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Sample records for bulk segregant analysis

  1. Quantitative trait loci detection of Edwardsiella tarda resistance in Japanese flounder Paralichthys olivaceus using bulked segregant analysis

    Science.gov (United States)

    Wang, Xiaoxia; Xu, Wenteng; Liu, Yang; Wang, Lei; Sun, Hejun; Wang, Lei; Chen, Songlin

    2016-03-01

    In recent years, Edwardsiella tarda has become one of the most deadly pathogens of Japanese flounder (Paralichthys olivaceus), causing serious annual losses in commercial production. In contrast to the rapid advances in the aquaculture of P. olivaceus, the study of E. tarda resistance-related markers has lagged behind, hindering the development of a disease-resistant strain. Thus, a marker-trait association analysis was initiated, combining bulked segregant analysis (BSA) and quantitative trait loci (QTL) mapping. Based on 180 microsatellite loci across all chromosomes, 106 individuals from the F1333 (♀: F0768 ×♂: F0915) (Nomenclature rule: F+year+family number) were used to detect simple sequence repeats (SSRs) and QTLs associated with E. tarda resistance. After a genomic scan, three markers (Scaffold 404-21589, Scaffold 404-21594 and Scaffold 270-13812) from the same linkage group (LG)-1 exhibited a significant difference between DNA, pooled/bulked from the resistant and susceptible groups (P disease-resistant Japanese flounder in the future.

  2. Bulk segregant analysis by high-throughput sequencing reveals a novel xylose utilization gene from Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Jared W Wenger

    2010-05-01

    Full Text Available Fermentation of xylose is a fundamental requirement for the efficient production of ethanol from lignocellulosic biomass sources. Although they aggressively ferment hexoses, it has long been thought that native Saccharomyces cerevisiae strains cannot grow fermentatively or non-fermentatively on xylose. Population surveys have uncovered a few naturally occurring strains that are weakly xylose-positive, and some S. cerevisiae have been genetically engineered to ferment xylose, but no strain, either natural or engineered, has yet been reported to ferment xylose as efficiently as glucose. Here, we used a medium-throughput screen to identify Saccharomyces strains that can increase in optical density when xylose is presented as the sole carbon source. We identified 38 strains that have this xylose utilization phenotype, including strains of S. cerevisiae, other sensu stricto members, and hybrids between them. All the S. cerevisiae xylose-utilizing strains we identified are wine yeasts, and for those that could produce meiotic progeny, the xylose phenotype segregates as a single gene trait. We mapped this gene by Bulk Segregant Analysis (BSA using tiling microarrays and high-throughput sequencing. The gene is a putative xylitol dehydrogenase, which we name XDH1, and is located in the subtelomeric region of the right end of chromosome XV in a region not present in the S288c reference genome. We further characterized the xylose phenotype by performing gene expression microarrays and by genetically dissecting the endogenous Saccharomyces xylose pathway. We have demonstrated that natural S. cerevisiae yeasts are capable of utilizing xylose as the sole carbon source, characterized the genetic basis for this trait as well as the endogenous xylose utilization pathway, and demonstrated the feasibility of BSA using high-throughput sequencing.

  3. Strategy for the mapping of interactive genes using bulked segregant analysis method and Mapmaker/Exp software

    Institute of Scientific and Technical Information of China (English)

    WU Weiren; HUANG Biguang

    2006-01-01

    A qualitative trait is usually controlled by a single gene, but it may be sometimes controlled by two or even more genes. This phenomenon is called gene interaction. Rapidly searching for linked molecular markers via bulked segregant analysis (BSA)and then constructing regional linkage map with Mapmaker/Exp has become a common approach to mapping single major genes. However, methods and computer programs developed for mapping single major genes cannot be simply applied to interactive genes because the genetic patterns of gene interactions are quite different from that of single-gene inheritance. Up to now, experimental methods for quickly screening molecular markers linked to interactive genes and statistical methods and corresponding computer softwares for simultaneously analyzing the linkage relationships of multiple molecular markers to an interactive gene have not been available. To solve this problem, in this paper, we propose a strategy for mapping interactive genes using BSA and Mapmaker/Exp. We demonstrate that Mapmaker/Exp' strategy using F2 generation (in a few cases, F3 generation is also needed). As BSA and Mapmaker/Exp have been broadly used in gene mapping studies and are well known by many researchers, the strategies proposed in this paper will be useful for practical researches.

  4. Evaluation and Bulked Segregant Analysis of Major Yield QTL qtl12.1 Introgressed into Indigenous Elite Line for Low Water Availability under Water Stress

    Institute of Scientific and Technical Information of China (English)

    N.Manikanda BOOPATHI; Gat SWAPNASHRI; P.KAVITHA; S.SATHISH; R.NITHYA; Wickneswari RATNAM; Arvind KUMAR

    2013-01-01

    Near isogenic lines carrying large-effect QTL (qtl12.1),which has a consistent influence on grain yield under upland drought stress conditions in a wide range of environments,were evaluated under water stress in the fields.The line which gave higher yield under drought was crossed with a local elite line,PMK3,and forwarded to F2:3 generation.Significant variation was found among the F2:3 lines for agronomic traits under water stress in the fields.Low to high broad sense heritability (H) for investigated traits was also found.Water stress indicators such as leaf rolling and leaf drying were negatively correlated with plant height,biomass and grain yield under stress.Bulked segregant analysis (BSA) was performed with the markers in the vicinity of qtl12.1,and RM27933 was found to be segregated perfectly well in individual components of drought resistant and drought susceptible bulks which were bulked based on yield under water stress among F2:3 lines.Hence,this simple and breeder friendly marker,RM27933,may be useful as a potentially valuable candidate marker for the transfer of the QTL qtl12.1 in the regional breeding program.Bioinformatic analysis of the DNA sequence of the qtl12.1 region was also done to identify and analyze positional candidate genes associated with this QTL and to ascertain the putative molecular basis of qtl12.1.

  5. Bulked segregant analysis of the pirarucu (Arapaima gigas) genome for identification of sex-specific molecular markers.

    Science.gov (United States)

    Almeida, I G; Ianella, P; Faria, M T; Paiva, S R; Caetano, A R

    2013-01-01

    Arapaima gigas (Osteoglossidae) is one of the largest fish species in the Amazon Basin, attaining lengths of over 2.5 m and weights of over 100 kg. Its flesh is prized, and it has great potential for production in aquaculture systems. However, live pirarucu cannot be reliably sexed visually, even after sexual development, since this species does not have clear external sexual dimorphism. Simple and inexpensive methods for sexing immature pirarucu based on DNA markers would facilitate production of this species in commercial operations. We analyzed A. gigas male and female DNA pools with 566 RAPD primers, generating 2609 fragments, with an estimated 1341 segregating polymorphic markers, and an estimated average spacing of 714 kb, which corresponds to less than 0.1% of the species' genome. Two putative sex-specific fragments were initially identified in bulked samples; but they were not confirmed in a study of individual male and female samples. We suggest that A. gigas has developed a non-chromosomal system of sex determination or, alternatively, that the species has undergone a recent loss of the chromosome carrying the sex-determining locus. PMID:24338425

  6. Application of subtracted gDNA microarray-assisted Bulked Segregant Analysis for rapid discovery of molecular markers associated with day-neutrality in strawberry (Fragaria x ananassa).

    Science.gov (United States)

    Gor, Mian Chee; Mantri, Nitin; Pang, Edwin

    2016-01-01

    A Fragaria Discovery Panel (FDP; strawberry-specific SDA) containing 287 features was constructed by subtracting the pooled gDNA of nine non-angiosperm species from the pooled gDNA of five strawberry genotypes. This FDP was used for Bulk Segregant Analysis (BSA) to enable identification of molecular markers associated with day-neutrality. Analysis of hybridisation patterns of a short day (SD) DNA bulk and three day-neutral (DN) DNA bulks varying in flowering strength allowed identification of a novel feature, FaP2E11, closely linked to CYTOKININ OXIDASE 1 (CKX1) gene possibly involved in promoting flowering under non-inductive condition. The signal intensities of FaP2E11 feature obtained from the strong DN bulk (DN1) is three fold higher than the short day bulk (SD), indicating that the putative marker may linked to a CKX1 variant allele with lower enzyme activity. We propose a model for flowering regulation based on the hypothesis that flowering strength may be regulated by the copy number of FaP2E11-linked CKX1 alleles. This study demonstrates the feasibility of the SDA-based BSA approach for the identification of molecular markers associated with day-neutrality in strawberry. This innovative strategy is an efficient and cost-effective approach for molecular marker discovery. PMID:27586242

  7. Development of a multiple bulked segregant analysis (MBSA) method used to locate a new stem rust resistance gene (Sr54) in the winter wheat cultivar Norin 40.

    Science.gov (United States)

    Ghazvini, Habibollah; Hiebert, Colin W; Thomas, Julian B; Fetch, Thomas

    2013-02-01

    An important aspect of studying putative new genes in wheat is determining their position on the wheat genetic map. The primary difficulty in mapping genes is determining which chromosome carries the gene of interest. Several approaches have been developed to address this problem, each with advantages and disadvantages. Here we describe a new approach called multiple bulked segregant analysis (MBSA). A set of 423 simple sequence repeat (SSR) markers were selected based on profile simplicity, frequency of polymorphism, and distribution across the wheat genome. SSR primers were preloaded in 384-well PCR plates with each primer occupying 16 wells. In practice, 14 wells are reserved for "mini-bulks" that are equivalent to four gametes (e.g. two F(2) individuals) comprised of individuals from a segregated population that have a known homozygous genotype for the gene of interest. The remaining two wells are reserved for the parents of the population. Each well containing a mini-bulk can have one of three allele compositions for each SSR: only the allele from one parent, only the allele from the other parent, or both alleles. Simulation experiments were performed to determine the pattern of mini-bulk allele composition that would indicate putative linkage between the SSR in question and the gene of interest. As a test case, MBSA was employed to locate an unidentified stem rust resistance (Sr) gene in the winter wheat cultivar Norin 40. A doubled haploid (DH) population (n = 267) was produced from hybrids of the cross LMPG-6S/Norin 40. The DH population segregated for a single gene (χ (1:1) (2) = 0.093, p = 0.76) for resistance to Puccinia graminis f.sp. tritici race LCBN. Four resistant DH lines were included in each of the 14 mini-bulks for screening. The Sr gene was successfully located to the long arm of chromosome 2D using MBSA. Further mapping confirmed the chromosome location and revealed that the Sr gene was located in a linkage block that may represent an alien

  8. Assessment of Functional EST-SSR Markers (Sugarcane) in Cross-Species Transferability, Genetic Diversity among Poaceae Plants, and Bulk Segregation Analysis

    Science.gov (United States)

    Ul Haq, Shamshad; Kumar, Pradeep; Singh, R. K.; Verma, Kumar Sambhav; Bhatt, Ritika; Sharma, Meenakshi; Kachhwaha, Sumita; Kothari, S. L.

    2016-01-01

    Expressed sequence tags (ESTs) are important resource for gene discovery, gene expression and its regulation, molecular marker development, and comparative genomics. We procured 10000 ESTs and analyzed 267 EST-SSRs markers through computational approach. The average density was one SSR/10.45 kb or 6.4% frequency, wherein trinucleotide repeats (66.74%) were the most abundant followed by di- (26.10%), tetra- (4.67%), penta- (1.5%), and hexanucleotide (1.2%) repeats. Functional annotations were done and after-effect newly developed 63 EST-SSRs were used for cross transferability, genetic diversity, and bulk segregation analysis (BSA). Out of 63 EST-SSRs, 42 markers were identified owing to their expansion genetics across 20 different plants which amplified 519 alleles at 180 loci with an average of 2.88 alleles/locus and the polymorphic information content (PIC) ranged from 0.51 to 0.93 with an average of 0.83. The cross transferability ranged from 25% for wheat to 97.22% for Schlerostachya, with an average of 55.86%, and genetic relationships were established based on diversification among them. Moreover, 10 EST-SSRs were recognized as important markers between bulks of pooled DNA of sugarcane cultivars through BSA. This study highlights the employability of the markers in transferability, genetic diversity in grass species, and distinguished sugarcane bulks. PMID:27340568

  9. Assessment of Functional EST-SSR Markers (Sugarcane) in Cross-Species Transferability, Genetic Diversity among Poaceae Plants, and Bulk Segregation Analysis.

    Science.gov (United States)

    Ul Haq, Shamshad; Kumar, Pradeep; Singh, R K; Verma, Kumar Sambhav; Bhatt, Ritika; Sharma, Meenakshi; Kachhwaha, Sumita; Kothari, S L

    2016-01-01

    Expressed sequence tags (ESTs) are important resource for gene discovery, gene expression and its regulation, molecular marker development, and comparative genomics. We procured 10000 ESTs and analyzed 267 EST-SSRs markers through computational approach. The average density was one SSR/10.45 kb or 6.4% frequency, wherein trinucleotide repeats (66.74%) were the most abundant followed by di- (26.10%), tetra- (4.67%), penta- (1.5%), and hexanucleotide (1.2%) repeats. Functional annotations were done and after-effect newly developed 63 EST-SSRs were used for cross transferability, genetic diversity, and bulk segregation analysis (BSA). Out of 63 EST-SSRs, 42 markers were identified owing to their expansion genetics across 20 different plants which amplified 519 alleles at 180 loci with an average of 2.88 alleles/locus and the polymorphic information content (PIC) ranged from 0.51 to 0.93 with an average of 0.83. The cross transferability ranged from 25% for wheat to 97.22% for Schlerostachya, with an average of 55.86%, and genetic relationships were established based on diversification among them. Moreover, 10 EST-SSRs were recognized as important markers between bulks of pooled DNA of sugarcane cultivars through BSA. This study highlights the employability of the markers in transferability, genetic diversity in grass species, and distinguished sugarcane bulks. PMID:27340568

  10. Assessment of Functional EST-SSR Markers (Sugarcane in Cross-Species Transferability, Genetic Diversity among Poaceae Plants, and Bulk Segregation Analysis

    Directory of Open Access Journals (Sweden)

    Shamshad Ul Haq

    2016-01-01

    Full Text Available Expressed sequence tags (ESTs are important resource for gene discovery, gene expression and its regulation, molecular marker development, and comparative genomics. We procured 10000 ESTs and analyzed 267 EST-SSRs markers through computational approach. The average density was one SSR/10.45 kb or 6.4% frequency, wherein trinucleotide repeats (66.74% were the most abundant followed by di- (26.10%, tetra- (4.67%, penta- (1.5%, and hexanucleotide (1.2% repeats. Functional annotations were done and after-effect newly developed 63 EST-SSRs were used for cross transferability, genetic diversity, and bulk segregation analysis (BSA. Out of 63 EST-SSRs, 42 markers were identified owing to their expansion genetics across 20 different plants which amplified 519 alleles at 180 loci with an average of 2.88 alleles/locus and the polymorphic information content (PIC ranged from 0.51 to 0.93 with an average of 0.83. The cross transferability ranged from 25% for wheat to 97.22% for Schlerostachya, with an average of 55.86%, and genetic relationships were established based on diversification among them. Moreover, 10 EST-SSRs were recognized as important markers between bulks of pooled DNA of sugarcane cultivars through BSA. This study highlights the employability of the markers in transferability, genetic diversity in grass species, and distinguished sugarcane bulks.

  11. A bulk segregant gene expression analysis of a peach population reveals components of the underlying mechanism of the fruit cold response.

    Science.gov (United States)

    Pons, Clara; Martí, Cristina; Forment, Javier; Crisosto, Carlos H; Dandekar, Abhaya M; Granell, Antonio

    2014-01-01

    Peach fruits subjected for long periods of cold storage are primed to develop chilling injury once fruits are shelf ripened at room temperature. Very little is known about the molecular changes occurring in fruits during cold exposure. To get some insight into this process a transcript profiling analyses was performed on fruits from a PopDG population segregating for chilling injury CI responses. A bulked segregant gene expression analysis based on groups of fruits showing extreme CI responses indicated that the transcriptome of peach fruits was modified already during cold storage consistently with eventual CI development. Most peach cold-responsive genes have orthologs in Arabidopsis that participate in cold acclimation and other stresses responses, while some of them showed expression patterns that differs in fruits according to their susceptibility to develop mealiness. Members of ICE1, CBF1/3 and HOS9 regulons seem to have a prominent role in differential cold responses between low and high sensitive fruits. In high sensitive fruits, an alternative cold response program is detected. This program is probably associated with dehydration/osmotic stress and regulated by ABA, auxins and ethylene. In addition, the observation that tolerant siblings showed a series of genes encoding for stress protective activities with higher expression both at harvest and during cold treatment, suggests that preprogrammed mechanisms could shape fruit ability to tolerate postharvest cold-induced stress. A number of genes differentially expressed were validated and extended to individual genotypes by medium-throughput RT-qPCR. Analyses presented here provide a global view of the responses of peach fruits to cold storage and highlights new peach genes that probably play important roles in the tolerance/sensitivity to cold storage. Our results provide a roadmap for further experiments and would help to develop new postharvest protocols and gene directed breeding strategies to better

  12. Bulk ordering and surface segregation in Ni50Pt50

    DEFF Research Database (Denmark)

    Pourovskii, L.P.; Ruban, Andrei; Abrikosov, I.A.;

    2001-01-01

    in the bulk compare well with experimental data. The surface-alloy compositions for the (111) and (110) facets above the ordering transition temperature are also found to be in a good agreement with experiments. It is demonstrated that the segregation profile at the (110) surface of NiPt is mainly caused...

  13. Combining SNP discovery from next-generation sequencing data with bulked segregant analysis (BSA to fine-map genes in polyploid wheat

    Directory of Open Access Journals (Sweden)

    Trick Martin

    2012-01-01

    Full Text Available Abstract Background Next generation sequencing (NGS technologies are providing new ways to accelerate fine-mapping and gene isolation in many species. To date, the majority of these efforts have focused on diploid organisms with readily available whole genome sequence information. In this study, as a proof of concept, we tested the use of NGS for SNP discovery in tetraploid wheat lines differing for the previously cloned grain protein content (GPC gene GPC-B1. Bulked segregant analysis (BSA was used to define a subset of putative SNPs within the candidate gene region, which were then used to fine-map GPC-B1. Results We used Illumina paired end technology to sequence mRNA (RNAseq from near isogenic lines differing across a ~30-cM interval including the GPC-B1 locus. After discriminating for SNPs between the two homoeologous wheat genomes and additional quality filtering, we identified inter-varietal SNPs in wheat unigenes between the parental lines. The relative frequency of these SNPs was examined by RNAseq in two bulked samples made up of homozygous recombinant lines differing for their GPC phenotype. SNPs that were enriched at least 3-fold in the corresponding pool (6.5% of all SNPs were further evaluated. Marker assays were designed for a subset of the enriched SNPs and mapped using DNA from individuals of each bulk. Thirty nine new SNP markers, corresponding to 67% of the validated SNPs, mapped across a 12.2-cM interval including GPC-B1. This translated to 1 SNP marker per 0.31 cM defining the GPC-B1 gene to within 13-18 genes in syntenic cereal genomes and to a 0.4 cM interval in wheat. Conclusions This study exemplifies the use of RNAseq for SNP discovery in polyploid species and supports the use of BSA as an effective way to target SNPs to specific genetic intervals to fine-map genes in unsequenced genomes.

  14. Analysis of dynamic segregation and crystallisation in Mg{sub 65}Cu{sub 25}Y{sub 10} bulk metallic glass using atom probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Laws, K.J., E-mail: k.laws@unsw.edu.au [Australian Research Council Centre of Excellence for Design in Light Metals (Australia); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Saxey, D.W. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH (United Kingdom); School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. (Australia); McKenzie, W.R. [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Electron Microscopy Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052 (Australia); Marceau, R.K.W. [Australian Research Council Centre of Excellence for Design in Light Metals (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Max-Planck Institut fuer Eisenforschung, Max-Planck-Str.1, Duesseldorf, D-40237 (Germany); Gun, B. [Australian Research Council Centre of Excellence for Design in Light Metals (Australia); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Ringer, S.P. [Australian Research Council Centre of Excellence for Design in Light Metals (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Ferry, M. [Australian Research Council Centre of Excellence for Design in Light Metals (Australia); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2012-10-30

    In order to develop an in-depth understanding of the flow behaviour and dynamic devitrification processes of metallic glasses in the supercooled liquid region, tensile testing of amorphous Mg{sub 65}Cu{sub 25}Y{sub 10} samples was carried out at temperatures from 150 to 170 Degree-Sign C and at strain rates from 1 Multiplication-Sign 10{sup -3} s{sup -1} to 1 Multiplication-Sign 10{sup -2} s{sup -1}. Tensile data showed a consistent and reproducible inflexion in flow stress at a particular strain that was largely independent of strain rate. This was followed by a dramatic increase in flow stress occuring prior to the determined onset times of static crystallisation. Samples were analysed using atom probe tomography and the results indicate that tensile straining of the initially homogeneous amorphous alloy results in segregation into two distinct glassy phases via a shear-related process, coincident with the maximum shear plane angle, followed by the evolution of regions corresponding to the composition of a number of equilibrium binary and ternary intermetallic phases.

  15. Next Generation Sequencing Bulk Segregant Analysis of Potato Support that Differential Flux into the Cholesterol and Stigmasterol Metabolite Pools Is Important for Steroidal Glycoalkaloid Content

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sørensen, Kirsten Kørup; Andersen, Mathias Neumann;

    2016-01-01

    Potatoes and other Solanaceae species produce biologically active secondary metabolites called steroidal glycoalkaloids (GAs) which have antimicrobial, fungicidal, antiviral and insecticidal properties. GAs are, however, also toxic to animals and humans. Compared to wild species of potato, the...... content within a diploid potato mapping population (n = 90) that shows a high variation in GA accumulation. The analysis was performed using a novel method based on next generation genome sequencing. A region on chromosome 1 was found to be associated with differential GA content. Within that region......, sterol 24-C-methyltransferase (SMT1), sterol desaturase (SD) and C-4 sterol methyl oxidase (SMO) genes were found, all encoding critical enzymes in the synthesis of the GAs precursor cholesterol....

  16. THE EFFECT OF THE PHYSICAL PROPERTIES OF PARTICLES OF BULK-BLENDED FERTILIZERS ON SEGREGATION BY CONING

    OpenAIRE

    1997-01-01

    Bulk blending is a way to produce compound fertilizers in which the different nutrients are present in different particles. Due to the heterogeneous composition of bulk blends, particle segregation, when it occurs, is a serious problem to the fertilizer producer, as well as to the farmer. Free fall is one of the main types of particle movement to promote segregation. The physical properties of the particles that potentially affect the tendency to segregate the most are size, density and shape...

  17. The Condensin Complex Is Essential for Amitotic Segregation of Bulk Chromosomes, but Not Nucleoli, in the Ciliate Tetrahymena thermophila†

    Science.gov (United States)

    Cervantes, Marcella D.; Coyne, Robert S.; Xi, Xiaohui; Yao, Meng-Chao

    2006-01-01

    The macronucleus of the binucleate ciliate Tetrahymena thermophila contains fragmented and amplified chromosomes that do not have centromeres, eliminating the possibility of mitotic nuclear division. Instead, the macronucleus divides by amitosis with random segregation of these chromosomes without detectable chromatin condensation. This amitotic division provides a special opportunity for studying the roles of mitotic proteins in segregating acentric chromatin. The Smc4 protein is a core component of the condensin complex that plays a role in chromatin condensation and has also been associated with nucleolar segregation, DNA repair, and maintenance of the chromatin scaffold. Mutants of Tetrahymena SMC4 have remarkable characteristics during amitosis. They do not form microtubules inside the macronucleus as normal cells do, and there is little or no bulk DNA segregation during cell division. Nevertheless, segregation of nucleoli to daughter cells still occurs, indicating the independence of this process and bulk DNA segregation in ciliate amitosis. PMID:16738332

  18. THE EFFECT OF THE PHYSICAL PROPERTIES OF PARTICLES OF BULK-BLENDED FERTILIZERS ON SEGREGATION BY CONING

    Directory of Open Access Journals (Sweden)

    Silva G.A. da

    1997-01-01

    Full Text Available Bulk blending is a way to produce compound fertilizers in which the different nutrients are present in different particles. Due to the heterogeneous composition of bulk blends, particle segregation, when it occurs, is a serious problem to the fertilizer producer, as well as to the farmer. Free fall is one of the main types of particle movement to promote segregation. The physical properties of the particles that potentially affect the tendency to segregate the most are size, density and shape. The main objective of this work is to study the influence of size and density of particles and distance of fall on segregation due to free fall. It was found that particle size is the most important physical characteristic to affect segregation; the greater the difference in particle size, the greater the segregation. Free fall is an important mechanical factor affecting segregation; the greater the distance of fall, the greater the segregation. No evidence of the influence of particle density on segregation was found

  19. Morphology versus Vertical Phase Segregation in Solvent Annealed Small Molecule Bulk Heterojunction Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Alexander Kovalenko

    2015-01-01

    Full Text Available The deep study of solvent annealed small molecules bulk heterojunction organic solar cells based on DPP(TBFu2 : PC60BM blend is carried out. To reveal the reason of the solvent annealing advantage over the thermal one, capacitance-voltage measurements were applied. It was found that controlling the vertical phase segregation in the solar cells a high fullerene population in the vicinity of the cathode could be achieved. This results in increase of the shunt resistance of the cell, thus improving the light harvesting efficiency.

  20. Segregation analysis of schizophrenia and related disorders.

    OpenAIRE

    Risch, N; Baron, M

    1984-01-01

    Segregation analysis was applied to 79 nuclear families ascertained through chronic schizophrenic probands. Analysis was performed on the diagnosis of schizophrenia alone and on schizophrenia and schizotypal personality disorder (milder phenotype) combined. The models used were the transmission probability model and the mixed model. Because the disease is associated with reduced fertility, all likelihoods were calculated conditional on parental phenotypes. However, compatibility of the mating...

  1. Integration and segregation in auditory scene analysis

    Science.gov (United States)

    Sussman, Elyse S.

    2005-03-01

    Assessment of the neural correlates of auditory scene analysis, using an index of sound change detection that does not require the listener to attend to the sounds [a component of event-related brain potentials called the mismatch negativity (MMN)], has previously demonstrated that segregation processes can occur without attention focused on the sounds and that within-stream contextual factors influence how sound elements are integrated and represented in auditory memory. The current study investigated the relationship between the segregation and integration processes when they were called upon to function together. The pattern of MMN results showed that the integration of sound elements within a sound stream occurred after the segregation of sounds into independent streams and, further, that the individual streams were subject to contextual effects. These results are consistent with a view of auditory processing that suggests that the auditory scene is rapidly organized into distinct streams and the integration of sequential elements to perceptual units takes place on the already formed streams. This would allow for the flexibility required to identify changing within-stream sound patterns, needed to appreciate music or comprehend speech..

  2. Bulk analysis using nuclear techniques

    International Nuclear Information System (INIS)

    Bulk analysis techniques developed for the mining industry are reviewed. Using penetrating neutron and #betta#-radiations, measurements are obtained directly from a large volume of sample (3-30 kg) #betta#-techniques were used to determine the grade of iron ore and to detect shale on conveyor belts. Thermal neutron irradiation was developed for the simultaneous determination of iron and aluminium in iron ore on a conveyor belt. Thermal-neutron activation analysis includes the determination of alumina in bauxite, and manganese and alumina in manganese ore. Fast neutron activation analysis is used to determine silicon in iron ores, and alumina and silica in bauxite. Fast and thermal neutron activation has been used to determine the soil in shredded sugar cane. (U.K.)

  3. A Social Network Analysis of Occupational Segregation

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian; van der Leij, Marco

    We develop a social network model of occupational segregation between different social groups, generated by the existence of positive inbreeding bias among individuals from the same group. If network referrals are important for job search, then expected homophily in the contact network structure...... social welfare optima. Surprisingly, we find that socially optimal policies involve segregation....... induces different career choices for individuals from different social groups. This further translates into stable occupational segregation equilibria in the labor market. We derive the conditions for wage and unemployment inequality in the segregation equilibria and characterize first and second best...

  4. Residential Segregation in United States Cities: A Causal Analysis

    Science.gov (United States)

    Marshall, Harvey; Jiobu, Robert

    1975-01-01

    Using the technique of path analysis and cities as units of analysis, this study investigates the causes of black residential segregation. The data suggest that the relative socioeconomic status of blacks and black population size are important determinants of segregation. Also relevant are percent black and the relative growth rates of the white…

  5. New segregation analysis of panic disorder

    Energy Technology Data Exchange (ETDEWEB)

    Vieland, V.J.; Fyer, A.J.; Chapman, T. [Columbia Univ., New York, NY (United States)] [and others

    1996-04-09

    We performed simple segregation analyses of panic disorder using 126 families of probands with DSM-III-R panic disorder who were ascertained for a family study of anxiety disorders at an anxiety disorders research clinic. We present parameter estimates for dominant, recessive, and arbitrary single major locus models without sex effects, as well as for a nongenetic transmission model, and compare these models to each other and to models obtained by other investigators. We rejected the nongenetic transmission model when comparing it to the recessive model. Consistent with some previous reports, we find comparable support for dominant and recessive models, and in both cases estimate nonzero phenocopy rates. The effect of restricting the analysis to families of probands without any lifetime history of comorbid major depression (MDD) was also examined. No notable differences in parameter estimates were found in that subsample, although the power of that analysis was low. Consistency between the findings in our sample and in another independently collected sample suggests the possibility of pooling such samples in the future in order to achieve the necessary power for more complex analyses. 32 refs., 4 tabs.

  6. Coupling between bulk ordering and surface segregation: from alloy surfaces to surface alloys

    International Nuclear Information System (INIS)

    -The knowledge of the alloy surfaces is of prime interest to understand their catalytic properties. On the one hand, the determination of the stability of the surface alloys depends very strongly on the behaviours of the AcB1-c alloy surfaces. On the other hand, the knowledge of the kinetics of the formation-dissolution of surface alloys can allow to understand the equilibrium segregation isotherm. We have then studied the relation between the equilibrium surface segregation in an alloy AcB1-c and the kinetics of dissolution of a few metallic layers of A/B and the inverse deposit. We have used an energetic model derived from the electronic structure (T.I.B.M.) allowing us to study the surface segregation both in the disordered state and in the ordered one. The kinetics of dissolution were studied using the kinetic version of this model (K.T.I.B.M.) consistent with the equilibrium model. To illustrate our study, we have chosen the Cu-Pd system, a model for the formation of surface alloys and for which a great number of studies, both experimental and theoretical, are in progress. We then have shown for the (111) surface of this system that the surface alloys obtained during the dissolution are related to the alloy surfaces observed for the equilibrium segregation. The Cu-Pd system is characteristic of systems which have a weak segregation energy. Then, we have performed an equivalent study for a system with a strong segregation energy. Our choice was directly put on the Pt-Sn system. The surface behaviour, both in equilibrium and during the kinetics of dissolution, is very different from the Cu-Pd case. In particular, we have found pure 2-D surface alloys. Finally, a quenched molecular dynamics study has allowed us to determine the relative stability of various possible surface superstructures. (author)

  7. Wilhelm Weinberg's early contribution to segregation analysis.

    Science.gov (United States)

    Stark, Alan; Seneta, Eugene

    2013-09-01

    Wilhelm Weinberg (1862-1937) is a largely forgotten pioneer of human and medical genetics. His name is linked with that of the English mathematician G. H. Hardy in the Hardy-Weinberg law, pervasive in textbooks on population genetics since it expresses stability over generations of zygote frequencies AA, Aa, aa under random mating. One of Weinberg's signal contributions, in an article whose centenary we celebrate, was to verify that Mendel's segregation law still held in the setting of human heredity, contrary to the then-prevailing view of William Bateson (1861-1926), the leading Mendelian geneticist of the time. Specifically, Weinberg verified that the proportion of recessive offspring genotypes aa in human parental crossings Aa × Aa (that is, the segregation ratio for such a setting) was indeed p=1/4. We focus in a nontechnical way on his procedure, called the simple sib method, and on the heated controversy with Felix Bernstein (1878-1956) in the 1920s and 1930s over work stimulated by Weinberg's article. PMID:24018765

  8. Segregation analysis of microsatellite (SSR) markers in sugarcane polyploids.

    Science.gov (United States)

    Lu, X; Zhou, H; Pan, Y-B; Chen, C Y; Zhu, J R; Chen, P H; Li, Y-R; Cai, Q; Chen, R K

    2015-01-01

    No information is available on segregation analysis of DNA markers involving both pollen and self-progeny. Therefore, we used capillary electrophoresis- and fluorescence-based DNA fingerprinting together with single pollen collection and polymerase chain reaction (PCR) to investigate simple sequence repeat (SSR) marker segregation among 964 single pollens and 288 self-progenies (S1) of sugarcane cultivar LCP 85-384. Twenty SSR DNA fragments (alleles) were amplified by five polymorphic SSR markers. Only one non-parental SSR allele was observed in 2392 PCRs. SSR allele inheritance was in accordance with Mendelian laws of segregation and independent assortment. Highly significant correlation coefficients were found between frequencies of observed and expected genotypes in pollen and S1 populations. Within the S1 population, the most frequent genotype of each SSR marker was the parental genotype of the same marker. The number of genotypes was higher in pollen than S1 population. PIC values of the five SSR markers were greater in pollen than S1 populations. Eleven of 20 SSR alleles (55%) were segregated in accordance with Mendelian segregation ratios expected from pollen and S1 populations of a 2n = 10x polyploid. Six of 20 SSR alleles were segregated in a 3:1 (presence:absence) ratio and were simplex markers. Four and one alleles were segregated in 77:4 and 143:1 ratios and considered duplex and triplex markers, respectively. Segregation ratios of remaining alleles were unexplainable. The results provide information about selection of crossing parents, estimation of seedling population optimal size, and promotion of efficient selection, which may be valuable for sugarcane breeders. PMID:26782486

  9. Electrum, the Gold-Silver Alloy, from the Bulk Scale to the Nanoscale: Synthesis, Properties, and Segregation Rules.

    Science.gov (United States)

    Guisbiers, Grégory; Mendoza-Cruz, Rubén; Bazán-Díaz, Lourdes; Velázquez-Salazar, J Jesús; Mendoza-Perez, Rafael; Robledo-Torres, José Antonio; Rodriguez-Lopez, José-Luis; Montejano-Carrizales, Juan Martín; Whetten, Robert L; José-Yacamán, Miguel

    2016-01-26

    The alloy Au-Ag system is an important noble bimetallic phase, both historically (as "Electrum") and now especially in nanotechnology, as it is applied in catalysis and nanomedicine. To comprehend the structural characteristics and the thermodynamic stability of this alloy, a knowledge of its phase diagram is required that considers explicitly its size and shape (morphology) dependence. However, as the experimental determination remains quite challenging at the nanoscale, theoretical guidance can provide significant advantages. Using a regular solution model within a nanothermodynamic approach to evaluate the size effect on all the parameters (melting temperature, melting enthalpy, and interaction parameters in both phases), the nanophase diagram is predicted. Besides an overall shift downward, there is a "tilting" effect on the solidus-liquidus curves for some particular shapes exposing the (100) and (110) facets (cube, rhombic dodecahedron, and cuboctahedron). The segregation calculation reveals the preferential presence of silver at the surface for all the polyhedral shapes considered, in excellent agreement with the latest transmission electron microscopy observations and energy dispersive spectroscopy analysis. By reviewing the nature of the surface segregated element of different bimetallic nanoalloys, two surface segregation rules, based on the melting temperatures and surface energies, are deduced. Finally, the optical properties of Au-Ag nanoparticles, calculated within the discrete dipole approximation, show the control that can be achieved in the tuning of the local surface plasmon resonance, depending of the alloy content, the chemical ordering, the morphology, the size of the nanoparticle, and the nature of the surrounding environment. PMID:26605557

  10. Bulk hydrogen analysis by neutron scattering

    International Nuclear Information System (INIS)

    The efforts of the UCT-based group now working on bulk analysis using neutrons are directed mainly towards developing methods for detecting concealed explosive or other hidden contraband, such as drugs. The technique which we are developing, called fast neutron scattering analysis (FNSA), is based on the detection and measurement of hydrogen and other elements, particularly carbon, nitrogen and oxygen, by means of fast neutron scattering measurements. This report describes progress achieved over the past year in the work on fast neutron scattering analysis and in the development of detection techniques for plastic land mines

  11. Racial segregation and maternal smoking during pregnancy: a multilevel analysis using the racial segregation interaction index

    OpenAIRE

    Yang, Tse-Chuan; Shoff, Carla; Aggie J. Noah; Black, Nyesha; Sparks, Corey S.

    2014-01-01

    Drawing from both the place stratification and ethnic enclave perspectives, we use multilevel modeling to investigate the relationships between women’s race/ethnicity (i.e., non-Hispanic white, non-Hispanic black, Asian, and Hispanic) and maternal smoking during pregnancy; and examine if these relationships are moderated by racial segregation in the continental United States. The results show that increased interaction with whites is associated with increased probability of maternal smoking d...

  12. Segregation Analysis on Genetic System of Quantitative Traits in Plants

    Institute of Scientific and Technical Information of China (English)

    Gai Junyi

    2006-01-01

    Based on the traditional polygene inheritance model of quantitative traits,the author suggests the major gene and polygene mixed inheritance model.The model was considered as a general one,while the pure major gene and pure polygene inheritance model was a specific case of the general model.Based on the proposed theory,the author established the segregation analysis procedure to study the genetic system of quantitative traits of plants.At present,this procedure can be used to evaluate the genetic effect of individual major genes (up to two to three major genes),the collective genetic effect of polygene,and their heritability value.This paper introduces how to establish the procedure,its main achievements,and its applications.An example is given to illustrate the steps,methods,and effectiveness of the procedure.

  13. Measuring Residential Segregation: An Application of Trend Surface Analysis.

    Science.gov (United States)

    Spriggs, William

    1984-01-01

    Presents a measure of racial residential segregation which conforms to the traditional attributes of segregation indices, but includes sensitivity to the spatial patterns of White and non-White residence in a city. Reviews earlier measures, describes the new one, and applies it to racial housing patterns in Norfolk, Virginia, in 1890. (KH)

  14. A novel approach to measure grain boundary segregation in bulk polycrystalline materials in dependence of the boundaries’ five rotational degrees of freedom

    International Nuclear Information System (INIS)

    We demonstrate a simplified nondestructive 3-D electron backscatter diffraction (EBSD) methodology that enables the measurement of all five degrees of freedom of grain boundaries (GBs) combined with segregation analysis using atom probe tomography (APT). The approach is based on two 2-D EBSD measurements on orthogonal surfaces at a sharp edge of the specimen followed by site-specific GB composition analysis using APT. An example of an asymmetric Σ9 boundary exhibiting GB segregation emphasizes the need for complete GB characterization in this context

  15. A Comparative Analysis of Black and Mexican American Residential Segregation in Southwestern Cities.

    Science.gov (United States)

    Meier, Michael; Feagin, Joe

    Discrimination, poverty, and ethnic attachment or choice have been identified as 3 factors that might explain residential segregation. This paper purported: (1) to comparatively document the nature and extent of metropolitan segregation of Mexican Americans and Blacks in the Southwest; (2) to perform an exploratory analysis of the significance of…

  16. Identification of Genome-Wide Variants and Discovery of Variants Associated with Brassica rapa Clubroot Resistance Gene Rcr1 through Bulked Segregant RNA Sequencing.

    Science.gov (United States)

    Yu, Fengqun; Zhang, Xingguo; Huang, Zhen; Chu, Mingguang; Song, Tao; Falk, Kevin C; Deora, Abhinandan; Chen, Qilin; Zhang, Yan; McGregor, Linda; Gossen, Bruce D; McDonald, Mary Ruth; Peng, Gary

    2016-01-01

    Clubroot, caused by Plasmodiophora brassicae, is an important disease on Brassica species worldwide. A clubroot resistance gene, Rcr1, with efficacy against pathotype 3 of P. brassicae, was previously mapped to chromosome A03 of B. rapa in pak choy cultivar "Flower Nabana". In the current study, resistance to pathotypes 2, 5 and 6 was shown to be associated with Rcr1 region on chromosome A03. Bulked segregant RNA sequencing was performed and short read sequences were assembled into 10 chromosomes of the B. rapa reference genome v1.5. For the resistant (R) bulks, a total of 351.8 million (M) sequences, 30,836.5 million bases (Mb) in length, produced 120-fold coverage of the reference genome. For the susceptible (S) bulks, 322.9 M sequences, 28,216.6 Mb in length, produced 109-fold coverage. In total, 776.2 K single nucleotide polymorphisms (SNPs) and 122.2 K insertion / deletion (InDels) in R bulks and 762.8 K SNPs and 118.7 K InDels in S bulks were identified; each chromosome had about 87% SNPs and 13% InDels, with 78% monomorphic and 22% polymorphic variants between the R and S bulks. Polymorphic variants on each chromosome were usually below 23%, but made up 34% of the variants on chromosome A03. There were 35 genes annotated in the Rcr1 target region and variants were identified in 21 genes. The numbers of poly variants differed significantly among the genes. Four out of them encode Toll-Interleukin-1 receptor / nucleotide-binding site / leucine-rich-repeat proteins; Bra019409 and Bra019410 harbored the higher numbers of polymorphic variants, which indicates that they are more likely candidates of Rcr1. Fourteen SNP markers in the target region were genotyped using the Kompetitive Allele Specific PCR method and were confirmed to associate with Rcr1. Selected SNP markers were analyzed with 26 recombinants obtained from a segregating population consisting of 1587 plants, indicating that they were completely linked to Rcr1. Nine SNP markers were used for marker

  17. Identification of Genome-Wide Variants and Discovery of Variants Associated with Brassica rapa Clubroot Resistance Gene Rcr1 through Bulked Segregant RNA Sequencing

    Science.gov (United States)

    Yu, Fengqun; Zhang, Xingguo; Huang, Zhen; Chu, Mingguang; Song, Tao; Falk, Kevin C.; Deora, Abhinandan; Chen, Qilin; Zhang, Yan; McGregor, Linda; Gossen, Bruce D.; McDonald, Mary Ruth; Peng, Gary

    2016-01-01

    Clubroot, caused by Plasmodiophora brassicae, is an important disease on Brassica species worldwide. A clubroot resistance gene, Rcr1, with efficacy against pathotype 3 of P. brassicae, was previously mapped to chromosome A03 of B. rapa in pak choy cultivar “Flower Nabana”. In the current study, resistance to pathotypes 2, 5 and 6 was shown to be associated with Rcr1 region on chromosome A03. Bulked segregant RNA sequencing was performed and short read sequences were assembled into 10 chromosomes of the B. rapa reference genome v1.5. For the resistant (R) bulks, a total of 351.8 million (M) sequences, 30,836.5 million bases (Mb) in length, produced 120-fold coverage of the reference genome. For the susceptible (S) bulks, 322.9 M sequences, 28,216.6 Mb in length, produced 109-fold coverage. In total, 776.2 K single nucleotide polymorphisms (SNPs) and 122.2 K insertion / deletion (InDels) in R bulks and 762.8 K SNPs and 118.7 K InDels in S bulks were identified; each chromosome had about 87% SNPs and 13% InDels, with 78% monomorphic and 22% polymorphic variants between the R and S bulks. Polymorphic variants on each chromosome were usually below 23%, but made up 34% of the variants on chromosome A03. There were 35 genes annotated in the Rcr1 target region and variants were identified in 21 genes. The numbers of poly variants differed significantly among the genes. Four out of them encode Toll-Interleukin-1 receptor / nucleotide-binding site / leucine-rich-repeat proteins; Bra019409 and Bra019410 harbored the higher numbers of polymorphic variants, which indicates that they are more likely candidates of Rcr1. Fourteen SNP markers in the target region were genotyped using the Kompetitive Allele Specific PCR method and were confirmed to associate with Rcr1. Selected SNP markers were analyzed with 26 recombinants obtained from a segregating population consisting of 1587 plants, indicating that they were completely linked to Rcr1. Nine SNP markers were used for marker

  18. Wilhelm Weinberg’s Early Contribution to Segregation Analysis

    OpenAIRE

    Stark, Alan; Seneta, Eugene

    2013-01-01

    Wilhelm Weinberg (1862–1937) is a largely forgotten pioneer of human and medical genetics. His name is linked with that of the English mathematician G. H. Hardy in the Hardy–Weinberg law, pervasive in textbooks on population genetics since it expresses stability over generations of zygote frequencies AA, Aa, aa under random mating. One of Weinberg’s signal contributions, in an article whose centenary we celebrate, was to verify that Mendel’s segregation law still held in the setting of human ...

  19. An Asymptotic Analysis of a 2-D Model of Dynamically Active Compartments Coupled by Bulk Diffusion

    Science.gov (United States)

    Gou, J.; Ward, M. J.

    2016-04-01

    A class of coupled cell-bulk ODE-PDE models is formulated and analyzed in a two-dimensional domain, which is relevant to studying quorum-sensing behavior on thin substrates. In this model, spatially segregated dynamically active signaling cells of a common small radius ɛ ≪ 1 are coupled through a passive bulk diffusion field. For this coupled system, the method of matched asymptotic expansions is used to construct steady-state solutions and to formulate a spectral problem that characterizes the linear stability properties of the steady-state solutions, with the aim of predicting whether temporal oscillations can be triggered by the cell-bulk coupling. Phase diagrams in parameter space where such collective oscillations can occur, as obtained from our linear stability analysis, are illustrated for two specific choices of the intracellular kinetics. In the limit of very large bulk diffusion, it is shown that solutions to the ODE-PDE cell-bulk system can be approximated by a finite-dimensional dynamical system. This limiting system is studied both analytically, using a linear stability analysis and, globally, using numerical bifurcation software. For one illustrative example of the theory, it is shown that when the number of cells exceeds some critical number, i.e., when a quorum is attained, the passive bulk diffusion field can trigger oscillations through a Hopf bifurcation that would otherwise not occur without the coupling. Moreover, for two specific models for the intracellular dynamics, we show that there are rather wide regions in parameter space where these triggered oscillations are synchronous in nature. Unless the bulk diffusivity is asymptotically large, it is shown that a diffusion-sensing behavior is possible whereby more clustered spatial configurations of cells inside the domain lead to larger regions in parameter space where synchronous collective oscillations between the small cells can occur. Finally, the linear stability analysis for these cell-bulk

  20. An Asymptotic Analysis of a 2-D Model of Dynamically Active Compartments Coupled by Bulk Diffusion

    Science.gov (United States)

    Gou, J.; Ward, M. J.

    2016-08-01

    A class of coupled cell-bulk ODE-PDE models is formulated and analyzed in a two-dimensional domain, which is relevant to studying quorum-sensing behavior on thin substrates. In this model, spatially segregated dynamically active signaling cells of a common small radius ɛ ≪ 1 are coupled through a passive bulk diffusion field. For this coupled system, the method of matched asymptotic expansions is used to construct steady-state solutions and to formulate a spectral problem that characterizes the linear stability properties of the steady-state solutions, with the aim of predicting whether temporal oscillations can be triggered by the cell-bulk coupling. Phase diagrams in parameter space where such collective oscillations can occur, as obtained from our linear stability analysis, are illustrated for two specific choices of the intracellular kinetics. In the limit of very large bulk diffusion, it is shown that solutions to the ODE-PDE cell-bulk system can be approximated by a finite-dimensional dynamical system. This limiting system is studied both analytically, using a linear stability analysis and, globally, using numerical bifurcation software. For one illustrative example of the theory, it is shown that when the number of cells exceeds some critical number, i.e., when a quorum is attained, the passive bulk diffusion field can trigger oscillations through a Hopf bifurcation that would otherwise not occur without the coupling. Moreover, for two specific models for the intracellular dynamics, we show that there are rather wide regions in parameter space where these triggered oscillations are synchronous in nature. Unless the bulk diffusivity is asymptotically large, it is shown that a diffusion-sensing behavior is possible whereby more clustered spatial configurations of cells inside the domain lead to larger regions in parameter space where synchronous collective oscillations between the small cells can occur. Finally, the linear stability analysis for these cell-bulk

  1. On-line and bulk analysis for the resource industries

    International Nuclear Information System (INIS)

    Nuclear techniques are the basis of many CSIRO on-line and bulk analysis systems that are now widely used in the mineral and energy industries. The continuous analysis and rapid response of these systems have led to improved control of mining, processing and blending operations. This paper reviews recent developments in neutron, gamma-ray and X-ray techniques for on-line and bulk analysis by CSIRO Minerals including neutron techniques for the on-conveyor belt determination of the composition of cement raw meal, the on-line analysis of composition in pyrometallurgical applications, the on-conveyor belt determination of ash in coal, and the rapid and accurate determination of gold in bulk laboratory samples. The paper also discusses a new gamma-ray technique for the on-line determination of ash in coal and the application of X-ray diffraction techniques for the on-line determination of mineralogy in the cement industry

  2. Cost-benefit analysis for waste segregation at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    This report presents a cost-benefit analysis for the segregation of mixed, hazardous, and nonhazardous wastes at Lawrence Livermore National Laboratory (LLNL). The cost-benefit analysis was conducted to determine if current waste segregation practices and additional candidates for waste segregation at LLNL might have the potential for significant waste source reduction and annual savings in treatment and disposal costs. In the following cost-benefit analysis, capital costs and recurring costs of waste segregation practices are compared to the economic benefits of savings in treatment and disposal costs. Indirect or overhead costs associated with these wastes are not available and have not been included. Not considered are additional benefits of waste segregation such as decreased potential for liability to LLNL for adverse environmental effects, improved worker safety, and enhanced LLNL image within the community because of environmental improvement. The economic evaluations in this report are presented on a Lab-wide basis. All hazardous wastes generated by a program are turned over to the Hazardous Waste Management (HWM) group, which is responsible for the storage, treatment, or disposal of these wastes and funded funded directly for this work

  3. Segregation analysis of hepatocellular carcinoma in a moderately high-incidence area of East China

    Institute of Scientific and Technical Information of China (English)

    Ru-Lin Cai; Wei Meng; Hong-Yan Lu; Wen-Yao Lin; Feng Jiang; Fu-Min Shen

    2003-01-01

    AIM: To explore the mode of inheritance of hepatocellular carcinoma (HCC) in a moderately high-incidence area of East China.METHODS: A pedigree survey was conducted in 210 families (3315 individuals) ascertained through 210 HCC probands in Haimen, Jiangsu Province. Simple segregation analysis was conducted using SEGRANB software. The probability of ascertainment (π), segregation ratio (p), and the proportion of sporadic cases (x) were estimated. Complex segregation analysis was performed using the REGTL program of S.A.G.E.Models were fitted on the data of 3212 individuals that allowed for personal HBsAg status and variable age of onset in REGTL program.RESULTS: The estimate of segregation ratio was 0.191 by SEGRANB. The probability of ascertainment was 0.0266, and the proportion of sporadic cases was 0.465. The results of complex segregation analysis showed that Mendelian autosomal recessive inheritance of a major gene that influenced the age of onset distribution of HCC, provided the best fit to the data. In the best-fitting recessive model,the frequency of the disease allele was 0.11138. HBsAg seropositive status would significantly increase the risk of developing HCC.CONCLUSION: These results suggest that at least one major gene is involved in the genetic predisposition to develop HCC at an earlier age of onset. The seropositive HBsAg status can significantly increase the risk of developing HCC, which provides strong support for the interaction between genetic and environmental risk factors.

  4. STRUCTURAL CHARACTERIZATION OF POLYETHYLENES BY DSC ANALYSIS AFTER CRYSTALLIZATION SEGREGATION

    Institute of Scientific and Technical Information of China (English)

    Yu Ma; Mao Xu

    2000-01-01

    The molecular structure of polyethylene (PE) samples with various comonomers including propylene, 1-butene and 1-hexene was investigated by DSC and 13C-NMR techniques. The density of the samples varies from 0.948 g/cm3 to 0.917 g/cm3, and the molecular weight determined by the GPC method is in the range of 1~2 × 105. The branch point content of the samples was determined by 13C-NMR measurements and was found to be less than 20 per 1000 C atoms along the main chain. Crystallization segregation DSC technique (CSDSC) was used to characterize the branch point distribution or the segment length distribution of PEs. The crystallization segregation was performed in a successive annealing process at decreasing temperatures. The interval of two successive annealing temperatures was 6 K, and the time length of each annealing step was 2.5 h. The CSDSC results clearly indicate that all the PE samples used, including some metallocene PEs,more or less exhibit their non-uniformity in segment length distribution, and bimodal or multimodal CSDSC curves were usually observed. For quantitative characterization of the CSDSC curves and the segment length distribution two parameters,the average melting point, TmAV, and the root-mean-square deviation of melting temperature, (ATm2AV)1/2, were proposed.TmAV is corresponding to the average segment length due to branching and (ATm2AV)1/2 gives information about the width of the segment length distribution. Experimental results show that both the degree of average melting temperature depression and the width of the distribution seem to increase with increasing the branching content and are dependent on the type of comonomers. Very good reproducibility and additivity of the CSDSC method were evidenced experimentally. It was concluded that the CSDSC technique is a sensitive and convenient method for characterizing the segment length distribution of branched polyethylenes and will be of great interest in structure-property relationship

  5. Integrated analysis software for bulk power system stability

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Nagao, T.; Takahashi, K. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1994-12-31

    This paper presents Central Research Inst.of Electric Power Industry - CRIEPI`s - own developed three softwares for bulk power network analysis and the user support system which arranges tremendous data necessary for these softwares with easy and high reliability. (author) 3 refs., 7 figs., 2 tabs.

  6. Study of microstructure and silicon segregation in cast iron using color etching and electron microprobe analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vazehrad, S., E-mail: vazehrad@kth.se [Dep. Materials Science and Engineering/Casting of Metals, Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Elfsberg, J., E-mail: jessica.elfsberg@scania.com [Scania CV AB, SE-151 87 Södertälje (Sweden); Diószegi, A., E-mail: attila.dioszegi@jth.hj.se [Dep. Materials Science and Engineering/Casting of Metals, Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Dep. Mechanical Engineering/Materials and Manufacturing-Foundry Technology, Jönköping University, SE-551 11 Jönköping (Sweden)

    2015-06-15

    An investigation on silicon segregation of lamellar, compacted and nodular graphite iron was carried out by applying a selective, immersion color etching and a modified electron microprobe to study the microstructure. The color etched micrographs of the investigated cast irons by revealing the austenite phase have provided data about the chronology and mechanism of microstructure formation. Moreover, electron microprobe has provided two dimensional segregation maps of silicon. A good agreement was found between the segregation profile of silicon in the color etched microstructure and the silicon maps achieved by electron microprobe analysis. However, quantitative silicon investigation was found to be more accurate than color etching results to study the size of the eutectic colonies. - Highlights: • Sensitivity of a color etchant to silicon segregation is quantitatively demonstrated. • Si segregation measurement by EMPA approved the results achieved by color etching. • Color etched micrographs provided data about solidification mechanism in cast irons. • Austenite grain boundaries were identified by measuring the local Si concentration.

  7. Study of microstructure and silicon segregation in cast iron using color etching and electron microprobe analysis

    International Nuclear Information System (INIS)

    An investigation on silicon segregation of lamellar, compacted and nodular graphite iron was carried out by applying a selective, immersion color etching and a modified electron microprobe to study the microstructure. The color etched micrographs of the investigated cast irons by revealing the austenite phase have provided data about the chronology and mechanism of microstructure formation. Moreover, electron microprobe has provided two dimensional segregation maps of silicon. A good agreement was found between the segregation profile of silicon in the color etched microstructure and the silicon maps achieved by electron microprobe analysis. However, quantitative silicon investigation was found to be more accurate than color etching results to study the size of the eutectic colonies. - Highlights: • Sensitivity of a color etchant to silicon segregation is quantitatively demonstrated. • Si segregation measurement by EMPA approved the results achieved by color etching. • Color etched micrographs provided data about solidification mechanism in cast irons. • Austenite grain boundaries were identified by measuring the local Si concentration

  8. Optimization of PGNAA instrument design for bulk coal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.; Salgado, J.; Carvalho, F.G. (National Laboratory for Industrial Technology and Engineering, Sacavem (Portugal). Physics Dept.)

    1993-06-01

    A simulation study of a PGNAA system for bulk coal analysis has been carried out using the MCNP code to investigate the dependence of the system's performance on design parameters for different coal compositions and bulk densities. Calculations were performed for simulated arrangements using a naked point [sup 252]Cf source and the source surrounded by a sphere of moderating material. Results for different sample sizes and different radii of the moderating sphere are reported. The system's optimization based upon the proper choice of sample size and amount of external thermalization is discussed. 3 refs., 18 figs., 1 tab.

  9. EBSD analysis of MgB2 bulk superconductors

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Inoue, K.; Muralidhar, M.; Berger, K.; Noudem, J.

    2016-04-01

    The grain orientation, the texture and the grain boundary misorientations are important parameters for the understanding of the magnetic properties of the bulk MgB2 samples intended for super-magnet applications. Such data can be provided by electron backscatter diffraction (EBSD) analysis. However, as the grain size (GS) of the MgB2 bulks is preferably in the 100-200 nm range, the common EBSD technique working in reflection operates properly only on highly dense samples. In order to achieve a reasonably good Kikuchi pattern quality on all samples, we apply here the newly developed transmission EBSD (t-EBSD) technique to several bulk MgB2 samples. This method requires the preparation of TEM slices by means of focused ion-beam milling, which are then analyzed within the SEM, operating with a specific sample holder. We present several EBSD mappings of samples prepared with different techniques and at various reaction temperatures.

  10. Nonmetropolitan Residential Segregation Revisited.

    Science.gov (United States)

    Murdock, Steve H.; And Others

    1994-01-01

    Analysis of 1980 and 1990 Censuses of Population and Housing for Texas found overall black-white and Anglo-Hispanic residential segregation declined substantially. Nonmetropolitan counties were more segregated than metropolitan counties in both years, but growing nonmetro places showed the greatest segregation declines. Analyses controlling for…

  11. Analysis of T-DNA integration and generative segregation in transgenic winter triticale (x Triticosecale Wittmack

    Directory of Open Access Journals (Sweden)

    Hensel Goetz

    2012-09-01

    Full Text Available Abstract Background While the genetic transformation of the major cereal crops has become relatively routine, to date only a few reports were published on transgenic triticale, and robust data on T-DNA integration and segregation have not been available in this species. Results Here, we present a comprehensive analysis of stable transgenic winter triticale cv. Bogo carrying the selectable marker gene HYGROMYCIN PHOSPHOTRANSFERASE (HPT and a synthetic green fluorescent protein gene (gfp. Progeny of four independent transgenic plants were comprehensively investigated with regard to the number of integrated T-DNA copies, the number of plant genomic integration loci, the integrity and functionality of individual T-DNA copies, as well as the segregation of transgenes in T1 and T2 generations, which also enabled us to identify homozygous transgenic lines. The truncation of some integrated T-DNAs at their left end along with the occurrence of independent segregation of multiple T-DNAs unintendedly resulted in a single-copy segregant that is selectable marker-free and homozygous for the gfp gene. The heritable expression of gfp driven by the maize UBI-1 promoter was demonstrated by confocal laser scanning microscopy. Conclusions The used transformation method is a valuable tool for the genetic engineering of triticale. Here we show that comprehensive molecular analyses are required for the correct interpretation of phenotypic data collected from the transgenic plants.

  12. Segregation in Minds. Analysis on the Statistical and Mental-based Socio-spatial Segregation in a Hungarian City

    OpenAIRE

    Rácz, Attila

    2015-01-01

    In this paper, I explore socio-spatial segregation from a particular perspective, which may probably be considered a novelty in the investigation of spatial social patterns, as it focuses on questions such as: What kind of distinction occurs between socio-spatial patterns designated by statistical data and the cognitive representations of those patterns in people’s minds? And what explains these differences, and what kind of impact can they generate?

  13. Segregation in Minds. Analysis on the Statistical and Mental-based Socio-spatial Segregation in a Hungarian City

    Directory of Open Access Journals (Sweden)

    RÁCZ, Attila

    2015-03-01

    Full Text Available In this paper, I explore socio-spatial segregation from a particular perspective, which may probably be considered a novelty in the investigation of spatial social patterns, as it focuses on questions such as: What kind of distinction occurs between socio-spatial patterns designated by statistical data and the cognitive representations of those patterns in people’s minds? And what explains these differences, and what kind of impact can they generate?

  14. An index of information content for genotype probabilities derived from segregation analysis.

    Science.gov (United States)

    Kinghorn, B P

    1997-02-01

    A genotype probability index (GPI) is proposed to indicate the information content of genotype probabilities derived from a segregation analysis. Typically, some individuals are genotyped at a marker locus or a quantitative trait locus, and segregation analysis is used to make genotype inferences about ungenotyped relatives. Genotype probabilities for a two-allele autosomal locus are plotted on a triangular surface. The GPI has a value of zero at the point corresponding to Hardy-Weinberg frequencies, and a value of 100% at the vertices of the triangle. Trigonometric functions are used to help calculate intermediate index values. It is proposed that such an index can be useful to help identify which ungenotyped individuals or loci should be genotyped to maximize the benefit/cost of genotyping operations. PMID:9071600

  15. Linkage and Segregation Analysis of Black and Brindle Coat Color in Domestic Dogs

    OpenAIRE

    Kerns, Julie A.; Cargill, Edward J; Clark, Leigh Anne; Candille, Sophie I.; Berryere, Tom G.; Olivier, Michael; Lust, George; Todhunter, Rory J.; Schmutz, Sheila M.; Murphy, Keith E; Barsh, Gregory S

    2007-01-01

    Mutations of pigment type switching have provided basic insight into melanocortin physiology and evolutionary adaptation. In all vertebrates that have been studied to date, two key genes, Agouti and Melanocortin 1 receptor (Mc1r), encode a ligand-receptor system that controls the switch between synthesis of red–yellow pheomelanin vs. black–brown eumelanin. However, in domestic dogs, historical studies based on pedigree and segregation analysis have suggested that the pigment type-switching sy...

  16. A variable age of onset segregation model for linkage analysis, with correction for ascertainment, applied to glioma

    DEFF Research Database (Denmark)

    Sun, Xiangqing; Vengoechea, Jaime; Elston, Robert;

    2012-01-01

    We propose a 2-step model-based approach, with correction for ascertainment, to linkage analysis of a binary trait with variable age of onset and apply it to a set of multiplex pedigrees segregating for adult glioma.......We propose a 2-step model-based approach, with correction for ascertainment, to linkage analysis of a binary trait with variable age of onset and apply it to a set of multiplex pedigrees segregating for adult glioma....

  17. Neutron Texture Analysis at bulk YBaCuO cylinders

    International Nuclear Information System (INIS)

    Complete text of publication follows. Complete text of publication follows. Neutron Texture Analysis is the only method to get bulk information about the tilting of the c-axes and about twists around the c-axes in a bulk YBaCuO cylinder. The YBaCuO cylinders were produced in a melt and recrystallisation is performed with a seed crystal implanted at the peritectic temperature into the melt. The implanted seed crystal produces a sharp texture, which is necessary for high induced superconducting currents in the HTS and therefore for a high repulsing force repulsing an inducting and levitated permanent magnet. One YBaCuO cylinder was cut into 21 pieces to study the decreasing ordering influence of the seed crystal in direction of the boundary of the YBaCuO cylinder. The c-axis orientation distribution was measured at the (005) reflection and the twists around the c-axes were measured at the (113) reflection. (author)

  18. Micro and bulk analysis of prostate tissues classified as hyperplasia

    Science.gov (United States)

    Kwiatek, W. M.; Banaś, A.; Banaś, K.; Cinque, G.; Dyduch, G.; Falkenberg, G.; Kisiel, A.; Marcelli, A.; Podgórczyk, M.

    2007-07-01

    BPH (Benign Prostatic Hyperplasia) is the most common benign neoplasm (non cancerous enlargement of the prostate gland), whose prevalence increases with age. The gland, when increased in size, exerts pressure on the urethra, causing obstruction to urine flow. The latter may result in severe urinary tract and kidney conditions. In this work prostate samples from patients diagnosed with BPH were analyzed using synchrotron radiation. Micro-analysis of the hyperplastic samples was carried out on the L-beam line at HASYLAB, DESY (Germany), while bulk analysis on selected samples was performed at the DRX2 beamline at LNF, Frascati (Italy). Microanalysis with a mono-energetic beam 15 μm in diameter confirmed that concentrations of certain elements, such as S, Mn, Cu, Fe and Zn, are good indicators of pathological disorders in prostate tissue that may be considered effective tracers of developing compliant. The concentrations of Mn, Cu, Fe and Zn are higher in hyperplastic tissues, as compared to normal ones, while for sulphur the opposite is observed. Additionally, Fe and S K-edge XANES (X-ray Absorption Near Edge Structure) spectroscopy experiments were carried out in order to determine the chemical speciation of these elements in our samples.

  19. Atomistic Analysis Of Radiation-Induced Segregation In Ion-Irradiated Stainless Steel 316

    Directory of Open Access Journals (Sweden)

    Lee G.-G.

    2015-06-01

    Full Text Available Stainless steel (SS is a well-known material for the internal parts of nuclear power plants. It is known that these alloys exhibit radiation-induced segregation (RIS at point defect sinks at moderate temperature, while in service. The RIS behavior of SS can be a potential problem by increasing the susceptibility to irradiation-assisted stress corrosion cracking. In this work, the RIS behavior of solute atoms at sinks in SS 316 irradiated with Fe4+ ions were characterized by atom probe tomography (APT. There were torus-shaped defects along with a depletion of Cr and enrichment of Ni and Si. These clusters are believed to be dislocation loops resulting from irradiation. The segregation of solutes was also observed for various defect shapes. These observations are consistent with other APT results from the literature. The composition of the clusters was analyzed quantitatively almost at the atomic scale. Despite the limitations of the experiments, the APT analysis was well suited for discovering the structure of irradiation defects and performing a quantitative analysis of RIS in irradiated specimens.

  20. SAFETY ANALYSIS OF THE DEMONSTRATION BULK VITRIFICATION SYSTEM

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) and CH2M HILL, Hanford Group, Inc. (CH2M HILL) [also referred to as the Tank Farm Contractor (TFC)] are evaluating the Demonstration Bulk Vitrification System (DBVS) as a supplemental treatment technology for low-activity waste (LAW) at the Hanford Site. As a new facility at Hanford, the safety analysis for the DBVS is being subjected to new and evolving DOE requirements. Hazard categorization for the facility is being closely examined since this determines whether performance category (PC)-2 or PC-3 requirements are to be applied for natural phenomena hazards, as well as differing requirements under Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 2004-2, Active Confinement Systems. Questions have also arisen regarding application of DOE-STD-3009-94, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses, or DOE-STD-1189-2008, Integration of Safety into the Design Process, format and content, as well as full implementation of DOE-STD-1186-2004, Specific Administrative Controls and naming conventions and content requirements for the interim safety analysis documents under DOE O 413.3A, Program and Project Management for the Acquisition of Capital Assets (e.g., Preliminary Documented Safety Analysis or Preliminary Safety Design Report). Another challenge is the integration of the programmatic chapters of the safety document with those of the Hanford tank farms, since the tank farms Safety Management Programs (SMP) are relied upon for the DBVS facility. All of these issues and their resolutions, as well as the level of scrutiny to which internal and external regulators have held this project's safety analysis, will be discussed in this paper

  1. Theoretical analysis of ac losses in high temperature superconducting bulks

    International Nuclear Information System (INIS)

    Ac loss behavior in HTS bulk materials is studied by developing an analytic method. The self-heating effect on the distributions of temperature in HTS bulks has been calculated. A critical frequency which sets the upper limit for driving frequency of the external field in sustaining a superconducting state is obtained. Our model provides useful information of understanding the experimental phenomena, including an anomalous ac loss behavior, a retardation of the inner field respect to the external ac field, etc., in HTS bulk materials

  2. Econometric Analysis of Bulk Shipping: implications for investment strategies and financial decision-making

    NARCIS (Netherlands)

    S. Tsolakis

    2005-01-01

    textabstractThis thesis provides an econometric analysis of the bulk shipping markets and the implications for shipping investment and financial decision making. Chapter 1 sets the scene by providing a historic analysis of bulk shipping markets over the last 55 years. From this analysis, four shipp

  3. Genetic analysis, in silico prediction, and family segregation in long QT syndrome.

    Science.gov (United States)

    Riuró, Helena; Campuzano, Oscar; Berne, Paola; Arbelo, Elena; Iglesias, Anna; Pérez-Serra, Alexandra; Coll-Vidal, Mònica; Partemi, Sara; Mademont-Soler, Irene; Picó, Ferran; Allegue, Catarina; Oliva, Antonio; Gerstenfeld, Edward; Sarquella-Brugada, Georgia; Castro-Urda, Víctor; Fernández-Lozano, Ignacio; Mont, Lluís; Brugada, Josep; Scornik, Fabiana S; Brugada, Ramon

    2015-01-01

    The heritable cardiovascular disorder long QT syndrome (LQTS), characterized by prolongation of the QT interval on electrocardiogram, carries a high risk of sudden cardiac death. We sought to add new data to the existing knowledge of genetic mutations contributing to LQTS to both expand our understanding of its genetic basis and assess the value of genetic testing in clinical decision-making. Direct sequencing of the five major contributing genes, KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2, was performed in a cohort of 115 non-related LQTS patients. Pathogenicity of the variants was analyzed using family segregation, allele frequency from public databases, conservation analysis, and Condel and Provean in silico predictors. Phenotype-genotype correlations were analyzed statistically. Sequencing identified 36 previously described and 18 novel mutations. In 51.3% of the index cases, mutations were found, mostly in KCNQ1, KCNH2, and SCN5A; 5.2% of cases had multiple mutations. Pathogenicity analysis revealed 39 mutations as likely pathogenic, 12 as VUS, and 3 as non-pathogenic. Clinical analysis revealed that 75.6% of patients with QTc≥500 ms were genetically confirmed. Our results support the use of genetic testing of KCNQ1, KCNH2, and SCN5A as part of the diagnosis of LQTS and to help identify relatives at risk of SCD. Further, the genetic tools appear more valuable as disease severity increases. However, the identification of genetic variations in the clinical investigation of single patients using bioinformatic tools can produce erroneous conclusions regarding pathogenicity. Therefore segregation studies are key to determining causality. PMID:24667783

  4. Analysis of Gibbsian segregation at heterophase interfaces using analytical transmission electron microscopy: a novel approach

    OpenAIRE

    Kooi, B. J.; Wouters, O.; De Hosson, J. Th. M.

    2002-01-01

    A new and general approach to analyze Gibbsian segregation at heterophase interfaces is proposed. It is tested on the possible segregation of indium dissolved in a copper matrix to interfaces between MnO precipitates and the copper matrix. In the present approach the actual concentration of the segregating element in a monolayer at the interface is obtained. This is in contrast to line-scans or maps where the concentrations determined are a convolution of the concentration profiles with the e...

  5. PIXE–PIGE analysis of size-segregated aerosol samples from remote areas

    International Nuclear Information System (INIS)

    The chemical characterization of size-segregated samples is helpful to study the aerosol effects on both human health and environment. The sampling with multi-stage cascade impactors (e.g., Small Deposit area Impactor, SDI) produces inhomogeneous samples, with a multi-spot geometry and a non-negligible particle stratification. At LABEC (Laboratory of nuclear techniques for the Environment and the Cultural Heritage), an external beam line is fully dedicated to PIXE–PIGE analysis of aerosol samples. PIGE is routinely used as a sidekick of PIXE to correct the underestimation of PIXE in quantifying the concentration of the lightest detectable elements, like Na or Al, due to X-ray absorption inside the individual aerosol particles. In this work PIGE has been used to study proper attenuation correction factors for SDI samples: relevant attenuation effects have been observed also for stages collecting smaller particles, and consequent implications on the retrieved aerosol modal structure have been evidenced

  6. [Effect of gametocidal chromosome 4S' on the phenotype segregation ratio in genetic analysis of common wheat lines].

    Science.gov (United States)

    Vdovichenko, Zh V; Antoniuk, M Z; Ternovskaia, T K

    2003-01-01

    Using experimental data on genetic analysis of introgressive lines for the character "hairy leaf sheath" controlled by the "cuckoo" chromosome 4S1, the algorithm for calculation of the theoretical segregation ratio in F2 was developed. Segregation distortion is caused by non-viability of the majority of gametes lacking the chromosome 4S1. The frequency of functioning gametes without the chromosome 4S1 is determined by the probability p versus the theoretically expected ratio 7 nonviable: 9 viable ones. Since segregation involves two characters, gamete viability and hairiness, the ratio 15 hairy: 1 hairless was used as a basis for search of the frequency p by maximum-likelihood method using 16 populations F2 from crossing the lines differing in the character studied. PMID:14650327

  7. Stability analysis of active acoustic metamaterial with programmable bulk modulus

    International Nuclear Information System (INIS)

    Acoustic metamaterials (AMMs) have been considered as an effective means of controlling the propagation of acoustical wave energy through metamaterials. However, most of the currently exerted efforts are focused on studying passive metamaterials with fixed material properties. In this paper, the emphasis is placed on the development of a new class of one-dimensional acoustic metamaterials with effective bulk moduli that are programmed to vary according to any prescribed pattern along the volume of the metamaterial. Acoustic cavities coupled with either actively controlled Helmholtz or flush-mounted resonators are introduced to develop two possible configurations for obtaining active AMMs (AAMMs) with programmable bulk modulus capabilities. The resonators are provided with piezoelectric boundaries to enable control of the overall bulk modulus of the acoustic cavity through direct acoustic pressure feedback. Theoretical analyses of these two configurations of AAMMs are presented using the lumped-parameter modeling approach. The presented analyses are utilized to study the stability characteristics of the two configurations in an attempt to define their stable regions of operation. Numerical examples are presented to demonstrate the performance characteristics of the proposed AAMM configurations and their potential for generating prescribed spatial and spectral patterns of bulk modulus variation

  8. A Quantitative Analysis of the Increase in Public School Segregation in Delaware: 1989-2006

    Science.gov (United States)

    Glenn, William J.

    2011-01-01

    This study analyzes the increase in school segregation in Delaware from a quantitative perspective. The article tests the hypothesis that the declaration of unitary status that released the Wilmington area school districts from their desegregation order caused the increase in segregation. The research reveals that the declaration of unitary status…

  9. Prevalence and phylogenetic analysis of HTLV-1 in a segregated population in Iran.

    Science.gov (United States)

    Rafatpanah, Houshang; Torkamani, Mahmood; Valizadeh, Narges; Vakili, Rosita; Meshkani, Baratali; Khademi, Hassan; Gerayli, Sina; Mozhgani, Sayed Hamid Reza; Rezaee, Seyed Abdolrahim

    2016-07-01

    Human T-lymphotropic virus type 1 (HTLV-1) infection is an important health issue that affects a variety of endemic areas. The Khorasan province, mainly its capital Mashhad in northeastern Iran, was reported to be as one of these endemic regions. Torbat-e Heydarieh, a large city Southwest border to Mashhad with a segregated population was investigated for the prevalence and associated risk factors of HTLV-1 infection in 400 randomly selected individuals. Blood samples were tested for the presence of HTLV-1 antibodies via the ELISA method and then were confirmed by an Immunoblot test. For the presence of HTLV-1 in lymphocytes of infected subjects, PCR was performed on LTR and TAX regions. DNA sequencing of LTR fragment was also carried out to determine the phylogenetic of HTLV-1, using the Maximum likelihood method. HTLV-1 sero-reactivity (sero-prevalence) among the study population was 2% (8/400), of which 1.25% had HTLV-1 provirus in lymphocytes (actual prevalence). HTLV-1 infection was significantly associated with the age, marital status, and history of blood transfusion (P analysis, age showed the most significant correlation with the infection (P = 0.006, OR = 4.33). Based on our phylogenetic study, the HTLV-1 prevalent sequence type of Torbat-e Heydarieh belongs to the cosmopolitan subtype A. HTLV-1 prevalence in Torbat-e Heydarieh (1.25%) is low comparing to those of both Mashhad (2-3%) and Neishabour (3.5-5%) in the province of Khorasan. Thus, traveling mobility and population mixing such as marriage, bureaucratic affairs, occupation, and economic activities could be the usual routs of HTLV-1 new wave of spreading in this segregated city. J. Med. Virol. 88:1247-1253, 2016. © 2015 Wiley Periodicals, Inc. PMID:26680556

  10. Thermocline bulk shear analysis in the northern North Sea

    Science.gov (United States)

    Chen, Shengli; Polton, Jeff A.; Hu, Jianyu; Xing, Jiuxing

    2016-04-01

    Thermocline bulk shear is investigated in the northern North Sea using historical observations. The conventional bulk shear is modified to define a thermocline bulk shear (TBS), in order to better represent the shear across the thermocline. The TBS computed by observed currents is decomposed into components at different frequency bands. The near-inertial TBS is the largest component. Its dominance is significant during the period of high wind. It is formed by the wind-driven near-inertial current which has a distinct phase shift (˜180°) across the thermocline. A linear model is presented, which well simulates the observed near-inertial TBS, especially during the period of relatively strong wind. The semidiurnal TBS makes a secondary contribution to the total TBS. It is only slightly smaller than the near-inertial TBS when the wind is relatively weak. The large values of semidiurnal TBS are associated with semidiurnal currents which have a phase shift (˜30-40°) or a magnitude difference (˜5 cm/s) across the thermocline. The low-frequency (<0.7 cpd) TBS also makes an episodic contribution to the total. Its variation coincides with the Ekman transport during the period of relatively strong wind. The low-frequency TBS is mainly formed by an Ekman-like clockwise spiraling of velocity with depth or a distinct magnitude difference in velocities between upper and lower layers.

  11. Segregated flux balance analysis constrained by population structure/function data: the case of PHA production by mixed microbial cultures.

    Science.gov (United States)

    Pardelha, F; Albuquerque, M G E; Carvalho, G; Reis, M A M; Dias, J M L; Oliveira, R

    2013-08-01

    In this study we developed a segregated flux balance analysis (FBA) method to calculate metabolic flux distributions of the individual populations present in a mixed microbial culture (MMC). Population specific flux data constraints were derived from the raw data typically obtained by the fluorescence in situ hybridization (FISH) and microautoradiography (MAR)-FISH techniques. This method was applied to study the metabolic heterogeneity of a MMC that produces polyhydroxyalkanoates (PHA) from fermented sugar cane molasses. Three populations were identified by FISH, namely Paracoccus sp., Thauera sp., and Azoarcus sp. The segregated FBA method predicts a flux distribution for each of the identified populations. The method is shown to predict with high accuracy the average PHA storage flux and the respective monomeric composition for 16 independent experiments. Moreover, flux predictions by segregated FBA were slightly better than those obtained by nonsegregated FBA, and also highly concordant with metabolic flux analysis (MFA) estimated fluxes. The segregated FBA method can be of high value to assess metabolic heterogeneity in MMC systems and to derive more efficient eco-engineering strategies. For the case of PHA-producing MMC considered in this work, it becomes apparent that the PHA average monomeric composition might be controlled not only by the volatile fatty acids (VFA) feeding profile but also by the population composition present in the MMC. PMID:23475571

  12. Core and Conal Component Analysis of Pulsar B1933+16 --- Investigation of the Segregated Modes

    CERN Document Server

    Mitra, Dipanjan; Arjunwadkar, Mihir

    2016-01-01

    Radio pulsar B1933+16 is brightest core-radiation dominated pulsar in the Arecibo sky, and here we carry out a comprehensive high resolution polarimetric study of its radiation at both 1.5 and 4.6 GHz. At 1.5 GHz, the polarization is largely compatible with a rotating-vector model with $\\alpha$ and $\\beta$ values of 125 and --1.2$^{\\circ}$, such that the core and conal regions can be identified with the primary and secondary polarization modes and plausibly with the extraordinary and ordinary propagation modes. Polarization modal segregation of profiles shows that the core is comprised of two parts which we associate with later X-mode and earlier O-mode emission. Analysis of the broad microstructures under the core shows that they have similar timescales to those of the largely conal radiation of other pulsars studied earlier. Aberration/retardation analysis was here possible for both the conal and core radiation and showed average physical emission heights of about 200 km for each. Comparison with other core...

  13. 3DAP analysis of phosphorus segregation for thermal aged model RPV steel

    International Nuclear Information System (INIS)

    Phosphorus segregation in thermal aged nuclear reactor model pressure vessel (RPV) steels was investigated by three dimensional atom probe (3DAP). The model steel containing less Mn, Ni, Mo and different P compared to A508-Ⅲ was prepared by vacuum induction melting. After the initial heart treatment at 880℃-0.5 h and water quenching, the specimens were aged at 400℃ for up to 500 h. The results show that phosphorus segregated to the carbide/matrix interface in both containing lower phosphorus and higher phosphorus specimens. A precipitate containing phosphorus, silicon and carbon, with a thickness of about 20 nm, formed in the specimens aged for 150 h in specimen containing higher phosphorus. With the extension of ageing time, phosphorus and silicon segregated and formed a thin layer at the boundaries of Fe3C. The silicon segregation baffled the growth of Fe3C. (authors)

  14. Econometric Analysis of Bulk Shipping: implications for investment strategies and financial decision-making

    OpenAIRE

    Tsolakis, S.

    2005-01-01

    textabstractThis thesis provides an econometric analysis of the bulk shipping markets and the implications for shipping investment and financial decision making. Chapter 1 sets the scene by providing a historic analysis of bulk shipping markets over the last 55 years. From this analysis, four shipping markets (freight, newbuilding, second-hand and demolition) are distinguished as well as a fifth one (ship finance) that acts as a facilitator to the other four. Also, with the help of correlatio...

  15. Neural Segregation of Concurrent Speech: Effects of Background Noise and Reverberation on Auditory Scene Analysis in the Ventral Cochlear Nucleus.

    Science.gov (United States)

    Sayles, Mark; Stasiak, Arkadiusz; Winter, Ian M

    2016-01-01

    Concurrent complex sounds (e.g., two voices speaking at once) are perceptually disentangled into separate "auditory objects". This neural processing often occurs in the presence of acoustic-signal distortions from noise and reverberation (e.g., in a busy restaurant). A difference in periodicity between sounds is a strong segregation cue under quiet, anechoic conditions. However, noise and reverberation exert differential effects on speech intelligibility under "cocktail-party" listening conditions. Previous neurophysiological studies have concentrated on understanding auditory scene analysis under ideal listening conditions. Here, we examine the effects of noise and reverberation on periodicity-based neural segregation of concurrent vowels /a/ and /i/, in the responses of single units in the guinea-pig ventral cochlear nucleus (VCN): the first processing station of the auditory brain stem. In line with human psychoacoustic data, we find reverberation significantly impairs segregation when vowels have an intonated pitch contour, but not when they are spoken on a monotone. In contrast, noise impairs segregation independent of intonation pattern. These results are informative for models of speech processing under ecologically valid listening conditions, where noise and reverberation abound. PMID:27080680

  16. Statistical analysis of atom probe data: Detecting the early stages of solute clustering and/or co-segregation

    International Nuclear Information System (INIS)

    Statistical analysis of atom probe data has improved dramatically in the last decade and it is now possible to determine the size, the number density and the composition of individual clusters or precipitates such as those formed in reactor pressure vessel (RPV) steels during irradiation. However, the characterisation of the onset of clustering or co-segregation is more difficult and has traditionally focused on the use of composition frequency distributions (for detecting clustering) and contingency tables (for detecting co-segregation). In this work, the authors investigate the possibility of directly examining the neighbourhood of each individual solute atom as a means of identifying the onset of solute clustering and/or co-segregation. The methodology involves comparing the mean observed composition around a particular type of solute with that expected from the overall composition of the material. The methodology has been applied to atom probe data obtained from several irradiated RPV steels. The results show that the new approach is more sensitive to fine scale clustering and co-segregation than that achievable using composition frequency distribution and contingency table analyses.

  17. Measuring Segregation

    OpenAIRE

    David M. Frankel; Oscar Volij

    2004-01-01

    We propose a set of axioms for the measurement of multigroup school segregation. They are motivated by two criteria: do ethnic groups have similar distributions across schools? And are schools ethnically representative of their district? Our axioms are satisfied by a unique ordering. It is represented by the Mutual Information index. This index, originally proposed by Henri Theil, has a more intuitive decomposition than other indices. As an application, we find that segregation between distri...

  18. Refinement of irradiation and analysis techniques for radiation-induced segregation

    Energy Technology Data Exchange (ETDEWEB)

    Allen, T.R.; Cookson, J.M.; Damcott, D.L.; Was, G.S. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences

    1997-11-01

    Radiation-induced segregation (RIS) has been implicated as a potential contributor to irradiation assisted stress corrosion cracking in light water reactor core components. To better understand changes to grain boundary chemistry during irradiation, RIS was measured in ultra-high purity (UHP) 304 stainless steel using Auger electron spectroscopy (AES). Variations in measured grain boundary concentration, both within a sample and between samples, are reduced by refinements in both the radiation and the AES techniques. These refinements include improvements in temperature control, uniformity of sample-to-sample dose, grain boundary acceptance criteria, amount of intergranular fracture, and amount of beam current uses in analysis. AES measurements on samples irradiated at 400 C to 1.0 dpa show how implementing the technique refinements reduces the variability in the measured concentrations. Additionally, measurements from regions of ductile tearing in samples irradiated to 0.1 and 1.0 dpa at 400 C, to 1.0 dpa at 200 C, and from unirradiated samples show that sensitivity factors must be determined to obtain the most accurate measurement of grain boundary composition.

  19. Waste segregation

    International Nuclear Information System (INIS)

    A scoping study has been undertaken to determine the state-of-the-art of waste segregation technology as applied to the management of low-level waste (LLW). Present-day waste segregation practices were surveyed through a review of the recent literature and by means of personal interviews with personnel at selected facilities. Among the nuclear establishments surveyed were Department of Energy (DOE) laboratories and plants, nuclear fuel cycle plants, public and private laboratories, institutions, industrial plants, and DOE and commercially operated shallow land burial sites. These survey data were used to analyze the relationship between waste segregation practices and waste treatment/disposal processes, to assess the developmental needs for improved segregation technology, and to evaluate the costs and benefits associated with the implementation of waste segregation controls. This task was planned for completion in FY 1981. It should be noted that LLW management practices are now undergoing rapid change such that the technology and requirements for waste segregation in the near future may differ significantly from those of the present day. 8 figures

  20. Targets for bulk hydrogen analysis using thermal neutrons

    CERN Document Server

    Csikai, J; Buczko, C M

    2002-01-01

    The reflection property of substances can be characterized by the reflection cross-section of thermal neutrons, sigma subbeta. A combination of the targets with thin polyethylene foils allowed an estimation of the flux depression of thermal neutrons caused by a bulk sample containing highly absorbing elements or compounds. Some new and more accurate sigma subbeta values were determined by using the combined target arrangement. For the ratio, R of the reflection and the elastic scattering cross-sections of thermal neutrons, R=sigma subbeta/sigma sub E sub L a value of 0.60+-0.02 was found on the basis of the data obtained for a number of elements from H to Pb. Using this correlation factor, and the sigma sub E sub L values, the unknown sigma subbeta data can be deduced. The equivalent thicknesses, to polyethylene or hydrogen, of the different target materials were determined from the sigma subbeta values.

  1. Single-nucleotide polymorphism versus microsatellite markers in a combined linkage and segregation analysis of a quantitative trait

    OpenAIRE

    Heath Simon C; Daw E Warwick; Lu Yue

    2005-01-01

    Abstract Increasingly, single-nucleotide polymorphism (SNP) markers are being used in preference to microsatellite markers. However, methods developed for microsatellites may be problematic when applied to SNP markers. We evaluated the results of using SNPs vs. microsatellites in Monte Carlo Markov chain (MCMC) oligogenic combined segregation and linkage analysis methods. These methods were developed with microsatellite markers in mind. We selected chromosome 7 from the Collaborative Study on...

  2. Analysis of the camouflage effect in time of segregation in texturized regions using the Cox proportional hazard model

    OpenAIRE

    Eduardo Yoshio Nakano; Juliana Ferrari Cunha

    2012-01-01

    Humans have trichromatic vision. However variations in gene can cause deficiency in color vision resulting to dichromatism. The aim of this work was to verify the real efficiency of dichromats to break colour camouflage. Total of nine colour-blind individuals participated in this study and the variable considered was the time to segregation of camouflaged targets. The interest was to compare the response time in several conditions of camouflage and the analysis was performed using the Cox pro...

  3. Segregation analysis of low levels of high-density lipoprotein cholesterol in the collaborative Lipid Research Clinics Program Family Study.

    OpenAIRE

    Bucher, K D; Kaplan, E B; Namboodiri, K K; Glueck, C J; Laskarzewski, P; Rifkind, B. M.

    1987-01-01

    Complex segregation analysis with the unified mixed model in white families from nine lipid research clinics was carried out to delineate the mode of familial transmission of plasma high-density-lipoprotein cholesterol (HDL-C). Three groups of families from the collaborative Lipid Research Clinics Program Family Study were assessed: 1,146 selected at random, 483 obtained through hypercholesterolemic probands, and 177 selected from the random sample because a number had low HDL-C, the sample s...

  4. Natural Selection with Nuclear and Cytoplasmic Transmission. III. Joint Analysis of Segregation and Mtdna in Drosophila Melanogaster

    OpenAIRE

    Clark, A. G.; Lyckegaard, EMS.

    1988-01-01

    Despite the widespread use of mitochondrial DNA by evolutionary geneticists, relatively little effort has been spent assessing the magnitude of forces maintaining mtDNA sequence diversity. In this study the influence of cytoplasmic variation on viability in Drosophila was examined by analysis of second chromosome segregation. A factorial experiment with balancer chromosomes permitted the effects of cytoplasm and reciprocal crosses to be individually distinguished. The first test used six line...

  5. A numerical analysis of inverted V-segregation and its dependency on alloy properties

    Science.gov (United States)

    Sawada, T.; Suzuki, S.; Kajikawa, K.

    2016-07-01

    We ran a numerical simulation to investigate the effect of liquidus slope on the formation of inverted V-segregation in laterally solidified ingots of a virtual Fe-based binary- alloy system. The criterion used in this research is based on Suzuki's criterion. Our criterion assumed that inverted V-segregation zones form when the product of the solidification velocity and the cooling rate is below a critical value which depends on the alloy system. We studied the change in the critical value caused by the density and the liquidus slope of added element X. When different elements of varying densities were added, the results were in line with previous experimental results where large density difference causes increased formation of inverted V-segregation. Finally, the effect of the liquidus slope on the formation of the inverted V-segregation was studied. With a decrease in the liquidus slope, the critical value increased and inverted V-segregation tended to form. Furthermore, the streaks formed were more highly concentrated and sharper, and the channel population increased when the solidification temperature range was narrow.

  6. Size-Segregated Multi-Elemental Aerosol Analysis at Williams Tower During Texas Air Quality 2000

    International Nuclear Information System (INIS)

    Size-segregated aerosol composition was investigated as part of the Texas 2000 air quality study. The sampling was performed continuously from August 16 to September 15, 2000 at the Williams Tower (62nd floor), Houston, Texas, using a Lundgren type 3-stage impactor (0.07-0.34 microns, 0.34-1.15 microns, and 1.15-2.5 microns cut points). Ex post facto analysis of the collected aerosol was performed using synchrotron x-ray fluorescence (s-XRF) at the Advanced Light Source (ALS) Lawrence Berkeley National Laboratory (LBNL) to yield time series data for many trace elements (Al, Si, S, Ca, Fe, Cl, K, Ti, Mn, Ni, and Cu). A principle component analysis of the data enabled the aerosol to be grouped into three primary types: (1) course mode soil and/or fly ash aerosol (Al, Si, S, Ca, Fe, K, Ti); (2) medium mode soil and/or fly ash aerosol (Al, Si, Ca, Fe, Ti); and (3) sulfur-containing aerosol containing a vanadium-to-nickel ratio of 3.231.35 (2 sigmas). An examination of time series data of element ratios has indicated that the first two aerosol types (Al:Si, Fe:Si, and Ca:Si ratios) may arise from multiple sources, whereas the latter aerosol type (V:S and Ni:S ratios) likely arises from a single source, such as fossil fuel combustion. The three aerosol types above were observed to have mass contributions, respectively, of 18.5%, 14.1%, and 65.8%. The statistical grouping of aerosol type is analyzed further according to air-mass history using classical back-trajectories and enables a source apportionment of the aerosol to be made

  7. From bulk to particle analysis - A new challenge for radioecology

    International Nuclear Information System (INIS)

    Full text: Radioactivity may be introduced in the environment through a variety of systems and processes. Human activities involving nuclear weapons and nuclear fuel cycle (including mining, milling, fuel enrichment, fabrication, reactor operation, spent fuel stores, reprocessing facilities, medical applications and waste storage) are important, leading to a significant creation and release of radioactivity. Human technology also releases pre-existing natural radionuclides, which would otherwise remain trapped in the earth's crust. For instance, burning of fossil fuel (oil and coal) dominates direct atmospheric release at pre-existing natural radioactivity. The distribution pattern of radioactive fallout depends on weather conditions (i.e. wet or dry) and on the nature of the surface and the physical-chemical form of the radionuclides, which may vary according to release and transport conditions as well as element properties. A general distinction can be made between gases, aerosols and particulate material. Particles with higher activity concentration, known as 'hot particles', may result from atmospheric nuclear weapon tests or nuclear reactor accidents. Their activity is diluted as material is transferred to soil and water directly or via vegetation and movement through other biota. Therefore, for monitoring radioactivity in the environment it is necessary to analyse bulk samples from all biosphere compartments as well as single microparticles. Analytical chemistry plays a determinant role for routine verifications as well as in case of radiological alarm to take decision for restoration of the environment and protection of the citizens. The reference laboratory for the measurement of radioactivity in the environment (MaRE lab) at the Institute for Transuranium Element (European Commission, Joint Research Centre) provides scientific and technical support to the policy of the Directorate General for Transport and Energy (DG TREN) of the European Commission, both

  8. An analysis of turbulent flow around a NACA4412 airfoil by using a segregated finite element method

    International Nuclear Information System (INIS)

    A turbulent flow around a NACA4412 airfoil is simulated by a segregated finite element method based on the SIMPLE algorithm and the low Reynolds number κ-ω turbulence model. The original κ-ω model and a modified version of the κ-ω model (shear stress transport model) are adopted, for which grid independent solutions are obtained, respectively. From the present numerical experiment, it has been shown that the segregated finite element method with the κ-ω turbulence model can predict the turbulent flow leading to separation satisfactorily with apparently reduced memories compared with the mixed integrated formulation. It is also recommended that for the analysis of external flows a modified κ-ω model should be used instead of the original κ-ω model, which combines the features of both the standard κ-ε model and the original κ-ω model

  9. School Segregation, Residential Segregation: Some Speculation.

    Science.gov (United States)

    Kantrowitz, Nathan

    This essay addressed the question of to what extent does school segregation and school desegregation policy shape residential segregation. Census data, ethnic segregation, voluntary self-segregation, and attitude surveys are discussed in the residential segregation section. The Wolf and Lebeaux study is critically appraised in reference to school…

  10. Neutron activation analysis of bulk samples from Chinese ancient porcelain to provenance research

    International Nuclear Information System (INIS)

    Neutron activation analysis (NAA) is an important technique to determine the provenance of ancient ceramics. The most common technique used for preparing ancient samples for NAA is to grind them into a powder and then encapsulate them before neutron irradiation. Unfortunately, ceramic materials are typically very hard making it a challenge to grind them into a powder. In this study we utilize bulk porcelain samples cut from ancient shards. The bulk samples are irradiated by neutrons alongside samples that have been conventionally ground into a powder. The NAA for both the bulk samples and powders are compared and shown to provide equivalent information regarding their chemical composition. Also, the multivariate statistical have been employed to the analysis data for check the consistency. The findings suggest that NAA results are less dependent on the state of the porcelain sample, and thus bulk samples cut from shards may be used to effectively determine their provenance. (author)

  11. Proteomic analysis of a segregant population reveals candidate proteins linked to mealiness in peach.

    Science.gov (United States)

    Almeida, Andréa Miyasaka; Urra, Claudio; Moraga, Carol; Jego, Marcela; Flores, Alejandra; Meisel, Lee; González, Mauricio; Infante, Rodrigo; Defilippi, Bruno G; Campos-Vargas, Reinaldo; Orellana, Ariel

    2016-01-10

    Peaches are stored at low temperatures to delay ripening and increase postharvest life. However some varieties are susceptible to chilling injury,which leads to fruit mealiness, browning and flesh bleeding. In order to identify potentialmarkers associated with chilling injury,we performed proteomic analyses on a segregating population with contrasting susceptibility to chilling-induced mealiness. Chilling-induced mealiness was assessed by measuring juiciness in fruits that have been stored in cold and then allowed to ripen. Fruitmesocarp and leaf proteome from contrasting segregants were analyzed using 2-DE gels. Comparison of protein abundance between segregants revealed 133 spots from fruit mesocarp and 36 from leaf. Thirty four fruit mesocarp proteins were identified from these spots. Most of these proteins were related to ethylene synthesis, ABA response and stress response. Leaf protein analyses identified 22 proteins, most of which related to energy metabolism. Some of the genes that code for these proteins have been previously correlated with chilling injury through transcript analyses and co-segregation with mealiness QTLs. The results from this study, further deciphers the molecular mechanisms associated with chilling response in peach fruit, and identifies candidate proteins linked to mealiness in peach which may be used as putative markers for this trait. PMID:26459401

  12. High resolution gamma-ray spectroscopy applied to bulk sample analysis

    International Nuclear Information System (INIS)

    A high resolution Ge(Li) gamma-ray spectrometer has been installed and made operational for use in routine bulk sample analysis by the Bendix Field Engineering Corporation (BFEC) geochemical analysis department. The Ge(Li) spectrometer provides bulk sample analyses for potassium, uranium, and thorium that are superior to those obtained by the BFEC sodium iodide spectrometer. The near term analysis scheme permits a direct assay for uranium that corrects for bulk sample self-absorption effects and is independent of the uranium/radium disequilibrium condition of the sample. A more complete analysis scheme has been developed that fully utilizes the gamma-ray data provided by the Ge(Li) spectrometer and that more properly accounts for the sample self-absorption effect. This new analysis scheme should be implemented on the BFEC Ge(Li) spectrometer at the earliest date

  13. Error analysis in the taking of samples from bulk material

    International Nuclear Information System (INIS)

    In the goods quality testing carried out on a sampling basis, errors must be accounted for regarding conclusions on the population. Here various methods for the error source analysis with several multistep sampling procedures are given and compared with concrete examples. (orig.)

  14. SSCP and segregation analysis of the human type X collagen gene (COL10A1) in heritable forms of chondrodysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Sweetman, W.A.; Rash, B.; Thomas, J.T.; Boot-Handford, R.; Grant, M.E.; Wallis, G.A. (Univ. of Manchester (United Kingdom)); Sykes, B. (Univ. of Oxford (United Kingdom)); Beighton, P. (Univ. of Cape Town (South Africa)); Hecht, J.T. (Univ. of Texas, Houston, TX (United States)); Zabell, B. (Johannes Gutenburg Universitaet, Mainz (Germany))

    1992-10-01

    Type X collagen is a homotrimeric, short chain, nonfibrillar collagen that is expressed exclusively by hypertrophic chondrocytes at the sites of endochondral ossification. The distribution and pattern of expression of the type X collagen gene (COL10A1) suggests that mutations altering the structure and synthesis of the protein may be responsible for causing heritable forms of chondrodysplasia. The authors investigated whether mutations within the human COL10A1 gene were responsible for causing the disorders achondroplasia, hypochondroplasia, pseudoachondroplasia, and thanatophoric dysplasia, by analyzing the coding regions of the gene by using PCR and the single-stranded conformational polymorphism technique. By this approach, seven sequence changes were identified within and flanking the coding regions of the gene of the affected persons. The authors demonstrated that six of these sequence changes were not responsible for causing these forms of chondrodysplasia but were polymorphic in nature. The sequence changes were used to demonstrate discordant segregation between the COL10A1 locus and achondroplasia and pseudoachondroplasia, in nuclear families. This lack of segregation suggests that mutations within or near the COL101A1 locus are not responsible for these disorders. The seventh sequence change resulted in a valine-to-methionine substitution in the carboxyl-terminal domain of the molecule and was identified in only two hypochondroplasic individuals from a single family. Segregation analysis in this family was inconclusive, and the significance of this substitution remains uncertain. 47 refs., 3 figs., 2 tabs.

  15. SWOT analysis for safer carriage of bulk liquid chemicals in tankers.

    Science.gov (United States)

    Arslan, Ozcan; Er, Ismail Deha

    2008-06-15

    The application of strengths, weaknesses, opportunities and threats (SWOT) analysis to formulation of strategy concerned with the safe carriage of bulk liquid chemicals in maritime tankers was examined in this study. A qualitative investigation using SWOT analysis has been implemented successfully for ships that are designed to carry liquid chemicals in bulk. The originality of this study lies in the use of SWOT analysis as a management tool to formulate strategic action plans for ship management companies, ship masters and officers for the carriage of dangerous goods in bulk. With this transportation-based SWOT analysis, efforts were made to explore the ways and means of converting possible threats into opportunities, and changing weaknesses into strengths; and strategic plans of action were developed for safer tanker operation. PMID:18093731

  16. Thermodynamic analysis of the bulk heating process in large chambers

    Energy Technology Data Exchange (ETDEWEB)

    Postrzednik, S.

    1987-05-01

    Analyzes the energy balance for heating of coke in coke ovens with heat transfer from heating surfaces. Equations are derived for heat absorbed in process cycle periods, for pseudo-stationary temperature fields in the system and for heating intensity and fuel energy utilization. An algorithm is established for efficiency analysis of fuel utilization. The influence of an adequate period length is pointed out, as well as relations for high and low fuel energy utilization efficiency. Graphs of thermal parameters are provided. 5 refs.

  17. Gamma self-shielding correction factors calculation for aqueous bulk sample analysis by PGNAA technique.

    Science.gov (United States)

    Nasrabadi, M N; Mohammadi, A; Jalali, M

    2009-01-01

    In this paper bulk sample prompt gamma neutron activation analysis (BSPGNAA) was applied to aqueous sample analysis using a relative method. For elemental analysis of an unknown bulk sample, gamma self-shielding coefficient was required. Gamma self-shielding coefficient of unknown samples was estimated by an experimental method and also by MCNP code calculation. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the gamma self-shielding within the sample volume is required. PMID:19328700

  18. Gamma self-shielding correction factors calculation for aqueous bulk sample analysis by PGNAA technique

    Energy Technology Data Exchange (ETDEWEB)

    Nasrabadi, M.N. [Department of Nuclear Engineering, Faculty of Modern Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)], E-mail: mnnasrabadi@ast.ui.ac.ir; Mohammadi, A. [Department of Physics, Payame Noor University (PNU), Kohandej, Isfahan (Iran, Islamic Republic of); Jalali, M. [Isfahan Nuclear Science and Technology Research Institute (NSTRT), Reactor and Accelerators Research and Development School, Atomic Energy Organization of Iran (Iran, Islamic Republic of)

    2009-07-15

    In this paper bulk sample prompt gamma neutron activation analysis (BSPGNAA) was applied to aqueous sample analysis using a relative method. For elemental analysis of an unknown bulk sample, gamma self-shielding coefficient was required. Gamma self-shielding coefficient of unknown samples was estimated by an experimental method and also by MCNP code calculation. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the gamma self-shielding within the sample volume is required.

  19. Heritability and complex segregation analysis of deafness in Jack Russell Terriers

    Directory of Open Access Journals (Sweden)

    Strain George M

    2007-11-01

    Full Text Available Abstract Background The association between patterns of pigmentation and deafness in the dog has a long-documented history, with reports dating back over one hundred years. Long suspected of having a genetic basis, the search for loci with a pronounced influence in the expression of hearing loss in the dog has yet to be successful. No studies in the dog to date have found a possible influence of a specific colour locus associated with deafness. The present study is intended to evaluate the heritability of deafness in the Jack Russell Terrier (JRT, characterize the mode of inheritance, and evaluate the existence of a sex, coat colour, or coat texture influence on the expression of sensorineural deafness. Results The estimation of heritability of deafness in the JRT was 0.22 when deafness was considered a binary (normal/deaf trait and 0.31 when deafness was considered a three-category (normal/unilateral/bilateral deafness. The influence of coat colour in the incidence of JRT deafness was statistically significant, indicating that dogs with more white are more likely to be deaf. The influence of sex or coat texture was not statistically significant in the incidence of JRT deafness. Complex segregation analysis revealed a model of a single locus with a large effect on the binary measure of hearing loss is not supported. Conclusion This is the first attempt, to our knowledge, to characterize a genetic component responsible for deafness in the JRT. The heritability of deafness in the JRT was found to be 0.22 and 0.31 considering deafness to be a two-category or three-category trait, respectively. There appears to be an influence of coat colour on the expression of deafness. In an attempt to characterize the mode of inheritance of deafness in the JRT, a model of a single locus with a large effect on hearing loss is not supported with this data. Further study is needed to determine if a single locus may be influencing deafness in the JRT. While the

  20. Preferences, constraints, and the process of sex segregation in college majors: A choice analysis.

    Science.gov (United States)

    Ochsenfeld, Fabian

    2016-03-01

    The persistence of horizontal sex segregation in higher education continues to puzzle social scientists. To help resolve this puzzle, we analyze a sample of college entrants in Germany with a discrete choice design that allows for social learning from the experiences of others. We make at least two contributions to the state of research. First, we test whether essentialist gender stereotypes affect major selection mostly through internalization or rather as external constraints that high school graduates adapt their behavior to. Empirically, we find that internalized vocational interests better explain gendered major choices than conformance with friends' and parents' expectations does. Second, we scrutinize whether segregation results from women's anticipation of gendered family roles or from their anticipation of sex-based discrimination, but we find no evidence for either of these hypotheses. As in most previous studies, differences in mathematics achievement fail to explain gendered patterns of selection into college majors. PMID:26857176

  1. Optimization of PGNAA instrument design for bulk coal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.; Salgado, J.; Carvalho, F.G. (National Lab. for Industrial Technology and Engineering, Scavem (Portugal))

    1992-01-01

    The application of prompt gamma neutron activation analysis (PGNAA) to the on-line characterization of raw materials is progressively gaining general acceptance as a technically and economically adequate method for solving process control-related problems in different industry branches, ranging from the efficient use of energy and materials to the limitation of environmental impacts. The Nuclear Instrumentation Group at Portugal's National Laboratory for Industrial Technology and Engineering is engaged in the design optimization of a prototype industrial PGNAA unit for on-line quality control of steam coal. To this end, an experimental setup was put together while a series of computer simulation studies was carried out using the MCNP code. In the simulation, a cube-shaped coal volume 30 cm in side was used as the sample. The neutron source and the gamma-ray detector were located at the center of opposite cube faces. Computer simulation runs were carried out for Am-Be and 252 Cf neutron sources with coal samples of four different chemical compositions and densities ranging from 0.8 to 1.6.

  2. Optimization of PGNAA instrument design for bulk coal analysis

    International Nuclear Information System (INIS)

    The application of prompt gamma neutron activation analysis (PGNAA) to the on-line characterization of raw materials is progressively gaining general acceptance as a technically and economically adequate method for solving process control-related problems in different industry branches, ranging from the efficient use of energy and materials to the limitation of environmental impacts. The Nuclear Instrumentation Group at Portugal's National Laboratory for Industrial Technology and Engineering is engaged in the design optimization of a prototype industrial PGNAA unit for on-line quality control of steam coal. To this end, an experimental setup was put together while a series of computer simulation studies was carried out using the MCNP code. In the simulation, a cube-shaped coal volume 30 cm in side was used as the sample. The neutron source and the gamma-ray detector were located at the center of opposite cube faces. Computer simulation runs were carried out for Am-Be and 252 Cf neutron sources with coal samples of four different chemical compositions and densities ranging from 0.8 to 1.6

  3. An analysis of segregation-induced changes in grain boundary cohesion in bcc iron

    Czech Academy of Sciences Publication Activity Database

    Lejček, Pavel; Šob, Mojmír

    2014-01-01

    Roč. 49, č. 6 (2014), 2477-2482. ISSN 0022-2461 R&D Projects: GA ČR GAP108/12/0144; GA AV ČR IAA100100920; GA ČR(CZ) GAP108/12/0311 Institutional support: RVO:68378271 ; RVO:68081723 Keywords : grain boundary segregation * grain boundary embrittlement * iron Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.371, year: 2014

  4. ED-XRF set-up for size-segregated aerosol samples analysis

    OpenAIRE

    Bernardoni, V.; E. Cuccia; G. Calzolai; Chiari, M.; Lucarelli, F.; D. Massabo; Nava, S.; Prati, P.; Valli, G; Vecchi, R.

    2011-01-01

    The knowledge of size-segregated elemental concentrations in atmospheric particulate matter (PM) gives a useful contribution to the complete chemical characterisation; this information can be obtained by sampling with multi-stage cascade impactors. In this work, samples were collected using a low-pressure 12-stage Small Deposit Impactor and a 13-stage rotating Micro Orifice Uniform Deposit Impactor™. Both impactors collect the aerosol in an inhomogeneous geometry, which needs a special set-up...

  5. Amphibian Sex Determination: Segregation and Linkage Analysis Using Members of the Tiger Salamander Species Complex (Ambystoma mexicanum and A. t. tigrinum)

    OpenAIRE

    Smith, Jeramiah J.; Voss, S. Randal

    2009-01-01

    Little is known about the genetic basis of sex determination in vertebrates though considerable progress has been made in recent years. In this study, segregation analysis and linkage mapping were performed to localize an amphibian sex-determining locus (ambysex) in the tiger salamander (Ambystoma) genome. Segregation of sex phenotypes (male, female) among 2nd generation individuals of interspecific crosses (A. mexicanum x A. t. tigrinum) was consistent with Mendelian expectations, although a...

  6. Residentielle Segregation

    OpenAIRE

    Dangschat, Jens S.

    2014-01-01

    "Die residentielle Segregation - verstanden als die ungleichmäßige Verteilung der Wohngelegenheiten sozialer Gruppen - wird über Segregationsindices als relative Abweichung der Anteilswerte in städtischen Teilgebieten gegenüber der Gesamtstadt gemessen. Diese Durchschnittswerte sagen jedoch nichts darüber aus, ob es in einer städtischen Agglomeration 'problematische' sozialräumliche Konstellationen gibt, sie haben daher keinen kommunalpolitischen oder stadtentwicklungsplanerischen Wert. Zudem...

  7. Measuring Inequality and Segregation

    CERN Document Server

    Roberto, Elizabeth

    2015-01-01

    In this paper, I introduce the Divergence Index, a conceptually intuitive and methodologically rigorous measure of inequality and segregation. The index measures the difference between a distribution of interest and another empirical, theoretical, or normative distribution. The Divergence Index provides flexibility in specifying a theoretically meaningful basis for evaluating inequality. It evaluates how surprising an empirical distribution is given a theoretical distribution that represents equality. I demonstrate the unique features of the new measure, as well as deriving its mathematical equivalence with Theil's Inequality Index and the Information Theory Index. I compare the dynamics of the measures using simulated data, and an empirical analysis of racial residential segregation in the Detroit, MI, metro area. The Information Theory Index has become the gold standard for decomposition analyses of segregation. I show that although the Information Theory Index can be decomposed for subareas, it is misleadi...

  8. 46 CFR 151.13-5 - Cargo segregation-tanks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo segregation-tanks. 151.13-5 Section 151.13-5... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... and list the various degrees of segregation required. Paragraphs and (2) of this section explain...

  9. Segregation Analysis of a Sex Ratio Distortion Locus in Congenic Mice

    OpenAIRE

    Casellas, Joaquim; Farber, Charles R; Verdugo, Ricardo A; Medrano, Juan F.

    2009-01-01

    The congenic HG.CAST-(D17Mit196-D17Mit190) (HQ17hg/hg) mouse strain showed a significant departure on the expected 50%/50% offspring sex ratio in more than 2400 progeny (55.7% females). The entire pedigree file included data from 13 nonoverlapping purebred generations and an F2 cross with the C57BL/6J inbred strain. Offspring sex ratio data were analyzed on the basis of 40 purebred HQ17hg/hg sires and 29 F1 HQ17hg/hg × B6 sires under a Bayesian Binomial segregation model accounting for 4 diff...

  10. Computational speech segregation based on an auditory-inspired modulation analysis

    DEFF Research Database (Denmark)

    May, Tobias; Dau, Torsten

    2014-01-01

    A monaural speech segregation system is presented that estimates the ideal binary mask from noisy speech based on the supervised learning of amplitude modulation spectrogram (AMS) features. Instead of using linearly scaled modulation filters with constant absolute bandwidth, an auditory- inspired...... modulation filterbank with logarithmically scaled filters is employed. To reduce the dependency of the AMS features on the overall background noise level, a feature normalization stage is applied. In addition, a spectro-temporal integration stage is incorporated in order to exploit the context information...

  11. Theoretical analysis of thermal rectification in a bulk Si/nanoporous Si device

    Energy Technology Data Exchange (ETDEWEB)

    Criado-Sancho, M., E-mail: mcriado@ccia.uned.es [Departamento de Ciencias y Técnicas Físicoquimicas, Facultad de Ciencias, UNED, Senda del Rey 9, 20040 Madrid (Spain); Castillo, L.F. del, E-mail: felipe@unam.mx [Departamento de Polímeros, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Ap. 70-360 Coyoacán, México DF, 04510 (Mexico); Casas-Vázquez, J., E-mail: Jose.Casas@uab.es [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Jou, D., E-mail: David.Jou@uab.es [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain)

    2012-04-09

    We present a theoretical analysis of thermal rectification in a porous Si/bulk Si device, taking into account ballistic effects in phonon-pore collisions when phonon mean free path is much longer than the radius of the pores. Starting from an approximate analytical expression for the effective thermal conductivity of porous Si, we obtain the thermal rectifying coefficient of the device as a function of porosity, pore size, temperature interval, and relative lengths of porous and bulk samples. -- Highlights: ► Heat conductivity of porous Si depends on the pore size. ► Thermal rectification for nanoporous Si/bulk Si is predicted. ► Thermal rectifying coefficient is calculated. ► It is shown to be comparable or higher to that of systems previously considered.

  12. Theoretical analysis of thermal rectification in a bulk Si/nanoporous Si device

    International Nuclear Information System (INIS)

    We present a theoretical analysis of thermal rectification in a porous Si/bulk Si device, taking into account ballistic effects in phonon-pore collisions when phonon mean free path is much longer than the radius of the pores. Starting from an approximate analytical expression for the effective thermal conductivity of porous Si, we obtain the thermal rectifying coefficient of the device as a function of porosity, pore size, temperature interval, and relative lengths of porous and bulk samples. -- Highlights: ► Heat conductivity of porous Si depends on the pore size. ► Thermal rectification for nanoporous Si/bulk Si is predicted. ► Thermal rectifying coefficient is calculated. ► It is shown to be comparable or higher to that of systems previously considered.

  13. Quantitative TEM analysis of precipitation and grain boundary segregation in neutron irradiated EUROFER 97

    International Nuclear Information System (INIS)

    Characterization of irradiation induced microstructural defects is essential for assessing the applicability of structural steels like the Reduced Activation Ferritic/Martensitic steel EUROFER 97 in upcoming fusion reactors. In this work Transmission Electron Microscopy (TEM) is used to analyze the types and structure of precipitates, and the evolution of their size distributions and densities caused by neutron irradiation to a dose of 32 displacements per atom (dpa) at 330–340 °C in the irradiation experiment ARBOR 1. A significant growth of MX and M23C6 type precipitates is observed after neutron irradiation, while the precipitate density remains unchanged. Hardening caused by MX and M23C6 precipitate growth is assessed by applying the Dispersed Barrier Hardening (DBH) model, and shown to be of minor importance when compared to other irradiation effects like dislocation loop formation. Additionally, grain boundary segregation of chromium induced by neutron irradiation was investigated and detected in irradiated specimens

  14. Quantitative analysis of solute segregation in alloys by transmission electron microscopy. Final report through October, 1980

    International Nuclear Information System (INIS)

    A fundamental understanding of the contrast effects from small defects of all common types is derived. This includes small precipitates and superpositions of solute atoms and/or precipitates and dislocation-based defects (e.g., loops, lines, stacking faults). Both the infinitesimal and finite approximations can be employed routinely in the isotropic case as need be. The anisotropic elastic effects have not been studied since these are most fruitfully studied case by case. Studies to two beam diffraction contrast using the column approximation have been restricted but extensions to multibeam conditions are straightforward. No fundamentally new contrast effects are expected either, by dropping the column approximation. A workable understanding of the contrast effects from small precipitates and solute/dislocation loop contrast has been reached. A good understanding of the useful limits to the diffraction contrast approach as it can be applied to solute segregation (or precipitation) has been derived

  15. MCCI analysis based on the 'segregation phase model', with application in the TOLBIAC-ICB code

    International Nuclear Information System (INIS)

    Full text of publication follows: In the event of a severe accident in a Pressurized Water Reactor, corium, a mixture of molten materials issued from the fuel, cladding and structural elements, appears in the reactor core. One of the scenario of the severe accidents assumes that corium melts through the reactor pressure vessel and spreads over the concrete basemat of the reactor pit. The main question that has to be addressed in these scenario is whether and when the corium will make one's way through the basemat since it would induce groundwater contamination for example. The general approach used in this work is based on the 'segregation phase' model developed by CEA. The solid phase is located at the corium pool boundaries as a solid crust composed of refractory oxides, whereas the corium pool contains no solid. The interfacial temperature between the crust and the pool is the liquidus temperature calculated with the composition of the pool. Thermal-hydraulics (mass and energy balances) is then coupled with physico-chemistry (liquidus temperature, crust composition, chemical reactions). The TOLBIAC-ICB code is developed in the frame of an agreement with EDF, in order to simulate MCCI with the phase segregation model. It is coupled with the GEMINI code for the determination of the physico-chemistry variables. The main purpose of this paper is to present the modelling used in TOLBIAC-ICB and some validation calculations using the data of prototypic experiments available in the literature. Part of the attention focuses on material effects highlighted in some tests and reproduced in the numerical simulations. (authors)

  16. Segregation analysis of blood oxygen saturation in broilers suggests a major gene influence on ascites.

    Science.gov (United States)

    Navarro, P; Visscher, P M; Chatziplis, D; Koerhuis, A N M; Haley, C S

    2006-12-01

    1. Blood oxygen saturation (SaO) is a potential indicator trait for resistance to ascites in chickens. 2. The objective of the study was to investigate the genetic architecture of SaO in a meat-type chicken line reared in commercial conditions. 3. Data were collected over 15 generations of selection and were divided into two data sets on the basis of a change in recording age from 6 to 5 weeks of age, approximately halfway through the period. The resulting pedigrees comprised in excess of 90,000 birds each and, on average, 12% of these birds had SaO records. 4. Segregation analyses of SaO were carried out assuming a mixed inheritance model that included a major locus segregating in a polygenic background. 5. The analyses suggest that a major gene is involved in the genetic control of SaO in this line. The putative gene acts in a dominant fashion and has an additive effect of around 0.90 sigma(p), equivalent to a predicted difference in SaO between the two homozygous classes of more than 10%. The frequency of the allele that increases SaO changed from 0.53 to 0.65 from the first to the second set of data, consistent with selection on SaO scores. 6. Using estimated genotype probabilities at the putative major locus, we inferred that it acts in an overdominant fashion on body weight and fleshing score. If the low SaO allele leads to susceptibility to ascites, its combined effects are consistent with it being maintained in the population by a balance of natural selection on fitness nad artificial selection on growth and carcase traits. 7. Even with selection on both SaO and growth traits, the combined genotypic effects would make it difficult to remove the unfavourable low-SaO allele by means of traditional selection without the use of genetic markers. PMID:17190674

  17. An Analysis of Bulk Data Movement Patterns in Large-scale Scientific Collaborations

    International Nuclear Information System (INIS)

    Large-scale research efforts such as LHC experiments, ITER, and climate modelling are built upon large, globally distributed collaborations. For reasons of scalability and agility and to make effective use of existing computing resources, data processing and analysis for these projects is based on distributed computing models. Such projects thus depend on predictable and efficient bulk data movement between collaboration sites. However, the available computing and networking resources to different collaboration sites vary greatly. Large collaboration sites (such as Fermilab, CERN) have created data centres comprising hundreds, and even thousands, of computation nodes to develop massively scaled, highly distributed cluster-computing platforms. These sites are usually well connected to outside worlds with high-speed networks with bandwidth greater than 10Gbps. On the other hand, some small collaboration sites have limited computing resources or poor networking connectivity. Therefore, the bulk data movements across collaboration sites vary greatly. Fermilab is the US-CMS Tier-1 Centre and the main data centre for a few other large-scale research collaborations. Scientific traffic (e.g., CMS) dominates the traffic volumes in both inbound and outbound directions of Fermilab off-site traffic. Fermilab has deployed a Flow-based network traffic collection and analysis system to monitor and analyze the status and patterns of bulk data movement between the Laboratory and its collaboration sites. In this paper, we discuss the current status and patterns of bulk data movement between Fermilab and its collaboration sites.

  18. Finite element analysis and simulation of rheological properties of bulk molding compound (BMC)

    Science.gov (United States)

    Ergin, M. Fatih; Aydin, Ismail

    2013-12-01

    Bulk molding compound (BMC) is one of the important composite materials with various engineering applications. BMC is a thermoset plastic resin blend of various inert fillers, fiber reinforcements, catalysts, stabilizers and pigments that form a viscous, molding compound. Depending on the end-use application, bulk molding compounds are formulated to achieve close dimensional control, flame and scratch resistance, electrical insulation, corrosion and stain resistance, superior mechanical properties, low shrink and color stability. Its excellent flow characteristics, dielectric properties, and flame resistance make this thermoset material well-suited to a wide variety of applications requiring precision in detail and dimensions as well as high performance. When a BMC is used for these purposes, the rheological behavior and properties of the BMC is the main concern. In this paper, finite element analysis of rheological properties of bulk molding composite material was studied. For this purpose, standard samples of composite material were obtained by means of uniaxial hot pressing. 3 point flexural tests were then carried out by using a universal testing machine. Finite element analyses were then performed with defined material properties within a specific constitutive material behavior. Experimental and numerical results were then compared. Good correlation between the numerical simulation and the experimental results was obtained. It was expected with this study that effects of various process parameters and boundary conditions on the rheological behavior of bulk molding compounds could be determined by means of numerical analysis without detailed experimental work.

  19. Superconductors, analysis and applications, with special reference to the utilisation of bulk (Re)BCO materials

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, T.A., E-mail: tac1000@cam.ac.u [University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2010-11-01

    The Electrical Power and Energy Conversion (EPEC) superconductivity group at Cambridge University has been working on the application of superconductivity to large scale devices. This work is taking place over a range of areas which cover FCLs, motors and generators, SMES, accelerator magnets and MRI. The research is underpinned by advanced modelling techniques using both pure Critical State models and E-J models to analyse the behaviour of the superconductors. As part of the device design we are concentrating on the analysis of AC losses in complicated geometries such as are found in motor windings and the magnetisation of bulk superconductors to enable their full potential to be realised. We are interested in the full range of high-temperature superconductors and have measured and predicted the performance of YBCO, MgB{sub 2} and BSCCO at a range of temperatures and in wire, tape and bulk forms. This paper concentrates on recent work which includes: modelling of coils using formulations based on H and A. A critical state model for the analysis of coils in SMES; crossed field effects in bulk superconductors; a magnetic model together with experimental results which explain and describe the method of flux pumping whereby a bulk superconductor can be magnetised to a high flux density using a repeatedly applied field of low flux density and finally a new configuration for MRI magnets

  20. Superconductors, analysis and applications, with special reference to the utilisation of bulk (Re)BCO materials

    Science.gov (United States)

    Coombs, T. A.

    2010-11-01

    The Electrical Power and Energy Conversion (EPEC) superconductivity group at Cambridge University has been working on the application of superconductivity to large scale devices. This work is taking place over a range of areas which cover FCLs, motors and generators, SMES, accelerator magnets and MRI. The research is underpinned by advanced modelling techniques using both pure Critical State models and E- J models to analyse the behaviour of the superconductors. As part of the device design we are concentrating on the analysis of AC losses in complicated geometries such as are found in motor windings and the magnetisation of bulk superconductors to enable their full potential to be realised. We are interested in the full range of high-temperature superconductors and have measured and predicted the performance of YBCO, MgB 2 and BSCCO at a range of temperatures and in wire, tape and bulk forms. This paper concentrates on recent work which includes: modelling of coils using formulations based on H and A. A critical state model for the analysis of coils in SMES; crossed field effects in bulk superconductors; a magnetic model together with experimental results which explain and describe the method of flux pumping whereby a bulk superconductor can be magnetised to a high flux density using a repeatedly applied field of low flux density and finally a new configuration for MRI magnets

  1. Bulk - Samples gamma-rays activation analysis (PGNAA) with Isotopic Neutron Sources

    International Nuclear Information System (INIS)

    An overview is given on research towards the Prompt Gamma-ray Neutron Activation Analysis (PGNAA) of bulk-samples. Some aspects in bulk-sample PGNAA are discussed, where irradiation by isotopic neutron sources is used mostly for in-situ or on-line analysis. The research was carried out in a comparative and/or qualitative way or by using a prior knowledge about the sample material. Sometimes we need to use the assumption that the mass fractions of all determined elements add up to 1. The sensitivity curves are also used for some elements in such complex samples, just to estimate the exact percentage concentration values. The uses of 252Cf, 241Arn/Be and 239Pu/Be isotopic neutron sources for elemental investigation of: hematite, ilmenite, coal, petroleum, edible oils, phosphates and pollutant lake water samples have been mentioned.

  2. Analysis of Bulk Sample of Salicylic Acid by Application of Hydrotropic Solubilization Method

    OpenAIRE

    Maheshwari R; Chavada V; Varghese S; Shahoo K

    2008-01-01

    In the present investigation, the poorly water-soluble drug, salicylic acid has been solubilized using 0.5 M ibuprofen sodium and 2.0 M sodium salicylate solution as hydrotropic agents for the titrimetric analysis precluding the use of organic solvents. Both hydrotropes are economic and pollution-free. The mean percent estimation of salicylic acid estimated in bulk sample by Indian Pharmacopoeial method is 98.78%. The mean percent estimation by ibuprofen sodium method and sodium salicy...

  3. Symmetry Analysis of the Kohn-Sham Band Structure of Bulk Lithium Fluoride

    OpenAIRE

    Mathar, Richard J.

    2003-01-01

    Kohn-Sham orbitals of face-centered cubic lithium fluoride are calculated in prototypical local-density approximations to the exchange-correlation functional. The symmetry analysis of these Bloch functions in a LCAO basis on a path Gamma-X-W-K-Gamma-L-W through the Brillouin Zone is compiled into a list of errata to symmetry labels in the LiF literature, the bulk of which dates back to the 1970's.

  4. Reanalysis of the NIMH collaborative bipolar family data: Results of complex segregation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Spence, M.A.; Flodman, P. [Univ. of California, Irvine, CA (United States); Sadovnick, A.D. [Univ. of British Columbia (Canada)] [and others

    1994-09-01

    To determine the inheritance of bipolar disorder (BP), Rice et al. analyzed a subset of the NIMH collaborative study. They report evidence for a single major locus (SML) even when allowing for a heritable background. Spence et al. analyzed an independent data set (from British Columbia) using a different algorithm (REGTL, SAGE statistical package), and found evidence for an SML model. The data lacked power to test for a heritable background. The current study was undertaken to reanalyze the NIMH data using REGTL, compare the two analyses, and pool the data sets. Probands (n=212) with a diagnosis of BP1 or BP2 were selected from the 612 NIMH probands. Phenotypes were defined by SADS-L and FHRDC criteria. Environmental, no major effects, SML, and arbitrary transmission models were estimated. The families of BP1 and BP2 probands were analyzed separately and pooled. In each subset, the SML model provided the best fit to the data, regardless of whether the relatives were defined as ill with BP or BP plus recurrent depression. No significant heterogeneity between the families of BP1 and BP2 probands was detected. These results are strikingly similar to those of Spence et al. (1993) and parallel those of Rice et al. (1987). Heterogeneity between the two datasets is being tested. If they can be combined, the increased power will yield more accurate estimation all the segregation parameters.

  5. Quantitative TEM analysis of precipitation and grain boundary segregation in neutron irradiated EUROFER 97

    Energy Technology Data Exchange (ETDEWEB)

    Dethloff, Christian, E-mail: christian.dethloff@kit.edu; Gaganidze, Ermile; Aktaa, Jarir

    2014-11-15

    Characterization of irradiation induced microstructural defects is essential for assessing the applicability of structural steels like the Reduced Activation Ferritic/Martensitic steel EUROFER 97 in upcoming fusion reactors. In this work Transmission Electron Microscopy (TEM) is used to analyze the types and structure of precipitates, and the evolution of their size distributions and densities caused by neutron irradiation to a dose of 32 displacements per atom (dpa) at 330–340 °C in the irradiation experiment ARBOR 1. A significant growth of MX and M{sub 23}C{sub 6} type precipitates is observed after neutron irradiation, while the precipitate density remains unchanged. Hardening caused by MX and M{sub 23}C{sub 6} precipitate growth is assessed by applying the Dispersed Barrier Hardening (DBH) model, and shown to be of minor importance when compared to other irradiation effects like dislocation loop formation. Additionally, grain boundary segregation of chromium induced by neutron irradiation was investigated and detected in irradiated specimens.

  6. Microstructural analysis of impurity segregation around β-Nb precipitates in Zr–Nb alloy using positron annihilation spectroscopy and atom probe tomography

    International Nuclear Information System (INIS)

    Graphical abstract: Fe segregation are evident at the interface between β-Nb precipitates and α-Zr matrix by atom probe tomography (APT). Defects are observed at the interface by positron annihilation spectroscopy. It is also suggested that Fe was segregated to a concentration of several tens of percent at a local region at the interface, which is approximately one order of magnitude higher than APT and difficult to observe directly even using APT. - Abstract: Impurity segregation at the interface between β-Nb precipitates and α-Zr matrix in Zr-2.5 wt.%Nb alloy was investigated by complementary analysis with positron annihilation spectroscopy (PAS) and atom probe tomography (APT). Fe segregation and Fe-decorated defects were found at the interface. PAS also suggested that Fe was segregated to a concentration of several tens of percent at a local region at the interface, which is approximately one order of magnitude higher than APT and difficult to observe directly even using APT

  7. Narrowing down the Determinants of Between-School Segregation: An Analysis of the Intake to All Schools in England, 1989-2011

    Science.gov (United States)

    Gorard, Stephen; Hordosy, Rita; See, Beng Huat

    2013-01-01

    This article describes the social and economic "segregation" of students between schools in England, and the likely causes of its levels and changes over time. It involves a re-analysis of the intakes to all schools in England 1989-2011, and shows how strongly clustered the students are in particular schools. The pattern for primary-age schools is…

  8. Glass Formation, Chemical Properties and Surface Analysis of Cu-Based Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Akihisa Inoue

    2011-04-01

    Full Text Available This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs. In order to obtain basic knowledge for application to the industry, corrosion resistance of the Cu–Hf–Ti–(Mo, Nb, Ta, Ni and Cu–Zr–Ag–Al–(Nb bulk glassy alloy systems in various solutions are reported in this work. Moreover, X-ray photoelectron spectroscopy (XPS analysis is performed to clarify the surface-related chemical characteristics of the alloy before and after immersion in the solutions; this has lead to a better understanding of the correlation between the surface composition and the corrosion resistance.

  9. Overcoming Triple Segregation

    Science.gov (United States)

    Gandara, Patricia

    2010-01-01

    Latinos are, after whites, the most segregated student group in the United States, and their segregation is closely tied to poor academic outcomes. Latinos experience a triple segregation: by race/ethnicity, poverty, and language. Racial segregation perpetuates negative stereotypes, reduces the likelihood of a strong teaching staff, and is often…

  10. Surface Segregation in YSZ

    DEFF Research Database (Denmark)

    Bay, Lasse; Zachau-Christiansen, Birgit; Jacobsen, Torben

    1998-01-01

    The space charge layer formed due to segregation of yttria and oxygen ion vacancies in YSZ is described by a simple model. Effects of impurities segregation are omitted.......The space charge layer formed due to segregation of yttria and oxygen ion vacancies in YSZ is described by a simple model. Effects of impurities segregation are omitted....

  11. Segregation mechanism of phosphorus in Ti-stabilized interstitial-free steel

    International Nuclear Information System (INIS)

    Highlights: • Segregation mechanism of phosphorus in interstitial-free steel was studied. • The segregation behaviors in IF steel were explained. • Phosphorus segregation had equilibrium segregation characteristics in IF steel. • The content of P and holding temperature strongly influenced segregation behavior. - Abstract: The grain boundary segregation of phosphorus in an interstitial-free (IF) steel aged for different times at 600 and 720 °C was investigated using Auger electron spectroscopy. Results revealed that a significant degree of phosphorus segregation occurred during annealing for Ti-stabilized IF steel with 0.045 wt% bulk content of phosphorus. In addition, the segregation degree increased with increased holding time. The segregation behavior of phosphorus in IF steel was analyzed based on the theory of grain boundary segregation, along with the present experimental data and previous results. The phosphorus segregation had equilibrium segregation characteristics, and the bulk concentration of phosphorus and holding temperature strongly influenced the final grain boundary segregation concentration of phosphorus in IF steel during annealing. Furthermore, the segregation level of phosphorus substantially decreased with increased annealing temperature or decreased bulk concentration of phosphorus. Results of theoretical calculation were consistent with the experimental ones, indicating that the grain boundary segregation behavior of phosphorus in IF steel during annealing can be qualitatively and quantitatively explained by the theory of equilibrium segregation

  12. Reliability analysis of the bulk cargo loading system including dependent components

    Science.gov (United States)

    Blokus-Roszkowska, Agnieszka

    2016-06-01

    In the paper an innovative approach to the reliability analysis of multistate series-parallel systems assuming their components' dependency is presented. The reliability function of a multistate series system with components dependent according to the local load sharing rule is determined. Linking these results for series systems with results for parallel systems with independent components, we obtain the reliability function of a multistate series-parallel system assuming dependence of components' departures from the reliability states subsets in series subsystem and assuming independence between these subsystems. As a particular case, the reliability function of a multistate series-parallel system composed of dependent components having exponential reliability functions is fixed. Theoretical results are applied practically to the reliability evaluation of a bulk cargo transportation system, which main area is to load bulk cargo on board the ships. The reliability function and other reliability characteristics of the loading system are determined in case its components have exponential reliability functions with interdependent departures rates from the subsets of their reliability states. Finally, the obtained results are compared with results for the bulk cargo transportation system composed of independent components.

  13. Analysis of bulk sample of salicylic acid by application of hydrotropic solubilization method

    Directory of Open Access Journals (Sweden)

    Maheshwari R

    2008-01-01

    Full Text Available In the present investigation, the poorly water-soluble drug, salicylic acid has been solubilized using 0.5 M ibuprofen sodium and 2.0 M sodium salicylate solution as hydrotropic agents for the titrimetric analysis precluding the use of organic solvents. Both hydrotropes are economic and pollution-free. The mean percent estimation of salicylic acid estimated in bulk sample by Indian Pharmacopoeial method is 98.78%. The mean percent estimation by ibuprofen sodium method and sodium salicylate method are 99.25% and 98.82%, respectively. The results of analysis by the proposed method are very close to the results of analysis by the standard method. This confirms the accuracy of the proposed method. The proposed method was validated statistically by low values of statistical parameters viz. standard deviation, percent coefficient of variation and standard error. The proposed method is new, accurate, simple and economic.

  14. High frequency of submicroscopic chromosomal imbalances in patients with syndromic craniosynostosis detected by a combined approach of microsatellite segregation analysis, multiplex ligation-dependent probe amplification and array-based comparative genome hybridisation.

    NARCIS (Netherlands)

    Jehee, F.S.; Krepischi-Santos, A.C.; Rocha, K.M.; Cavalcanti, D.P.; Kim, C.A.; Bertola, D.R.; Alonso, L.G.; D'Angelo, C.S.; Mazzeu, J.F.; Froyen, G.; Lugtenberg, D.; Vianna-Morgante, A.M.; Rosenberg, C.; Passos-Bueno, M.R.

    2008-01-01

    We present the first comprehensive study, to our knowledge, on genomic chromosomal analysis in syndromic craniosynostosis. In total, 45 patients with craniosynostotic disorders were screened with a variety of methods including conventional karyotype, microsatellite segregation analysis, subtelomeric

  15. School and Residential Ethnic Segregation:An Analysis of Variations across England’s Local Education Authorities

    OpenAIRE

    Ron Johnston; Deborah Wilson; Simon Burgess; Richard Harris

    2006-01-01

    Schools are central to the goals of a multi-cultural society, but their ability to act as arenas within which meaningful inter-cultural interactions take place depends on the degree to which students from various cultural backgrounds meet there. Using recently-released data on the ethnic composition of both schools and small residential areas, this paper explores not only the extent of ethnic segregation in England’s schools but also whether that segregation is greater than the underpinning s...

  16. Niche segregation amongst sympatric species at exposed sandy shores with contrasting wrack availabilities illustrated by stable isotopic analysis

    OpenAIRE

    Bessa, Filipa; BAETA Alexandra; Marques, João Carlos

    2014-01-01

    Wrack supplies (macroalgae, seagrasses and carrion) are a common feature of sandy beaches worldwide. These allochthonous inputs are a potential high-quality food subsidy for beach fauna, but little is known about the feeding ecology and niche segregation strategies of these species in beaches with limited wrack availabilities. We used stable isotopic ratios of nitrogen and carbon to examine the diets and niche segregation among three sympatric crustaceans, the amphipods Talitrus s...

  17. UNUSUAL SEGREGATION BEHAVIOR OF BORON AND ITS EFFECT ON SEGREGATION OF SULFUR IN NICKEL

    OpenAIRE

    Ladna, B.; Birnbaum, H

    1988-01-01

    The co-segregation of B and S to the surface and grain boundaries of Ni was studied by SAES and SIMS. B showed an unusual segregation behavior wich resulted in the precipitation of Ni3B in the near surface layer and a continuous monolayer type B segregation at the grain boundary. The S segregation was not influenced by the presence of B and resulted in a uniform monolayer surface and grain boundary coverage. Analysis of hydrogen charged samples fractured in situ suggests that B segregated to ...

  18. Social Exclusion: Residential Segregation in Bolivian Cities

    OpenAIRE

    George Gray-Molina; Wilson Jimenez; Ernesto Perez de Rada

    2002-01-01

    This study analyzes the impact of ethnic-based residential segregation on income and education outcomes in Bolivian cities. Three results stand out in the analysis. First, we find significant and negative segregation effects on income generation in both across-city and intra-city comparisons. Second, we find individual and neighborhood-level interactions between ethnicity and segregation to be significantly and negatively correlated with income and schooling attainment. Finally, we find posit...

  19. Preimplantation genetic diagnosis of Von Hippel-Lindau disease cancer syndrome by combined mutation and segregation analysis

    Directory of Open Access Journals (Sweden)

    Denilce R. Sumita

    2007-03-01

    Full Text Available Von Hippel-Lindau (VHL disease is an autosomal dominant cancer syndrome, associated with the development of tumors and cysts in multiple organ systems, whose expression and age of onset are highly variable. The VHL disease tumor suppressor gene (VHL maps to 3p25-p26 and mutations ranging from a single base change to large deletions have been detected in patients with VHL disease. We developed a single cell PCR protocol for preimplantation genetic diagnosis (PGD of VHL disease to select unaffected embryos on the basis of the detection of the specific mutation and segregation analysis of polymorphic linked markers. Multiplex-nested PCR using single buccal cells of an affected individual were performed in order to test the accuracy and reliability of this single-cell protocol. For each locus tested, amplification efficiency was 83% to 87% and allelic drop-out rates ranged from 12% to 8%. Three VHL disease PGD cycles were performed on cells from a couple with paternal transmission of a 436delC mutation in exon 2 of the VHL gene, leading to the identification of three unaffected embryos. Independent of the mutation present, this general PGD protocol for the diagnosis of VHL disease can be used in families informative for either the D3S1038 or D3S1317 microsatellite markers.

  20. Size-segregated compositional analysis of aerosol particles collected in the European Arctic during the ACCACIA campaign

    Science.gov (United States)

    Young, G.; Jones, H. M.; Darbyshire, E.; Baustian, K. J.; McQuaid, J. B.; Bower, K. N.; Connolly, P. J.; Gallagher, M. W.; Choularton, T. W.

    2016-03-01

    Single-particle compositional analysis of filter samples collected on board the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft is presented for six flights during the springtime Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA) campaign (March-April 2013). Scanning electron microscopy was utilised to derive size-segregated particle compositions and size distributions, and these were compared to corresponding data from wing-mounted optical particle counters. Reasonable agreement between the calculated number size distributions was found. Significant variability in composition was observed, with differing external and internal mixing identified, between air mass trajectory cases based on HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) analyses. Dominant particle classes were silicate-based dusts and sea salts, with particles notably rich in K and Ca detected in one case. Source regions varied from the Arctic Ocean and Greenland through to northern Russia and the European continent. Good agreement between the back trajectories was mirrored by comparable compositional trends between samples. Silicate dusts were identified in all cases, and the elemental composition of the dust was consistent for all samples except one. It is hypothesised that long-range, high-altitude transport was primarily responsible for this dust, with likely sources including the Asian arid regions.

  1. Environment-oriented life cycle analysis of bulk materials, applied in solar cell systems

    International Nuclear Information System (INIS)

    In the solar cell technology several bulk materials (glass, steel, aluminium, concrete, copper, zinc and synthetic materials) are applied intensively. By means of a life cycle analysis (LCA) the environmental effects and bottlenecks of the use of these materials is investigated in this report. Also attention is paid to the options to reduce the environmental effects of photovoltaic (PV) systems by changing processes and/or by redesign of the PV systems. Two systems are studied: solar cells, integrated in pitched roofs, and solar cells on the ground in solar cell arrays. The study is focused on the use of bulk materials in the solar module, the cables and the supporting construction. After brief introductions on the environment-oriented LCA method, the standard construction of PV modules and the principles of solar cells, an overview is given of the present and future material input for the above-mentioned PV-systems. Next, attention is paid to the energy consumption and the most important emissions of the production of the bulk materials. Based on these data three environmental effect scores of the PV systems are calculated and analyzed: the energy consumption, the greenhouse effect or global warming equivalent, and the acidifying effect or acidification equivalent. Also a fourth effect, for which the so-called environmental indicator human toxicity is defined, is described. By means of this indicator the hazardous effects for the public health can be indicated. The sum of the four indicators is a measure for the environmental profile of the roof PV-system and the ground PV-array system. Recommendations are given by which the systems and their environmental profiles can be improved. 29 figs., 50 tabs., 5 appendices, refs

  2. Materials Analysis of CED Nb Films Being Coated on Bulk Nb Single Cell SRF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xin; Reece, Charles; Palczewski, Ari; Ciovati, Gianluigi; Krishnan, Mahadevan; James, Colt; Irfan, Irfan

    2013-09-01

    This study is an on-going research on depositing a Nb film on the internal wall of bulk Nb single cell SRF cavities, via a cathodic arc Nb plasma ions source, an coaxial energetic condensation (CED) facility at AASC company. The motivation is to firstly create a homoepitaxy-like Nb/Nb film in a scale of a ~1.5GHz RF single cell cavity. Next, through SRF measurement and materials analysis, it might reveal the baseline properties of the CED-type homoepitaxy Nb films. Literally, a top-surface layer of Nb films which sustains SRF function, always grows up in homo-epitaxy mode, on top of a Nb nucleation layer. Homo-epitaxy growth of Nb must be the final stage (a crystal thickening process) of any coatings of Nb film on alternative cavity structure materials. Such knowledge of Nb-Nb homo-epitaxy is useful to create future realistic SRF cavity film coatings, such as hetero-epitaxy Nb/Cu Films, or template-layer-mitigated Nb films. One large-grain, and three fine grain bulk Nb cavities were coated. They went through cryogenic RF measurement. Preliminary results show that the Q0 of a Nb film could be as same as the pre-coated bulk Nb surface (which received a chemically-buffered polishing plus a light electro-polishing); but quality factor of two tested cavities dropped quickly. We are investigating if the severe Q-slope is caused by hydrogen incorporation before deposition, or is determined by some structural defects during Nb film growth.

  3. Digital image analysis measurements of bed expansion and segregation dynamics in dense gas-fluidized beds

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Link, J.M.; Mellema, S.; Kuipers, J.A.M.

    2003-01-01

    One of the most crucial steps in the development of fundamental hydrodynamic models is the validation of these models with accurate, detailed experimental data. Therefore a whole-field, non-intrusive digital image analysis technique has been developed which enables measurement of bed expansion and s

  4. Poisson Indices of Segregation

    OpenAIRE

    Angelo, Mele

    2009-01-01

    Existing indices of residential segregation are based on an arbitrary partition of the city in neighborhoods: given a spatial distribution of racial groups, the index provides different levels of segregation for different partitions. This paper proposes a method in which individual locations are mapped to aggregate levels of segregation, avoiding arbitrary partitions. Assuming a simple spatial process driving the locations of different racial groups, I define a location-specific segregation i...

  5. Matrix effects in compositional analysis of bulk materials by PGNAA (prompt gamma/neutron activation analysis). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, V.C.; Sandquist, G.M.; Merrell, G.B.; Gozani, T.

    1984-08-01

    This feasibility study has identified and evaluated the influence of important matrix effects which arise in the commercial application of prompt gamma/neutron activation analysis (PGNAA) methods to bulk-coal analysis as follows: neutron moderation and absorption changes; gamma-ray attenuation in the sample; sample density and volume changes. The neutron-induced capture gamma spectra were found to vary in a similar, predictable manner for all neutron absorbers found in coal such as hydrogen, boron, nitrogen, chlorine, and sulfur. Three different models have been proposed from this study to analyze coal by PGNAA methods and account for the significant matrix effects arising from hydrogen variation and other system perturbations.

  6. Matrix effects in compositional analysis of bulk materials by PGNAA (prompt gamma/neutron activation analysis). Final report

    International Nuclear Information System (INIS)

    This feasibility study has identified and evaluated the influence of important matrix effects which arise in the commercial application of prompt gamma/neutron activation analysis (PGNAA) methods to bulk-coal analysis as follows: neutron moderation and absorption changes; gamma-ray attenuation in the sample; sample density and volume changes. The neutron-induced capture gamma spectra were found to vary in a similar, predictable manner for all neutron absorbers found in coal such as hydrogen, boron, nitrogen, chlorine, and sulfur. Three different models have been proposed from this study to analyze coal by PGNAA methods and account for the significant matrix effects arising from hydrogen variation and other system perturbations

  7. Bulk velocity measurements by video analysis of dye tracer in a macro-rough channel

    International Nuclear Information System (INIS)

    Steep mountain rivers have hydraulic and morphodynamic characteristics that hinder velocity measurements. The high spatial variability of hydraulic parameters, such as water depth (WD), river width and flow velocity, makes the choice of a representative cross-section to measure the velocity in detail challenging. Additionally, sediment transport and rapidly changing bed morphology exclude the utilization of standard and often intrusive velocity measurement techniques. The limited technical choices are further reduced in the presence of macro-roughness elements, such as large, relatively immobile boulders. Tracer tracking techniques are among the few reliable methods that can be used under these conditions to evaluate the mean flow velocity. However, most tracer tracking techniques calculate bulk flow velocities between two or more fixed cross-sections. In the presence of intense sediment transport resulting in an important temporal variability of the bed morphology, dead water zones may appear in the few selected measurement sections. Thus a technique based on the analysis of an entire channel reach is needed in this study. A dye tracer measurement technique in which a single camcorder visualizes a long flume reach is described and developed. This allows us to overcome the problem of the presence of dead water zones. To validate this video analysis technique, velocity measurements were carried out on a laboratory flume simulating a torrent, with a relatively gentle slope of 1.97% and without sediment transport, using several commonly used velocity measurement instruments. In the absence of boulders, salt injections, WD and ultrasonic velocity profiler measurements were carried out, along with dye injection technique. When boulders were present, dye tracer technique was validated only by comparison with salt tracer. Several video analysis techniques used to infer velocities were developed and compared, showing that dye tracking is a valid technique for bulk velocity

  8. Bulk velocity measurements by video analysis of dye tracer in a macro-rough channel

    Science.gov (United States)

    Ghilardi, T.; Franca, M. J.; Schleiss, A. J.

    2014-03-01

    Steep mountain rivers have hydraulic and morphodynamic characteristics that hinder velocity measurements. The high spatial variability of hydraulic parameters, such as water depth (WD), river width and flow velocity, makes the choice of a representative cross-section to measure the velocity in detail challenging. Additionally, sediment transport and rapidly changing bed morphology exclude the utilization of standard and often intrusive velocity measurement techniques. The limited technical choices are further reduced in the presence of macro-roughness elements, such as large, relatively immobile boulders. Tracer tracking techniques are among the few reliable methods that can be used under these conditions to evaluate the mean flow velocity. However, most tracer tracking techniques calculate bulk flow velocities between two or more fixed cross-sections. In the presence of intense sediment transport resulting in an important temporal variability of the bed morphology, dead water zones may appear in the few selected measurement sections. Thus a technique based on the analysis of an entire channel reach is needed in this study. A dye tracer measurement technique in which a single camcorder visualizes a long flume reach is described and developed. This allows us to overcome the problem of the presence of dead water zones. To validate this video analysis technique, velocity measurements were carried out on a laboratory flume simulating a torrent, with a relatively gentle slope of 1.97% and without sediment transport, using several commonly used velocity measurement instruments. In the absence of boulders, salt injections, WD and ultrasonic velocity profiler measurements were carried out, along with dye injection technique. When boulders were present, dye tracer technique was validated only by comparison with salt tracer. Several video analysis techniques used to infer velocities were developed and compared, showing that dye tracking is a valid technique for bulk velocity

  9. Occupational segregation and the gender wage gap in Brazil: an empirical analysis

    Directory of Open Access Journals (Sweden)

    Regina Madalozzo

    2010-06-01

    Full Text Available Several countries experienced an increase in female labor participation during the twentieth century. Even so, few can be proud of the conditions female workers faced. This paper analyzes the occupational distribution by gender from 1978 to in 2007 in Brazil. It shows that women have penetrated traditionally male occupations to a certain extent, but that traditionally female occupations have maintained their gender composition over the past 30 years. We also provide a regression analysis with an Oaxaca decomposition that shows that the gender wage gap is lower than in 1978, but that it has remained constant over the last decade.

  10. Glass Stability and Kinetic Analysis of Iron-Metalloid Bulk Metallic Glass

    Science.gov (United States)

    Santhaweesuk, Charuayporn

    Multicomponent Fe-based bulk metallic glasses (BMGs) with a combination of excellent properties such as good soft magnetic properties, high strength, high hardness, and high corrosion resistance have attracted increasing attention both from a basic science research standpoint and due to their industrial application potential. However, many of the elemental additions which lead to the easiest glass formation are expensive. The identification of alloys composed of abundant and inexpensive elements that still retain excellent properties would promote applications for engineering and industry. In short, the development of the Fe-based BMG without any glass-forming metal elements and with high glass forming ability is desired. This study shows that the thermal stability of the Fe-based alloys can be improved beyond a simple rule of mixtures prediction by utilizing a well-balance multi-metalloid approach. The kinetics aspect of glass-forming ability is studied experimentally for Fe-B-Si-P alloys. The systematic variation in alloy composition gives access to differences in phase selection and the final dimensions of glass formation. Two alloys, representing the best glass-forming composition and the poorest glass-forming composition, were studied in terms of their stability to crystallization, solidification microstructure evolution and thermal history. The utility of the wedge-casting technique is developed to examine bulk glass-forming alloys by combining multiple temperature profiles of the quenching melt with a measurement-based kinetic analysis of the phase selection competition and critical cooling rate conditions. Based upon direct thermal measurement, microstructural analysis and kinetic modeling, it was found that both representative alloys show a board spectrum of solidification microstructures which include a critical cooling rate range. The kinetic competition in the formation of certain phases can enhance or detract from the final dimension of bulk glass

  11. Cluster analysis on the bulk elemental compositions of Antarctic stony meteorites

    Science.gov (United States)

    Miyamoto, Hideaki; Niihara, Takafumi; Kuritani, Takeshi; Hong, Peng K.; Dohm, James M.; Sugita, Seiji

    2016-05-01

    Remote sensing observations by recent successful missions to small bodies have revealed the difficulty in classifying the materials which cover their surfaces into a conventional classification of meteorites. Although reflectance spectroscopy is a powerful tool for this purpose, it is influenced by many factors, such as space weathering, lighting conditions, and surface physical conditions (e.g., particle size and style of mixing). Thus, complementary information, such as elemental compositions, which can be obtained by X-ray fluorescence (XRF) and gamma-ray spectrometers (GRS), have been considered very important. However, classifying planetary materials solely based on elemental compositions has not been investigated extensively. In this study, we perform principal component and cluster analyses on 12 major and minor elements of the bulk compositions of 500 meteorites reported in the National Institute of Polar Research (NIPR), Japan database. Our unique approach, which includes using hierarchical cluster analysis, indicates that meteorites can be classified into about 10 groups purely by their bulk elemental compositions. We suggest that Si, Fe, Mg, Ca, and Na are the optimal set of elements, as this set has been used successfully to classify meteorites of the NIPR database with more than 94% accuracy. Principal components analysis indicates that elemental compositions of meteorites form eight clusters in the three-dimensional space of the components. The three major principal components (PC1, PC2, and PC3) are interpreted as (1) degree of differentiations of the source body (i.e., primitive versus differentiated), (2) degree of thermal effects, and (3) degree of chemical fractionation, respectively.

  12. On-line bulk elemental analysis in the resource industries using neutron-gamma techniques

    International Nuclear Information System (INIS)

    There is an increasing need in industry, arising from both economic and environmental considerations, to reduce costs and improve product quality through the use of automation. The use of on-line analysis instrumentation provides plant operators with a means for continuous measurement and rapid response. This can result in better control of process efficiency, product quality and resource utilization, all of which produce significant economic and environmental benefits. On-line measurement of bulk elemental composition is important in many industrial applications and is best achieved with highly penetrating neutron-gamma techniques. Recent work by CSIRO Minerals on the development and implementation of such a technique, NITA (neutron inelastic-scattering and thermal-capture analysis) is presented. NITA is distinct from the more common PGNAA (prompt neutron gamma activation analysis) technique in its use of fast neutron sources to generate inelastic scattering reactions, and in its consequent ability to excite gamma-rays from industrially important elements such as carbon and oxygen. Features of NITA and PGNAA analysers are compared and applications of NITA in industry, including the on-line analysis of composition in pyrometallurgical applications and the on-conveyor belt monitoring of cement raw meal and coal are discussed. (author)

  13. Structural and segregation analysis of the type II collagen gene (COL2A1) in some heritable chondrodysplasias.

    OpenAIRE

    Wordsworth, P; Ogilvie, D.; Priestley, L; Smith, R.; Wynne-Davies, R; Sykes, B

    1988-01-01

    Seventy-seven persons with a variety of heritable chondrodysplasias were screened for gross rearrangements of the structural gene encoding the major cartilage collagen, collagen II. None was found. Segregation of the locus (COL2A1) was studied in 19 pedigrees using three restriction site dimorphisms (shown by PvuII, HindIII, and BamHI) and a length polymorphism as linkage markers. Discordant segregation between COL2A1 and the mutant locus was seen in pedigrees with multiple epiphyseal dysplas...

  14. Inheritance of 15 microsatellites in the Pacific oyster Crassostrea gigas: segregation and null allele identification for linkage analysis

    Institute of Scientific and Technical Information of China (English)

    LI Li; GUO Ximing; ZHANG Guofan

    2009-01-01

    Microsatellites were screened in a backcross family of the Pacific oyster, Crassostrea gigas. Fifteen microsatellite loci were distinguishable and polymorphic with 6 types of allele-combinations. Null alleles were detected in 46.7% of loci, accounting for 11.7% of the total alleles. Four loci did not segregate in Mendelian Ratios. Three linkage groups were identified among 7 of the 15 segregating loci. Fluorescence-based automated capillary electrophoresis (ABI 310 Genetic Analyzer) that used to detect the microsatellite loci, has been proved a fast, precise, and reliable method in microsatellite genotyping.

  15. Numerical comparisons of two formulations of the logistic regressive models with the mixed model in segregation analysis of discrete traits.

    Science.gov (United States)

    Demenais, F M; Laing, A E; Bonney, G E

    1992-01-01

    Segregation analysis of discrete traits can be conducted by the classical mixed model and the recently introduced regressive models. The mixed model assumes an underlying liability to the disease, to which a major gene, a multifactorial component, and random environment contribute independently. Affected persons have a liability exceeding a threshold. The regressive logistic models assume that the logarithm of the odds of being affected is a linear function of major genotype effects, the phenotypes of older relatives, and other covariates. A formulation of the regressive models, based on an underlying liability model, has been recently proposed. The regression coefficients on antecedents are expressed in terms of the relevant familial correlations and a one-to-one correspondence with the parameters of the mixed model can thus be established. Computer simulations are conducted to evaluate the fit of the two formulations of the regressive models to the mixed model on nuclear families. The two forms of the class D regressive model provide a good fit to a generated mixed model, in terms of both hypothesis testing and parameter estimation. The simpler class A regressive model, which assumes that the outcomes of children depend solely on the outcomes of parents, is not robust against a sib-sib correlation exceeding that specified by the model, emphasizing testing class A against class D. The studies reported here show that if the true state of nature is that described by the mixed model, then a regressive model will do just as well. Moreover, the regressive models, allowing for more patterns of family dependence, provide a flexible framework to understand gene-environment interactions in complex diseases. PMID:1487139

  16. A holistic life cycle analysis of waste management scenarios at increasing source segregation intensity: the case of an Italian urban area.

    Science.gov (United States)

    Di Maria, Francesco; Micale, Caterina

    2014-11-01

    Life cycle analysis of several waste management scenarios for an Italian urban area was performed on the basis of different source segregation collection (SS) intensities from 0% up to 52%. Source segregated waste was recycled and or/recovered by composting. Residual waste management options were by landfilling, incineration with energy recovery or solid recovered fuel (SRF) production to substitute for coal. The increase in fuel and materials consumption due to increase in SS had negligible influence on the environmental impact of the system. Recycling operations such as incineration and SRF were always advantageous for impact reduction. There was lower impact for an SS of 52% even though the difference with the SS intensity of 35% was quite limited, about 15%. In all the configurations analyzed, the best environmental performance was achieved for the management system producing SRF by the biodrying process. PMID:25008299

  17. The Effects of Living in Segregated vs. Mixed Areas in Northern Ireland: A Simultaneous Analysis of Contact and Threat Effects in the Context of Micro-Level Neighbourhoods

    Directory of Open Access Journals (Sweden)

    Joanne Hughes

    2008-06-01

    Full Text Available This study examines the consequences of living in segregated and mixed neighbourhoods on ingroup bias and offensive action tendencies, taking into consideration the role of intergroup experiences and perceived threat. Using adult data from a cross-sectional survey in Belfast, Northern Ireland, we tested a model that examined the relationship between living in segregated (N = 396 and mixed (N = 562 neighbourhoods and positive contact, exposure to violence, perceived threat and outgroup orientations. Our results show that living in mixed neighbourhoods was associated with lower ingroup bias and reduced offensive action tendencies. These effects were partially mediated by positive contact. However, our analysis also shows that respondents living in mixed neighbourhoods report higher exposure to political violence and higher perceived threat to physical safety. These findings demonstrate the importance of examining both social experience and threat perceptions when testing the relationship between social environment and prejudice.

  18. Immunosuppression in progeny of chinook salmon infected with Renibacterium salmoninarum: re-analysis of a brood stock segregation experiment.

    Science.gov (United States)

    Hamel, Owen S

    2005-06-14

    Female spawner infection level and temperature variation through rearing are sufficient to explain in-hatchery mortality rates and infection levels and smolt to adult return ratios (SARs) of progeny of Renibacterium salmoninarum infected spring chinook salmon. Data from published reports and manuscripts regarding a 1988 brood stock segregation experiment that held progeny of highly infected female spring chinook salmon spawners separate from progeny of other spawners during 16 mo of hatchery rearing are analyzed to test the hypothesis that immunosuppression could account for differences in survival and infection levels between the 2 segregates. Immunosuppression, caused by the presence of the p57 antigen of R. salmoninarum in sufficient concentration within the salmon egg before spawning, can account for differences in infection levels, mortality rates, and SARs for each hatchery raceway in that study. This immunosuppression may be characterized by immunotolerance, or might only affect cell mediated immunity, which appears the most effective defense mechanism against R. salmoninarum infection, as antibody production can result in tissue damaging antibody-antigen complexes. Low-temperature mediated immunosuppression can account for the nearly identical trajectories of infection and mortality between the 2 segregates during the first 8 mo of hatchery rearing. There is no evidence of widespread vertical infection from spawner to progeny, nor is there evidence that brood stock segregation reduces overall mortality. Rather, the suppression of cell-mediated immune mechanisms may condemn progeny of highly infected female spawners to an almost certain eventual premature demise. PMID:16042041

  19. Atomic-scale analysis of the segregation and precipitation mechanisms in a severely deformed Al–Mg alloy

    International Nuclear Information System (INIS)

    Due to their interaction with crystalline defects, solute atoms play a critical role in the microstructure evolution of aluminum alloys during deformation. In addition, deformed structures often exhibit a modified aging response. For a better understanding of these mechanisms, we provide here a thorough study of deformation-induced segregation and precipitation mechanisms in an aluminum alloy containing 5.8 wt.% Mg subjected to severe plastic deformation (SPD). The solutionized alloy was processed by high-pressure torsion at room temperature and at 200 °C. The investigation of the microstructure and of the distribution of Mg after deformation by scanning transmission electron microscopy and atom probe tomography revealed that clustering and segregations occurred during severe deformation. Mg atoms agglomerate on grain boundaries (GBs), forming mostly nanoscaled clusters at room temperature and more uniform segregation along GBs at 200 °C. In any case, however, the equilibrium Al3Mg2 phase does not nucleate. Using post-deformation annealing treatments, it was found that it can proceed only through a very specific orientation relationship with the face-centered-cubic Al matrix. Both the contribution of dislocations and deformation-induced vacancies were considered to account for the enhanced mobility of Mg atoms. From theoretical estimations it is, however, concluded that Mg atoms are dragged by the vacancy flux toward GBs while dislocations should not play a significant role. These data provide new insights about mechanisms controlling dynamic precipitation and segregation during SPD of aluminum alloys. The segregation and formation of clusters that is revealed can additionally contribute to the strengthening of these alloys, leading to a new understanding of dynamic ageing in non-age-hardenable alloys

  20. Development of environmental sample analysis technique in KAERI. Bulk analysis and establishment of clean laboratory facility (CLASS)

    International Nuclear Information System (INIS)

    The development of analytical methods for environmental samples in Korea Atomic Energy Research Institute (KAERI) is discussed. An analysis scheme for environmental samples has been established with an MCICP-MS based bulk analysis with adopting UTEVA resin for chemical separation and a particle analysis using FTTIMS and SIMS. A clean laboratory facility called CLASS (class 100∼ class 1000) was also established in order to prevent any cross contamination of the samples. The amount of U and Pu in the process blank sample prepared in the CLASS facility was estimated as 20 pg and less than 0.005 pg, respectively. The control chart of the analytical performance for the uranium standard sample of 100 ppt (NBL U030) indicated that the analytical performance of KAERI in CLASS is within 5 % of the certified values. (author)

  1. Pursuit of improvement in uranium bulk analysis at the clear facility for safeguards environmental samples

    International Nuclear Information System (INIS)

    Full text: In order to contribute to the IAEA strengthened safeguards system, a project started in Japan Atomic Energy Research Institute (JAERI) in 1998. Consequently, a clean room facility called as CLEAR, the Clean Laboratory for Environmental Analysis and Research, was constructed in June 2001 at JAERI Tokai and the analytical techniques of ultra-trace nuclear materials in environmental samples are being developed. As for the bulk analysis, performance of inductively-coupled plasma mass spectrometry (ICP-MS) was mainly examined because sample preparation for ICP-MS is simpler than that for thermal ionization mass spectrometry (TIMS). Interference of polyatomic ion (such as PtAr+) and coexisting element (such as Na) on the uranium ions, as well as mass bias caused by ICP-MS operating conditions, has been investigated for precise measurement on uranium isotope ratio. The authors have also studied on the uranium blanks during sample treatment process. The blank value below 10 pg uranium per sample treatment was obtained: dominant origins were elution from Teflon vessel surface in acid heating process of the sample to dry up. The work is in progress to minimize the blank. Compared with the process blank and the minimum uranium amount for isotope ratio measurement by ICP-MS (ca. 10 pg for natural uranium), the swipe cotton (Texwipe-304) which is currently used for IAEA Environmental Sampling includes much more amount of natural uranium in several nano-grams. If the amount of uranium collected on Texwipe-304 is small, sensitive and reliable measurement on isotope ratio will be impossible by bulk analysis. The authors are seeking alternative swipe materials with less amount of uranium. Recently, one of the authors devised an effective technique for recovery of uranium-containing particles from Texwipe-304. The technique, named as Vacuum Suction Method, uses a combination of polycarbonate membrane filters and a macro-pipette tip, which is connected to a vacuum pump

  2. Local versus overall segregation measures

    OpenAIRE

    Olga Alonso-Villar; Coral del Río

    2008-01-01

    This paper proposes a framework in which to study the segregation of a target group in a multigroup context, according either to an evenness perception or to a representativeness view of segregation, and offers a bridge between local segregation and overall segregation. In doing so, this paper first presents an axiomatic set-up within which local segregation measures can be evaluated, and defines local segregation curves. Next, a class of additive segregation indexes, related to the generaliz...

  3. On the Measurement of Segregation

    OpenAIRE

    Federico Echenique; Roland G. Fryer, Jr.

    2005-01-01

    This paper develops a measure of segregation based on two premises: (1) a measure of segregation should disaggregate to the level of individuals, and (2) an individual is more segregated the more segregated are the agents with whom she interacts. Developing three desirable axioms that any segregation measure should satisfy, we prove that one and only one segregation index satisfies our three axioms, and the two aims mentioned above; which we coin the Spectral Segregation Index. We apply the i...

  4. A model for calculating the errors of 2D bulk analysis relative to the true 3D bulk composition of an object, with application to chondrules

    Science.gov (United States)

    Hezel, Dominik C.

    2007-09-01

    Certain problems in Geosciences require knowledge of the chemical bulk composition of objects, such as, for example, minerals or lithic clasts. This 3D bulk chemical composition (bcc) is often difficult to obtain, but if the object is prepared as a thin or thick polished section a 2D bcc can be easily determined using, for example, an electron microprobe. The 2D bcc contains an error relative to the true 3D bcc that is unknown. Here I present a computer program that calculates this error, which is represented as the standard deviation of the 2D bcc relative to the real 3D bcc. A requirement for such calculations is an approximate structure of the 3D object. In petrological applications, the known fabrics of rocks facilitate modeling. The size of the standard deviation depends on (1) the modal abundance of the phases, (2) the element concentration differences between phases and (3) the distribution of the phases, i.e. the homogeneity/heterogeneity of the object considered. A newly introduced parameter " τ" is used as a measure of this homogeneity/heterogeneity. Accessory phases, which do not necessarily appear in 2D thin sections, are a second source of error, in particular if they contain high concentrations of specific elements. An abundance of only 1 vol% of an accessory phase may raise the 3D bcc of an element by up to a factor of ˜8. The code can be queried as to whether broad beam, point, line or area analysis technique is best for obtaining 2D bcc. No general conclusion can be deduced, as the error rates of these techniques depend on the specific structure of the object considered. As an example chondrules—rapidly solidified melt droplets of chondritic meteorites—are used. It is demonstrated that 2D bcc may be used to reveal trends in the chemistry of 3D objects.

  5. Measuring School Segregation

    OpenAIRE

    David M. Frankel; Volij, Oscar

    2011-01-01

    Using only ordinal axioms, we characterize several multi-group school segregation indices: the Atkinson Indices for the class of school districts with a given fixed number of ethnic groups and the Mutual Information Index for the class of all districts. Properties of other school segregation indices are also discussed. In an empirical application, we document a weakening of the effect of ethnicity on school assignment from 1987/8 to 2007/8. We also show that segregation between districts with...

  6. What Drives Racial Segregation? New Evidence Using Census Microdata

    OpenAIRE

    Bayer, Patrick; McMillan, Robert; Rueben, Kim

    2003-01-01

    This paper sheds new light on the forces that drive residential segregation on the basis of race, assessing the extent to which across-race differences in other household characteristics can explain a significant portion of observed racial segregation. The central contribution of the analysis is to provide a transparent new measurement framework for understanding segregation patterns. This framework allows researchers to characterize patterns of segregation, to decompose them in meaningful wa...

  7. Occupational segregation and the gender wage gap in private- and public-sector employment: a distributional analysis

    OpenAIRE

    Barón, Juan D.; Deborah A. Cobb-Clark

    2008-01-01

    We use HILDA data from 2001 - 2006 to analyse the source of the gender wage gap across public- and private-sector wage distributions in Australia. We are particularly interested in the role of gender segregation within sector-specific occupations in explaining relative wages. We find that, irrespective of labour market sector, the gender wage gap among low-paid, Australian workers is more than explained by differences in wage-related characteristics. The gender wage gap among high-wage worker...

  8. On the Segregation of Dark Matter Substructure

    CERN Document Server

    Bosch, Frank C van den; Campbell, Duncan; Behroozi, Peter

    2015-01-01

    We present the first comprehensive analysis of the segregation of dark matter subhaloes in their host haloes. Using numerical simulations, we examine the segregation of twelve different subhalo properties with respect to both orbital energy and halo-centric radius (in real space as well as in projection). Subhaloes are strongly segregated by accretion redshift, which is an outcome of the inside-out assembly of their host haloes. Since subhaloes that were accreted earlier have experienced more tidal stripping, subhaloes that have lost a larger fraction of their mass at infall are on more bound orbits. Subhaloes are also strongly segregated in their masses and maximum circular velocities at accretion. We demonstrate that part of this segregation is already imprinted in the infall conditions. For massive subhaloes it is subsequently boosted by dynamical friction, but only during their first radial orbit. The impact of these two effects is counterbalanced, though, by the fact that subhaloes with larger accretion ...

  9. Measuring segregation: an activity space approach

    Science.gov (United States)

    Wong, David W. S.; Shaw, Shih-Lung

    2011-06-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual's segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using the travel diary data collected from the tri-county area in southeast Florida and the imputed racial-ethnic data, this paper demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical spaces.

  10. Verification of the Bulk Analysis Procedure of Safeguards Environmental Samples by Thermal Ionization Mass Spectrometry in KAERI

    International Nuclear Information System (INIS)

    The Korea Atomic Energy Research Institute (KAERI) had been qualified as a member of the Network of Analytical Laboratories (NWAL) for bulk analysis on environmental samples (ES) in 2012. Recently a new clean facility had been constructed and opened in KAERI, which caused the validation issue as the analytical environment and the main analytical instrument had been changed after the qualification. This study is to verify the capability of KAERI to performed bulk analysis on environmental sample under the new analytical environment using thermal ionization mass spectrometry (TIMS). The verification of the quality assurance of the bulk analysis of environmental samples was performed by TIMS measurement of a simulated swipe sample. The analytical results for the determination of the isotopic ratios and the amount contents of nuclear materials in the simulated environmental samples were in good agreement with the certified values. Therefore, we believe that our laboratory can produce reliable results for the bulk analysis on environmental swipe samples performed in CLASS and contribute the analytical services as a member of NWAL

  11. Purification of U and Pu from Bulk Environmental Samples for Analysis by MC-ICPMS

    International Nuclear Information System (INIS)

    This procedure gives the methods used at LLNL for the purification of uranium and plutonium from bulk environmental samples provided by the IAEA through the DOE Network of Analytical Laboratories (NWAL)

  12. Geostatistical analysis of the spatial distribution of mycotoxin concentration in bulk cereals

    OpenAIRE

    Rivas Casado, Monica; Parsons, David J.; Weightman, Richard Mark; Magan, Naresh; Origgi, Simona

    2009-01-01

    Abstract Deoxynivalenol (DON) and Ochratoxin A (OTA) in agricultural commodities present hazards to human and animal health. Bulk lots are routinely sampled for their presence, but it is widely acknowledged that designing sampling plans is particularly problematical because of their heterogeneous distribution. Previous studies have not explicitly looked at the interactions between the spatial distribution of the mycotoxin and the strategy used to take samples from bulk. Sampling pl...

  13. Residential Segregation in Southern Cities: 1970

    Science.gov (United States)

    And Others; Roof, Wade Clark

    1976-01-01

    Based on an analysis of the age, size, percent black, and occupational income differential in 32 southern cities, the findings show that age is still the strongest predictor of residential segregation. (Author)

  14. Bulk-Flow Analysis of Hybrid Thrust Bearings for Advanced Cryogenic Turbopumps

    Science.gov (United States)

    SanAndres, Luis

    1998-01-01

    A bulk-flow analysis and computer program for prediction of the static load performance and dynamic force coefficients of angled injection, orifice-compensated hydrostatic/hydrodynamic thrust bearings have been completed. The product of the research is an efficient computational tool for the design of high-speed thrust bearings for cryogenic fluid turbopumps. The study addresses the needs of a growing technology that requires of reliable fluid film bearings to provide the maximum operating life with optimum controllable rotordynamic characteristics at the lowest cost. The motion of a cryogenic fluid on the thin film lands of a thrust bearing is governed by a set of bulk-flow mass and momentum conservation and energy transport equations. Mass flow conservation and a simple model for momentum transport within the hydrostatic bearing recesses are also accounted for. The bulk-flow model includes flow turbulence with fluid inertia advection, Coriolis and centrifugal acceleration effects on the bearing recesses and film lands. The cryogenic fluid properties are obtained from realistic thermophysical equations of state. Turbulent bulk-flow shear parameters are based on Hirs' model with Moody's friction factor equations allowing a simple simulation for machined bearing surface roughness. A perturbation analysis leads to zeroth-order nonlinear equations governing the fluid flow for the thrust bearing operating at a static equilibrium position, and first-order linear equations describing the perturbed fluid flow for small amplitude shaft motions in the axial direction. Numerical solution to the zeroth-order flow field equations renders the bearing flow rate, thrust load, drag torque and power dissipation. Solution to the first-order equations determines the axial stiffness, damping and inertia force coefficients. The computational method uses well established algorithms and generic subprograms available from prior developments. The Fortran9O computer program hydrothrust runs

  15. Cell wall elasticity: I. A critique of the bulk elastic modulus approach and an analysis using polymer elastic principles

    Science.gov (United States)

    Wu, H. I.; Spence, R. D.; Sharpe, P. J.; Goeschl, J. D.

    1985-01-01

    The traditional bulk elastic modulus approach to plant cell pressure-volume relations is inconsistent with its definition. The relationship between the bulk modulus and Young's modulus that forms the basis of their usual application to cell pressure-volume properties is demonstrated to be physically meaningless. The bulk modulus describes stress/strain relations of solid, homogeneous bodies undergoing small deformations, whereas the plant cell is best described as a thin-shelled, fluid-filled structure with a polymer base. Because cell walls possess a polymer structure, an alternative method of mechanical analysis is presented using polymer elasticity principles. This initial study presents the groundwork of polymer mechanics as would be applied to cell walls and discusses how the matrix and microfibrillar network induce nonlinear stress/strain relationships in the cell wall in response to turgor pressure. In subsequent studies, these concepts will be expanded to include anisotropic expansion as regulated by the microfibrillar network.

  16. Segregation and Civic Virtue

    Science.gov (United States)

    Merry, Michael S.

    2012-01-01

    In this essay Michael Merry defends the following prima facie argument: that civic virtue is not dependent on integration and in fact may be best fostered under conditions of segregation. He demonstrates that civic virtue can and does take place under conditions of involuntary segregation, but that voluntary separation--as a response to…

  17. A simple method for co-segregation analysis to evaluate the pathogenicity of unclassified variants; BRCA1 and BRCA2 as an example

    Directory of Open Access Journals (Sweden)

    Gómez García Encarna

    2009-06-01

    Full Text Available Abstract Background Assessment of the clinical significance of unclassified variants (UVs identified in BRCA1 and BRCA2 is very important for genetic counselling. The analysis of co-segregation of the variant with the disease in families is a powerful tool for the classification of these variants. Statistical methods have been described in literature but these methods are not always easy to apply in a diagnostic setting. Methods We have developed an easy to use method which calculates the likelihood ratio (LR of an UV being deleterious, with penetrance as a function of age of onset, thereby avoiding the use of liability classes. The application of this algorithm is publicly available http://www.msbi.nl/cosegregation. It can easily be used in a diagnostic setting since it requires only information on gender, genotype, present age and/or age of onset for breast and/or ovarian cancer. Results We have used the algorithm to calculate the likelihood ratio in favour of causality for 3 UVs in BRCA1 (p.M18T, p.S1655F and p.R1699Q and 5 in BRCA2 (p.E462G p.Y2660D, p.R2784Q, p.R3052W and p.R3052Q. Likelihood ratios varied from 0.097 (BRCA2, p.E462G to 230.69 (BRCA2, p.Y2660D. Typing distantly related individuals with extreme phenotypes (i.e. very early onset cancer or old healthy individuals are most informative and give the strongest likelihood ratios for or against causality. Conclusion Although co-segregation analysis on itself is in most cases insufficient to prove pathogenicity of an UV, this method simplifies the use of co-segregation as one of the key features in a multifactorial approach considerably.

  18. Bulk Analysis Method of Gold Determination in Ores Using Epithermal Neutrons of Electron Accelerator Microtron MT-22

    CERN Document Server

    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.

  19. Bulk analysis method of gold determination in ores using epithermal neutrons of electron accelerator microtron MT-22

    International Nuclear Information System (INIS)

    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

  20. Neighborhood Schools and Racial Segregation

    Science.gov (United States)

    Kelleher, Daniel T.

    1975-01-01

    Neighborhood school concept and racially segregated residential patterns account for most of the segregation in American public schools today. The focus of this article will be to explain the reasons for residential segregation. (Author/RK)

  1. On the segregation of dark matter substructure

    Science.gov (United States)

    van den Bosch, Frank C.; Jiang, Fangzhou; Campbell, Duncan; Behroozi, Peter

    2016-01-01

    We present the first comprehensive analysis of the segregation of dark matter subhaloes in their host haloes. Using three different numerical simulations, and two different segregation strength indicators, we examine the segregation of 12 different subhalo properties with respect to both orbital energy and halocentric radius (in real space as well as in projection). Subhaloes are strongly segregated by accretion redshift, which is an outcome of the inside-out assembly of their host haloes. Since subhaloes that were accreted earlier have experienced more tidal stripping, subhaloes that have lost a larger fraction of their mass at infall are on more bound orbits. Subhaloes are also strongly segregated in their masses and maximum circular velocities at accretion. We demonstrate that part of this segregation is already imprinted in the infall conditions. For massive subhaloes, it is subsequently boosted by dynamical friction, but only during their first radial orbit. The impact of these two effects is counterbalanced, though, by the fact that subhaloes with larger accretion masses are accreted later. Because of tidal stripping, subhaloes reveal little to no segregation by present-day mass or maximum circular velocity, while the corresponding torques cause subhaloes on more bound orbits to have smaller spin. There is a weak tendency for subhaloes that formed earlier to be segregated towards the centre of their host halo, which is an indirect consequence of the fact that (sub)halo formation time is correlated with other, strongly segregated properties. We discuss the implications of our results for the segregation of satellite galaxies in galaxy groups and clusters.

  2. Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis

    CERN Document Server

    Kishne, Andrea Sz; Chang, Hung-Chih; Kish, Laszlo B

    2007-01-01

    Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified re...

  3. Bulk hydrogen analysis, using neutrons. Final report of the first research co-ordination meeting

    International Nuclear Information System (INIS)

    There are many situations when hydrogen is required to be measured in a bulk medium. For this reason neutrons are used due to their high penetrating power in dense material. In addition, the mass attenuation coefficient for neutrons in hydrogen is significantly larger than for all other elements, meaning that neutrons have a higher probability of interacting with hydrogen than with other elements in the sample matrix. This CRP was recommended for further development of the techniques and new applications in the following areas: Fast Neutron/Gamma Transmission Technique; Digital Neutron Imaging; Hydrogen Detection by Epithermal Neutrons; Microscopic Behaviour of Hydrogen in Bulk Materials

  4. A Monte Carlo simulation of neutron activation analysis of bulk objects

    Energy Technology Data Exchange (ETDEWEB)

    Fantidis, J.G. [Faculty of Engineering, Department of Electrical and Computer Engineering, Laboratory of Nuclear Technology, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi (Greece); Nicolaou, G. [Faculty of Engineering, Department of Electrical and Computer Engineering, Laboratory of Nuclear Technology, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi (Greece)], E-mail: nicolaou@ee.duth.gr; Tsagas, N.F. [Faculty of Engineering, Department of Electrical and Computer Engineering, Laboratory of Nuclear Technology, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi (Greece)

    2009-03-15

    A PGNAA facility comprising an isotopic neutron source has been simulated using the Monte Carlo code MCNPX. The facility is envisaged for elemental composition studies of biomedical, environmental and industrial bulk objects. The study carried out, aimed to improve the detection sensitivity of prompt gamma-rays emitted by a bulk object, measured in the presence of higher energy ones. An appropriate collimator, a filter between the neutron source and the object and an optimisation of the positioning of the neutron beam and the detector relative to the object analysed were means to improve the desired sensitivity. The simulation is demonstrated for the in-vivo PGNAA of boron in the human liver.

  5. A Monte Carlo simulation of neutron activation analysis of bulk objects

    International Nuclear Information System (INIS)

    A PGNAA facility comprising an isotopic neutron source has been simulated using the Monte Carlo code MCNPX. The facility is envisaged for elemental composition studies of biomedical, environmental and industrial bulk objects. The study carried out, aimed to improve the detection sensitivity of prompt gamma-rays emitted by a bulk object, measured in the presence of higher energy ones. An appropriate collimator, a filter between the neutron source and the object and an optimisation of the positioning of the neutron beam and the detector relative to the object analysed were means to improve the desired sensitivity. The simulation is demonstrated for the in-vivo PGNAA of boron in the human liver.

  6. Optimization of ISOCS Parameters for Quantitative Non-Destructive Analysis of Uranium in Bulk Form

    Science.gov (United States)

    Kutniy, D.; Vanzha, S.; Mikhaylov, V.; Belkin, F.

    2011-12-01

    Quantitative calculation of the isotopic masses of fissionable U and Pu is important for forensic analysis of nuclear materials. γ-spectrometry is the most commonly applied tool for qualitative detection and analysis of key radionuclides in nuclear materials. Relative isotopic measurement of U and Pu may be obtained from γ-spectra through application of special software such as MGAU (Multi-Group Analysis for Uranium, LLNL) or FRAM (Fixed-Energy Response Function Analysis with Multiple Efficiency, LANL). If the concentration of U/Pu in the matrix is unknown, however, isotopic masses cannot be calculated. At present, active neutron interrogation is the only practical alternative for non-destructive quantification of fissionable isotopes of U and Pu. An active well coincidence counter (AWCC), an alternative for analyses of uranium materials, has the following disadvantages: 1) The detection of small quantities (≤100 g) of 235U is not possible in many models; 2) Representative standards that capture the geometry, density and chemical composition of the analyzed unknown are required for precise analysis; and 3) Specimen size is severely restricted by the size of the measuring chamber. These problems may be addressed using modified γ-spectrometry techniques based on a coaxial HPGe-detector and ISOCS software (In Situ Object Counting System software, Canberra). We present data testing a new gamma-spectrometry method uniting actinide detection with commonly utilized software, modified for application in determining the masses of the fissionable isotopes in unknown samples of nuclear materials. The ISOCS software, widely used in radiation monitoring, calculates the detector efficiency curve in a specified geometry and range of photon energies. In describing the geometry of the source-detector, it is necessary to clearly describe the distance between the source and the detector, the material and the thickness of the walls of the container, as well as material, density

  7. On impurity segregation on dislocations in metals

    OpenAIRE

    Netchaev, Yu.; Mukhina, L.

    1993-01-01

    Thermodynamic and crystallo-chemistry considerations are given about the possibility of existing linear distribution laws for some impurities in metals between bulk solution and near-dislocation segregation regions (NDSR) with composition and structure close to the corresponding intermetallic compound. The solutions of Fe in Al are considered. NDSR composition can be close to FeAl3. The experimental data on the solubilities are treated within the model developed to determine the effective bin...

  8. Possible segregation caused by centrifugal titanium casting.

    Science.gov (United States)

    Watanabe, K; Okawa, S; Kanatani, M; Nakano, S; Miyakawa, O; Kobayashi, M

    1996-12-01

    The possibility of the segregation under solidification process using a centrifugal casting machine was investigated using an electron probe microanalyzer with elemental distribution map, line analysis and quantitative analysis. When a very small quantity of platinum was added to local molten titanium during the casting process, macroscopic segregation was observed under conditions of density difference of 0.1 g/cm3 at the most, confirming that the centrifugal force of the casting machine is extremely strong. When a Ti-6Al-4V alloy was cast, however, no macroscopic segregation was observed. The centrifugal force of the casting machine examined in the present study hardly results in the body-force segregation in this titanium alloy. PMID:9550020

  9. Numerical analysis of bulk drag coefficient in dense vegetation by immersed boundary method

    NARCIS (Netherlands)

    Suzuki, T.; Arikawa, T.

    2010-01-01

    In this paper, bulk drag coefficient in rigid dense vegetation is investigated mainly by using a three dimensional numerical simulation model CADMAS-SURF/3D by incorporating Immersed Boundary Method to calculate flow around the vertical cylinder in the Cartesian grid. Large Eddy Simulation is also i

  10. Simulation of radiation dose distribution and thermal analysis for the bulk shielding of an optimized molten salt reactor

    Institute of Scientific and Technical Information of China (English)

    张志宏; 夏晓彬; 蔡军; 王建华; 李长园; 葛良全; 张庆贤

    2015-01-01

    The Chinese Academy of Science has launched a thorium-based molten-salt reactor (TMSR) research project with a mission to research and develop a fission energy system of the fourth generation. The TMSR project intends to construct a liquid fuel molten-salt reactor (TMSR-LF), which uses fluoride salt as both the fuel and coolant, and a solid fuel molten-salt reactor (TMSR-SF), which uses fluoride salt as coolant and TRISO fuel. An optimized 2 MWth TMSR-LF has been designed to solve major technological challenges in the Th-U fuel cycle. Preliminary conceptual shielding design has also been performed to develop bulk shielding. In this study, the radiation dose and temperature distribution of the shielding bulk due to the core were simulated and analyzed by performing Monte Carlo simulations and computational fluid dynamics (CFD) analysis. The MCNP calculated dose rate and neutron and gamma spectra indicate that the total dose rate due to the core at the external surface of the concrete wall was 1.91 µSv/h in the radial direction, 1.16 µSv/h above and 1.33 µSv/h below the bulk shielding. All the radiation dose rates due to the core were below the design criteria. Thermal analysis results show that the temperature at the outermost surface of the bulk shielding was 333.86 K, which was below the required limit value. The results indicate that the designed bulk shielding satisfies the radiation shielding requirements for the 2 MWth TMSR-LF.

  11. Plasmid segregation mechanisms

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Gerdes, Kenn; Charbon, Gitte Ebersbach

    2005-01-01

    Bacterial plasmids encode partitioning (par) loci that ensure ordered plasmid segregation prior to cell division. par loci come in two types: those that encode actin-like ATPases and those that encode deviant Walker-type ATPases. ParM, the actin-like ATPase of plasmid R1, forms dynamic filaments...... that segregate plasmids paired at mid-cell to daughter cells. Like microtubules, ParM filaments exhibit dynamic instability (i.e., catastrophic decay) whose regulation is an important component of the DNA segregation process. The Walker box ParA ATPases are related to MinD and form highly dynamic, oscillating...... filaments that are required for the subcellular movement and positioning of plasmids. The role of the observed ATPase oscillation is not yet understood. However, we propose a simple model that couples plasmid segregation to ParA oscillation. The model is consistent with the observed movement...

  12. A holistic life cycle analysis of waste management scenarios at increasing source segregation intensity: The case of an Italian urban area

    International Nuclear Information System (INIS)

    Highlights: • Waste management scenarios starting from different SS intensity were analyzed by LCA. • Several experimental data were utilized for the inventory. • Collection activities influences marginally global impact. • Maximum global environmental gain was achieved by SRF for coke substitution. - Abstract: Life cycle analysis of several waste management scenarios for an Italian urban area was performed on the basis of different source segregation collection (SS) intensities from 0% up to 52%. Source segregated waste was recycled and or/recovered by composting. Residual waste management options were by landfilling, incineration with energy recovery or solid recovered fuel (SRF) production to substitute for coal. The increase in fuel and materials consumption due to increase in SS had negligible influence on the environmental impact of the system. Recycling operations such as incineration and SRF were always advantageous for impact reduction. There was lower impact for an SS of 52% even though the difference with the SS intensity of 35% was quite limited, about 15%. In all the configurations analyzed, the best environmental performance was achieved for the management system producing SRF by the biodrying process

  13. Developments of segregation process and chemical analysis for virus receptor recognizing environmental signal substance by affinity binding assaying

    International Nuclear Information System (INIS)

    Virus receptors recognizing environmental signal were segregated and analyzed chemically by affinity binding assaying using radio-isotope marked compound. Pathogenic protein in rice stem virus was indicated possibility of a protein which participates in transfer process between the virus cells. An enzyme, Chitobiose was separated from a bacteria, actinomycete. It was cleared by 3H chitobiose affinity binding assaying that two kinds of chitobiose binding protein existed in cell membrane of the actinomycete. A different kind of protein was founded in the cell membrane which was raised in existence of chitobiose. Observation showed that the protein was different from a protein in the cell membrane which was raised in non-existence of chitobiose. These two kinds of protein might be formed a complex compound on the surface of cell membrane. (M. Suetake)

  14. Predicting polydisperse granular segregation

    OpenAIRE

    Isner, Austin; Schlick, Conor P.; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

    2014-01-01

    Most granular materials in industrial applications and natural settings are size-polydisperse, but most models and simulations of segregation consider only bidisperse particle distributions. Here, we extend our recently developed theoretical advection–diffusion–segregation model to polydisperse particle distributions. To test the theoretical approach, we model and simulate grains log-normally distributed by size in a chute flow. In steady state, material near the free surface is dominated by ...

  15. Segregation by friction

    OpenAIRE

    Kondic, L.; Hartley, R. R.; Tennakoon, S. G. K.; Painter, B; Behringer, R. P.

    2002-01-01

    Granular materials are known to separate by size under a variety of circumstances. Experiments presented here and elucidated by modeling and MD simulation document a new segregation mechanism, namely segregation by friction. The experiments are carried out by placing steel spheres on a horizontal plane enclosed by rectangular sidewalls, and subjecting them to horizontal shaking. Half the spheres are highly smooth; the remainder are identical to the first half, except that their surfaces have ...

  16. AFLP marker linked to water-stress-tolerant bulks in barley (Hordeum vulgare L.)

    OpenAIRE

    Altinkut A.; Kazan K.; Gozukirmizi N.

    2003-01-01

    The amplified fragment length polymorphism (AFLP) assay is an efficient method for the identification of molecular markers, useful in the improvement of numerous crop species. Bulked Segregant Analysis (BSA) was used to identify AFLP markers associated with water-stress tolerance in barley, as this would permit rapid selection of water-stress tolerant genotypes in breeding programs. AFLP markers linked to water-stress tolerance was identified in two DNA pools (tolerant and sensitive), which w...

  17. Distribution and segregation of dissolved elements in pipeline slab

    Institute of Scientific and Technical Information of China (English)

    Jianhua Liu; Yanping Bao; Xian Dong; Taiquan Li; Yi Ren; Shuai Zhang

    2007-01-01

    The chemical composition in a cross section of a high grade pipeline slab was measured point by point (in a scale of 1 μm)using original position statistic distribution analysis (OPA). The result indicated that negative segregation strips of Si, Mn, Mo, Ni, Cr,Nb, Cu, Ti, and V exist in the two sides 24 mm away from the central line, with a width of 8-12 mm, Negative segregation inside the central line is more severe than that outside the central line, and the highest positive segregation of the elements appears closely by the inner sides of the negative segregation strips. No obvious negative segregation strip of S and P is found. Segregation of the elements in the central area is higher than that in the outer and inner arc areas. The segregation of C, Ti, S, and P is high and that of Cr, Cu, Si, and Mn is low in the slab.

  18. Bulk hydrogen analysis, using neutrons. Final report of the second research co-ordination meeting

    International Nuclear Information System (INIS)

    The aims of the Second Co-ordination Meting (RCM) of the Coordinated Research Programme (CRP) were to report on and review progress against the work programme set at the beginning of the CRP and to discuss the work plans for the second half of the programme. In many cases hydrogen is required to be measured in a bulk medium rather than merely at a surface. For this reason neutrons are used due to their high penetrating power in dense material. In addition, the mass attenuation coefficient for neutrons in hydrogen is significantly larger than for all other elements, meaning that neutrons have a higher probability of interacting with hydrogen than with other elements in the sample matrix. Neutrons have been used in the following areas: Fast Neutron Transmission, Scattering and Activation Technique; Digital Neutron Imaging; Hydrogen Detection by Epithermal Neutrons; Microscopic Behaviour of Hydrogen in Bulk Materials

  19. Theoretical Analysis of Tuned HVAC Line for Low Loss Long Distance Bulk Power Transmission

    OpenAIRE

    Ukil, Abhisek

    2015-01-01

    One of the main objectives of the smart grid initiative is to enable bulk power transmission over long distance, with reduced transmission losses. Besides the traditional high-voltage alternating current (HVAC) transmission, with the advancement in power electronics, high-voltage direct current (HVDC) transmission is increasingly becoming important. One of the main factors impacting the transmission line parameters and the losses is the length of the transmission line (overhead). In this pape...

  20. An Econometric Analysis of the Dry Bulk Shipping Industry; Seasonality, Market Efficiency and Risk Premia

    OpenAIRE

    Alizadeh-Masoodian, A.H.

    2001-01-01

    This thesis aims to investigate four main areas of interest in the functioning of different markets in the dry bulk shipping sector using recent econometric and time series techniques. These areas include; seasonality patterns in freight markets, the efficient market hypothesis and the existence of time-varying risk premia in freight rate and ship price formation, the dynamic interrelationships between freight rate levels and spillover effects in freight rate volatilities, between sub-markets...

  1. Phase analysis of aluminium modified GeSbTe bulk prepared from XRD of samples

    Science.gov (United States)

    Sandhu, Sharanjit; Singh, D.; Kumar, S.; Thangaraj, R.

    2016-05-01

    Various compositions of Aluminium modified GST as Alx(Ge2Sb2Te5)1-x x= 0, 0.15, 0.20, 0.25, 0.30 are prepared to study as a phase change material. Bulk prepared is studied with XRD scans for various phases formed. Phases other than Ge2Sb2Te5 do come in but dominated one is Ge2Sb2Te5 hexagonal phase.

  2. Use of neutron reflection method for chemical analysis of bulk samples

    International Nuclear Information System (INIS)

    The aim of our study carried out during the last 5-6 years was to find the hidden organic materials (for example explosives or drugs) in bulk objects with the neutron reflection and activation methods. The applicability of the concept of the differential σβ and integral Σβ reflection cross sections is also demonstrated. Further investigations are also recommended to improve the neutron reflection method. (author)

  3. Axial segregation of granular media rotated in a drum mixer: Pattern evolution

    International Nuclear Information System (INIS)

    In the traditional axial segregation effect, a homogeneous mixture of different types of granular material rotated in a drum mixer segregates into surface bands of relatively pure single concentrations along the axis of rotation. This effect primarily has been studied with respect to the initial segregation. However, the initial pattern is not stable, but evolves in time with continued rotation through metastable states of fewer and fewer bands. We describe two experimental studies of this evolution that provide a more complete picture of the dynamics involved in the pattern progression. The use of a charge coupled device camera in conjunction with digital analysis techniques provides a quantitative measure of the state of the surface as a function of time, while magnetic resonance imaging techniques provide a noninvasive method for studying the segregation beneath the surface. These methods indicate that the underlying mechanisms for the pattern evolution may originate in the bulk of the material, beneath the avalanching surface. copyright 1997 The American Physical Society

  4. De novo DNA sequence driven bulk segregant analysis of Water Use Efficiency (WUE) in potato without prior knowledge of molecular markers

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sønderkær, Mads; Sørensen, Kirsten Kørup; Andersen, Mathias Neumann; Nielsen, Kåre Lehmann

    2012-01-01

    Population analyzed during the experiments originated from a cross between 90-HAF-01 (S.tuberosum1) and 90-HAG-15 (S.tuberosum2xS.sparsipilum), which was previously evaluated for total glycoalkaloid content (TGA)1. Responses of stomatal conductance to different combinations of light, humidity, CO2...

  5. De novo DNA sequence driven bulk segregant analysis can pinpoint candicate loci for Total Glycoalkaloid (TGA) content in potato without prior knowledge of molecular markers

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sønderkær, Mads; Petersen, Annabeth Høgh; Sørensen, Kirsten Kørup; Nielsen, Kåre Lehmann

    Potato breeding is a slow and costly affair, primarily done as a classical "mate and phenotype" approach using relatively small populations. In contrast, Marker Assisted Selection (MAS) allows cost-effective screening of much larger effective populations sizes because most of the offspring is dis...

  6. DESIGN, FABRICATION, TESTING AND MECHANICAL ANALYSIS OF BULK-MICROMACHINED FLOWMETERS

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaobao; Qian Jin; Zhang Dacheng

    2004-01-01

    Micromachined piezoresistive flowmeters with four different types of sensing structures have been designed, fabricated and tested. Piezoresistors were defined at the end of the sensors through p-diffusion, and their values were about 3.5 kΩ. Wheatstone bridge was configured with the piezoresistors in order to measure the output response. The output voltage increases with increasing flow rate of air, obeying determined relationships. The testing results show that the sensors that are designed for measuring 10L/M in full operational range have desired sensitivities. The sensor chip is manufactured with bulk-micromachining technologies, requiring a set of seven masks.

  7. On the pinning performance analysis in bulk RE-123 twin-free superconductors

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Petrenko, Pavlo; Yao, X.; Muralidhar, M.

    463-465, - (2007), s. 353-356. ISSN 0921-4534. [International Symposium on Superconductivity /19./. Nagoya, 01.10.2006-03.10.2006] R&D Projects: GA MŠk 1P05ME728 Grant ostatní: MOST(CN) 2006CB601003; SSTC(CN) 055207077 Institutional research plan: CEZ:AV0Z10100520 Keywords : Penk effect * bulk RE-123 superconductors * pinning force scaling * pinning classification Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.079, year: 2007

  8. Diffusion and segregation properties of iron in silicon dioxide

    Science.gov (United States)

    Ramappa, Deepak Arabagatte

    1999-09-01

    Iron contamination often originates at the surface of a wafer during processing in the IC fabrication line and is diffused into the wafer during subsequent thermal processing. Since the silicon wafer surface is often passivated with a silicon dioxide layer, comprehensive understanding of iron transport in silicon dioxide is necessary. The goal of this research is to advance the fundamental and practical knowledge of the diffusion properties of iron in silicon dioxide. This dissertation evaluates, for the first time, the diffusion parameters of iron in electronic grade silicon dioxide and presents a quantitative analysis of iron transport in silicon dioxide. A source of iron applied on the surface of thermally oxidized silicon wafers was diffused at temperatures ranging from 700 to 1100°C under oxygen, nitrogen, forming gas and chlorinated ambients to diffuse the iron impurity through the oxide and into the silicon. The iron concentration profile in the oxide and silicon was measured using the techniques of Total Reflection X-Ray Fluorescence (TXRF), Deep Level Transient Spectroscopy (DLTS) and Surface Photovoltage (SPV). A two-boundary diffusion model was applied to the experimental data to determine the diffasivity and segregation coefficient of iron in SiO 2. Iron diffusivity in Si02 was observed to obey the Arrhenius relationship and has a thermal activation energy of 1.51eV. Results showed, that processing factors such as oxide thickness, nature of oxide, temperature, time and ambient affect the transport of iron in SiO2. The minimum oxide thickness required to mask iron contaminate diffusion into the wafer was empirically determined using the diffusivity data. Iron was found to diffuse faster in wet oxides and under an annealing ambient of hydrogen. Chlorine ambients reduce the amount of iron transported to the silicon wafer through the oxide. Iron exhibits a strong tendency to preferentially segregate to the SiO2 side of the SiO2-Si interface and has

  9. Understanding Segregation Processes

    Science.gov (United States)

    Bruch, Elizabeth

    There is growing consensus that living in neighborhoods of concentrated poverty increases the likelihood of social problems such as teenage parenthood, drug and alcohol use, crime victimization, and chronic unemployment. Neighborhood inequality is also implicated in studies of enduring race/ethnic health disparities, and there are recent moves to broaden the definition of health care policy to policies targeting social inequality (Mechanic 2007). Residential segregation affects health outcomes in several different ways. First, income, education, and occupation are all strongly related to health (Adler and Newman 2002). Segregation is a key mechanism through which socioeconomic inequality is perpetuated and reinforced, as it hinders the upward mobility of disadvantaged groups by limiting their educational and employment opportunities. Second, segregation increases minority exposure to unhealthy neighborhood environments. Residential segregation creates areas with concentrated poverty and unemployment, both of which are key factors that predict violence and create racial differences in homicide (Samson and Wilson 1995). Neighborhood characteristics, such as exposure to environmental hazards, fear of violence, and access to grocery stores, affect health risks and health behaviors (Cheadle et al. 1991). Tobacco and alcohol industries also advertise their products disproportionately in poor, minority areas (Moore, Williams, and Qualls 1996). Finally, residential segregation leads to inequalitie in health care resources, which contributes to disparities in quality of treatment (Smedley, Stith, and Nelson 2002).

  10. Stability analysis of 5D gravitational solutions with N bulk scalar fields

    CERN Document Server

    Gherghetta, Tony

    2011-01-01

    We study the stability of 5D gravitational solutions containing an arbitrary number of scalar fields. A closed set of equations is derived which governs the background and perturbations of N scalar fields and the metric, for arbitrary bulk and boundary scalar potentials. In particular the effect of the energy-momentum tensor of the scalar fields on the geometry is fully taken into account, together with all the perturbations of the system. The equations are explicitly written as an eigenvalue problem, which can be readily solved to determine the stability of the system and obtain the properties of the fluctuations, such as masses and couplings. As an example, we study a dynamical soft-wall model with two bulk scalar fields used to model the hadron spectrum of QCD and the Higgs sector of electroweak physics. It is shown that there are no tachyonic modes, and that there is a (radion) mode whose mass is suppressed by a large logarithm compared to that of the other Kaluza-Klein modes.

  11. Segregation between Schools and Levels of Analysis: The Modifiable Areal Unit Problem. Measuring Markets: The Case of the ERA 1988. Working Paper.

    Science.gov (United States)

    Taylor, Chris; Gorard, Stephen; Fitz, John

    This paper reviews the use of a segregation ratio in analyzing changes in the pattern of socioeconomic segregation between schools in England and Wales, addressing how the modifiable areal unit problem affects results. Researchers are developing methods for assessing socioeconomic stratification among school admissions and for comparing those…

  12. Analysis of InAs-Si heterojunction nanowire tunnel FETs: Extreme confinement vs. bulk

    Science.gov (United States)

    Carrillo-Nuñez, Hamilton; Luisier, Mathieu; Schenk, Andreas

    2015-11-01

    Extremely narrow and bulk-like p-type InAs-Si nanowire TFETs are studied using (i) a full-band and atomistic quantum transport simulator based on the sp3d5s∗ tight-binding model and (ii) a drift-diffusion TCAD tool. As (iii) option, a two-band model and the WKB approximation have been adapted to work in heterostructures through a careful choice of the imaginary dispersion. It is found that for ultra-scaled InAs-Si nanowire TFETs, the WKB approximation and the quantum transport results agree very well, suggesting that the former could be applied to larger hetero-TFET structures and considerably reduce the simulation time while keeping a high accuracy.

  13. Segregation and sporadic cases in families with Hunter's syndrome.

    OpenAIRE

    Machill, G; Barbujani, G.; Danieli, G A; Herrmann, F H

    1991-01-01

    Segregation analysis on five samples of families with Hunter's syndrome (158 cases overall) shows that the mutant allele segregates in agreement with Mendelian expectations for an X linked recessive disease, but the proportion of sporadic cases is significantly lower than expected under mutation-selection equilibrium. Heterogeneity among the samples is apparent, but it is caused entirely by a sample of Ashkenazi families, whose segregation pattern has previously been interpreted as supporting...

  14. Effect of Disorder on Bulk Sound Wave Speed : A Multiscale Spectral Analysis.

    Science.gov (United States)

    Shrivastava, Rohit; Luding, Stefan

    2016-04-01

    Disorder in the form of size (polydispersity) and mass of discrete elements/particles in a disordered media (a granular matter like soil) have numerous effects on it's sound propagation characteristics [1,2]. The influence of disorder on the sound wave speed and it's frequency filtering characteristics is the subject of investigation. The study will assist in understanding the connection between particle-scale dynamics and system-scale behavior of wave propagation which can be further used for modeling during non-destructive testing, seismic exploration of buried objects (oil, mineral, etc.) or to study the internal structure of the Earth. Studying the wave propagation characteristics through Discrete Element Models with varying polydispersity and mass of discrete elements in real-time, frequency space as well as through dispersion curves (ω (frequency) v/s k (wavenumber)) can shed light on this aspect by providing better microscopic understanding. To isolate the P-wave from shear and rotational modes, a one-dimensional system of elements/particles is used to study the effect of mass disorder on bulk sound wave speed through ensemble averaging of signals. Increasing polydispersity/disorder decreases the sound wave speed because of decrease in the number of contacts between particles [2] but, in contrast, increasing mass disorder increases the sound wave speed (in 1 D chains). Thus we conclude that a competition exists between these two kinds of disorder for their influence on the bulk sound wave speed. References [1] Brian P. Lawney and Stefan Luding. Frequency filtering in disordered granular chains. Acta Mechanica, 225(8):2385-2407, 2014. [2] O. Mouraille and S. Luding. Sound wave propagation in weakly polydisperse granular materials. Ultrasonics, 48(6-7):498 - 505, 2008. Selected Papers from ICU 2007.

  15. Analysis of crystallization process of selected Fe-based bulk metallic glasses

    Directory of Open Access Journals (Sweden)

    P. Sakiewicz

    2012-12-01

    Full Text Available Purpose: The paper mainly aims to present the influence of annealing temperature on structural changes and magnetic properties of selected Fe-based bulk metallic glasses with chemical composition of Fe43Co14Ni14B20Si5Nb4 (at.%.Design/methodology/approach: The investigated samples were cast in form of the rods with diameter of 1.5 mm by the pressure die casting method. The structure changes in function of annealing temperature were examined by X-ray diffraction (XRD and transmission electron microscopy (TEM methods. The crystallization behaviour of the studied alloy was also examined by differential scanning calorimetry (DSC. Magnetic measurements of annealed samples included the initial magnetic permeability and the magnetic permeability relaxation measurements.Findings: The annealing process at temperature range from 373 to 773 K caused a structural relaxation of tested material, which caused the atomic rearrangements and changes of physical properties in relation to as-cast state. The annealing at higher temperatures (823-923 K obviously caused a formation of α-Fe and iron borides crystalline phases. The increasing of annealing temperature significantly improved soft magnetic properties of examined alloy by increase the initial magnetic permeability and decrease the magnetic permeability relaxation.Practical implications: The investigation of the crystallization process of Fe-based metallic glasses is important for understanding the mechanisms of forming controlled microstructures of these materials with specific physical properties.Originality/value: A proper understanding of crystallization process of Fe-based bulk metallic glasses is still novel scientific problem.

  16. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    DEFF Research Database (Denmark)

    Nishiura, M.; Kubo, S.; Tanaka, K.;

    2014-01-01

    electron densities of (1–2) × 1019 m−3 and electron temperatures of 2–4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v‖, v⊥) based on Monte...... Carlo simulation results. The analysis method of the CTS spectra is used to evaluate the ion temperature and fast-ion velocity distribution from the measured CTS data....

  17. The Role of Residential Segregation in Contemporary School Segregation

    Science.gov (United States)

    Frankenberg, Erica

    2013-01-01

    Inaction to address housing segregation in metropolitan areas has resulted in persistently high levels of residential segregation. As the Supreme Court has recently limited school districts' voluntary integration efforts, this article considers the role of residential segregation in maintaining racially isolated schools, namely what is known…

  18. 46 CFR 154.300 - Segregation of hold spaces from other spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Segregation of hold spaces from other spaces. 154.300 Section 154.300 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Equipment Ship Arrangements § 154.300 Segregation of hold spaces from other spaces. Hold spaces must...

  19. The analysis of size-segregated cloud condensation nuclei counter (CCNC data and its implications for cloud droplet activation

    Directory of Open Access Journals (Sweden)

    M. Paramonov

    2013-10-01

    Full Text Available Ambient aerosol, CCN (cloud condensation nuclei and hygroscopic properties were measured with a size-segregated CCNC (cloud condensation nuclei counter in a boreal environment of southern Finland at the SMEAR (Station for Measuring Ecosystem-Atmosphere Relations II station. The instrumental setup operated at five levels of supersaturation S covering a range from 0.1–1% and measured particles with a size range of 20–300 nm; a total of 29 non-consecutive months of data are presented. The median critical diameter Dc ranged from 150 nm at S of 0.1% to 46 nm at S of 1.0%. The median aerosol hygroscopicity parameter κ ranged from 0.41 at S of 0.1% to 0.14 at S of 1.0%, indicating that ambient aerosol in Hyytiälä is less hygroscopic than the global continental or European continental averages. It is, however, more hygroscopic than the ambient aerosol in an Amazon rainforest, a European high Alpine site or a forested mountainous site. A fairly low hygroscopicity in Hyytiälä is likely a result of a large organic fraction present in the aerosol mass comparative to other locations within Europe. A considerable difference in particle hygroscopicity was found between particles smaller and larger than ~100 nm in diameter, possibly pointing out to the effect of cloud processing increasing κ of particles > 100 nm in diameter. The hygroscopicity of the smaller, ~50 nm particles did not change seasonally, whereas particles with a diameter of ~150 nm showed a decreased hygroscopicity in the summer, likely resulting from the increased VOC emissions of the surrounding boreal forest and secondary organic aerosol (SOA formation. For the most part, no diurnal patterns of aerosol hygroscopic properties were found. Exceptions to this were the weak diurnal patterns of small, ~50 nm particles in the spring and summer, when a peak in hygroscopicity around noon was observed. No difference in CCN activation and hygroscopic properties was found on days with or

  20. The analysis of size-segregated cloud condensation nuclei counter (CCNC data and its implications for aerosol-cloud interactions

    Directory of Open Access Journals (Sweden)

    M. Paramonov

    2013-04-01

    Full Text Available Ambient aerosol, CCN and hygroscopic properties were measured with a size-segregated CCNC in a~boreal environment of Southern Finland at the SMEAR II station. The instrumental setup operated at five levels of supersaturation S covering a range from 0.1 to 1% and measured particles with a size range of 20–300 nm; a total of 29 non-consecutive months of data are presented. The median critical diameter Dc ranged from 150 nm at S of 0.1% to 46 nm at S of 1.0%. The median aerosol hygroscopicity parameter κ ranged from 0.41 at S of 0.1% to 0.14 at S of 1.0%, indicating that ambient aerosol in Hyytiälä is less hygroscopic than the global continental or European continental averages. It is, however, more hygroscopic than the ambient aerosol in an Amazon rainforest, a European high alpine site or a forested mountainous site. A fairly low hygroscopicity in Hyytiälä is likely a result of a large organic fraction present in the aerosol mass comparative to other locations within Europe. A considerable difference in particle hygroscopicity was found between particles smaller and larger than ~100 nm in diameter, possibly pointing out to the effect of cloud processing increasing κ of particles > 100 nm in diameter. The hygroscopicity of the smaller, ~50 nm particles did not change seasonally, whereas particles with a diameter of ~150 nm showed a decreased hygroscopicity in the summer, likely resulting from the increased VOC emissions of the surrounding boreal forest and secondary organic aerosol (SOA formation. For the most part, no diurnal patterns of aerosol hygroscopic properties were found. Exceptions to this were the weak diurnal patterns of small, ~50 nm particles in the spring and summer, when a peak in hygroscopicity around noon was observed. No difference in CCN activation and hygroscopic properties was found on days with or without atmospheric new particle formation. During all seasons, except summer, a CCN-inactive fraction was found to be

  1. Applied Thermodynamics: Grain Boundary Segregation

    OpenAIRE

    Pavel Lejček; Lei Zheng; Siegfried Hofmann; Mojmír Šob

    2014-01-01

    Chemical composition of interfaces—free surfaces and grain boundaries—is generally described by the Langmuir–McLean segregation isotherm controlled by Gibbs energy of segregation. Various components of the Gibbs energy of segregation, the standard and the excess ones as well as other thermodynamic state functions—enthalpy, entropy and volume—of interfacial segregation are derived and their physical meaning is elucidated. The importance of the thermodynamic state functions of grain boundary se...

  2. Histologic analysis of rabbit liver cancer treated by bulk ultrasound ablation

    Science.gov (United States)

    Karunakaran, Chandra Priya; Rudich, Steven M.; Alqadah, Amel; Burgess, Mark T.; Narmoneva, Daria A.; Mast, T. Douglas

    2012-10-01

    VX2 rabbit liver cancer, treated in vivo using bulk ultrasound ablation by miniaturized image-ablate arrays, was histologically analyzed using TTC vital stain and DAPI nucleic acid stain. VX2 cells were implanted into rabbit liver lobes and allowed to grow for 11-21 days. Liver lobes containing solid VX2 tumors were then treated with 4.8 MHz, 22.5-38.5 W/cm2 in situ intensity, unfocused ultrasound for exposure times of 20-120 s. After animal sacrifice, thermal lesions were bisected along the imaging/treatment plane, one face stained with TTC, and the other with DAPI. Levels of TTC uptake (no uptake, partial uptake, and complete uptake) in liver parenchyma corresponded to three discrete regions of tan, pink and red color. By processing images of DAPI-stained parenchymal tissue from these three regions, cellular damage was quantified. A viability index parameter incorporating the size and shape of DAPI-stained nuclei correlated significantly with levels of TTC uptake, and thus with local tissue viability. For ablation of normal liver, viability indices for parenchymal regions of no TTC uptake and partial TTC uptake were significantly different from those for viable tissue. For ablation of VX2 tumor, differences in viability index between regions of no TTC uptake and complete TTC uptake were smaller, but significant overall.

  3. Hall effect analysis of bulk ZnO comparing different crystal growth techniques

    Science.gov (United States)

    Yang, Xiaocheng; Giles, N. C.

    2009-03-01

    The relaxation time approximation was used to interpret Hall effect data from n-type ZnO bulk samples grown using the high-pressure melt, seeded-chemical-vapor transport, and hydrothermal techniques. These samples represent a range of free-carrier concentrations due to different amounts of donors and compensating acceptors. Treatment of intrinsic mechanisms includes polar-optical phonon scattering using an effective Tpo=750 K, piezoelectric potential scattering using P⊥=0.25, and deformation potential scattering using E1=3.8 eV. Intrinsic mobilities from 60 to 400 K for electrons and for holes in ZnO are predicted. For extrinsic behaviors, ionized and neutral impurities are included. Donor ionization energies for dilute concentrations were determined. Shallow group III donors (Al, Ga) are responsible for the free carriers in the high-pressure melt and seeded-chemical-vapor transport crystals. The hydrothermally grown sample is closely compensated and exhibits hopping conduction below 200 K. Free carriers in the hydrothermal ZnO crystal are generated by thermal activation of deep nickel donors with the Ni2+/3+ level at about 270 meV below the conduction band.

  4. Residential Segregation and School Integration.

    Science.gov (United States)

    Rivkin, Steven G.

    1994-01-01

    Asserts that school districts' efforts to integrate schools have failed to ameliorate the racial isolation of black students. Finds that schools remain segregated primarily because of continued residential segregation and that school integration efforts have had little long-term effect on residential segregation. (CFR)

  5. Element segregation on the surfaces of pure aluminum foils

    International Nuclear Information System (INIS)

    The surface segregation trend of trace elements in pure aluminum foils was investigated by density functional theory. The model of nine-layer Al(1 0 0) slab substituted partially by trace element atoms was proposed for calculating surface segregation energy. The calculating results show that (i) B, Mg, Si, Ga, Ge, Y, In, Sn, Sb, Pb and Bi exhibit negative segregation energy and possibly move to the surface, while Be, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zr exhibit positive segregation energies and migrated into the bulk; (ii) the segregation energy was found to be related with the covalent radius, the relaxed position at the surface of the substituting atom and the surface energy; (iii) the segregation behavior of trace element generates lots of defects and dislocation, which can increase the initial pitting nucleation sites in the surface of aluminum foils; (iv) the impurity atom concentration was tested with Pb-doped surfaces, the calculated negative segregation energies in all coverage increases rapidly with the Pb coverage. These conclusions are helpful for designing of the chemical composition and to advance the tunnel etching of aluminum foils.

  6. Chloroplast genetics of chlamydomonas. I. Allelic segregation ratios

    International Nuclear Information System (INIS)

    This paper presents allelic segregation data from a series of 16 crosses segregated for nuclear and chloroplast genes. By means of pedigree analysis, segregants of chloroplast genes. By means of pedigree analysis, segregants of chloroplast markers occurring in the zygote have been distinguished from those occurring in zoospore clones. The genes ac1, ac2, and tm1 showed little if any deviation from 1:1 either in zygotic segregation or in zoospore clones. The genes sm2, ery, and spc showed a significant excess of the allele from the mt+ parent in zygotes. However, in zoospores, mt+ excess was seen only when the allele was the mutant (resistant) form but not when it was wild type (sensitive). These results show that the extent of preferential segregation differs in zygotes and in zoospores, and that preferential segregation is influenced by map location and by allele specificity. A comparison of progeny from zygotes mated after 0, 15'', 30'', and 50'' uv irradiation of the mt+ gametes demonstrated the lack of an effect of uv upon allelic segregation ratios. In total, these results exclude the multi-copy model of chloroplast genome segregation suggested by Gillham. Boynton and Lee (1974) and support the diploid model we have previously proposed

  7. Chloroplast genetics of chlamydomonas. I. Allelic segregation ratios. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sager, R.; Ramanis, Z.

    1976-06-01

    This paper presents allelic segregation data from a series of 16 crosses segregated for nuclear and chloroplast genes. By means of pedigree analysis, segregants of chloroplast genes. By means of pedigree analysis, segregants of chloroplast markers occurring in the zygote have been distinguished from those occurring in zoospore clones. The genes ac1, ac2, and tm1 showed little if any deviation from 1:1 either in zygotic segregation or in zoospore clones. The genes sm2, ery, and spc showed a significant excess of the allele from the mt+ parent in zygotes. However, in zoospores, mt+ excess was seen only when the allele was the mutant (resistant) form but not when it was wild type (sensitive). These results show that the extent of preferential segregation differs in zygotes and in zoospores, and that preferential segregation is influenced by map location and by allele specificity. A comparison of progeny from zygotes mated after 0, 15'', 30'', and 50'' uv irradiation of the mt+ gametes demonstrated the lack of an effect of uv upon allelic segregation ratios. In total, these results exclude the multi-copy model of chloroplast genome segregation suggested by Gillham. Boynton and Lee (1974) and support the diploid model we have previously proposed.

  8. Bulk undercooling

    Science.gov (United States)

    Kattamis, T. Z.

    1984-01-01

    Bulk undercooling methods and procedures will first be reviewed. Measurement of various parameters which are necessary to understand the solidification mechanism during and after recalescence will be discussed. During recalescence of levitated, glass-encased large droplets (5 to 8 mm diam) high speed temperature sensing devices coupled with a rapid response oscilloscope are now being used at MIT to measure local thermal behavior in hypoeutectic and eutectic binary Ni-Sn alloys. Dendrite tip velocities were measured by various investigators using thermal sensors or high speed cinematography. The confirmation of the validity of solidification models of bulk-undercooled melts is made difficult by the fineness of the final microstructure, the ultra-rapid evolution of the solidifying system which makes measurements very awkward, and the continuous modification of the microstructure which formed during recalescence because of precipitation, remelting and rapid coarsening.

  9. Analysis of HLA class I-II haplotype frequency and segregation in a cohort of patients with advanced stage ovarian cancer.

    Science.gov (United States)

    Gamzatova, Z; Villabona, L; van der Zanden, H; Haasnoot, G W; Andersson, E; Kiessling, R; Seliger, B; Kanter, L; Dalianis, T; Bergfeldt, K; Masucci, G V

    2007-09-01

    In solid tumors, human leucocyte antigen (HLA)-A2 has been suggested to be a risk factor and a negative prognostic factor. The HLA-A2 allele in Scandinavia has a high prevalence; it decreases with latitude and also with ovarian cancer mortality in Europe. Furthermore, an association of the HLA-A2 allele with severe prognosis in serous adenocarcinoma of the ovary in stages III-IV was found. Thirty-two unrelated Swedish women with relapsing or progressive ovarian cancer were analysed for the genotypes at the HLA-A, HLA-B, HLA-Cw, and HLA-DRB1 loci by the polymerase chain reaction/sequence-specific primer method. The frequencies of HLA alleles of healthy Swedish bone marrow donors provided by the coordinating centre of the Bone Marrow Donors Worldwide Registries, Leiden, the Netherlands were used as controls. When this cohort of epithelial ovarian cancer patients was compared with healthy Swedish donors, the frequency of HLA-A1 and HLA-A2 gene/phenotype appears, although not statistically significant, to be increased in patients with ovarian carcinoma, while HLA-A3 was decreased. HLA-A2 homozygotes were twofold higher in patients. The A2-B8 haplotype was significantly increased (corrected P value). A2-B5, A2-B15, A2-DRB1*03, A2-DRB1*04, A2-B15-Cw3, and A2-B8-DRB1*03 had odds ratio as well as the level of the lower confidence interval above 1 and significant P value only when considered as single, non-corrected analysis. HLA-B15 and HLA-Cw3 were only present in HLA-A2-positive patients showing that the HLA-A2-HLA-Cw3 and HLA-B15 haplotypes were segregated. In this selected cohort with advanced disease, there are indications of an unusual overrepresentation of HLA class I and II genes/haplotypes as well as segregation for the HLA-A2-HLA-Cw3 and HLA-B15 haplotypes. These findings are presented as a descriptive analysis and need further investigations on a larger series of ovarian cancer patients to establish prognostic associations. PMID:17661908

  10. 77 FR 7600 - Notice of Segregation of Public Lands in the State of Arizona for the Restoration Design Energy...

    Science.gov (United States)

    2012-02-13

    ... Bureau of Land Management Notice of Segregation of Public Lands in the State of Arizona for the... this segregation total approximately 20,776 acres in Yuma County. DATES: This segregation is effective...: This segregation of public lands corresponds with the analysis of these same public lands as a...

  11. Occupational Segregation by Race and Ethnicity in the US: Differences across States

    OpenAIRE

    Gradín, Carlos; del Río, Coral; Alonso-Villar, Olga

    2011-01-01

    Using the 2005–2007 American Community Survey, this paper analyzes the extent of geographical disparities in occupational segregation by race and ethnicity across the United States. Although the unconditional analysis shows great geographical variation in segregation, with the largest levels in the Southwest, the analysis of segregation conditioned on the distribution of characteristics reveals that segregation of workers with similar characteristics is generally greater in the East Central r...

  12. Status of software for PGNAA bulk analysis by the Monte Carlo - Library Least-Squares (MCLLS) approach

    International Nuclear Information System (INIS)

    The Center for Engineering Applications of Radioisotopes (CEAR) has been working for about ten years on the Monte Carlo - Library Least-Squares (MCLLS) approach for treating the nonlinear inverse analysis problem for PGNAA bulk analysis. This approach consists essentially of using Monte Carlo simulation to generate the libraries of all the elements to be analyzed plus any other required libraries. These libraries are then used in the linear Library Least-Squares (LLS) approach with unknown sample spectra to analyze for all elements in the sample. The other libraries include all sources of background which includes: (1) gamma-rays emitted by the neutron source, (2) prompt gamma-rays produced in the analyzer construction materials, (3) natural gamma-rays from K-40 and the uranium and thorium decay chains, and (4) prompt and decay gamma-rays produced in the NaI detector by neutron activation. A number of unforeseen problems have arisen in pursuing this approach including: (1) the neutron activation of the most common detector (NaI) used in bulk analysis PGNAA systems, (2) the nonlinearity of this detector, and (3) difficulties in obtaining detector response functions for this (and other) detectors. These problems have been addressed by CEAR recently and have either been solved or are almost solved at the present time. Development of Monte Carlo simulation for all of the libraries has been finished except the prompt gamma-ray library from the activation of the NaI detector. Treatment for the coincidence schemes for Na and particularly I must be first determined to complete the Monte Carlo simulation of this last library. (author)

  13. Segregation in Minds

    OpenAIRE

    Rácz, Attila

    2015-01-01

    In this paper, I explore socio-spatial segregation from a particular perspective, which may probably be considered a novelty in the investigation of spatial social patterns, as it focuses on questions such as: What kind of distinction occurs between socio-spatial patterns designated by statistical data and the cognitive representations of those patterns in people's minds? and What explains these diff erences, and what kind of impact can they generate?

  14. Patterns of residential segregation

    OpenAIRE

    Louf, Rémi; Barthelemy, Marc

    2015-01-01

    The spatial distribution of income shapes the structure and organisation of cities and its understanding has broad societal implications. Despite an abundant literature, many issues remain however unclear: there is no clear definition of what segregation is, no unambiguous definition of income classes, no clear way to identify neighborhoods, and no method to deal with the polycentric organization of large cities. In this paper, we address all these questions within a unique theoretical framew...

  15. Continuous Flow - Cavity RingDown Spectroscopy Using a Novel Universal Interface for High-Precision Bulk 13C Analysis

    Science.gov (United States)

    Saad, Nabil; Richman, Bruce

    2010-05-01

    We have developed the world's first optical spectroscopy-based system for bulk stable isotope analysis of 13C. The system is based on a novel universal interface, named LIAISON, capable of coupling to almost any CO2-generating sample preparation front-end ranging from an elemental analyzer to any dissolved carbon analysis module, which are of significant use in geochemical, ecological and food authentication studies. In one specific application, we have coupled LIAISON to an elemental analyzer (EA) and to a cavity ring-down spectrometer (CRDS) for 13C isotopic analysis of adulterated honey samples. Another application was developed to analyze dissolved inorganic carbon in water samples. LIAISON is suited for handling a high-throughput sample analysis process by running three different gas handling operations in parallel: Admitting combustion gas from the EA into a first gas bellows, analyzing the previous sample collected into a second gas bellows with CRDS, and flushing and purging a third gas bellows in preparation for the upcoming sample collection operation. The sample-to-sample analysis time is 10 minutes and the operation is completely automated for the whole front-end auto-sampler tray capacity, requiring no operator intervention. The CRDS data are collected, tabulated and saved into an output text file. The memory effect between the USGS L-Glutamic acid standard at natural abundance and the moderately enriched USGS L-Glutamic acid standard is excluded by the selection of the adequate number and duration of flush and purge cycles of the gas sample bags. The system's proven accuracy was cross-checked with EA-IRMS and its achieved precision was typically less than 0.2 permil, including the 13C-enriched tested samples. The LIAISON-CRDS system presented here provides a fully automated solution for 13C bulk stable isotope analysis with unprecedented ease-of-use and possible field portability and application with the availability of a compact front-end. In

  16. Diversity, Racial Threat and Metropolitan Housing Segregation

    Science.gov (United States)

    DeFina, Robert; Hannon, Lance

    2009-01-01

    Previous studies have shown that as the percent black or percent Hispanic grows, that group's residential segregation from whites tends to increase as well. Typically, these findings are explained in terms of white discriminatory reaction to the perceived threat associated with minority population growth. The present analysis examines whether…

  17. Complex segregation analysis of obsessive-compulsive disorder in 141 families of eating disorder probands, with and without obsessive-compulsive disorder.

    Science.gov (United States)

    Cavallini, M C; Bertelli, S; Chiapparino, D; Riboldi, S; Bellodi, L

    2000-06-12

    Probands affected with eating disorders (ED) present a higher number of relatives affected with obsessive-compulsive disorders/tic disorders than a comparison population. Therefore, we hypothesized that ED and obsessive-compulsive disorder (OCD) might share the same biological liability, and that a single major gene might account for that liability. We tested this hypothesis by applying a complex segregation analysis to 141 families of probands affected with ED (89 with anorexia nervosa, restricting and binge-eating types, 52 with bulimia nervosa). Given the hypothesized relationship between OCD and genetic spectrum disorders, we considered these diagnoses as affected phenotype in relatives. In Italian ED families, ED and OCD followed a Mendelian dominant model of transmission. When probands were divided according to co-diagnosis of OCD, best fit in the subgroup of families of 114 probands without OCD co-diagnosis was for a Mendelian dominant model of transmission whereas a Mendelian additive model of transmission represented best fit in the subgroup of families of 27 probands with an OCD co-diagnosis. Genetic transmission was not shown in those families where the only affected phenotype was ED. The existence of a Mendelian mode of genetic transmission within ED families supports the hypothesis that a common genetic liability could account for both ED and OCD. PMID:10898919

  18. Smoking-based selection and influence in gender-segregated friendship networks : a social network analysis of adolescent smoking

    NARCIS (Netherlands)

    Mercken, Liesbeth; Snijders, Tom A. B.; Steglich, Christian; Vertiainen, Erkki; Vartiainen, E.; De Vries, H.

    2010-01-01

    Aims The main goal of this study was to examine differences between adolescent male and female friendship networks regarding smoking-based selection and influence processes using newly developed social network analysis methods that allow the current state of continuously changing friendship networks

  19. Studies on thermal neutron perturbation factor needed for bulk sample activation analysis

    CERN Document Server

    Csikai, J; Sanami, T; Michikawa, T

    2002-01-01

    The spatial distribution of thermal neutrons produced by an Am-Be source in a graphite pile was measured via the activation foil method. The results obtained agree well with calculated data using the MCNP-4B code. A previous method used for the determination of the average neutron flux within thin absorbing samples has been improved and extended for a graphite moderator. A procedure developed for the determination of the flux perturbation factor renders the thermal neutron activation analysis of bulky samples of unknown composition possible both in hydrogenous and graphite moderators.

  20. Compositional design and microstructure analysis of Zr-based bulk metallic glasses

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The systematical studies of Zr-based BMGs were summarized in terms of their compositional design and their structural characterization. In particular, several key issues of BMG materials were focused, including initial alloy design and subsequent composition optimization, solidification microstructure characterization and crystallization process specification. The results show that a compositional designing approach is successfully developed and, through extensive microstructure characterization using transmission electron microscopy, several new crystalline phases are discovered in these newly developed Zr-based BMG alloys.Crystallization behavior of Zr-based BMG is also determined based on the microstructure analysis.

  1. Yttrium segregation and oxygen diffusion along high-symmetry grain boundaries in YSZ

    Energy Technology Data Exchange (ETDEWEB)

    González-Romero, Robert L. [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, Caixa Postal 6165, CEP 13083-970, Campinas (Brazil); Meléndez, Juan J. [Department of Physics, University of Extremadura. Avda. de Elvas, s/n, 06006, Badajoz (Spain); Institute for Advanced Scientific Computing of Extremadura (ICCAEx). Avda. de Elvas, s/n, 06006, Badajoz (Spain)

    2015-02-15

    Highlights: • A study of yttrium segregation to three grain boundaries (GB) in YSZ is performed. • A steady concentration of yttrium is reached after a short transient regime. • Segregation does not change the coefficients for oxygen diffusion along the GB. • The main effect after segregation appears for oxygen bulk diffusion. • The effect is related to the rearrangement of oxygen vacancies after segregation. - Abstract: A study by Molecular Dynamics of yttrium segregation to high-symmetry grain boundaries of yttria-stabilized zirconia has been performed for different amounts of dopants. After an initial (and short) transient, segregation reaches a steady regime in which the concentration of the defect species at the grain-boundaries does not change in time. The maximum concentration of yttrium is reached at the grain-boundary planes, while oxygen vacancies screen the electric field created by segregation. Segregation of yttrium does not change appreciably the coefficients for oxygen diffusion along the grain boundaries, but instead modifies those for bulk diffusion. This effect is rationalized in terms of the rearrangement of the oxygen vacancies at the vicinities of the yttrium cations. The activation energies vary smoothly with the concentration of yttria for all the boundaries. Our data for diffusion coefficients and activation energies compare fairly well with experimental values when segregation is explicitly taken into account.

  2. Yttrium segregation and oxygen diffusion along high-symmetry grain boundaries in YSZ

    International Nuclear Information System (INIS)

    Highlights: • A study of yttrium segregation to three grain boundaries (GB) in YSZ is performed. • A steady concentration of yttrium is reached after a short transient regime. • Segregation does not change the coefficients for oxygen diffusion along the GB. • The main effect after segregation appears for oxygen bulk diffusion. • The effect is related to the rearrangement of oxygen vacancies after segregation. - Abstract: A study by Molecular Dynamics of yttrium segregation to high-symmetry grain boundaries of yttria-stabilized zirconia has been performed for different amounts of dopants. After an initial (and short) transient, segregation reaches a steady regime in which the concentration of the defect species at the grain-boundaries does not change in time. The maximum concentration of yttrium is reached at the grain-boundary planes, while oxygen vacancies screen the electric field created by segregation. Segregation of yttrium does not change appreciably the coefficients for oxygen diffusion along the grain boundaries, but instead modifies those for bulk diffusion. This effect is rationalized in terms of the rearrangement of the oxygen vacancies at the vicinities of the yttrium cations. The activation energies vary smoothly with the concentration of yttria for all the boundaries. Our data for diffusion coefficients and activation energies compare fairly well with experimental values when segregation is explicitly taken into account

  3. Smoking-based selection and influence in gender-segregated friendship networks: a social network analysis of adolescent smoking

    OpenAIRE

    Mercken, Liesbeth; Snijders, Tom A.B.; Steglich, Christian; Vertiainen, Erkki; Vartiainen, E.; de Vries, H.

    2010-01-01

    Aims The main goal of this study was to examine differences between adolescent male and female friendship networks regarding smoking-based selection and influence processes using newly developed social network analysis methods that allow the current state of continuously changing friendship networks to act as a dynamic constraint for changes in smoking behaviour, while allowing current smoking behaviour to be simultaneously a dynamic constraint for changes in friendship networks. Design Longi...

  4. Simple and sensitive spectrophotometric methods for the analysis of mesalamine in bulk and tablet dosage forms

    Directory of Open Access Journals (Sweden)

    Bala Sekaran Chandra

    2011-01-01

    Full Text Available Three simple, sensitive, economical and reproducible spectrophotometric methods (A, B and C are described for determination of mesalamine in pure drug as well as in tablet dosage forms. Method A is based on the reduction of tungstate and/or molybdate in Folin Ciocalteu's reagent; method B describes the reaction between the diazotized drug and α-naphthol and method C is based on the reaction of the drug with vanillin, in acidic medium. Under optimum conditions, mesalamine could be quantified in the concentration ranges, 1-30, 1-15 and 2-30 µg mL-1 by method A, B and C, respectively. All the methods have been applied to the determination of mesalamine in tablet dosage forms. Results of analysis are validated statistically.

  5. On quantitative analysis of interband recombination dynamics: Theory and application to bulk ZnO

    International Nuclear Information System (INIS)

    The issue of the quantitative analysis of time-resolved photoluminescence experiments is addressed by developing and describing two approaches for determination of unimolecular lifetime, bimolecular recombination coefficient, and equilibrium free-carrier concentration, based on a quite general second-order expression of the electron-hole recombination rate. Application to the case of band-edge emission of ZnO single crystals is reported, evidencing the signature of sub-nanosecond second-order recombination dynamics for optical transitions close to the interband excitation edge. The resulting findings are in good agreement with the model prediction and further confirm the presence, formerly evidenced in literature by non-optical methods, of near-surface conductive layers in ZnO crystals with sheet charge densities of about 3–5×1013 cm−2

  6. A critical evaluation of how ancient DNA bulk bone metabarcoding complements traditional morphological analysis of fossil assemblages

    Science.gov (United States)

    Grealy, Alicia C.; McDowell, Matthew C.; Scofield, Paul; Murray, Dáithí C.; Fusco, Diana A.; Haile, James; Prideaux, Gavin J.; Bunce, Michael

    2015-11-01

    caveats. Our results show that DNA analysis of bulk bone samples can be a universally useful tool for studying past biodiversity, when integrated with existing morphology-based approaches. Despite several limitations that remain, the BBM method offers a cost-effective and efficient way of studying fossil assemblages, offering complementary insights into evolution, extinction, and conservation.

  7. Patterns of Residential Segregation.

    Science.gov (United States)

    Louf, Rémi; Barthelemy, Marc

    2016-01-01

    The spatial distribution of income shapes the structure and organisation of cities and its understanding has broad societal implications. Despite an abundant literature, many issues remain unclear. In particular, all definitions of segregation are implicitely tied to a single indicator, usually rely on an ambiguous definition of income classes, without any consensus on how to define neighbourhoods and to deal with the polycentric organization of large cities. In this paper, we address all these questions within a unique conceptual framework. We avoid the challenge of providing a direct definition of segregation and instead start from a definition of what segregation is not. This naturally leads to the measure of representation that is able to identify locations where categories are over- or underrepresented. From there, we provide a new measure of exposure that discriminates between situations where categories co-locate or repel one another. We then use this feature to provide an unambiguous, parameter-free method to find meaningful breaks in the income distribution, thus defining classes. Applied to the 2014 American Community Survey, we find 3 emerging classes-low, middle and higher income-out of the original 16 income categories. The higher-income households are proportionally more present in larger cities, while lower-income households are not, invalidating the idea of an increased social polarisation. Finally, using the density-and not the distance to a center which is meaningless in polycentric cities-we find that the richer class is overrepresented in high density zones, especially for larger cities. This suggests that density is a relevant factor for understanding the income structure of cities and might explain some of the differences observed between US and European cities. PMID:27315283

  8. Patterns of Residential Segregation.

    Directory of Open Access Journals (Sweden)

    Rémi Louf

    Full Text Available The spatial distribution of income shapes the structure and organisation of cities and its understanding has broad societal implications. Despite an abundant literature, many issues remain unclear. In particular, all definitions of segregation are implicitely tied to a single indicator, usually rely on an ambiguous definition of income classes, without any consensus on how to define neighbourhoods and to deal with the polycentric organization of large cities. In this paper, we address all these questions within a unique conceptual framework. We avoid the challenge of providing a direct definition of segregation and instead start from a definition of what segregation is not. This naturally leads to the measure of representation that is able to identify locations where categories are over- or underrepresented. From there, we provide a new measure of exposure that discriminates between situations where categories co-locate or repel one another. We then use this feature to provide an unambiguous, parameter-free method to find meaningful breaks in the income distribution, thus defining classes. Applied to the 2014 American Community Survey, we find 3 emerging classes-low, middle and higher income-out of the original 16 income categories. The higher-income households are proportionally more present in larger cities, while lower-income households are not, invalidating the idea of an increased social polarisation. Finally, using the density-and not the distance to a center which is meaningless in polycentric cities-we find that the richer class is overrepresented in high density zones, especially for larger cities. This suggests that density is a relevant factor for understanding the income structure of cities and might explain some of the differences observed between US and European cities.

  9. Study on the influence of X-ray tube spectral distribution on the analysis of bulk samples and thin films: Fundamental parameters method and theoretical coefficient algorithms

    International Nuclear Information System (INIS)

    Knowledge of X-ray tube spectral distribution is necessary in theoretical methods of matrix correction, i.e. in both fundamental parameter (FP) methods and theoretical influence coefficient algorithms. Thus, the influence of X-ray tube distribution on the accuracy of the analysis of thin films and bulk samples is presented. The calculations are performed using experimental X-ray tube spectra taken from the literature and theoretical X-ray tube spectra evaluated by three different algorithms proposed by Pella et al. (X-Ray Spectrom. 14 (1985) 125-135), Ebel (X-Ray Spectrom. 28 (1999) 255-266), and Finkelshtein and Pavlova (X-Ray Spectrom. 28 (1999) 27-32). In this study, Fe-Cr-Ni system is selected as an example and the calculations are performed for X-ray tubes commonly applied in X-ray fluorescence analysis (XRF), i.e., Cr, Mo, Rh and W. The influence of X-ray tube spectra on FP analysis is evaluated when quantification is performed using various types of calibration samples. FP analysis of bulk samples is performed using pure-element bulk standards and multielement bulk standards similar to the analyzed material, whereas for FP analysis of thin films, the bulk and thin pure-element standards are used. For the evaluation of the influence of X-ray tube spectra on XRF analysis performed by theoretical influence coefficient methods, two algorithms for bulk samples are selected, i.e. Claisse-Quintin (Can. Spectrosc. 12 (1967) 129-134) and COLA algorithms (G.R. Lachance, Paper Presented at the International Conference on Industrial Inorganic Elemental Analysis, Metz, France, June 3, 1981) and two algorithms (constant and linear coefficients) for thin films recently proposed by Sitko (X-Ray Spectrom. 37 (2008) 265-272)

  10. First-principles computation of surface segregation in L10 CoPt magnetic nanoparticles

    Science.gov (United States)

    Liu, Zhenyu; Lei, Yinkai; Wang, Guofeng

    2016-07-01

    In this study, we have employed the first-principles density functional theory (DFT) computational method to predict the influence of surface segregation on the magnetic properties of small L10 CoPt nanoparticles. For both the modelled cuboidal (with a chemical formula of Co26Pt12) and cuboctahedral (with a chemical formula of Co18Pt20) CoPt nanoparticles, the DFT calculations predict that Pt surface segregation should occur thermodynamically. Associated with this Pt surface segregation, the surface-segregated CoPt magnetic nanoparticles are predicted to have significantly reduced magnetic moments and magnetic anisotropy energies than those of the corresponding bulk-terminated (i.e. non-segregated) nanoparticles. Hence, our study suggests that surface segregation could deteriorate the magnetic properties of CoPt nanoparticles.

  11. Relationship between School and Residential Segregation at the Turn of the Century.

    Science.gov (United States)

    Rickles, Jordan; Ong, Paul M.

    This paper examines the relationship between school and residential segregation, noting that while these two forms of segregation are fundamentally linked, other factors cause them to diverge. The analysis focuses on segregation in 329 metropolitan areas. Data come from the 1998-99 National Center for Education Statistics Common Core of Data…

  12. Genetic profile characterization and segregation analysis of 10 X-STRs in a sample from Santander, Colombia.

    Science.gov (United States)

    Pico, Adriana; Castillo, Adriana; Vargas, Clara; Amorim, António; Gusmão, Leonor

    2008-07-01

    Ten X-chromosome short tandem repeats (X-STRs: DXS8378, DXS7132, DXS9898, DXS6809, DXS6789, DXS101, GATA172D05, HPRTB, DXS8377, and DXS7423) were analyzed in a sample of unrelated individuals (108 males and 110 females) from the Santander Department in Colombia. In this sample, gene diversities varied between 63.56%, for DXS8378, and 91.41%, for DXS8377. For this set of 10 X-STRs, a high discrimination power was obtained for both male (1 in 3 x 10(6)) and female (1 in 9 x 10(10)) samples and a high mean exclusion chance in father/daughter duos (99.993%) and in father/mother/daughter trios (99.9999%), demonstrating the usefulness of this set of markers in forensic and kinship analysis. Hardy-Weinberg equilibrium was tested in the female sample and no significant deviations were found. Pairwise analysis showed significant differences in the comparison with samples from Spain, Peru, and Argentina and with African American and Hispanic samples from New York. This same set of X-STRs was also typed in 51 mother/father/daughter trios, 43 mother/son duos, and in a single father/daughter pair. In total, four mutations were observed; one at DXS7132 and at DXS6809, and two at DXS8377. Two mutations were paternal and one maternal; and to a fourth mutation, it was not possible to define its origin. PMID:18327601

  13. Competition of Brazil nut effect, buoyancy, and inelasticity induced segregation in a granular mixture

    OpenAIRE

    Brito López, Ricardo; Soto, R.

    2009-01-01

    It has been recently reported that a granular mixture in which grains differ in their restitution coefficients presents segregation: the more inelastic particles sink to the bottom. When other segregation mechanisms as buoyancy and the Brazil nut effect are present, the inelasticity induced segregation can compete with them. First, a detailed analysis, based on numerical simulations of two dimensional systems, of the competition between buoyancy and the inelasticity induced segregation is pre...

  14. The Impact of Social Exclusion in Residential Segregation: A gipsy Neighbourhood Fevzi Pasa in Turkey

    OpenAIRE

    GÜLTEKİN, Nevin

    2010-01-01

    In this article, residential segregation of a gypsy group is analyzed as ethnicity-based and in relation to social segregation (through the Canakkale - Fevzi Pasa Gypsy Neighborhood). The aim of this analysis is to define the conditions under which and areas in which this type of segregation provides (dis)advantages. As a result, residential segregation can be explained through three basic reasons as external factors and obligations, internal factors and willingness, and the circular interact...

  15. Association of Residential Segregation and Disability: A Multilevel Study Using Iranian Census Data

    OpenAIRE

    Hashemi Nazari, Seyed Saeed; Mahmoodi, Mahmood; Mansournia, Mohammad-Ali; Holakouie Naieni, Kourosh

    2012-01-01

    The association of racial segregation and health outcomes has been reviewed recently in the literature, but the health effect of other contexts of segregation with respect to residential environment has not as yet been fully reviewed. Besides, most of the literature on segregation has been performed in Western countries. Here, we undertake a multilevel analysis of residential segregation of socioeconomic and demographic factors and disability rate in an Eastern developing country in order to ...

  16. Simultaneous mapping of multiple gene loci with pooled segregants.

    Directory of Open Access Journals (Sweden)

    Jürgen Claesen

    Full Text Available The analysis of polygenic, phenotypic characteristics such as quantitative traits or inheritable diseases remains an important challenge. It requires reliable scoring of many genetic markers covering the entire genome. The advent of high-throughput sequencing technologies provides a new way to evaluate large numbers of single nucleotide polymorphisms (SNPs as genetic markers. Combining the technologies with pooling of segregants, as performed in bulked segregant analysis (BSA, should, in principle, allow the simultaneous mapping of multiple genetic loci present throughout the genome. The gene mapping process, applied here, consists of three steps: First, a controlled crossing of parents with and without a trait. Second, selection based on phenotypic screening of the offspring, followed by the mapping of short offspring sequences against the parental reference. The final step aims at detecting genetic markers such as SNPs, insertions and deletions with next generation sequencing (NGS. Markers in close proximity of genomic loci that are associated to the trait have a higher probability to be inherited together. Hence, these markers are very useful for discovering the loci and the genetic mechanism underlying the characteristic of interest. Within this context, NGS produces binomial counts along the genome, i.e., the number of sequenced reads that matches with the SNP of the parental reference strain, which is a proxy for the number of individuals in the offspring that share the SNP with the parent. Genomic loci associated with the trait can thus be discovered by analyzing trends in the counts along the genome. We exploit the link between smoothing splines and generalized mixed models for estimating the underlying structure present in the SNP scatterplots.

  17. Waste segregation procedures and benefits

    International Nuclear Information System (INIS)

    Segregation is a critical first step in handling hazardous and radioactive materials to minimize the generation of regulated wastes. In addition, segregation can significantly reduce the complexity and the total cost of managing waste. Procedures at Sandia National Laboratories, Albuquerque require that wastes be segregated, first, by waste type (acids, solvents, low level radioactive, mixed, classified, etc.). Higher level segregation requirements, currently under development, are aimed at enhancing the possibilities for recovery, recycle and reapplication; reducing waste volumes; reducing waste disposal costs, and facilitating packaging storage, shipping and disposal. 2 tabs

  18. Experimental determination of the segregation process using computer tomography

    Directory of Open Access Journals (Sweden)

    Konstantin Beckmann

    2016-07-01

    Full Text Available Modelling methods such as DEM and CFD are increasingly used for developing high efficient combine cleaning systems. For this purpose it is necessary to verify the complex segregation and separation processes in the combine cleaning system. One way is to determine the segregation and separation function using 3D computer tomography (CT. This method makes it possible to visualize and analyse the movement behaviour of the components of the mixture during the segregation and separation process as well as the derivation of descriptive process parameters. A mechanically excited miniature test rig was designed and built at the company CLAAS Selbstfahrende Erntemaschinen GmbH to achieve this aim. The investigations were carried out at the Fraunhofer Institute for Integrated Circuits IIS. Through the evaluation of the recorded images the segregation process is described visually. A more detailed analysis enabled the development of segregation and separation function based on the different densities of grain and material other than grain.

  19. Atomically ordered solute segregation behaviour in an oxide grain boundary

    Science.gov (United States)

    Feng, Bin; Yokoi, Tatsuya; Kumamoto, Akihito; Yoshiya, Masato; Ikuhara, Yuichi; Shibata, Naoya

    2016-01-01

    Grain boundary segregation is a critical issue in materials science because it determines the properties of individual grain boundaries and thus governs the macroscopic properties of materials. Recent progress in electron microscopy has greatly improved our understanding of grain boundary segregation phenomena down to atomistic dimensions, but solute segregation is still extremely challenging to experimentally identify at the atomic scale. Here, we report direct observations of atomic-scale yttrium solute segregation behaviours in an yttria-stabilized-zirconia grain boundary using atomic-resolution energy-dispersive X-ray spectroscopy analysis. We found that yttrium solute atoms preferentially segregate to specific atomic sites at the core of the grain boundary, forming a unique chemically-ordered structure across the grain boundary. PMID:27004614

  20. Atomically ordered solute segregation behaviour in an oxide grain boundary

    Science.gov (United States)

    Feng, Bin; Yokoi, Tatsuya; Kumamoto, Akihito; Yoshiya, Masato; Ikuhara, Yuichi; Shibata, Naoya

    2016-03-01

    Grain boundary segregation is a critical issue in materials science because it determines the properties of individual grain boundaries and thus governs the macroscopic properties of materials. Recent progress in electron microscopy has greatly improved our understanding of grain boundary segregation phenomena down to atomistic dimensions, but solute segregation is still extremely challenging to experimentally identify at the atomic scale. Here, we report direct observations of atomic-scale yttrium solute segregation behaviours in an yttria-stabilized-zirconia grain boundary using atomic-resolution energy-dispersive X-ray spectroscopy analysis. We found that yttrium solute atoms preferentially segregate to specific atomic sites at the core of the grain boundary, forming a unique chemically-ordered structure across the grain boundary.

  1. Source Segregation and Collection of Source-Segregated Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Matsufuji, Y.

    2011-01-01

    The Segregation of individual material fractions at the waste source and keeping the fractions separate for collection is one of the key issues in modern waste management. In most cases the waste is just kept segregated from other waste according to certain criteria that improve the possibility of...... optimal handling of the waste. But in a few cases, the waste must also be separated at source, for example removing the protective plastic cover from a commercial advertisement received by mail, prior to putting the advertisement into the waste collection bin for recyclable paper. These issues are often...... more important it is to consider source segregation of the waste, since the amount of waste links to the possibility of obtaining manageable amounts of segregated waste with reasonable logistics as well as to the manpower that can be allocated at the source to perform source segregation of waste...

  2. Si segregation at Fe grain boundaries analyzed by ab initio local energy and local stress

    International Nuclear Information System (INIS)

    Using density-functional theory calculations combined with recent local-energy and local-stress schemes, we studied the effects of Si segregation on the structural, mechanical and magnetic properties of the Σ3(1 1 1) and Σ11(3 3 2) Fe GBs formed by rotation around the [1 1 0] axis. The segregation mechanism was analyzed by the local-energy decomposition of the segregation energy, where the segregation energy is expressed as a sum of the following four terms: the local-energy change of Si atoms from the isolated state in bulk Fe to the GB segregated state, the stabilization of replaced Fe atoms from the GB to the bulk, the local-energy change of neighboring Fe atoms from the pure GB to the segregated GB and the local-energy change of neighboring Fe atoms from the system of an isolated Si atom in the bulk Fe to the pure bulk Fe. The segregation energy and value of each term greatly depends on the segregation site and Si concentration. The segregation at interface Fe sites with higher local energies in the original GB configurations naturally leads to higher segregation-energy gains, while interface sites with lower local energies can lead to larger energy gains if stronger Si–Fe interactions occur locally in the final segregated configurations. The high Si concentration reduces the segregation-energy gain per Si atom due to the local-energy increases of Si atoms neighboring to each other or through the reduction in the number of stabilized Fe atoms per Si atom as observed in a Si dimer in bulk Fe. In the Si-segregated GBs, Si–Fe bonds enhance local Young’s moduli and tend to suppress the interface weakening, while the GB adhesion is slightly reduced. And Fe atoms contacting Si atoms have reduced magnetic moments, due to Si–Fe sp-d hybridization interactions. (paper)

  3. Interfacial segregation in perovskites. Part 1

    International Nuclear Information System (INIS)

    Based on thermodynamic principles a theory for equilibrium interfacial segregation is proposed for perovskite materials, and this theory is applied to BaTiO3. An approach developed by Frenkel and refined by Kliewer and Koehler is extended to undoped ternary oxide materials such as BaTiO3. The approach uses regular solution approximations and considers space charge effects as the major driving force for segregation. The analysis based on this model indicates the presence of a negative space charge potential (-0.1 V at 800 degrees C) at the surface of pure BaTiO3. The model also predicts cation enrichment at the interface. The thickness of the space charge layer decreases with increasing temperature, and calculated values agree well with experimental results. Since both elastic and electrostatic driving forces are important for dopant/impurity segregation, an approach where the grain boundary is considered to be a two-dimensional phase, in equilibrium with the three-dimensional phase of the grain, proves useful. Solving for the impurity/dopant segregation ratio is case specific and requires knowledge of the charge neutrality conditions as well as the strain energy contribution

  4. Sex segregation in undergraduate engineering majors

    Science.gov (United States)

    Litzler, Elizabeth

    reducible to individual choice. This dissertation provides a broad, descriptive view of the state of sex segregation in engineering as well as a careful analysis of how individual and institutional factors inhibit or encourage sex segregation. This study contributes to the research literature through the use of novel data, testing of occupational segregation theories, and the use of multiple levels of analysis. The analyses provide new insight into an enduring phenomenon, and suggest new avenues for understanding sex segregation in higher education.

  5. Multilevel Modeling of Social Segregation

    Science.gov (United States)

    Leckie, George; Pillinger, Rebecca; Jones, Kelvyn; Goldstein, Harvey

    2012-01-01

    The traditional approach to measuring segregation is based upon descriptive, non-model-based indices. A recently proposed alternative is multilevel modeling. The authors further develop the argument for a multilevel modeling approach by first describing and expanding upon its notable advantages, which include an ability to model segregation at a…

  6. The Dimensions of Residential Segregation.

    Science.gov (United States)

    Massey, Douglas S.; Denton, Nancy A.

    1988-01-01

    Evaluates 20 potential indicators of residential segregation using census data on Hispanics, Blacks, Asians, and non-Hispanic Whites in 60 U.S. metropolitan areas. Factor-analyzes the results to select a single best indicator for each of five dimensions of residential segregation. Contains 69 references and 22 statistical formulas. (SV)

  7. Early selection of agronomic traits in segregating black bean populations

    Directory of Open Access Journals (Sweden)

    Juliano Garcia Bertoldo

    2010-01-01

    Full Text Available This study evaluated the agronomic performance of six segregating populations of black bean (BRS Supremo x CHP 97-01, BRS Supremo x CHP 97-04, BRS Supremo x CHP 97-05-16, BRS Supremo x CHP 97-26, BRS Supremo x IPR Graúna and BRS Supremo x Uirapuru IPR in the F3 generation, conducted by the bulk method. Populations and parents were evaluated in the 2007/08 growing season in a randomized block design with four replications. Results show promising traits of the segregating population BRS Supremo x CHP 97-04, which was superior to parent BRS Supremo, indicating the line for further selection. The segregating populations and their parents were grouped by Ward’s method, indicating the similarity of the selected lines.

  8. Patterns of residential segregation

    CERN Document Server

    Louf, Rémi

    2015-01-01

    The spatial distribution of income shapes the structure and organisation of cities and its understanding has broad societal implications. Despite an abundant literature, many issues remain however unclear: there is no clear definition of what segregation is, no unambiguous definition of income classes, no clear way to identify neighborhoods, and no method to deal with the polycentric organization of large cities. In this paper, we address all these questions within a unique theoretical framework. We assume that households belonging to the same class tend to live close to each other, and households from different classes tend to avoid one another. Applied to the US 2000 Census Income data, 3 distinct classes emerge from the clustering of the original 16 income classes. Using these unambiguously defined classes, we cluster together contiguous similar areas and find that the number of clusters for each category scales with the city population, an effect that is more pronounced for rich households. Finally, using...

  9. AFLP marker linked to water-stress-tolerant bulks in barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    A. Altinkut

    2003-01-01

    Full Text Available The amplified fragment length polymorphism (AFLP assay is an efficient method for the identification of molecular markers, useful in the improvement of numerous crop species. Bulked Segregant Analysis (BSA was used to identify AFLP markers associated with water-stress tolerance in barley, as this would permit rapid selection of water-stress tolerant genotypes in breeding programs. AFLP markers linked to water-stress tolerance was identified in two DNA pools (tolerant and sensitive, which were established using selected F2 individuals resulting from a cross between water-stress-tolerant and sensitive barley parental genotypes, based on their paraquat (PQ tolerance, leaf size, and relative water content (RWC. All these three traits were previously shown to be associated with water-stress tolerance in segregating F2 progeny of the barley cross used in a previous study. AFLP analysis was then performed on these DNA pools, using 40 primer pairs to detect AFLP fragments that are present/absent, respectively, in the two pools and their parental lines. One separate AFLP fragment, which was present in the tolerant parent and in the tolerant bulk, but absent in the sensitive parent and in the sensitive bulk, was identified. Polymorphism of the AFLP marker was tested among tolerant and sensitive F2 individuals. The presence of this marker that is associated with water-stress tolerance will greatly enhance selection for paraquat and water-stress tolerant genotypes in future breeding programs.

  10. Bulk Compositional Trends in Meteorites: A Guide for Analysis and Interpretation of NEAR XGRS Data from Asteroid 433 Eros

    Science.gov (United States)

    Nittler, L. R.; Clark, P. E.; McCoy, T. J.; Murphy, M. E.; Trombka, J. I.

    2000-01-01

    We have compiled a large database of bulk meteorite elemental compositions. We investigate compositional trends in a variety of meteorite classes to aid in interpretation of NEAR XGRS elemental abundance data from the asteroid Eros.

  11. Analysis of Bulk and Thin Film Model Samples Intended for Investigating the Strain Sensitivity of Niobium-Tin

    International Nuclear Information System (INIS)

    Bulk samples and thin films were fabricated and characterized to determine their suitability for studying the effect of composition and morphology on strain sensitivity. Heat capacity and resistivity data are used to determine the critical temperature distribution. It is found that all bulk samples contain stoichiometric Nb3Sn regardless of their nominal Nb to Sn ratio. Furthermore, in bulk samples with Cu additions, a bi-modal distribution of stoichiometric and off-stoichiometric Nb-Sn is found. Thus the nominally off-stoichiometric bulk samples require additional homogenization steps to yield homogeneous off-stoichiometric samples. A binary magnetron-sputtered thin film has the intended off-stoichiometric Nb-Sn phase with a mid-point critical temperature of 16.3 K. This type of sample is a suitable candidate for investigating the strain sensitivity of A15 Nb1-βSnβ, with 0.18 3Sn wires.

  12. Kinetic Monte Carlo simulation of surface segregation in Pd–Cu alloys

    International Nuclear Information System (INIS)

    The knowledge of surface composition and atomic arrangement is prerequisite for understanding of catalytic properties of an alloy catalyst. Gaining such knowledge is rather difficult, especially for those possessing surface segregation. Pd–Cu alloy is used in many fields and possesses surface segregation. In this paper kinetic Monte Carlo method is used to explore the surface composition and structure and to examine the effects of bulk composition and temperature on the surface segregation of Pd–Cu alloys. It is shown that the segregation basically completes within 900 s at 500 K. Below 900 K and within 20 min the enriched surface Cu atoms mainly come from the top five layers. For the first time we demonstrate that there exists a “bulk-inside flocking” or clustering phenomenon (the same component element congregates in bulk) in Pd–Cu alloys. Our results indicate that for alloys with higher Cu content there are small Pd ensembles like monomers, dimers and trimers with contiguous subsurface Pd atoms. - Highlights: • Kinetic Monte Carlo was first used to study surface segregation of Pd–Cu alloys. • Bulk-inside flocking (the same component element congregates in bulk) was observed. • Small Pd ensembles with contiguous subsurface Pd exist on surfaces of Cu-rich alloys

  13. Kinetic Monte Carlo simulation of surface segregation in Pd–Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Feng [Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of MOE, Nanjing University (China); He, Xiang [Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Chen, Zhao-Xu, E-mail: zxchen@nju.edu.cn [Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of MOE, Nanjing University (China); Huang, Yu-Gai [Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of MOE, Nanjing University (China); JiangSu Second Normal University, Nanjing (China)

    2015-11-05

    The knowledge of surface composition and atomic arrangement is prerequisite for understanding of catalytic properties of an alloy catalyst. Gaining such knowledge is rather difficult, especially for those possessing surface segregation. Pd–Cu alloy is used in many fields and possesses surface segregation. In this paper kinetic Monte Carlo method is used to explore the surface composition and structure and to examine the effects of bulk composition and temperature on the surface segregation of Pd–Cu alloys. It is shown that the segregation basically completes within 900 s at 500 K. Below 900 K and within 20 min the enriched surface Cu atoms mainly come from the top five layers. For the first time we demonstrate that there exists a “bulk-inside flocking” or clustering phenomenon (the same component element congregates in bulk) in Pd–Cu alloys. Our results indicate that for alloys with higher Cu content there are small Pd ensembles like monomers, dimers and trimers with contiguous subsurface Pd atoms. - Highlights: • Kinetic Monte Carlo was first used to study surface segregation of Pd–Cu alloys. • Bulk-inside flocking (the same component element congregates in bulk) was observed. • Small Pd ensembles with contiguous subsurface Pd exist on surfaces of Cu-rich alloys.

  14. Chromosome segregation in plant meiosis

    Directory of Open Access Journals (Sweden)

    Linda eZamariola

    2014-06-01

    Full Text Available Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved.

  15. Segregation driven phase transformation in medium Mn steel

    OpenAIRE

    Kuzmina, Margarita

    2016-01-01

    Equilibrium segregation occurs as a result of structural inhomogeneities in the solid giving rise to sites for which solute atoms have a lower Gibbs energy. These sites occur at defects such as free surfaces, grain boundaries and phase interphases as well as at dislocations and stacking faults. All these regions then may exhibit concentrations of solute atoms that differ from each other and from that of the bulk material. Besides a strong impact on mechanical and physical properties of solids...

  16. The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys

    International Nuclear Information System (INIS)

    The magnitudes of both void swelling and radiation-induced segregation (RIS) in iron-chromium-nickel alloys are dependent on bulk alloy composition. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation. This local composition change reduces the subsequent vacancy flux to the void, thereby reducing void swelling. In this work, the resistance to swelling from major element segregation is estimated using diffusivities derived from grain boundary segregation measurements in irradiated iron-chromium-nickel alloys. The resistance to void swelling in iron- and nickel-base alloys correlates with the segregation and both are functions of bulk alloy composition. Alloys that display the greatest amount of nickel enrichment and chromium depletion are found to be most resistant to void swelling, as predicted. Additionally, swelling is shown to be greater in alloys in which the RIS profiles are slow to develop

  17. Segregation and sporadic cases in families with Hunter's syndrome.

    Science.gov (United States)

    Machill, G; Barbujani, G; Danieli, G A; Herrmann, F H

    1991-01-01

    Segregation analysis on five samples of families with Hunter's syndrome (158 cases overall) shows that the mutant allele segregates in agreement with Mendelian expectations for an X linked recessive disease, but the proportion of sporadic cases is significantly lower than expected under mutation-selection equilibrium. Heterogeneity among the samples is apparent, but it is caused entirely by a sample of Ashkenazi families, whose segregation pattern has previously been interpreted as supporting the hypothesis of prenatal selection in favour of the pathological allele. Conversely, our joint analysis of the five samples by a maximum likelihood approach does not suggest segregation distortion. Possible reasons for the apparent lack of sporadic cases include the effect of ascertainment bias. PMID:1908009

  18. Measuring residential segregation in urban Mexico: Levels and patterns

    OpenAIRE

    Monkkonen, Paavo

    2010-01-01

    Changing patterns of urban development in Latin America have drawn increasing attention to residential segregation, yet systematic quantitative analysis remains limited. Using data from the Mexican census of 2000, this paper describes spatial patterns and levels of segregation by ethnicity and socioeconomic status in over 100 cities. Findings confirm many recognized patterns; low-income and informally employed households tend to live in peripheral areas of the city, while high-income and form...

  19. Can topology reshape segregation patterns?

    CERN Document Server

    Gandica, Yerali; Carletti, Timoteo

    2015-01-01

    We consider a metapopulation version of the Schelling model of segregation over several complex networks and lattice. We show that the segregation process is topology independent and hence it is intrinsic to the individual tolerance. The role of the topology is to fix the places where the segregation patterns emerge. In addition we address the question of the time evolution of the segregation clusters, resulting from different dynamical regimes of a coarsening process, as a function of the tolerance parameter. We show that the underlying topology may alter the early stage of the coarsening process, once large values of the tolerance are used, while for lower ones a different mechanism is at work and it results to be topology independent.

  20. School Desegregation and Residential Segregation.

    Science.gov (United States)

    Billingsley, Andrew; And Others

    1979-01-01

    This statement on school and residential segregation, signed by 38 educators and social scientists, was prepared for attorneys connected with litigation concerning the Dayton and Columbus school systems. (RLV)

  1. Analysis of wave attenuation and shore protection of a bulk carrier ship performing as a detached floating breakwater

    OpenAIRE

    Fernández Lázaro, Angel; Gutiérrez Serret, Ramón María; Negro Valdecantos, Vicente; López Gutiérrez, José Santos

    2014-01-01

    Análisis de la atenuación del oleaje por un carguero funcionando como dique flotante y aplicación a dos casos de protección portuaria y costera. The effectiveness of a bulk carrier working as a detached floating breakwater to protect a stretch of coast and form salients or tombolos is assessed in this paper. Experiments were conducted in the Madrid CEDEX facilities in a 30 m long, 3 m wide, 1/150 scale flume. The bulk carrier ship is 205 m long, 29 m wide and 18 m in height with a dr...

  2. Applied thermodynamics: Grain boundary segregation

    Czech Academy of Sciences Publication Activity Database

    Lejček, Pavel; Zheng, L.; Hofmann, S.; Šob, Mojmír

    2014-01-01

    Roč. 16, č. 3 (2014), s. 1462-1484. ISSN 1099-4300 R&D Projects: GA ČR(CZ) GAP108/12/0311; GA ČR GAP108/12/0144; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68378271 ; RVO:68081723 Keywords : interfacial segregation * Gibbs energy of segregation * enthalpy * entropy * volume * grain boundaries * iron Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.502, year: 2014

  3. Residential Segregation in General Equilibrium

    OpenAIRE

    Bayer, Patrick; McMillan, Robert; Rueben, Kim

    2005-01-01

    This paper studies the causes and consequences of racial segregation using a new general equilibrium model that treats neighborhood compositions as endogenous. The model is estimated using unusually detailed restricted Census microdata covering the entire San Francisco Bay Area, and in combination with a rich array of econometric estimates, serves as a powerful tool for carrying out counterfactual simulations that shed light on the causes and consequences of segregation. In terms of causes, a...

  4. Heterogeneous Immigration, Segregation and Trade

    OpenAIRE

    Fabien Candau

    2011-01-01

    By introducing taste heterogeneity between mobile workers in a New Economic Geography (NEG) model where the housing price is the main driving force behind dispersion of workers we show that residential segregation and agglomeration are not the sole stable equilibria and that dispersion also emerges with trade liberalization. In addition we find that contrary to the Tiebout hypothesis where segregation is efficient, here it is the dispersed and mixed equilibrium which can be improving for all.

  5. Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease-resistance genes in the common bean cultivar Ouro Negro

    OpenAIRE

    Gonçalves-Vidigal, MC; Cruz, AS; Lacanallo, GF; Vidigal Filho, PS; Sousa, LL; Pacheco, CMNA; McClean, P.; Gepts, P.; Pastor-Corrales, MA

    2013-01-01

    Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean (Phaseolus vulgaris L.). Ouro Negro is a highly productive common bean cultivar, which contains the Co-10 and Phg-ON genes for resistance to ANT and ALS, respectively. In this study, we performed a genetic co-segregation analysis of resistance to ANT and ALS using an F2 population from the Rudá × Ouro Negro cross and the F2:3 families from the AND 277 × Ouro Negro cross. Ouro Negro is resistant to races 7 an...

  6. Segregation effects in DEEP2 galaxy groups

    CERN Document Server

    Nascimento, Raquel S; Lopes, Paulo A A

    2016-01-01

    We investigate segregation phenomena in galaxy groups in the range of $0.20.6$) redshift groups. Assuming that the color index ${(U-B)_0}$ can be used as a proxy for the galaxy type, we found that the fraction of blue (star-forming) objects is higher in the high-z sample, with blue objects being dominant at $M_{B}>-19.5$ for both samples, and red objects being dominant at $M_{B}<-19.5$ only for the low-z sample. Also, the radial variation of the red fraction indicates that there are more red objects with $Ranalysis indicates statistical evidence of kinematic segregation, at the 99%c.l., for the low-z sample: redder and brighter galaxies present lower velocity dispersions than bluer and fainter ones. We also find a weaker evidence for spatial segregation between red and blue objects, at the 70%c.l. The analysis of the high-z sample reveals a different result: red and blue galaxies have velocity dispersion distributions not statistically distinc...

  7. School Segregation: The Case of Amsterdam.

    Science.gov (United States)

    Gramberg, Peter

    1998-01-01

    Deals with facets of school segregation in Amsterdam, a city in which two-thirds of youth have a non-native background. The role of residential segregation in the segregation of elementary schools and the importance of educational background in the segregation of secondary schools are discussed. There are implications for schooling in the United…

  8. A Revaluation of Indexes of Residential Segregation

    Science.gov (United States)

    Winship, Christopher

    1977-01-01

    Shows that there are at least two different perspectives from which residential segregation can be examined. Segregation can be measured as it deviates from a situation of complete desegregation or in terms of a situation in which there is random segregation in the city. New criteria for indexes of residential segregation are developed. (Author/JM)

  9. Application of a tangent curve mathematical model for analysis of the mechanical behaviour of sunflower bulk seeds

    Science.gov (United States)

    Sigalingging, Riswanti; Herák, David; Kabutey, Abraham; Dajbych, Oldřich; Hrabě, Petr; Mizera, Čestmír

    2015-10-01

    This paper evaluate the use of a tangent curve mathematical model for representation of the mechanical behaviour of sunflower bulk seeds. Compression machine (Tempos Model 50, Czech Republic) and pressing vessel diameter 60 mm were used for the loading experiment. Varying forces between 50 and 130 kN and speeds ranging from 10, 50, and 100 mm min-1 were applied respectively on the bulk seeds with moisture content 12.37±0.38% w.b. The relationship between force and deformation curves of bulk seeds of pressing height 80 mm was described. The oil point strain was also determined from the different deformation values namely 30, 35, 40, and 45 mm at speed 10 mm min-1. Based on the results obtained, model coefficients were determined for fitting the experimental load and deformation curves. The validity of these coefficients were dependent on the bulk seeds of pressing height, vessel diameter, maximum force 110 kN, and speed 10 mm min-1, where optimal oil yield was observed. The oil point was detected at 45 mm deformation giving the strain value of 0.56 with the corresponding force 16.65±3.51 kN and energy 1.06±0.18 MJ m-3. At the force of 130 kN, a serration effect on the curves was indicated; hence, the compression process was ceased.

  10. Structural analysis of nanocrystals and their role in the coercivity mechanism of Nd–Fe–Al–Dy bulk amorphous ferromagnets

    International Nuclear Information System (INIS)

    The magnetic property and microstructure of Nd60−xFe30Al10Dyx (x=0, 2, 4) bulk ferromagnets have been investigated. At room temperature, each alloy sample shows hard magnetic behavior, and the intrinsic coercivity increases significantly with increasing Dy content. Transmission electron microscopy (TEM) and Atom probe tomography (APT) results show nanocrystals of width 5–20 nm embedded in the Fe-rich amorphous matrix. The coercivity mechanism of the Nd60−xFe30Al10Dyx (x=0, 2, 4) amorphous alloys is discussed in the context of Gaunt's strong pinning model of domain walls. The crystallographic phases of nanocrystals identified by high-resolution TEM can act as pinning centers. Our findings give further insight into the coercivity mechanism of Nd-based bulk amorphous alloys through a better understanding of the nanostructural environment. - Highlights: • Study of the crystallographic phases present in the nanocrystals in Nd–Fe–Al–Dy bulk ferromagnets. • The phase composition of the nanocrystals varies with Dy content. • Shows the amorphous matrix is Fe-rich by atom probe tomography. • This work gives further insight into the coercivity mechanism of Nd-based bulk amorphous alloys through a better understanding of the nanostructural environment

  11. Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease-resistance genes in the common bean cultivar Ouro Negro.

    Science.gov (United States)

    Gonçalves-Vidigal, M C; Cruz, A S; Lacanallo, G F; Vidigal Filho, P S; Sousa, L L; Pacheco, C M N A; McClean, P; Gepts, P; Pastor-Corrales, M A

    2013-09-01

    Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean (Phaseolus vulgaris L.). Ouro Negro is a highly productive common bean cultivar, which contains the Co-10 and Phg-ON genes for resistance to ANT and ALS, respectively. In this study, we performed a genetic co-segregation analysis of resistance to ANT and ALS using an F2 population from the Rudá × Ouro Negro cross and the F2:3 families from the AND 277 × Ouro Negro cross. Ouro Negro is resistant to races 7 and 73 of the ANT and race 63-39 of the ALS pathogens. Conversely, cultivars AND 277 and Rudá are susceptible to races 7 and 73 of ANT, respectively. Both cultivars are susceptible to race 63-39 of ALS. Co-segregation analysis revealed that Co-10 and Phg-ON were inherited together, conferring resistance to races 7 and 73 of ANT and race 63-39 of ALS. The Co-10 and Phg-ON genes were co-segregated and were tightly linked at a distance of 0.0 cM on chromosome Pv04. The molecular marker g2303 was linked to Co-10 and Phg-ON at a distance of 0.0 cM. Because of their physical linkage in a cis configuration, the Co-10 and Phg-ON resistance alleles are inherited together and can be monitored with great efficiency using g2303. The close linkage between the Co-10 and Phg-ON genes and prior evidence are consistent with the existence of a resistance gene cluster at one end of chromosome Pv04, which also contains the Co-3 locus and ANT resistance quantitative trait loci. These results will be very useful for breeding programs aimed at developing bean cultivars with ANT and ALS resistance using marker-assisted selection. PMID:23760652

  12. Public School Segregation in Metropolitan Areas

    OpenAIRE

    Charles T. Clotfelter

    1998-01-01

    This paper presents measures of segregation in public schools for metropolitan areas. It shows that, not only are metropolitan areas very segregated, most of that segregation is due to racial disparities between districts rather than segregative patterns within districts. Metropolitan areas in the South and West tend to have larger districts, and thus feature less fragmentation by school district. Segregation at the metropolitan level appears to vary systematically with size, racial mix, and ...

  13. Occupational segregation of immigrant women in Spain

    OpenAIRE

    Coral del Río; Olga Alonso-Villar

    2010-01-01

    The aim of this paper is to analyze occupational segregation in the Spanish labor market from a gender and an immigration perspective. In doing so, several local and overall segregation measures are used. Our results suggest that immigrant women in Spain suffer a double segregation since segregation affects them to a greater extent than it does either native women or immigrant men. There are, however, remarkable discrepancies among the segregation of immigrant women depending on their region ...

  14. Radiation-induced segregation in Cu-Au alloys

    International Nuclear Information System (INIS)

    Radiation-induced segregation in a Cu-1 at. % Au alloy was investigated using in situ Rutherford Backscattering Spectrometry. Irradiation with 1.8-MeV He produced nonequilibrium Au atom depletion in the near surface region. The amount of segregation was measured as a function of dose, dose rate and temperature. Segregation was observed between 300 and 5000C. For a calculated dose rate of 3.9 x 10-5 dpa/s, the radiation-induced segregation rate peaked near 4000C. Theoretical analysis based on the Johnson-Lam model predicted that the amount of segregation would be directly proportional to dose at the early stage of irradiation, would deviate from linearity with a continuously decreasing slope at intermediate doses, and finally approach a constant value after high doses. The analysis also predicted that the segregation rate would vary as the -1/4th power of the dose rate at constant dose in the low temperature region. These predictions were all verified experimentally. A procedure for extracting relative defect production efficiencies from similar measurements is discussed

  15. Implementing spatial segregation measures in R.

    Science.gov (United States)

    Hong, Seong-Yun; O'Sullivan, David; Sadahiro, Yukio

    2014-01-01

    Reliable and accurate estimation of residential segregation between population groups is important for understanding the extent of social cohesion and integration in our society. Although there have been considerable methodological advances in the measurement of segregation over the last several decades, the recently developed measures have not been widely used in the literature, in part due to their complex calculation. To address this problem, we have implemented several newly proposed segregation indices in R, an open source software environment for statistical computing and graphics, as a package called seg. Although there are already a few standalone applications and add-on packages that provide access to similar methods, our implementation has a number of advantages over the existing tools. First, our implementation is flexible in the sense that it provides detailed control over the calculation process with a wide range of input parameters. Most of the parameters have carefully chosen defaults, which perform acceptably in many situations, so less experienced users can also use the implemented functions without too much difficulty. Second, there is no need to export results to other software programs for further analysis. We provide coercion methods that enable the transformation of our output classes into general R classes, so the user can use thousands of standard and modern statistical techniques, which are already available in R, for the post-processing of the results. Third, our implementation does not require commercial software to operate, so it is accessible to a wider group of people. PMID:25415326

  16. Implementing spatial segregation measures in R.

    Directory of Open Access Journals (Sweden)

    Seong-Yun Hong

    Full Text Available Reliable and accurate estimation of residential segregation between population groups is important for understanding the extent of social cohesion and integration in our society. Although there have been considerable methodological advances in the measurement of segregation over the last several decades, the recently developed measures have not been widely used in the literature, in part due to their complex calculation. To address this problem, we have implemented several newly proposed segregation indices in R, an open source software environment for statistical computing and graphics, as a package called seg. Although there are already a few standalone applications and add-on packages that provide access to similar methods, our implementation has a number of advantages over the existing tools. First, our implementation is flexible in the sense that it provides detailed control over the calculation process with a wide range of input parameters. Most of the parameters have carefully chosen defaults, which perform acceptably in many situations, so less experienced users can also use the implemented functions without too much difficulty. Second, there is no need to export results to other software programs for further analysis. We provide coercion methods that enable the transformation of our output classes into general R classes, so the user can use thousands of standard and modern statistical techniques, which are already available in R, for the post-processing of the results. Third, our implementation does not require commercial software to operate, so it is accessible to a wider group of people.

  17. Helium segregation on surfaces of plasma-exposed tungsten

    International Nuclear Information System (INIS)

    We report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile Hen (1  ⩽  n  ⩽  7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides the thermodynamic driving force for surface segregation. This elastic interaction force induces drift fluxes of these mobile Hen clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters’ drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. These near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components. (paper)

  18. Helium segregation on surfaces of plasma-exposed tungsten

    Science.gov (United States)

    Maroudas, Dimitrios; Blondel, Sophie; Hu, Lin; Hammond, Karl D.; Wirth, Brian D.

    2016-02-01

    We report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile He n (1  ⩽  n  ⩽  7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides the thermodynamic driving force for surface segregation. This elastic interaction force induces drift fluxes of these mobile He n clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters’ drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. These near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components.

  19. Design & Performance Analysis of DG-MOSFET for Reduction of Short Channel Effect over Bulk MOSFET at 20nm

    Directory of Open Access Journals (Sweden)

    Ankita Wagadre

    2014-07-01

    Full Text Available An aggressive scaling of conventional MOSFETs channel length reduces below 100nm and gate oxide thickness below 3nm to improved performance and packaging density. Due to this scaling short channel effect (SCEs like threshold voltage, Subthreshold slope, ON current and OFF current plays a major role in determining the performance of scaled devices. The double gate (DG MOSFETS are electro-statically superior to a single gate (SG MOSFET and allows for additional gate length scaling. Simulation work on both devices has been carried out and presented in paper. The comparative study had been carried out for threshold voltage (VT, Subthreshold slope (Sub VT, ION and IOFF Current. It is observed that DG MOSFET provide good control on leakage current over conventional Bulk (Single Gate MOSFET. The VT (Threshold Voltage is 2.7 times greater than & ION of DG MOSFET is 2.2 times smaller than the conventional Bulk (Single Gate MOSFET.

  20. TLC-densitometric analysis of α-escin in bulk drug substance and in pharmaceutical dosage forms

    OpenAIRE

    Dolowy Malgorzata; Pyka-Pajak Alina; Filip Katarzyna; Zagrodzka Joanna

    2015-01-01

    A quite simple and rapid TLC-densitometric method for the identification of α-escin (Aescin) in bulk drug substances was developed. In so doing, different chromatographic conditions, including various mobile and stationary phases, were tested. A TLC densitometric determination of the examined compound was performed without using visualizing reagent, yet with the use of appropriate dipping reagents, in order to obtain reliable UV-densitometric measurements of α-escin - a substance which has we...

  1. Understanding the Effect of Unintentional Doping on Transport Optimization and Analysis in Efficient Organic Bulk-Heterojunction Solar Cells

    OpenAIRE

    Deledalle, Florent; Kirchartz, Thomas; Vezie, Michelle S.; Campoy-Quiles, Mariano; Shakya Tuladhar, Pabitra; Nelson, Jenny; Durrant, James R.

    2015-01-01

    In this paper, we provide experimental evidence of the effects of unintentional p-type doping on the performance and the apparent recombination dynamics of bulk-heterojunction solar cells. By supporting these experimental observations with drift-diffusion simulations on two batches of the same efficient polymer-fullerene solar cells with substantially different doping levels and at different thicknesses, we investigate the way the presence of doping affects the interpretation of optoelectroni...

  2. Scanning Auger electron spectroscopy studies of grain-boundary segregation in Type 304 stainless steel

    International Nuclear Information System (INIS)

    Scanning Auger electron spectroscopy studies have been conducted on grain-boundary surfaces of Type 304 stainless steel that were fractured in situ. To enhance the probability of intergranular fracture, the specimens were first subjected to creep deformation for 1000 h at 7000C. A semiquantitative surface chemical composition was calculated from the peak heights of Auger electron spectra. The concentration of Cr at the fracture surface was not different from the bulk value. This indicates that the long-term heat treatment caused healing of the sensitization. The concentrations of S, C, and Si at the fracture surface were at least an order of magnitude higher than the bulk values. Chemical composition profiles obtained by ion-sputtering indicated that segregation of S, C, P, and Si occurred within a depth of several atomic monolayers from the grain-boundary surface. Mo, Mn and Cu were not detected. The concentrations of Ni and Fe are in good agreement with the bulk chemical analysis

  3. Polycyclic aromatic hydrocarbons in bulk deposition at a suburban site: assessment by principal component analysis of the influence of meteorological parameters

    Science.gov (United States)

    Motelay-Massei, A.; Ollivon, D.; Garban, B.; Chevreuil, M.

    Bulk deposition (wet+dry) of 14 polycyclic aromatic hydrocarbons (PAHs) was measured every week from 5 March 2001 to 4 March 2002 on a suburban site at Evreux located 100 km West of Paris (France). Measured concentrations in bulk depositions ranged from 1.1 to 222 ng l -1 with an average of 71.5 ng l -1. The most prevalent PAHs are phenanthrene, fluoranthene and pyrene, which represent 60% of the total concentration on average. The potentially carcinogenic PAHs represent 22% of the PAH concentrations. Statistical analysis, in particular principal component analysis (PCA), allowed us to analyse this data set, highlighting the influence of meteorological parameters (temperature, precipitation amount) on PAH concentration, both quantitatively and qualitatively. The temperature played an important role for PAH concentration in bulk deposition and influenced the efficiency of washout, while rainfall amounts seemed to have a minor influence. Thus, we found seasonal trends in PAH concentration. High rainfall correlated with high proportions of light PAHs. Finally, the study of wind directions allowed us to localize sources of PAHs and to estimate their respective contribution. The influence of the urban area of Rouen on PAH concentrations measured at Evreux is emphasized.

  4. Towards risk-based management of critical infrastructures : enabling insights and analysis methodologies from a focused study of the bulk power grid.

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Bryan T.; LaViolette, Randall A.; Cook, Benjamin Koger

    2008-02-01

    This report summarizes research on a holistic analysis framework to assess and manage risks in complex infrastructures, with a specific focus on the bulk electric power grid (grid). A comprehensive model of the grid is described that can approximate the coupled dynamics of its physical, control, and market components. New realism is achieved in a power simulator extended to include relevant control features such as relays. The simulator was applied to understand failure mechanisms in the grid. Results suggest that the implementation of simple controls might significantly alter the distribution of cascade failures in power systems. The absence of cascade failures in our results raises questions about the underlying failure mechanisms responsible for widespread outages, and specifically whether these outages are due to a system effect or large-scale component degradation. Finally, a new agent-based market model for bilateral trades in the short-term bulk power market is presented and compared against industry observations.

  5. The impact of carbon and oxygen in alpha-titanium: ab initio study of solution enthalpies and grain boundary segregation.

    Science.gov (United States)

    Aksyonov, D A; Hickel, T; Neugebauer, J; Lipnitskii, A G

    2016-09-28

    The solution, grain boundary (GB) segregation, and co-segregation of carbon and oxygen atoms in α-titanium are studied using density functional theory. For five titanium tilt boundaries, including T1, T2, and C1 twin systems, we determine the GB structure, as well as GB energy and excess volume. The segregation energies and volumes of carbon and oxygen are calculated for 23 inequivalent interstitial voids, while for co-segregation 75 configurations are considered. It is obtained that depending on the type of the segregation void both a positive and a negative segregation process is possible. The physical reasons of segregation are explained in terms of the analysis of the void atomic geometry, excess volume and features of the electronic structure at the Fermi level. Although carbon and oxygen show qualitatively similar properties in α-Ti, several distinctions are observed for their segregation behavior and mutual interactions. PMID:27460043

  6. The impact of carbon and oxygen in alpha-titanium: ab initio study of solution enthalpies and grain boundary segregation

    Science.gov (United States)

    Aksyonov, D. A.; Hickel, T.; Neugebauer, J.; Lipnitskii, A. G.

    2016-09-01

    The solution, grain boundary (GB) segregation, and co-segregation of carbon and oxygen atoms in α-titanium are studied using density functional theory. For five titanium tilt boundaries, including T1, T2, and C1 twin systems, we determine the GB structure, as well as GB energy and excess volume. The segregation energies and volumes of carbon and oxygen are calculated for 23 inequivalent interstitial voids, while for co-segregation 75 configurations are considered. It is obtained that depending on the type of the segregation void both a positive and a negative segregation process is possible. The physical reasons of segregation are explained in terms of the analysis of the void atomic geometry, excess volume and features of the electronic structure at the Fermi level. Although carbon and oxygen show qualitatively similar properties in α-Ti, several distinctions are observed for their segregation behavior and mutual interactions.

  7. Grain Boundary Segregation in Metals

    CERN Document Server

    Lejcek, Pavel

    2010-01-01

    Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

  8. COBALT SEGREGATION IN CARBIDE GRAIN BOUNDARIES IN WC-Co COMPOSITES

    OpenAIRE

    Vicens, J.; Dubon, A.; Laval, J; Benjdir, M.; Nouet, G.

    1990-01-01

    The cobalt concentration at WC-WC grain boundaries in WC-Co composites was determined via X-ray energy dispersive analysis in STEM. Cobalt profiles were performed-across coincidence grain boundaries Σ2 and Σ5 with a (10(-1)0) prismatic plane. A small cobalt segregation has been detected when dislocations were imaged in the grain boundaries. The cobalt segregation value is compared to the segregation ratio obtained in low angle and general grain boundaries.

  9. Linking Dichotomous Segregation with Multi-group Segregation: Weighted Segregation Ratios in Selected U. S. Metropolitan Areas

    OpenAIRE

    Hao, Lingxin; Fong, Eric

    2011-01-01

    The U. S. residential landscape is increasingly multi-racial and multi-ethnic, giving rise to the question of how to compare dichotomous segregation among multiple groups living in the same area. To address the problem in the existing dichotomous approach, which offers no common basis for comparing dichotomous segregation among multiple groups, this paper develops a weighted segregation ratio approach based on Theil's segregation index and its additive decomposability. This approach can be us...

  10. Short-term bulk energy storage system scheduling for load leveling in unit commitment: modeling, optimization, and sensitivity analysis.

    Science.gov (United States)

    Hemmati, Reza; Saboori, Hedayat

    2016-05-01

    Energy storage systems (ESSs) have experienced a very rapid growth in recent years and are expected to be a promising tool in order to improving power system reliability and being economically efficient. The ESSs possess many potential benefits in various areas in the electric power systems. One of the main benefits of an ESS, especially a bulk unit, relies on smoothing the load pattern by decreasing on-peak and increasing off-peak loads, known as load leveling. These devices require new methods and tools in order to model and optimize their effects in the power system studies. In this respect, this paper will model bulk ESSs based on the several technical characteristics, introduce the proposed model in the thermal unit commitment (UC) problem, and analyze it with respect to the various sensitive parameters. The technical limitations of the thermal units and transmission network constraints are also considered in the model. The proposed model is a Mixed Integer Linear Programming (MILP) which can be easily solved by strong commercial solvers (for instance CPLEX) and it is appropriate to be used in the practical large scale networks. The results of implementing the proposed model on a test system reveal that proper load leveling through optimum storage scheduling leads to considerable operation cost reduction with respect to the storage system characteristics. PMID:27222741

  11. Potential donor segregation to promote blood donation.

    Science.gov (United States)

    Martín-Santana, Josefa D; Beerli-Palacio, Asunción

    2008-04-01

    This work is set in the field of social marketing and more specifically in the context of blood donation. Its principal objective focuses on segregating potential donors by using the inhibitors or barriers to a blood donation behaviour as criteria. Moreover, an analysis of the predisposition to donate blood, the intrinsic and extrinsic motivations for donating blood, and the incentives that may stimulate their donation conduct was conducted for each of the four identified groups. The results reveal that the four segments differ significantly in their predisposition to donate, in their motivations and in the incentives that encourage them to donate blood. PMID:18343199

  12. Sexual orientation, prejudice and segregation

    NARCIS (Netherlands)

    E. Plug; D. Webbink; N. Martin

    2014-01-01

    This article examines whether gay and lesbian workers sort into tolerant occupations. With information on sexual orientation, prejudice, and occupational choice taken from Australian Twin Registers, we find that gays and lesbians shy away from prejudiced occupations. We show that our segregation res

  13. Nonequilibrium Segregation in Petroleum Reservoirs

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1999-01-01

    We analyse adsorption of a multicomponent mixture at high pressure on the basis of the potential theory of adsorption. The adsorbate is considered as a segregated mixture in the external field produced by a solid adsorbent. we derive an analytical equation for the thickness of a multicomponent fi...

  14. Why Our Schools Are Segregated

    Science.gov (United States)

    Rothstein, Richard

    2013-01-01

    "Residential segregation's causes are both knowable and known," writes Richard Rothstein. According to Rothstein, those causes are "20th century federal, state, and local policies explicitly designed to separate the races." Even seasoned policymakers are convinced that the residential isolation of low-income black children…

  15. Linking integration and residential segregation

    NARCIS (Netherlands)

    Bolt, G.S.; Özüekren, A.S.; Phillips, Deborah

    2010-01-01

    In the introduction to this special issue of JEMS, we question the strong link which is often made between the integration of minority ethnic groups and their residential segregation. In the literature on neighbourhood effects, the residential concentration of minorities is seen as a major obstacle

  16. Gender Segregation: Separate but Effective?

    Science.gov (United States)

    Holthouse, David

    2010-01-01

    In 2002, only 11 public schools in the United States had gender-segregated classrooms. As of December 2009, there were more than 550. The movement is based on the hypothesis that hard-wired differences in the ways that male and female brains develop and function in childhood through adolescence require classrooms in which boys and girls are not…

  17. Microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Rui [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Engineering Research Center of Large Size Alloy Structural Steel Bars of Shandong Province, Jinan 250061 (China); School of Materials Science and Engineering, Shandong University of Technology, Zibo 255049 (China); Li, Shengli, E-mail: lishengli@sdu.edu.cn [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Engineering Research Center of Large Size Alloy Structural Steel Bars of Shandong Province, Jinan 250061 (China); Zhu, Xinde [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Ao, Qing [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Engineering Research Center of Large Size Alloy Structural Steel Bars of Shandong Province, Jinan 250061 (China)

    2015-10-15

    In order to further reveal the microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel, the microstructure of this type steel was intensively studied with Scanning Auger Microprobe (SAM), etc. The results show that severe C–Mn segregation exists in the abnormal segregation band region at the center of hot rolled ferrite/pearlite steel, which results from the Mn segregation during solidification process of the continuous casting slab. The C–Mn segregation causes relative displacement of pearlite transformation curve and bainite transformation curve of C curve in the corresponding region, leading to bay-like shaped C curve. The bay-like shaped C curve creates conditions for the transformation from supercooling austenite to bainite at relatively lower cooling rate in this region. The Fe–Mn–C Atomic Segregation Zone (FASZ) caused by C–Mn segregation can powerfully retard the atomic motion, and increase the lattice reconstruction resistance of austenite transformation. These two factors provide thermodynamic and kinetic conditions for the bainite transformation, and result in the emergence of granular bainitic abnormal segregation band at the center of steel plate, which leads to lower plasticity and toughness of this region, and induces the layered fracture. - Highlights: • Scanning Auger Microprobe (SAM) is applied in the fracture analysis. • The abnormal segregation band region appears obvious C–Mn segregation. • The C–Mn segregation leads to bay-like shaped C curve. • The C–Mn segregation leads to Fe–Mn–C Atomic Segregation Zone.

  18. Microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel

    International Nuclear Information System (INIS)

    In order to further reveal the microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel, the microstructure of this type steel was intensively studied with Scanning Auger Microprobe (SAM), etc. The results show that severe C–Mn segregation exists in the abnormal segregation band region at the center of hot rolled ferrite/pearlite steel, which results from the Mn segregation during solidification process of the continuous casting slab. The C–Mn segregation causes relative displacement of pearlite transformation curve and bainite transformation curve of C curve in the corresponding region, leading to bay-like shaped C curve. The bay-like shaped C curve creates conditions for the transformation from supercooling austenite to bainite at relatively lower cooling rate in this region. The Fe–Mn–C Atomic Segregation Zone (FASZ) caused by C–Mn segregation can powerfully retard the atomic motion, and increase the lattice reconstruction resistance of austenite transformation. These two factors provide thermodynamic and kinetic conditions for the bainite transformation, and result in the emergence of granular bainitic abnormal segregation band at the center of steel plate, which leads to lower plasticity and toughness of this region, and induces the layered fracture. - Highlights: • Scanning Auger Microprobe (SAM) is applied in the fracture analysis. • The abnormal segregation band region appears obvious C–Mn segregation. • The C–Mn segregation leads to bay-like shaped C curve. • The C–Mn segregation leads to Fe–Mn–C Atomic Segregation Zone

  19. Spatial Stream Segregation by Cats.

    Science.gov (United States)

    Javier, Lauren K; McGuire, Elizabeth A; Middlebrooks, John C

    2016-06-01

    Listeners can perceive interleaved sequences of sounds from two or more sources as segregated streams. In humans, physical separation of sound sources is a major factor enabling such stream segregation. Here, we examine spatial stream segregation with a psychophysical measure in domestic cats. Cats depressed a pedal to initiate a target sequence of brief sound bursts in a particular rhythm and then released the pedal when the rhythm changed. The target bursts were interleaved with a competing sequence of bursts that could differ in source location but otherwise were identical to the target bursts. This task was possible only when the sources were heard as segregated streams. When the sound bursts had broad spectra, cats could detect the rhythm change when target and competing sources were separated by as little as 9.4°. Essentially equal levels of performance were observed when frequencies were restricted to a high, 4-to-25-kHz, band in which the principal spatial cues presumably were related to sound levels. When the stimulus band was restricted from 0.4 to 1.6 kHz, leaving interaural time differences as the principal spatial cue, performance was severely degraded. The frequency sensitivity of cats in this task contrasts with that of humans, who show better spatial stream segregation with low- than with high-frequency sounds. Possible explanations for the species difference includes the smaller interaural delays available to cats due to smaller sizes of their heads and the potentially greater sound-level cues available due to the cat's frontally directed pinnae and higher audible frequency range. PMID:26993807

  20. The Geographic Scale of Metropolitan Racial Segregation

    OpenAIRE

    Reardon, Sean F.; Matthews, Stephen A.; O’Sullivan, David; Lee, Barrett A.; Firebaugh, Glenn; Farrell, Chad R.; BISCHOFF, KENDRA

    2008-01-01

    This article addresses an aspect of racial residential segregation that has been largely ignored in prior work: the issue of geographic scale. In some metropolitan areas, racial groups are segregated over large regions, with predominately white regions, predominately black regions, and so on, whereas in other areas, the separation of racial groups occurs over much shorter distances. Here we develop an approach—featuring the segregation profile and the corresponding macro/micro segregation rat...

  1. Measuring segregation: an activity space approach

    OpenAIRE

    Wong, David W. S.; Shaw, Shih-Lung

    2011-01-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual’s segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehens...

  2. Is Segregation Bad for Your Health?

    OpenAIRE

    Kramer, Michael R; Hogue, Carol R.

    2009-01-01

    For decades, racial residential segregation has been observed to vary with health outcomes for African Americans, although only recently has interest increased in the public health literature. Utilizing a systematic review of the health and social science literature, the authors consider the segregation-health association through the lens of 4 questions of interest to epidemiologists: How is segregation best measured? Is the segregation-health association socially or biologically plausible? W...

  3. Analysis of auto-feed-back preventing latch-up mechanism in bulk CMOS devices exposed to transient ionizing irradiation

    International Nuclear Information System (INIS)

    Bulk complementary metal-oxide-semiconductor (CMOS) integrated circuits contain the parasitic silicon-controlled-rectifier (SCR) structure, which tend to latch- up, even burn out, when they are exposed to transient gamma irradiation. Therefore, it is significant to study latch-up prevention. The continuity equation based on the minority carrier in parasitic transistors was solved, the duration of photocurrent in the SCR structure was calculated, and the condition of auto-feed-back preventing the devices' latch-up was confirmed. Moreover, the relationship of the condition and dose rate was concluded. Two kinds of circuits which were SCR's equivalent circuit and CMOS circuit were irradiated by transient gamma rays. The experimental results match the theoretical results well. (authors)

  4. Analysis of Vertical Oscillations of a Permanent Magnet Freely Levitated above an YBCO Bulk in an AC External Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    Yong Zhang; Ya-Li Zhang; Cui-Hua Cheng; Yong Zhao

    2008-01-01

    The effect of the moving speed of perma- nent magnet (PM) on levitation force between PM and high temperature superconducting (HTS) bulk is analyzed and described in the PM-HTS levitation system. The PM vibration characteristic in the PM-HTS system is investigated. The PM may collide with the HTS in vibration if the amplitude and frequency of driving force satisfy the relationship Pmin = A f n. When the load of the system is below a threshold, the minimal collision amplitude of the driving force increases with the load increasing, however, it sharply drops to zero when the load exceeds the threshold. With the increase of the initial height of the PM, the threshold load increases, but the minimal driving force which causes a collision between PM and HTS decreases.

  5. Oxygen induced dissolution and segregation of silicon in platinum single crystals

    International Nuclear Information System (INIS)

    The segregation of silicon in platinum flat (111), stepped (553) and (332) surfaces is studied as a function of crystal temperature. Silicon segregates below 10000C with a segregation energy between 17 and 20 kcal/mol. In the retarding field mode, the maximum amount of segregated Si corresponds to a Si (93 eV)/Pt (242 eV) Auger peak ratio of about 5. In the presence of O2, Si dissolves into the bulk at T> or approx. =6000C. The rate of Si dissolution increases with O2 pressure and crystal temperatures. At an O2 pressure of 5 x 10-7 Torr, the activation energy for the dissolution process is 16 +- 2 kcal/mol. Continued exposure to O2 results in the reappearance of Si at the Pt surface as a new phase, SiO/sub x/, characterized by Auger peaks of Si (84 eV) and O

  6. The mechanism of radiation-induced segregation in ferritic–martensitic alloys

    International Nuclear Information System (INIS)

    The mechanism of radiation-induced segregation in Fe–Cr alloys was modeled using the inverse Kirkendall mechanism and compared to experimental measurements over a range of temperatures, bulk Cr compositions, and irradiation dose. The model showed that over a large temperature range chromium was enriched at sinks by interstitial migration, and at very high temperatures it was depleted by diffusing opposite to the vacancy flux. Experimental results and model predictions were in good qualitative and quantitative agreement with regard to the temperature dependence of segregation and the crossover from Cr enrichment to Cr depletion. The inverse Kirkendall mechanism was also in agreement with experimental findings that observed a decreasing amount of Cr enrichment with increasing bulk Cr composition. The effects of solute drag were modeled within the inverse Kirkendall framework, but were unable to account for either the crossover from Cr enrichment to Cr depletion or the magnitudes of segregation measured in experiments

  7. Electrical analysis of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors on flexible bulk mono-crystalline silicon

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-06-01

    We report on the electrical study of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors (MOSCAPs) on a flexible ultra-thin (25 μm) silicon fabric which is peeled off using a CMOS compatible process from a standard bulk mono-crystalline silicon substrate. A lifetime projection is extracted using statistical analysis of the ramping voltage (Vramp) breakdown and time dependent dielectric breakdown data. The obtained flexible MOSCAPs operational voltages satisfying the 10 years lifetime benchmark are compared to those of the control MOSCAPs, which are not peeled off from the silicon wafer. © 2014 IEEE.

  8. Simultaneous Analysis of Losartan Potassium, Amlodipine Besylate, and Hydrochlorothiazide in Bulk and in Tablets by High-Performance Thin Layer Chromatography with UV-Absorption Densitometry

    OpenAIRE

    Karunanidhi Santhana Lakshmi; Sivasubramanian Lakshmi

    2012-01-01

    A Simple high-performance thin layer chromatography (HPTLC) method for separation and quantitative analysis of losartan potassium, amlodipine, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to silica gel plates and developed with chloroform : methanol : acetone : formic acid 7.5 : 1.3 : 0.5 : 0.03 ( / / / ) as mobile phase. Zones were scanned densitometric...

  9. 18 CFR 401.113 - Segregable materials.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Segregable materials. 401.113 Section 401.113 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... Segregable materials. Any reasonably segregable portion of a record shall be provided to any...

  10. 17 CFR 31.12 - Segregation.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Segregation. 31.12 Section 31....12 Segregation. (a) Any person that accepts leverage customer funds from a leverage customer to enter.... Notwithstanding the foregoing, a leverage transaction merchant may exclude from its segregation...

  11. Socioeconomic School Segregation in a Market-Oriented Educational System. The Case of Chile

    Science.gov (United States)

    Valenzuela, Juan Pablo; Bellei, Cristian; de los Ríos, Danae

    2014-01-01

    This paper presents an empirical analysis of the socioeconomic status (SES) school segregation in Chile, whose educational system is regarded as an extreme case of a market-oriented education. The study estimated the magnitude and evolution of the SES segregation of schools at both national and local levels, and it studied the relationship between…

  12. The Shaping of Postcollege Colorblind Orientation among Whites: Residential Segregation and Campus Diversity Experiences

    Science.gov (United States)

    Jayakumar, Uma M.

    2015-01-01

    In this article, Uma M. Jayakumar investigates the cumulative impact of experiences with segregation or racial diversity prior to and during college on colorblind ideological orientation among white adults. An analysis of longitudinal data spanning ten years reveals that, for whites from segregated and diverse childhood neighborhoods, some…

  13. Simultaneous Analysis of Losartan Potassium, Amlodipine Besylate, and Hydrochlorothiazide in Bulk and in Tablets by High-Performance Thin Layer Chromatography with UV-Absorption Densitometry

    Directory of Open Access Journals (Sweden)

    Karunanidhi Santhana Lakshmi

    2012-01-01

    Full Text Available A Simple high-performance thin layer chromatography (HPTLC method for separation and quantitative analysis of losartan potassium, amlodipine, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to silica gel plates and developed with chloroform : methanol : acetone : formic acid 7.5 : 1.3 : 0.5 : 0.03 (/// as mobile phase. Zones were scanned densitometrically at 254 nm. The values of amlodipine besylate, hydrochlorothiazide, and losartan potassium were 0.35, 0.57, and 0.74, respectively. Calibration plots were linear in the ranges 500–3000 ng per spot for losartan potassium, amlodipine and hydrochlorothiazide, the correlation coefficients, r, were 0.998, 0.998, and 0.999, respectively. The suitability of this method for quantitative determination of these compounds was by validation in accordance with the requirements of pharmaceutical regulatory standards. The method can be used for routine analysis of these drugs in bulk and in formulation.

  14. TLC-densitometric analysis of α-escin in bulk drug substance and in pharmaceutical dosage forms

    Directory of Open Access Journals (Sweden)

    Dolowy Malgorzata

    2015-09-01

    Full Text Available A quite simple and rapid TLC-densitometric method for the identification of α-escin (Aescin in bulk drug substances was developed. In so doing, different chromatographic conditions, including various mobile and stationary phases, were tested. A TLC densitometric determination of the examined compound was performed without using visualizing reagent, yet with the use of appropriate dipping reagents, in order to obtain reliable UV-densitometric measurements of α-escin - a substance which has weak chromophore groups. Herein, the application of a mobile phase containing n-butanolacetic acid-water in volume composition 30:7:13, the use of silica gel 60F254 plates with concentrating zone, and subsequent application of 10% sulphuric acid in ethanol or 5% vanillin in methanol/sulphuric acid, respectively, provided the best results in a TLCdensitometric study of α-escin. The described method was successfully employed to identify α-escin in commercial samples that were in an oral dosage form (tablets and also in the form of gel containing 20 mg of α-escin.

  15. Benchmarking FENDL libraries through analysis of bulk shielding experiments on large SS316 assemblies for verification of ITER shielding characteristics

    International Nuclear Information System (INIS)

    FENDL-1 data base has been developed recently for use in ITER/EDA phase and other fusion-related design activities. It is now undergoing extensive testing and benchmarking using experimental data of differential and integral measured parameters obtained from fusion-oriented experiments. As part of co-operation between UCLA (U.S.) with JAERI (Japan) on executing the required neutronics R ampersand D tasks for ITER shield design, two bulk shielding experiments on large SS316 assemblies were selected for benchmarking FENDL/MG-1 multigroup data base and FENDL/MC-1 continous energy data base. The analyses with the multigroup data (performed with S8, P5, DORT calculations with shielded and unshielded data) also included library derived from ENDF/B-VI data base for comparison purposes. The MCNP Monte Carlo code was used by JAERI with the FENDL/MC-1 data. The results of this benchmarking is reported in this paper along with the observed deficiencies and discrepancies. 20 refs., 27 figs., 1 tab

  16. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation. PMID:26566111

  17. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  18. On the dynamics of segregation

    OpenAIRE

    Jofre-Monseny, Jordi; Dahlberg, Matz; Fredriksson, Peter

    2012-01-01

    Card et al (2008a) formalize a model of ethnic residential segregation where an ethnically mixed neighborhood is dynamically stable until its minority share reaches a threshold (the tipping point). Once the neighborhood has surpassed the tipping point, it will experience massive white flight. These authors propose methods to identify tipping points and, using population counts at the US Census tract level, find that tipping is a salient feature of neighborhood dynamics. The objective of this ...

  19. Segregation of alloying atoms on the Fe(1 0 0) surface and their effects on oxygen adsorption

    International Nuclear Information System (INIS)

    The segregation of 3d transition metals and their effects on oxygen adsorption on the Fe(1 0 0) surface are systematically studied using the first-principles calculations. On the one hand, Sc, Ti, Mn, Ni, Cu, and Zn have a tendency to segregate towards the surface, while V, Cr, and Co prefer to remain in the interior of Fe bulk. Furthermore, the segregation energies varies monotonically from layers 1–5 for all 3d transition metals except Ti, Cr, Mn, whose subsurface layer provides a large barrier for surface segregation. On the other hand, attractive/repulsive interaction has been observed between oxygen and alloying atom with lower/higher atomic number than that of Fe. Based on the above results, the oxidation should be expected to occur preferentially at the Sc, Ti, and Mn segregation regions on the Fe(1 0 0) surface

  20. Experience on domestic waste segregation in Ghana

    Directory of Open Access Journals (Sweden)

    Osei Bonsu Patterson

    2013-06-01

    Full Text Available Pollution from domestic wastes is a major environmental challenge in Ghana and many developing countries. Most of these countries depend almost entirely on landfills for waste management, which has proved to be expensive, inefficient and unsustainable. A sustainable solution to this problem is productive use of waste such as recycling. The main challenge that may limit recycling in Ghana and some of these countries is that a chunk of the wastes are littered on the environment, and the rest is collected in bulk in the same waste bin, thereby mixing them. The cost of collecting littered wastes, or separating mixed wastes could be prohibitive, making recycling uneconomical. In order to productively utilize wastes, adequate and separate waste bins must be provided for collecting the different components of wastes. However, budgetary constraints may not allow many countries to purchase expansive waste bins for the different components of wastes. Consequently, a simple waste bin, comprising a metal frame on which polypropylene sack (pp-sack can be hanged to collect inorganic wastes has been developed by the author. The waste bin (new bin can be manufactured industrially using plastic or fabricated by local artisans at an affordable price. This document describes the new bin. Experience in collecting organic and inorganic wastes generated in a house in separate waste bins (waste segregation for the past 16 years is also highlighted.

  1. Organization of texture segregation processing in primate visual cortex.

    Science.gov (United States)

    Lamme, V A; van Dijk, B W; Spekereijse, H

    1993-01-01

    We investigated the intracortical organization of neuronal mass activity that is related to texture segregation on the basis of orientation contrast. Evoked potentials were recorded to a stimulus, signalling a contribution from texture segregation-sensitive mechanisms by means of specific response components. The specific components could only be recorded when textons had a spatial organization that leads to the percept of image segmentation. Equivalent dipole estimations of the specific response components suggested the presence of texture segregation-related activity in the primary visual cortex. These results were corroborated by current-source-density analysis of intracortical recordings in the awake monkey. A specific involvement of layers 2/3 and 5 of area 17 in the global process of image segmentation could be demonstrated. PMID:8217932

  2. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    Energy Technology Data Exchange (ETDEWEB)

    Word, J Q; Ward, J A; Woodruff, D L

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs.

  3. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    International Nuclear Information System (INIS)

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs

  4. Diffusion and bulk flow in phloem loading: a theoretical analysis of the polymer trap mechanism for sugar transport in plants.

    Science.gov (United States)

    Dölger, Julia; Rademaker, Hanna; Liesche, Johannes; Schulz, Alexander; Bohr, Tomas

    2014-10-01

    Plants create sugar in the mesophyll cells of their leaves by photosynthesis. This sugar, mostly sucrose, has to be loaded via the bundle sheath into the phloem vascular system (the sieve elements), where it is distributed to growing parts of the plant. We analyze the feasibility of a particular loading mechanism, active symplasmic loading, also called the polymer trap mechanism, where sucrose is transformed into heavier sugars, such as raffinose and stachyose, in the intermediary-type companion cells bordering the sieve elements in the minor veins of the phloem. Keeping the heavier sugars from diffusing back requires that the plasmodesmata connecting the bundle sheath with the intermediary cell act as extremely precise filters, which are able to distinguish between molecules that differ by less than 20% in size. In our modeling, we take into account the coupled water and sugar movement across the relevant interfaces, without explicitly considering the chemical reactions transforming the sucrose into the heavier sugars. Based on the available data for plasmodesmata geometry, sugar concentrations, and flux rates, we conclude that this mechanism can in principle function, but that it requires pores of molecular sizes. Comparing with the somewhat uncertain experimental values for sugar export rates, we expect the pores to be only 5%-10% larger than the hydraulic radius of the sucrose molecules. We find that the water flow through the plasmodesmata, which has not been quantified before, contributes only 10%-20% to the sucrose flux into the intermediary cells, while the main part is transported by diffusion. On the other hand, the subsequent sugar translocation into the sieve elements would very likely be carried predominantly by bulk water flow through the plasmodesmata. Thus, in contrast to apoplasmic loaders, all the necessary water for phloem translocation would be supplied in this way with no need for additional water uptake across the plasma membranes of the

  5. An overview of nuclear micro-beam analysis of surface and bulk fuel retention in carbon-fibre composites from Tore Supra

    International Nuclear Information System (INIS)

    Surface and bulk retention of deuterium in tiles of the pump limiter from Tore Supra was examined with nuclear reaction analysis using both standard and micro-beam techniques. The aim was to determine the variations in the content and distribution of fuel species in carbon-fibre composites. On plasma-facing surfaces from the deposition zone, the D content reaches 2.5 x 1019 cm-2 in about 8 μm thick top layer, but lateral differences reach even more than one order of magnitude. This is also measured in the erosion zone: 6.6 x 1017 cm-2 to 7.7 x 1018 cm-2 D atoms. Bulk content was examined on cross-sections opened by fracturing the tiles. Fuel is detected up to the depth of 1-1.5 mm beneath the plasma-facing surface in tiles from both the erosion and deposition zones. It occurs in bands, about 100 μm wide and several mm long, roughly parallel to the original plasma-facing surface.

  6. Gamma-ray analysis for U, Th and K on bulk cutting samples from deep wells in the Danish Subbasin and the North German Basin

    International Nuclear Information System (INIS)

    A total of 1329 bulk cutting samples from deep wells in Denmark were analysed for U, Th and K by laboratory gamma-ray analysis. Contamination of the samples by drilling mud additives, mud solids and fall down was studied by means of a wash down experiment and by comparison with the total gamma-ray response from wireline logging. It is concluded that the inorganic geochemistry on bulk cutting samples must be applied with great caution. The data are useful for geochemical characterization of well sections and for regional geochemical correlation. Radioelement abundance logs and radioelement ratio logs are presented from 3 wells in the Danish Subbasin and 2 wells in the North German Basin. The radioelement geochemistry is discussed for the successive lithostratigraphical units and a reference radioelement profile is established for the central part of the Danish Subbasin. Finally, a model describing the relationship between common lithofacies and their U content and Th/U ratio is suggested. The model deliniates the depositional environment and the relative distances to the provenance areas. It is concluded that: (1) Uranium is mobile during deposition, but since then it is fixed by stable mineral phases at depth; (2) Thorium reflects source area characteristics and that any available ions are readily adsorbed by clay minerals. Thorium anomalies may thus serve as lithostratigraphical markers; (3) Potassium occurs in unstable rock forming mineral phases. The present distribution is controlled not only by the clastic mineral assemblage, but also by the diagenetic processes through geologic time

  7. Cluster analysis of the organic peaks in bulk mass spectra obtained during the 2002 New England Air Quality Study with an Aerodyne aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    C. Marcolli

    2006-06-01

    Full Text Available We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS bulk mass spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter most probably originating from both, anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent as much as 5 µg/m3 organic aerosol mass – 17% of the total organic mass – that can be attributed to biogenic sources. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

  8. Cluster Analysis of the Organic Peaks in Bulk Mass Spectra Obtained During the 2002 New England Air Quality Study with an Aerodyne Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    C. Marcolli

    2006-01-01

    Full Text Available We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS bulk mass spectral dataset collected aboard the NOAA research vessel R. H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter probably originating from both anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent on average 17% of the total organic mass that stems likely from biogenic sources during the ship's cruise. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

  9. New atom probe approaches to studying segregation in nanocrystalline materials

    Energy Technology Data Exchange (ETDEWEB)

    Samudrala, S.K.; Felfer, P.J.; Araullo-Peters, V.J. [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006 (Australia); The Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia); Cao, Y.; Liao, X.Z. [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006 (Australia); Cairney, J.M., E-mail: julie.cairney@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006 (Australia); The Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia)

    2013-09-15

    Atom probe is a technique that is highly suited to the study of nanocrystalline materials. It can provide accurate atomic-scale information about the composition of grain boundaries in three dimensions. In this paper we have analysed the microstructure of a nanocrystalline super-duplex stainless steel prepared by high pressure torsion (HPT). Not all of the grain boundaries in this alloy display obvious segregation, making visualisation of the microstructure challenging. In addition, the grain boundaries present in the atom probe data acquired from this alloy have complex shapes that are curved at the scale of the dataset and the interfacial excess varies considerably over the boundaries, making the accurate characterisation of the distribution of solute challenging using existing analysis techniques. In this paper we present two new data treatment methods that allow the visualisation of boundaries with little or no segregation, the delineation of boundaries for further analysis and the quantitative analysis of Gibbsian interfacial excess at boundaries, including the capability of excess mapping. - Highlights: ► New data treatment methods allow delineation of grain boundaries, even without segregation. ► Proxigrams calculated from the surfaces accurately show the extent of segregation. ► Tessellation of the data volume can be used to map the Gibbsian interfacial excess.

  10. New atom probe approaches to studying segregation in nanocrystalline materials

    International Nuclear Information System (INIS)

    Atom probe is a technique that is highly suited to the study of nanocrystalline materials. It can provide accurate atomic-scale information about the composition of grain boundaries in three dimensions. In this paper we have analysed the microstructure of a nanocrystalline super-duplex stainless steel prepared by high pressure torsion (HPT). Not all of the grain boundaries in this alloy display obvious segregation, making visualisation of the microstructure challenging. In addition, the grain boundaries present in the atom probe data acquired from this alloy have complex shapes that are curved at the scale of the dataset and the interfacial excess varies considerably over the boundaries, making the accurate characterisation of the distribution of solute challenging using existing analysis techniques. In this paper we present two new data treatment methods that allow the visualisation of boundaries with little or no segregation, the delineation of boundaries for further analysis and the quantitative analysis of Gibbsian interfacial excess at boundaries, including the capability of excess mapping. - Highlights: ► New data treatment methods allow delineation of grain boundaries, even without segregation. ► Proxigrams calculated from the surfaces accurately show the extent of segregation. ► Tessellation of the data volume can be used to map the Gibbsian interfacial excess

  11. Comparative analysis of the intrinsic voltage gain and unit gain frequency between SOI and bulk FinFETs up to high temperatures

    Science.gov (United States)

    Oliveira, Alberto Vinicius de; Agopian, Paula Ghedini Der; Martino, Joao Antonio; Simoen, Eddy; Claeys, Cor; Collaert, Nadine; Thean, Aaron

    2016-09-01

    This paper presents an experimental analysis of the analog application figures of merit: the intrinsic voltage gain (AV) and unit gain frequency, focusing on the performance comparison between silicon triple gate pFinFET devices, which were processed on both Si and Silicon-On-Insulator (SOI) substrates. The high temperature (from 25 °C to 150 °C) influence and different channel lengths and fin widths were also taken into account. While the temperature impact on the intrinsic voltage gain (AV) is limited, the unit gain frequency was strongly affected due to the carrier mobility degradation at higher temperatures, for both p- and n-type FinFET structures. In addition, the pFinFETs showed slightly larger AV values compared to the n-type counterparts, whereby the bulk FinFETs presented a higher dispersion than the SOI FinFETs.

  12. Improvement in the chemical separation and determination of uncertainties for bulk analysis of Pu isotopes at ultra-trace levels by using MC-ICP-MS

    International Nuclear Information System (INIS)

    Improved bulk analysis based on extraction chromatography and systematic evaluations of uncertainties of plutonium isotopes at ultra-trace levels in environmental swipe samples are presented. In the modified method based on a single column system using UTEVA resin for MC-ICP-MS, hydrogen peroxide was introduced to obtain pure plutonium isotopes from chemical separation by removing excess organic-based reducing reagents. We confirmed that hydrogen peroxide effectively decomposed the reducing reagents characterized by UV-Vis absorption spectroscopy and the peak fluctuations were significantly reduced. To examine the reliability of analytical performance, we systematically evaluated the combined uncertainties during the overall chemical procedures using simulated samples containing Pu reference materials. (author)

  13. Occurrence of enterotoxin genes and macrorestriction analysis of Staphylococcus aureus isolated from bovine mastitis and bulk-tank milk samples in Italy. An epidemiological study

    Directory of Open Access Journals (Sweden)

    Roberto Rosmini

    2010-01-01

    Full Text Available The goal of the study was to genotypically compare S. aureus isolates from mastitis milk and raw milk to identify therelation between strains and to assess the enterotoxigenicity of the isolates. Eighty-three Staphylococcus aureus isolatesrecovered from cows and bulk tank milk of five farms in northern Italy were compared genotypically. The genes for theenterotoxins A, D, G and I, but not for B, C, E and H and the toxic shock syndrome toxin 1 (TSST-1, were detected byPCR amplification. Macrorestriction analysis with the restrictions enzyme SmaI revealed 14 pulsed-field gel electrophoresispatterns. These were in part different from each other only in a few fragments and thus displayed a closeclonal relation. The results of the present investigation showed that identical or closely related clones seemed to beresponsible for the cases of bovine mastitis in the farms investigated and partly responsible for contamination of bulktank milk.

  14. Advanced numerical technique for analysis of surface and bulk acoustic waves in resonators using periodic metal gratings

    Science.gov (United States)

    Naumenko, Natalya F.

    2014-09-01

    A numerical technique characterized by a unified approach for the analysis of different types of acoustic waves utilized in resonators in which a periodic metal grating is used for excitation and reflection of such waves is described. The combination of the Finite Element Method analysis of the electrode domain with the Spectral Domain Analysis (SDA) applied to the adjacent upper and lower semi-infinite regions, which may be multilayered and include air as a special case of a dielectric material, enables rigorous simulation of the admittance in resonators using surface acoustic waves, Love waves, plate modes including Lamb waves, Stonely waves, and other waves propagating along the interface between two media, and waves with transient structure between the mentioned types. The matrix formalism with improved convergence incorporated into SDA provides fast and robust simulation for multilayered structures with arbitrary thickness of each layer. The described technique is illustrated by a few examples of its application to various combinations of LiNbO3, isotropic silicon dioxide and silicon with a periodic array of Cu electrodes. The wave characteristics extracted from the admittance functions change continuously with the variation of the film and plate thicknesses over wide ranges, even when the wave nature changes. The transformation of the wave nature with the variation of the layer thicknesses is illustrated by diagrams and contour plots of the displacements calculated at resonant frequencies.

  15. GRAIN BOUNDARY SEGREGATIONS AND HYDROGEN EMBRITTLEMENT

    OpenAIRE

    Aucouturier, M.

    1982-01-01

    The relation between grain boundary segregation and hydrogen embrittlement of metals may be discussed from two stand points : 1°) Hydrogen has a strong tendency to segregate in structure defects, among them, in grain boundaries. Hydrogen segregation controls the properties of hydrogenated materials in many cases (hydrogen diffusion, hydrogen induced cracking, electrical properties in semiconductors, etc) and more precisely their mechanical behaviour (embrittlement itself). 2°) The occurence o...

  16. Gender segregation : from birth to occupation

    OpenAIRE

    Ruiz-Castillo, Javier; Mora, Ricardo

    2003-01-01

    Most of the existing literature studies the gender segregation induced by occupational choices in the employed population. This paper also studies the segregation induced by age/education characteristics and labor market participation decisions in the population consisting of non-students of working age. The gender segregation index used, related to the entropy notion in information theory, is additively decomposable for any partition and it has a commutability property. The em...

  17. From particle segregation to the granular clock

    OpenAIRE

    Lambiotte, R.; Salazar, J. M.; Brenig, L.

    2005-01-01

    Recently several authors studied the segregation of particles for a system composed of mono-dispersed inelastic spheres contained in a box divided by a wall in the middle. The system exhibited a symmetry breaking leading to an overpopulation of particles in one side of the box. Here we study the segregation of a mixture of particles composed of inelastic hard spheres and fluidized by a vibrating wall. Our numerical simulations show a rich phenomenology: horizontal segregation and periodic beh...

  18. The Spatial Context of Residential Segregation

    OpenAIRE

    Roberto, Elizabeth

    2015-01-01

    Residential segregation is defined in a variety of ways to address a common concern: to what extent do social groups reside in separate or distinct places. The spatial pattern of segregation varies widely across cities, and distinct spatial patterns can be generated by different mechanisms and have different consequences for residents and their communities. However, the methods commonly employed to measure segregation ignore how a city is spatially organized. They do not take into account the...

  19. Segregation and Urban Unrest in Sweden

    OpenAIRE

    Malmberg, Bo; Eva, Andersson; Östh, John

    2013-01-01

    In 2009, Sweden experienced a wave of urban unrest concentrated in areas with large foreign-born populations. This episode was seen by many as reflecting a trend towards increased ethnically based residential segregation, in line with scholarly literatures that correlate inequality and rising segregation with increases in unrest or rebellion. In this paper, we analyze the empirical connection between ethnic residential segregation and episodes of urban unrest in Sweden. Unrest is measured by ...

  20. Socio-spatial lifestyles and segregation

    OpenAIRE

    Izhak, Schnell; Yoav, Benjamini

    1999-01-01

    The paper suggests an alternative index for socio-spatial segregation which emphasises agents’ segregation in everyday life. We argue that segregation should be studied for individual agents in respect to the spaces in which they perform their everyday life. The index refers both to the spatial and the social-interactive contexts of seven aspects (home, cluster of neighbouring homes, neighbourhood and city in the spatial context and friends, work and leisure activities in the social context) ...

  1. Nano-scale solute partitioning in devitrified bulk metallic glass

    International Nuclear Information System (INIS)

    Devitrification of bulk metallic glass leads to a novel microstructure, with high-density nanoscale crystalline precipitates evenly distributed in a glassy matrix. Significant chemical segregation is revealed at unprecedented detail by atom-probe tomography. This level of detail is crucial for understanding the interference peaks observed in small-angle X-ray and neutron scattering experiments, an unsolved mystery for over a decade

  2. DIFFUSION AND EQUILIBRIUM SEGREGATION IN GRAIN BOUNDARIES : EFFECTS OF LARGE SEGREGATION

    OpenAIRE

    Bernardini, J.; Cabane, F.

    1985-01-01

    From recent experiments in binary and ternary solid solutions, we discuss the determination of grain boundary diffusion coefficients, some structural aspects of diffusion and segregation and the influence of segregation on impurity diffusion.

  3. From particle segregation to the granular clock

    Energy Technology Data Exchange (ETDEWEB)

    Lambiotte, R. [Physique Statistique, Plasmas et Optique Non-lineaire, Universite Libre de Bruxelles, Campus Plaine, Boulevard du Triomphe, Code Postal 231, 1050 Brussels (Belgium)]. E-mail: rlambiot@ulb.ac.be; Salazar, J.M. [Universite De Bougogne-LRRS UMR-5613 CNRS, Faculte des Sciences Mirande, 9 Av. Alain Savary, 21078 Dijon Cedex (France)]. E-mail: jmarcos@u-bourgogne.fr; Brenig, L. [Physique Statistique, Plasmas et Optique Non-lineaire, Universite Libre de Bruxelles, Campus Plaine, Boulevard du Triomphe, Code Postal 231, 1050 Brussels (Belgium)]. E-mail: lbrenig@ulb.ac.be

    2005-08-01

    Recently several authors studied the segregation of particles for a system composed of mono-dispersed inelastic spheres contained in a box divided by a wall in the middle. The system exhibited a symmetry breaking leading to an overpopulation of particles in one side of the box. Here we study the segregation of a mixture of particles composed of inelastic hard spheres and fluidized by a vibrating wall. Our numerical simulations show a rich phenomenology: horizontal segregation and periodic behavior. We also propose an empirical system of ODEs representing the proportion of each type of particles and the segregation flux of particles. These equations reproduce the major features observed by the simulations.

  4. From particle segregation to the granular clock

    International Nuclear Information System (INIS)

    Recently several authors studied the segregation of particles for a system composed of mono-dispersed inelastic spheres contained in a box divided by a wall in the middle. The system exhibited a symmetry breaking leading to an overpopulation of particles in one side of the box. Here we study the segregation of a mixture of particles composed of inelastic hard spheres and fluidized by a vibrating wall. Our numerical simulations show a rich phenomenology: horizontal segregation and periodic behavior. We also propose an empirical system of ODEs representing the proportion of each type of particles and the segregation flux of particles. These equations reproduce the major features observed by the simulations

  5. Housing Systems and Ethnic Spatial Segregation

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter; Andersson, Roger; Wessel, Terje;

    Residential spatial segregation is related to housing markets and housing policies. In this paper, ethnic segregation is compared across four Nordic capitals and explanations for the differences are examined by comparing the housing markets and housing policies of the countries. The housing markets...... composition of neighbourhoods. Ethnic segmentation of housing tenures thus contributes to segregation, but the effect is much dependent on how tenures are distributed across space. In one of the cities, the policy of neighbourhood tenure mix has resulted in a relatively low degree of segregation in spite of...

  6. Dynamics of chromosome segregation in Escherichia coli

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck

    2007-01-01

    Since the 1960’es the conformation and segregation of the chromosome in Escherichia coli has been a subject of interest for many scientists. However, after 40 years of research, we still know incredibly little about how the chromosome is organized inside the cell, how it manages to duplicate this...... and reliable method enabled us to start the analysis on the distribution of various chromosomal loci inside slowly growing cells. With the actual counting and measuring no longer being any problem we could easily analyze 14 loci distributed on the E.coli chromosome. More than 15.000 cells were...... on the P1 par system. Using the new system, which is based on the pMT1 par system from Yersenia pestis, we labeled loci on opposite sides of the E.coli chromosome simultaneously and were able to show that the E.coli chromosome is organized with one chromosomal arm in each cell half. This astounding...

  7. Inductive Double-Contingency Analysis of UO2 Powder Bulk Blending Operations at a Commercial Fuel Plant (U)

    International Nuclear Information System (INIS)

    An inductive double-contingency analysis (DCA) method developed by the criticality safety function at the Savannah River Site, was applied in Criticality Safety Evaluations (CSEs) of five major plant process systems at the Westinghouse Electric Corporation's Commercial Nuclear Fuel Manufacturing Plant in Columbia, South Carolina (WEC-Cola.). The method emphasizes a thorough evaluation of the controls intended to provide barriers against criticality for postulated initiating events, and has been demonstrated effective at identifying common mode failure potential and interdependence among multiple controls. A description of the method and an example of its application is provided

  8. Bulk undercooling, nucleation, and macrosegregation of Pb-Sn alloys

    Science.gov (United States)

    Degroh, H. C., III; Laxmanan, V.

    1988-01-01

    Preliminary ground-based studies on the undercooling behavior of large samples (23 g) of lead-tin alloys are presented. Evidence of gravity-related segregation effects is found, and a possible area for future microgravity experimentation is thus identified. Detailed descriptions of the experimental procedure used to achieve bulk undercoolings of between 0.5 and 34 K, depending on composition, are given. The bulk undercoolings obtained in this study are comparable with those found in small droplets. The large size of the present samples enabled the observation of sedimentation and other macrosegregation processes.

  9. Back to the roots: segregation of univalent sex chromosomes in meiosis.

    Science.gov (United States)

    Fabig, Gunar; Müller-Reichert, Thomas; Paliulis, Leocadia V

    2016-06-01

    In males of many taxa, univalent sex chromosomes normally segregate during the first meiotic division, and analysis of sex chromosome segregation was foundational for the chromosome theory of inheritance. Correct segregation of single or multiple univalent sex chromosomes occurs in a cellular environment where every other chromosome is a bivalent that is being partitioned into homologous chromosomes at anaphase I. The mechanics of univalent chromosome segregation vary among animal taxa. In some, univalents establish syntelic attachment of sister kinetochores to the spindle. In others, amphitelic attachment is established. Here, we review how this problem of segregation of unpaired chromosomes is solved in different animal systems. In addition, we give a short outlook of how mechanistic insights into this process could be gained by explicitly studying model organisms, such as Caenorhabditis elegans. PMID:26511278

  10. Experimental analysis of segregation and porosity during the transient unidirectional solidification of an Al-9%Si-3%Cu ternary; Analise experimental da macrossegregacao e porosidade durante a solidificacao unidirecional transitoria de uma liga ternaria Al-9%Si-3%Cu

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, L.G.; Moutinho, D.J.; Rocha, O.L., E-mail: lgouvea@fem.unicamp.b [Instituto Federal de Educacao, Ciencia e Tecnologia do Para (IFPA), Belem, PA (Brazil); Ferreira, I.L. [Universidade Federal Fluminense (DEM/UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica; Garcia, A. [Universidade Estadual de Campinas (DEMa/UNICAMP), SP (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    The solute macro segregation and formation of micro porosity were experimental y investigated in the transient unidirectional solidification of a ternary league. The solute macro segregation profile, the specific theoretical mass and the apparent specific mass are presented alongside of ingot length. The experimental segregation profile of the solute were obtained through the X ray fluorescence spectrometry technique. The micro porosity measurements were performed by using the technique of picnometry. The presence of silicon on the league acted as inhibitor of inverse segregation of the copper, which is a typically observed in the transient unidirectional solidified of Al-Cu leagues. The volumetric fractions of porous has shown a ascendent tendency from the base to the top of ingot

  11. Resolving the bulk δ 15N values of ancient human and animal bone collagen via compound-specific nitrogen isotope analysis of constituent amino acids

    Science.gov (United States)

    Styring, Amy K.; Sealy, Judith C.; Evershed, Richard P.

    2010-01-01

    Stable nitrogen isotope analysis is a fundamental tool in assessing dietary preferences and trophic positions within contemporary and ancient ecosystems. In order to assess more fully the dietary contributions to human tissue isotope values, a greater understanding of the complex biochemical and physiological factors which underpin bulk collagen δ 15N values is necessary. Determinations of δ 15N values of the individual amino acids which constitute bone collagen are necessary to unravel these relationships, since different amino acids display different δ 15N values according to their biosynthetic origins. A range of collagen isolates from archaeological faunal and human bone ( n = 12 and 11, respectively), representing a spectrum of terrestrial and marine protein origins and diets, were selected from coastal and near-coastal sites at the south-western tip of Africa. The collagens were hydrolysed and δ 15N values of their constituent amino acids determined as N-acetylmethyl esters (NACME) via gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The analytical approach employed accounts for 56% of bone collagen nitrogen. Reconstruction of bulk bone collagen δ 15N values reveals a 2‰ offset from bulk collagen δ 15N values which is attributable to the δ 15N value of the amino acids which cannot currently be determined by GC-C-IRMS, notably arginine which comprises 53% of the nitrogen unaccounted for (23% of the total nitrogen). The δ 15N values of individual amino acids provide insights into both the contributions of various amino acids to the bulk δ 15N value of collagen and the factors influencing trophic position and the nitrogen source at the base of the food web. The similarity in the δ 15N values of alanine, glutamate, proline and hydroxyproline reflects the common origin of their amino groups from glutamate. The depletion in the δ 15N value of threonine with increasing trophic level indicates a fundamental difference between

  12. Inflation from bulk viscosity

    CERN Document Server

    Bamba, Kazuharu

    2015-01-01

    We explore the perfect fluid description of the inflationary universe. In particular, we investigate a fluid model with the bulk-viscosity term. We find that the three observables of inflationary cosmology: the spectral index of the curvature perturbations, the tensor-to-scalar ratio of the density perturbations, and the running of the spectral index, can be consistent with the recent Planck results. We also reconstruct the explicit equation of state (EoS) of the viscous fluid from the spectral index of the curvature perturbations compatible with the Planck analysis. In the reconstructed models of the viscous fluid, the tensor-to-scalar ratio of the density perturbations can satisfy the constraints obtained from the Planck satellite. The running of the spectral index can explain the Planck data. In addition, it is demonstrated that in the reconstructed models of the viscous fluid, the graceful exit from inflation can be realized. Furthermore, we show that the singular inflation can occur in the viscous fluid ...

  13. Gamma-ray analysis for U, TH and K on bulk cutting samples from deep wells in the Danish subbasin and the North German basin

    International Nuclear Information System (INIS)

    A total of 1329 bulk cutting samples from deep wells in Denmark were analysed for U, Th and K by laboratory gamma-ray analysis. Contamination of the samples by drilling mud additives, mud solids and fall down was studied by means of a wash down experiment and by comparison with the total gamma-ray response from wire-line logging. It is concluded that the inorganic geochemistry on bulk cutting samples must be applied with great caution. The data are useful for geochemical characterization of well sections and for regional geochemical correlation. Radioelement abundance logs and radioelement ratio logs are presented from 3 wells in the Danish Subbasin and 2 wells in the North German Basin. The radioelement geochemistry is discussed for the successive lithostratigraphical units and a reference radio element profile is established for the central part of the Danish Subbasin. Finally, a model describing the relationship between common lithofacies and their U content and Th/U ratio is suggested. The model deliniates the depositional environment and the relative distances to the provenance areas. It is concluded that 1) Uranium is mobile during deposition, but since then it is fixed by stable mineral phases at depth. 2) Thorium reflects source area characteristics and that any available ions are readily adsorped by clay minerals. Thorium anomalies may thus serve as lithostratigraphical markers. 3) Potassium occurs in unstable rock forming mineral phases. The present distribution is controlled not only by the clastic mineral assemblage, but also by the diagenetic processes through geologic time. 33 refs. (author)

  14. Multivariate Chemometric Assisted Analysis of Metformin Hydrochloride, Gliclazide and Pioglitazone Hydrochloride in Bulk Drug and Dosage Forms

    Directory of Open Access Journals (Sweden)

    Vipin Saini

    2013-02-01

    Full Text Available Purpose: In this work a numerical method, based on the use of spectrophotometric data coupled to partial least squares (PLS regression and net analyte preprocessing combined with classical least square (NAP/CLS multivariate calibration, is reported for the simultaneous determination of metformin hydrochloride (MET, gliclazide (GLZ and pioglitazone hydrochloride (PIO in synthetic samples and combined commercial tablets. Methods: Spectra of MET, GLZ and PIO were recorded at concentrations within their linear ranges (5-25 μg/ml, 0.5-8 μg/ml and 0.5-3 μg/ml respectively and were used to compute a total of 25 synthetic mixtures involving 15 calibration and 10 validation sets between wavelength range of 200 and 400 nm in 0.1N HCl. The suitability of the models was decided on the basis of root mean square error (RMSE values of calibration and validation data. Results: The analytical performances of these chemometric methods were characterized by relative prediction errors and recovery studies (% and were compared with each other. These two methods were successfully applied to pharmaceutical formulation, tablet, with no interference with excipients as indicated by the recovery study results. Mean recoveries of the commercial formulation set together with the figures of merit (calibration sensitivity, selectivity, limit of detection, limit of quantification etc. were estimated. Conclusion: The proposed methods are simple, rapid and can be easily used as an alternative analysis tool in the quality control of drugs and formulation.

  15. A Validated New Gradient Stability-Indicating LC Method for the Analysis of Doripenem in Bulk and Injection Formulation

    Directory of Open Access Journals (Sweden)

    Singaram Kathirvel

    2013-01-01

    Full Text Available A sensitive, precise, specific, linear, and stability-indicating gradient HPLC method was developed for the estimation of doripenem in active pharmaceutical ingredient (API and in injectable preparations. Chromatographic separation was achieved on C18 stationary phase with a mobile phase gradient consisting of acetonitrile, methanol, and pH 5.2 phosphate buffer. The mobile phase flow rate was 0.8 mL/min, and the eluted compounds were monitored at 210 nm. The method is linear over the range of 0.335 to 76.129 µg/mL. The correlation coefficient was found to be 0.999. The numbers of theoretical plates and tailing factor for doripenem were 53021 and 0.9, respectively. Doripenem was subjected to the International Conference on Harmonization (ICH prescribed hydrolytic (acid, base, and neutral, oxidative, photolytic, and thermal stress conditions. Among all the above-mentioned conditions, the drug was found to be stable under photolytic degradation. Peak homogeneity data for doripenem in the chromatograms from the stressed samples obtained by use of the photodiode array detector demonstrated the specificity of the method for analysis of doripenem in presence of the degradation products. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, and robustness.

  16. Unpackaging residential segregation: the importance of scale and informal market processes

    Directory of Open Access Journals (Sweden)

    Peter M. Ward

    2009-01-01

    further argue a case that such isolated (rural settlements serving nearby urban labor market, should also be included in any analysis of urban segregation patterns, even if they do not form part of the contiguous urban area.

  17. A mechanistic study of impurity segregation at silicon grain boundaries

    International Nuclear Information System (INIS)

    The segregation behavior of carbon and oxygen atoms at various silicon grain boundaries was studied using a combination of atomistic simulation and analytical modeling. First, quasi-lattice Grand Canonical Monte Carlo simulations were used to compute segregation isotherms as a function of grain boundary type, impurity atom loading level, and temperature. Next, the atomistic results were employed to regress different analytical segregation models and extract thermodynamic and structural properties. The multilayer Brunauer–Emmett–Teller (BET) isotherm was found to quantitatively capture all the simulation conditions probed in this work, while simpler, single layer models such as the Langmuir-McLean model did not. Some of the BET parameters, namely, the binding free energy of the first adsorption layer and the impurity holding capacity of each layer, were tested for correlation with various measures of grain boundary structure and/or mechanical properties. It was found that certain measures of the atomistic stress distribution correlate strongly with the first-layer binding free energy for substitutional carbon atoms, while common grain boundary identifiers such as sigma value and energy density are not useful in this regard. Preliminary analysis of the more complex case of interstitial oxygen segregation showed that similar measures based on atomistic stress also may be useful here, but more systematic correlative studies are needed to develop a comprehensive picture

  18. PARTICLE SEGREGATION IN FLUIDIZED BINARY-MIXTURES

    NARCIS (Netherlands)

    HOFFMANN, AC; JANSSEN, LPBM

    1993-01-01

    The particle segregation in fluidised beds consisting of different types of binary mixtures is shown to be governed by the same particle transport processes. The segregation behaviour of both ''different-density mixtures'' and ''equal-density mixtures'', two types of system which until now largely h

  19. Losing Ground: School Segregation in Massachuestts

    Science.gov (United States)

    Ayscue, Jennifer B.; Greenberg, Alyssa

    2013-01-01

    Though once a leader in school integration, Massachusetts has regressed over the last two decades as its students of color have experienced intensifying school segregation. This report investigates trends in school segregation in Massachusetts by examining concentration, exposure, and evenness measures by both race and class. First, the report…

  20. 17 CFR 32.6 - Segregation.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Segregation. 32.6 Section 32.6 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION REGULATION OF COMMODITY OPTION TRANSACTIONS § 32.6 Segregation. (a) Any person which accepts money, securities, or property from an...

  1. 49 CFR 176.708 - Segregation distances.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Segregation distances. 176.708 Section 176.708... Requirements for Radioactive Materials § 176.708 Segregation distances. (a) Table IV lists minimum separation... into account any relocation of cargo during the voyage. (e) Any departure from the...

  2. Ising, Schelling and Self-Organising Segregation

    CERN Document Server

    Stauffer, D

    2007-01-01

    The similarities between phase separation in physics and residential segregation by preference in the Schelling model of 1971 are reviewed. Also, new computer simulations of asymmetric interactions different from the usual Ising model are presented, showing spontaneous magnetisation (= self-organising segregation) and in one case a sharp phase transition.

  3. Residential Segregation: Challenge to White America.

    Science.gov (United States)

    Denton, Nancy A.

    1994-01-01

    Examines the problem of residential segregation and demonstrates that it is a problem of social structure. The author contends that residential segregation has affirmed the continued subordination of blacks in American society over the past 50 years. New leadership in the Department of Housing and Urban Development is viewed as a positive…

  4. Progressive segregation of the Escherichia coli chromosome

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.;

    2006-01-01

    We have followed the fate of 14 different loci around the Escherichia coli chromosome in living cells at slow growth rate using a highly efficient labelling system and automated measurements. Loci are segregated as they are replicated, but with a marked delay. Most markers segregate in a smooth...

  5. Interfacial analysis of the ex-situ reinforced phase of a laser spot welded Zr-based bulk metallic glass composite

    International Nuclear Information System (INIS)

    To study the interfacial reaction of the ex-situ reinforced phase (Ta) of a Zr-based ((Zr48Cu36Al8Ag8)Si0.75 + Ta5) bulk metallic glass composite after laser spot welding, the interfacial regions of the reinforced phases located at specific zones in the welds including the parent material, weld fusion zone and heat affected zone were investigated. Specimen preparation from the specific zones for transmission electron microscopy analysis was performed using the focused ion beam technique. The test results showed that the reinforced phases in the parent material, weld fusion zone and heat affected zone were all covered by an interfacial layer. From microstructure analysis, and referring to the phase diagram, it was clear that the thin layers are an intermetallic compound ZrCu phase. However, due to their different formation processes, those layers show the different morphologies or thicknesses. - Highlights: • An ex-situ Zr-based BMG composite was laser spot welded. • The interfacial regions of the RPs located at PM, WFZ and HAZ were investigated. • The RPs in the PM, WFZ and HAZ were all covered by a ZrCu interfacial layer. • Due to different formation processes, those layers show the different morphology

  6. The Spatial Context of Residential Segregation

    CERN Document Server

    Roberto, Elizabeth

    2015-01-01

    Scholars have engaged in a longstanding debate about how best to measure residential segregation, and scores of indexes have been developed in response. However, the methods commonly employed are aspatial -- they summarize the characteristics of segregation patterns, such as concentration or clustering, but ignore their spatial features, such as how neighborhoods are spatially arranged. As a consequence, many studies find the same level of segregation whether a city has a patchwork of racial and ethnic enclaves, or is divided into large areas with little or no diversity. New methods have been developed to capture the spatial proximity of neighborhoods and the geographic scale of clustering. However, they lack a realistic measure of distance and do not accurately represent how segregation varies within cities. In this paper, I introduce a new method for studying the spatial context of residential segregation. I measure the distance between locations along city roads rather than in a straight line. Road distanc...

  7. Simple queueing approach to segregation dynamics in Schelling model

    OpenAIRE

    Sobkowicz, Pawel

    2007-01-01

    A simple queueing approach for segregation of agents in modified one dimensional Schelling segregation model is presented. The goal is to arrive at simple formula for the number of unhappy agents remaining after the segregation.

  8. Coupling between different superficial kinetics: segregation, precipitation and dissolution; Cinetiques couplees au voisinage des surfaces: segregation, precipitation et dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Delage, St

    1998-12-31

    In most of alloys, the surface composition is different from bulk one. This phenomenon, called `surface segregation` have drawn up to now much attention in this case of alloys which have reached thermodynamic equilibrium in the solid solution. Using a kinetic model including bulk and surface driving forces, we study segregation phenomenon during dissolution and precipitation kinetics, in the case of the Fe-Cu alloy. Within a mean field approximation, we point out the dissolution modes for Fe/Cu and Cu/Fe deposit. If the substrate surface energy is lower than the deposit one (case of Fe/Cu deposit) the substrate element climbs through the deposit to reach the surface and forms a layer of the substrate element floating on the deposit. In the case of thick deposit (typically 10 monolayers), a competition between two layer by layer dissolution modes leads to a wide range of behaviours, depending on temperature and deposit thickness. Furthermore, the major part of the concentration profiles obtained during kinetics is at local equilibrium in a region near the surface. In the second part of this work, we study the surface influence during phase separation kinetics in thin layers using Monte-Carlo simulations. A surface directed spinodal decomposition occurs, leading to the appearance of a Cu-rich layer at the surface, which goes toward the layer`s core with time. This process is linked with bulk precipitation in layer`s core, and leads to different behaviours depending on average concentration and layer thickness. (authors) 125 refs.

  9. Referral Hiring and Gender Segregation in the Workplace

    OpenAIRE

    Troy Tassier

    2008-01-01

    Segregation by type of work or discrimination are two common explanations for gender segregation in the workplace. A third, gender segregation due to referral hiring through segregated social networks, is less well explored. In this paper, I use an agent-based model of referral hiring to demonstrate that it could create high levels of gender segregation near those observed in data. But the model cannot account for all of the segregation observed. Eastern Economic Journal (2008) 34, 429–440. d...

  10. Structure-Function Analysis of SUV39H1 Reveals a Dominant Role in Heterochromatin Organization, Chromosome Segregation, and Mitotic Progression

    OpenAIRE

    Melcher, Martin; Schmid, Manfred; Aagaard, Louise; Selenko, Philipp; Laible, Götz; Jenuwein, Thomas

    2000-01-01

    SUV39H1, a human homologue of the Drosophila position effect variegation modifier Su(var)3-9 and of the Schizosaccharomyces pombe silencing factor clr4, encodes a novel heterochromatic protein that transiently accumulates at centromeric positions during mitosis. Using a detailed structure-function analysis of SUV39H1 mutant proteins in transfected cells, we now show that deregulated SUV39H1 interferes at multiple levels with mammalian higher-order chromatin organization. First, forced express...

  11. Food resource utilisation by Magellanic penguin evaluated through stable isotope analysis: segregation by sex and age and influence of offspring quality.

    OpenAIRE

    Forero, Manuela G.; Hobson, Keith A.; Bortolotti, Gary R.; Donázar, José A.; Bertellotti, Marcelo; Blanco, Guillermo

    2002-01-01

    We used stable-isotope analysis (SIA) to evaluate sources of variation in the diet of and prey selection by Magellanic penguins Spheniscus magellanicus breeding on the Argentinean Patagonia coast. Our aim was to determine potential sources of variation in diet, focusing mainly on sex and age, although geographic and temporal effects were also taken into account. In addition, we evaluated how prey selection affects offspring quality. We measured stable nitrogen ( δ15N) and carbon (δ13C) isotop...

  12. Segregation of Sb in Ge epitaxial layers and its usage for the selective doping of Ge-based structures

    International Nuclear Information System (INIS)

    The segregation of Sb in Ge epitaxial layers grown by the method of molecular beam epitaxy on Ge (001) substrates is investigated. For a growth temperature range of 180–325°C, the temperature dependence is determined for the segregation ratio of Sb in Ge, which shows a sharp increase (by more than three orders of magnitude) with increasing temperature. The strong dependence of the segregation properties of Sb on the growth temperature makes it possible to adapt a method based on the controlled use of segregation developed previously for the doping of Si structures for the selective doping of Ge structures with a donor impurity. Using this method selectively doped Ge:Sb structures, in which the bulk impurity concentration varies by an order of magnitude at distances of 3–5 nm, are obtained

  13. Segregation of Sb in Ge epitaxial layers and its usage for the selective doping of Ge-based structures

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, A. V.; Drozdov, M. N.; Novikov, A. V., E-mail: anov@ipmras.ru; Yurasov, D. V. [Institute for Physics of Microstructures of the Russian Academy of Sciences (Russian Federation)

    2015-11-15

    The segregation of Sb in Ge epitaxial layers grown by the method of molecular beam epitaxy on Ge (001) substrates is investigated. For a growth temperature range of 180–325°C, the temperature dependence is determined for the segregation ratio of Sb in Ge, which shows a sharp increase (by more than three orders of magnitude) with increasing temperature. The strong dependence of the segregation properties of Sb on the growth temperature makes it possible to adapt a method based on the controlled use of segregation developed previously for the doping of Si structures for the selective doping of Ge structures with a donor impurity. Using this method selectively doped Ge:Sb structures, in which the bulk impurity concentration varies by an order of magnitude at distances of 3–5 nm, are obtained.

  14. Large zeolite H-ZSM-5 crystals as models for the methanol-to-hydrocarbons process: bridging the gap between single-particle examination and bulk catalyst analysis.

    Science.gov (United States)

    Hofmann, Jan P; Mores, Davide; Aramburo, Luis R; Teketel, Shewangizaw; Rohnke, Marcus; Janek, Jürgen; Olsbye, Unni; Weckhuysen, Bert M

    2013-06-24

    The catalytic, deactivation, and regeneration characteristics of large coffin-shaped H-ZSM-5 crystals were investigated during the methanol-to-hydrocarbons (MTH) reaction at 350 and 500 °C. Online gas-phase effluent analysis and examination of retained material thereof were used to explore the bulk properties of large coffin-shaped zeolite H-ZSM-5 crystals in a fixed-bed reactor to introduce them as model catalysts for the MTH reaction. These findings were related to observations made at the individual particle level by using polarization-dependent UV-visible microspectroscopy and mass spectrometric techniques after reaction in an in situ microspectroscopy reaction cell. Excellent agreement between the spectroscopic measurements and the analysis of hydrocarbon deposits by means of retained hydrocarbon analysis and time-of-flight secondary-ion mass spectrometry of spent catalyst materials was observed. The obtained data reveal a shift towards more condensed coke deposits on the outer zeolite surface at higher reaction temperatures. Zeolites in the fixed-bed reactor setup underwent more coke deposition than those reacted in the in situ microspectroscopy reaction cell. Regeneration studies of the large zeolite crystals were performed by oxidation in O2 /inert gas mixtures at 550 °C. UV-visible microspectroscopic measurements using the oligomerization of styrene derivatives as probe reaction indicated that the fraction of strong acid sites decreased during regeneration. This change was accompanied by a slight decrease in the initial conversion obtained after regeneration. H-ZSM-5 deactivated more rapidly at higher reaction temperature. PMID:23649944

  15. On-line bulk analysis of raw material in a cement plant using the neutron irradiation and capture gamma ray technique

    International Nuclear Information System (INIS)

    In collaboration with Ciments Lafarge, the Laboratoire central des ponts et chaussees (LCPC) has developed a technique, involving neutron irradiation, for on-line bulk analysis of raw material quality, along the input line to a cement plant, by determining the quantities of the following elements: calcium, silicon, aluminium and iron. A system was constructed and tested in a cement plant under actual service conditions. The system consists of a sampler placed on the on-stream line supplying the plant at a rate of 1000 t/h. An analysing hopper incorporating a neutron irradiation system, consisting of a 14 MeV neutron generator tube, and a gamma ray detection system, comprising a NaI(Tl) scintillator associated with a photomultiplier, are coupled to this sampler. The system is fed continuously with the raw material to be analysed. Gamma radiation spectra supplied by the detector are analysed on two distinct measurement channels. One of these channels processes the nuclear radiation generated by neutron capture phenomena, while the other channel processes the nuclear radiation resulting from neutron activation phenomena. The data collected under the operating conditions mentioned above (i.e. in real time) allows readings to be obtained every 2 min for silicon, calcium, aluminium and iron as a result of the processing method applied to gamma capture and activation spectra. A comparison was made between these measurements and the results of an analysis of the same piles, conducted simultaneously through a sampling tower delivering at an hourly rate a sample analysed in accord with the X ray fluorescence process. Comparison of the results obtained from both analysis methods highlights the advantages of the neutron irradiation process. (author). 4 figs, 2 tabs

  16. Bulk laundry monitoring system

    International Nuclear Information System (INIS)

    Protective wear (like boiler suits, hand gloves etc.) is essential while handling radioactive material in plants/laboratories. During the course of work, it is quite possible that protective wear may get contaminated. These protective wears are packed in laundry bags and send to Decontamination Centre (DC). There is a need for monitoring the laundry bags at the time of receipt, as well as before dispatch to respective locations to comply with AERB guidelines, To avoid cross contamination during wash cycle, contaminated bags (> 0.5 mR/h on surface) need to be segregated. Present paper describes the development of such system for monitoring surface dose rate on bags at the time of receipt. The system installed at ETP after calibration, effectively segregates the contaminated bags from the rest and prevents from cross contamination during wash cycle. Reduction in man-rem consumption due to semi automatic monitoring. Improved sensitivity due to good geometry, long counting time, background and attenuation corrections. Optimum utilization of decontamination chemicals based on level of contamination and keeping track of its inventory. Generation of decontamination process data base for improvement

  17. Modeling density segregation in granular flow

    Science.gov (United States)

    Xiao, Hongyi; Lueptow, Richard; Umbanhowar, Paul

    2015-11-01

    A recently developed continuum-based model accurately predicts segregation in flows of granular mixtures varying in particle size by considering the interplay of advection, diffusion and segregation. In this research, we extend the domain of the model to include density driven segregation. Discrete Element Method (DEM) simulations of density bidisperse flows of mono-sized particles in a quasi-2D bounded heap were performed to determine the dependence of the density driven segregation velocity on local shear rate, particle concentration, and a segregation length which scales with the particle size and the logarithm of the density ratio. With these inputs, the model yields theoretical predictions of density segregation patterns that quantitatively match the DEM simulations over a range of density ratios (1.11-3.33) and flow rates (19.2-113.6 cm3/s). Matching experiments with various combinations of glass, steel and ceramic particles were also performed which reproduced the segregation patterns obtained in both the simulations and the theory.

  18. 苯乙烯本体聚合工艺模拟与分析%Simulation and analysis of bulk polystyrene reaction process

    Institute of Scientific and Technical Information of China (English)

    顾凯; 刘太奇; 李翠清

    2007-01-01

    The steady process simulation models of bulk polystyrene unit process were developed by the polymer process simulation software Polymer Plus of Aspen Tech Inc. The effect of changing of initiator, temperature, etc. on the product and Mn Mw were discussed by the sensitivity analysis. The result shows that higher concentration of initiator leads to higher production rate but the lower Mn and the higher flow rate of chain agent cause the lower product ion rate and Mn, Mn Mw reach the maximum at 115 ℃ and 107 ℃ of first reactor.%利用Aspen Tech Inc.的polymer plus建立了本体聚苯乙烯聚合反应过程模型,利用其灵敏度分析方法对影响产品产量和分子量的引发剂浓度、反应温度等因素进行分析,得出了引发剂量的增加可以提高产量同时分子量下降;链转移剂量的增加使产量和分子量均下降;在首釜温度115℃和107℃出现Mn和Mw的最大值.

  19. Analysis of gain distribution in cladding-pumped thulium-doped fiber laser and optical feedback inhibition problem in fiber-bulk laser system

    Science.gov (United States)

    Ji, En-Cai; Liu, Qiang; Hu, Zhen-Yue; Gong, Ma-Li

    2015-10-01

    The steady-state gain distribution in cladding pumped thulium-doped fiber laser (TDFL) is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition (OFI) and always occurs in tandem TDFL-Ho:YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho:YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method. Project supported by the National Natural Science Foundation of China (Grant No. 61275146), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110066), and the Special Program of the Co-construction with Beijing Municipal Government of China (Grant No. 20121000302).

  20. Nuclear envelope expansion is crucial for proper chromosomal segregation during a closed mitosis

    Science.gov (United States)

    Takemoto, Ai; Kawashima, Shigehiro A.; Li, Juan-Juan; Jeffery, Linda; Yamatsugu, Kenzo; Elemento, Olivier; Nurse, Paul

    2016-01-01

    ABSTRACT Here, we screened a 10,371 library of diverse molecules using a drug-sensitive fission yeast strain to identify compounds which cause defects in chromosome segregation during mitosis. We identified a phosphorium-ylide-based compound Cutin-1 which inhibits nuclear envelope expansion and nuclear elongation during the closed mitosis of fission yeast, and showed that its target is the β-subunit of fatty acid synthase. A point mutation in the dehydratase domain of Fas1 conferred in vivo and in vitro resistance to Cutin-1. Time-lapse photomicrography showed that the bulk of the chromosomes were only transiently separated during mitosis, and nucleoli separation was defective. Subsequently sister chromatids re-associated leading to chromosomal mis-segregation. These segregation defects were reduced when the nuclear volume was increased and were increased when the nuclear volume was reduced. We propose that there needs to be sufficient nuclear volume to allow the nuclear elongation necessary during a closed mitosis to take place for proper chromosome segregation, and that inhibition of fatty acid synthase compromises nuclear elongation and leads to defects in chromosomal segregation. PMID:26869222

  1. How to build segregation complexes in bacteria: Use bridges

    OpenAIRE

    Funnell, Barbara E.

    2014-01-01

    This perspective discusses the novel molecular mechanism of ParB spreading that is reported by Graham et al. (this issue). Using single-molecule analysis, Graham et al. found that Bacillus subtilis ParB proteins use a previously uncharacterized looping and bridging activity to assemble three-dimensional nucleoprotein complexes with DNA flanking the parS site. Formation of this higher-order ParB/parS complex is necessary for SMC condensin complex recruitment and chromosome segregation.

  2. Bringing Proximate Neighbours into the Study of US Residential Segregation

    OpenAIRE

    Friedman, Samantha

    2011-01-01

    The race and ethnicity of neighbours are thought to be critical in shaping household mobility underlying residential segregation. However, studies on this topic have used data at the census-tract level of analysis rather than at the proximate-neighbour level. Using a non-publicly available version of the neighbour-cluster sample within the American Housing Survey, this study incorporates data on the race, ethnicity and socioeconomic characteristics of the proximate neighbours of White, Black ...

  3. The Effect of Strict Segregation on Pseudomonas aeruginosa in Cystic Fibrosis Patients

    Science.gov (United States)

    van Mansfeld, Rosa; de Vrankrijker, Angelica; Brimicombe, Roland; Heijerman, Harry; Teding van Berkhout, Ferdinand; Spitoni, Cristian; Grave, Sanne; van der Ent, Cornelis; Wolfs, Tom; Willems, Rob; Bonten, Marc

    2016-01-01

    Introduction Segregation of patients with cystic fibrosis (CF) was implemented to prevent chronic infection with epidemic Pseudomonas aeruginosa strains with presumed detrimental clinical effects, but its effectiveness has not been carefully evaluated. Methods The effect of strict segregation on the incidence of P. aeruginosa infection in CF patients was investigated through longitudinal protocolized follow-up of respiratory tract infection before and after segregation. In two nested cross-sectional studies in 2007 and 2011 the P. aeruginosa population structure was investigated and clinical parameters were determined in patients with and without infection with the Dutch epidemic P. aeruginosa clone (ST406). Results Of 784 included patients 315 and 382 were at risk for acquiring chronic P. aeruginosa infection before and after segregation. Acquisition rates were, respectively, 0.14 and 0.05 per 1,000 days at risk (HR: 0.66, 95% CI [0.2548–1.541]; p = 0.28). An exploratory subgroup analysis indicated lower acquisition after segregation in children < 15 years of age (HR: 0.43, 95% CI[0.21–0.95]; p = 0.04). P. aeruginosa population structure did not change after segregation and ST406 was not associated with lung function decline, death or lung transplantation. Conclusions Strict segregation was not associated with a statistically significant lower acquisition of chronic P. aeruginosa infection and ST406 was not associated with adverse clinical outcome. After segregation there were no new acquisitions of ST406. In an unplanned exploratory analysis chronic acquisition of P. aeruginosa was lower after implementation of segregation in patients under 15 years of age. PMID:27280467

  4. Quantification of segregation dynamics in ice mixtures

    OpenAIRE

    Öberg, Karin I.; Fayolle, Edith C.; Cuppen, Herma M.; van Dishoeck, Ewine F.; Linnartz, Harold

    2009-01-01

    (Abridged) The observed presence of pure CO2 ice in protostellar envelopes is attributed to thermally induced ice segregation, but a lack of quantitative experimental data has prevented its use as a temperature probe. Quantitative segregation studies are also needed to characterize diffusion in ices, which underpins all ice dynamics and ice chemistry. This study aims to quantify the segregation mechanism and barriers in different H2O:CO2 and H2O:CO ice mixtures covering a range of astrophysic...

  5. Granular size segregation in underwater sand ripples.

    Science.gov (United States)

    Rousseaux, G; Caps, H; Wesfreid, J-E

    2004-02-01

    We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly depend on the sand bed preparation. The initial wavelength of the mixture is measured. In the final steady state, a segregation in volume is observed instead of a segregation at the surface as reported before. The correlation between this phenomenon and the fluid flow is emphasised. Finally, different "exotic" patterns and their geophysical implications are presented. PMID:15052430

  6. Grain boundary structure and solute segregation in titanium-doped sapphire bicrystals

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Seth T.

    2002-05-17

    Solute segregation to ceramic grain boundaries governs material processing and microstructure evolution, and can strongly influence material properties critical to engineering performance. Understanding the evolution and implications of grain boundary chemistry is a vital component in the greater effort to engineer ceramics with controlled microstructures. This study examines solute segregation to engineered grain boundaries in titanium-doped sapphire (Al2O3) bicrystals, and explores relationships between grain boundary structure and chemistry at the nanometer scale using spectroscopic and imaging techniques in the transmission electron microscope (TEM). Results demonstrate dramatic changes in solute segregation stemming from small fluctuations in grain boundary plane and structure. Titanium and silicon solute species exhibit strong tendencies to segregate to non-basal and basal grain boundary planes, respectively. Evidence suggests that grain boundary faceting occurs in low-angle twis t boundaries to accommodate nonequilibrium solute segregation related to slow specimen cooling rates, while faceting of tilt grain boundaries often occurs to expose special planes of the coincidence site lattice (CSL). Moreover, quantitative analysis of grain boundary chemistry indicates preferential segregation of charged defects to grain boundary dislocations. These results offer direct proof that static dislocations in ionic materials can assume a net charge, and emphasize the importance of interactions between charged point, line, and planar defects in ionic materials. Efforts to understand grain boundary chemistry in terms of space charge theory, elastic misfit and nonequilibrium segregation are discussed for the Al2O3 system.

  7. The role of temporal resolution in modulation-based speech segregation

    DEFF Research Database (Denmark)

    May, Tobias; Bentsen, Thomas; Dau, Torsten

    2015-01-01

    This study is concerned with the challenge of automatically segregating a target speech signal from interfering background noise. A computational speech segregation system is presented which exploits logarithmically-scaled amplitude modulation spectrogram (AMS) features to distinguish between spe...... which the segregation system can manipulate individual T-F units. To clarify the consequences of this trade-off on modulation-based speech segregation performance, the influence of the window duration was systematically investigated......This study is concerned with the challenge of automatically segregating a target speech signal from interfering background noise. A computational speech segregation system is presented which exploits logarithmically-scaled amplitude modulation spectrogram (AMS) features to distinguish between...... speech and noise activity on the basis of individual time-frequency (T-F) units. One important parameter of the segregation system is the window duration of the analysis-synthesis stage, which determines the lower limit of modulation frequencies that can be represented but also the temporal acuity with...

  8. Effect of molybdenum on grain boundary segregation in Incoloy 901 superalloy

    International Nuclear Information System (INIS)

    Highlights: ► Grain boundary segregation in superalloys can be decreased by controlling of the chemical composition of alloys. ► One of the most effective element on decreasing of grain boundary segregation is Molybdenum. ► The Mo addition up to 6.7 % have a suitable effect on decreasing of grain boundary segregation of other elements.. ► The partitioning coefficients of all elements except Fe and Ni are less than one. - Abstract: In this paper, the effect of molybdenum on the grain boundary segregation of other elements was studied in Incoloy 901 superalloy. Initially, five alloys were prepared with different percentages of Mo by using a vacuum induction furnace. Then, these alloys were remelted by Electro-slag remelting (ESR) process and after homogenizing at 1160 °C for 2 h followed by air cooling, were rolled. The effect of Mo on segregation of elements was evaluated with Scanning Electron Microscopy, Linear Analysis, and the mechanical tests. The results showed that the grain boundary segregations of elements in Incoloy 901 superalloy were decreased by increasing of molybdenum content up to 6.7% and the mechanical properties (tensile and hardness properties) were improved. Also, the segregations of elements were increased by increasing the percentage of Mo from 6.7 to 7.5, and the mechanical properties were reduced

  9. Life cycle assessment of segregating fattening pig urine and feces compared to conventional liquid manure management.

    Science.gov (United States)

    De Vries, Jerke W; Aarnink, André J A; Groot Koerkamp, Peter W G; De Boer, Imke J M

    2013-02-01

    Gaseous emissions from in-house storage of liquid animal manure remain a major contributor to the environmental impact of manure management. Our aim was to assess the life cycle environmental consequences and reduction potential of segregating fattening pig urine and feces with an innovative V-belt system and to compare it to conventional liquid manure management, that is, the reference. Moreover, we aimed at analyzing the uncertainty of the outcomes related to applied emission factors. We compared a reference with two scenarios: segregation with solid, aerobically, stored feces and with liquid, anaerobically, stored feces. Results showed that, compared to the reference, segregation reduced climate change (CC) up to 82%, due to lower methane emission, reduced terrestrial acidification (TA) and particulate matter formation (PMF) up to 49%, through lower ammonia emission, but increased marine eutrophication up to 11% through nitrogen oxide emission from storage and nitrate leaching after field application. Fossil fuel depletion did not change. Segregation with liquid feces revealed lower environmental impact than segregation with solid feces. Uncertainty analysis supported the conclusion that segregating fattening pig urine and feces significantly reduced CC and additionally segregation with liquid feces significantly reduced TA and PMF compared to the reference. PMID:23268735

  10. Veil: A Wall of Segregation

    Directory of Open Access Journals (Sweden)

    Tayebeh Nowrouzi

    2015-08-01

    Full Text Available Moving behind the confines of the race has been the continuous efforts of African-Americans so as to reveal and confirm their true humanity and abilities to white race as well as their own race. African-Americans, Dubois posited, are shut out of the white America, inhabiting behind a vast veil which creates a deep division between the races. Veil is made of the fabric of racism interwoven thread by thread and imposed by white world. It is thrown discourteously and forcibly to the African-Americans whom their distorted images are imposed on them and their true humanity and identity are hidden behind the veil. This study overtakes to present how Loraine Hansberry, in her first and the most outstanding drama, A Raisin in the Sun examines the world within the veil. She demonstrated that Duboisian metaphoric veil is operating in the racist American society so that not only African-Americans are segregated physically and psychologically from the rest of the world but also are inflicted with obscurity of vision that are neither able to see themselves clearly nor be seen truly. On the other hand, it presents how the veil provides blacks with the second sight to observe and comprehend the racist nature of whites which is hidden and incomprehensible for them.

  11. Segregation of chain ends to polymer melt surfaces and interfaces

    International Nuclear Information System (INIS)

    The conformation of polymer chains in the melt near an impenetrable boundary has recently been studied by molecular dynamics and off-lattice Monte Carlo simulations. Both types of calculations show an enhancement of the chain end density within a distance of approximately two polymer segment lengths of the interface relative to the bulk. In the absence of preferential interactions between monomers and the interface, the segregation arises from minimizing the loss of conformational entropy near an impenetrable boundary; i.e., by positioning an end near the surface, only one unit rather than two is reflected. In order to obtain an experimental measure of this effect, monodisperse polystyrene (PS) chains of molecular weight 63 000 with short blocks of deuterated polystyrene (dPS) at each end were prepared. The block length was kept as short as possible, while yet producing sufficient neutron scattering contrast in order to minimize any preferential surface segregation due to isotopic effects. The synthesis was carried out via living anionic polymerization of a purified styrene monomer in cyclohexane at 60 C, utilizing sec-butyllithium as the initiator. The process was terminated using degassed methanol

  12. Dislocation core reconstruction induced by carbon segregation in bcc iron

    Science.gov (United States)

    Ventelon, Lisa; Lüthi, B.; Clouet, E.; Proville, L.; Legrand, B.; Rodney, D.; Willaime, F.

    2015-06-01

    The relative stability of dislocation core configurations in body-centered-cubic metals is profoundly modified by the presence of solutes. Considering the Fe(C) system, we demonstrate by using density functional theory that carbon atoms destabilize the usual easy core to the benefit of the hard core configuration of the screw dislocation, which is unstable in pure metals. The carbon atom is at the center of a regular prism in a cementitelike local environment. The same dislocation core reconstruction is also found with other solutes (B, N, O) and in W(C). This unexpected low-energy configuration induces a strong solute-dislocation attraction, leading to dislocation core saturation by solute atoms, even for very low bulk solute concentrations. This core reconstruction will constitute an essential factor to account for in solute-segregation related phenomena, such as strain aging.

  13. Combined effects of phosphorus segregation and partial intergranular fracture on the ductile-brittle transition temperature in structural alloy steels

    International Nuclear Information System (INIS)

    Research highlights: → Effective P segregation was proposed by segregated P and intergranular fracture. → The DBTT of aged and irradiated steel was analyzed by effective P segregation. → The DBTT of two classes of steels are controlled by differing mechanisms. → Hardening strongly influenced the embrittling potency of segregated P. - Abstract: This article introduced effective P segregation in terms of the product of the amount of segregated P and partial intergranular fracture to account for the combined effects on the ductile-brittle transition temperature (DBTT) measured by dynamic and static notched bar tests on several alloy steels. Effective P segregation characterized a DBTT shift caused by thermal ageing and/or neutron irradiation in various A533B and 2.25Cr-1Mo steels, while P segregation controlled the DBTT independent of the fraction of intergranular fracture in thermally aged 3.5Ni-1.7Cr steels with and without Mo and V. These DBTT behaviors of the two classes of steels are related to differing brittle fracture mechanisms. The present analysis enables one to investigate how the embrittling potency of segregated P in association with partial intergranular fracture is influenced by the differing plasticity and the addition of several alloying elements under dynamic and static loading conditions.

  14. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  15. Ferromagnetic bulk glassy alloys

    International Nuclear Information System (INIS)

    This paper deals with the review on the formation, thermal stability and magnetic properties of the Fe-based bulk glassy alloys in as-cast bulk and melt-spun ribbon forms. A large supercooled liquid region over 50 K before crystallization was obtained in Fe-(Al, Ga)-(P, C, B, Si), Fe-(Cr, Mo, Nb)-(Al, Ga)-(P, C, B) and (Fe, Co, Ni)-Zr-M-B (M=Ti, Hf, V, Nb, Ta, Cr, Mo and W) systems and bulk glassy alloys were produced in a thickness range below 2 mm for the Fe-(Al, Ga)-(P, C, B, Si) system and 6 mm for the Fe-Co-(Zr, Nb, Ta)-(Mo, W)-B system by copper-mold casting. The ring-shaped glassy Fe-(Al, Ga)-(P, C, B, Si) alloys exhibit much better soft magnetic properties as compared with the ring-shaped alloy made from the melt-spun ribbon because of the formation of the unique domain structure. The good combination of high glass-forming ability and good soft magnetic properties indicates the possibility of future development as a new bulk glassy magnetic material

  16. Demographic processes and ethnic residential segregation

    Directory of Open Access Journals (Sweden)

    Itzhak Omer

    1999-01-01

    Full Text Available This paper examines the involvement of demographic processes in the residential segregation of ethnic groups in an urban area. For this purpose, a two-part methodology has been employed. The first part comprises a conceptual framework which uses the concept of time–space resources as an analytical tool to clarify the structural constraints embedded in the changes in ethnic residential distribution. The second part comprises a simulation model of ethnic residential segregation. The model, which fits into the category of agent-based simulation models, serves as a tool for heuristic study. The methodology has been applied to examine the implications of fluctuations in ethnic group diffusion and the residential mobility rate on the majority–minority residential segregation, and on the internal ethnic segregation within the minority group.

  17. The Distribution of Segregation in Atlanta

    Science.gov (United States)

    Meade, Anthony

    1972-01-01

    A prediction from ecological theory relating the distribution of residential segregation between inner and outer zones of a metropolitan area to conditions of population growth, expansion, etc. was tested using 1960 data on the Atlanta standard metropolitan statistical area. (JM)

  18. Modeling size segregation of bidisperse granular flow: the roles of segregation, advection, and diffusion

    OpenAIRE

    Fan, Yi; Schlick, Conor; Isner, Austin; Ottino, Julio; Umbanhowar, Paul; Richard, Lueptow

    2014-01-01

    Segregation of granular materials composed of different-sized particles has important repercussions in various industrial processes and natural phenomena, but predicting size segregation remains a challenging problem. To address this problem, we have developed a theoretical model that captures the interplay between advection, segregation, and diffusion in size bidisperse granular materials. The fluxes associated with these three driving factors depend on the underlying kinematics, whose chara...

  19. Gender Differences in the Effect of Residential Segregation on Workplace Segregation among Newly Arrived Immigrants

    OpenAIRE

    Tammaru, Tiit; Strömgren, Magnus; van Ham, Maarten; Danzer, Alexander M.

    2015-01-01

    Contemporary cities are becoming more and more diverse in population as a result of immigration. Research also shows that within cities residential neighborhoods are becoming ethnically more diverse, but that residential segregation has remained persistently high. High levels of segregation are often seen as negative, preventing integration of immigrants in their host society and having a negative impact on people's lives. Segregation research often focuses on residential neighborhoods, but i...

  20. Heat transport in bulk/nanoporous/bulk silicon devices

    Energy Technology Data Exchange (ETDEWEB)

    Criado-Sancho, M. [Departamento de Ciencias y Técnicas Físicoquimicas, Facultad de Ciencias, UNED, Senda del Rey 9, 20040 Madrid (Spain); Jou, D., E-mail: David.Jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

    2013-02-04

    We study heat transport in bulk/nanoporous/bulk silicon devices; we show that, despite bulk/nanoporous devices may act as thermal rectifiers, the non-linear aspects of their joint thermal conductance are not strong enough to lead to a negative differential thermal resistance, necessary to allow bulk/nanoporous/bulk Si devices to act as thermal transistors. Furthermore, we explicitly study the effective thermal conductivity of the mentioned devices for several temperatures, geometries, porosities, and pore size.

  1. Human Papillomavirus Type 18 cis-Elements Crucial for Segregation and Latency.

    Directory of Open Access Journals (Sweden)

    Mart Ustav

    Full Text Available Stable maintenance replication is characteristic of the latency phase of HPV infection, during which the viral genomes are actively maintained as extrachromosomal genetic elements in infected proliferating basal keratinocytes. Active replication in the S-phase and segregation of the genome into daughter cells in mitosis are required for stable maintenance replication. Most of our knowledge about papillomavirus genome segregation has come from studies of bovine papillomavirus type 1 (BPV-1, which have demonstrated that the E2 protein cooperates with cellular trans-factors and that E2 binding sites act as cis-regulatory elements in the viral genome that are essential for the segregation process. However, the genomic organization of the regulatory region in HPVs, and the properties of the viral proteins are different from those of their BPV-1 counterparts. We have designed a segregation assay for HPV-18 and used it to demonstrate that the E2 protein performs segregation in combination with at least two E2 binding sites. The cooperative binding of the E2 protein to two E2 binding sites is a major determinant of HPV-18 genome segregation, as demonstrated by the change in spacing between adjacent binding sites #1 and #2 in the HPV-18 Upstream Regulatory Region (URR. Duplication or triplication of the natural 4 bp 5'-CGGG-3' spacer between the E2 binding sites increased the cooperative binding of the E2 molecules as well as E2-dependent segregation. Removal of any spacing between these sites eliminated cooperative binding of the E2 protein and disabled segregation of the URR and HPV-18 genome. Transfer of these configurations of the E2 binding sites into viral genomes confirmed the role of the E2 protein and binding sites #1 and #2 in the segregation process. Additional analysis demonstrated that these sites also play an important role in the transcriptional regulation of viral gene expression from different HPV-18 promoters.

  2. Human Papillomavirus Type 18 cis-Elements Crucial for Segregation and Latency.

    Science.gov (United States)

    Ustav, Mart; Castaneda, Fernando Rodriguez; Reinson, Tormi; Männik, Andres; Ustav, Mart

    2015-01-01

    Stable maintenance replication is characteristic of the latency phase of HPV infection, during which the viral genomes are actively maintained as extrachromosomal genetic elements in infected proliferating basal keratinocytes. Active replication in the S-phase and segregation of the genome into daughter cells in mitosis are required for stable maintenance replication. Most of our knowledge about papillomavirus genome segregation has come from studies of bovine papillomavirus type 1 (BPV-1), which have demonstrated that the E2 protein cooperates with cellular trans-factors and that E2 binding sites act as cis-regulatory elements in the viral genome that are essential for the segregation process. However, the genomic organization of the regulatory region in HPVs, and the properties of the viral proteins are different from those of their BPV-1 counterparts. We have designed a segregation assay for HPV-18 and used it to demonstrate that the E2 protein performs segregation in combination with at least two E2 binding sites. The cooperative binding of the E2 protein to two E2 binding sites is a major determinant of HPV-18 genome segregation, as demonstrated by the change in spacing between adjacent binding sites #1 and #2 in the HPV-18 Upstream Regulatory Region (URR). Duplication or triplication of the natural 4 bp 5'-CGGG-3' spacer between the E2 binding sites increased the cooperative binding of the E2 molecules as well as E2-dependent segregation. Removal of any spacing between these sites eliminated cooperative binding of the E2 protein and disabled segregation of the URR and HPV-18 genome. Transfer of these configurations of the E2 binding sites into viral genomes confirmed the role of the E2 protein and binding sites #1 and #2 in the segregation process. Additional analysis demonstrated that these sites also play an important role in the transcriptional regulation of viral gene expression from different HPV-18 promoters. PMID:26288015

  3. Demographic processes and ethnic residential segregation

    OpenAIRE

    Itzhak Omer

    1999-01-01

    This paper examines the involvement of demographic processes in the residential segregation of ethnic groups in an urban area. For this purpose, a two-part methodology has been employed. The first part comprises a conceptual framework which uses the concept of time–space resources as an analytical tool to clarify the structural constraints embedded in the changes in ethnic residential distribution. The second part comprises a simulation model of ethnic residential segregation. The model, whic...

  4. Decentralization as a Cause of Spatial Segregation

    OpenAIRE

    Jasarovic Ema Alihodzic; Komatina Dragan; Zaric Sanja Paunovic

    2016-01-01

    City represents an incomplete dynamic process prone to the expansion with a causal link between urban expansion and socio-spatial segregation. The socio-spatial distribution in the city is mostly related to the increased social polarization and inequality. There is a clear connection between divided society and divided city: if society is divided, urban space must be divided. It is the question of the relations between the social inequalities on one hand, and spatial segregation on the other....

  5. Segregation isotherms at the surfaces of oxide

    International Nuclear Information System (INIS)

    A non-Arrhenius segregation isotherm is derived which includes the change in the heat of segregation with surface coverage due to impurity-impurity interactions. It is shown that a linear dependence of log(xs) on the reciprocal temperature, where xs is the surface atomic ratio, can derive either from a constant heat of segregation, i.e., Arrhenius behavior, or from a heat of segregation that varies as xs-1. This isotherm is then used to calculate the equilibrium surface coverages of Ca at the {001} surface of MgO, Mg at the {0001} surface of α-Al2O3, Y at the {1012} and {1 bar 120} surfaces of α-Al2O3, and Na at the {111} and {110} surfaces of Li2O from the calculated heats of segregation. Where possible, comparisons are made with experiment. The more useful operational definition of the heat of segregation, namely, that derived from the measured coverage or that defined atomistically and obtained by calculation, is discussed

  6. Radiation-induced segregation in titanium alloys

    International Nuclear Information System (INIS)

    Radiation-induced segregation (RIS) of V, Mo, Nb, Ta, Zr, and Sn in binary titanium alloys was investigated to test the solute size effect correlation in hcp alloys. Undersize Mo segregates weakly toward the sinks. Nb and Ta, which are slightly oversize in Ti, undergo little or no RIS. Oversize Zr solute in Ti segregates away from the sinks, whereas undersize Ti solute in Zr is enriched at sinks. All of these results are in accord with the solute size effect correlation. Surprisingly, Sn, which is significantly oversize in Ti, appears to segregate very little. The postirradiation annealing of Ti-3V and Ti-8Al-1V-1Mo confirmed that segregation of undersize V toward sinks is radiation-induced. Measurements of temperature and dose dependence in binary and complex alloys showed that the degree of V segregation has a maximum at proportional6000C and obeys parabolic growth kinetics in its early stages but probably saturates at a rather low dose (proportional0.8 dpa). (orig.)

  7. 28 CFR 541.21 - Conditions of disciplinary segregation.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Conditions of disciplinary segregation... Conditions of disciplinary segregation. (a) Disciplinary segregation is the status of confinement of an... general population. Inmates housed in disciplinary segregation have significantly fewer privileges...

  8. What Should an Index of School Segregation Measure?

    Science.gov (United States)

    Allen, Rebecca; Vignoles, Anna

    2007-01-01

    The article aims to make a methodological contribution to the education segregation literature, providing a critique of previous measures of segregation used in the literature, as well as suggesting an alternative approach to measuring segregation. Specifically, the paper examines Gorard, Fitz and Taylor's finding that social segregation between…

  9. 41 CFR 109-1.5106 - Segregation of personal property.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Segregation of personal...-INTRODUCTION 1.51-Personal Property Management Standards and Practices § 109-1.5106 Segregation of personal...) The segregation of the property would materially hinder the progress of the work (i.e., segregation...

  10. Gender Segregation in the Spanish Labor Market: An Alternative Approach

    Science.gov (United States)

    del Rio, Coral; Alonso-Villar, Olga

    2010-01-01

    The aim of this paper is to study occupational segregation by gender in Spain, which is a country where occupational segregation explains a large part of the gender wage gap. As opposed to previous studies, this paper measures not only overall segregation, but also the segregation of several population subgroups. For this purpose, this paper uses…

  11. Hydrogen interstitial in H-ion implanted ZnO bulk single crystals: Evaluation by elastic recoil detection analysis and electron paramagnetic resonance

    Science.gov (United States)

    Kaida, T.; Kamioka, K.; Nishimura, T.; Kuriyama, K.; Kushida, K.; Kinomura, A.

    2015-12-01

    The origins of low resistivity in H ion-implanted ZnO bulk single crystals are evaluated by elastic recoil detection analysis (ERDA), electron paramagnetic resonance (EPR), and Van der Pauw methods. The H-ion implantation (peak concentration: 5.0 × 1015 cm-2) into ZnO is performed using a 500 keV implanter. The maximum of the concentration of the implanted H estimated by a TRIM simulation is at 3600 nm in depth. The resistivity decreases from ∼103 Ω cm for un implanted ZnO to 6.5 Ω cm for as-implanted, 2.3 × 10-1 Ω cm for 200 °C annealed, and 3.2 × 10-1 Ω cm for 400 °C annealed samples. The ERDA measurements can evaluate the concentration of hydrogens which move to the vicinity of the surface (surface to 300 nm or 100 nm) because of the diffusion by the annealing at 200 °C and 400 °C. The hydrogen concentration near the surface estimated using the 2.0 MeV helium beam is ∼3.8 × 1013 cm-2 for annealed samples. From EPR measurements, the oxygen vacancy of +charge state (Vo+) is observed in as-implanted samples. The Vo+ related signal (g = 1.96) observed under no illumination disappears after successive illumination with a red LED and appears again with a blue light illumination. The activation energy of as-implanted, 200 °C annealed, and 400 °C annealed samples estimated from the temperature dependence of carrier concentration lies between 29 meV and 23 meV, suggesting the existence of H interstitial as a shallow donor level.

  12. Amperometric determination of bonded glucose with an MnO(2) and glucose oxidase bulk-modified screen-printed electrode using flow-injection analysis.

    Science.gov (United States)

    Turkusic, Emir; Kalcher, Josef; Kahrovic, Emira; Beyene, Negussie W; Moderegger, Helmut; Sofic, Emin; Begic, Sabina; Kalcher, Kurt

    2005-01-30

    A screen-printed amperometric biosensor based on carbon ink double bulk-modified with MnO(2) as a mediator and glucose oxidase as a biocomponent was investigated for its ability to serve as a detector for bonded glucose in different compounds, such as cellobiose, saccharose, (-)-4-nitrophenyl-beta-d-glucopyranoside, as well as in beer samples by flow-injection analysis (FIA). The biosensor could be operated under physiological conditions (0.1M phosphate buffer, pH 7.5) and exhibited good reproducibility and stability. Bonded glucose was released with glucosidase in solution, and the free glucose was detected with the modified screen-printed electrode (SPE). The release of glucose by the aid of glucosidase from cellobiose, saccharose and (-)-4-nitrophenyl-beta-d-glucopyranoside in solution showed that stoichiometric quantities of free glucose could be monitored in all three cases. The linear range of the amperometric response of the biosensor in the FIA-mode flow rate 0.2mLmin(-1), injection volume 0.25mL, operation potential 0.48V versus Ag/AgCl) extends from 11 to 13,900mumolL(-1) glucose in free form. The limit of detection (3sigma) is 1mumolL(-1) glucose. A concentration of 100mumolL(-1) yields a relative standard deviation of approximately 7% with five injections. These values correspond to the same concentrations of bonded glucose supposed that it is liberated quantitatively (incubation for 2h with glucosidase). Bonded glucose could be determined in beer samples using the same assay. The results corresponded very well with the reference procedure. PMID:18969835

  13. Infrared radiation method for measuring ice segregation temperature of artificially frozen soils

    Institute of Scientific and Technical Information of China (English)

    Zhou Guoqing; Zhang Qi; Xu Zhiwei; Zhou Yang

    2012-01-01

    In order to study the evolution of the freezing fringe and final lenses of frost susceptible soils and advance the understanding of frost heave and mechanism of frost heave control,we used an open one-dimensional frost heave test system of infrared radiation technology,instead of a traditional thermistor method.Temperatures of the freezing fringe and segregated ice were measured in a non-contact mode.The results show that accurate and precise temperatures of ice segregation can be obtained by infrared thermal imaging systems.A self-developed inversion program inverted the temperature field of frozen soils.Based on our analysis of temperature variation in segregated ice and our study of the relationship between temperature and rate of ice segregation in cooling and warming processes during intermittent freezing,the mechanism of decreasing frost heave of frozen soils by controlling the growth of final lenses with an intermittent freezing mode,can be explained properly.

  14. A sampling algorithm for segregation analysis

    Directory of Open Access Journals (Sweden)

    Henshall John

    2001-11-01

    Full Text Available Abstract Methods for detecting Quantitative Trait Loci (QTL without markers have generally used iterative peeling algorithms for determining genotype probabilities. These algorithms have considerable shortcomings in complex pedigrees. A Monte Carlo Markov chain (MCMC method which samples the pedigree of the whole population jointly is described. Simultaneous sampling of the pedigree was achieved by sampling descent graphs using the Metropolis-Hastings algorithm. A descent graph describes the inheritance state of each allele and provides pedigrees guaranteed to be consistent with Mendelian sampling. Sampling descent graphs overcomes most, if not all, of the limitations incurred by iterative peeling algorithms. The algorithm was able to find the QTL in most of the simulated populations. However, when the QTL was not modeled or found then its effect was ascribed to the polygenic component. No QTL were detected when they were not simulated.

  15. A Social Network Analysis of Occupational Segregation

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian

    conference paper, NOT PUBLICATION. In Economics, for being accepted to a major conference, it will be peer reviewed, but this is not a publication in the usual cross-disciplinary sense of the word......conference paper, NOT PUBLICATION. In Economics, for being accepted to a major conference, it will be peer reviewed, but this is not a publication in the usual cross-disciplinary sense of the word...

  16. Segregation by thermal diffusion in granular shear flows

    OpenAIRE

    Garzó, Vicente; Reyes, Francisco Vega

    2010-01-01

    Segregation by thermal diffusion of an intruder immersed in a sheared granular gas is analyzed from the (inelastic) Boltzmann equation. Segregation is induced by the presence of a temperature gradient orthogonal to the shear flow plane and parallel to gravity. We show that, like in analogous systems without shear, the segregation criterion yields a transition between upwards segregation and downwards segregation. The form of the phase diagrams is illustrated in detail showing that they depend...

  17. Measuring Segregation: Basic Concepts and Extensions to Other Domains

    OpenAIRE

    Silber, Jacques

    2012-01-01

    This paper presents the main concepts used in measuring segregation. First it shows that the cardinal as well as the ordinal approach to the measurement of occupational segregation, when only two groups are considered (generally men and women), borrowed many ideas from the income inequality measurement literature. Second, it shows that more recent advances in segregation measurement, that were the consequence of an extension of segregation measures to the case of multi-group segregation and m...

  18. Industrial segregation of female and male workers in Spain

    OpenAIRE

    Olga Alonso-Villar; Coral del Río

    2009-01-01

    The aim of this paper is to study segregation in the Spanish labor market for both male and female workers, paying special attention to industrial segregation. As opposed to other studies, this article quantifies the segregation of each demographic group separately, rather than measuring overall segregation. For this purpose, it uses additively decomposable indices, together with local segregation curves, recently proposed in the literature, which allows us to go further in the empirical anal...

  19. A Measure of Segregation Based on Social Interactions

    OpenAIRE

    Echenique, Federico; Fryer, Roland

    2007-01-01

    We develop an index of segregation based on two premises: (1) a measure of segregation should disaggregate to the level of individuals, and (2) an individual is more segregated the more segregated are the agents with whom she interacts. We present an index that satisfies (1) and (2) and that is based on agents' social interactions: the extent to which blacks interact with blacks, whites with whites, etc. We use the index to measure school and residential segregation. Using detailed data on fr...

  20. Bulk materials handling review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-02-15

    The paper provides details of some of the most important coal handling projects and technologies worldwide. It describes development by Aubema Crushing Technology GmbH, Bedeschi, Cimbria Moduflex, DBT, Dynamic Air Conveying Systems, E & F Services, InBulk Technologies, Nord-Sen Metal Industries Ltd., Pebco Inc, Primasonics International Ltd., R.J.S. Silo Clean (International) Ltd., Takraf GmbH, and The ACT Group. 17 photos.

  1. Iron - based bulk amorphous alloys

    Directory of Open Access Journals (Sweden)

    R. Babilas

    2010-07-01

    Full Text Available Purpose: The paper presents a structure characterization, thermal and soft magnetic properties analysis of Fe-based bulk amorphous materials in as-cast state and after crystallization process. In addition, the paper gives some brief review about achieving, formation and structure of bulk metallic glasses as a special group of amorphous materials.Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in form of ribbons and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM methods. The thermal properties of the glassy samples were measured using differential thermal analysis (DTA and differential scanning calorimetry (DSC. The magnetic properties contained initial and maximum magnetic permeability, coercive force and magnetic after-effects measurements were determined by the Maxwell-Wien bridge and VSM methods.Findings: The X-ray diffraction and transmission electron microscopy investigations revealed that the studied as-cast bulk metallic glasses in form of ribbons and rods were amorphous. Two stage crystallization process was observed for studied bulk amorphous alloy. The differences of crystallization temperature between ribbons and rods with chosen thickness are probably caused by different amorphous structures as a result of the different cooling rates in casting process. The SEM images showed that studied fractures could be classified as mixed fractures with indicated two zones contained “river” and “smooth” areas. The changing of chosen soft magnetic properties (μr, Bs, Hc obtained for samples with different thickness is a result of the non-homogenous amorphous structure of tested metallic glasses. The annealing process in temperature range from 373 to 773 K causes structural relaxation of tested amorphous materials, which leads to changes in their physical properties. The qualitative

  2. OCCUPATIONAL SEGREGATION BY GENDER - WHERE DOES ROMANIA STAND?

    Directory of Open Access Journals (Sweden)

    Manciu Venera

    2015-07-01

    Full Text Available The issue of occupational segregation is a topic discussed in the foreign economic literature, but on which documents written by Romanian authors are not so numerous. Still, during the last decades, this problem gained attention and began to preoccupy more individuals, especially on the basis of female emancipation process. In the past, various occupations were destined to be developed only by male employees. Women represent more than half of the overall population of the world. Even if prejudices on women are no longer as intense as they were in the past, and the access to education is widely open even in less-developed countries, consequently increasing the number of female workers, there are still several issues regarding occupational segregation and gender inequality that need to be solved. Today, many prejudices are lost, and female employees are more appreciated and manage to occupy traditional positions, as well as the ones that in the past were allocated only for the opposite gender. An assumption met in literature is that a rich country is able to confront more efficiently its problems and that the level of development should lower the gender gaps also. The purpose of this paper is to illustrate the situation of occupational segregation in Romania, through both theoretical and empirical methods. Still, the research is a qualitative one, considering that the available data is limited, at the present moment. The first part illustrates the concept of gender equality and occupational segregation, followed by an interpretation of the official data provided by the reports elaborated by the institutes in the field. The last part consist in a brief analysis of the relationship between the gender equality index and the economic growth, illustrated by the values of GDP.

  3. Self-consistent electronic structure and segregation profiles of the Cu-Ni (001) random-alloy surface

    DEFF Research Database (Denmark)

    Ruban, Andrei; Abrikosov, I. A.; Kats, D. Ya.; Gorelikov, D.; Jacobsen, Karsten Wedel; Skriver, Hans Lomholt

    1994-01-01

    We have calculated the electronic structure and segregation profiles of the (001) surface of random Cu-Ni alloys with varying bulk concentrations by means of the coherent potential approximation and the linear muffin-tin-orbitals method. Exchange and correlation were included within the local......-density approximation. Temperature effects were accounted for by means of the cluster-variation method and, for comparison, by mean-field theory. The necessary interaction parameters were calculated by the Connolly-Williams method generalized to the case of a surface of a random alloy. We find the segregation profiles...

  4. Possibilities of S-EMS utilization for the improvement of central segregation in continuously cast billets in conditions of TŽ

    Directory of Open Access Journals (Sweden)

    J. Cibulka

    2012-12-01

    Full Text Available Purpose: The aim of the paper is to investigate practical possibilities of the strand stirrer (S-EMS for the improvement of inner quality and central segregation in high carbon billets. An optimal S-EMS setting was proposed for the billet caster producing billets 150x150 mm.Design/methodology/approach: Impact of different S-EMS settings on central segregation and inner quality of as-cast billets was investigated. A set of longitudinal and transverse samples were analysed including evaluation of baumann prints and central segregation by means of LECO method. Samples of wires for segregation survey in rolled products were picked up as well.Findings: It was observed that application of the strand stirrer (S-EMS is capable to suppress central segregation. However, its impact is visible just to a certain stirring level. Subsequent increasing of stirring intensity does not cause further improvement of segregation in the analyzed central part. On the contrary, stronger white band can be seen in the solidification line. Moreover, concentration gradient between the central part and surrounding ring of negative central segregation is lowered. These two effects can play a significant role in the evaluation of segregation level in rolled wires.Research limitations/implications: Analysis of central segregation in a lower size than used 6 mm.Practical implications: Optimal S-EMS setting seems to be 300 A/14 Hz.Originality/value: Impact of S-EMS setting on changes in central segregation of as-cast billets, relationship between central segregation level in wires and cast structure.

  5. Racial Segregation and the American Foreclosure Crisis.

    Science.gov (United States)

    Rugh, Jacob S; Massey, Douglas S

    2010-10-01

    Although the rise in subprime lending and the ensuing wave of foreclosures was partly a result of market forces that have been well-identified in the literature, in the United States it was also a highly racialized process. We argue that residential segregation created a unique niche of poor minority clients who were differentially marketed risky subprime loans that were in great demand for use in mortgage-backed securities that could be sold on secondary markets. We test this argument by regressing foreclosure actions in the top 100 U.S. metropolitan areas on measures of black, Hispanic, and Asian segregation while controlling for a variety of housing market conditions, including average creditworthiness, the extent of coverage under the Community Reinvestment Act, the degree of zoning regulation, and the overall rate of subprime lending. We find that black residential dissimilarity and spatial isolation are powerful predictors of foreclosures across U.S. metropolitan areas. In order to isolate subprime lending as the causal mechanism whereby segregation influences foreclosures, we estimate a two-stage least squares model that confirms the causal effect of black segregation on the number and rate of foreclosures across metropolitan areas. In the United States segregation was an important contributing cause of the foreclosure crisis, along with overbuilding, risky lending practices, lax regulation, and the bursting of the housing price bubble. PMID:25308973

  6. Analysis and improvement of Brinkman lattice Boltzmann schemes: Bulk, boundary, interface. Similarity and distinctness with finite elements in heterogeneous porous media

    Science.gov (United States)

    Ginzburg, Irina; Silva, Goncalo; Talon, Laurent

    2015-02-01

    This work focuses on the numerical solution of the Stokes-Brinkman equation for a voxel-type porous-media grid, resolved by one to eight spacings per permeability contrast of 1 to 10 orders in magnitude. It is first analytically demonstrated that the lattice Boltzmann method (LBM) and the linear-finite-element method (FEM) both suffer from the viscosity correction induced by the linear variation of the resistance with the velocity. This numerical artefact may lead to an apparent negative viscosity in low-permeable blocks, inducing spurious velocity oscillations. The two-relaxation-times (TRT) LBM may control this effect thanks to free-tunable two-rates combination Λ . Moreover, the Brinkman-force-based BF-TRT schemes may maintain the nondimensional Darcy group and produce viscosity-independent permeability provided that the spatial distribution of Λ is fixed independently of the kinematic viscosity. Such a property is lost not only in the BF-BGK scheme but also by "partial bounce-back" TRT gray models, as shown in this work. Further, we propose a consistent and improved IBF-TRT model which vanishes viscosity correction via simple specific adjusting of the viscous-mode relaxation rate to local permeability value. This prevents the model from velocity fluctuations and, in parallel, improves for effective permeability measurements, from porous channel to multidimensions. The framework of our exact analysis employs a symbolic approach developed for both LBM and FEM in single and stratified, unconfined, and bounded channels. It shows that even with similar bulk discretization, BF, IBF, and FEM may manifest quite different velocity profiles on the coarse grids due to their intrinsic contrasts in the setting of interface continuity and no-slip conditions. While FEM enforces them on the grid vertexes, the LBM prescribes them implicitly. We derive effective LBM continuity conditions and show that the heterogeneous viscosity correction impacts them, a property also shared

  7. The acoustic and perceptual cues affecting melody segregation for listeners with a cochlear implant.

    Directory of Open Access Journals (Sweden)

    Jeremy eMarozeau

    2013-11-01

    Full Text Available Our ability to listen selectively to single sound sources in complex auditory environments is termed ‘auditory stream segregation.’ This ability is affected by peripheral disorders such as hearing loss, as well as plasticity in central processing such as occurs with musical training. Brain plasticity induced by musical training can enhance the ability to segregate sound, leading to improvements in a variety of auditory abilities. The melody segregation ability of 12 cochlear-implant recipients was tested using a new method to determine the perceptual distance needed to segregate a simple 4-note melody from a background of interleaved random-pitch distractor notes. In experiment 1, participants rated the difficulty of segregating the melody from distracter notes. Four physical properties of the distracter notes were changed. In experiment 2, listeners were asked to rate the dissimilarity between melody patterns whose notes differed on the four physical properties simultaneously. Multidimensional scaling analysis transformed the dissimilarity ratings into perceptual distances. Regression between physical and perceptual cues then derived the minimal perceptual distance needed to segregate the melody.The most efficient streaming cue for CI users was loudness. For the normal hearing listeners without musical backgrounds, a greater difference on the perceptual dimension correlated to the temporal envelope is needed for stream segregation in CI users. No differences in streaming efficiency were found between the perceptual dimensions linked to the F0 and the spectral envelope.Combined with our previous results in normally-hearing musicians and non-musicians, the results show that differences in training as well as differences in peripheral auditory processing (hearing impairment and the use of a hearing device influences the way that listeners use different acoustic cues for segregating interleaved musical streams.

  8. The acoustic and perceptual cues affecting melody segregation for listeners with a cochlear implant.

    Science.gov (United States)

    Marozeau, Jeremy; Innes-Brown, Hamish; Blamey, Peter J

    2013-01-01

    Our ability to listen selectively to single sound sources in complex auditory environments is termed "auditory stream segregation."This ability is affected by peripheral disorders such as hearing loss, as well as plasticity in central processing such as occurs with musical training. Brain plasticity induced by musical training can enhance the ability to segregate sound, leading to improvements in a variety of auditory abilities. The melody segregation ability of 12 cochlear-implant recipients was tested using a new method to determine the perceptual distance needed to segregate a simple 4-note melody from a background of interleaved random-pitch distractor notes. In experiment 1, participants rated the difficulty of segregating the melody from distracter notes. Four physical properties of the distracter notes were changed. In experiment 2, listeners were asked to rate the dissimilarity between melody patterns whose notes differed on the four physical properties simultaneously. Multidimensional scaling analysis transformed the dissimilarity ratings into perceptual distances. Regression between physical and perceptual cues then derived the minimal perceptual distance needed to segregate the melody. The most efficient streaming cue for CI users was loudness. For the normal hearing listeners without musical backgrounds, a greater difference on the perceptual dimension correlated to the temporal envelope is needed for stream segregation in CI users. No differences in streaming efficiency were found between the perceptual dimensions linked to the F0 and the spectral envelope. Combined with our previous results in normally-hearing musicians and non-musicians, the results show that differences in training as well as differences in peripheral auditory processing (hearing impairment and the use of a hearing device) influences the way that listeners use different acoustic cues for segregating interleaved musical streams. PMID:24223563

  9. Morphology versus vertical phase segregation in solvent annealed small molecule bulk heterojunction organic solar cells

    Czech Academy of Sciences Publication Activity Database

    Kovalenko, A.; Stoyanova, V.; Pospisil, J.; Zhivkov, I.; Fekete, Ladislav; Karashanova, D.; Kratochvílová, Irena; Vala, M.; Weiter, M.

    2015-01-01

    Roč. 2015, Oct (2015), s. 238981. ISSN 1110-662X R&D Projects: GA ČR(CZ) GA15-05095S; GA TA ČR TA04020156; GA MŠk LO1409 Institutional support: RVO:68378271 Keywords : organic solar cells Subject RIV: JJ - Other Materials Impact factor: 1.563, year: 2014

  10. Multiscale simulation of xenon diffusion and grain boundary segregation in UO2

    International Nuclear Information System (INIS)

    In light water reactor fuel, gaseous fission products segregate to grain boundaries, resulting in the nucleation and growth of large intergranular fission gas bubbles. The segregation rate is controlled by diffusion of fission gas atoms through the grains and interaction with the boundaries. Based on the mechanisms established from earlier density functional theory (DFT) and empirical potential calculations, diffusion models for xenon (Xe), uranium (U) vacancies and U interstitials in UO2 have been derived for both intrinsic (no irradiation) and irradiation conditions. Segregation of Xe to grain boundaries is described by combining the bulk diffusion model with a model for the interaction between Xe atoms and three different grain boundaries in UO2 (Sigma 5 tilt, Sigma 5 twist and a high angle random boundary), as derived from atomistic calculations. The present model does not attempt to capture nucleation or growth of fission gas bubbles at the grain boundaries. The point defect and Xe diffusion and segregation models are implemented in the MARMOT phase field code, which is used to calculate effective Xe and U diffusivities as well as to simulate Xe redistribution for a few simple microstructures

  11. Interactions between solidification and fluid flow. Effects on cast structures and segregations

    International Nuclear Information System (INIS)

    Natural or forced fluid flow of the bulk melt can induce several changes in the solidification history of a casting : it may change the heat transfer conditions, the as-cast grain distribution, and the segregations. On the other hand, solidification can result in intense fluid flow due to natural solutal convection and in severe local segregations. The two following practical cases illustrate the variety and complexity of interactions between the fluid flow and the solidification of alloys : a) the effects of the stirring of the bulk liquid on the formation of the equiaxed zone during the continuous casting of steels, b) the formation of freckles and related segregations during the directional solidification of nickel-base alloys. Informations are given about, either new experimental observations, or up-dated physical and numerical models related to each case chosen here as examples. In the case of the influence of stirring on the formation of the equiaxed zone, emphasis is put on the importance of the interaction of the fluid flow with the dendrites in the columnar zone and in the stirred region itself. In the case of the freckles, evidence is brought forward that the dendritic nature and structure of the mushy zone are not the only causes of the dependence of the freckling on the heat transfer conditions during directional solidification. (orig.)

  12. Correlation between segregation and cold cracking

    International Nuclear Information System (INIS)

    An attempt is made to find a correlation between segregation in ferritic base metal and the occurrence of cold cracking. Besides describing the mechanical and engineering properties and chemical composition of the segregated areas, the paper discusses their behaviour when welded over. Characteristics and models of crack development are presented using cold cracking found in various components as an example. Suitable measures for limiting the risk of the occurrence of cold cracking are increasing the pre-heating temperature, use of weld filler material with optimum dryness, and heat treatment directly following welding. (author)

  13. Scaling behaviour in size segregation ("Brazil Nuts")

    OpenAIRE

    Devillard, Pierre

    1990-01-01

    Using a previously introduced Monte Carlo method, due to Rosato, Prinz, Strandburg and Swendsen, we carry out in two dimensions numerical studies of size segregation, a phenomenon which occurs when a granular medium made of particles of different sizes is shaken. We propose a new scaling law relating the segregation velocity υ to the amplitude of shaking A and to the ratio R of the diameters of the small disks to the large disks. ForA larger than a critical amplitude Ac, a scaling law holds: ...

  14. Carbon Segregation of Bearing Steel Concasting Billet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The formation mechanism of “white band” and central carbon segregation of high-carbon Cr bearing steel concasting billets are discussed in this paper. The maximum oxygen content in the steel produced by concasting process was 13x10-6 with an average oxygen content of 9.3x 10-6.Comparison of metallurgical quality and fatigue property between the concasting steel (CC) andingot casting steel (IC) showed that the carbon segregation (C/C0) in former steel was 0.92~1.10and its fatigue life was equal to that of the latter steel.

  15. Wormholes in Bulk Viscous Cosmology

    OpenAIRE

    Jamil, Mubasher

    2008-01-01

    We investigate the effects of the accretion of phantom energy with non-zero bulk viscosity onto a Morris-Thorne wormhole. We have found that if the bulk viscosity is large then the mass of wormhole increases rapidly as compared to small or zero bulk viscosity.

  16. The Naturalization of Gender Segregation in a Danish Bank

    DEFF Research Database (Denmark)

    Grosen, Sidsel Lond; Holt, Helle; Lund, Henrik Lambrecht

    2012-01-01

    Through a qualitative interview analysis of a document handling department in a Danish bank this article seeks to illuminate central aspects of how some jobs come to be seen as naturally female. Taking gendered organizational theory and Joan Acker’s concept of an ideal employee as our point of...... example by framing women as good at multitasking, as enjoying routine work and as primary caregivers. The article argues that this construction both draws on and alters historically formed stereotypes in ways which reinforces the gender segregation of the organization and make it hard to change....

  17. The Naturalization of Gender Segregation in a Danish Bank

    DEFF Research Database (Denmark)

    Grosen, Sidsel Lond; Lund, Henrik Lambrecht; Holt, Helle

    2012-01-01

    Through a qualitative interview analysis of a document handling department in a Danish bank, this article seeks to illuminate central aspects of how some jobs come to be seen as naturally female. Taking gendered organizational theory and Joan Acker’s concept of an ideal employee as our point of...... example, by framing women as good at multitasking, as enjoying routine work, and as primary caregivers. The article argues that this construction both draws on and alters historically formed stereotypes in ways that reinforce the gender segregation of the organization and make it hard to change....

  18. Explosive bulk charge

    Science.gov (United States)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  19. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  20. Bulk muscles, loose cables.

    Science.gov (United States)

    Liyanage, Chamari R D G; Kodali, Venkata

    2014-01-01

    The accessibility and usage of body building supplements is on the rise with stronger internet marketing strategies by the industry. The dangers posed by the ingredients in them are underestimated. A healthy young man came to the emergency room with palpitations and feeling unwell. Initial history and clinical examination were non-contributory to find the cause. ECG showed atrial fibrillation. A detailed history for any over the counter or herbal medicine use confirmed that he was taking supplements to bulk muscle. One of the components in these supplements is yohimbine; the onset of symptoms coincided with the ingestion of this product and the patient is symptom free after stopping it. This report highlights the dangers to the public of consuming over the counter products with unknown ingredients and the consequential detrimental impact on health. PMID:25326558

  1. Chromosome segregation: learning to let go.

    Science.gov (United States)

    Higgins, Jonathan M G

    2013-10-01

    To ensure accurate chromosome segregation, cohesion between sister chromatids must be released in a controlled manner during mitosis. A new study reveals how distinct centromere populations of the cohesin protector Sgo1 are regulated by microtubule attachments, cyclin-dependent kinases, and the kinetochore kinase Bub1. PMID:24112985

  2. Segregation--The Act of Sequestering

    Science.gov (United States)

    Foster, Charlotte

    2011-01-01

    In this article, the author points out that there are many reasons why self-segregation takes place. For example: People with motorcycle interests may choose to hang out with other bikers. A group of bikers may have a common interest but can be as diverse as a doctor that is a biker or a janitor that is into biking. Formally educated people may…

  3. 49 CFR 176.83 - Segregation.

    Science.gov (United States)

    2010-10-01

    ... Federal Register citations affecting § 176.83, see the List of CFR Sections Affected, which appears in the... 49 Transportation 2 2010-10-01 2010-10-01 false Segregation. 176.83 Section 176.83 Transportation..., DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY VESSEL General...

  4. Is Racial Segregation Changing in Charter Schools?

    Science.gov (United States)

    Lee, Jin; Lubienski, Christopher

    2011-01-01

    Charter schools embody the theoretical potential to promote integration since they can draw students from across district boundaries that often reflect segregated residential patterns. While a number of studies have examined overall racial composition of charter schools, virtually no attention has been paid to how charter school enrollment…

  5. Field induced phase segregation in ferrofluids

    NARCIS (Netherlands)

    Kooij, E.S.; Galca, A.C.; Poelsema, B.

    2008-01-01

    We study the phase segregation in magnetite ferrofluids under the influence of an external magnetic field. A phase with lower nanoparticle density and corresponding higher optical transmission is formed in the bottom of a glass cell in the presence of only a very modest magnetic field gradient (smal

  6. The Strata-l Experiment on Microgravity Regolith Segregation

    Science.gov (United States)

    Fries, M.; Abell, P.; Brisset, J.; Britt, D.; Colwell, J.; Durda, D.; Dove, A.; Graham, L.; Hartzell, C.; John, K.; Leonard, M.; Love, S.; Sanchez, D. P.

    2016-01-01

    The Strata-1 experiment studies the segregation of small-body regolith through long-duration exposure of simulant materials to the microgravity environment on the International Space Station (ISS). Many asteroids feature low bulk densities, which implies high values of porosity and a mechanical structure composed of loosely bound particles, (i.e. the "rubble pile" model), a prime example of a granular medium. Even the higher-density, mechanically coherent asteroids feature a significant surface layer of loose regolith. These bodies will evolve in response to very small perturbations such as micrometeoroid impacts, planetary flybys, and the YORP effect. A detailed understanding of asteroid mechanical evolution is needed in order to predict the surface characteristics of as-of-yet unvisited bodies, to understand the larger context of samples from sample return missions, and to mitigate risks for both manned and unmanned missions to asteroidal bodies. Due to observation of rocky regions on asteorids such as Eros and Itokawa, it has been hypothesized that grain size distribution with depth on an asteroid may be inhomogeneous: specifically, that large boulders have been mobilized to the surface. In terrestrial environments, this size-dependent sorting to the surface of the sample is called the Brazil Nut Effect. The microgravity and acceleration environment on the ISS is similar that of a small asteroid. Thus, Strata-1 investigates size segregation of regolith in an environment analogous to that of small bodies. Strata-1 consists of four regolith simulants in evacuated tubes, as shown in Figure 1 (Top and Middle). The simulants are (1) a crushed and sieved ordinary chondrite meteorite to simulate an asteroidal surface, (2) a carbonaceous chondrite simulant with a mixture of fine and course particles, and two simplified silicate glass simulants; (3) one with angular and (4) another with spherical particles. These materials were chosen to span a range of granular

  7. Measuring Trends in Segregation: Three Dimensions, Three Measures.

    Science.gov (United States)

    Stearns, Linda Brewster; Logan, John R.

    1986-01-01

    Three commonly used measures of segregation (index of dissimilarity, p* interaction probabilities, and the correlation ratio) reflect three conceptually distinct aspects of racial residential segregation. The results of empirical studies will depend on the measure chosen. (Author/KH)

  8. Control on Housing Segregation:Housing Modes and Public Policies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>1. Housing segregation:advocating or controlling?The phenomenon of housing segregation has become more and more obvious in Chinese cities in recent years; however, there is no agreement on whether it should

  9. Surface segregation assessment in poly(epsilon-caprolactone)-poly(ethylene glycol) multiblock copolymer films.

    Science.gov (United States)

    Cometa, Stefania; Chiellini, Federica; Bartolozzi, Irene; Chiellini, Emo; De Giglio, Elvira; Sabbatini, Luigia

    2010-03-10

    The ability to predict the in vivo performance of multiblock-copolymer-based biomaterials is crucial for their applicability in the biomedical field. In this work, XPS analysis of PCL-PEG copolymers was carried out, as well as morphological and wettability evaluations by SEM and CA measurements, respectively. XPS analysis on films equilibrated in PBS demonstrated a further enrichment in the PEG component on the surface. Copolymer films obtained by casting using different solvents showed a dependence in segregation according to the solvent employed. Cell adhesion tests demonstrated the importance of copolymer segregation and rearrangement in a wet environment, with a dependence of these phenomena on the copolymer molecular weight. PMID:19957286

  10. Spatial segregation in eastern North Pacific skate assemblages.

    Science.gov (United States)

    Bizzarro, Joseph J; Broms, Kristin M; Logsdon, Miles G; Ebert, David A; Yoklavich, Mary M; Kuhnz, Linda A; Summers, Adam P

    2014-01-01

    Skates (Rajiformes: Rajoidei) are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP) skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude) and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1) Are there regions of differential importance to skates?, 2) Are ENP skate assemblages spatially segregated?, and 3) When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots) were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska). Spatial niche differentiation in skates appears to be more pronounced than previously reported. PMID:25329312

  11. Spatial segregation in eastern North Pacific skate assemblages.

    Directory of Open Access Journals (Sweden)

    Joseph J Bizzarro

    Full Text Available Skates (Rajiformes: Rajoidei are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1 Are there regions of differential importance to skates?, 2 Are ENP skate assemblages spatially segregated?, and 3 When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska. Spatial niche differentiation in skates appears to be more pronounced than previously reported.

  12. New atom probe approaches to studying segregation in nanocrystalline materials.

    Science.gov (United States)

    Samudrala, S K; Felfer, P J; Araullo-Peters, V J; Cao, Y; Liao, X Z; Cairney, J M

    2013-09-01

    Atom probe is a technique that is highly suited to the study of nanocrystalline materials. It can provide accurate atomic-scale information about the composition of grain boundaries in three dimensions. In this paper we have analysed the microstructure of a nanocrystalline super-duplex stainless steel prepared by high pressure torsion (HPT). Not all of the grain boundaries in this alloy display obvious segregation, making visualisation of the microstructure challenging. In addition, the grain boundaries present in the atom probe data acquired from this alloy have complex shapes that are curved at the scale of the dataset and the interfacial excess varies considerably over the boundaries, making the accurate characterisation of the distribution of solute challenging using existing analysis techniques. In this paper we present two new data treatment methods that allow the visualisation of boundaries with little or no segregation, the delineation of boundaries for further analysis and the quantitative analysis of Gibbsian interfacial excess at boundaries, including the capability of excess mapping. PMID:23485412

  13. Portable non-destructive assay methods for screening and segregation of radioactive waste

    International Nuclear Information System (INIS)

    Significant cost-savings and operational efficiency may be realised by performing rapid non-destructive classification of radioactive waste at or near its point of retrieval or generation. There is often a need to quickly categorize and segregate bulk containers (drums, crates etc.) into waste streams defined at various boundary levels (based on its radioactive hazard) in order to meet disposal regulations and consignor waste acceptance criteria. Recent improvements in gamma spectroscopy technologies have provided the capability to perform rapid in-situ analysis using portable and hand-held devices such as battery-operated medium and high resolution detectors including lanthanum halide and high purity germanium (HPGe). Instruments and technologies that were previously the domain of complex lab systems are now widely available as touch-screen 'off-the-shelf' units. Despite such advances, the task of waste stream screening and segregation remains a complex exercise requiring a detailed understanding of programmatic requirements and, in particular, the capability to ensure data quality when operating in the field. This is particularly so when surveying historical waste drums and crates containing heterogeneous debris of unknown composition. The most widely used portable assay method is based upon far-field High Resolution Gamma Spectroscopy (HRGS) assay using HPGe detectors together with a well engineered deployment cart (such as the PSC TechniCARTTM technology). Hand-held Sodium Iodide (NaI) detectors are often also deployed and may also be used to supplement the HPGe measurements in locating hot spots. Portable neutron slab monitors may also be utilised in cases where gamma measurements alone are not suitable. Several case histories are discussed at various sites where this equipment has been used for in-situ characterization of debris waste, sludge, soil, high activity waste, depleted and enriched uranium, heat source and weapons grade plutonium, fission products

  14. Workplace Segregation in the United States: Race, Ethnicity, and Skill

    OpenAIRE

    Judith Hellerstein; David Neumark

    2005-01-01

    We study workplace segregation in the United States using a unique matched employer-employee data set that we have created. We present measures of workplace segregation by education and language, and by race and ethnicity, and ­ since skill is often correlated with race and ethnicity ­ we assess the role of education- and language-related skill differentials in generating workplace segregation by race and ethnicity. We define segregation based on the extent to which workers are more or less l...

  15. Segregation phases in a vibrated binary granular layer

    OpenAIRE

    Reis, P. M.; Ehrhardt, G.; Mullin, T.

    2003-01-01

    We present the results of an experimental study of patterned segregation in a horizontally shaken shallow layer of a binary mixture of dry particles. As the compacity, $C$, of the mixture was increased, the evolution of three distinct phases was observed. We classify them as binary gas, segregation liquid and segregation crystal phases using macroscopic and microscopic measures. The binary gas to segregation liquid transition is consistent with a continuous phase transition and includes the c...

  16. Occupational Gender Segregation in the Czech Republic (in English)

    OpenAIRE

    Štìpán Jurajda; Michal Franta

    2007-01-01

    The authors use labor force survey data to provide a detailed description and an international comparison of the level and structure of occupational gender segregation in the Czech Republic during 1994–2004. Based on 1999 data, they find Czech occupational segregation to be close to the EU average, with the exception of young, highly educated Czech workers, who faced relatively high segregation. However, segregation has declined rapidly for young workers since 1999, mainly due to the increase...

  17. Tipping and Residential Segregation: A Unified Schelling Model

    OpenAIRE

    Zhang, Junfu

    2009-01-01

    This paper presents a Schelling-type checkerboard model of residential segregation formulated as a spatial game. It shows that although every agent prefers to live in a mixed-race neighborhood, complete segregation is observed almost all of the time. A concept of tipping is rigorously defined, which is crucial for understanding the dynamics of segregation. Complete segregation emerges and persists in the checkerboard model precisely because tipping is less likely to occur to such residential ...

  18. Residential Segregation Effects on Poor’s Opportunities in Chile

    OpenAIRE

    Osvaldo Larrañaga Jiménez; Claudia Sanhueza Riveros

    2007-01-01

    This paper aims to identify whether or not the spatial concentration of poverty –also called economic residential segregation- affects the opportunities of the poor in Chile. Residential segregation is understood as the concentration particular population groups in determined geographical areas within cities. To identify the effects of segregation we use a panel of cross sections of the Casen household surveys, although the measures of segregation are computed from the Census data. The result...

  19. Tipologia segregării sociale în mediul urban

    Directory of Open Access Journals (Sweden)

    Viorel MIONEL

    2010-06-01

    Full Text Available The urban space complexity develops with the spatial and human dimensions of the city. For instance, the bigger the city the more complex and more radical the urban processes and phenomena. Moreover, in the anthropic environment, the most important processes and phenomena are connected to the two core components of the city: the physical and the social component. As a process that becomes widespread and affects more and more the cities of the world, social segregation is a key component in the evolution of urban space. The understanding of the variety of social forms embodied segregation (racial, ethnic, socioeconomic, religion etc. can lead us to a better urban governance. So, started from a theoretical explanation of social components as part of urban segregation, based on real cases, this analysis aims to highlight the most important types of social segregation that occur in urban settings, as well as clarifying terminological ambiguity: social segregation or social marginalization? Therefore, the conclusion is that such an analysis is essential for urban or municipal authorities for more effective management of such public dysfunctions by formulating strategies.

  20. Contact and the ecology of racial division: some varieties of informal segregation.

    Science.gov (United States)

    Dixon, John; Durrheim, Kevin

    2003-03-01

    The analysis of contact between groups must proceed from an uncomfortable realization. Notwithstanding its formal abolition in many societies, segregation remains pervasive as an informal mechanism for ordering and defining social relations. Social psychologists' tendency to investigate contact under 'optimal' conditions may obscure this fact. This article discusses an observational study that attempted to chart some varieties of informal segregation on an 'open' beach in post-apartheid South Africa. The study used a novel methodology to plot the ecology of racial distribution within this public setting over time. The analysis, which included measures of dissimilarity (D) and exposure (P), indicated that processes of segregation operated in various ways to limit the opportunities for racial contact. Follow-up interviews conducted with 'white' holiday-makers suggested that such processes embodied shared assumptions about the 'proper' socio-spatial organization of race relations. Some implications for research on the contact hypothesis are discussed. PMID:12713753

  1. Not Just Urban Policy: Suburbs, Segregation, and Charter Schools

    Science.gov (United States)

    Frankenberg, Erica; Siegel-Hawley, Genevieve

    2012-01-01

    As the charter school sector expands rapidly with federal support amid on-going diversification and growing segregation among traditional public school students, this article examines existing patterns of segregation in charter schools. Prior research has demonstrated that charter schools are substantially more segregated than our already…

  2. Segregation of Granular Mixtures in a Rotating Drum

    OpenAIRE

    Puri, Sanjay; Hayakawa, Hisao

    1999-01-01

    We formulate a phenomenological model for the segregation of binary mixtures of rough and smooth granular materials in a rotating drum. Our model successfully replicates a range of experimental behaviours, e.g., rapid radial segregation; slow axial segregation; and nonuniform radial structure of axial bands. We present some analytical results and detailed numerical results for our model.

  3. 49 CFR 176.145 - Segregation in single hold vessels.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Segregation in single hold vessels. 176.145 Section 176.145 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.145 Segregation...

  4. What is the primary source of the morphological segregation?

    OpenAIRE

    Andreon, S.

    1997-01-01

    In Coma and two other clusters of galaxies the primary morphological segregation is the one with respect to a privileged direction. Only when this segregation is not considered it appears that the morphological types are segregated in density or in clustercentric distance.

  5. 27 CFR 24.27 - Segregation of operations.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Segregation of operations. 24.27 Section 24.27 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... Segregation of operations. The appropriate TTB officer may require the proprietor to segregate...

  6. Revisiting Residential Segregation by Income: A Monte Carlo Test

    OpenAIRE

    Junfu Zhang

    2003-01-01

    A long-standing hypothesis states that racial housing segregation in the U.S. results from the income inequalities between blacks and whites. This paper reexamines this hypothesis with a new methodology. We present a Monte Carlo study to show that segregation by income explains only a small proportion of the high level of segregation.

  7. Residential segregation of socioeconomic variables and health indices in Iran

    Directory of Open Access Journals (Sweden)

    Seyed Saeed Hashemi Nazari

    2013-01-01

    Conclusions: Correlation of segregation of determinants of socioeconomic status with segregation of health indices is an indicator of existence of hot zones of health problems across some provinces. Further studies using multilevel modeling and individual data in health outcomes at individual level and segregation measures at appropriate geographic levels are required to confirm these relations.

  8. 26 CFR 301.7507-3 - Segregated or transferred assets.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Segregated or transferred assets. 301.7507-3... States § 301.7507-3 Segregated or transferred assets. (a) In general. In a case involving segregated or transferred assets, it is not necessary, for application of section 7507, that the assets shall...

  9. Synthesis of Bulk Superconducting Magnesium Diboride

    Directory of Open Access Journals (Sweden)

    Margie Olbinado

    2002-06-01

    Full Text Available Bulk polycrystalline superconducting magnesium diboride, MgB2, samples were successfully prepared via a one-step sintering program at 750°C, in pre Argon with a pressure of 1atm. Both electrical resistivity and magnetic susceptibility measurements confirmed the superconductivity of the material at 39K, with a transition width of 5K. The polycrystalline nature, granular morphology, and composition of the sintered bulk material were confirmed using X-ray diffractometry (XRD, scanning electron microscopy (SEM, and energy dispersive X-ray analysis (EDX.

  10. Generative Models of Segregation: Investigating Model-Generated Patterns of Residential Segregation by Ethnicity and Socioeconomic Status

    OpenAIRE

    Fossett, Mark

    2011-01-01

    This paper considers the potential for using agent models to explore theories of residential segregation in urban areas. Results of generative experiments conducted using an agent-based simulation of segregation dynamics document that varying a small number of model parameters representing constructs from urban-ecological theories of segregation can generate a wide range of qualitatively distinct and substantively interesting segregation patterns. The results suggest how complex, macro-level ...

  11. First-Principles Study of Mo Segregation in MoNi(111: Effects of Chemisorbed Atomic Oxygen

    Directory of Open Access Journals (Sweden)

    Yanlin Yu

    2015-12-01

    Full Text Available Segregation at metal alloy surfaces is an important issue because many electrochemical and catalytic properties are directly correlated to the surface composition. We have performed density functional theory calculations for Mo segregation in MoNi(111 in the presence of chemisorbed atomic oxygen. In particular, the coverage dependence and possible adsorption-induced segregation phenomena are addressed by investigating segregation energies of the Mo atom in MoNi(111. The theoretical calculated results show that the Mo atom prefers to be embedded in the bulk for the clean MoNi(111, while it segregates to the top-most layer when the oxygen coverage is thicker than 1/9 monolayer (ML. Furthermore, we analyze the densities of states for the clean and oxygen-chemisorbed MoNi(111, and see a strong covalent bonding between Mo d-band states and O p-states. The present study provides valuable insight for exploring practical applications of Ni-based alloys as hydrogen evolution electrodes.

  12. Solute and vacancy segregation to a/4 and a/2 antiphase domain boundaries in Fe3Al

    International Nuclear Information System (INIS)

    Segregation of solute atoms and vacancies to antiphase domain boundaries (APDBs) in Fe-Al alloys near the stoichiometry Fe3Al (Fe-22-28 at.% Al) was studied using a phase-field model based on the Bragg-Williams approximation. Local equilibrium vacancy concentration was determined from experimental data for vacancy formation enthalpy and the configurational entropy of vacancies assuming that the formation enthalpy is independent of long-range order and chemical composition. Fe atoms and vacancies segregate to APDB with the phase-shift vector a/2(D03-APDB) in crystals with stoichiometric composition (Fe-25 at.% Al) and with the Fe-rich composition, whereas both of them tend to be depleted in Al-rich crystals. On the other hand, Fe atoms and vacancies both segregate on APDBs with the phase-shift vector a/4(B2-APDB) in all compositions studied. The effects of vacancy segregation on APDB energy and thickness is negligibly small; however, the vacancy concentration at the center of APDBs can be up to 80% larger than in the bulk, and therefore it is anticipated that the mobility of APDBs can be significantly affected by the segregation of vacancies as well as by that of solute atoms

  13. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and...... three low-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low...

  14. Orchestrating Bulk Data Movement in Grid Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vazhkudai, SS

    2005-01-25

    Data Grids provide a convenient environment for researchers to manage and access massively distributed bulk data by addressing several system and transfer challenges inherent to these environments. This work addresses issues involved in the efficient selection and access of replicated data in Grid environments in the context of the Globus Toolkit{trademark}, building middleware that (1) selects datasets in highly replicated environments, enabling efficient scheduling of data transfer requests; (2) predicts transfer times of bulk wide-area data transfers using extensive statistical analysis; and (3) co-allocates bulk data transfer requests, enabling parallel downloads from mirrored sites. These efforts have demonstrated a decentralized data scheduling architecture, a set of forecasting tools that predict bandwidth availability within 15% error and co-allocation architecture, and heuristics that expedites data downloads by up to 2 times.

  15. Time scale of entropic segregation of flexible polymers in confinement: Implications for chromosome segregation in filamentous bacteria

    OpenAIRE

    Arnold, Axel; Jun, Suckjoon

    2007-01-01

    We report molecular dynamics simulations of the segregation of two overlapping chains in cylindrical confinement. We find that the entropic repulsion between the chains can be sufficiently strong to cause segregation on a time scale that is short compared to the one for diffusion. This result implies that entropic driving forces are sufficiently strong to cause rapid bacterial chromosome segregation.

  16. From Schelling to Schools : A comparison of a model of residential segregation with a model of school segregation

    NARCIS (Netherlands)

    Stoica, Victor; Flache, Andreas

    2014-01-01

    We address theoretically whether and under what conditions Schelling's celebrated result of 'self-organized' unintended residential segregation may also apply to school segregation. We propose here a computational model of school segregation that is aligned with a corresponding Schelling-type model

  17. Unperturbed Schelling Segregation in Two or Three Dimensions

    Science.gov (United States)

    Barmpalias, George; Elwes, Richard; Lewis-Pye, Andrew

    2016-07-01

    Schelling's models of segregation, first described in 1969 (Am Econ Rev 59:488-493, 1969) are among the best known models of self-organising behaviour. Their original purpose was to identify mechanisms of urban racial segregation. But his models form part of a family which arises in statistical mechanics, neural networks, social science, and beyond, where populations of agents interact on networks. Despite extensive study, unperturbed Schelling models have largely resisted rigorous analysis, prior results generally focusing on variants in which noise is introduced into the dynamics, the resulting system being amenable to standard techniques from statistical mechanics or stochastic evolutionary game theory (Young in Individual strategy and social structure: an evolutionary theory of institutions, Princeton University Press, Princeton, 1998). A series of recent papers (Brandt et al. in: Proceedings of the 44th annual ACM symposium on theory of computing (STOC 2012), 2012); Barmpalias et al. in: 55th annual IEEE symposium on foundations of computer science, Philadelphia, 2014, J Stat Phys 158:806-852, 2015), has seen the first rigorous analyses of 1-dimensional unperturbed Schelling models, in an asymptotic framework largely unknown in statistical mechanics. Here we provide the first such analysis of 2- and 3-dimensional unperturbed models, establishing most of the phase diagram, and answering a challenge from Brandt et al. in: Proceedings of the 44th annual ACM symposium on theory of computing (STOC 2012), 2012).

  18. Rock fracture by ice segregation: linking laboratory modelling and rock slope erosion

    Science.gov (United States)

    Murton, J.

    2009-04-01

    It has been unclear until recently if ice can fracture intact bedrock subject to natural freezing regimes, or whether it simply enlarges existing fractures or does both. This question is important, because if ice segregation in bedrock permafrost is widespread, then there may be considerable potential for significantly increased rock slope instability as ice-cemented discontinuities warm and active layers thicken. Laboratory modelling has now begun to elucidate the process of ice segregation in bedrock. Laboratory experiments indicate that moist, porous rock behaves remarkably like moist, frost-susceptible soil, with both substrates experiencing ice enrichment and fracture / fissuring of near-surface permafrost. It appears that significant concentrations of segregated ice are most likely in the transition zone between the active layer and the permafrost, as a result of downward migration of water in summer and upward advance of freezing at the beginning of the winter. Laboratory modelling indicates that given adequate water supply, ice segregation produces a zone of ice-bonded fractured bedrock immediately below the permafrost table. In general, the importance of ice segregation relative to in situ volume expansion increases with decreasing thermal gradients and increasing duration of freezing. Recent theoretical developments suggest that the maximum possible disjointing pressure is governed by the temperature depression below the bulk-melting point, even in the absence of large temperature gradients, and therefore slow ice segregation in bedrock may be possible at greater depths where the frozen permeability of rock limits the actual amount of heave produced. Thus, over long timescales, ice segregation may be highly significant in frozen steep bedrock slopes where the presence of ice-rich fractured bedrock may be critically important in releasing rock falls and rock slides during climate-induced warming and permafrost degradation. With recent climate warming

  19. Sensitivity of absorption spectra to surface segregation in InGaN/GaN quantum well structures

    International Nuclear Information System (INIS)

    We investigate the influence of the indium surface segregation on absorption spectra in InGaN/GaN quantum well structures having different indium amount. Results of the mathematical modeling show that such influence is more pronounced in quantum well structures with high indium amounts. The origin of this effect is related to the interplay between the indium surface segregation and internal electrostatic fields. Our theoretical analysis is performed using semiconductor Bloch equations within the Hartree-Fock approximation including into consideration excitonic effects. Results of the global sensitivity analysis evidence that the influence of the indium surface segregation is less than one order of magnitude in comparison with the impact of the quantum-well width and indium molar fraction. Also, the influence of the indium surface segregation is not the same for each interface of the quantum well

  20. Bulk Stable Isotope Analysis of Carbon from Solids and Liquids using an Elemental Analyzer Coupled to a Wavelength-Scanned Cavity Ring-Down Spectrophotometer

    Science.gov (United States)

    Saad, N.; Rella, C.; van Pelt, A.

    2009-04-01

    We report here on the novel employment of a small footprint Wavelength-Scanned Cavity Ring-Down Spectrometer (WS-CRDS) interfaced to an elemental analyzer for the measurement of the bulk isotopic carbon signature in plants and food products. The current system provides an inexpensive alternative with unparalleled ease-of-use as compared to standard methods using the more complex analytical instrumentation of isotope ratio mass spectrometry. A precision of carbon isotopic ratio measurements of less than 1 permil was achieved in minutes of measurement time. Such precision readily distinguishes the isotopic carbon signatures of a variety of environmental and agricultural products from different origins, providing information about food authenticity and climate changes effect on plant physiology.