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Sample records for accelerating epistasis analysis

  1. Accelerating epistasis analysis in human genetics with consumer graphics hardware

    Cancare Fabio

    2009-07-01

    Full Text Available Abstract Background Human geneticists are now capable of measuring more than one million DNA sequence variations from across the human genome. The new challenge is to develop computationally feasible methods capable of analyzing these data for associations with common human disease, particularly in the context of epistasis. Epistasis describes the situation where multiple genes interact in a complex non-linear manner to determine an individual's disease risk and is thought to be ubiquitous for common diseases. Multifactor Dimensionality Reduction (MDR is an algorithm capable of detecting epistasis. An exhaustive analysis with MDR is often computationally expensive, particularly for high order interactions. This challenge has previously been met with parallel computation and expensive hardware. The option we examine here exploits commodity hardware designed for computer graphics. In modern computers Graphics Processing Units (GPUs have more memory bandwidth and computational capability than Central Processing Units (CPUs and are well suited to this problem. Advances in the video game industry have led to an economy of scale creating a situation where these powerful components are readily available at very low cost. Here we implement and evaluate the performance of the MDR algorithm on GPUs. Of primary interest are the time required for an epistasis analysis and the price to performance ratio of available solutions. Findings We found that using MDR on GPUs consistently increased performance per machine over both a feature rich Java software package and a C++ cluster implementation. The performance of a GPU workstation running a GPU implementation reduces computation time by a factor of 160 compared to an 8-core workstation running the Java implementation on CPUs. This GPU workstation performs similarly to 150 cores running an optimized C++ implementation on a Beowulf cluster. Furthermore this GPU system provides extremely cost effective

  2. Epistasis analysis using artificial intelligence.

    Moore, Jason H; Hill, Doug P

    2015-01-01

    Here we introduce artificial intelligence (AI) methodology for detecting and characterizing epistasis in genetic association studies. The ultimate goal of our AI strategy is to analyze genome-wide genetics data as a human would using sources of expert knowledge as a guide. The methodology presented here is based on computational evolution, which is a type of genetic programming. The ability to generate interesting solutions while at the same time learning how to solve the problem at hand distinguishes computational evolution from other genetic programming approaches. We provide a general overview of this approach and then present a few examples of its application to real data. PMID:25403541

  3. Quantitative epistasis analysis and pathway inference from genetic interaction data.

    Hilary Phenix

    2011-05-01

    Full Text Available Inferring regulatory and metabolic network models from quantitative genetic interaction data remains a major challenge in systems biology. Here, we present a novel quantitative model for interpreting epistasis within pathways responding to an external signal. The model provides the basis of an experimental method to determine the architecture of such pathways, and establishes a new set of rules to infer the order of genes within them. The method also allows the extraction of quantitative parameters enabling a new level of information to be added to genetic network models. It is applicable to any system where the impact of combinatorial loss-of-function mutations can be quantified with sufficient accuracy. We test the method by conducting a systematic analysis of a thoroughly characterized eukaryotic gene network, the galactose utilization pathway in Saccharomyces cerevisiae. For this purpose, we quantify the effects of single and double gene deletions on two phenotypic traits, fitness and reporter gene expression. We show that applying our method to fitness traits reveals the order of metabolic enzymes and the effects of accumulating metabolic intermediates. Conversely, the analysis of expression traits reveals the order of transcriptional regulatory genes, secondary regulatory signals and their relative strength. Strikingly, when the analyses of the two traits are combined, the method correctly infers ~80% of the known relationships without any false positives.

  4. Analysis pipeline for the epistasis search – statistical versus biological filtering

    Xiangqing eSun

    2014-04-01

    Full Text Available Gene-gene interactions may contribute to the genetic variation underlying complex traits but have not always been taken fully into account. Statistical analyses that consider gene-gene interaction may increase the power of detecting associations, especially for low-marginal-effect markers, and may explain in part the missing heritability. Detecting pair-wise and higher-order interactions genome-wide requires enormous computational power. Filtering pipelines increase the computational speed by limiting the number of tests performed. We summarize existing filtering approaches to detect epistasis, after distinguishing the purposes that lead us to search for epistasis. Statistical filtering includes quality control on the basis of single marker statistics to avoid the analysis of bad and least informative data, and limits the search space for finding interactions. Biological filtering includes targeting specific pathways, integrating various databases based on known biological and metabolic pathways, gene function ontology and protein-protein interactions. It is increasingly possible to target single-nucleotide polymorphisms that have defined functions on gene expression, though not belonging to protein-coding genes. Filtering can improve the power of an interaction association study, but also increases the chance of missing important findings.

  5. Epistasis Test in Meta-Analysis: A Multi-Parameter Markov Chain Monte Carlo Model for Consistency of Evidence

    Lin, Chin; Chu, Chi-Ming; Su, Sui-Lung

    2016-01-01

    Conventional genome-wide association studies (GWAS) have been proven to be a successful strategy for identifying genetic variants associated with complex human traits. However, there is still a large heritability gap between GWAS and transitional family studies. The “missing heritability” has been suggested to be due to lack of studies focused on epistasis, also called gene–gene interactions, because individual trials have often had insufficient sample size. Meta-analysis is a common method for increasing statistical power. However, sufficient detailed information is difficult to obtain. A previous study employed a meta-regression-based method to detect epistasis, but it faced the challenge of inconsistent estimates. Here, we describe a Markov chain Monte Carlo-based method, called “Epistasis Test in Meta-Analysis” (ETMA), which uses genotype summary data to obtain consistent estimates of epistasis effects in meta-analysis. We defined a series of conditions to generate simulation data and tested the power and type I error rates in ETMA, individual data analysis and conventional meta-regression-based method. ETMA not only successfully facilitated consistency of evidence but also yielded acceptable type I error and higher power than conventional meta-regression. We applied ETMA to three real meta-analysis data sets. We found significant gene–gene interactions in the renin–angiotensin system and the polycyclic aromatic hydrocarbon metabolism pathway, with strong supporting evidence. In addition, glutathione S-transferase (GST) mu 1 and theta 1 were confirmed to exert independent effects on cancer. We concluded that the application of ETMA to real meta-analysis data was successful. Finally, we developed an R package, etma, for the detection of epistasis in meta-analysis [etma is available via the Comprehensive R Archive Network (CRAN) at https://cran.r-project.org/web/packages/etma/index.html]. PMID:27045371

  6. Epistasis Test in Meta-Analysis: A Multi-Parameter Markov Chain Monte Carlo Model for Consistency of Evidence

    Lin, Chin; Chu, Chi-Ming; Su, Sui-Lung

    2016-01-01

    Conventional genome-wide association studies (GWAS) have been proven to be a successful strategy for identifying genetic variants associated with complex human traits. However, there is still a large heritability gap between GWAS and transitional family studies. The “missing heritability” has been suggested to be due to lack of studies focused on epistasis, also called gene–gene interactions, because individual trials have often had insufficient sample size. Meta-analysis is a common method f...

  7. Analysis of heterogeneity and epistasis in physiological mixed populations by combined structural equation modelling and latent class analysis

    Werge Thomas

    2008-07-01

    studied in physiological homogenous subpopulations and on inclusion of epistasis in the analysis, whereas epistasis (i.e. genetic networks is ubiquitous and should be the basis in modelling any biological process.

  8. Experimental evolution and epistasis in variable environments

    Tans, Sander

    2014-03-01

    Environmental changes trigger cellular responses, but also impose selective pressures on the underlying regulatory systems. To disentangle this complex interplay we follow a synthetic biology approach. By linking the output of regulatory systems to bacterial growth, quantified temporally variable selective pressures can be applied to regulatory systems. This approach allows one to explore how networks evolve in complex variable environments. Epistatic interactions that underlie evolutionary constraint have mainly been studied for constant external conditions. However, environmental changes may modulate epistasis and hence affect genetic constraints. We investigate genetic constraints in the adaptive evolution of a novel regulatory function in variable environments, using the lac repressor, LacI, as a model system. We systematically reconstructed mutational trajectories from wild type LacI to three different variants that each exhibit an inverse response to the inducing ligand IPTG, and analyzed the higher-order interactions between genetic and environmental changes. We find epistasis to depend strongly on the environment. As a result, mutational steps essential to inversion but inaccessible by positive selection in one environment, become accessible in another. We present a graphical method to analyze the observed complex higher-order interactions between multiple mutations and environmental change, and show how they can be explained by a combination of mutational effects on allostery and thermodynamic stability. This dependency of genetic constraint on the environment should fundamentally affect evolutionary dynamics and phylogenetic analysis. NWO-FOM

  9. Weak Epistasis Generally Stabilizes Phenotypes in a Mouse Intercross

    Tyler, Anna L.; Donahue, Leah Rae; Churchill, Gary A.; Carter, Gregory W.

    2016-01-01

    The extent and strength of epistasis is commonly unresolved in genetic studies, and observed epistasis is often difficult to interpret in terms of biological consequences or overall genetic architecture. We investigated the prevalence and consequences of epistasis by analyzing four body composition phenotypes—body weight, body fat percentage, femoral density, and femoral circumference—in a large F2 intercross of B6-lit/lit and C3.B6-lit/lit mice. We used Combined Analysis of Pleiotropy and Epistasis (CAPE) to examine interactions for the four phenotypes simultaneously, which revealed an extensive directed network of genetic loci interacting with each other, circulating IGF1, and sex to influence these phenotypes. The majority of epistatic interactions had small effects relative to additive effects of individual loci, and tended to stabilize phenotypes towards the mean of the population rather than extremes. Interactive effects of two alleles inherited from one parental strain commonly resulted in phenotypes closer to the population mean than the additive effects from the two loci, and often much closer to the mean than either single-locus model. Alternatively, combinations of alleles inherited from different parent strains contribute to more extreme phenotypes not observed in either parental strain. This class of phenotype-stabilizing interactions has effects that are close to additive and are thus difficult to detect except in very large intercrosses. Nevertheless, we found these interactions to be useful in generating hypotheses for functional relationships between genetic loci. Our findings suggest that while epistasis is often weak and unlikely to account for a large proportion of heritable variance, even small-effect genetic interactions can facilitate hypotheses of underlying biology in well-powered studies. PMID:26828925

  10. Epistasis and Its Contribution to Genetic Variance Components

    Cheverud, J M; Routman, E J

    1995-01-01

    We present a new parameterization of physiological epistasis that allows the measurement of epistasis separate from its effects on the interaction (epistatic) genetic variance component. Epistasis is the deviation of two-locus genotypic values from the sum of the contributing single-locus genotypic values. This parameterization leads to statistical tests for epistasis given estimates of two-locus genotypic values such as can be obtained from quantitative trait locus studies. The contributions...

  11. Enabling personal genomics with an explicit test of epistasis.

    Greene, Casey S; Himmelstein, Daniel S; Nelson, Heather H; Kelsey, Karl T; Williams, Scott M; Andrew, Angeline S; Karagas, Margaret R; Moore, Jason H

    2010-01-01

    One goal of personal genomics is to use information about genomic variation to predict who is at risk for various common diseases. Technological advances in genotyping have spawned several personal genetic testing services that market genotyping services directly to the consumer. An important goal of consumer genetic testing is to provide health information along with the genotyping results. This has the potential to integrate detailed personal genetic and genomic information into healthcare decision making. Despite the potential importance of these advances, there are some important limitations. One concern is that much of the literature that is used to formulate personal genetics reports is based on genetic association studies that consider each genetic variant independently of the others. It is our working hypothesis that the true value of personal genomics will only be realized when the complexity of the genotype-to-phenotype mapping relationship is embraced, rather than ignored. We focus here on complexity in genetic architecture due to epistasis or nonlinear gene-gene interaction. We have previously developed a multifactor dimensionality reduction (MDR) algorithm and software package for detecting nonlinear interactions in genetic association studies. In most prior MDR analyses, the permutation testing strategy used to assess statistical significance was unable to differentiate MDR models that captured only interaction effects from those that also detected independent main effects. Statistical interpretation of MDR models required post-hoc analysis using entropy-based measures of interaction information. We introduce here a novel permutation test that allows the effects of nonlinear interactions between multiple genetic variants to be specifically tested in a manner that is not confounded by linear additive effects. We show using simulated nonlinear interactions that the power using the explicit test of epistasis is no different than a standard permutation

  12. Confronting the missing epistasis problem: on the reproducibility of gene-gene interactions.

    Murk, William; Bracken, Michael B; DeWan, Andrew T

    2015-08-01

    Epistasis (gene-gene interaction) is thought to play an integral role in the genetic basis of complex traits, and a significant amount of research has been invested into identifying this phenomenon in human disease. However, the overall success of empirical studies of epistasis in humans is unclear, as such studies are rarely systematically evaluated. Here, we have selected asthma as an example of a well-studied, complex human disease, and provide a critical analysis and replication attempt of nearly all prior reports of epistasis for this disease. Of 191 previously reported interactions, we find that 39.8% were not originally identified using an explicit test for interaction and thus may not have been true epistatic effects to begin with. Moreover, directions of effect were not described for 46.1% of the interactions, which prevents their rigorous replication. In the original studies, attempts at replication were made for 15.2% of the interactions, and 7.3% were actually replicated. In the current study, we were able to evaluate 85.9% of the interactions using a large asthma dataset from the GABRIEL Consortium. None of these interactions could be replicated based on strict criteria. However, we found nominally significant (p < 0.05) evidence in support of 23.8% of the evaluated interactions. Although many reports of epistasis are not robustly supported in the published literature, our results suggest that at least some of these reports may have been true-positive examples of epistasis. In general, improvements in empirical studies of epistasis are called for, in order to better understand the importance of this phenomenon in human disease. PMID:25998948

  13. A survey about methods dedicated to epistasis detection

    Clément eNiel

    2015-09-01

    Full Text Available During the past decade, findings of genome-wide association studies (GWAS improved our knowledge and understanding of disease genetics. To date, thousands of SNPs have been associated to diseases and other complex traits. Statistical analysis typically looks for association between a phenotype and a SNP taken individually via single-locus tests. However, geneticists admit this is an oversimplified approach to tackle the complexity of underlying biological mechanisms. Interaction between SNPs, namely epistasis, must be considered. Unfortunately, epistasis detection gives rise to analytic challenges since analyzing every SNP combination is at present impractical at a genome-wide scale. In this review, we will present the main strategies recently proposed to detect epistatic interactions, along with their operating principle. Some of these methods are exhaustive, such as multifactor dimensionality reduction, likelihood ratio-based tests or receiver operating characteristic curve analysis; some are non-exhaustive, such as machine learning techniques (random forests, Bayesian networks or combinatorial optimization approaches (ant colony optimization, computational evolution system.

  14. Compensatory mutations cause excess of antagonistic epistasis in RNA secondary structure folding

    Wilke, C O; Adami, C; Wilke, Claus O; Lenski, Richard E; Adami, Christoph

    2003-01-01

    Background: The rate at which fitness declines as an organism's genome accumulates random mutations is an important variable in several evolutionary theories. At an intuitive level, it might seem natural that random mutations should tend to interact synergistically, such that the rate of mean fitness decline accelerates as the number of random mutations is increased. However, in a number of recent studies, a prevalence of antagonistic epistasis (the tendency of multiple mutations to have a mitigating rather than reinforcing effect) has been observed. Results: We studied in silico the net amount and form of epistatic interactions in RNA secondary structure folding by measuring the fraction of neutral mutants as a function of mutational distance d. We found a clear prevalence of antagonistic epistasis in RNA secondary structure folding. By relating the fraction of neutral mutants at distance d to the average neutrality at distance d, we showed that this prevalence derives from the existence of many compensatory...

  15. Compensatory mutations cause excess of antagonistic epistasis in RNA secondary structure folding

    Adami Christoph

    2003-02-01

    Full Text Available Background The rate at which fitness declines as an organism's genome accumulates random mutations is an important variable in several evolutionary theories. At an intuitive level, it might seem natural that random mutations should tend to interact synergistically, such that the rate of mean fitness decline accelerates as the number of random mutations is increased. However, in a number of recent studies, a prevalence of antagonistic epistasis (the tendency of multiple mutations to have a mitigating rather than reinforcing effect has been observed. Results We studied in silico the net amount and form of epistatic interactions in RNA secondary structure folding by measuring the fraction of neutral mutants as a function of mutational distance d. We found a clear prevalence of antagonistic epistasis in RNA secondary structure folding. By relating the fraction of neutral mutants at distance d to the average neutrality at distance d, we showed that this prevalence derives from the existence of many compensatory mutations at larger mutational distances. Conclusions Our findings imply that the average direction of epistasis in simple fitness landscapes is directly related to the density with which fitness peaks are distributed in these landscapes.

  16. Coevolution of robustness, epistasis, and recombination favors asexual reproduction

    MacCarthy, Thomas; Bergman, Aviv

    2007-01-01

    The prevalence of sexual reproduction remains one of the most perplexing phenomena in evolutionary biology. The deterministic mutation hypothesis postulates that sexual reproduction will be advantageous under synergistic epistasis, a condition in which mutations cause a greater reduction in fitness when combined than would be expected from their individual effects. The inverse condition, antagonistic epistasis, correspondingly is predicted to favor asexual reproduction. To assess this hypothe...

  17. Learning genetic epistasis using Bayesian network scoring criteria

    Barmada M Michael; Neapolitan Richard E; Jiang Xia; Visweswaran Shyam

    2011-01-01

    Abstract Background Gene-gene epistatic interactions likely play an important role in the genetic basis of many common diseases. Recently, machine-learning and data mining methods have been developed for learning epistatic relationships from data. A well-known combinatorial method that has been successfully applied for detecting epistasis is Multifactor Dimensionality Reduction (MDR). Jiang et al. created a combinatorial epistasis learning method called BNMBL to learn Bayesian network (BN) ep...

  18. Protein evolution. Pervasive degeneracy and epistasis in a protein-protein interface.

    Podgornaia, Anna I; Laub, Michael T

    2015-02-01

    Mapping protein sequence space is a difficult problem that necessitates the analysis of 20(N) combinations for sequences of length N. We systematically mapped the sequence space of four key residues in the Escherichia coli protein kinase PhoQ that drive recognition of its substrate PhoP. We generated a library containing all 160,000 variants of PhoQ at these positions and used a two-step selection coupled to next-generation sequencing to identify 1659 functional variants. Our results reveal extensive degeneracy in the PhoQ-PhoP interface and epistasis, with the effect of individual substitutions often highly dependent on context. Together, epistasis and the genetic code create a pattern of connectivity of functional variants in sequence space that likely constrains PhoQ evolution. Consequently, the diversity of PhoQ orthologs is substantially lower than that of functional PhoQ variants. PMID:25657251

  19. Accelerator physics analysis with interactive tools

    Work is in progress on interactive tools for linear and nonlinear accelerator design, analysis, and simulation using X-based graphics. The BEAMLINE and MXYZPTLK class libraries, were used with an X Windows graphics library to build a program for interactively editing lattices and studying their properties

  20. Accelerator based techniques for aerosol analysis

    At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN (Florence, Italy) an external beam facility is fully dedicated to PIXE-PIGE measurements of elemental composition of atmospheric aerosols. Examples regarding recent monitoring campaigns, performed in urban and remote areas, both on a daily basis and with high time resolution, as well as with size selection, will be presented. It will be evidenced how PIXE can provide unique information in aerosol studies or can play a complementary role to traditional chemical analysis. Finally a short presentation of 14C analysis of the atmospheric aerosol by Accelerator Mass Spectrometry (AMS) for the evaluation of the contributions from either fossil fuel combustion or modern sources (wood burning, biogenic activity) will be given. (author)

  1. Analysis of FFAG accelerators and the evolution of circular accelerators

    After rapidly comparing circular machines with the linear accelerator and the reasons for the choice of an annular high energy and very high intensity accelerator, recent problems concerning accelerator theory are discussed, with emphasis on their physical character. The FFAG principle. The limit of the energy of FFAG cyclotron. The setting-up and interpreting of mean energy of focusing terms for a spiral FFAG synchrotron. The limiting amplitude stable near the non-linear resonance 2Qz = Qr, as well as the linear coupling resonance of Walkinshaw 2Qz = Qr. The crossed-beam accelerator. The 40 MeV electron model of MURA. Two other parts deal with linear and non-linear methods of injection and extraction using a variable disturbance applied to the magnetic field, as well as to collective effects. The interaction of the beam with the accelerating cavities and the walls. The modification of the phase oscillation equation. The influence of the beams' high frequency fields on the Nielsen longitudinal instability. (author)

  2. Accelerator physics analysis with an integrated toolkit

    Work is in progress on an integrated software toolkit for linear and nonlinear accelerator design, analysis, and simulation. As a first application, ''beamline'' and ''MXYZPTLK'' (differential algebra) class libraries, were used with an X Windows graphics library to build an user-friendly, interactive phase space tracker which, additionally, finds periodic orbits. This program was used to analyse a theoretical lattice which contains octupoles and decapoles to find the 20th order, stable and unstable periodic orbits and to explore the local phase space structure

  3. Epistasis: Obstacle or Advantage for Mapping Complex Traits?

    Verhoeven, K.J.F.; Casella, G.; McIntyre, L.M.

    2010-01-01

    Identification of genetic loci in complex traits has focused largely on one-dimensional genome scans to search for associations between single markers and the phenotype. There is mounting evidence that locus interactions, or epistasis, are a crucial component of the genetic architecture of biologica

  4. Code comparison for accelerator design and analysis

    This paper presents a comparison between results obtained from standard accelerator physics codes used for the design and analysis of sychrotrons and storage rings, with programs SYNCH, MAD, HARMON, PATRICIA, PATPET, BETA, DIMAD, MARYLIE and RACETRACK. In the analysis the authors have considered 5 (various size) lattices with large and small bend angles including AGS Booster (10 degrees bend) RHIC (2.24 degrees), SXLS, XLS (XUV ring with 45 degrees bend) and X-RAY rings. The differences in the integration methods used and the treatment of the fringe fields in these codes could lead to different results. The inclusion of nonlinear (e.g. dipole) terms may be necessary in these calculations specially for a small ring

  5. Code comparison for accelerator design and analysis

    We present a comparison between results obtained from standard accelerator physics codes used for the design and analysis of synchrotrons and storage rings, with programs SYNCH, MAD, HARMON, PATRICIA, PATPET, BETA, DIMAD, MARYLIE and RACE-TRACK. In our analysis we have considered 5 (various size) lattices with large and small angles including AGS Booster (10/degree/ bend), RHIC (2.24/degree/), SXLS, XLS (XUV ring with 45/degree/ bend) and X-RAY rings. The differences in the integration methods used and the treatment of the fringe fields in these codes could lead to different results. The inclusion of nonlinear (e.g., dipole) terms may be necessary in these calculations specially for a small ring. 12 refs., 6 figs., 10 tabs

  6. Performance analysis of acceleration resolution for radar signal

    赵宏钟; 付强

    2003-01-01

    The high acceleration of moving targets has brought severe problems in radar signal processing, such as the decrease in output signal-noise-ratio and the deterioration of Doppler resolution. This paper presents an acceleration ambiguity function (AAF) for characterizing the acceleration effects and the acceleration resolution property in radar signal processing. The definition of the acceleration resolution based on AAF is also presented. Using AAF as an analyzing tool, some factors are derived including the loss factor of output SNR, the broadening factor of Doppler resolution, and the optimal accumulative time (OPT) caused by acceleration in linear-phase matched filtering. The convergent property of quadratic-phase matched-filter for searching for and estimating the acceleration is discussed. The results and conclusions are helpful for the quantitative analysis of the acceleration effects on signal processing, and for evaluation of the performance of acceleration in radar signal waveform design.

  7. Accelerated life models modeling and statistical analysis

    Bagdonavicius, Vilijandas

    2001-01-01

    Failure Time DistributionsIntroductionParametric Classes of Failure Time DistributionsAccelerated Life ModelsIntroductionGeneralized Sedyakin's ModelAccelerated Failure Time ModelProportional Hazards ModelGeneralized Proportional Hazards ModelsGeneralized Additive and Additive-Multiplicative Hazards ModelsChanging Shape and Scale ModelsGeneralizationsModels Including Switch-Up and Cycling EffectsHeredity HypothesisSummaryAccelerated Degradation ModelsIntroductionDegradation ModelsModeling the Influence of Explanatory Varia

  8. Risk analysis of linear accelerator radiosurgery

    Purpose: To evaluate the toxicity of stereotactic single-dose irradiation and to compare the own results with already existing risk prediction models. Methods and Materials: Computed tomography (CT) or magnetic-resonance (MR) images, and clinical data of 133 consecutive patients treated with linear accelerator radiosurgery were analyzed retrospectively. Using the Cox proportional hazards model the relevance of treatment parameters and dose-volume relationships on the occurrence of radiation-induced tissue changes (edema, localized blood-brain barrier breakdown) were assessed. Results: Sixty-two intraparenchymal lesions (arteriovenous malformation (AVM): 56 patients, meningioma: 6 patients) and 73 skull base tumors were selected for analysis. The median follow-up was 28.1 months (range: 9.0-58.9 months). Radiation-induced tissue changes (32 out of 135, 23.7%) were documented on CT or MR images 3.6-58.7 months after radiosurgery (median time: 17.8 months). The actuarial risk at 2 years for the development of neuroradiological changes was 25.8% for all evaluated patients, 38.4% for intraparenchymal lesions, and 14.6% for skull base tumors. The coefficient: total volume receiving a minimum dose of 10 Gy (VTREAT10) reached statistical significance in a Cox proportional hazards model calculated for all patients, intraparenchymal lesions, and AVMs. In skull base tumors, the volume of normal brain tissue covered by the 10 Gy isodose line (VBRAIN10) was the only significant variable. Conclusions: These results demonstrate the particular vulnerability of normal brain tissue to single dose irradiation. Optimal conformation of the therapeutic isodose line to the 3D configuration of the target volume may help to reduce side effects

  9. Actinides analysis by accelerator mass spectrometry

    At the ANTARES accelerator at ANSTO a new beamline has been commissioned, incorporating new magnetic and electrostatic analysers, to optimise the efficiency for Actinides detection by Accelerator Mass Spectrometry (AMS). The detection of Actinides, particularly the isotopic ratios of uranium and plutonium, provide unique signatures for nuclear safeguards purposes. We are currently engaged in a project to evaluate the application of AMS to the measurement of Actinides in environmental samples for nuclear safeguards. Levels of certain fission products, Actinides and other radioactive species can be used as indicators of undeclared nuclear facilities or activities, either on-going or in the past Other applications of ultra-sensitive detection of Actinides are also under consideration. neutron-attenuation images of a porous reservoir rock

  10. Maternal-Zygotic Epistasis and the Evolution of Genetic Diseases

    Nicholas K. Priest

    2010-01-01

    Full Text Available Many birth defects and genetic diseases are expressed in individuals that do not carry the disease causing alleles. Genetic diseases observed in offspring can be caused by gene expression in mothers and by interactions between gene expression in mothers and offspring. It is not clear whether the underlying pattern of gene expression (maternal versus offspring affects the incidence of genetic disease. Here we develop a 2-locus population genetic model with epistatic interactions between a maternal gene and a zygotic gene to address this question. We show that maternal effect genes that affect disease susceptibility in offspring persist longer and at higher frequencies in a population than offspring genes with the same effects. We find that specific forms of maternal-zygotic epistasis can maintain disease causing alleles at high frequencies over a range of plausible values. Our findings suggest that the strength and form of epistasis and the underlying pattern of gene expression may greatly influence the prevalence of human genetic diseases.

  11. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  12. Diminishing-returns epistasis among random beneficial mutations in a multicellular fungus.

    Schoustra, Sijmen; Hwang, Sungmin; Krug, Joachim; de Visser, J Arjan G M

    2016-08-31

    Adaptive evolution ultimately is fuelled by mutations generating novel genetic variation. Non-additivity of fitness effects of mutations (called epistasis) may affect the dynamics and repeatability of adaptation. However, understanding the importance and implications of epistasis is hampered by the observation of substantial variation in patterns of epistasis across empirical studies. Interestingly, some recent studies report increasingly smaller benefits of beneficial mutations once genotypes become better adapted (called diminishing-returns epistasis) in unicellular microbes and single genes. Here, we use Fisher's geometric model (FGM) to generate analytical predictions about the relationship between the effect size of mutations and the extent of epistasis. We then test these predictions using the multicellular fungus Aspergillus nidulans by generating a collection of 108 strains in either a poor or a rich nutrient environment that each carry a beneficial mutation and constructing pairwise combinations using sexual crosses. Our results support the predictions from FGM and indicate negative epistasis among beneficial mutations in both environments, which scale with mutational effect size. Hence, our findings show the importance of diminishing-returns epistasis among beneficial mutations also for a multicellular organism, and suggest that this pattern reflects a generic constraint operating at diverse levels of biological organization. PMID:27559062

  13. Development of image acquisition and analysis software for accelerator applications

    The electron beam profile, beam size and beam position are some of the important parameters in an accelerator. Measurement of these parameters in a quantitative manner allows accelerator operators to optimize other beam and machine parameters. One of the most commonly used device for measurement of beam profile and beam size in an accelerator is fluorescent screen beam profile monitor. In Indus Accelerator Complex at Raja Ramanna Centre for Advanced Technology (RRCAT), fluorescent screen beam profile monitors are installed in Transport Lines, Booster Synchrotron, Indus-1 and Indus-2 ring. A software has been developed in-house for image acquisition and analysis which allows accelerator operators to capture the images of beam. Once image is acquired, user can process the image offline to find beam profile and beam position. The software supports various modes of image acquisition and has built-in function for viewing the beam profile. The software allows accelerator operators to create audio video interleave (AVI) files from the acquired images and built-in AVI file viewer allows operators to play the AVI files. The software has been installed in Indus accelerator control room and now routinely being used by Indus accelerator operation group. This paper presents the various features of the software. (author)

  14. Analysis of accelerated motion in the theory of relativity

    Jones, R. T.

    1976-01-01

    Conventional treatments of accelerated motion in the theory of relativity have led to certain difficulties of interpretation. Certain reversals in the apparent gravitational field of an accelerated body may be avoided by simpler analysis based on the use of restricted conformal transformations. In the conformal theory the velocity of light remains constant even for experimenters in accelerated motion. The problem considered is that of rectilinear motion with a variable velocity. The motion takes place along the x or x' axis of two coordinate systems.

  15. Accelerator-driven transmutation reactor analysis code system (ATRAS)

    Sasa, Toshinobu; Tsujimoto, Kazufumi; Takizuka, Takakazu; Takano, Hideki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    JAERI is proceeding a design study of the hybrid type minor actinide transmutation system which mainly consist of an intense proton accelerator and a fast subcritical core. Neutronics and burnup characteristics of the accelerator-driven system is important from a view point of the maintenance of subcriticality and energy balance during the system operation. To determine those characteristics accurately, it is necessary to involve reactions at high-energy region, which are not treated on ordinary reactor analysis codes. The authors developed a code system named ATRAS to analyze the neutronics and burnup characteristics of accelerator-driven subcritical reactor systems. ATRAS has a function of burnup analysis taking account of the effect of spallation neutron source. ATRAS consists of a spallation analysis code, a neutron transport codes and a burnup analysis code. Utility programs for fuel exchange, pre-processing and post-processing are also incorporated. (author)

  16. Accelerator-driven transmutation reactor analysis code system (ATRAS)

    JAERI is proceeding a design study of the hybrid type minor actinide transmutation system which mainly consist of an intense proton accelerator and a fast subcritical core. Neutronics and burnup characteristics of the accelerator-driven system is important from a view point of the maintenance of subcriticality and energy balance during the system operation. To determine those characteristics accurately, it is necessary to involve reactions at high-energy region, which are not treated on ordinary reactor analysis codes. The authors developed a code system named ATRAS to analyze the neutronics and burnup characteristics of accelerator-driven subcritical reactor systems. ATRAS has a function of burnup analysis taking account of the effect of spallation neutron source. ATRAS consists of a spallation analysis code, a neutron transport codes and a burnup analysis code. Utility programs for fuel exchange, pre-processing and post-processing are also incorporated. (author)

  17. Rapid Electromagnetic Analysis of Entire Accelerator Structures

    Cooke, Simon

    2005-01-01

    We present results of a new method for fast, accurate calculation, in 3-D, of the electromagnetic mode spectrum of long, tapered accelerator structures. Instead of discretizing the entire structure directly and solving a huge matrix eigenvalue problem, we use a new two-step technique that scales much better to long, multi-cavity structures. In the first step we compute a small number of eigenmodes of individual cavities, achieving 0.05% frequency accuracy using a new second-order finite-element code. In the second step we use these 3-D mode solutions as field basis functions to obtain a reduced matrix representation of Maxwell's equations for the complete structure. Solving the reduced system takes just a few minutes on a desktop PC even with more than 100 non-identical cavities, and gives the complete mode spectrum in the first few bands of the structure. By judicious choice of the basis modes, we retain 0.05% frequency accuracy for these global solutions, and can reconstruct the complete 3-D field of each m...

  18. Introduction to Physical and Technical Analysis of Accelerator Driven System

    In the present paper the main elements of the accelerator driven system (ADS) are discussed. Describing the spallation source it is underlined that beside the well accepted theory of spallation, the spallation phenomena is not yet sufficiently investigated. Dealing with the sub-critical reactor as an energy amplifier of the primary spallation source a suggestion for the specific neutron spectrum is proposed to obtain optimal conditions for energy production, burn-up and transmutation. In the chapter devoted for the accelerators which accelerates the charged particles, the two accelerator principles are presented on the examples of working accelerators: the linear accelerator - LINAC and cyclotron. Finally, there is presented the project of accelerator driven system - MYRHA for research and development worked out by the Belgian Nuclear Research Centre - SCK-CEN and the conception of nuclear power station of RBMK-1000 type with spallation source together with analysis of the balance of energy worked out by the Joint Institute of Nuclear Research, Dubna, Russia. (author)

  19. Radiation Shielding Analysis of Electron Beam Accelerator Facility

    The objective of this technical report are to establish the radiation shielding technology of a high-energy electron accelerator to the facilities which utilize with electron beam. The technologies of electron beam irradiation(300 KeV -10 MeV) demand on the diverse areas of material processing, surface treatment, treatments on foods or food processing, improvement of metal properties, semiconductors, and ceramics, sterilization of medical goods and equipment, treatment and control of contamination and pollution, and so on. In order to acquire safety design for the protection of personnel from the radiations produced by electron beam accelerators, it is important to develop the radiation shielding analysis technology. The shielding analysis are carried out by which define source term, calculation modelling and computer calculations for 2 MeV and 10 MeV accelerators. And the shielding analysis for irradiation dump shield with 10 MeV accelerators are also performed by solving the complex 3-D geometry and long computer run time problem. The technology development of shielding analysis will be contributed to extend the further high energy accelerator development

  20. Schottky noise analysis in linear accelerators

    An application of Schottky noise analysis is theoretically presented for the diagnosis of intense beams in linacs. Induced currents by betatron/synchroton oscillations of particles as well as mismatched-envelope oscillations are calculated by applying different models. The induced currents are analytically Fourier-analyzed. Resulting power spectra show some stochastic peaks which reflect basic parameters of these oscillations. (orig.)

  1. Estimation and analysis of neutron skyshine at particle accelerators

    This report deals with the neutron dosimetry at the accelerator environment with a special emphasis given to the neutron skyshine problem. Theoretical studies have been carried out for the estimation of neutron skyshine dose using experimentally measured neutron spectra as well as those obtained using theoretically simulated nuclear reaction model calculations. A detailed analysis has been performed with respect to several variables. (author)

  2. Accelerated FEM Analysis for Critical Engine Components

    Leonardo FRIZZIERO

    2014-10-01

    Full Text Available This paper introduces a method to simplify a nonlinear problem in order to use linear finite element analysis. This approach improves calculation time by 2 orders of magnitude. It is then possible to optimize the geometry of the components even without supercomputers. In this paper the method is applied to a very critical component: the aluminium alloy piston of a modern common rail diesel engine. The method consists in the subdivision of the component, in this case the piston, in several volumes, that have approximately a constant temperature. These volumes are then assembled through congruence constraints. To each volume a proper material is then assigned. It is assumed that material behaviour depends on average temperature, load magnitude and load gradient. This assumption is valid since temperatures vary slowly when compared to pressure (load. In fact pressures propagate with the speed of sound. The method is validated by direct comparison with nonlinear simulation of the same component, the piston, taken as an example. In general, experimental tests have confirmed the cost-effectiveness of this approach.

  3. Cancer type-dependent genetic interactions between cancer driver alterations indicate plasticity of epistasis across cell types.

    Park, Solip; Lehner, Ben

    2015-07-01

    Cancers, like many diseases, are normally caused by combinations of genetic alterations rather than by changes affecting single genes. It is well established that the genetic alterations that drive cancer often interact epistatically, having greater or weaker consequences in combination than expected from their individual effects. In a stringent statistical analysis of data from > 3,000 tumors, we find that the co-occurrence and mutual exclusivity relationships between cancer driver alterations change quite extensively in different types of cancer. This cannot be accounted for by variation in tumor heterogeneity or unrecognized cancer subtypes. Rather, it suggests that how genomic alterations interact cooperatively or partially redundantly to driver cancer changes in different types of cancers. This re-wiring of epistasis across cell types is likely to be a basic feature of genetic architecture, with important implications for understanding the evolution of multicellularity and human genetic diseases. In addition, if this plasticity of epistasis across cell types is also true for synthetic lethal interactions, a synthetic lethal strategy to kill cancer cells may frequently work in one type of cancer but prove ineffective in another. PMID:26227665

  4. Multidimensional epistasis and the transitory advantage of sex.

    Stefan Nowak

    2014-09-01

    Full Text Available Identifying and quantifying the benefits of sex and recombination is a long-standing problem in evolutionary theory. In particular, contradictory claims have been made about the existence of a benefit of recombination on high dimensional fitness landscapes in the presence of sign epistasis. Here we present a comparative numerical study of sexual and asexual evolutionary dynamics of haploids on tunably rugged model landscapes under strong selection, paying special attention to the temporal development of the evolutionary advantage of recombination and the link between population diversity and the rate of adaptation. We show that the adaptive advantage of recombination on static rugged landscapes is strictly transitory. At early times, an advantage of recombination arises through the possibility to combine individually occurring beneficial mutations, but this effect is reversed at longer times by the much more efficient trapping of recombining populations at local fitness peaks. These findings are explained by means of well-established results for a setup with only two loci. In accordance with the Red Queen hypothesis the transitory advantage can be prolonged indefinitely in fluctuating environments, and it is maximal when the environment fluctuates on the same time scale on which trapping at local optima typically occurs.

  5. Continuous-flow accelerator mass spectrometry for radiocarbon analysis

    Accelerator Mass Spectrometry (AMS) is a widely used technique for radiocarbon dating of archaeological or environmental samples that are very small or very old (up to 50,000 years before present). Because of the method's extreme sensitivity, AMS can also serve as an environmental tracer and supplements conventional nuclear counting techniques for monitoring 14C emissions from operating nuclear power plants and waste repositories. The utility of present AMS systems is limited by the complex sample preparation process required. Carbon from combusted artefacts must be incorporated into a solid metallic target from which a negative ion beam is produced and accelerated to MeV energies by an accelerator for subsequent analysis. This paper will describe a novel technique being developed by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Laboratory at the Woods Hole Oceanographic Institution for the production of negative carbon ion beams directly from a continuously flowing sample gas stream, eliminating the requirement for a solid target. A key component of the new technique is a microwave-driven, gaseous-feed ion source originally developed at Chalk River Laboratories for the very different requirements of a high current proton linear accelerator. A version of this ion source is now being adapted to serve as an injector for a dedicated AMS accelerator facility at NOSAMS. The paper begins with a review of the fundamentals of radiocarbon dating. Experiments carried out at NOSAMS with a prototype of the microwave ion source are described, including measurements of sample utilization efficiency and sample 'memory' effect. A new version of the microwave ion source, optimized for AMS, is also described. The report concludes with some predictions of new research opportunities that will become accessible to the technique of continuous-flow AMS. (author)

  6. Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

    Rubel, Oliver; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Wu, Kesheng; Prabhat,; Weber, Gunther H.; Ushizima, Daniela M.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

    2009-10-19

    Numerical simulations of laser wakefield particle accelerators play a key role in the understanding of the complex acceleration process and in the design of expensive experimental facilities. As the size and complexity of simulation output grows, an increasingly acute challenge is the practical need for computational techniques that aid in scientific knowledge discovery. To that end, we present a set of data-understanding algorithms that work in concert in a pipeline fashion to automatically locate and analyze high energy particle bunches undergoing acceleration in very large simulation datasets. These techniques work cooperatively by first identifying features of interest in individual timesteps, then integrating features across timesteps, and based on the information derived perform analysis of temporally dynamic features. This combination of techniques supports accurate detection of particle beams enabling a deeper level of scientific understanding of physical phenomena than hasbeen possible before. By combining efficient data analysis algorithms and state-of-the-art data management we enable high-performance analysis of extremely large particle datasets in 3D. We demonstrate the usefulness of our methods for a variety of 2D and 3D datasets and discuss the performance of our analysis pipeline.

  7. Model independent analysis on the slowing down of cosmic acceleration

    Zhang, Ming-Jian

    2016-01-01

    Possible slowing down of cosmic acceleration has attracted more and more attention. However, most analysis in previous work were commonly imposed in some parametrization models. In the present paper, we investigate this subject using the the Gaussian processes (GP), providing a model-independent analysis. We carry out the reconstruction by abundant data including luminosity distance from Union2, Union2.1 compilation and gamma-ray burst, and Hubble parameter from cosmic chronometer and baryon acoustic oscillation peaks. The GP reconstructions suggest that no slowing down of cosmic acceleration is approved within 95\\% C.L. from current observational data. We also test the influence of spatial curvature and Hubble constant, finding that spatial curvature does not present significant impact on the reconstructions. However, Hubble constant strongly influence the reconstructions especially at low redshift. In order to reveal the reason of inconsistence between our reconstruction and previous parametrization constra...

  8. Measuring epistasis in fitness landscapes: The correlation of fitness effects of mutations.

    Ferretti, Luca; Schmiegelt, Benjamin; Weinreich, Daniel; Yamauchi, Atsushi; Kobayashi, Yutaka; Tajima, Fumio; Achaz, Guillaume

    2016-05-01

    Genotypic fitness landscapes are constructed by assessing the fitness of all possible combinations of a given number of mutations. In the last years, several experimental fitness landscapes have been completely resolved. As fitness landscapes are high-dimensional, simple measures of their structure are used as statistics in empirical applications. Epistasis is one of the most relevant features of fitness landscapes. Here we propose a new natural measure of the amount of epistasis based on the correlation of fitness effects of mutations. This measure has a natural interpretation, captures well the interaction between mutations and can be obtained analytically for most landscape models. We discuss how this measure is related to previous measures of epistasis (number of peaks, roughness/slope, fraction of sign epistasis, Fourier-Walsh spectrum) and how it can be easily extended to landscapes with missing data or with fitness ranks only. Furthermore, the dependence of the correlation of fitness effects on mutational distance contains interesting information about the patterns of epistasis. This dependence can be used to uncover the amount and nature of epistatic interactions in a landscape or to discriminate between different landscape models. PMID:26854875

  9. Shadows of complexity: what biological networks reveal about epistasis and pleiotropy.

    Tyler, Anna L; Asselbergs, Folkert W; Williams, Scott M; Moore, Jason H

    2009-02-01

    Pleiotropy, in which one mutation causes multiple phenotypes, has traditionally been seen as a deviation from the conventional observation in which one gene affects one phenotype. Epistasis, or gene-gene interaction, has also been treated as an exception to the Mendelian one gene-one phenotype paradigm. This simplified perspective belies the pervasive complexity of biology and hinders progress toward a deeper understanding of biological systems. We assert that epistasis and pleiotropy are not isolated occurrences, but ubiquitous and inherent properties of biomolecular networks. These phenomena should not be treated as exceptions, but rather as fundamental components of genetic analyses. A systems level understanding of epistasis and pleiotropy is, therefore, critical to furthering our understanding of human genetics and its contribution to common human disease. Finally, graph theory offers an intuitive and powerful set of tools with which to study the network bases of these important genetic phenomena. PMID:19204994

  10. Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing

    Immonen, Elina; Collet, Marie; Goenaga, Julieta;

    2016-01-01

    Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex...... to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners...... beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due...

  11. Analysis of accelerants and fire debris using aroma detection technology

    Barshick, S.A.

    1997-01-17

    The purpose of this work was to investigate the utility of electronic aroma detection technologies for the detection and identification of accelerant residues in suspected arson debris. Through the analysis of known accelerant residues, a trained neural network was developed for classifying suspected arson samples. Three unknown fire debris samples were classified using this neural network. The item corresponding to diesel fuel was correctly identified every time. For the other two items, wide variations in sample concentration and excessive water content, producing high sample humidities, were shown to influence the sensor response. Sorbent sampling prior to aroma detection was demonstrated to reduce these problems and to allow proper neural network classification of the remaining items corresponding to kerosene and gasoline.

  12. Accelerated Gibbs Sampling for Infinite Sparse Factor Analysis

    Andrzejewski, D M

    2011-09-12

    The Indian Buffet Process (IBP) gives a probabilistic model of sparse binary matrices with an unbounded number of columns. This construct can be used, for example, to model a fixed numer of observed data points (rows) associated with an unknown number of latent features (columns). Markov Chain Monte Carlo (MCMC) methods are often used for IBP inference, and in this technical note, we provide a detailed review of the derivations of collapsed and accelerated Gibbs samplers for the linear-Gaussian infinite latent feature model. We also discuss and explain update equations for hyperparameter resampling in a 'full Bayesian' treatment and present a novel slice sampler capable of extending the accelerated Gibbs sampler to the case of infinite sparse factor analysis by allowing the use of real-valued latent features.

  13. GPU accelerated dynamic functional connectivity analysis for functional MRI data.

    Akgün, Devrim; Sakoğlu, Ünal; Esquivel, Johnny; Adinoff, Bryon; Mete, Mutlu

    2015-07-01

    Recent advances in multi-core processors and graphics card based computational technologies have paved the way for an improved and dynamic utilization of parallel computing techniques. Numerous applications have been implemented for the acceleration of computationally-intensive problems in various computational science fields including bioinformatics, in which big data problems are prevalent. In neuroimaging, dynamic functional connectivity (DFC) analysis is a computationally demanding method used to investigate dynamic functional interactions among different brain regions or networks identified with functional magnetic resonance imaging (fMRI) data. In this study, we implemented and analyzed a parallel DFC algorithm based on thread-based and block-based approaches. The thread-based approach was designed to parallelize DFC computations and was implemented in both Open Multi-Processing (OpenMP) and Compute Unified Device Architecture (CUDA) programming platforms. Another approach developed in this study to better utilize CUDA architecture is the block-based approach, where parallelization involves smaller parts of fMRI time-courses obtained by sliding-windows. Experimental results showed that the proposed parallel design solutions enabled by the GPUs significantly reduce the computation time for DFC analysis. Multicore implementation using OpenMP on 8-core processor provides up to 7.7× speed-up. GPU implementation using CUDA yielded substantial accelerations ranging from 18.5× to 157× speed-up once thread-based and block-based approaches were combined in the analysis. Proposed parallel programming solutions showed that multi-core processor and CUDA-supported GPU implementations accelerated the DFC analyses significantly. Developed algorithms make the DFC analyses more practical for multi-subject studies with more dynamic analyses. PMID:25805449

  14. Epistasis and Maternal Effect in Resistance to Puccinia coronata Cda.f.sp.avenae Eriks in Oats (Avena sp.)

    Bnejdi F; Hammami I; Allagui M B; Saadoun M; el Gazzah M

    2010-01-01

    The objective of this paper was to investigate the mode of heredity for resistance in oats (Arena sp.) to crown rust caused by Puccinia coronata Cda.f.sp.avenae Eriks.Eight generations of 2 crosses were used to estimate genetic effects and narrow-sense heritability (NSH).Separate generation means analysis (GMA) indicated a complex gene action controlling this trait with additive,dominance,epistatic and maternal effects (ME).The genetic model which assumed no epistasis and no ME did not accurately describe the resistance to P.coronata.In both crosses,the digenic epistatic model with ME epistatic components were negative in most cases,suggesting that gene effects contributed more to the resistance than to the susceptibility.The estimated values of NSH were 15-99% depending upon the cross and isolates.The results indicated that appropriate choice of maternal parent and recurrent selection would increase resistance to crown rust in oats.

  15. Acceleration of multivariate analysis techniques in TMVA using GPUs

    Hoecker, A; Therhaag, J; Washbrook, A

    2012-01-01

    A feasibility study into the acceleration of multivariate analysis techniques using Graphics Processing Units (GPUs) will be presented. The MLP-based Artificial Neural Network method contained in the TMVA framework has been chosen as a focus for investigation. It was found that the network training time on a GPU was lower than for CPU execution as the complexity of the network was increased. In addition, multiple neural networks can be trained simultaneously on a GPU within the same time taken for single network training on a CPU. This could be potentially leveraged to provide a qualitative performance gain in data classification.

  16. Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing.

    Immonen, E; Collet, M; Goenaga, J; Arnqvist, G

    2016-01-01

    Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex differences in the efficacy of selection on mitonuclear genotypes that should result in differences between females and males in mitochondrial genetic effects. Mitonuclear genotype of a focal individual may also indirectly affect trait expression in the mating partner. We tested these predictions in the seed beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity, egg size, longevity). These results demonstrate important consequences of sex-specific mitonuclear epistasis for both mating partners, consistent with a role for mitonuclear genetic constraints upon sex-specific adaptive evolution. PMID:26732015

  17. The development of a standard format for accelerator data analysis

    The purpose of specifying a standard file format is to facilitate the analysis of data sampled by accelerator beam diagnostic instrumentation. The format's design needs to be flexible enough to allow storage of information from disparate diagnostic devices placed in the beam line. The goal of this project was to establish a standard file layout and syntax that can be generated and ''understood'' by a large set of applications running on the control and data-analysis computers at LAMPF as well as applications on personal computers. Only one file-parsing algorithm is needed for all computing systems. It is a straightforward process to code a parser for both the control computer and pc's once a consensus on the file syntax has been established. This paper describes the file format and the methods used to integrate the format into existing diagnostic and control software

  18. Cosmic acceleration without dark energy: background tests and thermodynamic analysis

    A cosmic scenario with gravitationally induced particle creation is proposed. In this model the Universe evolves from an early to a late time de Sitter era, with the recent accelerating phase driven only by the negative creation pressure associated with the cold dark matter component. The model can be interpreted as an attempt to reduce the so-called cosmic sector (dark matter plus dark energy) and relate the two cosmic accelerating phases (early and late time de Sitter expansions). A detailed thermodynamic analysis including possible quantum corrections is also carried out. For a very wide range of the free parameters, it is found that the model presents the expected behavior of an ordinary macroscopic system in the sense that it approaches thermodynamic equilibrium in the long run (i.e., as it nears the second de Sitter phase). Moreover, an upper bound is found for the Gibbons–Hawking temperature of the primordial de Sitter phase. Finally, when confronted with the recent observational data, the current 'quasi'-de Sitter era, as predicted by the model, is seen to pass very comfortably the cosmic background tests

  19. GPU-ACCELERATED FEM SOLVER FOR THREE DIMENSIONAL ELECTROMAGNETIC ANALYSIS

    Tian Jin; Gong Li; Shi Xiaowei; Le Xu

    2011-01-01

    A new Graphics Processing Unit (GPU) parallelization strategy is proposed to accelerate sparse finite element computation for three dimensional electromagnetic analysis.The parallelization strategy is employed based on a new compression format called sliced ELL Four (sliced ELL-F).The sliced ELL-F format-based parallelization strategy is designed for hastening many addition,dot product,and Sparse Matrix Vector Product (SMVP) operations in the Conjugate Gradient Norm (CGN) calculation of finite element equations.The new implementation of SMVP on GPUs is evaluated.The proposed strategy executed on a GPU can efficiently solve sparse finite element equations,especially when the equations are huge sparse (size of most rows in a coefficient matrix is less than 8).Numerical results show the sliced ELL-F format-based parallelization strategy can reach significant speedups compared to Compressed Sparse Row (CSR) format.

  20. Discovering epistasis in large scale genetic association studies by exploiting graphics cards

    Gary K Chen

    2013-12-01

    Full Text Available Despite the enormous investments made in collecting DNA samples and generating germline variation data across thousands of individuals in modern genome wide association studies (GWAS, progress has been frustratingly slow in explaining much of the heritability in common disease. Today’s paradigm of testing independent hypotheses on each SNP marker is unlikely to adequately reflect the complex biological processes in disease risk. Alternatively, modeling risk as an ensemble of SNPs that act in concert in a pathway, and/or interact non-additively on log risk for example, may be a more sensible way to approach gene mapping in modern studies. Implementing such analyses genome-wide can quickly become intractable due to the fact that even modest size SNP panels on modern genotype arrays (500k markers pose a combinatorial nightmare, require tens of billions of models to be tested for evidence of interaction. In this article, we provide an in-depth analysis of programs that have been developed to explicitly overcome these enormous computational barriers through the use of processors on graphics cards known as Graphics Processing Units (GPU. We include tutorials on GPU technology, which will convey why they are growing in appeal with today’s numerical scientists. One obvious advantage is the impressive density of microprocessor cores that are available on only a single GPU. Whereas high end servers feature up to 24 Intel or AMD CPU cores, the latest GPU offerings from nVidia feature over 2,600 cores. Each compute node may be outfitted with up to 4 GPU devices. Success on GPUs varies across problems. However epistasis screens fare well due to the high degree of parallelism exposed in these problems. Papers that we review routinely report GPU speedups of over two orders of magnitude (>100x over standard CPU implementations.

  1. Discovering epistasis in large scale genetic association studies by exploiting graphics cards.

    Chen, Gary K; Guo, Yunfei

    2013-01-01

    Despite the enormous investments made in collecting DNA samples and generating germline variation data across thousands of individuals in modern genome-wide association studies (GWAS), progress has been frustratingly slow in explaining much of the heritability in common disease. Today's paradigm of testing independent hypotheses on each single nucleotide polymorphism (SNP) marker is unlikely to adequately reflect the complex biological processes in disease risk. Alternatively, modeling risk as an ensemble of SNPs that act in concert in a pathway, and/or interact non-additively on log risk for example, may be a more sensible way to approach gene mapping in modern studies. Implementing such analyzes genome-wide can quickly become intractable due to the fact that even modest size SNP panels on modern genotype arrays (500k markers) pose a combinatorial nightmare, require tens of billions of models to be tested for evidence of interaction. In this article, we provide an in-depth analysis of programs that have been developed to explicitly overcome these enormous computational barriers through the use of processors on graphics cards known as Graphics Processing Units (GPU). We include tutorials on GPU technology, which will convey why they are growing in appeal with today's numerical scientists. One obvious advantage is the impressive density of microprocessor cores that are available on only a single GPU. Whereas high end servers feature up to 24 Intel or AMD CPU cores, the latest GPU offerings from nVidia feature over 2600 cores. Each compute node may be outfitted with up to 4 GPU devices. Success on GPUs varies across problems. However, epistasis screens fare well due to the high degree of parallelism exposed in these problems. Papers that we review routinely report GPU speedups of over two orders of magnitude (>100x) over standard CPU implementations. PMID:24348518

  2. Numerical analysis of flow fields generated by accelerating flames

    Kurylo, J.

    1977-12-01

    Presented here is a numerical technique for the analysis of non-steady flow fields generated by accelerating flames in gaseous media. Of particular interest in the study is the evaluation of the non-steady effects on the flow field and the possible transition of the combustion process to detonation caused by an abrupt change in the burning speed of an initially steady flame propagating in an unconfined combustible gas mixture. Optically recorded observations of accelerating flames established that the flow field can be considered to consist of non-steady flow fields associated with an assembly of interacting shock waves, contact discontinuities, deflagration and detonation fronts. In the analysis, these flow fields are treated as spatially one-dimensional, the influence of transport phenomena is considered to be negligible, and unburned and burned substances are assumed to behave as perfect gases with constant, but different, specific heats. The basis of the numerical technique is an explicit, two step, second order accurate, finite difference scheme employed to integrate the flow field equations expressed in divergence form. The burning speed, governing the motion of the deflagration, is expressed in the form of a power law dependence on pressure and temperature immediately ahead of its front. The steady wave solution is obtained by the vector polar interaction technique, that is, by determining the point of intersection between the loci of end states in the plane of the two interaction invariants, pressure and particle velocity. The technique is illustrated by a numerical example in which a steady flame experiences an abrupt change in its burning speed. Solutions correspond either to the eventual reestablishment of a steady state flow field commensurate with the burning speed or to the transition to detonation. The results are in satisfactory agreement with experimental observations.

  3. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    Watrous, Matthew George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Adamic, Mary Louise [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, John Eric [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baeck, D. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fox, R. V. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hahn, P. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jenson, D. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lister, T. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world’s best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

  4. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    M. L. Adamic; J. E. Olson; D. D. Jenson; J. G. Eisenmenger; M. G. Watrous

    2012-09-01

    This NA 22 funded research project investigated the transition of iodine isotopic analyses from thermal ionization mass spectrometry (TIMS) to an accelerator mass spectrometry (AMS) system. Previous work (Fiscal Year 2010) had demonstrated comparable data from TIMS and AMS. With AMS providing comparable data with improved background levels and vastly superior sample throughput, improvement in the sample extraction from environmental sample matrices was needed to bring sample preparation throughput closer to the operation level of the instrument. Previous research used an extraction chemistry that was not optimized for yield or refined for reduced labor to prove the principle. This research was done to find an extraction with better yield using less labor per sample to produce a sample ready for the AMS instrument. An extraction method using tetramethyl ammonium hydroxide (TMAH) was developed for removal of iodine species from high volume air filters. The TMAH with gentle heating was superior to the following three extraction methods: ammonium hydroxide aided by sonication, acidic and basic extraction aided by microwave, and ethanol mixed with sodium hydroxide. Taking the iodine from the extraction solvent to being ready for AMS analysis was accomplished by a direct precipitation, as well as, using silver wool to harvest the iodine from the TMAH. Portions of the same filters processed in FY 2010 were processed again with the improved extraction scheme followed by successful analysis by AMS at the Swiss Federal Institute of Technology. The data favorably matched the data obtained in 2010. The time required for analysis has been reduced over the aqueous extraction/AMS approach developed in FY 2010. For a hypothetical batch of 30 samples, the AMS methodology is about 10 times faster than the traditional gas phase chemistry and TIMS analysis. As an additional benefit, background levels for the AMS method are about 1000 times lower than TIMS. This results from the

  5. Statistical analysis of accelerated temperature aging of semiconductor devices

    Johnson, W. A.; Milles, M. F.

    1981-05-01

    A number of semiconductor devices taken from a distribution were operated at several elevated temperatures to induce failure in all devices within a reasonable time. Assuming general characteristics of the device failure probability density function (pdf) and its temperature dependence, the expected cumulative failure function (cff) for devices in normal operation were estimated based on statistical inference, taking the average probability of a random device (from the same distribution but operated at a normal temperature) failing as a function of time. A review of the mathematical formalism employed in semiconductor reliability discussions is included. Three failure pdf's at particular usefulness to this analysis--exponential, normal, and lognormal - are discussed. The cff, at times orders of magnitude loss then, at times comparable to the desired system useful, life (*10 to the 4th power to 10 to the 5th power hr) is considered. A review of accelerated temperature aging is presented, and the assumption concerning the general characteristics of the failure pdf, which are fundamental to this analysis, are emphasized.

  6. Accelerated Sensitivity Analysis in High-Dimensional Stochastic Reaction Networks

    Arampatzis, Georgios; Katsoulakis, Markos A.; Pantazis, Yannis

    2015-01-01

    Existing sensitivity analysis approaches are not able to handle efficiently stochastic reaction networks with a large number of parameters and species, which are typical in the modeling and simulation of complex biochemical phenomena. In this paper, a two-step strategy for parametric sensitivity analysis for such systems is proposed, exploiting advantages and synergies between two recently proposed sensitivity analysis methodologies for stochastic dynamics. The first method performs sensitivity analysis of the stochastic dynamics by means of the Fisher Information Matrix on the underlying distribution of the trajectories; the second method is a reduced-variance, finite-difference, gradient-type sensitivity approach relying on stochastic coupling techniques for variance reduction. Here we demonstrate that these two methods can be combined and deployed together by means of a new sensitivity bound which incorporates the variance of the quantity of interest as well as the Fisher Information Matrix estimated from the first method. The first step of the proposed strategy labels sensitivities using the bound and screens out the insensitive parameters in a controlled manner. In the second step of the proposed strategy, a finite-difference method is applied only for the sensitivity estimation of the (potentially) sensitive parameters that have not been screened out in the first step. Results on an epidermal growth factor network with fifty parameters and on a protein homeostasis with eighty parameters demonstrate that the proposed strategy is able to quickly discover and discard the insensitive parameters and in the remaining potentially sensitive parameters it accurately estimates the sensitivities. The new sensitivity strategy can be several times faster than current state-of-the-art approaches that test all parameters, especially in “sloppy” systems. In particular, the computational acceleration is quantified by the ratio between the total number of parameters over

  7. Transient analysis of a coupled accelerator and decelerator system

    For an energy-efficient accelerator system to be used for a free-electron laser, the stability of an energy-recovery system utilizing a bridge coupler placed between the accelerator and the decelerator is studied numerically. Energy is recovered by recirculating the accelerated electron beam through the decelerator; the recovered energy is then transported through the bridge coupler to the accelerator. The calculation shows that a large transient voltage oscillation is induced into the system. This transient oscillation can be reduced significantly by slowly applying both the electron-beam current and the klystron power at the beginning. Two types of instabilities are predicted according to the scraping of the electron beam between the accelerator and the decelerator. When the energy spectrum of the electron beam is scraped at the high end, the system induces an oscillation. However, when the low-energy end is scraped the electron recirculation may stop unless the klystron power is boosted by a feedback system

  8. Beyond the single gene: How epistasis and gene-by-environment effects influence crop domestication

    Doust, Andrew N.; Lukens, Lewis; Olsen, Kenneth M; Mauro-Herrera, Margarita; Meyer, Ann; Rogers, Kimberly

    2014-01-01

    Recent archaeological studies of crop domestication have suggested a relatively slow spread and fixation of some key domestication traits, such as the loss of seed shattering. In contrast, genetic studies often indicate that domestication traits have a fairly simple genetic basis, which should facilitate their rapid evolution under selection. Here we examine previously underexplored factors that could account for this apparent disconnect: the roles of gene-by-gene interactions (epistasis) and...

  9. Prevalence of epistasis in the evolution of influenza A surface proteins.

    Sergey Kryazhimskiy

    2011-02-01

    Full Text Available The surface proteins of human influenza A viruses experience positive selection to escape both human immunity and, more recently, antiviral drug treatments. In bacteria and viruses, immune-escape and drug-resistant phenotypes often appear through a combination of several mutations that have epistatic effects on pathogen fitness. However, the extent and structure of epistasis in influenza viral proteins have not been systematically investigated. Here, we develop a novel statistical method to detect positive epistasis between pairs of sites in a protein, based on the observed temporal patterns of sequence evolution. The method rests on the simple idea that a substitution at one site should rapidly follow a substitution at another site if the sites are positively epistatic. We apply this method to the surface proteins hemagglutinin and neuraminidase of influenza A virus subtypes H3N2 and H1N1. Compared to a non-epistatic null distribution, we detect substantial amounts of epistasis and determine the identities of putatively epistatic pairs of sites. In particular, using sequence data alone, our method identifies epistatic interactions between specific sites in neuraminidase that have recently been demonstrated, in vitro, to confer resistance to the drug oseltamivir; these epistatic interactions are responsible for widespread drug resistance among H1N1 viruses circulating today. This experimental validation demonstrates the predictive power of our method to identify epistatic sites of importance for viral adaptation and public health. We conclude that epistasis plays a large role in shaping the molecular evolution of influenza viruses. In particular, sites with , which would normally not be identified as positively selected, can facilitate viral adaptation through epistatic interactions with their partner sites. The knowledge of specific interactions among sites in influenza proteins may help us to predict the course of antigenic evolution and

  10. STATISTICAL EPISTASIS NETWORKS REDUCE THE COMPUTATIONAL COMPLEXITY OF SEARCHING THREE-LOCUS GENETIC MODELS

    Hu, Ting; Andrew, Angeline S; KARAGAS, MARGARET R.; Moore, Jason H.

    2013-01-01

    The rapid development of sequencing technologies makes thousands to millions of genetic attributes available for testing associations with various biological traits. Searching this enormous high-dimensional data space imposes a great computational challenge in genome-wide association studies. We introduce a network-based approach to supervise the search for three-locus models of disease susceptibility. Such statistical epistasis networks (SEN) are built using strong pairwise epistatic interac...

  11. Cuckoo search epistasis: a new method for exploring significant genetic interactions

    Aflakparast, M; H. Salimi; Gerami, A; Dubé, M-P; Visweswaran, S.; Masoudi-Nejad, A

    2014-01-01

    The advent of high-throughput sequencing technology has resulted in the ability to measure millions of single-nucleotide polymorphisms (SNPs) from thousands of individuals. Although these high-dimensional data have paved the way for better understanding of the genetic architecture of common diseases, they have also given rise to challenges in developing computational methods for learning epistatic relationships among genetic markers. We propose a new method, named cuckoo search epistasis (CSE...

  12. What’s Downstream? A Set of Classroom Exercises to Help Students Understand Recessive Epistasis

    Jennifer K. Knight

    2013-08-01

    Full Text Available Undergraduate students in genetics and developmental biology courses often struggle with the concept of epistasis because they are unaware that the logic of gene interactions differs between enzymatic pathways and signaling pathways. If students try to develop and memorize a single simple rule for predicting epistatic relationships without taking into account the nature of the pathway under consideration, they can become confused by cases where the rule does not apply. To remedy this problem, we developed a short pre-/posttest, an in-class activity for small groups, and a series of clicker questions about recessive epistasis in the context of a signaling pathway that intersects with an enzymatic pathway. We also developed a series of homework problems that provide deliberate practice in applying concepts in epistasis to different pathways and experimental situations. Students show significant improvement from pretest to posttest, and perform well on homework and exam questions following this activity. Here we describe these materials, as well as the formative and summative assessment results from one group of students to show how the activities impact student learning.

  13. Systemic properties of metabolic networks lead to an epistasis-based model for heterosis.

    Fiévet, Julie B; Dillmann, Christine; de Vienne, Dominique

    2010-01-01

    The genetic and molecular approaches to heterosis usually do not rely on any model of the genotype-phenotype relationship. From the generalization of Kacser and Burns' biochemical model for dominance and epistasis to networks with several variable enzymes, we hypothesized that metabolic heterosis could be observed because the response of the flux towards enzyme activities and/or concentrations follows a multi-dimensional hyperbolic-like relationship. To corroborate this, we used the values of systemic parameters accounting for the kinetic behaviour of four enzymes of the upstream part of glycolysis, and simulated genetic variability by varying in silico enzyme concentrations. Then we "crossed" virtual parents to get 1,000 hybrids, and showed that best-parent heterosis was frequently observed. The decomposition of the flux value into genetic effects, with the help of a novel multilocus epistasis index, revealed that antagonistic additive-by-additive epistasis effects play the major role in this framework of the genotype-phenotype relationship. This result is consistent with various observations in quantitative and evolutionary genetics, and provides a model unifying the genetic effects underlying heterosis. PMID:19916003

  14. Reciprocal sign epistasis between frequently experimentally evolved adaptive mutations causes a rugged fitness landscape.

    Daniel J Kvitek

    2011-04-01

    Full Text Available The fitness landscape captures the relationship between genotype and evolutionary fitness and is a pervasive metaphor used to describe the possible evolutionary trajectories of adaptation. However, little is known about the actual shape of fitness landscapes, including whether valleys of low fitness create local fitness optima, acting as barriers to adaptive change. Here we provide evidence of a rugged molecular fitness landscape arising during an evolution experiment in an asexual population of Saccharomyces cerevisiae. We identify the mutations that arose during the evolution using whole-genome sequencing and use competitive fitness assays to describe the mutations individually responsible for adaptation. In addition, we find that a fitness valley between two adaptive mutations in the genes MTH1 and HXT6/HXT7 is caused by reciprocal sign epistasis, where the fitness cost of the double mutant prohibits the two mutations from being selected in the same genetic background. The constraint enforced by reciprocal sign epistasis causes the mutations to remain mutually exclusive during the experiment, even though adaptive mutations in these two genes occur several times in independent lineages during the experiment. Our results show that epistasis plays a key role during adaptation and that inter-genic interactions can act as barriers between adaptive solutions. These results also provide a new interpretation on the classic Dobzhansky-Muller model of reproductive isolation and display some surprising parallels with mutations in genes often associated with tumors.

  15. Genetic control of soybean seed isoflavone content: importance of statistical model and epistasis in complex traits.

    Gutierrez-Gonzalez, Juan Jose; Wu, Xiaolei; Zhang, Juan; Lee, Jeong-Dong; Ellersieck, Mark; Shannon, J Grover; Yu, Oliver; Nguyen, Henry T; Sleper, David A

    2009-10-01

    A major objective for geneticists is to decipher genetic architecture of traits associated with agronomic importance. However, a majority of such traits are complex, and their genetic dissection has been traditionally hampered not only by the number of minor-effect quantitative trait loci (QTL) but also by genome-wide interacting loci with little or no individual effect. Soybean (Glycine max [L.] Merr.) seed isoflavonoids display a broad range of variation, even in genetically stabilized lines that grow in a fixed environment, because their synthesis and accumulation are affected by many biotic and abiotic factors. Due to this complexity, isoflavone QTL mapping has often produced conflicting results especially with variable growing conditions. Herein, we comparatively mapped soybean seed isoflavones genistein, daidzein, and glycitein by using several of the most commonly used mapping approaches: interval mapping, composite interval mapping, multiple interval mapping and a mixed-model based composite interval mapping. In total, 26 QTLs, including many novel regions, were found bearing additive main effects in a population of RILs derived from the cross between Essex and PI 437654. Our comparative approach demonstrates that statistical mapping methodologies are crucial for QTL discovery in complex traits. Despite a previous understanding of the influence of additive QTL on isoflavone production, the role of epistasis is not well established. Results indicate that epistasis, although largely dependent on the environment, is a very important genetic component underlying seed isoflavone content, and suggest epistasis as a key factor causing the observed phenotypic variability of these traits in diverse environments. PMID:19626310

  16. Numerical analysis of acceleration obtained from pulsed-linear-MHD accelerator using model rocket engine

    To improve the thrust efficiency of a pulsed magnetohydrodynamic (MHD) accelerator, we perform numerical calculations that simulate the experimental conditions, which were used earlier, in an apparatus that include a model rocket engine. The one-fluid one-dimensional-MHD simulation results show agreement between the experimental and numerical results. We discuss simulation results for temporal and spatial distributions of the electrical conductivity and current density. (author)

  17. Survival dimensionality reduction (SDR: development and clinical application of an innovative approach to detect epistasis in presence of right-censored data

    Beretta Lorenzo

    2010-08-01

    Full Text Available Abstract Background Epistasis is recognized as a fundamental part of the genetic architecture of individuals. Several computational approaches have been developed to model gene-gene interactions in case-control studies, however, none of them is suitable for time-dependent analysis. Herein we introduce the Survival Dimensionality Reduction (SDR algorithm, a non-parametric method specifically designed to detect epistasis in lifetime datasets. Results The algorithm requires neither specification about the underlying survival distribution nor about the underlying interaction model and proved satisfactorily powerful to detect a set of causative genes in synthetic epistatic lifetime datasets with a limited number of samples and high degree of right-censorship (up to 70%. The SDR method was then applied to a series of 386 Dutch patients with active rheumatoid arthritis that were treated with anti-TNF biological agents. Among a set of 39 candidate genes, none of which showed a detectable marginal effect on anti-TNF responses, the SDR algorithm did find that the rs1801274 SNP in the FcγRIIa gene and the rs10954213 SNP in the IRF5 gene non-linearly interact to predict clinical remission after anti-TNF biologicals. Conclusions Simulation studies and application in a real-world setting support the capability of the SDR algorithm to model epistatic interactions in candidate-genes studies in presence of right-censored data. Availability: http://sourceforge.net/projects/sdrproject/

  18. Observation and analysis of oscillations in linear accelerators

    This report discusses the following on oscillation in linear accelerators: Betatron Oscillations; Betatron Oscillations at High Currents; Transverse Profile Oscillations; Transverse Profile Oscillations at High Currents.; Oscillation and Profile Transient Jitter; and Feedback on Transverse Oscillations

  19. Feature-based Analysis of Plasma-based Particle Acceleration Data

    Ruebel, Oliver; Geddes, Cameron G.R.; Chen, Min; Cormier-Michel, Estelle; Bethel, E. Wes

    2013-07-05

    Plasma-based particle accelerators can produce and sustain thousands of times stronger acceleration fields than conventional particle accelerators, providing a potential solution to the problem of the growing size and cost of conventional particle accelerators. To facilitate scientific knowledge discovery from the ever growing collections of accelerator simulation data generated by accelerator physicists to investigate next-generation plasma-based particle accelerator designs, we describe a novel approach for automatic detection and classification of particle beams and beam substructures due to temporal differences in the acceleration process, here called acceleration features. The automatic feature detection in combination with a novel visualization tool for fast, intuitive, query-based exploration of acceleration features enables an effective top-down data exploration process, starting from a high-level, feature-based view down to the level of individual particles. We describe the application of our analysis in practice to analyze simulations of single pulse and dual and triple colliding pulse accelerator designs, and to study the formation and evolution of particle beams, to compare substructures of a beam and to investigate transverse particle loss.

  20. Life Prediction of DC Motor using Time Series Analysis based on Accelerated Degradation Testing

    Li Wang

    2013-12-01

    Full Text Available This study presents a method of life prediction for DC motor using time series modeling procedure based on DC motor accelerated degradation testing data. DC motor accelerated degradation data are treated as time series and stochastic process are utilized to describe the degradation process for life prediction. An accelerated degradation test is processed for DC motor until they failed and the accelerated degradation data are collected for life prediction. A comparison between the predicted lifetime and the real lifetime of DC motors is processed and the results show that the life prediction of DC motors using time series analysis is effective.

  1. Trace element analysis in silicon by accelerator SIMS

    Ender, R.M.; Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Doebeli, M.; Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The accelerator SIMS technique has been applied to Si samples implanted with different elements. It has been shown that concentrations of several trace elements can be analysed down to about 1 ppb in depth profiling mode. (author) 2 figs., 1 ref.

  2. A Massively Parallel Solver for the Mechanical Harmonic Analysis of Accelerator Cavities

    Kononenko, O. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-02-17

    ACE3P is a 3D massively parallel simulation suite that developed at SLAC National Accelerator Laboratory that can perform coupled electromagnetic, thermal and mechanical study. Effectively utilizing supercomputer resources, ACE3P has become a key simulation tool for particle accelerator R and D. A new frequency domain solver to perform mechanical harmonic response analysis of accelerator components is developed within the existing parallel framework. This solver is designed to determine the frequency response of the mechanical system to external harmonic excitations for time-efficient accurate analysis of the large-scale problems. Coupled with the ACE3P electromagnetic modules, this capability complements a set of multi-physics tools for a comprehensive study of microphonics in superconducting accelerating cavities in order to understand the RF response and feedback requirements for the operational reliability of a particle accelerator. (auth)

  3. Cost analysis of low energy electron accelerator for film curing

    Low energy electron accelerators are recognized as one of the advanced curing means of converting processes for films and papers. In the last three years the price of the accelerator equipment has been greatly reduced. The targeted application areas are mainly processes of curing inks, coatings, and adhesives to make packaging materials. The operating cost analyses were made for electron beam (EB) processes over the conventional ones without EB. Then three new proposals for cost reduction of EB processes are introduced. Also being developed are new EB chemistries such as coatings, laminating adhesives and inks. EB processes give instantaneous cure and EB chemistries are basically non solvent causing less VOC emission to the environment. These developments of both equipment and chemistries might have a potential to change conventional packaging film industries. (author)

  4. Circuit simulation and analysis for Qiangguang-I Accelerator

    The Qiangguang-I accelerator is made up of linear transformer driver(LTD), water transmission line, water switch and diode. In this paper, parameters of the LTD, transmission line and water switch were estimated, and circuit models of nonlinear magnetic cores and pulse power drivers were established. In addition, properties of silicon steel magnetic cores were investigated by experiments, the results of which are perfectly in accord with the simulation ones of the LTD module and accelerator. The simulation shows that the magnetic cores was not saturated under current running status. And the output parameters would not alter for the LTD store capacitance changing from 2.8 μF to 4.0 μF with 35 kV charge voltage. These all would establish the basis for the enhancement of energy store and output parameters. (authors)

  5. Association mapping for epistasis and environmental interaction of yield traits in 323 cotton cultivars under 9 different environments.

    Yinhua Jia

    Full Text Available Improving yield is a major objective for cotton breeding schemes, and lint yield and its three component traits (boll number, boll weight and lint percentage are complex traits controlled by multiple genes and various environments. Association mapping was performed to detect markers associated with these four traits using 651 simple sequence repeats (SSRs. A mixed linear model including epistasis and environmental interaction was used to screen the loci associated with these four yield traits by 323 accessions of Gossypium hirsutum L. evaluated in nine different environments. 251 significant loci were detected to be associated with lint yield and its three components, including 69 loci with individual effects and all involved in epistasis interactions. These significant loci explain ∼ 62.05% of the phenotypic variance (ranging from 49.06% ∼ 72.29% for these four traits. It was indicated by high contribution of environmental interaction to the phenotypic variance for lint yield and boll numbers, that genetic effects of SSR loci were susceptible to environment factors. Shared loci were also observed among these four traits, which may be used for simultaneous improvement in cotton breeding for yield traits. Furthermore, consistent and elite loci were screened with -Log10 (P-value >8.0 based on predicted effects of loci detected in different environments. There was one locus and 6 pairs of epistasis for lint yield, 4 loci and 10 epistasis for boll number, 15 loci and 2 epistasis for boll weight, and 2 loci and 5 epistasis for lint percentage, respectively. These results provided insights into the genetic basis of lint yield and its components and may be useful for marker-assisted breeding to improve cotton production.

  6. Association Mapping for Epistasis and Environmental Interaction of Yield Traits in 323 Cotton Cultivars under 9 Different Environments

    Pan, Zhaoe; Wang, Xiwen; He, Shoupu; Xiao, Songhua; Shi, Weijun; Zhou, Zhongli; Pang, Baoyin; Wang, Liru; Liu, Jianguang; Ma, Jun; Du, Xiongming; Zhu, Jun

    2014-01-01

    Improving yield is a major objective for cotton breeding schemes, and lint yield and its three component traits (boll number, boll weight and lint percentage) are complex traits controlled by multiple genes and various environments. Association mapping was performed to detect markers associated with these four traits using 651 simple sequence repeats (SSRs). A mixed linear model including epistasis and environmental interaction was used to screen the loci associated with these four yield traits by 323 accessions of Gossypium hirsutum L. evaluated in nine different environments. 251 significant loci were detected to be associated with lint yield and its three components, including 69 loci with individual effects and all involved in epistasis interactions. These significant loci explain ∼ 62.05% of the phenotypic variance (ranging from 49.06% ∼ 72.29% for these four traits). It was indicated by high contribution of environmental interaction to the phenotypic variance for lint yield and boll numbers, that genetic effects of SSR loci were susceptible to environment factors. Shared loci were also observed among these four traits, which may be used for simultaneous improvement in cotton breeding for yield traits. Furthermore, consistent and elite loci were screened with −Log10 (P-value) >8.0 based on predicted effects of loci detected in different environments. There was one locus and 6 pairs of epistasis for lint yield, 4 loci and 10 epistasis for boll number, 15 loci and 2 epistasis for boll weight, and 2 loci and 5 epistasis for lint percentage, respectively. These results provided insights into the genetic basis of lint yield and its components and may be useful for marker-assisted breeding to improve cotton production. PMID:24810754

  7. Case–Cohort Analysis with Accelerated Failure Time Model

    Kong, Lan; Cai, Jianwen

    2008-01-01

    In a case–cohort design, covariates are assembled only for a subcohort that is randomly selected from the entire cohort and any additional cases outside the subcohort. This design is appealing for large cohort studies of rare disease, especially when the exposures of interest are expensive to ascertain for all the subjects. We propose statistical methods for analyzing the case–cohort data with a semiparametric accelerated failure time model that interprets the covariates effects as to acceler...

  8. QTL Mapping and Epistasis Analysis for Phytic Acid Concentration in Rice Grain by Using the Bayesian Model Selection%利用贝叶斯法进行水稻籽粒植酸含量性状的QTL定位及互作分析

    李茂柏; 王慧; 张建明; 李丁鲁; 杨润清; 周宇琼; 朴钟泽

    2009-01-01

    Main QTL and epistasis interaction effects for phytic acid concentration in rice grain were investigated by using a F_2 population consisted of 172 lines derived from the cross between an indica rice LPA(the grain phytic acid concentration was 7.11 mg/g) and a japonica rice Zhonghua 11(the phytic acid concentration was 11.92 mg/g) with the Bayesian model selection. A genetic linkage map including 126 SSR and 4 STS markers was constructed with the F_2 population. Three main QTLs related to phytic acid concentration in rice grain were detected. They were located on chromosomes 3, 5, and 6, explaining 5.38%, 8.02%, and 4.62% of phenotypic variation, respectively. The three alleles for reducing the phytic aid concentration were from the parent LPA. Ten pairs of epistatic interaction were detected on chromosomes 1, 3, 5, 6, and 11, with the interaction effects from 1.69 to 5.18 and the percentages of phenotypic variance ranged from 8.67% to 24.73%.%利用水稻植酸含量差异较大的品种中花11(粳型)和LPA(籼型)为亲本杂交获得F_2群体的172个单株,构建了含126个SSR和4个STS标记的遗传连锁图谱,利用贝叶斯(Bayesian)法对水稻籽粒植酸含量性状进行了主效应QTL定位和上位性互作分析.共检测到 3 个与水稻籽粒植酸含量性状有关的主效QTL,分布在第3、5和6 染色体的相应区间内,表型贡献率分别为5.38%、8.02%和4.62%,降低籽粒植酸含量的等位基因均来自亲本LPA.检测到10对上位性互作影响籽粒植酸含量, 分布于水稻第1、3、5、6、11染色体上,互作效应值为1.69~5.18,其表型变异的解释率为8.67%~24.73%.

  9. Tremor Analysis by Decomposition of Acceleration into Gravity and Inertial Acceleration Using Inertial Measurement Unit

    Šprdlík, Otakar; Hurák, Z.; Hoskovcová, M.; Růžička, E.

    Larnaca: IEEE, 2009, s. 1-4. ISBN 978-1-4244-5379-5. [9th International Conferece on Information Technology and Applications in Biomedicine. Larnaca (CY), 04.11.2009-07.11.2009] R&D Projects: GA MŠk(CZ) 1M0567 Institutional research plan: CEZ:AV0Z10750506 Keywords : Tremor analysis * accelerometer * inertial measurement unit * gravitational artifact Subject RIV: BC - Control Systems Theory

  10. Using Swarm Intelligence To Accelerate Pulsar Timing Analysis

    Taylor, Stephen R; Lentati, L

    2012-01-01

    We provide brief notes on a particle swarm-optimisation approach to constraining the properties of a stochastic gravitational-wave background in the first International Pulsar Timing Array data-challenge. The technique employs many computational-agents which explore parameter space, remembering their most optimal positions and also sharing this information with all other agents. It is this sharing of information which accelerates the convergence of all agents to the global best-fit location in a very short number of iterations. Error estimates can also be provided by fitting a multivariate Gaussian to the recorded fitness of all visited points.

  11. The set of prime numbers: Multiscale analysis and numeric accelerators

    In this work, we show that the prime numbers follow a multiscale distribution. Indeed they can be classified thanks to tree structures, which are expressed in terms of two maximal subsets of N and using multilayer selection rules, acting on these sets of prime candidates. Consequently, the prime numbers follow a specific deterministic rules. Indeed, a numeric accelerator for generating primes can be realized in terms of the above mentioned specific rules. From the comparison with the Fibonacci numbers a beautiful harmony comes in terms of the Golden Mean which is relevant to high energy physics and E-Infinity theory too.

  12. Accelerated testing statistical models, test plans, and data analysis

    Nelson, Wayne B

    2009-01-01

    The Wiley-Interscience Paperback Series consists of selected books that have been made more accessible to consumers in an effort to increase global appeal and general circulation. With these new unabridged softcover volumes, Wiley hopes to extend the lives of these works by making them available to future generations of statisticians, mathematicians, and scientists. "". . . a goldmine of knowledge on accelerated life testing principles and practices . . . one of the very few capable of advancing the science of reliability. It definitely belongs in every bookshelf on engineering.""-Dev G.

  13. A universal postprocessing toolkit for accelerator simulation and data analysis

    The Self-Describing Data Sets (SDDS) toolkit comprises about 70 generally-applicable programs sharing a common data protocol. At the Advanced Photon Source (APS), SDDS performs the vast majority of operational data collection and processing, most data display functions, and many control functions. In addition, a number of accelerator simulation codes use SDDS for all post-processing and data display. This has three principle advantages: first, simulation codes need not provide customized post-processing tools, thus simplifying development and maintenance. Second, users can enhance code capabilities without changing the code itself, by adding SDDS-based pre- and post-processing. Third, multiple codes can be used together more easily, by employing SDDS for data transfer and adaptation. Given its broad applicability, the SDDS file protocol is surprisingly simple, making it quite easy for simulations to generate SDDS-compliant data. This paper discusses the philosophy behind SDDS, contrasting it with some recent trends, and outlines the capabilities of the toolkit. The paper also gives examples of using SDDS for accelerator simulation

  14. A fast and powerful W-test for pairwise epistasis testing.

    Wang, Maggie Haitian; Sun, Rui; Guo, Junfeng; Weng, Haoyi; Lee, Jack; Hu, Inchi; Sham, Pak Chung; Zee, Benny Chung-Ying

    2016-07-01

    Epistasis plays an essential role in the development of complex diseases. Interaction methods face common challenge of seeking a balance between persistent power, model complexity, computation efficiency, and validity of identified bio-markers. We introduce a novel W-test to identify pairwise epistasis effect, which measures the distributional difference between cases and controls through a combined log odds ratio. The test is model-free, fast, and inherits a Chi-squared distribution with data adaptive degrees of freedom. No permutation is needed to obtain the P-values. Simulation studies demonstrated that the W-test is more powerful in low frequency variants environment than alternative methods, which are the Chi-squared test, logistic regression and multifactor-dimensionality reduction (MDR). In two independent real bipolar disorder genome-wide associations (GWAS) datasets, the W-test identified significant interactions pairs that can be replicated, including SLIT3-CENPN, SLIT3-TMEM132D, CNTNAP2-NDST4 and CNTCAP2-RTN4R The genes in the pairs play central roles in neurotransmission and synapse formation. A majority of the identified loci are undiscoverable by main effect and are low frequency variants. The proposed method offers a powerful alternative tool for mapping the genetic puzzle underlying complex disorders. PMID:27112568

  15. Epistasis among Drosophila persimilis factors conferring hybrid male sterility with D. pseudoobscura bogotana.

    Audrey S Chang

    Full Text Available The Bateson-Dobzhansky-Muller model posits that hybrid incompatibilities result from genetic changes that accumulate during population divergence. Indeed, much effort in recent years has been devoted to identifying genes associated with hybrid incompatibilities, often with limited success, suggesting that hybrid sterility and inviability are frequently caused by complex interactions between multiple loci and not by single or a small number of gene pairs. Our previous study showed that the nature of epistasis between sterility-conferring QTL in the Drosophila persimilis-D. pseudoobscura bogotana species pair is highly specific. Here, we further dissect one of the three QTL underlying hybrid male sterility between these species and provide evidence for multiple factors within this QTL. This result indicates that the number of loci thought to contribute to hybrid dysfunction may have been underestimated, and we discuss how linkage and complex epistasis may be characteristic of the genetics of hybrid incompatibilities. We further pinpoint the location of one locus that confers hybrid male sterility when homozygous, dubbed "mule-like", to roughly 250 kilobases.

  16. Survival of the Curviest: Noise-Driven Selection for Synergistic Epistasis.

    Wilkins, Jon F; McHale, Peter T; Gervin, Joshua; Lander, Arthur D

    2016-04-01

    A major goal of human genetics is to elucidate the genetic architecture of human disease, with the goal of fueling improvements in diagnosis and the understanding of disease pathogenesis. The degree to which epistasis, or non-additive effects of risk alleles at different loci, accounts for common disease traits is hotly debated, in part because the conditions under which epistasis evolves are not well understood. Using both theory and evolutionary simulation, we show that the occurrence of common diseases (i.e. unfit phenotypes with frequencies on the order of 1%) can, under the right circumstances, be expected to be driven primarily by synergistic epistatic interactions. Conditions that are necessary, collectively, for this outcome include a strongly non-linear phenotypic landscape, strong (but not too strong) selection against the disease phenotype, and "noise" in the genotype-phenotype map that is both environmental (extrinsic, time-correlated) and developmental (intrinsic, uncorrelated) and, in both cases, neither too little nor too great. These results suggest ways in which geneticists might identify, a priori, those disease traits for which an "epistatic explanation" should be sought, and in the process better focus ongoing searches for risk alleles. PMID:27123867

  17. Survival of the Curviest: Noise-Driven Selection for Synergistic Epistasis.

    Jon F Wilkins

    2016-04-01

    Full Text Available A major goal of human genetics is to elucidate the genetic architecture of human disease, with the goal of fueling improvements in diagnosis and the understanding of disease pathogenesis. The degree to which epistasis, or non-additive effects of risk alleles at different loci, accounts for common disease traits is hotly debated, in part because the conditions under which epistasis evolves are not well understood. Using both theory and evolutionary simulation, we show that the occurrence of common diseases (i.e. unfit phenotypes with frequencies on the order of 1% can, under the right circumstances, be expected to be driven primarily by synergistic epistatic interactions. Conditions that are necessary, collectively, for this outcome include a strongly non-linear phenotypic landscape, strong (but not too strong selection against the disease phenotype, and "noise" in the genotype-phenotype map that is both environmental (extrinsic, time-correlated and developmental (intrinsic, uncorrelated and, in both cases, neither too little nor too great. These results suggest ways in which geneticists might identify, a priori, those disease traits for which an "epistatic explanation" should be sought, and in the process better focus ongoing searches for risk alleles.

  18. Survival of the Curviest: Noise-Driven Selection for Synergistic Epistasis

    Gervin, Joshua; Lander, Arthur D.

    2016-01-01

    A major goal of human genetics is to elucidate the genetic architecture of human disease, with the goal of fueling improvements in diagnosis and the understanding of disease pathogenesis. The degree to which epistasis, or non-additive effects of risk alleles at different loci, accounts for common disease traits is hotly debated, in part because the conditions under which epistasis evolves are not well understood. Using both theory and evolutionary simulation, we show that the occurrence of common diseases (i.e. unfit phenotypes with frequencies on the order of 1%) can, under the right circumstances, be expected to be driven primarily by synergistic epistatic interactions. Conditions that are necessary, collectively, for this outcome include a strongly non-linear phenotypic landscape, strong (but not too strong) selection against the disease phenotype, and “noise” in the genotype-phenotype map that is both environmental (extrinsic, time-correlated) and developmental (intrinsic, uncorrelated) and, in both cases, neither too little nor too great. These results suggest ways in which geneticists might identify, a priori, those disease traits for which an “epistatic explanation” should be sought, and in the process better focus ongoing searches for risk alleles. PMID:27123867

  19. Cuckoo search epistasis: a new method for exploring significant genetic interactions.

    Aflakparast, M; Salimi, H; Gerami, A; Dubé, M-P; Visweswaran, S; Masoudi-Nejad, A

    2014-06-01

    The advent of high-throughput sequencing technology has resulted in the ability to measure millions of single-nucleotide polymorphisms (SNPs) from thousands of individuals. Although these high-dimensional data have paved the way for better understanding of the genetic architecture of common diseases, they have also given rise to challenges in developing computational methods for learning epistatic relationships among genetic markers. We propose a new method, named cuckoo search epistasis (CSE) for identifying significant epistatic interactions in population-based association studies with a case-control design. This method combines a computationally efficient Bayesian scoring function with an evolutionary-based heuristic search algorithm, and can be efficiently applied to high-dimensional genome-wide SNP data. The experimental results from synthetic data sets show that CSE outperforms existing methods including multifactorial dimensionality reduction and Bayesian epistasis association mapping. In addition, on a real genome-wide data set related to Alzheimer's disease, CSE identified SNPs that are consistent with previously reported results, and show the utility of CSE for application to genome-wide data. PMID:24549111

  20. The X-ray fluorescence method for elementary analysis of substances by means of accelerated ions

    The modern state of the elementary analysis of substances by their characteristic X radiation (CXR), excited by accelerated ions is considered. The dependence of the analysis sensitivity on the type of accelerated ions and on their energy is discussed. The sources of background radiation are considered, and their effect on the analysis sensitivity in various energy ranges of the CXR is discussed. Compared are analytical possibilities of the method of analysis during the CXR excitation by electron and γ-quanta beams. The technique is considered in brief and the fields of the practical application in medicine, biology, in the investigation of environmental contamination are considered

  1. Control system analysis for the perturbed linear accelerator rf system

    Sung Il Kwon

    2002-01-01

    This paper addresses the modeling problem of the linear accelerator RF system in SNS. Klystrons are modeled as linear parameter varying systems. The effect of the high voltage power supply ripple on the klystron output voltage and the output phase is modeled as an additive disturbance. The cavity is modeled as a linear system and the beam current is modeled as the exogenous disturbance. The output uncertainty of the low level RF system which results from the uncertainties in the RF components and cabling is modeled as multiplicative uncertainty. Also, the feedback loop uncertainty and digital signal processing signal conditioning subsystem uncertainties are lumped together and are modeled as multiplicative uncertainty. Finally, the time delays in the loop are modeled as a lumped time delay. For the perturbed open loop system, the closed loop system performance, and stability are analyzed with the PI feedback controller.

  2. Longitudinal jitter analysis of linear accelerator electron gun

    Mingshan, Liu; Iqbal, Munawar

    2015-01-01

    We present measurement and analyses of longitudinal timing jitter of Beijing Electron Positron Collider (BEPCII) linear accelerator electron gun. We simulated longitudinal jitter effect of the gun using PARMELA about beam performance including beam profile, average energy, energy spread, longitudinal phase of reference particle and XY emittance. The maximum percentage difference of the beam parameters are calculated to be; 100%, 13.27%, 42.24%, 7.79% and 65.01%, 86.81%, respectively due to which the bunching efficiency is reduced to 54%. The simulation results are in agreement with test and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

  3. Analysis on the Time and Frequency Domains of the Acceleration in Front Crawl Stroke

    Gil, Joaquín Madera; Moreno, Luis-Millán González; Mahiques, Juan Benavent; Muñoz, Víctor Tella

    2012-01-01

    The swimming involves accelerations and decelerations in the swimmer’s body. Thus, the main objective of this study is to make a temporal and frequency analysis of the acceleration in front crawl swimming, regarding the gender and the performance. The sample was composed by 31 male swimmers (15 of high-level and 16 of low-level) and 20 female swimmers (11 of high-level and 9 of low-level). The acceleration was registered from the third complete cycle during eight seconds in a 25 meters maximu...

  4. Omega3P: A Parallel Finite-Element Eigenmode Analysis Code for Accelerator Cavities

    Lee, Lie-Quan; Li, Zenghai; Ng, Cho; Ko, Kwok; /SLAC

    2009-03-04

    Omega3P is a parallel eigenmode calculation code for accelerator cavities in frequency domain analysis using finite-element methods. In this report, we will present detailed finite-element formulations and resulting eigenvalue problems for lossless cavities, cavities with lossy materials, cavities with imperfectly conducting surfaces, and cavities with waveguide coupling. We will discuss the parallel algorithms for solving those eigenvalue problems and demonstrate modeling of accelerator cavities through different examples.

  5. Report of the consultant's meeting on applications of accelerator based analysis

    At the present meeting, applications of accelerator based analytical methods, often referred as ion beam analysis (IBA) methods, to the following areas have been discussed: materials (including thin films), Earth sciences (including environmental studies), biology and medicine, art and archaeology (cultural heritage), and other applications (including forensic applications). This report gives brief overview of IBA applications in these areas, with short background about accelerators needed and corresponding analytical techniques

  6. Development of a multi-functional and small-scale ion accelerator for surface analysis

    A multi-functional and small-scale ion accelerator has been developed for surface analysis. The maximum power of the accelerator is 200 kV×1 mA and an extremely low-energy beam is produced by using a deceleration power supply in place of an acceleration one. A beam of 1 ns in minimum pulse width can be obtained by means of an electrostatic einzel lens and a fast electric deflector in order to improve the signal to noise ratio in beam measurement and also enable energy measurement using a TOF method. In addition, the accelerator is equipped with a microbeam apparatus. It delivers a micro beam around 3 μm in minimum diameter and can be used with a scanner fabricated from XY deflectors or a movable stage for surface analysis. Also the accelerator can be controlled remotely through the Internet with safety connection. A low-energy proton PIXE surface analysis experiment on a corpuscular sample was successfully performed with this accelerator system. (author)

  7. Analysis of human accelerated DNA regions using archaic hominin genomes.

    Burbano, Hernán A; Green, Richard E; Maricic, Tomislav; Lalueza-Fox, Carles; de la Rasilla, Marco; Rosas, Antonio; Kelso, Janet; Pollard, Katherine S; Lachmann, Michael; Pääbo, Svante

    2012-01-01

    Several previous comparisons of the human genome with other primate and vertebrate genomes identified genomic regions that are highly conserved in vertebrate evolution but fast-evolving on the human lineage. These human accelerated regions (HARs) may be regions of past adaptive evolution in humans. Alternatively, they may be the result of non-adaptive processes, such as biased gene conversion. We captured and sequenced DNA from a collection of previously published HARs using DNA from an Iberian Neandertal. Combining these new data with shotgun sequence from the Neandertal and Denisova draft genomes, we determine at least one archaic hominin allele for 84% of all positions within HARs. We find that 8% of HAR substitutions are not observed in the archaic hominins and are thus recent in the sense that the derived allele had not come to fixation in the common ancestor of modern humans and archaic hominins. Further, we find that recent substitutions in HARs tend to have come to fixation faster than substitutions elsewhere in the genome and that substitutions in HARs tend to cluster in time, consistent with an episodic rather than a clock-like process underlying HAR evolution. Our catalog of sequence changes in HARs will help prioritize them for functional studies of genomic elements potentially responsible for modern human adaptations. PMID:22412940

  8. Design, analysis and RF characterisation of copper lining for accelerators

    BARC is involved in the development of a 352.21 MHz Drift Tube Linac (DTL) for Low Energy High Intensity Proton Accelerator (LEHIPA). The copper lining forming the inner surface of DTL cavities must be extremely smooth and should be made out of high purity copper with good electrical conductivity, as the cavities are operated under high vacuum and high power RF in continuous wave (CW) mode. Uniformity of the copper deposition is one of the key requirements for these cavities so as to minimize the post plating machining processes. Qualitative tests of the plating were performed on pill box cavities whose fundamental mode (TM010) frequencies are higher than the operating frequency of the DTL cavity and a quality factor of 85% of the theoretical limit has been achieved. Electrostatic current flow simulations were done to optimize the anode array configuration for the electroplating setup. The key performance parameters were the uniformity and magnitude of the cathode current density and it was optimized under the constraints of maximum permissible cathode current densities, anode polarization density and the substrate material properties. An experimental anode arrangement was designed and developed for the electrodeposition of copper on scaled prototype of DTL cavity. The plating was carried out using a pulse periodical reversal power supply with 500 ms forward and 100 ms reverse cycle. This paper discusses the various design and development challenges associated with the plating process on high power CW mode radio-frequency cavities. (author)

  9. Complexity analysis of accelerated MCMC methods for Bayesian inversion

    Hoang, Viet Ha; Schwab, Christoph; Stuart, Andrew M.

    2013-08-01

    approximation methods used, in order for the accelerations of MCMC resulting from these strategies to lead to complexity reductions over ‘plain’ MCMC algorithms for the Bayesian inversion of PDEs.

  10. iLOCi: a SNP interaction prioritization technique for detecting epistasis in genome-wide association studies

    Piriyapongsa Jittima

    2012-12-01

    Full Text Available Abstract Background Genome-wide association studies (GWAS do not provide a full account of the heritability of genetic diseases since gene-gene interactions, also known as epistasis are not considered in single locus GWAS. To address this problem, a considerable number of methods have been developed for identifying disease-associated gene-gene interactions. However, these methods typically fail to identify interacting markers explaining more of the disease heritability over single locus GWAS, since many of the interactions significant for disease are obscured by uninformative marker interactions e.g., linkage disequilibrium (LD. Results In this study, we present a novel SNP interaction prioritization algorithm, named iLOCi (Interacting Loci. This algorithm accounts for marker dependencies separately in case and control groups. Disease-associated interactions are then prioritized according to a novel ranking score calculated from the difference in marker dependencies for every possible pair between case and control groups. The analysis of a typical GWAS dataset can be completed in less than a day on a standard workstation with parallel processing capability. The proposed framework was validated using simulated data and applied to real GWAS datasets using the Wellcome Trust Case Control Consortium (WTCCC data. The results from simulated data showed the ability of iLOCi to identify various types of gene-gene interactions, especially for high-order interaction. From the WTCCC data, we found that among the top ranked interacting SNP pairs, several mapped to genes previously known to be associated with disease, and interestingly, other previously unreported genes with biologically related roles. Conclusion iLOCi is a powerful tool for uncovering true disease interacting markers and thus can provide a more complete understanding of the genetic basis underlying complex disease. The program is available for download at http://www4a.biotec.or.th/GI/tools/iloci.

  11. Development of surface analysis with 1-MeV ion accelerator at Osaka Prefecture University

    This paper describes recent development of surface analysis with the 1-MeV ion accelerator at Osaka Prefecture University. The disktron-type accelerator was transferred to our university from TRI-Osaka in 2012 and its maintenance has been performed for two years to operate the accelerator again. A surface analysis system including this accelerator was developed for RBS (Rutherford Backscattering Spectrometry) and PIXE (Particle Induced X-ray Emission). A silicon detector and a silicon lithium X-ray detector were newly equipped to an analysis vacuum chamber. RBS measurement for the magnetic material inside a floppy disk clarified the depth profile of a thin iron layer. A nuclear reaction analysis was employed to detect a small amount of lithium in an aluminum metal plate. The alpha particles from the 7Li(p, α)4He reaction were measured at high energy region of the RBS spectrum. Several X-ray peaks were identified by the PIXE analysis for a mineral supplement. A CdTe detector was newly employed and used simultaneously to measure X-rays at higher energies. The X-rays over 20 keV were detected with the CdTe detector with high efficiency. Further development of the system is in progress to establish the method of quantitative analysis. (author)

  12. Incorporating epistasis interaction of genetic susceptibility single nucleotide polymorphisms in a lung cancer risk prediction model.

    Marcus, Michael W; Raji, Olaide Y; Duffy, Stephen W; Young, Robert P; Hopkins, Raewyn J; Field, John K

    2016-07-01

    Incorporation of genetic variants such as single nucleotide polymorphisms (SNPs) into risk prediction models may account for a substantial fraction of attributable disease risk. Genetic data, from 2385 subjects recruited into the Liverpool Lung Project (LLP) between 2000 and 2008, consisting of 20 SNPs independently validated in a candidate-gene discovery study was used. Multifactor dimensionality reduction (MDR) and random forest (RF) were used to explore evidence of epistasis among 20 replicated SNPs. Multivariable logistic regression was used to identify similar risk predictors for lung cancer in the LLP risk model for the epidemiological model and extended model with SNPs. Both models were internally validated using the bootstrap method and model performance was assessed using area under the curve (AUC) and net reclassification improvement (NRI). Using MDR and RF, the overall best classifier of lung cancer status were SNPs rs1799732 (DRD2), rs5744256 (IL-18), rs2306022 (ITGA11) with training accuracy of 0.6592 and a testing accuracy of 0.6572 and a cross-validation consistency of 10/10 with permutation testing Pmodel was 0.75 (95% CI 0.73-0.77). When epistatic data were incorporated in the extended model, the AUC increased to 0.81 (95% CI 0.79-0.83) which corresponds to 8% increase in AUC (DeLong's test P=2.2e-16); 17.5% by NRI. After correction for optimism, the AUC was 0.73 for the epidemiological model and 0.79 for the extended model. Our results showed modest improvement in lung cancer risk prediction when the SNP epistasis factor was added. PMID:27121382

  13. Enabling More than Moore: Accelerated Reliability Testing and Risk Analysis for Advanced Electronics Packaging

    Ghaffarian, Reza; Evans, John W.

    2014-01-01

    For five decades, the semiconductor industry has distinguished itself by the rapid pace of improvement in miniaturization of electronics products-Moore's Law. Now, scaling hits a brick wall, a paradigm shift. The industry roadmaps recognized the scaling limitation and project that packaging technologies will meet further miniaturization needs or ak.a "More than Moore". This paper presents packaging technology trends and accelerated reliability testing methods currently being practiced. Then, it presents industry status on key advanced electronic packages, factors affecting accelerated solder joint reliability of area array packages, and IPC/JEDEC/Mil specifications for characterizations of assemblies under accelerated thermal and mechanical loading. Finally, it presents an examples demonstrating how Accelerated Testing and Analysis have been effectively employed in the development of complex spacecraft thereby reducing risk. Quantitative assessments necessarily involve the mathematics of probability and statistics. In addition, accelerated tests need to be designed which consider the desired risk posture and schedule for particular project. Such assessments relieve risks without imposing additional costs. and constraints that are not value added for a particular mission. Furthermore, in the course of development of complex systems, variances and defects will inevitably present themselves and require a decision concerning their disposition, necessitating quantitative assessments. In summary, this paper presents a comprehensive view point, from technology to systems, including the benefits and impact of accelerated testing in offsetting risk.

  14. Detecting chaos in particle accelerators through the frequency map analysis method

    Papaphilippou, Yannis

    2014-01-01

    The motion of beams in particle accelerators is dominated by a plethora of non-linear effects which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of different particle accelerator categories, the theory of non-linear particle motion is outlined. The recent developments on the methods employed for the analysis of chaotic beam motion are detailed. In particular, the ability of the frequency map analysis method to detect chaotic motion and guide the correction of non-linear effects is demonstrated in particle tracking simulations but also experimental data.

  15. Detecting chaos in particle accelerators through the frequency map analysis method

    Papaphilippou, Yannis, E-mail: Ioannis.Papaphilippou@cern.ch [European Organisation of Nuclear Research—CERN, Geneva (Switzerland)

    2014-06-01

    The motion of beams in particle accelerators is dominated by a plethora of non-linear effects, which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of different particle accelerator categories, the theory of non-linear particle motion is outlined. The recent developments on the methods employed for the analysis of chaotic beam motion are detailed. In particular, the ability of the frequency map analysis method to detect chaotic motion and guide the correction of non-linear effects is demonstrated in particle tracking simulations but also experimental data.

  16. Detecting chaos in particle accelerators through the frequency map analysis method

    The motion of beams in particle accelerators is dominated by a plethora of non-linear effects, which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of different particle accelerator categories, the theory of non-linear particle motion is outlined. The recent developments on the methods employed for the analysis of chaotic beam motion are detailed. In particular, the ability of the frequency map analysis method to detect chaotic motion and guide the correction of non-linear effects is demonstrated in particle tracking simulations but also experimental data

  17. Materials analysis in archaeometrical studies at Bucharest accelerators

    The scientific analysis of archaeological objects ideally requires the availability of methods, which are simultaneously non-destructive, fast, universal, versatile, sensitive and multielemental. Analyses of source materials combined with analyses of the objects could distinguish from pieces produced in different regions. Our purpose is to help archaeologists to identify objects provenance (workshops, technologies, mines) and to explain different commercial, military and political aspects. For numismatic research, we used 241Am source based XRF (X-ray Fluorescence) and 4.7 MeV alphaparticles induced PIXE (Particle Induced X-ray Emission) methods. Coins emitted by Histria (Greek colony, IVth - IIIrd Century B.C.), late Roman Empire, Byzantine Empire (Xth - XIth Century) were examined. For ceramics and glasses studies three methods were used: 3 MeV protons PIXE, 241Am source based XRF and FNAA (Fast Neutron Activation Analysis). Using a fast neutrons beam, some light elements can be determined: Al, Mg, Na, Si, but also Ca, Ti, Fe, Zn, Cd, In, Sn, Sb, Ba, Pb. The above mentioned methods are complementary and they work better together. Some results on various ceramics objects from Romanian sites (glaze and painting agents) are presented. For glasses, the problem is to identify coloring agents, decolorants, opacifiers and fining agents. Some results on medieval and XVIIIth Century samples founded in South-Eastern Romania are presented. The last example we present is a study on ancient Dacian gold coins. The methods used were XRF and PAA (Proton Activation Analysis). Three groups of coins with different composition were found, corresponding to simple, complex and no monogram pieces. Possible historical conclusions are discussed. (author)

  18. GMRES Acceleration Analysis for a Convection Diffusion Model Problem

    Duintjer Tebbens, Jurjen

    Bratislava: Vydavateĺstvo STU, 2005 - (Handlovičová, A.; Krivá, Z.; Mikula, K.; Ševčovič, D.), s. 240-249 ISBN 978-80-227-2192-9. [ALGORITMY 2005. Conference on Scientific Computing /17./. Vysoké Tatry - Podbanské (SK), 13.03.2005-18.03.2005] R&D Projects: GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z10300504 Keywords : convection diffusion problem * GMRES convergence analysis * residual bound * tridiagonal non-symmetric Toeplitz matrix * diagonal translation * scaled power polynomial Subject RIV: BA - General Mathematics

  19. Materials analysis in archaeometrical studies at Bucharest accelerators

    The scientific analysis of archaeological objects ideally requires the availability of methods which are simultaneously non-destructive, fast, universal, versatile, sensitive and multielemental. Analyses of source materials combined with analyses of the objects could distinguish from pieces produced in different regions. Chemical differences which occur during refinement and preparation of materials (e.g. alloys) will affect the elemental composition and could be used for the identification of technologies and workshops involved. Our purpose is to help Romanian archaeologists to identify objects provenance (workshops, technologies, mines) and to explain different commercial, military and political aspects. For numismatic research (coin analysis), we use XRF (X-Ray Fluorescence) and in air PIXE (Proton Induced X-ray Emission) methods. XRF measurements are done with a spectrometer consisting of a 30 mCi Am-241 annual gamma-source attached to a support that defines the angle of the incident photons and collimates the fluorescent X-rays in their path to the Si(Li) detector, where they are recorded. A conventional electronic chain, consisting of preamplifier and MCA, is used to accumulate the spectra

  20. Automated detection and analysis of particle beams in laser-plasma accelerator simulations

    Ushizima, Daniela Mayumi; Geddes, C.G.; Cormier-Michel, E.; Bethel, E. Wes; Jacobsen, J.; Prabhat, ,; R.ubel, O.; Weber, G,; Hamann, B.

    2010-05-21

    Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of massive data sets over many time steps using several plots, a routine that is unfeasible for large data collections. Demand for automated analysis is growing along with the volume and size of simulations. Current 2D LWFA simulation datasets are typically between 1GB and 100GB in size, but simulations in 3D are of the order of TBs. The increase in the number of datasets and dataset sizes leads to a need for automatic routines to recognize particle patterns as particle bunches (beam of electrons) for subsequent analysis. Because of the growth in dataset size, the application of machine learning techniques for

  1. In situ accelerator analysis of palladium complex under deuterium permeation

    Preliminary results of experiments on D2 gas permeation using a system (vacuum/CaO/Sr/PdDx/D2) have shown some evidence of nuclear transmutation from Sr to Mo. The system is a little simpler than that used by Imamura et al., and has a reversed gas flow direction. The diagnostic method used to identify the elements was conventional X-ray photoelectron spectroscopy, giving the areal densities of 4.2x1014 cm-2 (Sr) and 3.3x1014 cm-2 (Mo). Extended analytical methods are now being prepared, including in situ and simultaneous particle induced X-ray emission, Rutherford backscattering spectroscopy, nuclear reaction analysis, and elastic recoil detection analyse for areal densities of transmutation elements and deuterium distribution. (author)

  2. Accelerating Climate Data Analysis and Visualization with Parallel Scripting

    Mickelson, S. A.; Jacob, R. L.; Wilde, M.; Wozniak, J.; Dennis, J.

    2011-12-01

    Climate models are continuing to increase both in their resolution and the number of variables used, resulting in multi-terabyte model outputs. This large volume of data overwhelms the series of processing steps used to derive climate averages and produce visualizations. Since many of the tasks in the post- processing sequence are independent, we have applied task-parallel scripting to speed up the post-processing. We have re-written portions of the complex shell script that processes output from the Community Atmosphere Model in Swift, a high-level implicitly-parallel scripting language that uses data dependencies to automatically parallelize a workflow. This has resulted in valuable speedups in model analysis for this heavily-used procedure. We describe the structure, usage, performance, and our experiences with the resulting script.

  3. Accelerating residential PV expansion: demand analysis for competitive electricity markets

    This article quantifies the potential market for grid-connected, residential photovoltaic (PV) electricity integrated into new homes built in the US. It complements an earlier supply-side analysis by the authors that demonstrates the potential to reduce PV module prices below $1.5/Wp by scaling up existing thin-film technology in 100 MWp/yr manufacturing facilities. The present article demonstrates that, at that price, PV modules may be cost effective in 125,000 new home installations per year (0.5 GWp/yr). While this market is large enough to support multiple scaled up thin-film PV factories, inefficient energy pricing and demand-side market failures will inhibit prospective PV consumers without strong public policy support. Net metering rules, already implemented in many states to encourage PV market launch, represent a crude but reasonable surrogate for efficient electricity pricing mechanisms that may ultimately emerge to internalize the externality benefits of PV. These public benefits include reduced air pollution damages (estimated costs of damage to human health from fossil fuel power plants are presented in Appendix A), deferral of transmission and distribution capital expenditures, reduced exposure to fossil fuel price risks, and increased electricity system reliability for end users. Thus, net metering for PV ought to be implemented as broadly as possible and sustained until efficient pricing is in place. Complementary PV 'buydowns' (e.g., a renewable portfolio standard with a specific PV requirement) are needed to jumpstart regional PV markets

  4. The present status of carbon 14 analysis and projects for beryllium 10 analysis at the Tandetron 1 accelerator, Nagoya University

    Nakamura, Toshio; Oda, Hirotaka; Ikeda, Akiko; Niu, Etsuko [Nagoya Univ. (Japan)

    2001-02-01

    The operation experience in 1999 of the Tandetron accelerator age estimation system, Nagoya University, is reported, after the overview and the history of the accelerator is briefly described. Total number of carbon 14 environmental samples analyzed was 8567. The project of introducing new HVEE Tandetron for C-14 analysis, and modifying the present GIC Tandetron for Be-10 analysis is presented. Ion source shall be replaced, and the heavy ion detector shall be installed. Projected geological and archaeological studies using Be-10 are enumerated. (A. Yamamoto)

  5. Current status of research and development of reactor noise analysis for accelerator-driven subcritical system

    This report presents a current status of the research and development of reactor noise analyses applicable to accelerator-driven subcritical reactor system. These research activities have been concentrated on the Feynman-α neutron correlation analysis on time domain and the power spectral analysis on frequency domain. At present, the latter power spectral analysis is of greater advantage than the former Feynman-α one, for periodic and pulsed neutron source. While Feynman-α formula for pulsed neutron source is too complicated to be fitted directly to variance-to-mean ratio data, the power spectral analysis has a simpler formula based on the first-order reactor transfer function. The Feynman-α should be improved to consider spatial effect of deeply subcritical system and instability of accelerator operation. Further subject of reactor noise analyses is an improvement for high power operation. (author)

  6. Design and Analysis of a Micro-Optical Position Readout for Acceleration Sensing

    Dickey, Fred M.; Holswade, Scott C.; Shagam, Richard N.

    1999-07-08

    Sandia National Laboratories is developing a MEMS-based trajectory safety subsystem, which allows enablement of critical functions only after a particular acceleration environment has been achieved. The device, known as an Environmental Sensing Device (ESD), consists of a suspended moving shuttle that translates a given distance when exposed to an appropriate acceleration environment. The shuttle contains an embedded code, consisting of grating structures, that is illuminated and optically read using a semiconductor laser and detector integrated together in a GaAs-based Photonic Integrated Circuit (PIC) flip-chip bonded to the assembly. This paper will describe the optical design and performance analysis of the embedded code features in the shuttle.

  7. The state of art of the NIES-TERRA (Accelerator analysis facility, National Institute for Environmental Studies)

    Yoneda, Minoru; Shibata, Yasuyuki; Tanaka, Atsushi; Uchida, Masao; Hirota, Masashi; Uehiro, Takashi; Morita, Masatoshi [National Inst. for Environmental Studies Tsukuba, Ibaraki (Japan)

    2001-02-01

    The status of the NIES-TERRA accelerator facility in FY1999 is presented. Accelerator Mass Spectrometry (AMS) has been performed mainly for the routine measurement of environmental, geological, archaeological samples. Analysis has been done for Al-26, Be-10, as well as C-14. The operation experiences are described. The accelerator has been operated 23000 hours since its construction. Minor troubles during the operation are reported. The pretreatment system, required for the analysis in further precision, is under development. (A. Yamamoto)

  8. Reliability Estimation based on Step-Stress Accelerated Degradation Testing by Unequal Interval Time Series Analysis

    Li Wang; Zaiwen Liu; Chongchong Yu

    2013-01-01

    This paper proposes a reliability estimation method based on Step-Stress Accelerated Degradation Testing (SSADT) data analysis using unequal interval time series analysis. A Multi-Regression Time Varying Auto-Regressive (MRTVAR) degradation time series model is proposed. Product SSADT data are treated as unequal interval composite time series and described using MRTVAR time series model and utilized to predict long-term trend of degradation. By using the suggested method, product reliability ...

  9. An improved method for statistical analysis of raw accelerator mass spectrometry data

    Hierarchical statistical analysis is an appropriate method for statistical treatment of raw accelerator mass spectrometry (AMS) data. Using Monte Carlo simulations we show that this method yields more accurate estimates of isotope ratios and analytical uncertainty than the generally used propagation of errors approach. The hierarchical analysis is also useful in design of experiments because it can be used to identify sources of variability. 8 refs., 2 figs

  10. Interjoint dynamic interaction during constrained human quiet standing examined by induced acceleration analysis.

    Sasagawa, Shun; Shinya, Masahiro; Nakazawa, Kimitaka

    2014-01-01

    Recent studies have demonstrated that human quiet standing is a multijoint movement, whereby the central nervous system (CNS) is required to deal with dynamic interactions among the joints to achieve optimal motor performance. The purpose of this study was to investigate how the CNS deals with such interjoint interaction during quiet standing by examining the relationship between the kinetics (torque) and kinematics (angular acceleration) within the multi-degree of freedom system. We modeled quiet standing as a double-link inverted pendulum involving both ankle and hip joints and conducted an "induced acceleration analysis." We found that the net ankle and hip torques induced angular accelerations of comparable magnitudes to the ankle (3.8 ± 1.4°/s(2) and 3.3 ± 1.2°/s(2)) and hip (9.1 ± 3.2°/s(2) and 10.5 ± 3.5°/s(2)) joints, respectively. Angular accelerations induced by the net ankle and hip torques were modulated in a temporally antiphase pattern to one another in each of the two joints. These quantitative and temporal relationships allowed the angular accelerations induced by the two net torques to countercompensate one another, thereby substantially (∼70%) reducing the resultant angular accelerations of the individual joints. These results suggest that, by taking advantage of the interjoint interaction, the CNS prevents the net torques from producing large amplitudes of the resultant angular accelerations when combined with the kinematic effects of all other torques in the chain. PMID:24089399

  11. DEVELOPMENT OF ACCELERATOR DATA REPORTING SYSTEM AND ITS APPLICATION TO TREND ANALYSIS OF BEAM CURRENT DATA

    Padilla, M.J.; Blokland, W.

    2009-01-01

    Detailed ongoing information about the ion beam quality is crucial to the successful operation of the Spallation Neutron Source at Oak Ridge National Laboratory. In order to provide the highest possible neutron production time, ion beam quality is monitored to isolate possible problems or performance-related issues throughout the accelerator and accumulator ring. For example, beam current monitor (BCM) data is used to determine the quality of the beam transport through the accelerator. In this study, a reporting system infrastructure was implemented and used to generate a trend analysis report of the BCM data. The BCM data was analyzed to facilitate the identifi cation of monitor calibration issues, beam trends, beam abnormalities, beam deviations and overall beam quality. A comparison between transformed BCM report data and accelerator log entries shows promising results which represent correlations between the data and changes made within the accelerator. The BCM analysis report is one of many reports within a system that assist in providing overall beam quality information to facilitate successful beam operation. In future reports, additional data manipulation functions and analysis can be implemented and applied. Built-in and user-defi ned analytic functions are available throughout the reporting system and can be reused with new data.

  12. Hyperfractionated or accelerated radiotherapy in head and neck cancer: a meta-analysis

    Bourhis, J.; Overgaard, Jens; Audry, H.;

    2006-01-01

    BACKGROUND: Several trials have studied the role of unconventional fractionated radiotherapy in head and neck squamous cell carcinoma, but the effect of such treatment on survival is not clear. The aim of this meta-analysis was to assess whether this type of radiotherapy could improve survival......-specified categories: hyperfractionated, accelerated, and accelerated with total dose reduction. FINDINGS: 15 trials with 6515 patients were included. The median follow-up was 6 years. Tumours sites were mostly oropharynx and larynx; 5221 (74%) patients had stage III-IV disease (International Union Against Cancer...... radiotherapy (2% with accelerated fractionation without total dose reduction and 1.7% with total dose reduction at 5 years, p=0.02). There was a benefit on locoregional control in favour of altered fractionation versus conventional radiotherapy (6.4% at 5 years; p<0.0001), which was particularly efficient in...

  13. Interface for the rapid analysis of liquid samples by accelerator mass spectrometry

    Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

    2014-02-04

    An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

  14. Verification of volumetric-modulated arc therapy plan by long-file analysis of linear accelerator

    Objective: To verify the dose delivery accuracy of volumetric-modulated arc therapy plan by log-file analysis of linear accelerator that can be created when a dynamic delivery occurs. Methods: Accelerator log file in binary format recorded the accelerator execution plan for each control point corresponding to the gantry angle, multi-leaf collimator leave position, cumulative machine monitor units (MU). These information were read from the accelerator log file with Matlab7.1, then the original control points in the plan file replaced the corresponding information for the log,which generated a new plan. New plan was exported into the planning system to recalculate the dose. The volume dose histogram (DVH) and dose distribution was contrasted to determine the accuracy of the accelerator plan of implementation between two plans. Results: Compared with the original plan, gantry angle difference over ± 1° accounted for about 35% of the entire arc of control points in 4 of 12 arcs and the percentage of the leave error of ±0.5 mm was about 95%. MU error of a single control point was larger, but the cumulative MU for each are was small which was located between-0.09% to 0.11% in the selected 12 arcs. Between the targets, the maximum dose,minimum dose, the mean dose differences were from -0.07% to 0.42%, -0.38% to 0.40%, 0.03% to 0.08%, respectively. The maximum dose and mean dose differences of organs at risks were located from -1.16% to 2.51%, -1.21% to 3.12%, respectively. Conclusions: Accelerator log-file analysis to verify the VMAT plan nan be supplied to the experimental method supplement. (authors)

  15. Analysis on the time and frequency domains of the acceleration in front crawl stroke.

    Gil, Joaquín Madera; Moreno, Luis-Millán González; Mahiques, Juan Benavent; Muñoz, Víctor Tella

    2012-05-01

    The swimming involves accelerations and decelerations in the swimmer's body. Thus, the main objective of this study is to make a temporal and frequency analysis of the acceleration in front crawl swimming, regarding the gender and the performance. The sample was composed by 31 male swimmers (15 of high-level and 16 of low-level) and 20 female swimmers (11 of high-level and 9 of low-level). The acceleration was registered from the third complete cycle during eight seconds in a 25 meters maximum velocity test. A position transducer (200Hz) was used to collect the data, and it was synchronized to an aquatic camera (25Hz). The acceleration in the temporal (root mean square, minimum and maximum of the acceleration) and frequency (power peak, power peak frequency and spectral area) domains was calculated with Fourier analysis, as well as the velocity and the spectrums distribution in function to present one or more main peaks (type 1 and type 2). A one-way ANOVA was used to establish differences between gender and performance. Results show differences between genders in all the temporal domain variables (p<0.05) and only the Spectral Area (SA) in the frequency domain (p<0.05). Between gender and performance, only the Root Mean Square (RMS) showed differences in the performance of the male swimmers (p<0.05) and in the higher level swimmers, the Maximum (Max) and the Power Peak (PP) of the acceleration showed differences between both genders (p<0.05). These results confirms the importance of knowing the RMS to determine the efficiency of the swimmers regarding gender and performance level. PMID:23487001

  16. A steady-state core analysis code for the modeling of accelerator-driven subcritical reactors

    In order to analyze and evaluate Accelerator Driven Subcritical Reactors (ADSR) efficiently, a neutronics/thermal-hydraulics coupling analysis code named LAVENDER has been developed. In the neutronics calculation, the three dimensional deterministic neutron transport method is adopted. The nuclides transmutation analysis is implemented by the micro-depletion method with the Transmutation Trajectory Analysis algorithm (TTA). In the thermal-hydraulics calculation, a heat transfer model is established to consider thermal feedback and examine thermal-hydraulics design. The validations are performed based on several benchmarks. Numerical results indicate that LAVENDER is reliable and efficient to be applied for the design and steady-state analysis of ADSR. (author)

  17. Stability analysis of multigrid acceleration methods for the solution of partial differential equations

    Fay, John F.

    1990-01-01

    A calculation is made of the stability of various relaxation schemes for the numerical solution of partial differential equations. A multigrid acceleration method is introduced, and its effects on stability are explored. A detailed stability analysis of a simple case is carried out and verified by numerical experiment. It is shown that the use of multigrids can speed convergence by several orders of magnitude without adversely affecting stability.

  18. LAVENDER: A steady-state core analysis code for design studies of accelerator driven subcritical reactors

    Zhou, Shengcheng; Wu, Hongchun; Cao, Liangzhi; Zheng, Youqi, E-mail: yqzheng@mail.xjtu.edu.cn; Huang, Kai; He, Mingtao; Li, Xunzhao

    2014-10-15

    Highlights: • A new code system for design studies of accelerator driven subcritical reactors (ADSRs) is developed. • S{sub N} transport solver in triangular-z meshes, fine deletion analysis and multi-channel thermal-hydraulics analysis are coupled in the code. • Numerical results indicate that the code is reliable and efficient for design studies of ADSRs. - Abstract: Accelerator driven subcritical reactors (ADSRs) have been proposed and widely investigated for the transmutation of transuranics (TRUs). ADSRs have several special characteristics, such as the subcritical core driven by spallation neutrons, anisotropic neutron flux distribution and complex geometry etc. These bring up requirements for development or extension of analysis codes to perform design studies. A code system named LAVENDER has been developed in this paper. It couples the modules for spallation target simulation and subcritical core analysis. The neutron transport-depletion calculation scheme is used based on the homogenized cross section from assembly calculations. A three-dimensional S{sub N} nodal transport code based on triangular-z meshes is employed and a multi-channel thermal-hydraulics analysis model is integrated. In the depletion calculation, the evolution of isotopic composition in the core is evaluated using the transmutation trajectory analysis algorithm (TTA) and fine depletion chains. The new code is verified by several benchmarks and code-to-code comparisons. Numerical results indicate that LAVENDER is reliable and efficient to be applied for the steady-state analysis and reactor core design of ADSRs.

  19. Wavelet Analysis of Acceleration Response of Beam Under the Moving Mass for Damage Assessment

    Vaidya, Tanuja; Chatterjee, Animesh

    2016-04-01

    In the present study, acceleration response of cracked beam is analyzed by using the wavelet transform to detect the crack presence, its location and also to predict the crack severity. The equation of motion of beam under the moving mass is solved by using the fourth order Runge-Kutta method. A code is written by expanding the equation for first three vibration modes. Acceleration signal of the damaged beam under the moving mass contains the discontinuity at the crack location. This discontinuity contained in the acceleration signal is sufficiently visible but it is very small for some signals. Therefore, the acceleration signals are transformed using the wavelet analysis. A wavelet coefficient peak occurs at the location of discontinuity, so that we can identify the crack presence and its location. From the value of wavelet coefficient peak, we can also predict the crack effect with respect to the change in velocity of moving mass and change in crack depth. The main advantage of this method is that the wavelet coefficient peak is sufficiently higher even for the higher velocities and small size crack.

  20. Three Dimensional Gait Analysis Using Wearable Acceleration and Gyro Sensors Based on Quaternion Calculations

    Hiroaki Miyagawa

    2013-07-01

    Full Text Available This paper proposes a method for three dimensional gait analysis using wearable sensors and quaternion calculations. Seven sensor units consisting of a tri-axial acceleration and gyro sensors, were fixed to the lower limbs. The acceleration and angular velocity data of each sensor unit were measured during level walking. The initial orientations of the sensor units were estimated using acceleration data during upright standing position and the angular displacements were estimated afterwards using angular velocity data during gait. Here, an algorithm based on quaternion calculation was implemented for orientation estimation of the sensor units. The orientations of the sensor units were converted to the orientations of the body segments by a rotation matrix obtained from a calibration trial. Body segment orientations were then used for constructing a three dimensional wire frame animation of the volunteers during the gait. Gait analysis was conducted on five volunteers, and results were compared with those from a camera-based motion analysis system. Comparisons were made for the joint trajectory in the horizontal and sagittal plane. The average RMSE and correlation coefficient (CC were 10.14 deg and 0.98, 7.88 deg and 0.97, 9.75 deg and 0.78 for the hip, knee and ankle flexion angles, respectively.

  1. Three dimensional gait analysis using wearable acceleration and gyro sensors based on quaternion calculations.

    Tadano, Shigeru; Takeda, Ryo; Miyagawa, Hiroaki

    2013-01-01

    This paper proposes a method for three dimensional gait analysis using wearable sensors and quaternion calculations. Seven sensor units consisting of a tri-axial acceleration and gyro sensors, were fixed to the lower limbs. The acceleration and angular velocity data of each sensor unit were measured during level walking. The initial orientations of the sensor units were estimated using acceleration data during upright standing position and the angular displacements were estimated afterwards using angular velocity data during gait. Here, an algorithm based on quaternion calculation was implemented for orientation estimation of the sensor units. The orientations of the sensor units were converted to the orientations of the body segments by a rotation matrix obtained from a calibration trial. Body segment orientations were then used for constructing a three dimensional wire frame animation of the volunteers during the gait. Gait analysis was conducted on five volunteers, and results were compared with those from a camera-based motion analysis system. Comparisons were made for the joint trajectory in the horizontal and sagittal plane. The average RMSE and correlation coefficient (CC) were 10.14 deg and 0.98, 7.88 deg and 0.97, 9.75 deg and 0.78 for the hip, knee and ankle flexion angles, respectively. PMID:23877128

  2. Feature-based Analysis of Plasma-based Particle Acceleration Data

    Ruebel, Oliver

    2014-01-01

    Plasma-based particle accelerators can produce and sustain thousands of times stronger acceleration fields than conventional particle accelerators, providing a potential solution to the problem of the growing size and cost of conventional particle accelerators. To facilitate scientific knowledge discovery from the ever growing collections of accelerator simulation data generated by accelerator physicists to investigate next-generation plasma-based particle accelerator designs, we describe a n...

  3. Experimental design and analysis for accelerated degradation tests with Li-ion cells.

    Doughty, Daniel Harvey; Thomas, Edward Victor; Jungst, Rudolph George; Roth, Emanuel Peter

    2003-08-01

    This document describes a general protocol (involving both experimental and data analytic aspects) that is designed to be a roadmap for rapidly obtaining a useful assessment of the average lifetime (at some specified use conditions) that might be expected from cells of a particular design. The proposed experimental protocol involves a series of accelerated degradation experiments. Through the acquisition of degradation data over time specified by the experimental protocol, an unambiguous assessment of the effects of accelerating factors (e.g., temperature and state of charge) on various measures of the health of a cell (e.g., power fade and capacity fade) will result. In order to assess cell lifetime, it is necessary to develop a model that accurately predicts degradation over a range of the experimental factors. In general, it is difficult to specify an appropriate model form without some preliminary analysis of the data. Nevertheless, assuming that the aging phenomenon relates to a chemical reaction with simple first-order rate kinetics, a data analysis protocol is also provided to construct a useful model that relates performance degradation to the levels of the accelerating factors. This model can then be used to make an accurate assessment of the average cell lifetime. The proposed experimental and data analysis protocols are illustrated with a case study involving the effects of accelerated aging on the power output from Gen-2 cells. For this case study, inadequacies of the simple first-order kinetics model were observed. However, a more complex model allowing for the effects of two concurrent mechanisms provided an accurate representation of the experimental data.

  4. Exergetic analysis of refrigeration system of the Pelletron-Linac particle accelerator of the University of Sao Paulo

    The Pelletron-Linac accelerator of the University of Sao Paulo will use the existing electrostatic Pelletron accelerator as an injector for the linear superconducting accelerator (Linac), to increase the acceleration of the particles. The Linac uses a forced flow circulation helium system to promote continuous refrigeration for long periods of time, at temperatures below or equal to 4,9 K. This paper shows the exergetic analysis of the Pelletron-linac refrigerator, identifying the main sources of irreversibilities and evaluating energetic consumption of the system. An exergy-enthalpy diagram for the helium shows the thermodynamic processes that take place in the refrigeration plant and the exergy losses. (author)

  5. Fundamental principles, measurement techniques and data analysis in a ion accelerator

    The present work is intended to be a general reference for students and professionals interested in the field. Here, we present an introduction to the analysis techniques and fundamental principles for data processing and operation of a typical ion accelerator that operates in the low energy range. We also present a detailed description of the apparatus and propose new analysis methods for the results. In addition, we introduce illustrative simulations of the ion's trajectories in the different components of the apparatus performed with specialized software and, a new computer data acquisition and control interface. (Author)

  6. RF-thermal-structural-RF coupled analysis on a travelling wave disk-loaded accelerating structure

    The travelling wave (TW) disk-loaded accelerating structure is one of the key components in normal conducting (NC) linear accelerators, and has been studied for many years. In the design process, usually after the dimensions of each cell and the two couplers are finalized, the structure is fabricated and tuned, and then the whole structure RF characteristics are measured by using a vector network analyzer. Before fabrication, the whole structure characteristics (including RF, thermal and structural ones) are less simulated due to the limited capability of currently available computers. In this paper, we described a method for performing RF-thermal-structural-RF coupled analysis on a TW disk-loaded structure using only one PC. In order to validate our method, we first analyzed and compared our RF simulation results on the 3 m long BEPC Ⅱ structure with the corresponding experimental results, which shows very good consistency. Finally, the RF-thermal-structure-RF coupled analysis results on the 1.35 m long NSC KIPT linac accelerating structure are presented. (authors)

  7. Selective accelerated solvent extraction for the analysis of soil polycyclic aromatic hydrocarbons and sterols

    Accelerated solvent extraction (ASE) has been successfully used in the analysis of a wide range of chemicals from many sample matrices. However, the main problem with accelerated solvent extraction is low selectivity towards the analyte because during the extraction process, many interfering components are co-extracted together with target analytes and thus requires post-extraction clean-up processes. In this study, a selective accelerated solvent extraction with clean-up step incorporated inside the extraction cell was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) and sterols in soil. PAHs (naphthalene, acenaphthene, anthracene, pyrene) and sterols (coprostanol, cholestrol, stigmasterol, stigmastanol) were extracted separately using two elution steps. The selectivity and efficiency of this approach were evaluated using several sorbents and proper choice of solvents. Using polar sorbents, PAHs were recovered in the first extraction using n-hexane while sterols were recovered in the second extraction using a more polar solvent such as methanol, isopropanol, acetone and mixture of DCM: MeOH (40:60, v/ v). Recoveries for PAHs ranged from 76.5-99.2 % and sterols from 83.7-91.4 % using silica as the sorbent, n-hexane as the first eluent, and methanol as the second eluent. (author)

  8. Automated detection and analysis of particle beams in laser-plasma accelerator simulations

    Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of massive data sets over many time steps using several plots, a routine that is unfeasible for large data collections. Demand for automated analysis is growing along with the volume and size of simulations. Current 2D LWFA simulation datasets are typically between 1GB and 100GB in size, but simulations in 3D are of the order of TBs. The increase in the number of datasets and dataset sizes leads to a need for automatic routines to recognize particle patterns as particle bunches (beam of electrons) for subsequent analysis. Because of the growth in dataset size, the application of machine learning techniques for

  9. Multiphysics Analysis of Frequency Detuning in Superconducting RF Cavities for Proton Particle Accelerators

    Awida, M. H. [Fermilab; Gonin, I. [Fermilab; Passarelli, D. [Fermilab; Sukanov, A. [Fermilab; Khabiboulline, T. [Fermilab; Yakovlev, V. [Fermilab

    2016-01-22

    Multiphysics analyses for superconducting cavities are essential in the course of cavity design to meet stringent requirements on cavity frequency detuning. Superconducting RF cavities are the core accelerating elements in modern particle accelerators whether it is proton or electron machine, as they offer extremely high quality factors thus reducing the RF losses per cavity. However, the superior quality factor comes with the challenge of controlling the resonance frequency of the cavity within few tens of hertz bandwidth. In this paper, we investigate how the multiphysics analysis plays a major role in proactively minimizing sources of frequency detuning, specifically; microphonics and Lorentz Force Detuning (LFD) in the stage of RF design of the cavity and mechanical design of the niobium shell and the helium vessel.

  10. Analysis of ballistic transport in nanoscale devices by using an accelerated finite element contact block reduction approach

    Li, H.; Li, G.

    2014-08-01

    An accelerated Finite Element Contact Block Reduction (FECBR) approach is presented for computational analysis of ballistic transport in nanoscale electronic devices with arbitrary geometry and unstructured mesh. Finite element formulation is developed for the theoretical CBR/Poisson model. The FECBR approach is accelerated through eigen-pair reduction, lead mode space projection, and component mode synthesis techniques. The accelerated FECBR is applied to perform quantum mechanical ballistic transport analysis of a DG-MOSFET with taper-shaped extensions and a DG-MOSFET with Si/SiO2 interface roughness. The computed electrical transport properties of the devices obtained from the accelerated FECBR approach and associated computational cost as a function of system degrees of freedom are compared with those obtained from the original CBR and direct inversion methods. The performance of the accelerated FECBR in both its accuracy and efficiency is demonstrated.

  11. Analysis of ballistic transport in nanoscale devices by using an accelerated finite element contact block reduction approach

    An accelerated Finite Element Contact Block Reduction (FECBR) approach is presented for computational analysis of ballistic transport in nanoscale electronic devices with arbitrary geometry and unstructured mesh. Finite element formulation is developed for the theoretical CBR/Poisson model. The FECBR approach is accelerated through eigen-pair reduction, lead mode space projection, and component mode synthesis techniques. The accelerated FECBR is applied to perform quantum mechanical ballistic transport analysis of a DG-MOSFET with taper-shaped extensions and a DG-MOSFET with Si/SiO2 interface roughness. The computed electrical transport properties of the devices obtained from the accelerated FECBR approach and associated computational cost as a function of system degrees of freedom are compared with those obtained from the original CBR and direct inversion methods. The performance of the accelerated FECBR in both its accuracy and efficiency is demonstrated

  12. Utilization of Integrated Process Control, Data Capture, and Data Analysis in Construction of Accelerator Systems

    Jefferson Lab has developed a web-based system that integrates commercial database, data analysis, document archiving and retrieval, and user interface software, into a coherent knowledge management product (Pansophy). This product provides important tools for the successful pursuit of major projects such as accelerator system development and construction, by offering elements of process and procedure control, data capture and review, and data mining and analysis. After a period of initial development, Pansophy is now being used in Jefferson Lab's SNS superconducting linac construction effort, as a means for structuring and implementing the QA program, for process control and tracking, and for cryomodule test data capture and presentation/analysis. Development of Pansophy is continuing, in particular data queries and analysis functions that are the cornerstone of its utility

  13. Will solid-state drives accelerate your bioinformatics? In-depth profiling, performance analysis and beyond.

    Lee, Sungmin; Min, Hyeyoung; Yoon, Sungroh

    2016-07-01

    A wide variety of large-scale data have been produced in bioinformatics. In response, the need for efficient handling of biomedical big data has been partly met by parallel computing. However, the time demand of many bioinformatics programs still remains high for large-scale practical uses because of factors that hinder acceleration by parallelization. Recently, new generations of storage devices have emerged, such as NAND flash-based solid-state drives (SSDs), and with the renewed interest in near-data processing, they are increasingly becoming acceleration methods that can accompany parallel processing. In certain cases, a simple drop-in replacement of hard disk drives by SSDs results in dramatic speedup. Despite the various advantages and continuous cost reduction of SSDs, there has been little review of SSD-based profiling and performance exploration of important but time-consuming bioinformatics programs. For an informative review, we perform in-depth profiling and analysis of 23 key bioinformatics programs using multiple types of devices. Based on the insight we obtain from this research, we further discuss issues related to design and optimize bioinformatics algorithms and pipelines to fully exploit SSDs. The programs we profile cover traditional and emerging areas of importance, such as alignment, assembly, mapping, expression analysis, variant calling and metagenomics. We explain how acceleration by parallelization can be combined with SSDs for improved performance and also how using SSDs can expedite important bioinformatics pipelines, such as variant calling by the Genome Analysis Toolkit and transcriptome analysis using RNA sequencing. We hope that this review can provide useful directions and tips to accompany future bioinformatics algorithm design procedures that properly consider new generations of powerful storage devices. PMID:26330577

  14. Mitonuclear Epistasis for Development Time and Its Modification by Diet in Drosophila.

    Mossman, Jim A; Biancani, Leann M; Zhu, Chen-Tseh; Rand, David M

    2016-05-01

    Mitochondrial (mtDNA) and nuclear genes have to operate in a coordinated manner to maintain organismal function, and the regulation of this homeostasis presents a substantial source of potential epistatic (G × G) interactions. How these interactions shape the fitness landscape is poorly understood. Here we developed a novel mitonuclear epistasis model, using selected strains of the Drosophila Genetic Reference Panel (DGRP) and mitochondrial genomes from within Drosophila melanogaster and D. simulans to test the hypothesis that mtDNA × nDNA interactions influence fitness. In total we built 72 genotypes (12 nuclear backgrounds × 6 mtDNA haplotypes, with 3 from each species) to dissect the relationship between genotype and phenotype. Each genotype was assayed on four food environments. We found considerable variation in several phenotypes, including development time and egg-to-adult viability, and this variation was partitioned into genetic (G), environmental (E), and higher-order (G × G, G × E, and G × G × E) components. Food type had a significant impact on development time and also modified mitonuclear epistases, evidencing a broad spectrum of G × G × E across these genotypes. Nuclear background effects were substantial, followed by mtDNA effects and their G × G interaction. The species of mtDNA haplotype had negligible effects on phenotypic variation and there was no evidence that mtDNA variation has different effects on male and female fitness traits. Our results demonstrate that mitonuclear epistases are context dependent, suggesting the selective pressure acting on mitonuclear genotypes may vary with food environment in a genotype-specific manner. PMID:26966258

  15. An end to endless forms: epistasis, phenotype distribution bias, and nonuniform evolution.

    Elhanan Borenstein

    2008-10-01

    Full Text Available Studies of the evolution of development characterize the way in which gene regulatory dynamics during ontogeny constructs and channels phenotypic variation. These studies have identified a number of evolutionary regularities: (1 phenotypes occupy only a small subspace of possible phenotypes, (2 the influence of mutation is not uniform and is often canalized, and (3 a great deal of morphological variation evolved early in the history of multicellular life. An important implication of these studies is that diversity is largely the outcome of the evolution of gene regulation rather than the emergence of new, structural genes. Using a simple model that considers a generic property of developmental maps-the interaction between multiple genetic elements and the nonlinearity of gene interaction in shaping phenotypic traits-we are able to recover many of these empirical regularities. We show that visible phenotypes represent only a small fraction of possibilities. Epistasis ensures that phenotypes are highly clustered in morphospace and that the most frequent phenotypes are the most similar. We perform phylogenetic analyses on an evolving, developmental model and find that species become more alike through time, whereas higher-level grades have a tendency to diverge. Ancestral phenotypes, produced by early developmental programs with a low level of gene interaction, are found to span a significantly greater volume of the total phenotypic space than derived taxa. We suggest that early and late evolution have a different character that we classify into micro- and macroevolutionary configurations. These findings complement the view of development as a key component in the production of endless forms and highlight the crucial role of development in constraining biotic diversity and evolutionary trajectories.

  16. Preliminary Safety Analysis Report (PSAR), The NSLS 200 MeV Linear Electron Accelerator

    Blumberg, L.N.; Ackerman, A.I.; Dickinson, T.; Heese, R.N.; Larson, R.A.; Neuls, C.W.; Pjerov, S.; Sheehan, J.F.

    1993-06-15

    The radiological, fire and electrical hazards posed by a 200 MeV electron Linear Accelerator, which the NSLS Department will install and commission within a newly assembled structure, are addressed in this Preliminary Safety Analysis Report. Although it is clear that this accelerator is intended to be the injector for a future experimental facility, we address only the Linac in the present PSAR since neither the final design nor the operating characteristics of the experimental facility are known at the present time. The fire detection and control system to be installed in the building is judged to be completely adequate in terms of the marginal hazard presented - no combustible materials other than the usual cabling associated with such a facility have been identified. Likewise, electrical hazards associated with power supplies for the beam transport magnets and accelerator components such as the accelerator klystrons and electron gun are classified as marginal in terms of potential personnel injury, cost of equipment lost, program downtime and public impact perceptions as defined in the BNL Environmental Safety and Health Manual and the probability of occurrence is deemed to be remote. No unusual features have been identified for the power supplies or electrical distribution system, and normal and customary electrical safety standards as practiced throughout the NSLS complex and the Laboratory are specified in this report. The radiation safety hazards are similarly judged to be marginal in terms of probability of occurrence and potential injury consequences since, for the low intensity operation proposed - a factor of 25 less than the maximum Linac capability specified by the vendor - the average beam power is only 0.4 watts. The shielding specifications given in this report will give adequate protection to both the general public and nonradiation workers in areas adjacent to the building as well as radiation workers within the controlled access building.

  17. Preliminary neutronics design and analysis for accelerator driven subcritical tritium production reactor ADS-T

    In this paper, by using self-developed multi-functional 4D neutronics simulation system VisualBUS4.2 and hybrid evaluated nuclear data library HENDL3.0, sensitivity analysis on spallation neutron energy, abundance of 6Li in tritium breeding material, structural steel, initial keff, neutron energy spectrum as well as the placement of tritium production assembly was performed for lead-alloy cooled accelerator driven subcritical nuclear waste transmutation and tritium production reactor ADS-T (ADS- Tritium). Finally, preliminary neutronics options of ADS-T were given, an attractive tritium production pathway was provided. (authors)

  18. Accelerator and klystron (3). Klystron failure analysis, emission control, phase variation and maintenance

    Klystron failure analysis, emission control, phase variation and maintenance are described in this last paper of three successive series. Four main failure causes extracted from SLAC data of SLAC 1965-1982, and KEK data are explained in detail. Regarding to Klystron life, KEKs dip test which is a quick way to examine the emission is explained. The phase variation should be small for accelerator and good stability on applied voltage and cooling water temperature are essential. Klystron maintenance which is important for the effective use is explained. (author)

  19. Analysis of HOM for alignment detection of 9-cell superconducting cavities in STF accelerator

    Cavity alignment requirements for ILC are less than 300 μm offset and 300 μrad tilt with respect to cryomodule axis. To achieve these requirements, we need to confirm alignment quality of the existing cryomodule. Beam induced HOM was measured with beam trajectory sweep in STF (Superconducting rf Test Facility) accelerator in 2012 - 2013. To detect alignment of 9-cell superconducting cavities, we propose to use electrical centers of TE111-1 and beam pipe modes. The detailed data analysis is discussed in this paper. (author)

  20. Analysis of damaging effects of laser-plasma accelerated shrapnels on protecting glass shield

    Analysis of the damage caused by laser plasma accelerated fragments of metal target was performed. Measured as well as calculated parameters of craters and shrapnel found in BK7 glass blast-shield are presented. Method applied for the measurement of parameters of craters is described. Potential damage of optical elements by the so-called striking cores (high-velocity stable objects arising due to collapse of cones or some other target parts toward their axes) that can be generated in IFE related experiments is evaluated. (authors)

  1. Elemental analysis of concrete samples using an accelerator-based PGNAA setup

    Naqvi, A. A.; Nagadi, M. M.; Baghabra Al-Amoudi, Omar S.

    2004-09-01

    Elemental analysis of concrete samples was carried out using an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup. The gamma rays were produced via the capture of thermal neutron in the concrete sample. The prompt gamma ray yield was measured for 12 cm long concrete samples as a function of sample radius over a range of 6-11.5 cm radii. The optimum yield of the prompt gamma rays from the concrete sample was measured from a sample with 11.5 cm radius. The gamma ray yield was also calculated for 12 cm long concrete samples with 6-11.5 cm radius using Monte Carlo simulations. The experimental results were in excellent agreement with the calculated yield of the prompt gamma rays from the samples. Result of this study has shown the useful application of an accelerator-based PGNAA setup in elemental analysis of concrete sample. The facility can be further used to determine the chloride and sulfate concentrations in concrete samples for corrosion studies of reinforcement steel in concrete structures.

  2. Elemental analysis of concrete samples using an accelerator-based PGNAA setup

    Elemental analysis of concrete samples was carried out using an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup. The gamma rays were produced via the capture of thermal neutron in the concrete sample. The prompt gamma ray yield was measured for 12 cm long concrete samples as a function of sample radius over a range of 6-11.5 cm radii. The optimum yield of the prompt gamma rays from the concrete sample was measured from a sample with 11.5 cm radius. The gamma ray yield was also calculated for 12 cm long concrete samples with 6-11.5 cm radius using Monte Carlo simulations. The experimental results were in excellent agreement with the calculated yield of the prompt gamma rays from the samples. Result of this study has shown the useful application of an accelerator-based PGNAA setup in elemental analysis of concrete sample. The facility can be further used to determine the chloride and sulfate concentrations in concrete samples for corrosion studies of reinforcement steel in concrete structures

  3. Uncertainty in the estimates of peak ground acceleration in seismic hazard analysis

    Pavlenko, V. A.

    2015-11-01

    Probabilistic seismic hazard analysis has become a standard procedure preceding the antiseismic construction. An important component of the relevant calculations is the allowance for the uncertainty in the strong motion parameters (e.g., peak ground acceleration (PGA)). In the present-day approaches of probabilistic analysis, this uncertainty is modeled by a random variable (a residual) which has a lognormal distribution. With this model, the extrapolation into the area of long return periods yields nonzero probabilities of unrealistically high PGA. In the present work, the distribution of the logarithmic PGA residuals is modeled by different parametric distributions. From the set of these distributions, the one which provides the closest approximation of the empirical data is selected by the statistical criteria. The analysis shows that the generalized extreme value distribution (GEVD) most accurately reproduces the residuals of the logarithmic PGA, and the tail of the distribution is approximated by the generalized Pareto distribution (GPD).

  4. Sensitivity analysis of core neutronic parameters in accelerator driven subcritical reactors

    Highlights: • Sensitivity analysis of ADSR core neutronic parameters has been investigated. • Uniform and parabolic proton beam spatial distributions have been considered. • TRIGA reactor was considered as the case study of the problem. - Abstract: In this paper, sensitivity of the ADSRs core neutronic parameters to the accelerator related parameters such as beam profile, source multiplication coefficient (ks) and proton beam energy (Ep) has been investigated. TRIGA reactor has been considered as the case study of the problem. Monte Carlo code MCNPX has been used to calculate neutronic parameters such as: effective multiplication coefficient (keff), net neutron multiplication (M), spallation neutron yield (Yn/p), energy constant gain (G0), energy gain (G), importance of neutron source (φ*), axial and radial distributions of neutron flux and power peaking factor (Pmax/Pave) in two axial and radial directions of the reactor core for three eigen values levels (ks) including: 0.91, 0.97 and 0.99. According to the results, using a parabolic spatial distribution instead of a uniform spatial distribution increases the relative differences of spallation neutron yield, net neutron multiplication and energy gain by 4.74%, 4.05% and 10.26% respectively. In consequence the required accelerator current (Ip) will be reduced by 7.14% to preserve the reactivity. Although safety margin is decreased in highest case of ks, but energy gain increases by 93.43% and the required accelerator current and importance of neutrons source decrease by 48.3% and 2.64% respectively. In addition, increasing Ep from 115 MeV up to1 GeV, improves spallation neutron yield and energy gain by 2798.71% and 205.12% and decreases the required accelerator current and power by 96.83% and 72.44%, respectively. Therefore, our results are indicative of the fact that investigating sensitivity of the core neutronic parameters to the accelerator related parameters are necessary in order to optimally design a

  5. The Statistical Power of Inclusive Composite Interval Mapping in Detecting Digenic Epistasis Showing Common F2 Segregation Ratios

    Luyan Zhang; Huihui Li; Jiankang Wang

    2012-01-01

    Epistasis is a commonly observed genetic phenomenon and an important source of variation of complex traits,which could maintain additive variance and therefore assure the long-term genetic gain in breeding.Inclusive composite interval mapping (ICIM) is able to identify epistatic quantitative trait loci (QTLs) no matter whether the two interacting QTLs have any additive effects.In this article,we conducted a simulation study to evaluate detection power and false discovery rate (FDR) of ICIM epistatic mapping,by considering F2 and doubled haploid (DH) populations,different F2 segregation ratios and population sizes.Results indicated that estimations of QTL locations and effects were unbiased,and the detection power of epistatic mapping was largely affected by population size,heritability of epistasis,and the amount and distribution of genetic effects.When the same likelihood of odd (LOD) threshold was used,detection power of QTL was higher in F2 population than power in DH population; meanwhile FDR in F2 was also higher than that in DH.The increase of marker density from 10 cM to 5 cM led to similar detection power but higher FDR.In simulated populations,ICIM achieved better mapping results than multiple interval mapping (MIM) in estimation of QTL positions and effect.At the end,we gave epistatic mapping results of ICIM in one actual population in rice (Oryza sativa L.).

  6. Accelerating policy decisions to adopt haemophilus influenzae type B vaccine: a global, multivariable analysis.

    Jessica C Shearer

    2010-03-01

    Full Text Available BACKGROUND: Adoption of new and underutilized vaccines by national immunization programs is an essential step towards reducing child mortality. Policy decisions to adopt new vaccines in high mortality countries often lag behind decisions in high-income countries. Using the case of Haemophilus influenzae type b (Hib vaccine, this paper endeavors to explain these delays through the analysis of country-level economic, epidemiological, programmatic and policy-related factors, as well as the role of the Global Alliance for Vaccines and Immunisation (GAVI Alliance. METHODS AND FINDINGS: Data for 147 countries from 1990 to 2007 were analyzed in accelerated failure time models to identify factors that are associated with the time to decision to adopt Hib vaccine. In multivariable models that control for Gross National Income, region, and burden of Hib disease, the receipt of GAVI support speeded the time to decision by a factor of 0.37 (95% CI 0.18-0.76, or 63%. The presence of two or more neighboring country adopters accelerated decisions to adopt by a factor of 0.50 (95% CI 0.33-0.75. For each 1% increase in vaccine price, decisions to adopt are delayed by a factor of 1.02 (95% CI 1.00-1.04. Global recommendations and local studies were not associated with time to decision. CONCLUSIONS: This study substantiates previous findings related to vaccine price and presents new evidence to suggest that GAVI eligibility is associated with accelerated decisions to adopt Hib vaccine. The influence of neighboring country decisions was also highly significant, suggesting that approaches to support the adoption of new vaccines should consider supply- and demand-side factors.

  7. AMS analysis of 36Cl induced in concrete of accelerator facilities

    Accelerator mass spectrometry (AMS) was applied to the analysis of 36Cl induced in concrete samples obtained from accelerator facilities. In order to use a small amount of concrete sample and to separate chlorine as pure as possible, an improvement of separation process was developed. Chlorine was extracted from 1-5 g of concrete into 0.01 M nitric acid in a pressurized decomposition vessel. After determining chlorine using ion chromatography, a certain amount of NaCl solution was added to obtain sufficient amounts of AgCl precipitate and to dilute to a suitable isotope ratio of 36Cl to 35Cl (36Cl/35Cl) for the AMS (10-12-10-10). A careful purification procedure was applied to reduce 36S interference in AMS. Good reproducibility and small error throughout the chemical process for sample preparation was attained. Depth profiles of 36Cl/35Cl in concrete of a medium-energy cyclotron were measured by the developed method and compared with the results of γ-emitters induced by thermal neutrons. Since it was confirmed that 36Cl was produced by thermal neutron capture of 35Cl, the thermal neutron fluence irradiated during accelerator operation could be obtained using 36Cl/35Cl. In order to estimate the neutron fluences, the 36Cl/35Cl measurement by AMS is more useful than radioactivity measurements of other isotopes such as γ-emitters because AMS directly provides the isotope ratio and the half-life of 36Cl is very long. (orig.)

  8. Analysis of the damaging effect of laser-plasma accelerated shrapnels on the optical shield

    The practical implementation of the laser ignited thermonuclear fusion brings also the whole variety of technical challenges which have to be solved in foreseeable future in order to implement new scale fusion facilities operating in high-rep regime (and not only for them). One of these tasks represent a problem related to the shielding of the final optics and other vulnerable equipment placed inside the interaction chamber[1,2,3] in the case when solid targets (hohlraums, fast ignition targets with cones, and others) are irradiated by high-energy lasers, producing plasma and vapors which can split target into fragments and accelerate the non-evaporated parts to velocities a few folds of km/s and even more (achieving a hyper-velocities over 10 km/s, corresponding to the velocities of the space-debris micro-particles). This way accelerated particles (generally in range from few tens or hundred milligrams to several micrograms) can reach energies capable to destroy a glass plate made of Fused Silica, BK7, or similar kinds of crown glasses up to several millimeters thickness. This may result in serious damage or even destruction of the diagnostic and optical components located in the path of the shrapnel or other objects with similar possible damaging effect[3]. In this contribution a recent analysis of the laser-plasma accelerated fragments originated from Cu target irradiated by the Prague Asterix Laser System (PALS) first harmonics (1315 nm) with pulse duration 350 ps and energy 605 J, as well as the examination of the parameters of target fragments and the level of the damage of the final optical shield will be presented. (author)

  9. SHEsisEpi, a GPU-enhanced genome-wide SNP-SNP interaction scanning algorithm, efficiently reveals the risk genetic epistasis in bipolar disorder

    Xiaohan Hu; Qiang Liu; Zhao Zhang; Zhiqiang Li; Shilin Wang; Lin He; Yongyong Shi

    2010-01-01

    @@ Dear Editor, We developed a GPU-based analytical method, named as SHEsisEpi, which purely focuses on risk epistasis in a genome-wide association study (GWAS) of complex traits, excluding the contamination of marginal effects caused by single-locus association. We analyzed the Wellcome Trust Case Control Consortium's (WTCCC)GWAS data of bipolar disorder (BPD) with 500K SNPs.

  10. Accelerator Mass Spectrometry and Ion Beam Analysis as complementary tools in Cultural Heritage diagnostics at CEDAD

    Among the analytical methods based on the use of ion beams with energies in the MeV range, those with a higher potential in cultural heritage diagnostics are surely IBA (Ion Beam Analysis) techniques and radiocarbon dating by AMS (Accelerator Mass Spectrometry). Taking advantages of the presence at the accelerator facility of the University of Salento (CEDAD) of experimental lines for 14C AMS dating and PIXEPIGE non-destructive analyses in external beam mode, different studies have been carried out by combining these methods for the study of the same archaeometric problem. After a review of the experimental beam lines available at CEDAD and a description of the ongoing projects, different case studies will be presented and discussed such as the 14C dating and compositional analyses of the inner cores of the Riace Bronzes, the determination of the provenance of obsidians tools from 14C dated Neolithic sites in the Mediterranean and the study of the diagenetic state of cremated bones submitted to 14C dating. (author)

  11. Waveband Analysis of Track Irregularities in High-Speed Railway from On-Board Acceleration Measurement

    Lee, Jun Seok; Choi, Sunghoon; Kim, Sang-Soo; Kim, Young Guk; Kim, Seog Won; Park, Choonsoo

    This paper is focused on waveband analysis of the lateral and vertical track irregularities from the on-board acceleration measurement of in-service high-speed trains. The track irregularities play important roles to determine dynamic stability of vehicles and ride quality of passengers, so that their amplitude and wavelength should be monitored continuously and carefully. Measuring acceleration at the axle-box or bogie of the trains has been under consideration for low-cost implementation and robust to a harsh railway environment. To estimate the track irregularities, lateral and vertical vibration caused by the wheel/track interaction is measured by the axle-box and bogie mounted accelerometers of an in-service high-speed train. A Kalman filter is used to prevent unrealistic drifts in the estimation. By applying the waveband-pass and compensation filters to the estimated displacement, it is possible to estimate the track irregularities. A distance-wavelength representation is used to identify their waveband in an intuitive way. It is verified by comparing with a commercial track geometry measurement system. From their comparison, it confirms that the representation can produce a satisfactory result.

  12. Analysis and performance of adjacent-cell preconditioners for accelerating multidimensional transport calculations

    The formal development of the Adjacent-cell Preconditioner (AP) and its implementation in the TORT code are briefly reviewed. Based on earlier experience with diffusion type acceleration, and excellent results in slab geometry the reciprocal averaging formula is used to mix the preconditioner elements across material and mesh discontinuities. Numerical testing of the method employing the Burre Suite of Test Problems (BSTeP), a collection of 144 cases covering a wide range in parameter space, using AP, Partial Current Rebalance (PCR), and TWODANT's Diffusion Synthetic Acceleration (DSA) is presented. While AP outperforms the other two methods for the majority of the cases included in BSTeP it consumes many more iterations than can be explained by spectral analysis of the homogeneous model problem in cases with sharp material discontinuity. In order to verify this undesirable behavior and explore potential remedies a model problem, the Periodic Horizontal Interface (PHI), is developed that permits discontinuity of nuclear properties and cell height across the interface. Fourier mode decomposition is applied to AP with the reciprocal averaging mixing formula for the PHI configuration and shown to possess a spectral radius that approaches unity as the material discontinuity gets larger. The question of whether an unconditionally stable AP exists for PHI is tackled and preliminary indications are negative. Novel preconditioners that have nontraditional cell-coupling schemes that remain stable in these regimes may have to be sought

  13. Analysis of secondary particle behavior in multiaperture, multigrid accelerator for the ITER neutral beam injector

    Heat load on acceleration grids by secondary particles such as electrons, neutrals, and positive ions, is a key issue for long pulse acceleration of negative ion beams. Complicated behaviors of the secondary particles in multiaperture, multigrid (MAMuG) accelerator have been analyzed using electrostatic accelerator Monte Carlo code. The analytical result is compared to experimental one obtained in a long pulse operation of a MeV accelerator, of which second acceleration grid (A2G) was removed for simplification of structure. The analytical results show that relatively high heat load on the third acceleration grid (A3G) since stripped electrons were deposited mainly on A3G. This heat load on the A3G can be suppressed by installing the A2G. Thus, capability of MAMuG accelerator is demonstrated for suppression of heat load due to secondary particles by the intermediate grids.

  14. Mapa-an object oriented code with a graphical user interface for accelerator design and analysis

    We developed a code for accelerator modeling which will allow users to create and analyze accelerators through a graphical user interface (GUI). The GUI can read an accelerator from files or create it by adding, removing and changing elements. It also creates 4D orbits and lifetime plots. The code includes a set of accelerator elements classes, C++ utility and GUI libraries. Due to the GUI, the code is easy to use and expand

  15. Mapa-an object oriented code with a graphical user interface for accelerator design and analysis

    We developed a code for accelerator modeling which will allow users to create and analyze accelerators through a graphical user interface (GUI). The GUI can read an accelerator from files or create it by adding, removing and changing elements. It also creates 4D orbits and lifetime plots. The code includes a set of accelerator elements classes, C++ utility and GUI libraries. Due to the GUI, the code is easy to use and expand. copyright 1997 American Institute of Physics

  16. Mapa-an object oriented code with a graphical user interface for accelerator design and analysis

    Shasharina, S.G.; Cary, J.R. [Tech-X Corporation 4588 Pussy Willow Court, Boulder, Colorado 80301 (United States)

    1997-02-01

    We developed a code for accelerator modeling which will allow users to create and analyze accelerators through a graphical user interface (GUI). The GUI can read an accelerator from files or create it by adding, removing and changing elements. It also creates 4D orbits and lifetime plots. The code includes a set of accelerator elements classes, C++ utility and GUI libraries. Due to the GUI, the code is easy to use and expand. {copyright} {ital 1997 American Institute of Physics.}

  17. On the Impact of a Quadratic Acceleration Term in the Analysis of Position Time Series

    Bogusz, Janusz; Klos, Anna; Bos, Machiel Simon; Hunegnaw, Addisu; Teferle, Felix Norman

    2016-04-01

    The analysis of Global Navigation Satellite System (GNSS) position time series generally assumes that each of the coordinate component series is described by the sum of a linear rate (velocity) and various periodic terms. The residuals, the deviations between the fitted model and the observations, are then a measure of the epoch-to-epoch scatter and have been used for the analysis of the stochastic character (noise) of the time series. Often the parameters of interest in GNSS position time series are the velocities and their associated uncertainties, which have to be determined with the highest reliability. It is clear that not all GNSS position time series follow this simple linear behaviour. Therefore, we have added an acceleration term in the form of a quadratic polynomial function to the model in order to better describe the non-linear motion in the position time series. This non-linear motion could be a response to purely geophysical processes, for example, elastic rebound of the Earth's crust due to ice mass loss in Greenland, artefacts due to deficiencies in bias mitigation models, for example, of the GNSS satellite and receiver antenna phase centres, or any combination thereof. In this study we have simulated 20 time series with different stochastic characteristics such as white, flicker or random walk noise of length of 23 years. The noise amplitude was assumed at 1 mm/y-/4. Then, we added the deterministic part consisting of a linear trend of 20 mm/y (that represents the averaged horizontal velocity) and accelerations ranging from minus 0.6 to plus 0.6 mm/y2. For all these data we estimated the noise parameters with Maximum Likelihood Estimation (MLE) using the Hector software package without taken into account the non-linear term. In this way we set the benchmark to then investigate how the noise properties and velocity uncertainty may be affected by any un-modelled, non-linear term. The velocities and their uncertainties versus the accelerations for

  18. Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

    NONE

    1994-10-01

    This document is the first volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, except for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of an introduction, summary/conclusion, site description and assessment, description of facility, and description of operation.

  19. Accelerated Monte Carlo Simulation for Safety Analysis of the Advanced Airspace Concept

    Thipphavong, David

    2010-01-01

    Safe separation of aircraft is a primary objective of any air traffic control system. An accelerated Monte Carlo approach was developed to assess the level of safety provided by a proposed next-generation air traffic control system. It combines features of fault tree and standard Monte Carlo methods. It runs more than one order of magnitude faster than the standard Monte Carlo method while providing risk estimates that only differ by about 10%. It also preserves component-level model fidelity that is difficult to maintain using the standard fault tree method. This balance of speed and fidelity allows sensitivity analysis to be completed in days instead of weeks or months with the standard Monte Carlo method. Results indicate that risk estimates are sensitive to transponder, pilot visual avoidance, and conflict detection failure probabilities.

  20. Design, development and analysis of high voltage, high frequency transformer for dc accelerator application

    This paper covers the design, development and analysis of High Voltage, High Frequency Transformer for DC Accelerator application. Distributed capacitance, leakage inductance, skin effect and HV Insulation are major design challenges for this type of Transformer. A prototype of 30 kV - 0 - 30 kV, 10 kHz, 500 W output power, Ferrite Core Transformer have been designed, fabricated and tested. Spice simulations have been done for estimating transformer parameters. Effect of high frequency and requirement of HV Insulation have been studied and analyzed. The effects of Magnetic Core behaviour and its losses have been studied. Based on study and test result, distributed capacitance, leakage inductance, and Transformer scheme has been optimized for 30 kV - 0 - 30 kV, 10 kHz, 10 kW output power. (author)

  1. Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

    NONE

    1994-10-01

    This document is the third volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, except for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of appendices C through U of the report

  2. Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

    NONE

    1994-10-01

    This document is the second volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, except for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of failure modes and effects analysis; accident analysis; operational safety requirements; quality assurance program; ES&H management program; environmental, safety, and health systems critical to safety; summary of waste-management program; environmental monitoring program; facility expansion, decontamination, and decommissioning; summary of emergency response plan; summary plan for employee training; summary plan for operating procedures; glossary; and appendices A and B.

  3. Thermal-hydraulic analysis of LBE spallation target for accelerator-driven systems

    Aniseh Ahmed Atef Abdalla; Jiyang Yu; Yongwel Yang

    2013-01-01

    In an accelerator-driven subcritical system (ADS), a high-performance spallation neutron source is used to feed the subcritical reactor. Neutron generation depends on the proton beam intensity. If the beam intensity is increased by a given factor, the number of generated neutrons will increase. The mechanism yielding a high rate of neutron production per energy is the spallation process, and this mechanism produces very high-energy deposition in the spallation target material. Producing a high rate of neutrons is accompanied by creation of problems of decay heat cooling and radiological protection. As a first step in designing a full-scale industrial ADS, a small-scale experimental ADS, which is similar to the European experimental ADS (XADS) is analysed. The analysis presented in this paper is based on lead–bismuth eutectic (LBE) cooled XADS-type experimental reactors, designed during the European experimental (PDS-XADS) project. Computational fluid dynamics analysis has been carried out for the spallation target. Steady-state behaviour and shear stress transport turbulence model with the automatic wall treatment were applied in the present analysis.

  4. Analysis of graduates' perceptions of an accelerated bachelor of science program in nursing.

    Kemsley, Martha; McCausland, Linda; Feigenbaum, Janice; Riegle, Elizabeth

    2011-01-01

    Rapid expansion of second-degree programs as one approach to addressing the nursing shortage by increasing the number of graduates in shorter periods of time prompted the need for program evaluation to identify the outcomes, strengths, and best practices of these programs. This study used both quantitative and qualitative methods of inquiry to analyze the responses of 28 of 56 recent graduates of an accelerated baccalaureate program. Respondents rated components of the program from preadmission to graduation on a Likert scale and responded to open-ended questions regarding strengths and weaknesses of the program. Analysis included descriptive statistics for quantitative data and content analysis for qualitative data. The analysis showed a high degree of similarity between the quantitative and qualitative data. Highly rated program components, that is, opportunity for graduate course work and integration with graduate students, clinical skill practice and experiences, variety of teaching methodologies, peer and faculty support, were reflected in the themes of cohort bonding, variety of clinical experiences, and supportive faculty and staff. Outcomes of program satisfaction, National Council Licensure Examination pass rates, successful nursing employment, and graduate school attendance were supported by the data. PMID:21272836

  5. THEORETICAL ANALYSIS AND EXPERIMENTAL VERIFICATION ON TERNARY-WAVES METHOD TO COMPILE ACCELERATED SPECTRA

    2002-01-01

    The equivalent damage calculation formulae of fatigue crack formation and growth are established. In order tocompile the fatigue crack formation and growth accelerated load spectra, the main wave shapes and load sequence of theactual load spectrum are kept constant, and the carrier waves are cut off. And secondary waves are put together into newsecondary waves to shorten the test time according to the equivalent damage calculation formulae respectively. Then bythe fatigue cumulative damage calculation of the fatigue crack formation and growth accelerated load spectra, the onecorresponding to the bigger damage is determined as the fatigue accelerated test load spectrum. Therefore in the test pro-cess, the fatigue accelerated test spectrum may be applied till fatigue failure, the engineering fatigue crack length of full-scale structure need not be inspected, and the fatigue crack formation accelerated load spectrum need not be transferredinto the fatigue crack growth accelerated load spectrum. Finally, it is verified by tests of two kinds of specimens that thedamages of the specimens caused by the accelerated load spectra are near to those by the actual load spectra; namely, thetested life of actual load spectra is similar to that of accelerated load spectra. But the test time of accelerated load spectrais shortened by about three-quarters that of actual load spectra. From these tests, it is also found that the fatigue accelerat-ed test spectrum has an advantage over FALSTAFF spectra.

  6. Effect of acceleration on osteoblastic and osteoclastic activities: Analysis of bone metabolism using goldfish scale as a model for bone

    Suzuki, S.; Kitamura, K.; Nemoto, N.; Shimizu, S.; Wada, W.; Kondo, K.; Tabata, T.; Sodeyama, S.; Ijiri, I.; Hattori, H.

    It is well known that hypo-gravity and hyper-gravity influence bone metabolism However basic data concerning the mechanism are a few because no in vitro model system of human bone is available Human bone consists of osteoblasts osteoclasts and the bone matrix No technique for the co-culture of these components has ever been developed Fish scale is a calcified tissue that contains osteoblasts osteoclasts and bone matrix all of which are similar to those found in human bone Recently we developed a new in vitro model system using goldfish scale This system can simultaneously detect the activities of both scale osteoclasts and osteoblasts with tartrate-resistant acid phosphatase and alkaline phosphatase as the respective markers Using this system we analyzed the bone metabolism under acceleration with a custom-made G-load apparatus Osteoclastic activity in the goldfish scales was suppressed under low-acceleration 0 5-G while osteoblastic activity did not change under this acceleration Under high-acceleration 6-G however the osteoblastic activity of the scales increased In addition the osteoclastic activity of the scales decreased These results suggest that both osteoblastic and osteoclastic activities are regulated by the strength of acceleration Therefore we strongly believe that our in vitro system is useful for analysis of bone metabolism under acceleration

  7. Analysis and measurement of focusing effects in a traveling wave linear accelerator

    For a recent precise linear accelerator, such as the x-ray free electron laser facility, SACLA, the beam orbit and the beam envelop should be properly calculated from the beam dynamics model of a traveling wave accelerating structure (TWA). Therefore, we compared a predicted beam orbit by a TWA model with a measured orbit by rf cavity beam position monitors. Although the beam orbit in the crest acceleration part was appropriately reproduced, that of the off-crest acceleration part did not agree with the prediction. We found out that the discrepancy came from a quadrupole field in the coupler cell of the TWA. The strength of the quadrupole field was estimated by using 3-dimensional rf simulation and the TWA model was modified by the addition of the quadrupole focusing effect. By using the modified model, the beam orbit was properly reproduced in both the crest acceleration part and the off-crest acceleration part. (author)

  8. Sensitivity and uncertainty analysis of burnup reactivity for an accelerator-driven system

    A burnup calculation is carried out for an accelerator-driven system (ADS) proposed by the Japan Atomic Energy Agency (JAEA) with the fourth version of JENDL, JENDL-4.0 and the previous one, JENDL-3.3. Considerable differences are seen in burnup reactivity between the nuclear data libraries for an initial phase (first burnup cycle) and an equilibrium phase (tenth burnup cycle). The differences in these values are investigated using two methods: a method by replacing a nuclear data library by nuclide and a sensitivity analysis technique. Among many contributors to them for the both phases, we identify major ones; (1) the initial phase: fission cross section and fission neutron multiplicity of 238Pu, capture cross section of 241Am, and (2) the equilibrium phase: capture cross section of 244Cm and 241Am, and inelastic scattering cross section of 206,207Pb. The uncertainty analysis shows that uncertainties in the burnup reactivity deduced from the JENDL-4.0 covariance data are comparable in magnitude to the differences between the nuclear data libraries, and are dominated by nuclear data parameters of 238Pu. Finally, we show the necessity of uncertainty evaluation of the branching ratio of 241Am capture reaction. (author)

  9. Steady-state responses of axially accelerating viscoelastic beams: Approximate analysis and numerical confirmation

    2008-01-01

    Nonlinear parametric vibration of axially accelerating viscoelastic beams is inves-tigated via an approximate analytical method with numerical confirmations. Based on nonlinear models of a finite-small-stretching slender beam moving at a speed with a periodic fluctuation, a solvability condition is established via the method of multiple scales for subharmonic resonance. Therefore, the amplitudes of steady-state periodic responses and their existence conditions are derived. The amplitudes of stable steady-state responses increase with the amplitude of the axial speed fluctuation, and decrease with the viscosity coefficient and the nonlinear coefficient. The minimum of the detuning parameter which causes the existence of a stable steady-state periodic response decreases with the amplitude of the axial speed fluctuation, and increases with the viscosity coefficient. Nu-merical solutions are sought via the finite difference scheme for a nonlinear par-tial-differential equation and a nonlinear integro-partial-differential equation. The calculation results qualitatively confirm the effects of the related parameters pre-dicted by the approximate analysis on the amplitude and the existence condition of the stable steady-state periodic responses. Quantitative comparisons demonstrate that the approximate analysis results have rather high precision.

  10. Performance Analysis of Mimo Radar Waveform Using Accelerated Particle Swarm Optimization Algorithm

    B. Roja Reddy

    2012-08-01

    Full Text Available The Accelerated Particle Swarm Optimization Algorithm is promoted to numerically design orthogonal Discrete Frequency Waveforms and Modified Discrete Frequency Waveforms (DFCWs with good correlation properties for MIMO radar. We employ Accelerated Particle Swarm Optimization algorithm (ACC_PSO, Particles of a swarm communicate good positions, velocity and accelerations to each other as well as dynamically adjust their own position, velocity and acceleration derived from the best of all particles. The simulation results show that the proposed algorithm is effective for the design of DFCWs signal used in MIMO radar.

  11. Accelerated leukocyte telomere erosion in schizophrenia: Evidence from the present study and a meta-analysis.

    Rao, Shuquan; Kota, Lakshmi Narayanan; Li, Zongchang; Yao, Yao; Tang, Jinsong; Mao, Canquan; Jain, Sanjeev; Xu, Yong; Xu, Qi

    2016-08-01

    Human telomeres consist of tandem nucleotide repeats (TTAGGG) and associated proteins, and telomere length (TL) is reduced progressively with cell division over the lifespan. Telomere erosion might be accelerated or prevented to varying degrees when exposure to serious medical illnesses. In previous studies, an association between TL decrease and schizophrenia has been extensively reported; however, the results remain largely controversial. To further investigate TL in schizophrenia patients and reconcile this controversy, we first measured leucocyte TL (LTL) in our samples (52 paranoid schizophrenia, 89 non-paranoid patients and 120 controls), and then conducted a comprehensive meta-analysis of the existing results of LTL in patients of schizophrenia compared to healthy subjects. Totally, 11 studies encompassing 1243 patients of schizophrenia and 1274 controls were included in the final meta-analysis model. In our samples, significant reduction of LTL in paranoid schizophrenia was observed compared to controls (F = 50.88, P meta-analysis, random-effects model showed significant LTL decrease in patients of schizophrenia when compared to controls (Z = 2.07, P = 0.039, SMD = -0.48, 95% CI = -0.94 to -0.03). Moreover, a marginal decrease in LTL was observed in medicated patients (Z = 1.92, P = 0.055, SMD = -0.58, 95% CI = -1.18-0.01) and those patients with poor response to antipsychotics (Z = 1.76, P = 0.078, SMD = -0.60, 95% CI = -1.27-0.07). In conclusion, we observed significant reduction of LTL in individuals with schizophrenia compared with controls. However, all the studies included in the meta-analysis were cross-sectional, and better controlled long-term studies are needed to replicate this result. PMID:27174400

  12. Computer codes for particle accelerator design and analysis: A compendium. Second edition

    The design of the next generation of high-energy accelerators will probably be done as an international collaborative efforts and it would make sense to establish, either formally or informally, an international center for accelerator codes with branches for maintenance, distribution, and consultation at strategically located accelerator centers around the world. This arrangement could have at least three beneficial effects. It would cut down duplication of effort, provide long-term support for the best codes, and provide a stimulating atmosphere for the evolution of new codes. It does not take much foresight to see that the natural evolution of accelerator design codes is toward the development of so-called Expert Systems, systems capable of taking design specifications of future accelerators and producing specifications for optimized magnetic transport and acceleration components, making a layout, and giving a fairly impartial cost estimate. Such an expert program would use present-day programs such as TRANSPORT, POISSON, and SUPERFISH as tools in the optimization process. Such a program would also serve to codify the experience of two generations of accelerator designers before it is lost as these designers reach retirement age. This document describes 203 codes that originate from 10 countries and are currently in use. The authors feel that this compendium will contribute to the dialogue supporting the international collaborative effort that is taking place in the field of accelerator physics today

  13. Effect of fatigue on the intra-cycle acceleration in front crawl swimming: A time-frequency analysis

    Tella, V.; Toca-Herrera, J. L.; Gallach, J. E.; J Benavent; Gonzalez, L.M.; Arellano, R.

    2008-01-01

    The present study analyzes the changes in acceleration produced by swimmers before and after fatiguing effort. The subjects (n=15) performed a 25-meter crawl series at maximum speed without fatigue, and a second series with fatigue. The data were registered with a synchronized system that consisted in a position transducer (1 kHz) and a video photogrametry (50Hz). The acceleration (ms-2) was obtained by the derivative analysis of the variation of the position with time. The amplitude in the t...

  14. Numerical Analysis of MHD Accelerator with Non-Equilibrium Air Plasma

    M. ANWARI; H. H. QAZI; SUKARSAN; N. HARADA

    2012-01-01

    Magnetohydrodynamic (MHD) accelerator is proposed as a next generation propulsion system. It can be used to increase the performance of a propulsion system. The objective of this study is to investigate the performance of MHD accelerator using non-equilibrium air plasma as working gas. In this study, the fundamental performance of MHD accelerator such as flow performance and electrical performance is evaluated at different levels of applied magnetic field using I-D numerical simulation. The numerical simulation is developed based on a set of differential equations with MHD approximation. To solve this set of differential equations the MacCormack scheme is used. A specified channel designed and developed at NASA Marshall Space Flight Centre is used in the numerical simulation. The composition of the simulated air plasma consists of seven species, namely, N2, N, O2, O, NO, NO+, and e-. The performance of the non-equilibrium MHD accelerator is also compared with the equilibrium MHD accelerator.

  15. Tank waste compositions and atmospheric dispersion coefficients for use in accelerated safety analysis consequence assessments. Revision 1

    This topical report contains technical support information used to determine accident consequences for the Tank Farms Accelerated Safety Analysis (ASA) Interim Chapter 3, Hazard and Accident Analysis: Potential for Releases and Required Mitigation and Prevention and the Tank Waste Remediation System (TWRS) environmental impact statement (EIS) accident consequence report. It does not determine accident consequences or describe specific accident scenarios, but instead provides generic information used to calculate radiological and toxic chemical consequences for postulated tank farms accident releases

  16. Analysis and environmental application of 129I at the Xi’an Accelerator Mass Spectrometry Center

    The newly established 3 MV Accelerator Mass Spectrometry (AMS) facility in Xi’an, with an instrument background of 2 × 10−14 for 129I/127I ratio, provides efficient analytical capability to carry out 129I environmental tracing studies. Chemical separation methods of iodine from different types of samples have been established at the Xi’an AMS Center, including solvent extraction and combustion followed by extraction or coprecipitation depending on sample types. A carrier free method for iodine separation and AMS measurement of ultra low level 129I in samples with low total iodine concentration has been established, which can be used for analysis of geological samples for 129I dating. Some environmental samples collected in China have been analyzed using the developed methods. The analytical results show 129I/127I ratios of (0.9–1.1) × 10−10 for seawater collected adjacent to a nuclear power plant, and (3.02–5.43) × 10−10 for soil samples collected in a less than 10 km area surrounding the NPP. These values are not significantly different from those measured in remote areas, reflecting a safe nuclear environment in terms of 129I level.

  17. Sample distillation/graphitization system for carbon pool analysis by accelerator mass spectrometry (AMS)

    A facility at the Naval Research Laboratory (NRL), Washington, DC, has been developed to extract, trap, cryogenically distill and graphitize carbon from a suite of organic and inorganic carbon pools for analysis by accelerator mass spectrometry (AMS). The system was developed to investigate carbon pools associated with the formation and stability of methane hydrates. However, since the carbon compounds found in hydrate fields are ubiquitous in aquatic ecosystems, this apparatus is applicable to a number of oceanographic and environmental sample types. Targeted pools are dissolved methane, dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), solid organic matrices (e.g., seston, tissue and sediments), biomarkers and short chained (C1-C5) hydrocarbons from methane hydrates. In most instances, the extraction, distillation and graphitization events are continuous within the system, thus, minimizing the possibility of fractionation or contamination during sample processing. A variety of methods are employed to extract carbon compounds and convert them to CO2 for graphitization. Dissolved methane and DIC from the same sample are sparged and cryogenically separated before the methane is oxidized in a high temperature oxygen stream. DOC is oxidized to CO2 by 1200 W ultraviolet photo-oxidation lamp, and solids oxidized in sealed, evacuated tubes. Hydrocarbons liberated from the disassociation of gas hydrates are cryogenically separated with a cryogenic temperature control unit, and biomarkers separated and concentrated by preparative capillary gas chromatography (PCGC). With this system, up to 20 samples, standards or blanks can be processed per day

  18. Accelerating All-Atom Normal Mode Analysis with Graphics Processing Unit.

    Liu, Li; Liu, Xiaofeng; Gong, Jiayu; Jiang, Hualiang; Li, Honglin

    2011-06-14

    All-atom normal mode analysis (NMA) is an efficient way to predict the collective motions in a given macromolecule, which is essential for the understanding of protein biological function and drug design. However, the calculations are limited in time scale mainly because the required diagonalization of the Hessian matrix by Householder-QR transformation is a computationally exhausting task. In this paper, we demonstrate the parallel computing power of the graphics processing unit (GPU) in NMA by mapping Householder-QR transformation onto GPU using Compute Unified Device Architecture (CUDA). The results revealed that the GPU-accelerated all-atom NMA could reduce the runtime of diagonalization significantly and achieved over 20× speedup over CPU-based NMA. In addition, we analyzed the influence of precision on both the performance and the accuracy of GPU. Although the performance of GPU with double precision is weaker than that with single precision in theory, more accurate results and an acceptable speedup of double precision were obtained in our approach by reducing the data transfer time to a minimum. Finally, the inherent drawbacks of GPU and the corresponding solution to deal with the limitation in computational scale are also discussed in this study. PMID:26596427

  19. Lorentz force detuning analysis of the Spallation Neutron Source (SNS) accelerating cavities.

    Mitchell, R.R. (Russell R.); Matsumoto, K. Y. (Kay Yuri); Ciovati, G. (Gianluigi); Davis, K. (Kirk); Macha, K. (Kurt); Sundelin, R. M. (Ronald M.)

    2001-01-01

    The Spallation Neutron Source (SNS) project incorporates a superconducting radio-frequency (SRF) accelerator for the final section of the pulsed mode linac. Cavities with geometrical {beta} values of {beta}=0.61 and {beta}=0.81 are utilized in the SRF section, and are constructed out of thin-walled niobium with stiffener rings welded between the cells near the iris. The welded titanium helium vessel and tuner assembly restrains the cavity beam tubes. Cavities with {beta} values less than one have relatively steep and flat side-walls making the cavities susceptible to Lorentz force detuning. In addition, the pulsed RF induces cyclic Lorentz pressures that mechanically excite the cavities, producing a dynamic Lorentz force detuning different from a continuous RF system. The amplitude of the dynamic detuning for a given cavity design is a function of the mechanical damping, stiffness of the tuner/helium vessel assembly, RF pulse profile, and the RF pulse rate. This paper presents analysis and testing results to date, and indicates areas where more investigation is required.

  20. Cost Based Failure Modes and Effects Analysis (FMEA) for Systems of Accelerator Magnets

    The proposed Next Linear Collider (NLC) has a proposed 85% overall availability goal, the availability specifications for all its 7200 magnets and their 6167 power supplies are 97.5% each. Thus all of the electromagnets and their power supplies must be highly reliable or quickly repairable. Improved reliability or repairability comes at a higher cost. We have developed a set of analysis procedures for magnet designers to use as they decide how much effort to exert, i.e. how much money to spend, to improve the reliability of a particular style of magnet. We show these procedures being applied to a standard SLAC electromagnet design in order to make it reliable enough to meet the NLC availability specs. First, empirical data from SLAC's accelerator failure database plus design experience are used to calculate MTBF for failure modes identified through a FMEA. Availability for one particular magnet can be calculated. Next, labor and material costs to repair magnet failures are used in a Monte Carlo simulation to calculate the total cost of all failures over a 30-year lifetime. Opportunity costs are included. Engineers choose from amongst various designs by comparing lifecycle costs

  1. A new convergence analysis and perturbation resilience of some accelerated proximal forward-backward algorithms with errors

    Reem, Daniel

    2015-01-01

    Many problems in science and engineering involve, as part of their solution process, the consideration of a separable function which is the sum of two convex functions, one of them possibly non-smooth. Recently a few works have discussed inexact versions of several accelerated proximal methods aiming at solving this minimization problem. This paper shows that inexact versions of a method of Beck and Teboulle (FISTA) preserve, in a Hilbert space setting, the same (non-asymptotic) rate of convergence under some assumptions on the decay rate of the error terms. The notion of inexactness discussed here seems to be rather simple, but, interestingly, when comparing to related works, similar decay rates of the errors terms yield similar convergence rates. The derivation sheds some light on the somewhat mysterious origin of some parameters which appear in various accelerated methods. A consequence of the analysis is that the accelerated method is perturbation resilient, making it suitable, in principle, for the super...

  2. Analysis of Higher Order Modes in Large Superconducting Radio Frequency Accelerating Structures

    Galek, Tomasz; Brackebusch, Korinna; Van Rienen, Ursula

    2015-01-01

    Superconducting radio frequency cavities used for accelerating charged particle beams are commonly used in accelerator facilities around the world. The design and optimization of modern superconducting RF cavities requires intensive numerical simulations. Vast number of operational parameters must be calculated to ensure appropriate functioning of the accelerating structures. In this study, we primarily focus on estimation and behavior of higher order modes in superconducting RF cavities connected in chains. To calculate large RF models the state-space concatenation scheme, an efficient hybrid method, is employed.

  3. Application of normal form methods to the analysis of resonances in particle accelerators

    The transformation to normal form in a Lie-algebraic framework provides a very powerful method for identifying and analysing non-linear behaviour and resonances in particle accelerators. The basic ideas are presented and illustrated. (author). 4 refs

  4. Analysis of Transmitted Optical Spectrum Enabling Accelerated Testing of CPV Designs: Preprint

    Miller, D. C.; Kempe, M. D.; Kennedy, C. E.; Kurtz, S. R.

    2009-07-01

    Reliability of CPV systems' materials is not well known; methods for accelerated UV testing have not been developed. UV and IR spectra transmitted through representative optical systems are evaluated.

  5. Detecting chaos in particle accelerators through the frequency map analysis method

    Papaphilippou, Yannis

    2014-01-01

    The motion of beams in particle accelerators is dominated by a plethora of non-linear effects which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of differen...

  6. Performances Analysis of Main Components Used in 60 MW Pulsed Supply for Particle Accelerator

    Peron, R; Pouliquen, JL; Gollentz, B; Bordry, F; Burnet, JP

    2010-01-01

    The Proton-Synchrotron (PS) accelerator at CERN will be supplied by a new power system. The pulsed operation of the PS accelerator requires a specific design of the main components of the power system. This paper presents some key elements of the design of DC/DC power converters in terms of aging of power semiconductors, the strategy of harmonics voltage suppression and the design of the output filters. Finally, the performance of this new power system is presented.

  7. Analysis of conditions to safety and radiological protection of Brazilian research particle accelerators facilities

    Eleven institutions of education and research in Brazil use particle accelerators, which fulfill different functions and activities. Currently, these institutions employ a total of fifteen accelerators. In this paper, the object of study is the radiological protection of occupationally exposed individuals, the general public and the radiation safety of particle accelerators. Research facilities with accelerators are classified in categories I and II according to the International Atomic Energy Agency or groups IX and X in accordance with the Brazilian National Commission of Nuclear Energy. Of the 15 accelerators in use for research in Brazil, four belong to category I or group X and eleven belong to category II or group IX. The methodology presented and developed in this work was made through the inspection and assessment of safety and radiological protection of thirteen particle accelerators facilities, and its main purpose was to promote safer use of this practice by following established guidelines for safety and radiological protection. The results presented in this work showed the need to create a program, in our country, for the control of safety and radiological protection of this ionizing radiation practice. (author)

  8. Evidence of statistical epistasis between DISC1, CIT and NDEL1 impacting risk for schizophrenia: biological validation with functional neuroimaging.

    Nicodemus, Kristin K; Callicott, Joseph H; Higier, Rachel G; Luna, Augustin; Nixon, Devon C; Lipska, Barbara K; Vakkalanka, Radhakrishna; Giegling, Ina; Rujescu, Dan; St Clair, David; Muglia, Pierandrea; Shugart, Yin Yao; Weinberger, Daniel R

    2010-04-01

    The etiology of schizophrenia likely involves genetic interactions. DISC1, a promising candidate susceptibility gene, encodes a protein which interacts with many other proteins, including CIT, NDEL1, NDE1, FEZ1 and PAFAH1B1, some of which also have been associated with psychosis. We tested for epistasis between these genes in a schizophrenia case-control study using machine learning algorithms (MLAs: random forest, generalized boosted regression andMonteCarlo logic regression). Convergence of MLAs revealed a subset of seven SNPs that were subjected to 2-SNP interaction modeling using likelihood ratio tests for nested unconditional logistic regression models. Of the 7C2 = 21 interactions, four were significant at the α = 0.05 level: DISC1 rs1411771-CIT rs10744743 OR = 3.07 (1.37, 6.98) p = 0.007; CIT rs3847960-CIT rs203332 OR = 2.90 (1.45, 5.79) p = 0.003; CIT rs3847960-CIT rs440299 OR = 2.16 (1.04, 4.46) p = 0.038; one survived Bonferroni correction (NDEL1 rs4791707-CIT rs10744743 OR = 4.44 (2.22, 8.88) p = 0.00013). Three of four interactions were validated via functional magnetic resonance imaging (fMRI) in an independent sample of healthy controls; risk associated alleles at both SNPs predicted prefrontal cortical inefficiency during the N-back task, a schizophrenia-linked intermediate biological phenotype: rs3847960-rs440299; rs1411771-rs10744743, rs4791707-rs10744743 (SPM5 p < 0.05, corrected), although we were unable to statistically replicate the interactions in other clinical samples. Interestingly, the CIT SNPs are proximal to exons that encode theDISC1 interaction domain. In addition, the 3' UTR DISC1 rs1411771 is predicted to be an exonic splicing enhancer and the NDEL1 SNP is ~3,000 bp from the exon encoding the region of NDEL1 that interacts with the DISC1 protein, giving a plausible biological basis for epistasis signals validated by fMRI. PMID:20084519

  9. A Tandem Repeat in Decay Accelerating Factor 1 Is Associated with Severity of Murine Mercury-Induced Autoimmunity

    David M. Cauvi

    2014-01-01

    Full Text Available Decay accelerating factor (DAF, a complement-regulatory protein, protects cells from bystander complement-mediated lysis and negatively regulates T cells. Reduced expression of DAF occurs in several systemic autoimmune diseases including systemic lupus erythematosus, and DAF deficiency exacerbates disease in several autoimmune models, including murine mercury-induced autoimmunity (mHgIA. Daf1, located within Hmr1, a chromosome 1 locus associated in DBA/2 mice with resistance to mHgIA, could be a candidate. Here we show that reduced Daf1 transcription in lupus-prone mice was not associated with a reduction in the Daf1 transcription factor SP1. Studies of NZB mice congenic for the mHgIA-resistant DBA/2 Hmr1 locus suggested that Daf1 expression was controlled by the host genome and not the Hmr1 locus. A unique pentanucleotide repeat variant in the second intron of Daf1 in DBA/2 mice was identified and shown in F2 intercrosses to be associated with less severe disease; however, analysis of Hmr1 congenics indicated that this most likely reflected the presence of autoimmunity-predisposing genetic variants within the Hmr1 locus or that Daf1 expression is mediated by the tandem repeat in epistasis with other genetic variants present in autoimmune-prone mice. These studies argue that the effect of DAF on autoimmunity is complex and may require multiple genetic elements.

  10. Effect of fatigue on the intra-cycle acceleration in front crawl swimming: a time-frequency analysis.

    Tella, V; Toca-Herrera, J L; Gallach, J E; Benavent, J; González, L M; Arellano, R

    2008-01-01

    The present study analyzes the changes in acceleration produced by swimmers before and after fatiguing effort. The subjects (n = 15) performed a 25-m crawl series at maximum speed without fatigue, and a second series with fatigue. The data were registered with a synchronized system that consisted of a position transducer (1 kHz) and a video photogrametry (50 Hz). The acceleration (ms(-2)) was obtained by the derivative analysis of the variation of the position with time. The amplitude in the time domain was calculated with the root mean square (RMS); while the peak power (PP), the peak power frequency (PPF) and the spectrum area (SA) were calculated in the frequency domain with Fourier analysis. On the one hand, the results of the temporal domain show that the RMS change percentage between series was 67.5% (p < 0.001). On the other hand, PP, PPF, and SA show significant changes (p < 0.001). PP and SA were reduced by 63.1% and 59.5%, respectively. Our results show that the acceleration analysis of the swimmer with Fourier analysis permits a more precise understanding of which propulsive forces contribute to the swimmer performance before and after fatigue appears. PMID:17714719

  11. Application of Failure Mode and Effects Analysis to Intraoperative Radiation Therapy Using Mobile Electron Linear Accelerators

    Purpose: Failure mode and effects analysis (FMEA) represents a prospective approach for risk assessment. A multidisciplinary working group of the Italian Association for Medical Physics applied FMEA to electron beam intraoperative radiation therapy (IORT) delivered using mobile linear accelerators, aiming at preventing accidental exposures to the patient. Methods and Materials: FMEA was applied to the IORT process, for the stages of the treatment delivery and verification, and consisted of three steps: 1) identification of the involved subprocesses; 2) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system, based on the product of three parameters (severity, frequency of occurrence and detectability, each ranging from 1 to 10); 3) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. Results: Twenty-four subprocesses were identified. Ten potential failure modes were found and scored, in terms of RPN, in the range of 42–216. The most critical failure modes consisted of internal shield misalignment, wrong Monitor Unit calculation and incorrect data entry at treatment console. Potential causes of failure included shield displacement, human errors, such as underestimation of CTV extension, mainly because of lack of adequate training and time pressures, failure in the communication between operators, and machine malfunctioning. The main effects of failure were represented by CTV underdose, wrong dose distribution and/or delivery, unintended normal tissue irradiation. As additional safety measures, the utilization of a dedicated staff for IORT, double-checking of MU calculation and data entry and finally implementation of in vivo dosimetry were suggested. Conclusions: FMEA appeared as a useful tool for prospective evaluation of patient safety in radiotherapy

  12. Comparison of different shielding materials used at proton accelerators and cost-benefit analysis

    During last decades physicians' and physicist's experience and confidence in proton beam radiotherapy has grown significantly. Construction of a number of new proton therapy facilities is already underway, and several are in planning stages for the near future. Cost-effective shielding design of these facilities is important. We present comparative analysis of different shielding materials that are typically used at proton accelerators and in proton radiotherapy facilities. We have used Geant4 tool-kit for simulation of the passage of particles through matter. We have analyzed shielding properties of iron, borated concrete, a water tank with borated polyethylene walls, borated polyethylene, and borated fire retardant plywood. We have simulated 240 MeV protons incident on a thin copper target that generated radiation fields of primary protons as well as secondaries produced in the target incident on the shielding block. We found that iron is most effective per unit length. It may be the most cost-effective option if one considers using the so called SEG blocks in combination with 1 to 2 ft of concrete layer. The material of the SEG block consists primarily of iron from recycled government facility metals, and is slightly radioactive. The slight inherent radioactivity as well as low energy (< 847 keV) secondary neutrons from iron will be shielded by a thin concrete layer. We also find that borated fire retardant plywood can be a cost-effective alternative for borated polyethylene in many shielding applications where borated polyethylene sheets are used that are arguably not less fire hazardous. (authors)

  13. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range.

    van Duijn, Esther; Sandman, Hugo; Grossouw, Dimitri; Mocking, Johannes A J; Coulier, Leon; Vaes, Wouter H J

    2014-08-01

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. Here, we describe the combination of automated sample combustion with an elemental analyzer (EA) online coupled to an AMS via a dedicated interface. This setup allows direct radiocarbon measurements for over 70 samples daily by AMS. No sample processing is required apart from the pipetting of the sample into a tin foil cup, which is placed in the carousel of the EA. In our system, up to 200 AMS analyses are performed automatically without the need for manual interventions. We present results on the direct total (14)C count measurements in <2 μL human plasma samples. The method shows linearity over a range of 0.65-821 mBq/mL, with a lower limit of quantification of 0.65 mBq/mL (corresponding to 0.67 amol for acetaminophen). At these extremely low levels of activity, it becomes important to quantify plasma specific carbon percentages. This carbon percentage is automatically generated upon combustion of a sample on the EA. Apparent advantages of the present approach include complete omission of sample preparation (reduced hands-on time) and fully automated sample analysis. These improvements clearly stimulate the standard incorporation of microtracer research in the drug development process. In combination with the particularly low sample volumes required and extreme sensitivity, AMS strongly improves its position as a bioanalysis method. PMID:25033319

  14. Advanced accelerators

    This report discusses the suitability of four novel particle acceleration technologies for multi-TeV particle physics machines: laser driven linear accelerators (linac), plasma beat-wave devices, plasma wakefield devices, and switched power and cavity wakefield linacs. The report begins with the derivation of beam parameters practical for multi-TeV devices. Electromagnetic field breakdown of materials is reviewed. The two-beam accelerator scheme for using a free electron laser as the driver is discussed. The options recommended and the conclusions reached reflect the importance of cost. We recommend that more effort be invested in achieving a self-consistent range of TeV accelerator design parameters. Beat-wave devices have promise for 1-100 GeV applications and, while not directly scalable to TeV designs, the current generation of ideas are encouraging for the TeV regime. In particular, surfatrons, finite-angle optical mixing devices, plasma grating accelerator, and the Raman forward cascade schemes all deserve more complete analysis. The exploitation of standard linac geometry operated in an unconventional mode is in a phase of rapid evolution. While conceptual projects abound, there are no complete designs. We recommend that a fraction of sponsored research be devoted to this approach. Wakefield devices offer a great deal of potential; trades among their benefits and constraints are derived and discussed herein. The study of field limitation processes has received inadequate attention; this limits experiment designers. The costs of future experiments are such that investment in understanding these processes is prudent. 34 refs., 12 figs., 3 tabs

  15. Neurocognitive outcome in brain metastases patients treated with accelerated-fractionation vs. accelerated-hyperfractionated radiotherapy: an analysis from Radiation Therapy Oncology Group Study 91-04

    Purpose: To evaluate neurocognitive outcome as measured by the Mini-Mental Status Examination (MMSE) among patients with unresectable brain metastases randomly assigned to accelerated fractionation (AF) vs. accelerated hyperfractionated (AH) whole-brain radiation therapy (WBRT). Methods and Materials: The Radiation Therapy Oncology Group (RTOG) accrued 445 patients with unresectable brain metastases to a Phase III comparison of AH (1.6 Gy b.i.d. to 54.4 Gy) vs. AF (3 Gy q.d. to 30 Gy). All had a KPS of ≥ 70 and a neurologic function status of 0-2. Three hundred fifty-nine patients had MMSEs performed and were eligible for this analysis. Changes in the MMSE were analyzed according to criteria previously defined in the literature. Results: The median survival was 4.5 months for both arms. The average change in MMSE at 2 and 3 months was a drop of 1.4 and 1.1, respectively, in the AF arm as compared to a drop of 0.7 and 1.3, respectively, in the AH arm (p=NS). Overall, 91 patients at 2 months and 23 patients at 3 months had both follow-up MMSE and computed tomography/magnetic resonance imaging documentation of the status of their brain metastases. When an analysis was performed taking into account control of brain metastases, a significant effect on MMSE was observed with time and associated proportional increase in uncontrolled brain metastases. At 2 months, the average change in MMSE score was a drop of 0.6 for those whose brain metastases were radiologically controlled as compared to a drop of 1.9 for those with uncontrolled brain metastases (p=0.47). At 3 months, the average change in MMSE score was a drop of 0.5 for those whose brain metastases were radiologically controlled as compared to a drop of 6.3 for those with uncontrolled brain metastases (p=0.02). Conclusion: Use of AH as compared to AF-WBRT was not associated with a significant difference in neurocognitive function as measured by MMSE in this patient population with unresectable brain metastases and

  16. Impedance-based analysis and study of phase sensitivity in slow-wave two-beam accelerators

    This paper presents a new formalism which makes the analysis and understanding of both the relativistic klystron (RK) and the standing-wave free-electron laser (SWFEL) two-beam accelerator (TBA) available to a wide audience of accelerator physicists. A ''coupling impedance'' for both the RK and SWFEWL is introduced, which can include realistic cavity features, such as beam and vacuum ports, in a simple manner. The RK and SWFEL macroparticle equations, which govern the energy and phase evolution of successive bunches in the beam, are of identical form, differing only by multiplicative factors. Expressions are derived for the phase and amplitude sensitivities of the TBA schemes to errors (shot-to-shot jitter) in current and energy. The analysis allows, for the first time, relative comparisons of the RK and the SWFEL TBAs

  17. Can Accelerators Accelerate Learning?

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  18. Neutron activation analysis with a deuteron accelerator. Application to the determination of copper in a Cu-Sn mixture

    Neutron activation analysis allows a rapid determination of trace elements. It has many applications in vegetal biology, agronomy, animal biology, medicine and industry. This report presents the different devices used (deuteron accelerator, 3H-Ti/Zr target, NaI(Tl) scintillation counter, Li-drifted Ge detector), the theory of the method and an application to the determination of copper in a copper-mixture

  19. Nuclear techniques for the analysis and dating of cultural heritage with the tandetron accelerator at the CEDAD

    Lucio Calcagnile

    2014-12-01

    Full Text Available The Accelerator Mass Spectrometry technique for measuring carbon isotopes and dating artifacts, together with nuclear techniques of ion beam analysis are widely used in the field of cultural heritage owing to the great advantage of their being non-destructive. In Italy, CEDAD - CEntro Di DAtazione e Diagnostica of the University of Salento, with its tandetron accelerator of 3MV, has played a major role for over ten years, in studying materials of cultural assets requiring the determination of their elemental composition and determination of absolute chronology using radiocarbon. This study describes the Accelerator Mass Spectrometry technique used with the accelerator at CEDAD to determine age by means of radiocarbon and PIXE-PIGE techniques, and to determine elements, even in traces, present in materials. Some case studies carried out at CEDAD are reported, including those on the Riace Bronzes and Capitoline Wolf. The latter has been definitively dated to the Middle Ages, 17 centuries later than the previously attributed dating by historians. In addition, an important technical innovation is described, achieved within the framework of the IT@CHA Project enabling organic materials to be dated using only 10 μg of carbon.

  20. Effect of fatigue on the intra-cycle acceleration in front crawl swimming: A time-frequency analysis

    Tella, V; Gallach, J E; Benavent, J; Gonzalez, L M; Arellano, R

    2008-01-01

    The present study analyzes the changes in acceleration produced by swimmers before and after fatiguing effort. The subjects (n=15) performed a 25-meter crawl series at maximum speed without fatigue, and a second series with fatigue. The data were registered with a synchronized system that consisted in a position transducer (1 kHz) and a video photogrametry (50Hz). The acceleration (ms-2) was obtained by the derivative analysis of the variation of the position with time. The amplitude in the time domain was calculated with the root mean square (RMS); while the peak power (PP), the peak power frequency (PPF) and the spectrum area (SA) was calculated in the frequency domain with Fourier analysis. On one hand, the results of the temporal domain show that the RMS change percentage between series was 67.5% (p<0.001). On the other hand, PP, PPF, and SA show significant changes (p<0.001). PP and SA were reduced by 63.1% and 59.5%, respectively. Our results show that the acceleration analysis of the swimmer with...

  1. Survey and analysis of line-frequency interference in the CEBAF accelerator

    Feedthrough of interference from the AC power line into accelerator components is a problem which in pulsed accelerators can be reduced by operation synchronous with the AC line. This means of avoiding line-frequency effects is ineffective for continuous wave machines such as the CEBAF accelerator. We have measured line-frequency perturbations at CEBAF both in beam position and energy by using the beam position monitor system as a multiple-channel sampling oscilloscope. Comparing these data against the measured static optics (taken synchronously with the AC line) we have been able to identify point sources of interference, and resolve line-synchronous variations in the beam energy at a level near 0.001%. 3 refs., 2 figs., 1 tab

  2. The application analysis of high energy electron accelerator in food irradiation processing

    Irradiation technology of high energy electron accelerator has been highly concerned in food processing industry with its fast development, especially in the field of food irradiation processing. In this paper, equipment and research situation of high energy electron accelerator were collected, meanwhile, the similarities and differences between high energy electron beam and 60Co γ-rays were discussed. In order to provide more references of high energy electron beam irradiation, the usages of high energy electron in food irradiation processing was prospected. These information would promote the development of domestic food irradiation industry and give a useful message to irradiation enterprises and researchers. (authors)

  3. Theoretical analysis of acceleration measurements in a model of an operating wind turbine

    White, Jonathan R.; Adams, Douglas E.; Rumsey, Mark A.

    2010-04-01

    Wind loading from turbulence and gusts can cause damage in horizontal axis wind turbines. These unsteady loads and the resulting damage initiation and propagation are difficult to predict. Unsteady loads enter at the rotor and are transmitted to the drivetrain. The current generation of wind turbine has drivetrain-mounted vibration and bearing temperature sensors, a nacelle-mounted inertial measurement unit, and a nacelle-mounted anemometer and wind vane. Some advanced wind turbines are also equipped with strain measurements at the root of the rotor. This paper analyzes additional measurements in a rotor blade to investigate the complexity of these unsteady loads. By identifying the spatial distribution, amplitude, and frequency bandwidth of these loads, design improvements could be facilitated to reduce uncertainties in reliability predictions. In addition, dynamic load estimates could be used in the future to control high-bandwidth aerodynamic actuators distributed along the rotor blade to reduce the saturation of slower pitch actuators currently used for wind turbine blades. Local acceleration measurements are made along a rotor blade to infer operational rotor states including deflection and dynamic modal contributions. Previous work has demonstrated that acceleration measurements can be experimentally acquired on an operating wind turbine. Simulations on simplified rotor blades have also been used to demonstrate that mean blade loading can be estimated based on deflection estimates. To successfully apply accelerometers in wind turbine applications for load identification, the spectral and spatial characteristics of each excitation source must be understood so that the total acceleration measurement can be decomposed into contributions from each source. To demonstrate the decomposition of acceleration measurements in conjunction with load estimation methods, a flexible body model has been created with MSC.ADAMSThe benefit of using a simulation model as opposed

  4. Theoretical analysis of acceleration measurements in a model of an operating wind turbine.

    Adams, Douglas E. (Purdue University, Lafayette, IN); Rumsey, Mark Allen; White, Jonathan Randall

    2010-04-01

    Wind loading from turbulence and gusts can cause damage in horizontal axis wind turbines. These unsteady loads and the resulting damage initiation and propagation are difficult to predict. Unsteady loads enter at the rotor and are transmitted to the drivetrain. The current generation of wind turbine has drivetrain-mounted vibration and bearing temperature sensors, a nacelle-mounted inertial measurement unit, and a nacelle-mounted anemometer and wind vane. Some advanced wind turbines are also equipped with strain measurements at the root of the rotor. This paper analyzes additional measurements in a rotor blade to investigate the complexity of these unsteady loads. By identifying the spatial distribution, amplitude, and frequency bandwidth of these loads, design improvements could be facilitated to reduce uncertainties in reliability predictions. In addition, dynamic load estimates could be used in the future to control high-bandwidth aerodynamic actuators distributed along the rotor blade to reduce the saturation of slower pitch actuators currently used for wind turbine blades. Local acceleration measurements are made along a rotor blade to infer operational rotor states including deflection and dynamic modal contributions. Previous work has demonstrated that acceleration measurements can be experimentally acquired on an operating wind turbine. Simulations on simplified rotor blades have also been used to demonstrate that mean blade loading can be estimated based on deflection estimates. To successfully apply accelerometers in wind turbine applications for load identification, the spectral and spatial characteristics of each excitation source must be understood so that the total acceleration measurement can be decomposed into contributions from each source. To demonstrate the decomposition of acceleration measurements in conjunction with load estimation methods, a flexible body model has been created with MSC.ADAMS{copyright} The benefit of using a simulation model

  5. Off-normal and failure condition analysis of the MITICA negative-ion accelerator

    Chitarin, Giuseppe, E-mail: chitarin@igi.cnr.it; Aprile, Daniele [Consorzio RFX, (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Department of Management and Engineering, University of Padova, Strad. S. Nicola 3, 36100 Vicenza (Italy); Agostinetti, Piero; Marconato, Nicolò; Marcuzzi, Diego; Serianni, Gianluigi; Veltri, Pierluigi; Zaccaria, Pierluigi [Consorzio RFX, (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy)

    2016-02-15

    The negative-ion accelerator for the MITICA neutral beam injector has been designed and optimized in order to reduce the thermo-mechanical stresses in all components below limits compatible with the required fatigue life. However, deviation from the expected beam performances can be caused by “off-normal” operating conditions of the accelerator. The purpose of the present work is to identify and analyse all the “off-normal” operating conditions, which could possibly become critical in terms of thermo-mechanical stresses or of degradation of the optical performances of the beam.

  6. Plasma accelerators

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  7. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.

  8. Predictors of Local Recurrence Following Accelerated Partial Breast Irradiation: A Pooled Analysis

    Shah, Chirag; Wilkinson, John Ben [Department of Radiation Oncology, Beaumont Cancer Institute, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Lyden, Maureen [Biostat Inc., Tampa, Florida (United States); Beitsch, Peter [Dallas Breast Center, Dallas, Texas (United States); Vicini, Frank A., E-mail: fvicini@pol.net [Department of Radiation Oncology, Beaumont Cancer Institute, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States)

    2012-04-01

    Purpose: To analyze a pooled set of nearly 2,000 patients treated on the American Society of Breast Surgeons (ASBS) Mammosite Registry Trial and at William Beaumont Hospital (WBH) to identify factors associated with local recurrence following accelerated partial breast irradiation (APBI). Methods and Materials: A total of 1,961 women underwent partial breast irradiation between April 1993 and November 2010 as part of the ASBS Registry Trial or at WBH. Rates of ipsilateral breast tumor recurrence (IBTR), regional recurrence (RR), distant metastases (DM), disease-free survival (DFS), cause-specific survival (CSS), and overall survival (OS) were analyzed for each group and for the pooled cohort. Clinical, pathologic, and treatment-related variables were analyzed including age, tumor stage/size, estrogen receptor status, surgical margins, and lymph node status to determine their association with IBTR. Results: The two groups weres similar, but WBH patients were more frequently node positive, had positive margins, and were less likely to be within the American Society for Radiation Oncology-unsuitable group. At 5 years, the rates of IBTR, RR, DM, DFS, CSS, and OS for the pooled group of patients were 2.9%, 0.5%, 2.4%, 89.1%, 98.5%, and 91.8%, respectively. The 5-year rate of true recurrence/marginal miss was 0.8%. Univariate analysis of IBTR found that negative estrogen receptor status (odds ratio [OR], 2.83, 95% confidence interval 1.55-5.13, p = 0.0007) was the only factor significantly associated with IBTR, while a trend was seen for age less than 50 (OR 1.80, 95% confidence interval 0.90-3.58, p = 0.10). Conclusions: Excellent 5-year outcomes were seen following APBI in over 1,900 patients. Estrogen receptor negativity was the only factor associated with IBTR, while a trend for age less than 50 was noted. Significant differences in factors associated with IBTR were noted between cohorts, suggesting that factors driving IBTR may be predicated based on the risk

  9. Predictors of Local Recurrence Following Accelerated Partial Breast Irradiation: A Pooled Analysis

    Purpose: To analyze a pooled set of nearly 2,000 patients treated on the American Society of Breast Surgeons (ASBS) Mammosite Registry Trial and at William Beaumont Hospital (WBH) to identify factors associated with local recurrence following accelerated partial breast irradiation (APBI). Methods and Materials: A total of 1,961 women underwent partial breast irradiation between April 1993 and November 2010 as part of the ASBS Registry Trial or at WBH. Rates of ipsilateral breast tumor recurrence (IBTR), regional recurrence (RR), distant metastases (DM), disease-free survival (DFS), cause-specific survival (CSS), and overall survival (OS) were analyzed for each group and for the pooled cohort. Clinical, pathologic, and treatment-related variables were analyzed including age, tumor stage/size, estrogen receptor status, surgical margins, and lymph node status to determine their association with IBTR. Results: The two groups weres similar, but WBH patients were more frequently node positive, had positive margins, and were less likely to be within the American Society for Radiation Oncology-unsuitable group. At 5 years, the rates of IBTR, RR, DM, DFS, CSS, and OS for the pooled group of patients were 2.9%, 0.5%, 2.4%, 89.1%, 98.5%, and 91.8%, respectively. The 5-year rate of true recurrence/marginal miss was 0.8%. Univariate analysis of IBTR found that negative estrogen receptor status (odds ratio [OR], 2.83, 95% confidence interval 1.55–5.13, p = 0.0007) was the only factor significantly associated with IBTR, while a trend was seen for age less than 50 (OR 1.80, 95% confidence interval 0.90–3.58, p = 0.10). Conclusions: Excellent 5-year outcomes were seen following APBI in over 1,900 patients. Estrogen receptor negativity was the only factor associated with IBTR, while a trend for age less than 50 was noted. Significant differences in factors associated with IBTR were noted between cohorts, suggesting that factors driving IBTR may be predicated based on the risk

  10. Pedestrian movement analysis in transfer station corridor: Velocity-based and acceleration-based

    Ji, Xiangfeng; Zhang, Jian; Hu, Yongkai; Ran, Bin

    2016-05-01

    In this paper, pedestrians are classified into aggressive and conservative ones by their temper. Aggressive pedestrians' walking through crowd in transfer station corridor is analyzed. Treating pedestrians as particles, this paper uses the modified social force model (MSFM) as the building block, where forces involve self-driving force, repulsive force and friction force. The proposed model in this paper is a discrete model combining the MSFM and cellular automata (CA) model, where the updating rules of the CA are redefined with MSFM. Due to the continuity of values generated by the MSFM, we use the fuzzy logic to discretize the continuous values into cells pedestrians can move in one step. With the observation that stimulus around pedestrians influences their acceleration directly, an acceleration-based movement model is presented, compared to the generally reviewed velocity-based movement model. In the acceleration-based model, a discretized version of kinematic equation is presented based on the acceleration discretized with fuzzy logic. In real life, some pedestrians would rather keep their desired speed and this is also mimicked in this paper, which is called inertia. Compared to the simple triangular membership function, a trapezoidal membership function and a piecewise linear membership function are used to capture pedestrians' inertia. With the trapezoidal and the piecewise linear membership function, many overlapping scenarios should be carefully handled and Dubois and Prade's four-index method is used to completely describe the relative relationship of fuzzy quantities. Finally, a simulation is constructed to demonstrate the effect of our model.

  11. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range

    Duijn, E. van; Sandman, H.; Grossouw, D.; Mocking, J.A.J.; Coulier, L.; Vaes, W.H.J.

    2014-01-01

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. H

  12. Analysis of Uncertainties in Protection Heater Delay Time Measurements and Simulations in Nb$_{3}$Sn High-Field Accelerator Magnets

    Salmi, Tiina; Marchevsky, Maxim; Bajas, Hugo; Felice, Helene; Stenvall, Antti

    2015-01-01

    The quench protection of superconducting high-field accelerator magnets is presently based on protection heaters, which are activated upon quench detection to accelerate the quench propagation within the winding. Estimations of the heater delay to initiate a normal zone in the coil are essential for the protection design. During the development of Nb3Sn magnets for the LHC luminosity upgrade, protection heater delays have been measured in several experiments, and a new computational tool CoHDA (Code for Heater Delay Analysis) has been developed for heater design. Several computational quench analyses suggest that the efficiency of the present heater technology is on the borderline of protecting the magnets. Quantifying the inevitable uncertainties related to the measured and simulated delays is therefore of pivotal importance. In this paper, we analyze the uncertainties in the heater delay measurements and simulations using data from five impregnated high-field Nb3Sn magnets with different heater geometries. ...

  13. Functional Data Analysis of Spaceflight-Induced Changes in Coordination and Phase in Head Pitch Acceleration During Treadmill Walking

    Miller, Christopher; Peters, Brian; Feiveson, Alan; Bloomberg, Jacob

    2011-01-01

    Astronauts returning from spaceflight experience neurovestibular disturbances during head movements and attempt to mitigate them by limiting head motion. Analyses to date of the head movements made during walking have concentrated on amplitude and variability measures extracted from ensemble averages of individual gait cycles. Phase shifts within each gait cycle can be determined by functional data analysis through the computation of time-warping functions. Large, localized variations in the timing of peaks in head kinematics may indicate changes in coordination. The purpose of this study was to determine timing changes in head pitch acceleration of astronauts during treadmill walking before and after flight. Six astronauts (5M/1F; age = 43.5+/-6.4yr) participated in the study. Subjects walked at 1.8 m/sec (4 mph) on a motorized treadmill while reading optotypes displayed on a computer screen 4 m in front of their eyes. Three-dimensional motion of the subject s head was recorded with an Inertial Measurement Unit (IMU) device. Data were recorded twice before flight and four times after landing. The head pitch acceleration was calculated by taking the time derivative of the pitch velocity data from the IMU. Data for each session with each subject were time-normalized into gait cycles, then registered to align significant features and create a mean curve. The mean curves of each postflight session for each subject were re-registered based on their preflight mean curve to create time-warping functions. The root mean squares (RMS) of these warping functions were calculated to assess the deviation of head pitch acceleration mean curves in each postflight session from the preflight mean curve. After landing, most crewmembers exhibited localized shifts within their head pitch acceleration regimes, with the greatest deviations in RMS occurring on landing day or 1 day after landing. These results show that the alteration of head pitch coordination due to spaceflight may be

  14. Wave packet analysis and break-up length calculations for an accelerating planar liquid jet

    This paper examines the process of transition to turbulence within an accelerating planar liquid jet. By calculating the propagation and spatial evolution of disturbance wave packets generated at a nozzle where the jet emerges, we are able to estimate break-up lengths and break-up times for different magnitudes of acceleration and different liquid to air density ratios. This study uses a basic jet velocity profile that has shear layers in both air and the liquid either side of the fluid interface. The shear layers are constructed as functions of velocity which behave in line with our CFD simulations of injecting diesel jets. The non-dimensional velocity of the jet along the jet centre-line axis is assumed to take the form V (t) = tanh(at), where the parameter a determines the magnitude of the acceleration. We compare the fully unsteady results obtained by solving the unsteady Rayleigh equation to those of a quasi-steady jet to determine when the unsteady effects are significant and whether the jet can be regarded as quasi-steady in typical operating conditions for diesel engines. For a heavy fluid injecting into a lighter fluid (density ratio ρair/ρjet = q < 1), it is found that unsteady effects are mainly significant at early injection times where the jet velocity profile is changing fastest. When the shear layers in the jet thin with time, the unsteady effects cause the growth rate of the wave packet to be smaller than the corresponding quasi-steady jet, whereas for thickening shear layers the unsteady growth rate is larger than that of the quasi-steady jet. For large accelerations (large a), the unsteady effect remains at later times but its effect on the growth rate of the wave packet decreases as the time after injection increases. As the rate of acceleration is reduced, the range of velocity values for which the jet can be considered as quasi-steady increases until eventually the whole jet can be considered quasi-steady. For a homogeneous jet (q = 1), the

  15. External-beam PIXE analysis of aerosol samples at GIC4117 Tandem Accelerator Laboratory of Beijing Normal University

    Full text: The external-beam facility at GIC4117 tandem accelerator laboratory of Beijing Normal University for PIXE analysis has been introduced, the influence of different aerosol sampling membrane filters on the beam current measurement with a homemade Faraday cup was studied by analysis of a Mn(44.0μg/cm2) MicroMatter standards sample with different filters behind it. Average and the lowest of the external-beam PIXE analysis compared with in-vacuum PIXE over about 360 aerosol samples. External-beam PIXE analysis results of PM2.5 aerosol fractions collected on Teflon filters on daily basis over 2010 at south campus of Beijing Normal University also were shown. (author)

  16. Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data

    Rubel, Oliver; Prabhat, Mr.; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

    2008-08-28

    Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset.

  17. Simulation and analysis of TE wave propagation for measurement of electron cloud densities in particle accelerators

    The use of transverse electric (TE) waves has proved to be a powerful, noninvasive method for estimating the densities of electron clouds formed in particle accelerators. Results from the plasma simulation program VSim have served as a useful guide for experimental studies related to this method, which have been performed at various accelerator facilities. This paper provides results of the simulation and modeling work done in conjunction with experimental efforts carried out at the Cornell electron storage ring “Test Accelerator” (CESRTA). This paper begins with a discussion of the phase shift induced by electron clouds in the transmission of RF waves, followed by the effect of reflections along the beam pipe, simulation of the resonant standing wave frequency shifts and finally the effects of external magnetic fields, namely dipoles and wigglers. A derivation of the dispersion relationship of wave propagation for arbitrary geometries in field free regions with a cold, uniform cloud density is also provided

  18. Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data

    Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset

  19. Simulation and Analysis of TE Wave Propagation as a Probe for Electron Clouds in Particle Accelerators

    Sonnad, Kiran G; Schwartz, Robert; Veitzer, Seth

    2013-01-01

    The use of transverse electric (TE) waves has proved to be a powerful, noninvasive method for estimating the densities of electron clouds formed in particle accelerators. Results from the plasma simulation program VORPAL have been a useful guide for experimental studies related to this method, which have been performed at various accelerator facilities. This paper provides results of the simulation and modeling work done in conjunction with experimental efforts carried out at CesrTA. The discussion starts from the phase shift induced by electron clouds in the transmission of the wave, followed by the effect of reflections along the beam-pipe, the simulation of the resonant wave method and the effects of external magnetic fields, namely dipoles and wigglers. A derivation of the dispersion relationship of wave propagation for arbitrary geometries in field free regions with a uniform cloud density is also provided.

  20. A cosmographic analysis of the transition to acceleration using SN-Ia and BAO

    Muthukrishna, Daniel

    2016-01-01

    We explore the distance-redshift relation using a cosmographic methodology, and show how the cosmographic parameters can be used to determine the redshift of transition from deceleration to acceleration. Such a transition at a low redshift occupies only a small region of the available parameter space, and the prior assumption of an early period of deceleration can significantly change the posterior constraints. We use available type Ia Supernovae (SN-Ia) and Baryon Acoustic Oscillation (BAO) data sets to determine the cosmographic deceleration $q_0$, jerk $j_0$, snap $s_0$ and lerk $l_0$ parameters. The parameters are consistent with the $\\Lambda$CDM model for a flat universe within 2-sigma. We derive constraints on the redshift of transition from deceleration to acceleration for the different expansions, and find $z_{\\rm acc} > 0.14$ at 95% confidence in the most conservative case.

  1. Analysis of burn up effects on kinetic parameters in an Accelerator Driven Subcritical TRIGA reactor

    Highlights: • Among the kinetic parameters, the most important ones are βeff and Λ. • The kinetic parameters at the end of cycle for 20 days operation at 1 MW reactor power have been calculated using MCNPX code. • The system sub-criticality levels, the required accelerator current and power have been calculated for each burnup step. • Burnup effects on neutronic parameters and accelerator requirements are analysed for a life cycle of the reactor core. - Abstract: In this paper, the kinetic parameters at the end of cycle for 20 days operation at 1 MW reactor power have been calculated using MCNPX code for source multiplication factors (Ks) of critical and 0.97 levels. Accelerator Driven Subcritical TRIGA reactor has been considered as the case study of the problem. The system sub-criticality levels, the required accelerator current (Ip) and power (Pacc) have been calculated for each burn up step. According to the results, the required Ip and Pacc increased as system sub-criticality level decreased. Also, the results show that the effective delayed neutron fraction (βeff) does not depend on sub-criticality levels significantly but the neutron reproduction time (Λ) strongly depends on the number of fuel elements in the core and sub-criticality levels. In addition, it was observed that in comparison with the beginning-of-cycle values, at end-of-cycle, the Λ increases by 112.6% and 108.4% respectively but the βeff decreases by 6.1% and 1.8% respectively in critical and 0.97 levels

  2. Accelerated protein evolution analysis reveals genes and pathways associated with the evolution of mammalian longevity

    Li, Yang; de Magalhães, João Pedro

    2011-01-01

    The genetic basis of the large species differences in longevity and aging remains a mystery. Thanks to recent large-scale genome sequencing efforts, the genomes of multiple species have been sequenced and can be used for cross-species comparisons to study species divergence in longevity. By analyzing proteins under accelerated evolution in several mammalian lineages where maximum lifespan increased, we identified genes and processes that are candidate targets of selection when longevity evolv...

  3. Composites Associated with Pulp-Protection Material: Color-Stability Analysis after Accelerated Artificial Aging

    Cruvinel, Diogo Rodrigues; Garcia, Lucas da Fonseca Roberti; Simonides CONSANI; de Carvalho Panzeri Pires-de-Souza, Fernanda

    2010-01-01

    Objectives: This study assessed the color stability of two composites associated with two pulp protectors submitted to accelerated artificial aging (AAA). Methods: 60 test specimens were made with 0.5 mm of protection material (calcium hydroxide - CH or glass ionomer cement - GIC) and 2.5 mm of restoration material (Concept or QuixFil) and divided into 3 groups (n=10) according to the type of protection material/composite, and the control group (no protection). After polishing, color readings...

  4. Implications of accelerated agricultural growth on household incomes and poverty in Ethiopia: A general equilibrium analysis

    Dorosh, Paul A.; Thurlow, James

    2009-01-01

    Ethiopia’s national development strategy, A Plan for Accelerated and Sustained Development to End Poverty for 2005/06 to 2009/10 (PASDEP) places a major emphasis on achieving high rates of agricultural and overall economic growth. Consistent with the PASDEP, Ethiopia is also in the process of implementing the Comprehensive Africa Agriculture Development Programme (CAADP) together with other African governments. As part of CAADP, the country has committed itself to meeting targets of devotin...

  5. Analysis of requirements for accelerating the development of geothermal energy resources in California

    Fredrickson, C. D.

    1978-01-01

    Various resource data are presented showing that geothermal energy has the potential of satisfying a singificant part of California's increasing energy needs. General factors slowing the development of geothermal energy in California are discussed and required actions to accelerate its progress are presented. Finally, scenarios for developing the most promising prospects in the state directed at timely on-line power are given. Specific actions required to realize each of these individual scenarios are identified.

  6. Probabilistic safety analysis of radiation treatments with linear accelerator (Spanish Ed.)

    This publication addresses the issue of accidental exposures of radiotherapy patients and how to avoid them. More proactive approaches are required to anticipate and thus avoid situations that could lead to accidental exposures. In this context, the International Atomic Energy Agency (IAEA) and the Ibero American Forum of Radiation and Nuclear and Safety Regulatory Agencies (the FORO) have applied proactive methods, such as probabilistic safety assessment to radiotherapy treatments with accelerators. The methodology and results of this exercise are described in this publication.

  7. Development and analysis of a metal-fueled accelerator-driven burner

    Lypsch, F. [Institute for Safety Research and Reactor Technology, Juelich GmbH (Germany); Hill, R.N. [Argonne National Lab., IL (United States)

    1994-08-01

    The purpose of this paper is to compare the safety characteristics of an accelerator driven metal fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcritically of the system. To accomplish this an accelerator proton beam/tungsten neutron source model is surrounded by a subcritical blanket using metallic fuel and sodium as coolant. The consequences of typical accident transients, namely unprotected transient overpower (TOP), loss of heat sink (LOHS), and loss of flow (LOP) were calculated for the hybrid system and compared to corresponding results for a metal-fueled fast reactor. Results indicate that the subcritical system exhibits superior performance for TOP (reactivity-induced) transits; however, only in the critical system are reactivity feedbacks able to cause passive shutdown in the LOHS ad LOP events. Therefore, for a full spectrum of accident initiators considered, the overall safety behavior of accelerator-driven metal-fueled systems can neither be concluded to be worse nor to be better than advanced reactor designs which rely on passive safety features.

  8. From tracking code to analysis generalised Courant-Snyder theory for any accelerator model

    Forest, Etienne

    2016-01-01

    This book illustrates a theory well suited to tracking codes, which the author has developed over the years. Tracking codes now play a central role in the design and operation of particle accelerators. The theory is fully explained step by step with equations and actual codes that the reader can compile and run with freely available compilers. In this book, the author pursues a detailed approach based on finite “s”-maps, since this is more natural as long as tracking codes remain at the center of accelerator design. The hierarchical nature of software imposes a hierarchy that puts map-based perturbation theory above any other methods. This is not a personal choice: it follows logically from tracking codes overloaded with a truncated power series algebra package. After defining abstractly and briefly what a tracking code is, the author illustrates most of the accelerator perturbation theory using an actual code: PTC. This book may seem like a manual for PTC; however, the reader is encouraged to explore...

  9. Continuous Wavelet Transform Analysis of Acceleration Signals Measured from a Wave Buoy

    Laurence Zsu-Hsin Chuang

    2013-08-01

    Full Text Available Accelerometers, which can be installed inside a floating platform on the sea, are among the most commonly used sensors for operational ocean wave measurements. To examine the non-stationary features of ocean waves, this study was conducted to derive a wavelet spectrum of ocean waves and to synthesize sea surface elevations from vertical acceleration signals of a wave buoy through the continuous wavelet transform theory. The short-time wave features can be revealed by simultaneously examining the wavelet spectrum and the synthetic sea surface elevations. The in situ wave signals were applied to verify the practicality of the wavelet-based algorithm. We confirm that the spectral leakage and the noise at very-low-frequency bins influenced the accuracies of the estimated wavelet spectrum and the synthetic sea surface elevations. The appropriate thresholds of these two factors were explored. To study the short-time wave features from the wave records, the acceleration signals recorded from an accelerometer inside a discus wave buoy are analysed. The results from the wavelet spectrum show the evidence of short-time nonlinear wave events. Our study also reveals that more surface profiles with higher vertical asymmetry can be found from short-time nonlinear wave with stronger harmonic spectral peak. Finally, we conclude that the algorithms of continuous wavelet transform are practical for revealing the short-time wave features of the buoy acceleration signals.

  10. Continuous wavelet transform analysis of acceleration signals measured from a wave buoy.

    Chuang, Laurence Zsu-Hsin; Wu, Li-Chung; Wang, Jong-Hao

    2013-01-01

    Accelerometers, which can be installed inside a floating platform on the sea, are among the most commonly used sensors for operational ocean wave measurements. To examine the non-stationary features of ocean waves, this study was conducted to derive a wavelet spectrum of ocean waves and to synthesize sea surface elevations from vertical acceleration signals of a wave buoy through the continuous wavelet transform theory. The short-time wave features can be revealed by simultaneously examining the wavelet spectrum and the synthetic sea surface elevations. The in situ wave signals were applied to verify the practicality of the wavelet-based algorithm. We confirm that the spectral leakage and the noise at very-low-frequency bins influenced the accuracies of the estimated wavelet spectrum and the synthetic sea surface elevations. The appropriate thresholds of these two factors were explored. To study the short-time wave features from the wave records, the acceleration signals recorded from an accelerometer inside a discus wave buoy are analysed. The results from the wavelet spectrum show the evidence of short-time nonlinear wave events. Our study also reveals that more surface profiles with higher vertical asymmetry can be found from short-time nonlinear wave with stronger harmonic spectral peak. Finally, we conclude that the algorithms of continuous wavelet transform are practical for revealing the short-time wave features of the buoy acceleration signals. PMID:23966188

  11. Doppler Broadening Analysis of Steel Specimens Using Accelerator Based In Situ Pair Production

    Positron Annihilation Spectroscopy (PAS) techniques can be utilized as a sensitive probe of defects in materials. Studying these microscopic defects is very important for a number of industries in order to predict material failure or structural integrity. We have been developing gamma-induced pair-production techniques to produce positrons in thick samples (∼4-40 g/cm2, or ∼0.5-5 cm in steel). These techniques are called 'Accelerator-based Gamma-induced Positron Annihilation Spectroscopy'(AG-PAS). We have begun testing the capabilities of this technique for imaging of defect densities in thick structural materials. As a first step, a linear accelerator (LINAC) was employed to produce photon beams by stopping 15 MeV electrons in a 1 mm thick tungsten converter. The accelerator is capable of operating with 30-60 ns pulse width, up to 200 mA peak current at 1 kHz repetition rate. The highly collimated bremsstrahlung beam impinged upon our steel tensile specimens, after traveling through a 1.2 m thick concrete wall. Annihilation radiation was detected by a well-shielded and collimated high-purity germanium detector (HPGe). Conventional Doppler broadening spectrometry (DBS) was performed to determine S, W and T parameters for our samples.

  12. Analysis of heterogeneity and epistasis in physiological mixed populations by combined structural equation modelling and latent class analysis

    Fenger, Mogens; Linneberg, Allan; Werge, Thomas;

    2008-01-01

    BACKGROUND: Biological systems are interacting, molecular networks in which genetic variation contributes to phenotypic heterogeneity. This heterogeneity is traditionally modelled as a dichotomous trait (e.g. affected vs. non-affected). This is far too simplistic considering the complexity and...... genetic variations of such networks. METHODS: In this study on type 2 diabetes mellitus, heterogeneity was resolved in a latent class framework combined with structural equation modelling using phenotypic indicators of distinct physiological processes. We modelled the clinical condition "the metabolic...

  13. Cooling the APS storage ring radio-frequency accelerating cavities: Thermal/stress/fatigue analysis and cavity cooling configuration

    The 7-GeV Advanced Photon Source positron storage ring requires sixteen separate 352-MHz radio-frequency (rf) accelerating cavities. Cavities are installed as groups of four, in straight sections used elsewhere for insertion devices. They occupy the first such straight section after injection, along with the last three just before injection. Cooling is provided by a subsystem of the sitewide deionized water system. Pumping equipment is located in a building directly adjacent to the accelerator enclosure. A prototype cavity was fabricated and tested where cooling was via twelve 19-mm-diameter [3/4 in] brazed-on tubes in a series-parallel flow configuration. Unfortunately, the thermal contact to some tubes was poor due to inadequate braze filler. Here, heat transfer studies, including finite-element analysis and test results, of the Advanced Photon Source (APS) storage ring 352-MHz rf accelerating cavities are described. Stress and fatigue life of the copper are discussed. Configuration of water cooling is presented

  14. Surface Analysis of OFE-Copper X-Band Accelerating Structures and Possible Correlation to RF Breakdown Events

    Harvey, S E; Kirby, R E; Marcelja, F; Adamson, K; Garwin, E L

    2003-01-01

    X-band accelerator structures meeting the Next Linear Collider (NLC) design requirements have been found to suffer vacuum surface damage caused by radio frequency (RF) breakdown, when processed to high electric-field gradients. Improved understanding of these breakdown events is desirable for the development of structure designs, fabrication procedures, and processing techniques that minimize structure damage. RF reflected wave analysis and acoustic sensor pickup have provided breakdowns localization in RF structures. Particle contaminations found following clean autopsy of four RF-processed travelling wave structures, have been catalogued and analyzed. Their influence on RF breakdown, as well as that of several other material-based properties, will be discussed.

  15. Calibration of a new experimental chamber for PIXE analysis at the Accelerator Facilities Division of Atomic Energy Centre Dhaka (AECD)

    A new experimental chamber has been installed at the 3 MV Van de Graaff Accelerator Facilities Division in the Atomic Energy Centre, Dhaka, to perform different Ion Beam Analysis (IBA) techniques. The calibration of this new setup for Particle Induced X-ray Emission (PIXE) technique has been done using a set of thin MicroMatter standards and GUPIX (PIXE spectrum analysis software), which is explicated in this paper. The effective thicknesses of the beryllium window of the X-ray detector and of the different absorbers used were determined. For standardization, the so called instrumental constant H (product of detector solid angle and the correction factor for the setup) as function of X-ray energy were determined and stored inside the GUPIX library for further PIXE analysis

  16. Calibration of a new experimental chamber for PIXE analysis at the Accelerator Facilities Division of Atomic Energy Centre Dhaka (AECD)

    Hassan, Md. Taufique, E-mail: thassan@tulane.edu [Department of Physics, University of Dhaka (Bangladesh); Shariff, Md. Asad [Tandem Accelerator Facilities division, INST, AERE, Savar (Bangladesh); Hossein, Amzad; Abedin, Md. Joynal [Accelerator Facilities division, AECD (Bangladesh); Fazlul Hoque, A.K.M. [Daffodil International University, Dhaka (Bangladesh); Chowdhuri, M.S. [Department of Physics, University of Dhaka (Bangladesh)

    2015-05-01

    A new experimental chamber has been installed at the 3 MV Van de Graaff Accelerator Facilities Division in the Atomic Energy Centre, Dhaka, to perform different Ion Beam Analysis (IBA) techniques. The calibration of this new setup for Particle Induced X-ray Emission (PIXE) technique has been done using a set of thin MicroMatter standards and GUPIX (PIXE spectrum analysis software), which is explicated in this paper. The effective thicknesses of the beryllium window of the X-ray detector and of the different absorbers used were determined. For standardization, the so called instrumental constant H (product of detector solid angle and the correction factor for the setup) as function of X-ray energy were determined and stored inside the GUPIX library for further PIXE analysis.

  17. SU-C-BRD-03: Analysis of Accelerator Generated Text Logs for Preemptive Maintenance

    Able, CM; Baydush, AH; Nguyen, C; Munley, MT [Wake Forest School of Medicine, Department of Radiation Oncology, Winston Salem, NC (United States); Gersh, J [Gibbs Cancer Center and Research Institute, Spartenburg Regional Medical Ce, Spartenburg, SC (United States); Ndlovu, A; Rebo, I [John Theuer Cancer Center, Hackensack University Medical Center, Hackensack, NJ (United States); Booth, J; Perez, M [North Sydney Cancer Center, Royal North Shore Hospital, Sydney, St Leonards (Australia); Sintay, B [Cone Health Cancer Center, Greensboro, NC (United States)

    2014-06-15

    Purpose: To develop a model to analyze medical accelerator generated parameter and performance data that will provide an early warning of performance degradation and impending component failure. Methods: A robust 6 MV VMAT quality assurance treatment delivery was used to test the constancy of accelerator performance. The generated text log files were decoded and analyzed using statistical process control (SPC) methodology. The text file data is a single snapshot of energy specific and overall systems parameters. A total of 36 system parameters were monitored which include RF generation, electron gun control, energy control, beam uniformity control, DC voltage generation, and cooling systems. The parameters were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and the parameter/system specification. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: the value of 1 standard deviation from the mean operating parameter of 483 TB systems, a small fraction (≤ 5%) of the operating range, or a fraction of the minor fault deviation. Results: There were 34 parameters in which synthetic errors were introduced. There were 2 parameters (radial position steering coil, and positive 24V DC) in which the errors did not exceed the limit of the I/MR chart. The I chart limit was exceeded for all of the remaining parameters (94.2%). The MR chart limit was exceeded in 29 of the 32 parameters (85.3%) in which the I chart limit was exceeded. Conclusion: Statistical process control I/MR evaluation of text log file parameters may be effective in providing an early warning of performance degradation or component failure for digital medical accelerator systems. Research is Supported by Varian Medical Systems, Inc.

  18. Improving the design and analysis of superconducting magnets for particle accelerators

    High energy particle accelerators are now the primary means of discovering the basic building blocks of matter and understanding the forces between them. In order to minimize the cost of building these machines, superconducting magnets are used in essentially all present day high energy proton and heavy ion colliders. The cost of superconducting magnets is typically in the range of 20--30% of the total cost of building such machines. The circulating particle beam goes through these magnets a large number of times (over hundreds of millions). The luminosity performance and life time of the beam in these machines depends significantly on the field quality in these magnets. Therefore, even a small error in the magnetic field shape may create a large cumulative effect in the beam trajectory to throw the particles of the magnet aperture. The superconducting accelerator magnets must, therefore, be designed and constructed so that these errors are small. In this thesis the research and development work will be described 3which has resulted in significant improvements in the field quality of the superconducting magnets for the Relativistic Heavy Ion Collider (RHIC). The design and the field quality improvements in the prototype of the main collider dipole magnet for the Superconducting Super Collider (SSC) will also be presented. RHIC will accelerate and collide two counter rotating beams of heavy ions up to 100 GeV/u and protons up to 250 GeV. It is expected that RHIC will create a hot, dense quark-gluon plasma and the conditions which, according to the Big Bang theory, existed in the early universe

  19. SU-C-BRD-03: Analysis of Accelerator Generated Text Logs for Preemptive Maintenance

    Purpose: To develop a model to analyze medical accelerator generated parameter and performance data that will provide an early warning of performance degradation and impending component failure. Methods: A robust 6 MV VMAT quality assurance treatment delivery was used to test the constancy of accelerator performance. The generated text log files were decoded and analyzed using statistical process control (SPC) methodology. The text file data is a single snapshot of energy specific and overall systems parameters. A total of 36 system parameters were monitored which include RF generation, electron gun control, energy control, beam uniformity control, DC voltage generation, and cooling systems. The parameters were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and the parameter/system specification. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: the value of 1 standard deviation from the mean operating parameter of 483 TB systems, a small fraction (≤ 5%) of the operating range, or a fraction of the minor fault deviation. Results: There were 34 parameters in which synthetic errors were introduced. There were 2 parameters (radial position steering coil, and positive 24V DC) in which the errors did not exceed the limit of the I/MR chart. The I chart limit was exceeded for all of the remaining parameters (94.2%). The MR chart limit was exceeded in 29 of the 32 parameters (85.3%) in which the I chart limit was exceeded. Conclusion: Statistical process control I/MR evaluation of text log file parameters may be effective in providing an early warning of performance degradation or component failure for digital medical accelerator systems. Research is Supported by Varian Medical Systems, Inc

  20. Statistical analysis of operating efficiency and failures of a medical linear accelerator for ten years

    To improve the management of a medical linear accelerator, the records of operational failures of a Varian CL2100C over a ten year period were retrospectively analyzed. The failures were classified according to the involved functional subunits, with each class rated into one of three levels depending on the operational conditions. The relationships between the failure rate and working ratio and between the failure rate and outside temperature were investigated. In addition, the average life time of the main part and the operating efficiency over the last 4 years were analyzed. Among the recorded failures (total 587 failures), the most frequent failure was observed in the parts related with the collimation system, including the monitor chamber, which accounted for 20% of all failures. With regard to the operational conditions, 2nd level of failures, which temporally interrupted treatments, were the most frequent. Third level of failures, which interrupted treatment for more than several hours, were mostly caused by the accelerating subunit. The number of failures was increased with number of treatments and operating time. The average life-times of the Klystron and Thyratron became shorter as the working ratio increased, and were 42 and 83% of the expected values, respectively. The operating efficiency was maintained at 95% or higher, but this value slightly decreased. There was no significant correlation between the number of failures and the outside temperature. The maintenance of detailed equipment problems and failures records over a long period of time can provide good knowledge of equipment function as well as the capability of predicting future failure. More rigorous equipment maintenance is required for old medical linear accelerators for the advanced avoidance of serious failure and to improve the quality of patient treatment

  1. Measurement and analysis of the electric field radiation in pulsed power system of linear induction accelerator

    The close of high voltage switch in pulsed power system of linear induction accelerator often radiates strong transient electric field, which may influence ambient sensitive electric equipment, signals and performance of other instruments, etc. By performing gridded measurement around the Marx generator, the general distribution law and basic characters of electric field radiation are summarized. The current signal of the discharge circuit is also measured, which demonstrates that the current and the radiated electric field both have a resonance frequency about 150 kHz, and contain much higher frequency components. (authors)

  2. Analysis of Anderson Acceleration on a Simplified Neutronics/Thermal Hydraulics System

    Toth, Alex [North Carolina State University (NCSU), Raleigh; Kelley, C. T. [North Carolina State University (NCSU), Raleigh; Slattery, Stuart R [ORNL; Hamilton, Steven P [ORNL; Clarno, Kevin T [ORNL; Pawlowski, R. P. P. [Sandia National Laboratories (SNL)

    2015-01-01

    ABSTRACT A standard method for solving coupled multiphysics problems in light water reactors is Picard iteration, which sequentially alternates between solving single physics applications. This solution approach is appealing due to simplicity of implementation and the ability to leverage existing software packages to accurately solve single physics applications. However, there are several drawbacks in the convergence behavior of this method; namely slow convergence and the necessity of heuristically chosen damping factors to achieve convergence in many cases. Anderson acceleration is a method that has been seen to be more robust and fast converging than Picard iteration for many problems, without significantly higher cost per iteration or complexity of implementation, though its effectiveness in the context of multiphysics coupling is not well explored. In this work, we develop a one-dimensional model simulating the coupling between the neutron distribution and fuel and coolant properties in a single fuel pin. We show that this model generally captures the convergence issues noted in Picard iterations which couple high-fidelity physics codes. We then use this model to gauge potential improvements with regard to rate of convergence and robustness from utilizing Anderson acceleration as an alternative to Picard iteration.

  3. DEX: Increasing the Capability of Scientific Data Analysis Pipelines by Using Efficient Bitmap Indices to Accelerate Scientific Visualization

    Stockinger, Kurt; Shalf, John; Bethel, Wes; Wu, Kesheng

    2005-02-04

    We describe a new approach to scalable data analysis that enables scientists to manage the explosion in size and complexity of scientific data produced by experiments and simulations. Our approach uses a novel combination of efficient query technology and visualization infrastructure. The combination of bit map indexing, which is a data management technology that accelerates queries on large scientific datasets, with a visualization pipeline for generating images of abstract data results in a tool suitable for use by scientists in fields where data size and complexity poses a barrier to efficient analysis. Our architecture and implementation, which we call DEX (short for dexterous data explorer), directly addresses the problem of ''too much data'' by focusing analysis on data deemed to be ''scientifically interesting'' via a user-specified selection criteria. The architectural concepts and implementation are applicable to wide variety of scientific data analysis and visualization applications. This paper presents an architectural overview of the system along with an analysis showing substantial performance over traditional visualization pipelines. While performance gains are a significant result, even more important is the new functionality not present in any visualization analysis software--namely the ability to perform interactive, multi-dimensional queries to refine regions of interest that are later used as input to analysis or visualization.

  4. Future accelerators (?)

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made

  5. Future accelerators (?)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  6. Shielding analysis of proton therapy accelerators: a demonstration using Monte Carlo-generated source terms and attenuation lengths.

    Lai, Bo-Lun; Sheu, Rong-Jiun; Lin, Uei-Tyng

    2015-05-01

    Monte Carlo simulations are generally considered the most accurate method for complex accelerator shielding analysis. Simplified models based on point-source line-of-sight approximation are often preferable in practice because they are intuitive and easy to use. A set of shielding data, including source terms and attenuation lengths for several common targets (iron, graphite, tissue, and copper) and shielding materials (concrete, iron, and lead) were generated by performing Monte Carlo simulations for 100-300 MeV protons. Possible applications and a proper use of the data set were demonstrated through a practical case study, in which shielding analysis on a typical proton treatment room was conducted. A thorough and consistent comparison between the predictions of our point-source line-of-sight model and those obtained by Monte Carlo simulations for a 360° dose distribution around the room perimeter showed that the data set can yield fairly accurate or conservative estimates for the transmitted doses, except for those near the maze exit. In addition, this study demonstrated that appropriate coupling between the generated source term and empirical formulae for radiation streaming can be used to predict a reasonable dose distribution along the maze. This case study proved the effectiveness and advantage of applying the data set to a quick shielding design and dose evaluation for proton therapy accelerators. PMID:25811254

  7. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...

  8. Detection of epitasis, additive and dominance variation in rice (Oryza sativa L. using triple test cross analysis

    N.R. Koli, Chandra Prakash, R.K. Mahawar ,B.L.Kumhar and S.S.Punia

    2014-12-01

    Full Text Available An investigation was carried out to detect the epistasis, additive and dominance components of genetic variance for yield and yield attributing traits through triple test cross analysis, involving three testers (P1, P2 and their F1 and ten lines of rice. The estimate of total epistasis was found non-significant for all the traits while partitioning of total epistasis revealed that, i type of epistasis (additive x additive were highly significant for yield per plant, plant height, number of panicle per meter square, panicle length and number of grains per panicle. The additive (D and dominance (H effects were highly significant for yield per plant, plant height, panicle length, number of grains per panicle and 1000 grain weight. The degree of dominance (H/D1/2 was less than the unity indicating, partial dominance for plant height, panicles / m2 and 1000 grain weight whereas, yield per plant, panicle length and number of grains per panicle indicating over dominance (>1 . Since, the predominance components of epistasis in autogamous crop is additive x additive (i type, we suggest that the selection may be delayed to later generation for the improvement of yield through yield components in rice.

  9. Accelerator mass spectrometry analysis of aroma compound absorption in plastic packaging materials

    Stenström, Kristina; Erlandsson, Bengt; Hellborg, Ragnar; Wiebert, Anders; Skog, Göran; Nielsen, Tim

    1994-05-01

    Absorption of aroma compounds in plastic packaging materials may affect the taste of the packaged food and it may also change the quality of the packaging material. A method to determine the aroma compound absorption in polymers by accelerator mass spectrometry (AMS) is being developed at the Lund Pelletron AMS facility. The high sensitivity of the AMS method makes it possible to study these phenomena under realistic conditions. As a first test low density polyethylene exposed to 14C-doped ethyl acetate is examined. After converting the polymer samples with the absorbed aroma compounds to graphite, the {14C }/{13C } ratio of the samples is measured by the AMS system and the degree of aroma compound absorption is established. The results are compared with those obtained by supercritical fluid extraction coupled to gas chromatography (SFE-GC).

  10. Oxygen concentrations by nuclear reaction analysis on the new STAR accelerator

    The new HVEE 2MV STAR accelerator was used to measure small concentrations of oxygen in blood samples taken from honey possums, an endangered marsupial from Western Australia. Samples were prepared by injecting the animals with a small (∼3ml/kg) amount of 97% 18O-enriched water (1H218O). After 24h, the animals were recaptured, and a small (∼60 micro-l) amount of blood was extracted, diluted and used for oxidising Ta plates, following an anodic oxidation process. The amount of 18O present in the blood samples was determined using the 18O(p,α)15N nuclear reaction, which has a resonance at 846keV. The results of 18O measurements were used to calculate the metabolic rate of honey possums, and thus gather additional information which will be used in the fight to save this endangered native animal. (author)

  11. Carbon pool analysis of methane hydrate regions in the seafloor by accelerator mass spectrometry

    Accelerator mass spectrometry for 14C was applied to the study of carbon pools associated with methane hydrate formations found in the seafloor at two continental margin sites. The Gulf of Mexico (GOM) site contains thermogenically produced methane that is ancient and thus free of 14C. The Cascadia Margin site contains biogenically produced methane, so may contain some 14C. This work reports on the 14C content of organic matter in the sediment at the GOM site, and of the methane in hydrates from both sites. In the GOM, the surface sediments contained ancient organic matter that was from 20% to 60% of the total organic carbon content. At both sites, the collected hydrates contained essentially no 14C

  12. The application software of the CERN PS accelerator controls system - analysis of its cost and resources

    The CERN PS accelerators have evolved into one of the world's most sophisticated high energy physics facility. The variety of beams and their high repetition rate means that a most sophisticated controls system is required. This reflects on the application software. At the time of the completion of the new control system, nearly 1000 programs, amounting to around 450 000 lines of code, have been developed at the cost of approximately 120 man-years. The span of this software ranges from real-time application programs to special purpose development and management tools. This paper documents the cost, resources and production of this software project. These are analyzed in terms of the structure of the application software. Rules-of-thumb are suggested for estimating the required effort at various phases of the project and to define the implementation strategy. (orig.)

  13. Fatigue analysis of the spallation module of a high power accelerator-driven demonstrator system

    In the framework of the study of a hybrid demonstrator system dedicated to waste transmutation, close attention has been paid to the mechanical design of the beam window plunging in the liquid metal target, since it ensures a critical function of confinement. First, the risk of fatigue induced by thermal cycling due to frequent beam trips of the accelerator has been assessed for an unirradiated T91 martensitic steel. This study has shown that the risk of fatigue will not be a limiting factor for the lifetime of the component even under severe operating conditions. A similar study has also been performed, with the help of adapted design rules, considering a T91 steel irradiated at 3.5 DPA. A similar conclusion has been found, which should, however, be confirmed by further studies at dose and temperature levels closer to the expected irradiation conditions of the window. (authors)

  14. An accelerated buoyancy adhesion assay combined with 3-D morphometric analysis for assessing osteoblast adhesion on microgrooved substrata.

    Sobral, J M; Malheiro, V N; Clyne, T W; Harris, J; Rezk, R; O'Neill, W; Markaki, A E

    2016-07-01

    An accelerated negative buoyancy method has been developed to assess cell adhesion strength. This method has been used in conjunction with 3-D morphometric analysis to understand the effects of surface topology on cell response. Aligned micro-grooved surface topographies (with a range of groove depths) were produced on stainless steel 316L substrates by laser ablation. An investigation was carried out on the effect of the micro-grooved surface topography on cell adhesion strength, cell and nucleus volumes, cell phenotypic expression and attachment patterns. Increased hydrophobicity and anisotropic wettability was observed on surfaces with deeper grooves. A reduction was noted in cell volume, projected areas and adhesion sites for deeper grooves, linked to lower cell proliferation and differentiation rates and also to reduced adhesion strength. The results suggest that the centrifugation assay combined with three-dimensional cell morphometric analysis has considerable potential for obtaining improved understanding of the cell/substrate interface. PMID:26773651

  15. ANALYSIS OF ACCELERATED LIFE TESTING USING LOG-LOGISTIC GEOMETRIC PROCESS MODEL IN CASE OF CENSORED DATA

    S. SAXENA

    2013-07-01

    Full Text Available Geometric process model has been used in a variety of situations such as the determination of the optimal replacement policy and the optimal inspection-repair replacement policy for standby systems, and the analysis of data with trends. This study deals with the analysis of accelerated life testing for Log-Logistic distribution using geometric process model. The case of type-I censoring is considered in this study. It is assumed that the lifetimes under increasing stress levels form a geometric process. The maximum likelihood estimates of the parameters and their confidence intervals using the asymptotic method are derived. The performance of the estimators is evaluated by a simulation study with different pre-fixed parameters.

  16. Accelerated radiotherapy for T1, 2 glottic carcinoma: analysis of results with KI-67 index

    Purpose: Hyperfractionated and accelerated radiotherapy without a split was performed to improve the local control probability of early glottic carcinomas. We analyzed the results of this regimen by using the Ki-67 index. Methods and Materials: Over a 12-year period, 85 T1N0M0 glottic cancers and 50 T2N0M0 glottic cancers were treated with conventional fractionation (CF) from 1984 to 1989 and with accelerated fractionation (AF) since 1990. The CF program consisted of five daily fractions of 2 Gy per week, for a total of 64 Gy. The AF program consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, for a total of 55 or 58 Gy. The specimens, taken before radiotherapy, were immunohistochemically stained with anti-Ki-67 antibody. Results: The 5-year local control probability for T1 tumors was 79.6 ± 6.9% with CF treatment, whereas with AF it was 86.9 ± 5.6%. For T2 tumors it was 62.7 ± 12.2% with CF, whereas it was 74.7 ± 7.8% with AF. The difference between CF and AF did not reach the point of statistical significance. However, when T1 tumors had a Ki-67 index lower than 50%, the local control rate achieved with AF was significantly better than that with CF (p = 0.018). When the tumors had a Ki-67 index that was 50% or more, there was no difference in the local control rate between CF and AF, whether they were T1 or T2. The peak mucosal reactions at the larynx and/or hypopharynx were much more severe and appeared at smaller doses and earlier in AF than in CF. The patients with AF showed no severe late complications. Conclusions: AF could not obtain statistically significant improvement in local control probability of T1 or T2 glottic carcinomas

  17. Switched Matrix Accelerator

    We describe a new concept for a microwave circuit functioning as a charged-particle accelerator at mm-wavelengths, permitting an accelerating gradient higher than conventional passive circuits can withstand consistent with cyclic fatigue. The device provides acceleration for multiple bunches in parallel channels, and permits a short exposure time for the conducting surface of the accelerating cavities. Our analysis includes scalings based on a smooth transmission line model and a complementary treatment with a coupled-cavity simulation. We provide also an electromagnetic design for the accelerating structure, arriving at rough dimensions for a seven-cell accelerator matched to standard waveguide and suitable for bench tests at low power in air at 91.392. GHz. A critical element in the concept is a fast mm-wave switch suitable for operation at high-power, and we present the considerations for implementation in an H-plane tee. We discuss the use of diamond as the photoconductor switch medium

  18. Mapping epistasis and environment × QTX interaction based on four-omics genotypes for the detected QTX loci controlling complex traits in tobacco

    Liyuan; Zhou; Ruiyuan; Li; Longjiang; Fan; Yuewei; Shi; Zhihong; Wang; Shengdong; Xie; Yijie; Gui; Xueliang; Ren; Jun; Zhu

    2013-01-01

    Using newly developed methods and software, association mapping was conducted for chromium content and total sugar in tobacco leaf, based on four-omics datasets. Our objective was to collect data on genotype and phenotype for 60 leaf samples at four developmental stages, from three plant architectural positions and for three cultivars that were grown in two locations. Association mapping was conducted to detect genetic variants at quantitative trait SNP(QTS) loci, quantitative trait transcript(QTT) differences,quantitative trait protein(QTP) variability, and quantitative trait metabolite(QTM) changes,which can be summarized as QTX locus variation. The total heritabilities of the four-omics loci for both traits tested were 23.60% for epistasis and 15.26% for treatment interaction.Epistasis and environment × treatment interaction had important impacts on complex traits at all-omics levels. For decreasing chromium content and increasing total sugar in tobacco leaf, six methylated loci can be directly used for marker-assisted selection, and expression of ten QTTs, seven QTPs and six QTMs can be modified by selection or cultivation.

  19. Mapping epistasis and environment × QTX interaction based on four -omics genotypes for the detected QTX loci controlling complex traits in tobacco

    Liyuan Zhou

    2013-12-01

    Full Text Available Using newly developed methods and software, association mapping was conducted for chromium content and total sugar in tobacco leaf, based on four -omics datasets. Our objective was to collect data on genotype and phenotype for 60 leaf samples at four developmental stages, from three plant architectural positions and for three cultivars that were grown in two locations. Association mapping was conducted to detect genetic variants at quantitative trait SNP (QTS loci, quantitative trait transcript (QTT differences, quantitative trait protein (QTP variability, and quantitative trait metabolite (QTM changes, which can be summarized as QTX locus variation. The total heritabilities of the four -omics loci for both traits tested were 23.60% for epistasis and 15.26% for treatment interaction. Epistasis and environment × treatment interaction had important impacts on complex traits at all -omics levels. For decreasing chromium content and increasing total sugar in tobacco leaf, six methylated loci can be directly used for marker-assisted selection, and expression of ten QTTs, seven QTPs and six QTMs can be modified by selection or cultivation.

  20. SU-E-T-144: Effective Analysis of VMAT QA Generated Trajectory Log Files for Medical Accelerator Predictive Maintenance

    Purpose: To determine the effectiveness of SPC analysis for a model predictive maintenance process that uses accelerator generated parameter and performance data contained in trajectory log files. Methods: Each trajectory file is decoded and a total of 131 axes positions are recorded (collimator jaw position, gantry angle, each MLC, etc.). This raw data is processed and either axis positions are extracted at critical points during the delivery or positional change over time is used to determine axis velocity. The focus of our analysis is the accuracy, reproducibility and fidelity of each axis. A reference positional trace of the gantry and each MLC is used as a motion baseline for cross correlation (CC) analysis. A total of 494 parameters (482 MLC related) were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and parameter/system specifications. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: TG-142 and published analysis of VMAT delivery accuracy. Results: All errors introduced were detected. Synthetic positional errors of 2mm for collimator jaw and MLC carriage exceeded the chart limits. Gantry speed and each MLC speed are analyzed at two different points in the delivery. Simulated Gantry speed error (0.2 deg/sec) and MLC speed error (0.1 cm/sec) exceeded the speed chart limits. Gantry position error of 0.2 deg was detected by the CC maximum value charts. The MLC position error of 0.1 cm was detected by the CC maximum value location charts for every MLC. Conclusion: SPC I/MR evaluation of trajectory log file parameters may be effective in providing an early warning of performance degradation or component failure for medical accelerator systems

  1. SU-E-T-144: Effective Analysis of VMAT QA Generated Trajectory Log Files for Medical Accelerator Predictive Maintenance

    Able, CM; Baydush, AH; Nguyen, C; Munley, MT [Wake Forest School of Medicine, Department of Radiation Oncology, Winston Salem, NC (United States); Gersh, J [Gibbs Cancer Center and Research Institute, Spartenburg Regional Medical Ce, Spartenburg, SC (United States); Ndlovu, A; Rebo, I [John Theuer Cancer Center, Hackensack University Medical Center, Hackensack, NJ (United States); Booth, J; Perez, M [North Sydney Cancer Center, Royal North Shore Hospital, Sydney, St Leonards (Australia); Sintay, B [Cone Health Cancer Center, Greensboro, NC (United States)

    2014-06-01

    Purpose: To determine the effectiveness of SPC analysis for a model predictive maintenance process that uses accelerator generated parameter and performance data contained in trajectory log files. Methods: Each trajectory file is decoded and a total of 131 axes positions are recorded (collimator jaw position, gantry angle, each MLC, etc.). This raw data is processed and either axis positions are extracted at critical points during the delivery or positional change over time is used to determine axis velocity. The focus of our analysis is the accuracy, reproducibility and fidelity of each axis. A reference positional trace of the gantry and each MLC is used as a motion baseline for cross correlation (CC) analysis. A total of 494 parameters (482 MLC related) were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and parameter/system specifications. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: TG-142 and published analysis of VMAT delivery accuracy. Results: All errors introduced were detected. Synthetic positional errors of 2mm for collimator jaw and MLC carriage exceeded the chart limits. Gantry speed and each MLC speed are analyzed at two different points in the delivery. Simulated Gantry speed error (0.2 deg/sec) and MLC speed error (0.1 cm/sec) exceeded the speed chart limits. Gantry position error of 0.2 deg was detected by the CC maximum value charts. The MLC position error of 0.1 cm was detected by the CC maximum value location charts for every MLC. Conclusion: SPC I/MR evaluation of trajectory log file parameters may be effective in providing an early warning of performance degradation or component failure for medical accelerator systems.

  2. High homocysteine and epistasis between MTHFR and APOE: association with cognitive performance in the elderly.

    Polito, Letizia; Poloni, Tino Emanuele; Vaccaro, Roberta; Abbondanza, Simona; Mangieri, Michela; Davin, Annalisa; Villani, Simona; Guaita, Antonio

    2016-04-01

    High total homocysteine (tHcy) is associated with cognitive impairment in the elderly. The impact of high tHcy on different cognitive domains deserves further investigation, as does the role of the C677T polymorphism of the 5,10 methylenetetrahydrofolate reductase (MTHFR) gene. A cross-sectional analysis of 903 subjects from the population-based "InveCe.Ab" study was performed. The participants had no psychosis or active neurological disorders. They underwent a neuropsychological assessment. Principal component analysis allowed cognitive performance to be condensed into two components: executive functions and memory. Novel components were evaluated for association with tHcy, controlling for potential confounders. Regression models showed that high serum tHcy was associated with lower executive functions, but not with memory. MTHFR C677T TT was associated with higher tHcy but did not affect cognitive performance per se. However, when combined with the apolipoprotein E (APOE)-ε4 allele, it was a risk factor for lower executive performance, independently of tHcy levels. In summary, high tHcy per se, or MTHFR C677T TT in combination with the APOE-ε4 allele, might be associated primarily with executive dysfunctions rather than memory loss. PMID:26774227

  3. Sensitivity analysis in multipole-accelerated panel methods for potential flow

    Leathrum, James F., Jr.

    1995-01-01

    In the design of an airframe, the effect of changing the geometry on resulting computations is necessary for design optimization. The geometry is defined in terms of a series of design variables, including design variables to define the wing planform, tail, canard, pylon, and nacelle. Design optimization in this research is based on how these design variable affect the potential flow. The potential flow is computed as a function of the geometry and location of a series of panels describing the airframe, which are in turn a function of the design variables. Multipole accelerated panel methods improve the computational complexity of the problem and thus are an attractive approach. To utilize the methods in design optimization, it was necessary to define the appropriate sensitivity derivatives. The overhead incurred from finding the sensitivity derivatives in conjunction with the original computation should be small. This research developed the background for multipole-accelerated panel methods and the framework for finding sensitivity derivatives in the methods. Potential flow panel codes are commonly used for powered-lift aerodynamic predictions for three dimensional geometries. Given an airframe which has been discretized into a series of panels to define the airframe geometry, potential is computed as a function of the influence of all panels on all other panels. This is a computationally intensive problem for which efficient solutions are desired to improve the computational time and to allow greater resolution by use of more panels. One such solution is the use of hierarchical multipole methods which entail approximations of the effects of far-field terms. Hierarchical multipole methods have become prevalent in molecular dynamics and gravitational physics, and have been introduced into the fields of capacitance calculations, computational fluid dynamics, and electromagnetics. The methods utilize multipole expansions to describe the effect of bodies (i

  4. Epistasis between MicroRNAs 155 and 146a during T Cell-Mediated Antitumor Immunity

    Thomas B. Huffaker

    2012-12-01

    Full Text Available An increased understanding of antitumor immunity is necessary for improving cell-based immunotherapies against human cancers. Here, we investigated the roles of two immune system-expressed microRNAs (miRNAs, miR-155 and miR-146a, in the regulation of antitumor immune responses. Our results indicate that miR-155 promotes and miR-146a inhibits interferon γ (IFNγ responses by T cells and reduces solid tumor growth in vivo. Using a double-knockout (DKO mouse strain deficient in both miR-155 and miR-146a, we have also identified an epistatic relationship between these two miRNAs. DKO mice had defective T cell responses and tumor growth phenotypes similar to miR-155−/− mice. Further analysis of the T cell compartment revealed that miR-155 modulates IFNγ expression through a mechanism involving repression of Ship1. Our work reveals critical roles for miRNAs in the reciprocal regulation of CD4+ and CD8+ T cell-mediated antitumor immunity and demonstrates the dominant nature of miR-155 during its promotion of immune responses.

  5. Magnetic field analysis for superferric accelerator magnets using elliptic multipoles and advantages

    Full text: FAIR (Facility for Antiproton and Ion Research) will build a set of accelerators and storage rings at GSI. Some of them transport charged particle beams of elliptical cross section. Two-dimensional magnetic field calculations as well as magnetic measurements provide precise field information, which is used to improve the properties of the machines using numerical simulations. We develop elliptical multipoles fulfilling Laplace's equation, which enable us to describe the field within the whole aperture consistently. This requires to find a complete set of particular solutions. This selection is not so obvious since the Laplacian in elliptic coordinates has different properties as compared to that of polar coordinates. We illustrate the advantage of this data representation on the FEM calculations performed during the magnet development along with an approach to measure such fields using rotating coils. The derivation of the field representation in elliptic coordinates from the field data measured on circles necessitates the conversion from circular to elliptic multipoles and the solution of overdetermined systems of equations for the expansions coefficients. (author)

  6. Preliminary neutronics design analysis on accelerator driven subcritical reactor for nuclear waste transmutation

    By taking minor actinides (MA) transmutation performance as evaluation index, preliminary neutronics design analyses were performed on ADS-NWT which is a lead-alloy cooled accelerator driven subcritical reactor for nuclear waste transmutation. In the specific design, liquid lead-bismuth eutectic (LBE) and transuranic metallic dispersion fuel were used as coolant and a fuel of ADS-NWT, respectively. The neutronics calculations and analyses were performed by using CAD-based multi-functional 4D neutronics and radiation simulation system named VisualBUS and the nuclear data library HENDL (Hybrid Evaluated Nuclear Data Library). The preliminary results showed that based on specific deign of MA/Pu volume ratio of 7 : 3, the transmutation rate of MA was approximately 650 kg/a, the high thermal reactor power output was ∼1000 MW when energy self-sustaining was satisfied and relatively deep subcriticality and negative reactivity coefficients made sure of good inherent safety of ADS-NWT. (authors)

  7. Accelerator mass spectrometry for analysis of 10Be. Applications in marine geology

    Using the Accelerator Mass Spectrometry the behaviour of long-lived (half time 1.5 Million years) cosmogenic isotopes 10Be in a marine environment was examined. The geochemical behaviour of 10Be in oceans was examined in a water profile of the eastern Atlantic and on sediment cores from the eastern Atlantic and the Antarctica. The retention period in oceans was calculated from the water profile to be 700-1000 years. The examination of sedimentary cores showed, that the 10Be flow into the sediment in areas of high bioproductivity surpasses the production rate. Comparison of 10Be flow with 230Th flow into the examined sedimentary cores showed a period of retention of 10Be in the ocean of only about 400 years. Changes in the sedimentation rate and changes in the mineralogical composition correlate with paleooceanographic events, the start of the Antarctica icing 14 million years ago, changes in the deep water circulation 6.5 million years ago and the icing over of the northern hemisphere 3 million years ago. The same paleooceanographic events find correlation with the inside structure of a total of 16 manganese nodes and crusts from diverse parts of the ocean which were also dated with 10Be. (orig./DG)

  8. A scientific and statistical analysis of accelerated aging for pharmaceuticals. Part 1: accuracy of fitting methods.

    Waterman, Kenneth C; Swanson, Jon T; Lippold, Blake L

    2014-10-01

    Three competing mathematical fitting models (a point-by-point estimation method, a linear fit method, and an isoconversion method) of chemical stability (related substance growth) when using high temperature data to predict room temperature shelf-life were employed in a detailed comparison. In each case, complex degradant formation behavior was analyzed by both exponential and linear forms of the Arrhenius equation. A hypothetical reaction was used where a drug (A) degrades to a primary degradant (B), which in turn degrades to a secondary degradation product (C). Calculated data with the fitting models were compared with the projected room-temperature shelf-lives of B and C, using one to four time points (in addition to the origin) for each of three accelerated temperatures. Isoconversion methods were found to provide more accurate estimates of shelf-life at ambient conditions. Of the methods for estimating isoconversion, bracketing the specification limit at each condition produced the best estimates and was considerably more accurate than when extrapolation was required. Good estimates of isoconversion produced similar shelf-life estimates fitting either linear or nonlinear forms of the Arrhenius equation, whereas poor isoconversion estimates favored one method or the other depending on which condition was most in error. PMID:25043838

  9. Analysis of primordial nuclides in high purity copper with Accelerator Mass Spectrometry

    The sensitivity of experiments in rare event physics like neutrino or direct dark matter detection crucially depends on the background level. Therefore, all material surrounding the detectors requires low contamination of radionuclides to not create additional background. A significant contribution originates from the primordial actinides thorium and uranium and the progenies of their decay chains. At the Maier Leibnitz Laboratorium in Munich the applicability of ultra-sensitive Accelerator Mass Spectrometry (AMS) for the direct detection of thorium and uranium impurities in a copper matrix was tested for the first time. For this special purpose, Th and U were extracted from the ion source as a copper compound. Two different samples of copper and one sample of a copper alloy were investigated. The lowest concentrations achieved with these first AMS measurements were (1.4±0.6).10-11 g/g for thorium and (7±4).10-14 g/g for uranium which correspond to (56±16) μBq/kg and (0.9±0.5) μBq/kg, respectively. The particular requirements on the AMS technique and the developed measurement procedure are presented, followed by a discussion of the results of the first measurements.

  10. Accelerated solvent extraction for gas chromatographic analysis of nicotine and cotinine in meconium samples.

    Sant'anna, Simone Gomes; Oliveira, Carolina Dizioli Rodrigues; Diniz, Edna Maria de Albuquerque; Yonamine, Mauricio

    2012-01-01

    Adverse effects associated with smoking during pregnancy are well documented. Although self-report surveys on drug consumption during pregnancy have been improved with new interviewing techniques, underreporting is still a concern. Therefore, a series of biological markers and specimens to diagnose fetal exposure to tobacco have been studied. In the present study, an analytical method was developed to detect nicotine and cotinine (the main nicotine metabolite) in meconium samples. Accelerated solvent extraction (ASE) followed by solid-phase extraction (SPE) were used as sample preparation techniques. The analytes were detected by gas-chromatography with nitrogen-phosphorus detection. The limits of detection were 3.0 and 30 ng/g for cotinine and nicotine, respectively. The method showed good linearity (r(2) > 0.98) in the concentration range studied (LOQ-500 ng/g). The intraday precision, given by the RSD of the method, was less than 15% for cotinine and nicotine. The method proved to be fast, practical, and sensitive. Smaller volumes of organic solvents are necessary compared to other chromatographic methods published in the scientific literature. This is the first report in which ASE was used as sample preparation technique in methods to detect xenobiotics in meconium. PMID:22290748

  11. Fusion-neutron-yield, activation measurements at the Z accelerator: Design, analysis, and sensitivity

    Hahn, K. D., E-mail: kdhahn@sandia.gov; Ruiz, C. L.; Fehl, D. L.; Chandler, G. A.; Knapp, P. F.; Smelser, R. M.; Torres, J. A. [Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123 (United States); Cooper, G. W.; Nelson, A. J. [Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Leeper, R. J. [Los Alamos National Laboratories, Plasma Physics Group, Los Alamos, New Mexico 87545 (United States)

    2014-04-15

    We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r{sup 2} decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm{sup 2} and is ∼ 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects.

  12. Time-Stretch Accelerated Processor for Real-time, In-service, Signal Analysis

    Lonappan, Cejo K.; Buckley, Brandon W.; Adam, Jost;

    2014-01-01

    We demonstrate real-time, in-service, digital signal analysis of 10 Gbit/s data using a 1.2 Tbit/s burst-mode digital processor. The processor comprises a time-stretch front-end and a custom data acquisition and real-time signal processing back- end. Experimental demonstration of real-time, in-service......, signal integrity analysis of streaming video packets at 10 Gbit/s is presented....

  13. Development of Three-dimensional Reactor Analysis Code System for Accelerator-Driven System, ADS3D

    To investigate an Accelerator-Driven System (ADS) with sub-criticality control mechanism such as control rods or burnable poison, the ADS3D code has been developed on MARBLE which is a next generation reactor analysis code system developed by JAEA. In the past neutronics calculation for the ADS, JAEA employed RZ calculation models to realize efficient investigations. However, it was very difficult to model sub-criticality control mechanisms in RZ calculation models. The ADS3D code system is able to calculate the transportation of protons and neutrons, the burn-up calculation and the fuel exchange in three-dimensional calculation models. It means this code system can treat ADS concepts with sub-criticality control mechanism and makes it possible to investigate a new concept of ADS. (author)

  14. Error analysis of linear optics measurements via turn-by-turn beam position data in circular accelerators

    Franchi, Andrea

    2016-01-01

    Many advanced techniques have been developed, tested and implemented in the last decades in almost all circular accelerators across the world to measure the linear optics. However, the greater availability and accuracy of beam diagnostics and the ever better correction of linear magnetic lattice imperfections (beta beating at 1% level and coupling at 0.1%) are reaching what seems to be the intrinsic accuracy and precision of different measurement techniques. This paper aims to highlight and quantify, when possible, the limitations of one standard method, the harmonic analysis of turn-by-turn beam position data. To this end, new analytic formulas for the evaluation of lattice parameters modified by focusing errors are derived. The unexpected conclusion of this study is that for the ESRF storage ring (and possibly for any third generation light source operating at ultra-low coupling and with similar diagnostics), measurement and correction of linear optics via orbit beam position data are to be preferred to the...

  15. Mediation Analysis with Survival Outcomes: Accelerated Failure Time Versus Proportional Hazards Models

    Lois A Gelfand

    2016-03-01

    Full Text Available Objective: Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH and fully parametric accelerated failure time (AFT approaches for illustration.Method: We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively under varied data conditions, some including censoring. A simulated data set illustrates the findings.Results: AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome – underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG.Conclusions: When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results.

  16. Experimental small field 6 MV output ratio analysis for various diode detector and accelerator combinations

    Background and purpose: The goal of this work was to measure 6 MV small field, detector specific, output ratios (ORdet) using the IBA stereotactic field diode (SFD) and the PTW T60008, T60012, T60016 and T60017 field diodes on both Varian iX and Elekta Synergy accelerators, to establish estimates for the experimental uncertainty and characterize the measurement precision under various conditions. Materials and methods: Data were acquired at depths of 1.5, 5.0 and 10.0 cm for square field sizes of 3.0, 1.0, 0.9, 0.8, 0.7, 0.6 and 0.5 cm. Three isocentric measurements comprised of five readings were made to calculate an experimental output ratio ORdet with respect to a field size of 5.0 cm. The coefficient of variation (CV) was calculated to characterize the precision associated with each detector-linac combination. Another measurement set was made to investigate the influence of jaw position accuracy. Results: As expected for field sizes smaller than 3.0 cm, the measured ORdet were not consistent across all detectors. The standard percent uncertainty in measured ORdet was found to be nearly consistent across all detector-linac combinations: less than ±0.25% for the 3.0 cm field size, increasing to approximately ±1.25% for the smallest field sizes. As the field size was reduced to 0.5 cm the CV increased to 0.10% and 0.15% on the Varian and Elekta linacs, respectively. Conclusion: Experimental small field ORdet measured with the diode detectors used in this study are reproducible to within ±1.25% (standard uncertainty), with the precision of any one set of measurements can be characterized with a CV between 0.10% and 0.15%.

  17. Analysis of low-level 129I in brine using accelerator mass spectrometry

    An improved solvent extraction procedure for iodine separation from brine samples has been applied at Xi'an Accelerator Mass Spectrometry (AMS) center. Oil in the brine sample has to be removed to avoid appearance of the third phase during solvent extraction and to improve the chemical yield of iodine. The small amount of oil remained in the water phase was first removed by phase separation through settling down sufficiently based on their immiscibility, and then by filtration through a cellulose filter, on which oil was absorbed and removed. After oil removed, extraction recovery of iodine could achieve more than 90 %. The sodium bisulfite as an effective reductant should be added before acidification to avoid loss of iodine by formation of I2 in sample via reaction of iodate and iodide at pH 1-2, and then pH was adjusted to 1-2 to reduce the iodate to iodide followed by oxidation of iodide to I2 and solvent extraction to separate all inorganic iodine. As a pre-nuclear era sample, 129I/127I ratio in brine is normally more than two orders of magnitude lower than that in present surface environmental samples, so prevention of cross-contamination and memory effect in apparatus during processing procedure are very critical for obtaining reliable results, and monitoring the procedure blank is very important for analytical quality of 129I. The 129I/127I isotopic ratio in the brine samples and procedure blank of iodine reagents were measured to be (1.9-2.7) × 10-13 and 2.08 × 10-13, respectively, 3-4 orders of magnitudes lower than that in environmental samples in Xi'an, and the result of procedure blank is in the same level as the previous experiments in past 3 years, indicating contamination is not observed in our method. (author)

  18. Time analysis of the slow neutron field generated by the accelerating tube downhole

    Pulsed neutron logging (PNL) consists in the irradiation of rocks around the well by a pulsed periodic flux of fast neutrons generated by a portable accelerating tube and detection of thermal neutrons during pauses between the neutron pulses. The main aim of the PNL is determining the time distribution of thermal neutrons in the well and formation. At present the PNL response is considered as the sum of two exponentially decaying components, one related to the well and another one - to rock formation: J(t) = A1 exp (-λ1t) + A2 exp (-λ2t) . This is a result of homogenization of a neutron field in the borehole and formation space which is characterized by complicated radial structure and heterogeneous neutron properties. The time base of measurements T is subdivided into a set consisting of I narrow time windows Δt and the PNL response is formed as the series of neutron registration events Ni for each time window Δt with number i =1 to I (time neutron spectrum). Presented is a noise-immune algorithm for decomposition of the experimental time neutron spectrum into two components using the following overdetermined system of equations: Ni - Δt (λ1 + λ2) Σk=i Nk + (Δt)2 λ1λ2 Σk=i Σj=k Nj + [T - (i - 1) Δt][J'(T) - (λ1 + λ2) J(T)]Δt - J(T) Δt 0. Two amplitudes and two time decay constants of these components give an information about the neutron absorption cross-section and porosity of rocks. Presented are physical characteristics of new Russian PNL tools and examples illustrating the processing of PNL in oil wells. (author)

  19. Participation in the definition, conduct, and analysis of particle accelerator experiments for the first Spacelab Mission

    Burch, J. L.

    1994-01-01

    The Space Experiments with Particle Accelerators (SEPAC) is a joint endeavor between NASA and the Institute of Space and Aeronautical Sciences (ISAS) in Japan. Its objectives are to use energetic electron beams to investigate beam-atmosphere interactions and beam-plasma interactions in the earth's upper atmosphere and ionosphere using the shuttle Spacelab. Two flights of SEPAC have occurred to date (Spacelab 1 on STS-9 in Nov.-Dec. 1983 and ATLAS 1 on STS-45 in Mar.-Apr. 1992). The SEPAC instrumentation is available for future missions, and the scientific results of the first two missions justify further investigations; however, at present there are no identifiable future flight opportunities. As specified in the contract, the primary purpose of this report is to review the scientific accomplishments of the ATLAS 1 SEPAC experiments, which have been documented in the published literature, with only a brief review of the earlier Spacelab 1 results. One of the main results of the Spacelab 1 SEPAC experiments was that the ejection of plasma from the magnetoplasmadynamic (MPD) arcjet was effective in maintaining vehicle charge neutralization during electron beam firings, but only for a brief period of 10 ms or so. Therefore, a xenon plasma contactor, which can provide continuous vehicle charge neutralization, was developed for the ATLAS 1 SEPAC experiments. Because of the successful operation of the plasma contactor on ATLAS 1, it was possible to perform experiments on beam-plasma interactions and beam-atmosphere interactions at the highest beam power levels of SEPAC. In addition, the ability of the plasma contactor to eject neutral xenon led to a successful experiment on the critical ionization velocity (CIV) phenomena on ATLAS 1.

  20. Laser accelerator

    Vigil, Ricardo

    2014-01-01

    Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significan...

  1. NRG1, ERBB4 and AKT1 Epistasis Increases Schizophrenia Risk and is Biologically Validated via Functional Neuroimaging in Healthy Controls

    Nicodemus, Kristin K.; Law, Amanda J.; Radulescu, Eugenia; Luna, Augustin; Kolachana, Bhaskar; Vakkalanka, Radhakrishna; Rujescu, Dan; Giegling, Ina; Straub, Richard E.; McGee, Kate; Gold, Bert; Dean, Michael; Muglia, Pierandrea; Callicott, Joseph H.; Tan, Hao-Yang; Weinberger, Daniel R.

    2014-01-01

    CONTEXT NRG1 is a schizophrenia candidate gene and plays an important role in brain development and neural function. Schizophrenia is a complex disorder, with etiology likely due to epistasis. OBJECTIVE We sought to examine epistasis between NRG1 and selected NMDA-glutamate pathway partners implicated in its effects, including ERBB4, AKT1, DLG4, NOS1, NOS1AP. DESIGN Schizophrenia case-control sample analyzed using machine learning algorithms and logistic regression with follow-up using neuroimaging on an independent sample of healthy controls. PARTICIPANTS A referred sample of schizophrenic patients (N = 296) meeting DSM-IV criteria for schizophrenia-spectrum disorder and a volunteer sample of controls for case-control comparison (N = 365) and a separate volunteer sample of controls for neuroimaging (N = 172). MAIN OUTCOME MEASURES Epistatic association between SNPs and case-control status; epistatic association between SNPs and the BOLD physiological response during working memory measured by functional magnetic resonance imaging (fMRI). RESULTS We observed interaction between NRG1 5’ and 3’ SNPs: rs4560751-rs3802160 (likelihood ratio test (LRT) p=0.00020) and schizophrenia which was validated using fMRI of working memory in healthy controls; carriers of risk-associated genotypes showed inefficient processing in dorsolateral prefrontal cortex (DLPFC) (p=0.015, FWE corrected). We observed epistasis between NRG1 (rs10503929; Val1066Ile) and its receptor ERBB4 (rs1026882; LRT p=0.035); a three-way interaction with these two SNPs and AKT1 (rs2494734) was also observed (OR=27.13; 95% confidence interval 3.30, 223.03; LRT p=0.042). These same two- and three-way interactions were further biologically validated via fMRI: healthy individuals carrying risk genotypes for NRG1 and ERBB4, or these two together with AKT1, were disproportionately less efficient in DLPFC processing. Lower-level interactions were not observed between NRG1/ERBB4-AKT1 in association or

  2. Split-course accelerated therapy in head and neck cancer: an analysis of toxicity

    Purpose: To retrospectively assess a protocol of split-course accelerated radiation therapy (SCAT) for selected head and neck cancers. Methods and Materials: SCAT consisted of 1.8 Gy per fraction administered twice daily with a minimum gap between fractions of 6 h. The treatment protocol prescribed an initial 16 fractions followed by a planned 5 to 12 day break, and then a further 20 to 22 fractions for a total dose ranging from 64.8 to 72 Gy delivered in 5 to 6 weeks. Results: Twenty-eight patients received SCAT for histologically confirmed head and neck cancer between January 1987 and August 1991. All patients were followed up until December 1, 1993. The mean potential follow-up time was 4.2 years (range: 2.9-6.2 years). All patients completed the treatment protocol. Thirteen tumors were laryngeal in origin, eight hypopharyngeal, four paranasal sinus, and three oropharyngeal. There were no Stage I, three Stage II, nine Stage III, and 12 Stage IV tumors. Four tumors were not staged (two paranasal sinus cancers and two surgical recurrences). Early and late toxicities were moderate to severe. Confluent mucositis was experienced by 27 of the 28 patients (96%). One patient required a prolonged midtreatment break of 24 days. Nine patients (32%) required narcotic analgesia for pain relief. Eleven patients (39%) required hospitalization for nasogastric feeding or pain control. The median length of hospital stay was 14 days (range 7-98 days). The actuarial rate of severe late toxicity at 3 years was 47% (standard error (SE) = 13%). A complete tumor response was achieved in 86% of patients. The actuarial local control rate at 3 years was 43% (SE = 11%) and the actuarial survival rate at 3 years was 25% (SE = 8%). Conclusion: Given the encouraging complete response rate and local control for such advanced tumors, SCAT for locoregionally advanced tumors merits further investigation. However, because of the significant late toxicity observed, the total dose, interfraction

  3. Retrospective analysis of linear accelerator output constancy checks using process control techniques.

    Sanghangthum, Taweap; Suriyapee, Sivalee; Srisatit, Somyot; Pawlicki, Todd

    2013-01-01

    Shewhart control charts have previously been suggested as a process control tool for use in routine linear accelerator (linac) output verifications. However, a comprehensive approach to process control has not been investigated for linac output verifications. The purpose of this work is to investigate a comprehensive process control approach to linac output constancy quality assurance (QA). The RBA-3 dose constancy check was used to verify outputs of photon beams and electron beams delivered by a Varian Clinac 21EX linac. The data were collected during 2009 to 2010. Shewhart-type control charts, exponentially weighted moving average (EWMA) charts, and capability indices were applied to these processes. The Shewhart-type individuals chart (X-chart) was used and the number of data points used to calculate the control limits was varied. The parameters tested for the EWMA charts (smoothing parameter (λ) and the control limit width (L)) were λ = 0.05, L = 2.492; λ = 0.10, L = 2.703; and λ = 0.20, L = 2.860, as well as the number of points used to estimate the initial process mean and variation. Lastly, the number of in-control data points used to determine process capability (C(p)) and acceptability (C(pk)) were investigated, comparing the first in-control run to the longest in-control run of the process data. C(p) and C(pk) values greater than 1.0 were considered acceptable. The 95% confidence intervals were reported. The X-charts detected systematic errors (e.g., device setup errors). In-control run lengths on the X-charts varied from 5 to 30 output measurements (about one to seven months). EWMA charts showed in-control runs ranging from 9 to 33 output measurements (about two to eight months). The C(p) and C(pk) ratios are higher than 1.0 for all energies, except 12 and 20 MeV. However, 10 MV and 6, 9, and 16 MeV were in question when considering the 95% confidence limits. The X-chart should be calculated using 8-12 data points. For EWMA chart, using 4 data points

  4. Accelerated partial-breast irradiation with interstitial implants. Analysis of factors affecting cosmetic outcome

    Ott, Oliver J.; Lotter, Michael; Fietkau, Rainer; Strnad, Vratislav [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

    2009-03-15

    Purpose: To analyze patient-, disease-, and treatment-related factors for their impact on cosmetic outcome (CO) after interstitial multicatheter accelerated partial-breast irradiation (APBI). Patients and Methods: Between April 2001 and January 2005, 171 patients with early breast cancer were recruited in Erlangen for this subanalysis of the German-Austrian APBI phase II-trial. 58% (99/171) of the patients received pulsed-dose-rate (PDR), and 42% (72/171) high-dose-rate (HDR) brachytherapy. Prescribed reference dose for HDR brachytherapy was 32 Gy in eight fractions of 4 Gy, twice daily. Prescribed reference dose in PDR brachytherapy was 49.8 Gy in 83 consecutive fractions of 0.6 Gy each hour. Total treatment time was 3-4 days. Endpoint of this evaluation was the CO, graded as excellent, good, fair, or poor. Patients were divided in two groups with an excellent (n = 102) or nonexcellent (n = 69) cosmetic result. Various factors were analyzed for their impact on excellent CO. Results: The median follow-up time was 52 months (range: 21-91 months). Cosmetic results were rated as excellent in 59.6% (102/171), good in 29.8% (51/171), fair in 9.9% (17/171), and poor in 0.6% (1/171). The initial cosmetic status was significantly worse for the nonexcellent CO group (p = 0.000). The percentage of patients who received PDR brachytherapy APBI was higher in the nonexcellent CO group (68.1% vs. 51%; p = 0.026). Acute toxicity was higher in the nonexcellent CO group (24.6% vs. 12.7%; p = 0.045). Furthermore, the presence of any late toxicity was found to be associated with a worse cosmetic result (65.2% vs. 18.6%; p = 0.000). In detail, the appearance of skin hyperpigmentation (p = 0.034), breast tissue fibrosis (p = 0.000), and telangiectasia (p = 0.000) had a negative impact on CO. Conclusion: The initial, surgery-associated cosmetic status, brachytherapy modality, and the presence of acute and late toxicities were found to have an impact on overall CO. Our data have proven

  5. Accelerated partial-breast irradiation with interstitial implants. Analysis of factors affecting cosmetic outcome

    Purpose: To analyze patient-, disease-, and treatment-related factors for their impact on cosmetic outcome (CO) after interstitial multicatheter accelerated partial-breast irradiation (APBI). Patients and Methods: Between April 2001 and January 2005, 171 patients with early breast cancer were recruited in Erlangen for this subanalysis of the German-Austrian APBI phase II-trial. 58% (99/171) of the patients received pulsed-dose-rate (PDR), and 42% (72/171) high-dose-rate (HDR) brachytherapy. Prescribed reference dose for HDR brachytherapy was 32 Gy in eight fractions of 4 Gy, twice daily. Prescribed reference dose in PDR brachytherapy was 49.8 Gy in 83 consecutive fractions of 0.6 Gy each hour. Total treatment time was 3-4 days. Endpoint of this evaluation was the CO, graded as excellent, good, fair, or poor. Patients were divided in two groups with an excellent (n = 102) or nonexcellent (n = 69) cosmetic result. Various factors were analyzed for their impact on excellent CO. Results: The median follow-up time was 52 months (range: 21-91 months). Cosmetic results were rated as excellent in 59.6% (102/171), good in 29.8% (51/171), fair in 9.9% (17/171), and poor in 0.6% (1/171). The initial cosmetic status was significantly worse for the nonexcellent CO group (p = 0.000). The percentage of patients who received PDR brachytherapy APBI was higher in the nonexcellent CO group (68.1% vs. 51%; p = 0.026). Acute toxicity was higher in the nonexcellent CO group (24.6% vs. 12.7%; p = 0.045). Furthermore, the presence of any late toxicity was found to be associated with a worse cosmetic result (65.2% vs. 18.6%; p = 0.000). In detail, the appearance of skin hyperpigmentation (p 0.034), breast tissue fibrosis (p = 0.000), and telangiectasia (p = 0.000) had a negative impact on CO. Conclusion: The initial, surgery-associated cosmetic status, brachytherapy modality, and the presence of acute and late toxicities were found to have an impact on overall CO. Our data have proven that

  6. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  7. Analysis and design of high power solid-state module at 350 MHz for RF accelerator

    Solid-sate power amplifier module using a high power LDMOS transistor has been analyzed and designed. Its performance matrices like power gain, power output, efficiency, and input and output match have been studied. Parametric analysis has been carried with respect to variation of matching elements. The design has been optimised for a power gain of >18 dB and a power output of 800 watts. The design is implemented on FR-4 substrate. Experimental results have been presented. (author)

  8. Industrial applications of accelerator-based infrared sources: Analysis using infrared microspectroscopy

    Bantignies, J.L.; Fuchs, G.; Wilhelm, C. [Elf Atochem, Pierre-Benite (France); Carr, G.L. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source; Dumas, P. [Centre Univ. Paris-Sud, Orsay (France)

    1997-09-01

    Infrared Microspectroscopy, using a globar source, is now widely employed in the industrial environment, for the analysis of various materials. Since synchrotron radiation is a much brighter source, an enhancement of an order of magnitude in lateral resolution can be achieved. Thus, the combination of IR microspectroscopy and synchrotron radiation provides a powerful tool enabling sample regions only few microns size to be studied. This opens up the potential for analyzing small particles. Some examples for hair, bitumen and polymer are presented.

  9. Throughput Analysis for a High-Performance FPGA-Accelerated Real-Time Search Application

    Wim Vanderbauwhede

    2012-01-01

    Full Text Available We propose an FPGA design for the relevancy computation part of a high-throughput real-time search application. The application matches terms in a stream of documents against a static profile, held in off-chip memory. We present a mathematical analysis of the throughput of the application and apply it to the problem of scaling the Bloom filter used to discard nonmatches.

  10. Coupled mechanical-electrostatic FE-BE analysis with FMM acceleration

    Sabariego, Ruth,; Gyselinck, J.; Dular, P.; De Coster, Jeroen; Henrotte, François; HAMEYER, Kay

    2004-01-01

    This paper deals with the coupled mechanical-electrostatic analysis of a shunt capacitive MEMS switch. The mechanical and electrostatic parts of the prob- lem are modelled by the FE method and BE method, respectively. The fast multipole method is applied to reduce the storage requirements and the computational cost of the BE electrostatic model. An adaptive truncation expansion of the 3D Laplace Green function is employed. The strong interaction between the mechanical and electrostatic system...

  11. [Analysis of gene loci and epistasis for drought tolerance in seedling stage of rice (Oryza sativa L.)].

    Teng, Sheng; Qian, Qian; Zeng, Da-Li; Kunihiro, Yasufumi; Fujimoto, Kan; Huang, Da-Nian; Zhu, Li-Huang

    2002-01-01

    Drought tolerance of rice is important because a considerable proportion of the world rice area is not irrigated and is prone to water deficit. In this study, an indica variety, Zhai Ye Qing 8 (ZYQ8), and a japonica variety, Jing Xi 17 (JX17), and their double haploid (DH) population were used for genetic study of drought tolerance. Water supply was stopped in seedling period for 15 days and then drought tolerance of the DH population and their parents were investigated. Mapping quantitative trait loci (QTLs) was undertaken base on the constructed molecular linkage map of this population. Two QTLs (qDR-5 and qDR-12) for drought tolerance were identified, they were in the region of GA41-GA257 on chromosome 5 and RG457-Y12817R on chromosome 12, respectively. The tolerance alleles of both QTLs were from the indica parent, ZYQ8. In the meantime two genes for drought tolerance near GA257 and Y12817R were detected too by using Epistat software, that is in accordance with the result by using Mapmaker/QTL. In addition, three loci (RG541, G318 and G192 on chromosome 1, 4 and 8, respectively) were found interacting with GA257 by Epistat software, while one locus (CT234 on chromosome 3) found interacting with Y12817R were also detected by Epistat software. PMID:12182078

  12. An efficient transcriptome analysis pipeline to accelerate venom peptide discovery and characterisation.

    Prashanth, Jutty Rajan; Lewis, Richard J

    2015-12-01

    Transcriptome sequencing is now widely adopted as an efficient means to study the chemical diversity of venoms. To improve the efficiency of analysis of these large datasets, we have optimised an analysis pipeline for cone snail venom gland transcriptomes. The pipeline combines ConoSorter with sequence architecture-based elimination and similarity searching using BLAST to improve the accuracy of sequence identification and classification, while reducing requirements for manual intervention. As a proof-of-concept, we used this approach reanalysed three previously published cone snail transcriptomes from diverse dietary groups. Our pipeline method generated similar results to the published studies with significantly less manual intervention. We additionally found undiscovered sequences in the piscovorous Conus geographus and vermivorous Conus miles and identified sequences in incorrect superfamilies in the molluscivorus Conus marmoreus and C. geographus transcriptomes. Our results indicate that this method can improve toxin detection without extending analysis time. While this method was evaluated on cone snail transcriptomes it can be easily optimised to retrieve toxins from other venomous animals. PMID:26376071

  13. Multidimensional analysis of suction feeding performance in fishes: fluid speed, acceleration, strike accuracy and the ingested volume of water.

    Higham, Timothy E; Day, Steven W; Wainwright, Peter C

    2006-07-01

    Suction feeding fish draw prey into the mouth using a flow field that they generate external to the head. In this paper we present a multidimensional perspective on suction feeding performance that we illustrate in a comparative analysis of suction feeding ability in two members of Centrarchidae, the largemouth bass (Micropterus salmoides) and bluegill sunfish (Lepomis macrochirus). We present the first direct measurements of maximum fluid speed capacity, and we use this to calculate local fluid acceleration and volumetric flow rate. We also calculated the ingested volume and a novel metric of strike accuracy. In addition, we quantified for each species the effects of gape magnitude, time to peak gape, and swimming speed on features of the ingested volume of water. Digital particle image velocimetry (DPIV) and high-speed video were used to measure the flow in front of the mouths of three fish from each species in conjunction with a vertical laser sheet positioned on the mid-sagittal plane of the fish. From this we quantified the maximum fluid speed (in the earthbound and fish's frame of reference), acceleration and ingested volume. Our method for determining strike accuracy involved quantifying the location of the prey relative to the center of the parcel of ingested water. Bluegill sunfish generated higher fluid speeds in the earthbound frame of reference, accelerated the fluid faster, and were more accurate than largemouth bass. However, largemouth bass ingested a larger volume of water and generated a higher volumetric flow rate than bluegill sunfish. In addition, because largemouth bass swam faster during prey capture, they generated higher fluid speeds in the fish's frame of reference. Thus, while bluegill can exert higher drag forces on stationary prey items, largemouth bass more quickly close the distance between themselves and prey. The ingested volume and volumetric flow rate significantly increased as gape increased for both species, while time to peak

  14. Induction accelerators

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  15. Imaging oxytocin x dopamine interactions: An epistasis effect of CD38 and COMT gene variants influences the impact of oxytocin on amygdala activation to social stimuli

    PeterKirsch

    2013-04-01

    Brain imaging results revealed no significant effects for VTA or ventral striatum. Regarding the fusiform gyrus, we could not find any effects apart from those already described in (Sauer et al., 2012. Analyses of amygdala activation resulted in no gene main effect, no gene x substance interaction but a significant gene x gene x substance interaction. While under PLA the effect of CD38 on bilateral amygdala activation to social stimuli was modulated by the COMT genotype, no such epistasis effect was found under OT. Our results provide evidence for an OTxDA interaction during responses to social stimuli. We postulate that the effect of central OT secretion on amygdala response is modulated by the availability of DA. Therefore, for an understanding of the effect of social hormones on social behavior, interactions of OT with other transmitter systems have to be taken into account.

  16. Angular velocities, angular accelerations, and coriolis accelerations

    Graybiel, A.

    1975-01-01

    Weightlessness, rotating environment, and mathematical analysis of Coriolis acceleration is described for man's biological effective force environments. Effects on the vestibular system are summarized, including the end organs, functional neurology, and input-output relations. Ground-based studies in preparation for space missions are examined, including functional tests, provocative tests, adaptive capacity tests, simulation studies, and antimotion sickness.

  17. BALSA: integrated secondary analysis for whole-genome and whole-exome sequencing, accelerated by GPU

    Ruibang Luo

    2014-06-01

    Full Text Available This paper reports an integrated solution, called BALSA, for the secondary analysis of next generation sequencing data; it exploits the computational power of GPU and an intricate memory management to give a fast and accurate analysis. From raw reads to variants (including SNPs and Indels, BALSA, using just a single computing node with a commodity GPU board, takes 5.5 h to process 50-fold whole genome sequencing (∼750 million 100 bp paired-end reads, or just 25 min for 210-fold whole exome sequencing. BALSA’s speed is rooted at its parallel algorithms to effectively exploit a GPU to speed up processes like alignment, realignment and statistical testing. BALSA incorporates a 16-genotype model to support the calling of SNPs and Indels and achieves competitive variant calling accuracy and sensitivity when compared to the ensemble of six popular variant callers. BALSA also supports efficient identification of somatic SNVs and CNVs; experiments showed that BALSA recovers all the previously validated somatic SNVs and CNVs, and it is more sensitive for somatic Indel detection. BALSA outputs variants in VCF format. A pileup-like SNAPSHOT format, while maintaining the same fidelity as BAM in variant calling, enables efficient storage and indexing, and facilitates the App development of downstream analyses. BALSA is available at: http://sourceforge.net/p/balsa.

  18. SU-E-T-627: Failure Modes and Effect Analysis for Monthly Quality Assurance of Linear Accelerator

    Purpose: To develop and implement a failure mode and effect analysis (FMEA) on routine monthly Quality Assurance (QA) tests (physical tests part) of linear accelerator. Methods: A systematic failure mode and effect analysis method was performed for monthly QA procedures. A detailed process tree of monthly QA was created and potential failure modes were defined. Each failure mode may have many influencing factors. For each factor, a risk probability number (RPN) was calculated from the product of probability of occurrence (O), the severity of effect (S), and detectability of the failure (D). The RPN scores are in a range of 1 to 1000, with higher scores indicating stronger correlation to a given influencing factor of a failure mode. Five medical physicists in our institution were responsible to discuss and to define the O, S, D values. Results: 15 possible failure modes were identified and all RPN scores of all influencing factors of these 15 failue modes were from 8 to 150, and the checklist of FMEA in monthly QA was drawn. The system showed consistent and accurate response to erroneous conditions. Conclusion: The influencing factors of RPN greater than 50 were considered as highly-correlated factors of a certain out-oftolerance monthly QA test. FMEA is a fast and flexible tool to develop an implement a quality management (QM) frame work of monthly QA, which improved the QA efficiency of our QA team. The FMEA work may incorporate more quantification and monitoring fuctions in future

  19. Accelerated partial irradiation for breast cancer: Systematic review and meta-analysis of 8653 women in eight randomized trials

    Background and purpose: Accelerated partial breast irradiation (APBI) is the strategy that allows adjuvant treatment delivery in a shorter period of time in smaller volumes. This study was undertaken to assess the effectiveness and outcomes of APBI in breast cancer compared with whole-breast irradiation (WBI). Material and methods: Systematic review and meta-analysis of randomized controlled trials of WBI versus APBI. Two authors independently selected and assessed the studies regarding eligibility criteria. Results: Eight studies were selected. A total of 8653 patients were randomly assigned for WBI versus APBI. Six studies reported local recurrence outcomes. Two studies were matched in 5 years and only one study for different time of follow-up. Meta-analysis of two trials assessing 1407 participants showed significant difference in the WBI versus APBI group regarding the 5-year local recurrence rate (HR = 4.54, 95% CI: 1.78–11.61, p = 0.002). Significant difference in favor of WBI for different follow-up times was also found. No differences in nodal recurrence, systemic recurrence, overall survival and mortality rates were observed. Conclusions: APBI is associated with higher local recurrence compared to WBI without compromising other clinical outcomes

  20. In silico analysis of gene expression profiles in the olfactory mucosae of aging senescence-accelerated mice.

    Getchell, Thomas V; Peng, Xuejun; Green, C Paul; Stromberg, Arnold J; Chen, Kuey-Chu; Mattson, Mark P; Getchell, Marilyn L

    2004-08-01

    We utilized high-density Affymetrix oligonucleotide arrays to investigate gene expression in the olfactory mucosae of near age-matched aging senescence-accelerated mice (SAM). The senescence-prone (SAMP) strain has a significantly shorter lifespan than does the senescence-resistant (SAMR) strain. To analyze our data, we applied biostatistical methods that included a correlation analysis to evaluate sources of methodologic and biological variability; a two-sided t-test to identify a subpopulation of Present genes with a biologically relevant P-value SAMRs (SAMR-Os, 12.5 months). Volcano plots related the variability in the mean hybridization signals as determined by the two-sided t-test to fold changes in gene expression. The genes were categorized into the six functional groups used previously in gene profiling experiments to identify candidate genes that may be relevant for senescence at the genomic and cellular levels in the aging mouse brain (Lee et al. [2000] Nat Genet 25:294-297) and in the olfactory mucosa (Getchell et al. [2003] Ageing Res Rev 2:211-243), which serves several functions that include chemosensory detection, immune barrier function, xenobiotic metabolism, and neurogenesis. Because SAMR-Os and SAMP-Os have substantially different median lifespans, we related the rate constant alpha in the Gompertz equation on aging to intrinsic as opposed to environmental mechanisms of senescence based on our analysis of genes modulated during aging in the olfactory mucosa. PMID:15248299

  1. Confronting Twin Paradox Acceleration

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  2. Applicatons of accelerators

    The great diversity of possible applications of accelerators has been demonstrated in the past few years. Apart from the more familiar uses of accelerators for fundamental particle, nuclear, and solid state physics research, the applications range from microscopic trace analysis through cancer therapy to nuclear power and large volume radiation processing. Accelerators are also being used for applied research in proton radiography, radiation damage studies, laser excitation and materials analysis. The required beam properties vary from an extremely low emittance with very low beam current to megawatt beam power with a low level of beam spill. At the Chalk River Nuclear Laboratories developments are underway on applications of accelerators to nuclear fuel breeding and to cancer therapy. (author)

  3. Analysis of the orbit errors in the CERN accelerators using model simulation

    This paper will describe the use of the PLUS program to find various types of machine and beam errors such as, quadrupole strength, dipole strength, beam position monitors (BPMs), energy profile, and beam launch. We refer to this procedure as the GOLD (Generic Orbit and Lattice Debugger) Method which is a general technique that can be applied to analysis of errors in storage rings and transport lines. One useful feature of the Method is that it analyzes segments of a machine at a time so that the application and efficiency is independent of the size of the overall machine. Because the techniques are the same for all the types of problems it solves, the user need learn only how to find one type of error in order to use the program

  4. Analysis of asphalt pavement structural response from an accelerated loading test

    2007-01-01

    This study was to compare theoretical calculation and practical measurement structure response of asphalt pavement. Analysis of the pavement layer moduli was determined from a Back-calculation of Falling Weight Deflectometer (FWD) data and the measured stiffness moduli of asphalt layer cores. The pavement response was calculated using a theoretical model and the measured strain response at the bottom different layers.Layered elastic theory was used to back-calculate the layer moduli and three different theory models were used to forward calculate the strain and deflection. The models were: Layered Elastic Theory (LET), the Method of Equivalent Thicknesses (MET) with linear elastic and the Finite Element Method (FEM) where asphalt layer may be viscoelastic. The results showed that the calculation structure response from FEM was consistent with measured results.

  5. Speciation analysis of 129I in seawater by carrier-free AgI-AgCl coprecipitation and accelerator mass spectrometric measurement

    Luo, Maoyi; Hou, Xiaolin; He, Chaohui;

    2013-01-01

    A rapid and simple method was developed for speciation analysis of 129I in seawater by selective coprecipitation of carrier-free iodide and accelerator mass spectrometry (AMS) measurement of 129I. Iodide was separated from seawater and other species of iodine by coprecipitation of AgI with Ag2SO3...

  6. Accelerated fluctuation analysis by graphic cards and complex pattern formation in financial markets

    The compute unified device architecture is an almost conventional programming approach for managing computations on a graphics processing unit (GPU) as a data-parallel computing device. With a maximum number of 240 cores in combination with a high memory bandwidth, a recent GPU offers resources for computational physics. We apply this technology to methods of fluctuation analysis, which includes determination of the scaling behavior of a stochastic process and the equilibrium autocorrelation function. Additionally, the recently introduced pattern formation conformity (Preis T et al 2008 Europhys. Lett. 82 68005), which quantifies pattern-based complex short-time correlations of a time series, is calculated on a GPU and analyzed in detail. Results are obtained up to 84 times faster than on a current central processing unit core. When we apply this method to high-frequency time series of the German BUND future, we find significant pattern-based correlations on short time scales. Furthermore, an anti-persistent behavior can be found on short time scales. Additionally, we compare the recent GPU generation, which provides a theoretical peak performance of up to roughly 1012 floating point operations per second with the previous one.

  7. Modelling, analysis, and acceleration of a printed circuit board fabrication process

    K S Aithal; Y Narahari; E Manjunath

    2001-10-01

    Product design and fabrication constitute an important business activity in any manufacturing firm. Designing an optimized product fabrication process is an important problem in itself and is of significant practical and research interest. In this paper, we look into a printed circuit board (PCB) fabrication process and investigate ways in which the fabrication cycle time can be minimized. Single class queueing networks constitute the modelling framework for our study. The model developed in this paper and the analysis experiments carried out are based on extensive data collected on a PCB fabrication company located in Bangalore, India. This is a representative PCB fabrication company involving multiple, concurrent fabrication works with contention for human/technical resources. Our model seeks to capture faithfully the flow of the fabrication process in this company and such other organisations, using queueing networks. Using the model developed, we explore how the cycle times can be reduced using input control, load balancing, and variability reduction. The model presented is sufficiently generic and conceptual; its scope extends beyond that of a PCB fabrication organization.

  8. High-throughput GC-ECD analysis of PCBs in food by accelerated solvent extraction. Method validation

    Piersanti, A.; Fioroni, L.; Paoloni, A.; Tavoloni, T.; Pecorelli, I.; Galarini, R. [Istituto Zooprofilattico Sperimentale dell' Umbria e delle Marche, Perugia (Italy)

    2004-09-15

    In the year 2000 the determination of the PCBs in food commodities was introduced in the Italian national residue control plan in which government labs were requested to estimate the total PCB content as sum of seven more representative congeners. Later on, in 2001, it was decided that a more appropriate estimation of the total PCBs was possible through analysis of eighteen rather than seven congeners. Therefore the need for simple and validated analytical methods arose. In this work a method for the analysis of the PCBs 18-congeners (T{sub 3}CB-28, T{sub 4}CB-52, P{sub 5}CB-95, P{sub 5}CB-99, P{sub 5}CB-101, P{sub 5}CB-105, P{sub 5}CB-110, P{sub 5}CB-118, H{sub 6}CB-138, H{sub 6}CB-146, H{sub 6}CB-149, H{sub 6}CB-151, H{sub 6}CB-153, H{sub 7}CB-170, H{sub 7}CB-177, H{sub 7}CB-180, H{sub 7}CB-183, H{sub 7}CB-187) is reported. This has been set up taking in account the advantages of the automated and high efficient Accelerated Solvent Extraction together with good purification achieved by a one-step acidic-extrelut/silica chromatography. The instrumental analysis is performed by capillary-GC equipped with an ECD detector. An in-house validation study has been made on swine muscle assessing the method performances in terms of limit of detection, response linearity range, trueness and precision.

  9. The potential of accelerating early detection of autism through content analysis of YouTube videos.

    Vincent A Fusaro

    Full Text Available Autism is on the rise, with 1 in 88 children receiving a diagnosis in the United States, yet the process for diagnosis remains cumbersome and time consuming. Research has shown that home videos of children can help increase the accuracy of diagnosis. However the use of videos in the diagnostic process is uncommon. In the present study, we assessed the feasibility of applying a gold-standard diagnostic instrument to brief and unstructured home videos and tested whether video analysis can enable more rapid detection of the core features of autism outside of clinical environments. We collected 100 public videos from YouTube of children ages 1-15 with either a self-reported diagnosis of an ASD (N = 45 or not (N = 55. Four non-clinical raters independently scored all videos using one of the most widely adopted tools for behavioral diagnosis of autism, the Autism Diagnostic Observation Schedule-Generic (ADOS. The classification accuracy was 96.8%, with 94.1% sensitivity and 100% specificity, the inter-rater correlation for the behavioral domains on the ADOS was 0.88, and the diagnoses matched a trained clinician in all but 3 of 22 randomly selected video cases. Despite the diversity of videos and non-clinical raters, our results indicate that it is possible to achieve high classification accuracy, sensitivity, and specificity as well as clinically acceptable inter-rater reliability with nonclinical personnel. Our results also demonstrate the potential for video-based detection of autism in short, unstructured home videos and further suggests that at least a percentage of the effort associated with detection and monitoring of autism may be mobilized and moved outside of traditional clinical environments.

  10. Analysis and development of a lamp using light emitting diodes, in order to accelerate the process of photosynthesis in plants

    A prototype lamp has been created in order to promote accelerated development of the plant under artificial lighting. The lamp has been constructed using light-emitting diodes; its efficiency has been proven by comparing the performance with other existing commercial lamps. The study has considered mainly the emission spectrum analysis, power consumption, longevity and experimental development of each lamp. Tests are performed with different types of plantations in short periods, between one and two weeks of exposure to artificial lighting, compared to the development of a plantation illuminated with natural sunlight. The importance that meets the illumination and variation of the emitted wavelengths to a plant have been shown in the development and morphological change of the plant. None of the lamps used were able to approach the natural development that the plant should have, and although height growth has exceeded the reference plant has not obtained a proper plant growth. Researches and tests have been a basis for further studies on the changes experienced by plants exposed to artificial lighting. (author)

  11. Analysis of coenzyme Q10 in bee pollen using online cleanup by accelerated solvent extraction and high performance liquid chromatography.

    Xue, Xiaofeng; Zhao, Jing; Chen, Lanzhen; Zhou, Jinhui; Yue, Bing; Li, Yi; Wu, Liming; Liu, Fengmao

    2012-07-15

    A method for the determination of coenzyme Q10 in bee pollen has been developed applying an online cleanup of accelerated solvent extraction and using environmentally acceptable organic solvents. The extracted samples were analysed by high performance liquid chromatography with diode array detection. The optimised method employed 10 mL extraction cells, 1g sample size, absolute ethanol as extraction solvent, 80°C of extraction temperature, one extraction cycle, 5 min of static time, Cleanert Alumina-N as sorbent and 60% flush volume. The method was validated by means of an evaluation of the matrix effects, linearity, limit of detection (LOD) and quantification (LOQ), trueness, precision and stability. The assay was linear over the concentration range of 0.25-200mg/L and the LOD and LOQ were 0.16 and 0.35 mg/kg, respectively. The recoveries were above 90%. The inter- and intra-day precision was below 6.3%. The method has been successfully applied to the analysis of bee pollen samples. For 20 bee pollen products, the coenzyme Q10 content varied from not detectable to 192.8 mg/kg. PMID:25683435

  12. Accelerated Aging of BKC 44306-10 Rigid Polyurethane Foam: FT-IR Spectroscopy, Dimensional Analysis, and Micro Computed Tomography

    Gilbertson, Robert D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patterson, Brian M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Smith, Zachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-02

    An accelerated aging study of BKC 44306-10 rigid polyurethane foam was carried out. Foam samples were aged in a nitrogen atmosphere at three different temperatures: 50 °C, 65 °C, and 80 °C. Foam samples were periodically removed from the aging canisters at 1, 3, 6, 9, 12, and 15 month intervals when FT-IR spectroscopy, dimensional analysis, and mechanical testing experiments were performed. Micro Computed Tomography imaging was also employed to study the morphology of the foams. Over the course of the aging study the foams the decreased in size by a magnitude of 0.001 inches per inch of foam. Micro CT showed the heterogeneous nature of the foam structure likely resulting from flow effects during the molding process. The effect of aging on the compression and tensile strength of the foam was minor and no cause for concern. FT-IR spectroscopy was used to follow the foam chemistry. However, it was difficult to draw definitive conclusions about the changes in chemical nature of the materials due to large variability throughout the samples.

  13. The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

    Shang, Jing; Li, Juexin; Xu, Bing; Li, Yuxiong

    2011-10-01

    Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the 60Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

  14. The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

    Shang Jing [National Synchrotron Radiation Lab, University of Science and Technology of China (China); Li Juexin, E-mail: juexin@ustc.edu.cn [National Synchrotron Radiation Lab, University of Science and Technology of China (China); Xu Bing; Li Yuxiong [National Synchrotron Radiation Lab, University of Science and Technology of China (China)

    2011-10-01

    Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the {sup 60}Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

  15. The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

    Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the 60Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

  16. Tandem accelerators

    After the installation of Ti-acceleration tubes and substantial modifications and additions to the EN tandem accelerator the performance of the machine has stabilized. The voltage behaviour of the tubes obviously improves as conditioning times necessary to run up to 6 MV decrease. A gridded lens has been added at the entrance of the first acceleration tube, and a second foil stripper is now installed in the short dead section between the high-energy tubes. The MP tandem also has been running stably during most of the year. However, beam instabilities originating from the last tube section and wear problems at the low-energy set of pelletron-chains caused some loss of beam time. During the fall, one set of pelletron charging chains has to be replaced after 49,000 hours of operation. In the course of the year, the MP and the EN tandem accelerators finished their 100,000th and 150,000th hours of operations, respectively. Preparations for the installation of the 3 MV negative heavy ion injector for the MP are progressing steadily. External beam transport, terminal ion optics, and data acquisition and control systems are to a major extent completed; the integration of the terminal power supplies has started. After the final assembly of the accelerator column structure, first voltage runs can be performed. (orig.)

  17. Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

    Bo Sun; Tianyuan Ye; Qiang Feng; Jinghua Yao; Mumeng Wei

    2015-01-01

    This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH)3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine c...

  18. Photon activation analysis of the scraper in a 200-MeV electron accelerator using gamma-spectrometry depth profiling

    Lijuan, He; Guobing, Yu; Guangyi, Ren; Zongjin, Duan

    2014-01-01

    For a high energy electron facility, the estimates of induced radioactivity in materials are of major importance to keep exposure to personnel and to the environment as low as reasonably achievable. In addition, an accurate prediction of induced radioactivity is also essential for the design, operation and decommissioning of a high energy electron linear accelerator. The research of induced radioactivity focuses on the photonuclear reaction, whose giant resonance response in the copper is ranging from 10 MeV to 28 MeV. The 200 MeV electron linac of NSRL is one of the earliest high-energy electron linear accelerators in P. R. China. The electrons are accelerated to 200 MeV by five acceleration tubes and collimated by the scrapers made of copper. At present, it is the first retired high-energy electron linear accelerator in domestic. Its decommissioning provides an efficient way for the induced radioactivity research of such accelerators, and is a matter of great significance to the accumulation of the induced ...

  19. GPU-accelerated nonparametric kinetic analysis of DCE-MRI data from glioblastoma patients treated with bevacizumab.

    Hsu, Yu-Han H; Ferl, Gregory Z; Ng, Chee M

    2013-05-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is often used to examine vascular function in malignant tumors and noninvasively monitor drug efficacy of antivascular therapies in clinical studies. However, complex numerical methods used to derive tumor physiological properties from DCE-MRI images can be time-consuming and computationally challenging. Recent advancement of computing technology in graphics processing unit (GPU) makes it possible to build an energy-efficient and high-power parallel computing platform for solving complex numerical problems. This study develops the first reported fast GPU-based method for nonparametric kinetic analysis of DCE-MRI data using clinical scans of glioblastoma patients treated with bevacizumab (Avastin®). In the method, contrast agent concentration-time profiles in arterial blood and tumor tissue are smoothed using a robust kernel-based regression algorithm in order to remove artifacts due to patient motion and then deconvolved to produce the impulse response function (IRF). The area under the curve (AUC) and mean residence time (MRT) of the IRF are calculated using statistical moment analysis, and two tumor physiological properties that relate to vascular permeability, volume transfer constant between blood plasma and extravascular extracellular space (K(trans)) and fractional interstitial volume (ve) are estimated using the approximations AUC/MRT and AUC. The most significant feature in this method is the use of GPU-computing to analyze data from more than 60,000 voxels in each DCE-MRI image in parallel fashion. All analysis steps have been automated in a single program script that requires only blood and tumor data as the sole input. The GPU-accelerated method produces K(trans) and ve estimates that are comparable to results from previous studies but reduces computational time by more than 80-fold compared to a previously reported central processing unit-based nonparametric method. Furthermore, it is at

  20. Particle acceleration

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  1. Accelerator design

    The feasibility of constructing a TeV region electron-positron linear collider in Japan is discussed. The design target of the collider is given as follows: Energy, 1 TeV + 1 TeV; luminosity, 1032-1033/cm2/s; total length, 25km; electric power, 250MW; energy dispersion, 1%-10%; the start of the first experiment, early 1990s. For realizing the above target, the following research and developmental works are necessary. (a) Development of an acceleration tube with short filling time and high shunt resistance. (b) Short pulse microwave source with high peak power. (c) High current, single bunch linac. (d) Beam dynamics. As for the acceleration tube, some possibility is considered: For example, the use of DAW (Disk and Washer) which is being developed for TRISTAN as a traveling-wave tube; and the Jungle Gym-type acceleration tube. As a promising candidate for the microwave source, the Lasertron has been studied. The total cost of the collider construction is estimated to be about 310 billion yen, of which 120 billion yen is for the tunnel and buildings, and 190 billion yen for the accelerator facilities. The operation cost is estimated to be about 3 billion yen per month. (Aoki, K.)

  2. Accelerator operations

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  3. Adjoint sensitivity analysis procedure of Markov chains with applications on reliability of IFMIF accelerator-system facilities

    This work presents the implementation of the Adjoint Sensitivity Analysis Procedure (ASAP) for the Continuous Time, Discrete Space Markov chains (CTMC), as an alternative to the other computational expensive methods. In order to develop this procedure as an end product in reliability studies, the reliability of the physical systems is analyzed using a coupled Fault-Tree - Markov chain technique, i.e. the abstraction of the physical system is performed using as the high level interface the Fault-Tree and afterwards this one is automatically converted into a Markov chain. The resulting differential equations based on the Markov chain model are solved in order to evaluate the system reliability. Further sensitivity analyses using ASAP applied to CTMC equations are performed to study the influence of uncertainties in input data to the reliability measures and to get the confidence in the final reliability results. The methods to generate the Markov chain and the ASAP for the Markov chain equations have been implemented into the new computer code system QUEFT/MARKOMAGS/MCADJSEN for reliability and sensitivity analysis of physical systems. The validation of this code system has been carried out by using simple problems for which analytical solutions can be obtained. Typical sensitivity results show that the numerical solution using ASAP is robust, stable and accurate. The method and the code system developed during this work can be used further as an efficient and flexible tool to evaluate the sensitivities of reliability measures for any physical system analyzed using the Markov chain. Reliability and sensitivity analyses using these methods have been performed during this work for the IFMIF Accelerator System Facilities. The reliability studies using Markov chain have been concentrated around the availability of the main subsystems of this complex physical system for a typical mission time. The sensitivity studies for two typical responses using ASAP have been

  4. Stationary plasma accelerator - ATON engine

    The principles of a stationary plasma accelerator (engine) with closed electron drift are described. The accelerator has record integral characteristics. A method for analysis of operating process features in the integral characteristics is proposed. Results are presented of local measurements of the plasma parameters in the accelerator channel and in the leaving plasma jet Main attention is paid to determination of the part of twice ionized ions in the plasma flow

  5. Genetic analysis for fruit yield and yield attributes in okra (Abelmoschus esculentus L. Moench

    P. K. Akotkar and D. K. De

    2014-12-01

    Full Text Available The components of gene effects for yield and its components in okra were studied using generation mean analysis from six generations (P1, P2, F1, F2, BC1, and BC2 derived from six different genotypes. Joint scaling test was applied to detect the presence of epistasis. Epistasis was detected in both the cases. Prevalence of duplicate type of epistasis was observed in all the cases except number of fruits/ plant, fruit length in C1 (IC 3307 x IC 433645, fruit diameter, inter node length in C2 (IC- 43736 x Parbhani Kranti, fruit length, fruit diameter and fruit weight in C3 (IC-342075 X IC-332453. Additive, dominance and epistatic gene effects contribute significantly to the inheritance of various yield characters studied. The joint scaling test confirmed the inadequacy of the additive dominance model in most of the crosses for majority of the characters and indicated the presence of epistasis. Low narrow sense heritability values for most of the characters indicating that these characters are more influenced by the environment and they cannot be improved by simple selection.

  6. Performance Analysis of GPU-Accelerated Filter-Based Source Finding for HI Spectral Line Image Data

    Westerlund, Stefan

    2015-01-01

    Searching for sources of electromagnetic emission in spectral-line radio astronomy interferometric data is a computationally intensive process. Parallel programming techniques and High Performance Computing hardware may be used to improve the computational performance of a source finding program. However, it is desirable to further reduce the processing time of source finding in order to decrease the computational resources required for the task. GPU acceleration is a method that may achieve significant increases in performance for some source finding algorithms, particularly for filtering image data. This work considers the application of GPU acceleration to the task of source finding and the techniques used to achieve the best performance, such as memory management. We also examine the changes in performance, where the algorithms that were GPU accelerated achieved a speedup of around 3.2 times the 12 core per node CPU-only performance, while the program as a whole experienced a speedup of 2.0 times.

  7. MUON ACCELERATION

    BERG,S.J.

    2003-11-18

    One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

  8. KEKB accelerator

    KEKB, the B-Factory at High Energy Accelerator Research Organization (KEK) recently achieved the luminosity of 1 x 1034 cm-2s-1. This luminosity is two orders higher than the world's level at 1990 when the design of KEKB started. This unprecedented result was made possible by KEKB's innovative design and technology in three aspects - beam focusing optics, high current storage, and beam - beam interaction. Now KEKB is leading the luminosity frontier of the colliders in the world. (author)

  9. Accelerating networks

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  10. Simulation and characterization of the RF system and global stability analysis at the REGAE linear electron accelerator

    Mayet, Frank

    2012-12-15

    LAOLA (LAboratory for Laser- and beam-driven plasma Acceleration), is a collaboration between groups from DESY and the University of Hamburg. Its mission is to complement basic research in the relatively new field of plasma wakefield acceleration (PWA) by an explicit combination with DESY's conventional, modern accelerators. The linear electron accelerator REGAE is designed to produce sub 10 fs low charge electron bunches with ultra-low emittance at a repetition rate of 50 Hz. The planned experiments include femtosecond electron diffraction (R.J. Dwayne Miller), as well as the probing of laser induced plasma wakefields with well characterized bunches (LAOLA). They all require high bunch time of flight stability down to 10 fs. The REGAE machine consists of two RF cavities, both fed by a single klystron. While the first one - the gun cavity - is used for acceleration of the electrons, the second one - the buncher cavity - can be used to reduce the electron bunch length. This scheme only works for a specific RF phase relation between the two cavities. This thesis is split into two parts. In the first one the implications of the unique two cavity design on day-to-day machine operation are analyzed. To this end an analytical model of the RF system is developed, which is necessary for understanding how to individually adjust the cavity phases. In the second part the influence of the setup on time of flight stability is discussed with an emphasis on phase jitter compensation. RF phase stability measurements reveal that the current machine setup allows for a time of flight stability down to 50 fs right after the gun.

  11. Simulation and characterization of the RF system and global stability analysis at the REGAE linear electron accelerator

    LAOLA (LAboratory for Laser- and beam-driven plasma Acceleration), is a collaboration between groups from DESY and the University of Hamburg. Its mission is to complement basic research in the relatively new field of plasma wakefield acceleration (PWA) by an explicit combination with DESY's conventional, modern accelerators. The linear electron accelerator REGAE is designed to produce sub 10 fs low charge electron bunches with ultra-low emittance at a repetition rate of 50 Hz. The planned experiments include femtosecond electron diffraction (R.J. Dwayne Miller), as well as the probing of laser induced plasma wakefields with well characterized bunches (LAOLA). They all require high bunch time of flight stability down to 10 fs. The REGAE machine consists of two RF cavities, both fed by a single klystron. While the first one - the gun cavity - is used for acceleration of the electrons, the second one - the buncher cavity - can be used to reduce the electron bunch length. This scheme only works for a specific RF phase relation between the two cavities. This thesis is split into two parts. In the first one the implications of the unique two cavity design on day-to-day machine operation are analyzed. To this end an analytical model of the RF system is developed, which is necessary for understanding how to individually adjust the cavity phases. In the second part the influence of the setup on time of flight stability is discussed with an emphasis on phase jitter compensation. RF phase stability measurements reveal that the current machine setup allows for a time of flight stability down to 50 fs right after the gun.

  12. Electrostatic accelerators fundamentals and applications

    2005-01-01

    Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

  13. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  14. Analysis of the power system from an electron beam accelerator and the correlation with the theoretical dosimetry for radiation processing

    Somessari, Samir Luiz; Somessari, Elizabeth S. Ribeiro; Silveira, Carlos Gaia da; Calvo, Wilson Aparecido Parejo, E-mail: somessar@ipen.br, E-mail: esomessa@ipen.br, E-mail: cgsilvei@ipen.br, E-mail: wapcalvo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Dynamitron DC1500/25/04 type electron beam accelerator (EBA), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN/CNEN-SP in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: for sterilization of medical, pharmaceutical and biological products; treatment of industrial and domestic effluents and sludge; preservation and disinfestation of foods and agricultural products; lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; treatment of effluent from petroleum production units; crosslinking of foams, wires and electric cables; composite and nanocomposite materials and carbon fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; natural polymers and multilayer packages irradiation, and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the point of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04 accelerator, such as, voltage and root-mean-square (RMS) current in the oscillator system, high voltage generator and waveform, using software developed in the

  15. Analysis of the power system from an electron beam accelerator and the correlation with the theoretical dosimetry for radiation processing

    Dynamitron DC1500/25/04 type electron beam accelerator (EBA), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN/CNEN-SP in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: for sterilization of medical, pharmaceutical and biological products; treatment of industrial and domestic effluents and sludge; preservation and disinfestation of foods and agricultural products; lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; treatment of effluent from petroleum production units; crosslinking of foams, wires and electric cables; composite and nanocomposite materials and carbon fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; natural polymers and multilayer packages irradiation, and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the point of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04 accelerator, such as, voltage and root-mean-square (RMS) current in the oscillator system, high voltage generator and waveform, using software developed in the

  16. accelerating cavity

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  17. Damage Based Analysis (DBA): Theory, Derivation and Practical Application - Using Both an Acceleration and Pseudo-Velocity Approach

    Grillo, Vince

    2016-01-01

    The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a Maximax approach.

  18. Simultaneous chemical fingerprint and quantitative analysis of Rhizoma Smilacis Glabrae by accelerated solvent extraction and high-performance liquid chromatography with tandem mass spectrometry.

    Dai, Weiquan; Zhao, Weiquan; Gao, Fangyuan; Shen, Jingjing; Lv, Diya; Qi, Yunpeng; Fan, Guorong

    2015-05-01

    Rhizoma Smilacis Glabrae (RSG) is a well-known herbal medicine with the homology of medicine and food. In this study, simultaneous chemical fingerprint and quantitative analysis of the bioactive flavonoid components of RSG were developed using accelerated solvent extraction and high-performance liquid chromatography coupled with ion trap tandem mass spectrometry. The operational parameters of accelerated solvent extraction including extraction solvent, extraction temperature, static extraction time, solid-to-liquid ratio, and extraction cycles were optimized. Hierarchical cluster analysis, similarity analysis, and principal component analysis were performed to evaluate the similarity and variation of the samples collected from several provinces in China. Subsequently, high-performance liquid chromatography fingerprints were established for the discrimination of 16 batches of RSG samples, and the major six flavonoids, namely, toxifolin, neoastilbin, astilbin, neoisoastilbin, isoastilbin, and engeletin were then quantitatively determined. The calibration curves for all the six analytes showed good linearity (r(2) > 0.999), and the limits of detection and quantification were less than 0.10 and 0.27 μg·mL(-1) , respectively. Therefore, the proposed extraction and determination methods were proved to be robust and reliable for the quality control of RSG. PMID:25678068

  19. Electron Accelerator Facilities

    Lecture presents main aspects of progress in development of industrial accelerators: adaptation of accelerators primary built for scientific experiments, electron energy and beam power increase in certain accelerator constructions, computer control system managing accelerator start-up, routine operation and technological process, maintenance (diagnostics), accelerator technology perfection (electrical efficiency, operation cost), compact and more efficient accelerator constructions, reliability improvement according to industrial standards, accelerators for MW power levels and accelerators tailored for specific use

  20. Analysis of quality control data of eight modern radiotherapy linear accelerators: the short- and long-term behaviours of the outputs and the reproducibility of quality control measurements

    Kapanen, Mika [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Tenhunen, Mikko [Department of Oncology, Helsinki University Central Hospital, Haartmaninkatu 4, 00029 Helsinki (Finland); Haemaelaeinen, Tuomo [Department of Oncology, Helsinki University Central Hospital, Haartmaninkatu 4, 00029 Helsinki (Finland); Sipilae, Petri [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Parkkinen, Ritva [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Jaervinen, Hannu [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland)

    2006-07-21

    Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and long-term drifts in outputs were quantified by fitting empirical mathematical models to the QC measurements. Normally, long-term drifts were well ({<=}1%) modelled by either a straight line or a single-exponential function. A drift of 2% occurred in 18 {+-} 12 months. The shortest drift times of only 2-3 months were observed for some new accelerators just after the commissioning but they stabilized during the first 2-3 years. The short-term reproducibility and the long-term stability of local constancy checks, carried out with a sealed plane parallel ion chamber, were also estimated by fitting empirical models to the QC measurements. The reproducibility was 0.2-0.5% depending on the positioning practice of a device. Long-term instabilities of about 0.3%/month were observed for some checking devices. The reproducibility of local absorbed dose measurements was estimated to be about 0.5%. The proposed empirical model fitting of QC data facilitates the recognition of erroneous QC measurements and abnormal output behaviour, caused by malfunctions, offering a tool to improve dose control.

  1. Analysis of quality control data of eight modern radiotherapy linear accelerators: the short- and long-term behaviours of the outputs and the reproducibility of quality control measurements

    Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and long-term drifts in outputs were quantified by fitting empirical mathematical models to the QC measurements. Normally, long-term drifts were well (≤1%) modelled by either a straight line or a single-exponential function. A drift of 2% occurred in 18 ± 12 months. The shortest drift times of only 2-3 months were observed for some new accelerators just after the commissioning but they stabilized during the first 2-3 years. The short-term reproducibility and the long-term stability of local constancy checks, carried out with a sealed plane parallel ion chamber, were also estimated by fitting empirical models to the QC measurements. The reproducibility was 0.2-0.5% depending on the positioning practice of a device. Long-term instabilities of about 0.3%/month were observed for some checking devices. The reproducibility of local absorbed dose measurements was estimated to be about 0.5%. The proposed empirical model fitting of QC data facilitates the recognition of erroneous QC measurements and abnormal output behaviour, caused by malfunctions, offering a tool to improve dose control

  2. Time-motion analysis of acceleration demands of 4v4 small-sided soccer games played on different pitch sizes.

    Hodgson, Craig; Akenhead, Richard; Thomas, Kevin

    2014-02-01

    We aimed to quantify the time-motion characteristics and technical demands of small-sided soccer games (SSGs) played on small, medium and large pitches using a high frequency non-differential global positioning system (NdGPS) that allowed assessment of acceleration and deceleration patterns. Eight male soccer players competed in SSGs comprising 4×4min quarters (3min recovery) on small (30×20m) medium (40×30m) and large (50×40m) pitch sizes. Time motion analysis using a NdGPS positioning system quantified distance covered sprinting (⩾6.7ms(-1)), high speed running (⩾5.8ms(-1)) and low (1-2ms(-2)), medium (2-3ms(-2)) and high (>3ms(-2)) acceleration. The frequency of common technical actions (passing, turning, dribbling, shooting, tackling, heading and interceptions) was performed using a hand notation system. SSGs played on medium and large pitches had a greater physical demand than on small pitches, with significantly more distance covered in all movement categories. Total distance covered in acceleration categories ranged from 230±111 (small pitch) to 356±72m (medium pitch). The small pitch imposed a greater technical demand on players (more passes, shots and tackles) compared to medium and large pitches. The study provides novel data demonstrating the acceleration patterns observed in SSGs are relatively greater than those observed during professional match play. Thus SSGs might offer a "density" type conditioning stimulus. Practitioners should be aware that changes in pitch size impact both the physical and technical demands of SSGs. PMID:24576705

  3. Accelerator system and method of accelerating particles

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  4. Equilibrium and linear stability analysis of a class of solutions of a thin ring model for a stationary field electron ring accelerator

    A class of equilibrium solutions is developed for a thin-ring model of a stationary field electron ring accelerator during the slow-moving electron ring stage. The problem is viewed as a generalized version of the Bernstein-Greene-Kruskal problem, leading to the solution of electron and ion charge densities. Linear stability analysis shows that this class of equilibrium solutions is linearly stable under J = 0 perturbations of all values of the ratio of the speed of the most energetic ions to the speed of the most energetic electrons. The values of the oscillation frequencies and the expressions for their corresponding eigenfunctions are found to exhibit convergence

  5. Epistasis between IL1A, IL1B, TNF, HTR2A, 5-HTTLPR and TPH2 Variations Does Not Impact Alcohol Dependence Disorder Features

    Anastasios Kalofoutis

    2009-07-01

    Full Text Available We assessed a set of biological (HDL, LDL, SGOT,SGPT, GGT, HTc, Hb and T levels and psychometric variables (investigated through HAM-D, HAM-A, GAS, Liebowitz Social Anxiety Scale, Mark & Mathews Scale, Leyton scale, and Pilowski scale in a sample of 64 alcohol dependent patients, at baseline and after a detoxification treatment. Moreover, we recruited 47 non-consanguineous relatives who did not suffer alcohol related disorders and underwent the same tests. In both groups we genotyped 11 genetic variations (rs1800587; rs3087258; rs1799724; 5-HTTLPR; rs1386493; rs1386494; rs1487275; rs1843809; rs4570625; rs2129575; rs6313 located in genes whose impact on alcohol related behaviors and disorders has been hypothesized (IL1A, IL1B, TNF, 5-HTTLPR, TPH2 and HTR2A. We analyzed the epistasis of these genetic variations upon the biological and psychological dimensions in the cases and their relatives. Further on, we analyzed the effects of the combined genetic variations on the short – term detoxification treatment efficacy. Finally, being the only not yet investigated variation within this sample, we analyzed the impact of the rs6313 alone on baseline assessment and treatment efficacy. We detected the following results: the couple rs6313 + rs2129575 affected the Leyton -Trait at admission (p = 0.01 (obsessive-compulsive trait, whilst rs1800587 + 5-HTTLPR impacted the Pilowski test at admission (p = 0.01 (hypochondriac symptoms. These results did not survive Bonferroni correction (p ≤ 0.004. This lack of association may depend on the incomplete gene coverage or on the small sample size which limited the power of the study. On the other hand, it may reflect a substantial absence of relevance of the genotype variants toward the alcohol related investigated dimensions. Nonetheless, the marginal significance we detected could witness an informative correlation worth investigating in larger samples.

  6. Epistasis between COMT Val158Met and DRD3 Ser9Gly polymorphisms and cognitive function in schizophrenia: genetic influence on dopamine transmission

    Alexandre A. Loch

    2015-09-01

    Full Text Available Objective:To assess the relationship between cognitive function, a proposed schizophrenia endophenotype, and two genetic polymorphisms related to dopamine function, catechol-O-methyl transferase (COMT Val158Met and dopamine receptor 3 (DRD3 Ser9Gly.Methods:Fifty-eight outpatients with schizophrenia/schizoaffective disorder and 88 healthy controls underwent neurocognitive testing and genotyping. Analyses of covariance (ANCOVAs using age, sex, and years of education as covariates compared cognitive performance for the proposed genotypes in patients and controls. ANCOVAs also tested for the epistatic effect of COMT and DRD3 genotype combinations on cognitive performance.Results:For executive functioning, COMT Val/Val patients performed in a similar range as controls (30.70-33.26 vs. 35.53-35.67, but as COMT Met allele frequency increased, executive functioning worsened. COMT Met/Met patients carrying the DRD3 Ser/Ser genotype performed poorest (16.184 vs. 27.388-31.824. Scores of carriers of this COMT/DRD3 combination significantly differed from all DRD3 Gly/Gly combinations (p < 0.05, from COMT Val/Met DRD3 Ser/Gly (p = 0.02, and from COMT Val/Val DRD3 Ser/Ser (p = 0.01 in patients. It also differed significantly from all control scores (p < 0.001.Conclusion:Combined genetic polymorphisms related to dopamine neurotransmission might influence executive function in schizophrenia. Looking at the effects of multiple genes on a single disease trait (epistasis provides a comprehensive and more reliable way to determine genetic effects on endophenotypes.

  7. Probabilistic analysis of flow-accelerated corrosion in French PWR: The probabilistic module of BRT-CICERO version 2

    This paper presents the probabilistic approach launched by Electricite de France (EDF) to master the flow-accelerated corrosion phenomenon, that concerns the carbon steel secondary-system pipes of pressurized water reactors. After a presentation of the physical phenomenon, it is given an overview of the existing deterministic computer program BRT-CICERO Version 1, currently used in EDF nuclear plants; then the probabilistic module of the version 2 is presented, together with the numerical methods employed to compose the under-thickness probabilities. Finally, future applications of BRT-CICERO are described. (author)

  8. New proposal for non-linear ghost-free massive F(R) gravity: Cosmic acceleration and Hamiltonian analysis

    Klusoň, Josef [Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno (Czech Republic); Nojiri, Shin' ichi [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Odintsov, Sergei D. [Instituciò Catalana de Recerca i Estudis Avançats (ICREA), Barcelona (Spain); Institut de Ciencies de l' Espai (IEEC-CSIC), Campus UAB, Torre C5-Par-2a pl, E-08193 Bellaterra (Barcelona) (Spain); Tomsk State Pedagogical University, Tomsk (Russian Federation)

    2013-11-04

    We propose new version of massive F(R) gravity which is natural generalization of convenient massive ghost-free gravity. Its Hamiltonian formulation in scalar-tensor frame is developed. We show that such F(R) theory is ghost-free. The cosmological evolution of such theory is investigated. Despite the strong Bianchi identity constraint the possibility of cosmic acceleration (especially, in the presence of cold dark matter) is established. Ghost-free massive F(R,T) gravity is also proposed.

  9. New proposal for non-linear ghost-free massive F(R) gravity: Cosmic acceleration and Hamiltonian analysis

    We propose new version of massive F(R) gravity which is natural generalization of convenient massive ghost-free gravity. Its Hamiltonian formulation in scalar-tensor frame is developed. We show that such F(R) theory is ghost-free. The cosmological evolution of such theory is investigated. Despite the strong Bianchi identity constraint the possibility of cosmic acceleration (especially, in the presence of cold dark matter) is established. Ghost-free massive F(R,T) gravity is also proposed

  10. Short Acceleration Times from Superdiffusive Shock Acceleration in the Heliosphere

    Perri, S.; Zimbardo, G.

    2015-12-01

    The analysis of time profiles of particles accelerated at interplanetary shocks allows particle transport properties to be inferred. The frequently observed power-law decay upstream, indeed, implies a superdiffusive particle transport when the level of magnetic field variance does not change as the time interval from the shock front increases. In this context, a superdiffusive shock acceleration (SSA) theory has been developed, allowing us to make predictions of the acceleration times. In this work we estimate for a number of interplanetary shocks, including the solar wind termination shock, the acceleration times for energetic protons in the framework of SSA and we compare the results with the acceleration times predicted by standard diffusive shock acceleration. The acceleration times due to SSA are found to be much shorter than in the classical model, and also shorter than the interplanetary shock lifetimes. This decrease of the acceleration times is due to the scale-free nature of the particle displacements in the framework of superdiffusion. Indeed, very long displacements are possible, increasing the probability for particles far from the front of the shock to return, and short displacements have a high probability of occurrence, increasing the chances for particles close to the front to cross the shock many times.

  11. Preliminary analysis of acceleration of sea level rise through the twentieth century using extended tide gauge data sets (August 2014)

    Hogarth, Peter

    2014-11-01

    This work explores the potential for extending tide gauge time series from the Permanent Service for Mean Sea Level (PSMSL) using historical documents, PSMSL ancillary data, and by developing additional composite time series using near neighbor tide gauges. The aim was to increase the number, completeness, and geographical extent of records covering most or all of the twentieth century. The number of at least 75% complete century-scale time series have been approximately doubled over the original PSMSL data set. In total, over 4800 station years have been added, with 294 of these added to 10 long Southern Hemisphere records. Individual century-scale acceleration values derived from this new extended data set tend to converge on a value of 0.01 ± 0.008 mm/yr2. This result agrees closely with recent work and is statistically significant at the 1 sigma level. Possible causes of acceleration and errors are briefly discussed. Results confirm the importance of current data archeology projects involving digitization of the remaining archives of hard copy tide gauge data for sea level and climate studies.

  12. Stochastic Analysis and Forecasts of the Patterns of Speed, Acceleration, and Levels of Material Stock Accumulation in Society.

    Fishman, Tomer; Schandl, Heinz; Tanikawa, Hiroki

    2016-04-01

    The recent acceleration of urbanization and industrialization of many parts of the developing world, most notably in Asia, has resulted in a fast-increasing demand for and accumulation of construction materials in society. Despite the importance of physical stocks in society, the empirical assessment of total material stock of buildings and infrastructure and reasons for its growth have been underexplored in the sustainability literature. We propose an innovative approach for explaining material stock dynamics in society and create a country typology for stock accumulation trajectories using the ARIMA (Autoregressive Integrated Moving Average) methodology, a stochastic approach commonly used in business studies and economics to inspect and forecast time series. This enables us to create scenarios for future demand and accumulation of building materials in society, including uncertainty estimates. We find that the so-far overlooked aspect of acceleration trends of material stock accumulation holds the key to explaining material stock growth, and that despite tremendous variability in country characteristics, stock accumulation is limited to only four archetypal growth patterns. The ability of nations to change their pattern will be a determining factor for global sustainability. PMID:26927731

  13. Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

    Bo Sun

    2015-09-01

    Full Text Available This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss, degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet.

  14. Design and analysis of a piezoelectric material based touch screen with additional pressure and its acceleration measurement functions

    Touch screens are becoming more and more prevalent in everyday environments due to their convenience and humanized operation. In this paper, a piezoelectric material based touch screen is developed and investigated. Piezoelectric ceramics arrayed under the touch panel at the edges or corners are used as tactile sensors to measure the touch positioning point similarly to conventional touch screens. However, additional touch pressure and its acceleration performance can also be obtained to obtain a higher-level human–machine interface. The piezoelectric ceramics can also be added to a traditional touch screen structure, or they can be used independently to construct a novel touch screen with a high light transmittance approach to a transparent glass. The piezoelectric ceramics were processed from PZT piezoelectric ceramic powder into a round or rectangular shape. According to the varied touch position and physical press strength of a finger, or even a gloved hand or fingernail, the piezoelectric tactile sensors will have different output voltage responses. By calculating the ratio of different piezoelectric tactile sensors’ responses and summing up all piezoelectric tactile sensors’ output voltages, the touch point position, touch pressure and touch force acceleration can be detected. A prototype of such a touch screen is manufactured and its position accuracy, touch pressure and response speed are measured in detail. The experimental results show that the prototype has many advantages such as high light transmittance, low energy cost and high durability. (paper)

  15. Software for virtual accelerator designing

    The article discusses appropriate technologies for software implementation of the Virtual Accelerator. The Virtual Accelerator is considered as a set of services and tools enabling transparent execution of computational software for modeling beam dynamics in accelerators on distributed computing resources. Distributed storage and information processing facilities utilized by the Virtual Accelerator make use of the Service-Oriented Architecture (SOA) according to a cloud computing paradigm. Control system tool-kits (such as EPICS, TANGO), computing modules (including high-performance computing), realization of the GUI with existing frameworks and visualization of the data are discussed in the paper. The presented research consists of software analysis for realization of interaction between all levels of the Virtual Accelerator and some samples of middle-ware implementation. A set of the servers and clusters at St.-Petersburg State University form the infrastructure of the computing environment for Virtual Accelerator design. Usage of component-oriented technology for realization of Virtual Accelerator levels interaction is proposed. The article concludes with an overview and substantiation of a choice of technologies that will be used for design and implementation of the Virtual Accelerator. (authors)

  16. OECD/NEA comparison calculations for an accelerator-driven minor actinide burner: analysis of preliminary results

    In the framework of the NEA Nuclear Science Committee, an international benchmark exercise for an accelerator-driven system is being undertaken. A model of a lead-bismuth cooled subcritical system driven by a beam of 1 GeV protons was chosen for the exercise. Except for the subassembly geometry, the design of the subcritical core is based on the ALMR reference design of a sodium-cooled actinide burner. To reduce the high pumping power for the lead-bismuth coolant, the reference subassembly was replaced by a subassembly with a smaller number of pins, and the fission power of the system was proportionally reduced. Lead-bismuth was chosen as target material to reflect the generally increased interest in this material for high-power spallation target applications. An interesting role of accelerator-driven systems is to burn actinide waste from reactors with conventional fuel cycles. The benchmark reactor is assumed to operate as a minor actinide burner in a 'double strata' fuel cycle scheme, featuring a fully closed fuel cycle with a top-up of pure minor actinides. Two fuel compositions for a start-up and an equilibrium core are considered, both differing considerably from normal U-Pu mixed oxide fuel compositions. Six organisations (ANL, CIEMAT, JAERI, KAERI, PSI/CEA and RIT) have contributed preliminary results for inclusion in this paper. The results are based on deterministic transport as well as Monte Carlo calculations using data from ENDF/B-VI, JENDL3.2 and JEF2.2. Significant difference in important neutronic parameters are observed. (authors)

  17. Accelerated tests of hardened cement pastes alteration by organic acids: analysis of the pH effect

    Effluents, such as liquid manure and silage effluents, stored in silos often made of concrete, contain organic acids that are chemically very aggressive for the cement-based matrix. The pH of liquid manure is comprised between 6 and 8, and the pH of silage effluent is about 4. There has already been much research done on manure's effect on concrete using aggressive solutions with a pH of or inferior to 4, in order to accelerate alteration kinetics. These studies aimed at simulating liquid manure and silage effluent, equally. The goal of this article is to validate the use of solutions with a pH of 4 to implement accelerated studies on alterations occurring to structures exposed to the acidic part of liquid manure. In this study, the alteration mechanisms of the cement-based matrix produced by two solutions of organic acids with pH of 4 and 6 were compared. At the end of the experiment, carried out on ordinary Portland cement and slag cement pastes, the kinetics of alteration of the cement pastes immersed in the solution with a pH of 4 was ninefold higher than in the solution with a pH of 6. The chemical and mineralogical modifications of the paste were analyzed by electron microprobe, XRD and BSE mode observations. It was shown that the alteration mechanisms of the paste are sensibly identical for both solutions: almost complete decalcification, the disappearance of the crystallized or amorphous hydrated phases and the probable formation of a silica gel containing aluminum and iron, mainly. The differences in alteration mechanisms between the two solutions are minor and mainly concern the stability of the anhydrous phases: C4AF and slag grains

  18. Statistical epistasis between candidate gene alleles for complex tuber traits in an association mapping population of tetraploid potato

    Li LI; Paulo, M.J.; Eeuwijk, van, F.A.; Gebhardt, C.

    2010-01-01

    Association mapping using DNA-based markers is a novel tool in plant genetics for the analysis of complex traits. Potato tuber yield, starch content, starch yield and chip color are complex traits of agronomic relevance, for which carbohydrate metabolism plays an important role. At the functional level, the genes and biochemical pathways involved in carbohydrate metabolism are among the best studied in plants. Quantitative traits such as tuber starch and sugar content are therefore models for...

  19. Development and application of compact and on-chip electron linear accelerators for dynamic tracking cancer therapy and DNA damage/repair analysis

    Uesaka, M.; Demachi, K.; Fujiwara, T.; Dobashi, K.; Fujisawa, H.; Chhatkuli, R. B.; Tsuda, A.; Tanaka, S.; Matsumura, Y.; Otsuki, S.; Kusano, J.; Yamamoto, M.; Nakamura, N.; Tanabe, E.; Koyama, K.; Yoshida, M.; Fujimori, R.; Yasui, A.

    2015-06-01

    We are developing compact electron linear accelerators (hereafter linac) with high RF (Radio Frequency) frequency (9.3 GHz, wavelength 32.3 mm) of X-band and applying to medicine and non-destructive testing. Especially, potable 950 keV and 3.95 MeV linac X-ray sources have been developed for on-site transmission testing at several industrial plants and civil infrastructures including bridges. 6 MeV linac have been made for pinpoint X-ray dynamic tracking cancer therapy. The length of the accelerating tube is ∼600 mm. The electron beam size at the X-ray target is less than 1 mm and X-ray spot size at the cancer is less than 3 mm. Several hardware and software are under construction for dynamic tracking therapy for moving lung cancer. Moreover, as an ultimate compact linac, we are designing and manufacturing a laser dielectric linac of ∼1 MeV with Yr fiber laser (283 THz, wavelength 1.06 pm). Since the wavelength is 1.06 μm, the length of one accelerating strcture is tens pm and the electron beam size is in sub-micro meter. Since the sizes of cell and nuclear are about 10 and 1 μm, respectively, we plan to use this “On-chip” linac for radiation-induced DNA damage/repair analysis. We are thinking a system where DNA in a nucleus of cell is hit by ∼1 μm electron or X-ray beam and observe its repair by proteins and enzymes in live cells in-situ.

  20. An Information Theoretical Study of the Epistasis Between the CNR1 1359 G/A Polymorphism and the Taq1A and Taq1B DRD2 Polymorphisms: Assessing the Susceptibility to Cannabis Addiction in a Turkish Population.

    Isir, Aysun Baransel; Baransel, Cesur; Nacak, Muradiye

    2016-04-01

    Addiction is a complex, multi-factorial disease, and thus, analyzing genetic variants at multiple loci and gene-gene interactions among them (epistasis) can provide crucial clues about causative factors of addiction which cannot be detected with single-nucleotide polymorphism (SNP) association studies. In this study, we discuss the interaction between the 1359 G/A polymorphism of the CNR1 gene and the DRD2 gene polymorphisms and the net effect of any possible epistasis on the cannabis addiction phenotype in a Turkish population. Using bivariate synergy and mutual information concepts as a means of capturing the magnitude of interaction between marker pairs, the present study not only confirms the A1 marker allele as a risk factor but also reveals a finer-grained association between A and B markers which manifests itself both as a preventive and a risk factor. Our results indicate that the increased phenotype of cases require an individual to be either heterozygous at both loci or homozygous at locus B with homozygous risk factor A1A1 present. We hypothesize that overlapping expressions of CB1 and D2R is the cause of CB1-D2R interactions in cases of substance abuse and the different polymorphisms of CNR1 and DRD2 genes may have decisive roles in the nature of these interactions in terms of promoting or alleviating the cannabis addiction risk factor of the individual. PMID:26833047

  1. Rapid dioxin analysis using accelerated solvent extraction (ASE), multi-column sample cleanup and Rtx-Dioxin2 gas chromatography column

    Robinson, C.; Blow, P. [Australian Laboratory Services, Brisbane (Australia); Dorman, F. [Restek Corporation, Bellefonte, PA (United States)

    2004-09-15

    One of the main aims of many dioxin analysis laboratories is to reduce sample turnaround times to the absolute minimum. Often shorter times between sample receipt and reporting of results can attract a premium price for the analysis. It is generally accepted that the GC-MS portion of dioxin/PCB analysis is not the rate determining step in the overall scheme. Therefore, sample extraction and clean up is the obvious step to investigate for time-saving purposes. The use of accelerated solvent extraction (ASE) and multi column cleanup has been investigated for soil, sediment, air sampling media (XAD-2 resin) and fly-ash samples. For water samples the ASE step is replaced with a liquid/liquid separatory funnel extraction. Environmental analyses regularly require the use of two GC-MS runs to produce dioxin results that may be relied upon. The use of the classical 5MS type column coupled with the more polar 2331 type to produce final results is typical. The innovative capillary GC column, Rtx-Dioxin2, has offered the possibility of performing a dioxin analysis in a single GC-MS run. The analysis of the WHO-12 PCB (PCBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169 and 189) congeners has also been investigated using this column.

  2. Pulsed DC accelerator for laser wakefield accelerator

    For the acceleration of ultra-short, high-brightness electron bunches, a pulsed DC accelerator was constructed. The pulser produced megavolt pulses of 1 ns duration in a vacuum diode. Results are presented from field emission of electrons in the diode. The results indicate that the accelerating gradient in the diode is approximately 1.5 GV/m

  3. Linear Accelerator (LINAC)

    ... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays to ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...

  4. Two-step accelerated mineral carbonation and decomposition analysis for the reduction of CO₂ emission in the eco-industrial parks.

    Jung, Seok; Wang, Li Pang; Dodbiba, Gjergj; Fujita, Toyohisa

    2014-07-01

    Carbon dioxide (CO₂) emissions are a leading contributor to the negative effects of global warming. Globally, research has focused on effective means of reducing and mitigating CO₂ emissions. In this study, we examined the efficacy of eco-industrial parks (EIPs) and accelerated mineral carbonation techniques in reducing CO₂ emissions in South Korea. First, we used Logarithmic Mean Divisia Index (LMDI) analysis to determine the trends in carbon production and mitigation at the existing EIPs. We found that, although CO₂ was generated as byproducts and wastes of production at these EIPs, improved energy intensity effects occurred at all EIPs, and we strongly believe that EIPs are a strong alternative to traditional industrial complexes for reducing net carbon emissions. We also examined the optimal conditions for using accelerated mineral carbonation to dispose of hazardous fly ash produced through the incineration of municipal solid wastes at these EIPs. We determined that this technique most efficiently sequestered CO₂ when micro-bubbling, low flow rate inlet gas, and ammonia additives were employed. PMID:25079989

  5. Measurement and analysis of the radio frequency radiation (non-ionizing) in DC accelerator based 14 MeV neutron generator facility

    Radio frequency (RF) driven ion sources are used in various scientific applications like neutral beam injection systems for fusion reactors, particle accelerators, proton therapy machines, ion implantation systems, neutron generator and neutron spallation source. In BARC, a DC accelerator based 14 MeV neutron generator uses RF type ion source for generation of deuterium ion beam current that is used in DT reaction for neutron generation. An indigenously developed RF amplifier system, capacitively couples (via two electrode rings) the RF power at 100 MHz to deuterium gas filled RF ion source assembly. The RF radiation (non ionizing radiation) emanates from the capacitively coupling that is in the form of circular electrode (metal) rings across deuterium plasma column. A very minor RF leakage may arise from the amplifier assembly itself. This total radiation was measured at various locations within the neutron generator facility and also in two set ups. It was then quantified, analyzed and qualified from the allowed RF emissions standards. This would and have ensured equipment and personnel safety in addition to avoiding of the radio frequency interference (RFI) towards other instrumentation. This paper describes in detail all these measurements and their analysis done. (author)

  6. A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck

    Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX) to radiotherapy (RT) and to some extent also for the use of hyperfractionated radiation therapy (HFRT) and accelerated radiation therapy (AFRT) in locally advanced squamous cell carcinoma (SCC) of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in <4 weeks) on SCC of the oral cavity, oropharynx, hypopharynx, and larynx published as full paper or in abstract form between 1975 and 2003 were eligible. Trials comparing RT alone with concurrent or alternating chemoradiation (5-fluorouracil (5-FU), cisplatin, carboplatin, mitomycin C) were analyzed according to the employed radiation schedule and the used CHX regimen. Studies comparing conventionally fractionated radiotherapy (CFRT) with either HFRT or AFRT without CHX were separately examined. End point of the meta-analysis was overall survival. Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p < 0.001). Separate analyses by cytostatic drug indicate a prolongation of survival of 24.0 months, 16.8 months, 6.7 months, and 4.0 months, respectively, for the simultaneous administration of 5-FU, cisplatin-based, carboplatin-based, and mitomycin C-based CHX to RT (each p < 0.01). Whereas no significant gain in overall survival was observed for AFRT in comparison to CFRT, a substantial prolongation of median survival (14.2 months, p < 0.001) was seen for HFRT compared to CFRT (both without CHX). RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as

  7. Vol. 34 - Optimization of quench protection heater performance in high-field accelerator magnets through computational and experimental analysis

    Salmi, Tiina

    2016-01-01

    Superconducting accelerator magnets with increasingly hi gh magnetic fields are being designed to improve the performance of the Large Hadron Collider (LHC) at CERN. One of the technical challenges is the magnet quench p rotection, i.e., preventing damage in the case of an unexpected loss of superc onductivity and the heat generation related to that. Traditionally this is d one by disconnecting the magnet current supply and using so-called protection he aters. The heaters suppress the superconducting state across a large fraction of the winding thus leading to a uniform dissipation of the stored energy. Preli minary studies suggested that the high-field Nb 3 Sn magnets under development for the LHC luminosity upgrade (HiLumi) could not be reliably protected using the existing heaters. In this thesis work I analyzed in detail the present state-of-the-art protection heater technology, aiming to optimize its perfo rmance and evaluate the prospects in high-field magnet protection. The heater efficiency analyses ...

  8. Analysis of accelerated degradation of a HT-PEM fuel cell caused by cell reversal in fuel starvation condition

    Zhou, Fan; Andreasen, Søren Juhl; Kær, Søren Knudsen;

    2015-01-01

    starvation condition, and the cell performance indicated by cell voltage at H2 stoichiometry of 3.0 declines from 0.59 V to 0.41 V in 19 cycles. Since CO2 is detected in anode exhaust under H2 starvation condition, carbon corrosion is believed to be the reason for the degradation in this test. After the test......This paper reports an accelerated degradation test of a high temperature PEM fuel cell under repeated H2 starvation condition. The H2 stoichiometry is cycled between 3.0 and 0.8 every 2 min during the test. The experimental results show that the polarity of the fuel cell is reversed under H2......, there is only a slight decrease in open circuit voltage of the fuel cell which implies the membrane is not affected by the test. The electrochemical impedance spectrum measurement shows that the H2 starvation can cause significant increase in the ohmic resistance and charge transfer resistance. By...

  9. High gradient experiments on NLCTA accelerator structures

    This paper presents new results of high-gradient studies performed on a 1.8 m traveling-wave accelerator section with detuned high-order deflecting modes. This structure was designed initially for studies of detuned structures and will be installed in the Next Linear Collider Test Accelerator (NLCTA). The paper describes the test set-up in the Accelerator Structure Test Area (ASTA) including electron gun, prebuncher, pre-accelerator, spectrometer, Faraday cups, 200 MW SLED-II power compression system, Magic-T type phase shifters and attenuators. Rf processing, detailed dark current analysis, radiation problems, and beam acceleration measurements are discussed

  10. Bulk Analysis Method of Gold Determination in Ores Using Epithermal Neutrons of Electron Accelerator Microtron MT-22

    Gerbish, Sh; Baatarkhuu, D; Ganbold, G; Belov, A G

    2004-01-01

    Bulk analysis method of gold determination in ores by Instrumental Neutron Activation Analysis (INAA) is described. The powder (100-200 mesh) samples were irradiated in Cd foils of 1 mm thick with photo-neutrons at the Microtron MT-22 of the Nuclear Research Center, Mongolian State University (Ulaanbaatar). The sensitivity of 0.1 mg/kg Au can be obtained using 30-50 g samples and irradiation time of 1-2 h.

  11. Bulk analysis method of gold determination in ores using epithermal neutrons of electron accelerator microtron MT-22

    Bulk analysis method of gold determination in ores by Instrumental Neutron Activation Analysis (INAA) is described. The powder (100-200 mesh) samples were irradiated in Cd foils of 1 mm thick with photo-neutrons at the Microtron MT-22 of the Nuclear Research Center, Mongolian State University (Ulaanbaatar). The sensitivity of 0.1 mg/kg Au can be obtained using 30-50 g samples and irradiation time of 1-2 h

  12. The new external ion beam analysis setup at the Demokritos Tandem accelerator and first applications in cultural heritage

    Sokaras, Dimosthenis; Bistekos, Euthimios; Georgiou, Lambros; Salomon, Joseph; Bogovac, Mladen; Aloupi-Siotis, Eleni; Paschalis, Vasilis; Aslani, Ioanna; Karabagia, Sofia; Lagoyannis, Anastasios; Harissopulos, Sotirios; Kantarelou, Vasiliki; Karydas, Andreas-Germanos

    2011-03-01

    At the 5.5 MV Tandem VdG accelerator of the Institute of Nuclear Physics of N.C.S.R. "Demokritos", Athens, Greece, an external ion-beam set-up has been recently developed and installed. The aim of this development was to integrate the analytical capabilities of the PIXE, RBS and PIGE ion beam techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. A careful 3D mechanical drawing optimized the set-up experimental parameters achieving probe dimensions at the millimeter range (1 mm 2) and fulfilling the special requirements imposed for optimum performance of the aforementioned techniques, including the possibility to use heavier, than protons, ion beams. For the digital pulse processing of the X-ray, γ-ray and charged particle detector signals, novel hardware and software tools were developed based on a custom FPGA configuration. The first applications were focused in the quality control of materials that have been intentionally contaminated with a particular tracer-element ("tagged" materials). The tagged materials which were developed and tested are technologically authentic replicas of ancient attic ceramics with black glazed decoration. Analytical diagnostic studies were carried out for a few representative paintings of contemporary Greek painters in order to identify and document materials/pigments and techniques and eventually to prevent trade of fakes. Finally, ancient glass beads were also examined with respect to the sodium concentration and its in-depth homogeneity.

  13. Analysis of tetragonal to monoclinic phase transformation caused by accelerated artificial aging and the effects of microstructure in stabilized zirconia

    Lucas, Thomas J.

    This investigation addresses the issue that yttria stabilized zirconia is being used as a dental biomaterial without substantial evidence of its long-term viability. Furthermore, stabilized zirconia (SZ) undergoes low temperature degradation (LTD), which can lead to roughening of the surface. A rougher exterior can lead to increased wear of the antagonist in the oral environment. Despite the LTD concerns, SZ is now widely used in restorative dentistry, including full contour crowns. A comparison of aging methods to determine the role of artificial aging on inducing the transformation has not been extensively studied. Therefore, simulations of the transformation process were investigated by comparing different methods of accelerated aging. The rejected null hypothesis is that the temperature of aging treatment will not affect the time required to cause measurable monoclinic transformation of yttria stabilized zirconia. The transformation of SZ starts at the surface and progresses inward; however, it is unclear whether the progression is constant for different aging conditions. This investigation analyzed the depth of transformation as a function of aging conditions for stabilized zirconia in the top 5-6 mum from the surface. The rejected null hypothesis is that the transformation amount is constant throughout the first six micrometers from the surface. The effects of grain size on the amount of monoclinic transformation were also investigated. This study aimed to determine if the grain size of partially stabilized zirconia affects the amount of monoclinic transformation, surface roughness, and property degradation due to aging. The rejected null hypothesis is that the grain size will not affect the amount of monoclinic transformation, thus have no effect on surface roughening or property degradation. The final part of this study addresses the wear of enamel when opposing zirconia by observing how grain size and aging affected the wear rate of an enamel antagonist

  14. Accelerated tryptic digestion for the analysis of biopharmaceutical monoclonal antibodies in plasma by liquid chromatography with tandem mass spectrometric detection.

    Lesur, Antoine; Varesio, Emmanuel; Hopfgartner, Gérard

    2010-01-01

    Accelerated tryptic digestion of a therapeutic protein including microwave irradiation and thermal transfer by convection at 60 degrees C and 37 degrees C was investigated. An analytical setup was devised to follow the protein digestion rate using 1D gel electrophoresis and liquid chromatography coupled a triple quadrupole linear ion trap mass spectrometer. The formation kinetic of its tryptic peptides was monitored in the selected monitoring mode (LC-SRM/MS). Different digestion end points (e.g. 2, 5, 10, 15, 30 and 60min) as well as an overnight digestion were tested using a therapeutic human monoclonal antibody (mAb) with the goal of its LC-SRM/MS quantification in human plasma. The peptides from the human mAb were generated at different rates and were classified into three categories: (1) the fast forming peptides, (2) the slow forming peptides and (3) the peptides degrading over time. For many monitored peptides, a heating temperature of 37 degrees C with a 750rpm mixing applied for at least 30min provided equivalent results to microwave-assisted digestion and generally allowed the achievement of an equivalent peptide concentration as an overnight digestion carried out at 37 degrees C. The disappearance of the protein of the heavy and light chains can be monitored by 1D gel electrophoresis but was found not to be representative of the final tryptic peptide concentrations. For quantitative purposes a stable isotope labeled version ((13)C(4), (15)N(1)) of the therapeutic protein was used. The labeled protein as internal standard was found to be very efficient to compensate for incomplete digestion or losses during sample preparation. PMID:19939394

  15. The new external ion beam analysis setup at the Demokritos Tandem accelerator and first applications in cultural heritage

    Sokaras, Dimosthenis, E-mail: dsokaras@inp.demokritos.g [Institute of Nuclear Physics, N.C.S.R. ' Demokritos' , Aghia Paraskevi, 15310 Athens (Greece); Bistekos, Euthimios; Georgiou, Lambros [Philon Models, 18541 Piraeus (Greece); Salomon, Joseph [Laboratoire du C2RMF, Centre de Rechereche et de Restauration des Musees du France, 75001 Paris (France); Bogovac, Mladen [Institute Ruder Boskovic, 10002 Zagreb (Croatia); Aloupi-Siotis, Eleni [Thetis Authentics Ltd., 11636 Athens (Greece); Paschalis, Vasilis [Benaki Museum, 10674 Athens (Greece); Aslani, Ioanna [Thetis Authentics Ltd., 11636 Athens (Greece); Karabagia, Sofia; Lagoyannis, Anastasios; Harissopulos, Sotirios; Kantarelou, Vasiliki [Institute of Nuclear Physics, N.C.S.R. ' Demokritos' , Aghia Paraskevi, 15310 Athens (Greece); Karydas, Andreas-Germanos [Institute of Nuclear Physics, N.C.S.R. ' Demokritos' , Aghia Paraskevi, 15310 Athens (Greece); Nuclear Spectrometry and Applications Laboratory, International Atomic Energy Agency (IAEA), 2444 Seibersdorf (Austria)

    2011-03-01

    At the 5.5 MV Tandem VdG accelerator of the Institute of Nuclear Physics of N.C.S.R. 'Demokritos', Athens, Greece, an external ion-beam set-up has been recently developed and installed. The aim of this development was to integrate the analytical capabilities of the PIXE, RBS and PIGE ion beam techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. A careful 3D mechanical drawing optimized the set-up experimental parameters achieving probe dimensions at the millimeter range (1 mm{sup 2}) and fulfilling the special requirements imposed for optimum performance of the aforementioned techniques, including the possibility to use heavier, than protons, ion beams. For the digital pulse processing of the X-ray, {gamma}-ray and charged particle detector signals, novel hardware and software tools were developed based on a custom FPGA configuration. The first applications were focused in the quality control of materials that have been intentionally contaminated with a particular tracer-element ('tagged' materials). The tagged materials which were developed and tested are technologically authentic replicas of ancient attic ceramics with black glazed decoration. Analytical diagnostic studies were carried out for a few representative paintings of contemporary Greek painters in order to identify and document materials/pigments and techniques and eventually to prevent trade of fakes. Finally, ancient glass beads were also examined with respect to the sodium concentration and its in-depth homogeneity.

  16. The new external ion beam analysis setup at the Demokritos Tandem accelerator and first applications in cultural heritage

    At the 5.5 MV Tandem VdG accelerator of the Institute of Nuclear Physics of N.C.S.R. 'Demokritos', Athens, Greece, an external ion-beam set-up has been recently developed and installed. The aim of this development was to integrate the analytical capabilities of the PIXE, RBS and PIGE ion beam techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. A careful 3D mechanical drawing optimized the set-up experimental parameters achieving probe dimensions at the millimeter range (1 mm2) and fulfilling the special requirements imposed for optimum performance of the aforementioned techniques, including the possibility to use heavier, than protons, ion beams. For the digital pulse processing of the X-ray, γ-ray and charged particle detector signals, novel hardware and software tools were developed based on a custom FPGA configuration. The first applications were focused in the quality control of materials that have been intentionally contaminated with a particular tracer-element ('tagged' materials). The tagged materials which were developed and tested are technologically authentic replicas of ancient attic ceramics with black glazed decoration. Analytical diagnostic studies were carried out for a few representative paintings of contemporary Greek painters in order to identify and document materials/pigments and techniques and eventually to prevent trade of fakes. Finally, ancient glass beads were also examined with respect to the sodium concentration and its in-depth homogeneity.

  17. Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up

    Shaikh Arif Y

    2012-02-01

    Full Text Available Abstract Background There are limited data on accelerated partial breast irradiation (APBI using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC are suitable for APBI. Methods The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC, ILC, or Tis (DCIS treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF was pathologically confirmed as a local failure (LF or an elsewhere failure (EF. Results Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9% including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. Conclusions External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not

  18. Study on particle transport to wall in JFT-2M edge plasma by accelerator-based analysis

    Transport of hydrogen-isotope particles, D and H, in the scrape-off layer (SOL) of JFT-2M having S.S.304 wall (partially covered with carbon ∼ 40%) was studied using an accelerator-based collector probe method. Here irradiation conditions were provided with the Taylor discharge cleaning (TDC) and the ohmically heated discharge (OHD) with or without neutral beam injection (NBI). First, effects of the wall on TDC-particle transport were examined with Si probes in the D-OHD after the D2-(or H2-)TDC; some of the D(or H) particles absorbed in the wall in the preceding D2-(or H2-)TDC are recycled in the subsequent OHD to reach the plasma boundary through the SOL. This effect was also confirmed in another experiment; in the H2-TDC followed by the D-OHD the H/D fluence ratio distribution is found to increase toward the wall, indicating that some of the H particles due to the H2-TDC are recycled from the wall to join the SOL plasma. Next, we measured the effect of high-fluence H2-TDC particles on the H retention of two C probes (C: Type AX-650K of Toyo Carbon Co., which is the same as JFT-2M divertor-plate material). In spite of the same H fluence (∼6 x 1020 cm-2) the retention of a sample having the smooth surface reached a saturated level of 5.44 x 1017 cm-2 while that of the other sample having the rough surface (as made) was in an unsaturated region (1.6 x 1017 cm-2), suggesting an importance of the surface condition. Finally, it becomes evident from the C-probe experiment in the D2→H2 (or H2→D2) TDC that some of the D(or H) particles absorbed in C during the preceding D2-(or H2-) TDC are replaced 'partially' by the H(or D) particles entering during the subsequent H2-(or D2-) TDC even under the 'unsaturated' condition. (J.P.N.)

  19. Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up

    There are limited data on accelerated partial breast irradiation (APBI) using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC) are suitable for APBI. The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC), ILC, or Tis (DCIS) treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF) was pathologically confirmed as a local failure (LF) or an elsewhere failure (EF). Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9%) including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not differentiate a subset of patients with a higher rate of IBF

  20. Effectiveness of surgery and individualized high-dose hyperfractionated accelerated radiotherapy on survival in clinical stage I non-small cell lung cancer. A propensity score matched analysis

    Background and purpose: Surgery is considered the treatment of choice for early-stage non-small cell lung cancer (NSCLC). Patients with poor pulmonary function or other comorbidities are treated with radiotherapy. The objective of this investigation is to compare the 3-year survival of two early-stage NSCLC populations treated in two different hospitals, either by surgical resection (lobectomy) or by individualized high-dose accelerated radiotherapy, after matching patients by propensity scoring analysis. Methods: A retrospective comparative study has been performed on two series of consecutive patients with cytohistological diagnosis of NSCLC, clinically staged IA by means of PET-scan (radiotherapy group) and pathologically staged IA (surgery group). Results: A total of 157 cases were initially selected for the analysis (110 operated and 47 treated by radiotherapy). Patients in the radiotherapy group were older, with higher comorbidity and lower FEV1% with 3-years probability of survival for operated patients higher than that found for patients treated by radiotherapy. After matching by propensity scoring (using age and FEV1%), differences disappear and 3-years probability of survival had no statistical differences. Conclusions: Although this is a non-randomized retrospective analysis, we have not found 3-years survival differences after matching cases between surgery and radiotherapy. Nevertheless, data presented here support the continuous investigation for non-surgical alternatives in this disease.

  1. Microwave View on Particle Acceleration in Flares

    Fleishman, Gregory D

    2013-01-01

    The thermal-to-nonthermal partition was found to vary greatly from one flare to another resulting in a broad variety of cases from 'heating without acceleration' to 'acceleration without heating'. Recent analysis of microwave data of these differing cases suggests that a similar acceleration mechanism, forming a power-law nonthermal tail up to a few MeV or even higher, operates in all the cases. However, the level of this nonthermal spectrum compared to the original thermal distribution differs significantly from one case to another, implying a highly different thermal-to-nonthermal energy partition in various cases. This further requires a specific mechanism capable of extracting the charged particles from the thermal pool and supplying them to a bulk acceleration process to operate in flares \\textit{in addition} to the bulk acceleration process itself, which, in contrast, efficiently accelerates the seed particles, while cannot accelerate the thermal particles. Within this 'microwave' view on the flare ener...

  2. Acceleration without Horizons

    Doria, Alaric; Munoz, Gerardo

    2015-01-01

    We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} < c$. The motion of the accelerating observer is completely determined by the distance of closest approach and terminal velocity or, equivalently, by an acceleration parameter and terminal velocity.

  3. Transmission electron microscopic x-ray quantitative analysis of human dentin at 200 kV accelerating voltage

    Qualitative and quantitative x-ray energy dispersive spectroscopy is now used successfully to analyze many features and processes in inorganic samples. When applied to inorganic samples, however, the results are often less satisfactory due to problems of preparation of organic samples, difficulty of measuring x-rays from organic samples, damage of the sample by the electron beam, and other practical problems. In the present study we used a high voltage transmission electron microscope equipped with an energy dispersive x-ray spectrometer to examine accurate quantitative standardless analysis of thin sections of an organic sample, human dentin. Based on our experiments we found the important parameters for quantitative analysis were sample thickness and appropriate choice of model sample. Further, we show that the method of Cliff and Lorimer can be used with biological samples at 200 kV, and we show that quantitative analysis of human dentin can be carried out at 200 kV. Finally, we show that areas of human dentin can be differentiated by their morphological characteristics and x-ray analyses obtained in the transmission electron microscope

  4. High-Intensity Proton Accelerator

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  5. Determination of chlorine in high purity materials by charged particle activation analysis using deuteron beam from VEC accelerator

    The quantitative determination of chlorine by conventional methods viz., AAS, ICP-OES is difficult and erroneous at times due to gaseous nature of elemental chlorine. It is possible to determine chlorine by NAA and charged particle activation analysis (CPAA) producing activation product 38Cl (t1/2 = 37.2 min, 1642 (32.8 %), 2168 keV (44 %)). Fast INAA method has been applied to determine Cl in concentration ranges 10 mgkg-1 in some suitable matrices in PCF of DHRUVA reactor with a neutron flux of 1013 cm-2s-1 with a detection limit of Cl of ∼1 mgkg-1

  6. The Los Alamos accelerator code group

    The Los Alamos Accelerator Code Group (LAACG) is a national resource for members of the accelerator community who use and/or develop software for the design and analysis of particle accelerators, beam transport systems, light sources, storage rings, and components of these systems. Below the authors describe the LAACG's activities in high performance computing, maintenance and enhancement of POISSON/SUPERFISH and related codes and the dissemination of information on the INTERNET

  7. Quantitative analysis of results of quality control tests in linear accelerators used in radiotherapy; Analise quantitativa dos resultados de testes de controle de qualidade em aceleradores lineares usados em radioterapia

    Passaro, Bruno M.; Rodrigues, Laura N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Videira, Heber S., E-mail: bruno.passaro@gmail.com [Universidade de Sao Paulo (HCFMRP/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas

    2013-04-15

    The aim of this study is to assess and analyze the stability of the calibration factor of three linear accelerators, as well as the other dosimetric parameters normally included in a program of quality control in radiotherapy. The average calibration factors of the accelerators for the period of approximately four years for the Clinac 600C and Clinac 6EX were (0.998±0.012) and (0.996±0.014), respectively. For the Clinac 2100CD 6 MV and 15 MV was (1.008±0.009) and (1.006±0.010), respectively, in a period of approximately four years. The data of the calibration factors were divided into four subgroups for a more detailed analysis of behavior over the years. Through statistical analysis of calibration factors, we found that for the 600C and Clinacs 2100CD, is an expected probability that more than 90% of cases the values are within acceptable ranges according to TG-142, while for the Clinac 6EX is expected around 85% since this had several exchanges of accelerator components. The values of TPR20,10 of three accelerators are practically constant and within acceptable limits according to the TG-142. It can be concluded that a detailed study of data from the calibration factor of the accelerators and TPR{sub 20},{sub 10} from a quantitative point of view, is extremely useful in a quality assurance program. (author)

  8. Liquid fuel accelerator-driven long-lived waste incinerator. Burning capability evaluation and safety aspects analysis

    Two Monte Carlo models are developed in order to perform criticality calculations and to determine the burning capability for both MAs and plutonium. 99Tc was selected as representative of the LLFPs. The MA burners can incinerate the production of ten or more PWR. The plutonium burners can destroy the production of one or two PWR. The analysis confirms that, for MA burners, the void fraction has a positive feedback on keff. The results of the calculations corresponding to the MA plus LLFP burner show how to solve this problem, the presence of 99Tc in the reflector markedly curtails the increase of keff. The problem of the positive reactivity, introduced in the Pu burner by temperature increase, can be solved by augmenting the absorption, adding 99Tc in the core. It is convenient to develop and ad hoc burner concept for each task, namely: minor actinides, long-lived fission products and plutonium (with perhaps its associated MAs). (author)

  9. In situ X-ray pair distribution function analysis of accelerated carbonation of a synthetic calcium-silicate-hydrate gel

    Morandeau, Antoine E.; White, Claire E. [Princeton

    2015-04-21

    Calcium–silicate–hydrate (C–S–H) gel is the main binder component in hydrated ordinary Portland cement (OPC) paste, and is known to play a crucial role in the carbonation of cementitious materials, especially for more sustainable alternatives containing supplementary cementitious materials. However, the exact atomic structural changes that occur during carbonation of C–S–H gel remain unknown. Here, we investigate the local atomic structural changes that occur during carbonation of a synthetic calcium–silicate–hydrate gel exposed to pure CO₂ vapour, using in situ X-ray total scattering measurements and subsequent pair distribution function (PDF) analysis. By analysing both the reciprocal and real-space scattering data as the C–S–H carbonation reaction progresses, all phases present during the reaction (crystalline and non-crystalline) have been identified and quantified, with the results revealing the emergence of several polymorphs of crystalline calcium carbonate (vaterite and calcite) in addition to the decalcified C–S–H gel. Furthermore, the results point toward residual calcium being present in the amorphous decalcified gel, potentially in the form of an amorphous calcium carbonate phase. As a result of the quantification process, the reaction kinetics for the evolution of the individual phases have been obtained, revealing new information on the rate of growth/dissolution for each phase associated with C–S–H gel carbonation. Moreover, the investigation reveals that the use of real space diffraction data in the form of PDFs enables more accurate determination of the phases that develop during complex reaction processes such as C–S–H gel carbonation in comparison to the conventional reciprocal space Rietveld analysis approach.

  10. High intensity hadron accelerators

    In this paper we give an introductory discussion of high intensity hadron accelerators with special emphasis on the high intensity feature. The topics selected for this discussion are: Types of acclerator - The principal actions of an accelerator are to confine and to accelerate a particle beam. Focusing - This is a discussion of the confinement of single particles. Intensity limitations - These are related to confinement of intense beams of particles. Power economics - Considerations related to acceleration of intense beams of particles. Heavy ion kinematics - The adaptation of accelerators to accelerate all types of heavy ions

  11. The direction of acceleration

    Wilhelm, Thomas; Burde, Jan-Philipp; Lück, Stephan

    2015-11-01

    Acceleration is a physical quantity that is difficult to understand and hence its complexity is often erroneously simplified. Many students think of acceleration as equivalent to velocity, a ˜ v. For others, acceleration is a scalar quantity, which describes the change in speed Δ|v| or Δ|v|/Δt (as opposed to the change in velocity). The main difficulty with the concept of acceleration therefore lies in developing a correct understanding of its direction. The free iOS app AccelVisu supports students in acquiring a correct conception of acceleration by showing acceleration arrows directly at moving objects.

  12. Method of determination of super-low losses of particles based on analysis of the charge spatial distribution evolution for computer modeling of the beam dynamics in linear accelerator

    Using maximum entropy principle, statistical semi-invariants of high orders, symmetry and excess coefficients, a methodic of super-low losses of beam current in a high capacity accelerator was grounded. An analysis of beam dynamics numerical modelling with coordinated input parameters in the structures with spatial homogenous quadrupole focusing was made

  13. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  14. Epistatic interaction between BANK1 and BLK in rheumatoid arthritis: results from a large trans-ethnic meta-analysis

    Emmanuelle Génin; Baptiste Coustet; Yannick Allanore; Ikue Ito; Maria Teruel; Arnaud Constantin; Thierry Schaeverbeke; Adeline Ruyssen-Witrand; Shigeto Tohma; Alain Cantagrel; Olivier Vittecoq; Thomas Barnetche; Xavier Le Loët; Patrice Fardellone; Hiroshi Furukawa

    2013-01-01

    BACKGROUND: BANK1 and BLK belong to the pleiotropic autoimmune genes; recently, epistasis between BANK1 and BLK was detected in systemic lupus erythematosus. Although BLK has been reproducibly identified as a risk factor in rheumatoid arthritis (RA), reports are conflicting about the contribution of BANK1 to RA susceptibility. To ascertain the real impact of BANK1 on RA genetic susceptibility, we performed a large meta-analysis including our original data and tested for an epistatic interacti...

  15. Determination of elemental concentrations at trace levels in alumina by charged particle activation analysis using proton beam from VEC accelerator

    The elemental impurities have been determined in high purity alumina material used in nuclear reactors at ppb (μg kg-1) to ppm (mg kg-1) levels by CPAA using proton beam from VEC machine. Proton beam has the advantage of high cross section for (p, n) reaction to produce suitable nuclide for activation analysis by instrumental approach. The cross sections of higher reaction channels like (p, 2n), (p, pn) are found to be less than 1 mb below 13 MeV proton by theoretical calculation using ALICE 91 computer code. Therefore, 13 MeV proton beam was used to irradiate the alumina samples along with standards, Lake (IAEA-SL-1) and Marine (PACS-2) sediments, both in pellet and powder forms. The irradiation was carried out with 50 nA to 1μA beam current for 10 min to 10 h depending on types of samples and standards. The beam current was measured by Faraday cup and also checked by putting Ti monitoring foil before the target. Ni is determined by (p, pn) reaction using 18 MeV proton as there is no suitable product from (p, n) reaction. The counting measurements of irradiated samples were performed with a high resolution γ-spectrometer using HPGe detector (relative efficiency - 40%, resolution - 2.0 keV at 1332 keV) coupled to a PC based 8 k MCA. The validation of the CPAA results has been carried out by INAA with the same alumina samples, carried out in Dhruva reactor with neutron flux 1014 cm2 s-1 using standards IAEA-SL-1 and PACS-2

  16. San Francisco Accelerator Conference

    'Where are today's challenges in accelerator physics?' was the theme of the open session at the San Francisco meeting, the largest ever gathering of accelerator physicists and engineers

  17. Dielectric Laser Acceleration

    England, R. Joel; Noble, Robert J.; Wu, Ziran; Qi, Minghao

    2013-01-01

    We describe recent advances in the study of particle acceleration using dielectric near-field structures driven by infrared lasers, which we refer to as Dielectric Laser Accelerators. Implications for high energy physics and other applications are discussed.

  18. Standing wave linear accelerator

    Consideration is being given to standing wave linear accelerator containing generator, phase shifter, two accelerating resonator sections, charged particle injector and waveguide bridge. Its first arm is oined up with generator via the phase shifter, the second and the third ones-with accelerating sections and the fourth one - with HF-power absorber. HF-power absorber represents a section of circular diaphragmatic wavequide with transformer with input wave and intrawaveguide output load located between injector and the first accelerating section. The section possesses holes in side walls lying on accelerator axis. The distances between centers of the last cell of the fast accelerating section and the first cell of the second accelerating sectiOn equal (2n+3)lambda/4, where n=1, 2, 3..., lambda - wave length of generator. The suggested system enables to improve by one order spectral characteristics of accelerators as compared to the prototype in which magnetrons are used as generator

  19. Improved plasma accelerator

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  20. High Energy Particle Accelerators

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  1. Use of accelerators in industry

    Low energy charged particle accelerators are fast replacing the conventional cobalt sources in several industrial applications. The field of applications include: (1) radiography of thick steel plates (upto 500 mm), (2) activation analysis for onspot oxygen determination in many elements of interest to metallurgical and steel industries, (3) radiation chemistry, (4) sterilization and food irradiation, (5) welding special steels and treating of refractory and hard metals, (6) environment and water pollution and (7) agriculture. The requirements and the feasibility of a suitable accelerator for these purposes has been discussed. (auth.)

  2. Maximal Acceleration Is Nonrotating

    Page, Don N.

    1997-01-01

    In a stationary axisymmetric spacetime, the angular velocity of a stationary observer that Fermi-Walker transports its acceleration vector is also the angular velocity that locally extremizes the magnitude of the acceleration of such an observer, and conversely if the spacetime is also symmetric under reversing both t and phi together. Thus a congruence of Nonrotating Acceleration Worldlines (NAW) is equivalent to a Stationary Congruence Accelerating Locally Extremely (SCALE). These congruenc...

  3. Accelerators at school

    Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required

  4. A Solid state accelerator

    We present a solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal. Acceleration gradients of order 100 GV/cm are theoretically possible, but channeling radiation limits the maximum attainable energy to 105 TeV for protons. Beam dechanneling due to multiple scattering is substantially reduced by the high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed

  5. Superconducting accelerator technology

    Modern and future accelerators for high energy and nuclear physics rely increasingly on superconducting components to achieve the required magnetic fields and accelerating fields. This paper presents a practical overview of the phenomenon of superconductivity, and describes the design issues and solutions associated with superconducting magnets and superconducting rf acceleration structures. Further development and application of superconducting components promises increased accelerator performance at reduced electric power cost

  6. Applications of particle accelerators

    Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)

  7. Accelerated Stem Growth Rates and Improved Fiber Properties of Loblolly Pine: Functional Analysis Of CyclinD from Pinus taeda

    Dr. John Cairney, School of Biology and Institute of Paper Science and Technology @ Georgia Tech, Georgia Institute of Technology; Dr. Gary Peter, University of Florida; Dr. Ulrika Egertsdotter, Dept. of Forestry, Virgina Tech; Dr. Armin Wagner, New Zealand Forest Research Institute Ltd. (Scion Research.)

    2005-11-30

    A sustained supply of low-cost, high quality raw materials is essential for the future success of the U.S. forest products industry. To maximize stem (trunk) growth, a fundamental understanding of the molecular mechanisms that regulate cell divisions within the cambial meristem is essential. We hypothesize that auxin levels within the cambial meristem regulate cyclin gene expression and this in turn controls cell cycle progression as occurs in all eukaryotic cells. Work with model plant species has shown that ectopic overexpression of cyclins promotes cell division thereby increasing root growth > five times. We intended to test whether ectopic overexpression of cambial cyclins in the cambial zone of loblolly pine also promotes cell division rates that enhance stem growth rates. Results generated in model annual angiosperm systems cannot be reliably extrapolated to perennial gymnosperms, thus while the generation and development of transgenic pine is time consuming, this is the necessary approach for meaningful data. We succeeded in isolating a cyclin D gene and Clustal analysis to the Arabidopsis cyclin D gene family indicates that it is more closely related to cyclin D2 than D1 or D3 Using this gene as a probe we observed a small stimulation of cyclin D expression in somatic embryo culture upon addition of auxin. We hypothesized that trees with more cells in the vascular cambial and expansion zones will have higher cyclin mRNA levels. We demonstrated that in trees under compressive stress where the rates of cambial divisions are increased on the underside of the stem relative to the top or opposite side, there was a 20 fold increase in the level of PtcyclinD1 mRNA on the compressed side of the stem relative to the opposite. This suggests that higher secondary growth rates correlate with PtcyclinD1 expression. We showed that larger diameter trees show more growth during each year and that the increased growth in loblolly pine trees correlates with more cell

  8. Research on feedback system of synchrotron accelerator

    It is a very complex problem to use feedback control system in synchrotron accelerator. Some scientists design feedback control system to make high energy beam stable in synchrotron accelerator, but it is very rare to see theoretically analysis feedback system in synchrotron accelerator by using new concept of control model. One new feedback control model is a fresh idea to discuss the feedback system more deeply. A topic about feedback control system discussed here will be useful for synchrotron accelerator design and operation. It is an good idea for some scientists and technician to continue study. (authors)

  9. Beam dynamics in high energy particle accelerators

    Wolski, Andrzej

    2014-01-01

    Particle accelerators are essential tools for scientific research in fields as diverse as high energy physics, materials science and structural biology. They are also widely used in industry and medicine. Producing the optimum design and achieving the best performance for an accelerator depends on a detailed understanding of many (often complex and sometimes subtle) effects that determine the properties and behavior of the particle beam. Beam Dynamics in High Energy Particle Accelerators provides an introduction to the concepts underlying accelerator beam line design and analysis, taking an approach that emphasizes the elegance of the subject and leads into the development of a range of powerful techniques for understanding and modeling charged particle beams.

  10. Sampling and analysis plan for the Bear Creek Valley Boneyard/Burnyard Accelerated Action Project, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    NONE

    1998-03-01

    In the Bear Creek Valley Watershed Remedial Investigation, the Boneyard/Burnyard was identified as the source of the largest releases of uranium into groundwater and surface water in Bear Creek Valley. The proposed action for remediation of this site is selective excavation and removal of source material and capping of the remainder of the site. The schedule for this action has been accelerated so that this is the first remedial action planned to be implemented in the Bear Creek Valley Record of Decision. Additional data needs to support design of the remedial action were identified at a data quality objectives meeting held for this project. Sampling at the Boneyard/Burnyard will be conducted through the use of a phased approach. Initial or primary samples will be used to make in-the-field decisions about where to locate follow-up or secondary samples. On the basis of the results of surface water, soil, and groundwater analysis, up to six test pits will be dug. The test pits will be used to provide detailed descriptions of source materials and bulk samples. This document sets forth the requirements and procedures to protect the personnel involved in this project. This document also contains the health and safety plan, quality assurance project plan, waste management plan, data management plan, implementation plan, and best management practices plan for this project as appendices.

  11. Analysis of K-net and Kik-net data: implications for ground motion prediction - acceleration time histories, response spectra and nonlinear site response

    This thesis intends to characterize ground motion during earthquake. This work is based on two Japanese networks. It deals with databases of shallow events, depth less than 25 km, with magnitude between 4.0 and 7.3. The analysis of K-net allows to compute a spectral ground motion prediction equation and to review the shape of the Eurocode 8 design spectra. We show the larger amplification at short period for Japanese data and bring in light the soil amplification that takes place at large period. In addition, we develop a new empirical model for simulating synthetic stochastic nonstationary acceleration time histories. By specifying magnitude, distance and site effect, this model allows to produce many time histories, that a seismic event is liable to produce at the place of interest. Furthermore, the study of near-field borehole records of the Kik-net allows to explore the validity domain of predictive equations and to explain what occurs by extrapolating ground motion predictions. Finally, we show that nonlinearity reduces the dispersion of ground motion at the surface. (author)

  12. An Analysis on the Radioactivity Uncertainty Caused by Monte Carlo Stochastic Errors Using Sampling Based Method for the Accelerator Activation Problem

    In this study, to estimate the uncertainty caused by the MC stochastic error, the sampling based sensitivity and uncertainty method is introduced. After the estimation procedure was constructed, the activation analyses were performed for the βNMR (beta-radiation-detected Nuclear Magnetic Resonance) facility. In this study, procedure and program to analyze the activity uncertainty caused by stochastic error of MC method were developed. Using the flux and standard deviation information in MC transport output, 300 randomly sampled flux sets were produced to calculate the uncertainty. It is widely used to couple Monte Carlo (MC) transport code and activation code for the activation analysis of the accelerators. MC method is a stochastic approach for the particle transport; hence, the stochastic errors are always included in the MC transport results. Using the developed procedure, the air activation calculation in βNMR facility was performed. From the results, the major nuclide affected by the flux uncertainty was analyzed. Also, the guideline on the number of particle history is proposed to have a reliable result of the activation. The developed method and procedure will contribute to increasing the accuracy and reliability on the activation calculation

  13. Sampling and analysis plan for the Bear Creek Valley Boneyard/Burnyard Accelerated Action Project, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    In the Bear Creek Valley Watershed Remedial Investigation, the Boneyard/Burnyard was identified as the source of the largest releases of uranium into groundwater and surface water in Bear Creek Valley. The proposed action for remediation of this site is selective excavation and removal of source material and capping of the remainder of the site. The schedule for this action has been accelerated so that this is the first remedial action planned to be implemented in the Bear Creek Valley Record of Decision. Additional data needs to support design of the remedial action were identified at a data quality objectives meeting held for this project. Sampling at the Boneyard/Burnyard will be conducted through the use of a phased approach. Initial or primary samples will be used to make in-the-field decisions about where to locate follow-up or secondary samples. On the basis of the results of surface water, soil, and groundwater analysis, up to six test pits will be dug. The test pits will be used to provide detailed descriptions of source materials and bulk samples. This document sets forth the requirements and procedures to protect the personnel involved in this project. This document also contains the health and safety plan, quality assurance project plan, waste management plan, data management plan, implementation plan, and best management practices plan for this project as appendices

  14. Accelerator development in BARC

    Charged particle accelerators have played crucial role in the field of both basic and applied sciences. This has been possible because the accelerators have been extensively utilized from unraveling the secrets of nature to diverse applications such as implantation, material modification, medical diagnostics and therapy, nuclear energy and clean air and water. The development of accelerators in BARC can be categorized in two broad categories namely proton and heavy ion based accelerators and electron based accelerators. The heavy ion accelerators with sufficiently high energies are currently being used for conducting frontline nuclear and allied research whereas the electron accelerators are being routinely used for various industrial applications. Recently, there is a strong interest for developing the high energy and high intensity accelerators due to their possibility of effective utilization towards concept of energy amplification (Accelerator Driven System), incineration nuclear waste and transmutation. This talk will discuss details of the accelerator development program in BARC with particular emphasis on the recent development at Low Energy High Intensity Proton Accelerator (LEHIPA) Facility in Ion Accelerator Development Division, BARC. (author)

  15. Far field acceleration

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  16. The CERN Accelerator School

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  17. Accelerators and Dinosaurs

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  18. Acceleration: It's Elementary

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  19. Genome-wide association analysis identifies new susceptibility loci for Behçet's disease and epistasis between HLA-B*51 and ERAP1

    Kirino, Yohei; Bertsias, George; Ishigatsubo, Yoshiaki; Mizuki, Nobuhisa; Tugal-Tutkun, Ilknur; Seyahi, Emire; Ozyazgan, Yilmaz; Sacli, F. Sevgi; Erer, Burak; Inoko, Hidetoshi; Emrence, Zeliha; Cakar, Atilla; Abaci, Neslihan; Ustek, Duran; Satorius, Colleen

    2013-01-01

    Patients with Behçet's disease (BD) suffer from episodic inflammation often affecting the orogenital mucosa, skin, and eyes. To discover new BD-susceptibility loci, we performed a genome-wide association study (GWAS) of 779,465 SNPs with imputed genotypes in 1,209 Turkish BD patients and 1,278 controls. We identified novel associations at CCR1, STAT4, and KLRC4. Additionally, two SNPs in ERAP1, encoding ERAP1 p.Asp575Asn and p.Arg725Gln, recessively conferred disease risk. These findings repl...

  20. A variable acceleration calibration system

    Johnson, Thomas H.

    2011-12-01

    A variable acceleration calibration system that applies loads using gravitational and centripetal acceleration serves as an alternative, efficient and cost effective method for calibrating internal wind tunnel force balances. Two proof-of-concept variable acceleration calibration systems are designed, fabricated and tested. The NASA UT-36 force balance served as the test balance for the calibration experiments. The variable acceleration calibration systems are shown to be capable of performing three component calibration experiments with an approximate applied load error on the order of 1% of the full scale calibration loads. Sources of error are indentified using experimental design methods and a propagation of uncertainty analysis. Three types of uncertainty are indentified for the systems and are attributed to prediction error, calibration error and pure error. Angular velocity uncertainty is shown to be the largest indentified source of prediction error. The calibration uncertainties using a production variable acceleration based system are shown to be potentially equivalent to current methods. The production quality system can be realized using lighter materials and a more precise instrumentation. Further research is needed to account for balance deflection, forcing effects due to vibration, and large tare loads. A gyroscope measurement technique is shown to be capable of resolving the balance deflection angle calculation. Long term research objectives include a demonstration of a six degree of freedom calibration, and a large capacity balance calibration.

  1. Lectures in accelerator theory

    Lecture I deals with the behavior of particles in the nonlinear field arising from the electromagnetic interaction of colliding beams. The case treated, that of counter-rotating proton beams crossing each other at a non-zero angle, has the simple feature that the force between the beam is one dimensional. In lecture II, an analysis of the development of traveling waves on particle beams is presented. The situation studied is that of a uniform beam current in a circular accelerator and the excitation for the coherent motion is induced by the resistivity of the vacuum chamber wall. Finally, in lecture III, a description of the current accumulation process used at the proton storage rings at CERN (The ISR) is given. Particle pulses of rather low average current are injected and stored along the length and width of the vacuum chamber. The efficiency is very high and large currents (over 40 amperes) have been achieved

  2. Dirichlet Analysis Method for the Accelerated Storage Test of Electronic Machine%电子整机加速贮存试验的Dirichlet分析方法

    周秀峰; 姚军; 张俊

    2012-01-01

    System electronic machine level product has a complex structure and with many failure mechanisms, the method of using accelerated model to analysis the storage life and reliability is not correct. This paper presents a method based on the sequence Dirichlet distribution model. According to the acceleration model, electronic equipment experiences multiple-type, multiple-level environmental stresses, this model assumes that the failure rate is of exponential distribution at each stress level. Through priori information and the modified accelerated storage model based on the reaction theory, the priori message of failure rate is obtained. Then a multi-variable sequence Dirichlet distribution is applied to describe the probability density of priori failure rate. The parameters are calculated and the physical meaning is clearly stated. By analyzing the constant-stress experiment data, the likelihood function is generated. The Gibbs rejection sampling method is used to solve the posteriori inference problem and get the posterior modified message. A case study is then performed using this method. The sampling process and the quantile values of the failure rate are presented as a result of the case study. Through comparing the priori and posteriori reliability variation trend in the normal state, the effectiveness of this method is shown. Thus a new method of life prediction and evaluation for electronic equipment is developed.%针对电子整机系统结构复杂,失效机理众多.无法利用传统的加速模型外推对其寿命和可靠性特征进行分析的问题,提出一种基于顺序Dirichlet分布的分析模型,利用多应力、多水平的环境应力,对每一阶段上的失效率建立指数分布模型.通过先验信息和基于反应论的修正加速模型,给出各应力水平上的失效率先验信息,利用多变量顺序Dirichlet分布描述先验失效率概率密度函数,并根据先验信息对Dirichlet分布参数进行辨识设计和对

  3. The Accelerator Reliability Forum

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  4. Direct Laser Acceleration in Laser Wakefield Accelerators

    Shaw, Jessica

    2016-01-01

    In this dissertation, the direct laser acceleration (DLA) of ionization-injected electrons in a laser wakefield accelerator (LWFA) operating in the quasi-blowout regime has been investigated through experiment and simulation. In the blowout regime of LWFA, the radiation pressure of an intense laser pulse can push a majority of the plasma electrons out and around the main body of the pulse. The expelled plasma electrons feel the electrostatic field of the relatively-stationary ions and are t...

  5. Generation mean analysis of grain yield and its related traits in barley (Hordeum vulgare L.

    R. S. Raikwar

    2015-03-01

    Full Text Available Generation mean analysis was performed using three crosses namely DL 88 x K 560, K 603 x Azad, RD 2552 x NDB 1020 to study the nature and magnitude of gene effects for yield and its component characters in barley (Hordeum vulgare L.. The F1, F2, BC1 and BC2 of these crosses along with P1 and P2 were studied for six morphological traits. Additive x additive (i epistatic effect was more important and higher than the dominance x dominance (l epistatic effect in the inheritance of no. of effective tillers/plant in DL88 x K560, length of main spike and grain yield/plant in RD 2552 x NDB1020. The length of main spike, weight of grains/main spike, 1000-grain weight and grain yield/plant were significantly higher in RD 2552 x NDB 1020.Thus, these characters were mainly under the control of dominance x dominance (l type of epistasis. Therefore, selection for these characters would be fruitful, if delayed till dominance and epistasis effects are reduced to minimum. The additive × additive (i type gene interaction and duplicate epistasis also seen in this trait suggest the possibilities of obtaining transgressive segregants in later generations. The study revealed the importance of both additive and non-additive types of gene interaction for all the traits studied.

  6. The future of particle accelerators

    Plasma-based accelerators are developing as credible, and compact, accelerators for the future. We review the status and prospects for electron and proton accelerators using laser Wakefield acceleration. (author)

  7. Accelerated Aging in Electrolytic Capacitors for Prognostics

    National Aeronautics and Space Administration — The focus of this work is the analysis of different degradation phenomena based on thermal overstress and electrical overstress accelerated aging systems and the...

  8. Particle-accelerator decommissioning

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

  9. An introduction to acceleration mechanisms

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration

  10. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

    Mutyala Subhakar

    2008-11-01

    Full Text Available Abstract Purpose To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite™ applicator and compare to those produced by whole breast external beam radiotherapy (WBRT. Materials and methods Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10 and the dose received by 20 cc of the structure (D20, were calculated as well as the maximum and mean doses received. Results Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925–1380 cc. Cardiac volumes ranged from 337–551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. Conclusion This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets. Trial registration Dana Farber Trial Registry number 03-179

  11. Use of combination of accelerator-based ion-beam analysis techniques to the investigation of the corrosion behavior of CoCrMo alloy

    Noli, F., E-mail: noli@chem.auth.gr [Department of Chemistry, Aristotle University, GR-54124 Thessaloniki (Greece); Misaelides, P. [Department of Chemistry, Aristotle University, GR-54124 Thessaloniki (Greece); Lagoyannis, A. [Tandem Accelerator Laboratory, Nuclear Physics Institute, NCSR Demokritos, GR-15310 Aghia Paraskevi, Attiki (Greece); Pichon, L. [Institut P’ UPR 3346 Université de Poitiers, CNRS F-86960 Futuroscope, Cedex (France); Ozturk, O. [Department of Physics, Izmir Institute of Technology, Gulbahce-Urla, 35430 Izmir (Turkey)

    2014-07-15

    Highlights: •Effect of plasma nitriding-oxidizing on the corrosion and mechanical properties of CoCrMo alloy. •The double treatment (nitriding+oxidizing) led to higher improvement. •This effect is attributed to the presence of a stable nitride layer. -- Abstract: Nuclear Reaction Analysis – NRA in combination with d-RBS (E{sub d}: 1.35 MeV) was applied in order to investigate the corrosion behavior of CoCrMo alloy. The corrosion resistance of the alloy was compared to that of modified CoCrMo samples by several techniques as plasma nitriding and oxidizing at moderate temperature (∼400 °C). Electrochemical techniques in simulated body fluid 0.9% NaCl (37 °C) were applied in order to accelerate the corrosion process. The nitrogen depth distribution before and after the corrosion was determined using the {sup 14}N(d,α){sup 12}C and the {sup 14}N(d,p){sup 15}N nuclear reactions whereas the oxygen by the {sup 16}O(d,p){sup 17}O. The surface morphology and microstructure was investigated using microscopy techniques. It was found that surface treatments produce thick nitrided layers (5–6 μm) consisting of a supersaturated nitrogen solution (nitrogen concentration is ∼30 at.%) in the matrix (expanded phase γ{sub N}) and a thin oxygen solution (0.3 μm). The samples subjected to plasma nitridation and oxidation exhibited the lowest deterioration and better resistance to corrosion compared to the single nitrided or single oxidized and the untreated material. This could be attributed to the modified surface region with the high nitrogen content and the presence of oxygen.

  12. Use of combination of accelerator-based ion-beam analysis techniques to the investigation of the corrosion behavior of CoCrMo alloy

    Highlights: •Effect of plasma nitriding-oxidizing on the corrosion and mechanical properties of CoCrMo alloy. •The double treatment (nitriding+oxidizing) led to higher improvement. •This effect is attributed to the presence of a stable nitride layer. -- Abstract: Nuclear Reaction Analysis – NRA in combination with d-RBS (Ed: 1.35 MeV) was applied in order to investigate the corrosion behavior of CoCrMo alloy. The corrosion resistance of the alloy was compared to that of modified CoCrMo samples by several techniques as plasma nitriding and oxidizing at moderate temperature (∼400 °C). Electrochemical techniques in simulated body fluid 0.9% NaCl (37 °C) were applied in order to accelerate the corrosion process. The nitrogen depth distribution before and after the corrosion was determined using the 14N(d,α)12C and the 14N(d,p)15N nuclear reactions whereas the oxygen by the 16O(d,p)17O. The surface morphology and microstructure was investigated using microscopy techniques. It was found that surface treatments produce thick nitrided layers (5–6 μm) consisting of a supersaturated nitrogen solution (nitrogen concentration is ∼30 at.%) in the matrix (expanded phase γN) and a thin oxygen solution (0.3 μm). The samples subjected to plasma nitridation and oxidation exhibited the lowest deterioration and better resistance to corrosion compared to the single nitrided or single oxidized and the untreated material. This could be attributed to the modified surface region with the high nitrogen content and the presence of oxygen

  13. The preparation of computer-supported methods for the analysis of radiation situation at particle accelerators and their exemplary application to the cooler synchrotron COSY

    In this thesis the applicability of modern particle transport programs for the radiation protection of the new cooler synchrotron COSY has been investigated. Monte Carlo codes as the program system HERMES offer a large flexibility in geometry simulation and a wide spread applicability up to the GeV energy region because of its implemented physical models. These codes are very suitable for detailed analysis of radiation sources within the accelerator and for dose rate estimations behind radiation shields. Detailed calculations of double differentional flux spectra and surface dose rate distributions at a cylindrical standard target for different materials (iron, copper and lead) were done for 2.5GeV protons incident. In case of deep penetration problems it turns out, that the CPU-time requirement of the Monte Carlo codes increases rapidely. Therefore the Monte Carlo codes were coupled with a one-dimentional Sn transport code to treat deep penetration problems in a reasonable computer CPU-time. For this purpose a new high energy neutron-γ transport library was evaluated taking into account the upper energy limit of COSY with 2.8GeV. The needed cross sections have been calculated by using the physical models of one of the HERMES-codes. Several Fortran-routines were developed to get an automatically procedure, which is used to evaluate the results and determine Legendre polynominals of order P3, which had to be inserted as coefficients into the library. The coupling procedure between the programs has been automated by means of several Fortran-routines, which does transformation, normalisation and formatting of the flux-data. (orig./HST)

  14. Status of the MALT tandem electrostatic accelerator

    Matsuzaki, Hiroyuki; Kobayashi, Koichi; Nakano, Chuichiro; Sunohara, Yoko; Yamashita, Hiroshi; Makita, Hajime; Horiuchi, Kazuho [Tokyo Univ. (Japan)

    2001-02-01

    Seven years have passed since the start of MALT (Micro Analysis Laboratory, Tandem accelerator). An increasing emphasis has been placed, among others, on the accelerator mass spectroscopy (AMS), and also on proton-induced X-ray emission analysis (PIXE). The present paper describes major recent modifications of the system. A cesium sputter ion source dedicated to carbon 14 AMS was manufactured. The contamination of a source plasma chamber and electrodes decreases markedly, but still insufficient. As is increased ion currents injected to the accelerator, the electric field near the beam inlet section may be distorted, and thus deteriorate the beam transmission. (M. Tanaka)

  15. Analysis of thickness measurements on secondary lines in EDF PWRs to evaluate the accuracy of the flow accelerated corrosion monitoring software: BRT-CICERO

    Persoz, Matthieu [CAP AMPERE, 1 place Pleyel, 93282 Saint Denis (France); Bouvier, Jean-Baptiste [CNEN, 165-173 av. Pierre Brossolette, 92542 Montrouge Cedex (France); Ardillon, Emmanuel [R and D Division, EDF, 6 quai Watier, 78401 Chatou Cedex (France); Trevin, Stephane [SEPTEN, 12 - 14 av. Dutrievoz, 69628 Villeurbanne Cedex (France)

    2006-09-15

    The surveillance of Flow Accelerated Corrosion (FAC) on secondary pipes is a major concern for every nuclear power plant operator. After the Surry accident in 1986, EDF launched a computer code development program to monitor this degradation phenomenon. A chemical corrosion model has been developed, based on laboratory test results obtained by EDF R and D since the late 70's. This model enables to compute the wall thickness loss of pipes submitted to FAC, with respect to the thermo-hydraulic conditions, the fluid chemistry, the material chromium content, the pipe geometry and the cycles duration. The computer code, called BRT-CICERO(TM), has first been tested on a few plants in the years 1993-1995. Most of the EDF NPPs began to use it afterwards. In 2001, after the discovery of a severe damage on a 4'' x 6'' reducer at Fessenheim unit 2, that was correctly predicted by BRT-CICERO(TM), the EDF corporate level made its use mandatory for each of its 58 Pressurized Water Reactors (PWR). Several years of operation and experience feedback have enabled to carry out different improvements on the BRT-CICERO(TM) software. Since 2003, EDF NPPs are using the 2.2 version. At the beginning of year 2005, the 58 BRT-CICERO(TM) input-databases were gathered and structured in a form such that statistical treatments could be made. A very great number of data were collected from BRT-CICERO(TM) input-databases by a specific modification of a tool integrated into the software. It appears that a statistical approach could allow an effective analysis of these data. The first goal of this study was to give the degree of confidence in the application and this approach appeared effective. The second goal was to prove that a part of the conservatism is due to the FAC kinetics calculation algorithm implemented in BRT-CICERO(TM). The investigation of the relative difference between measured and calculated thicknesses shows that a part of the conservatism should be due

  16. Accelerator and radiation physics

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  17. Leaky Fermi accelerators

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  18. Accelerator reliability workshop

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  19. Nuclear physics accelerator facilities

    This paper describes many of the nuclear physics heavy-ion accelerator facilities in the US and the research programs being conducted. The accelerators described are: Argonne National Laboratory--ATLAS; Brookhaven National Laboratory--Tandem/AGS Heavy Ion Facility; Brookhaven National Laboratory--Relativistic Heavy Ion Collider (RHIC) (Proposed); Continuous Electron Beam Accelerator Facility; Lawrence Berkeley Laboratory--Bevalac; Lawrence Berkeley Laboratory--88-Inch Cyclotron; Los Alamos National Laboratory--Clinton P. Anderson Meson Physics Facility (LAMPF); Massachusetts Institute of Technology--Bates Linear Accelerator Center; Oak Ridge National Laboratory--Holifield Heavy Ion Research Facility; Oak Ridge National Laboratory--Oak Ridge Electron Linear Accelerator; Stanford Linear Accelerator Center--Nuclear Physics Injector; Texas AandM University--Texas AandM Cyclotron; Triangle Universities Nuclear Laboratory (TUNL); University of Washington--Tandem/Superconducting Booster; and Yale University--Tandem Van de Graaff

  20. Accelerator reliability workshop

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  1. CAS - CERN Accelerator School: RF for Accelerators

    2012-01-01

    These proceedings present the lectures given at the twenty-fourth specialized course organized by the CERN Accelerator School (CAS). The course was held in Ebeltoft, Denmark, from 8-17 June, 2010 in collaboration with Aarhus University, with the topic 'RF for Accelerators' While this topic has been covered by CAS previously, early in the 1990s and again in 2000, it was recognized that recent advances in the field warranted an updated course. Following introductory courses covering the background physics, the course attempted to cover all aspects of RF for accelerators; from RF power generation and transport, through cavity and coupler design, electronics and low level control, to beam diagnostics and RF gymnastics. The lectures were supplemented with several sessions of exercises, which were completed by discussion sessions on the solutions.

  2. Accelerator shielding benchmark problems

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  3. Accelerator shielding benchmark problems

    Hirayama, H.; Ban, S.; Nakamura, T. [and others

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author).

  4. The foxhole accelerating structure

    This report examines some properties of a new type of open accelerating structure. It consists of a series of rectangular cavities, which we call foxholes, joined by a beam channel. The power for accelerating the particles comes from an external radiation source and enters the cavities through their open upper surfaces. Analytic and computer calculations are presented showing that the foxhole is a suitable structure for accelerating relativistic electrons

  5. Japan Accelerator Conference

    At the international level, the high energy accelerator scene evolves rapidly and the International Conference on High Energy Accelerators is where its strong pulse can best be felt. This year, the Conference was held for the first time in Japan, with the 14th meeting in the series having been hosted in August by the Japanese KEK National Laboratory for High Energy Physics, Tsukuba. The venue was a recognition of the premier accelerator physics and technology status achieved by this diligent nation

  6. Comparison of GC-ICP-MS and HPLC-ICP-MS for species-specific isotope dilution analysis of tributyltin in sediment after accelerated solvent extraction

    This study describes a direct comparison of GC and HPLC hyphenated to ICP-MS determination of tributyltin (TBT) in sediment by species-specific isotope dilution analysis (SS-IDMS). The certified reference sediment PACS-2 (NRC, Canada) and a candidate reference sediment (P-18/HIPA-1) were extracted using an accelerated solvent extraction (ASE) procedure. For comparison of GC and LC methods an older bottle of PACS-2 was used, whilst a fresh bottle was taken for demonstration of the accuracy of the methods. The data obtained show good agreement between both methods for both the PACS-2 sediment (LC-ICP-IDMS 828±87 ng g-1 TBT as Sn, GC-ICP-IDMS 848±39 ng g-1 TBT as Sn) and the P-18/ HIPA-1 sediment (LC-ICP-IDMS 78.0±9.7 ng g-1 TBT as Sn, GC-ICP-IDMS 79.2±3.8 ng g-1 TBT as Sn). The analysis by GC-ICP-IDMS offers a greater signal-to-noise ratio and hence a superior detection limit of 0.03 pg TBT as Sn, in the sediment extracts compared to HPLC-ICP-IDMS (3 pg TBT as Sn). A comparison of the uncertainties associated with both methods indicates superior precision of the GC approach. This is related to the better reproducibility of the peak integration, which affects the isotope ratio measurements used for IDMS. The accuracy of the ASE method combined with HPLC-ICP-IDMS was demonstrated during the international interlaboratory comparison P-18 organised by the Comite Consultatif pour la Quantite de Matiere (CCQM). The results obtained by GC-ICP-IDMS for a newly opened bottle of PACS-2 were 1087±77 ng g-1 Sn for DBT and 876±51 ng g-1 Sn for TBT (expanded uncertainties with a coverage factor of 2), which are in good agreement with the certified values of 1090±150 ng g-1 Sn and 980±130 ng g-1 Sn, respectively. (orig.)

  7. Analysis of organochlorine pesticides in coral (Porites evermanni) samples using accelerated solvent extraction and gas chromatography/ion trap mass spectrometry.

    Wang, Dongli; Miao, Xiusheng; Li, Qing X

    2008-02-01

    A gas chromatography/ion trap mass spectrometry method was developed for analysis of organochlorine pesticides (OCPs) in coral samples, which were extracted with accelerated solvent extraction (ASE) and cleaned up on a sulfuric acid-modified silica gel column. The optimal ASE conditions were found to be 100 degrees C and 2000 psi, with a mixture of acetone and methylene chloride (1:1, v/v). The target analytes include hexachlorocyclohexanes (HCHs, specifically, alpha-, beta-, gamma-, and delta-HCH isomers), heptachlor, and hexachlorobenzene (HCB), o,p'-, p,p'-dichlorodiphenyltrichloroethane (o,p'-, p,p'-DDT), o,p'-, p,p'-dichlorodiphenyl-dichloroethylene (o,p'-, p,p'-DDE), and o,p'-, p,p'-dichlorodiphenyldichloroethane (o,p'-, p,p'-DDD). Standard sand samples were used as an alternative matrix spiked with OCP standards to determine the method precision and accuracy. Average recoveries of OCPs ranged from 82% to 102%, with relative standard deviations (RSDs) of 3%-6%, at a level of 10 ng/g and from 50% to 68%, with RSDs of 13%-19% at a level of 2 ng/g. The developed method was applied for analysis of OCPs in coral samples collected from Tern Island and Bikini Atoll in the Pacific Ocean. The concentrations of HCB were 7-26 pg/g dry weight in the samples from Bikini Atoll and 3-45 pg/g in those from Tern Island, and heptachlor concentrations were 208-2200 and 44-104 pg/g in the coral samples from Bikini Atoll and Tern Island, respectively. (summation operator)HCH (sum of alpha-, beta-, gamma-, and delta-HCH) were 8-82 pg/g in Bikini Atoll coral and 86-629 pg/g in Tern island coral, and (summation operator)DDT (sum of o,p'-, p,p'-DDD, o,p'-, p,p'-DDE, and o,p'- p,p'-DDT) were 80-212 pg/g in Bikini Atoll coral and 593-3165 pg/g in Tern Island coral. The results suggest that coral is a viable indicator species for pollution monitoring, which pollutants and their concentrations may be related to dated carbonate layers. PMID:17721673

  8. Comparison of GC-ICP-MS and HPLC-ICP-MS for species-specific isotope dilution analysis of tributyltin in sediment after accelerated solvent extraction

    Wahlen, Raimund; Wolff-Briche, Celine [LGC Limited, Queens Road, TW11 0LY, Teddington, Middlesex (United Kingdom)

    2003-09-01

    This study describes a direct comparison of GC and HPLC hyphenated to ICP-MS determination of tributyltin (TBT) in sediment by species-specific isotope dilution analysis (SS-IDMS). The certified reference sediment PACS-2 (NRC, Canada) and a candidate reference sediment (P-18/HIPA-1) were extracted using an accelerated solvent extraction (ASE) procedure. For comparison of GC and LC methods an older bottle of PACS-2 was used, whilst a fresh bottle was taken for demonstration of the accuracy of the methods. The data obtained show good agreement between both methods for both the PACS-2 sediment (LC-ICP-IDMS 828{+-}87 ng g{sup -1} TBT as Sn, GC-ICP-IDMS 848{+-}39 ng g{sup -1} TBT as Sn) and the P-18/ HIPA-1 sediment (LC-ICP-IDMS 78.0{+-}9.7 ng g{sup -1} TBT as Sn, GC-ICP-IDMS 79.2{+-}3.8 ng g{sup -1} TBT as Sn). The analysis by GC-ICP-IDMS offers a greater signal-to-noise ratio and hence a superior detection limit of 0.03 pg TBT as Sn, in the sediment extracts compared to HPLC-ICP-IDMS (3 pg TBT as Sn). A comparison of the uncertainties associated with both methods indicates superior precision of the GC approach. This is related to the better reproducibility of the peak integration, which affects the isotope ratio measurements used for IDMS. The accuracy of the ASE method combined with HPLC-ICP-IDMS was demonstrated during the international interlaboratory comparison P-18 organised by the Comite Consultatif pour la Quantite de Matiere (CCQM). The results obtained by GC-ICP-IDMS for a newly opened bottle of PACS-2 were 1087{+-}77 ng g{sup -1} Sn for DBT and 876{+-}51 ng g{sup -1} Sn for TBT (expanded uncertainties with a coverage factor of 2), which are in good agreement with the certified values of 1090{+-}150 ng g{sup -1} Sn and 980{+-}130 ng g{sup -1} Sn, respectively. (orig.)

  9. Split Course Hyperfractionated Accelerated Radio-Chemotherapy (SCHARC) for patients with advanced head and neck cancer: Influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis

    The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol 'SCHARC' and the overall survival of our patients. From 1997 to 2004, 64 patients suffering from advanced head and neck cancer (88 % stage IV, 12 % stage III) were assigned to receive the SCHARC protocol. Around half of the patients were diagnosed with oro-hypopharynx carcinoma (52 %), one third with tongue and floor of mouth tumors (29 %) and one fifth (19 %) suffered from H & N cancer at other sites. The schedule consisted of one therapy block with 30 Gy in 20 fractions over a two week period with concomitant chemotherapy (d 1–5: 20 mg/m2/d DDP + 750–1000 mg/m2/d 5FU (cont. infusion). This therapy block was repeated after a fortnight break up to a cumulative dose of 60 Gy and followed by a boost up to 70 Gy (69–70.5 Gy). All patients assigned to this scheme were included in the survival evaluation. Forty patients (63 %) received both radiation and chemotherapy according to the protocol. The mean follow up was 2.3 years (829 d) and the median follow up was 1.9 years (678 d), respectively. The analysis of survival revealed an estimated 3 year overall survival rate of 57 %. No patient died of complications, 52 patients (80 %) had acute grade 2–3 mucositis, and 33 patients (58 %) suffered from acute grade 3 skin toxicity. Leucopenia was no major problem (mean nadir 3.4 g/nl, no patient < 1.0 g/nl) and the mean hemoglobin value decreased from 13.2 to 10.5 g/dl. Univariate analysis of survival showed a better outcome for patients with a hemoglobin nadir >10.5 g/dl and for patients who completed the protocol. The SCHARC protocol was effective in patients diagnosed with advanced head and neck cancer. It led to

  10. Comparison of GC-ICP-MS and HPLC-ICP-MS for species-specific isotope dilution analysis of tributyltin in sediment after accelerated solvent extraction.

    Wahlen, Raimund; Wolff-Briche, Céline

    2003-09-01

    This study describes a direct comparison of GC and HPLC hyphenated to ICP-MS determination of tributyltin (TBT) in sediment by species-specific isotope dilution analysis (SS-IDMS). The certified reference sediment PACS-2 (NRC, Canada) and a candidate reference sediment (P-18/HIPA-1) were extracted using an accelerated solvent extraction (ASE) procedure. For comparison of GC and LC methods an older bottle of PACS-2 was used, whilst a fresh bottle was taken for demonstration of the accuracy of the methods. The data obtained show good agreement between both methods for both the PACS-2 sediment (LC-ICP-IDMS 828+/-87 ng g(-1) TBT as Sn, GC-ICP-IDMS 848+/-39 ng g(-1) TBT as Sn) and the P-18/ HIPA-1 sediment (LC-ICP-IDMS 78.0+/-9.7 ng g(-1) TBT as Sn, GC-ICP-IDMS 79.2+/-3.8 ng g(-1) TBT as Sn). The analysis by GC-ICP-IDMS offers a greater signal-to-noise ratio and hence a superior detection limit of 0.03 pg TBT as Sn, in the sediment extracts compared to HPLC-ICP-IDMS (3 pg TBT as Sn). A comparison of the uncertainties associated with both methods indicates superior precision of the GC approach. This is related to the better reproducibility of the peak integration, which affects the isotope ratio measurements used for IDMS. The accuracy of the ASE method combined with HPLC-ICP-IDMS was demonstrated during the international interlaboratory comparison P-18 organised by the Comité Consultatif pour la Quantité de Matière (CCQM). The results obtained by GC-ICP-IDMS for a newly opened bottle of PACS-2 were 1087+/-77 ng g(-1) Sn for DBT and 876+/-51 ng g(-1) Sn for TBT (expanded uncertainties with a coverage factor of 2), which are in good agreement with the certified values of 1090+/-150 ng g(-1) Sn and 980+/-130 ng g(-1) Sn, respectively. PMID:12879193

  11. A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid esters in contaminated soils

    Tingting MA; Ying TENG; Peter CHRISTIE; Yongming LUO; Yongshan CHEN; Mao YE

    2013-01-01

    An optimized procedure based on gas chromatography-mass spectrometry (GC-MS) combined with accelerated solvent extraction (ASE) is developed for the analysis of six phthalic acid esters (PAEs), which are priority soil pollutants nominated by United States Environmental Protection Agency (USEPA). Quantification of PAEs in soil employs ultrasonic extraction (UE) (USEPA 3550) and ASE (USEPA 3545), followed by clean up procedures involving three different chromatography columns and two combined elution methods. GC-MS conditions under selected ion monitoring (SIM) mode are described and quality assurance and quality control (QA/ QC) criteria with high accuracy and sensitivity for target analytes were achieved. Method reliability is assured with the use of an isotopically labeled PAE, di-n-butyl phthalate-d4 (DnBP-D4), as a surrogate, and benzyl benzoate (BB) as an internal standard, and with the analysis of certified reference materials (CRM). QA/QC for the developed procedure was tested in four PAE-spiked soils and one PAE-contaminated soil. The four spiked soils were originated from typical Chinese agricultural fields and the contaminated soil was obtained from an electronic waste dismantling area. Instrument detection limits (IDLs) for the six PAEs ranged 0.10-0.31 μg·L-1 and method detection limits (MDLs) of the four spiked soils varied from a range of 20-70 μg· kg -1 to a range of 90-290 μg· kg-1. Lineal-iVy of response between 20 μg· L-1 and 2mg.L~ was also established and the correlation coefficients (R) were a11〉0.998. Spiked soil matrix showed relative recovery rates between 75 and 120% for the six target compounds and about 93% for the surrogate substance. The developed procedure is anticipated to be highly applicable for field surveys of soil PAE pollution in China.

  12. Superconducting accelerator magnets

    In the near future, a large number of high quality superconducting dipole and quadrupole magnets will be required for construction of the next generation multi-TeV high energy hadron accelerator-colliders. To establish the construction technology of such accelerator- colliders, extensive and world-wide R and D programs are now carrying out at several laboratories. In this paper the important issues in superconducting accelerator magnets such as cables, design, fabrication, testing and cryogenic system are discussed together with some details on coil cross- sectional current configurations, quality control of materials, quench protections, radiation heating and etc. The key technology in superconducting accelerator magnets is summarized

  13. High Gradient Accelerator Research

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  14. High-intensity accelerators

    The design of high-intensity accelerators is described, using examples of machines being built at the Los Alamos National Laboratory. The major design problem with these accelerators is associated with control of beam loss when accelerator intensity is increased. Beam dynamics, beam loss, and the radio-frequency quadrupole structure are discussed in the first part of the chapter followed by an explanation of plans to achieve high-intensity operation in three projects: the Fusion Material Irradiation Tests (a joint effort with the Hanford Development Laboratory in Richland, Washington), the Proton Storage Ring (an addition to the LAMPF accelerator), and the Racetrack Microtron Project

  15. Cost minimization analysis at the Hospital Mexico in the Caja Costarricense de Seguro Social for the accommodation of patients with radiotherapy with linear accelerator: shelter vs transfers

    Patients with oncological pathology have attended daily in sessions for several weeks in the linear accelerator radiation therapy. Persons subject to this intervention have moved to the Hospital Mexico of the social security of Costa Rica, place that centralizes this treatment. The Caja Costarricense de Seguro Social (CCSS) has considered two options depending on the place of origin of users: bear the costs of commuting from the area of habitual residence, or place them temporarily in a shelter provided by the institution; the CCSS has chosen the first alternative. This research has consisted of a cost-minimization analysis between these two alternatives. The study population are patients with oncological pathology attending sessions of radiotherapy with linear accelerator at the Hospital Mexico in the first half of 2009 using ambulances of Cruz Roja Costarricense. The size of the study population is 107 persons, the total number of transferred recorded in the Fondo Rotatorio de Operaciones of Hospital Mexico is 998. Patients came from five regions and twenty areas of health according to the geographical division of the CCSS. The variables included have been: cost per day by way of transfer, which involves the distance to the radiotherapy center of Hospital Mexico and the cost of the rate at Cruz Roja ambulance per Km (326.86 colons, according to the agreement CCSS-Cruz Roja in June 2009) estimated daily cost of lodging in a shelter, and the reason daily cost of relocation / daily cost of shelter. The cost of shelter includes food and were used data from the company International Medical Suppliers S. A. as a basis for estimating the daily cost, the price fixed by the company was 65 dollars a day, and the conversion into colons exchange rate as established by the Banco Central de Costa Rica; dated April 30, 2010, the amount has been 33.542.60 colons. The reason for each area of health was given by the ratio of the average daily cost in colons by way of ambulance of

  16. Fitness Landscape Analysis for Optimum Multiuser Detection Problem

    WANG Shaowei; ZHU Qiuping

    2007-01-01

    Optimum multiuser detection (OMD) for CDMA systems is an NP-complete combinatorial optimization problem. Fitness landscape has been proven to be very useful for understanding the behavior of combinatorial optimization algorithms and can help in predicting their performance. This paper analyzes the statistic properties of the fitness landscape of the OMD problem by performing autocorrelation analysis, fitness distance correlation test and epistasis measure. The analysis results explain why some random search algorithms are effective methods for OMD problem and give hints how to design more efficient randomized search heuristic algorithms for OMD.

  17. Sp-brane accelerating cosmologies

    We investigate time dependent solutions (S-brane solutions) for product manifolds consisting of factor spaces where only one of them is non-Ricci-flat. Our model contains a minimally coupled free scalar field as a matter source. We discuss a possibility of generating late-time acceleration of the Universe. The analysis is performed in conformally related Brans-Dicke and Einstein frames. Dynamical behavior of our Universe is described by its scale factor. Since the scale factors of our Universe are described by different variables in both frames, they can have different dynamics. Indeed, we show that with our S-brane ansatz in the Brans-Dicke frame the stages of accelerating expansion exist for all types of the external space (flat, spherical, and hyperbolic). However, applying the same ansatz for the metric in the Einstein frame, we find that a model with flat external space and hyperbolic compactification of the internal space is the only one with the stage of the accelerating expansion. A scalar field can prevent this acceleration. It is shown that the case of hyperbolic external space in the Brans-Dicke frame is the only model which can satisfy experimental bounds for the fine-structure constant variations. We obtain a class of models where a pair of dynamical internal spaces have fixed total volume. This results in a fixed fine-structure constant. However, these models are unstable and external space is nonaccelerating

  18. Double (implicit and explicit) dependence of the electromagnetic field of an accelerated charge on time Mathematical and physical analysis of the problem

    Chubykalo, A E; Chubykalo, Andrew E.; Vlaev, Stoyan J.

    1999-01-01

    We considered the electromagnetic field of a charge moving with a constant acceleration along an axis. We found that this field obtained from the Liénard-Wiechert potentials does not satisfy Maxwell equations if one considers exclusively a retarded interaction (i.e. pure implicit dependence this field on time). We show that if and only if one takes into account both retarded interaction and direct interaction (so called "action-at-a-distance") the field produced by an accelerated charge satisfies Maxwell equations.

  19. Boundary-projection acceleration: A new approach to synthetic acceleration of transport calculations

    We present a new class of synthetic acceleration methods which can be applied to transport calculations regardless of geometry, discretization scheme, or mesh shape. Unlike other synthetic acceleration methods which base their acceleration on P1 equations, these methods use acceleration equations obtained by projecting the transport solution onto a coarse angular mesh only on cell boundaries. We demonstrate, via Fourier analysis of a simple model problem as well as numerical calculations of various problems, that the simplest of these methods are unconditionally stable with spectral radius ≤c/3 (c being the scattering ratio), for several different discretization schemes in slab geometry. 28 refs., 4 figs., 3 tabs

  20. Boundary-projection acceleration: A new approach to synthetic acceleration of transport calculations

    Adams, M.L.; Martin, W.R.

    1987-01-01

    We present a new class of synthetic acceleration methods which can be applied to transport calculations regardless of geometry, discretization scheme, or mesh shape. Unlike other synthetic acceleration methods which base their acceleration on P1 equations, these methods use acceleration equations obtained by projecting the transport solution onto a coarse angular mesh only on cell boundaries. We demonstrate, via Fourier analysis of a simple model problem as well as numerical calculations of various problems, that the simplest of these methods are unconditionally stable with spectral radius less than or equal toc/3 (c being the scattering ratio), for several different discretization schemes in slab geometry. 28 refs., 4 figs., 3 tabs.

  1. Accelerator Modeling with MATLAB Accelerator Toolbox

    This paper introduces Accelerator Toolbox (AT)--a collection of tools to model storage rings and beam transport lines in the MATLAB environment. The objective is to illustrate the flexibility and efficiency of the AT-MATLAB framework. The paper discusses three examples of problems that are analyzed frequently in connection with ring-based synchrotron light sources

  2. Accelerator-based BNCT

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the 9Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. - Highlights: • The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. • Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. • The present status and recent progress of the Argentine project will be reviewed. • Topics cover intense ion sources, accelerator tubes, transport of intense beams and beam diagnostics, among others

  3. COLLECTIVE-FIELD ACCELERATION

    Sessler, Andrew M.

    1969-07-04

    Diverse methods proposed for the acceleration of particles by means of collective fields are reviewed. A survey is made of the various currently active experimental programs devoted to investigating collective acceleration, and the present status of the research is briefly noted.

  4. Racetrack linear accelerators

    An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)

  5. Hamburg Accelerator Conference (2)

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). The HEACC Conference traditionally reviews the status of all major accelerator projects whether they are already running like clockwork, still in the construction phase, or waiting impatiently for financial approval

  6. Asia honours accelerator physicists

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  7. Accelerators for energy production

    A tremendous progress of accelerators for these several decades, has been motivated mainly by the research on subnuclear physics. The culmination in high energy accelerators might be SSC, 20 TeV collider in USA, probably the ultimate accelerator being built with the conventional principle. The technology cultivated and integrated for the accelerator development, can now stably offer the high power beam which could be used for the energy problems. The Inertial Confinement Fusion (ICF) with high current, 10 kA and short pulse, 20 ns heavy ion beam (HIB) of mass number ∼200, would be the most promising application of accelerators for energy production. In this scenario, the fuel containing D-T mixture, will be compressed to the high temperature, ∼10 keV and to the high density state, ∼1000 times the solid density with the pressure of ablative plasma or thermal X ray produced by bombarding of high power HIB. The efficiency, beam power/electric power for accelerator, and the repetition rate of HIB accelerators could be most suitable for the energy production. In the present paper, the outline of HIB ICF (HIF) is presented emphasizing the key issues of high current heavy ion accelerator system. (author)

  8. KEK digital accelerator

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  9. Accelerators Beyond The Tevatron?

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  10. Accelerator for nuclear transmutation

    A review on nuclear transmutation of radioactive wastes using particle accelerators is given. Technical feasibility, nuclear data, costs of various projects are discussed. It appears that one high energy accelerator (1500 MeV, 300 mA proton) could probably handle the amount of actinides generated by the actual French nuclear program

  11. Thoughts of accelerator tubes

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  12. Maximal Acceleration Is Nonrotating

    Page, D N

    1998-01-01

    In a stationary axisymmetric spacetime, the angular velocity of a stationary observer that Fermi-Walker transports its acceleration vector is also the angular velocity that locally extremizes the magnitude of the acceleration of such an observer, and conversely if the spacetime is also symmetric under reversing both t and phi together. Thus a congruence of Nonrotating Acceleration Worldlines (NAW) is equivalent to a Stationary Congruence Accelerating Locally Extremely (SCALE). These congruences are defined completely locally, unlike the case of Zero Angular Momentum Observers (ZAMOs), which requires knowledge around a symmetry axis. The SCALE subcase of a Stationary Congruence Accelerating Maximally (SCAM) is made up of stationary worldlines that may be considered to be locally most nearly at rest in a stationary axisymmetric gravitational field. Formulas for the angular velocity and other properties of the SCALEs are given explicitly on a generalization of an equatorial plane, infinitesimally near a symmetry...

  13. Collinear wake field acceleration

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  14. Plasma based accelerators

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  15. Controllable Laser Ion Acceleration

    Kawata, S.; Kamiyama, D.; Ohtake, Y.; Takano, M.; Barada, D.; Kong, Q.; Wang, P. X.; Gu, Y. J.; Wang, W. M.; Limpouch, J.; Andreev, A.; Bulanov, S. V.; Sheng, Z. M.; Klimo, O.; Psikal, J.; Ma, Y. Y.; Li, X. F.; Yu, Q. S.

    2016-02-01

    In this paper a future laser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. Especially a collimation device is focused in this paper. The future laser ion accelerator should have an ion source, ion collimators, ion beam bunchers, and ion post acceleration devices [Laser Therapy 22, 103(2013)]: the ion particle energy and the ion energy spectrum are controlled to meet requirements for a future compact laser ion accelerator for ion cancer therapy or for other purposes. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching would be successfully realized by a multistage laser-target interaction.

  16. Linear induction accelerator

    This paper examines a new layout for the injector and accelerating sectins of a linear induction accelerator. The sections are combined in a single housing: an induction system with a current-pulse generator based on double strip shaping lines laid over ferromagnetic cores; a multichannel spark discharger with forced current division among channels; and a system for core demagnetization and electron-beam formation and transport. The results of formation of an electron beam in the injector system and its acceleration in the first accelerating section of the accelerator for injection of beams with energies of 0.2-0.4 MeV, currents of 1-2 kA, and pulse durations of 60 nsec are given

  17. Power requirements for cosmic ray propagation models involving re-acceleration and a comment on second order Fermi acceleration theory

    Thornbury, Andrew

    2014-01-01

    We derive an analytic expression for the power transferred from interstellar turbulence to the Galactic cosmic rays in propagation models which include re-acceleration. This is used to estimate the power required in such models and the relative importance of the primary acceleration as against re-acceleration. The analysis provides a formal mathematical justification for Fermi's heuristic account of second order acceleration in his classic 1949 paper.

  18. A study of the ASR of an aggregate with high chert content by means of ultra-accelerated mortar bar test and pore fluid analysis

    Larbi, J.A.; Visser, J.H.M.

    2002-01-01

    Various studies have indicated that the use of some ultra-accelerated mortar bar expansion test methods for assessing the alkali-silica reactivity of concrete aggregates (particularly those using 1 M NaOH solution at 80 oC) can give rise to misleading results causing certain types of aggregates to b

  19. The connection between supernova remnants and the Galactic magnetic field: An analysis of quasi-parallel and quasi-perpendicular cosmic ray acceleration for the axisymmetric sample

    West, J L; Ferrand, G

    2016-01-01

    The mechanism for acceleration of cosmic rays in supernova remnants (SNRs) is an outstanding question in the field. We model a sample of 32 axisymmetric SNRs using the quasi-perpendicular and quasi-parallel cosmic-ray-electron (CRE) acceleration cases. The axisymmetric sample is defined to include SNRs with a double-sided, bilateral morphology, and also those with a one-sided morphology where one limb is much brighter than the other. Using a coordinate transformation technique, we insert a bubble-like model SNR into a model of the Galactic magnetic field. Since radio emission of SNRs is dominated by synchrotron emission and since this emission depends on the magnetic field and CRE distribution, we are able to simulate the SNRs emission and compare this to data. We find that the quasi-perpendicular CRE acceleration case is much more consistent with the data than the quasi-parallel CRE acceleration case, with G327.6+14.6 (SN1006) being a notable exception. We propose that SN1006 may be a case where both quasi-p...

  20. Accelerator as a repairable system

    An accelerator is a prime example of a repairable system which is the type of device that can be restored to a fully operational condition via a process of repair other than replacement of the entire system. Since repairable systems can fail two or more times, the analysis of their reliability focuses on predicting the trends in the pattern of failures and repairs rather than the time to first failure. Thus, it needs to focus on the underlying random processes rather than the probability distribution function of the component failures. This paper summarises the analysis methods available today and proposes an approach to development of a simulation. (author)