations

    Science.gov (United States)

    Kao, Chiu Yen; Osher, Stanley; Qian, Jianliang

    2004-05-01

    We propose a simple, fast sweeping method based on the Lax-Friedrichs monotone numerical Hamiltonian to approximate viscosity solutions of arbitrary static Hamilton-Jacobi equations in any number of spatial dimensions. By using the Lax-Friedrichs numerical Hamiltonian, we can easily obtain the solution at a specific grid point in terms of its neighbors, so that a Gauss-Seidel type nonlinear iterative method can be utilized. Furthermore, by incorporating a group-wise causality principle into the Gauss-Seidel iteration by following a finite group of characteristics, we have an easy-to-implement, sweeping-type, and fast convergent numerical method. However, unlike other methods based on the Godunov numerical Hamiltonian, some computational boundary conditions are needed in the implementation. We give a simple recipe which enforces a version of discrete min-max principle. Some convergence analysis is done for the one-dimensional eikonal equation. Extensive 2-D and 3-D numerical examples illustrate the efficiency and accuracy of the new approach. To our knowledge, this is the first fast numerical method based on discretizing the Hamilton-Jacobi equation directly without assuming convexity and/or homogeneity of the Hamiltonian.

  1. Solving the Capacitive Effect in the High-Frequency sweep for Langmuir Probe in SYMPLE

    Science.gov (United States)

    Pramila; Patel, J. J.; Rajpal, R.; Hansalia, C. J.; Anitha, V. P.; Sathyanarayana, K.

    2017-04-01

    Langmuir Probe based measurements need to be routinely carried out to measure various plasma parameters such as the electron density (ne), the electron temperature (Te), the floating potential (Vf), and the plasma potential (Vp). For this, the diagnostic electronics along with the biasing power supplies is installed in standard industrial racks with a 2KV isolation transformer. The Signal Conditioning Electronics (SCE) system is populated inside the 4U-chassis based system with the front-end electronics, designed using high common mode differential amplifiers which can measure small differential signal in presence of high common mode dc- bias or ac ramp voltage used for biasing the probes. DC-biasing of the probe is most common method for getting its I-V characteristic but method of biasing the probe with a sweep at high frequency encounters the problem of corruption of signal due to capacitive effect specially when the sweep period and the discharge time is very fast and die down in the order of μs or lesser. This paper presents and summarises the method of removing such effects encountered while measuring the probe current.

  2. The characteristics of void distribution in spalled high purity copper cylinder under sweeping detonation

    Science.gov (United States)

    Yang, Yang; Jiang, Zhi; Chen, Jixinog; Guo, Zhaoliang; Tang, Tiegang; Hu, Haibo

    2018-03-01

    The effects of different peak compression stresses (2-5 GPa) on the spallation behaviour of high purity copper cylinder during sweeping detonation were examined by Electron Backscatter Diffraction Microscopy, Doppler Pins System and Optical Microscopy techniques. The velocity history of inner surface and the characteristics of void distributions in spalled copper cylinder were investigated. The results indicated that the spall strength of copper in these experiments was less than that revealed in previous reports concerning plate impact loading. The geometry of cylindrical copper and the obliquity of incident shock during sweeping detonation may be the main reasons. Different loading stresses seemed to be responsible for the characteristics of the resultant damage fields, and the maximum damage degree increased with increasing shock stress. Spall planes in different cross-sections of sample loaded with the same shock stress of 3.29 GPa were found, and the distance from the initiation end has little effect on the maximum damage degree (the maximum damage range from 12 to 14%), which means that the spallation behaviour was stable along the direction parallel to the detonation propagation direction under the same shock stress.

  3. Grain boundary sweeping and dissolution effects on fission product behavior under severe fuel damage accident conditions

    International Nuclear Information System (INIS)

    Rest, J.

    1985-10-01

    The theoretical FASTGRASS-VFP model has been used in the interpretation of fission gas, iodine, tellurium, and cesium release from severe-fuel-damage (SFD) tests performed in the PBF reactor in Idaho. A theory of grain boundary sweeping of gas bubbles, gas bubble behavior during fuel liquefaction (destruction of grain boundaries due to formation of a U-rich melt phase), and during U-Zr eutectic melting has been included within the FASTGRASS-VFP formalism. The grain-boundary-sweeping theory considers the interaction between the moving grain boundary and two distinct size classes of bubbles, those on grain faces and on grain edges. The theory of the effects of fuel liquefaction and U-Zr eutectic melting on fission product behavior considers the migration and coalescence of fission gas bubbles in either molten uranium, or a zircaloy-uranium eutectic melt. The FASTGRASS-VFP predictions, measured release rates from the above tests, and previously published release rates are compared and differences between fission product behavior in trace-irradiated and in normally irradiated fuel are highlighted

  4. Objective quantification of the tinnitus decompensation by synchronization measures of auditory evoked single sweeps.

    Science.gov (United States)

    Strauss, Daniel J; Delb, Wolfgang; D'Amelio, Roberto; Low, Yin Fen; Falkai, Peter

    2008-02-01

    Large-scale neural correlates of the tinnitus decompensation might be used for an objective evaluation of therapies and neurofeedback based therapeutic approaches. In this study, we try to identify large-scale neural correlates of the tinnitus decompensation using wavelet phase stability criteria of single sweep sequences of late auditory evoked potentials as synchronization stability measure. The extracted measure provided an objective quantification of the tinnitus decompensation and allowed for a reliable discrimination between a group of compensated and decompensated tinnitus patients. We provide an interpretation for our results by a neural model of top-down projections based on the Jastreboff tinnitus model combined with the adaptive resonance theory which has not been applied to model tinnitus so far. Using this model, our stability measure of evoked potentials can be linked to the focus of attention on the tinnitus signal. It is concluded that the wavelet phase stability of late auditory evoked potential single sweeps might be used as objective tinnitus decompensation measure and can be interpreted in the framework of the Jastreboff tinnitus model and adaptive resonance theory.

  5. Femtosecond Laser Tagging Characterization of a Sweeping Jet Actuator Operating in the Compressible Regime

    Science.gov (United States)

    Peters, Christopher J.; Miles, Richard B.; Burns, Ross A.; Bathel, Brett F.; Jones, Gregory S.; Danehy, Paul M.

    2016-01-01

    A sweeping jet (SWJ) actuator operating over a range of nozzle pressure ratios (NPRs) was characterized with femtosecond laser electronic excitation tagging (FLEET), single hot-wire anemometry (HWA) and high-speed/phase-averaged schlieren. FLEET velocimetry was successfully demonstrated in a highly unsteady, oscillatory flow containing subsonic through supersonic velocities. Qualitative comparisons between FLEET and HWA (which measured mass flux since the flow was compressible) showed relatively good agreement in the external flow profiles. The spreading rate was found to vary from 0.5 to 1.2 depending on the pressure ratio. The precision of FLEET velocity measurements in the external flow field was poorer (is approximately equal to 25 m/s) than reported in a previous study due to the use of relatively low laser fluences, impacting the velocity fluctuation measurements. FLEET enabled velocity measurements inside the device and showed that choking likely occurred for NPR = 2.0, and no internal shockwaves were present. Qualitative oxygen concentration measurements using FLEET were explored in an effort to gauge the jet's mixing with the ambient. The jet was shown to mix well within roughly four throat diameters and mix fully within roughly eight throat diameters. Schlieren provided visualization of the internal and external flow fields and showed that the qualitative structure of the internal flow does not vary with pressure ratio and the sweeping mechanism observed for incompressible NPRs also probably holds for compressible NPRs.

  6. Effects of Sweep Angle on the Boundary-Layer Stability Characteristics of an Untapered Wing at Low Speeds

    Science.gov (United States)

    Boltz, Frederick W.; Kenyon, George C.; Allen, Clyde Q.

    1960-01-01

    An investigation was conducted in the Ames 12-Foot Low-Turbulence Pressure Tunnel to determine the effects of sweep on the boundary-layer stability characteristics of an untapered variable-sweep wing having an NACA 64(2)A015 section normal to the leading edge. Pressure distribution and transition were measured on the wing at low speeds at sweep angles of 0, 10, 20, 30, 40, and 50 deg. and at angles of attack from -3 to 3 deg. The investigation also included flow-visualization studies on the surface at sweep angles from 0 to 50 deg. and total pressure surveys in the boundary layer at a sweep angle of 30 deg. for angles of attack from -12 to 0 deg. It was found that sweep caused premature transition on the wing under certain conditions. This effect resulted from the formation of vortices in the boundary layer when a critical combination of sweep angle, pressure gradient, and stream Reynolds number was attained. A useful parameter in indicating the combined effect of these flow variables on vortex formation and on beginning transition is the crossflow Reynolds number. The critical values of crossflow Reynolds number for vortex formation found in this investigation range from about 135 to 190 and are in good agreement with those reported in previous investigations. The values of crossflow Reynolds number for beginning transitions were found to be between 190 and 260. For each condition (i.e., development of vortices and initiation of transition at a given location) the lower values in the specified ranges were obtained with a light coating of flow-visualization material on the surface. A method is presented for the rapid computation of crossflow Reynolds number on any swept surface for which the pressure distribution is known. From calculations based on this method, it was found that the maximum values of crossflow Reynolds number are attained under conditions of a strong pressure gradient and at a sweep angle of about 50 deg. Due to the primary dependence on pressure

  7. Controlling retention, selectivity and magnitude of EOF by segmented monolithic columns consisting of octadecyl and naphthyl monolithic segments--applications to RP-CEC of both neutral and charged solutes.

    Science.gov (United States)

    Karenga, Samuel; El Rassi, Ziad

    2011-04-01

    Monolithic capillaries made of two adjoining segments each filled with a different monolith were introduced for the control and manipulation of the electroosmotic flow (EOF), retention and selectivity in reversed phase-capillary electrochromatography (RP-CEC). These columns were called segmented monolithic columns (SMCs) where one segment was filled with a naphthyl methacrylate monolith (NMM) to provide hydrophobic and π-interactions, while the other segment was filled with an octadecyl acrylate monolith (ODM) to provide solely hydrophobic interaction. The ODM segment not only provided hydrophobic interactions but also functioned as the EOF accelerator segment. The average EOF of the SMC increased linearly with increasing the fractional length of the ODM segment. The neutral SMC provided a convenient way for tuning EOF, selectivity and retention in the absence of annoying electrostatic interactions and irreversible solute adsorption. The SMCs allowed the separation of a wide range of neutral solutes including polycyclic aromatic hydrocarbons (PAHs) that are difficult to separate using conventional alkyl-bonded stationary phases. In all cases, the k' of a given solute was a linear function of the fractional length of the ODM or NMM segment in the SMCs, thus facilitating the tailoring of a given SMC to solve a given separation problem. At some ODM fractional length, the fabricated SMC allowed the separation of charged solutes such as peptides and proteins that could not otherwise be achieved on a monolithic column made from NMM as an isotropic stationary phase due to the lower EOF exhibited by this monolith. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A field-sweep/field-lock system for superconducting magnets--Application to high-field EPR.

    Science.gov (United States)

    Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G

    2006-12-01

    We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of +/-0.4 T and a resolution of up to 10(-5) T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR.

  9. A Field-Sweep/Field-Lock System for Superconducting Magnets-Application to High-Field EPR

    Science.gov (United States)

    Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G.

    2007-01-01

    We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H-NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of ± 0.4 T and a resolution of up to 10-5 T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR. PMID:17027306

  10. Measuring process and knowledge consistency

    DEFF Research Database (Denmark)

    Edwards, Kasper; Jensen, Klaes Ladeby; Haug, Anders

    2007-01-01

    When implementing configuration systems, knowledge about products and processes are documented and replicated in the configuration system. This practice assumes that products are specified consistently i.e. on the same rule base and likewise for processes. However, consistency cannot be taken...... for granted; rather the contrary, and attempting to implement a configuration system may easily ignite a political battle. This is because stakes are high in the sense that the rules and processes chosen may only reflect one part of the practice, ignoring a majority of the employees. To avoid this situation......, this paper presents a methodology for measuring product and process consistency prior to implementing a configuration system. The methodology consists of two parts: 1) measuring knowledge consistency and 2) measuring process consistency. Knowledge consistency is measured by developing a questionnaire...

  11. A parallel sweeping preconditioner for frequency-domain seismic wave propagation

    KAUST Repository

    Poulson, Jack

    2012-09-01

    We present a parallel implementation of Engquist and Ying\\'s sweeping preconditioner, which exploits radiation boundary conditions in order to form an approximate block LDLT factorization of the Helmholtz operator with only O(N4/3) work and an application (and memory) cost of only O(N logN). The approximate factorization is then used as a preconditioner for GMRES, and we show that essentially O(1) iterations are required for convergence, even for the full SEG/EAGE over-thrust model at 30 Hz. In particular, we demonstrate the solution of said problem in a mere 15 minutes on 8192 cores of TACC\\'s Lonestar, which may be the largest-scale 3D heterogeneous Helmholtz calculation to date. Generalizations of our parallel strategy are also briefly discussed for time-harmonic linear elasticity and Maxwell\\'s equations.

  12. Production of artificial ionospheric layers by frequency sweeping near the 2nd gyroharmonic

    Directory of Open Access Journals (Sweden)

    T. Pedersen

    2011-01-01

    Full Text Available Artificial ionospheric plasmas descending from the background F-region have been observed on multiple occasions at the High Frequency Active Auroral Research Program (HAARP facility since it reached full 3.6 MW power. Proximity of the transmitter frequency to the 2nd harmonic of the electron gyrofrequency (2fce has been noted as a requirement for their occurrence, and their disappearance after only a few minutes has been attributed to the increasing frequency mismatch at lower altitudes. We report new experiments employing frequency sweeps to match 2fce in the artificial plasmas as they descend. In addition to revealing the dependence on the 2fce resonance, this technique reliably produces descending plasmas in multiple transmitter beam positions and appears to increase their stability and lifetime. High-speed ionosonde measurements are used to monitor the altitude and density of the artificial plasmas during both the formation and decay stages.

  13. Unsteady Flow Simulation of a Sweeping Jet Actuator Using a Lattice-Boltzmann Method

    Science.gov (United States)

    Duda, B.; Wessels, M.; Fares, E.; Vatsa, V.

    2016-01-01

    Active flow control technology is increasingly used in aerospace applications to control flow separation and to improve aerodynamic performance. In this paper, PowerFLOW is used to simulate the flow through a sweeping jet actuator at two different pressure ratios. The lower pressure ratio leads to a high subsonic flow, whereas the high pressure ratio produces a choked flow condition. Comparison of numerical results with experimental data is shown, which includes qualitatively good agreement of pressure histories and spectra. PIV measurements are also available but the simulation overestimates mean and fluctuation quantities outside the actuator. If supply pressure is matched at one point inside the mixing chamber a good qualitative agreement is achieved at all other monitor points.

  14. Reducing Side-Sweep Accidents with Vehicle-to-Vehicle Communication

    Directory of Open Access Journals (Sweden)

    Gamini Bulumulle

    2016-12-01

    Full Text Available Side-sweep accidents are one of the major causes of loss of life and property damage on highways. This type of accident is caused by a driver initiating a lane change while another vehicle is blocking the road in the target lane. In this article, we are trying to quantify the degree to which different implementations of vehicle-to-vehicle (V2V communication could reduce the occurrence of such accidents. We present the design of a simulator that takes into account common sources of lack of driver awareness such as blind-spots and lack of attention. Then, we study the impact of both traditional, non-technological communication means such as turning signals as well as unidirectional and bidirectional V2V communications.

  15. Life assessment of PVD based hard coatings by linear sweep voltammetry for high performance industrial application

    International Nuclear Information System (INIS)

    Malik, M.; Alam, S.; Irfan, M.; Hassan, Z.

    2006-01-01

    PVD based hard coatings have remarkable achievements in order to improve Tribological and surface properties of coating tools and dies. As PVD based hard coatings have a wide range of industrial applications especially in aerospace and automobile parts where they met different chemical attacks and in order to improve industrial performance these coatings must provide an excellent resistance against corrosion, high temperature oxidation and chemical reaction. This paper focuses on study of behaviour of PVD based hard coatings under different corrosive environments like as H/sub 2/SO/sub 4/, HCl, NaCl, KCl, NaOH etc. Corrosion rate was calculate under linear sweep voltammetry method where the Tafel extrapolation curves used for continuously monitoring the corrosion rate. The results show that these coatings have an excellent resistance against chemical attack. (author)

  16. An Adaptive Sweep-Circle Spatial Clustering Algorithm Based on Gestalt

    Directory of Open Access Journals (Sweden)

    Qingming Zhan

    2017-08-01

    Full Text Available An adaptive spatial clustering (ASC algorithm is proposed in this present study, which employs sweep-circle techniques and a dynamic threshold setting based on the Gestalt theory to detect spatial clusters. The proposed algorithm can automatically discover clusters in one pass, rather than through the modification of the initial model (for example, a minimal spanning tree, Delaunay triangulation, or Voronoi diagram. It can quickly identify arbitrarily-shaped clusters while adapting efficiently to non-homogeneous density characteristics of spatial data, without the need for prior knowledge or parameters. The proposed algorithm is also ideal for use in data streaming technology with dynamic characteristics flowing in the form of spatial clustering in large data sets.

  17. Thermo-mechanical design of a CW sweep plate emittance scanner

    International Nuclear Information System (INIS)

    Rathke, J.; Peacock, M.; Sredniawski, J.

    1996-01-01

    A sweep plate emittance scanner for use with high power, continuous wave (CW) beams has been designed, fabricated and commissioned at Northrop Grumman. The design is capable of scanning beams of up to 20 kW beam power with a spot diameter as small as 2 cm. The scanner pod is mounted on a ball screw driven linear bearing table that is driven through the beam by a stepper motor at velocities up to 30 cm/sec. This paper presents the thermo-mechanical analysis of the pod moving through a gaussian beam and the details of the mechanical design of the pod and motion system. Analyses to determine scanner cooling schemes and structural materials are presented. (author)

  18. An angularly refineable phase space finite element method with approximate sweeping procedure

    International Nuclear Information System (INIS)

    Kophazi, J.; Lathouwers, D.

    2013-01-01

    An angularly refineable phase space finite element method is proposed to solve the neutron transport equation. The method combines the advantages of two recently published schemes. The angular domain is discretized into small patches and patch-wise discontinuous angular basis functions are restricted to these patches, i.e. there is no overlap between basis functions corresponding to different patches. This approach yields block diagonal Jacobians with small block size and retains the possibility for S n -like approximate sweeping of the spatially discontinuous elements in order to provide efficient preconditioners for the solution procedure. On the other hand, the preservation of the full FEM framework (as opposed to collocation into a high-order S n scheme) retains the possibility of the Galerkin interpolated connection between phase space elements at arbitrary levels of discretization. Since the basis vectors are not orthonormal, a generalization of the Riemann procedure is introduced to separate the incoming and outgoing contributions in case of unstructured meshes. However, due to the properties of the angular discretization, the Riemann procedure can be avoided at a large fraction of the faces and this fraction rapidly increases as the level of refinement increases, contributing to the computational efficiency. In this paper the properties of the discretization scheme are studied with uniform refinement using an iterative solver based on the S 2 sweep order of the spatial elements. The fourth order convergence of the scalar flux is shown as anticipated from earlier schemes and the rapidly decreasing fraction of required Riemann faces is illustrated. (authors)

  19. From sweeping to the caress: similarities and discrepancies between human and non-human primates' pleasant touch

    Directory of Open Access Journals (Sweden)

    Laura Clara Grandi

    2016-09-01

    Full Text Available Affective touch plays a key role in affiliative behavior, offering a mechanism for the formation and maintenance of social bonds among conspecifics, both in humans and non-human primates. Furthermore, it has been speculated that the CT fiber system is a specific coding channel for affiliative touch that occurs during skin-to-skin interactions with conspecifics. In humans, this touch is commonly referred to as the caress, and its correlation with the CT fiber system has been widely demonstrated. It has been hypothesized that the sweeping touch that occurs during grooming in non-human primates may modulate the CT fibers, with recent preliminary studies on rhesus monkeys supporting this hypothesis. The present mini-review proposes a comparison between the pleasant touch, caress and sweeping of humans and non-human primates, respectively. The currently available data was therefore reviewed regarding i the correlation between pleasant touch and CT fibers both in humans and non-human primates, ii the autonomic effects, iii the encoding at the central nervous system, iv the development from early life to adulthood, and v the potential applications of pleasant touch in the daily lives of both humans and non-human primates. Moreover, by considering both the similarities and discrepancies between the human caress and non-human primate sweeping, a possible evolutionary mechanism can be proposed that has developed from sweeping as a utilitarian action with affiliative meaning among monkeys, to the caress as a purely affective gesture associated with humans.

  20. A TV camera system for digitizing single shot oscillograms at sweep rate of 0.1 ns/cm

    International Nuclear Information System (INIS)

    Kienlen, M.; Knispel, G.; Miehe, J.A.; Sipp, B.

    1976-01-01

    A TV camera digitizing system associated with a 5 GHz photocell-oscilloscope apparatus allows the digitizing of single shot oscillograms; with an oscilloscope sweep rate of 0.1 ns/cm an accuracy on time measurements of 4 ps is obtained [fr

  1. Natural Selection and Genetic Diversity in the Butterfly Heliconius melpomene.

    Science.gov (United States)

    Martin, Simon H; Möst, Markus; Palmer, William J; Salazar, Camilo; McMillan, W Owen; Jiggins, Francis M; Jiggins, Chris D

    2016-05-01

    A combination of selective and neutral evolutionary forces shape patterns of genetic diversity in nature. Among the insects, most previous analyses of the roles of drift and selection in shaping variation across the genome have focused on the genus Drosophila A more complete understanding of these forces will come from analyzing other taxa that differ in population demography and other aspects of biology. We have analyzed diversity and signatures of selection in the neotropical Heliconius butterflies using resequenced genomes from 58 wild-caught individuals of Heliconius melpomene and another 21 resequenced genomes representing 11 related species. By comparing intraspecific diversity and interspecific divergence, we estimate that 31% of amino acid substitutions between Heliconius species are adaptive. Diversity at putatively neutral sites is negatively correlated with the local density of coding sites as well as nonsynonymous substitutions and positively correlated with recombination rate, indicating widespread linked selection. This process also manifests in significantly reduced diversity on longer chromosomes, consistent with lower recombination rates. Although hitchhiking around beneficial nonsynonymous mutations has significantly shaped genetic variation in H. melpomene, evidence for strong selective sweeps is limited overall. We did however identify two regions where distinct haplotypes have swept in different populations, leading to increased population differentiation. On the whole, our study suggests that positive selection is less pervasive in these butterflies as compared to fruit flies, a fact that curiously results in very similar levels of neutral diversity in these very different insects. Copyright © 2016 by the Genetics Society of America.

  2. Acidic sweep gas with carbonic anhydrase coated hollow fiber membranes synergistically accelerates CO2 removal from blood.

    Science.gov (United States)

    Arazawa, D T; Kimmel, J D; Finn, M C; Federspiel, W J

    2015-10-01

    The use of extracorporeal carbon dioxide removal (ECCO2R) is well established as a therapy for patients suffering from acute respiratory failure. Development of next generation low blood flow (carbonic anhydrase (CA) immobilized bioactive hollow fiber membrane (HFM) which significantly accelerates CO2 removal from blood in model gas exchange devices by converting bicarbonate to CO2 directly at the HFM surface. This present study tested the hypothesis that dilute sulfur dioxide (SO2) in oxygen sweep gas could further increase CO2 removal by creating an acidic microenvironment within the diffusional boundary layer adjacent to the HFM surface, facilitating dehydration of bicarbonate to CO2. CA was covalently immobilized onto poly (methyl pentene) (PMP) HFMs through glutaraldehyde activated chitosan spacers, potted in model gas exchange devices (0.0151 m(2)) and tested for CO2 removal rate with oxygen (O2) sweep gas and a 2.2% SO2 in oxygen sweep gas mixture. Using pure O2 sweep gas, CA-PMP increased CO2 removal by 31% (258 mL/min/m(2)) compared to PMP (197 mL/min/m(2)) (Premoval by 17% (230 mL/min/m(2)) compared to pure oxygen sweep gas control (Premoval increased by 109% (411 mL/min/m(2)) (Premoval, and when used in combination with bioactive CA-HFMs has a synergistic effect to more than double CO2 removal while maintaining physiologic pH. Through these technologies the next generation of intravascular and paracorporeal respiratory assist devices can remove more CO2 with smaller blood contacting surface areas. A clinical need exists for more efficient respiratory assist devices which utilize low blood flow rates (removal efficiency by shifting equilibrium from bicarbonate to gaseous CO2, through either a bioactive carbonic anhydrase enzyme coating or bulk blood acidification with lactic acid. In this study we demonstrate a novel approach to local blood acidification using an acidified sweep gas in combination with a bioactive coating to more than double CO2 removal

  3. Consistency argued students of fluid

    Science.gov (United States)

    Viyanti; Cari; Suparmi; Winarti; Slamet Budiarti, Indah; Handika, Jeffry; Widyastuti, Fatma

    2017-01-01

    Problem solving for physics concepts through consistency arguments can improve thinking skills of students and it is an important thing in science. The study aims to assess the consistency of the material Fluid student argmentation. The population of this study are College students PGRI Madiun, UIN Sunan Kalijaga Yogyakarta and Lampung University. Samples using cluster random sampling, 145 samples obtained by the number of students. The study used a descriptive survey method. Data obtained through multiple-choice test and interview reasoned. Problem fluid modified from [9] and [1]. The results of the study gained an average consistency argmentation for the right consistency, consistency is wrong, and inconsistent respectively 4.85%; 29.93%; and 65.23%. Data from the study have an impact on the lack of understanding of the fluid material which is ideally in full consistency argued affect the expansion of understanding of the concept. The results of the study as a reference in making improvements in future studies is to obtain a positive change in the consistency of argumentations.

  4. Coordinating user interfaces for consistency

    CERN Document Server

    Nielsen, Jakob

    2001-01-01

    In the years since Jakob Nielsen's classic collection on interface consistency first appeared, much has changed, and much has stayed the same. On the one hand, there's been exponential growth in the opportunities for following or disregarding the principles of interface consistency-more computers, more applications, more users, and of course the vast expanse of the Web. On the other, there are the principles themselves, as persistent and as valuable as ever. In these contributed chapters, you'll find details on many methods for seeking and enforcing consistency, along with bottom-line analys

  5. Choice, internal consistency, and rationality

    OpenAIRE

    Aditi Bhattacharyya; Prasanta K. Pattanaik; Yongsheng Xu

    2010-01-01

    The classical theory of rational choice is built on several important internal consistency conditions. In recent years, the reasonableness of those internal consistency conditions has been questioned and criticized, and several responses to accommodate such criticisms have been proposed in the literature. This paper develops a general framework to accommodate the issues raised by the criticisms of classical rational choice theory, and examines the broad impact of these criticisms from both no...

  6. Self-consistent quark bags

    International Nuclear Information System (INIS)

    Rafelski, J.

    1979-01-01

    After an introductory overview of the bag model the author uses the self-consistent solution of the coupled Dirac-meson fields to represent a bound state of strongly ineteracting fermions. In this framework he discusses the vivial approach to classical field equations. After a short description of the used numerical methods the properties of bound states of scalar self-consistent Fields and the solutions of a self-coupled Dirac field are considered. (HSI) [de

  7. Time-consistent and market-consistent evaluations

    NARCIS (Netherlands)

    Pelsser, A.; Stadje, M.A.

    2014-01-01

    We consider evaluation methods for payoffs with an inherent financial risk as encountered for instance for portfolios held by pension funds and insurance companies. Pricing such payoffs in a way consistent to market prices typically involves combining actuarial techniques with methods from

  8. Market-consistent actuarial valuation

    CERN Document Server

    Wüthrich, Mario V

    2016-01-01

    This is the third edition of this well-received textbook, presenting powerful methods for measuring insurance liabilities and assets in a consistent way, with detailed mathematical frameworks that lead to market-consistent values for liabilities. Topics covered are stochastic discounting with deflators, valuation portfolio in life and non-life insurance, probability distortions, asset and liability management, financial risks, insurance technical risks, and solvency. Including updates on recent developments and regulatory changes under Solvency II, this new edition of Market-Consistent Actuarial Valuation also elaborates on different risk measures, providing a revised definition of solvency based on industry practice, and presents an adapted valuation framework which takes a dynamic view of non-life insurance reserving risk.

  9. The Principle of Energetic Consistency

    Science.gov (United States)

    Cohn, Stephen E.

    2009-01-01

    A basic result in estimation theory is that the minimum variance estimate of the dynamical state, given the observations, is the conditional mean estimate. This result holds independently of the specifics of any dynamical or observation nonlinearity or stochasticity, requiring only that the probability density function of the state, conditioned on the observations, has two moments. For nonlinear dynamics that conserve a total energy, this general result implies the principle of energetic consistency: if the dynamical variables are taken to be the natural energy variables, then the sum of the total energy of the conditional mean and the trace of the conditional covariance matrix (the total variance) is constant between observations. Ensemble Kalman filtering methods are designed to approximate the evolution of the conditional mean and covariance matrix. For them the principle of energetic consistency holds independently of ensemble size, even with covariance localization. However, full Kalman filter experiments with advection dynamics have shown that a small amount of numerical dissipation can cause a large, state-dependent loss of total variance, to the detriment of filter performance. The principle of energetic consistency offers a simple way to test whether this spurious loss of variance limits ensemble filter performance in full-blown applications. The classical second-moment closure (third-moment discard) equations also satisfy the principle of energetic consistency, independently of the rank of the conditional covariance matrix. Low-rank approximation of these equations offers an energetically consistent, computationally viable alternative to ensemble filtering. Current formulations of long-window, weak-constraint, four-dimensional variational methods are designed to approximate the conditional mode rather than the conditional mean. Thus they neglect the nonlinear bias term in the second-moment closure equation for the conditional mean. The principle of

  10. Broadband W-band Rapid Frequency Sweep Considerations for Fourier Transform EPR.

    Science.gov (United States)

    Strangeway, Robert A; Hyde, James S; Camenisch, Theodore G; Sidabras, Jason W; Mett, Richard R; Anderson, James R; Ratke, Joseph J; Subczynski, Witold K

    2017-12-01

    A multi-arm W-band (94 GHz) electron paramagnetic resonance spectrometer that incorporates a loop-gap resonator with high bandwidth is described. A goal of the instrumental development is detection of free induction decay following rapid sweep of the microwave frequency across the spectrum of a nitroxide radical at physiological temperature, which is expected to lead to a capability for Fourier transform electron paramagnetic resonance. Progress toward this goal is a theme of the paper. Because of the low Q-value of the loop-gap resonator, it was found necessary to develop a new type of automatic frequency control, which is described in an appendix. Path-length equalization, which is accomplished at the intermediate frequency of 59 GHz, is analyzed. A directional coupler is favored for separation of incident and reflected power between the bridge and the loop-gap resonator. Microwave leakage of this coupler is analyzed. An oversize waveguide with hyperbolic-cosine tapers couples the bridge to the loop-gap resonator, which results in reduced microwave power and signal loss. Benchmark sensitivity data are provided. The most extensive application of the instrument to date has been the measurement of T 1 values using pulse saturation recovery. An overview of that work is provided.

  11. Moving Difference (MDIFF) Non-adiabatic rapid sweep (NARS) EPR of copper(II)

    Science.gov (United States)

    Hyde, James S.; Bennett, Brian; Kittell, Aaron W.; Kowalski, Jason M.; Sidabras, Jason W.

    2014-01-01

    Non Adiabatic Rapid Sweep (NARS) EPR spectroscopy has been introduced for application to nitroxide-labeled biological samples (AW Kittell et al, (2011)). Displays are pure absorption, and are built up by acquiring data in spectral segments that are concatenated. In this paper we extend the method to frozen solutions of copper-imidazole, a square planar copper complex with four in-plane nitrogen ligands. Pure absorption spectra are created from concatenation of 170 5-gauss segments spanning 850 G at 1.9 GHz. These spectra, however, are not directly useful since nitrogen superhyperfine couplings are barely visible. Application of the moving difference (MDIFF) algorithm to the digitized NARS pure absorption spectrum is used to produce spectra that are analogous to the first harmonic EPR. The signal intensity is about 4 times higher than when using conventional 100 kHz field modulation, depending on line shape. MDIFF not only filters the spectrum, but also the noise, resulting in further improvement of the SNR for the same signal acquisition time. The MDIFF amplitude can be optimized retrospectively, different spectral regions can be examined at different amplitudes, and an amplitude can be used that is substantially greater than the upper limit of the field modulation amplitude of a conventional EPR spectrometer, which improves the signal-to-noise ratio of broad lines. PMID:24036469

  12. A Support Vector Machine Approach for Truncated Fingerprint Image Detection from Sweeping Fingerprint Sensors

    Science.gov (United States)

    Chen, Chi-Jim; Pai, Tun-Wen; Cheng, Mox

    2015-01-01

    A sweeping fingerprint sensor converts fingerprints on a row by row basis through image reconstruction techniques. However, a built fingerprint image might appear to be truncated and distorted when the finger was swept across a fingerprint sensor at a non-linear speed. If the truncated fingerprint images were enrolled as reference targets and collected by any automated fingerprint identification system (AFIS), successful prediction rates for fingerprint matching applications would be decreased significantly. In this paper, a novel and effective methodology with low time computational complexity was developed for detecting truncated fingerprints in a real time manner. Several filtering rules were implemented to validate existences of truncated fingerprints. In addition, a machine learning method of supported vector machine (SVM), based on the principle of structural risk minimization, was applied to reject pseudo truncated fingerprints containing similar characteristics of truncated ones. The experimental result has shown that an accuracy rate of 90.7% was achieved by successfully identifying truncated fingerprint images from testing images before AFIS enrollment procedures. The proposed effective and efficient methodology can be extensively applied to all existing fingerprint matching systems as a preliminary quality control prior to construction of fingerprint templates. PMID:25835186

  13. Acetate and phosphate anion adsorption linear sweep voltammograms simulated using density functional theory

    KAUST Repository

    Savizi, Iman Shahidi Pour

    2011-04-01

    Specific adsorption of anions to electrode surfaces may alter the rates of electrocatalytic reactions. Density functional theory (DFT) methods are used to predict the adsorption free energy of acetate and phosphate anions as a function of Pt(1 1 1) electrode potential. Four models of the electrode potential are used including a simple vacuum slab model, an applied electric field model with and without the inclusion of a solvating water bi-layer, and the double reference model. The linear sweep voltammogram (LSV) due to anion adsorption is simulated using the DFT results. The inclusion of solvation at the electrochemical interface is necessary for accurately predicting the adsorption peak position. The Langmuir model is sufficient for predicting the adsorption peak shape, indicating coverage effects are minor in altering the LSV for acetate and phosphate adsorption. Anion adsorption peak positions are determined for solution phase anion concentrations present in microbial fuel cells and microbial electrolysis cells and discussion is provided as to the impact of anion adsorption on oxygen reduction and hydrogen evolution reaction rates in these devices. © 2011 Elsevier Ltd. All rights reserved.

  14. A Support Vector Machine Approach for Truncated Fingerprint Image Detection from Sweeping Fingerprint Sensors

    Directory of Open Access Journals (Sweden)

    Chi-Jim Chen

    2015-03-01

    Full Text Available A sweeping fingerprint sensor converts fingerprints on a row by row basis through image reconstruction techniques. However, a built fingerprint image might appear to be truncated and distorted when the finger was swept across a fingerprint sensor at a non-linear speed. If the truncated fingerprint images were enrolled as reference targets and collected by any automated fingerprint identification system (AFIS, successful prediction rates for fingerprint matching applications would be decreased significantly. In this paper, a novel and effective methodology with low time computational complexity was developed for detecting truncated fingerprints in a real time manner. Several filtering rules were implemented to validate existences of truncated fingerprints. In addition, a machine learning method of supported vector machine (SVM, based on the principle of structural risk minimization, was applied to reject pseudo truncated fingerprints containing similar characteristics of truncated ones. The experimental result has shown that an accuracy rate of 90.7% was achieved by successfully identifying truncated fingerprint images from testing images before AFIS enrollment procedures. The proposed effective and efficient methodology can be extensively applied to all existing fingerprint matching systems as a preliminary quality control prior to construction of fingerprint templates.

  15. Field-amplified sample stacking-sweeping of vitamins B determination in capillary electrophoresis.

    Science.gov (United States)

    Dziomba, Szymon; Kowalski, Piotr; Bączek, Tomasz

    2012-12-07

    A capillary electrophoretic method for determination of five water soluble vitamins B along with baclofen as an internal standard has been developed and assessed in context of precision, accuracy, sensitivity, freedom from interference, linearity, detection and quantification limits. On-line preconcentration technique, namely field-amplified sample stacking (FASS)-sweeping, has been employed in respect to obtain more sensitive analysis. Separation conditions received after optimization procedure were as following background electrolyte (BGE), 10 mM NaH(2)PO(4), 80 mM SDS, (pH 7.25); sample matrix (SM), 10 mM NaH(2)PO(4) (pH 4.60); uncoated fused silica capillary (50 μm i.d. × 67 cm length); UV spectrophotometric detection at 200 nm; injection times: 10s and 30s at 3.45 kPa; applied voltage 22 kV; temperature 22°C. Validation parameters, namely precision, accuracy and linearity, were considered as satisfactory. Under the optimized conditions, it has been also successfully applied for vitamins B determination in bacterial growth medium and commercially available Ilex paraguariensis leaves. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Frequency comb calibrated frequency-sweeping interferometry for absolute group refractive index measurement of air.

    Science.gov (United States)

    Yang, Lijun; Wu, Xuejian; Wei, Haoyun; Li, Yan

    2017-04-10

    The absolute group refractive index of air at 194061.02 GHz is measured in real time using frequency-sweeping interferometry calibrated by an optical frequency comb. The group refractive index of air is calculated from the calibration peaks of the laser frequency variation and the interference signal of the two beams passing through the inner and outer regions of a vacuum cell when the frequency of a tunable external cavity diode laser is scanned. We continuously measure the refractive index of air for 2 h, which shows that the difference between measured results and Ciddor's equation is less than 9.6×10-8, and the standard deviation of that difference is 5.9×10-8. The relative uncertainty of the measured refractive index of air is estimated to be 8.6×10-8. The data update rate is 0.2 Hz, making it applicable under conditions in which air refractive index fluctuates fast.

  17. Singlet Oxygen Production by Illuminated Road Dust and Winter Street Sweepings

    Science.gov (United States)

    Schneider, S.; Gan, L.; Gao, S.; Hoy, K. S.; Kwasny, J. R.; Styler, S. A.

    2017-12-01

    Road dust is an important urban source of primary particulate matter, especially in cities where sand and other traction materials are applied to roadways in winter. Although the composition and detrimental health effects of road dust are reasonably well characterized, little is currently known regarding its chemical behaviour. Motivated by our previous work, in which we showed that road dust is a photochemical source of singlet oxygen (1O2), we investigated 1O2 production by bulk winter street sweepings and by road dust collected in a variety of urban, industrial, and suburban locations in both autumn and spring. In all cases, the production of 1O2 by road dust was greater than that by Arizona test dust and desert-sourced dust, which highlights the unique photochemical environment afforded by this substrate. Mechanistically, we observed correlations between 1O2 production and the UV absorbance properties of dust extracts, which suggests the involvement of chromophoric dissolved organic matter in the observed photochemistry. Taken together, this work provides evidence that road dust-mediated photochemistry may influence the environmental lifetime of pollutants that react via 1O2-mediated pathways, including polycyclic aromatic hydrocarbons.

  18. Acoustic emission in a superconductor (Nb-Ti) during magnetic field and current sweep

    International Nuclear Information System (INIS)

    Nomura, Harehiko

    1980-01-01

    Though superconducting magnets are indispensable in the fields of nuclear fusion, MHD power generation, high energy technology, and the trains using magnetic levitation, the safety of the magnets used for those fields is required to be fully investigated because their accumulating energy reaches up to several GJ. For this purpose, the improvement of monitoring techniques is extremely important to grasp exactly the magnetization of such large energy magnets. Although the detection of the terminal voltage of the magnets has been mainly used so far, the purpose has not yet been fulfilled because various phenomena appear in the form of noises in the terminal voltage. The authors have found the monitoring method using acoustic emission in a system completely independent from voltage observation. From this viewpoint, the experiments have been performed aiming at the generation of acoustic emission in conjunction with magnetization out of the fine structure of super-conductors, taking notice of the emitted sound frequency ranging over several hundred kHz. The results and investigation revealed that the superconductor itself emitted ultrasonic sound. It was found that the observation of this acoustic power intensity was able to monitor not only the magnetization of superconductors but also its current sweep. Since the motion of the magnetic flux is converted into the signal of acoustic field, this measuring method is less affected by noise disturbance from electromagnetic systems, and is expected to be useful for the researches on analyzing superconductor characteristics. (Wakatsuki, Y.)

  19. Consistent guiding center drift theories

    International Nuclear Information System (INIS)

    Wimmel, H.K.

    1982-04-01

    Various guiding-center drift theories are presented that are optimized in respect of consistency. They satisfy exact energy conservation theorems (in time-independent fields), Liouville's theorems, and appropriate power balance equations. A theoretical framework is given that allows direct and exact derivation of associated drift-kinetic equations from the respective guiding-center drift-orbit theories. These drift-kinetic equations are listed. Northrop's non-optimized theory is discussed for reference, and internal consistency relations of G.C. drift theories are presented. (orig.)

  20. Weak consistency and strong paraconsistency

    Directory of Open Access Journals (Sweden)

    Gemma Robles

    2009-11-01

    Full Text Available In a standard sense, consistency and paraconsistency are understood as, respectively, the absence of any contradiction and as the absence of the ECQ (“E contradictione quodlibet” rule that allows us to conclude any well formed formula from any contradiction. The aim of this paper is to explain the concepts of weak consistency alternative to the standard one, the concepts of paraconsistency related to them and the concept of strong paraconsistency, all of which have been defined by the author together with José M. Méndez.

  1. Consistent force fields for saccharides

    DEFF Research Database (Denmark)

    Rasmussen, Kjeld

    1999-01-01

    Consistent force fields for carbohydrates were hitherto developed by extensive optimization ofpotential energy function parameters on experimental data and on ab initio results. A wide range of experimental data is used: internal structures obtained from gas phase electron diffraction and from x......-anomeric effects are accounted for without addition of specific terms. The work is done in the framework of the Consistent Force Field which originatedin Israel and was further developed in Denmark. The actual methods and strategies employed havebeen described previously. Extensive testing of the force field...

  2. Glass consistency and glass performance

    International Nuclear Information System (INIS)

    Plodinec, M.J.; Ramsey, W.G.

    1994-01-01

    Glass produced by the Defense Waste Processing Facility (DWPF) will have to consistently be more durable than a benchmark glass (evaluated using a short-term leach test), with high confidence. The DWPF has developed a Glass Product Control Program to comply with this specification. However, it is not clear what relevance product consistency has on long-term glass performance. In this report, the authors show that DWPF glass, produced in compliance with this specification, can be expected to effectively limit the release of soluble radionuclides to natural environments. However, the release of insoluble radionuclides to the environment will be limited by their solubility, and not glass durability

  3. Time-consistent actuarial valuations

    NARCIS (Netherlands)

    Pelsser, A.A.J.; Salahnejhad Ghalehjooghi, A.

    2016-01-01

    Time-consistent valuations (i.e. pricing operators) can be created by backward iteration of one-period valuations. In this paper we investigate the continuous-time limits of well-known actuarial premium principles when such backward iteration procedures are applied. This method is applied to an

  4. Dynamically consistent oil import tariffs

    International Nuclear Information System (INIS)

    Karp, L.; Newbery, D.M.

    1992-01-01

    The standard theory of optimal tariffs considers tariffs on perishable goods produced abroad under static conditions, in which tariffs affect prices only in that period. Oil and other exhaustable resources do not fit this model, for current tariffs affect the amount of oil imported, which will affect the remaining stock and hence its future price. The problem of choosing a dynamically consistent oil import tariff when suppliers are competitive but importers have market power is considered. The open-loop Nash tariff is solved for the standard competitive case in which the oil price is arbitraged, and it was found that the resulting tariff rises at the rate of interest. This tariff was found to have an equilibrium that in general is dynamically inconsistent. Nevertheless, it is shown that necessary and sufficient conditions exist under which the tariff satisfies the weaker condition of time consistency. A dynamically consistent tariff is obtained by assuming that all agents condition their current decisions on the remaining stock of the resource, in contrast to open-loop strategies. For the natural case in which all agents choose their actions simultaneously in each period, the dynamically consistent tariff was characterized, and found to differ markedly from the time-inconsistent open-loop tariff. It was shown that if importers do not have overwhelming market power, then the time path of the world price is insensitive to the ability to commit, as is the level of wealth achieved by the importer. 26 refs., 4 figs

  5. Consistently violating the non-Gaussian consistency relation

    International Nuclear Information System (INIS)

    Mooij, Sander; Palma, Gonzalo A.

    2015-01-01

    Non-attractor models of inflation are characterized by the super-horizon evolution of curvature perturbations, introducing a violation of the non-Gaussian consistency relation between the bispectrum's squeezed limit and the power spectrum's spectral index. In this work we show that the bispectrum's squeezed limit of non-attractor models continues to respect a relation dictated by the evolution of the background. We show how to derive this relation using only symmetry arguments, without ever needing to solve the equations of motion for the perturbations

  6. Consistence of Network Filtering Rules

    Institute of Scientific and Technical Information of China (English)

    SHE Kun; WU Yuancheng; HUANG Juncai; ZHOU Mingtian

    2004-01-01

    The inconsistence of firewall/VPN(Virtual Private Network) rule makes a huge maintainable cost.With development of Multinational Company,SOHO office,E-government the number of firewalls/VPN will increase rapidly.Rule table in stand-alone or network will be increased in geometric series accordingly.Checking the consistence of rule table manually is inadequate.A formal approach can define semantic consistence,make a theoretic foundation of intelligent management about rule tables.In this paper,a kind of formalization of host rules and network ones for auto rule-validation based on SET theory were proporsed and a rule validation scheme was defined.The analysis results show the superior performance of the methods and demonstrate its potential for the intelligent management based on rule tables.

  7. Self-consistent radial sheath

    International Nuclear Information System (INIS)

    Hazeltine, R.D.

    1988-12-01

    The boundary layer arising in the radial vicinity of a tokamak limiter is examined, with special reference to the TEXT tokamak. It is shown that sheath structure depends upon the self-consistent effects of ion guiding-center orbit modification, as well as the radial variation of E /times/ B-induced toroidal rotation. Reasonable agreement with experiment is obtained from an idealized model which, however simplified, preserves such self-consistent effects. It is argued that the radial sheath, which occurs whenever confining magnetic field-lines lie in the plasma boundary surface, is an object of some intrinsic interest. It differs from the more familiar axial sheath because magnetized charges respond very differently to parallel and perpendicular electric fields. 11 refs., 1 fig

  8. Initial tests of the dual-sweep streak camera system planned for APS particle-beam diagnostics

    International Nuclear Information System (INIS)

    Lumpkin, A.; Yang, B.; Gai, W.; Cieslik, W.

    1995-01-01

    Initial tests of a dual-sweep streak system planned for use on the Advanced Photon Source (APS) have been performed using assets of the Argonne Wakefield Accelerator (AWA) facility. The short light pulses from the photoelectric injector drive laser in both the visible (λ=496 nm, Δt∼1.5 ps (FWHM)), and the ultraviolet (λ=248 nm, Δt∼5 ps (FWHM)) were used. Both a UV-visible S20 photocathode streak tube and a UV-to-x-ray Au photocathode streak tube were tested. Calibration data with an etalon were also obtained. A sample of dual-sweep streak data using optical synchrotron radiation on the APS injector synchrotron is also presented

  9. Cross-calibrating Spatial Positions of Light-viewing Diagnostics using Plasma Edge Sweeps in DIII-D

    International Nuclear Information System (INIS)

    Solomon, W.M.; Burrell, K.H.; Gohil, P.; Groebner, R.; Kaplan, D.

    2003-01-01

    An experimental technique is presented that permits diagnostics viewing light from the plasma edge to be spatially calibrated relative to one another. By sweeping the plasma edge, each chord of each diagnostic sweeps out a portion of the light emission profile. A nonlinear least-squares fit to such data provides superior cross-calibration of diagnostics located at different toroidal locations compared with simple surveying. Another advantage of the technique is that it can be used to monitor the position of viewing chords during an experimental campaign to ensure that alignment does not change over time. Moreover, should such a change occur, the data can still be cross-calibrated and its usefulness retained

  10. Potential effects of structural controls and street sweeping on stormwater loads to the lower Charles River, Massachusetts

    Science.gov (United States)

    Zarriello, Phillip J.; Breault, Robert F.; Weiskel, Peter K.

    2002-01-01

    The water quality of the lower Charles River is periodically impaired by combined sewer overflows (CSOs) and non-CSO stormwater runoff. This study examined the potential non-CSO load reductions of suspended solids, fecal coliform bacteria, total phosphorus, and total lead that could reasonably be achieved by implementation of stormwater best management practices, including both structural controls and systematic street sweeping. Structural controls were grouped by major physical or chemical process; these included infiltration-filtration (physical separation), biofiltration-bioretention (biological mechanisms), or detention-retention (physical settling). For each of these categories, upper and lower quartiles, median, and average removal efficiencies were compiled from three national databases of structural control performance. Removal efficiencies obtained indicated a wide range of performance. Removal was generally greatest for infiltration-filtration controls and suspended solids, and least for biofiltration-bioretention controls and fecal coliform bacteria. Street sweeping has received renewed interest as a water-quality control practice because of reported improvements in sweeper technology and the recognition that opportunities for implementing structural controls are limited in highly urbanized areas. The Stormwater Management Model that was developed by the U.S. Geological Survey for the lower Charles River Watershed was modified to simulate the effects of street sweeping in a single-family land-use basin. Constituent buildup and washoff variable values were calibrated to observed annual and storm-event loads. Once calibrated, the street sweeping model was applied to various permutations of four sweeper efficiencies and six sweeping frequencies that ranged from every day to once every 30 days. Reduction of constituent loads to the lower Charles River by the combined hypothetical practices of structural controls and street sweeping was estimated for a range

  11. Lagrangian multiforms and multidimensional consistency

    Energy Technology Data Exchange (ETDEWEB)

    Lobb, Sarah; Nijhoff, Frank [Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2009-10-30

    We show that well-chosen Lagrangians for a class of two-dimensional integrable lattice equations obey a closure relation when embedded in a higher dimensional lattice. On the basis of this property we formulate a Lagrangian description for such systems in terms of Lagrangian multiforms. We discuss the connection of this formalism with the notion of multidimensional consistency, and the role of the lattice from the point of view of the relevant variational principle.

  12. Consistency and Communication in Committees

    OpenAIRE

    Inga Deimen; Felix Ketelaar; Mark T. Le Quement

    2013-01-01

    This paper analyzes truthtelling incentives in pre-vote communication in heterogeneous committees. We generalize the classical Condorcet jury model by introducing a new informational structure that captures consistency of information. In contrast to the impossibility result shown by Coughlan (2000) for the classical model, full pooling of information followed by sincere voting is an equilibrium outcome of our model for a large set of parameter values implying the possibility of ex post confli...

  13. Deep Feature Consistent Variational Autoencoder

    OpenAIRE

    Hou, Xianxu; Shen, Linlin; Sun, Ke; Qiu, Guoping

    2016-01-01

    We present a novel method for constructing Variational Autoencoder (VAE). Instead of using pixel-by-pixel loss, we enforce deep feature consistency between the input and the output of a VAE, which ensures the VAE's output to preserve the spatial correlation characteristics of the input, thus leading the output to have a more natural visual appearance and better perceptual quality. Based on recent deep learning works such as style transfer, we employ a pre-trained deep convolutional neural net...

  14. Investigation at Low Speeds of the Effect of Aspect Ratio and Sweep on Rolling Stability Derivatives of Untapered Wings

    Science.gov (United States)

    Goodman, Alex; Fisher, Lewis R

    1950-01-01

    A low-scale wind-tunnel investigation was conducted in rolling flow to determine the effects of aspect ratio and sweep (when varied independently) on the rolling stability derivatives for a series of untapered wings. The rolling-flow equipment of the Langley stability tunnel was used for the tests. The data of the investigation have been used to develop a method of accounting for the effects of the drag on the yawing moment due to rolling throughout the lift range.

  15. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation.

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  16. EQUATIONS OF RADIATION TRANSFER IN INFRARED TOMOGRAPHY IN THE CASE OF ACTIVE-PASSIVE DIAGNOSIS AND SWEEPING SCANNING

    Directory of Open Access Journals (Sweden)

    A. A. Makarova

    2014-01-01

    Full Text Available Sweeping scanning scheme of a hot gas in the task of infrared tomography is formulated. Two diagnosis regimes are used: the active one (ON – with included source and the passive one (OFF – without it. Two integral equations are deduced concerning the absorption coefficient k and the Planck function B of a medium (by which it is possible to calculate the temperature profile of a medium T.

  17. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  18. Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

    KAUST Repository

    Hong, Jongsup

    2013-02-01

    The interactions between oxygen permeation and homogeneous fuel oxidation reactions on the sweep side of an ion transport membrane (ITM) are examined using a comprehensive model, which couples the dependency of the oxygen permeation rate on the membrane surface conditions and detailed chemistry and transport in the vicinity of the membrane. We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. Results show that increasing the sweep gas inlet temperature and fuel concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases the gas temperature near the membrane. Faster reactions at higher fuel concentration and higher inlet gas temperature support substantial fuel conversion and lead to a higher oxygen permeation flux without the contribution of surface catalytic activity. Beyond a certain maximum in the fuel concentration, extensive heat loss to the membrane (and feed side) reduces the oxidation kinetic rates and limits oxygen permeation as the reaction front reaches the membrane. The sweep gas flow rate and channel height have moderate impacts on oxygen permeation and fuel conversion due to the residence time requirements for the chemical reactions and the location of the reaction zone relative to the membrane surface. © 2012 Elsevier B.V.

  19. Improving the sweeping efficiency of permanganate into low permeable zones to treat TCE: experimental results and model development.

    Science.gov (United States)

    Chokejaroenrat, Chanat; Kananizadeh, Negin; Sakulthaew, Chainarong; Comfort, Steve; Li, Yusong

    2013-11-19

    The residual buildup and treatment of dissolved contaminants in low permeable zones (LPZs) is a particularly challenging issue for injection-based remedial treatments. Our objective was to improve the sweeping efficiency of permanganate into LPZs to treat dissolved-phase TCE. This was accomplished by conducting transport experiments that quantified the ability of xanthan-MnO4(-) solutions to penetrate and cover (i.e., sweep) an LPZ that was surrounded by transmissive sands. By incorporating the non-Newtonian fluid xanthan with MnO4(-), penetration of MnO4(-) into the LPZ improved dramatically and sweeping efficiency reached 100% in fewer pore volumes. To quantify how xanthan improved TCE removal, we spiked the LPZ and surrounding sands with (14)C-lableled TCE and used a multistep flooding procedure that quantified the mass of (14)C-TCE oxidized and bypassed during treatment. Results showed that TCE mass removal was 1.4 times greater in experiments where xanthan was employed. Combining xanthan with MnO4(-) also reduced the mass of TCE in the LPZ that was potentially available for rebound. By coupling a multiple species reactive transport model with the Brinkman equation for non-Newtonian flow, the simulated amount of (14)C-TCE oxidized during transport matched experimental results. These observations support the use of xanthan as a means of enhancing MnO4(-) delivery into LPZs for the treatment of dissolved-phase TCE.

  20. Influence of high-conductivity buffer composition on field-enhanced sample injection coupled to sweeping in CE.

    Science.gov (United States)

    Anres, Philippe; Delaunay, Nathalie; Vial, Jérôme; Thormann, Wolfgang; Gareil, Pierre

    2013-02-01

    The aim of this work was to clarify the mechanism taking place in field-enhanced sample injection coupled to sweeping and micellar EKC (FESI-Sweep-MEKC), with the utilization of two acidic high-conductivity buffers (HCBs), phosphoric acid or sodium phosphate buffer, in view of maximizing sensitivity enhancements. Using cationic model compounds in acidic media, a chemometric approach and simulations with SIMUL5 were implemented. Experimental design first enabled to identify the significant factors and their potential interactions. Simulation demonstrates the formation of moving boundaries during sample injection, which originate at the initial sample/HCB and HCB/buffer discontinuities and gradually change the compositions of HCB and BGE. With sodium phosphate buffer, the HCB conductivity increased during the injection, leading to a more efficient preconcentration by staking (about 1.6 times) than with phosphoric acid alone, for which conductivity decreased during injection. For the same injection time at constant voltage, however, a lower amount of analytes was injected with sodium phosphate buffer than with phosphoric acid. Consequently sensitivity enhancements were lower for the whole FESI-Sweep-MEKC process. This is why, in order to maximize sensitivity enhancements, it is proposed to work with sodium phosphate buffer as HCB and to use constant current during sample injection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Consistent Estimation of Partition Markov Models

    Directory of Open Access Journals (Sweden)

    Jesús E. García

    2017-04-01

    Full Text Available The Partition Markov Model characterizes the process by a partition L of the state space, where the elements in each part of L share the same transition probability to an arbitrary element in the alphabet. This model aims to answer the following questions: what is the minimal number of parameters needed to specify a Markov chain and how to estimate these parameters. In order to answer these questions, we build a consistent strategy for model selection which consist of: giving a size n realization of the process, finding a model within the Partition Markov class, with a minimal number of parts to represent the process law. From the strategy, we derive a measure that establishes a metric in the state space. In addition, we show that if the law of the process is Markovian, then, eventually, when n goes to infinity, L will be retrieved. We show an application to model internet navigation patterns.

  2. Maintaining consistency in distributed systems

    Science.gov (United States)

    Birman, Kenneth P.

    1991-01-01

    In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability.

  3. A method for consistent precision radiation therapy

    International Nuclear Information System (INIS)

    Leong, J.

    1985-01-01

    Using a meticulous setup procedure in which repeated portal films were taken before each treatment until satisfactory portal verifications were obtained, a high degree of precision in patient positioning was achieved. A fluctuation from treatment to treatment, over 11 treatments, of less than +-0.10 cm (S.D.) for anatomical points inside the treatment field was obtained. This, however, only applies to specific anatomical points selected for this positioning procedure and does not apply to all points within the portal. We have generalized this procedure and have suggested a means by which any target volume can be consistently positioned which may approach this degree of precision. (orig.)

  4. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  5. Detecting loci under recent positive selection in dairy and beef cattle by combining different genome-wide scan methods.

    Directory of Open Access Journals (Sweden)

    Yuri Tani Utsunomiya

    Full Text Available As the methodologies available for the detection of positive selection from genomic data vary in terms of assumptions and execution, weak correlations are expected among them. However, if there is any given signal that is consistently supported across different methodologies, it is strong evidence that the locus has been under past selection. In this paper, a straightforward frequentist approach based on the Stouffer Method to combine P-values across different tests for evidence of recent positive selection in common variations, as well as strategies for extracting biological information from the detected signals, were described and applied to high density single nucleotide polymorphism (SNP data generated from dairy and beef cattle (taurine and indicine. The ancestral Bovinae allele state of over 440,000 SNP is also reported. Using this combination of methods, highly significant (P<3.17×10(-7 population-specific sweeps pointing out to candidate genes and pathways that may be involved in beef and dairy production were identified. The most significant signal was found in the Cornichon homolog 3 gene (CNIH3 in Brown Swiss (P = 3.82×10(-12, and may be involved in the regulation of pre-ovulatory luteinizing hormone surge. Other putative pathways under selection are the glucolysis/gluconeogenesis, transcription machinery and chemokine/cytokine activity in Angus; calpain-calpastatin system and ribosome biogenesis in Brown Swiss; and gangliosides deposition in milk fat globules in Gyr. The composite method, combined with the strategies applied to retrieve functional information, may be a useful tool for surveying genome-wide selective sweeps and providing insights in to the source of selection.

  6. Decentralized Consistent Updates in SDN

    KAUST Repository

    Nguyen, Thanh Dang

    2017-04-10

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and blackholes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes information needed by the switches during the update execution. This information is distributed to the switches, which use partial knowledge and direct message passing to efficiently realize the update. This separation of concerns has the key benefit of improving update performance as the communication and computation bottlenecks at the controller are removed. Our evaluations via network emulations and large-scale simulations demonstrate the efficiency of ez-Segway, which compared to a centralized approach, improves network update times by up to 45% and 57% at the median and the 99th percentile, respectively. A deployment of a system prototype in a real OpenFlow switch and an implementation in P4 demonstrate the feasibility and low overhead of implementing simple network update functionality within switches.

  7. Predictive Accuracy of Sweep Frequency Impedance Technology in Identifying Conductive Conditions in Newborns.

    Science.gov (United States)

    Aithal, Venkatesh; Kei, Joseph; Driscoll, Carlie; Murakoshi, Michio; Wada, Hiroshi

    2018-02-01

    Diagnosing conductive conditions in newborns is challenging for both audiologists and otolaryngologists. Although high-frequency tympanometry (HFT), acoustic stapedial reflex tests, and wideband absorbance measures are useful diagnostic tools, there is performance measure variability in their detection of middle ear conditions. Additional diagnostic sensitivity and specificity measures gained through new technology such as sweep frequency impedance (SFI) measures may assist in the diagnosis of middle ear dysfunction in newborns. The purpose of this study was to determine the test performance of SFI to predict the status of the outer and middle ear in newborns against commonly used reference standards. Automated auditory brainstem response (AABR), HFT (1000 Hz), transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and SFI tests were administered to the study sample. A total of 188 neonates (98 males and 90 females) with a mean gestational age of 39.4 weeks were included in the sample. Mean age at the time of testing was 44.4 hr. Diagnostic accuracy of SFI was assessed in terms of its ability to identify conductive conditions in neonates when compared with nine different reference standards (including four single tests [AABR, HFT, TEOAE, and DPOAE] and five test batteries [HFT + DPOAE, HFT + TEOAE, DPOAE + TEOAE, DPOAE + AABR, and TEOAE + AABR]), using receiver operating characteristic (ROC) analysis and traditional test performance measures such as sensitivity and specificity. The test performance of SFI against the test battery reference standard of HFT + DPOAE and single reference standard of HFT was high with an area under the ROC curve (AROC) of 0.87 and 0.82, respectively. Although the HFT + DPOAE test battery reference standard performed better than the HFT reference standard in predicting middle ear conductive conditions in neonates, the difference in AROC was not significant. Further analysis revealed that the

  8. Continuous sweep versus discrete step protocols for studying effects of wearable robot assistance magnitude.

    Science.gov (United States)

    Malcolm, Philippe; Rossi, Denise Martineli; Siviy, Christopher; Lee, Sangjun; Quinlivan, Brendan Thomas; Grimmer, Martin; Walsh, Conor J

    2017-07-12

    kinetic parameters, there were no differences between all conditions. The finding that there were no differences in biomechanical parameters between all conditions suggests that biomechanical parameters can be recorded with the shortest protocol condition (i.e. single Continuous directions). The shorter time and higher resolution data of continuous sweep protocols hold promise for the future study of human interaction with wearable robots.

  9. PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

    Energy Technology Data Exchange (ETDEWEB)

    Mukul Sharma; Steven Bryant; Chun Huh

    2008-03-31

    There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and

  10. Parallel selection on TRPV6 in human populations

    OpenAIRE

    Hughes, David A; Tang, Kun; Strotmann, Rainer; Schöneberg, Torsten; Prenen, Jean; Nilius, Bernd; Stoneking, Mark

    2008-01-01

    We identified and examined a candidate gene for local directional selection in Europeans, TRPV6, and conclude that selection has acted on standing genetic variation at this locus, creating parallel soft sweep events in humans. A novel modification of the extended haplotype homozygosity (EHH) test was utilized, which compares EHH for a single allele across populations, to investigate the signature of selection at TRPV6 and neighboring linked loci in published data sets for Europeans, Asians an...

  11. Standing genetic variation as a major contributor to adaptation in the Virginia chicken lines selection experiment.

    Science.gov (United States)

    Sheng, Zheya; Pettersson, Mats E; Honaker, Christa F; Siegel, Paul B; Carlborg, Örjan

    2015-10-01

    Artificial selection provides a powerful approach to study the genetics of adaptation. Using selective-sweep mapping, it is possible to identify genomic regions where allele-frequencies have diverged during selection. To avoid false positive signatures of selection, it is necessary to show that a sweep affects a selected trait before it can be considered adaptive. Here, we confirm candidate, genome-wide distributed selective sweeps originating from the standing genetic variation in a long-term selection experiment on high and low body weight of chickens. Using an intercross between the two divergent chicken lines, 16 adaptive selective sweeps were confirmed based on their association with the body weight at 56 days of age. Although individual additive effects were small, the fixation for alternative alleles across the loci contributed at least 40 % of the phenotypic difference for the selected trait between these lines. The sweeps contributed about half of the additive genetic variance present within and between the lines after 40 generations of selection, corresponding to a considerable portion of the additive genetic variance of the base population. Long-term, single-trait, bi-directional selection in the Virginia chicken lines has resulted in a gradual response to selection for extreme phenotypes without a drastic reduction in the genetic variation. We find that fixation of several standing genetic variants across a highly polygenic genetic architecture made a considerable contribution to long-term selection response. This provides new fundamental insights into the dynamics of standing genetic variation during long-term selection and adaptation.

  12. Association Mapping and the Genomic Consequences of Selection in Sunflower

    Science.gov (United States)

    Mandel, Jennifer R.; Nambeesan, Savithri; Bowers, John E.; Marek, Laura F.; Ebert, Daniel; Rieseberg, Loren H.; Knapp, Steven J.; Burke, John M.

    2013-01-01

    The combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L.) association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. We used these data to characterize overall patterns of genomic diversity and to perform association analyses on plant architecture (i.e., branching) and flowering time, successfully identifying numerous associations underlying these agronomically and evolutionarily important traits. Overall, we found variable levels of linkage disequilibrium (LD) across the genome. In general, islands of elevated LD correspond to genomic regions underlying traits that are known to have been targeted by selection during the evolution of cultivated sunflower. In many cases, these regions also showed significantly elevated levels of differentiation between the two major sunflower breeding groups, consistent with the occurrence of divergence due to strong selection. One of these regions, which harbors a major branching locus, spans a surprisingly long genetic interval (ca. 25 cM), indicating the occurrence of an extended selective sweep in an otherwise recombinogenic interval. PMID:23555290

  13. Disentangling the effects of demography and selection in human history.

    Science.gov (United States)

    Stajich, Jason E; Hahn, Matthew W

    2005-01-01

    Demographic events affect all genes in a genome, whereas natural selection has only local effects. Using publicly available data from 151 loci sequenced in both European-American and African-American populations, we attempt to distinguish the effects of demography and selection. To analyze large sets of population genetic data such as this one, we introduce "Perlymorphism," a Unix-based suite of analysis tools. Our analyses show that the demographic histories of human populations can account for a large proportion of effects on the level and frequency of variation across the genome. The African-American population shows both a higher level of nucleotide diversity and more negative values of Tajima's D statistic than does a European-American population. Using coalescent simulations, we show that the significantly negative values of the D statistic in African-Americans and the positive values in European-Americans are well explained by relatively simple models of population admixture and bottleneck, respectively. Working within these nonequilibrium frameworks, we are still able to show deviations from neutral expectations at a number of loci, including ABO and TRPV6. In addition, we show that the frequency spectrum of mutations--corrected for levels of polymorphism--is correlated with recombination rate only in European-Americans. These results are consistent with repeated selective sweeps in non-African populations, in agreement with recent reports using microsatellite data.

  14. Grain boundary sweeping and liquefaction-induced fission product behavior in nuclear fuel under severe-core damage accident conditions

    International Nuclear Information System (INIS)

    Rest, J.

    1984-05-01

    The theoretical FASTGRASS-VFP model has been used in the interpretation of fission gas, iodine, tellurium, and cesium release from: (1) irradiated high-burnup LWR fuel in a flowing steam atmosphere during high-temperature, in-cell heating tests performed at Oak Ridge National Laboratory; and (2) trace-irradiated and high-burnup LWR fuel during severe-fuel-damage (SFD) tests performed in the PBF reactor in Idaho. A theory of grain boundary sweeping of gas bubbles, gas bubble behavior during fuel liquefaction (destruction of grain boundaries due to formation of a U-rich melt phase), and U-Zr eutectic melting has been included within the FASTGRASS-VFP formalism. Results of the analyses demonstrate that intragranular fission product behavior during both types of tests can be interpreted in terms of a grain-growth/grain-boundary-sweeping mechanism that enhances the flow of fission products from within the grains to the grain boundaries. Whereas fuel liquefaction leads to an enhanced release of fission products in trace-irradiated fuel, the occurrence of fuel liquefaction in high-burnup fuel can degrade fission product release. This phenomenon is due in part to reduced gas-bubble mobilities in a viscous medium as compared to vapor transport, and in part to a degradation of grain growth rates and the subsequent decrease in grain-boundary sweeping of intragranular fission products into the liquefied lamina. The analysis shows that total UO 2 dissolution due to eutectic melting leads to increased release for both trace-irradiated and high-burnup fuel. The FASTGRASS-VFP predictions, measured release rates from the above tests, and previously published release rates are compared and differences between fission product behavior in trace-irradiated and in high-burnup fuel are highlighted

  15. A consistent thermodynamic database for cement minerals

    International Nuclear Information System (INIS)

    Blanc, P.; Claret, F.; Burnol, A.; Marty, N.; Gaboreau, S.; Tournassat, C.; Gaucher, E.C.; Giffault, E.; Bourbon, X.

    2010-01-01

    work - the formation enthalpy and the Cp(T) function are taken from the literature or estimated - finally, the Log K(T) function is calculated, based on the selected dataset and it is compared to experimental data gathered at different temperatures. Each experimental point is extracted from solution compositions by using PHREEQC with a selection of aqueous complexes, consistent with the Thermochimie database. The selection was tested namely by drawing activity diagrams, allowing to assess phases relations. An example of such a diagram, drawn in the CaO-Al 2 O 3 -SiO 2 -H 2 O system is displayed. It can be seen that low pH concrete alteration proceeds essentially in decreasing the C/S ratio in C-S-H phases to the point where C-S-H are no longer stable and replaced by zeolite, then clay minerals. This evolution corresponds to a decrease in silica activity, which is consistent with the pH decrease, as silica concentration depends essentially on pH. Some rather consistent phase relations have been obtained for the SO 3 -Al 2 O 3 -CaO-CO 2 -H 2 O system. Addition of iron III enlarges the AFm-SO 4 stability field to the low temperature domain, whereas it decreases the pH domain where ettringite is stable. On the other hand, the stability field of katoite remains largely ambiguous, namely with respect to a hydro-garnet/grossular solid solution. With respect to other databases this work was made in consistency with a larger mineral selection, so that it can be used for modelling works in the cement clay interaction context

  16. Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM

    International Nuclear Information System (INIS)

    Paul, William; Lutz, Christopher P.; Heinrich, Andreas J.; Baumann, Susanne

    2016-01-01

    We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5–35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.

  17. SIMPLE-2: a computer code for calculation of steady-state thermal behavior of rod bundles with flow sweeping

    International Nuclear Information System (INIS)

    Jones, O.C. Jr.; Yao, S.; Henry, R.E.

    1976-01-01

    A computer code has been developed for use in making single-phase thermal hydraulic calculations in rod bundle arrays with flow sweeping due to spiral wraps as the predominant crossflow mixing effect. This code, called SIMPLE-2, makes the assumption that the axial pressure gradient is identical for each subchannel over a given axial increment, and is unique in that no empirical coefficients must be specified for its use. Results from this code have been favorably compared with experimental data for both uniform and highly nonuniform power distributions. Typical calculations for various bundle sizes applicable to the LMBR program are included

  18. Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM

    Energy Technology Data Exchange (ETDEWEB)

    Paul, William; Lutz, Christopher P.; Heinrich, Andreas J. [IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States); Baumann, Susanne [IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States); Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

    2016-07-15

    We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5–35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.

  19. Evaluation on sweep gas pressure drop in fusion blanket mock-up for in-pile test

    International Nuclear Information System (INIS)

    Ishitsuka, Etsuo; Kawamura, Hiroshi; Sagawa, Hisashi; Nagakura, Masaaki; Kanzawa, Toru.

    1993-03-01

    In the ITER/CDA (Conceptual Design Activity) of a tritium breeding blanket, Japan have proposed the pebble-typed blanket. The in-pile mock-up test will be preparing in JMTR (Japan Materials Testing Reactor) for Japanese engineering design with the pebble-typed blanket. Therefore, the He sweep gas pressure drop in the pebble bed was measured for the design of the mock-up used on in-pile test. From the results of this test, it was clear that the pressure drop was predicted on Kozeny- Carman's equation within +25 ∼ -60 %, and that the pressure drop was not affected by moisture concentration (< 100 ppm). (author)

  20. Frequency sweep of the field scattered by an inhomogeneous structure using method of moments and asymptotic waveform evaluation

    DEFF Research Database (Denmark)

    Troelsen, Jens; Meincke, Peter; Breinbjerg, Olav

    2000-01-01

    into account. To the knowledge of the authors the AWE technique has not previously been applied to a MoM solution based on this kind of integral equation. It is the purpose of this paper to investigate the use of the AWE technique as a tool to obtain a fast frequency sweep of the field scattered......In many radar applications it is necessary to determine the scattering from an object over a wide frequency band. The asymptotic waveform evaluation (AWE), which is a moment matching (MM) technique, constitutes a method to this end. In general, MM techniques provide a reduced-order model...

  1. Determination of underivatized amino acids to evaluate quality of beer by capillary electrophoresis with online sweeping technique.

    Science.gov (United States)

    Luo, Tian; Ke, Jing; Xie, Yunfei; Dong, Yuming

    2017-10-01

    Capillary electrophoresis (CE) with ultraviolet detection was applied to determine underivatized amino acids in beer, based on the coordination interaction of copper ions and amino acids. An online sweeping technique was combined with CE to improve detection sensitivity. Using the United Nations Food Agriculture Organization/World Health Organization model of essential amino acid pattern and flavor of amino acids, the quality and taste in three kinds of beer were evaluated. It was found that Beer2 had higher quality than the other two kinds and the content of phenylalanine, proline, serine, and isoleucine was relatively large in all three kinds of beers with a great influence on beer flavor. Optimal conditions for separation were as follows: 50mM CuSO 4 at pH 4.40 as buffer; total length of fused silica capillary, 73 cm; effective length, 65 cm; separation voltage, 22.5 kV; and optimized sweeping condition, 70 seconds. In the appropriate range, linearity (r 2  > 0.9989), precision with a relative standard deviation amino acids in beer and to perform quantitative analysis directly without derivatization for the first time. Copyright © 2017. Published by Elsevier B.V.

  2. The Influence of Sweep on the Aerodynamic Loading of an Oscillating NACA0012 Airfoil. Volume 2: Data Report

    Science.gov (United States)

    St.hilaire, A. O.; Carta, F. O.

    1979-01-01

    The effect of sweep on the dynamic response of the NACA 0012 airfoil was investigated. Unsteady chordwise distributed pressure data were obtained from a tunnel spanning wing equipped with 21 single surface transducers (13 on the suction side and 8 on the pressure side of the airfoil). The pressure data were obtained at pitching amplitudes of 8 and 10 degrees over a tunnel Mach number range of 0.10 to 0.46 and a pitching frequency range of 2.5 to 10.6 cycles per second. The wing was oscillated in the unswept and swept positions about the quarter-chord pivot axis relative to mean incidence angle settings of 0, 9, 12, and 15 degrees. A compilation of all the response data obtained during the test program is presented. These data are in the form of normal force, chord force, lift force, pressure drag, and moment hysteresis loops derived from chordwise integrations of the unsteady pressure distributions. The hysteresis loops are organized in two main sections. In the first section, the loop data are arranged to show the effect of sweep (lambda = 0 and 30 deg) for all available combinations of mean incidence angle, pitching amplitude, reduced frequency, and chordwise Mach number. The second section shows the effect of chordwise Mach number (MC = 0.30 and MC = 0.40) on the swept wing response for all available combinations of mean incidence angle, pitching amplitude, and reduced frequency.

  3. Pamplin College partners with Deloitte to prepare students for sweeping changes to United States accounting profession

    OpenAIRE

    Ho, Sookhan

    2008-01-01

    Virginia Tech's Pamplin College of Business is one of two schools selected to partner with audit and consulting firm Deloitte to develop much needed college accounting curricula on the International Financial Reporting Standards (IFRS).

  4. Toward a consistent model for glass dissolution

    International Nuclear Information System (INIS)

    Strachan, D.M.; McGrail, B.P.; Bourcier, W.L.

    1994-01-01

    Understanding the process of glass dissolution in aqueous media has advanced significantly over the last 10 years through the efforts of many scientists around the world. Mathematical models describing the glass dissolution process have also advanced from simple empirical functions to structured models based on fundamental principles of physics, chemistry, and thermodynamics. Although borosilicate glass has been selected as the waste form for disposal of high-level wastes in at least 5 countries, there is no international consensus on the fundamental methodology for modeling glass dissolution that could be used in assessing the long term performance of waste glasses in a geologic repository setting. Each repository program is developing their own model and supporting experimental data. In this paper, we critically evaluate a selected set of these structured models and show that a consistent methodology for modeling glass dissolution processes is available. We also propose a strategy for a future coordinated effort to obtain the model input parameters that are needed for long-term performance assessments of glass in a geologic repository. (author) 4 figs., tabs., 75 refs

  5. High-sweeping-speed optically synchronized dual-channel terahertz-signal generator for driving a superconducting tunneling mixer and its application to active gas sensing.

    Science.gov (United States)

    Oh, Kyoung-Hwan; Shimizu, Naofumi; Kohjiro, Satoshi; Kikuchi, Ken'ichi; Wakatsuki, Atsushi; Kukutsu, Naoya; Kado, Yuichi

    2009-10-12

    We propose a high-sweeping-speed optically synchronized dual-channel terahertz (THz) signal generator for an active gas-sensing system with a superconductor-insulator-superconductor (SIS) mixer. The generator can sweep a frequency range from 200 to 500 GHz at a speed of 375 GHz/s and a frequency resolution of 500 MHz. With the developed gas-sensing system, a gas-absorption-line measurement was successfully carried out with N(2)O gas in that frequency range.

  6. Quarter-Sweep Iteration Concept on Conjugate Gradient Normal Residual Method via Second Order Quadrature - Finite Difference Schemes for Solving Fredholm Integro-Differential Equations

    International Nuclear Information System (INIS)

    Aruchunan, E.

    2015-01-01

    In this paper, we have examined the effectiveness of the quarter-sweep iteration concept on conjugate gradient normal residual (CGNR) iterative method by using composite Simpson's (CS) and finite difference (FD) discretization schemes in solving Fredholm integro-differential equations. For comparison purposes, Gauss- Seidel (GS) and the standard or full- and half-sweep CGNR methods namely FSCGNR and HSCGNR are also presented. To validate the efficacy of the proposed method, several analyses were carried out such as computational complexity and percentage reduction on the proposed and existing methods. (author)

  7. Evaluation on sweep gas pressure drop in fusion blanket mock-up for in-pile test

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo; Kawamura, Hiroshi; Sagawa, Hisashi (Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment); Nagakura, Masaaki; Kanzawa, Toru.

    1993-03-01

    In the ITER/CDA (Conceptual Design Activity) of a tritium breeding blanket, Japan have proposed the pebble-typed blanket. The in-pile mock-up test will be preparing in JMTR (Japan Materials Testing Reactor) for Japanese engineering design with the pebble-typed blanket. Therefore, the He sweep gas pressure drop in the pebble bed was measured for the design of the mock-up used on in-pile test. From the results of this test, it was clear that the pressure drop was predicted on Kozeny- Carman's equation within +25 [approx] -60 %, and that the pressure drop was not affected by moisture concentration (< 100 ppm). (author).

  8. Evaluation on sweep gas pressure drop in fusion blanket mock-up for in-pile test

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo; Kawamura, Hiroshi; Sagawa, Hisashi [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Nagakura, Masaaki; Kanzawa, Toru

    1993-03-01

    In the ITER/CDA (Conceptual Design Activity) of a tritium breeding blanket, Japan have proposed the pebble-typed blanket. The in-pile mock-up test will be preparing in JMTR (Japan Materials Testing Reactor) for Japanese engineering design with the pebble-typed blanket. Therefore, the He sweep gas pressure drop in the pebble bed was measured for the design of the mock-up used on in-pile test. From the results of this test, it was clear that the pressure drop was predicted on Kozeny- Carman`s equation within +25 {approx} -60 %, and that the pressure drop was not affected by moisture concentration (< 100 ppm). (author).

  9. Sweep efficiency improvement of waterfloods in Steelman Units V and VII through the application of computer models

    Energy Technology Data Exchange (ETDEWEB)

    Woods, W S

    1967-01-01

    The use of a digital computer program as a tool to investigate the position of flood fronts in 2 Steelman units is described. The program involves a simulated potentiometric analyzer. Several years of historical performance were utilized and alterations to the model were made to match the historical performance until a satisfactory prediction is obtained. Subsequent to matching the historical performance, future predictions were obtained to evaluate the efficiency of the ultimate sweep configuration in the reservoir. These data are used as directives for improving the operation of the waterfloods. Rather than the complicated and elaborate computer techniques currently in use, it is suggested that the results obtained in this particular application of simple techniques provide sufficient economic operating directives.

  10. A Consistent Phylogenetic Backbone for the Fungi

    Science.gov (United States)

    Ebersberger, Ingo; de Matos Simoes, Ricardo; Kupczok, Anne; Gube, Matthias; Kothe, Erika; Voigt, Kerstin; von Haeseler, Arndt

    2012-01-01

    The kingdom of fungi provides model organisms for biotechnology, cell biology, genetics, and life sciences in general. Only when their phylogenetic relationships are stably resolved, can individual results from fungal research be integrated into a holistic picture of biology. However, and despite recent progress, many deep relationships within the fungi remain unclear. Here, we present the first phylogenomic study of an entire eukaryotic kingdom that uses a consistency criterion to strengthen phylogenetic conclusions. We reason that branches (splits) recovered with independent data and different tree reconstruction methods are likely to reflect true evolutionary relationships. Two complementary phylogenomic data sets based on 99 fungal genomes and 109 fungal expressed sequence tag (EST) sets analyzed with four different tree reconstruction methods shed light from different angles on the fungal tree of life. Eleven additional data sets address specifically the phylogenetic position of Blastocladiomycota, Ustilaginomycotina, and Dothideomycetes, respectively. The combined evidence from the resulting trees supports the deep-level stability of the fungal groups toward a comprehensive natural system of the fungi. In addition, our analysis reveals methodologically interesting aspects. Enrichment for EST encoded data—a common practice in phylogenomic analyses—introduces a strong bias toward slowly evolving and functionally correlated genes. Consequently, the generalization of phylogenomic data sets as collections of randomly selected genes cannot be taken for granted. A thorough characterization of the data to assess possible influences on the tree reconstruction should therefore become a standard in phylogenomic analyses. PMID:22114356

  11. Consistency based correlations for tailings consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Azam, S.; Paul, A.C. [Regina Univ., Regina, SK (Canada). Environmental Systems Engineering

    2010-07-01

    The extraction of oil, uranium, metals and mineral resources from the earth generates significant amounts of tailings slurry. The tailings are contained in a disposal area with perimeter dykes constructed from the coarser fraction of the slurry. There are many unique challenges pertaining to the management of the containment facilities for several decades beyond mine closure that are a result of the slow settling rates of the fines and the high standing toxic waters. Many tailings dam failures in different parts of the world have been reported to result in significant contaminant releases causing public concern over the conventional practice of tailings disposal. Therefore, in order to reduce and minimize the environmental footprint, the fluid tailings need to undergo efficient consolidation. This paper presented an investigation into the consolidation behaviour of tailings in conjunction with soil consistency that captured physicochemical interactions. The paper discussed the large strain consolidation behaviour (volume compressibility and hydraulic conductivity) of six fine-grained soil slurries based on published data. The paper provided background information on the study and presented the research methodology. The geotechnical index properties of the selected materials were also presented. The large strain consolidation, volume compressibility correlations, and hydraulic conductivity correlations were provided. It was concluded that the normalized void ratio best described volume compressibility whereas liquidity index best explained the hydraulic conductivity. 17 refs., 3 tabs., 4 figs.

  12. Simulating Linear Sweep Voltammetry from First-Principles: Application to Electrochemical Oxidation of Water on Pt(111) and Pt3Ni(111)

    DEFF Research Database (Denmark)

    Viswanathan, Venkatasubramanian; Hansen, Heine Anton; Rossmeisl, Jan

    2012-01-01

    Cyclic voltammetry is a fundamental experimental method for characterizing adsorbates on electrochemical surfaces. We present a model for the electrochemical solid–liquid interface, and we simulate the linear sweep voltammogram of the electrochemical oxidation of H2O on Pt(111) and Pt3Ni(111...

  13. Fast backprojection-based reconstruction of spectral-spatial EPR images from projections with the constant sweep of a magnetic field.

    Science.gov (United States)

    Komarov, Denis A; Hirata, Hiroshi

    2017-08-01

    In this paper, we introduce a procedure for the reconstruction of spectral-spatial EPR images using projections acquired with the constant sweep of a magnetic field. The application of a constant field-sweep and a predetermined data sampling rate simplifies the requirements for EPR imaging instrumentation and facilitates the backprojection-based reconstruction of spectral-spatial images. The proposed approach was applied to the reconstruction of a four-dimensional numerical phantom and to actual spectral-spatial EPR measurements. Image reconstruction using projections with a constant field-sweep was three times faster than the conventional approach with the application of a pseudo-angle and a scan range that depends on the applied field gradient. Spectral-spatial EPR imaging with a constant field-sweep for data acquisition only slightly reduces the signal-to-noise ratio or functional resolution of the resultant images and can be applied together with any common backprojection-based reconstruction algorithm. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Sensitive Detection of Organophosphorus Pesticides in Medicinal Plants Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with Sweeping Micellar Electrokinetic Chromatography.

    Science.gov (United States)

    Wei, Jin-Chao; Hu, Ji; Cao, Ji-Liang; Wan, Jian-Bo; He, Cheng-Wei; Hu, Yuan-Jia; Hu, Hao; Li, Peng

    2016-02-03

    A simple, rapid, and sensitive method using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with sweeping micellar electrokinetic chromatography (sweeping-MEKC) has been developed for the determination of nine organophosphorus pesticides (chlorfenvinphos, parathion, quinalphos, fenitrothion, azinphos-ethyl, parathion-methyl, fensulfothion, methidathion, and paraoxon). The important parameters that affect the UA-DLLME and sweeping efficiency were investigated. Under the optimized conditions, the proposed method provided 779.0-6203.5-fold enrichment of the nine pesticides compared to the normal MEKC method. The limits of detection ranged from 0.002 to 0.008 mg kg(-1). The relative standard deviations of the peak area ranged from 1.2 to 6.5%, indicating the good repeatability of the method. Finally, the developed UA-DLLME-sweeping-MEKC method has been successfully applied to the analysis of the investigated pesticides in several medicinal plants, including Lycium chinense, Dioscorea opposite, Codonopsis pilosula, and Panax ginseng, indicating that this method is suitable for the determination of trace pesticide residues in real samples with complex matrices.

  15. Consistently Showing Your Best Side? Intra-individual Consistency in #Selfie Pose Orientation

    Science.gov (United States)

    Lindell, Annukka K.

    2017-01-01

    Painted and photographic portraits of others show an asymmetric bias: people favor their left cheek. Both experimental and database studies confirm that the left cheek bias extends to selfies. To date all such selfie studies have been cross-sectional; whether individual selfie-takers tend to consistently favor the same pose orientation, or switch between multiple poses, remains to be determined. The present study thus examined intra-individual consistency in selfie pose orientations. Two hundred selfie-taking participants (100 male and 100 female) were identified by searching #selfie on Instagram. The most recent 10 single-subject selfies for the each of the participants were selected and coded for type of selfie (normal; mirror) and pose orientation (left, midline, right), resulting in a sample of 2000 selfies. Results indicated that selfie-takers do tend to consistently adopt a preferred pose orientation (α = 0.72), with more participants showing an overall left cheek bias (41%) than would be expected by chance (overall right cheek bias = 31.5%; overall midline bias = 19.5%; no overall bias = 8%). Logistic regression modellng, controlling for the repeated measure of participant identity, indicated that sex did not affect pose orientation. However, selfie type proved a significant predictor when comparing left and right cheek poses, with a stronger left cheek bias for mirror than normal selfies. Overall, these novel findings indicate that selfie-takers show intra-individual consistency in pose orientation, and in addition, replicate the previously reported left cheek bias for selfies and other types of portrait, confirming that the left cheek bias also presents within individuals’ selfie corpora. PMID:28270790

  16. Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy

    Science.gov (United States)

    Kittell, Aaron W.; Hyde, James S.

    2015-01-01

    Non-adiabatic rapid passage (NARS) electron paramagnetic resonance (EPR) spectroscopy was introduced by Kittell, A.W., Camenisch, T.G., Ratke, J.J. Sidabras, J.W., Hyde, J.S., 2011 as a general purpose technique to collect the pure absorption response. The technique has been used to improve sensitivity relative to sinusoidal magnetic field modulation, increase the range of inter-spin distances that can be measured under near physiological conditions, and enhance spectral resolution in copper (II) spectra. In the present work, the method is extended to CW microwave power saturation of spin-labeled T4 Lysozyme (T4L). As in the cited papers, rapid triangular sweep of the polarizing magnetic field was superimposed on slow sweep across the spectrum. Adiabatic rapid passage (ARP) effects were encountered in samples undergoing very slow rotational diffusion as the triangular magnetic field sweep rate was increased. The paper reports results of variation of experimental parameters at the interface of adiabatic and non-adiabatic rapid sweep conditions. Comparison of the forward (up) and reverse (down) triangular sweeps is shown to be a good indicator of the presence of rapid passage effects. Spectral turning points can be distinguished from spectral regions between turning points in two ways: differential microwave power saturation and differential passage effects. Oxygen accessibility data are shown under NARS conditions that appear similar to conventional field modulation data. However, the sensitivity is much higher, permitting, in principle, experiments at substantially lower protein concentrations. Spectral displays were obtained that appear sensitive to rotational diffusion in the range of rotational correlation times of 10−3 to 10−7 s in a manner that is analogous to saturation transfer spectroscopy. PMID:25917132

  17. Speed Consistency in the Smart Tachograph.

    Science.gov (United States)

    Borio, Daniele; Cano, Eduardo; Baldini, Gianmarco

    2018-05-16

    In the transportation sector, safety risks can be significantly reduced by monitoring the behaviour of drivers and by discouraging possible misconducts that entail fatigue and can increase the possibility of accidents. The Smart Tachograph (ST), the new revision of the Digital Tachograph (DT), has been designed with this purpose: to verify that speed limits and compulsory rest periods are respected by drivers. In order to operate properly, the ST periodically checks the consistency of data from different sensors, which can be potentially manipulated to avoid the monitoring of the driver behaviour. In this respect, the ST regulation specifies a test procedure to detect motion conflicts originating from inconsistencies between Global Navigation Satellite System (GNSS) and odometry data. This paper provides an experimental evaluation of the speed verification procedure specified by the ST regulation. Several hours of data were collected using three vehicles and considering light urban and highway environments. The vehicles were equipped with an On-Board Diagnostics (OBD) data reader and a GPS/Galileo receiver. The tests prescribed by the regulation were implemented with specific focus on synchronization aspects. The experimental analysis also considered aspects such as the impact of tunnels and the presence of data gaps. The analysis shows that the metrics selected for the tests are resilient to data gaps, latencies between GNSS and odometry data and simplistic manipulations such as data scaling. The new ST forces an attacker to falsify data from both sensors at the same time and in a coherent way. This makes more difficult the implementation of frauds in comparison to the current version of the DT.

  18. Consistency Anchor Formalization and Correctness Proofs

    OpenAIRE

    Miguel, Correia; Bessani, Alysson

    2014-01-01

    This is report contains the formal proofs for the techniques for increasing the consistency of cloud storage as presented in "Bessani et al. SCFS: A Cloud-backed File System. Proc. of the 2014 USENIX Annual Technical Conference. June 2014." The consistency anchor technique allows one to increase the consistency provided by eventually consistent cloud storage services like Amazon S3. This technique has been used in the SCFS (Shared Cloud File System) cloud-backed file system for solving rea...

  19. The signature of positive selection at randomly chosen loci.

    Science.gov (United States)

    Przeworski, Molly

    2002-03-01

    In Drosophila and humans, there are accumulating examples of loci with a significant excess of high-frequency-derived alleles or high levels of linkage disequilibrium, relative to a neutral model of a random-mating population of constant size. These are features expected after a recent selective sweep. Their prevalence suggests that positive directional selection may be widespread in both species. However, as I show here, these features do not persist long after the sweep ends: The high-frequency alleles drift to fixation and no longer contribute to polymorphism, while linkage disequilibrium is broken down by recombination. As a result, loci chosen without independent evidence of recent selection are not expected to exhibit either of these features, even if they have been affected by numerous sweeps in their genealogical history. How then can we explain the patterns in the data? One possibility is population structure, with unequal sampling from different subpopulations. Alternatively, positive selection may not operate as is commonly modeled. In particular, the rate of fixation of advantageous mutations may have increased in the recent past.

  20. Molecular signature of epistatic selection: interrogating genetic interactions in the sex-ratio meiotic drive of Drosophila simulans.

    Science.gov (United States)

    Chevin, Luis-Miguel; Bastide, Héloïse; Montchamp-Moreau, Catherine; Hospital, Frédéric

    2009-06-01

    Fine scale analyses of signatures of selection allow assessing quantitative aspects of a species' evolutionary genetic history, such as the strength of selection on genes. When several selected loci lie in the same genomic region, their epistatic interactions may also be investigated. Here, we study how the neutral polymorphism pattern was shaped by two close recombining loci that cause 'sex-ratio' meiotic drive in Drosophila simulans, as an example of strong selection with potentially strong epistasis. We compare the polymorphism data observed in a natural population with the results of forward stochastic simulations under several contexts of epistasis between the candidate loci for the drive. We compute the likelihood of different possible scenarios, in order to determine which configuration is most consistent with the data. Our results highlight that fine scale analyses of well-chosen candidate genomic regions provide information-rich data that can be used to investigate the genotype-phenotype-fitness map, which can hardly be studied in genome-wide analyses. We also emphasize that initial conditions and time of observation (here, time after the interruption of a partial selective sweep) are crucial parameters in the interpretation of real data, while these are often overlooked in theoretical studies.

  1. Consistency of the Self-Schema in Depression.

    Science.gov (United States)

    Ross, Michael J.; Mueller, John H.

    Depressed individuals may filter or distort environmental information in direct relationship to their self perceptions. To investigate the degree of uncertainty about oneself and others, as measured by consistent/inconsistent responses, 72 college students (32 depressed and 40 nondepressed) rated selected adjectives from the Derry and Kuiper…

  2. Genomic selection in maritime pine.

    Science.gov (United States)

    Isik, Fikret; Bartholomé, Jérôme; Farjat, Alfredo; Chancerel, Emilie; Raffin, Annie; Sanchez, Leopoldo; Plomion, Christophe; Bouffier, Laurent

    2016-01-01

    A two-generation maritime pine (Pinus pinaster Ait.) breeding population (n=661) was genotyped using 2500 SNP markers. The extent of linkage disequilibrium and utility of genomic selection for growth and stem straightness improvement were investigated. The overall intra-chromosomal linkage disequilibrium was r(2)=0.01. Linkage disequilibrium corrected for genomic relationships derived from markers was smaller (rV(2)=0.006). Genomic BLUP, Bayesian ridge regression and Bayesian LASSO regression statistical models were used to obtain genomic estimated breeding values. Two validation methods (random sampling 50% of the population and 10% of the progeny generation as validation sets) were used with 100 replications. The average predictive ability across statistical models and validation methods was about 0.49 for stem sweep, and 0.47 and 0.43 for total height and tree diameter, respectively. The sensitivity analysis suggested that prior densities (variance explained by markers) had little or no discernible effect on posterior means (residual variance) in Bayesian prediction models. Sampling from the progeny generation for model validation increased the predictive ability of markers for tree diameter and stem sweep but not for total height. The results are promising despite low linkage disequilibrium and low marker coverage of the genome (∼1.39 markers/cM). Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Rhabdoviruses in two species of Drosophila: vertical transmission and a recent sweep.

    Science.gov (United States)

    Longdon, Ben; Wilfert, Lena; Obbard, Darren J; Jiggins, Francis M

    2011-05-01

    Insects are host to a diverse range of vertically transmitted micro-organisms, but while their bacterial symbionts are well-studied, little is known about their vertically transmitted viruses. We have found that two sigma viruses (Rhabdoviridae) recently discovered in Drosophila affinis and Drosophila obscura are both vertically transmitted. As is the case for the sigma virus of Drosophila melanogaster, we find that both males and females can transmit these viruses to their offspring. Males transmit lower viral titers through sperm than females transmit through eggs, and a lower proportion of their offspring become infected. In natural populations of D. obscura in the United Kingdom, we found that 39% of flies were infected and that the viral population shows clear evidence of a recent expansion, with extremely low genetic diversity and a large excess of rare polymorphisms. Using sequence data we estimate that the virus has swept across the United Kingdom within the past ∼11 years, during which time the viral population size doubled approximately every 9 months. Using simulations based on our lab estimates of transmission rates, we show that the biparental mode of transmission allows the virus to invade and rapidly spread through populations at rates consistent with those measured in the field. Therefore, as predicted by our simulations, the virus has undergone an extremely rapid and recent increase in population size. In light of this and earlier studies of a related virus in D. melanogaster, we conclude that vertically transmitted rhabdoviruses may be common in insects and that these host-parasite interactions can be highly dynamic.

  4. Rhabdoviruses in Two Species of Drosophila: Vertical Transmission and a Recent Sweep

    Science.gov (United States)

    Longdon, Ben; Wilfert, Lena; Obbard, Darren J.; Jiggins, Francis M.

    2011-01-01

    Insects are host to a diverse range of vertically transmitted micro-organisms, but while their bacterial symbionts are well-studied, little is known about their vertically transmitted viruses. We have found that two sigma viruses (Rhabdoviridae) recently discovered in Drosophila affinis and Drosophila obscura are both vertically transmitted. As is the case for the sigma virus of Drosophila melanogaster, we find that both males and females can transmit these viruses to their offspring. Males transmit lower viral titers through sperm than females transmit through eggs, and a lower proportion of their offspring become infected. In natural populations of D. obscura in the United Kingdom, we found that 39% of flies were infected and that the viral population shows clear evidence of a recent expansion, with extremely low genetic diversity and a large excess of rare polymorphisms. Using sequence data we estimate that the virus has swept across the United Kingdom within the past ∼11 years, during which time the viral population size doubled approximately every 9 months. Using simulations based on our lab estimates of transmission rates, we show that the biparental mode of transmission allows the virus to invade and rapidly spread through populations at rates consistent with those measured in the field. Therefore, as predicted by our simulations, the virus has undergone an extremely rapid and recent increase in population size. In light of this and earlier studies of a related virus in D. melanogaster, we conclude that vertically transmitted rhabdoviruses may be common in insects and that these host–parasite interactions can be highly dynamic. PMID:21339477

  5. Critical system issues and modeling requirements - the problem of beam energy sweep in an electron linear induction accelerator

    International Nuclear Information System (INIS)

    Turner, W.C.; Barrett, D.M.; Sampayan, S.E.

    1991-01-01

    In this paper the authors attempt to motivate the development of modeling tools for linear induction accelerator components by giving examples of performance limitations related to energy sweep. The most pressing issues is the development of an accurate model of the switching behavior of large magnetic cores at high dB/dt in the accelerator and magnetic compression modulators. Ideally one would like to have a model with as few parameters as possible that allows the user to choose the core geometry and magnetic material and perhaps a few parameters characterizing the switch model. Beyond this, the critical modeling tasks are: simulation of a magnetic compression modulator, modeling the reset dynamics of a magnetic compression modulator, modeling the loading characteristics of a linear induction accelerator cell, and modeling the electron injector current including the dynamics of feedback modulation and beam loading in an accelerator cell. Of course in the development of these models care should be given to benchmarking them against data from experimental systems. Beyond that one should aim for tools that have predictive power so that they can be used as design tools and not merely to replicate existing data

  6. A Compact Two-Stage 120 W GaN High Power Amplifier for SweepSAR Radar Systems

    Science.gov (United States)

    Thrivikraman, Tushar; Horst, Stephen; Price, Douglas; Hoffman, James; Veilleux, Louise

    2014-01-01

    This work presents the design and measured results of a fully integrated switched power two-stage GaN HEMT high-power amplifier (HPA) achieving 60% power-added efficiency at over 120Woutput power. This high-efficiency GaN HEMT HPA is an enabling technology for L-band SweepSAR interferometric instruments that enable frequent repeat intervals and high-resolution imagery. The L-band HPA was designed using space-qualified state-of-the-art GaN HEMT technology. The amplifier exhibits over 34 dB of power gain at 51 dBm of output power across an 80 MHz bandwidth. The HPA is divided into two stages, an 8 W driver stage and 120 W output stage. The amplifier is designed for pulsed operation, with a high-speed DC drain switch operating at the pulsed-repetition interval and settles within 200 ns. In addition to the electrical design, a thermally optimized package was designed, that allows for direct thermal radiation to maintain low-junction temperatures for the GaN parts maximizing long-term reliability. Lastly, real radar waveforms are characterized and analysis of amplitude and phase stability over temperature demonstrate ultra-stable operation over temperature using integrated bias compensation circuitry allowing less than 0.2 dB amplitude variation and 2 deg phase variation over a 70 C range.

  7. Sensitive determination of pyrrolizidine alkaloids in Tussilago farfara L. by field-amplified, sample-stacking, sweeping micellar electrokinetic chromatography.

    Science.gov (United States)

    Cao, Kun; Xu, Yi; Mu, Xiuni; Zhang, Qing; Wang, Renjie; Lv, Junjiang

    2016-11-01

    Pyrrolizidine alkaloids are the toxic components in Tussilago farfara L. Due to the lack of standard substances for quantitative analysis and traces of pyrrolizidine alkaloids in total alkaloids, the full quality control of Tussilago farfara L has been limited. In this study, we aimed to solve the difficulty of determination of pyrrolizidine alkaloids and identify more components in the total alkaloids. An on-line preconcentration method has been applied to improve determining sensitivity of pyrrolizidine alkaloids in Tussilago farfara L. in which included field-amplified sample stacking and sweeping in micellar electrokinetic capillary chromatography. The main parameters that affected separation and stacking efficiency were investigated in details. Under the optimal conditions, the sensitivity enhancement factors obtained by the developed method for the analytes were from 15- to 12-fold, the limits of detection of senkirkine and senecionine were 2∼5 μg/L. Senkirkine and senecionine have been detected in alkaloids (c) of Tussilago farfara L, along ferulic acid methyl ester and methyl caffeate. The developed method was also applied to the analysis of acid extraction (a) of Tussilago farfara L, and senkirkine could be detected directly. The results indicated that the developed method is feasible for the analysis of pyrrolizidine alkaloids in Tussilago farfara L with good recoveries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Harnessing electro driven separation technique for the separation of selected agrochemicals

    International Nuclear Information System (INIS)

    Wan Aini Wan Ibrahim; Alam, S.M. Monjurul; Azli Sulaiman

    2008-01-01

    Electro driven separation techniques offer a different approach to the analysis of complex mixtures than do traditional pressure-driven chromatographic system; it may rely on electrophoresis, the transport of charged species through a medium by an applied field or may rely on electro driven mobile phase to provide a true chromatographic separation. In the current work the potential of an electro driven separation technique viz. Micellar electrokinetic chromatography (MEKC), is harnessed for the separation of selected agrochemicals (organophosphorus pesticides, OPPs) widely used in the agriculture sector in Malaysia. The current study compares the use of MEKC in normal mode (NM) and reverse mode (RM) for the separation of the selected OPPS. This study also highlights the difference in separations produced by performing separations in normal mode-MEKC (NM-MEKC) and reverse mode-MEKC (RM-MEKC) for the selected OPPs. In RM-MEKC, separation is conducted at acidic pH (pH 2.5 in the current work) where the electro osmotic flow (EOF) is weak whereas in NM-MEKC, the separation is carried out under basic pH (9.3 in this work) where the EOF is strong. A reverse migration order of the OPPs was observed under RM-MEKC. Separation under NM-MEKC was found to be superior to those of RM- MEKC. A comparison is also made between separations performed under sweeping-NM-MEKC and sweeping-RM-MEKC. In sweeping, the OPPs are prepared in the same background solution (BGS) minus the micelles and is adjusted to the same conductivity as the BGS. The study showed that NM-MEKC is more sensitive than RM-MEKC but sweeping-RM-MEKC is superior to sweeping-NM-MEKC. However, sweeping-RM-MEKC only separates two of the OPPs in a single run whereas sweeping-NM-MEKC separates four OPPs in a single run. The better choice of separation mode would be sweeping-NM- MEKC for more OPPs separation in a single run. (author)

  9. A new approach to hull consistency

    Directory of Open Access Journals (Sweden)

    Kolev Lubomir

    2016-06-01

    Full Text Available Hull consistency is a known technique to improve the efficiency of iterative interval methods for solving nonlinear systems describing steady-states in various circuits. Presently, hull consistency is checked in a scalar manner, i.e. successively for each equation of the nonlinear system with respect to a single variable. In the present poster, a new more general approach to implementing hull consistency is suggested which consists in treating simultaneously several equations with respect to the same number of variables.

  10. Replica consistency in a Data Grid

    International Nuclear Information System (INIS)

    Domenici, Andrea; Donno, Flavia; Pucciani, Gianni; Stockinger, Heinz; Stockinger, Kurt

    2004-01-01

    A Data Grid is a wide area computing infrastructure that employs Grid technologies to provide storage capacity and processing power to applications that handle very large quantities of data. Data Grids rely on data replication to achieve better performance and reliability by storing copies of data sets on different Grid nodes. When a data set can be modified by applications, the problem of maintaining consistency among existing copies arises. The consistency problem also concerns metadata, i.e., additional information about application data sets such as indices, directories, or catalogues. This kind of metadata is used both by the applications and by the Grid middleware to manage the data. For instance, the Replica Management Service (the Grid middleware component that controls data replication) uses catalogues to find the replicas of each data set. Such catalogues can also be replicated and their consistency is crucial to the correct operation of the Grid. Therefore, metadata consistency generally poses stricter requirements than data consistency. In this paper we report on the development of a Replica Consistency Service based on the middleware mainly developed by the European Data Grid Project. The paper summarises the main issues in the replica consistency problem, and lays out a high-level architectural design for a Replica Consistency Service. Finally, results from simulations of different consistency models are presented

  11. Influence of sweeping detonation-wave loading on damage evolution during spallation loading of tantalum in both a planar and curved geometry

    Energy Technology Data Exchange (ETDEWEB)

    Gray, George Thompson III [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hull, Lawrence Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Livescu, Veronica [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Faulkner, James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Briggs, Matthew E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Meyer, Ross Keith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Andrews, Heather Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hare, Steven John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jakulewicz, Micah Shawn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shinas, Michael A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-30

    Widespread research over the past five decades has provided a wealth of experimental data and insight concerning the shock hardening, damage evolution, and the spallation response of materials subjected to square-topped shock-wave loading profiles. However, fewer quantitative studies have been conducted on the effect of direct, in-contact, high explosive (HE)-driven Taylor wave (unsupported shocks) loading on the shock hardening, damage evolution, or spallation response of materials. Systematic studies quantifying the effect of sweeping-detonation wave loading are yet sparser. In this study, the damage evolution and spallation response of Ta is shown to be critically dependent on the peak shock stress, the geometry of the sample (flat or curved plate geometry), and the shock obliquity during sweeping-detonation-wave shock loading. Sweepingwave loading in the flat-plate geometry is observed to: a) yield a lower spall strength than previously documented for 1-D supported-shock-wave loading, b) exhibit increased shock hardening as a function of increasing obliquity, and c) lead to an increased incidence of deformation twin formation with increasing shock obliquity. Sweeping-wave loading of a 10 cm radius curved Ta plate is observed to: a) lead to an increase in the shear stress as a function of increasing obliquity, b) display a more developed level of damage evolution, extensive voids and coalescence, and lower spall strength with obliquity in the curved plate than seen in the flat-plate sweeping-detonation wave loading for an equivalent HE loading, and c) no increased propensity for deformation twin formation with increasing obliquity as seen in the flat-plate geometry. The overall observations comparing and contrasting the flat versus curved sweeping-wave spall experiments with 1D loaded spallation behavior suggests a coupled influence of obliquity and geometry on dynamic shock-induced damage evolution and spall strength. Coupled experimental and modeling research

  12. Student Effort, Consistency, and Online Performance

    Science.gov (United States)

    Patron, Hilde; Lopez, Salvador

    2011-01-01

    This paper examines how student effort, consistency, motivation, and marginal learning, influence student grades in an online course. We use data from eleven Microeconomics courses taught online for a total of 212 students. Our findings show that consistency, or less time variation, is a statistically significant explanatory variable, whereas…

  13. Translationally invariant self-consistent field theories

    International Nuclear Information System (INIS)

    Shakin, C.M.; Weiss, M.S.

    1977-01-01

    We present a self-consistent field theory which is translationally invariant. The equations obtained go over to the usual Hartree-Fock equations in the limit of large particle number. In addition to deriving the dynamic equations for the self-consistent amplitudes we discuss the calculation of form factors and various other observables

  14. Sticky continuous processes have consistent price systems

    DEFF Research Database (Denmark)

    Bender, Christian; Pakkanen, Mikko; Sayit, Hasanjan

    Under proportional transaction costs, a price process is said to have a consistent price system, if there is a semimartingale with an equivalent martingale measure that evolves within the bid-ask spread. We show that a continuous, multi-asset price process has a consistent price system, under...

  15. Consistent-handed individuals are more authoritarian.

    Science.gov (United States)

    Lyle, Keith B; Grillo, Michael C

    2014-01-01

    Individuals differ in the consistency with which they use one hand over the other to perform everyday activities. Some individuals are very consistent, habitually using a single hand to perform most tasks. Others are relatively inconsistent, and hence make greater use of both hands. More- versus less-consistent individuals have been shown to differ in numerous aspects of personality and cognition. In several respects consistent-handed individuals resemble authoritarian individuals. For example, both consistent-handedness and authoritarianism have been linked to cognitive inflexibility. Therefore we hypothesised that consistent-handedness is an external marker for authoritarianism. Confirming our hypothesis, we found that consistent-handers scored higher than inconsistent-handers on a measure of submission to authority, were more likely to identify with a conservative political party (Republican), and expressed less-positive attitudes towards out-groups. We propose that authoritarianism may be influenced by the degree of interaction between the left and right brain hemispheres, which has been found to differ between consistent- and inconsistent-handed individuals.

  16. Testing the visual consistency of web sites

    NARCIS (Netherlands)

    van der Geest, Thea; Loorbach, N.R.

    2005-01-01

    Consistency in the visual appearance of Web pages is often checked by experts, such as designers or reviewers. This article reports a card sort study conducted to determine whether users rather than experts could distinguish visual (in-)consistency in Web elements and pages. The users proved to

  17. Consistent spectroscopy for a extended gauge model

    International Nuclear Information System (INIS)

    Oliveira Neto, G. de.

    1990-11-01

    The consistent spectroscopy was obtained with a Lagrangian constructed with vector fields with a U(1) group extended symmetry. As consistent spectroscopy is understood the determination of quantum physical properties described by the model in an manner independent from the possible parametrizations adopted in their description. (L.C.J.A.)

  18. Personality consistency in dogs: a meta-analysis.

    Science.gov (United States)

    Fratkin, Jamie L; Sinn, David L; Patall, Erika A; Gosling, Samuel D

    2013-01-01

    Personality, or consistent individual differences in behavior, is well established in studies of dogs. Such consistency implies predictability of behavior, but some recent research suggests that predictability cannot be assumed. In addition, anecdotally, many dog experts believe that 'puppy tests' measuring behavior during the first year of a dog's life are not accurate indicators of subsequent adult behavior. Personality consistency in dogs is an important aspect of human-dog relationships (e.g., when selecting dogs suitable for substance-detection work or placement in a family). Here we perform the first comprehensive meta-analysis of studies reporting estimates of temporal consistency of dog personality. A thorough literature search identified 31 studies suitable for inclusion in our meta-analysis. Overall, we found evidence to suggest substantial consistency (r = 0.43). Furthermore, personality consistency was higher in older dogs, when behavioral assessment intervals were shorter, and when the measurement tool was exactly the same in both assessments. In puppies, aggression and submissiveness were the most consistent dimensions, while responsiveness to training, fearfulness, and sociability were the least consistent dimensions. In adult dogs, there were no dimension-based differences in consistency. There was no difference in personality consistency in dogs tested first as puppies and later as adults (e.g., 'puppy tests') versus dogs tested first as puppies and later again as puppies. Finally, there were no differences in consistency between working versus non-working dogs, between behavioral codings versus behavioral ratings, and between aggregate versus single measures. Implications for theory, practice, and future research are discussed.

  19. Personality consistency in dogs: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Jamie L Fratkin

    Full Text Available Personality, or consistent individual differences in behavior, is well established in studies of dogs. Such consistency implies predictability of behavior, but some recent research suggests that predictability cannot be assumed. In addition, anecdotally, many dog experts believe that 'puppy tests' measuring behavior during the first year of a dog's life are not accurate indicators of subsequent adult behavior. Personality consistency in dogs is an important aspect of human-dog relationships (e.g., when selecting dogs suitable for substance-detection work or placement in a family. Here we perform the first comprehensive meta-analysis of studies reporting estimates of temporal consistency of dog personality. A thorough literature search identified 31 studies suitable for inclusion in our meta-analysis. Overall, we found evidence to suggest substantial consistency (r = 0.43. Furthermore, personality consistency was higher in older dogs, when behavioral assessment intervals were shorter, and when the measurement tool was exactly the same in both assessments. In puppies, aggression and submissiveness were the most consistent dimensions, while responsiveness to training, fearfulness, and sociability were the least consistent dimensions. In adult dogs, there were no dimension-based differences in consistency. There was no difference in personality consistency in dogs tested first as puppies and later as adults (e.g., 'puppy tests' versus dogs tested first as puppies and later again as puppies. Finally, there were no differences in consistency between working versus non-working dogs, between behavioral codings versus behavioral ratings, and between aggregate versus single measures. Implications for theory, practice, and future research are discussed.

  20. Personality Consistency in Dogs: A Meta-Analysis

    Science.gov (United States)

    Fratkin, Jamie L.; Sinn, David L.; Patall, Erika A.; Gosling, Samuel D.

    2013-01-01

    Personality, or consistent individual differences in behavior, is well established in studies of dogs. Such consistency implies predictability of behavior, but some recent research suggests that predictability cannot be assumed. In addition, anecdotally, many dog experts believe that ‘puppy tests’ measuring behavior during the first year of a dog's life are not accurate indicators of subsequent adult behavior. Personality consistency in dogs is an important aspect of human-dog relationships (e.g., when selecting dogs suitable for substance-detection work or placement in a family). Here we perform the first comprehensive meta-analysis of studies reporting estimates of temporal consistency of dog personality. A thorough literature search identified 31 studies suitable for inclusion in our meta-analysis. Overall, we found evidence to suggest substantial consistency (r = 0.43). Furthermore, personality consistency was higher in older dogs, when behavioral assessment intervals were shorter, and when the measurement tool was exactly the same in both assessments. In puppies, aggression and submissiveness were the most consistent dimensions, while responsiveness to training, fearfulness, and sociability were the least consistent dimensions. In adult dogs, there were no dimension-based differences in consistency. There was no difference in personality consistency in dogs tested first as puppies and later as adults (e.g., ‘puppy tests’) versus dogs tested first as puppies and later again as puppies. Finally, there were no differences in consistency between working versus non-working dogs, between behavioral codings versus behavioral ratings, and between aggregate versus single measures. Implications for theory, practice, and future research are discussed. PMID:23372787

  1. Modeling and Testing Legacy Data Consistency Requirements

    DEFF Research Database (Denmark)

    Nytun, J. P.; Jensen, Christian Søndergaard

    2003-01-01

    An increasing number of data sources are available on the Internet, many of which offer semantically overlapping data, but based on different schemas, or models. While it is often of interest to integrate such data sources, the lack of consistency among them makes this integration difficult....... This paper addresses the need for new techniques that enable the modeling and consistency checking for legacy data sources. Specifically, the paper contributes to the development of a framework that enables consistency testing of data coming from different types of data sources. The vehicle is UML and its...... accompanying XMI. The paper presents techniques for modeling consistency requirements using OCL and other UML modeling elements: it studies how models that describe the required consistencies among instances of legacy models can be designed in standard UML tools that support XMI. The paper also considers...

  2. Genome-wide selection signatures in Pinzgau cattle

    Directory of Open Access Journals (Sweden)

    Radovan Kasarda

    2015-08-01

    Full Text Available The aim of this study was to identify the evidence of recent selection based on estimation of the integrated Haplotype Score (iHS, population differentiation index (FST and characterize affected regions near QTL associated with traits under strong selection in Pinzgau cattle. In total 21 Austrian and 19 Slovak purebreed bulls genotyped with Illumina bovineHD and  bovineSNP50 BeadChip were used to identify genomic regions under selection. Only autosomal loci with call rate higher than 90%, minor allele frequency higher than 0.01 and Hardy-Weinberg equlibrium limit of 0.001 were included in the subsequent analyses of selection sweeps presence. The final dataset was consisted from 30538 SNPs with 81.86 kb average adjacent SNPs spacing. The iHS score were averaged into non-overlapping 500 kb segments across the genome. The FST values were also plotted against genome position based on sliding windows approach and averaged over 8 consecutive SNPs. Based on integrated Haplotype Score evaluation only 7 regions with iHS score higher than 1.7 was found. The average iHS score observed for each adjacent syntenic regions indicated slight effect of recent selection in analysed group of Pinzgau bulls. The level of genetic differentiation between Austrian and Slovak bulls estimated based on FST index was low. Only 24% of FST values calculated for each SNP was greather than 0.01. By using sliding windows approach was found that 5% of analysed windows had higher value than 0.01. Our results indicated use of similar selection scheme in breeding programs of Slovak and Austrian Pinzgau bulls. The evidence for genome-wide association between signatures of selection and regions affecting complex traits such as milk production was insignificant, because the loci in segments identified as affected by selection were very distant from each other. Identification of genomic regions that may be under pressure of selection for phenotypic traits to better understanding of the

  3. On the consistent histories approach to quantum mechanics

    International Nuclear Information System (INIS)

    Dowker, F.; Kent, A.

    1996-01-01

    We review the consistent histories formulations of quantum mechanics developed by Griffiths, Omnes, Gell-Man, and Hartle, and we describe the classifications of consistent sets. We illustrate some general features of consistent sets by a few lemmas and examples. We also consider various interpretations of the formalism, and we examine the new problems which arise in reconstructing the past and predicting the future. It is shown that Omnes characterization of true statements---statements that can be deduced unconditionally in his interpretation---is incorrect. We examine critically Gell-Mann and Hartle's interpretation of the formalism, and in particular, their discussions of communication, prediction, and retrodiction, and we conclude that their explanation of the apparent persistence of quasiclassicality relies on assumptions about an as-yet-unknown theory of experience. Our overall conclusion is that the consistent histories approach illustrates the need to supplement quantum mechanics by some selection principle in order to produce a fundamental theory capable of unconditional predictions

  4. Selective mutism.

    Science.gov (United States)

    Hua, Alexandra; Major, Nili

    2016-02-01

    Selective mutism is a disorder in which an individual fails to speak in certain social situations though speaks normally in other settings. Most commonly, this disorder initially manifests when children fail to speak in school. Selective mutism results in significant social and academic impairment in those affected by it. This review will summarize the current understanding of selective mutism with regard to diagnosis, epidemiology, cause, prognosis, and treatment. Studies over the past 20 years have consistently demonstrated a strong relationship between selective mutism and anxiety, most notably social phobia. These findings have led to the recent reclassification of selective mutism as an anxiety disorder in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. In addition to anxiety, several other factors have been implicated in the development of selective mutism, including communication delays and immigration/bilingualism, adding to the complexity of the disorder. In the past few years, several randomized studies have supported the efficacy of psychosocial interventions based on a graduated exposure to situations requiring verbal communication. Less data are available regarding the use of pharmacologic treatment, though there are some studies that suggest a potential benefit. Selective mutism is a disorder that typically emerges in early childhood and is currently conceptualized as an anxiety disorder. The development of selective mutism appears to result from the interplay of a variety of genetic, temperamental, environmental, and developmental factors. Although little has been published about selective mutism in the general pediatric literature, pediatric clinicians are in a position to play an important role in the early diagnosis and treatment of this debilitating condition.

  5. Identification of genomic regions associated with phenotypic variation between dog breeds using selection mapping.

    Directory of Open Access Journals (Sweden)

    Amaury Vaysse

    2011-10-01

    Full Text Available The extraordinary phenotypic diversity of dog breeds has been sculpted by a unique population history accompanied by selection for novel and desirable traits. Here we perform a comprehensive analysis using multiple test statistics to identify regions under selection in 509 dogs from 46 diverse breeds using a newly developed high-density genotyping array consisting of >170,000 evenly spaced SNPs. We first identify 44 genomic regions exhibiting extreme differentiation across multiple breeds. Genetic variation in these regions correlates with variation in several phenotypic traits that vary between breeds, and we identify novel associations with both morphological and behavioral traits. We next scan the genome for signatures of selective sweeps in single breeds, characterized by long regions of reduced heterozygosity and fixation of extended haplotypes. These scans identify hundreds of regions, including 22 blocks of homozygosity longer than one megabase in certain breeds. Candidate selection loci are strongly enriched for developmental genes. We chose one highly differentiated region, associated with body size and ear morphology, and characterized it using high-throughput sequencing to provide a list of variants that may directly affect these traits. This study provides a catalogue of genomic regions showing extreme reduction in genetic variation or population differentiation in dogs, including many linked to phenotypic variation. The many blocks of reduced haplotype diversity observed across the genome in dog breeds are the result of both selection and genetic drift, but extended blocks of homozygosity on a megabase scale appear to be best explained by selection. Further elucidation of the variants under selection will help to uncover the genetic basis of complex traits and disease.

  6. Consistency in the World Wide Web

    DEFF Research Database (Denmark)

    Thomsen, Jakob Grauenkjær

    Tim Berners-Lee envisioned that computers will behave as agents of humans on the World Wide Web, where they will retrieve, extract, and interact with information from the World Wide Web. A step towards this vision is to make computers capable of extracting this information in a reliable...... and consistent way. In this dissertation we study steps towards this vision by showing techniques for the specication, the verication and the evaluation of the consistency of information in the World Wide Web. We show how to detect certain classes of errors in a specication of information, and we show how...... the World Wide Web, in order to help perform consistent evaluations of web extraction techniques. These contributions are steps towards having computers reliable and consistently extract information from the World Wide Web, which in turn are steps towards achieving Tim Berners-Lee's vision. ii...

  7. Consistent histories and operational quantum theory

    International Nuclear Information System (INIS)

    Rudolph, O.

    1996-01-01

    In this work a generalization of the consistent histories approach to quantum mechanics is presented. We first critically review the consistent histories approach to nonrelativistic quantum mechanics in a mathematically rigorous way and give some general comments about it. We investigate to what extent the consistent histories scheme is compatible with the results of the operational formulation of quantum mechanics. According to the operational approach, nonrelativistic quantum mechanics is most generally formulated in terms of effects, states, and operations. We formulate a generalized consistent histories theory using the concepts and the terminology which have proven useful in the operational formulation of quantum mechanics. The logical rule of the logical interpretation of quantum mechanics is generalized to the present context. The algebraic structure of the generalized theory is studied in detail

  8. Maintenance measures for preservation and recovery of permeable pavement surface infiltration rate--The effects of street sweeping, vacuum cleaning, high pressure washing, and milling.

    Science.gov (United States)

    Winston, Ryan J; Al-Rubaei, Ahmed M; Blecken, Godecke T; Viklander, Maria; Hunt, William F

    2016-03-15

    The surface infiltration rates (SIR) of permeable pavements decline with time as sediment and debris clog pore spaces. Effective maintenance techniques are needed to ensure the hydraulic functionality and water quality benefits of this stormwater control. Eight different small-scale and full-scale maintenance techniques aimed at recovering pavement permeability were evaluated at ten different permeable pavement sites in the USA and Sweden. Maintenance techniques included manual removal of the upper 2 cm of fill material, mechanical street sweeping, regenerative-air street sweeping, vacuum street sweeping, hand-held vacuuming, high pressure washing, and milling of porous asphalt. The removal of the upper 2 cm of clogging material did not significantly improve the SIR of concrete grid paves (CGP) and permeable interlocking concrete pavers (PICP) due to the inclusion of fines in the joint and bedding stone during construction, suggesting routine maintenance cannot overcome improper construction. For porous asphalt maintenance, industrial hand-held vacuum cleaning, pressure washing, and milling were increasingly successful at recovering the SIR. Milling to a depth of 2.5 cm nearly restored the SIR for a 21-year old porous asphalt pavement to like-new conditions. For PICP, street sweepers employing suction were shown to be preferable to mechanical sweepers; additionally, maintenance efforts may become more intensive over time to maintain a threshold SIR, as maintenance was not 100% effective at removing clogging material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Effect of current compliance and voltage sweep rate on the resistive switching of HfO2/ITO/Invar structure as measured by conductive atomic force microscopy

    International Nuclear Information System (INIS)

    Wu, You-Lin; Liao, Chun-Wei; Ling, Jing-Jenn

    2014-01-01

    The electrical characterization of HfO 2 /ITO/Invar resistive switching memory structure was studied using conductive atomic force microscopy (AFM) with a semiconductor parameter analyzer, Agilent 4156C. The metal alloy Invar was used as the metal substrate to ensure good ohmic contact with the substrate holder of the AFM. A conductive Pt/Ir AFM tip was placed in direct contact with the HfO 2 surface, such that it acted as the top electrode. Nanoscale current-voltage (I-V) characteristics of the HfO 2 /ITO/Invar structure were measured by applying a ramp voltage through the conductive AFM tip at various current compliances and ramp voltage sweep rates. It was found that the resistance of the low resistance state (RLRS) decreased with increasing current compliance value, but resistance of high resistance state (RHRS) barely changed. However, both the RHRS and RLRS decreased as the voltage sweep rate increased. The reasons for this dependency on current compliance and voltage sweep rate are discussed.

  10. Connecting the failure of K-theory inside and above vegetation canopies and ejection-sweep cycles by a large eddy simulation

    International Nuclear Information System (INIS)

    Banerjee, Tirtha; De Roo, Frederik; Mauder, Matthias

    2017-01-01

    Parameterizations of biosphere-atmosphere interaction processes in climate models and other hydrological applications require characterization of turbulent transport of momentum and scalars between vegetation canopies and the atmosphere, which is often modeled using a turbulent analogy to molecular diffusion processes. However, simple flux-gradient approaches (K-theory) fail for canopy turbulence. One cause is turbulent transport by large coherent eddies at the canopy scale, which can be linked to sweep-ejection events, and bear signatures of non-local organized eddy motions. K-theory, that parameterizes the turbulent flux or stress proportional to the local concentration or velocity gradient, fails to account for these non-local organized motions. The connection to sweep-ejection cycles and the local turbulent flux can be traced back to the turbulence triple moment (C ′ W ′ W ′ )-bar. In this work, we use large-eddy simulation to investigate the diagnostic connection between the failure of K-theory and sweep-ejection motions. Analyzed schemes are quadrant analysis (QA) and a complete and incomplete cumulant expansion (CEM and ICEM) method. The latter approaches introduce a turbulence timescale in the modeling. Furthermore, we find that the momentum flux needs a different formulation for the turbulence timescale than the sensible heat flux. In conclusion, accounting for buoyancy in stratified conditions is also deemed to be important in addition to accounting for non-local events to predict the correct momentum or scalar fluxes.

  11. Calculating qP-wave traveltimes in 2-D TTI media by high-order fast sweeping methods with a numerical quartic equation solver

    Science.gov (United States)

    Han, Song; Zhang, Wei; Zhang, Jie

    2017-09-01

    A fast sweeping method (FSM) determines the first arrival traveltimes of seismic waves by sweeping the velocity model in different directions meanwhile applying a local solver. It is an efficient way to numerically solve Hamilton-Jacobi equations for traveltime calculations. In this study, we develop an improved FSM to calculate the first arrival traveltimes of quasi-P (qP) waves in 2-D tilted transversely isotropic (TTI) media. A local solver utilizes the coupled slowness surface of qP and quasi-SV (qSV) waves to form a quartic equation, and solve it numerically to obtain possible traveltimes of qP-wave. The proposed quartic solver utilizes Fermat's principle to limit the range of the possible solution, then uses the bisection procedure to efficiently determine the real roots. With causality enforced during sweepings, our FSM converges fast in a few iterations, and the exact number depending on the complexity of the velocity model. To improve the accuracy, we employ high-order finite difference schemes and derive the second-order formulae. There is no weak anisotropy assumption, and no approximation is made to the complex slowness surface of qP-wave. In comparison to the traveltimes calculated by a horizontal slowness shooting method, the validity and accuracy of our FSM is demonstrated.

  12. Self-consistent areas law in QCD

    International Nuclear Information System (INIS)

    Makeenko, Yu.M.; Migdal, A.A.

    1980-01-01

    The problem of obtaining the self-consistent areas law in quantum chromodynamics (QCD) is considered from the point of view of the quark confinement. The exact equation for the loop average in multicolor QCD is reduced to a bootstrap form. Its iterations yield new manifestly gauge invariant perturbation theory in the loop space, reproducing asymptotic freedom. For large loops, the areas law apprears to be a self-consistent solution

  13. Consistency of the MLE under mixture models

    OpenAIRE

    Chen, Jiahua

    2016-01-01

    The large-sample properties of likelihood-based statistical inference under mixture models have received much attention from statisticians. Although the consistency of the nonparametric MLE is regarded as a standard conclusion, many researchers ignore the precise conditions required on the mixture model. An incorrect claim of consistency can lead to false conclusions even if the mixture model under investigation seems well behaved. Under a finite normal mixture model, for instance, the consis...

  14. Self-consistent asset pricing models

    Science.gov (United States)

    Malevergne, Y.; Sornette, D.

    2007-08-01

    We discuss the foundations of factor or regression models in the light of the self-consistency condition that the market portfolio (and more generally the risk factors) is (are) constituted of the assets whose returns it is (they are) supposed to explain. As already reported in several articles, self-consistency implies correlations between the return disturbances. As a consequence, the alphas and betas of the factor model are unobservable. Self-consistency leads to renormalized betas with zero effective alphas, which are observable with standard OLS regressions. When the conditions derived from internal consistency are not met, the model is necessarily incomplete, which means that some sources of risk cannot be replicated (or hedged) by a portfolio of stocks traded on the market, even for infinite economies. Analytical derivations and numerical simulations show that, for arbitrary choices of the proxy which are different from the true market portfolio, a modified linear regression holds with a non-zero value αi at the origin between an asset i's return and the proxy's return. Self-consistency also introduces “orthogonality” and “normality” conditions linking the betas, alphas (as well as the residuals) and the weights of the proxy portfolio. Two diagnostics based on these orthogonality and normality conditions are implemented on a basket of 323 assets which have been components of the S&P500 in the period from January 1990 to February 2005. These two diagnostics show interesting departures from dynamical self-consistency starting about 2 years before the end of the Internet bubble. Assuming that the CAPM holds with the self-consistency condition, the OLS method automatically obeys the resulting orthogonality and normality conditions and therefore provides a simple way to self-consistently assess the parameters of the model by using proxy portfolios made only of the assets which are used in the CAPM regressions. Finally, the factor decomposition with the

  15. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  16. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Roesen, Hanne Ravn

    In this report the design basis for the geotechnical design of the suction caisson at the K15-FA-1 location is described. The derived design soil parameters are based on the site specific CPTs conducted autumn 2010 by Wintershall Nederlands B.V. (Wintershall Netherlands B.V. and Noordhoek Survey ...

  17. Plasma's sweeping arc

    International Nuclear Information System (INIS)

    Pichon, Max

    2010-01-01

    Full text: It is purely elemental, returning materials to their basic atoms through extreme heat and then recondensing them in useful ways. Plasma arc gasification is the latest advanced waste treatment (AWT)concept to hit our shores, courtesy of Zenergy Australia. According to its fans, plasma technology can eliminate all domestic waste to landfill and turn it into beneficial by-products. Japan has toyed with it for a decade, but the idea is now creating a bit of buzz, in the US in particular. Consultancy URS last year undertook a review of 16 advanced technologies for the City of Los Angeles and determined plasma arc gasification was one of the most promising. The Waste Management Association of Australia (VVMAA), however, is cautious - too many AWT projects here have failed to live up to their promises. Plasma arc gasification works on the same principle as a welding machine. An inert gas is passed through an electrical arc between two electrodes and becomes ionised (called plasma), reaching temperatures as high as 13,900°C. It is then injected into the plasma converter holding the waste. Zenergy is working with US technology company Plasma Waste Recycling (PWR), which says it can convert 80 per cent of waste to syngas, a mixture of carbon monoxide and hydrogen that can be used to generate renewable electricity. The inorganic compounds in the waste come out as a solid, either molten metal to be cast as scrap steel or a slag that can be used as a building material aggregate or spun into mineral wool. “The plasma arc process is the next generation for AWT plants as there is no incineration involved, no fly ash, no bottom ash and nothing left to landfill,” said Zenergy Australia's Paul Prasad. He estimates a plant could convert up to 175,000 tonnes of household waste a year into energy or reusable by-products. Technically, it also gets around Australia's fears over incineration, though whether that is really the case in practice remains to be seen. Prasad says there are no air discharges from the process, which is under negative pressure, and the syngas is clean burning. “We know that emissions from the produced syngas when used in a gas turbine are lower than emissions from natural gas and within US EPA standards,” he said. Zenergy's next step is a feasibility study prior to provide all the costing. However, it estimates the cost of producing 1MVV of electricity would be about US$2.5 million ($2.8 million). Part of the unknown is the composition of input wastes, and that's what gives WMAA knowledge manager Mark Glover cause for concern. “The proposition by some plasma companies that I have spoken to is that they want to up the ante and take MSW and start producing energy and other reusable materials,” Glover told WME. While he loves the technology, he reckons it's not right for the waste sector. He uses the old 'garbage in, garbage out' idea. “If you put low-grade material into plasma, you will get low-grade material out at the other end, and this and other AWT technologies tend to be very sensitive to variations. MSW is a very complex material and it is very hard to control,” he said. It's not dioxins he's worried about- the ultra-high temperatures would destroy all the organic molecules that create them - but the robustness of the process.There's another worry, this one strategic. Glover says it would fail WMAA's energy from waste guidelines, which say that the material to be converted to energy would not be accepted as the best alternative to converting the MSW. It says any recover able organic fraction of the waste should be separated and turned to compost, a higher order use than energy conversion. What's more, it remains largely untested at scale, meaning considerable technological and budgetary uncertainties remain. But that won't stop Prasad from pushing the technology into Australia and it that hasn't silenced the buzz offshore. PWR is full steam ahead with plans to build a US$20 million pilot plant in Montgomery, currently undergoing a feasibility study. If successful, the Missouri city would be the first in the world to use graphite arc plasma to gasify household waste.

  18. Superstorm Sweeps Over England

    Science.gov (United States)

    2002-01-01

    A large, low-pressure system swept across the United Kingdom on Monday, spawning at least three tornadoes there before continuing on toward Scandanavia. This image, acquired on October 30, by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), shows the storm after it brought torrential rain and hurricane-strength winds to Britain in perhaps the worst storm to hit the country since 1987. High seas nearing 23 feet (7 meters) and winds gusting up to 109 mph wreaked havoc on sea traffic, causing delays or cancelled ferries across the English Channel and necessitating the rescue of crews from stranded ships, including a Norwegian freighter and an Italian cargo ship. Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  19. Towards thermodynamical consistency of quasiparticle picture

    International Nuclear Information System (INIS)

    Biro, T.S.; Shanenko, A.A.; Toneev, V.D.; Research Inst. for Particle and Nuclear Physics, Hungarian Academy of Sciences, Budapest

    2003-01-01

    The purpose of the present article is to call attention to some realistic quasi-particle-based description of the quark/gluon matter and its consistent implementation in thermodynamics. A simple and transparent representation of the thermodynamical consistency conditions is given. This representation allows one to review critically and systemize available phenomenological approaches to the deconfinement problem with respect to their thermodynamical consistency. A particular attention is paid to the development of a method for treating the string screening in the dense matter of unbound color charges. The proposed method yields an integrable effective pair potential, which can be incorporated into the mean-field picture. The results of its application are in reasonable agreement with lattice data on the QCD thermodynamics [ru

  20. Toward thermodynamic consistency of quasiparticle picture

    International Nuclear Information System (INIS)

    Biro, T.S.; Toneev, V.D.; Shanenko, A.A.

    2003-01-01

    The purpose of the present article is to call attention to some realistic quasiparticle-based description of quark/gluon matter and its consistent implementation in thermodynamics. A simple and transparent representation of the thermodynamic consistency conditions is given. This representation allows one to review critically and systemize available phenomenological approaches to the deconfinement problem with respect to their thermodynamic consistency. Particular attention is paid to the development of a method for treating the string screening in the dense matter of unbound color charges. The proposed method yields an integrable effective pair potential that can be incorporated into the mean-field picture. The results of its application are in reasonable agreement with lattice data on the QCD thermodynamics

  1. Toward a consistent RHA-RPA

    International Nuclear Information System (INIS)

    Shepard, J.R.

    1991-01-01

    The authors examine the RPA based on a relativistic Hartree approximation description for nuclear ground states. This model includes contributions from the negative energy sea at the 1-loop level. They emphasize consistency between the treatment of the ground state and the RPA. This consistency is important in the description of low-lying collective levels but less important for the longitudinal (e, e') quasi-elastic response. They also study the effect of imposing a 3-momentum cutoff on negative energy sea contributions. A cutoff of twice the nucleon mass improves agreement with observed spin orbit splittings in nuclei compared to the standard infinite cutoff results, an effect traceable to the fact that imposing the cutoff reduces m*/m. The cutoff is much less important than consistency in the description of low-lying collective levels. The cutoff model provides excellent agreement with quasi-elastic (e, e') data

  2. Personalized recommendation based on unbiased consistence

    Science.gov (United States)

    Zhu, Xuzhen; Tian, Hui; Zhang, Ping; Hu, Zheng; Zhou, Tao

    2015-08-01

    Recently, in physical dynamics, mass-diffusion-based recommendation algorithms on bipartite network provide an efficient solution by automatically pushing possible relevant items to users according to their past preferences. However, traditional mass-diffusion-based algorithms just focus on unidirectional mass diffusion from objects having been collected to those which should be recommended, resulting in a biased causal similarity estimation and not-so-good performance. In this letter, we argue that in many cases, a user's interests are stable, and thus bidirectional mass diffusion abilities, no matter originated from objects having been collected or from those which should be recommended, should be consistently powerful, showing unbiased consistence. We further propose a consistence-based mass diffusion algorithm via bidirectional diffusion against biased causality, outperforming the state-of-the-art recommendation algorithms in disparate real data sets, including Netflix, MovieLens, Amazon and Rate Your Music.

  3. Financial model calibration using consistency hints.

    Science.gov (United States)

    Abu-Mostafa, Y S

    2001-01-01

    We introduce a technique for forcing the calibration of a financial model to produce valid parameters. The technique is based on learning from hints. It converts simple curve fitting into genuine calibration, where broad conclusions can be inferred from parameter values. The technique augments the error function of curve fitting with consistency hint error functions based on the Kullback-Leibler distance. We introduce an efficient EM-type optimization algorithm tailored to this technique. We also introduce other consistency hints, and balance their weights using canonical errors. We calibrate the correlated multifactor Vasicek model of interest rates, and apply it successfully to Japanese Yen swaps market and US dollar yield market.

  4. Linear augmented plane wave method for self-consistent calculations

    International Nuclear Information System (INIS)

    Takeda, T.; Kuebler, J.

    1979-01-01

    O.K. Andersen has recently introduced a linear augmented plane wave method (LAPW) for the calculation of electronic structure that was shown to be computationally fast. A more general formulation of an LAPW method is presented here. It makes use of a freely disposable number of eigenfunctions of the radial Schroedinger equation. These eigenfunctions can be selected in a self-consistent way. The present formulation also results in a computationally fast method. It is shown that Andersen's LAPW is obtained in a special limit from the present formulation. Self-consistent test calculations for copper show the present method to be remarkably accurate. As an application, scalar-relativistic self-consistent calculations are presented for the band structure of FCC lanthanum. (author)

  5. Proteolysis and consistency of Meshanger cheese

    NARCIS (Netherlands)

    Jong, de L.

    1978-01-01

    Proteolysis in Meshanger cheese, estimated by quantitative polyacrylamide gel electrophoresis is discussed. The conversion of α s1 -casein was proportional to rennet concentration in the cheese. Changes in consistency, after a maximum, were correlated to breakdown of

  6. Developing consistent pronunciation models for phonemic variants

    CSIR Research Space (South Africa)

    Davel, M

    2006-09-01

    Full Text Available Pronunciation lexicons often contain pronunciation variants. This can create two problems: It can be difficult to define these variants in an internally consistent way and it can also be difficult to extract generalised grapheme-to-phoneme rule sets...

  7. Image recognition and consistency of response

    Science.gov (United States)

    Haygood, Tamara M.; Ryan, John; Liu, Qing Mary A.; Bassett, Roland; Brennan, Patrick C.

    2012-02-01

    Purpose: To investigate the connection between conscious recognition of an image previously encountered in an experimental setting and consistency of response to the experimental question. Materials and Methods: Twenty-four radiologists viewed 40 frontal chest radiographs and gave their opinion as to the position of a central venous catheter. One-to-three days later they again viewed 40 frontal chest radiographs and again gave their opinion as to the position of the central venous catheter. Half of the radiographs in the second set were repeated images from the first set and half were new. The radiologists were asked of each image whether it had been included in the first set. For this study, we are evaluating only the 20 repeated images. We used the Kruskal-Wallis test and Fisher's exact test to determine the relationship between conscious recognition of a previously interpreted image and consistency in interpretation of the image. Results. There was no significant correlation between recognition of the image and consistency in response regarding the position of the central venous catheter. In fact, there was a trend in the opposite direction, with radiologists being slightly more likely to give a consistent response with respect to images they did not recognize than with respect to those they did recognize. Conclusion: Radiologists' recognition of previously-encountered images in an observer-performance study does not noticeably color their interpretation on the second encounter.

  8. Consistent Valuation across Curves Using Pricing Kernels

    Directory of Open Access Journals (Sweden)

    Andrea Macrina

    2018-03-01

    Full Text Available The general problem of asset pricing when the discount rate differs from the rate at which an asset’s cash flows accrue is considered. A pricing kernel framework is used to model an economy that is segmented into distinct markets, each identified by a yield curve having its own market, credit and liquidity risk characteristics. The proposed framework precludes arbitrage within each market, while the definition of a curve-conversion factor process links all markets in a consistent arbitrage-free manner. A pricing formula is then derived, referred to as the across-curve pricing formula, which enables consistent valuation and hedging of financial instruments across curves (and markets. As a natural application, a consistent multi-curve framework is formulated for emerging and developed inter-bank swap markets, which highlights an important dual feature of the curve-conversion factor process. Given this multi-curve framework, existing multi-curve approaches based on HJM and rational pricing kernel models are recovered, reviewed and generalised and single-curve models extended. In another application, inflation-linked, currency-based and fixed-income hybrid securities are shown to be consistently valued using the across-curve valuation method.

  9. Guided color consistency optimization for image mosaicking

    Science.gov (United States)

    Xie, Renping; Xia, Menghan; Yao, Jian; Li, Li

    2018-01-01

    This paper studies the problem of color consistency correction for sequential images with diverse color characteristics. Existing algorithms try to adjust all images to minimize color differences among images under a unified energy framework, however, the results are prone to presenting a consistent but unnatural appearance when the color difference between images is large and diverse. In our approach, this problem is addressed effectively by providing a guided initial solution for the global consistency optimization, which avoids converging to a meaningless integrated solution. First of all, to obtain the reliable intensity correspondences in overlapping regions between image pairs, we creatively propose the histogram extreme point matching algorithm which is robust to image geometrical misalignment to some extents. In the absence of the extra reference information, the guided initial solution is learned from the major tone of the original images by searching some image subset as the reference, whose color characteristics will be transferred to the others via the paths of graph analysis. Thus, the final results via global adjustment will take on a consistent color similar to the appearance of the reference image subset. Several groups of convincing experiments on both the synthetic dataset and the challenging real ones sufficiently demonstrate that the proposed approach can achieve as good or even better results compared with the state-of-the-art approaches.

  10. Consistent application of codes and standards

    International Nuclear Information System (INIS)

    Scott, M.A.

    1989-01-01

    The guidelines presented in the US Department of Energy, General Design Criteria (DOE 6430.1A), and the Design and Evaluation Guidelines for Department of Energy Facilities Subject to Natural Phenomena Hazards (UCRL-15910) provide a consistent and well defined approach to determine the natural phenomena hazards loads for US Department of Energy site facilities. The guidelines for the application of loads combinations and allowables criteria are not as well defined and are more flexible in interpretation. This flexibility in the interpretation of load combinations can lead to conflict between the designer and overseer. The establishment of an efficient set of acceptable design criteria, based on US Department of Energy guidelines, provides a consistent baseline for analysis, design, and review. Additionally, the proposed method should not limit the design and analytical innovation necessary to analyze or qualify the unique structure. This paper investigates the consistent application of load combinations, analytical methods, and load allowables and suggests a reference path consistent with the US Department of Energy guidelines

  11. Consistency in multi-viewpoint architectural design

    NARCIS (Netherlands)

    Dijkman, R.M.; Dijkman, Remco Matthijs

    2006-01-01

    This thesis presents a framework that aids in preserving consistency in multi-viewpoint designs. In a multi-viewpoint design each stakeholder constructs his own design part. We call each stakeholder’s design part the view of that stakeholder. To construct his view, a stakeholder has a viewpoint.

  12. Consistent Visual Analyses of Intrasubject Data

    Science.gov (United States)

    Kahng, SungWoo; Chung, Kyong-Mee; Gutshall, Katharine; Pitts, Steven C.; Kao, Joyce; Girolami, Kelli

    2010-01-01

    Visual inspection of single-case data is the primary method of interpretation of the effects of an independent variable on a dependent variable in applied behavior analysis. The purpose of the current study was to replicate and extend the results of DeProspero and Cohen (1979) by reexamining the consistency of visual analysis across raters. We…

  13. Consistent Stochastic Modelling of Meteocean Design Parameters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Sterndorff, M. J.

    2000-01-01

    Consistent stochastic models of metocean design parameters and their directional dependencies are essential for reliability assessment of offshore structures. In this paper a stochastic model for the annual maximum values of the significant wave height, and the associated wind velocity, current...

  14. On the existence of consistent price systems

    DEFF Research Database (Denmark)

    Bayraktar, Erhan; Pakkanen, Mikko S.; Sayit, Hasanjan

    2014-01-01

    We formulate a sufficient condition for the existence of a consistent price system (CPS), which is weaker than the conditional full support condition (CFS). We use the new condition to show the existence of CPSs for certain processes that fail to have the CFS property. In particular this condition...

  15. Dynamic phonon exchange requires consistent dressing

    International Nuclear Information System (INIS)

    Hahne, F.J.W.; Engelbrecht, C.A.; Heiss, W.D.

    1976-01-01

    It is shown that states with undersirable properties (such as ghosts, states with complex eigenenergies and states with unrestricted normalization) emerge from two-body calculations using dynamic effective interactions if one is not careful in introducing single-particle self-energy insertions in a consistent manner

  16. Consistent feeding positions of great tit parents

    NARCIS (Netherlands)

    Lessells, C.M.; Poelman, E.H.; Mateman, A.C.; Cassey, Ph.

    2006-01-01

    When parent birds arrive at the nest to provision their young, their position on the nest rim may influence which chick or chicks are fed. As a result, the consistency of feeding positions of the individual parents, and the difference in position between the parents, may affect how equitably food is

  17. Consistency of the postulates of special relativity

    International Nuclear Information System (INIS)

    Gron, O.; Nicola, M.

    1976-01-01

    In a recent article in this journal, Kingsley has tried to show that the postulates of special relativity contradict each other. It is shown that the arguments of Kingsley are invalid because of an erroneous appeal to symmetry in a nonsymmetric situation. The consistency of the postulates of special relativity and the relativistic kinematics deduced from them is restated

  18. Consistency of Network Traffic Repositories: An Overview

    NARCIS (Netherlands)

    Lastdrager, E.; Lastdrager, E.E.H.; Pras, Aiko

    2009-01-01

    Traffc repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffc that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  19. Consistency analysis of network traffic repositories

    NARCIS (Netherlands)

    Lastdrager, Elmer; Lastdrager, E.E.H.; Pras, Aiko

    Traffic repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffic that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  20. Defining the effect of sweep tillage tool cutting edge geometry on tillage forces using 3D discrete element modelling

    Directory of Open Access Journals (Sweden)

    Mustafa Ucgul

    2015-09-01

    Full Text Available The energy required for tillage processes accounts for a significant proportion of total energy used in crop production. In many tillage processes decreasing the draft and upward vertical forces is often desired for reduced fuel use and improved penetration, respectively. Recent studies have proved that the discrete element modelling (DEM can effectively be used to model the soil–tool interaction. In his study, Fielke (1994 [1] examined the effect of the various tool cutting edge geometries, namely; cutting edge height, length of underside rub, angle of underside clearance, on draft and vertical forces. In this paper the experimental parameters of Fielke (1994 [1] were simulated using 3D discrete element modelling techniques. In the simulations a hysteretic spring contact model integrated with a linear cohesion model that considers the plastic deformation behaviour of the soil hence provides better vertical force prediction was employed. DEM parameters were determined by comparing the experimental and simulation results of angle of repose and penetration tests. The results of the study showed that the simulation results of the soil-various tool cutting edge geometries agreed well with the experimental results of Fielke (1994 [1]. The modelling was then used to simulate a further range of cutting edge geometries to better define the effect of sweep tool cutting edge geometry parameters on tillage forces. The extra simulations were able to show that by using a sharper cutting edge with zero vertical cutting edge height the draft and upward vertical force were further reduced indicating there is benefit from having a really sharp cutting edge. The extra simulations also confirmed that the interpolated trends for angle of underside clearance as suggested by Fielke (1994 [1] where correct with a linear reduction in draft and upward vertical force for angle of underside clearance between the ranges of −25 and −5°, and between −5 and 0°. The

  1. Effectiveness of common fish screen materials for protecting lamprey ammocoetes—Influence of sweeping velocities and decreasing flows

    Science.gov (United States)

    Mesa, Matthew G.; Liedtke, Theresa L.; Weiland, Lisa K.; Christiansen, Helena E.

    2017-12-14

    In previous tests of the effectiveness of four common fish screen materials for excluding lamprey ammocoetes, we determined that woven wire (WW) allowed substantially more entrainment than perforated plate (PP), profile bar (PB), or Intralox (IL) material. These tests were simplistic because they used small vertically-oriented screens positioned perpendicular to the flow without a bypass or a sweeping velocity (SV). In the subsequent test discussed in this report, we exposed ammocoetes to much larger (2.5-m-wide) screen panels with flows up to 10 ft3 /s, a SV component, and a simulated bypass channel. The addition of a SV modestly improved protection of lamprey ammocoetes for all materials tested. A SV of 35 cm/s with an approach velocity (AV) of 12 cm/s, was able to provide protection for fish about 5–15 mm smaller than the protection provided by an AV of 12 cm/s without a SV component. The best-performing screen panels (PP, IL, and PB) provided nearly complete protection from entrainment for fish greater than 50-mm toal length, but the larger openings in the WW material only protected fish greater than 100-mm total length. Decreasing the AV and SV by 50 percent expanded the size range of protected lampreys by about 10–15 mm for those exposed to IL and WW screens, and it decreased the protective ability of PP screens by about 10 mm. Much of the improvement for IL and WW screens under the reduced flow conditions resulted from an increase in the number of lampreys swimming away from the screen. Fish of all sizes became impinged (that is, stuck on the screen surface for more than 1 s) on the screens, with the rate of impingement highest on PP (39– 72 percent) and lowest on WW (7–22 percent). Although impingements were common, injuries were rare, and 24-h post-test survival was greater than 99 percent. Our results refined the level of protection provided by these screen materials when both an AV and SV are present and confirmed our earlier recommendation that

  2. A consistent interpretation of quantum mechanics

    International Nuclear Information System (INIS)

    Omnes, Roland

    1990-01-01

    Some mostly recent theoretical and mathematical advances can be linked together to yield a new consistent interpretation of quantum mechanics. It relies upon a unique and universal interpretative rule of a logical character which is based upon Griffiths consistent history. Some new results in semi-classical physics allow classical physics to be derived from this rule, including its logical aspects, and to prove accordingly the existence of determinism within the quantum framework. Together with decoherence, this can be used to retrieve the existence of facts, despite the probabilistic character of the theory. Measurement theory can then be made entirely deductive. It is accordingly found that wave packet reduction is a logical property, whereas one can always choose to avoid using it. The practical consequences of this interpretation are most often in agreement with the Copenhagen formulation but they can be proved never to give rise to any logical inconsistency or paradox. (author)

  3. Self-consistency in Capital Markets

    Science.gov (United States)

    Benbrahim, Hamid

    2013-03-01

    Capital Markets are considered, at least in theory, information engines whereby traders contribute to price formation with their diverse perspectives. Regardless whether one believes in efficient market theory on not, actions by individual traders influence prices of securities, which in turn influence actions by other traders. This influence is exerted through a number of mechanisms including portfolio balancing, margin maintenance, trend following, and sentiment. As a result market behaviors emerge from a number of mechanisms ranging from self-consistency due to wisdom of the crowds and self-fulfilling prophecies, to more chaotic behavior resulting from dynamics similar to the three body system, namely the interplay between equities, options, and futures. This talk will address questions and findings regarding the search for self-consistency in capital markets.

  4. Student Effort, Consistency and Online Performance

    Directory of Open Access Journals (Sweden)

    Hilde Patron

    2011-07-01

    Full Text Available This paper examines how student effort, consistency, motivation, and marginal learning, influence student grades in an online course. We use data from eleven Microeconomics courses taught online for a total of 212 students. Our findings show that consistency, or less time variation, is a statistically significant explanatory variable, whereas effort, or total minutes spent online, is not. Other independent variables include GPA and the difference between a pre-test and a post-test. The GPA is used as a measure of motivation, and the difference between a post-test and pre-test as marginal learning. As expected, the level of motivation is found statistically significant at a 99% confidence level, and marginal learning is also significant at a 95% level.

  5. Consistent thermodynamic properties of lipids systems

    DEFF Research Database (Denmark)

    Cunico, Larissa; Ceriani, Roberta; Sarup, Bent

    different pressures, with azeotrope behavior observed. Available thermodynamic consistency tests for TPx data were applied before performing parameter regressions for Wilson, NRTL, UNIQUAC and original UNIFAC models. The relevance of enlarging experimental databank of lipids systems data in order to improve......Physical and thermodynamic properties of pure components and their mixtures are the basic requirement for process design, simulation, and optimization. In the case of lipids, our previous works[1-3] have indicated a lack of experimental data for pure components and also for their mixtures...... the performance of predictive thermodynamic models was confirmed in this work by analyzing the calculated values of original UNIFAC model. For solid-liquid equilibrium (SLE) data, new consistency tests have been developed [2]. Some of the developed tests were based in the quality tests proposed for VLE data...

  6. Consistency relation for cosmic magnetic fields

    DEFF Research Database (Denmark)

    Jain, R. K.; Sloth, M. S.

    2012-01-01

    If cosmic magnetic fields are indeed produced during inflation, they are likely to be correlated with the scalar metric perturbations that are responsible for the cosmic microwave background anisotropies and large scale structure. Within an archetypical model of inflationary magnetogenesis, we show...... that there exists a new simple consistency relation for the non-Gaussian cross correlation function of the scalar metric perturbation with two powers of the magnetic field in the squeezed limit where the momentum of the metric perturbation vanishes. We emphasize that such a consistency relation turns out...... to be extremely useful to test some recent calculations in the literature. Apart from primordial non-Gaussianity induced by the curvature perturbations, such a cross correlation might provide a new observational probe of inflation and can in principle reveal the primordial nature of cosmic magnetic fields. DOI...

  7. Internal Branding and Employee Brand Consistent Behaviours

    DEFF Research Database (Denmark)

    Mazzei, Alessandra; Ravazzani, Silvia

    2017-01-01

    constitutive processes. In particular, the paper places emphasis on the role and kinds of communication practices as a central part of the nonnormative and constitutive internal branding process. The paper also discusses an empirical study based on interviews with 32 Italian and American communication managers...... and 2 focus groups with Italian communication managers. Findings show that, in order to enhance employee brand consistent behaviours, the most effective communication practices are those characterised as enablement-oriented. Such a communication creates the organizational conditions adequate to sustain......Employee behaviours conveying brand values, named brand consistent behaviours, affect the overall brand evaluation. Internal branding literature highlights a knowledge gap in terms of communication practices intended to sustain such behaviours. This study contributes to the development of a non...

  8. Self-consistent velocity dependent effective interactions

    International Nuclear Information System (INIS)

    Kubo, Takayuki; Sakamoto, Hideo; Kammuri, Tetsuo; Kishimoto, Teruo.

    1993-09-01

    The field coupling method is extended to a system with a velocity dependent mean potential. By means of this method, we can derive the effective interactions which are consistent with the mean potential. The self-consistent velocity dependent effective interactions are applied to the microscopic analysis of the structures of giant dipole resonances (GDR) of 148,154 Sm, of the first excited 2 + states of Sn isotopes and of the first excited 3 - states of Mo isotopes. It is clarified that the interactions play crucial roles in describing the splitting of the resonant structure of GDR peaks, in restoring the energy weighted sum rule values, and in reducing B (Eλ) values. (author)

  9. Evaluating Temporal Consistency in Marine Biodiversity Hotspots

    OpenAIRE

    Piacenza, Susan E.; Thurman, Lindsey L.; Barner, Allison K.; Benkwitt, Cassandra E.; Boersma, Kate S.; Cerny-Chipman, Elizabeth B.; Ingeman, Kurt E.; Kindinger, Tye L.; Lindsley, Amy J.; Nelson, Jake; Reimer, Jessica N.; Rowe, Jennifer C.; Shen, Chenchen; Thompson, Kevin A.; Heppell, Selina S.

    2015-01-01

    With the ongoing crisis of biodiversity loss and limited resources for conservation, the concept of biodiversity hotspots has been useful in determining conservation priority areas. However, there has been limited research into how temporal variability in biodiversity may influence conservation area prioritization. To address this information gap, we present an approach to evaluate the temporal consistency of biodiversity hotspots in large marine ecosystems. Using a large scale, public monito...

  10. Cloud Standardization: Consistent Business Processes and Information

    Directory of Open Access Journals (Sweden)

    Razvan Daniel ZOTA

    2013-01-01

    Full Text Available Cloud computing represents one of the latest emerging trends in distributed computing that enables the existence of hardware infrastructure and software applications as services. The present paper offers a general approach to the cloud computing standardization as a mean of improving the speed of adoption for the cloud technologies. Moreover, this study tries to show out how organizations may achieve more consistent business processes while operating with cloud computing technologies.

  11. Consistency Analysis of Nearest Subspace Classifier

    OpenAIRE

    Wang, Yi

    2015-01-01

    The Nearest subspace classifier (NSS) finds an estimation of the underlying subspace within each class and assigns data points to the class that corresponds to its nearest subspace. This paper mainly studies how well NSS can be generalized to new samples. It is proved that NSS is strongly consistent under certain assumptions. For completeness, NSS is evaluated through experiments on various simulated and real data sets, in comparison with some other linear model based classifiers. It is also ...

  12. Consistency relations in effective field theory

    Energy Technology Data Exchange (ETDEWEB)

    Munshi, Dipak; Regan, Donough, E-mail: D.Munshi@sussex.ac.uk, E-mail: D.Regan@sussex.ac.uk [Astronomy Centre, School of Mathematical and Physical Sciences, University of Sussex, Brighton BN1 9QH (United Kingdom)

    2017-06-01

    The consistency relations in large scale structure relate the lower-order correlation functions with their higher-order counterparts. They are direct outcome of the underlying symmetries of a dynamical system and can be tested using data from future surveys such as Euclid. Using techniques from standard perturbation theory (SPT), previous studies of consistency relation have concentrated on continuity-momentum (Euler)-Poisson system of an ideal fluid. We investigate the consistency relations in effective field theory (EFT) which adjusts the SPT predictions to account for the departure from the ideal fluid description on small scales. We provide detailed results for the 3D density contrast δ as well as the scaled divergence of velocity θ-bar . Assuming a ΛCDM background cosmology, we find the correction to SPT results becomes important at k ∼> 0.05 h/Mpc and that the suppression from EFT to SPT results that scales as square of the wave number k , can reach 40% of the total at k ≈ 0.25 h/Mpc at z = 0. We have also investigated whether effective field theory corrections to models of primordial non-Gaussianity can alter the squeezed limit behaviour, finding the results to be rather insensitive to these counterterms. In addition, we present the EFT corrections to the squeezed limit of the bispectrum in redshift space which may be of interest for tests of theories of modified gravity.

  13. Consistent probabilities in loop quantum cosmology

    International Nuclear Information System (INIS)

    Craig, David A; Singh, Parampreet

    2013-01-01

    A fundamental issue for any quantum cosmological theory is to specify how probabilities can be assigned to various quantum events or sequences of events such as the occurrence of singularities or bounces. In previous work, we have demonstrated how this issue can be successfully addressed within the consistent histories approach to quantum theory for Wheeler–DeWitt-quantized cosmological models. In this work, we generalize that analysis to the exactly solvable loop quantization of a spatially flat, homogeneous and isotropic cosmology sourced with a massless, minimally coupled scalar field known as sLQC. We provide an explicit, rigorous and complete decoherent-histories formulation for this model and compute the probabilities for the occurrence of a quantum bounce versus a singularity. Using the scalar field as an emergent internal time, we show for generic states that the probability for a singularity to occur in this model is zero, and that of a bounce is unity, complementing earlier studies of the expectation values of the volume and matter density in this theory. We also show from the consistent histories point of view that all states in this model, whether quantum or classical, achieve arbitrarily large volume in the limit of infinite ‘past’ or ‘future’ scalar ‘time’, in the sense that the wave function evaluated at any arbitrary fixed value of the volume vanishes in that limit. Finally, we briefly discuss certain misconceptions concerning the utility of the consistent histories approach in these models. (paper)

  14. Orthology and paralogy constraints: satisfiability and consistency.

    Science.gov (United States)

    Lafond, Manuel; El-Mabrouk, Nadia

    2014-01-01

    A variety of methods based on sequence similarity, reconciliation, synteny or functional characteristics, can be used to infer orthology and paralogy relations between genes of a given gene family  G. But is a given set  C of orthology/paralogy constraints possible, i.e., can they simultaneously co-exist in an evolutionary history for  G? While previous studies have focused on full sets of constraints, here we consider the general case where  C does not necessarily involve a constraint for each pair of genes. The problem is subdivided in two parts: (1) Is  C satisfiable, i.e. can we find an event-labeled gene tree G inducing  C? (2) Is there such a G which is consistent, i.e., such that all displayed triplet phylogenies are included in a species tree? Previous results on the Graph sandwich problem can be used to answer to (1), and we provide polynomial-time algorithms for satisfiability and consistency with a given species tree. We also describe a new polynomial-time algorithm for the case of consistency with an unknown species tree and full knowledge of pairwise orthology/paralogy relationships, as well as a branch-and-bound algorithm in the case when unknown relations are present. We show that our algorithms can be used in combination with ProteinOrtho, a sequence similarity-based orthology detection tool, to extract a set of robust orthology/paralogy relationships.

  15. Consistency of color representation in smart phones.

    Science.gov (United States)

    Dain, Stephen J; Kwan, Benjamin; Wong, Leslie

    2016-03-01

    One of the barriers to the construction of consistent computer-based color vision tests has been the variety of monitors and computers. Consistency of color on a variety of screens has necessitated calibration of each setup individually. Color vision examination with a carefully controlled display has, as a consequence, been a laboratory rather than a clinical activity. Inevitably, smart phones have become a vehicle for color vision tests. They have the advantage that the processor and screen are associated and there are fewer models of smart phones than permutations of computers and monitors. Colorimetric consistency of display within a model may be a given. It may extend across models from the same manufacturer but is unlikely to extend between manufacturers especially where technologies vary. In this study, we measured the same set of colors in a JPEG file displayed on 11 samples of each of four models of smart phone (iPhone 4s, iPhone5, Samsung Galaxy S3, and Samsung Galaxy S4) using a Photo Research PR-730. The iPhones are white LED backlit LCD and the Samsung are OLEDs. The color gamut varies between models and comparison with sRGB space shows 61%, 85%, 117%, and 110%, respectively. The iPhones differ markedly from the Samsungs and from one another. This indicates that model-specific color lookup tables will be needed. Within each model, the primaries were quite consistent (despite the age of phone varying within each sample). The worst case in each model was the blue primary; the 95th percentile limits in the v' coordinate were ±0.008 for the iPhone 4 and ±0.004 for the other three models. The u'v' variation in white points was ±0.004 for the iPhone4 and ±0.002 for the others, although the spread of white points between models was u'v'±0.007. The differences are essentially the same for primaries at low luminance. The variation of colors intermediate between the primaries (e.g., red-purple, orange) mirror the variation in the primaries. The variation in

  16. Do Health Systems Have Consistent Performance Across Locations and Is Consistency Associated With Higher Performance?

    Science.gov (United States)

    Crespin, Daniel J; Christianson, Jon B; McCullough, Jeffrey S; Finch, Michael D

    This study addresses whether health systems have consistent diabetes care performance across their ambulatory clinics and whether increasing consistency is associated with improvements in clinic performance. Study data included 2007 to 2013 diabetes care intermediate outcome measures for 661 ambulatory clinics in Minnesota and bordering states. Health systems provided more consistent performance, as measured by the standard deviation of performance for clinics in a system, relative to propensity score-matched proxy systems created for comparison purposes. No evidence was found that improvements in consistency were associated with higher clinic performance. The combination of high performance and consistent care is likely to enhance a health system's brand reputation, allowing it to better mitigate the financial risks of consumers seeking care outside the organization. These results suggest that larger health systems are most likely to deliver the combination of consistent and high-performance care. Future research should explore the mechanisms that drive consistent care within health systems.

  17. Performance and consistency of indicator groups in two biodiversity hotspots.

    Directory of Open Access Journals (Sweden)

    Joaquim Trindade-Filho

    Full Text Available In a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities. Several studies have evaluated the effectiveness of indicator groups, but still little is known about the consistency in performance of these groups in different regions, which would allow their a priori selection.We systematically examined the effectiveness and the consistency of nine indicator groups in representing mammal species in two top-ranked Biodiversity Hotspots (BH: the Brazilian Cerrado and the Atlantic Forest. To test for group effectiveness we first found the best sets of sites able to maximize the representation of each indicator group in the BH and then calculated the average representation of different target species by the indicator groups in the BH. We considered consistent indicator groups whose representation of target species was not statistically different between BH. We called effective those groups that outperformed the target-species representation achieved by random sets of species. Effective indicator groups required the selection of less than 2% of the BH area for representing target species. Restricted-range species were the most effective indicators for the representation of all mammal diversity as well as target species. It was also the only group with high consistency.We show that several indicator groups could be applied as shortcuts for representing mammal species in the Cerrado and the Atlantic Forest to develop conservation plans, however, only restricted-range species consistently held as the most effective indicator group for such a task. This group is of particular importance in conservation planning as it captures high diversity of endemic and endangered species.

  18. Performance and consistency of indicator groups in two biodiversity hotspots.

    Science.gov (United States)

    Trindade-Filho, Joaquim; Loyola, Rafael Dias

    2011-01-01

    In a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities. Several studies have evaluated the effectiveness of indicator groups, but still little is known about the consistency in performance of these groups in different regions, which would allow their a priori selection. We systematically examined the effectiveness and the consistency of nine indicator groups in representing mammal species in two top-ranked Biodiversity Hotspots (BH): the Brazilian Cerrado and the Atlantic Forest. To test for group effectiveness we first found the best sets of sites able to maximize the representation of each indicator group in the BH and then calculated the average representation of different target species by the indicator groups in the BH. We considered consistent indicator groups whose representation of target species was not statistically different between BH. We called effective those groups that outperformed the target-species representation achieved by random sets of species. Effective indicator groups required the selection of less than 2% of the BH area for representing target species. Restricted-range species were the most effective indicators for the representation of all mammal diversity as well as target species. It was also the only group with high consistency. We show that several indicator groups could be applied as shortcuts for representing mammal species in the Cerrado and the Atlantic Forest to develop conservation plans, however, only restricted-range species consistently held as the most effective indicator group for such a task. This group is of particular importance in conservation planning as it captures high diversity of endemic and endangered species.

  19. Natural Selection and Origin of a Melanistic Allele in North American Gray Wolves.

    Science.gov (United States)

    Schweizer, Rena M; Durvasula, Arun; Smith, Joel; Vohr, Samuel H; Stahler, Daniel R; Galaverni, Marco; Thalmann, Olaf; Smith, Douglas W; Randi, Ettore; Ostrander, Elaine A; Green, Richard E; Lohmueller, Kirk E; Novembre, John; Wayne, Robert K

    2018-05-01

    Pigmentation is often used to understand how natural selection affects genetic variation in wild populations since it can have a simple genetic basis, and can affect a variety of fitness-related traits (e.g., camouflage, thermoregulation, and sexual display). In gray wolves, the K locus, a β-defensin gene, causes black coat color via a dominantly inherited KB allele. The allele is derived from dog-wolf hybridization and is at high frequency in North American wolf populations. We designed a DNA capture array to probe the geographic origin, age, and number of introgression events of the KB allele in a panel of 331 wolves and 20 dogs. We found low diversity in KB, but not ancestral ky, wolf haplotypes consistent with a selective sweep of the black haplotype across North America. Further, North American wolf KB haplotypes are monophyletic, suggesting that a single adaptive introgression from dogs to wolves most likely occurred in the Northwest Territories or Yukon. We use a new analytical approach to date the origin of the KB allele in Yukon wolves to between 1,598 and 7,248 years ago, suggesting that introgression with early Native American dogs was the source. Using population genetic simulations, we show that the K locus is undergoing natural selection in four wolf populations. We find evidence for balancing selection, specifically in Yellowstone wolves, which could be a result of selection for enhanced immunity in response to distemper. With these data, we demonstrate how the spread of an adaptive variant may have occurred across a species' geographic range.

  20. Consistency of variables in PCS and JASTRO great area database

    International Nuclear Information System (INIS)

    Nishino, Tomohiro; Teshima, Teruki; Abe, Mitsuyuki

    1998-01-01

    To examine whether the Patterns of Care Study (PCS) reflects the data for the major areas in Japan, the consistency of variables in the PCS and in the major area database of the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) were compared. Patients with esophageal or uterine cervical cancer were sampled from the PCS and JASTRO databases. From the JASTRO database, 147 patients with esophageal cancer and 95 patients with uterine cervical cancer were selected according to the eligibility criteria for the PCS. From the PCS, 455 esophageal and 432 uterine cervical cancer patients were surveyed. Six items for esophageal cancer and five items for uterine cervical cancer were selected for a comparative analysis of PCS and JASTRO databases. Esophageal cancer: Age (p=.0777), combination of radiation and surgery (p=.2136), and energy of the external beam (p=.6400) were consistent for PCS and JASTRO. However, the dose of the external beam for the non-surgery group showed inconsistency (p=.0467). Uterine cervical cancer: Age (p=.6301) and clinical stage (p=.8555) were consistent for the two sets of data. However, the energy of the external beam (p<.0001), dose rate of brachytherapy (p<.0001), and brachytherapy utilization by clinical stage (p<.0001) showed inconsistencies. It appears possible that the JASTRO major area database could not account for all patients' backgrounds and factors and that both surveys might have an imbalance in the stratification of institutions including differences in equipment and staffing patterns. (author)

  1. Evaluating Temporal Consistency in Marine Biodiversity Hotspots.

    Science.gov (United States)

    Piacenza, Susan E; Thurman, Lindsey L; Barner, Allison K; Benkwitt, Cassandra E; Boersma, Kate S; Cerny-Chipman, Elizabeth B; Ingeman, Kurt E; Kindinger, Tye L; Lindsley, Amy J; Nelson, Jake; Reimer, Jessica N; Rowe, Jennifer C; Shen, Chenchen; Thompson, Kevin A; Heppell, Selina S

    2015-01-01

    With the ongoing crisis of biodiversity loss and limited resources for conservation, the concept of biodiversity hotspots has been useful in determining conservation priority areas. However, there has been limited research into how temporal variability in biodiversity may influence conservation area prioritization. To address this information gap, we present an approach to evaluate the temporal consistency of biodiversity hotspots in large marine ecosystems. Using a large scale, public monitoring dataset collected over an eight year period off the US Pacific Coast, we developed a methodological approach for avoiding biases associated with hotspot delineation. We aggregated benthic fish species data from research trawls and calculated mean hotspot thresholds for fish species richness and Shannon's diversity indices over the eight year dataset. We used a spatial frequency distribution method to assign hotspot designations to the grid cells annually. We found no areas containing consistently high biodiversity through the entire study period based on the mean thresholds, and no grid cell was designated as a hotspot for greater than 50% of the time-series. To test if our approach was sensitive to sampling effort and the geographic extent of the survey, we followed a similar routine for the northern region of the survey area. Our finding of low consistency in benthic fish biodiversity hotspots over time was upheld, regardless of biodiversity metric used, whether thresholds were calculated per year or across all years, or the spatial extent for which we calculated thresholds and identified hotspots. Our results suggest that static measures of benthic fish biodiversity off the US West Coast are insufficient for identification of hotspots and that long-term data are required to appropriately identify patterns of high temporal variability in biodiversity for these highly mobile taxa. Given that ecological communities are responding to a changing climate and other

  2. Self-consistent gravitational self-force

    International Nuclear Information System (INIS)

    Pound, Adam

    2010-01-01

    I review the problem of motion for small bodies in general relativity, with an emphasis on developing a self-consistent treatment of the gravitational self-force. An analysis of the various derivations extant in the literature leads me to formulate an asymptotic expansion in which the metric is expanded while a representative worldline is held fixed. I discuss the utility of this expansion for both exact point particles and asymptotically small bodies, contrasting it with a regular expansion in which both the metric and the worldline are expanded. Based on these preliminary analyses, I present a general method of deriving self-consistent equations of motion for arbitrarily structured (sufficiently compact) small bodies. My method utilizes two expansions: an inner expansion that keeps the size of the body fixed, and an outer expansion that lets the body shrink while holding its worldline fixed. By imposing the Lorenz gauge, I express the global solution to the Einstein equation in the outer expansion in terms of an integral over a worldtube of small radius surrounding the body. Appropriate boundary data on the tube are determined from a local-in-space expansion in a buffer region where both the inner and outer expansions are valid. This buffer-region expansion also results in an expression for the self-force in terms of irreducible pieces of the metric perturbation on the worldline. Based on the global solution, these pieces of the perturbation can be written in terms of a tail integral over the body's past history. This approach can be applied at any order to obtain a self-consistent approximation that is valid on long time scales, both near and far from the small body. I conclude by discussing possible extensions of my method and comparing it to alternative approaches.

  3. Quantum consistency of open string theories

    International Nuclear Information System (INIS)

    Govaerts, J.

    1989-01-01

    We discuss how Virasoro anomalies in open string theories uniquely select the gauge group SO(2 D/2 ) independently of any regularisation, although the cancellation of these anomalies does not occur in tachyonic theories, and regulators can always be chosen to make these theories (one-loop) finite for any SO(n) and USp(n) gauge group. The discussion is mainly restricted to open bosonic strings. These results open new perspectives for the recent suggestion made by Sagnotti, the generalisations of which allow for the construction of new open string theories in less than ten dimensions. (orig.)

  4. Influence of hydrogen addition to a sweep gas on tritium behavior in a blanket module containing Li{sub 2}TiO{sub 3} pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, K., E-mail: kadzu@nucl.kyushu-u.ac.jp [Department of Advanced Energy Engineering Science, Kyushu University 6-1, Kasugakoen, Kasuga-shi, Fukuoka 816-8580 (Japan); Someya, Y.; Tobita, K. [National Institutes for Quantum and radiological Science and Technology, 2-166 Omotedate, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Fukada, S. [Department of Advanced Energy Engineering Science, Kyushu University 6-1, Kasugakoen, Kasuga-shi, Fukuoka 816-8580 (Japan); Hatano, Y. [Hydrogen Isotope Research Center, University of Toyama, Gofuku 3190, Toyama 930-8555 (Japan); Chikada, T. [Department of Chemistry, Graduate school of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529 (Japan)

    2016-12-15

    Highlights: • Mass balance equations of H{sub 2}, H{sub 2}O, T{sub 2} and T{sub 2}O in a Li{sub 2}TiO{sub 3} pebble bed were numerically calculated. • In the temperature rising process, the pebbles were exposed to water vapor of relatively high concentration. • Tritium permeation rate to cooling water reduced with increasing hydrogen concentration in the sweep gas. • Tritium inventory in the grain bulk and the grain surface occupied 99.6% of total inventory. - Abstract: Hydrogen addition to a sweep gas of a solid breeder blanket module has been proposed to enhance tritium recovery from the surface of the breeders. However, the influence of hydrogen addition on the bred tritium behavior is not understood completely. Tritium behavior in the simplified blanket module of Li{sub 2}TiO{sub 3} pebbles was numerically calculated considering diffusion in the grain bulk, surface reactions on the grain surface and permeation through the cooling pipe. Although a partial pressure of T{sub 2} increases with increasing a partial pressure of H{sub 2} in the sweep gas, it was estimated that tritium permeation rate to the cooling water decreases. Additionally, the release duration of water vapor generated by the reaction of the pebbles and hydrogen is shortened with increasing a partial pressure of H{sub 2}. Tritium inventory in the grain bulk and the grain surface occupies 99.6 % of total tritium inventory in the blanket module.

  5. Consistency Checking of Web Service Contracts

    DEFF Research Database (Denmark)

    Cambronero, M. Emilia; Okika, Joseph C.; Ravn, Anders Peter

    2008-01-01

    Behavioural properties are analyzed for web service contracts formulated in Business Process Execution Language (BPEL) and Choreography Description Language (CDL). The key result reported is an automated technique to check consistency between protocol aspects of the contracts. The contracts...... are abstracted to (timed) automata and from there a simulation is set up, which is checked using automated tools for analyzing networks of finite state processes. Here we use the Concurrency Work Bench. The proposed techniques are illustrated with a case study that include otherwise difficult to analyze fault...

  6. Gentzen's centenary the quest for consistency

    CERN Document Server

    Rathjen, Michael

    2015-01-01

    Gerhard Gentzen has been described as logic’s lost genius, whom Gödel called a better logician than himself. This work comprises articles by leading proof theorists, attesting to Gentzen’s enduring legacy to mathematical logic and beyond. The contributions range from philosophical reflections and re-evaluations of Gentzen’s original consistency proofs to the most recent developments in proof theory. Gentzen founded modern proof theory. His sequent calculus and natural deduction system beautifully explain the deep symmetries of logic. They underlie modern developments in computer science such as automated theorem proving and type theory.

  7. Two consistent calculations of the Weinberg angle

    International Nuclear Information System (INIS)

    Fairlie, D.B.

    1979-01-01

    The Weinberg-Salam theory is reformulated as a pure Yang-Mills theory in a six-dimensional space, the Higgs field being interpreted as gauge potentials in the additional dimensions. Viewed in this way, the condition that the Higgs field transforms as a U(1) representation of charge one is equivalent to requiring a value of 30 0 C for the Weinberg angle. A second consistent determination comes from the idea borrowed from monopole theory that the electromagnetic field is in the direction of the Higgs field. (Author)

  8. Consistent resolution of some relativistic quantum paradoxes

    International Nuclear Information System (INIS)

    Griffiths, Robert B.

    2002-01-01

    A relativistic version of the (consistent or decoherent) histories approach to quantum theory is developed on the basis of earlier work by Hartle, and used to discuss relativistic forms of the paradoxes of spherical wave packet collapse, Bohm's formulation of the Einstein-Podolsky-Rosen paradox, and Hardy's paradox. It is argued that wave function collapse is not needed for introducing probabilities into relativistic quantum mechanics, and in any case should never be thought of as a physical process. Alternative approaches to stochastic time dependence can be used to construct a physical picture of the measurement process that is less misleading than collapse models. In particular, one can employ a coarse-grained but fully quantum-mechanical description in which particles move along trajectories, with behavior under Lorentz transformations the same as in classical relativistic physics, and detectors are triggered by particles reaching them along such trajectories. States entangled between spacelike separate regions are also legitimate quantum descriptions, and can be consistently handled by the formalism presented here. The paradoxes in question arise because of using modes of reasoning which, while correct for classical physics, are inconsistent with the mathematical structure of quantum theory, and are resolved (or tamed) by using a proper quantum analysis. In particular, there is no need to invoke, nor any evidence for, mysterious long-range superluminal influences, and thus no incompatibility, at least from this source, between relativity theory and quantum mechanics

  9. Self-consistent model of confinement

    International Nuclear Information System (INIS)

    Swift, A.R.

    1988-01-01

    A model of the large-spatial-distance, zero--three-momentum, limit of QCD is developed from the hypothesis that there is an infrared singularity. Single quarks and gluons do not propagate because they have infinite energy after renormalization. The Hamiltonian formulation of the path integral is used to quantize QCD with physical, nonpropagating fields. Perturbation theory in the infrared limit is simplified by the absence of self-energy insertions and by the suppression of large classes of diagrams due to vanishing propagators. Remaining terms in the perturbation series are resummed to produce a set of nonlinear, renormalizable integral equations which fix both the confining interaction and the physical propagators. Solutions demonstrate the self-consistency of the concepts of an infrared singularity and nonpropagating fields. The Wilson loop is calculated to provide a general proof of confinement. Bethe-Salpeter equations for quark-antiquark pairs and for two gluons have finite-energy solutions in the color-singlet channel. The choice of gauge is addressed in detail. Large classes of corrections to the model are discussed and shown to support self-consistency

  10. Subgame consistent cooperation a comprehensive treatise

    CERN Document Server

    Yeung, David W K

    2016-01-01

    Strategic behavior in the human and social world has been increasingly recognized in theory and practice. It is well known that non-cooperative behavior could lead to suboptimal or even highly undesirable outcomes. Cooperation suggests the possibility of obtaining socially optimal solutions and the calls for cooperation are prevalent in real-life problems. Dynamic cooperation cannot be sustainable if there is no guarantee that the agreed upon optimality principle at the beginning is maintained throughout the cooperation duration. It is due to the lack of this kind of guarantees that cooperative schemes fail to last till its end or even fail to get started. The property of subgame consistency in cooperative dynamic games and the corresponding solution mechanism resolve this “classic” problem in game theory. This book is a comprehensive treatise on subgame consistent dynamic cooperation covering the up-to-date state of the art analyses in this important topic. It sets out to provide the theory, solution tec...

  11. Sludge characterization: the role of physical consistency

    Energy Technology Data Exchange (ETDEWEB)

    Spinosa, Ludovico; Wichmann, Knut

    2003-07-01

    The physical consistency is an important parameter in sewage sludge characterization as it strongly affects almost all treatment, utilization and disposal operations. In addition, in many european Directives a reference to the physical consistency is reported as a characteristic to be evaluated for fulfilling the regulations requirements. Further, in many analytical methods for sludge different procedures are indicated depending on whether a sample is liquid or not, is solid or not. Three physical behaviours (liquid, paste-like and solid) can be observed with sludges, so the development of analytical procedures to define the boundary limit between liquid and paste-like behaviours (flowability) and that between solid and paste-like ones (solidity) is of growing interest. Several devices can be used for evaluating the flowability and solidity properties, but often they are costly and difficult to be operated in the field. Tests have been carried out to evaluate the possibility to adopt a simple extrusion procedure for flowability measurements, and a Vicat needle for solidity ones. (author)

  12. Consistent mutational paths predict eukaryotic thermostability

    Directory of Open Access Journals (Sweden)

    van Noort Vera

    2013-01-01

    Full Text Available Abstract Background Proteomes of thermophilic prokaryotes have been instrumental in structural biology and successfully exploited in biotechnology, however many proteins required for eukaryotic cell function are absent from bacteria or archaea. With Chaetomium thermophilum, Thielavia terrestris and Thielavia heterothallica three genome sequences of thermophilic eukaryotes have been published. Results Studying the genomes and proteomes of these thermophilic fungi, we found common strategies of thermal adaptation across the different kingdoms of Life, including amino acid biases and a reduced genome size. A phylogenetics-guided comparison of thermophilic proteomes with those of other, mesophilic Sordariomycetes revealed consistent amino acid substitutions associated to thermophily that were also present in an independent lineage of thermophilic fungi. The most consistent pattern is the substitution of lysine by arginine, which we could find in almost all lineages but has not been extensively used in protein stability engineering. By exploiting mutational paths towards the thermophiles, we could predict particular amino acid residues in individual proteins that contribute to thermostability and validated some of them experimentally. By determining the three-dimensional structure of an exemplar protein from C. thermophilum (Arx1, we could also characterise the molecular consequences of some of these mutations. Conclusions The comparative analysis of these three genomes not only enhances our understanding of the evolution of thermophily, but also provides new ways to engineer protein stability.

  13. Consistency of extreme flood estimation approaches

    Science.gov (United States)

    Felder, Guido; Paquet, Emmanuel; Penot, David; Zischg, Andreas; Weingartner, Rolf

    2017-04-01

    Estimations of low-probability flood events are frequently used for the planning of infrastructure as well as for determining the dimensions of flood protection measures. There are several well-established methodical procedures to estimate low-probability floods. However, a global assessment of the consistency of these methods is difficult to achieve, the "true value" of an extreme flood being not observable. Anyway, a detailed comparison performed on a given case study brings useful information about the statistical and hydrological processes involved in different methods. In this study, the following three different approaches for estimating low-probability floods are compared: a purely statistical approach (ordinary extreme value statistics), a statistical approach based on stochastic rainfall-runoff simulation (SCHADEX method), and a deterministic approach (physically based PMF estimation). These methods are tested for two different Swiss catchments. The results and some intermediate variables are used for assessing potential strengths and weaknesses of each method, as well as for evaluating the consistency of these methods.

  14. Consistent biokinetic models for the actinide elements

    International Nuclear Information System (INIS)

    Leggett, R.W.

    2001-01-01

    The biokinetic models for Th, Np, Pu, Am and Cm currently recommended by the International Commission on Radiological Protection (ICRP) were developed within a generic framework that depicts gradual burial of skeletal activity in bone volume, depicts recycling of activity released to blood and links excretion to retention and translocation of activity. For other actinide elements such as Ac, Pa, Bk, Cf and Es, the ICRP still uses simplistic retention models that assign all skeletal activity to bone surface and depicts one-directional flow of activity from blood to long-term depositories to excreta. This mixture of updated and older models in ICRP documents has led to inconsistencies in dose estimates and interpretation of bioassay for radionuclides with reasonably similar biokinetics. This paper proposes new biokinetic models for Ac, Pa, Bk, Cf and Es that are consistent with the updated models for Th, Np, Pu, Am and Cm. The proposed models are developed within the ICRP's generic model framework for bone-surface-seeking radionuclides, and an effort has been made to develop parameter values that are consistent with results of comparative biokinetic data on the different actinide elements. (author)

  15. Consistency of canonical formulation of Horava gravity

    International Nuclear Information System (INIS)

    Soo, Chopin

    2011-01-01

    Both the non-projectable and projectable version of Horava gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian constraint, thus allowing for an extra graviton mode which can be problematic. A new formulation (based on arXiv:1007.1563) of Horava gravity which is naturally realized as a representation of the master constraint algebra (instead of the Dirac algebra) studied by loop quantum gravity researchers is presented. This formulation yields a consistent canonical theory with first class constraints; and captures the essence of Horava gravity in retaining only spatial diffeomorphisms as the physically relevant non-trivial gauge symmetry. At the same time the local Hamiltonian constraint is equivalently enforced by the master constraint.

  16. Consistency of canonical formulation of Horava gravity

    Energy Technology Data Exchange (ETDEWEB)

    Soo, Chopin, E-mail: cpsoo@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan, Taiwan (China)

    2011-09-22

    Both the non-projectable and projectable version of Horava gravity face serious challenges. In the non-projectable version, the constraint algebra is seemingly inconsistent. The projectable version lacks a local Hamiltonian constraint, thus allowing for an extra graviton mode which can be problematic. A new formulation (based on arXiv:1007.1563) of Horava gravity which is naturally realized as a representation of the master constraint algebra (instead of the Dirac algebra) studied by loop quantum gravity researchers is presented. This formulation yields a consistent canonical theory with first class constraints; and captures the essence of Horava gravity in retaining only spatial diffeomorphisms as the physically relevant non-trivial gauge symmetry. At the same time the local Hamiltonian constraint is equivalently enforced by the master constraint.

  17. Evaluating the hydrological consistency of evaporation products

    KAUST Repository

    Lopez Valencia, Oliver Miguel; Houborg, Rasmus; McCabe, Matthew

    2017-01-01

    Advances in space-based observations have provided the capacity to develop regional- to global-scale estimates of evaporation, offering insights into this key component of the hydrological cycle. However, the evaluation of large-scale evaporation retrievals is not a straightforward task. While a number of studies have intercompared a range of these evaporation products by examining the variance amongst them, or by comparison of pixel-scale retrievals against ground-based observations, there is a need to explore more appropriate techniques to comprehensively evaluate remote-sensing-based estimates. One possible approach is to establish the level of product agreement between related hydrological components: for instance, how well do evaporation patterns and response match with precipitation or water storage changes? To assess the suitability of this "consistency"-based approach for evaluating evaporation products, we focused our investigation on four globally distributed basins in arid and semi-arid environments, comprising the Colorado River basin, Niger River basin, Aral Sea basin, and Lake Eyre basin. In an effort to assess retrieval quality, three satellite-based global evaporation products based on different methodologies and input data, including CSIRO-PML, the MODIS Global Evapotranspiration product (MOD16), and Global Land Evaporation: the Amsterdam Methodology (GLEAM), were evaluated against rainfall data from the Global Precipitation Climatology Project (GPCP) along with Gravity Recovery and Climate Experiment (GRACE) water storage anomalies. To ensure a fair comparison, we evaluated consistency using a degree correlation approach after transforming both evaporation and precipitation data into spherical harmonics. Overall we found no persistent hydrological consistency in these dryland environments. Indeed, the degree correlation showed oscillating values between periods of low and high water storage changes, with a phase difference of about 2–3 months

  18. Self-consistent modelling of ICRH

    International Nuclear Information System (INIS)

    Hellsten, T.; Hedin, J.; Johnson, T.; Laxaaback, M.; Tennfors, E.

    2001-01-01

    The performance of ICRH is often sensitive to the shape of the high energy part of the distribution functions of the resonating species. This requires self-consistent calculations of the distribution functions and the wave-field. In addition to the wave-particle interactions and Coulomb collisions the effects of the finite orbit width and the RF-induced spatial transport are found to be important. The inward drift dominates in general even for a symmetric toroidal wave spectrum in the centre of the plasma. An inward drift does not necessarily produce a more peaked heating profile. On the contrary, for low concentrations of hydrogen minority in deuterium plasmas it can even give rise to broader profiles. (author)

  19. Non linear self consistency of microtearing modes

    International Nuclear Information System (INIS)

    Garbet, X.; Mourgues, F.; Samain, A.

    1987-01-01

    The self consistency of a microtearing turbulence is studied in non linear regimes where the ergodicity of the flux lines determines the electron response. The current which sustains the magnetic perturbation via the Ampere law results from the combines action of the radial electric field in the frame where the island chains are static and of the thermal electron diamagnetism. Numerical calculations show that at usual values of β pol in Tokamaks the turbulence can create a diffusion coefficient of order ν th p 2 i where p i is the ion larmor radius and ν th the electron ion collision frequency. On the other hand, collisionless regimes involving special profiles of each mode near the resonant surface seem possible

  20. Consistent evolution in a pedestrian flow

    Science.gov (United States)

    Guan, Junbiao; Wang, Kaihua

    2016-03-01

    In this paper, pedestrian evacuation considering different human behaviors is studied by using a cellular automaton (CA) model combined with the snowdrift game theory. The evacuees are divided into two types, i.e. cooperators and defectors, and two different human behaviors, herding behavior and independent behavior, are investigated. It is found from a large amount of numerical simulations that the ratios of the corresponding evacuee clusters are evolved to consistent states despite 11 typically different initial conditions, which may largely owe to self-organization effect. Moreover, an appropriate proportion of initial defectors who are of herding behavior, coupled with an appropriate proportion of initial defectors who are of rationally independent thinking, are two necessary factors for short evacuation time.

  1. Evaluating the hydrological consistency of evaporation products

    KAUST Repository

    Lopez Valencia, Oliver Miguel

    2017-01-18

    Advances in space-based observations have provided the capacity to develop regional- to global-scale estimates of evaporation, offering insights into this key component of the hydrological cycle. However, the evaluation of large-scale evaporation retrievals is not a straightforward task. While a number of studies have intercompared a range of these evaporation products by examining the variance amongst them, or by comparison of pixel-scale retrievals against ground-based observations, there is a need to explore more appropriate techniques to comprehensively evaluate remote-sensing-based estimates. One possible approach is to establish the level of product agreement between related hydrological components: for instance, how well do evaporation patterns and response match with precipitation or water storage changes? To assess the suitability of this "consistency"-based approach for evaluating evaporation products, we focused our investigation on four globally distributed basins in arid and semi-arid environments, comprising the Colorado River basin, Niger River basin, Aral Sea basin, and Lake Eyre basin. In an effort to assess retrieval quality, three satellite-based global evaporation products based on different methodologies and input data, including CSIRO-PML, the MODIS Global Evapotranspiration product (MOD16), and Global Land Evaporation: the Amsterdam Methodology (GLEAM), were evaluated against rainfall data from the Global Precipitation Climatology Project (GPCP) along with Gravity Recovery and Climate Experiment (GRACE) water storage anomalies. To ensure a fair comparison, we evaluated consistency using a degree correlation approach after transforming both evaporation and precipitation data into spherical harmonics. Overall we found no persistent hydrological consistency in these dryland environments. Indeed, the degree correlation showed oscillating values between periods of low and high water storage changes, with a phase difference of about 2–3 months

  2. Robust Visual Tracking Via Consistent Low-Rank Sparse Learning

    KAUST Repository

    Zhang, Tianzhu

    2014-06-19

    Object tracking is the process of determining the states of a target in consecutive video frames based on properties of motion and appearance consistency. In this paper, we propose a consistent low-rank sparse tracker (CLRST) that builds upon the particle filter framework for tracking. By exploiting temporal consistency, the proposed CLRST algorithm adaptively prunes and selects candidate particles. By using linear sparse combinations of dictionary templates, the proposed method learns the sparse representations of image regions corresponding to candidate particles jointly by exploiting the underlying low-rank constraints. In addition, the proposed CLRST algorithm is computationally attractive since temporal consistency property helps prune particles and the low-rank minimization problem for learning joint sparse representations can be efficiently solved by a sequence of closed form update operations. We evaluate the proposed CLRST algorithm against 14 state-of-the-art tracking methods on a set of 25 challenging image sequences. Experimental results show that the CLRST algorithm performs favorably against state-of-the-art tracking methods in terms of accuracy and execution time.

  3. Thermodynamically consistent model calibration in chemical kinetics

    Directory of Open Access Journals (Sweden)

    Goutsias John

    2011-05-01

    Full Text Available Abstract Background The dynamics of biochemical reaction systems are constrained by the fundamental laws of thermodynamics, which impose well-defined relationships among the reaction rate constants characterizing these systems. Constructing biochemical reaction systems from experimental observations often leads to parameter values that do not satisfy the necessary thermodynamic constraints. This can result in models that are not physically realizable and may lead to inaccurate, or even erroneous, descriptions of cellular function. Results We introduce a thermodynamically consistent model calibration (TCMC method that can be effectively used to provide thermodynamically feasible values for the parameters of an open biochemical reaction system. The proposed method formulates the model calibration problem as a constrained optimization problem that takes thermodynamic constraints (and, if desired, additional non-thermodynamic constraints into account. By calculating thermodynamically feasible values for the kinetic parameters of a well-known model of the EGF/ERK signaling cascade, we demonstrate the qualitative and quantitative significance of imposing thermodynamic constraints on these parameters and the effectiveness of our method for accomplishing this important task. MATLAB software, using the Systems Biology Toolbox 2.1, can be accessed from http://www.cis.jhu.edu/~goutsias/CSS lab/software.html. An SBML file containing the thermodynamically feasible EGF/ERK signaling cascade model can be found in the BioModels database. Conclusions TCMC is a simple and flexible method for obtaining physically plausible values for the kinetic parameters of open biochemical reaction systems. It can be effectively used to recalculate a thermodynamically consistent set of parameter values for existing thermodynamically infeasible biochemical reaction models of cellular function as well as to estimate thermodynamically feasible values for the parameters of new

  4. Magnetovoltage Measurements and Field Sweep Rate Dependence of V-H curves in Superconducting Polycrystalline Y1Ba2Cu3O7-x

    International Nuclear Information System (INIS)

    Yetis, H; Altinkok, A; Olutas, M; Kilic, A; Kilic, K; Cetin, O

    2006-01-01

    Magnetovoltage measurements (V-H curves) were carried out in superconducting polycrystalline bulk Y 1 Ba 2 Cu 3 O 7-x (YBCO) material as a function of current (I), temperature (T), field sweep rate (dH/dt) and field orientation with respect to the transport current. A relative decrease in the dissipation measured in V-H curves was observed as dH/dt is increased, which implies that the time spent to plot the whole cycle has an importance on the evolution of the V-H curves. Thus, it could be possible to observe the relaxation effects in magnetovoltage measurements. In addition, the several significant steps and plateaus in V-H curves evolve depending on the magnitude of the transport current and also dH/dt. These observations were attributed to locking of the flux lines to decrease or increase in size of the easy motion flow channels. The strong hysteresis effects in V-H curves were discussed mainly by means of the flux trapping within the granularity of sample and the different degree of the inhomogeneous flux motion with respect to the sweeping of the external magnetic field up and down

  5. Self-consistent field with pseudowavefunctions

    International Nuclear Information System (INIS)

    Szasz, L.

    1976-01-01

    A computational method is given in which the energy of an atom is computed by using pseudowavefunctions only. The method centers on a model energy expression E/sub M/ which is similar to the Hartree--Fock energy expression, but contains only pseudowavefunctions. A theorem is proved according to which the Hartree--Fock orbitals can be transformed by a linear transformation into a set of uniquely defined pseudowavefunctions which have the property that, when substituted into E/sub M/, this quantity will closely approximate the Hartree--Fock energy E/sub F/. The new method is then formulated by identifying the total energy of an atom with the minimum of E/sub M/. Application of the energy minimum principle leads to a set of equations for the pseudowavefunctions which are similar to but simpler than the Hartree--Fock equations. These equations contain pseudopotentials for which explicit expressions are derived. The possibility of replacing these pseudopotentials by simpler model potentials is discussed, and the criteria for the selection of the model potential are outlined

  6. Exploring the Consistent behavior of Information Services

    Directory of Open Access Journals (Sweden)

    Kapidakis Sarantos

    2016-01-01

    Full Text Available Computer services are normally assumed to work well all the time. This usually happens for crucial services like bank electronic services, but not necessarily so for others, that there is no commercial interest in their operation. In this work we examined the operation and the errors of information services and tried to find clues that will help predicting the consistency of the behavior and the quality of the harvesting, which is harder because of the transient conditions and the many services and the huge amount of harvested information. We found many unexpected situations. The services that always successfully satisfy a request may in fact return part of it. A significant part of the OAI services have ceased working while many other serves occasionally fail to respond. Some services fail in the same way each time, and we pronounce them dead, as we do not see a way to overcome that. Others also always, or sometimes fail, but not in the same way, and we hope that their behavior is affected by temporary factors, that may improve later on. We categorized the services into classes, to study their behavior in more detail.

  7. [Consistent Declarative Memory with Depressive Symptomatology].

    Science.gov (United States)

    Botelho de Oliveira, Silvia; Flórez, Ruth Natalia Suárez; Caballero, Diego Andrés Vásquez

    2012-12-01

    Some studies have suggested that potentiated remembrance of negative events on people with depressive disorders seems to be an important factor in the etiology, course and maintenance of depression. Evaluate the emotional memory in people with and without depressive symptomatology by means of an audio-visual test. 73 university students were evaluated, male and female, between 18 and 40 years old, distributed in two groups: with depressive symptomatology (32) and without depressive symptomatology (40), using the Scale from the Center of Epidemiologic Studies for Depression (CES-D, English Abbreviation) and a cutting point of 20. There were not meaningful differences between free and voluntary recalls, with and without depressive symptomatology, in spite of the fact that both groups had granted a higher emotional value to the audio-visual test and that they had associated it with emotional sadness. People with depressive symptomatology did not exhibit the effect of mnemonic potentiation generally associated to the content of the emotional version of the test; therefore, the hypothesis of emotional consistency was not validated. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  8. Self consistent field theory of virus assembly

    Science.gov (United States)

    Li, Siyu; Orland, Henri; Zandi, Roya

    2018-04-01

    The ground state dominance approximation (GSDA) has been extensively used to study the assembly of viral shells. In this work we employ the self-consistent field theory (SCFT) to investigate the adsorption of RNA onto positively charged spherical viral shells and examine the conditions when GSDA does not apply and SCFT has to be used to obtain a reliable solution. We find that there are two regimes in which GSDA does work. First, when the genomic RNA length is long enough compared to the capsid radius, and second, when the interaction between the genome and capsid is so strong that the genome is basically localized next to the wall. We find that for the case in which RNA is more or less distributed uniformly in the shell, regardless of the length of RNA, GSDA is not a good approximation. We observe that as the polymer-shell interaction becomes stronger, the energy gap between the ground state and first excited state increases and thus GSDA becomes a better approximation. We also present our results corresponding to the genome persistence length obtained through the tangent-tangent correlation length and show that it is zero in case of GSDA but is equal to the inverse of the energy gap when using SCFT.

  9. Consistency between GRUAN sondes, LBLRTM and IASI

    Directory of Open Access Journals (Sweden)

    X. Calbet

    2017-06-01

    Full Text Available Radiosonde soundings from the GCOS Reference Upper-Air Network (GRUAN data record are shown to be consistent with Infrared Atmospheric Sounding Instrument (IASI-measured radiances via LBLRTM (Line-By-Line Radiative Transfer Model in the part of the spectrum that is mostly affected by water vapour absorption in the upper troposphere (from 700 hPa up. This result is key for climate data records, since GRUAN, IASI and LBLRTM constitute reference measurements or a reference radiative transfer model in each of their fields. This is specially the case for night-time radiosonde measurements. Although the sample size is small (16 cases, daytime GRUAN radiosonde measurements seem to have a small dry bias of 2.5 % in absolute terms of relative humidity, located mainly in the upper troposphere, with respect to LBLRTM and IASI. Full metrological closure is not yet possible and will not be until collocation uncertainties are better characterized and a full uncertainty covariance matrix is clarified for GRUAN.

  10. Self-consistent nuclear energy systems

    International Nuclear Information System (INIS)

    Shimizu, A.; Fujiie, Y.

    1995-01-01

    A concept of self-consistent energy systems (SCNES) has been proposed as an ultimate goal of the nuclear energy system in the coming centuries. SCNES should realize a stable and unlimited energy supply without endangering the human race and the global environment. It is defined as a system that realizes at least the following four objectives simultaneously: (a) energy generation -attain high efficiency in the utilization of fission energy; (b) fuel production - secure inexhaustible energy source: breeding of fissile material with the breeding ratio greater than one and complete burning of transuranium through recycling; (c) burning of radionuclides - zero release of radionuclides from the system: complete burning of transuranium and elimination of radioactive fission products by neutron capture reactions through recycling; (d) system safety - achieve system safety both for the public and experts: eliminate criticality-related safety issues by using natural laws and simple logic. This paper describes the concept of SCNES and discusses the feasibility of the system. Both ''neutron balance'' and ''energbalance'' of the system are introduced as the necessary conditions to be satisfied at least by SCNES. Evaluations made so far indicate that both the neutron balance and the energy balance can be realized by fast reactors but not by thermal reactors. Concerning the system safety, two safety concepts: ''self controllability'' and ''self-terminability'' are introduced to eliminate the criticality-related safety issues in fast reactors. (author)

  11. Selection on plant male function genes identifies candidates for reproductive isolation of yellow monkeyflowers.

    Directory of Open Access Journals (Sweden)

    Jan E Aagaard

    Full Text Available Understanding the genetic basis of reproductive isolation promises insight into speciation and the origins of biological diversity. While progress has been made in identifying genes underlying barriers to reproduction that function after fertilization (post-zygotic isolation, we know much less about earlier acting pre-zygotic barriers. Of particular interest are barriers involved in mating and fertilization that can evolve extremely rapidly under sexual selection, suggesting they may play a prominent role in the initial stages of reproductive isolation. A significant challenge to the field of speciation genetics is developing new approaches for identification of candidate genes underlying these barriers, particularly among non-traditional model systems. We employ powerful proteomic and genomic strategies to study the genetic basis of conspecific pollen precedence, an important component of pre-zygotic reproductive isolation among yellow monkeyflowers (Mimulus spp. resulting from male pollen competition. We use isotopic labeling in combination with shotgun proteomics to identify more than 2,000 male function (pollen tube proteins within maternal reproductive structures (styles of M. guttatus flowers where pollen competition occurs. We then sequence array-captured pollen tube exomes from a large outcrossing population of M. guttatus, and identify those genes with evidence of selective sweeps or balancing selection consistent with their role in pollen competition. We also test for evidence of positive selection on these genes more broadly across yellow monkeyflowers, because a signal of adaptive divergence is a common feature of genes causing reproductive isolation. Together the molecular evolution studies identify 159 pollen tube proteins that are candidate genes for conspecific pollen precedence. Our work demonstrates how powerful proteomic and genomic tools can be readily adapted to non-traditional model systems, allowing for genome-wide screens

  12. View from Europe: stability, consistency or pragmatism

    International Nuclear Information System (INIS)

    Dunster, H.J.

    1988-01-01

    The last few years of this decade look like a period of reappraisal of radiation protection standards. The revised risk estimates from Japan will be available, and the United Nations Scientific Committee on the Effects of Atomic Radiation will be publishing new reports on biological topics. The International Commission on Radiological Protection (ICRP) has started a review of its basic recommendations, and the new specification for dose equivalent in radiation fields of the International Commission on Radiation Units and Measurements (ICRU) will be coming into use. All this is occurring at a time when some countries are still trying to catch up with committed dose equivalent and the recently recommended change in the value of the quality factor for neutrons. In Europe, the problems of adapting to new ICRP recommendations are considerable. The European Community, including 12 states and nine languages, takes ICRP recommendations as a basis and develops council directives that are binding on member states, which have then to arrange for their own regulatory changes. Any substantial adjustments could take 5 y or more to work through the system. Clearly, the regulatory preference is for stability. Equally clearly, trade unions and public interest groups favor a rapid response to scientific developments (provided that the change is downward). Organizations such as the ICRP have to balance their desire for internal consistency and intellectual purity against the practical problems of their clients in adjusting to change. This paper indicates some of the changes that might be necessary over the next few years and how, given a pragmatic approach, they might be accommodated in Europe without too much regulatory confusion

  13. The Consistency Between Clinical and Electrophysiological Diagnoses

    Directory of Open Access Journals (Sweden)

    Esra E. Okuyucu

    2009-09-01

    Full Text Available OBJECTIVE: The aim of this study was to provide information concerning the impact of electrophysiological tests in the clinical management and diagnosis of patients, and to evaluate the consistency between referring clinical diagnoses and electrophysiological diagnoses. METHODS: The study included 957 patients referred to the electroneuromyography (ENMG laboratory from different clinics with different clinical diagnoses in 2008. Demographic data, referring clinical diagnoses, the clinics where the requests wanted, and diagnoses after ENMG testing were recorded and statistically evaluated. RESULTS: In all, 957 patients [644 (67.3% female and 313 (32.7% male] were included in the study. Mean age of the patients was 45.40 ± 14.54 years. ENMG requests were made by different specialists; 578 (60.4% patients were referred by neurologists, 122 (12.8% by orthopedics, 140 (14.6% by neurosurgeons, and 117 (12.2% by physical treatment and rehabilitation departments. According to the results of ENMG testing, 513 (53.6% patients’ referrals were related to their referral diagnosis, whereas 397 (41.5% patients had normal ENMG test results, and 47 (4.9% patients had a diagnosis that differed from the referring diagnosis. Among the relation between the referral diagnosis and electrophysiological diagnosis according to the clinics where the requests were made, there was no statistical difference (p= 0.794, but there were statistically significant differences between the support of different clinical diagnoses, such as carpal tunnel syndrome, polyneuropathy, radiculopathy-plexopathy, entrapment neuropathy, and myopathy based on ENMG test results (p< 0.001. CONCLUSION: ENMG is a frequently used neurological examination. As such, referrals for ENMG can be made to either support the referring diagnosis or to exclude other diagnoses. This may explain the inconsistency between clinical referring diagnoses and diagnoses following ENMG

  14. Self-consistent meson mass spectrum

    International Nuclear Information System (INIS)

    Balazs, L.A.P.

    1982-01-01

    A dual-topological-unitarization (or dual-fragmentation) approach to the calculation of hadron masses is presented, in which the effect of planar ''sea''-quark loops is taken into account from the beginning. Using techniques based on analyticity and generalized ladder-graph dynamics, we first derive the approximate ''generic'' Regge-trajectory formula α(t) = max (S 1 +S 2 , S 3 +S 4 )-(1/2) +2alpha-circumflex'[s/sub a/ +(1/2)(t-summationm/sub i/ 2 )] for any given hadronic process 1+2→3+4, where S/sub i/ and m/sub i/ are the spins and masses of i = 1,2,3,4, and √s/sub a/ is the effective mass of the lowest nonvanishing contribution (a) exchanged in the crossed channel. By requiring a minimization of secondary (background, etc.) contributions to a, and demanding simultaneous consistency for entire sets of such processes, we are then able to calculate the masses of all the lowest pseudoscalar and vector qq-bar states with q = u,d,s and the Regge trajectories on which they lie. By making certain additional assumptions we are also able to do this with q = u,d,c and q = u,d,b. Our only arbitrary parameters are m/sub rho/, m/sub K/*, m/sub psi/, and m/sub Upsilon/, one of which merely serves to fix the energy scale. In contrast to many other approaches, a small m/sub π/ 2 /m/sub rho/ 2 ratio arises quite naturally in the present scheme

  15. The study of consistent properties of gelatinous shampoo with minoxidil

    Directory of Open Access Journals (Sweden)

    I. V. Gnitko

    2016-04-01

    Full Text Available The aim of the work is the study of consistent properties of gelatinous shampoo with minoxidil 1% for the complex therapy and prevention of alopecia. This shampoo with minoxidil was selected according to the complex physical-chemical, biopharmaceutical and microbiological investigations. Methods and results. It has been established that consistent properties of the gelatinous minoxidil 1% shampoo and the «mechanical stability» (1.70 describe the formulation as exceptionally thixotropic composition with possibility of restoration after mechanical loads. Also this fact allows to predict stability of the consistent properties during long storage. Conclusion. Factors of dynamic flowing for the foam detergent gel with minoxidil (Кd1=38.9%; Kd2=78.06% quantitatively confirm sufficient degree of distribution at the time of spreading composition on the skin surface of the hairy part of head or during technological operations of manufacturing. Insignificant difference of «mechanical stability» for the gelatinous minoxidil 1% shampoo and its base indicates the absence of interactions between active substance and the base.

  16. A genome-wide scan for signatures of directional selection in domesticated pigs.

    Science.gov (United States)

    Moon, Sunjin; Kim, Tae-Hun; Lee, Kyung-Tai; Kwak, Woori; Lee, Taeheon; Lee, Si-Woo; Kim, Myung-Jick; Cho, Kyuho; Kim, Namshin; Chung, Won-Hyong; Sung, Samsun; Park, Taesung; Cho, Seoae; Groenen, Martien Am; Nielsen, Rasmus; Kim, Yuseob; Kim, Heebal

    2015-02-25

    Animal domestication involved drastic phenotypic changes driven by strong artificial selection and also resulted in new populations of breeds, established by humans. This study aims to identify genes that show evidence of recent artificial selection during pig domestication. Whole-genome resequencing of 30 individual pigs from domesticated breeds, Landrace and Yorkshire, and 10 Asian wild boars at ~16-fold coverage was performed resulting in over 4.3 million SNPs for 19,990 genes. We constructed a comprehensive genome map of directional selection by detecting selective sweeps using an F ST-based approach that detects directional selection in lineages leading to the domesticated breeds and using a haplotype-based test that detects ongoing selective sweeps within the breeds. We show that candidate genes under selection are significantly enriched for loci implicated in quantitative traits important to pig reproduction and production. The candidate gene with the strongest signals of directional selection belongs to group III of the metabolomics glutamate receptors, known to affect brain functions associated with eating behavior, suggesting that loci under strong selection include loci involved in behaviorial traits in domesticated pigs including tameness. We show that a significant proportion of selection signatures coincide with loci that were previously inferred to affect phenotypic variation in pigs. We further identify functional enrichment related to behavior, such as signal transduction and neuronal activities, for those targets of selection during domestication in pigs.

  17. Engasgamento em bebês após busca às cegas com os dedos Infants choking following blind finger sweep

    Directory of Open Access Journals (Sweden)

    Hasan A. Abder-Rahman

    2009-06-01

    Full Text Available OBJETIVO: Em situações estressantes, as pessoas geralmente usam os dedos para retirar corpos estranhos de faringe da boca. Este artigo relata três casos de óbito de bebês após o uso dessa técnica. MÉTODOS: Um total de 26 casos de engasgamento causado por aspiração de corpos estranhos nas vias respiratórias superiores e inferiores envolvendo crianças menores de 11 anos submetidas a autopsia no Departamento de Medicina Forense da Universidade da Jordânia entre 1996 e 2006 foram revisados. RESULTADOS: O uso de busca às cegas com os dedos para retirar corpos estranhos de faringe foi relatado em três bebês durante o choro. Todas as crianças eram menores de 1 ano e haviam se engasgado com grãos-de-bico, uma bola de gude e um lápis curto. A diversidade, o tamanho, a forma, e a maciez da superfície são as principais características que fazem com que esses corpos estranhos sejam mais difíceis de ser removidos com os dedos e facilitam sua entrada via respiratória. CONCLUSÃO: Esses casos mostraram que a busca às cegas com os dedos na boca de bebês durante o choro não é somente uma manobra perigosa, mas também pode ser fatal.OBJECTIVE: In stressful situations, people usually use finger sweep to remove pharyngeal foreign bodies from the mouth. This article reports on three cases of death of infants following the use of this technique. METHODS: A total of 26 cases of choking caused by foreign bodies aspiration in the upper and lower respiratory passages involving children younger than 11 years of age autopsied at the Forensic Department of University of Jordânia between 1996 and 2006 were reviewed. RESULTS: Blind finger sweep to remove pharyngeal foreign bodies were reported in three crying infants. All of these cases were younger than 1 year of age and choked on a chickpea, a marble and a short pencil. Diversity, size, shape and smoothness of the surface are the main characteristics that render the foreign bodies less easily

  18. Strong signatures of selection in the domestic pig genome

    DEFF Research Database (Denmark)

    Rubin, Carl-Johan; Megens, Hendrik-Jan; Barrio, Alvaro Martinez

    2012-01-01

    Domestication of wild boar (Sus scrofa) and subsequent selection have resulted in dramatic phenotypic changes in domestic pigs for a number of traits, including behavior, body composition, reproduction, and coat color. Here we have used whole-genome resequencing to reveal some of the loci that un...... to strong directional selection.......Domestication of wild boar (Sus scrofa) and subsequent selection have resulted in dramatic phenotypic changes in domestic pigs for a number of traits, including behavior, body composition, reproduction, and coat color. Here we have used whole-genome resequencing to reveal some of the loci...... that underlie phenotypic evolution in European domestic pigs. Selective sweep analyses revealed strong signatures of selection at three loci harboring quantitative trait loci that explain a considerable part of one of the most characteristic morphological changes in the domestic pig—the elongation of the back...

  19. Consistency in long-distance bird migration: contrasting patterns in time and space for two raptors

    NARCIS (Netherlands)

    Vardanis, Yannis; Nilsson, Jan-Ake; Klaassen, Raymond H. G.; Strandberg, Roine; Alerstam, Thomas

    As the evolutionary responses to environmental change depend on selection acting on individual differences, disentangling within- and between-individual variation becomes imperative. In animal migration research, multiyear tracks are thus needed to estimate the individual consistency of phenotypic

  20. Tracing the origins and signatures of selection of antifolate resistance in island populations of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Pinto João

    2010-06-01

    Full Text Available Abstract Background Resistance of the malaria parasite Plasmodium falciparum to sulfadoxine-pyrimethamine (SP has evolved worldwide. In the archipelago of São Tomé and Principe (STP, West Africa, although SP resistance is highly prevalent the drug is still in use in particular circumstances. To address the evolutionary origins of SP resistance in these islands, we genotyped point mutations at P. falciparum dhfr and dhps genes and analysed microsatellites flanking those genes. Methods Blood samples were collected in July and December 2004 in three localities of São Tomé Island and one in Principe Island. Species-specific nested-PCR was used to identify P. falciparum infected samples. Subsequently, SNPs at the dhfr and dhps genes were identified through PCR-RFLP. Isolates were also analysed for three microsatellite loci flanking the dhfr gene, three loci flanking dhps and four loci located at putative neutral genomic regions. Results An increase of resistance-associated mutations at dhfr and dhps was observed, in particular for the dhfr/dhps quintuple mutant, associated with clinical SP failure. Analysis of flanking microsatellites suggests multiple independent introductions for dhfr and dhps mutant haplotypes, possibly from West Africa. A reduced genetic diversity and increased differentiation at flanking microsatellites when compared to neutral loci is consistent with a selective sweep for resistant alleles at both loci. Conclusions This study provides additional evidence for the crucial role of gene flow and drug selective pressures in the rapid spread of SP resistance in P. falciparum populations, from only a few mutation events giving rise to resistance-associated mutants. It also highlights the importance of human migration in the spread of drug resistant malaria parasites, as the distance between the islands and mainland is not consistent with mosquito-mediated parasite dispersal.

  1. Sweeping the floor or putting a man on the moon : How to define and measure meaningful work

    NARCIS (Netherlands)

    Both-Nwabuwe, Jitske M.C.; Dijkstra, Maria T.M.; Beersma, Bianca

    2017-01-01

    Meaningful work is integral to well-being and a flourishing life. The construct of "meaningful work" is, however, consistently affected by conceptual ambiguity. Although there is substantial support for arguments to maintain the status of conceptual ambiguity, we make a case for the benefits of

  2. A Genomic Map of the Effects of Linked Selection in Drosophila.

    Directory of Open Access Journals (Sweden)

    Eyal Elyashiv

    2016-08-01

    Full Text Available Natural selection at one site shapes patterns of genetic variation at linked sites. Quantifying the effects of "linked selection" on levels of genetic diversity is key to making reliable inference about demography, building a null model in scans for targets of adaptation, and learning about the dynamics of natural selection. Here, we introduce the first method that jointly infers parameters of distinct modes of linked selection, notably background selection and selective sweeps, from genome-wide diversity data, functional annotations and genetic maps. The central idea is to calculate the probability that a neutral site is polymorphic given local annotations, substitution patterns, and recombination rates. Information is then combined across sites and samples using composite likelihood in order to estimate genome-wide parameters of distinct modes of selection. In addition to parameter estimation, this approach yields a map of the expected neutral diversity levels along the genome. To illustrate the utility of our approach, we apply it to genome-wide resequencing data from 125 lines in Drosophila melanogaster and reliably predict diversity levels at the 1Mb scale. Our results corroborate estimates of a high fraction of beneficial substitutions in proteins and untranslated regions (UTR. They allow us to distinguish between the contribution of sweeps and other modes of selection around amino acid substitutions and to uncover evidence for pervasive sweeps in untranslated regions (UTRs. Our inference further suggests a substantial effect of other modes of linked selection and of adaptation in particular. More generally, we demonstrate that linked selection has had a larger effect in reducing diversity levels and increasing their variance in D. melanogaster than previously appreciated.

  3. A Genomic Map of the Effects of Linked Selection in Drosophila.

    Science.gov (United States)

    Elyashiv, Eyal; Sattath, Shmuel; Hu, Tina T; Strutsovsky, Alon; McVicker, Graham; Andolfatto, Peter; Coop, Graham; Sella, Guy

    2016-08-01

    Natural selection at one site shapes patterns of genetic variation at linked sites. Quantifying the effects of "linked selection" on levels of genetic diversity is key to making reliable inference about demography, building a null model in scans for targets of adaptation, and learning about the dynamics of natural selection. Here, we introduce the first method that jointly infers parameters of distinct modes of linked selection, notably background selection and selective sweeps, from genome-wide diversity data, functional annotations and genetic maps. The central idea is to calculate the probability that a neutral site is polymorphic given local annotations, substitution patterns, and recombination rates. Information is then combined across sites and samples using composite likelihood in order to estimate genome-wide parameters of distinct modes of selection. In addition to parameter estimation, this approach yields a map of the expected neutral diversity levels along the genome. To illustrate the utility of our approach, we apply it to genome-wide resequencing data from 125 lines in Drosophila melanogaster and reliably predict diversity levels at the 1Mb scale. Our results corroborate estimates of a high fraction of beneficial substitutions in proteins and untranslated regions (UTR). They allow us to distinguish between the contribution of sweeps and other modes of selection around amino acid substitutions and to uncover evidence for pervasive sweeps in untranslated regions (UTRs). Our inference further suggests a substantial effect of other modes of linked selection and of adaptation in particular. More generally, we demonstrate that linked selection has had a larger effect in reducing diversity levels and increasing their variance in D. melanogaster than previously appreciated.

  4. Time-Consistent and Market-Consistent Evaluations (Revised version of 2012-086)

    NARCIS (Netherlands)

    Stadje, M.A.; Pelsser, A.

    2014-01-01

    Abstract: We consider evaluation methods for payoffs with an inherent financial risk as encountered for instance for portfolios held by pension funds and insurance companies. Pricing such payoffs in a way consistent to market prices typically involves combining actuarial techniques with methods from

  5. On-line identification of lysergic acid diethylamide (LSD) in tablets using a combination of a sweeping technique and micellar electrokinetic chromatography/77 K fluorescence spectroscopy.

    Science.gov (United States)

    Fang, Ching; Liu, Ju-Tsung; Lin, Cheng-Huang

    2003-03-01

    This work describes a novel method for the accurate determination of lysergic acid diethylamide (LSD) in tablets. A technique involving sweeping-micellar electrokinetic chromatography (MEKC) was used for the initial on-line concentration and separation, after which a cryogenic molecular fluorescence experiment was performed at 77 K. Using this approach, not only the separation of LSD from the tablet extract was achieved, but on-line spectra were readily distinguishable and could be unambiguously assigned. The results are in agreement with analyses by gas chromatography-mass spectrometry (GC-MS). Thus, this method, which was found to be accurate, sensitive and rapid, has the potential for use as a reliable complementary method to GC-MS in such analyses.

  6. Study on the sweep gas effect on the surface of Li{sub 4}SiO{sub 4} by means of work function measurement

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsushi; Yamaguchi, Kenji; Yamawaki, Michio [Tokyo Univ. (Japan)

    1998-03-01

    In the establishment of fuel cycle of tritium, it is important to make research on how the sweep gas composition affects the surface properties of breeder materials and the release of tritium from the surface of them. In this study, the change of contact potential difference (CPD) between Li{sub 4}SiO{sub 4} and Pt was measured in various gas compositions with a high temperature Kelvin probe. The work function change of Li{sub 4}SiO{sub 4} was obtained from the measured CPD and the work function change of Pt which was estimated from blank tests. From the results, the effect of oxygen deficient layer near the surface of Li{sub 4}SiO{sub 4} was observed, and the effect of OH{sup -} at the surface of Li{sub 4}SiO{sub 4} was considered. (author)

  7. Will the consistent organic food consumer step forward?

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Fenger, Morten H. J.; Thøgersen, John

    2017-01-01

    registered transactions over 20 months from 8,704 randomly selected customers with a loyalty card are analyzed using a hidden Markov model, capturing the dynamics in consumers’ purchases. The model identifies latent states representing identifiable, accessible, and actionable dynamic customer segments...... and it captures the movements between states or segments. A pattern emerges which is consistent with the theory of behavioral spillover and inconsistent with the theory of moral licensing, including a tendency to buy organic products in an increasing number of product categories over time. The order in which...... organic products are adopted is inversely related to the behavioral costs of adopting them. The employed approach provides a firm basis for personalized communication aiming to increase cross-selling of organic products, increase the sale of less popular organic products, and to accelerate movements from...

  8. Domain Adaptation for Pedestrian Detection Based on Prediction Consistency

    Directory of Open Access Journals (Sweden)

    Yu Li-ping

    2014-01-01

    Full Text Available Pedestrian detection is an active area of research in computer vision. It remains a quite challenging problem in many applications where many factors cause a mismatch between source dataset used to train the pedestrian detector and samples in the target scene. In this paper, we propose a novel domain adaptation model for merging plentiful source domain samples with scared target domain samples to create a scene-specific pedestrian detector that performs as well as rich target domain simples are present. Our approach combines the boosting-based learning algorithm with an entropy-based transferability, which is derived from the prediction consistency with the source classifications, to selectively choose the samples showing positive transferability in source domains to the target domain. Experimental results show that our approach can improve the detection rate, especially with the insufficient labeled data in target scene.

  9. Consistent approach to air-cleaning system duct design

    International Nuclear Information System (INIS)

    Miller, W.H.; Ornberg, S.C.; Rooney, K.L.

    1981-01-01

    Nuclear power plant air-cleaning system effectiveness is dependent on the capability of a duct system to safely convey contaminated gas to a filtration unit and subsequently to a point of discharge. This paper presents a logical and consistent design approach for selecting sheet metal ductwork construction to meet applicable criteria. The differences in design engineers' duct construction specifications are acknowledged. Typical duct construction details and suggestions for their effective use are presented. Improvements in duct design sections of ANSI/ASME N509-80 are highlighted. A detailed leakage analysis of a control room HVAC system is undertaken to illustrate the effects of conceptual design variations on duct construction requirements. Shortcomings of previously published analyses and interpretations of a current standard are included

  10. Multi-Scale Experiments to Evaluate Mobility Control Methods for Enhancing the Sweep Efficiency of Injected Subsurface Remediation Amendments

    Science.gov (United States)

    2010-08-01

    degrading or fermenting a larger and more complex molecule (such as the polymers involved in this work), but it is unknown if other microbes naturally...Jackson Lee in 2009 from a sludge holding tank at a beer brewery were also utilized in select microcosm experiments. These microbes (referred to as the...tested another derivative of the Environment 2 scenario, wherein the NBB anaerobes (capable of fermentation of large organic molecules) could

  11. Selection of suitable propagation method for consistent plantlets production in Stevia rebaudiana (Bertoni)

    Science.gov (United States)

    Khalil, Shahid Akbar; Zamir, Roshan; Ahmad, Nisar

    2014-01-01

    Stevia rebaudiana (Bert.) is an emerging sugar alternative and anti-diabetic plant in Pakistan. That is why people did not know the exact time of propagation. The main objective of the present study was to establish feasible propagation methods for healthy biomass production. In the present study, seed germination, stem cuttings and micropropagation were investigated for higher productivity. Fresh seeds showed better germination (25.51–40%) but lost viability after a few days of storage. In order to improve the germination percentage, seeds were irradiated with 2.5, 5.0, 7.5 and 10 Gy gamma doses. But gamma irradiation did not show any significant change in seed germination. A great variation in survival of stem cutting was observed in each month of 2012. October and November were found the most suitable months for stem cutting survival (60%). In order to enhance survival, stem cuttings were also dipped in different plant growth regulators (PGRs) solution. Only indole butyric acid (IBA; 1000 ppm) treated cutting showed a higher survival (33%) than control (11.1%). Furthermore, simple and feasible indirect regeneration system was established from leaf explants. Best callus induction (84.6%) was observed on MS-medium augmented with 6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D; 2.0 mg l−1). For the first time, we obtained the highest number of shoots (106) on a medium containing BA (1.5 mg l−1) and gibberellic acid (GA3; 0.5 mg l−1). Plantlets were successfully acclimatized in plastic pots. The current results preferred micropropagation (85%) over seed germination (25.51–40%) and stem cutting (60%). PMID:25473365

  12. Selection of suitable propagation method for consistent plantlets production in Stevia rebaudiana (Bertoni)

    OpenAIRE

    Khalil, Shahid Akbar; Zamir, Roshan; Ahmad, Nisar

    2014-01-01

    Stevia rebaudiana (Bert.) is an emerging sugar alternative and anti-diabetic plant in Pakistan. That is why people did not know the exact time of propagation. The main objective of the present study was to establish feasible propagation methods for healthy biomass production. In the present study, seed germination, stem cuttings and micropropagation were investigated for higher productivity. Fresh seeds showed better germination (25.51–40%) but lost viability after a few days of storage. In o...

  13. Selection of suitable propagation method for consistent plantlets production in Stevia rebaudiana (Bertoni).

    Science.gov (United States)

    Khalil, Shahid Akbar; Zamir, Roshan; Ahmad, Nisar

    2014-12-01

    Stevia rebaudiana (Bert.) is an emerging sugar alternative and anti-diabetic plant in Pakistan. That is why people did not know the exact time of propagation. The main objective of the present study was to establish feasible propagation methods for healthy biomass production. In the present study, seed germination, stem cuttings and micropropagation were investigated for higher productivity. Fresh seeds showed better germination (25.51-40%) but lost viability after a few days of storage. In order to improve the germination percentage, seeds were irradiated with 2.5, 5.0, 7.5 and 10 Gy gamma doses. But gamma irradiation did not show any significant change in seed germination. A great variation in survival of stem cutting was observed in each month of 2012. October and November were found the most suitable months for stem cutting survival (60%). In order to enhance survival, stem cuttings were also dipped in different plant growth regulators (PGRs) solution. Only indole butyric acid (IBA; 1000 ppm) treated cutting showed a higher survival (33%) than control (11.1%). Furthermore, simple and feasible indirect regeneration system was established from leaf explants. Best callus induction (84.6%) was observed on MS-medium augmented with 6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D; 2.0 mg l(-1)). For the first time, we obtained the highest number of shoots (106) on a medium containing BA (1.5 mg l(-1)) and gibberellic acid (GA3; 0.5 mg l(-1)). Plantlets were successfully acclimatized in plastic pots. The current results preferred micropropagation (85%) over seed germination (25.51-40%) and stem cutting (60%).

  14. Syllable type consistency is related to age, social status and reproductive success in the tropical mockingbird

    NARCIS (Netherlands)

    Botero, Carlos A.; Rossman, Rachel J.; Caro, Lina M.; Stenzler, Laura M.; Lovette, Irby J.; de Kort, Selvino R.; Vehrencamp, Sandra L.

    Many animals repeat standardized displays multiple times while attracting a mate or deterring a rival. In such contexts the ability to perform each display or signal type in a consistent fashion may be under direct selection. Studies on sexual selection on song learning in birds have focused on

  15. Parton Distributions based on a Maximally Consistent Dataset

    Science.gov (United States)

    Rojo, Juan

    2016-04-01

    The choice of data that enters a global QCD analysis can have a substantial impact on the resulting parton distributions and their predictions for collider observables. One of the main reasons for this has to do with the possible presence of inconsistencies, either internal within an experiment or external between different experiments. In order to assess the robustness of the global fit, different definitions of a conservative PDF set, that is, a PDF set based on a maximally consistent dataset, have been introduced. However, these approaches are typically affected by theory biases in the selection of the dataset. In this contribution, after a brief overview of recent NNPDF developments, we propose a new, fully objective, definition of a conservative PDF set, based on the Bayesian reweighting approach. Using the new NNPDF3.0 framework, we produce various conservative sets, which turn out to be mutually in agreement within the respective PDF uncertainties, as well as with the global fit. We explore some of their implications for LHC phenomenology, finding also good consistency with the global fit result. These results provide a non-trivial validation test of the new NNPDF3.0 fitting methodology, and indicate that possible inconsistencies in the fitted dataset do not affect substantially the global fit PDFs.

  16. Signatures of Selection in the Genomes of Commercial and Non-Commercial Chicken Breeds

    Science.gov (United States)

    Elferink, Martin G.; Megens, Hendrik-Jan; Vereijken, Addie; Hu, Xiaoxiang; Crooijmans, Richard P. M. A.; Groenen, Martien A. M.

    2012-01-01

    Identifying genomics regions that are affected by selection is important to understand the domestication and selection history of the domesticated chicken, as well as understanding molecular pathways underlying phenotypic traits and breeding goals. While whole-genome approaches, either high-density SNP chips or massively parallel sequencing, have been successfully applied to identify evidence for selective sweeps in chicken, it has been difficult to distinguish patterns of selection and stochastic and breed specific effects. Here we present a study to identify selective sweeps in a large number of chicken breeds (67 in total) using a high-density (58 K) SNP chip. We analyzed commercial chickens representing all major breeding goals. In addition, we analyzed non-commercial chicken diversity for almost all recognized traditional Dutch breeds and a selection of representative breeds from China. Based on their shared history or breeding goal we in silico grouped the breeds into 14 breed groups. We identified 396 chromosomal regions that show suggestive evidence of selection in at least one breed group with 26 of these regions showing strong evidence of selection. Of these 26 regions, 13 were previously described and 13 yield new candidate genes for performance traits in chicken. Our approach demonstrates the strength of including many different populations with similar, and breed groups with different selection histories to reduce stochastic effects based on single populations. PMID:22384281

  17. Consistent realization of Celestial and Terrestrial Reference Frames

    Science.gov (United States)

    Kwak, Younghee; Bloßfeld, Mathis; Schmid, Ralf; Angermann, Detlef; Gerstl, Michael; Seitz, Manuela

    2018-03-01

    The Celestial Reference System (CRS) is currently realized only by Very Long Baseline Interferometry (VLBI) because it is the space geodetic technique that enables observations in that frame. In contrast, the Terrestrial Reference System (TRS) is realized by means of the combination of four space geodetic techniques: Global Navigation Satellite System (GNSS), VLBI, Satellite Laser Ranging (SLR), and Doppler Orbitography and Radiopositioning Integrated by Satellite. The Earth orientation parameters (EOP) are the link between the two types of systems, CRS and TRS. The EOP series of the International Earth Rotation and Reference Systems Service were combined of specifically selected series from various analysis centers. Other EOP series were generated by a simultaneous estimation together with the TRF while the CRF was fixed. Those computation approaches entail inherent inconsistencies between TRF, EOP, and CRF, also because the input data sets are different. A combined normal equation (NEQ) system, which consists of all the parameters, i.e., TRF, EOP, and CRF, would overcome such an inconsistency. In this paper, we simultaneously estimate TRF, EOP, and CRF from an inter-technique combined NEQ using the latest GNSS, VLBI, and SLR data (2005-2015). The results show that the selection of local ties is most critical to the TRF. The combination of pole coordinates is beneficial for the CRF, whereas the combination of Δ UT1 results in clear rotations of the estimated CRF. However, the standard deviations of the EOP and the CRF improve by the inter-technique combination which indicates the benefits of a common estimation of all parameters. It became evident that the common determination of TRF, EOP, and CRF systematically influences future ICRF computations at the level of several μas. Moreover, the CRF is influenced by up to 50 μas if the station coordinates and EOP are dominated by the satellite techniques.

  18. Assessing distances and consistency of kinematics in Gaia/TGAS

    Science.gov (United States)

    Schönrich, Ralph; Aumer, Michael

    2017-12-01

    We apply the statistical methods by Schönrich, Binney & Asplund to assess the quality of distances and kinematics in the Radial Velocity Experiment (RAVE)-Tycho-Gaia Astrometric Solution (TGAS) and Large Sky Area Multiobject Fiber Spectroscopic Telescope (LAMOST)-TGAS samples of Solar neighbourhood stars. These methods yield a nominal distance accuracy of 1-2 per cent. Other than common tests on parallax accuracy, they directly test distance estimations including the effects of distance priors. We show how to construct these priors including the survey selection functions (SSFs) directly from the data. We demonstrate that neglecting the SSFs causes severe distance biases. Due to the decline of the SSFs in distance, the simple 1/parallax estimate only mildly underestimates distances. We test the accuracy of measured line-of-sight velocities (vlos) by binning the samples in the nominal vlos uncertainties. We find: (i) the LAMOST vlos have a ∼-5 km s-1 offset; (ii) the average LAMOST measurement error for vlos is ∼7 km s-1, significantly smaller than, and nearly uncorrelated with the nominal LAMOST estimates. The RAVE sample shows either a moderate distance underestimate, or an unaccounted source of vlos dispersion (e∥) from measurement errors and binary stars. For a subsample of suspected binary stars in RAVE, our methods indicate significant distance underestimates. Separating a sample in metallicity or kinematics to select thick-disc/halo stars, discriminates between distance bias and e∥. For LAMOST, this separation yields consistency with pure vlos measurement errors. We find an anomaly near longitude l ∼ (300 ± 60)° and distance s ∼ (0.32 ± 0.03) kpc on both sides of the galactic plane, which could be explained by either a localized distance error or a breathing mode.

  19. Sweeping the Floor or Putting a Man on the Moon: How to Define and Measure Meaningful Work.

    Science.gov (United States)

    Both-Nwabuwe, Jitske M C; Dijkstra, Maria T M; Beersma, Bianca

    2017-01-01

    Meaningful work is integral to well-being and a flourishing life. The construct of "meaningful work" is, however, consistently affected by conceptual ambiguity. Although there is substantial support for arguments to maintain the status of conceptual ambiguity, we make a case for the benefits of having consensus on a definition and scale of meaningful work in the context of paid work. The objective of this article, therefore, was twofold. Firstly, we wanted to develop a more integrative definition of meaningful work. Secondly, we wanted to establish a corresponding operationalization. We reviewed the literature on the existing definitions of meaningful work and the scales designed to measure it. We found 14 definitions of meaningful work. Based on these definitions, we identified four categories of definitions, which led us to propose an integrative and comprehensive definition of meaningful work. We identified two validated scales that were partly aligned with the proposed definition. Based on our review, we conclude that scholars in this field should coalesce rather than diverge their efforts to conceptualize and measure meaningful work.

  20. Positive selection on gene expression in the human brain

    DEFF Research Database (Denmark)

    Khaitovich, Philipp; Tang, Kun; Franz, Henriette

    2006-01-01

    Recent work has shown that the expression levels of genes transcribed in the brains of humans and chimpanzees have changed less than those of genes transcribed in other tissues [1] . However, when gene expression changes are mapped onto the evolutionary lineage in which they occurred, the brain...... shows more changes than other tissues in the human lineage compared to the chimpanzee lineage [1] , [2] and [3] . There are two possible explanations for this: either positive selection drove more gene expression changes to fixation in the human brain than in the chimpanzee brain, or genes expressed...... in the brain experienced less purifying selection in humans than in chimpanzees, i.e. gene expression in the human brain is functionally less constrained. The first scenario would be supported if genes that changed their expression in the brain in the human lineage showed more selective sweeps than other genes...

  1. Improving risk assessment by defining consistent and reliable system scenarios

    Directory of Open Access Journals (Sweden)

    B. Mazzorana

    2009-02-01

    Full Text Available During the entire procedure of risk assessment for hydrologic hazards, the selection of consistent and reliable scenarios, constructed in a strictly systematic way, is fundamental for the quality and reproducibility of the results. However, subjective assumptions on relevant impact variables such as sediment transport intensity on the system loading side and weak point response mechanisms repeatedly cause biases in the results, and consequently affect transparency and required quality standards. Furthermore, the system response of mitigation measures to extreme event loadings represents another key variable in hazard assessment, as well as the integral risk management including intervention planning. Formative Scenario Analysis, as a supplement to conventional risk assessment methods, is a technique to construct well-defined sets of assumptions to gain insight into a specific case and the potential system behaviour. By two case studies, carried out (1 to analyse sediment transport dynamics in a torrent section equipped with control measures, and (2 to identify hazards induced by woody debris transport at hydraulic weak points, the applicability of the Formative Scenario Analysis technique is presented. It is argued that during scenario planning in general and with respect to integral risk management in particular, Formative Scenario Analysis allows for the development of reliable and reproducible scenarios in order to design more specifically an application framework for the sustainable assessment of natural hazards impact. The overall aim is to optimise the hazard mapping and zoning procedure by methodologically integrating quantitative and qualitative knowledge.

  2. Comprehensive and consistent interpretation of local fault experiments and application to hypothetical local overpower accident in Monju

    International Nuclear Information System (INIS)

    Fukano, Yoshitaka

    2013-01-01

    Experimental studies on local fault (LF) accidents in fast breeder reactors have been performed in many countries because LFs have been historically considered as one of the possible causes of severe accidents. Comprehensive and consistent interpretations of in-pile and out-of-pile experiments related to LF were arrived at in this study based on state-of-the-art review and data analysis techniques. Safety margins for a hypothetical local overpower accident, which was evaluated as a LF accident in the licensing document of the construction permit for a prototype fast breeder reactor called Monju, were also studied. Based on comprehensive interpretations of the latest experimental database, including those performed after the permission of Monju construction, it was clarified that the evaluation of the hypothetical local overpower accident in the Monju licensing was sufficiently conservative. Furthermore, it incorporated adequate safety margins in terms of failure thresholds of the fuel pin, molten fuel ejection, fuel sweep-out behavior after molten fuel ejection, and pin-to-pin failure propagation. Moreover, these comprehensive interpretations are valid and applicable to the safety evaluation of LF accidents of other fast breeder reactors with various fuel and core designs. (author)

  3. Potential applications of a dual-sweep streak camera system for characterizing particle and photon beams of VUV, XUV, and x-ray FELS

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. [Argonne National Lab., IL (United States)

    1995-12-31

    The success of time-resolved imaging techniques in the Characterization of particle beams and photon beams of the recent generation of L-band linac-driven or storage ring FELs in the infrared, visible, and ultraviolet wavelength regions can be extended to the VUV, XUV, and x-ray FELs. Tests and initial data have been obtained with the Hamamatsu C5680 dual-sweep streak camera system which includes a demountable photocathode (thin Au) assembly and a flange that allows windowless operation with the transport vacuum system. This system can be employed at wavelengths shorter than 100 nm and down to 1 {Angstrom}. First tests on such a system at 248-nm wavelengths have been performed oil the Argonne Wakefield Accelerator (AWA) drive laser source. A quartz window was used at the tube entrance aperture. A preliminary test using a Be window mounted on a different front flange of the streak tube to look at an x-ray bremsstrahlung source at the AWA was limited by photon statistics. This system`s limiting resolution of {sigma}{approximately}1.1 ps observed at 248 nm would increase with higher incoming photon energies to the photocathode. This effect is related to the fundamental spread in energies of the photoelectrons released from the photocathodes. Possible uses of the synchrotron radiation sources at the Advanced Photon Source and emerging short wavelength FELs to test the system will be presented.

  4. Determination of phthalic acid esters in Chinese white spirit using dispersive liquid-liquid microextraction coupled with sweeping β-cyclodextrin-modified micellar electrokinetic chromatography.

    Science.gov (United States)

    Sun, Jianzhi; He, Hui; Liu, Shuhui

    2014-07-01

    A simple method that consumes low organic solvent is proposed for the analysis of phthalic acid esters in Chinese white spirit using dispersive liquid-liquid microextraction coupled with sweeping-micellar electrokinetic chromatography. Tetrachloromethane and white-spirit-containing ethanol were used as the extraction and dispersing solvents, respectively. The electrophoresis separation buffer was composed of 5 mM β-cyclodextrin, 50 mM sodium dodecyl sulfate and 25 mM borate buffer (pH 9.2) with 9% acetonitrile, enabling the baseline resolution of the analytes within 13 min. Under the optimum conditions, satisfactory linearities (5-1000 ng/mL, r ≥ 0.9909), good reproducibility (RSD ≤ 6.7% for peak area, and RSD ≤ 2.8% for migration time), low detection limits (0.4-0.8 ng/mL) and acceptable recovery rates (89.6-105.7%) were obtained. The proposed method was successfully applied to 22 Chinese white spirits, and the content of dibutyl phthalate in 55% of the samples exceeded the Specific Migration Limit of 0.3 mg/kg established by the domestic and international regulations. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The effects of sweep numbers per average and protocol type on the accuracy of the p300-based concealed information test.

    Science.gov (United States)

    Dietrich, Ariana B; Hu, Xiaoqing; Rosenfeld, J Peter

    2014-03-01

    In the first of two experiments, we compared the accuracy of the P300 concealed information test protocol as a function of numbers of trials experienced by subjects and ERP averages analyzed by investigators. Contrary to Farwell et al. (Cogn Neurodyn 6(2):115-154, 2012), we found no evidence that 100 trial based averages are more accurate than 66 or 33 trial based averages (all numbers led to accuracies of 84-94 %). There was actually a trend favoring the lowest trial numbers. The second study compared numbers of irrelevant stimuli recalled and recognized in the 3-stimulus protocol versus the complex trial protocol (Rosenfeld in Memory detection: theory and application of the concealed information test, Cambridge University Press, New York, pp 63-89, 2011). Again, in contrast to expectations from Farwell et al. (Cogn Neurodyn 6(2):115-154, 2012), there were no differences between protocols, although there were more irrelevant stimuli recognized than recalled, and irrelevant 4-digit number group stimuli were neither recalled nor recognized as well as irrelevant city name stimuli. We therefore conclude that stimulus processing in the P300-based complex trial protocol-with no more than 33 sweep averages-is adequate to allow accurate detection of concealed information.

  6. Sensitivity of the downward to sweeping velocity ratio to the bypass flow percentage along a guide wall for downstream fish passage

    Science.gov (United States)

    Mulligan, Kevin; Towler, Brett; Haro, Alexander J.; Ahlfeld, David P.

    2017-01-01

    Partial-depth impermeable guidance structures (or guide walls) are used as a method to assist in the downstream passage of fish at a hydroelectric facility. However, guide walls can result in a strong downward velocity causing the approaching fish to pass below the wall and into the direction of the turbine intakes. The objective of this study was to describe how the ratio of the vertical velocity to the sweeping velocity magnitude changes along the full length and depth of a guide wall under a wide range of bypass flow percentages within a power canal. This paper focused on two guide wall configurations, each set at an angle of 45 ° to the approaching flow field and at a depth of 10 and 20 ft (3.05 and 6.10 m). The hydraulic conditions upstream of each guide wall configuration were shown to be impacted by a change in the bypass flow percentage, not only near the bypass but also at upstream sections of the guide wall. Furthermore, the effect of changing the bypass flow percentage was similar for both guide wall depths. In both cases, the effect of increasing the bypass flow percentage was magnified closer to the bypass and deeper in the water column along the guide wall.

  7. Cereal domestication and evolution of branching: evidence for soft selection in the Tb1 orthologue of pearl millet (Pennisetum glaucum [L.] R. Br..

    Directory of Open Access Journals (Sweden)

    Marie-Stanislas Remigereau

    Full Text Available BACKGROUND: During the Neolithic revolution, early farmers altered plant development to domesticate crops. Similar traits were often selected independently in different wild species; yet the genetic basis of this parallel phenotypic evolution remains elusive. Plant architecture ranks among these target traits composing the domestication syndrome. We focused on the reduction of branching which occurred in several cereals, an adaptation known to rely on the major gene Teosinte-branched1 (Tb1 in maize. We investigate the role of the Tb1 orthologue (Pgtb1 in the domestication of pearl millet (Pennisetum glaucum, an African outcrossing cereal. METHODOLOGY/PRINCIPAL FINDINGS: Gene cloning, expression profiling, QTL mapping and molecular evolution analysis were combined in a comparative approach between pearl millet and maize. Our results in pearl millet support a role for PgTb1 in domestication despite important differences in the genetic basis of branching adaptation in that species compared to maize (e.g. weaker effects of PgTb1. Genetic maps suggest this pattern to be consistent in other cereals with reduced branching (e.g. sorghum, foxtail millet. Moreover, although the adaptive sites underlying domestication were not formerly identified, signatures of selection pointed to putative regulatory regions upstream of both Tb1 orthologues in maize and pearl millet. However, the signature of human selection in the pearl millet Tb1 is much weaker in pearl millet than in maize. CONCLUSIONS/SIGNIFICANCE: Our results suggest that some level of parallel evolution involved at least regions directly upstream of Tb1 for the domestication of pearl millet and maize. This was unanticipated given the multigenic basis of domestication traits and the divergence of wild progenitor species for over 30 million years prior to human selection. We also hypothesized that regular introgression of domestic pearl millet phenotypes by genes from the wild gene pool could explain

  8. Multiplicative Consistency for Interval Valued Reciprocal Preference Relations

    OpenAIRE

    Wu, Jian; Chiclana, Francisco

    2014-01-01

    The multiplicative consistency (MC) property of interval additive reciprocal preference relations (IARPRs) is explored, and then the consistency index is quantified by the multiplicative consistency estimated IARPR. The MC property is used to measure the level of consistency of the information provided by the experts and also to propose the consistency index induced ordered weighted averaging (CI-IOWA) operator. The novelty of this operator is that it aggregates individual IARPRs in such ...

  9. Thrust Measurement of Dielectric Barrier Discharge (DBD) Plasma Actuators: New Anti-Thrust Hypothesis, Frequency Sweeps Methodology, Humidity and Enclosure Effects

    Science.gov (United States)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust, or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a grounded large-diameter metal sleeve. Strong dependence on humidity is also shown; the thrust significantly increased with decreasing humidity, e

  10. Whole-genome sequencing of two North American Drosophila melanogaster populations reveals genetic differentiation and positive selection.

    Science.gov (United States)

    Campo, D; Lehmann, K; Fjeldsted, C; Souaiaia, T; Kao, J; Nuzhdin, S V

    2013-10-01

    The prevailing demographic model for Drosophila melanogaster suggests that the colonization of North America occurred very recently from a subset of European flies that rapidly expanded across the continent. This model implies a sudden population growth and range expansion consistent with very low or no population subdivision. As flies adapt to new environments, local adaptation events may be expected. To describe demographic and selective events during North American colonization, we have generated a data set of 35 individual whole-genome sequences from inbred lines of D. melanogaster from a west coast US population (Winters, California, USA) and compared them with a public genome data set from Raleigh (Raleigh, North Carolina, USA). We analysed nuclear and mitochondrial genomes and described levels of variation and divergence within and between these two North American D. melanogaster populations. Both populations exhibit negative values of Tajima's D across the genome, a common signature of demographic expansion. We also detected a low but significant level of genome-wide differentiation between the two populations, as well as multiple allele surfing events, which can be the result of gene drift in local subpopulations on the edge of an expansion wave. In contrast to this genome-wide pattern, we uncovered a 50-kilobase segment in chromosome arm 3L that showed all the hallmarks of a soft selective sweep in both populations. A comparison of allele frequencies within this divergent region among six populations from three continents allowed us to cluster these populations in two differentiated groups, providing evidence for the action of natural selection on a global scale. © 2013 John Wiley & Sons Ltd.

  11. Signatures of selection in tilapia revealed by whole genome resequencing.

    Science.gov (United States)

    Xia, Jun Hong; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Wan, Zi Yi; Li, Jiale; Lin, Haoran; Yue, Gen Hua

    2015-09-16

    Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10-100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia.

  12. Composite selection signals can localize the trait specific genomic regions in multi-breed populations of cattle and sheep

    Science.gov (United States)

    2014-01-01

    Background Discerning the traits evolving under neutral conditions from those traits evolving rapidly because of various selection pressures is a great challenge. We propose a new method, composite selection signals (CSS), which unifies the multiple pieces of selection evidence from the rank distribution of its diverse constituent tests. The extreme CSS scores capture highly differentiated loci and underlying common variants hauling excess haplotype homozygosity in the samples of a target population. Results The data on high-density genotypes were analyzed for evidence of an association with either polledness or double muscling in various cohorts of cattle and sheep. In cattle, extreme CSS scores were found in the candidate regions on autosome BTA-1 and BTA-2, flanking the POLL locus and MSTN gene, for polledness and double muscling, respectively. In sheep, the regions with extreme scores were localized on autosome OAR-2 harbouring the MSTN gene for double muscling and on OAR-10 harbouring the RXFP2 gene for polledness. In comparison to the constituent tests, there was a partial agreement between the signals at the four candidate loci; however, they consistently identified additional genomic regions harbouring no known genes. Persuasively, our list of all the additional significant CSS regions contains genes that have been successfully implicated to secondary phenotypic diversity among several subpopulations in our data. For example, the method identified a strong selection signature for stature in cattle capturing selective sweeps harbouring UQCC-GDF5 and PLAG1-CHCHD7 gene regions on BTA-13 and BTA-14, respectively. Both gene pairs have been previously associated with height in humans, while PLAG1-CHCHD7 has also been reported for stature in cattle. In the additional analysis, CSS identified significant regions harbouring multiple genes for various traits under selection in European cattle including polledness, adaptation, metabolism, growth rate, stature

  13. Privacy, Time Consistent Optimal Labour Income Taxation and Education Policy

    OpenAIRE

    Konrad, Kai A.

    1999-01-01

    Incomplete information is a commitment device for time consistency problems. In the context of time consistent labour income taxation privacy reduces welfare losses and increases the effectiveness of public education as a second best policy.

  14. Longitudinal tDCS: Consistency across Working Memory Training Studies

    Directory of Open Access Journals (Sweden)

    Marian E. Berryhill

    2017-04-01

    Full Text Available There is great interest in enhancing and maintaining cognitive function. In recent years, advances in noninvasive brain stimulation devices, such as transcranial direct current stimulation (tDCS, have targeted working memory in particular. Despite controversy surrounding outcomes of single-session studies, a growing field of working memory training studies incorporate multiple sessions of tDCS. It is useful to take stock of these findings because there is a diversity of paradigms employed and the outcomes observed between research groups. This will be important in assessing cognitive training programs paired with stimulation techniques and identifying the more useful and less effective approaches. Here, we treat the tDCS+ working memory training field as a case example, but also survey training benefits in other neuromodulatory techniques (e.g., tRNS, tACS. There are challenges associated with the broad parameter space including: individual differences, stimulation intensity, duration, montage, session number, session spacing, training task selection, timing of follow up testing, near and far transfer tasks. In summary, although the field of assisted cognitive training is young, some design choices are more favorable than others. By way of heuristic, the current evidence supports including more training/tDCS sessions (5+, applying anodal tDCS targeting prefrontal regions, including follow up testing on trained and transfer tasks after a period of no contact. What remains unclear, but important for future translational value is continuing work to pinpoint optimal values for the tDCS parameters on a per cognitive task basis. Importantly the emerging literature shows notable consistency in the application of tDCS for WM across various participant populations compared to single session experimental designs.

  15. Generalized contexts and consistent histories in quantum mechanics

    International Nuclear Information System (INIS)

    Losada, Marcelo; Laura, Roberto

    2014-01-01

    We analyze a restriction of the theory of consistent histories by imposing that a valid description of a physical system must include quantum histories which satisfy the consistency conditions for all states. We prove that these conditions are equivalent to imposing the compatibility conditions of our formalism of generalized contexts. Moreover, we show that the theory of consistent histories with the consistency conditions for all states and the formalism of generalized context are equally useful representing expressions which involve properties at different times

  16. Personality and Situation Predictors of Consistent Eating Patterns

    OpenAIRE

    Vainik, Uku; Dub?, Laurette; Lu, Ji; Fellows, Lesley K.

    2015-01-01

    Introduction A consistent eating style might be beneficial to avoid overeating in a food-rich environment. Eating consistency entails maintaining a similar dietary pattern across different eating situations. This construct is relatively under-studied, but the available evidence suggests that eating consistency supports successful weight maintenance and decreases risk for metabolic syndrome and cardiovascular disease. Yet, personality and situation predictors of consistency have not been studi...

  17. Método de varredura para exame de criadouros de vetores de dengue e febre amarela urbana Sweeping method to scan breeding places for dengue and urban yellow fever vectors

    Directory of Open Access Journals (Sweden)

    Roseane Lieko Kubota

    2003-04-01

    Full Text Available Com objetivo de estimar o número mínimo de varreduras para coletar uma amostra representativa das larvas presentes em um grande recipiente, foram adicionadas 200 larvas de quarto estádio em um tambor de 80 litros de água. Com auxílio de peneira plástica, foram feitas dez varreduras em cada réplica do experimento. Os resultados indicaram que oito varreduras foram suficientes para coletar até 72% do total de 200 larvas de quarto estadio presentes no criadouro, ou seja, uma média de 143±1,97. A técnica mostrou ser de fácil e eficiente execução quanto à inspeção de criadouros com grande volume de água. Isto reforça sua utilização como instrumento com grande potencial para vigilância vetorial na rotina dos programas de controle de vetores do dengue e febre amarela.To estimate the minimum numbers of "sweepings" for a representative sampling of larvae in a large container. 200 larvae in 4th stage were added in an 80-liter drum to carry out the experiment, in each retort was made 10 sweepings using a plastic sieve. Two hundred larvae in stage 4 were added to an 80-liter-drum and using a plastic sieve10 sweepings were carried out in each experiment replicate. The results showed that 8 sweepings were enough to collect up to 72% of the total sample in the container, i.e., an average of 143±1.97. The proposed method proved to be easily and effectively implemented and allowed for the inspection of containers with large water volumes. These findings reinforce its use as an important potential tool in the routine vectorial surveillance of control programs of dengue and yellow fever.

  18. [Selective mutism].

    Science.gov (United States)

    Ytzhak, A; Doron, Y; Lahat, E; Livne, A

    2012-10-01

    Selective mutism is an uncommon disorder in young children, in which they selectively don't speak in certain social situations, while being capable of speaking easily in other social situations. Many etiologies were proposed for selective mutism including psychodynamic, behavioral and familial etc. A developmental etiology that includes insights from all the above is gaining support. Accordingly, mild language impairment in a child with an anxiety trait may be at the root of developing selective mutism. The behavior will be reinforced by an avoidant pattern in the family. Early treatment and followup for children with selective mutism is important. The treatment includes non-pharmacological therapy (psychodynamic, behavioral and familial) and pharmacologic therapy--mainly selective serotonin reuptake inhibitors (SSRI).

  19. Two Impossibility Results on the Converse Consistency Principle in Bargaining

    OpenAIRE

    Youngsub Chun

    1999-01-01

    We present two impossibility results on the converse consistency principle in the context of bargaining. First, we show that there is no solution satis-fying Pareto optimality, contraction independence, and converse consistency. Next, we show that there is no solution satisfying Pareto optimality, strong individual rationality, individual monotonicity, and converse consistency.

  20. Personality consistency analysis in cloned quarantine dog candidates

    Directory of Open Access Journals (Sweden)

    Jin Choi

    2017-01-01

    Full Text Available In recent research, personality consistency has become an important characteristic. Diverse traits and human-animal interactions, in particular, are studied in the field of personality consistency in dogs. Here, we investigated the consistency of dominant behaviours in cloned and control groups followed by the modified Puppy Aptitude Test, which consists of ten subtests to ascertain the influence of genetic identity. In this test, puppies are exposed to stranger, restraint, prey-like object, noise, startling object, etc. Six cloned and four control puppies participated and the consistency of responses at ages 7–10 and 16 weeks in the two groups was compared. The two groups showed different consistencies in the subtests. While the average scores of the cloned group were consistent (P = 0.7991, those of the control group were not (P = 0.0089. Scores of Pack Drive and Fight or Flight Drive were consistent in the cloned group, however, those of the control group were not. Scores of Prey Drive were not consistent in either the cloned or the control group. Therefore, it is suggested that consistency of dominant behaviour is affected by genetic identity and some behaviours can be influenced more than others. Our results suggest that cloned dogs could show more consistent traits than non-cloned. This study implies that personality consistency could be one of the ways to analyse traits of puppies.