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Sample records for composite gre sites

  1. Beyond the GRE: Using a Composite Score to Predict 
the Success of Puerto Rican Students in a Biomedical 
PhD Program

    PubMed Central

    Pacheco, Wendy I.; Noel, Richard J.; Porter, James T.; Appleyard, Caroline B.

    2015-01-01

    The use and validity of the Graduate Record Examination General Test (GRE) to predict the success of graduate school applicants is heavily debated, especially for its possible impact on the selection of underrepresented minorities into science, technology, engineering, and math fields. To better identify candidates who would succeed in our program with less reliance on the GRE and grade point average (GPA), we developed and tested a composite score (CS) that incorporates additional measurable predictors of success to evaluate incoming applicants. Uniform numerical values were assigned to GPA, GRE, research experience, advanced course work or degrees, presentations, and publications. We compared the CS of our students with their achievement of program goals and graduate school outcomes. The average CS was significantly higher in those students completing the graduate program versus dropouts (p < 0.002) and correlated with success in competing for fellowships and a shorter time to thesis defense. In contrast, these outcomes were not predicted by GPA, science GPA, or GRE. Recent implementation of an impromptu writing assessment during the interview suggests the CS can be improved further. We conclude that the CS provides a broader quantitative measure that better predicts success of students in our program and allows improved evaluation and selection of the most promising candidates. PMID:25828404

  2. Beyond the GRE: using a composite score to predict 
the success of Puerto Rican students in a biomedical 
PhD program.

    PubMed

    Pacheco, Wendy I; Noel, Richard J; Porter, James T; Appleyard, Caroline B

    2015-01-01

    The use and validity of the Graduate Record Examination General Test (GRE) to predict the success of graduate school applicants is heavily debated, especially for its possible impact on the selection of underrepresented minorities into science, technology, engineering, and math fields. To better identify candidates who would succeed in our program with less reliance on the GRE and grade point average (GPA), we developed and tested a composite score (CS) that incorporates additional measurable predictors of success to evaluate incoming applicants. Uniform numerical values were assigned to GPA, GRE, research experience, advanced course work or degrees, presentations, and publications. We compared the CS of our students with their achievement of program goals and graduate school outcomes. The average CS was significantly higher in those students completing the graduate program versus dropouts (p < 0.002) and correlated with success in competing for fellowships and a shorter time to thesis defense. In contrast, these outcomes were not predicted by GPA, science GPA, or GRE. Recent implementation of an impromptu writing assessment during the interview suggests the CS can be improved further. We conclude that the CS provides a broader quantitative measure that better predicts success of students in our program and allows improved evaluation and selection of the most promising candidates. PMID:25828404

  3. Physics GRE Practice

    NASA Astrophysics Data System (ADS)

    Ernst, David

    2008-10-01

    This session is for students to practice the physics subject matter GRE exam. Guidance on taking the exam will be given. The students will be furnished a collection of problems taken from previous exams. Students will practice a couple problems and discuss the underlying physics knowledge and strategies that relate to these problems.

  4. GRE Policies in Electrical Engineering.

    ERIC Educational Resources Information Center

    Morris, J. E.

    1987-01-01

    Describes a survey of electrical engineering education departments at 147 universities to find out if the Graduate Record Examinations (GRE) were used in the admissions process and under what conditions. Tabulates the data according to GRE requirements. Discusses the purposes of requiring the GRE in admissions. (CW)

  5. Beyond the GRE: Using a Composite Score to Predict the Success of Puerto Rican Students in a Biomedical PhD Program

    ERIC Educational Resources Information Center

    Pacheco, Wendy I.; Noel, Richard J., Jr.; Porter, James T.; Appleyard, Caroline B.

    2015-01-01

    The use and validity of the Graduate Record Examination General Test (GRE) to predict the success of graduate school applicants is heavily debated, especially for its possible impact on the selection of underrepresented minorities into science, technology, engineering, and math fields. To better identify candidates who would succeed in our program…

  6. Crystal Structure of Thermus Aquaticus Gfh1, a Gre-factor Paralog that Inhibits rather than Stimulates transcript Cleavage

    SciTech Connect

    Lamour,V.; Hogan, B.; Erie, D.; Darst, S.

    2006-01-01

    Transcription elongation in bacteria is promoted by Gre-factors, which stimulate an endogenous, endonucleolytic transcript cleavage activity of the RNA polymerase. A GreA paralog, Gfh1, present in Thermus aquaticus and Thermus thermophilus, has the opposite effect on elongation complexes, inhibiting rather than stimulating transcript cleavage. We have determined the 3.3 Angstroms-resolution X-ray crystal structure of T. aquaticus Gfh1. The structure reveals an N-terminal and a C-terminal domain with close structural similarity to the domains of GreA, but with an unexpected conformational change in terms of the orientation of the domains with respect to each other. However, structural and functional analysis suggests that when complexed with RNA polymerase, Gfh1 adopts a conformation similar to that of GreA. These results reveal considerable structural flexibility for Gfh1, and for Gre-factors in general, as suggested by structural modeling, and point to a possible role for the conformational switch in Gre-factor and Gfh1 regulation. The opposite functional effect of Gfh1 compared with GreA may be determined by three structural characteristics. First, Gfh1 lacks the basic patch present in Gre-factors that likely plays a role in anchoring the 3'-fragment of the backtracked RNA. Second, the loop at the tip of the N-terminal coiled-coil is highly flexible and contains extra acidic residues compared with GreA. Third, the N-terminal coiled-coil finger lacks a kink in the first a-helix, resulting in a straight coiled-coil compared with GreA. The latter two characteristics suggest that Gfh1 chelates a magnesium ion in the RNA polymerase active site (like GreA) but in a catalytically inactive configuration.

  7. Cliffs' GRE StudyWare Package: A Critical Evaluation.

    ERIC Educational Resources Information Center

    Brooke, Stephanie L.

    1995-01-01

    Provides evaluation of Cliffs' GRE StudyWare package (Bobrow, 1992). Discusses the educational implications of using Cliffs' approach, in addition to focusing on software considerations. Makes recommendations concerning Cliffs' method for Graduate Record Examination (GRE) preparation. (Author/LKS)

  8. The Predictive Validity of GRE Aptitude Test.

    ERIC Educational Resources Information Center

    Kaiser, Javaid

    The continued controversy concerning the predictive validity of the Graduate Record Examination (GRE) aptitude test and its influence on selection decisions, including admission and financial aid, has necessitated the establishment of local norms. The sample involved 407 University of Kansas education and computer science students. Information on…

  9. The GRE Psychology Test: A Useful but Poorly Understood Test.

    ERIC Educational Resources Information Center

    Kalat, James W.; Matlin, Margaret W.

    2000-01-01

    Provides an overview of the Graduate Record Examination (GRE) Psychology test focusing on the scoring system for the GRE Psychology test, who prepares the test and how the test is prepared, and the usefulness of the GRE Psychology test. Explores some future directions for the test. (CMK)

  10. Faculty Forum: The GRE Analytical Writing Test-- Description and Utilization

    ERIC Educational Resources Information Center

    Briihl, Deborah S.; Wasieleski, David T.

    2007-01-01

    The authors surveyed graduate programs to see how they use the Graduate Record Examination Analytic Writing (GRE-AW) Test. Only 35% of the graduate programs that responded use the GRE-AW test in their admission policy; of the programs not using it, most do not plan to do so. The programs using the GRE-AW rated it as medium or low in importance in…

  11. Comparative Validity of the GRE-Analytical Test.

    ERIC Educational Resources Information Center

    Mowsesian, Richard; Hays, William L.

    The predictive validity of the revised Graduate Record Examination Analytical Test (GRE-A) was compared with the experimental form of the GRE-A, in terms of graduate school admissions as well as advancement to Ph.D. candidacy decisions. Prior to 1974 the Graduate Record Examination included just a verbal and a quantitative test; in 1974 it was…

  12. The Correlation Between GRE Scores and Performance in Graduate School

    NASA Astrophysics Data System (ADS)

    Morin, David

    1996-05-01

    We investigate the correlation between GRE scores and various measures of performance for graduate students in the Physics Department at Harvard University. We consider students who entered the program between 1980 and 1989. The degree to which GRE scores can predict performance is shown for different subgroups of students.

  13. Effect of Extra Time on Verbal and Quantitative GRE Scores

    ERIC Educational Resources Information Center

    Bridgeman, Brent; Cline, Frederick; Hessinger, James

    2004-01-01

    The Graduate Record Examination General Test (GRE) is a measure of academic reasoning abilities that is intended to be a power test in which speed of responding plays at most a minor role. To test this assumption, we experimentally administered both the verbal and quantitative sections of the GRE with standard time limits and with 1.5 times the…

  14. Perceptions of International Students toward Graduate Record Examination (GRE)

    ERIC Educational Resources Information Center

    Mupinga, Emily E.; Mupinga, Davison M.

    2005-01-01

    The Graduate Record Examination (GRE) is an aptitude test, thought to reflect intelligence or the capacity to learn (Larsen & Buss, 2003). It is a standardized admission exam designed to predict performance in graduate school through verbal, quantitative, and analytical reasoning questions. The GRE Board encourages graduate schools, departments,…

  15. A novel dissociative steroid VBP15 reduces MUC5AC gene expression in airway epithelial cells but lacks the GRE mediated transcriptional properties of dexamethasone.

    PubMed

    Garvin, Lindsay M; Chen, Yajun; Damsker, Jesse M; Rose, Mary C

    2016-06-01

    Overproduction of secretory mucins contributes to morbidity/mortality in inflammatory lung diseases. Inflammatory mediators directly increase expression of mucin genes, but few drugs have been shown to directly repress mucin gene expression. IL-1β upregulates the MUC5AC mucin gene in part via the transcription factors NFκB while the glucocorticoid Dexamethasone (Dex) transcriptionally represses MUC5AC expression by Dex-activated GR binding to two GRE cis-sites in the MUC5AC promoter in lung epithelial cells. VBP compounds (ReveraGen BioPharma) maintain anti-inflammatory activity through inhibition of NFκB but exhibit reduced GRE-mediated transcriptional properties associated with adverse side-effects and thus have potential to minimize harmful side effects of long-term steroid therapy in inflammatory lung diseases. We investigated VBP15 efficacy as an anti-mucin agent in two types of airway epithelial cells and analyzed the transcription factor activity and promoter binding associated with VBP15-induced MUC5AC repression. VBP15 reduced MUC5AC mRNA abundance in a dose- and time-dependent manner similar to Dex in the presence or absence of IL-1β in A549 and differentiated human bronchial epithelial cells. Repression was abrogated in the presence of RU486, demonstrating a requirement for GR in the VBP15-induced repression of MUC5AC. Inhibition of NFκB activity resulted in reduced baseline expression of MUC5AC indicating that constitutive activity maintains MUC5AC production. Chromatin immunoprecipitation analysis demonstrated lack of GR and of p65 (NFκB) binding to composite GRE domains in the MUC5AC promoter following VBP15 exposure of cells, in contrast to Dex. These data demonstrate that VBP15 is a novel anti-mucin agent that mediates the reduction of MUC5AC gene expression differently than the classical glucocorticoid, Dex. PMID:27133900

  16. Highly inducible expression from vectors containing multiple GRE's in CHO cells overexpressing the glucocorticoid receptor.

    PubMed Central

    Israel, D I; Kaufman, R J

    1989-01-01

    A conditional glucocorticoid-responsive expression vector system is described for highly inducible expression of heterologous genes in mammalian cells. This host-vector system requires high level expression of the glucocorticoid receptor (GR) protein in the host cell and multiple copies of the receptor binding site within the expression vector. Transfection and selection of Chinese hamster ovary cells with expression vectors encoding the rat GR yielded cell lines which express functional receptor at high levels. Insertion of multiple copies of the MMTV enhancer (glucocorticoid responsive element, GRE) into an Adenovirus major late promoter (AdMLP) based expression vector yielded greater than 1000-fold inducible expression by dexamethasone (dex) in transient DNA transfection assays. The induced expression level was 7-fold greater than that obtained with an AdMLP based vector containing an SV40 enhancer, but lacking GRE's. Vectors containing the SV40 enhancer in combination with multiple GRE's exhibited elevated basal expression in the absence of dex, but retained inducibility in both transient assays and after integration and amplification in the CHO genome. This expression system should be of general utility for studying gene regulation and for expressing heterologous genes in a regulatable fashion. Images PMID:2546123

  17. Using Minimum Acceptable GRE Scores for Graduate Admissions Suppresses Diversity

    NASA Astrophysics Data System (ADS)

    Miller, Casey

    2014-01-01

    I will present data showing that significant performance disparities on the GRE general test exist based on the test taker's race and gender [1]. Because of the belief that high GRE scores qualify one for graduate studies, the diversity issues faced by STEM fields may originate, at least in part, in misuse of the GRE scores by graduate admissions committees. I will quantitatively demonstrate this by showing that the combination of a hard cut-off and the different score distributions leads to the systematic underrepresentation of certain groups. I will present data from USF’s PhD program that shows a lack of correlation between GRE scores and research ability; similar null results are emerging from numerous other programs. I will then discuss how assessing non-cognitive competencies in the selection process may lead to a more enlightened search for the next generation of scientists. [1] C. W. Miller, "Admissions Criteria and Diversity in Graduate School", APS News Vol 22, Issue 2, The Back Page (2013) http://www.aps.org/publications/apsnews/201302/backpage.cfm

  18. The GRE: A Barrier to Women Returning to Graduate School?

    ERIC Educational Resources Information Center

    Tisue, Linda J.; Whitaker, Dianne P.

    1999-01-01

    Discusses the Graduate Record Examination (GRE) as a possible admission barrier for women returning to graduate school, including data from an informal survey of ten universities in the southeastern United States. The validity of the exams for this population is examined, and alternatives are suggested for identifying older adult women who would…

  19. Scattering from conducting open cavities by generalized ray expansion (GRE)

    NASA Astrophysics Data System (ADS)

    Garcia-Pino, Antonio; Obelleiro, Fernando; Rodriguez, Jose L.

    1993-07-01

    The problem of electromagnetic (EM) scattering by metallic open cavities is addressed here using a generalized ray expansion (GRE) method. The wave coupled into the cavity is modeled as a combination of a number of spherical waves, the propagation of such waves being described in terms of geometrical optics (GO). A brief description of the method including some details about aperture discretization as well as results for three-dimensional problems such as circular and rectangular cross-section cavities are presented. The GRE method gives results that agree well with those of modal analysis and allow, like ray methods, for greater flexibility in geometric modeling. Furthermore, the ray-tracing process must be done only once for different incident waves, so its computational cost is lower than that of the classic ray methods, where the incoming wave is described as a different bundle of parallel rays for each direction of incidence.

  20. Turning the knots in your stomach into bows: Reappraising arousal improves performance on the GRE

    PubMed Central

    Jamieson, Jeremy P.; Mendes, Wendy Berry; Blackstock, Erin; Schmader, Toni

    2009-01-01

    This research examined the benefits of interpreting physiological arousal as a challenge response on practice and actual Graduate Record Examination (GRE) scores. Participants who were preparing to take the GRE reported to the laboratory for a practice GRE study. Participants assigned to a reappraisal condition were told arousal improves performance, whereas control participants were not given this information. We collected saliva samples at baseline and after the appraisal manipulation, which were then assayed for salivary alpha amylase (sAA), a measure of sympathetic nervous system activation. Reappraisal participants exhibited a significant increase in sAA and outperformed controls on the GRE-math section. One to three months later, participants returned to the lab and provided their score reports from their actual GRE. Again, reappraisal participants scored higher than controls on the GRE-math section. These findings illuminate the powerful influence appraisal has on physiology and performance both in and out of the laboratory. PMID:20161454

  1. Gasoline Composition Regulations Affecting LUST Sites

    EPA Science Inventory

    Passage of the Clean Air Act Amendments in 1990 imposed requirements on gasoline composition in the United States. Impacts to ground water are affected by the provisions that required oxygenated additives and limited benzene concentration. Reformulated and oxygenated gasoline w...

  2. New test data on structural behavior of GRE pipe and joint systems

    SciTech Connect

    Ma, A.; Bellamy, M.J.; Williams, S.P.

    1995-12-31

    In order to generate essential information for design purposes, a series of tests on the structural behavior of Glass Reinforced Epoxy (GRE) pipe and joint systems has now been completed. The testing program formed part of a research program, funded by the European Commission, the UK Health and Safety Executive and industry, on the development of using GRE piping systems offshore. The tests generated information on modulus of elasticity, axial strength and fatigue life for GRE pipe and joint systems. The test program and the results obtained are disseminated in this paper. The test program carries a certificate issued by Lloyd`s Register of Shipping for the suitability of GRE pipes tested.

  3. GRE as a Predictor of Graduate Student Success at a Hispanic Serving Institution of Higher Education

    ERIC Educational Resources Information Center

    Perez, Katherine

    2011-01-01

    Accurately predicting the success of graduate students is an important aspect of determining which students should be admitted into graduate programs. The GRE is a pivotal factor to examine since it is one of the most widely used criteria for graduate school admission. Even though the GRE is advertised as an accurate tool for predicting first year…

  4. A GRE Test for the STEM Disciplines: Developing an Assessment "of" and "for" Learning

    ERIC Educational Resources Information Center

    Payne, David G.; Briel, Jacqueline B.; Hawthorn, John; Riedeburg, Karen

    2006-01-01

    Plans are described for creating a Graduate Record Examination (GRE) test for the STEM (science, technology, engineering, and mathematics) disciplines. Previous work showed that a quantitative measure for the STEM disciplines exacerbated group differences beyond those reflected in the current GRE General Test. A test development approach is…

  5. Graduate Record Examination (GRE) Scores as an Assessment Tool. AIR 1998 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Underwood, David G.; Craighead, Michelle M.

    This paper examines whether graduate record examination (GRE) scores are a legitimate assessment tool for measuring institutional accountability and effectiveness that is, how well its graduates will do after having attended the institution for four or more years. Following a discussion of the various pros and cons of using the GRE as an…

  6. How Selective Are Psychology Graduate Programs? The Effect of the Selection Ratio on GRE Score Validity.

    ERIC Educational Resources Information Center

    Chernyshenko, Oleksandr S.; Ones, Deniz S.

    1999-01-01

    Examined the selection ratio for 253 doctorate-level psychology programs. Used the selection ratio to estimate the existing range restriction on the Graduate Examination (GRE) (referred to as General Record Examination) scores in validation studies. Results show that the GRE is a valid predictor of graduate school performance. (SLD)

  7. A Study of the Validity of the GRE Battery in Predicting Four Criteria of Success in Doctoral Degree Programs

    ERIC Educational Resources Information Center

    Houston, Samuel H.; Strohmeyer, Eric

    1970-01-01

    Predictor variables included two Graduate Record Examination (GRE) aptitude scores, three GRE area scores, plus the GRE advanced education score. Criterion variables included: (a) grade point average; (b) graduation versus dismissal from program; (c) normative judgment analysis (JAN) rating; and (d) ipsative JAN rating. Except for normative JAN…

  8. ER–endosome contact sites: molecular compositions and functions

    PubMed Central

    Raiborg, Camilla; Wenzel, Eva M; Stenmark, Harald

    2015-01-01

    Recent studies have revealed the existence of numerous contact sites between the endoplasmic reticulum (ER) and endosomes in mammalian cells. Such contacts increase during endosome maturation and play key roles in cholesterol transfer, endosome positioning, receptor dephosphorylation, and endosome fission. At least 7 distinct contact sites between the ER and endosomes have been identified to date, which have diverse molecular compositions. Common to these contact sites is that they impose a close apposition between the ER and endosome membranes, which excludes membrane fusion while allowing the flow of molecular signals between the two membranes, in the form of enzymatic modifications, or ion, lipid, or protein transfer. Thus, ER–endosome contact sites ensure coordination of molecular activities between the two compartments while keeping their general compositions intact. Here, we review the molecular architectures and cellular functions of known ER–endosome contact sites and discuss their implications for human health. PMID:26041457

  9. Site-specific group selection drives locally adapted group compositions.

    PubMed

    Pruitt, Jonathan N; Goodnight, Charles J

    2014-10-16

    Group selection may be defined as selection caused by the differential extinction or proliferation of groups. The socially polymorphic spider Anelosimus studiosus exhibits a behavioural polymorphism in which females exhibit either a 'docile' or 'aggressive' behavioural phenotype. Natural colonies are composed of a mixture of related docile and aggressive individuals, and populations differ in colonies' characteristic docile:aggressive ratios. Using experimentally constructed colonies of known composition, here we demonstrate that population-level divergence in docile:aggressive ratios is driven by site-specific selection at the group level--certain ratios yield high survivorship at some sites but not others. Our data also indicate that colonies responded to the risk of extinction: perturbed colonies tended to adjust their composition over two generations to match the ratio characteristic of their native site, thus promoting their long-term survival in their natal habitat. However, colonies of displaced individuals continued to shift their compositions towards mixtures that would have promoted their survival had they remained at their home sites, regardless of their contemporary environment. Thus, the regulatory mechanisms that colonies use to adjust their composition appear to be locally adapted. Our data provide experimental evidence of group selection driving collective traits in wild populations. PMID:25274310

  10. Coma chemical composition at the Abydos landing site

    NASA Astrophysics Data System (ADS)

    Morse, A.; Sheridan, S.; Morgan, G.; Andrews, D.; Barber, S.; Wright, I.

    2015-10-01

    The Ptolemy instrument, onboard the Rosetta Philae Lander, made measurements of the chemical composition of the coma mid-bounce, just after the non-nominal landing on the surface, and subsequently at the Abydos landing site. This presentation will discuss Ptolemy's operations throughout this 45 hour period and the results obtained.

  11. Developing Macroinvertebrate Indicators for the Mid-continent Great Rivers: Lessons from EMAP-GRE

    EPA Science Inventory

    As part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE) we developed new macroinvertebrate-assemblage based indicators of condition. In this presentation, we will summarize some of the practical and philosophical challenges encountered...

  12. Imprecise transcription termination within Escherichia coli greA leader gives rise to an array of short transcripts, GraL

    PubMed Central

    Potrykus, Katarzyna; Murphy, Helen; Chen, Xiongfong; Epstein, Jonathan A.; Cashel, Michael

    2010-01-01

    We report that greA expression is driven by two strong, overlapping P1 and P2 promoters. The P1 promoter is σ70-dependent and P2 is σE-dependent. Two-thirds of transcripts terminate within the leader region and the remaining third comprises greA mRNA. Termination efficiency seems to be unaffected by growth phase. Two collections of small 40–50 (initiating from P2) and 50–60 nt (from P1) RNA chains, termed GraL, are demonstrable in vivo and in vitro. We document that GraL arrays arise from an intrinsic terminator with an 11 bp stem followed by an AU7GCU2 sequence. Atypical chain termination occurs at multiple sites; the 3′-ends differ by 1 nt over a range of 10 nt. Transcripts observed are shown to be insensitive to Gre factors and physically released from RNAP–DNA complexes. The abundance of individual chains within each cluster displays a characteristic pattern, which can be differentially altered by oligonucleotide probes. Multiple termination sites are particularly sensitive to changes at the bottom of the stem. Evolutionarily conserved GraL stem structures and fitness assays suggest a biological function for the RNA clusters themselves. Although GraL overexpression induces ≥3-fold transcriptional changes of over 100 genes, a direct target remains elusive. PMID:20008510

  13. Comparison between optimized GRE and RARE sequences for 19F MRI studies

    NASA Astrophysics Data System (ADS)

    Soffientini, Chiara D.; Mastropietro, Alfonso; Caffini, Matteo; Cocco, Sara; Zucca, Ileana; Scotti, Alessandro; Baselli, Giuseppe; Bruzzone, Maria Grazia

    2014-03-01

    In 19F-MRI studies limiting factors are the presence of a low signal due to the low concentration of 19F-nuclei, necessary for biological applications, and the inherent low sensitivity of MRI. Hence, acquiring images using the pulse sequence with the best signal to noise ratio (SNR) by optimizing the acquisition parameters specifically to a 19F compound is a core issue. In 19F-MRI, multiple-spin-echo (RARE) and gradient-echo (GRE) are the two most frequently used pulse sequence families; therefore we performed an optimization study of GRE pulse sequences based on numerical simulations and experimental acquisitions on fluorinated compounds. We compared GRE performance to an optimized RARE sequence. Images were acquired on a 7T MRI preclinical scanner on phantoms containing different fluorinated compounds. Actual relaxation times (T1, T2, T2*) were evaluated in order to predict SNR dependence on sequence parameters. Experimental comparisons between spoiled GRE and RARE, obtained at a fixed acquisition time and in steady state condition, showed RARE sequence outperforming the spoiled GRE (up to 406% higher). Conversely, the use of the unbalanced-SSFP showed a significant increase in SNR compared to RARE (up to 28% higher). Moreover, this sequence (as GRE in general) was confirmed to be virtually insensitive to T1 and T2 relaxation times, after proper optimization, thus improving marker independence from the biological environment. These results confirm the efficacy of the proposed optimization tool and foster further investigation addressing in-vivo applicability.

  14. Reducing Test Form Overlap of the GRE Subject Test in Mathematics Using IRT Triple-Part Equating. GRE Board Professional Report No. 86-14P.

    ERIC Educational Resources Information Center

    McKinley, Robert L.; Schaeffer, Gary A.

    A study was conducted to evaluate the feasibility of using item response theory (IRT) equating to reduce test form overlap of the Graduate Record Examinations (GRE) Subject Test in Mathematics. Monte Carlo methods were employed to compare double-part equating with 20-item common item blocks to triple-part equating with 10-item common item blocks.…

  15. An Investigation of the Feasibility of Obtaining Additional Subscores on the GRE Advanced Psychology Test. GRE Board Professional Report GREB No. 74-4P.

    ERIC Educational Resources Information Center

    McPeek, Miles; And Others

    This study was undertaken to determine whether additional information useful for guidance or placement could be derived from the existing Graduate Record Examinations (GRE) Advanced Psychology Test. The number of subscores currently reported is limited by the high reliability required to make admissions decisions; subscores used only for guidance…

  16. Fitting New Measurement Models to GRE General Test Constructed-Response Item Data. GRE Board Professional Report No. 89-11P.

    ERIC Educational Resources Information Center

    Bennett, Randy Elliot; And Others

    This exploratory study applied two new cognitively sensitive measurement models to constructed-response quantitative data. The models, intended to produce qualitative characteristics of examinee performance, were fitted to algebra word problem solutions produced by 285 examinees taking the Graduate Record Examinations (GRE) General Test. The two…

  17. Diversity in Physics: Impact of Using Minimum Acceptable GRE Scores for Graduate Admissions

    NASA Astrophysics Data System (ADS)

    Miller, Casey W.

    2013-03-01

    About 180 graduate programs in physics are listed in the AIP Graduate Programs book. ~ 96% require the general GRE test; a quarter of these have an explicitly stated minimum score for admission, with the median stated cut-off being 700 (64th percentile) on GRE Quantitative; ~ 48% require the physics GRE; about half of these have an explicitly stated minimum score for admission, with the median being 600 (32nd percentile). It does not seem unreasonable to expect students to be among the top test scorers, until you dissect the test results by race and gender. In this talk, I will present data showing that the use of minimum acceptable scores on the GRE exam will have (have had?) a negative impact on diversity in Physics. I will remind the community that this practice is in opposition to ETS's Guide to the Use of Scores. I will make some suggestions for admissions committees, based in part on analyses I have performed. I will then pose challenges related to reducing the influence of GRE scores to the community, ranging from the department and university administration, to ranking bodies and professional societies. Supported by NSF.

  18. Compositions and pollutant sources of haze in Beijing urban sites.

    PubMed

    Wang, Junmei; Song, Yujun; Zuo, Jiangnan; Wu, Hongwen

    2016-05-01

    Haze from urban sites in Beijing was collected with a self-assembled electrostatic dust collector. The sizes and morphologies, thermal properties, and compositions of the particles in the haze were characterized by scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and X-ray photoelectric spectroscopy (XPS), respectively. Based on these results, the causes and pollutant sources of the chemicals in the haze were analyzed, and some countermeasures were further advanced to reduce the related pollutant sources. Graphical abstract ᅟ. PMID:26810665

  19. Identification of greA encoding a transcriptional elongation factor as a member of the carA-orf-carB-greA operon in Pseudomonas aeruginosa PAO1.

    PubMed Central

    Lu, C D; Kwon, D H; Abdelal, A T

    1997-01-01

    A homolog of the transcriptional elongation factor, GreA, was identified in Pseudomonas aeruginosa PAO1. The deduced amino acid sequence for GreA from this organism exhibits 65.2% identity to its counterpart in Escherichia coli K-12. The nucleotide sequence of greA from P. aeruginosa overlaps by four bases the 3' terminus of carB which encodes the large subunit of carbamoylphosphate synthetase. S1 nuclease experiments showed that level of the greA transcript is elevated approximately 10-fold under conditions of pyrimidine limitation, consistent with the conclusion that transcription is initiated from the previously identified pyrimidine-sensitive promoter upstream of the carA-orf-carB-greA operon. Transcriptional fusion experiments showed the presence of an additional weak promoter within the carB sequence. A greA insertional mutant of Pseudomonas aerugionsa was constructed by gene replacement. The mutant derivative grew well in rich medium but did not grow in minimal medium supplemented by arginine and nucleosides. The greA phenotype was suppressed by secondary mutations at a relatively high rate, consistent with the notion of an important physiological role for GreA. PMID:9139926

  20. Examining the Predictive Validity of GRE Scores on Doctoral Education: Students' Success and Methodology Choices in the Dissertation Process

    ERIC Educational Resources Information Center

    Rockinson-Szapkiw, Amanda J.; Bray, Oliver R., Jr.; Spaulding, Lucinda S.

    2014-01-01

    This study examines how GRE scores can be used to better understand Education doctoral candidates' methodology choices for the dissertation as well as their persistence behaviors. Candidates' of one online doctoral education program were examined. Results of a MANOVA suggested that there is no difference in GRE scores based on doctoral candidates'…

  1. The GRE Analytical Score as a Predictor for Admission to Ph.D. Candidacy: A Two Year Study.

    ERIC Educational Resources Information Center

    Mowsesian, Richard; Hays, William L.

    The purpose of this study was to test the predictive efficiency of the Graduate Record Examination Analytical (GRE-A) score when used in combination with other predictors for doctoral candidacy decisions in an educational psychology department. It was hypothesized that the GRE-A would be a more efficient predictor than faculty ratings on a…

  2. Evidence Suggesting We Should Admit Students Who Score Extremely Low on GRE Subtests or the GMAT to Graduate School Programs

    ERIC Educational Resources Information Center

    Micceri, Ted

    2002-01-01

    This study sought to determine whether GRE subscores (or GMAT) could predict graduation rates in related areas (math-oriented majors for GRE quantitative, etc.) in a sample of over 9,000 graduate students at a major public research university. Because few low quantitative scores were present in math-oriented majors, an attempt was made to…

  3. Being a binding site: characterizing residue composition of binding sites on proteins.

    PubMed

    Iván, Gábor; Szabadka, Zoltán; Grolmusz, Vince

    2007-01-01

    The Protein Data Bank contains the description of more than 45,000 three-dimensional protein and nucleic-acid structures today. Started to exist as the computer-readable depository of crystallographic data complementing printed articles, the proper interpretation of the content of the individual files in the PDB still frequently needs the detailed information found in the citing publication. This fact implies that the fully automatic processing of the whole PDB is a very hard task. We first cleaned and re-structured the PDB data, then analyzed the residue composition of the binding sites in the whole PDB for frequency and for hidden association rules. Main results of the paper: (i) the cleaning and repairing algorithm (ii) redundancy elimination from the data (iii) application of association rule mining to the cleaned non-redundant data set. We have found numerous significant relations of the residue-composition of the ligand binding sites on protein surfaces, summarized in two figures. One of the classical data-mining methods for exploring implication-rules, the association-rule mining, is capable to find previously unknown residue-set preferences of bind ligands on protein surfaces. Since protein-ligand binding is a key step in enzymatic mechanisms and in drug discovery, these uncovered preferences in the study of more than 19,500 binding sites may help in identifying new binding protein-ligand pairs. PMID:18305831

  4. Aptamers to Escherichia coli core RNA polymerase that sense its interaction with rifampicin, sigma-subunit and GreB.

    PubMed

    Kulbachinskiy, Andrey; Feklistov, Andrey; Krasheninnikov, Igor; Goldfarb, Alex; Nikiforov, Vadim

    2004-12-01

    Bacterial RNA polymerase (RNAP) is the central enzyme of gene expression that is responsible for the synthesis of all types of cellular RNAs. The process of transcription is accompanied by complex structural rearrangements of RNAP. Despite the recent progress in structural studies of RNAP, detailed mechanisms of conformational changes of RNAP that occur at different stages of transcription remain unknown. The goal of this work was to obtain novel ligands to RNAP which would target different epitopes of the enzyme and serve as specific probes to study the mechanism of transcription and conformational flexibility of RNAP. Using in vitro selection methods, we obtained 13 classes of ssDNA aptamers against Escherichia coli core RNAP. The minimal nucleic acid scaffold (an oligonucleotide construct imitating DNA and RNA in elongation complex), rifampicin and the sigma70-subunit inhibited binding of the aptamers to RNAP core but did not affect the dissociation rate of preformed RNAP-aptamer complexes. We argue that these ligands sterically block access of the aptamers to their binding sites within the main RNAP channel. In contrast, transcript cleavage factor GreB increased the rate of dissociation of preformed RNAP-aptamer complexes. This suggested that GreB that binds RNAP outside the main channel actively disrupts RNAP-aptamer complexes by inducing conformational changes in the channel. We propose that the aptamers obtained in this work will be useful for studying the interactions of RNAP with various ligands and regulatory factors and for investigating the conformational flexibility of the enzyme. PMID:15606780

  5. Differential Item Functioning of GRE Mathematics Items across Computerized and Paper-and-Pencil Testing Media

    ERIC Educational Resources Information Center

    Gu, Lixiong; Drake, Samuel; Wolfe, Edward W.

    2006-01-01

    This study seeks to determine whether item features are related to observed differences in item difficulty (DIF) between computer- and paper-based test delivery media. Examinees responded to 60 quantitative items similar to those found on the GRE general test in either a computer-based or paper-based medium. Thirty-eight percent of the items were…

  6. Subgroup Differences on the GRE Quantitative Test Based on the Underlying Cognitive Processes and Knowledge.

    ERIC Educational Resources Information Center

    Tatsuoka, Kikumi K.; Boodoo, Gwyneth M.

    This chapter describes a study adopting the findings from an investigation of the cognitive processing and knowledge requirements of individuals taking the Graduate Record Examination Quantitative (GRE-Q) Test. The study investigates subgroup differences such as major field of study, gender, and racial-ethnic backgrounds of students taking the…

  7. GRE Use among the Higher Education Community: Historical Practice Is Not Always Best Practice.

    ERIC Educational Resources Information Center

    Johnson, Troy

    2001-01-01

    Describes three areas in which the graduate community is vulnerable to substandard practice when using Graduate Record Examinations (GRE) scores in decision processes: percentile versus raw scores, cut-off scores, and summed scores. Asserts that the graduate community is generally unaware that raw scores on the verbal, quantitative, and analytical…

  8. On the Relationship Between Site Geology and the Distribution of Surface Regolith Compositions at the Apollo Sites

    NASA Technical Reports Server (NTRS)

    Korotev, Randy L.

    2000-01-01

    Some considerations are discussed on how information on site geology can be obtained from the distribution of data points on 2-element plots of composition of lunar regolith samples collected along a traverse.

  9. Control of transcription elongation by GreA determines rate of gene expression in Streptococcus pneumoniae.

    PubMed

    Yuzenkova, Yulia; Gamba, Pamela; Herber, Martijn; Attaiech, Laetitia; Shafeeq, Sulman; Kuipers, Oscar P; Klumpp, Stefan; Zenkin, Nikolay; Veening, Jan-Willem

    2014-01-01

    Transcription by RNA polymerase may be interrupted by pauses caused by backtracking or misincorporation that can be resolved by the conserved bacterial Gre-factors. However, the consequences of such pausing in the living cell remain obscure. Here, we developed molecular biology and transcriptome sequencing tools in the human pathogen Streptococcus pneumoniae and provide evidence that transcription elongation is rate-limiting on highly expressed genes. Our results suggest that transcription elongation may be a highly regulated step of gene expression in S. pneumoniae. Regulation is accomplished via long-living elongation pauses and their resolution by elongation factor GreA. Interestingly, mathematical modeling indicates that long-living pauses cause queuing of RNA polymerases, which results in 'transcription traffic jams' on the gene and thus blocks its expression. Together, our results suggest that long-living pauses and RNA polymerase queues caused by them are a major problem on highly expressed genes and are detrimental for cell viability. The major and possibly sole function of GreA in S. pneumoniae is to prevent formation of backtracked elongation complexes. PMID:25190458

  10. Control of transcription elongation by GreA determines rate of gene expression in Streptococcus pneumoniae

    PubMed Central

    Yuzenkova, Yulia; Gamba, Pamela; Herber, Martijn; Attaiech, Laetitia; Shafeeq, Sulman; Kuipers, Oscar P.; Klumpp, Stefan; Zenkin, Nikolay; Veening, Jan-Willem

    2014-01-01

    Transcription by RNA polymerase may be interrupted by pauses caused by backtracking or misincorporation that can be resolved by the conserved bacterial Gre-factors. However, the consequences of such pausing in the living cell remain obscure. Here, we developed molecular biology and transcriptome sequencing tools in the human pathogen Streptococcus pneumoniae and provide evidence that transcription elongation is rate-limiting on highly expressed genes. Our results suggest that transcription elongation may be a highly regulated step of gene expression in S. pneumoniae. Regulation is accomplished via long-living elongation pauses and their resolution by elongation factor GreA. Interestingly, mathematical modeling indicates that long-living pauses cause queuing of RNA polymerases, which results in ‘transcription traffic jams’ on the gene and thus blocks its expression. Together, our results suggest that long-living pauses and RNA polymerase queues caused by them are a major problem on highly expressed genes and are detrimental for cell viability. The major and possibly sole function of GreA in S. pneumoniae is to prevent formation of backtracked elongation complexes. PMID:25190458

  11. The Consequences of Physics GRE Requirements for Graduate School: A Case Study at UT Austin

    NASA Astrophysics Data System (ADS)

    Siders, Jennifer L. W.

    1996-05-01

    Five years ago the Physics Department at the University of Texas at Austin began requiring a 700 on the Physics GRE for admission to Ph.D. Candidacy. This requirement eventually led the admissions committee to use an unofficial requirement of 600 for graduate admissions because of the difficulty students had bringing up their scores. Shortly thereafter, we noticed a dramatic drop in the number of women graduate students entering our department. Three years worth of data from American applicants to the UT Physics department was analyzed (31 women, 363 men). The 600 cutoff eliminated 55 percent of the female applicants and 24 percent of male applicants. Only 10 percent of the women applicants had over a 700 while 47 percent of the male applicants had already achieved a score higher than 700. The average Physics GRE score for male applicants was 100 points higher than the average female applicants score. The correlation between undergraduate GPA and Physics GRE score is very small. 97 percent of the female applicants and 90 percent of the male applicants had GPA's over a 3.00. We will discuss our results and the changes that were made at UT.

  12. The Greek Database of Seismogenic Sources (GreDaSS): the new version.

    NASA Astrophysics Data System (ADS)

    Caputo, Riccardo; Pavlides, Spyros; GreDaSS Working Group

    2014-05-01

    The Greek Database of Seismogenic Sources (GreDaSS) is a repository of geological, tectonic and active fault data for the Greek territory and its surroundings including sectors of western Anatolia, southern Bulgaria, FYR of Macedonia and Albania. The principal aim of this international project is to create a homogenized framework of all data relevant to the seismotectonics, and especially the seismic hazard assessment, of Greece and its surroundings as well as a common research platform for performing seismic hazard analyses, modelling and scenarios from specific seismogenic structures. GreDaSS represents an on-going project based on the results of decades of investigations by the GreDaSS Working Group* and by numerous other researchers working on the active tectonics of the broader Aegean Region. Members of the WG have contributed in several national and European projects like FAUST (Faults as a seismological tool, 1998-2000) and SHARE (Seismic Hazard and Armonization in Europe, 2009-2012). The database is continuously updated by the WG, with the aim of improving its completeness in terms of seismogenic sources analysed and included, but also of enriching and better defining all parametric and ancillary information on each source. Preliminary and partial versions of GreDaSS have been already presented at previous congresses (Pavlides et al., 2010; Caputo et al., 2012; Sboras et al., 2013), but at next EGU the whole area and the most recent version of the database will be displayed. *) the principal scientific contributors belonging to the GreDaSS WG are: Sboras. S., Chatzipetros A., Koukouvelas I., Michailidou A., Valkaniotis S., Tarabusi G. Caputo R., Chatzipetros A., Pavlides S. and Sboras S. (2012): Ann. Geophysics, 55(5), 859-894, doi: 10.4401/ag-5168 Pavlides S., Caputo R., Sboras S., Chatzipetros A., Papathanasiou G. & Valkaniotis S. (2010): Bull. Geol. Soc. Greece, 43(1), 486-494 Sboras S., Pavlides S., Caputo R., Chatzipetros A., Michailidou A

  13. Women, Minorities, and Admissions Testing: The SAT II and GRE Physics Tests

    NASA Astrophysics Data System (ADS)

    Zolandz, A. M.

    1996-05-01

    The differences in average scores on standardized assessments between gender and minority subgroups of examinees is a continuing concern, both for Educational Testing Service (ETS) and the organizations that sponsor the assessments developed at ETS. The test development and analysis procedures used by ETS will be described, with an emphasis on those related to the fairness of the assessments for all subgroups and the understanding of the diffferences in performance among the groups. Relevant information for the SAT II and GRE Physics tests will be presented and discussed.

  14. Narrowing the Pipeline: The SAT and GRE General Tests as Arbitrary Gatekeepers

    NASA Astrophysics Data System (ADS)

    Zappardino, Pamela

    1996-05-01

    Before the stage of taking more specialized standardized exams (with their attendant problems) is reached, scores on the SAT and/or GRE general tests eliminate or discourage many capable students from entering specific programs of study. The artificial bottleneck that this creates and the disparate impact that the use of these tests as gatekeepers has on qualified women, minority group members and low-income students will be described. Implications of this process for diversifying the pool of graduate students in physics will be discussed.

  15. Measurements of fog composition at a rural site

    NASA Astrophysics Data System (ADS)

    Straub, Derek J.; Hutchings, James W.; Herckes, Pierre

    2012-02-01

    Studies that focus on fog chemistry in the United States have been limited to relatively few locations. Apart from measurements along the East and West coasts and extensive analysis of radiation fog in the Central Valley of California, fog composition has been characterized in only a handful of other locations. To complement and expand the existing fog chemistry data that are currently available, a new field campaign was established at a rural location in Central Pennsylvania to produce a unique, long term record of fog composition. From 2007 to 2010, 41 fog events were sampled with an automated Caltech Heated Rod Cloudwater Collector (CHRCC). The collected samples were analyzed primarily for pH and major inorganic ions. Dissolved organic carbon (DOC) and trace metals were analyzed in selected samples and N-nitrosodimethylamine (NDMA) was quantified in two samples. Sample composition varied widely during the study period. Sulfate concentrations ranged from 15 to 955 (median = 123) μN and pH varied between 3.08 and 7.41 (median = 5.77). In terms of volume weighted averages, ammonium was the most abundant ionic species followed by sulfate, calcium, and nitrate. For the subset of samples in which DOC was analyzed, concentrations ranged from 2.2 to 22.6 mgC l -1. Comparisons with regional precipitation chemistry measurements reveal the influence of local agricultural and soil sources on fog composition. The sum of sulfate, nitrate, and ammonium measured in the present study is considerably lower than the majority of radiation, precipitation, and coastal fogs collected in the United States although the ammonium/(nitrate + sulfate) ratio is similar to those found in the Central Valley of California.

  16. The Grenoble Analysis Toolkit (GreAT)-A statistical analysis framework

    NASA Astrophysics Data System (ADS)

    Putze, A.; Derome, L.

    2014-12-01

    The field of astroparticle physics is currently the focus of prolific scientific activity. In the last decade, this field has undergone significant developments thanks to several experimental results from CREAM, PAMELA, Fermi, and H.E.S.S. Moreover, the next generation of instruments, such as AMS-02 (launched on 16 May 2011) and CTA, will undoubtedly facilitate more sensitive and precise measurements of the cosmic-ray and γ-ray fluxes. To fully exploit the wealth of high precision data generated by these experiments, robust and efficient statistical tools such as Markov Chain Monte Carlo algorithms or evolutionary algorithms, able to handle the complexity of joint parameter spaces and datasets, are necessary for a phenomenological interpretation. The Grenoble Analysis Toolkit (GreAT) is an user-friendly and modular object orientated framework in C++, which samples the user-defined parameter space with a pre- or user-defined algorithm. The functionality of GreAT is presented in the context of cosmic-ray physics, where the boron-to-carbon (B/C) ratio is used to constrain cosmic-ray propagation models.

  17. GRE2 from Scheffersomyces stipitis as an aldehyde reductase contributes tolerance to aldehyde inhibitors derived from lignocellulosic biomass.

    PubMed

    Wang, Xu; Ma, Menggen; Liu, Z Lewis; Xiang, Quanju; Li, Xi; Liu, Na; Zhang, Xiaoping

    2016-08-01

    Scheffersomyces (Pichia) stipitis is one of the most promising yeasts for industrial bioethanol production from lignocellulosic biomass. S. stipitis is able to in situ detoxify aldehyde inhibitors (such as furfural and 5-hydroxymethylfurfural (HMF)) to less toxic corresponding alcohols. However, the reduction enzymes involved in this reaction remain largely unknown. In this study, we reported that an uncharacterized open reading frame PICST_72153 (putative GRE2) from S. stipitis was highly induced in response to furfural and HMF stresses. Overexpression of this gene in Saccharomyces cerevisiae improved yeast tolerance to furfural and HMF. GRE2 was identified as an aldehyde reductase which can reduce furfural to FM with either NADH or NADPH as the co-factor and reduce HMF to FDM with NADPH as the co-factor. This enzyme can also reduce multiple aldehydes to their corresponding alcohols. Amino acid sequence analysis indicated that it is a member of the subclass "intermediate" of the short-chain dehydrogenase/reductase (SDR) superfamily. Although GRE2 from S. stipitis is similar to GRE2 from S. cerevisiae in a three-dimensional structure, some differences were predicted. GRE2 from S. stipitis forms loops at D133-E137 and T143-N145 locations with two α-helices at E154-K157 and E252-A254 locations, different GRE2 from S. cerevisiae with an α-helix at D133-E137 and a β-sheet at T143-N145 locations, and two loops at E154-K157 and E252-A254 locations. This research provided guidelines for the study of other SDR enzymes from S. stipitis and other yeasts on tolerant mechanisms to aldehyde inhibitors derived from lignocellulosic biomass. PMID:27003269

  18. Atomic level understanding of site-specific interactions in Polyaniline/TiO2 composite

    NASA Astrophysics Data System (ADS)

    Chabungbam, Satyananda; Loh, G. C.; Sahariah, Munima B.; Pal, Arup R.; Pandey, Ravindra

    2016-02-01

    Spin-polarized density functional theory calculations have been performed to understand the interactions in polyaniline (PAni) and TiO2 composite at the atomic level. Binding energy calculation shows that composite structure is energetically more stable when Ti atom of TiO2 sits on top of PAni. It is also found that there is a dependency of the CBM on the site of TiO2 interaction in this composite system. The results suggest that optimization of the synthesis parameters at atomic level can be an effective way to improve the performance of a photovoltaic device based on PAni-TiO2 composite.

  19. The Performance of Native Speakers of English and ESL Speakers on the Computer-based TOEFL and GRE General Test

    ERIC Educational Resources Information Center

    Stricker, L. J.

    2004-01-01

    The purpose of this study was to replicate previous research on the construct validity of the paper-based version of the TOEFL and extend it to the computer-based TOEFL. Two samples of Graduate Record Examination (GRE) General Test-takers were used: native speakers of English specially recruited to take the computer-based TOEFL, and ESL…

  20. A Five-Year Analysis of GRE, Race, Gender, and Undergraduate GPA as Predictors of State Certification Examination Results.

    ERIC Educational Resources Information Center

    Wilmore, Elaine L.; McNeil, Jesse Jai, Jr.

    This study addressed the factors of Graduate Record Examination scores (GRE), race, gender, and undergraduate grade point average (GPA) as predictors of success on the Texas state administrator certification examination. The paper was presented as the entry point for expected discussion of the effects of high stakes accountability policies on the…

  1. Geographic and Operational Site Parameters List (GOSPL) for the 2004 Composite Analysis

    SciTech Connect

    Last, George V.; Nichols, William E.; Kincaid, Charles T.

    2004-07-01

    This report briefly describes each of the key data fields, including the source(s) of data, and provides the resulting inputs to be used for the 2004 Composite Analysis. A master spreadsheet termed the Geographic and Operational Site Parameters List (GOSPL) was assembled to facilitate the generation of keyword input files containing general information on each waste site, its operational/disposal history, and its environmental settings (past, current, and future).

  2. Studies of phase composition of contact sites of diamond crystals and the surrounding rocks

    NASA Astrophysics Data System (ADS)

    Skvortsova, V. L.; Samoylovich, M. I.; Belyanin, A. F.

    2015-11-01

    The composition, structure, and morphology of iron-containing diamond-kimberlite contact sites were studied by means of scanning electron microscopy and Raman spectroscopy. The data obtained confirm the hypothesis of the similarity of mechanisms of diamond formation in nature and in experiments.

  3. Variation in the Composition and In Vitro Proinflammatory Effect of Urban Particulate Matter from Different Sites

    PubMed Central

    Manzano-León, Natalia; Quintana, Raúl; Sánchez, Brisa; Serrano, Jesús; Vega, Elizabeth; Vázquez-López, Inés; Rojas-Bracho, Leonora; López-Villegas, Tania; O’Neill, Marie S.; Vadillo-Ortega, Felipe; De Vizcaya-Ruiz, Andrea; Rosas, Irma

    2015-01-01

    Spatial variation in particulate matter–related health and toxicological outcomes is partly due to its composition. We studied spatial variability in particle composition and induced cellular responses in Mexico City to complement an ongoing epidemiologic study. We measured elements, endotoxins, and polycyclic aromatic hydrocarbons in two particle size fractions collected in five sites. We compared the in vitro proinflammatory response of J774A.1 and THP-1 cells after exposure to particles, measuring subsequent TNFα and IL-6 secretion. Particle composition varied by site and size. Particle constituents were subjected to principal component analysis, identifying three components: C1 (Si, Sr, Mg, Ca, Al, Fe, Mn, endotoxin), C2 (polycyclic aromatic hydrocarbons), and C3 (Zn, S, Sb, Ni, Cu, Pb). Induced TNFα levels were higher and more heterogeneous than IL-6 levels. Cytokines produced by both cell lines only correlated with C1, suggesting that constituents associated with soil induced the inflammatory response and explain observed spatial differences. PMID:23335408

  4. Composite Analysis for the Area 5 Radioactive Waste Management Site at the Nevada Test Site, Nye County, Nevada

    SciTech Connect

    V. Yucel

    2001-09-01

    This report summarizes the results of a Composite Analysis (CA) for the Area 5 Radioactive Waste Management Site (RWMS). The Area 5 RWMS is a US Department of Energy (DOE)-operated low-level radioactive waste (LLW) management site located in northern Frenchman Flat on the Nevada Test Site (NTS). The Area 5 RWMS has disposed of low-level radioactive waste in shallow unlined pits and trenches since 1960. Transuranic waste (TRU) and high-specific activity waste was disposed in Greater Confinement Disposal (GCD) boreholes from 1983 to 1989. The purpose of this CA is to determine if continuing operation of the Area 5 RWMS poses an acceptable or unacceptable risk to the public considering the total waste inventory and all other interacting sources of radioactive material in the vicinity. Continuing operation of the Area 5 RWMS will be considered acceptable if the total effective dose equivalent (TEDE) is less than 100 mrem in a year. If the TEDE exceeds 30 mrem in a year, a cost-benefit options analysis must be performed to determine if cost-effective management options exist to reduce the dose further. If the TEDE is found to be less than 30 mrem in a year, an analysis may be performed if warranted to determine if doses are as low as reasonably achievable (ALARA).

  5. Synthesis of supported bimetallic nanoparticles with controlled size and composition distributions for active site elucidation

    SciTech Connect

    Hakim, Sikander H.; Sener, Canan; Alba Rubio, Ana C.; Gostanian, Thomas M.; O'neill, Brandon J; Ribeiro, Fabio H.; Miller, Jeffrey T.; Dumesic, James A

    2015-08-01

    Elucidation of active sites in supported bimetallic catalysts is complicated by the high level of dispersity in the nanoparticle size and composition that is inherent in conventional methods of catalyst preparation. We present a synthesis strategy that leads to highly dispersed, bimetallic nanoparticles with uniform particle size and composition by means of controlled surface reactions. We demonstrate the synthesis of three systems, RhMo, PtMo, and RhRe, consisting of a highly reducible metal with an oxophilic promoter. These catalysts are characterized by FTIR, CO chemisorption, STEM/EDS, TPR, and XAS analysis. The catalytic properties of these bimetallic nanoparticles were probed for the selective CO hydrogenolysis of (hydroxymethyl)tetrahydropyran to produce 1,6 hexanediol. Based on the characterization results and reactivity trends, the active sites in the hydrogenolysis reaction are identified to be small ensembles of the more noble metal (Rh, Pt) adjacent to highly reduced moieties of the more oxophilic metal (Mo, Re).

  6. Aerosol measurements at a high-elevation site: composition, size, and cloud condensation nuclei activity

    SciTech Connect

    Friedman, Beth; Zelenyuk, Alla; Beranek, Josef; Kulkarni, Gourihar R.; Pekour, Mikhail S.; Hallar, Anna G.; McCubbin, Ian; Thornton, Joel A.; Cziczo, D. J.

    2013-12-09

    We present measurements of CCN concentrations and associated aerosol composition and size properties at a high-elevation research site in March 2011. CCN closure and aerosol hygroscopicity were assessed using simplified assumptions of bulk aerosol properties as well as a new method utilizing single particle composition and size to assess the importance of particle mixing state in CCN activation. Free troposphere analysis found no significant difference between the CCN activity of free tropospheric aerosol and boundary layer aerosol at this location. Closure results indicate that using only size and number information leads to adequate prediction, in the majority of cases within 50%, of CCN concentrations, while incorporating the hygroscopicity parameters of the individual aerosol components measured by single particle mass spectrometry adds to the agreement, in most cases within 20%, between predicted and measured CCN concentrations. For high-elevation continental sites, with largely aged aerosol and low amounts of local area emissions, a lack of chemical knowledge and hygroscopicity may not hinder models in predicting CCN concentrations. At sites influenced by fresh emissions or more heterogeneous particle types, single particle composition information may be more useful in predicting CCN concentrations and understanding the importance of particle mixing state on CCN activation.

  7. Correlated compositional and mineralogical investigations at the Chang'e-3 landing site.

    PubMed

    Ling, Zongcheng; Jolliff, Bradley L; Wang, Alian; Li, Chunlai; Liu, Jianzhong; Zhang, Jiang; Li, Bo; Sun, Lingzhi; Chen, Jian; Xiao, Long; Liu, Jianjun; Ren, Xin; Peng, Wenxi; Wang, Huanyu; Cui, Xingzhu; He, Zhiping; Wang, Jianyu

    2015-01-01

    The chemical compositions of relatively young mare lava flows have implications for the late volcanism on the Moon. Here we report the composition of soil along the rim of a 450-m diameter fresh crater at the Chang'e-3 (CE-3) landing site, investigated by the Yutu rover with in situ APXS (Active Particle-induced X-ray Spectrometer) and VNIS (Visible and Near-infrared Imaging Spectrometer) measurements. Results indicate that this region's composition differs from other mare sample-return sites and is a new type of mare basalt not previously sampled, but consistent with remote sensing. The CE-3 regolith derived from olivine-normative basaltic rocks with high FeO/(FeO+MgO). Deconvolution of the VNIS data indicates abundant high-Ca ferropyroxene (augite and pigeonite) plus Fe-rich olivine. We infer from the regolith composition that the basaltic source rocks formed during late-stage magma-ocean differentiation when dense ferropyroxene-ilmenite cumulates sank and mixed with deeper, relatively ferroan olivine and orthopyroxene in a hybridized mantle source. PMID:26694712

  8. Correlated compositional and mineralogical investigations at the Chang′e-3 landing site

    PubMed Central

    Ling, Zongcheng; Jolliff, Bradley L.; Wang, Alian; Li, Chunlai; Liu, Jianzhong; Zhang, Jiang; Li, Bo; Sun, Lingzhi; Chen, Jian; Xiao, Long; Liu, Jianjun; Ren, Xin; Peng, Wenxi; Wang, Huanyu; Cui, Xingzhu; He, Zhiping; Wang, Jianyu

    2015-01-01

    The chemical compositions of relatively young mare lava flows have implications for the late volcanism on the Moon. Here we report the composition of soil along the rim of a 450-m diameter fresh crater at the Chang′e-3 (CE-3) landing site, investigated by the Yutu rover with in situ APXS (Active Particle-induced X-ray Spectrometer) and VNIS (Visible and Near-infrared Imaging Spectrometer) measurements. Results indicate that this region's composition differs from other mare sample-return sites and is a new type of mare basalt not previously sampled, but consistent with remote sensing. The CE-3 regolith derived from olivine-normative basaltic rocks with high FeO/(FeO+MgO). Deconvolution of the VNIS data indicates abundant high-Ca ferropyroxene (augite and pigeonite) plus Fe-rich olivine. We infer from the regolith composition that the basaltic source rocks formed during late-stage magma-ocean differentiation when dense ferropyroxene-ilmenite cumulates sank and mixed with deeper, relatively ferroan olivine and orthopyroxene in a hybridized mantle source. PMID:26694712

  9. Correlated compositional and mineralogical investigations at the Chang'e-3 landing site

    NASA Astrophysics Data System (ADS)

    Ling, Zongcheng; Jolliff, Bradley L.; Wang, Alian; Li, Chunlai; Liu, Jianzhong; Zhang, Jiang; Li, Bo; Sun, Lingzhi; Chen, Jian; Xiao, Long; Liu, Jianjun; Ren, Xin; Peng, Wenxi; Wang, Huanyu; Cui, Xingzhu; He, Zhiping; Wang, Jianyu

    2015-12-01

    The chemical compositions of relatively young mare lava flows have implications for the late volcanism on the Moon. Here we report the composition of soil along the rim of a 450-m diameter fresh crater at the Chang'e-3 (CE-3) landing site, investigated by the Yutu rover with in situ APXS (Active Particle-induced X-ray Spectrometer) and VNIS (Visible and Near-infrared Imaging Spectrometer) measurements. Results indicate that this region's composition differs from other mare sample-return sites and is a new type of mare basalt not previously sampled, but consistent with remote sensing. The CE-3 regolith derived from olivine-normative basaltic rocks with high FeO/(FeO+MgO). Deconvolution of the VNIS data indicates abundant high-Ca ferropyroxene (augite and pigeonite) plus Fe-rich olivine. We infer from the regolith composition that the basaltic source rocks formed during late-stage magma-ocean differentiation when dense ferropyroxene-ilmenite cumulates sank and mixed with deeper, relatively ferroan olivine and orthopyroxene in a hybridized mantle source.

  10. Long-term changes in species composition and relative abundances of sharks at a provisioning site.

    PubMed

    Brunnschweiler, Juerg M; Abrantes, Kátya G; Barnett, Adam

    2014-01-01

    Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier) displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas) of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive exclusion among shark

  11. Long-Term Changes in Species Composition and Relative Abundances of Sharks at a Provisioning Site

    PubMed Central

    Brunnschweiler, Juerg M.; Abrantes, Kátya G.; Barnett, Adam

    2014-01-01

    Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today’s recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier) displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas) of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004–2006 and 2007–2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004–2006 and very rare in the period of 2007–2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive exclusion

  12. Chemical composition and mass closure of ambient PM10 at urban sites

    NASA Astrophysics Data System (ADS)

    Terzi, Eleni; Argyropoulos, George; Bougatioti, Aikaterini; Mihalopoulos, Nikolaos; Nikolaou, Kostas; Samara, Constantini

    2010-06-01

    The chemical composition of PM10 was studied during summer and winter sampling campaigns conducted at two different urban sites in the city of Thessaloniki, Greece (urban-traffic, UT and urban-industrial, UI). PM10 samples were chemically analysed for minerals (Si, Al, Ca, Mg, Fe, Ti, K), trace elements (Cd, Cr, Cu, Mn, Pb, V, Zn, Te, Co, Ni, Se, Sr, As, and Sb), water-soluble ions (Cl -, NO 3-, SO 42-, Na +, K +, NH 4+, Ca 2+, Mg 2+) and carbonaceous compounds (OC, EC). Spatial variations of atmospheric concentrations showed significantly higher levels of minerals, some trace metals and TC at the UI site, while at the UT site significantly higher levels of elements like Cd, Ba, Sn, Sb and Te were observed. Crustal elements, excepting Ca at the UI site, did not exhibit significant seasonal variations at any site pointing to constant emissions throughout the year. In order to reconstruct the particle mass, the determined components were classified into six classes as follows: mineral matter (MIN), trace elements (TE), organic matter (OM), elemental carbon (EC), sea salt (SS) and secondary inorganic aerosol (SIA). Good correlations with slopes close to 1 were found between chemically determined and gravimetrically measured PM10 masses for both sites. According to the chemical mass closure obtained, the major components of PM10 at both sites were MIN (soil-derived compounds), followed by OM and SIA. The fraction unaccounted for by chemical analysis comprised on average 8% during winter and 15% during summer at the urban-industrial site, while at the urban-traffic site the percentages were 21.5% in winter and 4.8% in summer.

  13. Quasi-static and multi-site high velocity impact response of composite structures

    NASA Astrophysics Data System (ADS)

    Deka, Lakshya

    Understanding of low and high velocity transverse impact of laminated fiber reinforced composites is of interest in military, aerospace, marine and civilian structures. Recent advances in the field of numerical simulation provide a means of predicting the performance characteristics of layered materials for impact protection. The overall objective of this work is to investigate the behavior of laminated composites which include both thermoplastic and thermoset systems subjected to quasi-static, low and high velocity impact; both from an experimental and numerical modeling view point. To analyze this problem, a series of quasi-static, low and high velocity impact tests have been performed on laminated composite plates namely E-glass/polypropylene, S2-glass/epoxy and carbon/polyphenylene sulphide. To analyze the perforation mechanism, ballistic limit and damage evolution, an explicit three-dimensional finite element code LS-DYNA is used. Selecting proper material models and contact definition is one of the major criteria for obtaining accurate numerical simulation. Material model 162 (MAT 162), a progressive failure model based on modified Hashin's criteria and continuum damage mechanics (CDM) has been assigned to predict failure of the laminate. This approach is used because during transverse impact, a composite laminate undergoes progressive damage. The laminate and the projectile are meshed using brick elements with single integration points. The impact velocity ranges from 180 to 400 m s -1. This work focuses on three main aspects; (i) To obtain static and dynamic material properties to incorporate into the finite element model and predict the ballistic limit of a composite laminate based on the information from quasi-static punch shear test; (ii) To understand penetration, material erosion, ballistic limit and delamination mechanisms for single and multi-site high velocity (or ballistic) impact of composite laminates; (iii) To investigate the different failure

  14. Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE-RBS

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Zhang, K.; Xia, C. D.; Liu, M. T.; Zhu, J. J.; An, Z.; Bai, B.

    2015-03-01

    A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271-1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB6 crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907-960 A.D.) had been propagated to the Waguantan kiln site of Guizhou Province in the Yuan Dynasty.

  15. Using Apollo Sites and Soils to Compositionally Ground Truth Diviner Lunar Radiometer Observations

    NASA Technical Reports Server (NTRS)

    Greenhagen, Benjamin T.; Lucey, P. G.; Song, E.; Thomas, I R.; Bowles, N. E.; DonaldsonHanna, K. L.; Allen, C.; Foote, E. J.; Paige, D .A.

    2012-01-01

    Apollo landing sites and returned soils afford us a unique opportunity to "ground truth" Diviner Lunar Radiometer compositional observations, which are the first global, high resolution , thermal infrared measurements of an airless body. The Moon is the most accessible member of the most abundant class of solar system objects, which includes Mercury, asteroids, and icy satellites. And the Apollo samples returned from the Moon are the only extraterrestrial samples with known spatial context. Here we compare Diviner observations of Apollo landing sites and compositional and spectral laboratory measurements of returned Apollo soils. Diviner, onboard NASA's Lunar Reconnaissance Orbiter, has three spectral channels near 8 micron that were designed to characterize the mid-infrared emissivity maximum known as the Christiansen feature (CF), a well-studied indicator of silicate mineralogy. It has been observed that thermal infrared spectra measured in simulated lunar environment (SLE) are significantly altered from spectra measured under terrestrial or martian conditions, with enhanced CF contrast and shifted CF position relative to other spectral features. Therefore only thermal emission experiments conducted in SLE are directly comparable to Diviner data. With known compositions, Apollo landing sites and soils are important calibration points for the Diviner dataset, which includes all six Apollo sites at approximately 200 m spatial resolution. Differences in measured CFs caused by composition and space weathering are apparent in Diviner data. Analyses of Diviner observations and SLE measurements for a range of Apollo soils show good agreement, while comparisons to thermal reflectance measurements under ambient conditions do not agree well, which underscores the need for SLE measurements and validates our measurement technique. Diviner observations of Apollo landing sites are also correlated with geochemical measurements of Apollo soils from the Lunar Sample Compendium

  16. Identifying 2'-O-methylationation sites by integrating nucleotide chemical properties and nucleotide compositions.

    PubMed

    Chen, Wei; Feng, Pengmian; Tang, Hua; Ding, Hui; Lin, Hao

    2016-06-01

    2'-O-methylationation is an important post-transcriptional modification and plays important roles in many biological processes. Although experimental technologies have been proposed to detect 2'-O-methylationation sites, they are cost-ineffective. As complements to experimental techniques, computational methods will facilitate the identification of 2'-O-methylationation sites. In the present study, we proposed a support vector machine-based method to identify 2'-O-methylationation sites. In this method, RNA sequences were formulated by nucleotide chemical properties and nucleotide compositions. In the jackknife cross-validation test, the proposed method obtained an accuracy of 95.58% for identifying 2'-O-methylationation sites in the human genome. Moreover, the model was also validated by identifying 2'-O-methylation sites in the Mus musculus and Saccharomyces cerevisiae genomes, and the obtained accuracies are also satisfactory. These results indicate that the proposed method will become a useful tool for the research on 2'-O-methylation. PMID:27191866

  17. Atmospheric dust loads and their elemental composition at a background site in India.

    PubMed

    Negi, B S; Jha, S K; Chavan, S B; Sadasivan, S; Goyal, A; Sapru, M L; Bhat, C L

    2002-01-01

    Air particulate samples collected during 1995-96 at a background site situated on the east coast of Thar Desert in Rajsthan State of India were analysed for atmospheric dust loads (Suspended Particulate Matter) and elemental composition. The values of SPM ranged from 9 microg M(-3) to 97 microg M(-3) with an average of 43 microg M(-3) except a few episodic values, which were 3 to 5 times higher than the average during summer months. The results for elemental composition of the particulate samples showed that the concentrations of anthropogenic toxic trace elements viz. Br, Cr, Pb, Sb, Se and Zn are lower by a factor of 2 to 10 as compared to urban areas. The high enrichment factors for anthropogenic elements viz. Br, Pb, Sb and Zn show an input from coal/wood fuel burning and vehicular pollution at the sampling site. The depletion of Si in SPM samples shows long distance transport of dust to the sampling site. PMID:11878626

  18. Atmospheric aerosol compositions and sources at two national background sites in northern and southern China

    NASA Astrophysics Data System (ADS)

    Zhu, Qiao; He, Ling-Yan; Huang, Xiao-Feng; Cao, Li-Ming; Gong, Zhao-Heng; Wang, Chuan; Zhuang, Xin; Hu, Min

    2016-08-01

    Although China's severe air pollution has become a focus in the field of atmospheric chemistry and the mechanisms of urban air pollution there have been researched extensively, few field sampling campaigns have been conducted at remote background sites in China, where air pollution characteristics on a larger scale are highlighted. In this study, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), together with an Aethalometer, was deployed at two of China's national background sites in northern (Lake Hongze site; 33.23° N, 118.33° E; altitude 21 m) and southern (Mount Wuzhi site; 18.84° N, 109.49° E; altitude 958 m) China in the spring seasons in 2011 and 2015, respectively, in order to characterize submicron aerosol composition and sources. The campaign-average PM1 concentration was 36.8 ± 19.8 µg m-3 at the northern China background (NCB) site, which was far higher than that at the southern China background (SCB) site (10.9 ± 7.8 µg m-3). Organic aerosol (OA) (27.2 %), nitrate (26.7 %), and sulfate (22.0 %) contributed the most to the PM1 mass at NCB, while OA (43.5 %) and sulfate (30.5 %) were the most abundant components of the PM1 mass at SCB, where nitrate only constituted a small fraction (4.7 %) and might have contained a significant amount of organic nitrates (5-11 %). The aerosol size distributions and organic aerosol elemental compositions all indicated very aged aerosol particles at both sites. The OA at SCB was more oxidized with a higher average oxygen to carbon (O / C) ratio (0.98) than that at NCB (0.67). Positive matrix factorization (PMF) analysis was used to classify OA into three components, including a hydrocarbon-like component (HOA, attributed to fossil fuel combustion) and two oxygenated components (OOA1 and OOA2, attributed to secondary organic aerosols from different source areas) at NCB. PMF analysis at SCB identified a semi-volatile oxygenated component (SV-OOA) and a low-volatility oxygenated

  19. Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth

    SciTech Connect

    Hanson, P.J.

    2001-09-04

    This numeric data package provides data sets, and accompanying documentation, on site characterization, system performance, weather, species composition, and growth for the Throughfall Displacement Experiment, which was established in the Walker Branch Watershed of East Tennessee to provide data on the responses of forests to altered precipitation regimes. The specific data sets include soil water content and potential, coarse fraction of the soil profile, litter layer temperature, soil temperature, monthly weather, daily weather, hourly weather, species composition of trees and saplings, mature tree and sapling annual growth, and relative leaf area index. Fortran and SAS{trademark} access codes are provided to read the ASCII data files. The data files and this documentation are available without charge on a variety of media and via the Internet from the Carbon Dioxide Information Analysis Center (CDIAC).

  20. Metals other than uranium affected microbial community composition in a historical uranium-mining site.

    PubMed

    Sitte, Jana; Löffler, Sylvia; Burkhardt, Eva-Maria; Goldfarb, Katherine C; Büchel, Georg; Hazen, Terry C; Küsel, Kirsten

    2015-12-01

    To understand the links between the long-term impact of uranium and other metals on microbial community composition, ground- and surface water-influenced soils varying greatly in uranium and metal concentrations were investigated at the former uranium-mining district in Ronneburg, Germany. A soil-based 16S PhyloChip approach revealed 2358 bacterial and 35 archaeal operational taxonomic units (OTU) within diverse phylogenetic groups with higher OTU numbers than at other uranium-contaminated sites, e.g., at Oak Ridge. Iron- and sulfate-reducing bacteria (FeRB and SRB), which have the potential to attenuate uranium and other metals by the enzymatic and/or abiotic reduction of metal ions, were found at all sites. Although soil concentrations of solid-phase uranium were high, ranging from 5 to 1569 μg·g (dry weight) soil(-1), redundancy analysis (RDA) and forward selection indicated that neither total nor bio-available uranium concentrations contributed significantly to the observed OTU distribution. Instead, microbial community composition appeared to be influenced more by redox potential. Bacterial communities were also influenced by bio-available manganese and total cobalt and cadmium concentrations. Bio-available cadmium impacted FeRB distribution while bio-available manganese and copper as well as solid-phase zinc concentrations in the soil affected SRB composition. Archaeal communities were influenced by the bio-available lead as well as total zinc and cobalt concentrations. These results suggest that (i) microbial richness was not impacted by heavy metals and radionuclides and that (ii) redox potential and secondary metal contaminants had the strongest effect on microbial community composition, as opposed to uranium, the primary source of contamination. PMID:26122566

  1. Assessment of fish abundance and species composition at selected sites in South Dakota: an overview

    USGS Publications Warehouse

    Harwood, Alison

    2010-01-01

    The U.S. Geological Survey (USGS) conducted surveys of streams throughout the State of South Dakota during 2008-09 as part of the U.S. Environmental Protection Agency?s (USEPA) National Rivers and Streams Assessment (NRSA) Program. During 2008-09, as part of the stream assessment, the USGS completed surveys of fish populations and species composition at 64 sites. Fish were inventoried at 60 of the 64 sites, but not at four of the sites because water was too low to sustain fish or specific conductivity was too high to electroshock effectively. Four of the sites were surveyed in 2000-04 during the USEPA's Environmental Monitoring and Assessment Program-West (EMAP-West) project. Two wadeable sites and two boatable sites were revisited for quality-assurance/quality-control requirements. During the study, both wadeable and boatable streams were sampled using electrofishing equipment and methods. Of the 64 sites, 62 were wadeable and 2 were boatable. Procedures for sampling wadeable streams differed slightly from procedures for boatable streams. Backpack electrofishing equipment was used for wadeable streams, whereas boat electrofishing equipment was used for boatable streams. Wadeable streams also were fished in an opposite direction than boatable streams. Several species of fish were collected during the NRSA. Species diversity ranged from 0-11 species in wadeable streams and from 6-26 species in boatable streams. Many common species were sampled during the study. The most frequently sampled fish was the sand shiner (Notropis stramineus), with 609 individuals sampled. In contrast, only one heritage species, the skipjack herring (Alosa chrysochloris), was identified during 2008-09. Common anomalies found in fish caught were parasitic lesions, "black spot disease," and tumors. When comparing the fish sampling results for the four sites visited in both 2000-04 and in 2008-09, more individuals and species were collected during 2008-09 than in 2000-04 at two sites, whereas

  2. Composition and temperature dependences of site occupation for Al, Cr, W, and Nb in MoSi2

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ping; Sun, Shun-Ping; Yu, Yun; Wang, Hong-Jin; Jiang, Yong; Yi, Dan-Qing

    2015-12-01

    The composition and temperature dependences of site occupation for Al, Cr, W, and Nb in MoSi2 are investigated by using a thermodynamics model and first principles calculations. A simple parameter measuring the substitution energy difference between Si and Mo sites reflects the nature of site occupancy. At 0 K, these elements prefer Si sites in Mo-rich and Mo sites in Si-rich, and show no site preference in stoichiometric MoSi2. At elevated temperature, the site occupation behaviors show strong dependence on both composition and temperature. Some calculated results have been certified in previous experiments. Project supported by the National Natural Science Foundation of China (Grant No. 51401093) and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20130233).

  3. New Composite Membranes for High Throughput Solid-Liquid Separations at the Savannah River Site

    SciTech Connect

    Bhave, Ramesh R

    2012-01-01

    New Composite Membranes for High Throughput Solid-Liquid Separations at the Savannah River Site R. Bhave (Oak Ridge National Laboratory. Oak Ridge, TN) and M. R. Poirier* (Savannah River National Laboratory, Aiken SC) Solid-liquid separation is the limiting step for many waste treatment processes at the Savannah River Site. SRNL researchers have identified the rotary microfilter as a technology to improve the rate of solid-liquid separation processes. SRNL is currently developing the rotary microfilter for radioactive service and plans to deploy the technology as part of the small column ion exchange process. The rotary microfilter can utilize any filter media that is available as a flat sheet. The current baseline membrane is a 0.5 micron (nominal) porous metal filter (Pall PMM050). Previous testing with tubular filters showed that filters composed of a ceramic membrane on top of a stainless steel support produce higher flux than filters composed only of porous metal. The authors are working to develop flat sheet filter media composed of a ceramic membrane and/or ceramic-metal composite on top of a porous stainless steel support that can be used with the rotary microfilter to substantially increase filter flux resulting in a more compact, energy efficient and cost-effective high level radioactive waste treatment system. Composite membranes with precisely controlled pore size distribution were fabricated on porous metal supports. High quality uniform porous metal (316SS) supports were fabricated to achieve high water permeability. Separative layers of several different materials such as ultrafine metal particles and ceramic oxides were used to fabricate composite membranes. The fabrication process involved several high temperature heat treatments followed by characterization of gas and liquid permeability measurements and membrane integrity analysis. The fabricated composite membrane samples were evaluated in a static test cell manufactured by SpinTek. The

  4. Why Doesn't The GRE or GPA Work in Selecting Graduate Students & What Alternatives Are There ?

    NASA Astrophysics Data System (ADS)

    Sedlacek, William

    2014-01-01

    The simplest response to the title of this paper is that the measures that are commonly employed in evaluating prospective graduate and professional students don’t work. That is, scores from the Graduate Record Examination (GRE) and prior grades (GPA) appear to have little validity in assessing postbaccalaureate student potential (Sternberg & Williams, 1997; Sedlacek, 1998, 2004; Bair & Haworth, 1999). Measurement problems such as restriction of range will discussed and the need to consider a multiverse statistical model presented. An alternative assessment system based on noncognitive variables will be presented and examples of its use with graduate and professional students discussed (Sedlacek, 2004, 2012, in press).

  5. A framework to spatially cluster air pollution monitoring sites in US based on the PM2.5 composition

    PubMed Central

    Austin, Elena; Coull, Brent A.; Zanobetti, Antonella; Koutrakis, Petros

    2013-01-01

    Background Heterogeneity in the response to PM2.5 is hypothesized to be related to differences in particle composition across monitoring sites which reflect differences in source types as well as climatic and topographic conditions impacting different geographic locations. Identifying spatial patterns in particle composition is a multivariate problem that requires novel methodologies. Objectives Use cluster analysis methods to identify spatial patterns in PM2.5 composition. Verify that the resulting clusters are distinct and informative. Methods 109 monitoring sites with 75% reported speciation data during the period 2003–2008 were selected. These sites were categorized based on their average PM2.5 composition over the study period using k-means cluster analysis. The obtained clusters were validated and characterized based on their physico-chemical characteristics, geographic locations, emissions profiles, population density and proximity to major emission sources. Results Overall 31 clusters were identified. These include 21 clusters with 2 or more sites which were further grouped into 4 main types using hierarchical clustering. The resulting groupings are chemically meaningful and represent broad differences in emissions. The remaining clusters, encompassing single sites, were characterized based on their particle composition and geographic location. Conclusions The framework presented here provides a novel tool which can be used to identify and further classify sites based on their PM2.5 composition. The solution presented is fairly robust and yielded groupings that were meaningful in the context of air-pollution research. PMID:23850585

  6. Addendum to Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site

    SciTech Connect

    Bergeron, Marcel P.; Freeman, Eugene J.; Wurstner, Signe K.; Kincaid, Charles T.; Coony, Mike M.; Strenge, Dennis L.; Aaberg, Rosanne L.; Eslinger, Paul W.

    2001-09-28

    This report summarizes efforts to complete an addendum analysis to the first iteration of the Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site (Composite Analysis). This document describes the background and performance objectives of the Composite Analysis and this addendum analysis. The methods used, results, and conclusions for this Addendum analysis are summarized, and recommendations are made for work to be undertaken in anticipation of a second analysis.

  7. Unsaturated zone carbon dioxide flux, mixing, and isotopic composition at the USGS Amargosa Desert Research Site

    NASA Astrophysics Data System (ADS)

    Conaway, C. H.; Thordsen, J. J.; Thomas, B.; Haase, K.; Moreo, M. T.; Walvoord, M. A.; Andraski, B. J.; Stonestrom, D. A.

    2015-12-01

    Elevated concentrations of tritium, radiocarbon, and volatile organic compounds at the USGS Amargosa Desert Research Site, adjacent to a low-level radioactive waste disposal facility, have stimulated research on factors affecting transport of these contaminants. This research includes an examination of unsaturated zone carbon dioxide (CO2) fluxes, mixing, and isotopic composition, which can help in understanding these factors. In late April 2015 we collected 76 soil-gas samples in multi-layer foil bags from existing 1.5-m deep tubes, both inside and outside the low-level waste area, as well as from two 110-m-deep multilevel gas-sampling boreholes and a distant background site. These samples were analyzed for carbon dioxide concentration and isotopic composition by direct injection into a cavity ring-down spectrometer. Graphical analysis of results indicates mixing of CO2 characteristic of the root zone (δ13C -18 ‰ VPDB), deep soil gas of the capillary fringe (-20‰), and CO2 produced by microbial respiration of organic matter disposed in the waste area trenches (-28‰). Land-surface boundary conditions are being constrained by the application of a novel non-dispersive infrared sensor and traditional concentration and flux measurements, including discrete CO2 flux data using a gas chamber method to complement continuous data from surface- and tower-based CO2 sensors. These results shed light on radionuclide and VOC mobilization and transport mechanisms from this and similar waste disposal facilities.

  8. Influence of cultivation site on sesquiterpene lactone composition of forage chicory (Cichorium intybus L.).

    PubMed

    Foster, Joyce G; Clapham, William M; Belesky, David P; Labreveux, Maria; Hall, Marvin H; Sanderson, Matt A

    2006-03-01

    The forage potential of chicory (Cichorium intybus L.) has not been realized in southern West Virginia (WV) because ruminants are reluctant to consume the herbage. Chicory contains bitter sesquiterpene lactones that can adversely impact palatability. This study was undertaken to determine whether sesquiterpene lactone concentrations in chicory grown in southern WV differ from those in chicory grown in central Pennsylvania (PA) where chicory is grazed readily. Herbage was collected in 1997 and 1998 from cultivars Grasslands Puna (Puna), INIA le Lacerta (Lacerta), and Forage Feast established at research sites near State College, PA, and Beckley, WV. The total concentration of sesquiterpene lactones in WV-grown cultivars was 0.58% (dry matter basis) in Puna, 0.59% in Lacerta, and 0.79% in Forage Feast in 1997 and ranged from 1.03 (Lacerta) to 1.52% (Forage Feast) in 1998. In PA-grown cultivars, sesquiterpene lactones represented 0.16 (Puna), 0.18 (Lacerta), and 0.27% (Forage Feast) of the forage dry matter in 1997 and ranged from 0.32 (Lacerta) to 0.55% (Forage Feast) in 1998. Concentrations of lactucin, lactucopicrin, and total sesquiterpene lactones in Forage Feast exceeded those in the other cultivars grown at the same site. The lowest concentrations of lactucopicrin and total sesquiterpene lactones observed among WV-grown cultivars were higher (2-fold or more) than the highest concentrations present in cultivars grown the same year in PA. Mineral analyses of soils from the two cultivation sites indicate that P availability may influence sesquiterpene lactone composition of chicory herbage. Results provide a foundation for future studies of environmental effects on sesquiterpene lactone composition and palatability of chicory herbage. PMID:16506832

  9. [Chemical composition analysis of early neolithic pottery unearthed from Xiaohuangshang site, Zhejiang Province and Jiahu site, Henan Province by energy disperse X-ray fluorescence].

    PubMed

    Chen, Qian-Qian; Yang, Yu-Zhang; Zhang, Ju-Zhong; Cui, Wei

    2011-11-01

    The major elements in the early neolithic potteries unearthed from Xiaohuangshan site, Zhejiang Province and Jiahu site, Henan Province were determined by energy disperse X-ray fluorescence (EDXRF). The results show that the chemical compositions of the potteries from these two sites possess obvious regional features respectively. Compared with the specimen from Jiahu site, the potteries from Xiaohuangshan site have the common feature of ancient Chinese southern ceramics with high silicon and low aluminum contents. Simultaneously, the chemical composition of Xiaohuangshan pottery samples nearly unchanged from its early stage to the last stage. This phenomenon indicates that the source of the ceramic raw materials of Xiaohuangshan site was stable, and the continuous improvement of its pottery quality was mainly due to the progress in sintering techniques. However, the chemical composition of Jiahu potteries changed a lot in its three different periods. This change occurred because a large number of admixtures were added to the pottery bodies to improve their operating performances. These results also show that the improvements of pottery making techniques in different Chinese areas may have their own evolution directions respectively for the different geographical environments. PMID:22242535

  10. HANFORD SITE LOW EXPOSURE PIPELINE REPAIR USING A NON-METALLIC COMPOSITE SYSTEM

    SciTech Connect

    HUTH RJ

    2009-11-12

    At the Department of Energy, Richland Operations (DOE-RL) Hanford site in eastern Washington, a 350 mm (14 inch) diameter high density polyethylene (HDPE) pump recirculation pipeline failed at a bonded joint adjacent to a radiologically and chemically contaminated groundwater storage basin. The responsible DOE-RL contractor, CH2MHill Plateau Remediation Company, applied a fiberglass reinforced plastic (composite) field repair system to the failed joint. The system was devised specifically for the HDPE pipe repair at the Hanford site, and had not been used on this type of plastic piping previously. This paper introduces the pipe failure scenario, describes the options considered for repair and discusses the ultimate resolution of the problem. The failed pipeline was successfully returned to service with minimal impact on waste water treatment plant operating capacity. Additionally, radiological and chemical exposures to facility personnel were maintained as low as reasonably achievable (ALARA). The repair is considered a success for the near term, and future monitoring will prove whether the repair can be considered for long term service and as a viable alternative for similar piping failures at the Hanford site.

  11. Evaluation of distance maps from fast GRE MRI as a tool to study the knee joint space

    NASA Astrophysics Data System (ADS)

    Tamez-Pena, Jose G.; Lerner, Amy L.; Yao, Jiang; Salo, Arthur D.; Totterman, Saara

    2003-05-01

    A new three-dimensional (3D) method of evaluating the joint space from fast GRE MRI has been developed that allows the reconstruction of the two dimensional (2D) distance map between the femur and the tibia bone plates. This method uses the MRI data, an automated 3D segmentation, and an unsupervised joint space extraction algorithm that identify the medial and lateral compartments of the knee joint. The extracted medial and lateral compartments of the tibia-femur joint space were analyzed by 2D distance maps, where visual as well quantitative information was extracted. This method was applied to study the dynamic behavior of the knee joint space under axial load. Three healthy volunteers' knees were imaged using fast GRE sequences in a clinical scanner under unloaded (normal) conditions and with an axial load that mimics the person's standing load. Furthermore, one volunteer's knee was imaged at four regular time intervals while the load was applied and at four regular intervals without load. The results show that changes of 50 microns in the average distance between bones can be measured and that normal axial loads reduce the joint space width significantly and can be detected by this method.

  12. Ionic composition of rainwater at selected sites of Kuantan, Pahang, Malaysia: a preliminary study.

    PubMed

    Tay, Joo Hui; Jaafar, Syakhsiah; Mohd Tahir, Norhayati

    2014-03-01

    A short-term investigation on the chemical composition of rainwater was carried out at five selected sampling stations in Kuantan district, Pahang, Malaysia. Sampling of rainwater was conducted by event basis between September and November 2011. Rainwater samples were collected using polyethylene containers and the parameters measured were cations (sodium, potassium, ammonium, calcium and magnesium) and anions (chlorides, nitrates and sulphates). The average pH value for rainwater samples was 6.0 ± 0.57 in which most of the sampling sites exhibited pH values >5.6. Calcium and sulphate were the most abundant cation and anion, respectively, whilst the concentrations of other major ions varied according to sampling location. PMID:24435136

  13. Factors, origin and sources affecting PM1 concentrations and composition at an urban background site

    NASA Astrophysics Data System (ADS)

    Squizzato, Stefania; Masiol, Mauro; Agostini, Chiara; Visin, Flavia; Formenton, Gianni; Harrison, Roy M.; Rampazzo, Giancarlo

    2016-11-01

    PM1 is widely believed to provide better information on the anthropogenic fraction of particulate matter pollution than PM2.5. However, data on PM1 are still limited in Europe as well as comprehensive information about its chemical composition and source apportionment and this gap is more evident in the pollution hot-spots still remaining in Europe, such as the Po Valley (Northern Italy). Elemental and organic carbon, 7 water soluble inorganic ions and 17 elements were quantified in 117 PM1 samples collected at an urban background site in Venice-Mestre, a large city located in the eastern Po Valley, during winter (December 2013-February 2014) and summer (May-July 2014) periods. Results show a strong seasonality for PM1 mass concentration (averages ranging from 6 ± 2 in summer to 34 ± 24 μg m- 3 in winter) and for most of the analysed species. Components mainly related to road traffic, residential heating, biomass burning and secondary inorganic aerosol (ammonium nitrate) reached their highest levels in winter, while mineral dust and marine components were elevated in summer. PMF analysis revealed 7 potential sources. Secondary inorganic aerosol (33%) and biomass burning (33%) are the major contributor in winter followed by EC-primary emissions (16%), aged sulphate (6%), road traffic (7%), fossil fuel combustion (%) and marine aerosol (3%). During summer, these sources account for 12%, 14%, 20%, 22%, 8%, 14% and 10%, respectively. Some PM1 sources are located near the sampling site (residential area, traffic road, industrial area) but a major contribution of long range transport is observed when high pollution events occur. The results give useful insights into PM1 composition in an urban area and chemical profiles of sources helpful in the interpretation of receptor model results.

  14. Culicoides species composition and environmental factors influencing African horse sickness distribution at three sites in Namibia.

    PubMed

    Liebenberg, Danica; Piketh, Stuart; Labuschagne, Karien; Venter, Gert; Greyling, Telane; Mienie, Charlotte; de Waal, Tania; van Hamburg, Huib

    2016-11-01

    African horse sickness (AHS) is one of the most lethal infectious, non-contagious, vector-borne disease of equids. The causative agent, African horse sickness virus (AHSV) is transmitted via Culicoides midges (Diptera: Ceratopogonidae). AHS is endemic to Namibia but detailed studies of Culicoides communities and influencing environmental parameters are limited. This study aims to determine the Culicoides species composition at three different sites and to assess environmental parameters influencing the geographical distribution of AHS in Namibia. Weekly collections of Culicoides were made during the AHS peak season from January to May for 2013 and 2014 using the Onderstepoort 220V UV-light trap. Out of 397 collections made, 124 collections (3287 Culicoides) were analysed for AHSV presence with RT-qPCR. A total of 295 collections were analysed for total Culicoides (all collected Culicoides individuals) and in 75% of these collections the Culicoides were identified to species level. C. imicola was the dominant species with proportional representation of 29.9%. C. subschultzei, C. exspectator and C. ravus each contribute more than 10% to the species composition. The lowest number of Culicoides was collected at Aus 9980, a total of 21819 at Windhoek and the highest number at Okahandja 47343. AHSV was present at all three sites during 2013 but only in Windhoek and Okahandja during 2014. Multivariate analyses of data from the two year survey indicate the environmental parameters in order of importance for the distribution of AHS in Namibia as precipitation>temperature>clay>relative humidity>NDVI. The implication of these findings is that any precipitation event increases Culicoides numbers significantly. Together with these results the high number of species found of which little is known regarding their vector competence, add to the complexity of the distribution of AHS in Namibia. PMID:27491343

  15. Motif types, motif locations and base composition patterns around the RNA polyadenylation site in microorganisms, plants and animals

    PubMed Central

    2014-01-01

    Background The polyadenylation of RNA is critical for gene functioning, but the conserved sequence motifs (often called signal or signature motifs), motif locations and abundances, and base composition patterns around mRNA polyadenylation [poly(A)] sites are still uncharacterized in most species. The evolutionary tendency for poly(A) site selection is still largely unknown. Results We analyzed the poly(A) site regions of 31 species or phyla. Different groups of species showed different poly(A) signal motifs: UUACUU at the poly(A) site in the parasite Trypanosoma cruzi; UGUAAC (approximately 13 bases upstream of the site) in the alga Chlamydomonas reinhardtii; UGUUUG (or UGUUUGUU) at mainly the fourth base downstream of the poly(A) site in the parasite Blastocystis hominis; and AAUAAA at approximately 16 bases and approximately 19 bases upstream of the poly(A) site in animals and plants, respectively. Polyadenylation signal motifs are usually several hundred times more abundant around poly(A) sites than in whole genomes. These predominant motifs usually had very specific locations, whether upstream of, at, or downstream of poly(A) sites, depending on the species or phylum. The poly(A) site was usually an adenosine (A) in all analyzed species except for B. hominis, and there was weak A predominance in C. reinhardtii. Fungi, animals, plants, and the protist Phytophthora infestans shared a general base abundance pattern (or base composition pattern) of “U-rich—A-rich—U-rich—Poly(A) site—U-rich regions”, or U-A-U-A-U for short, with some variation for each kingdom or subkingdom. Conclusion This study identified the poly(A) signal motifs, motif locations, and base composition patterns around mRNA poly(A) sites in protists, fungi, plants, and animals and provided insight into poly(A) site evolution. PMID:25052519

  16. Impact of wildfires on size-resolved aerosol composition at a coastal California site

    NASA Astrophysics Data System (ADS)

    Maudlin, L. C.; Wang, Z.; Jonsson, H. H.; Sorooshian, A.

    2015-10-01

    Size-resolved aerosol composition measurements were conducted at a coastal site in central California during the Nucleation in California Experiment (NiCE) between July and August of 2013. The site is just east of ship and marine emission sources and is also influenced by continental pollution and wildfires, such as those near the California-Oregon border which occurred near the end of NiCE. Two micro-orifice uniform deposit impactors (MOUDIs) were used, and water-soluble and elemental compositions were measured. The five most abundant water-soluble species (in decreasing order) were chloride, sodium, non-sea salt (nss) sulfate, ammonium, and nitrate. During wildfire periods, nss K mass concentrations were not enhanced as strongly as other species in the sub-micrometer stages and even decreased in the super-micrometer stages; species other than nss K are more reliable tracers for biomass burning in this region. Chloride levels were reduced in the fire sets likely due to chloride depletion by inorganic and organic acids that exhibited elevated levels in transported plumes. During wildfire periods, the mass size distribution of most dicarboxylic acids changed from unimodal to bimodal with peaks in the 0.32 μm and 1.0-1.8 μm stages. Furthermore, sulfate's peak concentration shifted from the 0.32 μm to 0.56 μm stage, and nitrate also shifted to larger sizes (1.0 μm to 1.8-3.2 μm stages). Mass concentrations of numerous soil tracer species (e.g., Si, Fe) were strongly enhanced in samples influenced by wildfires, especially in the sub-micrometer range. Airborne cloud water data confirm that soil species were associated with fire plumes transported south along the coast. In the absence of biomass burning, cloud condensation nuclei (CCN) composition is dominated by nss sulfate and ammonium, and the water-soluble organic fraction is dominated by methanesulfonate, whereas for the samples influenced by wildfires, ammonium becomes the dominant overall species, and

  17. Bacterial community composition of chronic periodontitis and novel oral sampling sites for detecting disease indicators

    PubMed Central

    2014-01-01

    Background Periodontitis is an infectious and inflammatory disease of polymicrobial etiology that can lead to the destruction of bones and tissues that support the teeth. The management of chronic periodontitis (CP) relies heavily on elimination or at least control of known pathogenic consortia associated with the disease. Until now, microbial plaque obtained from the subgingival (SubG) sites has been the primary focus for bacterial community analysis using deep sequencing. In addition to the use of SubG plaque, here, we investigated whether plaque obtained from supragingival (SupG) and tongue dorsum sites can serve as alternatives for monitoring CP-associated bacterial biomarkers. Results Using SubG, SupG, and tongue plaque DNA from 11 healthy and 13 diseased subjects, we sequenced V3 regions (approximately 200 bases) of the 16S rRNA gene using Illumina sequencing. After quality filtering, approximately 4.1 million sequences were collapsed into operational taxonomic units (OTUs; sequence identity cutoff of >97%) that were classified to a total of 19 phyla spanning 114 genera. Bacterial community diversity and overall composition was not affected by health or disease, and multiresponse permutation procedure (MRPP) on Bray-Curtis distance measures only supported weakly distinct bacterial communities in SubG and tongue plaque depending on health or disease status (P < 0.05). Nonetheless, in SubG and tongue sites, the relative abundance of Firmicutes was increased significantly from health to disease and members of Synergistetes were found in higher abundance across all sites in disease. Taxa indicative of CP were identified in all three locations (for example, Treponema denticola, Porphyromonas gingivalis, Synergistes oral taxa 362 and 363). Conclusions For the first time, this study demonstrates that SupG and tongue dorsum plaque can serve as alternative sources for detecting and enumerating known and novel bacterial biomarkers of CP. This finding is clinically

  18. Machine-Scorable Complex Constructed-Response Quantitative Items: Agreement between Expert System and Human Raters' Scores. GRE Board Professional Report No. 88-07aP.

    ERIC Educational Resources Information Center

    Sebrechts, Marc M.; And Others

    This study evaluated agreement between expert system and human scores on 12 algebra word problems taken by Graduate Record Examinations (GRE) General Test examinees from a general sample of 285 and a study sample of 30. Problems were drawn from three content classes (rate x time, work, and interest) and presented in four constructed-response…

  19. Development and Evaluation of Computer-Administered Analytical Questions for the Graduate Record Examinations General Test. GRE Board Professional Report No. 88-06P.

    ERIC Educational Resources Information Center

    Bridgeman, Brent; Rock, Donald A.

    Three new computer-administered item types for the analytical scale of the Graduate Record Examination (GRE) General Test were developed and evaluated. One item type was a free-response version of the current analytical reasoning item type. The second item type was a somewhat constrained free-response version of the pattern identification (or…

  20. Test Anxiety and Test Performance: Comparing Paper-based and Computer-Adaptive Versions of the Graduate Record Examinations (GRE) General Test.

    ERIC Educational Resources Information Center

    Powers, Donald E.

    2001-01-01

    Tests the hypothesis that the introduction of computer-adaptive testing may help to alleviate test anxiety and diminish the relationship between test anxiety and test performance. Compares a sample of Graduate Record Examinations (GRE) General Test takers who took the computer-adaptive version of the test with another sample who took the…

  1. The Relationship between GRE Scores and Performance on the Standard Principal Examination for Certification of Educators in Texas (ExCET).

    ERIC Educational Resources Information Center

    Jones, Timothy B.; Sherman, Ross B.; Ninness, H. A.; Hallman, Patsy J.

    Graduate programs in Educational Administration use a variety of screening strategies, including the Graduate Records Examination (GRE) when selecting and admitting students. In order to earn Standard Principal Certification in Texas, an Educational Administration candidate, in addition to completing a graduate program, must also pass the Standard…

  2. How Well Does the GRE Work for Your University? An Empirical Institutional Case Study of the Graduate Record Examination across Multiple Disciplines.

    ERIC Educational Resources Information Center

    Rubio, Doris McGartland; Rubin, Robert S.; Brennan, Donald G.

    2003-01-01

    This case study was designed to demonstrate how an institution could use readily available archival data to produce a simple yet informative validity study as a necessary step in understanding the effectiveness of their selection process. Results indicated the GRE does not significantly predict graduate school success across all disciplines…

  3. The Predictive Validity of the GRE and TOEFL Exams with GGPA as the Criterion of Graduate Success for International Graduate Students in Science and Engineering.

    ERIC Educational Resources Information Center

    Neal, Menka E.

    This study investigated the relationship between graduate grade-point-average (GGPA) and the total score, as well as the scores on each part, of the Graduate Record Examination (GRE). It also investigated the relationship between GGPA and the total score, as well as the scores on each part, of the Test of English as a Foreign Language (TOEFL). The…

  4. The GRE Subject Test Performance of U.S. and Non-U.S. Examinees, 1982-84: A Comparative Analysis.

    ERIC Educational Resources Information Center

    Wilson, Kenneth M.

    The Graduate Record Examination (GRE) subject-matter achievement tests are offered in 17 fields. This study investigated the performance of U.S. and non-U.S. citizens on the Subject Tests, and the relationship of selected English-proficiency-related background variables to the test performance of non-U.S. citizens. It was also concerned with…

  5. MO-G-17A-03: MR-Based Cortical Bone Segmentation for PET Attenuation Correction with a Non-UTE 3D Fast GRE Sequence

    SciTech Connect

    Ai, H; Pan, T; Hwang, K

    2014-06-15

    Purpose: To determine the feasibility of identifying cortical bone on MR images with a short-TE 3D fast-GRE sequence for attenuation correction of PET data in PET/MR. Methods: A water-fat-bone phantom was constructed with two pieces of beef shank. MR scans were performed on a 3T MR scanner (GE Discovery™ MR750). A 3D GRE sequence was first employed to measure the level of residual signal in cortical bone (TE{sub 1}/TE{sub 2}/TE{sub 3}=2.2/4.4/6.6ms, TR=20ms, flip angle=25°). For cortical bone segmentation, a 3D fast-GRE sequence (TE/TR=0.7/1.9ms, acquisition voxel size=2.5×2.5×3mm{sup 3}) was implemented along with a 3D Dixon sequence (TE{sub 1}/TE{sub 2}/TR=1.2/2.3/4.0ms, acquisition voxel size=1.25×1.25×3mm{sup 3}) for water/fat imaging. Flip angle (10°), acquisition bandwidth (250kHz), FOV (480×480×144mm{sup 3}) and reconstructed voxel size (0.94×0.94×1.5mm{sup 3}) were kept the same for both sequences. Soft tissue and fat tissue were first segmented on the reconstructed water/fat image. A tissue mask was created by combining the segmented water/fat masks, which was then applied on the fast-GRE image (MRFGRE). A second mask was created to remove the Gibbs artifacts present in regions in close vicinity to the phantom. MRFGRE data was smoothed with a 3D anisotropic diffusion filter for noise reduction, after which cortical bone and air was separated using a threshold determined from the histogram. Results: There is signal in the cortical bone region in the 3D GRE images, indicating the possibility of separating cortical bone and air based on signal intensity from short-TE MR image. The acquisition time for the 3D fast-GRE sequence was 17s, which can be reduced to less than 10s with parallel imaging. The attenuation image created from water-fat-bone segmentation is visually similar compared to reference CT. Conclusion: Cortical bone and air can be separated based on intensity in MR image with a short-TE 3D fast-GRE sequence. Further research is required

  6. Adaptive robust motion trajectory tracking control of pneumatic cylinders with LuGre model-based friction compensation

    NASA Astrophysics Data System (ADS)

    Meng, Deyuan; Tao, Guoliang; Liu, Hao; Zhu, Xiaocong

    2014-07-01

    Friction compensation is particularly important for motion trajectory tracking control of pneumatic cylinders at low speed movement. However, most of the existing model-based friction compensation schemes use simple classical models, which are not enough to address applications with high-accuracy position requirements. Furthermore, the friction force in the cylinder is time-varying, and there exist rather severe unmodelled dynamics and unknown disturbances in the pneumatic system. To deal with these problems effectively, an adaptive robust controller with LuGre model-based dynamic friction compensation is constructed. The proposed controller employs on-line recursive least squares estimation (RLSE) to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. In addition, in order to realize LuGre model-based friction compensation, the modified dual-observer structure for estimating immeasurable friction internal state is developed. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology is applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping is used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Finally, the proposed controller is tested for tracking sinusoidal trajectories and smooth square trajectory under different loads and sudden disturbance. The testing results demonstrate that the achievable performance of the proposed controller is excellent and is much better than most other studies in literature. Especially when a 0.5 Hz sinusoidal trajectory is tracked, the maximum tracking error is 0.96 mm and the average tracking error is 0.45 mm. This

  7. Non-rigid registration and KLT filter to improve SNR and CNR in GRE-EPI myocardial perfusion imaging.

    PubMed

    Mihai, Georgeta; Ding, Yu; Xue, Hui; Chung, Yiu-Cho; Rajagopalan, Sanjay; Guehring, Jens; Simonetti, Orlando P

    2012-12-01

    The purpose of the study was to evaluate the effect of motion compensation by non-rigid registration combined with the Karhunen-Loeve Transform (KLT) filter on the signal to noise (SNR) and contrast-to-noise ratio (CNR) of hybrid gradient-echo echoplanar (GRE-EPI) first-pass myocardial perfusion imaging. Twenty one consecutive first-pass adenosine stress perfusion MR data sets interpreted positive for ischemia or infarction were processed by non-rigid Registration followed by KLT filtering. SNR and CNR were measured in abnormal and normal myocardium in unfiltered and KLT filtered images following non-rigid registration to compensate for respiratory and other motions. Image artifacts introduced by filtering in registered and nonregistered images were evaluated by two observers. There was a statistically significant increase in both SNR and CNR between normal and abnormal myocardium with KLT filtering (mean SNR increased by 62.18% ± 21.05% and mean CNR increased by 58.84% ± 18.06%; p = 0.01). Motion correction prior to KLT filtering reduced significantly the occurrence of filter induced artifacts (KLT only-artifacts in 42 out of 55 image series vs. registered plus KLT-artifacts in 3 out of 55 image series). In conclusion the combination of non- rigid registration and KLT filtering was shown to increase the SNR and CNR of GRE-EPI perfusion images. Subjective evaluation of image artifacts revealed that prior motion compensation significantly reduced the artifacts introduced by the KLT filtering process. PMID:23936584

  8. Organic aerosol molecular composition and gas-particle partitioning coefficients at a Mediterranean site (Corsica).

    PubMed

    Rossignol, Stéphanie; Couvidat, Florian; Rio, Caroline; Fable, Sébastien; Grignion, Guillaume; Savelli; Pailly, Olivier; Leoz-Garziandia, Eva; Doussin, Jean-Francois; Chiappini, Laura

    2016-02-01

    Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica (June 2011). Aimed at assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography-mass spectrometry (GC-MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls (C3-C7), mono and di-carboxylic acids (C3-C18), and compounds bearing up to three functionalities. Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached. PMID:26969549

  9. Fine mode aerosol composition at three long-term atmospheric monitoring sites in the Amazon Basin

    SciTech Connect

    Artaxo, P.; Gerab, F.; Yamasoe, M.A.; Martins, J.V.

    1994-11-01

    The Amazon Basin tropical rain forest is a key region to study processes that are changing the composition of the global atmosphere, including the large amount of fine mode aerosol particles emitted during biomass burning that might influence the global atmosphere. Three background monitoring stations, Alta Floresta, Cuiaba, and Serra do Navio, are operating continuously measuring aerosol composition. Fine (particle diameter less than 2.0 microns) and coarse (particle diameter greater than 2.0 microns and less than 10 microns) mode aerosol particles were collected using stacked filter units. Particle-induced X-ray emission was used to measure concentrations of up to 20 elements in the fine mode: Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, and Pb. Soot carbon and gravimetric mass analysis were also performed. Absolute Principal Factor Analysis (APFA) has derived absolute elemental source profiles. APFA showed four aerosol particle components: soil dust (Al, Ca, Ti, Mn, Fe), biomass burning (soot, fine mode mass concentration, K, Cl), natural primary biogenic particles with gas-to-particle component (K, S, Ca, Mn, Zn), and marine aerosol (Cl). Biogenic and biomass burning aerosol particles dominate the fine mode mass concentration, with the presence of K, P, S, Cl, Zn, Br, and fine mode mass concentration (FPM). At the Alta Floresta and Cuiaba sites, during the dry season, a strong component of biomass burning is observed. Inhalable particulate matter (particle diameter less than 10 microns) mass concentration up to 700 micrograms/cu m was measured. Fine particle mass concentration alone can go as high as 400 micrograms/cu m for large regions.

  10. Diurnal patterns in PM 2.5 mass and composition at a background, complex terrain site

    NASA Astrophysics Data System (ADS)

    Tanner, Roger L.; Bairai, Solomon T.; Olszyna, Kenneth J.; Valente, Myra L.; Valente, Ralph J.

    Current fine particle NAAQS specify 24 h integrated mass measurements as the compliance metric. However, the value of continuous short-time resolution sampling (1 h or less) is recognized and being included in US EPA-monitoring strategies. An extensive body of fine mass concentration data has been acquired using continuous PM 2.5 monitoring by TEOM at Look Rock, TN, augmented by trace gas measurements and, during enhanced monitoring periods, continuous sampling for aerosol sulfate (2 methods) and elemental (black) carbon. Continuous data are compared to the 24 h-averaged values of mass and composition from integrated samplers at the site, and for fine mass and sulfate are found to be excellent ( r2=0.97-0.99). We then report the diurnal variations in concentrations from extensive continuous monitoring during 3 summer periods (2000-2002) and for more limited periods throughout calendar year 2001. Levels of the several continuously measured gases and particulate constituents vary in magnitude diurnally according to expected patterns based on their emissions, their formation and loss processes, their lifetimes toward wet and dry deposition, the dynamics of up-slope—down-slope circulation, and solar-driven boundary layer growth and decay. Thus, concentrations of short-lifetime gases have minima at sunrise and maxima in the evening. Long-lived primary species (CO and black carbon) increase in mid-morning as the boundary layer height reaches the site and decay thereafter. Long-lived secondary species (sulfate and fine mass) show little diurnal variability. Factors controlling the observed diurnal variability thus significantly influence the extent and timing of human exposure to pollutant species, as well as affecting visibility impairment in complex terrain environments near the Great Smoky Mountains National Park.

  11. Effects of short-term cattle exclusion on plant community composition: Prairie dog and ecological site influences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant community composition is an important indicator of healthy, proper functioning rangelands. We evaluated the impacts prairie dog grazing, ecological site and short term cattle exclusion on Northern Mixed-Grass prairie near McLaughlin, SD. Modified Daubenmire frames provided canopy cover, litte...

  12. Molecular composition of organic aerosols at urban background and road tunnel sites using ultra-high resolution mass spectrometry.

    PubMed

    Tong, Haijie; Kourtchev, Ivan; Pant, Pallavi; Keyte, Ian J; O'Connor, Ian P; Wenger, John C; Pope, Francis D; Harrison, Roy M; Kalberer, Markus

    2016-07-18

    Organic aerosol composition in the urban atmosphere is highly complex and strongly influenced by vehicular emissions which vary according to the make-up of the vehicle fleet. Normalized test measurements do not necessarily reflect real-world emission profiles and road tunnels are therefore ideal locations to characterise realistic traffic particle emissions with minimal interference from other particle sources and from atmospheric aging processes affecting their composition. In the current study, the composition of fine particles (diameter ≤2.5 μm) at an urban background site (Elms Road Observatory Site) and a road tunnel (Queensway) in Birmingham, UK, were analysed with direct infusion, nano-electrospray ionisation ultrahigh resolution mass spectrometry (UHRMS). The overall particle composition at these two sites is compared with an industrial harbour site in Cork, Ireland, with special emphasis on oxidised mono-aromatics, polycyclic aromatic hydrocarbons (PAHs) and nitro-aromatics. Different classification criteria, such as double bond equivalents, aromaticity index and aromaticity equivalent are used and compared to assess the fraction of aromatic components in the approximately one thousand oxidized organic compounds at the different sampling locations. PMID:27143100

  13. Flavor-violation tests of the warped/composite standard model in the two-site approach

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Azatov, Aleksandr; Zhu, Lijun

    2009-03-01

    We study flavor violation in the quark sector in a purely 4D, two-site effective field theory description of the standard model (SM) and just their first Kaluza-Klein excitations from a warped extra dimension. The warped 5D framework can provide solutions to both the Planck-weak and flavor hierarchies of the SM. It is also related (via the AdS/CFT correspondence) to partial compositeness of the SM. We focus on the dominant contributions in the two-site model to two observables which we argue provide the strongest constraints from flavor violation, namely, γK and BR(b→sγ), where contributions in the two-site model occur at tree and loop-level, respectively. In particular, we demonstrate that a “tension” exists between these two observables in the sense that they have opposite dependence on composite site Yukawa couplings, making it difficult to decouple flavor-violating effects using this parameter. We choose the size of the composite site QCD coupling based on the relation of the two-site model to the 5D model (addressing the Planck-weak hierarchy), where we match the 5D QCD coupling to the 4D coupling at the loop-level and assuming negligible tree-level brane-localized kinetic terms. We estimate that a larger size of the 5D gauge coupling is constrained by the requirement of 5D perturbativity. We find that ˜O(5)TeV mass scale for the new particles in the two-site model can then be consistent with both observables. We also compare our analysis of γK in the two-site model to that in 5D models, including both the cases of a brane-localized and bulk Higgs.

  14. Technical Scope and Approach for the 2004 Composite Analysis of Low Level Waste Disposal at the Hanford Site

    SciTech Connect

    Kincaid, Charles T.; Bryce, Robert W.; Buck, John W.

    2004-07-09

    A composite analysis is required by U.S. Department of Energy (DOE) Manual 435.1-1 to ensure public safety through the management of active and planned low-level radioactive waste disposal facilities associated with the Hanford Site (DOE/HQ-Manual 435.1-1). A Composite Analysis is defined as ''a reasonably conservative assessment of the cumulative impact from active and planned low-level waste disposal facilities, and all other sources from radioactive contamination that could interact with the low-level waste disposal facility to affect the dose to future members of the public''. At the Hanford Site, a composite analysis is required for continued disposal authorization for the immobilized low-activity waste, tank waste vitrification plant melters, low level waste in the 200 East and 200 West Solid Waste Burial Grounds, and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) waste in the Environmental Restoration Disposal Facility. The 2004 Composite Analysis will be a site-wide analysis, considering final remedial actions for the Columbia River corridor and the Central Plateau at the Hanford Site. The river corridor includes waste sites and facilities in each of the 100 Areas as well as the 300, 400, and 600 Areas. The remedial actions for the river corridor are being conducted to meet residential land use standards with the vision of the river corridor being devoted to a combination of recreation and preservation. The ''Central Plateau'' describes the region associated with operations and waste sites of the 200 Areas. DOE is developing a strategy for closure of the Central Plateau area by 2035. At the time of closure, waste management activities will shrink to a Core Zone within the Central Plateau. The Core Zone will contain the majority of Hanford's permanently disposed waste

  15. Chemical composition and mass closure of particulate matter at six urban sites in Europe

    NASA Astrophysics Data System (ADS)

    Sillanpää, Markus; Hillamo, Risto; Saarikoski, Sanna; Frey, Anna; Pennanen, Arto; Makkonen, Ulla; Spolnik, Zoya; Van Grieken, René; Braniš, Martin; Brunekreef, Bert; Chalbot, Marie-Cecile; Kuhlbusch, Thomas; Sunyer, Jordi; Kerminen, Veli-Matti; Kulmala, Markku; Salonen, Raimo O.

    The chemical composition of fine (PM 2.5) and coarse (PM 2.5-10) particulate matter was investigated in 7-week field campaigns of contrasting air pollution at six urban background sites in Europe. The campaigns were scheduled to include seasons of local public health concern due to high particulate concentrations or findings in previously conducted epidemiological studies. The sampling campaigns were carried out as follows: Duisburg/Germany October-November 2002 (autumn), Prague/Czech Republic November 2002-January 2003 (winter), Amsterdam/Netherlands January-March 2003 (winter), Helsinki/Finland March-May 2003 (spring), Barcelona/Spain March-May 2003 (spring) and Athens/Greece June-July 2003 (summer). Aerosol samples were collected in 3+4-day periods per week ( N=14) using two identical virtual impactors (VI). All the filter samples were analysed with the same instruments to obtain particulate mass, inorganic ions, total and watersoluble elements, and elemental and organic carbon content. The campaign means of PM 2.5 and PM 2.5-10 ranged from 8.3 to 30 and 5.4 to 29 μg m -3, respectively. The "wet and cool" seasons favoured a low coarse-to-fine particulate mass ratio (<1), whereas the ratio was high (>1) during the warmer and drier spring and summer campaigns. According to chemical mass closure, the major components in PM 2.5 were carbonaceous compounds (organic matter+elemental carbon), secondary inorganic ions and sea salt, whereas those in PM 2.5-10 were soil-derived compounds, carbonaceous compounds, sea salt and nitrate. The major and minor components together accounted for 79-106% and 77-96% of the gravimetrically measured PM 2.5 and PM 2.5-10 mass, respectively. In conclusion, the measured PM 2.5 and PM 2.5-10 in the campaigns could be reconstructed to a large extent with the help of harmonized particulate sampling and analysis of the selected chemical constituents. The health significance of the observed differences in chemical composition and emission

  16. Composite analysis for low-level waste disposal in the 200 area plateau of the Hanford Site

    SciTech Connect

    Kincaid, C.T.; Bergeron, M.P.; Cole, C.R.

    1998-03-01

    This report presents the first iteration of the Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site (Composite Analysis) prepared in response to the U.S. Department of Energy Implementation Plan for the Defense Nuclear Facility Safety Board Recommendation 94-2. The Composite Analysis is a companion document to published analyses of four active or planned low-level waste disposal actions: the solid waste burial grounds in the 200 West Area, the solid waste burial grounds in the 200 East Area, the Environmental Restoration Disposal Facility, and the disposal facilities for immobilized low-activity waste. A single Composite Analysis was prepared for the Hanford Site considering only sources on the 200 Area Plateau. The performance objectives prescribed in U.S. Department of Energy guidance for the Composite Analysis were 100 mrem in a year and examination of a lower dose (30 mrem in a year) to ensure the {open_quotes}as low as reasonably achievable{close_quotes} concept is followed. The 100 mrem in a year limit was the maximum allowable all-pathways dose for 1000 years following Hanford Site closure, which is assumed to occur in 2050. These performance objectives apply to an accessible environment defined as the area between a buffer zone surrounding an exclusive waste management area on the 200 Area Plateau, and the Columbia River. Estimating doses to hypothetical future members of the public for the Composite Analysis was a multistep process involving the estimation or simulation of inventories; waste release to the environment; migration through the vadose zone, groundwater, and atmospheric pathways; and exposure and dose. Doses were estimated for scenarios based on agriculture, residential, industrial, and recreational land use. The radionuclides included in the vadose zone and groundwater pathway analyses of future releases were carbon-14, chlorine-36, selenium-79, technetium-99, iodine-129, and uranium isotopes.

  17. Effect of Geopolymer filler in Glass Reinforced Epoxy (GRE) Pipe for Piping Application: Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Firdaus Abu Hashim, Mohammad; Bakri Abdullah, Mohd Mustafa Al; Mohd Ruzaidi Ghazali, Che; Hussin, Kamarudin; Binhussain, Mohammed

    2016-06-01

    The present work is aimed to carry out the effect of geopolymer material which is fly ash as filler in the glass reinforced epoxy pipe on the micro structure of fly ash geopolymer, compression properties, and bulk density using the filament winding method. Conventional glass reinforced epoxy pipes has its own disadvantages such as high corrosion resistance at acidic environment and low strength which can be replaced by the composite pipes. Geopolymer is a type of amorphous alumino-silicate and can be synthesized by geopolymerization process. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 - 40 weight percentage geopolymer filler which is fly ash with 4 Molarity were prepared. Morphology of the raw material fly ash and fly ash based-geopolymer surface was characterized using scanning electron microscopy. It was found that the additions of fly ash at the beginning with 10 wt% are showing higher compressive strength than glass reinforced epoxy pipe without fly ash geopolymer filler. The compressive test of these series of samples was determined using Instron Universal Testing under compression mode. It was found that compressive strength for samples fly ash based-geopolymer filler are higher as compared to glass reinforced epoxy pipe without geopolymer filler. However, the compressive strength of glass reinforced epoxy pipe with fly ash geopolymer filler continues to decline when added to 20 wt% - 40 wt% of geopolymer filler loading. The results showed that the mixing of geopolymer materials in epoxy system can be obtained in this study.

  18. Physical Properties and Chemical Composition of Aerosols sampled in T1 site during MILAGRO Campaign

    NASA Astrophysics Data System (ADS)

    Castro, T.; Mamani-Paco, R.; Saavedra, M. I.; Garcia, J.; Amador, O.; Carabali, G.; Salcido, A.; Herrera, E.; Baez, A.

    2007-05-01

    Results from pollutant measurements and meteorological variables corresponding to the month of March of 2006 during the MILAGRO campaign at site T1 are presented (Tecamac, State of Mexico). Three 8-stage cascade impactors (MOUDI) were employed to obtain aerosol samples of different sizes. For organic species analysis, samples were collected with a PM2.5 High Volume sampler. Mass and chemical composition (inorganic and organic species) were obtained with the use of analytical techniques. Particle morphology analysis was done with a TEM-EDAX System. Physical properties of aerosols were measured with a PSAP, a nephelometer and a CPC. According with area meteorology, days with Mexico City urban influence on T1 (March 9-12) and without influence (March 14 and 15) were analyzed. The particle average concentration during the whole campaign was 20,000 particles/cm3. For the days with and without urban influence the average concentrations were 17,500 and 8,000 particles/cm3 respectively. From the MOUDI data the highest particle concentration through the campaign was during the morning in the mode d50=0.32 μm. On the other hand, the cumulative highest concentration of all the stages was observed for March 19 followed by March 9. Scattering and absorption coefficients average obtained on T1 were 5.1x10-5 m-1 and 2.54x10-5 m-1 respectively and single scattering albedo was 0.676. These values show T1 as a polluted atmosphere, just as happens with megacities. Morphology of particles captured in a MOUDI impactor was studied. Particles between d50=0.18 μm and d50=1.8 μm sampled in T1 associated with urban influence (March 9) tended to show less irregular shapes through different periods of that day. These findings suggest the presence of large numbers of secondary aerosols and aged agglomerated particles. Particles ranging from d50=0.18 μm to d50=1.8 μm sampled in T1 and associated mainly with surrounding areas influence, e.g. Tizayuca Industrial Park (March 15) showed

  19. Site-specific specimen preparation by focused ion beam milling for transmission electron microscopy of metal matrix composites.

    PubMed

    Gasser, Philippe; Klotz, Ulrich E; Khalid, Fazal A; Beffort, Olivier

    2004-04-01

    This work describes the application and usefulness of the focused ion beam (FIB) technique for the preparation of transmission electron microscopy (TEM) samples from metal matrix composite materials. Results on an Aldiamond composite, manufactured by the squeeze casting infiltration process, were chosen for demonstration. It is almost impossible to prepare TEM specimens of this material by any other conventional method owing to the presence of highly inhomogeneous phases and reinforcement diamond particles. The present article gives a detailed account of the salient features of the FIB technique and its operation. One of the big advantages is the possibility to prepare site-specific TEM specimens with high spatial resolution. The artifacts occurring during the specimen preparation, for example, Ga-ion implantation, curtain effects, amorphous layers, bending of the lamella, or different milling behaviors of the materials have been discussed. Furthermore, TEM examination of the specimens prepared revealed an ultrafine amorphous layer of graphite formed at the interface between the Al and diamond particles that may affect the interfacial properties of the composite materials. This may not have been feasible without the successful application of the FIB technique for production of good quality site-specific TEM specimens. PMID:15306057

  20. Computational Identification of Protein Pupylation Sites by Using Profile-Based Composition of k-Spaced Amino Acid Pairs.

    PubMed

    Hasan, Md Mehedi; Zhou, Yuan; Lu, Xiaotian; Li, Jinyan; Song, Jiangning; Zhang, Ziding

    2015-01-01

    Prokaryotic proteins are regulated by pupylation, a type of post-translational modification that contributes to cellular function in bacterial organisms. In pupylation process, the prokaryotic ubiquitin-like protein (Pup) tagging is functionally analogous to ubiquitination in order to tag target proteins for proteasomal degradation. To date, several experimental methods have been developed to identify pupylated proteins and their pupylation sites, but these experimental methods are generally laborious and costly. Therefore, computational methods that can accurately predict potential pupylation sites based on protein sequence information are highly desirable. In this paper, a novel predictor termed as pbPUP has been developed for accurate prediction of pupylation sites. In particular, a sophisticated sequence encoding scheme [i.e. the profile-based composition of k-spaced amino acid pairs (pbCKSAAP)] is used to represent the sequence patterns and evolutionary information of the sequence fragments surrounding pupylation sites. Then, a Support Vector Machine (SVM) classifier is trained using the pbCKSAAP encoding scheme. The final pbPUP predictor achieves an AUC value of 0.849 in 10-fold cross-validation tests and outperforms other existing predictors on a comprehensive independent test dataset. The proposed method is anticipated to be a helpful computational resource for the prediction of pupylation sites. The web server and curated datasets in this study are freely available at http://protein.cau.edu.cn/pbPUP/. PMID:26080082

  1. Computational Identification of Protein Pupylation Sites by Using Profile-Based Composition of k-Spaced Amino Acid Pairs

    PubMed Central

    Lu, Xiaotian; Li, Jinyan; Song, Jiangning; Zhang, Ziding

    2015-01-01

    Prokaryotic proteins are regulated by pupylation, a type of post-translational modification that contributes to cellular function in bacterial organisms. In pupylation process, the prokaryotic ubiquitin-like protein (Pup) tagging is functionally analogous to ubiquitination in order to tag target proteins for proteasomal degradation. To date, several experimental methods have been developed to identify pupylated proteins and their pupylation sites, but these experimental methods are generally laborious and costly. Therefore, computational methods that can accurately predict potential pupylation sites based on protein sequence information are highly desirable. In this paper, a novel predictor termed as pbPUP has been developed for accurate prediction of pupylation sites. In particular, a sophisticated sequence encoding scheme [i.e. the profile-based composition of k-spaced amino acid pairs (pbCKSAAP)] is used to represent the sequence patterns and evolutionary information of the sequence fragments surrounding pupylation sites. Then, a Support Vector Machine (SVM) classifier is trained using the pbCKSAAP encoding scheme. The final pbPUP predictor achieves an AUC value of 0.849 in10-fold cross-validation tests and outperforms other existing predictors on a comprehensive independent test dataset. The proposed method is anticipated to be a helpful computational resource for the prediction of pupylation sites. The web server and curated datasets in this study are freely available at http://protein.cau.edu.cn/pbPUP/. PMID:26080082

  2. Effect of rotation, site, and clone on the chemical composition of Populus hybrids

    SciTech Connect

    Blanckenhorn, P.R.; Bowersox, T.W.; Kuklewski, K.M.; Stimely, S.L.

    1985-01-01

    Chemical content values were determined for three Populus clones grown on two dissimilar sites by component (wood, bark, and wood/bark specimens), tissue age (1-, 2- and 4-year-old), and rotation. The chemical content values obtained included extractives, holocellulose, ..alpha..-cellulose, and lignin. In general, analysis of the data for the wood, bark, and wood/bark specimens indicated that: 1) wood was high in holocellulose and ..alpha..-cellulose content compared to bark, 2) bark was high in lignin and extractive content values compared to wood, and 3) wood/bark chemical content values were between the values for the wood and bark specimens. The chemical content data were analyzed to identify: 1) significant differences between rotations by component (wood, bark and wood/bark) for a given age, clone, and site, and 2) significant differences between sites for four-year-old wood, bark and wood/bark specimens of a given rotation, and clone. Statistical analyses indicated that significant differences existed among clones, sites, ages, and rotations. Within the wood, bark and wood/bark specimens, tissue age, rotation, and site influenced the chemical content values more than the parentage. Potential chemical yields derived from the three Populus hybrid clones investigated will depend on component, age, rotation, and site with limited parentage effects.

  3. Effects of Re-vegetation on Herbaceous Species Composition and Biological Soil Crusts Development in a Coal Mine Dumping Site.

    PubMed

    Zhao, Yang; Zhang, Peng; Hu, Yigang; Huang, Lei

    2016-02-01

    Despite the critical roles of plant species' diversity and biological soil crusts (BSCs) in arid and semi-arid ecosystems, the restoration of the diversity of herbaceous species and BSCs are rarely discussed during the process of vegetation restoration of anthropogenically damaged areas in these regions. In this study, the herbaceous plant species composition, along with the BSCs coverage and thicknesses, was investigated at six different re-vegetation type sites, and the natural vegetation site of the Heidaigou open pit coal mine in China's Inner Mongolia Autonomous Region was used as a reference. The highest total species richness (16), as well as the species richness (4.4), occurred in the Tree and Herbaceous vegetation type site. The species composition similarities between the restored sites and the reference site were shown to be very low, and ranged from 0.09 to 0.42. Also, among the restored sites, the similarities of the species were fairly high and similar, and ranged from 0.45 to 0.93. The density and height of the re-vegetated woody plants were significantly correlated with the indexes of the diversity of the species. The Shrub vegetation type site showed the greatest total coverage (80%) of BSCs and algae crust coverage (48%). The Shrub and Herbaceous type had the greatest thicknesses of BSCs, with as much as 3.06 mm observed, which was followed by 2.64 mm for the Shrub type. There was a significant correlation observed between the coverage of the total BSCs, and the total vegetation and herbaceous vegetation coverage, as well as between the algae crust coverage and the herbaceous vegetation coverage. It has been suggested that the re-vegetated dwarf woody plant species (such as shrubs and semi-shrubs) should be chosen for the optimal methods of the restoration of herbaceous species diversity at dumping sites, and these should be planted with low density. Furthermore, the effects of vegetation coverage on the colonization and development the BSCs

  4. Effects of Re-vegetation on Herbaceous Species Composition and Biological Soil Crusts Development in a Coal Mine Dumping Site

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Zhang, Peng; Hu, Yigang; Huang, Lei

    2016-02-01

    Despite the critical roles of plant species' diversity and biological soil crusts (BSCs) in arid and semi-arid ecosystems, the restoration of the diversity of herbaceous species and BSCs are rarely discussed during the process of vegetation restoration of anthropogenically damaged areas in these regions. In this study, the herbaceous plant species composition, along with the BSCs coverage and thicknesses, was investigated at six different re-vegetation type sites, and the natural vegetation site of the Heidaigou open pit coal mine in China's Inner Mongolia Autonomous Region was used as a reference. The highest total species richness (16), as well as the species richness (4.4), occurred in the Tree and Herbaceous vegetation type site. The species composition similarities between the restored sites and the reference site were shown to be very low, and ranged from 0.09 to 0.42. Also, among the restored sites, the similarities of the species were fairly high and similar, and ranged from 0.45 to 0.93. The density and height of the re-vegetated woody plants were significantly correlated with the indexes of the diversity of the species. The Shrub vegetation type site showed the greatest total coverage (80 %) of BSCs and algae crust coverage (48 %). The Shrub and Herbaceous type had the greatest thicknesses of BSCs, with as much as 3.06 mm observed, which was followed by 2.64 mm for the Shrub type. There was a significant correlation observed between the coverage of the total BSCs, and the total vegetation and herbaceous vegetation coverage, as well as between the algae crust coverage and the herbaceous vegetation coverage. It has been suggested that the re-vegetated dwarf woody plant species (such as shrubs and semi-shrubs) should be chosen for the optimal methods of the restoration of herbaceous species diversity at dumping sites, and these should be planted with low density. Furthermore, the effects of vegetation coverage on the colonization and development the BSCs

  5. Analysis of the site-specific carbon isotope composition of propane by gas source isotope ratio mass spectrometer

    NASA Astrophysics Data System (ADS)

    Piasecki, Alison; Sessions, Alex; Lawson, Michael; Ferreira, A. A.; Neto, E. V. Santos; Eiler, John M.

    2016-09-01

    Site-specific isotope ratio measurements potentially provide valuable information about the formation and degradation of complex molecules-information that is lost in conventional bulk isotopic measurements. Here we discuss the background and possible applications of such measurements, and present a technique for studying the site-specific carbon isotope composition of propane at natural abundance based on mass spectrometric analysis of the intact propane molecule and its fragment ions. We demonstrate the feasibility of this approach through measurements of mixtures of natural propane and propane synthesized with site-specific 13C enrichment, and we document the limits of precision of our technique. We show that mass balance calculations of the bulk δ13C of propane based on our site-specific measurements is generally consistent with independent constraints on bulk δ13C. We further demonstrate the accuracy of the technique, and illustrate one of its simpler applications by documenting the site-specific carbon isotope signature associated with gas phase diffusion of propane, confirming that our measurements conform to the predictions of the kinetic theory of gases. This method can be applied to propane samples of moderate size (tens of micromoles) isolated from natural gases. Thus, it provides a means of studying the site-specific stable isotope systematics of propane at natural isotope abundances on sample sizes that are readily recovered from many natural environments. This method may also serve as a model for future techniques that apply high-resolution mass spectrometry to study the site-specific isotopic distributions of larger organic molecules, with potential applications to biosynthesis, forensics and other geochemical subjects.

  6. PM2.5 ORGANIC COMPOSITION FROM SEVERAL SITES IN THE UNITED STATES

    EPA Science Inventory

    Organic constituents make up an important component of fine particulate matter (PM2.5) in ambient environments. While part of the composition of organic aerosol results from emissions of primary sources, an additional component appears to come from gas-to-particle conversion o...

  7. Constraints on the origins of hydrocarbon gas from compositions of gases at their site of origin

    USGS Publications Warehouse

    Price, L.C.; Schoell, M.

    1995-01-01

    IT is widely accepted that natural gas is formed from thermal decomposition of both oil in reservoirs and, to a lesser extent, the organic matter in shales from which the oil was derived1-6. But laboratory pyrolysis experiments on shales do not reproduce the methane-rich composition typical of most gas reservoirs7, leading to suggestions7 that other mechanisms, such as transition-metal catalysis, may be important. The discrepancy might, however, instead arise because gas (and oil) deposits have migrated from their source rocks, so that the reservoir composition might not be representative of the composition in the source rocks where the hydrocarbons were generated. To address this question, we have analysed gas samples coproduced with oils directly from a source rock (the Bakken shales, North Dakota, USA) where the local geology has prevented significant hydrocarbon migration. The methane contents of these Bakken-shale gases are much lower than that of conventional gas reservoirs, but are consistent with that from pyrolysis experiments8,9 on these shales. Thus, because these Bakken gases form with (rather than from) oils, we argue that compositional differences between gases from source rocks and conventional gas deposits result from fractionation processes occurring after hydrocarbon expulsion from the source rock.

  8. Constraints on the origins of hydrocarbon gas from compositions of gases at their site of origin

    PubMed

    Price, L C; Schoell, M

    1995-11-23

    It is widely accepted that natural gas is formed from thermal decomposition of both oil in reservoirs and, to a lesser extent, the organic matter in shales from which the oil was derived. But laboratory pyrolysis experiments on shales do not reproduce the methane-rich composition typical of most gas reservoirs, leading to suggestions that other mechanisms, such as transition-metal catalysis, may be important. The discrepancy might, however, instead arise because gas (and oil) deposits have migrated from their source rocks, so that the reservoir composition might not be representative of the composition in the source rocks where the hydrocarbons were generated. To address this question, we have analysed gas samples coproduced with oils directly from a source rock (the Bakken shales, North Dakota, USA) where the local geology has prevented significant hydrocarbon migration. The methane contents of these Bakken-shale gases are much lower than that of conventional gas reservoirs, but are consistent with that from pyrolysis experiments on these shales. Thus, because these Bakken gases form with (rather than from) oils, we argue that compositional differences between gases from source rocks and conventional gas deposits result from fractionation processes occurring after hydrocarbon expulsion from the source rock. PMID:11536709

  9. Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site

    SciTech Connect

    V. Yucel

    2002-09-01

    U.S. Department of Energy (DOE) Order 435.1 requires that performance assessments (PAs) and composite analyses (CAs) for low-level waste (LLW) disposal facilities be maintained by the field offices. This plan describes the activities to be performed in maintaining the Performance Assessment (PA) and Composite Analysis (CA) for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS). The Disposal Authorization Statement (DAS) for the continuing operations of a LLW facility at the DOE complex specifies the conditions for operations based on approval of a PA and CA, and requires the facility to implement a maintenance program to assure that these conditions will remain protective of the public health and the environment in the future. The goal of the maintenance program is to provide that assurance. The maintenance process is an iterative one in which changing conditions may result in a revision of PA and CA; the revised PA and CA may impose a different set of conditions for facility operation, closure, and postclosure. The maintenance process includes managing uncertainty, performing annual reviews, submitting annual summary reports to DOE Headquarters (DOE/HQ), carrying out special analyses, and revising the PAs and CAs, if necessary. Management of uncertainty is an essential component of the maintenance program because results of the original PAs and CAs are understood to be based on uncertain assumptions about the conceptual models; the mathematical models and parameters; and the future state of the lands, disposal facilities, and human activities. The annual reviews for the PAs include consideration of waste receipts, facility specific factors, results of monitoring, and results of research and development (R&D) activities. Likewise, results of ongoing R&D, changes in land-use planning, new information on known sources of residual radioactive materials, and identification of new sources may warrant an evaluation to determine

  10. Prediction of Initiation Site of Destruction of Flat Braided Carbon Fiber Composites Using HTS-SQUID Gradiometer

    NASA Astrophysics Data System (ADS)

    Shinyama, Y.; Hatsukade, Y.; Tanaka, S.; Takai, Y.; Aly-Hassan, M. S.; Nakai, A.; Hamada, H.

    Carbon fiber reinforced polymers (CFRPs) are composite materials with lightweight and high specific strength. As the braided CFRPs have continuous carbon-fiber bundles in their longitudinal direction, they are stronger than conventional CFRPs. In this study, we applied a current-injection-based NDE method using a HTS-SQUID gradiometer to the flat braided CFRPs with and without carbon nanotubes (CNTs), and estimated conditions of the carbon fibers while applying a step-by-step tensile load to the CFRPs. From the results, a possibility to predict an initiation site of the destruction in the braided CFRPs was demonstrated.

  11. Site occupancy and glycan compositional analysis of two soluble recombinant forms of the attachment glycoprotein of Hendra virus.

    PubMed

    Colgrave, Michelle L; Snelling, Hayley J; Shiell, Brian J; Feng, Yan-Ru; Chan, Yee-Peng; Bossart, Katharine N; Xu, Kai; Nikolov, Dimitar B; Broder, Christopher C; Michalski, Wojtek P

    2012-04-01

    Hendra virus (HeV) continues to cause morbidity and mortality in both humans and horses with a number of sporadic outbreaks. HeV has two structural membrane glycoproteins that mediate the infection of host cells: the attachment (G) and the fusion (F) glycoproteins that are essential for receptor binding and virion-host cell membrane fusion, respectively. N-linked glycosylation of viral envelope proteins are critical post-translation modifications that have been implicated in roles of structural integrity, virus replication and evasion of the host immune response. Deciphering the glycan composition and structure on these glycoproteins may assist in the development of glycan-targeted therapeutic intervention strategies. We examined the site occupancy and glycan composition of recombinant soluble G (sG) glycoproteins expressed in two different mammalian cell systems, transient human embryonic kidney 293 (HEK293) cells and vaccinia virus (VV)-HeLa cells, using a suite of biochemical and biophysical tools: electrophoresis, lectin binding and tandem mass spectrometry. The N-linked glycans of both VV and HEK293-derived sG glycoproteins carried predominantly mono- and disialylated complex-type N-glycans and a smaller population of high mannose-type glycans. All seven consensus sequences for N-linked glycosylation were definitively found to be occupied in the VV-derived protein, whereas only four sites were found and characterized in the HEK293-derived protein. We also report, for the first time, the existence of O-linked glycosylation sites in both proteins. The striking characteristic of both proteins was glycan heterogeneity in both N- and O-linked sites. The structural features of G protein glycosylation were also determined by X-ray crystallography and interactions with the ephrin-B2 receptor are discussed. PMID:22171062

  12. Sea urchin larvae decipher the epiphytic bacterial community composition when selecting sites for attachment and metamorphosis.

    PubMed

    Nielsen, Shaun J; Harder, Tilmann; Steinberg, Peter D

    2015-01-01

    Most marine invertebrates have dispersive larvae and relatively immobile adults. These developmental stages are linked by a settlement event, which is often mediated by specific cues in bacterial biofilms. While larvae distinguish between biofilms from different environments, it remains unknown if they receive information from all, only a few or even just a single bacterial species in natural biofilms. Here we asked how specific is larval settlement to the bacterial community structure and/or taxonomically distinguishable groups of bacteria in epiphytic marine biofilms? We used novel multivariate statistical approaches to investigate if larval settlement of two sea urchins correlated with the microbial community composition. Larval settlement of Heliocidaris erythrogramma revealed a strong correlation with the community composition, highlighted by canonical analysis of principle components, a constrained ordination technique. Using this technique, the importance of operational taxonomic units (OTUs) within communities relative to larval settlement was investigated. Larval settlement not only correlated, both positively and negatively, with the epiphytic bacterial community composition but also with the relative abundance of few OTUs within these communities. In contrast, no such correlation was observed for the other urchin, Holopneustes purpurascens, whose larvae likely respond to bacterial biofilms in a more general way and specifically respond to a defined settlement cue of algal origin. PMID:25764535

  13. Delineation of surf scoter habitat in Chesapeake Bay, Maryland: macrobenthic and sediment composition of surf scoter feeding sites

    USGS Publications Warehouse

    Kidwell, D.M.; Perry, M.C.

    2005-01-01

    Surveys of surf scoters (Melanitta perspicillata) along the Atlantic coast of the United States have shown population declines in recent decades. The Chesapeake Bay has traditionally been a key wintering area for surf scoters. Past and present research has shown that bivalves constitute a major food item for seaducks in the Chesapeake Bay, with surf scoters feeding primarily on hooked mussel (Ischadium recurvum) and dwarf surf clam (Mulinia lateralis). Degraded water quality conditions in the Chesapeake Bay have been well documented and have been shown to greatly influence the composition of benthic communities. Large concentrations of feeding surf scoters (>500 individuals) in the Bay were determined through monthly boat surveys. Locations consistently lacking surf scoters were also determined. Macrobenthos were seasonally sampled at 3 locations containing scoters and 3 locations without scoters. A 1 kilometer square grid was superimposed over each location using GIS and sampling sites within the square were randomly chosen. Benthos were sampled at each site using SCUBA and a meter square quadrat. Biomass and size class estimates were determined for all bivalves within each kilometer square. Results indicated that scoter feeding sites contained significantly greater biomass of M. lateralis, I. recurvum, and Gemma gemma than locations where no scoters were present. Substrate differences were also detected, with scoter feeding sites being composed of a sand/shell mix while non-scoter sites consisted primarily of mud. This data indicates that surf scoters in the Chesapeake Bay are selecting areas with high densities of preferred food items, potentially maximizing there foraging energetics. In addition, two scoter feeding sites also contained a patchwork of eastern oyster (Crassostrea virginica) and oyster shell, on which much of the I. recurvum was attached. This suggests the possibility that surf scoters utilize eastern oyster habitat and the dramatic depletion of

  14. Composition and sources of carbonaceous aerosols at three contrasting sites in Hong Kong

    NASA Astrophysics Data System (ADS)

    Zheng, Mei; Hagler, Gayle S. W.; Ke, Lin; Bergin, Michael H.; Wang, Fu; Louie, Peter K. K.; Salmon, Lynn; Sin, Della W. M.; Yu, Jian Zhen; Schauer, James J.

    2006-10-01

    A significant fraction of the fine particulate matter in Hong Kong is made up of organic carbon. In order to quantitatively assess the contributions of various sources to carbonaceous aerosol in Hong Kong, a chemical mass balance (CMB) receptor model in combination with organic tracers was employed. Organic tracers including n-alkanes, polycyclic aromatic hydrocarbons (PAHs), steranes, hopanes, resin acids, cholesterol, levoglucosan, and picene in PM2.5 collected from three air monitoring sites located at roadside, urban, and rural areas in Hong Kong are quantified using gas chromatography-mass spectrometry (GC/MS) in the present study. Analyses of some overlapping species from two separate laboratories will be compared for the first time. Spatial and seasonal source contributions to organic carbon (OC) in PM2.5 from up to nine air pollution sources are assessed, including diesel engine exhaust, gasoline engine exhaust, meat cooking, cigarette smoke, biomass burning, road dust, vegetative detritus, coal combustion, and natural gas combustion. Diesel engine exhaust dominated fine organic carbon in Hong Kong (57 ± 13% at urban sites and 25 ± 2% at the rural site). Other sources that play an important role are meat cooking and biomass burning, which can account for as much as 14% of fine organic carbon. The primary sources identified by this technique explained 49%, 79%, and 94% of the measured fine organic carbon mass concentration at the rural, the urban, and the roadside sites, respectively. The unexplained fine OC is likely due to secondary organic aerosol formation.

  15. Composition and Antigenic Effects of Individual Glycan Sites of a Trimeric HIV-1 Envelope Glycoprotein

    PubMed Central

    Behrens, Anna-Janina; Vasiljevic, Snezana; Pritchard, Laura K.; Harvey, David J.; Andev, Rajinder S.; Krumm, Stefanie A.; Struwe, Weston B.; Cupo, Albert; Kumar, Abhinav; Zitzmann, Nicole; Seabright, Gemma E.; Kramer, Holger B.; Spencer, Daniel I.R.; Royle, Louise; Lee, Jeong Hyun; Klasse, Per J.; Burton, Dennis R.; Wilson, Ian A.; Ward, Andrew B.; Sanders, Rogier W.; Moore, John P.; Doores, Katie J.; Crispin, Max

    2016-01-01

    Summary The HIV-1 envelope glycoprotein trimer is covered by an array of N-linked glycans that shield it from immune surveillance. The high density of glycans on the trimer surface imposes steric constraints limiting the actions of glycan-processing enzymes, so that multiple under-processed structures remain on specific areas. These oligomannose glycans are recognized by broadly neutralizing antibodies (bNAbs) that are not thwarted by the glycan shield but, paradoxically, target it. Our site-specific glycosylation analysis of a soluble, recombinant trimer (BG505 SOSIP.664) maps the extremes of simplicity and diversity of glycan processing at individual sites and reveals a mosaic of dense clusters of oligomannose glycans on the outer domain. Although individual sites usually minimally affect the global integrity of the glycan shield, we identify examples of how deleting some glycans can subtly influence neutralization by bNAbs that bind at distant sites. The network of bNAb-targeted glycans should be preserved on vaccine antigens. PMID:26972002

  16. Magnesium isotopic compositions of altered oceanic basalts and gabbros from IODP site 1256 at the East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Huang, Jian; Ke, Shan; Gao, Yongjun; Xiao, Yilin; Li, Shuguang

    2015-08-01

    To investigate the behaviour of Mg isotopes during alteration of oceanic crust and constrain the Mg isotopic compositions of the altered oceanic crust (AOC), high-precision Mg isotope analyses have been conducted on forty-four altered basalts and gabbros recovered from IODP site 1256, which represent the carbonate-barren AOC formed at the East Pacific Rise (EPR). These samples were altered by interaction of seawater-derived fluids with oceanic crust at different temperatures and water/rock ratios. With the exception of one sample that has a slightly heavier Mg isotopic composition (δ26Mg = 0.01 ± 0.08‰), all the other samples have relatively homogenous and mantle-like Mg isotopic compositions, with δ26Mg ranging from - 0.36 to - 0.14‰ (an average value of - 0.25 ± 0.11‰, 2SD, n = 43). This suggests that limited Mg isotope fractionation occurred during alteration of oceanic crust at the EPR at bulk rock scale, irrespective of highly variable alteration temperatures and variable water/rock ratios. Thus, our study suggests that the offset of δ26Mg values between seawater and global runoff dominantly results from the formation of marine dolomite as a sink for Mg. The mantle-like Mg isotopic composition further indicates that recycling of carbonate-barren AOC would not result in Mg isotope heterogeneity of the mantle at global scale. Consequently, the light Mg isotopic compositions of the mantle at local scale must result from incorporation of recycled Mg isotopically light carbonates.

  17. Composition.

    ERIC Educational Resources Information Center

    Nemanich, Donald, Ed.

    1974-01-01

    The articles in this special issue of the "Illinois English Bulletin" concern the state of composition instruction at the secondary and college levels. The titles and authors are "Monologues or Dialogues? A Plea for Literacy" by Dr. Alfred J. Lindsey, "Teaching Composition: Curiouser and Curiouser" by Denny Brandon, and "Teaching Writing to High…

  18. Subunit composition determines E2F DNA-binding site specificity.

    PubMed Central

    Tao, Y; Kassatly, R F; Cress, W D; Horowitz, J M

    1997-01-01

    The product of the retinoblastoma (Rb) susceptibility gene, Rb-1, regulates the activity of a wide variety of transcription factors, such as E2F, in a cell cycle-dependent fashion. E2F is a heterodimeric transcription factor composed of two subunits each encoded by one of two related gene families, denoted E2F and DP. Five E2F genes, E2F-1 through E2F-5, and two DP genes, DP-1 and DP-2, have been isolated from mammals, and heterodimeric complexes of these proteins are expressed in most, if not all, vertebrate cells. It is not yet clear whether E2F/DP complexes regulate overlapping and/or specific cellular genes. Moreover, little is known about whether Rb regulates all or a subset of E2F-dependent genes. Using recombinant E2F, DP, and Rb proteins prepared in baculovirus-infected cells and a repetitive immunoprecipitation-PCR procedure (CASTing), we have identified consensus DNA-binding sites for E2F-1/DP-1, E2F-1/DP-2, E2F-4/DP-1, and E2F-4/DP-2 complexes as well as an Rb/E2F-1/DP-1 trimeric complex. Our data indicate that (i) E2F, DP, and Rb proteins each influence the selection of E2F-binding sites; (ii) E2F sites differ with respect to their intrinsic DNA-bending properties; (iii) E2F/DP complexes induce distinct degrees of DNA bending; and (iv) complex-specific E2F sites selected in vitro function distinctly as regulators of cell cycle-dependent transcription in vivo. These data indicate that the specific sequence of an E2F site may determine its role in transcriptional regulation and suggest that Rb/E2F complexes may regulate subsets of E2F-dependent cellular genes. PMID:9372931

  19. Isotopic composition of water from a mine drainage site in Creede County in south central Colorado

    NASA Astrophysics Data System (ADS)

    Michel, R. L.; Williams, M. W.; Krupicka, A.; Wireman, M.; Graves, J.

    2011-12-01

    Creede County in South Central Colorado was an active area of silver mining beginning in the early 1890s. To relieve flooding in some of the mines, the Nelson Tunnel was built in the late 1890s. This tunnel still exists and acid mine drainage from the tunnel eventually flows into the Willow Creek Watershed which eventually flows into the Upper Rio Grande. The water coming out of the tunnel is high in toxic metals and the area has become part of an EPA Superfund site in an effort to find a suitable method to remediate the metal problems. Among the approaches used in the program is the use of isotopes of water and carbon to identify sources and estimate ages of the water in the drainage. Samples were collected for analysis of isotopic ratios and tritium concentrations at a series of sites within the tunnel complex from 2008-2010. In 2009 samples were also collected for analysis of isotopes in groundwater and surface water. In 2010 sampling was expanded to include four precipitation and one snow sample. Tritium concentrations in precipitation and snowfall in 2010 ranged from 3-6 tritium units with the lowest concentration found in the snow sample. The 18O isotopic ratios in precipitation for this site ranged from an average of -8.9 o/oo in summer to about -19 o/oo in winter. The six groundwater samples collected in 2009 had an average 18O isotopic concentration of -15 o/oo and tritium concentrations ranging from 7.4-9.3 TU. These results suggest that the groundwater sampled is composed largely of a mixture of summer and winter precipitation with the latter source being dominant. The tritium concentrations in groundwater exceed recent precipitation concentrations, suggesting the presence of water from the bomb-tritium transient and an age of a decade or more for the groundwater. Eight sites in the tunnel were sampled I from 2008-2010, although not all sites were sampled every year. The sampling sites included waters seeping into the tunnel as well as the outlet water

  20. Wolbachia Transcription Elongation Factor “Wol GreA” Interacts with α2ββ′σ Subunits of RNA Polymerase through Its Dimeric C-Terminal Domain

    PubMed Central

    Nag, Jeetendra Kumar; Shrivastava, Nidhi; Chahar, Dhanvantri; Gupta, Chhedi Lal; Bajpai, Preeti; Misra-Bhattacharya, Shailja

    2014-01-01

    Objectives Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for therapy against lymphatic filariasis. Transcription elongation factor GreA is an essential factor that mediates transcriptional transition from abortive initiation to productive elongation by stimulating the escape of RNA polymerase (RNAP) from native prokaryotic promoters. Upon screening of 6257 essential bacterial genes, 57 were suggested as potential future drug targets, and GreA is among these. The current study emphasized the characterization of Wol GreA with its domains. Methodology/Principal Findings Biophysical characterization of Wol GreA with its N-terminal domain (NTD) and C-terminal domain (CTD) was performed with fluorimetry, size exclusion chromatography, and chemical cross-linking. Filter trap and far western blotting were used to determine the domain responsible for the interaction with α2ββ′σ subunits of RNAP. Protein-protein docking studies were done to explore residual interaction of RNAP with Wol GreA. The factor and its domains were found to be biochemically active. Size exclusion and chemical cross-linking studies revealed that Wol GreA and CTD exist in a dimeric conformation while NTD subsists in monomeric conformation. Asp120, Val121, Ser122, Lys123, and Ser134 are the residues of CTD through which monomers of Wol GreA interact and shape into a dimeric conformation. Filter trap, far western blotting, and protein-protein docking studies revealed that dimeric CTD of Wol GreA through Lys82, Ser98, Asp104, Ser105, Glu106, Tyr109, Glu116, Asp120, Val121, Ser122, Ser127, Ser129, Lys140, Glu143, Val147, Ser151, Glu153, and Phe163 residues exclusively participates in binding with α2ββ′σ subunits of polymerase. Conclusions/Significance To the best of our knowledge, this research is the first documentation of the residual mode of action in wolbachial mutualist. Therefore, findings may be crucial to understanding the transcription mechanism of

  1. Igneous and Sedimentary Compositions from Four Landing Sites on Mars from the Alpha Particle X-Ray Spectrometer (APXS)

    NASA Technical Reports Server (NTRS)

    Gellert, R.; Arvidson, R. E.; Clark, B. C.; Ming, D. W.; Mittlefehldt, D. W.; Morris, R. W.; Squyres, S. W.; VanBommel, S.; Yen, A. S.

    2016-01-01

    The APXS - supported and promoted strongly by Heinrich Waenke - on all four Mars Rovers has returned compositional data from about 1000 rocks and soil targets along the combined traverses of over 60 kilometers. Providing precise and accurate bulk chemistry with typically 16 quantified elements, the APXS is a powerful and versatile tool that when combined with the ability to traverse to key rocks and soils has provided critical information needed to understand the geologic evolution of Mars. APXS data allow comparisons among landing sites, provide ground truth for orbiters and connections back to SNC meteorites. The soils and dust are basaltic in character and represent the average Mars composition similar to Adirondack basalts from Gusev crater but with unambiguous elevated and correlated S, Cl and Zn contents. At all four landing sites the APXS found several rocks with a felsic composition. The similarity is best assessed in a logarithmic ratio plot of rock normalized to the average soil composition (Fig.1). High alkaline, Al, and low Mg, Fe, low S, Cl and Ni, Zn as well as an Fe/Mn ratio of approximately 50 indicate a likely unaltered and igneous origin. Sediments, e.g. the Burns formation, with approximately 25 wt% SO3 at Meridiani Planum have been documented over 10s of kilometers (Fig. 2). This formation is compositionally homogeneous, but showing the removal of MgSO4 and a threefold increase in Cl downhill in 2 craters. The degraded rim of the Noachian crater Endeavour resembles average Mars crust, with local Ca, Mg and Fe sulfate alteration and elevated Mn, some felsic rocks, and high Al, Si and low Fe rocks, possibly indicating clays. Unusual soils at Gusev crater in the area surrounding Home Plate include some very rich in ferric sulfate salts (up to 35 wt% SO3) and some with 90% wt% SiO2, possibly indicating fumerolic activities. Rocks in the Columbia Hills show significant signs of alteration including elevated S, Cl and Br in the abraded interior. At

  2. A Graphene Composite Material with Single Cobalt Active Sites: A Highly Efficient Counter Electrode for Dye-Sensitized Solar Cells.

    PubMed

    Cui, Xiaoju; Xiao, Jianping; Wu, Yihui; Du, Peipei; Si, Rui; Yang, Huaixin; Tian, Huanfang; Li, Jianqi; Zhang, Wen-Hua; Deng, Dehui; Bao, Xinhe

    2016-06-01

    The design of catalysts that are both highly active and stable is always challenging. Herein, we report that the incorporation of single metal active sites attached to the nitrogen atoms in the basal plane of graphene leads to composite materials with superior activity and stability when used as counter electrodes in dye-sensitized solar cells (DSSCs). A series of composite materials based on different metals (Mn, Fe, Co, Ni, and Cu) were synthesized and characterized. Electrochemical measurements revealed that CoN4 /GN is a highly active and stable counter electrode for the interconversion of the redox couple I(-) /I3 (-) . DFT calculations revealed that the superior properties of CoN4 /GN are due to the appropriate adsorption energy of iodine on the confined Co sites, leading to a good balance between adsorption and desorption processes. Its superior electrochemical performance was further confirmed by fabricating DSSCs with CoN4  /GN electrodes, which displayed a better power conversion efficiency than the Pt counterpart. PMID:27089044

  3. GR SUMOylation and formation of an SUMO-SMRT/NCoR1-HDAC3 repressing complex is mandatory for GC-induced IR nGRE-mediated transrepression.

    PubMed

    Hua, Guoqiang; Paulen, Laetitia; Chambon, Pierre

    2016-02-01

    Unique among the nuclear receptor superfamily, the glucocorticoid (GC) receptor (GR) can exert three distinct transcriptional regulatory functions on binding of a single natural (cortisol in human and corticosterone in mice) and synthetic [e.g., dexamethasone (Dex)] hormone. The molecular mechanisms underlying GC-induced positive GC response element [(+)GRE]-mediated activation of transcription are partially understood. In contrast, these mechanisms remain elusive for GC-induced evolutionary conserved inverted repeated negative GC response element (IR nGRE)-mediated direct transrepression and for tethered indirect transrepression that is mediated by DNA-bound NF-κB/activator protein 1 (AP1)/STAT3 activators and instrumental in GC-induced anti-inflammatory activity. We demonstrate here that SUMOylation of lysine K293 (mouse K310) located within an evolutionary conserved sequence in the human GR N-terminal domain allows the formation of a GR-small ubiquitin-related modifiers (SUMOs)-NCoR1/SMRT-HDAC3 repressing complex mandatory for GC-induced IR nGRE-mediated direct repression in vitro, but does not affect transactivation. Importantly, these results were validated in vivo: in K310R mutant mice and in mice ablated selectively for nuclear receptor corepressor 1 (NCoR1)/silencing mediator for retinoid or thyroid-hormone receptors (SMRT) corepressors in skin keratinocytes, Dex-induced direct repression and the formation of repressing complexes on IR nGREs were impaired, whereas transactivation was unaffected. In mice selectively ablated for histone deacetylase 3 (HDAC3) in skin keratinocytes, GC-induced direct repression, but not bindings of GR and of corepressors NCoR1/SMRT, was abolished, indicating that HDAC3 is instrumental in IR nGRE-mediated repression. Moreover, we demonstrate that the binding of HDAC3 to IR nGREs in vivo is mediated through interaction with SMRT/NCoR1. We also show that the GR ligand binding domain (LBD) is not required for SMRT

  4. Measurements of dew and fog chemical composition at a rural site

    NASA Astrophysics Data System (ADS)

    Straub, D.; Sokoloff, R.; Ressler, D.; Herckes, P.

    2012-12-01

    Liquid water in the atmosphere has been shown to play an important role in the transport, transformation, and removal of aerosol particles and soluble gases. Dew and fog represent two forms of the atmospheric aqueous phase, both of which may enhance the deposition of trace species and enable fast aqueous phase reactions. Compared to precipitation, dews and fogs have longer residence times at ground level and therefore may be strongly influenced by local sources. Fog composition measurements in the United States have been limited to relatively few locations along the East and West coasts while only a handful of studies have focused on dew composition. To extend our knowledge of dew and fog composition, measurements have been made on the campus of Susquehanna University in central Pennsylvania. Fog samples have been collected since 2007 using an automated Caltech Heated Rod Cloudwater Collector (CHRCC). Dew sampling began during the summer of 2012 using a 90 cm by 90 cm Teflon sheet mounted on a polystyrene foam panel. All samples were analyzed for pH and one of more of the following: major inorganic ions, organic acids, total organic carbon (TOC), and trace metals. Dew and fog concentrations varied widely between samples, though concentrations of most species in fog generally exceeded those in dew. The median pH was approximately 6.0 for fog and 7.0 for dew, both of which are much higher than the median value of 4.6 for precipitation in this region. Ammonium was the most abundant ionic species in the fog samples, followed by sulfate, calcium, and nitrate. Dew samples were also dominated by ammonium, though calcium was significant in some samples. Sulfate and nitrate concentrations were substantially lower in the dew samples. Formate and acetate were the most abundant organic acids in both types of samples, although those species made up much larger fraction of the total solute in the dew samples. In addition, oxalate and propionate were observed in both types of

  5. Localization of binding sites in protein structures by optimization of a composite scoring function.

    PubMed

    Rossi, Andrea; Marti-Renom, Marc A; Sali, Andrej

    2006-10-01

    The rise in the number of functionally uncharacterized protein structures is increasing the demand for structure-based methods for functional annotation. Here, we describe a method for predicting the location of a binding site of a given type on a target protein structure. The method begins by constructing a scoring function, followed by a Monte Carlo optimization, to find a good scoring patch on the protein surface. The scoring function is a weighted linear combination of the z-scores of various properties of protein structure and sequence, including amino acid residue conservation, compactness, protrusion, convexity, rigidity, hydrophobicity, and charge density; the weights are calculated from a set of previously identified instances of the binding-site type on known protein structures. The scoring function can easily incorporate different types of information useful in localization, thus increasing the applicability and accuracy of the approach. To test the method, 1008 known protein structures were split into 20 different groups according to the type of the bound ligand. For nonsugar ligands, such as various nucleotides, binding sites were correctly identified in 55%-73% of the cases. The method is completely automated (http://salilab.org/patcher) and can be applied on a large scale in a structural genomics setting. PMID:16963645

  6. Localization of binding sites in protein structures by optimization of a composite scoring function

    PubMed Central

    Rossi, Andrea; Marti-Renom, Marc A.; Sali, Andrej

    2006-01-01

    The rise in the number of functionally uncharacterized protein structures is increasing the demand for structure-based methods for functional annotation. Here, we describe a method for predicting the location of a binding site of a given type on a target protein structure. The method begins by constructing a scoring function, followed by a Monte Carlo optimization, to find a good scoring patch on the protein surface. The scoring function is a weighted linear combination of the z-scores of various properties of protein structure and sequence, including amino acid residue conservation, compactness, protrusion, convexity, rigidity, hydrophobicity, and charge density; the weights are calculated from a set of previously identified instances of the binding-site type on known protein structures. The scoring function can easily incorporate different types of information useful in localization, thus increasing the applicability and accuracy of the approach. To test the method, 1008 known protein structures were split into 20 different groups according to the type of the bound ligand. For nonsugar ligands, such as various nucleotides, binding sites were correctly identified in 55%–73% of the cases. The method is completely automated (http://salilab.org/patcher) and can be applied on a large scale in a structural genomics setting. PMID:16963645

  7. Chemical, multispectral, and textural constraints on the composition and origin of rocks at the Mars Pathfinder landing site

    USGS Publications Warehouse

    McSween, H.Y., Jr.; Murchie, S.L.; Crisp, J.A.; Bridges, N.T.; Anderson, R.C.; Bell, J.F., III; Britt, D.T.; Brückner, J.; Dreibus, G.; Economou, T.; Ghosh, A.; Golombek, M.P.; Greenwood, J.P.; Johnson, J. R.; Moore, H.J.; Morris, R.V.; Parker, T.J.; Rieder, R.; Singer, R.; Wänke, H.

    1999-01-01

    Rocks at the Mars Pathfinder site are probably locally derived. Textures on rock surfaces may indicate volcanic, sedimentary, or impact-generated rocks, but aeolian abration and dust coatings prevent unambiguous interpretation. Multispectral imaging has resolved four spectral classes of rocks: gray and red, which occur on different surfaces of the same rocks; pink, which is probably soil crusts; and maroon, which occurs as large boulders, mostly in the far field. Rocks are assigned to two spectral trends based on the position of peak reflectance: the primary spectral trend contains gray, red, and pink rocks; maroon rocks constitute the secondary spectral trend. The spatial pattern of spectral variations observed is oriented along the prevailing wind direction. The primary spectral trend arises from thin ferric coatings of aeolian dust on darker rocks. The secondary spectral trend is apparently due to coating by a different mineral, probably maghemite or ferrihydrite. A chronology based on rock spectra suggests that rounded maroon boulders constitute the oldest petrologic unit (a flood deposit), succeeded by smaller cobbles possibly deposited by impact, and followed by aeolian erosion and deposition. Nearly linear chemical trends in alpha proton X-ray spectrometer rock compositions are interpreted as mixing lines between rock and adhering dust, a conclusion supported by a correlation between sulfur abundance and red/blue spectral ratio. Extrapolations of regression lines to zero sulfur give the composition of a presumed igneous rock. The chemistry and normative mineralogy of the sulfur-free rock resemble common terrestrial volcanic rocks, and its classification corresponds to andesite. Igneous rocks of this composition may occur with clastic sedimentary rocks or impact melts and breccias. However, the spectral mottling expected on conglomerates or breccias is not observed in any APXS-analyzed rocks. Interpretation of the rocks as andesites is complicated by absence

  8. Ferromanganese nodules from MANOP Sites H, S, and R-Control of mineralogical and chemical composition by multiple accretionary processes

    USGS Publications Warehouse

    Dymond, J.; Lyle, M.; Finney, B.; Piper, D.Z.; Murphy, K.; Conard, R.; Pisias, N.

    1984-01-01

    The chemical composition of ferromanganese nodules from the three nodule-bearing MANOP sites in the Pacific can be accounted for in a qualitative way by variable contributions of distinct accretionary processes. These accretionary modes are: 1. (1) hydrogenous, i.e., direct precipitation or accumulation of colloidal metal oxides in seawater, 2. (2) oxic diagenesis which refers to a variety of ferromanganese accretion processes occurring in oxic sediments; and 3. (3) suboxic diagenesis which results from reduction of Mn+4 by oxidation of organic matter in the sediments. Geochemical evidence suggests processes (1) and (2) occur at all three MANOP nodule-bearing sites, and process (3) occurs only at the hemipelagic site, H, which underlies the relatively productive waters of the eastern tropical Pacific. A normative model quantitatively accounts for the variability observed in nearly all elements. Zn and Na, however, are not well explained by the three end-member model, and we suggest that an additional accretionary process results in greater variability in the abundances of these elements. Variable contributions from the three accretionary processes result in distinct top-bottom compositional differences at the three sites. Nodule tops from H are enriched in Ni, Cu, and Zn, instead of the more typical enrichments of these elements in nodule bottoms. In addition, elemental correlations typical of most pelagic nodules are reversed at site H. The three accretionary processes result in distinct mineralogies. Hydrogenous precipitation produces ??MnO2. Oxic diagenesis, however, produces Cu-Ni-rich todorokite, and suboxic diagenesis results in an unstable todorokite which transforms to a 7 A?? phase ("birnessite") upon dehydration. The presence of Cu and Ni as charge-balancing cations influence the stability of the todorokite structure. In the bottoms of H nodules, which accrete dominantly by suboxic diagenesis, Na+ and possibly Mn+2 provide much of the charge balance for

  9. Measurements of the Concentration and Composition of CCN and IN at a High Elevation Site

    NASA Astrophysics Data System (ADS)

    Friedman, B.; Kulkarni, G.; Zelenyuk, A.; Beranek, J.; Pekour, M. S.; Hallar, A. G.; Mccubbin, I. B.; Cziczo, D. J.; Thornton, J. A.

    2011-12-01

    Field measurements of cloud condensation nuclei (CCN) and ice nuclei (IN) were conducted in March 2011 at Storm Peak Laboratory (elevation 3220 m m.s.l.). Measurements of CCN number concentrations and droplet size distributions at supersaturations of 0.05%, 0.1%, 0.2%, 0.4%, and 0.7% were conducted in parallel with Scanning Mobility Particle Sizer (SMPS) measurements of size distributions and number concentrations of ambient particles. SMPS number concentrations of the overall ambient aerosol population were used to calculate the fraction of particles activating as droplets at the supersaturations studied. Single Particle Mass Spectrometer (SPLAT II) was used to characterize number concentration, size, internal composition, and densities of individual particles present in the ambient air. In a separate set of experiments, a pumped counterflow virtual impactor (PCVI) was used to separate particles that activated as CCN from unactivated particles, using a 50% cutsize of approximately 2.5 microns. The droplet residuals from the activated particles were characterized by SPLAT and compared to the properties of the overall aerosol population in order to examine the effect of single particle mixing state, aerosol composition, and size on CCN activity as a function of supersaturation. The PNNL Compact Ice Chamber (CIC) was deployed to measure IN concentrations and ice crystal size distributions at temperatures ranging from 253K to 233K. SMPS number concentrations, size distributions, and SPLAT single particle measurements were also utilized to assess the ice nucleation properties of ambient particles as a function of the processing conditions in the PNNL CIC.

  10. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2011-11-29

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington State (USA) was investigated by analyzing samples recovered from depths of 9 to 52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analyzed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units at the 97% identity level), respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (ca. 90%) of Proteobacteria. The Bacterial community in the oxic sediments contained not only members of 9 well-recognized phyla but also an unusually high proportion of 3 candidate divisions (GAL15, NC10, and SPAM). Additionally, novel phylogenetic orders were identified within the Delta-proteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site.

  11. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site.

    PubMed

    Lin, Xueju; Kennedy, David; Fredrickson, Jim; Bjornstad, Bruce; Konopka, Allan

    2012-02-01

    Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington state (USA) was investigated by analysing 21 samples recovered from depths of 9-52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analysed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (operational taxonomic units at the 97% identity level) respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (> 700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (c. 90%) of Proteobacteria. The bacterial community in the oxic sediments contained not only members of nine well-recognized phyla but also an unusually high proportion of three candidate divisions (GAL15, NC10 and SPAM). Additionally, 13 novel phylogenetic orders were identified within the Deltaproteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site. PMID:22122741

  12. Composites

    SciTech Connect

    Chou, T.; McCullough, R.L.; Pipes, R.B.

    1986-10-01

    The degree of control over material properties that is typified by hybrid composites is transforming engineering design. In part because homogeneous materials such as metals and alloys do not offer comparable control, specifying a material and designing a component have traditionally taken place separately. As composites begin to replace traditional materials in fields and such as aerospace, component design and the specification of a material are merging and becoming aspects of a single process. The controllable microstructure of a composite allows it to be tailored to match the distribution of stresses to which it will be subject. At the same time components must come to reflect the distinctive nature of composites: their directional properties and the intricate forms they can be given through processes such as injection molding, filament winding and three-dimensional weaving. The complexity inherent in conceiving components and their materials at the same time suggests engineering design will grow increasingly dependent on computers and multidisciplinary teams. Such an approach will harness the full potential of composites for the technologies of the future. 10 figures.

  13. Composite active site of chondroitin lyase ABC accepting both epimers of uronic acid

    SciTech Connect

    Shaya, D.; Hahn, Bum-Soo; Bjerkan, Tonje Marita; Kim, Wan Seok; Park, Nam Young; Sim, Joon-Soo; Kim, Yeong-Shik; Cygler, M.

    2008-03-19

    Enzymes have evolved as catalysts with high degrees of stereospecificity. When both enantiomers are biologically important, enzymes with two different folds usually catalyze reactions with the individual enantiomers. In rare cases a single enzyme can process both enantiomers efficiently, but no molecular basis for such catalysis has been established. The family of bacterial chondroitin lyases ABC comprises such enzymes. They can degrade both chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans at the nonreducing end of either glucuronic acid (CS) or its epimer iduronic acid (DS) by a {beta}-elimination mechanism, which commences with the removal of the C-5 proton from the uronic acid. Two other structural folds evolved to perform these reactions in an epimer-specific fashion: ({alpha}/{alpha}){sub 5} for CS (chondroitin lyases AC) and {beta}-helix for DS (chondroitin lyases B); their catalytic mechanisms have been established at the molecular level. The structure of chondroitinase ABC from Proteus vulgaris showed surprising similarity to chondroitinase AC, including the presence of a Tyr-His-Glu-Arg catalytic tetrad, which provided a possible mechanism for CS degradation but not for DS degradation. We determined the structure of a distantly related Bacteroides thetaiotaomicron chondroitinase ABC to identify additional structurally conserved residues potentially involved in catalysis. We found a conserved cluster located {approx}12 {angstrom} from the catalytic tetrad. We demonstrate that a histidine in this cluster is essential for catalysis of DS but not CS. The enzyme utilizes a single substrate-binding site while having two partially overlapping active sites catalyzing the respective reactions. The spatial separation of the two sets of residues suggests a substrate-induced conformational change that brings all catalytically essential residues close together.

  14. Isotopic Composition of Gaseous Elemental Mercury (Hg0) at Various Sites in Japan

    NASA Astrophysics Data System (ADS)

    Yamakawa, A.; Moriya, K.; Yoshinaga, J.

    2015-12-01

    Mercury (Hg) is a toxic heavy metal, which exists in various chemical forms in the environmental system. In the atmosphere, Hg exists in three forms (Hg0(g), Hg+2(g), and Hg(p)). Hg0(g) is the dominant species of atmospheric Hg, accounting for >95% of the total Hg in the atmosphere. Because Hg0(g) is highly volatile and has limited solubility in water, it cannot be easily removed by wet or dry deposition processes. Therefore, the residence time of Hg0(g) in the atmosphere is relatively long (1 to 2 years), allowing long-range transport from mercury emission source(s). Conversely, Hg+2(g) and Hg(p) are effectively removed from the atmosphere through wet and dry depositions. The determination of mercury source attribution using quantitative data is challenging because Hg0(g) may be deposited on an area upon oxidation to Hg+2(g) and associated with aerosols and particulates to form Hg(p) while the global cycling of Hg0(g). Over the last decade, the development of analytical methods of highly precise Hg isotopic measurements demonstrated mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) of Hg isotopes in environmental samples. For instance, MDF of Hg isotopes is thought to occur during various natural and industrial Hg transformations. MIF of Hg isotopes is observed during abiotic reduction, photochemical and non-photochemical, and physical and chemical processes. Such processes lead to differences in the Hg isotopic composition of different emission sources, both natural and anthropogenic, and atmospheric processes (i.e., transportation, oxidation/reduction, deposition, and reemission). Therefore, Hg isotopic compositions could be used to trace the sources and processes of atmospheric Hg. For securing the reliability and accuracy of atmospheric Hg isotope data, the methods of collection, pretreatment, and isotopic measurement for Hg0(g) were developed to obtain high recovery yield of samples with no Hg isotopic fractionation during each

  15. Gas production, composition and emission at a modern disposal site receiving waste with a low-organic content.

    PubMed

    Scheutz, Charlotte; Fredenslund, Anders M; Nedenskov, Jonas; Samuelsson, Jerker; Kjeldsen, Peter

    2011-05-01

    AV Miljø is a modern waste disposal site receiving non-combustible waste with a low-organic content. The objective of the current project was to determine the gas generation, composition, emission, and oxidation in top covers on selected waste cells as well as the total methane (CH(4)) emission from the disposal site. The investigations focused particularly on three waste disposal cells containing shredder waste (cell 1.5.1), mixed industrial waste (cell 2.2.2), and mixed combustible waste (cell 1.3). Laboratory waste incubation experiments as well as gas modeling showed that significant gas generation was occurring in all three cells. Field analysis showed that the gas generated in the cell with mixed combustible waste consisted of mainly CH(4) (70%) and carbon dioxide (CO(2)) (29%) whereas the gas generated within the shredder waste, primarily consisted of CH(4) (27%) and nitrogen (N(2)) (71%), containing no CO(2). The results indicated that the gas composition in the shredder waste was governed by chemical reactions as well as microbial reactions. CH(4) mass balances from three individual waste cells showed that a significant part (between 15% and 67%) of the CH(4) generated in cell 1.3 and 2.2.2 was emitted through leachate collection wells, as a result of the relatively impermeable covers in place at these two cells preventing vertical migration of the gas. At cell 1.5.1, which is un-covered, the CH(4) emission through the leachate system was low due to the high gas permeability of the shredder waste. Instead the gas was emitted through the waste resulting in some hotspot observations on the shredder surface with higher emission rates. The remaining gas that was not emitted through surfaces or the leachate collection system could potentially be oxidized as the measured oxidation capacity exceeded the potential emission rate. The whole CH(4) emission from the disposal site was found to be 820 ± 202 kg CH(4)d(-1). The total emission rate through the leachate

  16. Transient effects on groundwater chemical compositions from pumping of supply wells at the Nevada National Security Site, 1951-2008

    USGS Publications Warehouse

    Paces, James B.; Elliott, Peggy E.; Fenelon, Joseph M.; Laczniak, Randell J.; Moreo, Michael T.

    2012-01-01

    Nuclear testing and support activities at the Nevada National Security Site have required large amounts of water for construction, public consumption, drilling, fire protection, hydraulic and nuclear testing, and dust control. To supply this demand, approximately 20,000 million gallons of water have been pumped from 23 wells completed in 19 boreholes located across the Nevada National Security Site starting as early as the 1950s. As a consequence of more or less continuous pumping from many of these wells for periods as long as 58 years, transient groundwater flow conditions have been created in the aquifers that supplied the water. To evaluate whether long-term pumping caused changes in water compositions over time, available chemical analyses of water samples from these 19 boreholes were compiled, screened, and evaluated for variability including statistically significant temporal trends that can be compared to records of groundwater pumping. Data used in this report have been extracted from a large database (Geochem08, revision 3.0, released in September 2008) containing geochemical and isotopic information created and maintained by primary contractors to the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office. Data extracted from this source were compiled for the entire period of record, converted to uniform reporting units, and screened to eliminate analyses of poor or unknown quality, as well as clearly spurious values. The resulting data are included in accompanying spreadsheets that give values for (1) pH and specific conductance, (2) major ion concentrations, (3) trace element concentrations and environmental isotope ratios, and (4) mean, median, and variance estimates for major ion concentrations. The resulting data vary widely in quality and time-series density. An effort has been made to establish reasonable ranges of analytical uncertainty expected for each analyte and eliminate analyses that are obvious outliers

  17. Numerical studies of gas composition differentiation during gas hydrate formation: An application to the IODP site 1327

    NASA Astrophysics Data System (ADS)

    Yuncheng, C.; Chen, D.

    2014-12-01

    Structure I methane hydrate is the most common type found in nature. Structure I gas hydrate has two types of cages that gas molecules may be hosted. Because the larger cavities filled with ethane would be more stable than those filled by methane (Sloan and Koh, 2008), the larger cavities preferentially enclose ethane during the formation of gas hydrate, which results gas composition differentiation during gas hydrate formation. Based on the principle of gas composition differentiation, we establish a numerical model for the gas composition differentiation between methane and ethane during gas hydrate accumulation and applied the model to IODP site 1327. The simulation shows that the gas composition differentiation only occurs at the interval where gas hydrate presents. The lowest methane/ethane (C1/C2) point indicates the bottom of hydrate zone, and the composition differentiation produces the upward increase of C1/C2 within the gas hydrate zone. The C1/C2 reaches the largest value at the top occurrence of gas hydrate and keeps relative stable above the top occurrence of gas hydrate. The top and bottom occurrence of gas hydrate indicated by the inflection points of the C1/C2 profile are similar to those indicated by the negative anomalies of measured chloride concentrations (Riedel et al., 2006). By comparing with the measured C1/C2, the differentiation coefficient (kh=Xe,h/Xe,w, Xe,h is C1/C2 of the formed gas hydrate, Xe,w [mol/kg] is the concentration of ethane in water ) is calculated to 70 kg/mol. The top occurrence of gas hydrate indicated by the C1/C2 profile also confines the water flux to be 0.4kg/m2-year, similar to that confined by the chloride profile. To best fit the measured C1/C2 profile, the methane flux is calculated to 0.04mol/m2-year. Therefore, the C1/C2 profile could be used to obtain the gas hydrate accumulation information. Acknowledgments:This study was supported by Chinese National Science Foundation (grant 41303044, 91228206 ) References

  18. Analysis of High Frequency Site-Specific Nitrogen and Oxygen Isotopic Composition of Atmospheric Nitrous Oxide at Mace Head, Ireland

    NASA Astrophysics Data System (ADS)

    McClellan, M. J.; Harris, E. J.; Olszewski, W.; Ono, S.; Prinn, R. G.

    2014-12-01

    Atmospheric nitrous oxide (N2O) significantly impacts Earth's climate due to its dual role as an inert potent greenhouse gas in the troposphere and as a reactive source of ozone-destroying nitrogen oxides in the stratosphere. However, there remain significant uncertainties in the global budget of this gas. The marked spatial divide in its reactivity means that all stages in the N2O life cycle—emission, transport, and destruction—must be examined to understand the overall effect of N2O on climate. Source and sink processes of N2O lead to varying concentrations of N2O isotopologues (14N14N16O, 14N15N16O, 15N14N16O, and 14N14N18O being measured) due to preferential isotopic production and elimination in different environments. Estimation of source and sink fluxes can be improved by combining isotopically resolved N2O observations with simulations using a chemical transport model with reanalysis meteorology and treatments of isotopic signatures of specific surface sources and stratospheric intrusions. We present the first few months of site-specific nitrogen and oxygen isotopic composition data from the Stheno-TILDAS instrument (Harris et al, 2013) at Mace Head, Ireland and compare these to results from MOZART-4 (Model for Ozone and Related Chemical Tracers, version 4) chemical transport model runs including N2O isotopic fractionation processes and reanalysis meterological fields (NCEP/NCAR, MERRA, and GEOS-5). This study forms the basis for future inverse modeling experiments that will improve the accuracy of isotopically differentiated N2O emission and loss estimates. Ref: Harris, E., D. Nelson, W. Olszewski, M. Zahniser, K. Potter, B. McManus, A. Whitehill, R. Prinn, and S. Ono, Development of a spectroscopic technique for continuous online monitoring of oxygen and site-specific nitrogen isotopic composition of atmospheric nitrous oxide, Analytical Chemistry, 2013; DOI: 10.1021/ac403606u.

  19. Chemical compositions of wet precipitation and anthropogenic influences at a developing urban site in southeastern China

    NASA Astrophysics Data System (ADS)

    Zhang, Miaoyun; Wang, Shijie; Wu, Fengchang; Yuan, Xianghong; Zhang, Ying

    2007-06-01

    A comprehensive study on the chemical compositions of wet precipitation was carried out from January 2004 to December 2004 in Jinhua, southeastern China's Zhejiang Province. All samples were analyzed for pH, electrical conductivity and major ions (F -, Cl -, NO 3-, SO 42-, K +, Na +, Ca 2+, Mg 2+ and NH 4+). The rainwater was typically acidic with a volume-weighted mean pH of 4.54, which ranged from 3.64 to 6.76. SO 42- and NO 3- were the main anions, while NH 4+ and Ca 2+ were the main cations. The concentrations of these major ions were generally higher compared to those reported in other parts of the world, but much lower than those in northern China. Wet deposition fluxes of major ions showed pronounced seasonal variations with maximum in spring and minimum in autumn. Significant correlations were found in soil-derived species among Ca 2+, Mg 2+ and K + and sea-salt species between Na + and Cl -. Other relatively good correlations were also observed between Ca 2+ and SO 42-, Mg 2+ and SO 42-, Mg 2+ and NO 3-, Mg 2+ and Cl -. Principal component analysis was also performed on individual precipitation to find possible sources of the major ionic species. Varimax rotated four components accounting for 85.9% of the total variance, and were interpreted as acid and alkaline pollutants, sea spray and mixed source, soil and acid/neutralization. Calculation of enrichment factors for rainwater components relative to soil and seawater indicated that Ca 2+ and K + mainly originated from the terrestrial source, and SO 42- and NO 3- were mostly attributed for the anthropogenic activities in the study area. In general, the results suggested that precipitation chemistry is strongly influenced by anthropogenic sources rather than natural and marine sources. The pollutants in rainwater were mainly derived from long distance transport, local industry and traffic sources.

  20. Benson Beach Demonstration Project: Composition and Abundance of Biota at Three Alternative Sump Sites

    SciTech Connect

    Williams, Greg D.; Pearson, Walter H.; Evans, Nathan R.; Anderson, Michael G.

    2004-01-15

    The Portland District of the U.S. Army Corps of Engineers is investigating plans to provide sediment to nourish beaches north of the Mouth of the Columbia River (MCR). Under the currently designed proposal, sediment dredged from the MCR will be temporarily stored at one of three proposed areas south of the North Jetty before being redredged and moved by a cutterhead pipeline dredge over the jetty to nourish Benson Beach. Resulting potential impacts to resident Dungeness crab (Cancer magister) and fishes represent one of the criteria for evaluating each of the alternative locations. To establish the species composition and relative abundance of crabs and fishes associated with each of the three proposed sump areas, researchers from the Pacific Northwest National Laboratory Marine Sciences Division completed nine field sampling trips from July 8, 2003, to November 1, 2003, for a total of 113 successful trawls comprising an area of over 7.4 ha (74,156 m2). This report documents the results of that effort. To understand the relative risk of losses to crab populations associated with dredging impacts at the sump alternative areas, it is recommended that a modified dredge impact model be developed using the data collected in this study. This model should estimate crab adult equivalent loss and associated error rates to gain a population-level perspective on the potential entrainment impacts at each of the three alternative sump areas. As well, a sustained survey of Dungeness crab distribution and movement within the Columbia River estuary would clarify the relative value of the sump areas as a migratory corridor for crab populations, and support management decisions relative to issues associated with dredged material handling and disposal.

  1. Composition and stability of the condensate observed at the Viking Lander 2 site on Mars

    NASA Technical Reports Server (NTRS)

    Hart, H. M.; Jakosky, B. M.

    1986-01-01

    Surface energy balance and near-surface temperature data from the Viking Lander 2 site taken during the first winter that condensated were observed and analyzed to determine the relative stability of CO2 and H2O frosts. The CO2 frost stability is calculated with an equilibrium surface energy balance model, i.e., the total energy incident on a frost surface is compared with the blackbody energy emitted by the surface. The energy sources considered were IR emission from the atmosphere, sunlight, and the sensible heat flux from the atmosphere. H2O stability was examined as a function of buoyant diffusion and turbulent mixing processes which could remove saturated near-surface gases. The CO2 frost is found to be sufficiently unstable at the time the condensate was observed on the ground, so all CO2 ice deposited at night would boil away in a few hours of sunlight. CO2 ice would not form during a dust storm. Water frost would be stable during the condensate observations, since sublimation would occur at a rate below 1 micron/day. A stable winter thickness of 10 microns is projected for the water ice.

  2. Muscle fibre types in the human vastus lateralis muscles: do symmetrical sites differ in their composition?

    PubMed

    Erzen, I; Pernus, F; Sirca, A

    1990-01-01

    Muscle samples obtained from distinct symmetrical sites of left and right vastus lateralis muscles from 10 young healthy males were analysed. A computer-aided system was applied for the determination of muscle fibre types I, IIA, IIB and IIC and for their quantitative analysis. No statistically significant differences were established regarding percentage and surface area of all the four fibre types studied. In 2 cases of IIA and in one case of IIB fibre type significantly different diameters were measured between the left and right muscle. Regarding percentage and surface area no differences were proved between superficial and deep layers of the muscles observed. Fibre diameter but differed significantly in many muscles, there was no rule about whether it was larger in superficial or in deep muscle layers. One biopsy sample can not represent the whole muscle, especially as far as the relative number and surface area of the type IIA and IIB fibres are concerned. A slight asymmetry in fibre diameters of biopsy samples from both legs does not indicate any pathological change and can still be taken for normal. PMID:2403213

  3. Studying the effect of the Semipalatinsk Test Site on radionuclide and elemental composition of water objects in the Irtysh River.

    PubMed

    Solodukhin, V; Аidarkhanov, A; Lukashenko, S; Gluchshenko, V; Poznyak, V; Lyahova, O

    2015-06-01

    The results of the field and laboratory studies of radiation and environmental state at the specific area of Irtysh River adjacent to the Semipalatinsk Test Site are provided. It was found that the radiation situation in this area is normal: equivalent dose of γ-radiation = (0.11-0.13) µSv h(-1). Determination of radionuclide composition of soil, bottom sediment and water samples was performed by the methods of instrumental γ-spectrometry, radiochemical analysis and the liquid scintillation β-spectrometry. It was found that concentrations of the studied natural and artificial radionuclides in these objects are very low; no contamination with radionuclides was detected in this segment of Irtysh River. The article provides the results of elemental composition determination for samples of soil and bottom sediment (by X-ray fluorescence method) and water samples (by inductively coupled plasma mass spectrometry method). It is shown that the content of some elements (Li, Be, B, V, Cu, Sr, Mo) in the water of Irtysh River increases downstream. The additional studies are required to explain this peculiarity. PMID:25971345

  4. Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site

    SciTech Connect

    Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan

    2012-02-01

    The microbial diversity in subsurface sediments at the Hanford Site's 300 Area in southeastern Washington State was investigated by analyzing 21 samples recovered from depths that ranged from 9 to 52 m. Approximately 8000 non-chimeric Bacterial and Archaeal 16S rRNA gene sequences were analyzed across geological strata that contain a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units, defined at the 97% identity level). Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (based upon Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic transition zone, richness was about 325 and declined to less than 50 in the deeper reduced zones. The Bacterial community in the oxic Hanford and Ringold Formations contained members of 9 major well-recognized phyla as well 30 as unusually high proportions of 3 candidate divisions (GAL15, NC10, and SPAM). The deeper Ringold strata were characterized by low OTU richness and a very high preponderance (ca. 90%) of Proteobacteria. The study has greatly expanded the intralineage phylogenetic diversity within some major divisions. These subsurface sediments have been shown to contain a large number of phylogenetically novel microbes, with substantial heterogeneities between sediment samples from the same geological formation.

  5. The fat-fascia paddle only with a composite fibula flap: marked reduction in donor site morbidity.

    PubMed

    Mohindra, A; Parmar, S; Praveen, P; Martin, T

    2016-08-01

    Fibula free flaps are used widely in head and neck reconstruction, primarily for their versatility and contribution to aesthetic and functional outcomes. The literature suggests that early complications such as wound dehiscence and skin graft loss can occur in up to a third of patients. The healing of these donor sites can be prolonged, and in certain cases may require an operative intervention. A method to overcome this problem is described herein. In raising the skin paddle, a standard lateral approach to the fibula harvest is used. The skin paddle is not isolated and the posterior margin of the paddle is maintained. The skin paddle epithelium is separated with a small cuff of adipose tissue from the underlying fat-fascia layer. This fat-fascia paddle is then raised with the fibula as normal and tacked to the margins of the recipient soft tissue defect. The fat-fascia paddle heals, resulting in a thin mucosal covering for prosthetic dental rehabilitation. This technique can reduce the incidence of donor site wound complications when raising a composite fibula flap. PMID:27061479

  6. COMPOSITE ANALYSIS OF LLW DISPOSAL FACILITIES AT THE U.S. DEPARTMENT OF ENERGY'S SAVANNAH RIVER SITE

    SciTech Connect

    Hiergesell, R; Mark Phifer, M; Frank02 Smith, F

    2009-01-08

    Composite Analyses (CA's) are required per DOE Order 435.1 [1], in order to provide a reasonable expectation that DOE low-level waste (LLW) disposal, high-level waste tank closure, and transuranic (TRU) waste disposal in combination with Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Resource Conservation and Recovery Act (RCRA), and deactivation and decommissioning (D&D) actions, will not result in the need for future remedial actions in order to ensure radiological protection of the public and environment. This Order requires that an accounting of all sources of DOE man-made radionuclides and DOE enhanced natural radionuclides that are projected to remain on the site after all DOE site operations have ceased. This CA updates the previous CA that was developed in 1997. As part of this CA, an inventory of expected radionuclide residuals was conducted, exposure pathways were screened and a model was developed such that a dose to the MOP at the selected points of exposure might be evaluated.

  7. Composition and sources of fine particulate matter across urban and rural sites in the Midwestern United States

    PubMed Central

    Kundu, Shuvashish; Stone, Elizabeth. A.

    2014-01-01

    The composition and sources of fine particulate matter (PM2.5) were investigated in rural and urban locations in Iowa, located in the agricultural and industrial Midwestern United States from April 2009 to December 2012. Major chemical contributors to PM2.5 mass were sulfate, nitrate, ammonium, and organic carbon. Non-parametric statistical analyses demonstrated that the two rural sites had significantly enhanced levels of crustal materials (Si, Al) driven by agricultural activities and unpaved roads. Meanwhile, the three urban areas had enhanced levels of secondary aerosol (nitrate, sulfate, and ammonium) and combustion (organic and elemental carbon). The heavily industrialized Davenport site had significantly higher levels of PM2.5 and trace metals (Fe, Pb, Zn), demonstrating the important local impact of industrial point sources on air quality. Sources of PM2.5 were evaluated by the multi-variant positive matrix factorization (PMF) source apportionment model. For each individual site, seven to nine factors were identified: secondary sulfate (accounting for 29–30% of PM2.5), secondary nitrate (17–24%), biomass burning (9–21%), gasoline combustion (6–16), diesel combustion (3–9%), dust (6–11%), industry (0.4–5%) and winter salt (2–6%). Source contributions demonstrated a clear urban enhancement in PM2.5 from gasoline engines (by a factor of 1.14) and diesel engines (by a factor of 2.3), which is significant due to the well-documented negative health impacts of vehicular emissions. This study presents the first source apportionment results from the state of Iowa and is broadly applicable to understanding the differences in anthropogenic and natural sources in the urban-rural continuum of particle air pollution. PMID:24736797

  8. A functional glucocorticoid-responsive unit composed of two overlapping inactive receptor-binding sites: evidence for formation of a receptor tetramer.

    PubMed Central

    Garlatti, M; Daheshia, M; Slater, E; Bouguet, J; Hanoune, J; Beato, M; Barouki, R

    1994-01-01

    An unusual glucocorticoid-responsive element (called GRE A) was found to mediate the induction of the cytosolic aspartate aminotransferase gene by glucocorticoids and was bound by the glucocorticoid receptor in a DNase I footprinting assay. GRE A consists of two overlapping GREs, each comprising a conserved half-site and an imperfect half-site. The complete unit was able to confer glucocorticoid inducibility to a heterologous promoter (delta MTV-CAT). Mutation of any of the half-sites, including the imperfect ones, abolished inducibility by the hormone, demonstrating that each of the isolated GREs was inactive. In electrophoretic mobility shift assays, purified rat liver glucocorticoid receptor (GR) formed a low-mobility complex with GRE A, presumably containing a GR tetramer. When purified bacterially expressed DBD was used, low-mobility complexes as well as dimer and monomer complexes were formed. In inactive mutated oligonucleotides, no GR tetramer formation was detected. Modification of the imperfect half-sites in order to increase their affinity for GR gave a DNA sequence that bound a GR tetramer in a highly cooperative manner. This activated unit consisting of two overlapping consensus GREs mediated glucocorticoid induction with a higher efficiency than consensus GRE. Images PMID:7969140

  9. sup 1 H NMR studies of DNA recognition by the glucocorticoid receptor: Complex of the DNA binding domain with a half-site response element

    SciTech Connect

    Remerowski, M.L.; Kellenbach, E.; Boelens, R.; Kaptein, R. ); van der Marel, G.A.; van Boom, J.H. ); Maler, B.A.; Yamamoto, K.R. )

    1991-12-17

    The complex of the rat glucocorticoid receptor (GR) DNA binding domain (DBD) and half-site sequence of the consensus glucocorticoid response element (GRE) has been studied by two-dimensional {sup 1}H NMR spectroscopy. The DNA fragment is a 10 base-pair oligonucleotide, 5{prime}d(GCTGTTCTGC)3{prime}{center dot}5{prime}d-(GCAGAACAGC)3{prime}, containing the stronger binding GRE half-site hexamer, with GC base pairs at each end. The 93-residue GR-DBD contains an 86-residue segment corresponding to residues 440-525 of the rat GR. Eleven NOE cross peaks between the protein and DNA have been identified, and changes in the chemical shift of the DNA protons upon complex formation have been analyzed. Using these protein-DNA contact points, it can be concluded that (1) the 'recognition helix' formed by residues C460-E469 lies in the major groove of the DNA; (2) the GR-DBD is oriented on the GRE half-site such that residues A477-D481, forming the so-called D-loop, are available for protein-protein interaction in the GR-DBD dimer on the intact consensus GRE; and (3) the 5-methyl of the second thymine in the half-site and valine 462 interact, confirming indirect evidence that both play an important role in GR-DBD DNA binding.

  10. Composites

    NASA Astrophysics Data System (ADS)

    Taylor, John G.

    The Composites market is arguably the most challenging and profitable market for phenolic resins aside from electronics. The variety of products and processes encountered creates the challenges, and the demand for high performance in critical operations brings value. Phenolic composite materials are rendered into a wide range of components to supply a diverse and fragmented commercial base that includes customers in aerospace (Space Shuttle), aircraft (interiors and brakes), mass transit (interiors), defense (blast protection), marine, mine ducting, off-shore (ducts and grating) and infrastructure (architectural) to name a few. For example, phenolic resin is a critical adhesive in the manufacture of honeycomb sandwich panels. Various solvent and water based resins are described along with resin characteristics and the role of metal ions for enhanced thermal stability of the resin used to coat the honeycomb. Featured new developments include pultrusion of phenolic grating, success in RTM/VARTM fabricated parts, new ballistic developments for military vehicles and high char yield carbon-carbon composites along with many others. Additionally, global regional market resin volumes and sales are presented and compared with other thermosetting resin systems.

  11. Biomarker Compositions as Source Indicators of Heinrich Layers in the Northern North Atlantic (IODP Exp. 303/306, Site 1305)

    NASA Astrophysics Data System (ADS)

    Hefter, J.; Stein, R.

    2006-12-01

    During IODP Expeditions 303/306, multiple cores from different locations in the North Atlantic were recovered. One of the major objectives of these expeditions was to capture Miocene-Quaternary millenial-scale climate variability in sensitive regions at the mouth of the Labrador Sea and in the North Atlantic ice-rafted debris (IRD) belt. Site 1305 is located in the Labrador Sea close to the southwest extremity of the Eirik Drift and in proximity to the former major iceberg discharge pathway derived via the Hudson Strait from the Laurentide-Ice- Shield (LIS). The upper Pleistocene part of Site 1305 afforded discrete IRD-containing detrital carbonate sections known as Heinrich layers (HL). About 30 samples from within and in between these layers were investigated in terms of quantitative and qualitative biomarker distribution using gas chromatography-mass spectrometry to (a) extend previous knowledge of biomarker inventories from identified Heinrich layers and (b) to investigate the potential of specific compounds to trace the occurrence and first appearance of Heinrich event-like episodes. Samples from HL1, HL2 and HL4 at Site 1305 are clearly distinguishable from samples between those layers due to the abundance of characteristic biomarker groups such as benzohopanes, D-ring monoaromatic 8,14- secohopanes, mono- and triaromatic steranes, aryl isoprenoids including isorenieratene-derivatives and increased pristane/n-C17 and phytane/n-C18 ratios. Such biomarker compositions are typically observed as diagenetic products within different types of mature (including Palaeozoic) source rocks and oils found in different North American/Canadian Basins, but cannot derive from sources contemporary to the time when Heinrich events occurred. More likely, these compounds originate from LIS basal erosion of Palaeozoic sedimentary outcrops, subsequently transported as IRD through the Hudson Strait and released at Site 1305 during Heinrich events. Thus, the study of specific

  12. Chemical composition and mass size distribution of PM1.0 at an elevated site in central east China

    NASA Astrophysics Data System (ADS)

    Zhang, Y. M.; Zhang, X. Y.; Sun, J. Y.; Hu, G. Y.; Shen, X. J.; Wang, Y. Q.; Wang, T. T.; Wang, D. Z.; Zhao, Y.

    2014-06-01

    Size-resolved aerosol chemical compositions were measured continuously for one and half years with an aerosol mass spectrometer (AMS) to characterize the mass and size distributions (MSDs) of each component in bulk, fresh and aged submicron particles (approximately PM1.0) at Mountain Tai, an elevated site in Central East China (CEC) from June 2010 to January 2012. The majority of the regionally-dispersed aerosols were found to be contributed from short distance mixed aerosol, mostly from its south with organics and sulfate as the major components. The annual mean mass concentrations of organics, sulfate, nitrate, ammonium and chloride were 11.2, 9.2, 7.2, 5.8 and 0.95 μg m-3, respectively, which are much lower for organics and sulfate, and slightly lower for nitrate, ammonium and chloride than those at the nearby surface rural sites. High organics were observed for all four seasons, and the relatively fresh organic aerosol (OA) containing high proportion of less-photo chemically OA, were found from long-range transported aerosol from northwest. Semi-volatile and low-volatile oxidized OAs together contributed approximately 49%, 55% in spring and 72% and 51% in winter of total OA, showing at least 50% of OA can be attributable to SOA. Seasonally, the chemical components at the elevated site showed a "winter high and autumn low" pattern, with organics, sulfate and ammonium peaking in summer. Though no obvious differences of MSDs were seen for various chemical components in the planetary boundary layer (PBL) and free troposphere (FT), the concentrations were a factor of 5-7 higher in PBL than in FT. The averaged MSDs of particles between 30-1000 nm for organics, sulfate, nitrate, and ammonium are approximately log-normal with similar mass median diameters (MMDs) of 539, 585, 542, and 545 nm, respectively, which were slightly larger than those in ground sites within North China Plain (NCP). Obvious differences in MMDs were found between fresh and aged aerosols for

  13. Characterisation of the organic composition of size segregated atmospheric particulate matter at traffic exposed and background sites in Madrid

    NASA Astrophysics Data System (ADS)

    Mirante, F.; Perez, R.; Alves, C.; Revuelta, M.; Pio, C.; Artiñano, B.; Nunes, T.

    2010-05-01

    The growing awareness of the impact of atmospheric particulate matter (PM) on climate, and the incompletely recognised but serious effects of anthropogenic aerosols on air quality and human health, have led to diverse studies involving almost exclusively the coarse or the fine PM fractions. However, these environmental effects, the PM formation processes and the source assignment depend greatly on the particle size distribution. The innovative character of this study consists in obtaining time series with a size-segregated detailed chemical composition of PM for differently polluted sites. In this perspective, a summer sampling campaign was carried out from 1 of June to 1 of July 2009. One of the sampling sites was located at a representative urban monitoring station (Escuelas Aguirre) belonging to the municipal network, located at a heavy traffic street intersection in downtown Madrid. Other sampling point was positioned within the CIEMAT area, located in the NW corner of the city, which can be considered an urban background or suburban site. Particulate matter was sampled with high volume cascade impactors at 4 size stages: 10-2.5, 2.5-0.95, 0.95-0.45 and < 0.45 µm. Daily sampling was carried out on quartz fibre filters. Based on meteorological conditions and PM mass concentrations, each one of the 7 groups of filters collected during the first week were combined with the corresponding filters of the third week. The same procedure was undertaken with samples of the second and fourth weeks. Filters of 0.95-0.45 and < 0.45 µm were pooled to obtain the PM0.95 organic composition. The PM size-segregated samples were subjected to organic analysis by gas chromatography-mass spectrometry (GC-MS), after solvent extraction of filters and an appropriate derivatisation technique. Besides the homologous compound series of organic classes (e.g. n-alkanes, n-alkanols and n-alkanoic acids), special attention was given to the determination of specific molecular markers for

  14. An Examination of the Link between Rater Calibration Performance and Subsequent Scoring Accuracy in Graduate Record Examinations[R] (GRE[R]) Writing. Research Report. ETS RR-11-03

    ERIC Educational Resources Information Center

    Ricker-Pedley, Kathryn L.

    2011-01-01

    A pseudo-experimental study was conducted to examine the link between rater accuracy calibration performances and subsequent accuracy during operational scoring. The study asked 45 raters to score a 75-response calibration set and then a 100-response (operational) set of responses from a retired Graduate Record Examinations[R] (GRE[R]) writing…

  15. Composites

    NASA Astrophysics Data System (ADS)

    Chmielewski, M.; Nosewicz, S.; Pietrzak, K.; Rojek, J.; Strojny-Nędza, A.; Mackiewicz, S.; Dutkiewicz, J.

    2014-11-01

    It is commonly known that the properties of sintered materials are strongly related to technological conditions of the densification process. This paper shows the sintering behavior of a NiAl-Al2O3 composite, and its individual components sintered separately. Each kind of material was processed via the powder metallurgy route (hot pressing). The progress of sintering at different stages of the process was tested. Changes in the microstructure were examined using scanning and transmission electron microscopy. Metal-ceramics interface was clean and no additional phases were detected. Correlation between the microstructure, density, and mechanical properties of the sintered materials was analyzed. The values of elastic constants of NiAl/Al2O3 were close to intermetallic ones due to the volume content of the NiAl phase particularly at low densities, where small alumina particles had no impact on the composite's stiffness. The influence of the external pressure of 30 MPa seemed crucial for obtaining satisfactory stiffness for three kinds of the studied materials which were characterized by a high dense microstructure with a low number of isolated spherical pores.

  16. Gas production, composition and emission at a modern disposal site receiving waste with a low-organic content

    SciTech Connect

    Scheutz, Charlotte; Fredenslund, Anders M.; Nedenskov, Jonas; Samuelsson, Jerker

    2011-05-15

    AV Miljo is a modern waste disposal site receiving non-combustible waste with a low-organic content. The objective of the current project was to determine the gas generation, composition, emission, and oxidation in top covers on selected waste cells as well as the total methane (CH{sub 4}) emission from the disposal site. The investigations focused particularly on three waste disposal cells containing shredder waste (cell 1.5.1), mixed industrial waste (cell 2.2.2), and mixed combustible waste (cell 1.3). Laboratory waste incubation experiments as well as gas modeling showed that significant gas generation was occurring in all three cells. Field analysis showed that the gas generated in the cell with mixed combustible waste consisted of mainly CH{sub 4} (70%) and carbon dioxide (CO{sub 2}) (29%) whereas the gas generated within the shredder waste, primarily consisted of CH{sub 4} (27%) and nitrogen (N{sub 2}) (71%), containing no CO{sub 2}. The results indicated that the gas composition in the shredder waste was governed by chemical reactions as well as microbial reactions. CH{sub 4} mass balances from three individual waste cells showed that a significant part (between 15% and 67%) of the CH{sub 4} generated in cell 1.3 and 2.2.2 was emitted through leachate collection wells, as a result of the relatively impermeable covers in place at these two cells preventing vertical migration of the gas. At cell 1.5.1, which is un-covered, the CH{sub 4} emission through the leachate system was low due to the high gas permeability of the shredder waste. Instead the gas was emitted through the waste resulting in some hotspot observations on the shredder surface with higher emission rates. The remaining gas that was not emitted through surfaces or the leachate collection system could potentially be oxidized as the measured oxidation capacity exceeded the potential emission rate. The whole CH{sub 4} emission from the disposal site was found to be 820 {+-} 202 kg CH{sub 4} d

  17. Stable Carbon and Oxygen Isotope Composition of Soil and Shell from an Archeological Site in Kimble County, Texas

    NASA Astrophysics Data System (ADS)

    Salazar, K. K.; Paul, D.; Skrzypek, G.; Tomka, S. A.

    2007-12-01

    We report stable carbon (δ13C) and oxygen (δ18O) isotopic composition of inorganic carbonates, soil organic matter (SOM), and terrestrial gastropod shells present in a 130cm soil profile (radiocarbon date of 2340-2120 B.P) recovered from archeological site 41KM69, Kimble County, Texas. Prior to soil carbonate and SOM analyses, samples were treated with 5% sodium hypochlorite to remove organic matter and treated with 4% HCl to remove inorganic carbonate, respectively. Isotopic compositions of samples were obtained utilizing a Gasbench II (for carbonate-acid reaction technique) and a CHNS Elemental Analyzer (for SOM) coupled with a DeltaPlus XP Isotope Ratio Mass Spectrometer in continuous-flow. δ13C of carbonates in the soil profile varies in the range -2.15 to -4.63 ‰. δ18O of carbonates (ranging from -3.22 to -3.92‰) show little variation within the profile. δ13C of SOM (-25.61‰ to -22.83‰) suggests that C3 plants were predominant in the study area. There is ~3‰ enrichment in 13C of SOM at the bottom of profile relative to the top. Previous studies have shown that δ13C of modern soil carbonates are higher by 14-16‰ than SOM, whereas our results show about 20‰ difference. δ13C of land snail shells ( Rabdotus, Polygyra, Helicina) recovered from the soil show strong linear correlation with depth (R2= 0.88): -9.46‰ at 60cm to -5.4‰ at 112cm. δ18O of shells show no correlation with depth and range from - 3.34‰ to 0.62‰. Excluding one shell analysis, δ13C of shells and SOM exhibit good correlation (R2= 0.80). Previous studies of variation in δ13C in land snail shell document that carbon isotopic composition in shell are primarily a function of snail diet. Balakrishnan et al. (2005) have shown that δ13C of shells in C3 vegetation regimes range from -10.0‰ to -8.8‰, which is consistent with our results. Although, the interpretation of δ18O values in land snails is not straightforward, values are probably related to several different

  18. Osmotically regulated floating asymmetric membrane capsule for controlled site-specific delivery of ranitidine hydrochloride: optimization by central composite design.

    PubMed

    Chauhan, Manvendra S; Kumar, Anil; Pathak, Kamla

    2012-12-01

    A nondisintegrating, floating asymmetric membrane capsule (FAMC) was developed to achieve site-specific osmotic flow of a highly water-soluble drug, ranitidine hydrochloride (RHCl), in a controlled manner. Solubility suppression of RHCl was achieved by the common ion effect, using optimized coated sodium chloride as a formulation component. The capsular wall of FAMC was prepared by the phase inversion process wherein the polymeric membrane was precipitated on glass pins by dipping them in a solution of cellulose acetate followed by quenching. Central composite design was utilized to investigate the influence of independent variables, namely, level(s) of membrane former, pore former, and osmogen, on percent cumulative drug release (response). The release mechanism of RHCl through FAMC was confirmed as osmotic pumping. The asymmetry of the membrane was characterized by scanning electron microscopy that revealed a dense nonporous outer region of membrane supported by an inner porous region. Differential scanning calorimetry indicated no incompatibility between the drug and excipients. In vitro drug release in three biorelevant media, pH 2.5 (low fed), pH 4.5 (intermediate fed), and pH 6.5 (high fed), demonstrated pH-independent release of RHCl (P > 0.05). Floating ability for 12 h of the optimized FAMC9 was visually examined during the in vitro release studies that showed maximal drug release with zero-order kinetics (r (2) = 0.9991). Thus, a novel osmotically regulated floating capsular system was developed for site-specific delivery of RHCl. PMID:23104305

  19. Fine and coarse PM composition and sources in rural and urban sites in Switzerland: local or regional pollution?

    PubMed

    Minguillón, M C; Querol, X; Baltensperger, U; Prévôt, A S H

    2012-06-15

    The chemical composition and sources of ambient particulate matter (PM) in Switzerland were studied. PM(1) and PM(10) samples were collected in winter and summer at an urban background site in Zurich and a rural background site in Payerne. Concentrations of major and trace elements, NO(3)(-), SO(4)(2-), NH(4)(+), organic and elemental carbon were determined. A subsequent Positive Matrix Factorization (PMF) analysis was performed. PM(10) and PM(1) concentrations varied similarly at both sites, with average PM(10) concentrations 24-25 μg/m(3) and 13-14 μg/m(3) in winter and summer, respectively, and average PM(1) concentrations 12-17 μg/m(3) and 6-7 μg/m(3). The influence of local sources was found to be higher in winter. PM was dominated by nitrate and organic matter in winter, and by mineral matter and organic matter in summer. Trace element concentrations related to road traffic (Zn, Cu, Sb, Sn) were higher at Zurich. Concentrations of Tl and Cs, attributed to the influence of a glass industry, were higher at Payerne. The elements mainly present in the coarse fraction were those related to mineral matter and brake and tyre abrasion (Cu, Mn, Ti, Sb, Sr, Bi, Li, La, Nd), and those in the fine fraction were related to high temperature anthropogenic processes (Pb, As, Cd, Tl, Cs). Common PM(1) and PM(1-10) sources identified by PMF were: ammonium nitrate, present in winter, negligible in summer; ammonium sulfate+K(biomass burning)+road traffic; and road traffic itself, related to exhaust emissions in PM(1) and to road dust resuspension in PM(1-10). Size-fraction specific sources were: a PM(1) glass industry source characterized by Cs, Tl, Rb, Li and Na, only present in Payerne; a PM(1) background source characterized by V, Ni, sulfate and Fe; two PM(1-10) mineral-related sources, with higher contribution in summer; a PM(1-10) salt source; and a PM(1-10) organic source, with higher contribution in summer, attributed to bioaerosols. PMID:22572211

  20. Evaluation of the Community Multiscale Air Quality (CMAQ) modeling system against size-resolved measurements of inorganic particle composition across sites in North America

    EPA Science Inventory

    This work evaluates particle size-composition distributions simulated by the Community Multiscale Air Quality (CMAQ) model using Micro-Orifice Uniform Deposit Impactor (MOUDI) measurements at 18 sites across North America. Size-resolved measurements of particulate SO4<...

  1. Organic composition of size segregated atmospheric particulate matter, during summer and winter sampling campaigns at representative sites in Madrid, Spain

    NASA Astrophysics Data System (ADS)

    Mirante, Fátima; Alves, Célia; Pio, Casimiro; Pindado, Oscar; Perez, Rosa; Revuelta, M.a. Aranzazu; Artiñano, Begoña

    2013-10-01

    Madrid, the largest city of Spain, has some and unique air pollution problems, such as emissions from residential coal burning, a huge vehicle fleet and frequent African dust outbreaks, along with the lack of industrial emissions. The chemical composition of particulate matter (PM) was studied during summer and winter sampling campaigns, conducted in order to obtain size-segregated information at two different urban sites (roadside and urban background). PM was sampled with high volume cascade impactors, with 4 stages: 10-2.5, 2.5-1, 1-0.5 and < 0.5 μm. Samples were solvent extracted and organic compounds were identified and quantified by GC-MS. Alkanes, polycyclic aromatic hydrocarbons (PAHs), alcohols and fatty acids were chromatographically resolved. The PM1-2.5 was the fraction with the highest mass percentage of organics. Acids were the organic compounds that dominated all particle size fractions. Different organic compounds presented apparently different seasonal characteristics, reflecting distinct emission sources, such as vehicle exhausts and biogenic sources. The benzo[a]pyrene equivalent concentrations were lower than 1 ng m- 3. The estimated carcinogenic risk is low.

  2. Structure and composition of vegetation of longleaf pine plantations compared to natural stands occurring along an environmental gradient at the Savannah River Site.

    SciTech Connect

    Smith, Gregory, P.; Shelburne, Victor, B.; Walker, Joan, L.

    2001-12-30

    Study plots in 33-43 year old longleaf pine plantations were compared to remnant longleaf plots on the Savannah River Site in South Carolina. Within these stands, the structure and composition of primarily the herb layer relative to a presumed soil moisture or soil texture gradient was studied using the North Carolina Vegetation Survey methodology. Data were also collected on soils and landform variables. Based on ordination and cluster analyses, both plantation plots and natural stand plots were separated into three distinct site units (xeric, sub-xeric, and sub-mesic). Lack of a major compositional difference between xeric plantation and natural longleaf sites suggests that restoration of the herbaceous layer may not be as complex as once thought. This provides reasonable encouragement for the restoration of the longleaf pine ecosystem.

  3. Correspondence and Least Squares Analyses of Soil and Rock Compositions for the Viking Lander 1 and Pathfinder Sites

    NASA Technical Reports Server (NTRS)

    Larsen, K. W.; Arvidson, R. E.; Jolliff, B. L.; Clark, B. C.

    2000-01-01

    Correspondence and Least Squares Mixing Analysis techniques are applied to the chemical composition of Viking 1 soils and Pathfinder rocks and soils. Implications for the parent composition of local and global materials are discussed.

  4. Experiences from the offshore installation of a composite materials firewater system

    SciTech Connect

    Ciaraldi, S.W.

    1993-12-31

    A prototype 300 m composite dry deluge firewater system was installed in December 1991 at the Valhall Field in the southern North Sea Norwegian offshore sector. This installation followed successful safety verification of the explosion and fire resistant design concept consisting of glass-fiber reinforced epoxy (GRE) piping components protected with a reinforced intumescent epoxy fire insulation. The installation was based primarily on the use of prefabricated GRE piping spools and fire insulation cast onto the piping or applied in the form of cast half shells. Significant experiences gained from the project are described. These experiences involve pre-engineering activities, detailed engineering, onshore fabrication, shipping, offshore hook-up, quality assurance, safety and economics. Although the overall installation was successful and the system is functioning as intended, areas of possible optimization and cost reduction for future composite firewater systems were identified. These findings are also briefly reviewed.

  5. Lung Toxicity of Ambient Particulate Matter from Southeastern U.S. Sites with Different Contributing Sources: Relationships between Composition and Effects

    PubMed Central

    Seagrave, JeanClare; McDonald, Jacob D.; Bedrick, Edward; Edgerton, Eric S.; Gigliotti, Andrew P.; Jansen, John J.; Ke, Lin; Naeher, Luke P.; Seilkop, Steven K.; Zheng, Mei; Mauderly, Joe L.

    2006-01-01

    Background Exposure to air pollution and, more specifically, particulate matter (PM) is associated with adverse health effects. However, the specific PM characteristics responsible for biological effects have not been defined. Objectives In this project we examined the composition, sources, and relative toxicity of samples of PM with aerodynamic diameter ≥2.5 μm (PM2.5) collected from sites within the Southeastern Aerosol Research and Characterization (SEARCH) air monitoring network during two seasons. These sites represent four areas with differing sources of PM2.5, including local urban versus regional sources, urban areas with different contributions of transportation and industrial sources, and a site influenced by Gulf of Mexico weather patterns. Methods We collected samples from each site during the winter and summer of 2004 for toxicity testing and for chemical analysis and chemical mass balance–based source apportionment. We also collected PM2.5 downwind of a series of prescribed forest burns. We assessed the toxicity of the samples by instillation into rat lungs and assessed general toxicity, acute cytotoxicity, and inflammation. Statistical dose–response modeling techniques were used to rank the relative toxicity and compare the seasonal differences at each site. Projection-to-latent-surfaces (PLS) techniques examined the relationships among sources, chemical composition, and toxicologic end points. Results and conclusions Urban sites with high contributions from vehicles and industry were most toxic. PMID:16966093

  6. Application of Aerosol Hygroscopicity Measured at the Atmospheric Radiation Measurement Program's Southern Great Plains Site to Examine Composition and Evolution

    NASA Technical Reports Server (NTRS)

    Gasparini, Roberto; Runjun, Li; Collins, Don R.; Ferrare, Richard A.; Brackett, Vincent G.

    2006-01-01

    A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) was used to measure submicron aerosol size distributions, hygroscopicity, and occasionally volatility during the May 2003 Aerosol Intensive Operational Period (IOP) at the Central Facility of the Atmospheric Radiation Measurement Program's Southern Great Plains (ARM SGP) site. Hygroscopic growth factor distributions for particles at eight dry diameters ranging from 0.012 micrometers to 0.600 micrometers were measured throughout the study. For a subset of particle sizes, more detailed measurements were occasionally made in which the relative humidity or temperature to which the aerosol was exposed was varied over a wide range. These measurements, in conjunction with backtrajectory clustering, were used to infer aerosol composition and to gain insight into the processes responsible for evolution. The hygroscopic growth of both the smallest and largest particles analyzed was typically less than that of particles with dry diameters of about 0.100 micrometers. It is speculated that condensation of secondary organic aerosol on nucleation mode particles is largely responsible for the minimal hygroscopic growth observed at the smallest sizes considered. Growth factor distributions of the largest particles characterized typically contained a nonhygroscopic mode believed to be composed primarily of dust. A model was developed to characterize the hygroscopic properties of particles within a size distribution mode through analysis of the fixed size hygroscopic growth measurements. The performance of this model was quantified through comparison of the measured fixed size hygroscopic growth factor distributions with those simulated through convolution of the size-resolved concentration contributed by each of the size modes and the mode-resolved hygroscopicity. This transformation from sizeresolved hygroscopicity to mode-resolved hygroscopicity facilitated examination of changes in the hygroscopic

  7. Spatial and temporal variability of snow chemical composition and accumulation rate at Talos Dome site (East Antarctica).

    PubMed

    Caiazzo, Laura; Becagli, Silvia; Frosini, Daniele; Giardi, Fabio; Severi, Mirko; Traversi, Rita; Udisti, Roberto

    2016-04-15

    Five snow pits and five firn cores were sampled during the 2003-2004 Italian Antarctic Campaign at Talos Dome (East Antarctica), where a deep ice core (TALDICE, TALos Dome Ice CorE, 1650m depth) was drilled in 2005-2008 and analyzed for ionic content. Particular attention is spent in applying decontamination procedures to the firn cores, as core sections were stored for approximately 10years before analysis. By considering the snow pit samples to be unperturbed, the comparison with firn core samples from the same location shows that ammonium, nitrate and MSA are affected by storage post-depositional losses. All the other measured ions are confirmed to be irreversibly deposited in the snow layer. The removal of the most external layers (few centimeters) from the firn core sections is proved to be an effective decontamination procedure. High-resolution profiles of seasonal markers (nitrate, sulfate and MSA) allow a reliable stratigraphic dating and a seasonal characterization of the samples. The calculated mean accumulation-rate values range from 70 to 85mmw.e.year(-1), in the period 2003-1973 with small differences between two sectors: 70-74mmw.e.year(-1) in the NNE sector (spanning 2003-1996years) and 81-92mmw.e.year(-1) in the SSW sector (spanning 2003-1980years). This evidence is interpreted as a coupled effect of wind-driven redistribution processes in accumulation/ablation areas. Statistical treatment applied to the concentration values of the snow pits and firn cores samples collected in different points reveals a larger temporal variability than spatial one both in terms of concentration of chemical markers and annual accumulation. The low spatial variability of the accumulation rate and chemical composition measured in the five sites demonstrates that the TALDICE ice core paleo-environmental and paleo-climatic stratigraphies can be considered as reliably representative for the Talos Dome area. PMID:26849319

  8. Motif composition, conservation and condition-specificity of single and alternative transcription start sites in the Drosophila genome

    PubMed Central

    Rach, Elizabeth A; Yuan, Hsiang-Yu; Majoros, William H; Tomancak, Pavel; Ohler, Uwe

    2009-01-01

    Background Transcription initiation is a key component in the regulation of gene expression. mRNA 5' full-length sequencing techniques have enhanced our understanding of mammalian transcription start sites (TSSs), revealing different initiation patterns on a genomic scale. Results To identify TSSs in Drosophila melanogaster, we applied a hierarchical clustering strategy on available 5' expressed sequence tags (ESTs) and identified a high quality set of 5,665 TSSs for approximately 4,000 genes. We distinguished two initiation patterns: 'peaked' TSSs, and 'broad' TSS cluster groups. Peaked promoters were found to contain location-specific sequence elements; conversely, broad promoters were associated with non-location-specific elements. In alignments across other Drosophila genomes, conservation levels of sequence elements exceeded 90% within the melanogaster subgroup, but dropped considerably for distal species. Elements in broad promoters had lower levels of conservation than those in peaked promoters. When characterizing the distributions of ESTs, 64% of TSSs showed distinct associations to one out of eight different spatiotemporal conditions. Available whole-genome tiling array time series data revealed different temporal patterns of embryonic activity across the majority of genes with distinct alternative promoters. Many genes with maternally inherited transcripts were found to have alternative promoters utilized later in development. Core promoters of maternally inherited transcripts showed differences in motif composition compared to zygotically active promoters. Conclusions Our study provides a comprehensive map of Drosophila TSSs and the conditions under which they are utilized. Distinct differences in motif associations with initiation pattern and spatiotemporal utilization illustrate the complex regulatory code of transcription initiation. PMID:19589141

  9. Temporal variability of atmospheric particulate matter and chemical composition during a growing season at an agricultural site in northeastern China.

    PubMed

    Chen, Weiwei; Tong, Daniel; Zhang, Shichun; Dan, Mo; Zhang, Xuelei; Zhao, Hongmei

    2015-12-01

    This study presents the observations of PM10 and PM2.5 concentrations at an agricultural site from April to October 2012 in Dehui city, China. Ambient air was sampled by filter-based samplers and online PM monitors. The filter samples were analyzed to determine the abundance of ionic/inorganic elements, organic carbon (OC) and elemental carbon (EC). The daily PM10 concentrations varied significantly over the monitoring period, with an average of 168±63 (in the range of 52-277)μg/m(3) during the land preparation/planting period (26 April-15 June), 85±65 (36-228)μg/m(3) during the growing season (16 June-25 September), and 207±88 (103-310)μg/m(3) during the harvest period (26 September-31 October). PM2.5 accounted for 44%, 56% and 66% of atmospheric PM10 during these periods, respectively. The PM10 diurnal variation showed a distinct peak from 16:00 to 21:00 (LST) during the growing and harvesting seasons, while a gradual increase throughout the daytime until 17:00 was observed during tilling season. Mineral dust elements (Al, Ca, Fe, and Mg) dominated the PM10 chemical composition during the tilling season; OC, NO3(-), SO4(2-) and NH4(+) during the growing season; and carbonaceous species (i.e., OC and EC) during the harvesting season. Our results indicate that the soil particles emitted by farm tillage and organic matter released from straw burning are the two most significant sources of PM10 emissions contributing to the recurring high pollution events in this region. Therefore, development of agricultural PM inventories from soil tillage and straw burning is prioritized to support air quality modeling. PMID:26702977

  10. Mass, black carbon and elemental composition of PM2.5 at an industrial site in Kingston, Jamaica

    NASA Astrophysics Data System (ADS)

    Boman, Johan; Gaita, Samuel M.

    2015-11-01

    An estimated three million premature deaths yearly can be attributed to ambient particulate pollution, a majority of them in low and middle income countries. The rapid increase in the vehicle fleet in urban areas of the Caribbean countries have experienced contributes to the bad urban air quality. In this study aerosol particles with an aerodynamic diameter smaller than, or equal to, 2.5 μm (PM2.5) were collected over 24 h at a site along Spanish Town Road, one of the main commuter roads in Kingston, Jamaica. The study was aimed at determining the mass, black carbon and elemental composition of PM2.5 in Kingston. Although lead in the gasoline was phased out in the year 2000, up to 5000 ppm of sulfur is still allowed in the diesel, leading to an extensive secondary particle formation. PM2.5 samples were collected using a Mini-vol sampler between 12 December 2013 and 21 March 2014 and analyzed for trace elements using the Particle-Induced X-ray Emission (PIXE) facility at Lund University, Sweden. Concentrations of Si, S, Cl, K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Br and Pb were determined. Elemental concentrations showed a high temporal variation and the average PM2.5 concentration (44 μg m-3) is higher than the air quality standards that apply in the European Union (25 μg m-3) and in the USA (12 μg m-3). From this we can conclude that the air quality in the area is severely influenced by PM2.5 pollution and that there is a need to develop plans for improving the air quality in Kingston city.

  11. 2008 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site, Nye County, Nevada: Review of the Performance Assessments and Composite Analyses

    SciTech Connect

    NSTec Environmental Management

    2009-03-30

    The Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site requires an annual review to assess the adequacy of the Performance Assessments (PAs) and Composite Analyses (CAs) for each of the facilities, with the results submitted annually to U.S. Department of Energy (DOE) Headquarters. The Disposal Authorization Statements for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) also require that such reviews be made and that secondary or minor unresolved issues be tracked and addressed as part of the maintenance plan. The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) performed an annual review in fiscal year (FY) 2008 by evaluating operational factors and research results that impact the continuing validity of the PAs and CAs. This annual summary report presents data and conclusions from the FY 2008 review, and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R&D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the Nevada Test Site relevant to the sources of residual radioactive material that are considered in the CAs, the land-use planning, and the results of the environmental monitoring and R&D activities were reviewed to determine the adequacy of the CAs.

  12. CUSTOM WATERSHEDS AND LANDSCAPE METRICS FOR EMAP-GRE SAMPLE SITES ON THE MISSISSIPPI, THE MISSOURI AND THE OHIO RIVERS: GIS APPROACH

    EPA Science Inventory

    This research and work is a novel use of the latest advancement of a hydrology-with-elevation seamless data layer for the entire United States, namely NDHPlus and for the newest (ca 2001) imaging and classification of land cover, the National Land Cover Database (NLCD 2001) which...

  13. Thermal Evolution and Composition of the July 2009 Jupiter Impact Site from 7-25 Micron Imaging and Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fletcher, L. N.; Orton, G. S.; Mousis, O.; de Pater, I.; Hammel, H. B.; Golisch, W.; Edwards, M.; Yanamandra-Fisher, P. A.; Fisher, B.; Greene, Z.; Lai, S.; Otto, E.; Reshetnikov, N.; Sanchez-Lavega, A.; Simon-Miller, A. A.; Hueso, R.; Perez-Hoyos, S.

    2009-12-01

    narrow wavelength ranges near 8.02, 10.49, 11.31, 11.60, 12.24 and 13.36 microns, sensitive to NH3, CH4 and hydrocarbon emission features. Iterative forward modelling of these spectra will be used to deduce the unique chemical composition and the three-dimensional thermal structure of the impact site, compared with the ‘unperturbed’ atmosphere at the same latitude. * Fletcher is supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory/California Institute of Technology, administered by Oak Ridge Associated Universities through a contract with NASA. We wish to acknowledge the invaluable contributions of the support staff at IRTF, VLT and Gemini.

  14. Chemical composition of North American microtektites and tektite fragments from Barbados and DSDP site 612 on the continental slope off New Jersey

    NASA Astrophysics Data System (ADS)

    Koeberl, C.; Glass, B. P.

    1988-02-01

    The major element and trace element content of tektite fragments and microtektites found in deep-sea sediments from Barbados and DSDP (Deep Sea Drilling Project) Site 612 on the continental slope off New Jersey have been determined. The compositions are consistent with the conclusion that the samples from both occurrences belong to the North American tektite strewn field. However, the chemistry of the samples from both occurrences is not identical with the bediasite or georgianite chemistry. These differences show that there are geographical variations in composition in the North American strewn field.

  15. Sorption testing and generalized composite surface complexation models for determining uranium sorption parameters at a proposed in-situ recovery site

    DOE PAGESBeta

    Johnson, Raymond H.; Truax, Ryan A.; Lankford, David A.; Stone, James J.

    2016-02-03

    Solid-phase iron concentrations and generalized composite surface complexation models were used to evaluate procedures in determining uranium sorption on oxidized aquifer material at a proposed U in situ recovery (ISR) site. At the proposed Dewey Burdock ISR site in South Dakota, USA, oxidized aquifer material occurs downgradient of the U ore zones. Solid-phase Fe concentrations did not explain our batch sorption test results,though total extracted Fe appeared to be positively correlated with overall measured U sorption. Batch sorption test results were used to develop generalized composite surface complexation models that incorporated the full genericsorption potential of each sample, without detailedmore » mineralogiccharacterization. The resultant models provide U sorption parameters (site densities and equilibrium constants) for reactive transport modeling. The generalized composite surface complexation sorption models were calibrated to batch sorption data from three oxidized core samples using inverse modeling, and gave larger sorption parameters than just U sorption on the measured solidphase Fe. These larger sorption parameters can significantly influence reactive transport modeling, potentially increasing U attenuation. Because of the limited number of calibration points, inverse modeling required the reduction of estimated parameters by fixing two parameters. The best-fit models used fixed values for equilibrium constants, with the sorption site densities being estimated by the inversion process. While these inverse routines did provide best-fit sorption parameters, local minima and correlated parameters might require further evaluation. Despite our limited number of proxy samples, the procedures presented provide a valuable methodology to consider for sites where metal sorption parameters are required. Furthermore, these sorption parameters can be used in reactive transport modeling to assess downgradient metal attenuation, especially when no other

  16. Prediction of mucin-type O-glycosylation sites in mammalian proteins using the composition of k-spaced amino acid pairs

    PubMed Central

    Chen, Yong-Zi; Tang, Yu-Rong; Sheng, Zhi-Ya; Zhang, Ziding

    2008-01-01

    Background As one of the most common protein post-translational modifications, glycosylation is involved in a variety of important biological processes. Computational identification of glycosylation sites in protein sequences becomes increasingly important in the post-genomic era. A new encoding scheme was employed to improve the prediction of mucin-type O-glycosylation sites in mammalian proteins. Results A new protein bioinformatics tool, CKSAAP_OGlySite, was developed to predict mucin-type O-glycosylation serine/threonine (S/T) sites in mammalian proteins. Using the composition of k-spaced amino acid pairs (CKSAAP) based encoding scheme, the proposed method was trained and tested in a new and stringent O-glycosylation dataset with the assistance of Support Vector Machine (SVM). When the ratio of O-glycosylation to non-glycosylation sites in training datasets was set as 1:1, 10-fold cross-validation tests showed that the proposed method yielded a high accuracy of 83.1% and 81.4% in predicting O-glycosylated S and T sites, respectively. Based on the same datasets, CKSAAP_OGlySite resulted in a higher accuracy than the conventional binary encoding based method (about +5.0%). When trained and tested in 1:5 datasets, the CKSAAP encoding showed a more significant improvement than the binary encoding. We also merged the training datasets of S and T sites and integrated the prediction of S and T sites into one single predictor (i.e. S+T predictor). Either in 1:1 or 1:5 datasets, the performance of this S+T predictor was always slightly better than those predictors where S and T sites were independently predicted, suggesting that the molecular recognition of O-glycosylated S/T sites seems to be similar and the increase of the S+T predictor's accuracy may be a result of expanded training datasets. Moreover, CKSAAP_OGlySite was also shown to have better performance when benchmarked against two existing predictors. Conclusion Because of CKSAAP encoding's ability of

  17. 2009 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site, Nye County, Nevada: Review of the Performance Assessments and Composite Analysis

    SciTech Connect

    NSTec Environmental Management

    2010-03-15

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office performed an annual review of the Area 3 and Area 5 Radioactive Wate Management Site (RWMS) Performance Assessments (PAs) and Composite Analyses (CAs) in fiscal year (FY) 2009. This annual summary report presents data and conclusions from the FY 2009 review, and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R&D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the Nevada Test Site relevant to the sources of residual radioactive material that are considered in the CAs, the land-use planning, and the results of the environmental monitoring and R&D activities were reviewed to determine the adequacy of the CAs.

  18. Technical refinements of composite thoracodorsal system free flaps for 1-stage lower extremity reconstruction resulting in reduced donor-site morbidity.

    PubMed

    Bannasch, Holger; Strohm, Peter C; Al Awadi, Khalid; Stark, G Björn; Momeni, Arash

    2008-04-01

    A multitude of local flaps has been suggested for lower extremity reconstruction. However, the gold standard for defect coverage remains free tissue transfer. In this regard, the scapular vascular axis is a well-established source of expendable skin, fascia, muscle, and bone for use in free flap reconstruction of defects requiring bone and soft tissue in complex 3-dimensional relationships. Composite bone and soft-tissue flaps derived from the subscapular vascular axis include the osteocutaneous scapular flap, the "latissimus/bone flap," and the thoracodorsal artery perforator-scapular osteocutaneous flap.Patient outcome following reconstruction of lower extremity defects with composite free flaps from the thoracodorsal system were analyzed. Here, we demonstrate the execution of technical refinements on free composite flap transfers based on the thoracodorsal vascular axis, thus resulting in a stepwise reduction of donor-site morbidity. PMID:18362565

  19. Bats Swarm Where They Hibernate: Compositional Similarity between Autumn Swarming and Winter Hibernation Assemblages at Five Underground Sites

    PubMed Central

    van Schaik, Jaap; Janssen, René; Bosch, Thijs; Haarsma, Anne-Jifke; Dekker, Jasja J. A.; Kranstauber, Bart

    2015-01-01

    During autumn in the temperate zone of both the new and old world, bats of many species assemble at underground sites in a behaviour known as swarming. Autumn swarming behaviour is thought to primarily serve as a promiscuous mating system, but may also be related to the localization and assessment of hibernacula. Bats subsequently make use of the same underground sites during winter hibernation, however it is currently unknown if the assemblages that make use of a site are comparable across swarming and hibernation seasons. Our purpose was to characterize the bat assemblages found at five underground sites during both the swarming and the hibernation season and compare the assemblages found during the two seasons both across sites and within species. We found that the relative abundance of individual species per site, as well as the relative proportion of a species that makes use of each site, were both significantly correlated between the swarming and hibernation seasons. These results suggest that swarming may indeed play a role in the localization of suitable hibernation sites. Additionally, these findings have important conservation implications, as this correlation can be used to improve monitoring of underground sites and predict the importance of certain sites for rare and cryptic bat species. PMID:26153691

  20. Bats Swarm Where They Hibernate: Compositional Similarity between Autumn Swarming and Winter Hibernation Assemblages at Five Underground Sites.

    PubMed

    van Schaik, Jaap; Janssen, René; Bosch, Thijs; Haarsma, Anne-Jifke; Dekker, Jasja J A; Kranstauber, Bart

    2015-01-01

    During autumn in the temperate zone of both the new and old world, bats of many species assemble at underground sites in a behaviour known as swarming. Autumn swarming behaviour is thought to primarily serve as a promiscuous mating system, but may also be related to the localization and assessment of hibernacula. Bats subsequently make use of the same underground sites during winter hibernation, however it is currently unknown if the assemblages that make use of a site are comparable across swarming and hibernation seasons. Our purpose was to characterize the bat assemblages found at five underground sites during both the swarming and the hibernation season and compare the assemblages found during the two seasons both across sites and within species. We found that the relative abundance of individual species per site, as well as the relative proportion of a species that makes use of each site, were both significantly correlated between the swarming and hibernation seasons. These results suggest that swarming may indeed play a role in the localization of suitable hibernation sites. Additionally, these findings have important conservation implications, as this correlation can be used to improve monitoring of underground sites and predict the importance of certain sites for rare and cryptic bat species. PMID:26153691

  1. Feasibility of T2* mapping for the evaluation of hip joint cartilage at 1.5T using a three-dimensional (3D), gradient-echo (GRE) sequence: a prospective study.

    PubMed

    Bittersohl, Bernd; Hosalkar, Harish S; Hughes, Tim; Kim, Young-Jo; Werlen, Stefan; Siebenrock, Klaus A; Mamisch, Tallal C

    2009-10-01

    This study defines the feasibility of utilizing three-dimensional (3D) gradient-echo (GRE) MRI at 1.5T for T(2)* mapping to assess hip joint cartilage degenerative changes using standard morphological MR grading while comparing it to delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). MRI was obtained from 10 asymptomatic young adult volunteers and 33 patients with symptomatic femoroacetabular impingement (FAI). The protocol included T(2)* mapping without gadolinium-enhancement utilizing a 3D-GRE sequence with six echoes, and after gadolinium injection, routine hip sequences, and a dual-flip-angle 3D-GRE sequence for dGEMRIC T(1) mapping. Cartilage was classified as normal, with mild changes, or with severe degenerative changes based on morphological MRI. T(1) and T(2)* findings were subsequently correlated. There were significant differences between volunteers and patients in normally-rated cartilage only for T(1) values. Both T(1) and T(2)* values decreased significantly with the various grades of cartilage damage. There was a statistically significant correlation between standard MRI and T(2)* (T(1)) (P < 0.05). High intraclass correlation was noted for both T(1) and T(2)*. Correlation factor was 0.860 to 0.954 (T(2)*-T(1) intraobserver) and 0.826 to 0.867 (T(2)*-T(1) interobserver). It is feasible to gather further information about cartilage status within the hip joint using GRE T(2)* mapping at 1.5T. PMID:19645008

  2. Inducible scAAV2.GRE.MMP1 lowers IOP long-term in a large animal model for steroid-induced glaucoma gene therapy

    PubMed Central

    Borrás, Teresa; Buie, LaKisha K.; Spiga, Maria Grazia

    2016-01-01

    Current treatment of glaucoma relies on administration of daily drops or eye surgery. A gene therapy approach to treat steroid-induced glaucoma would bring a resolution to millions of people worldwide that depend on glucocorticoid therapy for a myriad of inflammatory disorders. Previously, we had characterized a short-term Adh.GRE.MMP1 gene vector for the production of steroid-induced MMP1 in the trabecular meshwork and tested reduction of elevated intraocular pressure (IOP) in a sheep model. Here we conducted a trial transferring the same transgene cassette to a clinically safe vector (scAAV2), and extended the therapeutic outcome to longer periods of times. No evidence of ocular and/or systemic toxicity was observed. Viral genome distributions showed potential re-inducible vector DNAs in the trabecular meshwork (0.4 vg/cell) and negligible copies in six major internal organs (0.00002-0.005 vg/cell). Histological sections confirmed successful transduction of scAAV2.GFP to the trabecular meshwork. Optimization of the sheep steroid–induced hypertensive model revealed that topical ophthalmic drug difluprednate 0.05% (durezol) induced the highest IOP elevation in the shortest time. This is the first efficacy/toxicity study of a feasible gene therapy treatment of steroid-induced hypertension using clinically accepted scAAV vectors in a large animal model. PMID:26855269

  3. Inducible scAAV2.GRE.MMP1 lowers IOP long-term in a large animal model for steroid-induced glaucoma gene therapy.

    PubMed

    Borrás, T; Buie, L K; Spiga, M G

    2016-05-01

    Current treatment of glaucoma relies on administration of daily drops or eye surgery. A gene therapy approach to treat steroid-induced glaucoma would bring a resolution to millions of people worldwide who depend on glucocorticoid therapy for a myriad of inflammatory disorders. Previously, we had characterized a short-term Adh.GRE.MMP1 gene vector for the production of steroid-induced MMP1 in the trabecular meshwork and tested reduction of elevated intraocular pressure (IOP) in a sheep model. Here we conducted a trial transferring the same transgene cassette to a clinically safe vector (scAAV2), and extended the therapeutic outcome to longer periods of times. No evidence of ocular and/or systemic toxicity was observed. Viral genome distributions showed potential reinducible vector DNAs in the trabecular meshwork (0.4 v.g. per cell) and negligible copies in six major internal organs (0.00002-0.005 v.g. per cell). Histological sections confirmed successful transduction of scAAV2.GFP to the trabecular meshwork. Optimization of the sheep steroid-induced hypertensive model revealed that topical ophthalmic drug difluprednate 0.05% (durezol) induced the highest IOP elevation in the shortest time. This is the first efficacy/toxicity study of a feasible gene therapy treatment of steroid-induced hypertension using clinically accepted self-complementary adeno-associated vectors (scAAV) vectors in a large animal model. PMID:26855269

  4. Incorporating substrate sequence motifs and spatial amino acid composition to identify kinase-specific phosphorylation sites on protein three-dimensional structures

    PubMed Central

    2013-01-01

    Background Protein phosphorylation catalyzed by kinases plays crucial regulatory roles in cellular processes. Given the high-throughput mass spectrometry-based experiments, the desire to annotate the catalytic kinases for in vivo phosphorylation sites has motivated. Thus, a variety of computational methods have been developed for performing a large-scale prediction of kinase-specific phosphorylation sites. However, most of the proposed methods solely rely on the local amino acid sequences surrounding the phosphorylation sites. An increasing number of three-dimensional structures make it possible to physically investigate the structural environment of phosphorylation sites. Results In this work, all of the experimental phosphorylation sites are mapped to the protein entries of Protein Data Bank by sequence identity. It resulted in a total of 4508 phosphorylation sites containing the protein three-dimensional (3D) structures. To identify phosphorylation sites on protein 3D structures, this work incorporates support vector machines (SVMs) with the information of linear motifs and spatial amino acid composition, which is determined for each kinase group by calculating the relative frequencies of 20 amino acid types within a specific radial distance from central phosphorylated amino acid residue. After the cross-validation evaluation, most of the kinase-specific models trained with the consideration of structural information outperform the models considering only the sequence information. Furthermore, the independent testing set which is not included in training set has demonstrated that the proposed method could provide a comparable performance to other popular tools. Conclusion The proposed method is shown to be capable of predicting kinase-specific phosphorylation sites on 3D structures and has been implemented as a web server which is freely accessible at http://csb.cse.yzu.edu.tw/PhosK3D/. Due to the difficulty of identifying the kinase-specific phosphorylation

  5. Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the NTS

    SciTech Connect

    Vefa Yucel

    2007-01-03

    U.S. Department of Energy (DOE) Manual M 435.1-1 requires that performance assessments (PAs) and composite analyses (CAs) for low-level waste (LLW) disposal facilities be maintained by the field offices. This plan describes the activities performed to maintain the PA and the CA for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site (NTS). This plan supersedes the Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site (DOE/NV/11718--491-REV 1, dated September 2002). The plan is based on U.S. Department of Energy (DOE) Order 435.1 (DOE, 1999a), DOE Manual M 435.1-1 (DOE, 1999b), the DOE M 435.1-1 Implementation Guide DOE G 435.1-1 (DOE, 1999c), and the Maintenance Guide for PAs and CAs (DOE, 1999d). The plan includes a current update on PA/CA documentation, a revised schedule, and a section on Quality Assurance.

  6. Impacts of aggregate dredging on sediment composition and associated benthic fauna at an offshore dredge site in the southern North Sea.

    PubMed

    Robinson, J E; Newell, R C; Seiderer, L J; Simpson, N M

    2005-07-01

    Dredging and associated screening at a dredge site in the southern North Sea (Area 408) is associated with areas of well-sorted fine sand that extend for up to 3 km to the south-east of the dredged area and overlay sediments with a more variable particle size composition. This well-sorted fine sand may reflect deposition and transport of material mobilised by the dredging and screening processes at the dredge site. Multivariate analysis of the benthic community structure suggests that marine aggregate dredging, at the level of intensity employed in the study area prior to sample collection, has had a limited impact on benthic community composition compared with that reported from studies elsewhere. This is ascribed to the likely rapid rates of recolonisation by the mobile opportunistic polychaetes and crustaceans that dominate the macrofauna of the sandy gravel deposits at this particular dredge site. Analysis of variance showed, however, that significant differences existed between the sample treatments in terms of species evenness (Pielou's J). Dredged samples were found to have the lowest mean species evenness (0.71) when compared to controls (0.77). The present study highlights the inherent difficulties in the application of general impact/recovery predictions to dredged sites with varying environmental characteristics. PMID:15649527

  7. Summary of Inorganic Compositional Data for Groundwater, Soil-Water, and Surface-Water Samples at the Headgate Draw Subsurface Drip Irrigation Site

    SciTech Connect

    Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupanic, John W.

    2007-01-01

    As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

  8. Summary of inorganic compositional data for groundwater, soil-water, and surface-water samples collected at the Headgate Draw subsurface drip irrigation site, Johnson County, Wyoming

    USGS Publications Warehouse

    Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupancic, John W.

    2011-01-01

    As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

  9. The effects of crushing speed on the energy-absorption capability of composite material

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1987-01-01

    The energy-absorption capability as a function of crushing speed was determined for Thornel 300/Fiberite 934 (Gr/E) and Kevlar-49/Fiberite 934 (K/E) composite material. Circular cross section tube specimens were crushed at quasi-static, 6 m/sec, and 12 m/sec speeds. Ply orientations of the tube specimens were (0/+ or - theta) sub 2 and (+ or - theta) sub 3 where theta=15, 45, and 75 degress. Based on the results of these tests the energy-absortion capability of Gr/E and K/E was determined to be a function of crushing speed. The crushing modes based on exterior appearance of the crushed tubes were unchanged for either material. However, the interlaminar crushing behavior changed with crushing speed.

  10. Hygroscopicity Behavior, Activation Properties and Chemical Composition of Atmospheric Aerosol at a Background Site in the Megacity Region of Peking

    NASA Astrophysics Data System (ADS)

    Henning, Silvia; Nowak, Andreas; Mildenberger, Katrin; Göbel, Tina; Nekat, Bettina; van Pinxteren, Dominik; Herrmann, Hartmut; Zhao, Chunsheng; Wiedensohler, Alfred; Stratmann, Frank

    2010-05-01

    Large areas of China suffer from heavy air pollution (both gaseous and particulate) caused by strong economic growth in the last two decades. However, knowledge concerning the physical and chemical properties of the resulting aerosol particles populations, and their effects on the optical properties of the atmosphere, is still sparse. In the framework of the investigations presented here, comprehensive measurements concerning aerosol particle hygroscopicity, CCN ability, composition, and optical properties were performed. The investigations are part of the DFG-funded project HaChi (Haze in China) and are conducted in collaboration with the Peking University. A conclusive parameterization of aerosol hygroscopicity and activation data is aimed for, which will then be implemented in a meso-scale model to investigate aerosol-cloud-radiation and precipitation interactions. During two intensive measurements campaigns (March 2009 and July/ August 2009), in-situ aerosol measurements have been performed in an air-conditioned mobile laboratory next to the Wuqing Meteorological Station (39°23'8.53"N, 117°1'25.88"E), which is located between Bejing and Tijanjin and is thereby an ideal background site in a megacity region. The particle number size distribution (TDMPS), the particle optical properties (MAAP and nephelometer) and their hygroscopic properties at high RH (HH-TDMA, LACIS-mobile) were characterized as well as their cloud nucleating properties above supersaturation (DMT-CCNC). 24 h PM1 particle samples were continuously collected over the two campaigns in winter and summer using a DIGITEL high volume sampler (DHA-80). Additionally two 6h size-resolved samples (daytime and night-time) were collected each day applying an 11-stage Berner impactor. The size-selection of HH-TDMA, LACIS and the CCNC was synchronized with the Berner stages. Opening analysis of the winter campaign data showed that the HH-TDMA usually detected a hydrophobic and a hygroscopic mode, i.e., the

  11. Ionic composition of PM2.5 at urban sites of northern Greece: secondary inorganic aerosol formation.

    PubMed

    Voutsa, D; Samara, C; Manoli, E; Lazarou, D; Tzoumaka, P

    2014-04-01

    This study investigates the water-soluble ionic constituents (Na(+), K(+), NH4 (+), Ca(2+), Mg(2+), Cl(-), NO3 (-), SO4 (2-)) associated to PM2.5 particle fraction at two urban sites in the city of Thessaloniki, northern Greece, an urban traffic site (UT) and urban background site (UB). Ionic constituents represent a significant fraction of PM2.5 mass (29.6 at UT and 41.5 % at UB). The contribution of marine aerosol was low (<1.5 %). Secondary inorganic aerosols (SIA) represent a significant fraction of PM2.5 mass contributing to 26.9 ± 12.4 % and 39.2 ± 13.2 % at UT and UB sites, respectively. Nitrate and sulfate are fully neutralized by ammonium under the existing conditions. The ionic constituents were evaluated in relation to their spatial and temporal variation, their gaseous precursors, meteorological conditions, local and long-range transport. PMID:24363054

  12. Atmospheric fate of nuclei-mode particles estimated from the number concentrations and chemical composition of particles measured at roadside and background sites

    NASA Astrophysics Data System (ADS)

    Fushimi, Akihiro; Hasegawa, Shuichi; Takahashi, Katsuyuki; Fujitani, Yuji; Tanabe, Kiyoshi; Kobayashi, Shinji

    Number concentrations and size-resolved chemical compositions of atmospheric particles at a roadside site in Kawasaki City, Japan, and a background site 200 m away were measured in winter to estimate the atmospheric fate of nuclei-mode particles emitted from vehicles. Measurements with a scanning mobility particle sizer showed a sharp peak in nuclei-mode particles with a modal diameter of around 0.020 μm at the roadside site; in contrast, no peak for nuclei-mode particles was observed at the background site. For chemical analysis, size-resolved particles were sampled by low-pressure impactors. Carbon analysis suggested that diesel exhaust particles contributed to both the roadside and background Stage 1 (S1; 0.030-0.060 μm) particles. The ratios of organic carbon (OC) to total carbon (TC) increased for smaller particles, and were 28% and 51% for the roadside and the background S1 particles, respectively. It is likely that the OC/TC ratio for nuclei-mode particles was larger than for the S1 particles, and that OC was one of the major constituents of the nuclei-mode particles at the roadside site. From this result and the greater Kelvin effect for smaller particles, it is likely that nuclei-mode particles in the roadside atmosphere are more volatile than the S1 particles. Organic analysis of the size-resolved particles suggested that lubricating oil from vehicles affected the organic composition of both the roadside and background S1 particles, and that C 33n-alkane and more volatile organic compounds in the S1 particles partially evaporated in the atmosphere following the emission of the particles from diesel vehicles. It is likely that evaporation of the constituents (or possibly coagulation with pre-existing particles after shrinking by partial evaporation) of the nuclei-mode particles in the atmosphere was responsible for the absence of nuclei-mode particles in the background atmosphere.

  13. Chemical compositions of some soils and rock types from the Apollo 15, 16, and 17 lunar sites

    NASA Technical Reports Server (NTRS)

    Nava, D. F.

    1974-01-01

    The major and minor element compositions of three Apollo 15 mare basalts, four Apollo 16 breccias, one soil, three Apollo 17 soils, one mare basalt, and one breccia have been determined by semimicro combined atomic absorption and colorimetric spectrophotometries. A discussion regarding analysis of small subsamples of coarse-grained lunar materials, such as certain Apollo 15 and 17 basalts, is given in which the suggestion is made that analytical methods designed to determine the bulk 'representative' chemical composition as well as the presence and extent of specimen heterogeneity are fundamentally necessary for a more complete understanding of genesis and history of lunar materials.

  14. Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada, and Inyo County, California

    USGS Publications Warehouse

    Paces, James B.; Peterman, Zell E.; Futo, Kiyoto; Oliver, Thomas A.; Marshall, Brian D.

    2007-01-01

    Ground water moving through permeable Paleozoic carbonate rocks represents the most likely pathway for migration of radioactive contaminants from nuclear weapons testing at the Nevada Test Site, Nye County, Nevada. The strontium isotopic composition (87Sr/86Sr) of ground water offers a useful means of testing hydrochemical models of regional flow involving advection and reaction. However, reaction models require knowledge of 87Sr/86Sr data for carbonate rock in the Nevada Test Site vicinity, which is scarce. To fill this data gap, samples of core or cuttings were selected from 22 boreholes at depth intervals from which water samples had been obtained previously around the Nevada Test Site at Yucca Flat, Frenchman Flat, Rainier Mesa, and Mercury Valley. Dilute acid leachates of these samples were analyzed for a suite of major- and trace-element concentrations (MgO, CaO, SiO2, Al2O3, MnO, Rb, Sr, Th, and U) as well as for 87Sr/86Sr. Also presented are unpublished analyses of 114 Paleozoic carbonate samples from outcrops, road cuts, or underground sites in the Funeral Mountains, Bare Mountain, Striped Hills, Specter Range, Spring Mountains, and ranges east of the Nevada Test Site measured in the early 1990's. These data originally were collected to evaluate the potential for economic mineral deposition at the potential high-level radioactive waste repository site at Yucca Mountain and adjacent areas (Peterman and others, 1994). Samples were analyzed for a suite of trace elements (Rb, Sr, Zr, Ba, La, and Ce) in bulk-rock powders, and 87Sr/86Sr in partial digestions of carbonate rock using dilute acid or total digestions of silicate-rich rocks. Pre-Tertiary core samples from two boreholes in the central or western part of the Nevada Test Site also were analyzed. Data are presented in tables and summarized in graphs; however, no attempt is made to interpret results with respect to ground-water flow paths in this report. Present-day 87Sr/86Sr values are compared to values

  15. Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada and Inyo County, California.

    SciTech Connect

    James B. Paces; Zell E. Peterman; Kiyoto Futa; Thomas A. Oliver; and Brian D. Marshall.

    2007-08-07

    Ground water moving through permeable Paleozoic carbonate rocks represents the most likely pathway for migration of radioactive contaminants from nuclear weapons testing at the Nevada Test Site, Nye County, Nevada. The strontium isotopic composition (87Sr/86Sr) of ground water offers a useful means of testing hydrochemical models of regional flow involving advection and reaction. However, reaction models require knowledge of 87Sr/86Sr data for carbonate rock in the Nevada Test Site vicinity, which is scarce. To fill this data gap, samples of core or cuttings were selected from 22 boreholes at depth intervals from which water samples had been obtained previously around the Nevada Test Site at Yucca Flat, Frenchman Flat, Rainier Mesa, and Mercury Valley. Dilute acid leachates of these samples were analyzed for a suite of major- and trace-element concentrations (MgO, CaO, SiO2, Al2O3, MnO, Rb, Sr, Th, and U) as well as for 87Sr/86Sr. Also presented are unpublished analyses of 114 Paleozoic carbonate samples from outcrops, road cuts, or underground sites in the Funeral Mountains, Bare Mountain, Striped Hills, Specter Range, Spring Mountains, and ranges east of the Nevada Test Site measured in the early 1990's. These data originally were collected to evaluate the potential for economic mineral deposition at the potential high-level radioactive waste repository site at Yucca Mountain and adjacent areas (Peterman and others, 1994). Samples were analyzed for a suite of trace elements (Rb, Sr, Zr, Ba, La, and Ce) in bulk-rock powders, and 87Sr/86Sr in partial digestions of carbonate rock using dilute acid or total digestions of silicate-rich rocks. Pre-Tertiary core samples from two boreholes in the central or western part of the Nevada Test Site also were analyzed. Data are presented in tables and summarized in graphs; however, no attempt is made to interpret results with respect to ground-water flow paths in this report. Present-day 87Sr/86Sr values are compared to values

  16. Evaluation of the Community Multiscale Air Quality (CMAQ) model v5.0 against size-resolved measurements of inorganic particle composition across sites in North America

    NASA Astrophysics Data System (ADS)

    Nolte, C. G.; Appel, K. W.; Kelly, J. T.; Bhave, P. V.; Fahey, K. M.; Collett, J. L., Jr.; Zhang, L.; Young, J. O.

    2015-09-01

    This work evaluates particle size-composition distributions simulated by the Community Multiscale Air Quality (CMAQ) model using micro-orifice uniform deposit impactor (MOUDI) measurements at 18 sites across North America. Size-resolved measurements of particulate SO42-, NO3-, NH4+, Na+, Cl-, Mg2+, Ca2+, and K+ are compared to CMAQ model output for discrete sampling periods between 2002 and 2005. The observation sites were predominantly in remote areas (e.g., National Parks) in the USA and Canada, and measurements were typically made for a period of roughly 1 month. For SO42- and NH4+, model performance was consistent across the USA and Canadian sites, with the model slightly overestimating the peak particle diameter and underestimating the peak particle concentration compared to the observations. Na+ and Mg2+ size distributions were generally well represented at coastal sites, indicating reasonable simulation of emissions from sea spray. CMAQ is able to simulate the displacement of Cl- in aged sea spray aerosol, though the extent of Cl- depletion relative to Na+ is often underpredicted. The model performance for NO3- exhibited much more site-to-site variability than that of SO42- and NH4+, with the model ranging from an underestimation to overestimation of both the peak diameter and peak particle concentration across the sites. Computing PM2.5 from the modeled size distribution parameters rather than by summing the masses in the Aitken and accumulation modes resulted in differences in daily averages of up to 1 μg m-3 (10 %), while the difference in seasonal and annual model performance compared to observations from the Interagency Monitoring of Protected Visual Environments (IMPROVE), Chemical Speciation Network (CSN), and Air Quality System (AQS) networks was very small. Two updates to the CMAQ aerosol model - changes to the assumed size and mode width of emitted particles and the implementation of gravitational settling - resulted in small improvements in

  17. Chemical Compositions of Precipitation at Three Non-urban Sites of Hebei Province, North China: Influence of Terrestrial Sources on Ionic Composition

    NASA Astrophysics Data System (ADS)

    Xu, Z.

    2015-12-01

    Rapid economic development and increased energy demand have resulted in severe air pollution problems throughout China, and the increasing emissions of SO2 and NOx have led to significant deposition of acid rain in China. Despite high SO2 concentrations are observed in both southern and northern China, acid rain is mainly observed in the south area in history. It is believed that high content of alkaline matters in the soil in the North China is one of the key factors that contribute to the neutralization of acidic ions in the rainwater. However, an increasing trend of the precipitation acidity was observed at many sites in North, Central and East China after 2000, with more pronounced trends in the Beijing-Tianjin region and Bohai Sea surrounding area. In this study, precipitations were collected from April to October in 2008 at three non-urban sites (Chicheng, Huailai and Xuanhua) in Hebei Province, North China. The pH values of precipitation events ranged from 4.08 to 7.53 for the three sampling sites. About 61.8% of the total precipitation had a pH value higher than 6.0. The predominant ions in the precipitation were SO42-, NO3- and Ca2+, and their concentrations were significantly higher than other sites in South China. The high concentration of acidic ions reflects that atmospheric pollution has already been severe in this area. The volume-weighted mean (VWM) concentration of major ions and pH value showed obvious seasonal differences, precipitation in dry season had high pH values and VWM concentrations of major ions. According to the equivalent ratio of NP/AP and the results of neutralization factors, the strong acid neutralization is mainly brought about by Ca2+ followed by NH4+ and Mg2+. Using Na as an indicator of marine origin, the proportions of sea salt and non-sea-salt were estimated from elemental ratios. Combining with the results of correlation analysis and enrichment factors, the main acidic ions (SO42- and NO3-) and NH4+ were mainly derived from

  18. Retrospection-Simulation-Revision: Approach to the Analysis of the Composition and Characteristics of Medical Waste at a Disaster Relief Site

    PubMed Central

    Zhang, Li; Wu, Lihua; Tian, Feng; Wang, Zheng

    2016-01-01

    A large amount of medical waste is produced during disaster relief, posing a potential hazard to the habitat and the environment. A comprehensive understanding of the composition and characteristics of medical waste that requires management is one of the most basic steps in the development of a plan for medical waste management. Unfortunately, limited reliable information is available in the open literature on the characteristics of the medical waste that is generated at disaster relief sites. This paper discusses the analysis of the composition and characteristics of medical waste at a disaster relief site using the retrospection-simulation-revision method. For this study, we obtained 35 medical relief records of the Wenchuan Earthquake, Sichuan, May 2008 from a field cabin hospital. We first present a retrospective analysis of the relief medical records, and then, we simulate the medical waste generated in the affected areas. We ultimately determine the composition and characteristics of medical waste in the affected areas using untreated medical waste to revise the composition of the simulated medical waste. The results from 35 cases showed that the medical waste generated from disaster relief consists of the following: plastic (43.2%), biomass (26.3%), synthetic fiber (15.3%), rubber (6.6%), liquid (6.6%), inorganic salts (0.3%) and metals (1.7%). The bulk density of medical relief waste is 249 kg/m3, and the moisture content is 44.75%. The data should be provided to assist the collection, segregation, storage, transportation, disposal and contamination control of medical waste in affected areas. In this paper, we wish to introduce this research method of restoring the medical waste generated in disaster relief to readers and researchers. In addition, we hope more disaster relief agencies will become aware of the significance of medical case recording and storing. This may be very important for the environmental evaluation of medical waste in disaster areas, as

  19. Retrospection-Simulation-Revision: Approach to the Analysis of the Composition and Characteristics of Medical Waste at a Disaster Relief Site.

    PubMed

    Zhang, Li; Wu, Lihua; Tian, Feng; Wang, Zheng

    2016-01-01

    A large amount of medical waste is produced during disaster relief, posing a potential hazard to the habitat and the environment. A comprehensive understanding of the composition and characteristics of medical waste that requires management is one of the most basic steps in the development of a plan for medical waste management. Unfortunately, limited reliable information is available in the open literature on the characteristics of the medical waste that is generated at disaster relief sites. This paper discusses the analysis of the composition and characteristics of medical waste at a disaster relief site using the retrospection-simulation-revision method. For this study, we obtained 35 medical relief records of the Wenchuan Earthquake, Sichuan, May 2008 from a field cabin hospital. We first present a retrospective analysis of the relief medical records, and then, we simulate the medical waste generated in the affected areas. We ultimately determine the composition and characteristics of medical waste in the affected areas using untreated medical waste to revise the composition of the simulated medical waste. The results from 35 cases showed that the medical waste generated from disaster relief consists of the following: plastic (43.2%), biomass (26.3%), synthetic fiber (15.3%), rubber (6.6%), liquid (6.6%), inorganic salts (0.3%) and metals (1.7%). The bulk density of medical relief waste is 249 kg/m3, and the moisture content is 44.75%. The data should be provided to assist the collection, segregation, storage, transportation, disposal and contamination control of medical waste in affected areas. In this paper, we wish to introduce this research method of restoring the medical waste generated in disaster relief to readers and researchers. In addition, we hope more disaster relief agencies will become aware of the significance of medical case recording and storing. This may be very important for the environmental evaluation of medical waste in disaster areas, as

  20. Impact of moisture source regions on the isotopic composition of precipitation events at high-mountain continental site Kasprowy Wierch, southern Poland

    NASA Astrophysics Data System (ADS)

    Rozanski, Kazimierz; Chmura, Lukasz; Dulinski, Marek

    2016-04-01

    Five-year record of deuterium and oxygen-18 isotope composition of precipitation events collected on top of the Kasprowy Wierch mountain (49° 14'N, 19° 59'E, 1989 m a.s.l.) located in north-western High Tatra mountain ridge, southern Poland, is presented and discussed. In total 670 precipitation samples have been collected and analysed. Stable isotope composition of the analysed precipitation events varied in a wide range, from -2.9 to -26.6‰ for δ18O and from -7 to -195 ‰ for δ2H. The local meteoric water line (LMWL) defined by single events data (δ2H=(7.86±0.05)δ18O+(12.9±0.6) deviate significantly from the analogous line defined by monthly composite precipitation data available for IAEA/GNIP station Krakow-Balice (50o04'N, 19o55'E, 220 m a.s.l.), located ca. 100 km north of Kasprowy Wierch ((δ2H=(7.82±0.11)δ18O+(6.9±1.1). While slopes of those two LMWLs are statistically indistinguishable, the intercept of Kasprowy Wierch line is almost two times higher that that characterizing Krakow monthly precipitation. This is well-documented effect associated with much higher elevation of Kasprowy Wierch sampling site when compared to Krakow. The isotope data for Kasprowy Wierch correlate significantly with air temperature, with the slope of the regression line being equal 0.35±0.02 ‰oC for δ18O, whereas no significant correlation with precipitation amount could be established. The impact of moisture source regions on the isotopic composition of precipitation events collected at Kasprowy Wierch site was analysed using HYSPLITE back trajectory model. Five-days back trajectories were calculated for all analysed precipitation events and seasonal maps of trajectory distribution were produced. They illustrate changes in the prevailing transport patterns of air masses bringing precipitation to the sampling site. Back trajectories for the events yielding extreme isotopic composition of precipitation collected at Kasprowy Wierch were analyzed in detail

  1. Chemical composition of the major components of PM in different sites at the Metropolitan Region of Chile

    NASA Astrophysics Data System (ADS)

    Reyes, F.; Castillo, M. A.; Rubio, M.; Gramsch, E.; Vasquez, Y.; Oyola, P.

    2013-05-01

    Santiago, Chile's capital is one of most polluted megacity (5.5 million of people) of the world. Currently, PM2.5 annual concentration is over 2.2 times the Chilean standard (20 μg/m3). Continuous measurements of non-refractory PM1.0 (sulfate, nitrate, chloride, ammonium and organics aerosols), black carbon, and PM2,5 mass concentration were determined using Aerosol Chemical Speciation Monitor (ACSM, Aerodyne Research, Inc), absorption coefficient monitor (SIMCA, Santiago University) and dustrack monitor (TSI Inc) in order to know the temporal variability of the major components of PM. The measurements were carried out at kerbside, urban background, industrial and mixed residential/industrial locations during year 2012 and -2013. Meteorological data (Relative Humidity, temperature, wind speed, wind direction and precipitations) were obtained from the air quality network operated by the environmental authority. The results show strong correlation with the metropolitan region major sources. Multiple regression analysis indicates that precipitations have a strong impact on PM1.0 soluble components; relative humidity has effects only on chloride, sulfate and black carbon. Chloride concentration decrease when temperature is increasing. The perceptual contribution of each component is similar among all sites. All sites shows that OA (Organics Aerosol) as the major constituent of PM1.0 (>50%), followed of nitrates (>13%). Sulfate could be used to differentiate the industrial site; due to there is a strong impact of SO2 emission. Combustion sources direct impact can be seen at BC contribution at industrial and kerbside site. Also, the OA/BC ratio shows slow value at kerbside (3.05) and industrial (3.26) site, and higher at urban background site (4.15). Aged organics aerosols are majority found at all sites (f43/f44 plot), indicating that regional background is strong in all results. These results will be compared with size distribution measurements available from previous

  2. Influence of human activity patterns, particle composition, and residential air exchange rates on modeled distributions of PM2.5 exposure compared with central-site monitoring data.

    PubMed

    Baxter, Lisa K; Burke, Janet; Lunden, Melissa; Turpin, Barbara J; Rich, David Q; Thevenet-Morrison, Kelly; Hodas, Natasha; Ökaynak, Halûk

    2013-01-01

    Central-site monitors do not account for factors such as outdoor-to-indoor transport and human activity patterns that influence personal exposures to ambient fine-particulate matter (PM(2.5)). We describe and compare different ambient PM(2.5) exposure estimation approaches that incorporate human activity patterns and time-resolved location-specific particle penetration and persistence indoors. Four approaches were used to estimate exposures to ambient PM(2.5) for application to the New Jersey Triggering of Myocardial Infarction Study. These include: Tier 1, central-site PM(2.5) mass; Tier 2A, the Stochastic Human Exposure and Dose Simulation (SHEDS) model using literature-based air exchange rates (AERs); Tier 2B, the Lawrence Berkeley National Laboratory (LBNL) Aerosol Penetration and Persistence (APP) and Infiltration models; and Tier 3, the SHEDS model where AERs were estimated using the LBNL Infiltration model. Mean exposure estimates from Tier 2A, 2B, and 3 exposure modeling approaches were lower than Tier 1 central-site PM(2.5) mass. Tier 2A estimates differed by season but not across the seven monitoring areas. Tier 2B and 3 geographical patterns appeared to be driven by AERs, while seasonal patterns appeared to be due to variations in PM composition and time activity patterns. These model results demonstrate heterogeneity in exposures that are not captured by the central-site monitor. PMID:23321856

  3. Field study of the composition of greywater and comparison of microbiological indicators of water quality in on-site systems.

    PubMed

    Leonard, Margaret; Gilpin, Brent; Robson, Beth; Wall, Katrina

    2016-08-01

    Thirty on-site greywater systems were sampled to determine greywater characteristics and practices in the field. Kitchen greywater was present at eight sites and urine was included at seven sites. These non-traditional sources resulted in significantly higher concentrations of enterococci and 5-day biochemical oxygen demand (BOD5) in greywater. Even with the removal of these sources, the concentrations of microbial indicators indicated high levels of contamination could occur across all greywater sources, including "light" greywater. Using multiple microbial indicators showed that all samples had the potential for faecal contamination. Bacteroidales markers were confirmed in treated greywater and in each greywater source, highlighting the potential for human faecal contamination. Although Escherichia coli was absent in treated greywater recycled to the house, other microbial indicators were present; hence, caution is required in using E. coli concentrations as the sole indicator of microbiological water quality. High BOD5 or total suspended solid concentrations exceeded the levels recommended for effective disinfection. Subsurface irrigation, which is assumed to provide a five-log reduction in exposure, is a suitable reuse option for non-disinfected greywater. Only half the occupants had a good understanding of their greywater systems and 25 % of systems were poorly maintained. Elevated microbial indicator contamination of greywater sludge is a potential hazard during maintenance. PMID:27435622

  4. Study on the chemical composition features of Longquan celadon excavated from the Chuzhou site of Huai'an City in Jiangsu Province by EDXRF

    NASA Astrophysics Data System (ADS)

    Li, Li; Feng, Song-Lin; Feng, Xiang-Qian; Xu, Qing; Yan, Ling-Tong; Ma, Bo; Huo, Hua

    2011-07-01

    A mass of Longquan celadon shards were excavated from the Chuzhou site of Huai'an City in Jiangsu Province, China. These celadon shards were fired during the period of the Late Yuan Dynasty to the Tianshun era of the Ming Dynasty, as identified by archaeologists at Nanjing Museum. In order to research the chemical composition features of this ancient celadon porcelain, energy dispersive X-ray fluorescence (EDXRF) for non-destructive analysis was used to determine the chemical composition of the porcelain body and glaze in these shards. The results indicate that Ti and Fe in the body of Longquan celadon are characteristic elements which can distinguish porcelain produced during the Late Yuan Dynasty from those produced in the Ming Dynasties. The results of the principal component analysis (PCA) show that different body and glaze raw materials were used for the production of porcelain in different periods and the raw materials of the body and glaze are also different for various vessel shapes. The chemical compositions in the porcelain body of civilian ware are slightly different. The imperial and civilian Longquan celadon porcelains produced during the Hongwu era to the Tianshun era of the Ming Dynasty are distinguishable by the MnO, Fe2O3, Rb2O and SrO content in their porcelain glaze.

  5. The effects of crushing speed on the energy-absorption capability of composite tubes

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1991-01-01

    The energy-absorption capability as a function of crushing speed was determined for Thornel 300-Fiberite 934 (Gr-E) and Kevlar-49-Fiberite 934 (K-E) composite material. Circular cross section tube specimens were crushed at speeds ranging from 0.01 to 12 m/sec. Ply orientations of the tube specimens were (0/ +/- theta)2 and (+/- theta)2 where theta = 15, 45, and 75 deg. Based upon the results of these tests, the energy-absorption capability of Gr-E and K-E was determined to be a function of crushing speed. The magnitude of the effects of crushing speed on energy-absorption capability was determined to be a function of the mechanisms that control the crushing process. The effects of crushing speed on the energy-absorption capability is related to whether the mechanical response of the crushing mechanism that controls the crushing process is a function of strain rate. Energy-absorption capability of Gr-E and K-E tubes ranged between 0 and 35 percent and 20 and 45 percent, respectively, depending upon ply orientation.

  6. Sampling errors associated with soil composites used to estimate mean Ra-226 concentrations at an UMTRA remedial-action site

    SciTech Connect

    Gilbert, R.O.; Baker, K.R.; Nelson, R.A.; Miller, R.H.; Miller, M.L.

    1987-07-01

    The decision whether to take additional remedial action (removal of soil) from regions contaminated by uranium mill tailings involves collecting 20 plugs of soil from each 10-m by 10-m plot in the region and analyzing a 500-g portion of the mixed soil for /sup 226/Ra. A soil sampling study was conducted in the windblown mill-tailings flood plain area at Shiprock, New Mexico, to evaluate whether reducing the number of soil plugs to 9 would have any appreciable impact on remedial-action decisions. The results of the Shiprock study are described and used in this paper to develop a simple model of the standard deviation of /sup 226/Ra measurements on composite samples formed from 21 or fewer plugs. This model is used to predict as a function of the number of soil plugs per composite, the percent accuracy with which the mean /sup 226/Ra concentration in surface soil can be estimated, and the probability of making incorrect remedial action decisions on the basis of statistical tests. 8 refs., 15 figs., 9 tabs.

  7. Springtime carbon emission episodes at the Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    NASA Astrophysics Data System (ADS)

    Jung, J.; Kawamura, K.

    2011-11-01

    In order to investigate the emission of carbonaceous aerosols at the Gosan background super-site (33.17° N, 126.10° E) in East Asia, total suspended particles (TSP) were collected during spring of 2007 and 2008 and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during pollen emission episodes (range: -26.2‰ to -23.5‰, avg. -25.2 ± 0.9‰), approaching those of the airborne pollen (-28.0‰) collected at the Gosan site. Based on a carbon isotope mass balance equation, we found that ~42% of TC in the TSP samples during the pollen episodes was attributed to airborne pollen from Japanese cedar trees planted around tangerine farms in Jeju Island. A negative correlation between the citric acid-carbon/TC ratios and δ13CTC was obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollen and then transported to the Gosan site. Thermal evolution patterns of organic carbon during the pollen episodes were characterized by high OC evolution in the OC2 temperature step (450 °C). Since thermal evolution patterns of organic aerosols are highly influenced by their molecular weight, they can be used as additional information on the formation of secondary organic aerosols and the effect of aging of organic aerosols during the long-range atmospheric transport and sources of organic aerosols.

  8. Springtime carbon episodes at Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    NASA Astrophysics Data System (ADS)

    Jung, J.; Kawamura, K.

    2011-05-01

    In order to investigate the carbon episodes at Gosan background super-site (33.17° N, 126.10° E) in East Asia during spring of 2007 and 2008, total suspended particles (TSP) were collected and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The carbon episodes at the Gosan site were categorized as long-range transported anthropogenic pollutant (LTP) from Asian continent, Asian dust (AD) accompanying with LTP, and local pollen episodes. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during the pollen episodes (range: -26.2 ‰ to -23.5 ‰, avg.: -25.2 ± 0.9 ‰), followed by the LTP episodes (range: -23.5 ‰ to -23.0 ‰, avg.: -23.3 ± 0.3 ‰) and the AD episodes (range: -23.3 to -20.4 %, avg.: -21.8 ± 2.0 ‰). The δ13CTC of the airborne pollens (-28.0 ‰) collected at the Gosan site showed value similar to that of tangerine fruit (-28.1 ‰) produced from Jeju Island. Based on the carbon isotope mass balance equation and the TN and TC regression approach, we found that ∼40-45 % of TC in the TSP samples during the pollen episodes was attributed to airborne pollens from Japanese cedar trees planted around tangerine farms in Jeju Island. The δ13C of citric acid in the airborne pollens (-26.3 ‰) collected at the Gosan site was similar to that in tangerine fruit (-27.4 ‰). The negative correlation between the citric acid-carbon/TC ratios and δ13CTC were obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollens and then transported to the Gosan site. Based on the thermal evolution pattern of organic aerosols during the carbon episodes, we found that organic aerosols originated from East China are more volatile on heating and are more likely to form pyrolized organic carbon than the pollen-enriched organic aerosols and organic

  9. Chemical composition, sources and evolution processes of aerosol at an urban site in Yangtze River Delta, China during wintertime

    NASA Astrophysics Data System (ADS)

    Zhang, Yunjiang; Tang, Lili; Yu, Hongxia; Wang, Zhuang; Sun, Yele; Qin, Wei; Chen, Wentai; Chen, Changhong; Ding, Aijun; Wu, Jing; Ge, Shun; Chen, Cheng; Zhou, Hong-cang

    2015-12-01

    To investigate the composition, sources and evolution processes of submicron aerosol during wintertime, a field experiment was conducted during December 1-31, 2013 in urban Nanjing, a megacity in Yangtze River Delta of China. Non-refractory submicron aerosol (NR-PM1) species were measured with an Aerodyne Aerosol Chemical Speciation Monitor. NR-PM1 is dominated by secondary inorganic aerosol (55%) and organic aerosol (OA, 42%) during haze periods. Six OA components were identified by positive matrix factorization of the OA mass spectra. The hydrocarbon-like OA and cooking-related OA represent the local traffic and cooking sources, respectively. A highly oxidized factor related to biomass burning OA accounted for 15% of the total OA mass during haze periods. Three types of oxygenated OA (OOA), i.e., a less-oxidized OOA (LO-OOA), a more-oxidized OOA (MO-OOA), and a low-volatility OOA (LV-OOA), were identified. LO-OOA is likely associated with fresh urban secondary OA. MO-OOA likely represents photochemical products showing a similar diurnal cycle to nitrate with a pronounced noon peak. LV-OOA appears to be a more oxidized factor with a pronounced noon peak. The OA composition is dominated by secondary species, especially during haze events. LO-OOA, MO-OOA and LV-OOA on average account for 11%, (18%), 24% (21%) and 23% (18%) of the total OA mass for the haze (clean) periods respectively. Analysis of meteorological influence suggested that regional transport from the northern and southeastern areas of the city is responsible for large secondary and low-volatility aerosol formation.

  10. Chemical Composition, Seasonal Variation and Size distribution of Atmospheric Aerosols at an Alpine Site in Guanzhong Plain, China

    NASA Astrophysics Data System (ADS)

    Li, J.

    2015-12-01

    PM10 and size-segregated aerosol samples were collected at Mt. Hua (2065 a.s.m) in central China, and determined for carbonaceous fraction, ions and organic composition. The concentration of most chemical compositions in summer are lower than those in winter, due to decreased emissions of biomass and coal burning for house heating. High temperature and relative humidity (RH) conditions are favorable for secondary aerosol formation, resulting in higher concentrations of SO42- and NH4+ in summer. Non-dehydrated sugars are increased in summer because of the enhanced metabolism. Carbon preference index results indicate that n-alkanes at Mt. Hua are derived mostly by plant wax. Low Benzo(a)pyrene/Benzo(a)pyrene ratios indicate that mountain aerosols are more aged. Concentrations of biogenic (BSOA, the isoprene/pinene/caryophyllene oxidation products) and anthropogenic (ASOA, mainly aromatic acids) SOA positively correlated with temperature . However, a decreasing trend of BSOA concentration with an increase in RH was observed during the sampling period, although a clear trend between ASOA and RH was not found. Based on the AIM Model calculation, we found that during the sampling period an increase in RH resulted in a decrease in the aerosol acidity and thus reduced the effect of acid-catalysis on BSOA formation. Size distributions of K+ and NH4+ present as an accumulation mode, in contrast to Ca2+ and Mg2+, which are mainly existed in coarse particles. SO42- and NO3- show a bimodal pattern. Dehydrated sugars, fossil fuel derived n-alkanes and PAHs presented unimode size distribution, whereas non-dehydrated sugars and plant wax derived n-alkanes showed bimodal pattern. Most of the determined BSOA are formed in the aerosol phase and enriched in the fine mode except for cis-pinonic acid, which is formed in the gas phase and subsequently partitioned into aerosol phase and thus presents a bimodal pattern with a major peak in the coarse mode.

  11. Geochemical Analyses of Surface and Shallow Gas Flux and Composition Over a Proposed Carbon Sequestration Site in Eastern Kentucky

    SciTech Connect

    Thomas Parris; Michael Solis; Kathryn Takacs

    2009-12-31

    Using soil gas chemistry to detect leakage from underground reservoirs (i.e. microseepage) requires that the natural range of soil gas flux and chemistry be fully characterized. To meet this need, soil gas flux (CO{sub 2}, CH{sub 4}) and the bulk (CO{sub 2}, CH{sub 4}) and isotopic chemistry ({delta}{sup 13}C-CO2) of shallow soil gases (<1 m, 3.3 ft) were measured at 25 locations distributed among two active oil and gas fields, an active strip mine, and a relatively undisturbed research forest in eastern Kentucky. The measurements apportion the biologic, atmospheric, and geologic influences on soil gas composition under varying degrees of human surface disturbance. The measurements also highlight potential challenges in using soil gas chemistry as a monitoring tool where the surface cover consists of reclaimed mine land or is underlain by shallow coals. For example, enrichment of ({delta}{sup 13}C-CO2) and high CH{sub 4} concentrations in soils have been historically used as indicators of microseepage, but in the reclaimed mine lands similar soil chemistry characteristics likely result from dissolution of carbonate cement in siliciclastic clasts having {delta}{sup 13}C values close to 0{per_thousand} and degassing of coal fragments. The gases accumulate in the reclaimed mine land soils because intense compaction reduces soil permeability, thereby impeding equilibration with the atmosphere. Consequently, the reclaimed mine lands provide a false microseepage anomaly. Further potential challenges arise from low permeability zones associated with compacted soils in reclaimed mine lands and shallow coals in undisturbed areas that might impede upward gas migration. To investigate the effect of these materials on gas migration and composition, four 10 m (33 ft) deep monitoring wells were drilled in reclaimed mine material and in undisturbed soils with and without coals. The wells, configured with sampling zones at discrete intervals, show the persistence of some of the

  12. Site-Selective Modification of Cellulose Nanocrystals with Isophorone Diisocyanate and Formation of Polyurethane-CNC Composites.

    PubMed

    Girouard, Natalie M; Xu, Shanhong; Schueneman, Gregory T; Shofner, Meisha L; Meredith, J Carson

    2016-01-20

    The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified cellulose nanocrystals (CNCs) with both urethane and isocyanate functionality. The chemical functionality of the modified CNCs was verified with ATR-FTIR analysis and elemental analysis. The selectivity for the secondary isocyanate group using dibutyl tin dilaurate (DBTDL) as the reaction catalyst was confirmed with (13)C NMR. The modified CNCs showed improvements in the onset of thermal degradation by 35 °C compared to the unmodified CNCs. Polyurethane composites based on IPDI and a trifunctional polyether alcohol were synthesized using unmodified (um-CNC) and modified CNCs (m-CNC). The degree of nanoparticle dispersion was qualitatively assessed with polarized optical microscopy. It was found that the modification step facilitated superior nanoparticle dispersion compared to the um-CNCs, which resulted in increases in the tensile strength and work of fracture of over 200% compared to the neat matrix without degradation of elongation at break. PMID:26713564

  13. Depth, soil type, water table, and site effects on microbial community composition in sediments of pesticide-contaminated aquifer.

    PubMed

    Mattsson, Marja K; Liu, Xinxin; Yu, Dan; Kontro, Merja H

    2015-07-01

    Microbial community compositions in pesticide-contaminated aquifers have not been studied, although such information is important for remediation and maintaining freshwater sources clean under changing climate. Therefore, phospholipid (PLFAs), glycolipid (GLFAs), and neutral lipid (NLFAs) fatty acids were determined from sand and clay sediments at depths of 0.3-24.8 m, all contaminated with triazines and dichlobenil/2,6-dichlorobenzamide. The portion of fungi and Gram-negative bacteria at 0.3 m was greater than at 0.8 m, where the percentage of Gram-positive bacteria, actinobacteria, and sulfate-reducing bacteria (SRB) increased. In deeper sediments, microbial biomass, activity, and diversity decreased. Clay sediments seemed to serve as a reservoir for slow pesticide elution to groundwater, and their biomarker portion for all bacteria except actinobacteria was greater than in sand sediments. The slow pesticide dissipation seemed to occur in the main groundwater flow zone, resulting in nitrogen release simultaneously with organic matter elution from gardening and bank filtration. As a result, microbial biomass, activity, and diversity were increased. This shift in conditions towards that in surface soil may be appropriate for enhanced natural attenuation of pesticides in groundwater sources. PMID:25703619

  14. Pore-lining composition and capillary breakthrough pressure of mudstone caprocks : sealing efficiency of geologic CO2 storage sites.

    SciTech Connect

    Petrusak, Robin; Heath, Jason E.; McPherson, Brian J. O. L.; Dewers, Thomas A.; Kotula, Paul Gabriel

    2010-08-01

    Subsurface containment of CO2 is predicated on effective caprock sealing. Many previous studies have relied on macroscopic measurements of capillary breakthrough pressure and other petrophysical properties without direct examination of solid phases that line pore networks and directly contact fluids. However, pore-lining phases strongly contribute to sealing behavior through interfacial interactions among CO2, brine, and the mineral or non-mineral phases. Our high resolution (i.e., sub-micron) examination of the composition of pore-lining phases of several continental and marine mudstones indicates that sealing efficiency (i.e., breakthrough pressure) is governed by pore shapes and pore-lining phases that are not identifiable except through direct characterization of pores. Bulk X-ray diffraction data does not indicate which phases line the pores and may be especially lacking for mudstones with organic material. Organics can line pores and may represent once-mobile phases that modify the wettability of an originally clay-lined pore network. For shallow formations (i.e., < {approx}800 m depth), interfacial tension and contact angles result in breakthrough pressures that may be as high as those needed to fracture the rock - thus, in the absence of fractures, capillary sealing efficiency is indicated. Deeper seals have poorer capillary sealing if mica-like wetting dominates the wettability.

  15. Pore-lining composition and capillary breakthrough pressure of mudstone caprocks : sealing efficiency at geologic CO2 storage sites.

    SciTech Connect

    Heath, Jason E.; Nemer, Martin B.; McPherson, Brian J. O. L.; Dewers, Thomas A.; Kotula, Paul Gabriel

    2010-12-01

    Subsurface containment of CO2 is predicated on effective caprock sealing. Many previous studies have relied on macroscopic measurements of capillary breakthrough pressure and other petrophysical properties without direct examination of solid phases that line pore networks and directly contact fluids. However, pore-lining phases strongly contribute to sealing behavior through interfacial interactions among CO2, brine, and the mineral or non-mineral phases. Our high resolution (i.e., sub-micron) examination of the composition of pore-lining phases of several continental and marine mudstones indicates that sealing efficiency (i.e., breakthrough pressure) is governed by pore shapes and pore-lining phases that are not identifiable except through direct characterization of pores. Bulk X-ray diffraction data does not indicate which phases line the pores and may be especially lacking for mudstones with organic material. Organics can line pores and may represent once-mobile phases that modify the wettability of an originally clay-lined pore network. For shallow formations (i.e., < {approx}800 m depth), interfacial tension and contact angles result in breakthrough pressures that may be as high as those needed to fracture the rock - thus, in the absence of fractures, capillary sealing efficiency is indicated. Deeper seals have poorer capillary sealing if mica-like wetting dominates the wettability. We thank the U.S. Department of Energy's National Energy Technology Laboratory and the Office of Basic Energy Sciences, and the Southeast and Southwest Carbon Sequestration Partnerships for supporting this work.

  16. In vitro toxicity of particulate matter (PM) collected at different sites in the Netherlands is associated with PM composition, size fraction and oxidative potential - the RAPTES project

    PubMed Central

    2011-01-01

    Background Ambient particulate matter (PM) exposure is associated with respiratory and cardiovascular morbidity and mortality. To what extent such effects are different for PM obtained from different sources or locations is still unclear. This study investigated the in vitro toxicity of ambient PM collected at different sites in the Netherlands in relation to PM composition and oxidative potential. Method PM was sampled at eight sites: three traffic sites, an underground train station, as well as a harbor, farm, steelworks, and urban background location. Coarse (2.5-10 μm), fine (< 2.5 μm) and quasi ultrafine PM (qUF; < 0.18 μm) were sampled at each site. Murine macrophages (RAW 264.7 cells) were exposed to increasing concentrations of PM from these sites (6.25-12.5-25-50-100 μg/ml; corresponding to 3.68-58.8 μg/cm2). Following overnight incubation, MTT-reduction activity (a measure of metabolic activity) and the release of pro-inflammatory markers (Tumor Necrosis Factor-alpha, TNF-α; Interleukin-6, IL-6; Macrophage Inflammatory Protein-2, MIP-2) were measured. The oxidative potential and the endotoxin content of each PM sample were determined in a DTT- and LAL-assay respectively. Multiple linear regression was used to assess the relationship between the cellular responses and PM characteristics: concentration, site, size fraction, oxidative potential and endotoxin content. Results Most PM samples induced a concentration-dependent decrease in MTT-reduction activity and an increase in pro-inflammatory markers with the exception of the urban background and stop & go traffic samples. Fine and qUF samples of traffic locations, characterized by a high concentration of elemental and organic carbon, induced the highest pro-inflammatory activity. The pro-inflammatory response to coarse samples was associated with the endotoxin level, which was found to increase dramatically during a three-day sample concentration procedure in the laboratory. The underground samples

  17. Influence of substrate tectonic heritage on the evolution of composite volcanoes: Predicting sites of flank eruption, lateral collapse, and erosion

    NASA Astrophysics Data System (ADS)

    Tibaldi, Alessandro; Corazzato, Claudia; Kozhurin, Andrey; Lagmay, Alfredo F. M.; Pasquarè, Federico A.; Ponomareva, Vera V.; Rust, Derek; Tormey, Daniel; Vezzoli, Luigina

    2008-04-01

    This paper aims to aid understanding of the complicated interplay between construction and destruction of volcanoes, with an emphasis on the role of substrate tectonic heritage in controlling magma conduit geometry, lateral collapse, landslides, and preferential erosion pathways. The influence of basement structure on the development of six composite volcanoes located in different geodynamic/geological environments is described: Stromboli (Italy), in an island arc extensional tectonic setting, Ollagüe (Bolivia-Chile) in a cordilleran extensional setting, Kizimen (Russia) in a transtensional setting, Pinatubo (Philippines) in a transcurrent setting, Planchon (Chile) in a compressional cordilleran setting, and Mt. Etna (Italy) in a complex tectonic boundary setting. Analogue and numerical modelling results are used to enhance understanding of processes exemplified by these volcanic centres. We provide a comprehensive overview of this topic by considering a great deal of relevant, recently published studies and combine these with the presentation of new results, in order to contribute to the discussion on substrate tectonics and its control on volcano evolution. The results show that magma conduits in volcanic rift zones can be geometrically controlled by the regional tectonic stress field. Rift zones produce a lateral magma push that controls the direction of lateral collapse and can also trigger collapse. Once lateral collapse occurs, the resulting debuttressing produces a reorganization of the shallow-level magma migration pathways towards the collapse depression. Subsequent landslides and erosion tend to localize along rift zones. If a zone of weakness underlies a volcano, long-term creep can occur, deforming a large sector of the cone. This deformation can trigger landslides that propagate along the destabilized flank axis. In the absence of a rift zone, normal and transcurrent faults propagating from the substrate through the volcano can induce flank

  18. A study of summer and winter highly time-resolved submicron aerosol composition measured at a suburban site in Prague

    NASA Astrophysics Data System (ADS)

    Kubelová, Lucie; Vodička, Petr; Schwarz, Jaroslav; Cusack, Michael; Makeš, Otakar; Ondráček, Jakub; Ždímal, Vladimír

    2015-10-01

    The variability of aerosol chemical composition and the impact of the origin of respective air masses were studied in high time resolution for selected periods of high and low levels of aerosol burden at a suburban station in Prague-Suchdol, Czech Republic in summer and winter. Ambient aerosol measurements were performed using the compact-Time of Flight-Aerosol Mass Spectrometer (c-ToF-AMS) and variations in concentration of the main species are discussed. The average mass concentrations for the main species were (summer; winter): organic matter (4.2 μg/m3; 8.4 μg/m3), SO42- (2.0 μg/m3; 4.4 μg/m3), NH4+ (1.2 μg/m3; 2.8 μg/m3), NO3- (0.8 μg/m3; 5.4 μg/m3) and Cl- (0.1 μg/m3; 0.23 μg/m3). We found an inverse relationship between non-refractory submicron particulate matter (NR-PM1) levels and the boundary layer height, mainly in winter. Furthermore, levels of pollution were influenced by the air mass origin, where cleaner maritime air masses resulted in lower aerosol levels compared to those of continental origin. Analysis of the diurnal variation of NR-PM1 showed minimum concentrations in the afternoon caused by dilution as a result of an increase in the boundary layer height. Most maximum concentrations of the main species occurred in the morning or night except sulphate which had a midday maximum, probably due to downdraft from upper boundary layer air and photochemical formation in the afternoon.

  19. Strong Lithium Polysulfide Chemisorption on Electroactive Sites of Nitrogen-Doped Carbon Composites For High-Performance Lithium-Sulfur Battery Cathodes

    SciTech Connect

    Song, Jiangxuan; Gordin, Mikhail L.; Xu, Terrence; Chen, Shuru; Yu, Zhaoxin; Sohn, Hiesang; Lu, Jun; Ren, Yang; Duan, Yuhua; Wang, Donghai

    2015-03-27

    Despite the high theoretical capacity of lithium–sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAhg-1after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca.6 mAhcm-2) with a high sulfur loading of approximately 5 mgcm-2, which is ideal for practical applications of the lithium–sulfur batteries.

  20. Chemical composition and thermal stability of GaAs oxides grown by AFM anodic oxidation for site-controlled growth of InAs quantum dots

    NASA Astrophysics Data System (ADS)

    Cha, K. M.; Shibata, K.; Horiuchi, I.; Kamiko, M.; Yamamoto, R.; Hirakawa, K.

    2011-12-01

    We have fabricated GaAs oxides by using atomic force microscope (AFM)-assisted anodic oxidation at various bias voltages, Vox, and studied their chemical compositions and thermal stabilities. The oxides grown at bias voltages less than 30 V desorbed after standard thermal cleaning in molecular beam epitaxy, while the oxide patterns fabricated at Vox≥40 V survived on the surface. We have further investigated the chemical composition of the oxides by X-ray photoemission spectroscopy. It has been found that the AFM oxides grown at Vox˜10 V predominantly consist of Ga2O and GaO, whereas those grown at Vox˜50 V contain a Ga2O3-component. This result indicates that the better thermal stability of AFM oxides grown at Vox≥40 V can be attributed to the formation of Ga2O3. We grew a GaAs buffer layer on the oxide nanomasks and obtained nanoholes. After supplying InAs, selective dot nucleation took place in the nanoholes, resulting in successful formation of site-controlled QDs.

  1. Strong Lithium Polysulfide Chemisorption on Electroactive Sites of Nitrogen-Doped Carbon Composites For High-Performance Lithium–Sulfur Battery Cathodes

    SciTech Connect

    Song, Jiangxuan; Gordin, Mikhail; Xu, Terrence; Chen, Shuru; Yu, Zhaoxin; Sohn, Hiesang; Lu, Jun; Ren, Yang; Duan, Yuhua; wang, Donghai

    2015-03-27

    Despite the high theoretical capacity of lithium–sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAh g-1 after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca. 6 mAh cm-2) with a high sulfur loading of approximately 5 mg cm-2, which is ideal for practical applications of the lithium–sulfur batteries.

  2. Changes in the Cytoplasmic Composition of Amino Acids and Proteins Observed in Staphylococcus aureus during Growth under Variable Growth Conditions Representative of the Human Wound Site

    PubMed Central

    Alreshidi, Mousa M.; Dunstan, R. Hugh; Gottfries, Johan; Macdonald, Margaret M.; Crompton, Marcus J.; Ang, Ching-Seng; Williamson, Nicholas A.; Roberts, Tim K.

    2016-01-01

    Staphylococcus aureus is an opportunistic pathogen responsible for a high proportion of nosocomial infections. This study was conducted to assess the bacterial responses in the cytoplasmic composition of amino acids and ribosomal proteins under various environmental conditions designed to mimic those on the human skin or within a wound site: pH6-8, temperature 35–37°C, and additional 0–5% NaCl. It was found that each set of environmental conditions elicited substantial adjustments in cytoplasmic levels of glutamic acid, aspartic acid, proline, alanine and glycine (P< 0.05). These alterations generated characteristic amino acid profiles assessed by principle component analysis (PCA). Substantial alterations in cytoplasmic amino acid and protein composition occurred during growth under conditions of higher salinity stress implemented via additional levels of NaCl in the growth medium. The cells responded to additional NaCl at pH 6 by reducing levels of ribosomal proteins, whereas at pH 8 there was an upregulation of ribosomal proteins compared with the reference control. The levels of two ribosomal proteins, L32 and S19, remained constant across all experimental conditions. The data supported the hypothesis that the bacterium was continually responding to the dynamic environment by modifying the proteome and optimising metabolic homeostasis. PMID:27442022

  3. Strong lithium polysulfide chemisorption on electroactive sites of nitrogen-doped carbon composites for high-performance lithium-sulfur battery cathodes.

    PubMed

    Song, Jiangxuan; Gordin, Mikhail L; Xu, Terrence; Chen, Shuru; Yu, Zhaoxin; Sohn, Hiesang; Lu, Jun; Ren, Yang; Duan, Yuhua; Wang, Donghai

    2015-03-27

    Despite the high theoretical capacity of lithium-sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAh g(-1) after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca. 6 mAh cm(-2)) with a high sulfur loading of approximately 5 mg cm(-2), which is ideal for practical applications of the lithium-sulfur batteries. PMID:25663183

  4. Species composition of by-catch from milkfish (Chanos chanos) fry fishery in selected sites in the Philippines as determined by DNA barcodes.

    PubMed

    Asis, Angelli Marie Jacynth M; Destura, Irma; Santos, Mudjekeewis D

    2016-05-01

    Milkfish fry fishery, an important industry in the Philippines, uses non-selective fishing gears and push nets in coastal areas which lead to the capture of other non-targeted juvenile aquatic species. Unfortunately, information on the amount and the identity of by-catch species is lacking thus the extent of impact of the fry fishery is not known. In this study, the species composition of milkfish fry fishery by-catch sampled from selected coastal areas that are known to be fry collection sites in the country were identified and assessed through the use of DNA barcoding. Analyses revealed that by-catch fish species of the milkfish fry industry included Black Tiger shrimp (Peneaus monodon), Tarpon (Megalops cyprinoides), Glass perchlets (Ambasis gymnocephalus and Ambasis buruensis), Ladyfish (Elops hawaiensis), Snapper (Lutjanus fulviflamma), Cardinal fishes (Apogon hyalosoma and Sphaeramia orbicularis), Whipfin siver biddy (Gerres filamentosus), Mullet (Liza sp.), Anchovy (Encrasicholina heteroloba), and Tiger perch (Terapon jarbua), almost all of which are potential marketable food fish and culture species. The results of the study provide preliminary information, as well as awareness, on the species composition of milkfish fry by-catch. PMID:25329278

  5. Outdoor and indoor aerosol size, number, mass and compositional dynamics at an urban background site during warm season

    NASA Astrophysics Data System (ADS)

    Talbot, N.; Kubelova, L.; Makes, O.; Cusack, M.; Ondracek, J.; Vodička, P.; Schwarz, J.; Zdimal, V.

    2016-04-01

    This paper describes the use of a unique valve switching system that allowed for high temporal resolution indoor and outdoor data to be collected concurrently from online C-ToF-AMS, SMPS and OC/EC, and offline BLPI measurements. The results reveal near real-time dynamic aerosol behaviour along a migration path from an outdoor to indoor environment. An outdoor reduction in NR-PM1 mass concentration occurred daily from AM (06:00-12:00) to PM (12:00-18:00). SO4 (26%-37%) [AM/PM] increased proportionally during afternoons at the expense of NO3 (18%-7%). The influences of mixing height, temperature and solar radiation were considered against the mean mass concentration loss for each species. Losses were then calculated according to species via a basic input/output model. NO3 lost the most mass during afternoon periods, which we attribute to the accelerated dissociation of NH4NO3 through increasing temperature and decreasing relative humidity. Indoor/outdoor (I/O) ratios varied from 0.46 for <40 nm to 0.65 for >100 nm. These ratios were calculated using average SMPS PNC measurements over the full campaign and corroborated using a novel technique of calculating I/O penetration ratios through the indoor migration of particles during a new particle formation event. This ratio was then used to observe changes in indoor composition relative to those outdoors. Indoor sampling was carried out in an undisturbed room with no known sources. Indoor concentrations were found to be proportional to those outdoors, with organic matter [2.7 μg/m3] and SO4 [1.7 μg/m3] being the most prominent species. These results are indicative of fairly rapid aerosol penetration, a source-free indoor environment and small afternoon I/O temperature gradients. Fine fraction NO3 was observed indoors in both real-time AMS PM1 and off-line BLPI measurements. Greater mass concentration losses were observed from filter measurements, highlighting an important time dependency factor when investigating semi

  6. Uranium-series disequilibrium in ground water and core composite samples from the San Juan Basin and Copper Mountain research sites

    SciTech Connect

    Osmond, J.K.; Cowart, J.B.

    1981-09-01

    The study of the patterns of /sup 238/U, /sup 234/U, and /sup 230/Th disequilibrium in two secondary uranium deposits shows that, on a 10/sup 4/ to 10/sup 5/ year time scale, considerable movement of the uranium has occurred. The deposit at the San Juan Basin Research Site is classified as a tabular ore body, and that at the Copper Mountain Research Site as a residual deposit; yet both can be recognized as having disequilibrium sectors consistent with a general model developed to explain roll-front dynamics. The disequilibrium patterns at the two deposits were studied in two ways: core composite samples, leached of their labile uranium and daughters; and ground water samples from the associated aquifer. In general, the core data and the water data are consistent. The uranium in the residual Copper Mountain deposits appears to be more mobile than does the ore of the San Juan Basin deposit. The ground water at Copper Mountain appears to be moving the uranium southward.

  7. PM chemical composition and oxidative potential of the soluble fraction of particles at two sites in the urban area of Milan, Northern Italy

    NASA Astrophysics Data System (ADS)

    Perrone, Maria Grazia; Zhou, Jun; Malandrino, Mery; Sangiorgi, Giorgia; Rizzi, Cristiana; Ferrero, Luca; Dommen, Josef; Bolzacchini, Ezio

    2016-03-01

    Recent epidemiological evidence support the hypothesis that health effects from inhalation of air particles are governed by more than just particle mass, since specific chemical components have been identified as important contributors to mortality and hospitality admissions. We studied the chemical composition and the oxidative potential (OP) of total suspended particle (TSP) samples from Milan at two sites with different traffic loads: a site in the low emission zone (LEZ) and a traffic site (TR) outside. Two a-cellular assays; dithiothreitol (OPDTT) and 2‧,7' dichlorofluorescin (OPDCFH) were used to characterize the OP of the soluble fraction of particles. TSP samples from LEZ showed significantly lower concentrations of traffic-related chemical components compared to TR. The decrease in the concentrations from TR to LEZ was maximum for EC, with a LEZ/TR ratio of 0.64 (±0.18), and a significant reduction (p < 0.01) was also observed for PAHs (LEZ/TR = 0.73 ± 0.16), elements (Mn, Cu, Zn, Cd, Pb: LEZ/TR ranged between 0.64 and 0.82), OC (LEZ/TR = 0.85 ± 0.12) and NH4+ (LEZ/TR = 0.92 ± 0.07). OP measures, expressed as OP/m3 or OP/mg, were comparable between sites both for OPDTT and OPDCFH, thus not showing any significant impact of local traffic on OP values at sites. OPDTT and OPDCFH showed contrasting seasonal and daily trends, indicating that the two a-cellular assays gave complementary information on the OP of particles in Milan. The two OP assays resulted to be sensitive to different chemical properties of PM samples. OPDTT correlated positively only with Global Radiation (Spearman's rs = 0.38, p < 0.05), which could be considered as a proxy for high concentrations of secondary oxidizing organics, while OPDCFH was related to various PM chemical species, mainly correlated with total mass (rs = 0.65; p < 0.01), elements (e.g. Zn, rs = 0.67; As, rs = 0.65; p < 0.01) and the sum of sulfate and nitrate (rs = 0.63; p < 0.01), a proxy for secondary aerosol.

  8. Water soluble aerosols and gases at a UK background site - Part 1: Controls of PM2.5 and PM10 aerosol composition

    NASA Astrophysics Data System (ADS)

    Twigg, M. M.; Di Marco, C. F.; Leeson, S.; van Dijk, N.; Jones, M. R.; Leith, I. D.; Morrison, E.; Coyle, M.; Proost, R.; Peeters, A. N. M.; Lemon, E.; Frelink, T.; Braban, C. F.; Nemitz, E.; Cape, J. N.

    2015-02-01

    There is limited availability of long-term, high temporal resolution, chemically speciated aerosol measurements, which can lead to further insight into the health and environmental impacts of particulate matter. The Monitor for AeRosols and Gases (MARGA, Applikon B.V., NL) allows characterisation of the inorganic components of PM10 and PM2.5 (NH4+, NO3-, SO42-, Cl-, Na+, K+, Ca2+, Mg2+) and inorganic reactive gases (NH3, SO2, HCl, HONO and HNO3) at hourly resolution. The following study presents 6.5 years (June 2006 to December 2012) of quasi-continuous observations of PM2.5 and PM10 using the MARGA at the UK EMEP "Supersite", Auchencorth Moss, SE Scotland. Auchencorth Moss was found to be representative of a remote European site with average total water soluble inorganic mass of PM2.5 of 3.82 μg m-3. Anthropogenically derived secondary inorganic aerosols (sum of NH4+, NO3- and nss-SO42-), were the dominating species (63%) of PM2.5. In terms of equivalent concentrations, NH4+ provided the single largest contribution to PM2.5 fraction in all seasons. Sea salt, was the main component (73%) of the PMcoarse fraction (PM10-PM2.5), though NO3- was also found to make a relatively large contribution to the measured mass (17%) as providing evidence of considerable processing of sea salt in the coarse mode. There was on occasions evidence of aerosol from combustion events being transported to the site in 2012 as high K+ concentrations (deviating from the known ratio in sea salt) coincided with increases in black carbon at the site. Pollution events in PM10 (defined as concentrations > 12 μg m-3) were on average dominated by NH4+ and NO3-, where as smaller loadings at the site tended to be dominated by sea salt. As with other Western European sites, the charge balance of the inorganic components resolved were biased towards cations, suggesting the aerosol was basic or more likely, that organic acids contributed to the charge

  9. Water soluble aerosols and gases at a UK background site - Part 1: Controls of PM2.5 and PM10 aerosol composition

    NASA Astrophysics Data System (ADS)

    Twigg, M. M.; Di Marco, C. F.; Leeson, S.; van Dijk, N.; Jones, M. R.; Leith, I. D.; Morrison, E.; Coyle, M.; Proost, R.; Peeters, A. N. M.; Lemon, E.; Frelink, T.; Braban, C. F.; Nemitz, E.; Cape, J. N.

    2015-07-01

    There is limited availability of long-term, high temporal resolution, chemically speciated aerosol measurements which can provide further insight into the health and environmental impacts of particulate matter. The Monitor for AeRosols and Gases (MARGA, Applikon B.V., NL) allows for the characterisation of the inorganic components of PM10 and PM2.5 (NH4+, NO3-, SO42-, Cl-, Na+, K+, Ca2+, Mg2+) and inorganic reactive gases (NH3, SO2, HCl, HONO and HNO3) at hourly resolution. The following study presents 6.5 years (June 2006 to December 2012) of quasi-continuous observations of PM2.5 and PM10 using the MARGA at the UK EMEP supersite, Auchencorth Moss, SE Scotland. Auchencorth Moss was found to be representative of a remote European site with average total water soluble inorganic mass of PM2.5 of 3.82 μg m-3. Anthropogenically derived secondary inorganic aerosols (sum of NH4+, NO3- and nss-SO42-) were the dominating species (63 %) of PM2.5. In terms of equivalent concentrations, NH4+ provided the single largest contribution to PM2.5 fraction in all seasons. Sea salt was the main component (73 %) of the PMcoarse fraction (PM10-PM2.5), though NO3- was also found to make a relatively large contribution to the measured mass (17 %) providing evidence of considerable processing of sea salt in the coarse mode. There was on occasions evidence of aerosol from combustion events being transported to the site in 2012 as high K+ concentrations (deviating from the known ratio in sea salt) coincided with increases in black carbon at the site. Pollution events in PM10 (defined as concentrations > 12 μg m-3) were on average dominated by NH4+ and NO3-, where smaller loadings at the site tended to be dominated by sea salt. As with other western European sites, the charge balance of the inorganic components resolved were biased towards cations, suggesting the aerosol was basic or more likely that organic acids contributed to the charge balance. This study demonstrates the UK

  10. Trends of particulate matter (PM2.5) and chemical composition at a regional background site in the Western Mediterranean over the last nine years (2002-2010)

    NASA Astrophysics Data System (ADS)

    Cusack, M.; Alastuey, A.; Pérez, N.; Pey, J.; Querol, X.

    2012-09-01

    The time variability and long term trends of PM2.5 (particulate matter of diameter < 2.5 μm) at various regional background (RB) sites across Europe are studied and interpreted in this work. Data on mean annual levels of PM2.5 measured at Montseny (MSY, North East Spain) and various RB sites in Spain and Europe are evaluated and compared, and subsequently analysed for statistically significant trends. The MSY site registered higher average PM2.5 levels than those measured at a selection of other RB sites across Spain, Portugal, Germany and Scandinavia by percentage compared to the mean of all the stations in these countries, but lower than those measured in Switzerland, Italy and Austria. Reductions in PM2.5 were observed across all stations in Spain and Europe to varying degrees (7-49%). MSY underwent a statistically significant reduction since measurements began, indicating a year-on-year gradual decrease (-3.7 μg m-3, calculated from the final year of data compared to the mean). Similar trends were observed in other RB sites across Spain (-1.9 μg m-3). Reductions recorded in PM2.5 across Europe were varied, with many experiencing gradual, year-on-year decreases (-1.8 μg m-3). These reductions have been attributed to various causes: the introduction and implementation of pollution abatement strategies in EU member states, the effect of the current economic crisis on emissions of PM2.5 and the influence of meteorology observed during the winters of 2009 and 2010. In addition, the North Atlantic Oscillation (NAO), a large scale meteorological phenomenon most prevalent during winter, was observed to influence the frequency of Saharan dust intrusions across the Iberian Peninsula. Chemical composition of PM2.5 at MSY is characterised by high levels of organic matter (OM) and sulphate, followed by crustal material, nitrate and ammonia. Sea Spray and elemental carbon (EC) comprised a minor part of the total PM2.5 mass. Statistical trend analysis was performed on the

  11. 2013 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada National Security Site, Nye County, Nevada; Review of the Performance Assessments and Composite Analyses

    SciTech Connect

    Shott, Gregory

    2014-03-01

    The Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site (National Security Technologies, LLC 2007a) requires an annual review to assess the adequacy of the performance assessments (PAs) and composite analyses (CAs), with the results submitted to the U.S. Department of Energy (DOE) Office of Environmental Management. The Disposal Authorization Statements for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) also require that such reviews be made and that secondary or minor unresolved issues be tracked and addressed as part of the maintenance plan (DOE 1999a, 2000). The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office performed an annual review of the Area 3 and Area 5 RWMS PAs and CAs for fiscal year (FY) 2013. This annual summary report presents data and conclusions from the FY 2013 review, and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R&D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the Nevada National Security Site (NNSS) relevant to the sources of residual radioactive material that are considered in the CAs, the land-use planning, and the results of the environmental monitoring and R&D activities were reviewed to determine the adequacy of the CAs. Important developments in FY 2013 include the following: • Development of a new Area 5 RWMS closure inventory estimate based on disposals through FY 2013 • Evaluation of new or revised waste streams by special analysis • Development of version 4.115 of the Area 5 RWMS GoldSim PA/CA model The Area 3 RWMS has been in inactive status since July 1, 2006, with the last shipment received in April 2006. The FY 2013 review of operations

  12. Abrasion resistance of linings in filament wound composite pipe

    SciTech Connect

    Hall, S.C.

    1999-07-01

    Fiberglass filament wound composite pipe has numerous industrial applications including transportation of petroleum and natural gas. Its corrosion resistance is well known but it can be susceptible to abrasion and erosion when it is used to transport slurries or dry gas containing sand particles. However, composite pipe can be manufactured integrally with abrasion resistant linings which protect the pipe from abrasion and erosion and increase its life. Laboratory investigations were performed to determine the effect of abrasive flows through polyurea-lined and unlined glass-reinforced epoxy (GRE) pipe, ultra-high molecular weight (UHMW) polyethylene (PE) pipe, and unlined steel pipe. Results are provided for the abrasion resistance, chemical resistance, adhesion strength, elongation, tensile strength, impact resistance and hardness of selected linings. The abrasion resistance of polyurea-lined composite pipe proved to be almost as resistant to abrasion and erosion as unlined steel pipe without the electrochemical corrosion associated with steel pipe.

  13. 2011 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada National Security Site, Nye County, Nevada: Review of the Performance Assessments and Composite Analyses

    SciTech Connect

    NSTec Environmental Management

    2012-03-20

    The Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site (National Security Technologies, LLC, 2007a) requires an annual review to assess the adequacy of the Performance Assessments (PAs) and Composite Analyses (CAs), with the results submitted annually to U.S. Department of Energy (DOE) Office of Environmental Management. The Disposal Authorization Statements for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) also require that such reviews be made and that secondary or minor unresolved issues be tracked and addressed as part of the maintenance plan (DOE, 1999a; 2000). The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office performed an annual review of the Area 3 and Area 5 RWMS PAs and CAs for fiscal year (FY) 2011. This annual summary report presents data and conclusions from the FY 2011 review, and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R and D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the Nevada National Security Site (NNSS) (formerly the Nevada Test Site) relevant to the sources of residual radioactive material that are considered in the CAs, the land-use planning, and the results of the environmental monitoring and R and D activities were reviewed to determine the adequacy of the CAs. Important developments in FY 2011 include the following: (1) Operation of a new shallow land disposal unit and a new Resource Conservation and Recovery Act (RCRA)-compliant lined disposal unit at the Area 5 RWMS; (2) Development of new closure inventory estimates based on disposals through FY 2011; (3) Evaluation of new or revised waste streams by special analysis; (4) Development of

  14. Variation of particle number size distributions and chemical compositions at the urban and downwind regional sites in the Pearl River Delta during summertime pollution episodes

    NASA Astrophysics Data System (ADS)

    Yue, D. L.; Hu, M.; Wu, Z. J.; Guo, S.; Wen, M. T.; Nowak, A.; Wehner, B.; Wiedensohler, A.; Takegawa, N.; Kondo, Y.; Wang, X. S.; Li, Y. P.; Zeng, L. M.; Zhang, Y. H.

    2010-10-01

    In order to characterize the features of particulate pollution in the Pearl River Delta (PRD) in the summer, continuous measurements of particle number size distributions and chemical compositions were simultaneously performed at Guangzhou urban site (GZ) and Back-garden downwind regional site (BG) in July 2006. Particle number concentration from 20 nm to 10 μm at BG was (1.7±0.8)×104 cm-3, about 40% lower than that at GZ, (2.9±1.1)×104 cm-3. The total particle volume concentration at BG was 94±34 μm3 cm-3, similar to that at GZ, 96±43 μm3 cm-3. More 20-100 nm particles, significantly affected by the traffic emissions, were observed at GZ, while 100-660 nm particle number concentrations were similar at both sites as they are more regional. PM2.5 values were similar at GZ (69±43 μg m-3) and BG (69±58 μg m-3) with R2 of 0.71 for the daily average PM2.5 at these two sites, indicating the fine particulate pollution in the PRD region to be regional. Two kinds of pollution episodes, the accumulation pollution episode and the regional transport pollution episode, were observed. Fine particles over 100 nm dominated both number and volume concentrations of total particles during the late periods of these pollution episodes. Accumulation and secondary transformation are the main reasons for the nighttime accumulation pollution episode. SO42-, NO3- accounted for about 60% in 100-660 nm particle mass and PM2.5 increase. When south or southeast wind prevailed in the PRD region, regional transport of pollutants took place. Regional transport contributed about 30% to fine particulate pollution at BG during a regional transport case. Secondary transformation played an important role during regional transport, causing higher increase rates of secondary ions in PM1.0 than other species and shifting the peaks of sulfate and ammonium mass size distributions to larger sizes. SO42-, NO3-, and NH4+ accounted for about 70% and 40% of PM1.0 and PM2.5, respectively.

  15. PM2.5 chemical composition at a rural background site in Central Europe, including correlation and air mass back trajectory analysis

    NASA Astrophysics Data System (ADS)

    Schwarz, Jaroslav; Cusack, Michael; Karban, Jindřich; Chalupníčková, Eva; Havránek, Vladimír; Smolík, Jiří; Ždímal, Vladimír

    2016-07-01

    PM2.5 mass concentrations and chemical compositions sampled over a 13-month period at a Central European rural background site (Košetice) are presented in this work. A comprehensive chemical analysis of PM2.5 was performed, which provided elemental composition (Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, and Pb) and the concentration of water-soluble inorganic anions (SO42 -, NO3-. Cl-, NO2-, Br-, and H2PO4-) and cations (Na+, NH4+, K+, Ca2 +, and Mg2 +), elemental and organic carbon (EC and OC), and levoglucosan. Spearman correlation coefficients between individual chemical species and particle number concentrations were calculated for the following six size ranges: 10-25 nm (N10-25), 25-50 nm (N25-50), 50-80 nm (N50-80), 80-150 nm (N80-150), 150-300 nm (N150-300), and 300-800 nm (N300-800). Average concentrations of individual species were comparable with concentrations reported from similar sites across Central Europe. Organic matter (OM) accounted for 45% of the PM2.5 mass (calculated from OC by a factor of 1.6), while the second most common component were secondary aerosols (SO42 -: 19%, NO3-: 14%, NH4+: 10%), which accounted for 43% of the mass. Based on levoglucosan analysis, 31% of OM was attributed to emissions associated with biomass burning (OMBB). EC concentrations, determined using the EUSAAR_2 thermal optical protocol, contributed 4% to PM2.5 mass. A total of 1% of the mass was attributed to a mineral matter source, while the remaining 6% was from an undetermined mass. Seasonal variations showed highest concentrations of NO3- and OMBB in winter, nitrate share in spring, and an increase in percentage of SO42 - and mineral matter in summer. The largest seasonal variation was found for species associated with wood and coal combustion (levoglucosan, K+, Zn, Pb, As), which had clear maxima during winter. Correlation analysis of different size fraction particle number concentrations was used to distinguish the influence

  16. Nuclear resonance vibrational spectroscopy reveals the FeS cluster composition and active site vibrational properties of an O2-tolerant NAD+-reducing [NiFe] hydrogenase

    DOE PAGESBeta

    Lauterbach, Lars; Wang, Hongxin; Horch, Marius; Gee, Leland B.; Yoda, Yoshitaka; Tanaka, Yoshihito; Zebger, Ingo; Lenz, Oliver; Cramer, Stephen P.

    2014-10-30

    Hydrogenases are complex metalloenzymes that catalyze the reversible splitting of molecular hydrogen into protons and electrons essentially without overpotential. The NAD+-reducing soluble hydrogenase (SH) from Ralstonia eutropha is capable of H2 conversion even in the presence of usually toxic dioxygen. The molecular details of the underlying reactions are largely unknown, mainly because of limited knowledge of the structure and function of the various metal cofactors present in the enzyme. Here, all iron-containing cofactors of the SH were investigated by 57Fe specific nuclear resonance vibrational spectroscopy (NRVS). Our data provide experimental evidence for one [2Fe2S] center and four [4Fe4S] clusters, whichmore » is consistent with the amino acid sequence composition. Only the [2Fe2S] cluster and one of the four [4Fe4S] clusters were reduced upon incubation of the SH with NADH. This finding explains the discrepancy between the large number of FeS clusters and the small amount of FeS cluster-related signals as detected by electron paramagnetic resonance spectroscopic analysis of several NAD+-reducing hydrogenases. For the first time, Fe–CO and Fe–CN modes derived from the [NiFe] active site could be distinguished by NRVS through selective 13C labeling of the CO ligand. This strategy also revealed the molecular coordinates that dominate the individual Fe–CO modes. The present approach explores the complex vibrational signature of the Fe–S clusters and the hydrogenase active site, thereby showing that NRVS represents a powerful tool for the elucidation of complex biocatalysts containing multiple cofactors.« less

  17. An Advanced Reservoir Simulator for Tracer Transport in Multicomponent Multiphase Compositional Flow and Applications to the Cranfield CO2 Sequestration Site

    NASA Astrophysics Data System (ADS)

    Moortgat, J.

    2015-12-01

    Reservoir simulators are widely used to constrain uncertainty in the petrophysical properties of subsurface formations by matching the history of injection and production data. However, such measurements may be insufficient to uniquely characterize a reservoir's properties. Monitoring of natural (isotopic) and introduced tracers is a developing technology to further interrogate the subsurface for applications such as enhanced oil recovery from conventional and unconventional resources, and CO2 sequestration. Oak Ridge National Laboratory has been piloting this tracer technology during and following CO2 injection at the Cranfield, Mississippi, CO2 sequestration test site. Two campaigns of multiple perfluorocarbon tracers were injected together with CO2 and monitored at two wells at 68 m and 112 m from the injection site. The tracer data suggest that multiple CO2 flow paths developed towards the monitoring wells, indicative of either channeling through high permeability pathways or of fingering. The results demonstrate that tracers provide an important complement to transient pressure data. Numerical modeling is essential to further explain and interpret the observations. To aid the development of tracer technology, we enhanced a compositional multiphase reservoir simulator to account for tracer transport. Our research simulator uses higher-order finite element (FE) methods that can capture the small-scale onset of fingering on the coarse grids required for field-scale modeling, and allows for unstructured grids and anisotropic heterogeneous permeability fields. Mass transfer between fluid phases and phase behavior are modeled with rigorous equation-of-state based phase-split calculations. We present our tracer simulator and preliminary results related to the Cranfield experiments. Applications to noble gas tracers in unconventional resources are presented by Darrah et al.

  18. Understanding the Composition and Distribution of Megafauna at Diffuse Flow Sites in the East Lau Basin Back-Arc Spreading Center

    NASA Astrophysics Data System (ADS)

    Podowski, L.; Fisher, C.; Luther, G.; Kim, S.; Waite, T.; Moore, T.; Zelnio, K.; Zook, B.; Telesnicki, G.; Hsu, H.; Paschal, A.; Hourdez, S.; Desbruyères, D.

    2005-12-01

    Ridge 2000 research at the Lau Basin Integrated Studies Site spans a range of scales, from hundreds of kilometers to fractions of a centimeter. Here we report on an interdisciplinary study of the relations between megafaunal distribution and diffuse flow chemistry, conducted in an area of about 30 m2. This work was enabled by, and interpretation will be nested within, the results from the three cruises that preceded our field effort. In June 2005, the remotely operated vehicle (ROV) Jason II collected a series of geo-referenced, high-resolution images using the Insite Scorpio digital still camera at the ABE vent site (176°11'29''W, 20°45'47''S) in the East Lau Basin back-arc spreading center. Twenty pictures were mosaicked together at sea, using a MatLab program (courtesy of Tim Shank, Dana Yoerger, Hanu Singh, and Vicki Ferrini of Woods Hole Oceanographic Institution) to create one seamless image of the biological community covering an area of approximately 30 m2. The mosaic was used to guide electrochemical and temperature scans during a subsequent dive to provide data on the concentrations of reactive sulfur species and oxygen, temperature, and pH at 60 different locations within the community. To allow quantification of the biomass within the imaged community and obtain data on smaller and/or cryptic fauna, five area-specific quantitative-samples of representative animal aggregations were collected from within the same area and analyzed. Separate layers for each dataset (imagery, chemistry, temperature, community composition, and biomass) are being created with GIS to visualize and analyze trends in each individual layer, such as the co-occurrence of different megafaunal species and changes in chemical speciation. Overlays and statistical analyses of these layers in GIS are used to elucidate correlations between datasets that will contribute to our ultimate goal of understanding the distribution patterns of the megafauna in this spatially and temporally

  19. Identification of protein-protein binding sites by incorporating the physicochemical properties and stationary wavelet transforms into pseudo amino acid composition.

    PubMed

    Jia, Jianhua; Liu, Zi; Xiao, Xuan; Liu, Bingxiang; Chou, Kuo-Chen

    2016-09-01

    With the explosive growth of protein sequences entering into protein data banks in the post-genomic era, it is highly demanded to develop automated methods for rapidly and effectively identifying the protein-protein binding sites (PPBSs) based on the sequence information alone. To address this problem, we proposed a predictor called iPPBS-PseAAC, in which each amino acid residue site of the proteins concerned was treated as a 15-tuple peptide segment generated by sliding a window along the protein chains with its center aligned with the target residue. The working peptide segment is further formulated by a general form of pseudo amino acid composition via the following procedures: (1) it is converted into a numerical series via the physicochemical properties of amino acids; (2) the numerical series is subsequently converted into a 20-D feature vector by means of the stationary wavelet transform technique. Formed by many individual "Random Forest" classifiers, the operation engine to run prediction is a two-layer ensemble classifier, with the 1st-layer voting out the best training data-set from many bootstrap systems and the 2nd-layer voting out the most relevant one from seven physicochemical properties. Cross-validation tests indicate that the new predictor is very promising, meaning that many important key features, which are deeply hidden in complicated protein sequences, can be extracted via the wavelets transform approach, quite consistent with the facts that many important biological functions of proteins can be elucidated with their low-frequency internal motions. The web server of iPPBS-PseAAC is accessible at http://www.jci-bioinfo.cn/iPPBS-PseAAC , by which users can easily acquire their desired results without the need to follow the complicated mathematical equations involved. PMID:26375780

  20. Offshore wind farms as productive sites or ecological traps for gadoid fishes?--impact on growth, condition index and diet composition.

    PubMed

    Reubens, Jan T; Vandendriessche, Sofie; Zenner, Annemie N; Degraer, Steven; Vincx, Magda

    2013-09-01

    With the construction of wind farms all across the North Sea, numerous artificial reefs are created. These windmill artificial reefs (WARs) harbour high abundances of fish species which can be attracted from elsewhere or can be the result of extra production induced by these wind farms. To resolve the attraction-production debate in suddenly altered ecosystems (cf. wind farms), the possible consequences of attraction should be assessed; thereby bearing in mind that ecological traps may arise. In this paper we investigated whether the wind farms in the Belgian part of the North Sea act as ecological traps for pouting and Atlantic cod. Length-at-age, condition and diet composition of fish present at the windmill artificial reefs was compared to local and regional sandy areas. Fish data from the period 2009-2012 were evaluated. Mainly I- and II-group Atlantic cod were present around the WARs; while the 0- and I-group dominated for pouting. For Atlantic cod, no differences in length were observed between sites, indicating that fitness was comparable at the WARs and in sandy areas. No significant differences in condition index were observed for pouting. At the WARs, they were slightly larger and stomach fullness was enhanced compared to the surrounding sandy areas. Also diet differed considerably among the sites. The outcome of the proxies indicate that fitness of pouting was slightly enhanced compared to the surrounding sandy areas. No evidence was obtained supporting the hypothesis that the WARs act as an ecological trap for Atlantic cod and pouting. PMID:23800713

  1. The Mg isotopic composition of marine pore fluids from ODP Site 807A (Ontong Java Plateau): Implications for the Cenozoic Mg chemistry of the ocean

    NASA Astrophysics Data System (ADS)

    Fantle, M. S.; Teng, F.

    2011-12-01

    The Mg isotopic compositions (δ26Mg, relative to DSM3) of pore fluids from ODP Leg 130, Site 807A, as measured by MC-ICP-MS, are found to be between -0.25 and -0.79% (ave: -0.55%). The shallowest pore fluid measured was sampled at 13.4 mbsf while the deepest was sampled at 738 mbsf (a time span of ~35 Ma); the total section thickness is ~1350 meters. The sedimentary section is carbonate-rich, with a hole average CaCO3 content of ~92 wt%, and overlies basaltic basement. There is a systematic decrease in δ26Mg from the top of the section (~ -0.8%) to deeper in the section (~ -0.3%) that coincides with a decrease in pore fluid Mg and an increase in pore fluid Ca concentrations. The δ26Mg values at the upper and lower boundaries of the column are consistent with the isotopic composition of laboratory seawater (-0.84 ± 0.10%) and Kilbourne Hole olivine (-0.26 ± 0.05%) standards, respectively, the latter of which is isotopically identical to fresh basalt. The most basic interpretation of the data is that the pore fluids at 807A reflect modern seawater δ26Mg at the top of the section and basement basaltic Mg at ~800 mbsf. Because the section contains ~550 meters of carbonate below the deepest pore fluid measured, this implies a strong basement influence on Mg isotopic composition well above the sediment-basement interface. That the bulk carbonate and pore fluid are out of equilibrium is an expected result, based on the large reactive length scale at 807A (~1500 m) [1-2]. Consequently, because the previously measured δ26Mg values of bulk carbonates at 807A are ~ -4 to -5%, there is long-term leverage to change the isotopic composition of carbonates over time scales of tens of millions of years if we assume that the fractionation factor during diagenesis is different from ~0.9963 (the value assumed for biogenic carbonate formed in the surface ocean). Unlike Ca isotopes, the pore fluid is not well buffered with respect to Mg over geological time scales. Therefore, if

  2. Optimization of sedimentation of tungsten on copper substrate for production of 186gRe via 186W(p,n) nuclear reaction: Feasibility of using high current, long irradiation

    NASA Astrophysics Data System (ADS)

    Kakavand, T.; Mirzaii, M.; Khaleghi, M.; Eslami, M.

    2016-01-01

    Tungsten is recognized as one of the important metals used in cyclotron targets for production of several vital radioisotopes. Adequate adhesion of the prepared targets to its substrate is a significant parameter that makes them optimized for high current beam collisions. The target morphology should be paid special attention as another important parameter. In this work, a rather thick layer of tungsten is deposited on a copper substrate by sedimentation technique to produce 186gRe radionuclide via 186W(p,n) reaction. Consecutive sedimentation experiments are carried out to determine the best suspension solution. The prepared targets are evaluated in morphology by scanning electron microscope. A mixture of 1 g tungsten powder, 250 mg ethyl cellulose and 5 mL acetone is concluded for desirable target adhesion. Irradiation of the targets by 20 μA proton current (15 MeV energy) for 5 h shows that they can withstand the proton beam.

  3. Variation of particle number size distributions and chemical compositions at the urban and downwind regional sites in the Pearl River Delta during summertime pollution episodes

    NASA Astrophysics Data System (ADS)

    Yue, D. L.; Hu, M.; Wu, Z. J.; Guo, S.; Wen, M. T.; Nowak, A.; Wehner, B.; Wiedensohler, A.; Takegawa, N.; Kondo, Y.; Wang, X. S.; Li, Y. P.; Zeng, L. M.; Zhang, Y. H.

    2010-06-01

    In order to characterize the features of particulate pollution in the Pearl River Delta (PRD) in the summer, continuous measurements of particle number size distributions and chemical compositions were simultaneously performed at Guangzhou urban site (GZ) and Back-garden downwind regional site (BG) in July 2006. Particle number concentration from 20 nm to 10 μm at BG was (1.7±0.8)×104 cm-3, about 40% lower than that at GZ, (2.9±1.1)×104 cm-3 with intensive traffic emissions. The total particle volume concentration at BG was 94±34 μm3 cm-3, similar to that at GZ, 96±43 μm3 cm-3. More 20-100 nm particles, significantly affected by the traffic emissions, were observed at GZ, while 100-660 nm particle number concentrations were similar at both sites as they are more regional. PM2.5 values were also similar at GZ (69±43 μg m-3) and BG (69±58 μg m-3), indicating the fine particulate pollution in the PRD region to be regional. Two kinds of pollution episodes, the accumulation pollution episode and the regional transport pollution episode, were observed. Fine particles over 100 nm dominated both number and volume concentrations of total particles during the late periods of these pollution episodes. Accumulation and secondary transformations are two main reasons for the nighttime accumulation pollution episode. SO4-2, NO3-, and NH4+ accounted for about 60% in 100-660 nm particle mass and PM2.5. When south or south-southeast wind prevailed in the PRD region, regional transport of pollutants takes place. Regional transport contributed about 30% to fine particulate pollution at BG during a regional transport case. Secondary transformation played an important role during regional transport, causing higher increase rates of secondary ions in PM1.0 than other species and shifting the peaks of sulfate and ammonium mass size distributions to larger sizes. SO4-2, NO3-, and NH4+ accounted for about 70% and 40% of PM1.0 and PM2.5, respectively.

  4. Reducing Uncertainty in the Distribution of Hydrogeologic Units within Volcanic Composite Units of Pahute Mesa Using High-Resolution 3-D Resistivity Methods, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Rodriguez, Brian D.; Sweetkind, Don; Burton, Bethany L.

    2010-01-01

    The U.S. Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management program and, in particular, the Underground Test Area (UGTA) project. From 1951 to 1992, 828 underground nuclear tests were conducted at the Nevada Test Site (NTS) northwest of Las Vegas (DOE UGTA, 2003). Most of these tests were conducted hundreds of feet above the groundwater table; however, more than 200 of the tests were near, or within, the water table. This underground testing was limited to specific areas of the NTS including Pahute Mesa, Rainier Mesa/Shoshone Mountain, Frenchman Flat, and Yucca Flat. Volcanic composite units make up much of the area within the Pahute Mesa Corrective Action Unit (CAU) at the NTS, Nevada. The extent of many of these volcanic composite units extends throughout and south of the primary areas of past underground testing at Pahute and Rainier Mesas. As situated, these units likely influence the rate and direction of groundwater flow and radionuclide transport. Currently, these units are poorly resolved in terms of their hydrologic properties introducing large uncertainties into current CAU-scale flow and transport models. In 2007, the U.S. Geological Survey (USGS), in cooperation with DOE and NNSA-NSO acquired three-dimensional (3-D) tensor magnetotelluric data at the NTS in Area 20 of Pahute Mesa CAU. A total of 20 magnetotelluric recording stations were established at about 600-m spacing on a 3-D array and were tied to ER20-6 well and other nearby well control (fig. 1). The purpose of this survey was to determine if closely spaced 3-D resistivity measurements can be used to characterize the distribution of shallow (600- to 1,500-m-depth range) devitrified rhyolite lava-flow aquifers (LFA) and zeolitic tuff confining units (TCU) in areas of limited drill hole control on

  5. Trends of particulate matter (PM2.5) and chemical composition at a regional background site in the Western Mediterranean over the last nine years (2002-2010)

    NASA Astrophysics Data System (ADS)

    Cusack, M.; Alastuey, A.; Pérez, N.; Pey, J.; Querol, X.

    2012-04-01

    The time variability and long term trends of PM2.5 (particulate matter of diameter <2.5 μm) at various regional background (RB) sites across Europe are studied and interpreted in this work. Long-term trends of PM2.5 concentrations are relatively scarce across Europe, with few studies outlining the changes measured in PM2.5 concentrations over a significant period of time. To this end, data on mean annual levels of PM2.5 measured at Montseny (MSY, North East Spain) and various RB sites in Spain and Europe are evaluated and compared, and subsequently analysed for statistically significant trends. The MSY site registered higher average PM2.5 levels than those measured at a selection of other RB sites across Spain, Portugal, Germany and Scandinavia, but lower than those measured in Switzerland, Italy and Austria. Reductions in PM2.5 were observed across all stations in Spain and Europe to varying degrees. MSY underwent a statistically significant reduction since measurements began, indicating a year-on-year gradual decrease (-3.7 μg m-3, calculated from the final year of data compared to the mean). Similar trends were observed in other RB sites across Spain (-1.9 μg m-3). Reductions recorded in PM2.5 across Europe were varied, with many experiencing gradual, year-on-year decreases (-1.8 μg m-3). These reductions have been attributed to various causes: the introduction and implementation of pollution abatement strategies in EU member states, the effect of the current economic crisis on emissions of PM2.5 and the influence of anomalous meteorology observed during the winters of 2009 and 2010. The North Atlantic Oscillation (NAO), a large scale meteorological phenomenon most prevalent during winter, was observed to influence the frequency of Saharan dust intrusions across the Iberian Peninsula. Chemical composition of PM2.5 at MSY is characterised by high levels of organic matter (OM) and sulphate, followed by crustal material, nitrate and ammonia. Sea Spray and

  6. 2012 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada National Security Site, Nye County, Nevada: Review of the Performance Assessments and Composite Analyses

    SciTech Connect

    Shott, G.

    2013-03-18

    The Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site (National Security Technologies, LLC 2007a) requires an annual review to assess the adequacy of the performance assessments (PAs) and composite analyses (CAs), with the results submitted to the U.S. Department of Energy (DOE) Office of Environmental Management. The Disposal Authorization Statements for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) also require that such reviews be made and that secondary or minor unresolved issues be tracked and addressed as part of the maintenance plan (DOE 1999a, 2000). The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office performed an annual review of the Area 3 and Area 5 RWMS PAs and CAs for fiscal year (FY) 2012. This annual summary report presents data and conclusions from the FY 2012 review, and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R&D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the Nevada National Security Site (NNSS) relevant to the sources of residual radioactive material that are considered in the CAs, the land-use planning, and the results of the environmental monitoring and R&D activities were reviewed to determine the adequacy of the CAs. Important developments in FY 2012 include the following: Release of a special analysis for the Area 3 RWMS assessing the continuing validity of the PA and CA; Development of a new Area 5 RWMS closure inventory estimate based on disposals through FY 2012; Evaluation of new or revised waste streams by special analysis; and Development of version 4.114 of the Area 5 RWMS GoldSim PA model. The Area 3 RWMS has been in inactive status since

  7. Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens Probe Landing Site

    USGS Publications Warehouse

    Soderblom, L.A.; Kirk, R.L.; Lunine, J.I.; Anderson, J.A.; Baines, K.H.; Barnes, J.W.; Barrett, J.M.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Cruikshank, D.P.; Elachi, C.; Janssen, M.A.; Jaumann, R.; Karkoschka, E.; Le Mouélic, Stéphane; Lopes, R.M.; Lorenz, R.D.; McCord, T.B.; Nicholson, P.D.; Radebaugh, J.; Rizk, B.; Sotin, C.; Stofan, E.R.; Sucharski, T.L.; Tomasko, M.G.; Wall, S.D.

    2007-01-01

    Titan's vast equatorial fields of RADAR-dark longitudinal dunes seen in Cassini RADAR synthetic aperture images correlate with one of two dark surface units discriminated as "brown" and "blue" in Visible and Infrared Mapping Spectrometer (VIMS) color composites of short-wavelength infrared spectral cubes (RGB as 2.0, 1.6, 1.3 ??m). In such composites bluer materials exhibit higher reflectance at 1.3 ??m and lower at 1.6 and 2.0 ??m. The dark brown unit is highly correlated with the RADAR-dark dunes. The dark brown unit shows less evidence of water ice suggesting that the saltating grains of the dunes are largely composed of hydrocarbons and/or nitriles. In general, the bright units also show less evidence of absorption due to water ice and are inferred to consist of deposits of bright fine precipitating tholin aerosol dust. Some set of chemical/mechanical processes may be converting the bright fine-grained aerosol deposits into the dark saltating hydrocarbon and/or nitrile grains. Alternatively the dark dune materials may be derived from a different type of air aerosol photochemical product than are the bright materials. In our model, both the bright aerosol and dark hydrocarbon dune deposits mantle the VIMS dark blue water ice-rich substrate. We postulate that the bright mantles are effectively invisible (transparent) in RADAR synthetic aperture radar (SAR) images leading to lack of correlation in the RADAR images with optically bright mantling units. RADAR images mostly show only dark dunes and the water ice substrate that varies in roughness, fracturing, and porosity. If the rate of deposition of bright aerosol is 0.001-0.01 ??m/yr, the surface would be coated (to optical instruments) in hundreds-to-thousands of years unless cleansing processes are active. The dark dunes must be mobile on this very short timescale to prevent the accumulation of bright coatings. Huygens landed in a region of the VIMS bright and dark blue materials and about 30 km south of the

  8. Site-specific functionalization for chemical speciation of Cr(III) and Cr(VI) using polyaniline impregnated nanocellulose composite: equilibrium, kinetic, and thermodynamic modeling

    NASA Astrophysics Data System (ADS)

    Jain, Priyanka; Varshney, Shilpa; Srivastava, Shalini

    2015-10-01

    Site-specific functionalizations are the emergent attention for the enhancement of sorption latent of heavy metals. Limited chemistry has been applied for the fabrication of diafunctionalized materials having potential to tether both environmentally stable oxidation states of chromium (Cr(III) and Cr(VI). Polyaniline impregnated nanocellulose composite (PANI-NCC) has been fabricated using click chemistry and explored for the removal of Cr(III) and Cr(VI) from hydrological environment. The structure, stability, morphology, particle size, surface area, hydrophilicity, and porosity of fabricated PANI-NCC were characterized comprehensively using analytical techniques and mathematical tools. The maximum sorption performance of PANI-NCC was procured for (Cr(III): 47.06 mg g-1; 94.12 %) and (Cr(VI): 48.92 mg g-1; 97.84 %) by equilibrating 0.5 g sorbent dose with 1000 mL of 25 mg L-1 chromium conc. at pH 6.5 and 2.5 for Cr(III) and Cr(VI), respectively. The sorption data showed a best fit to the Langmuir isotherm and pseudo-second-order kinetic model. The negative value of ∆ G° (-8.59 and -11.16 kJ mol-1) and ∆ H° (66.46 × 10-1 and 17.84 × 10-1 kJ mol-1), and positive value of ∆ S° (26.66 and 31.46 J mol-1K-1) for Cr(III) and Cr(VI), respectively, reflect the spontaneous, feasibility, and exothermic nature of the sorption process. The application of fabricated PANI-NCC for removing both the forms of chromium in the presence of other heavy metals was also tested at laboratory and industrial waste water regime. These findings open up new avenues in the row of high performance, scalable, and economic nanobiomaterial for the remediation of both forms of chromium from water streams.

  9. Size and elemental composition of dry-deposited particles during a severe dust storm at a coastal site of Eastern China.

    PubMed

    Niu, Hongya; Zhang, Daizhou; Hu, Wei; Shi, Jinhui; Li, Ruipeng; Gao, Huiwang; Pian, Wei; Hu, Min

    2016-02-01

    Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao (36.15 °N, 120.49 °E), a city located in Eastern China. The size, morphology, and elemental composition of the particles were quantified with a scanning electron microscope equipped with an energy dispersive X-ray instrument (SEM-EDX). The particles appeared in various shapes, and their size mainly varied from 0.4 to 10 μm, with the mean diameters of 0.5, 1.5, and 1.0 μm before, during, and after the dust storm, respectively. The critical size of the mineral particles settling on the surface in the current case was about 0.3-0.4 μm before the dust storm and about 0.5-0.7 μm during the dust storm. Particles that appeared in high concentration but were smaller than the critical size deposited onto the surface at a small number flux. The elements Al, Si and Mg were frequently detected in all samples, indicating the dominance of mineral particles. The frequency of Al in particles collected before the dust storm was significantly lower than for those collected during and after the dust storm. The frequencies of Cl and Fe did not show obvious changes, while those of S, K and Ca decreased after the dust arrival. These results indicate that the dust particles deposited onto the surface were less influenced by anthropogenic pollutants in terms of particle number. PMID:26969556

  10. The effects of marine sand and gravel extraction on the sediment composition and macrofaunal community of a commercial dredging site (15 years post-dredging).

    PubMed

    Waye-Barker, Georgia A; McIlwaine, Paul; Lozach, Sophie; Cooper, Keith M

    2015-10-15

    A prediction that faunal recovery of a marine aggregate extraction site subjected to high dredging intensity was likely to take 15-20 years was investigated. Samples were collected at the high dredging intensity site and two reference sites in 2011 (15 years post-dredging). Results indicated that the high site had similar sediment characteristics to the reference sites by 2011. Macrofaunal data analyses showed no difference between the values of all calculated univariate measures (abundance, number of taxa, biomass and evenness) between the high and reference sites. Multivariate analyses found that the macrofaunal community at the high site was comparable to those of the reference sites by 2011. Overall, the results supported the predicted recovery time. The findings of the study suggest that persistent physical impacts prolonged the biological recovery of the high site. PMID:26254881

  11. Differences in composition of above and below legal limit PM10 at two contrasting sites in the city of Oporto, Portugal.

    NASA Astrophysics Data System (ADS)

    Caseiro, Alexandre; Oliveira, César; Pio, Casimiro; Nunes, Teresa; Santos, Patrícia; Mao, Hongjun; Sokhi, Ranjeet; Luhanna, Lakhu

    2010-05-01

    Particulate matter, either with aerodynamical diameter below 10 μm (PM10) or the fine (aerodynamical diameter below 2.5 μm, PM2.5) or coarse (aerodynamical diameter between 2.5 and 10 μm, PM2.5-10) modes only, are presently regarded as one of the main threats to public health instigated by air pollution. The levels of ambient air particulates are regulated but the limits are frequently surpassed. It is therefore necessary to identify and quantify PM sources and their variability, as well as the biogenic processes that to some extent control their ambient load, in order to effectively regulate on the anthropogenic activities which originate PM. PM2.5-10 and PM2.5 were monitored in Oporto, NW Portugal, at two contrasting sites (directly impacted by traffic, roadside, and at the urban background) during two one-month campaigns (winter and summer). Sampling was conducted independently during daytime and night-time. Out of the 207 sampling periods analysed, 38 (18%) were above the European legal PM10 limit of 50 ?g m-3. PM2.5 concentrations above the limit of 25 ?g m-3 proposed by the EC occurred in 70 out of 202 sampling (35%). More exceedances occurred in winter than in summer and at roadside than at the urban background. Within the scope of this work, the relationship between PM concentrations, namely the occurrence of exceeding PM limit values, and meteorological variables or the sampling period (day/night, work day/weekend) and will be presented. Besides PM mass, the soluble ionic composition (Cl-, SO42-, NO3-, Na+, NH4+, K+, Ca2+ and Mg2+) as well as the elemental composition (Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr, Sn, Ba and Pb) were also determined. This allowed the application of multivariate analysis (principal component analysis with multi-linear regression analysis, PCA-MLRA, and positive matrix factorisation, PMF). Five main sources were identified in the fine and coarse modes (direct road traffic emissions

  12. Identification of S-glutathionylation sites in species-specific proteins by incorporating five sequence-derived features into the general pseudo-amino acid composition.

    PubMed

    Zhao, Xiaowei; Ning, Qiao; Ai, Meiyue; Chai, Haiting; Yang, Guifu

    2016-06-01

    As a selective and reversible protein post-translational modification, S-glutathionylation generates mixed disulfides between glutathione (GSH) and cysteine residues, and plays an important role in regulating protein activity, stability, and redox regulation. To fully understand S-glutathionylation mechanisms, identification of substrates and specific S-Glutathionylated sites is crucial. Experimental identification of S-glutathionylated sites is labor-intensive and time consuming, so establishing an effective computational method is much desirable due to their convenient and fast speed. Therefore, in this study, a new bioinformatics tool named SSGlu (Species-Specific identification of Protein S-glutathionylation Sites) was developed to identify species-specific protein S-glutathionylated sites, utilizing support vector machines that combine multiple sequence-derived features with a two-step feature selection. By 5-fold cross validation, the performance of SSGlu was measured with an AUC of 0.8105 and 0.8041 for Homo sapiens and Mus musculus, respectively. Additionally, SSGlu was compared with the existing methods, and the higher MCC and AUC of SSGlu demonstrated that SSGlu was very promising to predict S-glutathionylated sites. Furthermore, a site-specific analysis showed that S-glutathionylation intimately correlated with the features derived from its surrounding sites. The conclusions derived from this study might help to understand more of the S-glutathionylation mechanism and guide the related experimental validation. For public access, SSGlu is freely accessible at http://59.73.198.144:8080/SSGlu/. PMID:27025952

  13. Influence of the X-site composition on tourmaline's crystal structure: investigation of synthetic K-dravite, dravite, oxy-uvite, and magnesio-foitite using SREF and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Berryman, E. J.; Wunder, B.; Ertl, A.; Koch-Müller, M.; Rhede, D.; Scheidl, K.; Giester, G.; Heinrich, W.

    2016-02-01

    The crystal structures of synthetic K-dravite [XKYMg 3 Z Al 6 T Si6O18(BO3) 3 V (OH) 3 W (OH)], dravite [XNaYMg 3 Z Al 6 T Si6O18(BO3) 3 V (OH) 3 W (OH)], oxy-uvite [XCaYMg 3 Z Al 6 T Si6O18(BO3) 3 V (OH) 3 W O], and magnesio-foitite [X☐Y(Mg2Al)ZAl 6 T Si6O18(BO3) 3 V (OH) 3 W (OH)] are investigated by polarized Raman spectroscopy, single-crystal structure refinement (SREF), and powder X-ray diffraction. The use of compositionally simple tourmalines characterized by electron microprobe analysis facilitates the determination of site occupancy in the SREF and band assignment in the Raman spectra. The synthesized K-dravite, oxy-uvite, and magnesio-foitite have significant Mg-Al disorder between their octahedral sites indicated by their respective average < Y-O> and < Z-O> bond lengths. The Y- and Z-site compositions of oxy-uvite (YMg1.52Al1.48(10) and ZAl4.90Mg1.10(15)) and magnesio-foitite (YAl1.62Mg1.38(18) and ZAl4.92Mg1.08(24)) are refined from the electron densities at each site. The Mg-Al ratio of the Y and Z sites is also determined from the relative integrated peak intensities of the Raman bands in the O-H stretching vibrational range (3250-3850 cm-1), producing values in good agreement with the SREF data. The unit cell volume of tourmaline increases from magnesio-foitite (1558.4(3) Å3) to dravite (1569.5(4)-1571.7(3) Å3) to oxy-uvite (1572.4(2) Å3) to K-dravite (1588.1(2) Å3), mainly due to lengthening of the crystallographic c-axis. The increase in the size of the X-site coordination polyhedron from dravite (Na) to K-dravite (K) is accommodated locally in the crystal structure, resulting in the shortening of the neighboring O1- H1 bond. In oxy-uvite, Ca2+ is locally associated with a deprotonated W (O1) site, whereas vacant X sites are neighbored by protonated W ( O1) sites. Increasing the size of the X-site-occupying ion does not detectably affect bonding between the other sites; however, the higher charge of Ca and the deprotonated W ( O1) site in

  14. Subcutaneous fat patterning in athletes: selection of appropriate sites and standardisation of a novel ultrasound measurement technique: ad hoc working group on body composition, health and performance, under the auspices of the IOC Medical Commission

    PubMed Central

    Müller, Wolfram; Lohman, Timothy G; Stewart, Arthur D; Maughan, Ronald J; Meyer, Nanna L; Sardinha, Luis B; Kirihennedige, Nuwanee; Reguant-Closa, Alba; Risoul-Salas, Vanessa; Sundgot-Borgen, Jorunn; Ahammer, Helmut; Anderhuber, Friedrich; Fürhapter-Rieger, Alfred; Kainz, Philipp; Materna, Wilfried; Pilsl, Ulrike; Pirstinger, Wolfram; Ackland, Timothy R

    2016-01-01

    Background Precise and accurate field methods for body composition analyses in athletes are needed urgently. Aim Standardisation of a novel ultrasound (US) technique for accurate and reliable measurement of subcutaneous adipose tissue (SAT). Methods Three observers captured US images of uncompressed SAT in 12 athletes and applied a semiautomatic evaluation algorithm for multiple SAT measurements. Results Eight new sites are recommended: upper abdomen, lower abdomen, erector spinae, distal triceps, brachioradialis, lateral thigh, front thigh, medial calf. Obtainable accuracy was 0.2 mm (18 MHz probe; speed of sound: 1450 m/s). Reliability of SAT thickness sums (N=36): R2=0.998, SEE=0.55 mm, ICC (95% CI) 0.998 (0.994 to 0.999); observer differences from their mean: 95% of the SAT thickness sums were within ±1 mm (sums of SAT thicknesses ranged from 10 to 50 mm). Embedded fibrous tissues were also measured. Conclusions A minimum of eight sites is suggested to accommodate inter-individual differences in SAT patterning. All sites overlie muscle with a clearly visible fascia, which eases the acquisition of clear images and the marking of these sites takes only a few minutes. This US method reaches the fundamental accuracy and precision limits for SAT measurements given by tissue plasticity and furrowed borders, provided the measurers are trained appropriately. PMID:26702017

  15. Influence of Human Activity Patterns, particle composition, and residential air exchange rates on modeled distributions of PM 2.5 exposure compared with central-site monitoring data

    EPA Science Inventory

    Central-site monitors do not account for factors such as outdoor-to-indoor transport and human activity patterns that influence personal exposures to ambient fine-particulate matter (PM2.5). We describe and compare different ambient PM2.5 exposure estimation...

  16. Chemical composition of size-resolved particulate matter at near-freeway and urban background sites in the greater Beirut area

    NASA Astrophysics Data System (ADS)

    Daher, Nancy; Saliba, Najat A.; Shihadeh, Alan L.; Jaafar, Malek; Baalbaki, Rima; Sioutas, Constantinos

    2013-12-01

    To characterize road-traffic emissions in the greater Beirut area, size-resolved PM10-2.5, PM2.5-0.25 and PM0.25 samples were concurrently collected at near-freeway and background sites. While particle mass levels were 1.3-2.6 times greater at the roadside than background location, PM10-2.5 and PM0.25 prevailed at both sites (36-43% of PM10). A chemical mass closure showed that PM10-2.5 was mostly composed of crustal material, contributing to 12-23% of its mass across sites. On the other hand, in PM2.5-0.25 and PM0.25, organic matter (46-56%) was dominant at the roadside location, while secondary ions (SI, 54-68%) were more abundant at the background site. In the vicinity of the freeway, organic carbon (OC) levels varied from 4 μg m-3 in PM10-2.5 to 10.1 μg m-3 in PM0.25, exceeding those at the background site by 4-7 times. In contrast, OC was largely water-soluble at the background location, with its water-soluble fraction displaying comparable PM2.5-0.25- and PM0.25-concentrations at both sites, corroborating its regional secondary origin. PM0.25-elemental carbon (EC), which dominated overall EC mass, was 7-fold greater at the near-freeway than background location, indicating a contribution from diesel or also smoking vehicles to road-traffic emissions. PM2.5-SI showed fairly uniform concentrations across sites, confirming their mainly regional source. Polycyclic aromatic hydrocarbons (PAHs) were undetected at the coastal background site, whereas their levels peaked at 11.5 ng m-3 in proximity to the freeway, with the majority confined to PM0.25. Compared to other roadways, organic compounds at the freeway location exhibited high hopanes plus steranes-to-total carbon ratios (0.16-1.1 ng μg-1), indicative of different engine configurations, fleet or also lubricating oil formulation. At both locations, PM0.25-bound n-alkanes (C19-C34) showed a predominance of high molecular weight homologues and no carbon number preference, suggesting their likely road dust

  17. Nucleotide sequence composition adjacent to intronic splice sites improves splicing efficiency via its effect on pre-mRNA local folding in fungi.

    PubMed

    Zafrir, Zohar; Tuller, Tamir

    2015-10-01

    RNA splicing is the central process of intron removal in eukaryotes known to regulate various cellular functions such as growth, development, and response to external signals. The canonical sequences indicating the splicing sites needed for intronic boundary recognition are well known. However, the roles and evolution of the local folding of intronic and exonic sequence features adjacent to splice sites has yet to be thoroughly studied. Here, focusing on four fungi (Saccharomyces cerevisiae, Schizosaccharomyces pombe, Aspergillus nidulans, and Candida albicans), we performed for the first time a comprehensive high-resolution study aimed at characterizing the encoding of intronic splicing efficiency in pre-mRNA transcripts and its effect on intron evolution. Our analysis supports the conjecture that pre-mRNA local folding strength at intronic boundaries is under selective pressure, as it significantly affects splicing efficiency. Specifically, we show that in the immediate region of 12-30 nucleotides (nt) surrounding the intronic donor site there is a preference for weak pre-mRNA folding; similarly, in the region of 15-33 nt surrounding the acceptor and branch sites there is a preference for weak pre-mRNA folding. We also show that in most cases there is a preference for strong pre-mRNA folding further away from intronic splice sites. In addition, we demonstrate that these signals are not associated with gene-specific functions, and they correlate with splicing efficiency measurements (r = 0.77, P = 2.98 × 10(-21)) and with expression levels of the corresponding genes (P = 1.24 × 10(-19)). We suggest that pre-mRNA folding strength in the above-mentioned regions has a direct effect on splicing efficiency by improving the recognition of intronic boundaries. These new discoveries are contributory steps toward a broader understanding of splicing regulation and intronic/transcript evolution. PMID:26246046

  18. Composition and variation of sediment bacterial and nirS-harboring bacterial communities at representative sites of the Bohai Gulf coastal zone, China.

    PubMed

    Guan, Xiangyu; Zhu, Lingling; Li, Youxun; Xie, Yuxuan; Zhao, Mingzhang; Luo, Ximing

    2014-04-01

    With rapid urbanization, anthropogenic activities are increasingly influencing the natural environment of the Bohai Bay. In this study, the composition and variation of bacterial and nirS-harboring bacterial communities in the coastal zone sediments of the Bohai Gulf were analyzed using PCR-based clone libraries. A total of 95 genera were detected in the bacterial communities, with Proteobacteria (72.1 %), Acidobacteria (10.5 %), Firmicutes (1.7 %), Bacteroidetes (1.4 %), Chloroflexi (0.7 %) and Planctomycetes (0.7 %) being the dominated phyla. The NirS sequences were divided into nine Clusters (A-I). Canonical correlation analysis showed that the bacterial or denitrifying communities were correlated with different environmental factors, such as total organic carbon, total nitrogen, ammonium, sulfate, etc. Furthermore, bacterial communities' composition and diversity are influenced by oil exploration, sewage discharge and other anthropogenic activities in the coastal area of the Bohai Sea. Thus, this study provided useful information on further research on regional or global environmental control and restore. PMID:24214680

  19. Origin and transport of pore fluids in the Nankai accretionary prism inferred from chemical and isotopic compositions of pore water at cold seep sites off Kumano

    NASA Astrophysics Data System (ADS)

    Toki, Tomohiro; Higa, Ryosaku; Ijiri, Akira; Tsunogai, Urumu; Ashi, Juichiro

    2014-12-01

    We used push corers during manned submersible dives to obtain sediment samples of up to 30 cm from the subseafloor at the Oomine Ridge. The concentrations of B in pore water extracted from the sediment samples from cold seep sites were higher than could be explained by organic matter decomposition, suggesting that the seepage fluid at the site was influenced by B derived from smectite-illite alteration, which occurs between 50°C and 160°C. Although the negative δ18OH2O and δDH2O values of the pore fluids cannot be explained by freshwater derived from clay mineral dehydration (CMD), we considered the contribution of pore fluids in the shallow sediments of the accretionary prism, which showed negative δ18OH2O and δDH2O values according to the results obtained during Integrated Ocean Drilling Program (IODP) Expeditions 315 and 316. We calculated the mixing ratios based on a four-end-member mixing model including freshwater derived from CMD, pore fluids in the shallow (SPF) accretionary prism sediment, seawater (SW), and freshwater derived from methane hydrate (MH) dissociation. However, the Oomine seep fluids were unable to be explained without four end members, suggesting that deep-sourced fluids in the accretionary prism influenced the seeping fluids from this area. This finding presents the first evidence of deep-sourced fluids at cold seep sites in the Oomine Ridge, indicating that a megasplay fault is a potential pathway for the deep-sourced fluids.

  20. Composition of pore water in lake sediments, research site "B", Osage County, Oklahoma: Implications for lake water quality and benthic organisms

    USGS Publications Warehouse

    Zielinski, R.A.; Herkelrath, W.N.; Otton, J.K.

    2007-01-01

    Shallow ground water at US Geological Survey research site B in northeastern Oklahoma is contaminated with NaCl-rich brine from past and present oil production operations. Contaminated ground water provides a potential source of salts, metals, and hydrocarbons to sediment and water of adjacent Skiatook Lake. A former brine storage pit 10 m in diameter that is now submerged just offshore from site B provides an additional source of contamination. Cores of the upper 16-40 cm of lake sediment were taken at the submerged brine pit, near an offshore saline seep, and at a location containing relatively uncontaminated lake sediment. Pore waters from each 2-cm interval were separated by centrifugation and analyzed for dissolved anions, cations, and trace elements. High concentrations of dissolved Cl- in pore waters (200-5000 mg/L) provide the most direct evidence of contamination, and contrast sharply with an average value of only about 37 mg/L in Skiatook Lake. Chloride/Br- mass ratios of 220-240 in contaminated pore waters are comparable to values in contaminated well waters collected onshore. Dissolved concentrations of Se, Pb, Cu and Ni in Cl--rich pore waters exceed current US Environmental Protection Agency criteria for probable toxicity to aquatic life. At the submerged brine storage pit, the increase of Cl- concentration with depth is consistent with diffusion-dominant transport from deeper contaminated sediments. Near the offshore saline seep, pore water Cl- concentrations are consistently high and vary irregularly with depth, indicating probable Cl- transport by layer-directed advective flow. Estimated annual contributions of Cl- to the lake from the brine storage pit (???20 kg) and the offshore seep (???9 kg) can be applied to any number of similar sources. Generous estimates of the number of such sources at site B indicate minimal impact on water quality in the local inlet of Skiatook Lake. Similar methodologies can be applied at other sites of Na

  1. Negative Coefficients in the GRE Validity Study Service. GRE Research. GRE Board Professional Report No. 89-05P.

    ERIC Educational Resources Information Center

    Longford, Nicholas T.

    Operational procedures for the Graduate Record Examinations Validity Study Service are reviewed, with emphasis on the problem of frequent occurrence of negative coefficients in the fitted within-department regressions obtained by the empirical Bayes method of H. I. Braun and D. Jones (1985). Several alterations of the operational procedures are…

  2. Evidence for a hypogene paleohydrogeological event at the prospective nuclear waste disposal site Yucca Mountain, Nevada, USA, revealed by the isotope composition of fluid-inclusion water

    NASA Astrophysics Data System (ADS)

    Dublyansky, Yuri V.; Spötl, Christoph

    2010-01-01

    Secondary calcite residing in open cavities in the unsaturated zone of Yucca Mountain has long been interpreted as the result of downward infiltration of meteoric water through open fractures. In order to obtain information on the isotopic composition (δD and δ 18O) of the mineral-forming water we studied fluid inclusions from this calcite. Water was extracted from inclusions by heated crushing and the δD values were measured using a continuous-flow isotope-ratio mass spectrometry method. The δ 18O values were calculated from the δ 18O values of the host calcite assuming isotopic equilibrium at the temperature of formation determined by fluid-inclusion microthermometry. The δD values measured in all samples range between - 110 and - 90‰, similar to Holocene meteoric water. Coupled δ 18O-δD values plot significantly, 2 to 8‰, to the right of the meteoric water line. Among the various processes operating at the topographic surface and/or in the unsaturated zone only two processes, evaporation and water-rock exchange, could alter the isotope composition of percolating water. Our analysis indicates, however, that none of these processes could produce the observed large positive δ 18O-shifts. The latter require isotopic interaction between mineral-forming fluid and host rock at elevated temperature (>100 °C), which is only possible in the deep-seated hydrothermal environment. The stable isotope data are difficult to reconcile with a meteoric origin of the water from which the secondary minerals at Yucca Mountain precipitated; instead they point to the deep-seated provenance of the mineral-forming waters and their introduction into the unsaturated zone from below, i.e. a hypogene origin.

  3. Concentration measurements and chemical composition of PM10-2.5 and PM2.5 at a coastal site in Beirut, Lebanon

    NASA Astrophysics Data System (ADS)

    Shaka', Huda; Saliba, Najat A.

    Emission measurements and chemical profiles of PM10-2.5 (coarse) and PM2.5 (fine) in Lebanon are reported for the months of February till May of 2003. A 4 month average of 76 μg m -3 for PM10-2.5 and 40 μg m -3 for PM2.5 compared well with East Mediterranean cities but was higher than most emission measurements reported for the West Mediterranean basin. Using the ATR-FTIR technique, the chemical composition of aerosols was identified. Inorganic ions such as SO 42-, NO 3-, SiO 42-, CO 32-, and NH 4+, showed higher concentrations of PM2.5 when compared to PM10-2.5. Organic functional groups like aliphatic carbons, alcohols, carbonyls, and organic nitrates were also detected. Higher concentrations of organic species, i.e. aliphatic hydrocarbons and long chains of alcoholic and carboxylic acid substances, were identified in PM2.5 while in PM10-2.5, higher water concentrations were observed. Comparison between the ATR spectra of samples collected on a "regular" and a "sandy" day clearly showed the increase of SiO 42- ions and calcium carbonate during the sand storm due to dust loading on the Teflon filters. This study is one of the few works that have reported emission measurements in the Eastern Mediterranean, complementing thereby the large amount of data available in the Western Mediterranean. More importantly, this paper establishes a comparison between the main constituents of PM10-2.5 and PM2.5 using ATR-infrared spectroscopy, for the first time. Understanding the composition of different aerosol size fractions in the atmosphere enables us to better predict detailed chemical environmental variations.

  4. Tracing the Southwest African climate development during the Miocene - changes in elemental distribution and clay mineral composition at DSDP Site 530A (southeastern Angola Basin)

    NASA Astrophysics Data System (ADS)

    Roters, B.

    2009-04-01

    During the middle and late Miocene the climatic system in Southwest Africa was reorganized leading to generally drier conditions as known from today. The reason for this was the cooling of the coastal-near ocean by the initialization of the Benguela Current. Thus the temperature difference between the continent and the sea increased and a system of seaward blowing winds developed. This lead to (1) the development of the Benguela Upwelling System in front of the Namibian coast and (2) it prevented the landward flow of humid air masses. The Mid-Miocene climate change in SW-Africa has been shown by data-sets from the Cape Basin and the Walvis Ridge (Kastanja et al., 2006; Westerhold et al., 2005; Diester-Haass et al., 2002; Roters & Henrich, in press). The DSDP Site 530A is situated in the SE corner of the Walvis Basin at the toe of the Walvis Ridge in a water depth of 4629 m. Today the distance to the coast is about 285 km. The idea is to trace the climatic development between 19 and 9 Myr with the help of (1) a clay mineral record and (2) the results of XRF-scanning of the core. The sediment is carbonate-depleted, which, inversely, enriches the terrigenous components. On the other hand mass accumulation rates are low and the age control of the sediments is difficult. XRF scanning was done on the archive cores at the MARUM, Bremen in a resolution of about 10 kyr, while the clay mineral contents were measured in the isolated clay fraction (< 2µm) on a XRD machine at the AWI, Bremerhaven in a 100 kyr resolution. By grain size analysis it was found that the content of clays (fraction < 2µm) of the sediments averages out to about 75%. The most prominent clays found in the samples are Illites. The remaining material is nearly completely composed of silt. The sediments could have been transported to site 530A by three different processes: (1) in the sediment load of the Kunene River and onwards by surface ocean currents, (2) with the dust load from the African continent

  5. Epstein-Barr virus nuclear antigen 3C binds to BATF/IRF4 or SPI1/IRF4 composite sites and recruits Sin3A to repress CDKN2A.

    PubMed

    Jiang, Sizun; Willox, Bradford; Zhou, Hufeng; Holthaus, Amy M; Wang, Anqi; Shi, Tommy T; Maruo, Seiji; Kharchenko, Peter V; Johannsen, Eric C; Kieff, Elliott; Zhao, Bo

    2014-01-01

    Epstein-Barr virus nuclear antigen 3C (EBNA3C) repression of CDKN2A p14(ARF) and p16(INK4A) is essential for immortal human B-lymphoblastoid cell line (LCL) growth. EBNA3C ChIP-sequencing identified >13,000 EBNA3C sites in LCL DNA. Most EBNA3C sites were associated with active transcription; 64% were strong H3K4me1- and H3K27ac-marked enhancers and 16% were active promoters marked by H3K4me3 and H3K9ac. Using ENCODE LCL transcription factor ChIP-sequencing data, EBNA3C sites coincided (±250 bp) with RUNX3 (64%), BATF (55%), ATF2 (51%), IRF4 (41%), MEF2A (35%), PAX5 (34%), SPI1 (29%), BCL11a (28%), SP1 (26%), TCF12 (23%), NF-κB (23%), POU2F2 (23%), and RBPJ (16%). EBNA3C sites separated into five distinct clusters: (i) Sin3A, (ii) EBNA2/RBPJ, (iii) SPI1, and (iv) strong or (v) weak BATF/IRF4. EBNA3C signals were positively affected by RUNX3, BATF/IRF4 (AICE) and SPI1/IRF4 (EICE) cooccupancy. Gene set enrichment analyses correlated EBNA3C/Sin3A promoter sites with transcription down-regulation (P < 1.6 × 10(-4)). EBNA3C signals were strongest at BATF/IRF4 and SPI1/IRF4 composite sites. EBNA3C bound strongly to the p14(ARF) promoter through SPI1/IRF4/BATF/RUNX3, establishing RBPJ-, Sin3A-, and REST-mediated repression. EBNA3C immune precipitated with Sin3A and conditional EBNA3C inactivation significantly decreased Sin3A binding at the p14(ARF) promoter (P < 0.05). These data support a model in which EBNA3C binds strongly to BATF/IRF4/SPI1/RUNX3 sites to enhance transcription and recruits RBPJ/Sin3A- and REST/NRSF-repressive complexes to repress p14(ARF) and p16(INK4A) expression. PMID:24344258

  6. Composition and arsenic-attenuating capacity of biogenic iron (hydr)oxide flocs at the Lava Cap Mine Superfund Site, Nevada County, CA.

    NASA Astrophysics Data System (ADS)

    Foster, A. L.; Ona-Nguema, G.; Tufano, K.; Brown, G. E.

    2008-12-01

    The Lava Cap Mine Site (LCMS) is on the National Priority List due to the elevated human health risk presented by the catastrophic release of several thousand cubic meters of arsenic (As) enriched tailings (average: 500 ppm As ) from the site. These tailings were released into a creek and lake (former tailings retention pond) in a low-density residential area where ground water is the primary source of drinking water. Although oxidation of iron (Fe) sulfides (pyrite and arsenopyrite) from tailings are the main sources of As and Fe, buffering by carbonate minerals prevents formation of acidic waters. Macroscopic accumulations of fluffy Fe (hydr)oxide are observed suspended in the water column or at the sediment-water interface in creeks, ponds, and seeps of the LCMS. Microscopic analysis indicates that the Fe (hydr)oxide is predominantly associated with the sheaths of bacteria identified as members of the genus Leptothrix, which are known to enzymatically oxidize Fe and manganese (Mn) under oligotrophic, near-neutral, sub oxic conditions. Both Fe- encrusted Leptothrix sheaths (which are largely devoid of cells) and free aggolmerations of Fe hydr(oxide) support morphologically distinct Eubacteria whose identity is currently under investigation. Dried biogenic Fe (hydr)oxide averages 4.4 % organic carbon, 20.2 % Fe, and 0.91% As (9100 ppm), making it attractive as a potential natural biosorbent for As and Fe. Water flow rate is a very important control on the amount of As retained in biogenic Fe (hydr)oxide flocs, based on monitoring of a natural passive bioreactor system. In addition, a pond with nearly stagnant water accumulated approximately one order of magnitude more As (dried) than a seep site with faster-running water, even though there was only a 5-fold difference in their median filtered (0.45 micron) arsenic concentrations. Most Probable Number estimates and analysis of PCR amplicons of Eubacterial DNA indicate that populations of Fe-, As-, and sulfate

  7. LPS-Induced Formation of Immunoproteasomes: TNF-α and Nitric Oxide Production are Regulated by Altered Composition of Proteasome-Active Sites

    PubMed Central

    Reis, Julia; Guan, Xiu Qin; Kisselev, Alexei F.; Papasian, Christopher J.; Qureshi, Asaf A.; Morrison, David C.; Van Way, Charles W.; Vogel, Stefanie N.

    2011-01-01

    Stimulation of mouse macrophages with LPS leads to tumor necrosis factor (TNF-α) secretion and nitric oxide (NO) release at different times through independent signaling pathways. While the precise regulatory mechanisms responsible for these distinct phenotypic responses have not been fully delineated, results of our recent studies strongly implicate the cellular cytoplasmic ubiquitin–proteasome pathway as a key regulator of LPS-induced macrophage inflammatory responses. Our objective in this study was to define the relative contribution of specific proteasomal active-sites in induction of TNF-α and NO after LPS treatment of RAW 264.7 macrophages using selective inhibitors of these active sites. Our data provide evidence that LPS stimulation of mouse macrophages triggers a selective increase in the levels of gene and protein expression of the immunoproteasomes, resulting in a modulation of specific functional activities of the proteasome and a corresponding increase in NO production as compared to untreated controls. These findings suggest the LPS-dependent induction of immunoproteasome. In contrast, we also demonstrate that TNF-α expression is primarily dependent on both the chymotrypsin- and the trypsin-like activities of X, Y, Z subunits of the proteasome. Proteasome-associated post-acidic activity alone also contributes to LPS-induced expression of TNF-α. Taken together; our results indicate that LPS-induced TNF-α in macrophages is differentially regulated by each of the three proteasome activities. Since addition of proteasome inhibitors to mouse macrophages profoundly affects the degradation of proteins involved in signal transduction, we conclude that proteasome-specific degradation of several signaling proteins is likely involved in differential regulation of LPS-dependent secretion of proinflammatory mediators. PMID:21455682

  8. Fine particles (PM2.5) at a CAWNET background site in Central China: Chemical compositions, seasonal variations and regional pollution events

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Cheng, Hai-rong; Wang, Zu-wu; Lv, Xiao-pu; Zhu, Zhong-min; Zhang, Gan; Wang, Xin-ming

    2014-04-01

    Fine particle (PM2.5) samples were collected at Jinsha (JSH), a regional background China Atmosphere Watch Network (CAWNET) site in Central China from March 2012 to March 2013. The mass concentrations of water-soluble inorganic ions (WSIIs), organic carbon (OC) and elemental carbon (EC) in PM2.5 were measured. The average PM2.5 mass concentration was 48.7 ± 26.9 μg m-3, exceeding the Chinese National Ambient Air Quality Standards (NAAQS) (35 μg m-3), implying that PM2.5 is a pollutant of regional concern in Central China. The average concentrations of total WSIIs, OC and EC were 26.1 ± 18.8, 7.5 ± 3.5 and 0.7 ± 0.5 μg m-3, accounting for 53.5%, 15.1% and 1.5% of the PM2.5 concentrations at JSH, respectively. Clear seasonal variations in PM2.5 and the levels of its main chemical species were observed in the following order: winter > autumn > spring > summer. Backward air trajectory analysis and potential source contribution function (PSCF) analysis implied that the areas north and northeast of JSH contributed significantly to the levels of SO42-, NO3-, NH4+ and OC, while sandstorms originating from Mongolia and traveling across Northwest China may have contributed significantly to the levels of Na+, Ca2+, and Mg2+ in PM2.5 at JSH. Two pollution events, related to regional biomass burning and haze, respectively, were recorded at JSH during the sampling campaign.

  9. Effects of A-site composition and oxygen nonstoichiometry on the thermodynamic stability of compounds in the Ba–Sr–Co–Fe–O system

    SciTech Connect

    Tanasescu, Speranta; Yáng, Zhèn; Martynczuk, Julia; Varazashvili, Vera; Maxim, Florentina; Teodorescu, Florina; Botea, Alina; Totir, Nicolae; and others

    2013-04-15

    The thermodynamic stability of the perovskite-type oxides in the Ba{sub x}Sr{sub 1−x}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} (BSCF) system was investigated with varying Ba:Sr ratios (x=0.2, 0.4, 0.5, 0.6, 0.8) and correlated with the charge compensation mechanism and the change in the oxygen stoichiometry of the materials. Thermodynamic properties represented by the relative partial molar free energies, enthalpies and entropies of oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressures of oxygen have been obtained in the temperature range of 823–1273 K using solid electrolyte electrochemical cells (EMF) method. The influence of the oxygen stoichiometry change on the thermodynamic properties was examined using a coulometric titration technique coupled with EMF measurements. The temperature dependence of enthalpy increment (H{sub T}−H{sub 298}) in the temperature range of 700–900 K was measured by drop calorimetry. The energetic parameters allow for the correlation of the structural and electrical stability with the defect structures. - Graphical abstract: Partial molar energy of oxygen dissolution (ΔG{sup ¯}{sub O{sub 2}}) (EMF measurements) and enthalpy increment (H{sub T}−H{sub 298}) (drop calorimetry data) of perovskite materials with the composition Ba{sub x}Sr{sub 1−x}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} as a function of temperature and Barium content. Highlights: ► We report relevant data for thermodynamic stability of Ba{sub x}Sr{sub 1−x}Co{sub 1−y}Fe{sub y}O{sub 3−δ} compounds. ► Temperature of structural transformations is evidenced as a function of Ba content. ► Correlation between thermodynamic, electrical and structural data is investigated. ► The results are discussed based on the properties-defect structure relationship.

  10. Biochemical composition of seston in two upwelling sites within the Humboldt Current System (21°S to 23°S): Summer conditions

    NASA Astrophysics Data System (ADS)

    Isla, Enrique; Homs, Patricia; Sañé, Elisabet; Escribano, Rubén; Claramunt, Gabriel; Teixidó, Nuria

    2010-07-01

    The biochemical composition of seston within the Humboldt Current System (HCS) in two bays off northern Chile (21°S-23°S) was assessed to estimate its chemical quality as potential food supply for benthic communities, large zooplankton and fish larvae. As part of the CENSOR project, in the summer of 2006 physical and biochemical variables were analyzed in Chipana and Mejillones Bays during one week at four depths determined by the occurrence of the upper boundary of the oxygen minimum zone and fluorescence peaks. The depth of the oxy- and pycnoclines controlled the distribution of biochemical variables in both bays. There were significant differences in the concentration of protein (PRT), lipid (LPD) and carbohydrates (CHO) among depths in both bays. The differences were also found in the PRT and LPD contribution to the biopolymeric carbon (BPC) among bays and among depths in the case of CHO. However, the concentration of suspended particulate matter and biogenic silica (bSi) were similar in both bays. PRT, LPD and CHO showed the highest concentrations in the upper meters of the water column and small peaks close to the seabed related to sediment resuspension and/or lateral transport. In Chipana Bay, the high nutritive quality of seston occurring near the seabed suggests a rapid sinking of diatom aggregates and a reduced respiration of the particulate organic matter. PRT, LPD and CHO varied between 0.05 and 0.47 mg l - 1 , 0.06 and 0.39 mg l - 1 and 0.07 and 0.51 mg l - 1 , respectively. LPD were the most important contributors to the BPC in both bays. The seston in these bays presented a high PRT and LPD content in comparison to a number of settings of different latitudes and oceanographic characteristics. The high quantity and biochemical quality of the particulate matter in both bays may reflect the high productivity of this zone and partially explain their condition as spawning areas within the HCS.

  11. Reconstruction of local fallout composition and gamma-ray exposure in a village contaminated by the first USSR nuclear test in the Semipalatinsk nuclear test site in Kazakhstan.

    PubMed

    Imanaka, Tetsuji; Yamamoto, Masayoshi; Kawai, Kenta; Sakaguchi, Aya; Hoshi, Masaharu; Chaizhunusova, Nailya; Apsalikov, Kazbek

    2010-11-01

    After the disintegration of the USSR in end of 1991, it became possible for foreign scientists to visit Kazakhstan, in order to investigate the radiological consequences of nuclear explosions that had been conducted at the Semipalatinsk nuclear test site (SNTS). Since the first visit in 1994, our group has been continuing expeditions for soil sampling at various areas around SNTS. The current level of local fallout at SNTS was studied through γ-spectrometry for (137)Cs as well as α-spectrometry for (239,240)Pu. Average values of soil inventory from wide areas around SNTS were 3,500 and 3,700 Bq m(-2) for (137)Cs and (239,240)Pu, respectively, as of January 1, 2000. The average level of (137)Cs is comparable to that in Japan due to global fallout, while the level of (239,240)Pu is several tens of times larger than that in Japan. Areas of strong contamination were found along the trajectories of radioactive fallout, information on which was declassified after the collapse of the USSR. Our recent efforts of soil sampling were concentrated on the area around the Dolon village heavily affected by the radioactive plume from the first USSR atomic bomb test in 1949 and located 110 km east from ground zero of the explosion. Using soil inventory data, retrospective dosimetry was attempted by reconstructing γ-ray exposure from fission product nuclides deposited on the ground. Adopting representative parameters for the initial (137)Cs deposition (13 kBq m(-2)), the refractory/volatile deposition ratio (3.8) and the plume arrival time after explosion (2.5 h), an absorbed dose in air of 600 mGy was obtained for the 1-year cumulative dose in Dolon village, due to the first bomb test in 1949. Considering possible ranges of the parameters, 350 and 910 mGy were estimated for high and low cases of γ-ray dose in air, respectively. It was encouraging that the deduced value was consistent with other estimations using thermal luminescence and archived monitoring data. The present

  12. Composition for detecting uranyl

    SciTech Connect

    Baylor, L.C.; Stephens, S.M.

    1995-06-13

    A composition for detecting the presence and concentration of a substance, such as uranyl, comprises an organohalide covalently bonded to an indicator for said substance. The composition has at least one active OH site for forming a complex with the substance to be detected. The composition is made by reacting equimolar amounts of the indicator and the organohalide in a polar organic solvent. The absorbance spectrum of the composition-uranyl complex is shifted with respect to the absorbance spectrum of the indicator-uranyl complex, to provide better spectral resolution for detecting uranyl. 6 figs.

  13. Composition for detecting uranyl

    DOEpatents

    Baylor, Lewis C.; Stephens, Susan M.

    1995-01-01

    A composition for detecting the presence and concentration of a substance such as uranyl, comprising an organohalide covalently bonded to an indicator for said substance. The composition has at least one active OH site for forming a complex with the substance to be detected. The composition is made by reacting equimolar amounts of the indicator and the organohalide in a polar organic solvent. The absorbance spectrum of the composition-uranyl complex is shifted with respect to the absorbance spectrum of the indicator-uranyl complex, to provide better spectral resolution for detecting uranyl.

  14. Paleoceanographic Inferences from Carbon and Nitrogen Isotopic Compositions of Cenomanian Black Shales from DSDP/ODP Sites 367, 530, 603, 641, 1257-1261, and 1276 in the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Yum, J.; Meyers, P. A.; Bernasconi, S. M.; Arnaboldi, M.

    2005-12-01

    The mid-Cretaceous (Cenomanian- Turonian) was characterized as a peak global greenhouse period with highest sea level, highest CO2 concentration in atmosphere and low thermal gradients from the poles to the equator. The depositional environment of the organic-carbon-rich black shales that typify this period remains an open question. A total of 180 Cenomanian- Turonian core samples were selected from multiple ODP and DSDP sites in the Atlantic Ocean: 530 (Cape Basin), 603 (Hatteras Rise), 641 (Galicia Bank), 1257-1261 (Demerara Rise), 1276 (Newfoundland Basin). Total organic carbon and nitrogen concentrations and isotopic compositions were measured to investigate variations in the proto-Atlantic Ocean paleoceanographic conditions that contributed to the origin of the black shales for this period. These new data were combined with existing data from Sites 367 (Senegal Rise), 530, and 603. Both the black shales and the organic-carbon-poor background sediments (less than 1 percent) have carbon isotope values between -29 to -22 permil. The C/N ratios of the background sediments are low (less than 20) compared to those of the black shales (20-40). Nitrogen isotope values range from 0 to 4 permil in the background samples. All black shales have similarly low nitrogen isotope values that range between -4 to 0 permil. These exceptionally low values are inferred to reflect the productivity of blue green algae and cyanobacteria under strongly surface stratified oceanic conditions. Although carbon isotope and C/N values of black shales show almost similar patterns at each location, there are site-specific shifts in these data that could be related to the amount of continental run off and/or the effect of latitude. Our multi-site comparison suggests that specially stratified depositional environments that could produce and accumulate the abnormally high carbon concentrations in sediments occurred throughout the proto-Atlantic ocean during the mid-Cretaceous. However, regional

  15. Nuclear resonance vibrational spectroscopy reveals the FeS cluster composition and active site vibrational properties of an O2-tolerant NAD+-reducing [NiFe] hydrogenase

    SciTech Connect

    Lauterbach, Lars; Wang, Hongxin; Horch, Marius; Gee, Leland B.; Yoda, Yoshitaka; Tanaka, Yoshihito; Zebger, Ingo; Lenz, Oliver; Cramer, Stephen P.

    2014-10-30

    Hydrogenases are complex metalloenzymes that catalyze the reversible splitting of molecular hydrogen into protons and electrons essentially without overpotential. The NAD+-reducing soluble hydrogenase (SH) from Ralstonia eutropha is capable of H2 conversion even in the presence of usually toxic dioxygen. The molecular details of the underlying reactions are largely unknown, mainly because of limited knowledge of the structure and function of the various metal cofactors present in the enzyme. Here, all iron-containing cofactors of the SH were investigated by 57Fe specific nuclear resonance vibrational spectroscopy (NRVS). Our data provide experimental evidence for one [2Fe2S] center and four [4Fe4S] clusters, which is consistent with the amino acid sequence composition. Only the [2Fe2S] cluster and one of the four [4Fe4S] clusters were reduced upon incubation of the SH with NADH. This finding explains the discrepancy between the large number of FeS clusters and the small amount of FeS cluster-related signals as detected by electron paramagnetic resonance spectroscopic analysis of several NAD+-reducing hydrogenases. For the first time, Fe–CO and Fe–CN modes derived from the [NiFe] active site could be distinguished by NRVS through selective 13C labeling of the CO ligand. This strategy also revealed the molecular coordinates that dominate the individual Fe–CO modes. The present approach explores the complex vibrational signature of the Fe–S clusters and the hydrogenase active site, thereby showing that NRVS represents a powerful tool for the elucidation of complex biocatalysts containing multiple cofactors.

  16. SITE RANK

    EPA Science Inventory

    Site rank is formulated for ranking the relative hazard of contamination sources and vulnerability of drinking water wells. Site rank can be used with a variety of groundwater flow and transport models.

  17. Fire water systems in composite materials

    SciTech Connect

    Sundt, J.L.

    1993-12-31

    Due to corrosion problems in fire water systems offshore there is a need for a corrosion resistant material to improve the reliability of onboard fire fighting systems. Glass Reinforced Epoxy (GRE) pipe is seen as a cost effective and light weight alternative to metals. Through a test program run by AMAT, Advanced Materials a/s in collaboration with the Norwegian Fire and Research Laboratory (NBL, SINTEF), GRE pipes have proved to be viable materials for offshore fire water systems. The test program included furnace testing, jetfire testing and simulated explosion testing. GRE pipes (2--12 inches) from two suppliers were fire tested and evaluated. Both adhesively bonded joints and flange connections were tested. During the course of the project, application methods of passive fire protection and nozzle attachments were improved.

  18. Direct GR Binding Sites Potentiate Clusters of TF Binding across the Human Genome.

    PubMed

    Vockley, Christopher M; D'Ippolito, Anthony M; McDowell, Ian C; Majoros, William H; Safi, Alexias; Song, Lingyun; Crawford, Gregory E; Reddy, Timothy E

    2016-08-25

    The glucocorticoid receptor (GR) binds the human genome at >10,000 sites but only regulates the expression of hundreds of genes. To determine the functional effect of each site, we measured the glucocorticoid (GC) responsive activity of nearly all GR binding sites (GBSs) captured using chromatin immunoprecipitation (ChIP) in A549 cells. 13% of GBSs assayed had GC-induced activity. The responsive sites were defined by direct GR binding via a GC response element (GRE) and exclusively increased reporter-gene expression. Meanwhile, most GBSs lacked GC-induced reporter activity. The non-responsive sites had epigenetic features of steady-state enhancers and clustered around direct GBSs. Together, our data support a model in which clusters of GBSs observed with ChIP-seq reflect interactions between direct and tethered GBSs over tens of kilobases. We further show that those interactions can synergistically modulate the activity of direct GBSs and may therefore play a major role in driving gene activation in response to GCs. PMID:27565349

  19. Value siting

    SciTech Connect

    Ferrar, T.A.; Howes, J.A.

    1995-02-01

    Finding an appropriate site is becoming an increasing challenge in building new power projects. One of the first orders of business in project development is identifying a site that offers the maximum spread between the cost of fuel and net power price. The collection of sites that exhibit an adequate spread - presenting a first-order, acceptable economic expectation - must now be subjected to an ever increasing number of political, societal, technical, and economic exclusion screens. The barriers can include cooling water constraints, community resistance, visual incompatibility, archaeological concerns and endangered species preservation issues. Most power siting difficulties can be substantially mitigated by gaining access to developed, but under-used sites, whose current owners are bound by circumstances - political or financial - that prevent them from using such locations. There are two such categories of sites: Utilities that have sites on which depreciated power production assets rest; and, The federal government, with numerous sites throughout the country, particularly military bases subject to closure under the Base Realignment and Closure (BRAC) proceedings. It is in the interests of developers, as well as consumers, investors and taxpayers, ti undertake a thorough examination of these overlooked pearls of opportunities and develop their potential.

  20. A SEDIMENT TOXICITY EVALUATION OF THREE LARGE RIVER SYSTEMS

    EPA Science Inventory

    Sediment toxicity samples were collected from selected sites on the Ohio River, Missouri River and upper Mississippi River as part of the 2004 and 2005 Environmental Monitoring and Assessment Program-Great Rivers Ecosystems Study (EMAP-GRE). Samples were collected by compositing...

  1. Electrocatalyst compositions

    DOEpatents

    Mallouk, Thomas E.; Chan, Benny C.; Reddington, Erik; Sapienza, Anthony; Chen, Guoying; Smotkin, Eugene; Gurau, Bogdan; Viswanathan, Rameshkrishnan; Liu, Renxuan

    2001-09-04

    Compositions for use as catalysts in electrochemical reactions are described. The compositions are alloys prepared from two or more elemental metals selected from platinum, molybdenum, osmium, ruthenium, rhodium, and iridium. Also described are electrode compositions including such alloys and electrochemical reaction devices including such catalysts.

  2. 40 CFR 761.289 - Compositing samples.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... porous surface from nearby locations for a single chemical analysis. There are two procedures for... sampling site locations in § 761.283(b) and (c). The single chemical analysis of a composite sample results... following procedures. (a) Compositing in the field or in a laboratory. Compositing may occur either in...

  3. Site Construction.

    ERIC Educational Resources Information Center

    Richardson, Eric C.

    1996-01-01

    Presents a guide to planning and building a Web site, with an emphasis on setting up a Web server. Discussion includes hiring a consultant, contracts and payment, assembly of teams, training, development of a business plan, registration of domain name, purchase of hardware and software, local area networks, and types of Internet connection. (JKP)

  4. Composite Materials

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Composites are lighter and stronger than metals. Aramid fibers like Kevlar and Nomex were developed by DuPont Corporation and can be combined in a honeycomb structure which can give an airplane a light, tough structure. Composites can be molded into many aerodynamic shapes eliminating rivets and fasteners. Langley Research Center has tested composites for both aerospace and non-aerospace applications. They are also used in boat hulls, military shelters, etc.

  5. Composites review

    NASA Technical Reports Server (NTRS)

    Hordonneau, A.

    1987-01-01

    The properties and applications of composite materials are reviewed. Glass, carbon, Kevlar, ceramic, whisker, and metal fibers are discussed along with polyester, epoxy, polyimide, Peek, carbon, ceramic, and metal matrices. The quantitative distribution of high technology fiber in various applications is given. The role of aerospace industry in the development and promotion of composite utilization is discussed. Consumption trends indicate a rapid development of the composite market.

  6. Energetic composites

    DOEpatents

    Danen, Wayne C.; Martin, Joe A.

    1993-01-01

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

  7. Energetic composites

    DOEpatents

    Danen, W.C.; Martin, J.A.

    1993-11-30

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application. 3 figures.

  8. Composite floorpan

    SciTech Connect

    Frutiger, R.L.; Baskar, S.

    1993-02-01

    Composite applications for automotive components have been a topic of increased interest. Some applications--load-bearing composites such as bumpers and leaf springs--have been implemented successfully in production vehicles. On the other hand, semi-structural load-bearing composites such as floorpans have not been investigated as extensively for stiffness, strength, and durability. Past studies have used structural composites to achieve parts consolidation in van crossmembers. A rear floorpan has also been demonstrated in composites. A hybrid vehicle structure consisting of a composite passenger module on a steel frame has been proposed. Assessments of the energy management of full composite front structures have also been reported. There remains a need to assess structural composites for a major load-bearing panel with real-vehicle packaging and design requirements; a floorplan is one such application. This design concept might be used in a space-frame vehicle structure in which composite panels could be used to complete the structure and provide additional torsional rigidity while meeting local strength and stiffness requirements.

  9. Electrode compositions

    DOEpatents

    Block, J.; Fan, X.

    1998-10-27

    An electrode composition is described for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C{sub 8}-C{sub 15} alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5--4.5 volts.

  10. Electrode compositions

    DOEpatents

    Block, Jacob; Fan, Xiyun

    1998-01-01

    An electrode composition for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C.sub.8 -C.sub.15 alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5-4.5 volts.

  11. Physical characteristics and fish assemblage composition at site and mesohabitat scales over a range of streamflows in the Middle Rio Grande, New Mexico, winter 2011-12, summer 2012

    USGS Publications Warehouse

    Braun, Christopher L.; Pearson, Daniel K.; Porter, Michael D.; Moring, J. Bruce

    2015-01-01

    Water-quality properties were only collected during summer 2012, when low-streamflow conditions existed and water-quality properties were thought to be potentially most limiting to aquatic life. Area-weighted mean water temperatures tended to be higher at the sites that were sampled in August 2012 (25.57 degrees Celsius [°C]) compared to June 2012 (24.61 °C). The highest area-weighted mean water temperature at a given site (29.03 °C) was measured at the Lemitar site on August 7, 2012, coincident with the lowest measured discharge (4.13 cubic feet per second [ft3/s]). Area-weighted mean dissolved oxygen concentrations tended to be lower in August (7.46 milligrams per liter [mg/L]) compared to June (8.33 mg/L). The highest area-weighted mean dissolved oxygen concentration (9.13 mg/L) was measured at the Lemitar site on August 7, 2012, and the lowest area-weighted mean dissolved oxygen concentration (6.23 mg/L) was measured at the Los Padillas site on August 10, 2012. Area-weighted specific conductance in the sites upstream from La Joya did not exceed 400 microsiemens per centimeter (μS/cm) at 25 °C, whereas the area-weighted mean specific conductance at La Joya (837 μs/cm at 25 °C), Rio Salado (857 μs/cm at 25 °C), and Lemitar (1,300 μs/cm at 25 °C) were all well above the average of the area-weighted means for the 10 remaining sites (433 μs/cm at 25 °C). Lower area-weighted mean pH values were measured at the 3 sites in and near Albuquerque (La Orilla, Barelas, and Los Padillas—7.98, 8.08, and 7.81, respectively) compared to any of the 10 remaining sites, which had an overall mean pH of 8.44.

  12. Comparing Composites.

    ERIC Educational Resources Information Center

    Mathras, Michael S.

    1993-01-01

    Presents an activity that models the work of chemical engineers. Students design, fabricate, and perform mechanical tests on plaster matrix composites and compare the strength to mass ratios of several products. (PR)

  13. Fuel composition

    SciTech Connect

    Johnson, T.H.

    1990-06-26

    This patent describes a motor fuel composition. It comprises: a mixture of hydrocarbons in the gasoline boiling range containing a deposit preventing or reducing effective amount of poly(olefin)-N-substituted- carbamate.

  14. Hydride compositions

    DOEpatents

    Lee, Myung W.

    1995-01-01

    A composition for use in storing hydrogen, and a method for making the composition. The composition comprises a mixture of two or more hydrides, each hydride having a different series of hydrogen sorption isotherms that contribute to the overall isotherms of the mixture. The hydrides are chosen so that the isotherms of the mixture have regions wherein the hydrogen equilibrium pressure increases with increasing hydrogen, preferably linearly. The isotherms of the mixture can be adjusted by selecting hydrides with different isotherms and by varying the amounts of the individual hydrides, or both. Preferably, the mixture is made up of hydrides that have isotherms with substantially flat plateaus and in nearly equimolar amounts. The composition is activated by degassing, exposing to hydrogen and then heating at a temperature below the softening temperature of any of the. constituents so that their chemical and structural integrity is preserved. When the composition is used to store hydrogen, its hydrogen content can be found simply by measuring P.sub.H.sbsb.2 and determining H/M from the isothermic function of the composition.

  15. Hydride compositions

    DOEpatents

    Lee, Myung, W.

    1994-01-01

    Disclosed are a composition for use in storing hydrogen and a method for making the composition. The composition comprises a mixture of two or more hydrides, each hydride having a different series of hydrogen sorption isotherms that contribute to the overall isotherms of the mixture. The hydrides are chosen so that the isotherms of the mixture have regions wherein the H equilibrium pressure increases with increasing hydrogen, preferably linearly. The isotherms of the mixture can be adjusted by selecting hydrides with different isotherms and by varying the amounts of the individual hydrides, or both. Preferably, the mixture is made up of hydrides that have isotherms with substantially flat plateaus and in nearly equimolar amounts. The composition is activated by degassing, exposing to H, and then heating below the softening temperature of any of the constituents. When the composition is used to store hydrogen, its hydrogen content can be found simply by measuring P{sub H}{sub 2} and determining H/M from the isothermic function of the composition.

  16. Pd(0.213)Cd(0.787) and Pd(0.235)Cd(0.765) structures: their long c axis and composite crystals, chemical twinning, and atomic site preferences.

    PubMed

    Schmidt, Joshua Teal; Lee, Stephen; Fredrickson, Daniel C; Conrad, Matthias; Sun, Junliang; Harbrecht, Bernd

    2007-01-01

    We present single-crystal studies of Pd(0.213)Cd(0.787) and Pd(0.235)Cd(0.765), synchrotron powder studies of Pd(1-x)Cd(x), 0.755> or =x> or =0.800, and LDA-DFT and extended Hückel (eH) calculations on these or related phases. The two single-crystal structures have a, b, and c axis lengths of 9.9013(7), 14.0033(10), 37.063(24) and 9.9251(3), 14.0212(7), 60.181(3) A, respectively and they crystallize in the space groups Ccme and F2mm, respectively (solved as (3+1)-dimensional crystals their most convenient superspace group is Xmmm(00gamma)s00). The structures have two different structural components each with their own separate axis parameters. Powder data shows that the ratio of these separate axes (S/L) varies from 1.615 to 1.64, values near the golden mean (1.618). For Pd(0.213)Cd(0.787), different Pd and Cd site occupancies lead to variation in the R factor from 2.6-3.6 %. The site occupancy pattern with the lowest R factor (among the 26 820 variants studied) is the exact site occupancy pattern predicted by LDA-DFT parameterized eH Mulliken charge populations. The phases can be understood through a chemical twinning principle found in gamma-brass, the parent structure for the above phases (a relation with the MgCu(2) Laves phase is also noted). This twinning principle can be used to account for Cd and Pd site preferences. At the same time there is a clean separation among the Cd and Pd atoms for the two separate chain types at height b=0 and 1/2. These results indicate that Cd:Pd stoichiometry plays a role in phase stability. PMID:17091515

  17. Photoimageable composition

    DOEpatents

    Dentinger, Paul; Krafick, Karen L.; Simison, Kelby Liv

    2005-02-22

    The use of photoacid generators including an alkoxyphenylphenyliodonium salt and/or bis(t-butylphenyl)iodonium salt in a photoimageable composition helps improve resolution. Suitable photoimageable compositions includes: (a) a multifuctional polymeric epoxy resin that is dissolved in an organic solvent wherein the epoxy resin comprises oligomers of bisphenol A that is quantitatively protected by glycidyl ether and wherein the oligomers have an average functionality that ranges from about 3 to 12; and a photoacid generator comprising an alkoxyphenylphenyliodonium salt and/or bis(t-butylphenyl)iodonium salt. Preferred alkoxyphenylphenyliodonium salts include 4-octyloxyphenyl phenyliodonium hexafluoroantimonate and 4-methoxyphenyl phenyliodonium hexafluoroantimonate. The photoimageable composition is particularly suited for producing high aspect ratio microstructures.

  18. Photoimageable composition

    DOEpatents

    Simison, Kelby Liv; Dentinger, Paul

    2003-11-11

    The use of selected buffering amines in a photoimageable composition prevents process bias which with conventional photoresists causes designed features to be distorted, especially in corners and high resolution features. It is believed that the amines react with the catalysts, e.g., photoacids, generated to create an inert salt. The presence of the amines also increases resolution. Suitable photoimageable compositions includes: (a) a multifunctional polymeric epoxy resin that is dissolved in an organic solvent wherein the epoxy resin comprises oligomers of bisphenol A that is quantitatively protected by glycidyl ether and wherein the oligomers have an average functionality that ranges from about 3 to 12; (b) a photoactive compound; and (c) an amine that is selected from the group consisting of triisobutylamine, 1,8-bis(dimethylamino)naphthalene (also known as PROTON SPONGET.TM.), 2,2'-diazabicyclo[2.2.2] octane and mixtures thereof. The photoimageable composition is particularly suited for producing high aspect ratio metal microstructures.

  19. Composite material

    DOEpatents

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O'Neill, Hugh M.

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  20. Surfactant compositions

    SciTech Connect

    Novakovic, M.; Abend, P.G.

    1987-09-29

    A surfactant composition is described for subsequent addition to a soap slurring comprising an acyloxy alkane sulfonate salt. The sulfonate salt is present in an amount by weight of about 44 percent of about 56 percent. The polyol is present in an amount by weight of about 2 percent to about 6 percent, and water is present in an amount by weight of 26 to 36 percent. The composition constituting a solid reversible solution at ambient temperature and having a solids content of about 58 to 72 percent, whereby subsequent addition of the surfactant composition to a soap slurry results in formation of a soap/detergent bar having a smooth texture, uniform wear properties and a lack of grittiness.

  1. Physical composition

    NASA Astrophysics Data System (ADS)

    Healey, Richard

    2013-02-01

    Atomistic metaphysics motivated an explanatory strategy which science has pursued with great success since the scientific revolution. By decomposing matter into its atomic and subatomic parts physics gave us powerful explanations and accurate predictions as well as providing a unifying framework for the rest of science. The success of the decompositional strategy has encouraged a widespread conviction that the physical world forms a compositional hierarchy that physics and other sciences are progressively articulating. But this conviction does not stand up to a closer examination of how physics has treated composition, as a variety of case studies will show.

  2. Composite Riflescope

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Bushnell Division of Bausch & Lomb's Armor-Sight riflescope combines the company's world-renowned optics with a graphite composite (Graphlon VI) developed for space applications. The riflescope is 10 percent lighter than aluminum scopes, and, because its thermal expansion coefficient is near zero, optical distortion from heat and cold extremes is eliminated. It is fogproof and waterproof; advanced multicoated optics provide maximum light transmission to brighten target ranges. Bushnell was assisted by NIAC/USC in searching for technical information on graphic composites and in overcoming difficulties with bonding and porosity.

  3. Composite Cores

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

  4. EVALUATION OF COMPOSITE RECEPTOR METHODS

    EPA Science Inventory

    A composite receptor model for PM-10 apportionment was evaluated to determine the stability of its solutions and to devise cost-effective measurement strategies. Ambient aerosol samples used in the evaluation were obtained with dichotomous samplers at three sites in the vicinity ...

  5. COMPOSITE ELEMENT

    DOEpatents

    Schaner, B.E.; Wolfe, R.A.

    1962-12-18

    Composite fuel eiements of the sandwich type are reported. The invention resides in the use of a layer of graphite on the interfaces of the flssile material and the cladding to prevent interdiffusion of the fissile material and the ciadding material. (AEC)

  6. Music Composition

    ERIC Educational Resources Information Center

    Helfer, Jason A.

    2015-01-01

    Historically, music programs in K-12 schools have emphasized performance opportunities for children and young people. Until the release of the 1994 National Standards in Music, targeted instruction in composition was frequently overlooked due to the emphasis on performance as well as the expectations of what a school music program ought to produce…

  7. Phosphorescent compositions, methods of making the compositions, and methods of using the compositions

    DOEpatents

    Jia, Weiyi; Wang, Xiaojun; Jia, George D.; Lewis, Linda; Yen, Laurel C.

    2014-06-24

    Compositions, methods of making compositions, materials including compositions, crayons including compositions, paint including compositions, ink including compositions, waxes including compositions, polymers including compositions, vesicles including the compositions, methods of making each, and the like are disclosed.

  8. Phosphorescent compositions, methods of making the compositions, and methods of using the compositions

    DOEpatents

    Jia, Weiyi; Wang, Xiaojun; Yen, William; Yen, Laurel C.; Jia, George D.

    2012-12-04

    Compositions, methods of making compositions, materials including compositions, crayons including compositions, paint including compositions, ink including compositions, waxes including compositions, polymers including compositions, vesicles including the compositions, methods of making each, and the like are disclosed.

  9. 40 CFR 761.289 - Compositing samples.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROHIBITIONS Sampling To Verify Completion of Self-Implementing Cleanup and On-Site Disposal of Bulk PCB.... Compositing is a method of combining several samples of a specific type of bulk PCB remediation waste or... compositing bulk PCB remediation waste samples. These procedures are based on the method for...

  10. 40 CFR 761.289 - Compositing samples.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROHIBITIONS Sampling To Verify Completion of Self-Implementing Cleanup and On-Site Disposal of Bulk PCB.... Compositing is a method of combining several samples of a specific type of bulk PCB remediation waste or... compositing bulk PCB remediation waste samples. These procedures are based on the method for...

  11. 40 CFR 761.289 - Compositing samples.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROHIBITIONS Sampling To Verify Completion of Self-Implementing Cleanup and On-Site Disposal of Bulk PCB.... Compositing is a method of combining several samples of a specific type of bulk PCB remediation waste or... compositing bulk PCB remediation waste samples. These procedures are based on the method for...

  12. 40 CFR 761.289 - Compositing samples.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sampling site locations in § 761.283(b) and (c). The single chemical analysis of a composite sample results in an averaging of the concentrations of its component samples. The area of inference of a composite... porous surface from nearby locations for a single chemical analysis. There are two procedures...

  13. Perturbation of DNA hairpins containing the EcoRI recognition site by hairpin loops of varying size and composition: physical (NMR and UV) and enzymatic (EcoRI) studies.

    PubMed Central

    Germann, M W; Kalisch, B W; Lundberg, P; Vogel, H J; van de Sande, J H

    1990-01-01

    We have investigated loop-induced structural perturbation of the stem structure in hairpins d(GAATTCXnGAATTC) (X = A, T and n = 3, 4, 5 and 6) that contain an EcoRI restriction site in close proximity to the hairpin loop. Oligonucleotides containing either a T3 or a A3 loop were not hydrolyzed by the restriction enzyme and also showed only weak binding to EcoRI in the absence of the cofactor Mg2+. In contrast, hairpins with larger loops are hydrolyzed by the enzyme at the scission site next to the loop although the substrate with a A4 loop is significantly more resistant than the oligonucleotide containing a T4 loop. The hairpin structures with 3 loop residues were found to be thermally most stable while larger hairpin loops resulted in structures with lower melting temperatures. The T-loop hairpins are thermally more stable than the hairpins containing the same number of A residues in the loop. As judged from proton NMR spectroscopy and the thermodynamic data, the base pair closest to the hairpin loop did form in all cases studied. The hairpin loops did, however, affect the conformation of the stem structure of the hairpins. From 31P and 1H NMR spectroscopy we conclude that the perturbation of the stem structure is stronger for smaller hairpin loops and that the extent of the perturbation is limited to 2-3 base pairs for hairpins with T3 or A4 loops. Our results demonstrate that hairpin loops modulate the conformation of the stem residues close to the loop and that this in turn reduces the substrate activity for DNA sequence specific proteins. Images PMID:2326190

  14. New innovations in composites

    NASA Technical Reports Server (NTRS)

    Bluck, R. M.; Johnson, R. R.

    1984-01-01

    Procedures for manufacturing metal clad graphite resin structural elements applicable to optical systems requiring precisely controlled thermal and mechanical properties are described. Analytical estimates were made of the material properties that can be obtained for various ratios of graphite epoxy and aluminum cladding. Three graphite fiber systems were evaluated. Two manufacturing processes are described. One method is a procedure for manufacturing long tubes by wrapping aluminum foil over dry graphite fiber. Resin was applied by spreading before applying the aluminum wrap. A second approach, offering the opportunity for precise tuning of the coefficient of expansion, is by die flattening metal tubing through which a measured amount of fiber has been drawn. Prior to flattening, resin is injected, and after flattening or shaping the part is cured. This latter procedure offers the opportunity to fine tune the structure to achieve a CTE with a precision equal to that of the measuring systems-by modifying the number of fiber tows prior to manufacturing or by etching the metal after manufacturing. Experimental verification and demonstration data are presented for Gr/E bars with aluminum and steel skins.

  15. A-site compositional effects in Ga-doped hollandite materials of the form BaxCsyGa2x+yTi8-2x-yO16: implications for Cs immobilization in crystalline ceramic waste forms.

    PubMed

    Xu, Yun; Wen, Yi; Grote, Rob; Amoroso, Jake; Shuller Nickles, Lindsay; Brinkman, Kyle S

    2016-01-01

    The hollandite structure is a promising crystalline host for Cs immobilization. A series of Ga-doped hollandite BaxCsyGa2x+yTi8-2x-yO16 (x = 0, 0.667, 1.04, 1.33; y = 1.33, 0.667, 0.24, 0) was synthesized through a solid oxide reaction method resulting in a tetragonal hollandite structure (space group I4/m). The lattice parameter associated with the tunnel dimension was found to increases as Cs substitution in the tunnel increased. A direct investigation of cation mobility in tunnels using electrochemical impedance spectroscopy was conducted to evaluate the ability of the hollandite structure to immobilize cations over a wide compositional range. Hollandite with the largest tunnel size and highest aspect ratio grain morphology resulting in rod-like microstructural features exhibited the highest ionic conductivity. The results indicate that grain size and optimized Cs stoichiometry control cation motion and by extension, the propensity for Cs release from hollandite. PMID:27273791

  16. Chemical and Isotopic Composition and Gas Concentrations of Ground Water and Surface Water from Selected Sites At and Near the Idaho National Engineering and Environmental Laboratory, Idaho, 1994-97

    SciTech Connect

    E. Busenberg; L. N. Plummer; M. W. Doughten; P. K. Widman; R. C. Bartholomay

    2000-05-30

    >From May 1994 through May 1997, the US Geological Survey, in cooperation with the US Department of Energy, collected water samples from 86 wells completed in the Snake River Plain aquifer at and near the Idaho National Engineering and Environmental Laboratory. The samples were analyzed for a variety of chemical constituents including all major elements and 22 trace elements. Concentrations of scandium, yttrium, and the lanthanide series were measured in samples from 11 wells and 1 hot spring. The data will be used to determine the fraction of young water in the ground water. The fraction of young water must be known to calculate the ages of ground water using chlorofluorocarbons. The concentrations of the isotopes deuterium, oxygen-18, carbon-13, carbon-14, and tritium were measured in many ground water, surface-water and spring samples. The isotopic composition will provide clues to the origin and sources of water in the Snake River Plain aquifer. Concentrations ! of helium-3 , helium-4, total helium, and neon were measured in most groundwater samples, and the results will be used to determine the recharge temperature, and to date the ground waters.

  17. A-site compositional effects in Ga-doped hollandite materials of the form BaxCsyGa2x+yTi8−2x−yO16: implications for Cs immobilization in crystalline ceramic waste forms

    PubMed Central

    Xu, Yun; Wen, Yi; Grote, Rob; Amoroso, Jake; Shuller Nickles, Lindsay; Brinkman, Kyle S.

    2016-01-01

    The hollandite structure is a promising crystalline host for Cs immobilization. A series of Ga-doped hollandite BaxCsyGa2x+yTi8−2x−yO16 (x = 0, 0.667, 1.04, 1.33; y = 1.33, 0.667, 0.24, 0) was synthesized through a solid oxide reaction method resulting in a tetragonal hollandite structure (space group I4/m). The lattice parameter associated with the tunnel dimension was found to increases as Cs substitution in the tunnel increased. A direct investigation of cation mobility in tunnels using electrochemical impedance spectroscopy was conducted to evaluate the ability of the hollandite structure to immobilize cations over a wide compositional range. Hollandite with the largest tunnel size and highest aspect ratio grain morphology resulting in rod-like microstructural features exhibited the highest ionic conductivity. The results indicate that grain size and optimized Cs stoichiometry control cation motion and by extension, the propensity for Cs release from hollandite. PMID:27273791

  18. A-site compositional effects in Ga-doped hollandite materials of the form BaxCsyGa2x+yTi8‑2x‑yO16: implications for Cs immobilization in crystalline ceramic waste forms

    NASA Astrophysics Data System (ADS)

    Xu, Yun; Wen, Yi; Grote, Rob; Amoroso, Jake; Shuller Nickles, Lindsay; Brinkman, Kyle S.

    2016-06-01

    The hollandite structure is a promising crystalline host for Cs immobilization. A series of Ga-doped hollandite BaxCsyGa2x+yTi8‑2x‑yO16 (x = 0, 0.667, 1.04, 1.33; y = 1.33, 0.667, 0.24, 0) was synthesized through a solid oxide reaction method resulting in a tetragonal hollandite structure (space group I4/m). The lattice parameter associated with the tunnel dimension was found to increases as Cs substitution in the tunnel increased. A direct investigation of cation mobility in tunnels using electrochemical impedance spectroscopy was conducted to evaluate the ability of the hollandite structure to immobilize cations over a wide compositional range. Hollandite with the largest tunnel size and highest aspect ratio grain morphology resulting in rod-like microstructural features exhibited the highest ionic conductivity. The results indicate that grain size and optimized Cs stoichiometry control cation motion and by extension, the propensity for Cs release from hollandite.

  19. Investigation of Response Changes in the GRE Revised General Test

    ERIC Educational Resources Information Center

    Liu, Ou Lydia; Bridgeman, Brent; Gu, Lixiong; Xu, Jun; Kong, Nan

    2015-01-01

    Research on examinees' response changes on multiple-choice tests over the past 80 years has yielded some consistent findings, including that most examinees make score gains by changing answers. This study expands the research on response changes by focusing on a high-stakes admissions test--the Verbal Reasoning and Quantitative Reasoning measures…

  20. Structure of the unique SEFIR domain from human interleukin 17 receptor A reveals a composite ligand-binding site containing a conserved α-helix for Act1 binding and IL-17 signaling

    SciTech Connect

    Zhang, Bing; Liu, Caini; Qian, Wen; Han, Yue; Li, Xiaoxia; Deng, Junpeng

    2014-05-01

    Crystal structure of the SEFIR domain from human IL-17 receptor A provides new insights into IL-17 signaling. Interleukin 17 (IL-17) cytokines play a crucial role in mediating inflammatory and autoimmune diseases. A unique intracellular signaling domain termed SEFIR is found within all IL-17 receptors (IL-17Rs) as well as the key adaptor protein Act1. SEFIR-mediated protein–protein interaction is a crucial step in IL-17 cytokine signaling. Here, the 2.3 Å resolution crystal structure of the SEFIR domain of IL-17RA, the most commonly shared receptor for IL-17 cytokine signaling, is reported. The structure includes the complete SEFIR domain and an additional α-helical C-terminal extension, which pack tightly together to form a compact unit. Structural comparison between the SEFIR domains of IL-17RA and IL-17RB reveals substantial differences in protein topology and folding. The uniquely long insertion between strand βC and helix αC in IL-17RA SEFIR is mostly well ordered, displaying a helix (αCC′{sub ins}) and a flexible loop (CC′). The DD′ loop in the IL-17RA SEFIR structure is much shorter; it rotates nearly 90° with respect to the counterpart in the IL-17RB SEFIR structure and shifts about 12 Å to accommodate the αCC′{sub ins} helix without forming any knots. Helix αC was identified as critical for its interaction with Act1 and IL-17-stimulated gene expression. The data suggest that the heterotypic SEFIR–SEFIR association via helix αC is a conserved and signature mechanism specific for IL-17 signaling. The structure also suggests that the downstream motif of IL-17RA SEFIR together with helix αC could provide a composite ligand-binding surface for recruiting Act1 during IL-17 signaling.

  1. Transcript abundance of the pig stearoyl-CoA desaturase gene has no effect on fatty acid composition in muscle and fat tissues, but its polymorphism within the putative microRNA target site is associated with daily body weight gain and feed conversion ratio.

    PubMed

    Bartz, M; Szydlowski, M; Kociucka, B; Salamon, S; Jeleń, H H; Switonski, M

    2013-01-01

    Fatty acid composition in porcine intramuscular fat affects the dietetic value and technological properties of meat. The stearoyl-CoA desaturase (SCD) gene is a strong positional and functional candidate for fatty acid composition. Our sequence analysis in 4 breeds (Duroc, Pietrain, Polish Landrace, and Polish Large White) revealed a novel SNP in the 5'-flanking sequence and 9 novel SNP and 2 novel indels in the 3' untranslated region (UTR). Transcript level of the SCD in subcutaneous fat was significantly greater than in muscle tissue (n=83; P<0.001) and the interbreed comparison revealed a greater transcript level in the fat tissue of Polish Landrace (P<0.01). We found no association between the abundance of the SCD transcript and fatty acid composition in any of the tissues. We performed an association analysis between 4 SNP (c.-353C>T, c.-233T>C, c.*164A>G, and c.*928G>C), 1 indel (c.*2574_2576delGTC), and production traits in Polish Large White (n=185) and synthetic line 990 (n=243). The most pronounced associations were observed for the c.*928G>C polymorphism, which occurs within a predicted target site for 2 microRNA (ssc-miR-185 and ssc-miR-491). In line 990, this polymorphism was significantly associated with daily BW gain (P<0.04 under the general model) and feed conversion ratio (P<0.0004) but not with fatness traits. The same tendency, but not significant, was observed in the Polish Large White breed. When both breeds were analyzed together, these associations were again highly significant (daily BW gain P<0.003; feed conversion ratio P<0.0001). We conclude that c.*928G>C is a promising marker for both porcine traits. PMID:23048140

  2. Elemental composition, isotopes, electrons and positrons in cosmic rays

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.

    1979-01-01

    Papers presented at the 16th International Cosmic Ray Conference, Kyoto, Japan, dealing with the composition of cosmic rays are reviewed. Particular interest is given to data having bearing on nucleosynthesis sites, supernovae, gamma-process, comparison with solar system composition, multiplicity of sources, and the energy dependence of composition.

  3. Concrete compositions and methods

    SciTech Connect

    Chen, Irvin; Lee, Patricia Tung; Patterson, Joshua

    2015-06-23

    Provided herein are compositions, methods, and systems for cementitious compositions containing calcium carbonate compositions and aggregate. The compositions find use in a variety of applications, including use in a variety of building materials and building applications.

  4. ) Hybrid Composite

    NASA Astrophysics Data System (ADS)

    Show, Bijay Kumar; Mondal, Dipak Kumar; Maity, Joydeep

    2014-12-01

    In this research work, the dry sliding wear behavior of 6351 Al-(4 vol.% SiC + 4 vol.% Al2O3) hybrid composite was investigated at low sliding speed (1 m/s) against a hardened EN 31 disk at different loads. In general, the wear mechanism involved adhesion (along with associated subsurface cracking and delamination) and microcutting abrasion at lower load. While at higher load, abrasive wear involving microcutting and microploughing along with adherent oxide formation was observed. The overall wear rate increased with increasing normal load. The massive particle clusters as well as individual reinforcement particles were found to stand tall to resist abrasive wear. Besides, at higher load, the generation of adherent nodular tribo-oxide through nucleation and epitaxial growth on existing Al2O3 particles lowered down the wear rate. Accordingly, at any normal load, 6351 Al-(4 vol.% SiC + 4 vol.% Al2O3) hybrid composite exhibited superior wear resistance (lower overall wear rate) than the reported wear resistance of monolithic 6351 Al alloy.

  5. Implementation: Preparing the Site.

    ERIC Educational Resources Information Center

    Epstein, Susan Baerg

    1983-01-01

    Considers site requirements that should be specified by the library and the vendor for a library automated system located at a central site away from the library, including size of site, the environment, cleanliness, electrical power, security/safety (fire, restricted access), site certification, telecommunications, and terminal sites. (EJS)

  6. Promoting Your Web Site.

    ERIC Educational Resources Information Center

    Raeder, Aggi

    1997-01-01

    Discussion of ways to promote sites on the World Wide Web focuses on how search engines work and how they retrieve and identify sites. Appropriate Web links for submitting new sites and for Internet marketing are included. (LRW)

  7. Composite Tank

    NASA Technical Reports Server (NTRS)

    DeLay, Thomas K. (Inventor)

    2000-01-01

    A composite tank for containing liquid oxygen and the method of making the same Wherein a water-soluble mandrel having ing the desired tank configuration and a cylindrical protuberance on at least one end is fitted with an inner boss conformance, to the configuration of the mandrel and in outer boss conforming to the configuration of the inner boss, the bosses each having a tubular portion for receiving the protuberance on the mandrel and a spherical portion. The mandrel and the bosses are first coated with a nickel coating. The mandrel is then wrapped with graphite fibers wetted with an epoxy resin and this resin is cured. A layer of insulating foam is then applied to the tank and cured. The insulating foam is machined to a desired concentration and a layer of aramid fibers wetted with a second epoxy resin is wrapped around the tank. The second resin is cured and the water soluble mandrel is washed from inside the tank.

  8. Composite foams

    DOEpatents

    Williams, Jr., Joel M.; Nyitray, Alice M.; Wilkerson, Mark H.

    1990-01-01

    Composite foams are provided comprising a first rigid, microcellular, open-celled organic polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 1 micron to about 30 microns, said first foam containing a second polymer having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 or a second polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 0.01 microns to about 1.0 micron within the open cells of said first foam.

  9. Composite foams

    DOEpatents

    Williams, Jr., Joel M.; Nyitray, Alice M.; Wilkerson, Mark H.

    1991-01-01

    Composite foams are provided comprising a first rigid, microcellular, open-celled organic polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 1 micron to about 30 microns, said first foam containing a second polymer having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 or a second polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 0.01 microns to about 1.0 micron within the open cells of said first foam.

  10. Hanford Site Development Plan

    SciTech Connect

    Rinne, C.A.; Curry, R.H.; Hagan, J.W.; Seiler, S.W.; Sommer, D.J. ); Yancey, E.F. )

    1990-01-01

    The Hanford Site Development Plan (Site Development Plan) is intended to guide the short- and long-range development and use of the Hanford Site. All acquisition, development, and permanent facility use at the Hanford Site will conform to the approved plan. The Site Development Plan also serves as the base document for all subsequent studies that involve use of facilities at the Site. This revision is an update of a previous plan. The executive summary presents the highlights of the five major topics covered in the Site Development Plan: general site information, existing conditions, planning analysis, Master Plan, and Five-Year Plan. 56 refs., 67 figs., 31 tabs.

  11. A composite photobioelectronic material

    SciTech Connect

    Greenbaum, E.

    1988-01-01

    The research described presents a method for chemically modifying the surface of green plant photosynthetic membranes in such a way that electrical contact can be made. Colloidal platinum was prepared, precipitated directly onto photosynthetic thylakoid membranes from aqueous solution, and entrapped on fiberglass filter paper. This composition of matter was capable of sustained simultaneous photoevolution of hydrogen and oxygen when irradiated at any wavelength in the chlorophyll absorption spectrum. Experimental data support the interpretation that part of the platinum metal catalyst is precipitated adjacent to the photosystem-I reduction site of photosynthesis and that electron transfer occurs across the interface between photosystem-I and the catalyst. When contacted with metal electrodes, the thylakoid-platinum combination is capable of generating a sustained flow of current through an external load resistor. Procedures for preparing this material and experimental data on its catalytic and electronic properties are presented. 14 refs., 6 figs.

  12. Al Composites

    NASA Astrophysics Data System (ADS)

    Chandanayaka, Tharaka; Azarmi, Fardad

    2014-05-01

    In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

  13. Hanford Site Development Plan

    SciTech Connect

    Hathaway, H.B.; Daly, K.S.; Rinne, C.A.; Seiler, S.W.

    1993-05-01

    The Hanford Site Development Plan (HSDP) provides an overview of land use, infrastructure, and facility requirements to support US Department of Energy (DOE) programs at the Hanford Site. The HSDP`s primary purpose is to inform senior managers and interested parties of development activities and issues that require a commitment of resources to support the Hanford Site. The HSDP provides an existing and future land use plan for the Hanford Site. The HSDP is updated annually in accordance with DOE Order 4320.1B, Site Development Planning, to reflect the mission and overall site development process. Further details about Hanford Site development are defined in individual area development plans.

  14. SCHOOL SITE STANDARDS AND SITE SELECTION.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany.

    THIS REPORT PRESENTS ELEMENTARY AND SECONDARY SCHOOL SITE DEVELOPMENT DATA COMPILED BY THE DIVISION OF EDUCATIONAL FACILITIES PLANNING, NEW YORK STATE EDUCATION DEPARTMENT. ENROLLMENT FIGURES USED REPRESENT THE ULTIMATE SIZE OF THE SCHOOLS. THE STANDARDS ARE MINIMUM FOR THE STATE OF NEW YORK WITH ELEMENTARY SCHOOL SITES BASED ON THREE ACRES PLUS…

  15. Fatigue of composites

    NASA Technical Reports Server (NTRS)

    Salkind, M. J.

    1972-01-01

    The failure mechanisms in the fatigue of composite materials are analyzed in terms of the requirements for designing fatigue-critical composite structures. Fiber reinforced polymers, fiber reinforced metals, fatigue of composite structures, and composite design considerations are discussed. It is concluded that composite materials offer the engineer the opportunity for tailoring stiffness in different directions for designing dynamic components.

  16. Composite powder particles

    NASA Technical Reports Server (NTRS)

    Parker, Donald S. (Inventor); MacDowell, Louis G. (Inventor)

    2009-01-01

    A liquid coating composition including a coating vehicle and composite powder particles disposed within the coating vehicle. Each composite powder particle may include a magnesium component, a zinc component, and an indium component.

  17. SITE CHARACTERIZATION USING BIRD SPECIES COMPOSITION IN EASTERN OREGON, USA

    EPA Science Inventory

    We conducted riparian bird surveys at 25 randomly selected stream reaches in the John Day River Basin of eastern Oregon as part of the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP). At each reach along a kilometer-length transect, ...

  18. Environmental effects on composites for aircraft

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1978-01-01

    A number of ongoing, long-term environmental effects programs for composite materials are evaluated. The flight service experience was evaluated for 142 composite aircraft components after more than 5 years and 1 million successful component flight hours. Ground-based outdoor exposures of composite material coupons after 3 years of exposure at 5 sites have reached equilibrium levels of moisture pickup which are predictable. Solar ultraviolet-induced material loss is discussed for these same exposures. No significant degradation was observed in residual strength for either stressed or unstressed specimens, or for exposures to aviation fuels and fluids.

  19. The Nifty Assignments Site.

    ERIC Educational Resources Information Center

    Parlante, Nick

    2001-01-01

    Describes a Web site called Nifty Assignments that offers assignments for computer science education. Topics include programming assignments; student appeal; appropriateness for high school classes; and links to other related Web sites. (LRW)

  20. Field site selection

    NASA Technical Reports Server (NTRS)

    Schwarz, D. E.; Ellefsen, R. E.

    1981-01-01

    Several general guidelines should be kept in mind when considering the selection of field sites for teaching remote sensing fundamentals. Proximity and vantage point are two very practical considerations. Only through viewing a broad enough area to place the site in context can one make efficient use of a site. The effects of inclement weather when selecting sites should be considered. If field work is to be an effective tool to illustrate remote sensing principles, the following criteria are critical: (1) the site must represent the range of class interest; (2) the site must have a theme or add something no other site offers; (3) there should be intrasite variation within the theme; (4) ground resolution and spectral signature distinction should be illustrated; and (5) the sites should not be ordered sequentially.

  1. Site Environmental Report, 1993

    SciTech Connect

    Not Available

    1994-06-01

    The Site Environmental Report (SER) is prepared annually in accordance with DOE Order 5400.1, ``General Environmental Protection Program.`` This 1993 SER provides the general public as well as scientists and engineers with the results from the site`s ongoing Environmental Monitoring Program. Also included in this report is information concerning the site`s progress toward achieving full compliance with requirements set forth by DOE, US Environmental Protection Agency (USEPA), and Ohio EPA (OEPA). For some readers, the highlights provided in the Executive Summary may provide sufficient information. Many readers, however, may wish to read more detailed descriptions of the information than those which are presented here.

  2. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Loewy, R. G.; Wiberley, S. E.

    1985-01-01

    Various topics relating to composite structural materials for use in aircraft structures are discussed. The mechanical properties of high performance carbon fibers, carbon fiber-epoxy interface bonds, composite fractures, residual stress in high modulus and high strength carbon fibers, fatigue in composite materials, and the mechanical properties of polymeric matrix composite laminates are among the topics discussed.

  3. Conducting Compositions of Matter

    NASA Technical Reports Server (NTRS)

    Viswanathan, Tito (Inventor)

    1999-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  4. Conducting compositions of matter

    NASA Technical Reports Server (NTRS)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  5. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

    1983-01-01

    Transverse properties of fiber constituents in composites, fatigue in composite materials, matrix dominated properties of high performance composites, numerical investigation of moisture effects, numerical investigation of the micromechanics of composite fracture, advanced analysis methods, compact lug design, and the RP-1 and RP-2 sailplanes projects are discussed.

  6. Site Development Planning Handbook

    SciTech Connect

    1981-01-01

    The Handbook provides facility managers and site planners at DOE organizations responsible for planning site developments and facilities utilization a step-by-step planning checklist to ensure that planners at each site are focusing on Department-wide goals and objectives. It begins with a brief discussion of a site development-by-objectives program design to promote, recognize, and implement opportunities for improvements in site utilization through planning. Additional information is included on: assembling existing data, plans, programs, and procedures; establishing realistic objectives; identifying site problems, opportunities; and development needs; determining priorities among development needs; developing short and long-range plans; choosing the right development solutions and meeting minimum legal site restrictions; presenting the plan; implementing elements of the plan; monitoring and reporting plan status; and modifying development program plans. (MCW)

  7. Dynamic response and acoustic fatigue of stiffened composite structure

    NASA Technical Reports Server (NTRS)

    Soovere, J.

    1984-01-01

    The results of acoustic fatigue and dynamic response tests performed on L-1011 graphite-epoxy (GrE) aileron and panel components are reported. The aileron featured glass microballoons between the GrE skins. Tests yielded random fatigue data from double and single cantilever coupons and modal data from impedance hammer and loudspeaker impulses. Numerical and sample test data were obtained on combined acoustic and shear loads, acoustic and thermal loads, random fatigue and damping of the integrally stiffened and secondary bonded panels. The fatigue data indicate a fatigue life beyond 10 million cycles. The acoustic data suggested that noise transmission could be enhanced in the integrally stiffened panels, which were more acoustic-fatigue resistant than were the secondary bonded panels.

  8. Development of metal hydride composites

    SciTech Connect

    Congdon, J.W.

    1992-12-01

    Most of current hydride technology at Savannah River Site is based on beds of metal hydride powders; the expansion upon hydridation and the cycling results in continued breakdown into finer particles. Goal is to develop a composite which will contain the fines in a dimensionally stable matrix, for use in processes which require a stable gas flow through a hydride bed. Metal hydride composites would benefit the advanced Thermal Cycling Absorption process (hydrogen isotope separation), and the Replacement Tritium Facility (storage, pumping, compression, purification of hydrogen isotopes). These composites were fabricated by cold compaction of a mixture of metal hydride granules and coarse copper powder; the porosity in the granules was introduced by means of ammonium carbonate. The composite pellets were cycled 138 times in hydrogen with the loss of LANA0.75 (LaNi{sub 4.25}Al{sub 0.75}) limited to the surface. Vacuum sintering can provide additional strength at the edges. Without a coating, the metal hydride particles exposed at the pellet surface can be removed by cycling several times in hydrogen.

  9. Hanford Site Comprehensive site Compliance Evaluation Report

    SciTech Connect

    Tollefson, K.S.

    1997-08-05

    This document is the second annual submittal by WHC, ICF/KH, PNL and BHI and contains the results of inspections of the stormwater outfalls listed in the Hanford Site Storm Water Pollution Prevention Plan (SWPPP) (WHC 1993a) as required by General Permit No. WA-R-00-000F (WA-R-00-A17F): This report also describes the methods used to conduct the Storm Water Comprehensive Site Compliance Evaluation, as required in Part IV, Section D, {ampersand} C of the General Permit, summarizes the results of the compliance evaluation, and documents significant leaks and spills.

  10. Hanford Site comprehensive site compliance evaluation report

    SciTech Connect

    Tollefson, K.S.

    1995-09-01

    This document is the second annual submittal by WHC, ICF/KH, PNL and BHI and contains the results of inspections of the storm water outfalls listed in the Hanford Site Storm Water Pollution Prevention Plan (SWPPP) (WHC 1993a) as required by General Permit No. WA-R-00- 000F (WA-R-00-A17F): This report also describes the methods used to conduct the Storm Water Comprehensive Site Compliance Evaluation, as required in Part IV, Section D. $. C. of the General Permit, summarizes the results of the compliance evaluation, and documents significant leaks and spills.

  11. Composite Classes: The Murezi School Experience

    ERIC Educational Resources Information Center

    Nyoni, Tsitsi; Nyoni, Mika

    2012-01-01

    The research looks at the phenomenon of composite classes as experienced by the Murezi community. To gather the required data and to have an in-depth understanding of the Murezi school experience, the case study was employed and the questionnaire, interview and on-site observations were employed as data gathering instruments. The three were used…

  12. DEVELOPMENT AND EVALUATION OF COMPOSITE RECEPTOR METHODS

    EPA Science Inventory

    A composite receptor method for PM-10 apportionment was evaluated to determine the stability of its solutions and to devise cost-effective measurement strategies. Aerosol samples used in the evaluation were collected during summer, 1982, by dichotomous samplers at three sites in ...

  13. Strategy for selecting Mars Pathfinder landing sites

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Kuzmin, Ruslin O.

    1994-01-01

    A strategy for Pathfinder site selection must be developed that is fundamentally different from most previous considerations. At least two approaches can be identified. In one approach, the objective is to select a site representing a key geologic unit on Mars, i.e., a unit that is widespread, easily recognized, and used frequently as a datum in various investigations. The second approach is to select a site that potentially affords access to a wide variety of rock types. Because rover range is limited, rocks from a variety of sources must be assembled in a small area for sampling. Regardless of the approach taken in site selection, the Pathfinder site should include eolian deposits and provisions should be made to obtain measurements on soils. A recommended approach for selecting the Mars Pathfinder landing site is to identify a deltaic deposit, composed of sediments derived from sources of various ages and geologic units that shows evidence of eolian activity. The site should be located as close as possible to the part of the outwash where rapid deposition occurred because the likelihood of 'sorting' by size and composition increases with distance, decreasing the probability of heterogeneity. In addition, it is recommended that field operation tests be conducted to gain experience and insight into conducting science with Pathfinder.

  14. Compositional trends in Apollo 16 soils

    NASA Astrophysics Data System (ADS)

    Korotev, R. L.

    Data on the bulk chemical composition of the soils collected at and under the surface of the Apollo 16 landing site are synthesized and reviewed, with emphasis placed on the way in which the compositional trends within the soils relate to the site geology. Two distinct compositional mixing trends are discerned. One involves addition to this surface Cayley component of a material such as that ejected by North Ray Crater. The other is thought to be a segment of a mixing line between the average melt fraction of the local Cayley component and pure or nearly pure anorthosite. Grain size fractions of Apollo 16 soils exhibit a general trend of higher concentrations of large ion lithophile (LIL) elements associated with plagioclase in the finest fraction compared with the coarse fractions. The suite of pristine nonmare rocks (as currently recognized) is found to be insufficient to model the Apollo 16 soils.

  15. The CYP2B2 phenobarbital response unit contains binding sites for hepatocyte nuclear factor 4, PBX-PREP1, the thyroid hormone receptor beta and the liver X receptor.

    PubMed

    Beaudet, Marie-Josée; Desrochers, Marc; Lachaud, Antoine Amaury; Anderson, Alan

    2005-06-01

    A 163 bp enhancer in the CYP2B2 5' flank confers PB (phenobarbital) inducibility and constitutes a PBRU (PB response unit). The PBRU contains several transcription factor binding sites, including NR1, NR2 and NR3, which are direct repeats separated by 4 bp of the nuclear receptor consensus half-site AGGTCA, as well as an ER (everted repeat) separated by 7 bp (ER-7). Constitutive androstane receptor (CAR)-RXR (retinoic X receptor) heterodimers are known to bind to NR1, NR2 and NR3. Electrophoretic mobility-shift analysis using nuclear extracts from livers of untreated or PB-treated rats revealed binding of several other proteins to different PBRU elements. Using supershift analysis and in vitro coupled transcription and translation, the proteins present in four retarded complexes were identified as TRbeta (thyroid hormone receptor beta), LXR (liver X receptor), HNF-4 (hepatocyte nuclear factor 4) and heterodimers of PBX-PREP1 (pre-B cell homoeobox-Pbx regulatory protein 1). LXR-RXR heterodimers bound to NR3 and TRbeta bound to NR3, NR1 and ER-7, whereas the PBX-PREP1 site is contained within NR2. The HNF-4 site overlaps with NR1. A mutation described previously, GRE1m1, which decreases PB responsiveness, increased the affinity of this site for HNF-4. The PBRU also contains a site for nuclear factor 1. The PBRU thus contains a plethora of transcription factor binding sites. The profiles of transcription factor binding to NR1 and NR3 were quite similar, although strikingly different from, and more complex than, that of NR2. This parallels the functional differences in conferring PB responsiveness between NR1 and NR3 on the one hand, and NR2 on the other. PMID:15656786

  16. The CYP2B2 phenobarbital response unit contains binding sites for hepatocyte nuclear factor 4, PBX–PREP1, the thyroid hormone receptor β and the liver X receptor

    PubMed Central

    2005-01-01

    A 163 bp enhancer in the CYP2B2 5′ flank confers PB (phenobarbital) inducibility and constitutes a PBRU (PB response unit). The PBRU contains several transcription factor binding sites, including NR1, NR2 and NR3, which are direct repeats separated by 4 bp of the nuclear receptor consensus half-site AGGTCA, as well as an ER (everted repeat) separated by 7 bp (ER-7). Constitutive androstane receptor (CAR)–RXR (retinoic X receptor) heterodimers are known to bind to NR1, NR2 and NR3. Electrophoretic mobility-shift analysis using nuclear extracts from livers of untreated or PB-treated rats revealed binding of several other proteins to different PBRU elements. Using supershift analysis and in vitro coupled transcription and translation, the proteins present in four retarded complexes were identified as TRβ (thyroid hormone receptor β), LXR (liver X receptor), HNF-4 (hepatocyte nuclear factor 4) and heterodimers of PBX–PREP1 (pre-B cell homoeobox–Pbx regulatory protein 1). LXR–RXR heterodimers bound to NR3 and TRβ bound to NR3, NR1 and ER-7, whereas the PBX–PREP1 site is contained within NR2. The HNF-4 site overlaps with NR1. A mutation described previously, GRE1m1, which decreases PB responsiveness, increased the affinity of this site for HNF-4. The PBRU also contains a site for nuclear factor 1. The PBRU thus contains a plethora of transcription factor binding sites. The profiles of transcription factor binding to NR1 and NR3 were quite similar, although strikingly different from, and more complex than, that of NR2. This parallels the functional differences in conferring PB responsiveness between NR1 and NR3 on the one hand, and NR2 on the other. PMID:15656786

  17. TOPOGRAPHIC SITE RESPONSE AT HARD ROCK SITES

    NASA Astrophysics Data System (ADS)

    Yong, A. K.; Hough, S. E.

    2009-12-01

    Site (material impedance) and topographic (geometric form) effects are known to be key factors that influence seismic ground motions. To characterize site effects, Yong et al. (2009) developed a terrain-based Vs30 prediction model using an automated classification method (Iwahashi and Pike, 2007) that relied on taxonomic criteria (slope gradient, local convexity and surface texture) developed from geomorphometry to identify 16 terrain types from a 1-km spatial resolution (SRTM30 data) digital elevation model of California. On the basis that the underlying framework for this model contains parameters (esp., local convexity) which aptly describe the geometry (i.e., base to height ratio) of relief features that are known to also control the behavior of ground motions (Bouchon, 1973), we extend our investigation to study topographic effects. Focusing on sites that would generally be considered “hard rock,” the classification scheme distinguishes 7 separate terrain types ranging from “moderately eroded mountains” to “well dissected alpine summits.” Observed 1-Hz amplification factors at Southern California Seismographic Network sites reveal a weak but systematic correlation with these 7 terrain types. Significant scatter is also found within each terrain type; typical standard deviations of logarithmic amplification factors are 0.2-0.3. Considering stations that have high amplification factors, we find some that have apparently been misclassified due to data resolution limitations. Many of the remaining stations with higher than expected amplifications are located on or near topographic peaks or ridges. The unusually high amplification factors at hard-rock sites, typically factors of 1.5-2, can most plausibly be explained as a topographic effect.

  18. Site environmental report summary

    SciTech Connect

    Not Available

    1992-12-31

    In this summary of the Fernald 1992 Site Environmental Report the authors will describe the impact of the Fernald site on man and the environment and provide results from the ongoing Environmental Monitoring Program. Also included is a summary of the data obtained from sampling conducted to determine if the site complies with DOE, US Environmental Protection Agency (USEPA), and Ohio EPA (OEPA) requirements. These requirements are set to protect both man and the environment.

  19. Site environmental programs

    SciTech Connect

    Schmidt, J.W.; Hanf, R.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the site environmental programs. Effluent monitoring and environmental surveillance programs monitor for impacts from operations in several areas. The first area consists of the point of possible release into the environment. The second area consists of possible contamination adjacent to DOE facilities, and the third area is the general environment both on and off the site.

  20. Viking landing sites

    NASA Technical Reports Server (NTRS)

    Panagakos, N.

    1973-01-01

    A valley near the mouth of the 20,000-foot-deep Martian Grand Canyon has been chosen by NASA as the site of its first automated landing on the planet Mars. The landing site for the second mission of the 1975-76 Viking spacecraft will probably be an area about 1,000 miles northeast of the first site, where the likelihood of water increases the chances of finding evidence of life.

  1. 1994 Site environmental report

    SciTech Connect

    1995-07-01

    The Fernald site is a Department of Energy (DOE)-owned facility that produced high-quality uranium metals for military defense for nearly 40 years. DOE suspended production at the site in 1989 and formally ended production in 1991. Although production activities have ceased, the site continues to examine the air and liquid pathways as possible routes through which pollutants from past operations and current remedial activities may leave the site. The Site Environmental Report (SER) is prepared annually in accordance with DOE Order 5400.1, General Environmental Protection Program. This 1994 SER provides the general public as well as scientists and engineers with the results from the site`s ongoing Environmental Monitoring Program. Also included in this report is information concerning the site`s progress toward achieving full compliance with requirements set forth by DOE, U.S. Environmental Protection Agency (USEPA), and Ohio EPA (OEPA). For some readers, the highlights provided in this Executive Summary may provide sufficient information. Many readers, however, may wish to read more detailed descriptions of the information than those which are presented here. All information presented in this summary is discussed more fully in the main body of this report.

  2. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

    1979-01-01

    A multifaceted program is described in which aeronautical, mechanical, and materials engineers interact to develop composite aircraft structures. Topics covered include: (1) the design of an advanced composite elevator and a proposed spar and rib assembly; (2) optimizing fiber orientation in the vicinity of heavily loaded joints; (3) failure mechanisms and delamination; (4) the construction of an ultralight sailplane; (5) computer-aided design; finite element analysis programs, preprocessor development, and array preprocessor for SPAR; (6) advanced analysis methods for composite structures; (7) ultrasonic nondestructive testing; (8) physical properties of epoxy resins and composites; (9) fatigue in composite materials, and (10) transverse thermal expansion of carbon/epoxy composites.

  3. SITE QUARTERLY REPORT HIGHLIGHTS (SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION (SITE) PROGRAM)

    EPA Science Inventory

    The SITE Quarterly Report Highlights were designed to keep readers and stakeholders informed of recent developments in the SITE program. Pertinent items listed in the Highlights include (1) schedules for planned SITE Demonstrations, (2) SITE solicitation updates, (3) new developm...

  4. How to measure the quality of surgery-related web sites.

    PubMed

    Yermilov, Irina; Chow, Warren; Devgan, Lara; Makary, Martin; Ko, Clifford Y

    2008-10-01

    Appropriateness and adequacy of health information on the Internet varies. Given there is no validated instrument for web site evaluation focusing on elective general surgical procedures, our goal was to create a composite score as a web site quality rating system. The components of a composite score were developed through a literature review and included Agency for Healthcare Research and Quality guidelines of "Having Surgery? What You Need to Know" and previously published health-related web site scales. All criteria are given equal weight (0/1 scale). The composite score is reported as a percentage of a total possible 16 points. To pilot the rating scale, a web search for roux-en-y gastric bypass (RYGB) was used. Validation compared the composite score with an evaluation by surgeons. Mean composite score for 18 RYGB web sites was 48 per cent (range, 19% to 75%). Composite score validation used a cutoff value of 50 per cent. There was 100 per cent agreement (kappa = 1.0) between composite and surgeon scores. This is the first validated comprehensive composite score to evaluate the web site quality for patients undergoing elective surgery. This score shows promise in increasing efficiency of surgical practices by providing a way in which we can evaluate web sites and encourage our patients to become well informed by reading only high-quality web sites. PMID:18942631

  5. Savannah River Site's Site Specific Plan

    SciTech Connect

    Not Available

    1991-08-01

    This Site Specific Plan (SSP) has been prepared by the Savannah River Site (SRS) in order to show the Environmental Restoration and Waste Management activities that were identified during the preparation of the Department of Energy-Headquarters (DOE-HQ) Environmental Restoration and Waste Management Five-Year Plan (FYP) for FY 1992--1996. The SSP has been prepared in accordance with guidance received from DOE-HQ. DOE-SR is accountable to DOE-HQ for the implementation of this plan. The purpose of the SSP is to develop a baseline for policy, budget, and schedules for the DOE Environmental Restoration and Waste Management activities. The plan explains accomplishments since the Fiscal Year (FY) 1990 plan, demonstrates how present and future activities are prioritized, identifies currently funded activities and activities that are planned to be funded in the upcoming fiscal year, and describes future activities that SRS is considering.

  6. Stretchable heterogeneous composites with extreme mechanical gradients.

    PubMed

    Libanori, Rafael; Erb, Randall M; Reiser, Alain; Le Ferrand, Hortense; Süess, Martin J; Spolenak, Ralph; Studart, André R

    2012-01-01

    Heterogeneous composite materials with variable local stiffness are widespread in nature, but are far less explored in engineering structural applications. The development of heterogeneous synthetic composites with locally tuned elastic properties would allow us to extend the lifetime of functional devices with mechanically incompatible interfaces, and to create new enabling materials for applications ranging from flexible electronics to regenerative medicine. Here we show that heterogeneous composites with local elastic moduli tunable over five orders of magnitude can be prepared through the site-specific reinforcement of an entangled elastomeric matrix at progressively larger length scales. Using such a hierarchical reinforcement approach, we designed and produced composites exhibiting regions with extreme soft-to-hard transitions, while still being reversibly stretchable up to 350%. The implementation of the proposed methodology in a mechanically challenging application is illustrated here with the development of locally stiff and globally stretchable substrates for flexible electronics. PMID:23232395

  7. Stretchable heterogeneous composites with extreme mechanical gradients

    NASA Astrophysics Data System (ADS)

    Libanori, Rafael; Erb, Randall M.; Reiser, Alain; Le Ferrand, Hortense; Süess, Martin J.; Spolenak, Ralph; Studart, André R.

    2012-12-01

    Heterogeneous composite materials with variable local stiffness are widespread in nature, but are far less explored in engineering structural applications. The development of heterogeneous synthetic composites with locally tuned elastic properties would allow us to extend the lifetime of functional devices with mechanically incompatible interfaces, and to create new enabling materials for applications ranging from flexible electronics to regenerative medicine. Here we show that heterogeneous composites with local elastic moduli tunable over five orders of magnitude can be prepared through the site-specific reinforcement of an entangled elastomeric matrix at progressively larger length scales. Using such a hierarchical reinforcement approach, we designed and produced composites exhibiting regions with extreme soft-to-hard transitions, while still being reversibly stretchable up to 350%. The implementation of the proposed methodology in a mechanically challenging application is illustrated here with the development of locally stiff and globally stretchable substrates for flexible electronics.

  8. Plugged-in SITE.

    ERIC Educational Resources Information Center

    Phillips, Rhys

    2003-01-01

    Examines form, color, and technology at the University of Ottawa's School of Information Technology and Engineering (SITE) building, focusing on systems (e.g., SITE is a data wired building, but with no expensive raised floors or cheap dropped ceilings); assembly rather than construction (replacing standard notions of construction with the process…

  9. Site characterization handbook

    SciTech Connect

    Not Available

    1988-06-01

    This Handbook discusses both management and technical elements that should be considered in developing a comprehensive site characterization program. Management elements typical of any project of a comparable magnitude and complexity are combined with a discussion of strategies specific to site characterization. Information specific to the technical elements involved in site characterization is based on guidance published by the Nuclear Regulatory Commission (NRC) with respect to licensing requirements for LLW disposal facilities. The objective of this Handbook is to provide a reference for both NRC Agreement States and non-Agreement States for use in developing a comprehensive site characterization program that meets the specific objectives of the State and/or site developer/licensee. Each site characterization program will vary depending on the objectives, licensing requirements, schedules/budgets, physical characteristics of the site, proposed facility design, and the specific concerns raised by government agencies and the public. Therefore, the Handbook is not a prescriptive guide to site characterization. 18 refs., 6 figs.

  10. Sites of the Holocaust.

    ERIC Educational Resources Information Center

    McCleary, George F., Jr.

    1995-01-01

    Presents a map of Europe identifying the location of major concentration camps, extermination camps, and massacre sites during World War II. Maintains that only a few of the over 400 sites in the former Soviet Union where entire Jewish villages were exterminated are shown. (CFR)

  11. SAMPLING OF CONTAMINATED SITES

    EPA Science Inventory

    A critical aspect of characterization of the amount and species of contamination of a hazardous waste site is the sampling plan developed for that site. f the sampling plan is not thoroughly conceptualized before sampling takes place, then certain critical aspects of the limits o...

  12. Improving Web Site Usability

    ERIC Educational Resources Information Center

    Watts, Chris

    2004-01-01

    Over the last 10 years the Internet has become an essential part of the way companies do business. These days, it is as important to have a Web site as it is to have a phone book listing. Unfortunately, many Web sites are riddled with perplexing navigation and unclear priorities that leave many users confused and frustrated. This article presents…

  13. The Iowa Validation Site

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing can be used to observe the land surface hydrologic cycle, but the quantitative aspects of these observations are not well known. We present a small (1 km^2) experimental validation site, the Iowa Validation Site. Initially we have focused on validating remotely-sensed observations of ...

  14. WWW: Neuroscience Web Sites

    ERIC Educational Resources Information Center

    Liu, Dennis

    2006-01-01

    The human brain contains an estimated 100 billion neurons, and browsing the Web, one might be led to believe that there's a Web site for every one of those cells. It's no surprise that there are lots of Web sites concerning the nervous system. After all, the human brain is toward the top of nearly everyone's list of favorite organs and of…

  15. Commercial Web Site Links.

    ERIC Educational Resources Information Center

    Thelwall, Mike

    2001-01-01

    Discusses business use of the Web and related search engine design issues as well as research on general and academic links before reporting on a survey of the links published by a collection of business Web sites. Results indicate around 66% of Web sites do carry external links, most of which are targeted at a specific purpose, but about 17%…

  16. Preliminary Site Characterization Report, Rulsion Site, Colorado

    SciTech Connect

    1996-08-01

    This report is a summary of environmental information gathered during a review of the documents pertaining to Project Rulison and interviews with personnel who worked on the project. Project Rulison was part of Operation Plowshare (a program designed to explore peaceful uses for nuclear devices). The project consisted of detonating a 43-kiloton nuclear device on September 10, 1969, in western Colorado to stimulate natural gas production. Following the detonation, a reentry well was drilled and several gas production tests were conducted. The reentry well was shut-in after the last gas production test and was held in standby condition until the general cleanup was undertaken in 1972. A final cleanup was conducted after the emplacement and testing wells were plugged in 1976. However, some surface radiologic contamination resulted from decontamination of the drilling equipment and fallout from the gas flaring during drilling operations. With the exception of the drilling effluent pond, all surface contamination at the Rulison Site was removed during the cleanup operations. All mudpits and other excavations were backfilled, and both upper and lower drilling pads were leveled and dressed. This report provides information regarding known or suspected areas of contamination, previous cleanup activities, analytical results, a review of the regulatory status, the site`s physical environment, and future recommendations for Project Ruhson. Based on this research, several potential areas of contamination have been identified. These include the drilling effluent pond and mudpits used during drilling operations. In addition, contamination could migrate in the gas horizon.

  17. Academic Enhancement site.

    PubMed

    DeJong, Judith A; Holder, Stanley R

    2006-01-01

    This off-reservation boarding school serves over 600 students in grades 4-12; approximately 85% of the students reside in campus dormitories. After having documented significant improvement on a number of outcomes during a previous High Risk Youth Prevention demonstration grant, the site submitted a Therapeutic Residential Model proposal, requesting funding to continue successful elements developed under the demonstration grant and to expand mental health services. The site received Therapeutic Residential Model funding for school year 2001-2002. Once funds were received, the site chose to shift Therapeutic Residential Model funds to an intensive academic enhancement effort. While not in compliance with the Therapeutic Residential Model initiative and therefore not funded in subsequent years, this site created the opportunity to enhance the research design by providing a naturally occurring placebo condition at a site with extensive cross-sectional data baselines that addressed issues related to current federal educational policies. PMID:17602403

  18. Site directed recombination

    DOEpatents

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  19. Site-specific photochemistry

    NASA Astrophysics Data System (ADS)

    Koplitz, Brent D.; Brum, Jeffrey L.; Deshmukh, Subhash; Xu, Xiaodong; Wang, Zhongrui; Yen, Yu-Fong

    1992-04-01

    We present results on `site-specific' H-atom production in photolysis experiments conducted under collisionless conditions. H and D atoms are used as labels to investigate the site(s) at which C-H (or C-D) bond cleavage occurs in a variety of haloalkane systems. Experiments using two photolysis lasers clearly indicate that photon absorption by an intermediate, presumably an alkyl radical, is important in many of the systems studied. The site(s) (e.g., (alpha) , (beta) , or (gamma) ) at which C-H (or C-D) bond cleavage occurs is dependent not only on the nature of the molecule, but also on the photolysis wavelength. As a diagnostic tool, H- and D-atom Doppler spectroscopy allows us to gain insight into the energetics associated with the various dissociation processes. Our overall aim is to gain a further understanding of the photolysis properties of a variety of simple molecules and their associated radicals.

  20. Site decommissioning management plan

    SciTech Connect

    Fauver, D.N.; Austin, J.H.; Johnson, T.C.; Weber, M.F.; Cardile, F.P.; Martin, D.E.; Caniano, R.J.; Kinneman, J.D.

    1993-10-01

    The Nuclear Regulatory Commission (NRC) staff has identified 48 sites contaminated with radioactive material that require special attention to ensure timely decommissioning. While none of these sites represent an immediate threat to public health and safety they have contamination that exceeds existing NRC criteria for unrestricted use. All of these sites require some degree of remediation, and several involve regulatory issues that must be addressed by the Commission before they can be released for unrestricted use and the applicable licenses terminated. This report contains the NRC staff`s strategy for addressing the technical, legal, and policy issues affecting the timely decommissioning of the 48 sites and describes the status of decommissioning activities at the sites.

  1. Tough Composite Materials

    NASA Technical Reports Server (NTRS)

    Vosteen, L. F. (Compiler); Johnson, N. J. (Compiler); Teichman, L. A. (Compiler)

    1984-01-01

    Papers and working group summaries are presented which address composite material behavior and performance improvement. Topic areas include composite fracture toughness and impact characterization, constituent properties and interrelationships, and matrix synthesis and characterization.

  2. Carbon Fibers and Composites

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1979-01-01

    The basic nature of composite materials is considered. Carbon fiber composites and their area of current and planned application in civil aircraft are discussed, specifically within the framework of the various aspects of risk analysis.

  3. ACEE composite structures technology

    NASA Technical Reports Server (NTRS)

    Quinlivan, John T.; Wilson, Robert D.; Smith, Peter J.; Johnson, Ronald W.

    1984-01-01

    Toppics addressed include: advanced composites on Boeing commercial aircraft; composite wing durability; damage tolerance technology development; heavily loaded wing panel design; and pressure containment and damage tolerance in fuselages.

  4. Design of electronic composites

    SciTech Connect

    Taya, M.

    1995-12-31

    This report describes the requirements of selected electronic composites with application to electronic packaging, then focuses on the modeling for the microstructure-macrobehavior relation of electronic composites. The modeling depends on the microstructure, percolative and non-percolative.

  5. Heteroporphyrin nanotubes and composites

    DOEpatents

    Shelnutt, John A.; Medforth, Craig J.; Wang, Zhongchun

    2007-05-29

    Heteroporphyrin nanotubes, metal nanostructures, and metal/porphyrin-nanotube composite nanostructures formed using the nanotubes as photocatalysts and structural templates, and the methods for forming the nanotubes and composites.

  6. Heteroporphyrin nanotubes and composites

    DOEpatents

    Shelnutt, John A.; Medforth, Craig J.; Wang, Zhongchun

    2006-11-07

    Heteroporphyrin nanotubes, metal nanostructures, and metal/porphyrin-nanotube composite nanostructures formed using the nanotubes as photocatalysts and structural templates, and the methods for forming the nanotubes and composites.

  7. Thermoset molecular composites

    DOEpatents

    Benicewicz, Brian C.; Douglas, Elliot P.; Hjelm, Jr., Rex P.

    1996-01-01

    A polymeric composition including a liquid crystalline polymer and a thermosettable liquid crystalline monomer matrix, said polymeric composition characterized by a phase separation on the scale of less than about 500 Angstroms and a polymeric composition including a liquid crystalline polymer and a liquid crystalline thermoset matrix, said polymeric composition characterized by a phase separation on the scale of less than about 500 Angstroms are disclosed.

  8. Amorphous metal composites

    DOEpatents

    Byrne, Martin A.; Lupinski, John H.

    1984-01-01

    An improved amorphous metal composite and process of making the composite. The amorphous metal composite comprises amorphous metal (e.g. iron) and a low molecular weight thermosetting polymer binder. The process comprises placing an amorphous metal in particulate form and a thermosetting polymer binder powder into a container, mixing these materials, and applying heat and pressure to convert the mixture into an amorphous metal composite.

  9. Composite fuel cell membranes

    DOEpatents

    Plowman, Keith R.; Rehg, Timothy J.; Davis, Larry W.; Carl, William P.; Cisar, Alan J.; Eastland, Charles S.

    1997-01-01

    A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  10. Nano-composite materials

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

    2010-05-25

    Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

  11. Composite fuel cell membranes

    DOEpatents

    Plowman, K.R.; Rehg, T.J.; Davis, L.W.; Carl, W.P.; Cisar, A.J.; Eastland, C.S.

    1997-08-05

    A bilayer or trilayer composite ion exchange membrane is described suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  12. Infiltrated carbon foam composites

    NASA Technical Reports Server (NTRS)

    Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

    2012-01-01

    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

  13. Advanced composites for windmills

    NASA Astrophysics Data System (ADS)

    Bourquardez, G.

    A development status assessment is conducted for advanced composite construction techniques for windmill blade structures which, as in the case of composite helicopter rotors, promise greater reliability, longer service life, superior performance, and lower costs. Composites in wind turbine applications must bear aerodynamic, inertial and gravitational loads in complex interaction cycles. Attention is given to large Darrieus-type vertical axis windmills, to which composite construction methods may offer highly effective pitch-control mechanisms, especially in the 'umbrella' configuration.

  14. Fog chemistry at three sites in Norway

    NASA Astrophysics Data System (ADS)

    Wang, Youliang; Zhang, Jinwei; Marcotte, Aurelie R.; Karl, Matthias; Dye, Christian; Herckes, Pierre

    2015-01-01

    Fog composition was investigated at three sites in Norway, one in suburban Oslo and two coastal sites in the area of the Mongstad refinery. Overall fog frequency during the study periods was low. Fog pH was around 5 with slightly lower values at Hakadal, the suburban site, compared to the coastal sites, which were slightly above 5. Major ions at the coastal sites were sodium and chloride consistent with the marine environment. The ion chemistry at the suburban site was dominated by ammonium, sulfate and nitrate, consistent with fogs in anthropogenically impacted environments. Overall concentrations of major ions were very low, orders of magnitude lower than those in polluted urban fogs. Organic matter concentrations were also low (< 3 mgC/L) consistent with limited anthropogenic impact and little biogenic activity in the winter months. Selected amine concentrations were determined and ranged from nanomolar concentrations for ethylamines to several hundred nanomolar concentrations for dimethylamine, the most abundant amine investigated. While N-nitrosodimehylamine was detected in fog, the concentrations were very low in the fogs.

  15. Lunar Polar Landing Sites

    NASA Astrophysics Data System (ADS)

    Kamps, Oscar; Foing, Bernard H.; Flahaut, Jessica

    2016-07-01

    An important step for a scientific mission is to assess on where the mission should be conducted. This study on landing site selection focuses on a mission to the poles of the Moon where an in-situ mission should be conducted to answer the questions with respect to volatiles and ices. The European interest for a mission to the poles of the Moon is presented in the mission concept called Heracles. This mission would be a tele-operated, sample return mission where astronauts will controlling a rover from an Orion capsule in cislunar orbit. The primary selection of landing sites was based on the scientific interest of areas near the poles. The maximum temperature map from Diviner was used to select sites where CO^2¬ should always be stable. This means that the maximum temperature is lower than 54K which is the sublimation temperature for CO^2¬ in lunar atmospheric pressure. Around these areas 14 potential regions of interest were selected. Further selection was based on the epoch of the surface in these regions of interest. It was thought that it would be of high scientific value if sites are sampled which have another epoch than already sampled by one of the Apollo or Luna missions. Only 6 sites on both North as South Pole could contain stable CO^2 ¬and were older than (Pre-)Necterian. Before a landing site and rover traverse was planned these six sites were compared on their accessibility of the areas which could contain stable CO^2. It was assumed that slope lower than 20^o is doable to rove. Eventually Amundsen and Rozhdestvenskiy West were selected as regions of interest. Assumptions for selecting landing sites was that area should have a slope lower than 5^o, a diameter of 1km, in partial illuminated area, and should not be isolated but inside an area which is in previous steps marked as accessible area to rove. By using multiple tools in ArcGIS it is possible to present the area's which were marked as potential landing sites. The closest potential landing

  16. Solid polymer electrolyte compositions

    DOEpatents

    Garbe, James E.; Atanasoski, Radoslav; Hamrock, Steven J.; Le, Dinh Ba

    2001-01-01

    An electrolyte composition is featured that includes a solid, ionically conductive polymer, organically modified oxide particles that include organic groups covalently bonded to the oxide particles, and an alkali metal salt. The electrolyte composition is free of lithiated zeolite. The invention also features cells that incorporate the electrolyte composition.

  17. Phase change compositions

    DOEpatents

    Salyer, Ival O.

    1989-01-01

    Compositions containing crystalline, straight chain, alkyl hydrocarbons as phase change materials including cementitious compositions containing the alkyl hydrocarbons neat or in pellets or granules formed by incorporating the alkyl hydrocarbons in polymers or rubbers; and polymeric or elastomeric compositions containing alkyl hydrocarbons.

  18. Phase change compositions

    DOEpatents

    Salyer, Ival O.; Griffen, Charles W.

    1986-01-01

    Compositions containing crystalline, long chain, alkyl hydrocarbons as phase change materials including cementitious compositions containing the alkyl hydrocarbons neat or in pellets or granules formed by incorporating the alkyl hydrocarbons in polymers or rubbers; and polymeric or elastomeric compositions containing alkyl hydrocarbons.

  19. Metal etching composition

    NASA Technical Reports Server (NTRS)

    Otousa, Joseph E. (Inventor); Thomas, Clark S. (Inventor); Foster, Robert E. (Inventor)

    1991-01-01

    The present invention is directed to a chemical etching composition for etching metals or metallic alloys. The composition includes a solution of hydrochloric acid, phosphoric acid, ethylene glycol, and an oxidizing agent. The etching composition is particularly useful for etching metal surfaces in preparation for subsequent fluorescent penetrant inspection.

  20. Refiguring Composition through Theory

    ERIC Educational Resources Information Center

    Lynch-Biniek, Amy

    2009-01-01

    In this dissertation, I argue that curricular choices in Composition are overdetermined by the academic labor system and its negative effect on the status of composition theory. Despite the growth of disciplinary knowledge, composition programs are still staffed largely with underpaid and under supported faculty and graduate students, many of whom…

  1. Composite Golf Clubs

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Babcock & Wilcox Co. under a partnership with Marshall Space Flight Center, produced composite materials, originally from the shuttle program, for improving golf clubs. Company used Marshall Space Flight Center's data summary file summarizing typical processing techniques and mechanical and physical properties of graphite and boron- reinforced composite materials. Reinforced composites provide combination of shaft rigidity and flexibility that provide maximum distance.

  2. Master Plans for Park Sites.

    ERIC Educational Resources Information Center

    Van Meter, Jerry R.

    This booklet is a general guide to park site planning. The four basic steps involved in developing a park site are a) determination of the uses of the site, b) analysis of the site potential for these uses, c) identification of the functional relationship among the uses, and d) coordination of the uses to the park sites. Uses of park sites are…

  3. A PROBABILITY SURVEY OF SUCCESSIONAL FOREST COMPOSITION AND CONDITION IN A GREAT RIVER FLOODPLAIN LANDSCAPE

    EPA Science Inventory

    Floodplains within the Great River Ecosystems (GREs) of the central U.S. are composed of dynamic mosaics of successional habitat that (when unmodified) are typically dominated by cottonwood forest (Populus ssp.). GRE riparian habitat condition and successional dynamics are linked...

  4. Expedited site characterization

    SciTech Connect

    McCreary, I.; Booth, S.R.

    1997-03-01

    Expedited Site Characterization (ESC) is being offered as a new, more cost-effective way to perform DOE environmental site characterizations. Site characterization of environmental cleanup sites can be costly and time consuming. {open_quotes}Traditional techniques,{close_quotes} though effective, are the outgrowth of cautious and often restrictive regulatory control. At some sites up to 40% of the funds and 70% of the time spent on cleanup operations have been devoted to characterization. More realistically, the DOE`s Ten Year Plan (TYP) Cost Rollup by Category (high budgetary version) budgets $1.34 billion to remedial action assessments out of a total of $9.7 billion in remedial actions - about 14% of the total TYP expenditures for this type of cleanup work. The expenditure percentage for characterization drops to a much lower 3% of total expenditures during outyears, after 2006, as most of the assessments will have been completed during the early TYP years. (The sampling and monitoring costs, however, rise from 7% of the budget during the TYP to 30% during the outyears as this activity continues and others decline. Improved characterizations could have the potential to reduce the need for some of these ongoing monitoring costs.) Fortunately, regulatory agencies have begun to relax many of the constraints on site characterization allowing more efficient and innovative approaches to be applied. Argonne National Laboratory`s Expedited Site Characterization is perhaps the best defined of these new approaches. ESC is founded on the premise that it is cheaper, faster, and more efficient to develop and test a conceptual model (or {open_quotes}hypothesis{close_quotes}) of contamination at a site than it is to collect data on a statistical basis and then attempt to model a site from those data. The difference between these two approaches has been described as a {open_quotes}scientific versus an engineering approach{close_quotes}.

  5. ACEE composite structures technology

    NASA Technical Reports Server (NTRS)

    Klotzsche, M. (Compiler)

    1984-01-01

    The NASA Aircraft Energy Efficiency (ACEE) Composite Primary Aircraft Structures Program has made significant progress in the development of technology for advanced composites in commercial aircraft. Commercial airframe manufacturers have demonstrated technology readiness and cost effectiveness of advanced composites for secondary and medium primary components and have initiated a concerted program to develop the data base required for efficient application to safety-of-flight wing and fuselage structures. Oral presentations were compiled into five papers. Topics addressed include: damage tolerance and failsafe testing of composite vertical stabilizer; optimization of composite multi-row bolted joints; large wing joint demonstation components; and joints and cutouts in fuselage structure.

  6. Air electrode composition for solid oxide fuel cell

    DOEpatents

    Kuo, L.; Ruka, R.J.; Singhal, S.C.

    1999-08-03

    An air electrode composition for a solid oxide fuel cell is disclosed. The air electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO{sub 3}. The A-site of the air electrode composition comprises a mixed lanthanide in combination with rare earth and alkaline earth dopants. The B-site of the composition comprises Mn in combination with dopants such as Mg, Al, Cr and Ni. The mixed lanthanide comprises La, Ce, Pr and, optionally, Nd. The rare earth A-site dopants preferably comprise La, Nd or a combination thereof, while the alkaline earth A-site dopant preferably comprises Ca. The use of a mixed lanthanide substantially reduces raw material costs in comparison with compositions made from high purity lanthanum starting materials. The amount of the A-site and B-site dopants is controlled in order to provide an air electrode composition having a coefficient of thermal expansion which closely matches that of the other components of the solid oxide fuel cell. 3 figs.

  7. Air electrode composition for solid oxide fuel cell

    DOEpatents

    Kuo, Lewis; Ruka, Roswell J.; Singhal, Subhash C.

    1999-01-01

    An air electrode composition for a solid oxide fuel cell is disclosed. The air electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO.sub.3. The A-site of the air electrode composition comprises a mixed lanthanide in combination with rare earth and alkaline earth dopants. The B-site of the composition comprises Mn in combination with dopants such as Mg, Al, Cr and Ni. The mixed lanthanide comprises La, Ce, Pr and, optionally, Nd. The rare earth A-site dopants preferably comprise La, Nd or a combination thereof, while the alkaline earth A-site dopant preferably comprises Ca. The use of a mixed lanthanide substantially reduces raw material costs in comparison with compositions made from high purity lanthanum starting materials. The amount of the A-site and B-site dopants is controlled in order to provide an air electrode composition having a coefficient of thermal expansion which closely matches that of the other components of the solid oxide fuel cell.

  8. Developing composite signatures

    NASA Astrophysics Data System (ADS)

    Hawley, Chadwick T.; Carpenter, Tom; Cappelaere, Patrice G.; Frye, Stu; Lemoigne-Stewart, Jacqueline J.; Mandle, Dan; Montgomery, Sarah; Williams-Bess, Autumn

    2011-06-01

    A composite signature is a group of signatures that are related in such a way to more completely or further define a target or operational endeavor at a higher fidelity. This paper explores the merits of using composite signatures, in lieu of waiting for opportunities for the more elusive diagnostic signatures, to satisfy key essential elements of information Keywords: signature, composite signature, civil disaster (EEI) associated with civil disaster-related problems. It discusses efforts to refine composite signature development methodology and quantify the relative value of composite vs. diagnostic signatures. The objectives are to: 1) investigate and develop innovative composite signatures associated with civil disasters, including physical, chemical and pattern/behavioral; 2) explore the feasibility of collecting representative composite signatures using current and emerging intelligence, surveillance, and reconnaissance (ISR) collection architectures leveraging civilian and commercial architectures; and 3) collaborate extensively with scientists and engineers from U.S. government organizations and laboratories, the defense industry, and academic institutions.

  9. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

    1984-01-01

    Progress is reported in studies of constituent materials composite materials, generic structural elements, processing science technology, and maintaining long-term structural integrity. Topics discussed include: mechanical properties of high performance carbon fibers; fatigue in composite materials; experimental and theoretical studies of moisture and temperature effects on the mechanical properties of graphite-epoxy laminates and neat resins; numerical investigations of the micromechanics of composite fracture; delamination failures of composite laminates; effect of notch size on composite laminates; improved beam theory for anisotropic materials; variation of resin properties through the thickness of cured samples; numerical analysis composite processing; heat treatment of metal matrix composites, and the RP-1 and RP2 gliders of the sailplane project.

  10. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Loewy, Robert G.; Wiberley, Stephen E.

    1987-01-01

    The development and application of composite materials to aerospace vehicle structures which began in the mid 1960's has now progressed to the point where what can be considered entire airframes are being designed and built using composites. Issues related to the fabrication of non-resin matrix composites and the micro, mezzo and macromechanics of thermoplastic and metal matrix composites are emphasized. Several research efforts are presented. They are entitled: (1) The effects of chemical vapor deposition and thermal treatments on the properties of pitch-based carbon fiber; (2) Inelastic deformation of metal matrix laminates; (3) Analysis of fatigue damage in fibrous MMC laminates; (4) Delamination fracture toughness in thermoplastic matrix composites; (5) Numerical investigation of the microhardness of composite fracture; and (6) General beam theory for composite structures.

  11. Advanced composites X

    SciTech Connect

    1994-12-31

    In the past ten years, high volume, high performance applications of advanced composites in transportation have grown substantially. The 10th annual ASM/ESD Advanced Composites Conference and Exposition presents the latest developments in composite applications and technologies with over 70 papers presented. The conference is organized in tracks covering body, chassis, powertrain and infrastructure applications, material sciences, manufacturing processes and recycling. Polymer composite and metal matrix composite technologies are included throughout. Body sessions feature adhesive bonding, analysis and test methods and crash energy absorption. The Chassis sessions showcase polymer and metal composite applications. The Powertrain/Propulsion track includes emerging materials as well as design and processing case studies. The Materials Science track features papers on new materials, their performance and theoretical treatment. Manufacturing Processes sessions cover process, modelling, fiber preforming and emerging manufacturing methods. The Infrastructure and Recycling track includes a panel discussion of infrastructure applications and technical papers on the recycling of polymer composites and nondestructive testing.

  12. Lunar Skylights and Their Chemical Compositions

    NASA Astrophysics Data System (ADS)

    Wong, J.; Torres, J.; FitzHoward, S.; Luu, E.; Hua, J.; Irby, R.

    2013-12-01

    In 2009, the Japanese orbiter, SELenological and Engineering Explorer (SELENE) discovered a skylight on the near side of the moon. Skylights are collapsed ceilings of rilles, thought to be caused by moonquakes, meteoroids, or incomplete formation of these lava tube ceilings. Since then, NASA's Lunar Reconnaissance Orbiter has discovered two more skylights, also located on the near side of the moon. Previous research has shown that the physical characteristics of known rilles, can be used as indicators of the presence of yet undiscovered rille and lava dome locations across the lunar surface. We hypothesize that skylights have a signature chemical composition that is unique, and can be used to predict the location of additional skylights on the surface of the moon. For this study, we compared chemical composition data of the three mare sites containing skylights with the 21 mare sites without skylights. Using the software JMARS for the Moon, we compiled multiple datasets to measure the concentrations of 13 different chemical compounds including calcium, iron oxide, titanium dioxide, and thorium. We then conducted a two-tailed T-test of the data, which generated probability values for the mean differences across all 13 chemical compounds of the maria sites with skylights and the maria sites without skylights. Our results show that there is no statistical difference in chemical composition across all of the maria sites examined. Therefore, we conclude that chemical composition does not predict or indicate potential skylight locations on the moon. Further research on other skylight characteristics, for example depth and surrounding underground lava channels, may shed light on the relationships between mare and skylights locations. Three Skylight Locations Found on Lunar Surface 100m View of Mare Tranquilitatis Skylight

  13. Solar site test module

    NASA Technical Reports Server (NTRS)

    Kissel, R. R.; Scott, D. R.

    1980-01-01

    A solar site test module using the Rockwell AIM 65microcomputer is described. The module is designed to work at any site where an IBM site data acquisition system (SDAS) is installed and is intended primarily as a troubleshooting tool. It collects sensor information (temperatures, flow rates, etc.) and displays or prints it immediately in calibrated engineering units. It will read one sensor on demand, periodically read up to 10sensors or periodically read all sensors. Performance calculations can also be included with sensor data. Unattended operation is possible to, e.g., monitor a group of sensors once per hour. Work is underway to add a data acquisition system to the test module so that it can be used at sites which have no SDAS.

  14. Slipcovering a superfund site

    SciTech Connect

    Gascoyne, S.

    1993-09-01

    The Rocky Mountain Arsenal is both a Superfund cleanup site (one of the most contaminated in the United States) and a recently named provisional wildlife refuge. In this article, the history of the Rocky Mountain arsenal is reviewed. The decontamination program for the arsenal and the probable effects of cleanup on the ecology of the site are described. Some of the diverse responses to the program are included in the discussion.

  15. USGIN Lab site

    Energy Science and Technology Software Center (ESTSC)

    2009-08-01

    This web site provides information related to service profiles and implementation in development for the US Geoscience information network (USGIN). It is meant to be a site where developers can learn about the standard in use, the objectives of the application profiles being developed, software being used or tested for implementation of services, and details about particular implementations. Forums are provided for asking questions about the services, profiles, and implemenation issues.

  16. GSM Cell Site Porensics

    NASA Astrophysics Data System (ADS)

    Swenson, Christopher; Moore, Tyler; Shenoi, Sujeet

    Cell site forensics is a new and growing area of digital forensics, enabling investigators to verify a mobile phone subscriber's location at specific times. This paper focuses on cell site forensics in GSM networks. In particular, it discusses current methods utilizing call detail records generated from telephone switches that provide information about cellular calls and text messages, and the cellular towers on which calls/messages were placed and received.

  17. Bacterial start site prediction.

    PubMed

    Hannenhalli, S S; Hayes, W S; Hatzigeorgiou, A G; Fickett, J W

    1999-09-01

    With the growing number of completely sequenced bacterial genes, accurate gene prediction in bacterial genomes remains an important problem. Although the existing tools predict genes in bacterial genomes with high overall accuracy, their ability to pinpoint the translation start site remains unsatisfactory. In this paper, we present a novel approach to bacterial start site prediction that takes into account multiple features of a potential start site, viz., ribosome binding site (RBS) binding energy, distance of the RBS from the start codon, distance from the beginning of the maximal ORF to the start codon, the start codon itself and the coding/non-coding potential around the start site. Mixed integer programing was used to optimize the discriminatory system. The accuracy of this approach is up to 90%, compared to 70%, using the most common tools in fully automated mode (that is, without expert human post-processing of results). The approach is evaluated using Bacillus subtilis, Escherichia coli and Pyrococcus furiosus. These three genomes cover a broad spectrum of bacterial genomes, since B.subtilis is a Gram-positive bacterium, E.coli is a Gram-negative bacterium and P. furiosus is an archaebacterium. A significant problem is generating a set of 'true' start sites for algorithm training, in the absence of experimental work. We found that sequence conservation between P. furiosus and the related Pyrococcus horikoshii clearly delimited the gene start in many cases, providing a sufficient training set. PMID:10446249

  18. Development of clinical sites.

    PubMed

    O'Brien, Mary

    2015-02-01

    Clinical experiences are vital to all types of healthcare educational programs. Supervised clinical experiences provide the opportunity for the learner to apply didactic knowledge and theory to real world situations and hone skills necessary for entry into practice. Nurse anesthesia programs utilize a wide variety of clinical sites to expose student registered nurse anesthetists to experiences that will prepare them clinically, academically and professionally to enter practice as a Certified Registered Nurse Anesthetist. This article describes the process of developing a clinical site. A thorough evaluation will determine the types of experiences meant to be offered at the site, the resources available to house and educate the students, and how to evaluate the effectiveness of the clinical site. Open communication between the clinical coordinator and the program director or designee is essential to ensure success of the clinical site. The Council on Accreditation of Nurse Anesthesia Educational Programs has resources available to guide those interested in becoming a clinical site, as well as for program administrators who seek to add new experiences to their programs. PMID:25842629

  19. Hanford Site Secondary Waste Roadmap

    SciTech Connect

    Westsik, Joseph H.

    2009-01-29

    Summary The U.S. Department of Energy (DOE) is making plans to dispose of 54 million gallons of radioactive tank wastes at the Hanford Site near Richland, Washington. The high-level wastes and low-activity wastes will be vitrified and placed in permanent disposal sites. Processing of the tank wastes will generate secondary wastes, including routine solid wastes and liquid process effluents, and these need to be processed and disposed of also. The Department of Energy Office of Waste Processing sponsored a meeting to develop a roadmap to outline the steps necessary to design the secondary waste forms. Representatives from DOE, the U.S. Environmental Protection Agency, the Washington State Department of Ecology, the Oregon Department of Energy, Nuclear Regulatory Commission, technical experts from the DOE national laboratories, academia, and private consultants convened in Richland, Washington, during the week of July 21-23, 2008, to participate in a workshop to identify the risks and uncertainties associated with the treatment and disposal of the secondary wastes and to develop a roadmap for addressing those risks and uncertainties. This report describes the results of the roadmap meeting in Richland. Processing of the tank wastes will generate secondary wastes, including routine solid wastes and liquid process effluents. The secondary waste roadmap workshop focused on the waste streams that contained the largest fractions of the 129I and 99Tc that the Integrated Disposal Facility risk assessment analyses were showing to have the largest contribution to the estimated IDF disposal impacts to groundwater. Thus, the roadmapping effort was to focus on the scrubber/off-gas treatment liquids with 99Tc to be sent to the Effluent Treatment Facility for treatment and solidification and the silver mordenite and carbon beds with the captured 129I to be packaged and sent to the IDF. At the highest level, the secondary waste roadmap includes elements addressing regulatory and

  20. Ecological Characterization Data for the 2004 Composite Analysis

    SciTech Connect

    Downs, Janelle L.; Simmons, Mary A.; Stegen, Jennifer A.; Bunn, Amoret L.; Tiller, Brett L.; Thorsten, Susan L.; Zufelt, Rhett K.

    2004-11-01

    A composite analysis is required by U.S. Department of Energy (DOE) Order 435.1 to ensure public safety through the management of active and planned low-level radioactive waste disposal facilities associated with the Hanford Site. The original Hanford Site Composite Analysis of 1998 must be revised and submitted to DOE Headquarters (DOE-HQ) in 2004 because of revisions to waste site information in the 100, 200, and 300 Areas, updated performance assessments and environmental impact statements (EIS), changes in inventory estimates for key sites and constituents, and a change in the definition of offsite receptors. Beginning in fiscal year (FY) 2003, the DOE Richland Operations Office (DOE-RL) initiated activities, including the development of data packages, to support the 2004 Composite Analysis. This report describes the data compiled in FY 2003 to support ecological site assessment modeling for the 2004 Composite Analysis. This work was conducted as part of the Characterization of Systems Task of the Groundwater Remediation Project (formerly the Groundwater Protection Program) managed by Fluor Hanford, Inc., Richland, Washington. The purpose of this report is to provide summaries of the characterization information and available spatial data on the biological resources and ecological receptors found in the upland, riparian, aquatic, and island habitats on the Hanford Site. These data constitute the reference information used to establish parameters for the ecological risk assessment module of the System Assessment Capability and other assessment activities requiring information on the presence and distribution of biota on the Hanford Site.

  1. Composite technology for total hip arthroplasty.

    PubMed

    Skinner, H B

    1988-10-01

    Composite materials, which can be very strong while having a low modulus of elasticity, are being studied because such materials have potential to be made into isoelastic hip prostheses. Composites intended for medical applications incorporate carbon or polyamide as a fiber component, while polysulfone, polyetheretherketone, or polyethylene is used as a matrix component. Mechanical properties (especially the modulus of elasticity) are emphasized because of the desire to match those properties of the proximal femur. Many of the variables that affect the mechanical properties of these materials are explained. The application of stress to different fiber orientations demonstrates the mechanical properties of the composite, and this is proved mathematically. It is shown that in composites with fibers oriented in the same direction, the modulus of elasticity in the direction of the fibers generally approaches that of the fibers as the amount of matrix decreases. Perpendicular to the fibers, the modulus of elasticity of the composite is only slightly greater than that of the matrix material. For isotropic chopped-fiber composites, the modulus of elasticity approaches that of the matrix as the fiber content decreases; at high-fiber content, the modulus is significantly less than that of oriented long-fiber composites. In general, the modulus of elasticity and fiber content have a linear relationship. Composites have fatigue properties that vary with direction and approach ultimate strength in tension but are lower in compression. The fatigue properties of proposed composites are discussed. Abrasion as a cause of stress concentration sites and wear particles is considered. PMID:3416528

  2. Site clearance working group

    SciTech Connect

    1997-03-01

    The Gulf of Mexico and Louisiana continue to be areas with a high level of facility removal, and the pace of removal is projected to increase. Regulations were promulgated for the Gulf of Mexico and Louisiana requiring that abandoned sites be cleared of debris that could interfere with fishing and shrimping activities. The site clearance regulations also required verification that the sites were clear. Additionally, government programs were established to compensate fishermen for losses associated with snagging their equipment on oil and gas related objects that remained on the water bottoms in areas other than active producing sites and sites that had been verified as clear of obstructions and snags. The oil and gas industry funds the compensation programs. This paper reviews the regulations and evolving operating practices in the Gulf of Mexico and Louisiana where site clearance and fisherman`s gear compensation regulations have been in place for a number of years. Although regulations and guidelines may be in place elsewhere in the world, this paper focuses on the Gulf of Mexico and Louisiana. Workshop participants are encouraged to bring up international issues during the course of the workshop. Additionally, this paper raises questions and focuses on issues that are of concern to the various Gulf of Mexico and Louisiana water surface and water bottom stakeholders. This paper does not have answers to the questions or issues. During the workshop participants will debate the questions and issues in an attempt to develop consensus opinions and/or make suggestions that can be provided to the appropriate organizations, both private and government, for possible future research or policy adjustments. Site clearance and facility removal are different activities. Facility removal deals with removal of the structures used to produce oil and gas including platforms, wells, casing, piles, pipelines, well protection structures, etc.

  3. Lunar base siting

    NASA Technical Reports Server (NTRS)

    Staehle, Robert L.; Dowling, Richard

    1991-01-01

    As with any planetary body, the lunar surface is quite heterogeneous. There are widely dispersed sites of particular interest for known and potential resource availability, selenology, and lunar observatories. Discriminating characteristics include solar illumination, view of earth, local topography, engineering properties of the regolith and certain geological features, and local mineralogy and petrology. Space vehicle arrival and departure trajectories constitute a minor consideration. Over time, a variety of base sites will be developed serving different purposes. Resource-driven sites may see the fastest growth during the first decades of lunar development, but selection of the most favorable sites is likely to be driven by suitability for a combination of activities. As on earth, later development may be driven by geographical advantages of surface transportation routes. With the availability of near-constant sunlight for power generation, as well as permanently shadowed areas at cryogenic temperatures, polar sites are attractive because they require substantially less earth-launched mass and lower equipment complexity for an initial permanent base. Discovery of accessible volatiles reservoirs, either in the form of polar permafrost or gas reservoirs at other locations, would dramatically increase the attractiveness of any site from a logistical support and selenological point of view. Amid such speculation, no reliable evidence of such volatiles exist. More reliable evidence exists for areas of certain mineral concentrations, such as ilmenite, which could form a feedstock for some proposed resource extraction schemes. While tentative selections of advantageous base sites are made, new data from lunar polar orbiters and the Galileo polar flybys would be very helpful.

  4. Suite versus composite statistics

    USGS Publications Warehouse

    Balsillie, J.H.; Tanner, W.F.

    1999-01-01

    Suite and composite methodologies, two statistically valid approaches for producing statistical descriptive measures, are investigated for sample groups representing a probability distribution where, in addition, each sample is probability distribution. Suite and composite means (first moment measures) are always equivalent. Composite standard deviations (second moment measures) are always larger than suite standard deviations. Suite and composite values for higher moment measures have more complex relationships. Very seldom, however, are they equivalent, and they normally yield statistically significant but different results. Multiple samples are preferable to single samples (including composites) because they permit the investigator to examine sample-to-sample variability. These and other relationships for suite and composite probability distribution analyses are investigated and reported using granulometric data.

  5. Hydrogen storage compositions

    DOEpatents

    Li, Wen; Vajo, John J.; Cumberland, Robert W.; Liu, Ping

    2011-04-19

    Compositions for hydrogen storage and methods of making such compositions employ an alloy that exhibits reversible formation/deformation of BH.sub.4.sup.- anions. The composition includes a ternary alloy including magnesium, boron and a metal and a metal hydride. The ternary alloy and the metal hydride are present in an amount sufficient to render the composition capable of hydrogen storage. The molar ratio of the metal to magnesium and boron in the alloy is such that the alloy exhibits reversible formation/deformation of BH.sub.4.sup.- anions. The hydrogen storage composition is prepared by combining magnesium, boron and a metal to prepare a ternary alloy and combining the ternary alloy with a metal hydride to form the hydrogen storage composition.

  6. Investigation of Composite Structures

    NASA Technical Reports Server (NTRS)

    Hyer, Michael W.

    2000-01-01

    This final report consists of a compilation of four separate written documents, three dealing with the response and failure of elliptical composite cylinders to an internal pressure load, and the fourth dealing with the influence of manufacturing imperfections in curved composite panels. The three focused on elliptical cylinders consist of the following: 1 - A paper entitled "Progressive Failure Analysis of Internally Pressurized Elliptical Composite Cylinders," 2 - A paper entitled "Influence of Geometric Nonlinearities on the Response and Failure of Internally Pressurized Elliptical Composite Cylinders," and 3 - A report entitled "Response and Failure of Internally Pressurized Elliptical Composite Cyclinders." The document which deals with the influence of manufacturing imperfections is a paper entitled "Manufacturing Distortions of Curved Composite Panels."

  7. Composite Intersection Reinforcement

    NASA Technical Reports Server (NTRS)

    Misciagna, David T. (Inventor); Fuhrer, Jessica J. (Inventor); Funk, Robert S. (Inventor); Tolotta, William S. (Inventor)

    2013-01-01

    An assembly and method for manufacturing a composite reinforcement for unitizing a structure are provided. According to one embodiment, the assembly includes a base having a plurality of pins extending outwardly therefrom to define a structure about which a composite fiber is wound to define a composite reinforcement preform. The assembly also includes a plurality of mandrels positioned adjacent to the base and at least a portion of the composite reinforcement preform, and a cap that is positioned over at least a portion of the plurality of mandrels. The cap is configured to engage each of the mandrels to support the mandrels and the composite reinforcement preform during a curing process to form the composite reinforcement.

  8. Composite intersection reinforcement

    NASA Technical Reports Server (NTRS)

    Misciagna, David T. (Inventor); Fuhrer, Jessica J. (Inventor); Funk, Robert S. (Inventor); Tolotta, William S. (Inventor)

    2010-01-01

    An assembly and method for manufacturing a composite reinforcement for unitizing a structure are provided. According to one embodiment, the assembly includes a base having a plurality of pins extending outwardly therefrom to define a structure about which a composite fiber is wound to define a composite reinforcement preform. The assembly also includes a plurality of mandrels positioned adjacent to the base and at least a portion of the composite reinforcement preform, and a cap that is positioned over at least a portion of the plurality of mandrels. The cap is configured to engage each of the mandrels to support the mandrels and the composite reinforcement preform during a curing process to form the composite reinforcement.

  9. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

    1981-01-01

    The composite aircraft program component (CAPCOMP) is a graduate level project conducted in parallel with a composite structures program. The composite aircraft program glider (CAPGLIDE) is an undergraduate demonstration project which has as its objectives the design, fabrication, and testing of a foot launched ultralight glider using composite structures. The objective of the computer aided design (COMPAD) portion of the composites project is to provide computer tools for the analysis and design of composite structures. The major thrust of COMPAD is in the finite element area with effort directed at implementing finite element analysis capabilities and developing interactive graphics preprocessing and postprocessing capabilities. The criteria for selecting research projects to be conducted under the innovative and supporting research (INSURE) program are described.

  10. Indirect resin composites

    PubMed Central

    Nandini, Suresh

    2010-01-01

    Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ‘indirect resin composites,’ composite inlays,’ and ‘fiber-reinforced composites.’ PMID:21217945

  11. Composite structural materials

    NASA Technical Reports Server (NTRS)

    Loewy, Robert G.; Wiberley, Stephen E.

    1988-01-01

    A decade long program to develop critical advanced composite technology in the areas of physical properties, structural concept and analysis, manufacturing, reliability, and life predictions is reviewed. Specific goals are discussed. The status of the chemical vapor deposition effects on carbon fiber properties; inelastic deformation of metal matrix laminates; fatigue damage in fibrous MMC laminates; delamination fracture toughness in thermoplastic matrix composites; and numerical analysis of composite micromechanical behavior are presented.

  12. Galactic cosmic ray composition

    NASA Technical Reports Server (NTRS)

    Meyer, J. P.

    1986-01-01

    An assessment is given of the galactic cosmic ray source (GCRS) elemental composition and its correlation with first ionization potential. The isotopic composition of heavy nuclei; spallation cross sections; energy spectra of primary nuclei; electrons; positrons; local galactic reference abundances; comparison of solar energetic particles and solar coronal compositions; the hydrogen; lead; nitrogen; helium; and germanium deficiency problems; and the excess of elements are among the topics covered.

  13. Continuous Fiber Ceramic Composites

    SciTech Connect

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  14. Composite Material Switches

    NASA Technical Reports Server (NTRS)

    Javadi, Hamid (Inventor)

    2001-01-01

    A device to protect electronic circuitry from high voltage transients is constructed from a relatively thin piece of conductive composite sandwiched between two conductors so that conduction is through the thickness of the composite piece. The device is based on the discovery that conduction through conductive composite materials in this configuration switches to a high resistance mode when exposed to voltages above a threshold voltage.

  15. Site investigation for Magnus

    SciTech Connect

    Semple, R.M.; Rigden, W.J.

    1983-05-01

    In April 1982, BP's Magnus structure was installed about 150 km northeast of the Shetland Islands. The most northerly, deepest water platform in the North Sea, the steel tower is supported on groups of 2 m diameter piles that were driven, in good accordance with predictions, to an average penetration of 85 m in strong cohesive soils. The paper describes investigations performed at the platform site, and documents soil characteristics for conventional and state of the art pile analyses. Reference is made to several innovative techniques first used at the Magnus site that have since been incorporated into the larger North Sea investigations. Information is given about the geological history of the site. Test results are presented on soil strength and stiffness, including critical state soil mechanics parameters, on residual pore pressures after sampling, and on the effect of sample size on strength characteristics.

  16. SLAC site design aesthetics

    SciTech Connect

    Hall, F.F.

    1985-10-01

    Stanford Linear Accelerator Center (SLAC) is a single mission laboratory dedicated to basic research in high energy particle physics. SLAC site also houses Stanford Synchrotron Radiation Laboratory (SSRL) which is a multi-mission laboratory for research using beams of ultraviolet light and low energy photons as emitted tangentially from SLAC colliding beam facilities. This paper discusses various aspects of SLAC site design aesthetics under the following headings: (1) imposed footprint of SLAC, (2) description of selected site, (3) use of earth cover for radiation and sight screens, (4) use of landscaping for cosmetic purposes, (5) use of exterior paint colors to soften SLAC impact on neighbors, (6) relocation of SLAC main entrance, (7) relocation of SLAC collider arcs and experimental hall, (8) parking lots and storage yards, and (9) land use zoning at SLAC.

  17. statement of significance, location map, site plan, landscape plan, site ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    statement of significance, location map, site plan, landscape plan, site sections, evolution of cemetery landscape. - San Francisco National Cemetery, 1 Lincoln Boulevard, San Francisco, San Francisco County, CA

  18. Cometary dust composition

    NASA Technical Reports Server (NTRS)

    Gehrz, R. D.; Hanner, M. S.

    1988-01-01

    The earth based measurements and in situ sampling of Comet Halley have provided new data about the chemical composition of cometary grains. Recent progress in laboratory studies of interplanetary dust particles (IDPs) complement the comet data, allowing inferences about the mineralogy and physical structure of the comet dust to be drawn from the observed elemental composition and infrared spectra. The in situ dust composition measurements at Halley, the composition of IDPs and their relation to comet dust, and the origin of the 3.4 micron hydrocarbon feature is discussed. Related discussion is also presented on aromatic components in comets and the 3.4 micron feature. These topics are briefly summarized.

  19. Polyimide composites: Application histories

    NASA Technical Reports Server (NTRS)

    Poveromo, L. M.

    1985-01-01

    Advanced composite hardware exposed to thermal environments above 127 C (260 F) must be fabricated from materials having resin matrices whose thermal/moisture resistance is superior to that of conventional epoxy-matrix systems. A family of polyimide resins has evolved in the last 10 years that exhibits the thermal-oxidative stability required for high-temperature technology applications. The weight and structural benefits for organic-matrix composites can now be extended by designers and materials engineers to include structures exposed to 316 F (600 F). Polyimide composite materials are now commercially available that can replace metallic or epoxy composite structures in a wide range of aerospace applications.

  20. Pitch carbon microsphere composite

    NASA Technical Reports Server (NTRS)

    Price, H. L.; Nelson, J. B.

    1977-01-01

    Petroleum pitch carbon microspheres were prepared by flash heating emulsified pitch and carbonizing the resulting microspheres in an inert atmosphere. Microsphere composites were obtained from a mixture of microspheres and tetraester precursor pyrrone powder. Scanning electron micrographs of the composite showed that it was an aggregate of microspheres bonded together by the pyrrone at the sphere contact points, with voids in and among the microspheres. Physical, thermal, and sorption properties of the composite are described. Composite applications could include use as a honeycomb filler in elevated-temperature load-bearing sandwich boards or in patient-treatment tables for radiation treatment of tumors.

  1. Probabilistic composite analysis

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Murthy, P. L. N.

    1991-01-01

    Formal procedures are described which are used to computationally simulate the probabilistic behavior of composite structures. The computational simulation starts with the uncertainties associated with all aspects of a composite structure (constituents, fabrication, assembling, etc.) and encompasses all aspects of composite behavior (micromechanics, macromechanics, combined stress failure, laminate theory, structural response, and tailoring) optimization. Typical cases are included to illustrate the formal procedure for computational simulation. The collective results of the sample cases demonstrate that uncertainties in composite behavior and structural response can be probabilistically quantified.

  2. Electrically conductive cellulose composite

    DOEpatents

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  3. RADIATION SHIELDING COMPOSITION

    DOEpatents

    Dunegan, H.L.

    1963-01-29

    A light weight radiation shielding composition is described whose mechanical and radiological properties can be varied within wide limits. The composition of this shielding material consists of four basic ingredients: powder of either Pb or W, a plastic resin, a resin plasticizer, and a polymerization catalyst to promote an interaction of the plasticizer with the plastic resin. Air may be mixed into the above ingredients in order to control the density of the final composition. For equivalent gamma attenuation, the shielding composition weighs one-third to one-half as much as conventional Pb shielding. (AEC)

  4. Reactive composite compositions and mat barriers

    DOEpatents

    Langton, Christine A.; Narasimhan, Rajendran; Karraker, David G.

    2001-01-01

    A hazardous material storage area has a reactive multi-layer composite mat which lines an opening into which a reactive backfill and hazardous material are placed. A water-inhibiting cap may cover the hazardous material storage area. The reactive multi-layer composite mat has a backing onto which is placed an active layer which will neutralize or stabilize hazardous waste and a fronting layer so that the active layer is between the fronting and backing layers. The reactive backfill has a reactive agent which can stabilize or neutralize hazardous material and inhibit the movement of the hazardous material through the hazardous material storage area.

  5. YUCCA MOUNTAIN SITE DESCRIPTION

    SciTech Connect

    A.M. Simmons

    2004-04-16

    The ''Yucca Mountain Site Description'' summarizes, in a single document, the current state of knowledge and understanding of the natural system at Yucca Mountain. It describes the geology; geochemistry; past, present, and projected future climate; regional hydrologic system; and flow and transport within the unsaturated and saturated zones at the site. In addition, it discusses factors affecting radionuclide transport, the effect of thermal loading on the natural system, and tectonic hazards. The ''Yucca Mountain Site Description'' is broad in nature. It summarizes investigations carried out as part of the Yucca Mountain Project since 1988, but it also includes work done at the site in earlier years, as well as studies performed by others. The document has been prepared under the Office of Civilian Radioactive Waste Management quality assurance program for the Yucca Mountain Project. Yucca Mountain is located in Nye County in southern Nevada. The site lies in the north-central part of the Basin and Range physiographic province, within the northernmost subprovince commonly referred to as the Great Basin. The basin and range physiography reflects the extensional tectonic regime that has affected the region during the middle and late Cenozoic Era. Yucca Mountain was initially selected for characterization, in part, because of its thick unsaturated zone, its arid to semiarid climate, and the existence of a rock type that would support excavation of stable openings. In 1987, the United States Congress directed that Yucca Mountain be the only site characterized to evaluate its suitability for development of a geologic repository for high-level radioactive waste and spent nuclear fuel.

  6. PPPL Site Environmental Report

    SciTech Connect

    Virginia Finley; Sheneman, Robert S.; Levine, Jerry D.

    2012-12-01

    Contained in the following report are data for radioactivity in the environment collected and analyzed by Princeton Plasma Physics Laboratory’s Princeton Environmental, Analytical, and Radiological Laboratory (PEARL). The PEARL is located on-site and is certified for analyzing radiological and non-radiological parameters through the New Jersey Department of Environmental Protection’s Laboratory Certification Program, Certification Number 12471. Non-radiological surface and ground water samples are analyzed by NJDEP certified subcontractor laboratories – QC, Inc. and Accutest Laboratory. To the best of our knowledge, these data, as contained in the “Annual Site Environmental Report for 2011,” are documented and certified to be correct.

  7. Phoenix Site Panorama

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This movie is compiled of images from Phoenix's Stereo Surface Imager (SSI) camera that were taken on sols 1 and 3. The top images, highlighted in yellow at the beginning of the movie, have been stretched eight times to show details of features in the background. Phoenix's parachute, backshell, heatshield, and impact site can also be seen.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Waste Site Mapping

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Old aircraft considered not restorable are melted down in on-site furnaces to reclaim the aluminum in their airframes. The process produces aluminum ingots and leaves a residue known as "dross." Because dross contains contaminants like lead silver cadmium and copper, Pima County, the dross dumping site, wanted to locate areas where dross had been dumped. Dr. Larry Lepley and Sandra L. Perry used the Landsat Thematic Mapper to screen for dross. A special two-step procedure was developed to separate the dross dumps (typically no larger than 50 meters across) from the desert background. The project has opened the door for similar applications.

  9. Composite materials: Testing and design

    NASA Technical Reports Server (NTRS)

    Whitcomb, John D. (Editor)

    1988-01-01

    The present conference discusses topics in the analysis of composite structures, composite materials' impact and compression behavior, composite materials characterization methods, composite failure mechanisms, NDE methods for composites, and filament-wound and woven composite materials' fabrication. Attention is given to the automated design of a composite plate for damage tolerance, the effects of adhesive layers on composite laminate impact damage, instability-related delamination growth in thermoset and thermoplastic composites, a simple shear fatigue test for unidirectional E-glass epoxy, the growth of elliptic delaminations in laminates under cyclic transverse shear, and the mechanical behavior of braided composite materials.

  10. Beagle-2 landing site atlas

    NASA Astrophysics Data System (ADS)

    Michael, G.; Chicarro, A.; Rodionova, J.; Shevchenko, V.; Ilukhina, J.; Kozlova, K.

    2003-04-01

    The Beagle-2 lander of the Mars Express mission will come to rest on the surface of Isidis Planitia in late December 2003 to carry out a range of geochemistry and exobiology experi-ments. We are compiling an atlas of the presently available data products pertinent to the landing site at 11.6N 90.75E, which is intended for distribution both as a printed and an electronic resource. The atlas will include Viking and MOC-WA image mosaics, and a catalogue of high-resolution im-ages from MOC and THEMIS with location maps. There will be various MOLA topography-based products: colour-scaled, contoured, and shaded maps, slope, and detrended relief. Simulated camera panoramas from various potential landing locations may assist in determining the spacecraft’s position. Other maps, both raw, and in composites with image mosa-ics, will cover TES thermal inertia and spectroscopy, and Odyssey gamma and neutron spectroscopy. Maps at the scale of the Isidis context will additionally cover geology, tem-perature cycles, and atmospheric circulation. Sample are shown below.

  11. Metal-bonded, carbon fiber-reinforced composites

    DOEpatents

    Sastri, S.A.; Pemsler, J.P.; Cooke, R.A.; Litchfield, J.K.; Smith, M.B.

    1996-03-05

    Metal bonded carbon fiber-reinforced composites are disclosed in which the metal and the composite are strongly bound by (1) providing a matrix-depleted zone in the composite of sufficient depth to provide a binding site for the metal to be bonded and then (2) infiltrating the metal into the matrix-free zone to fill a substantial portion of the zone and also provide a surface layer of metal, thereby forming a strong bond between the composite and the metal. The invention also includes the metal-bound composite itself, as well as the provision of a coating over the metal for high-temperature performance or for joining to other such composites or to other substrates. 2 figs.

  12. Metal-bonded, carbon fiber-reinforced composites

    DOEpatents

    Sastri, Suri A.; Pemsler, J. Paul; Cooke, Richard A.; Litchfield, John K.; Smith, Mark B.

    1996-01-01

    Metal bonded carbon fiber-reinforced composites are disclosed in which the metal and the composite are strongly bound by (1) providing a matrix-depleted zone in the composite of sufficient depth to provide a binding site for the metal to be bonded and then (2) infiltrating the metal into the matrix-free zone to fill a substantial portion of the zone and also provide a surface layer of metal, thereby forming a strong bond between the composite and the metal. The invention also includes the metal-bound composite itself, as well as the provision of a coating over the metal for high-temperature performance or for joining to other such composites or to other substrates.

  13. Small Wind Site Assessment Guidelines

    SciTech Connect

    Olsen, Tim; Preus, Robert

    2015-09-01

    Site assessment for small wind energy systems is one of the key factors in the successful installation, operation, and performance of a small wind turbine. A proper site assessment is a difficult process that includes wind resource assessment and the evaluation of site characteristics. These guidelines address many of the relevant parts of a site assessment with an emphasis on wind resource assessment, using methods other than on-site data collection and creating a small wind site assessment report.

  14. Phase 1 of the North Site cleanup: Definition of product streams. Volume 1

    SciTech Connect

    Sorini, S.; Merriam, N.

    1994-03-01

    Various materials and equipment have accumulated at the Western Research Institute (WRI) North Site Facility since its commissioning in 1968. This facility was built by the US Bureau of Mines, transferred to the US Energy Research Development Administration (ERDA) in 1976, and transferred once again to the US Department of Energy (DOE) shortly thereafter. In 1983, the North Site Facility became part of WRI. The materials that have accumulated over the years at the site have been stored in drums, tanks, and open piles. They vary from oil shale, tar sand, and coal feedstocks to products and materials associated with in situ simulation and surface process developments associated with these feedstocks. The majority of these materials have been associated with DOE North Site activities and work performed at the North Site under DOE-WRI cooperative agreement contracts. In phase I of the North Site Facility cleanup project, these materials were sampled and evaluated to determine their chemical characteristics for proper disposal or use in accordance with current local, state, and federal regulations. Phase I of the North Site Facility cleanup project involved dividing the stored materials into product streams and dividing each product stream into composite groups. Composite groups contain materials known to be similar in composition, source, and process exposure. For each composite group, materials, which are representative of the composite, were selected for sampling, compositing, and analysis.

  15. Science. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Roach, Linda E., Ed.

    This document contains the following papers on science from the SITE (Society for Information Technology & Teacher Education) 2001 conference: (1) "Using a Computer Simulation before Dissection To Help Students Learn Anatomy" (Joseph Paul Akpan and Thomas Andre); (2) "EARTH2CLASS: A Unique Workshop/On-Line/Distance-Learning Teacher Training…

  16. Site characterization rover missions

    NASA Technical Reports Server (NTRS)

    Pivirotto, Donna Shirley

    1990-01-01

    Concepts for site characterization rovers capable of efficient operation on Mars with human supervision from earth are discussed. In particular, attention is given to strategies for developing and evaluating the necessary technology for implementing the roving vehicles and process technologies required for a systematic and integrated implementation of technologically advanced rovers. A vehicle testbed program is also described.

  17. Research. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Curtis, Reagan, Ed.

    This document contains papers on instructional technology research from the SITE (Society for Information Technology & Teacher Education) 2002 conference. Topics covered include: professors share their thoughts and feelings with their students; faculty reflections on teaching online; integrating technology into preservice teacher education;…

  18. Mathematics. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Connell, Michael L., Ed.; Lowery, Norene Vail, Ed.; Harnisch, Delwyn L., Ed.

    This document contains the following papers on mathematics from the SITE (Society for Information Technology & Teacher Education) 2001 conference: "Secondary Mathematics Methods Course with Technology Units: Encouraging Pre-Service Teachers To Use Technology" (Rajee Amarasinghe); "Competency Exams in College Mathematics" (Kathy R. Autrey and Leigh…

  19. International. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Willis, Dee Anna, Ed.

    This document contains the following papers on international issues from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "The Management of Technological Change within Faculties in International American Schools" (Martine Audeoud); (2) "Going Global: Using a Website Development Project To Teach Technology…

  20. Mathematics. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Connell, Michael L., Ed.; Lowery, Norene Vail, Ed.; Harnisch, Delwyn L., Ed.

    This document contains the following papers on mathematics from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Teachers' Learning of Mathematics in the Presence of Technology: Participatory Cognitive Apprenticeship" (Mara Alagic); (2) "A Fractal Is a Pattern in Your Neighborhood" (Craig N. Bach); (3)…

  1. Academic Enhancement Site

    ERIC Educational Resources Information Center

    DeJong, Judith A.; Holder, Stanley R.

    2006-01-01

    This off-reservation boarding school serves over 600 students in grades 4-12; approximately 85% of the students reside in campus dormitories. After having documented significant improvement on a number of outcomes during a previous High Risk Youth Prevention demonstration grant, the site submitted a Therapeutic Residential Model proposal,…

  2. International. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Willis, Dee Anna, Ed.

    This document contains the following papers on international issues from the SITE (Society for Information Technology & Teacher Education) 2001 conference: (1) "Attitudes of Malaysian Vocational Trainee Teachers towards the Integration of Computer in Teaching" (Ab. Rahim Bakar and Shamsiah Mohamed); (2) "Views from an Asian Bridge: How…

  3. Site authorization service (SAZ)

    SciTech Connect

    Dane Skow; Igor Mandrichenko; Vijay Sehkri

    2003-10-01

    In this paper the authors present a methodology to provide an additional level of centralized control for the grid resources. This centralized control is applied to site-wide distribution of various grids and thus provides an upper hand in the maintenance.

  4. Ignitor Siting Evaluations

    NASA Astrophysics Data System (ADS)

    Zucchetti, Massimo; Zunino, Cristina

    2002-11-01

    Ignitor is a compact high-magnetic field experiment aimed at studying plasma burning conditions in Deuterium-Tritium plasmas up to ignition. The ENEL-TERNA center in Rondissone (Italy) has been selected for its localisation. The main positive features of this site are the presence of electrical facilities because of the distribution node of Rondissone, the availability of the main office building and of the space for the construction of the Ignitor machine. Available data concerning the nearby nuclear site of Saluggia, only five kilometers away, are in fact used. The non-site dependent accidental analysis of Ignitor has been recently reviewed. New design of the Tritium Handling System has reduced tritium inventory in Ignitor to about 3 g. Then, many of the environmental source terms considered in previous accidental analyses are reduced. Design Basis Accidents (DBA) bring to maximum doses for the public below 1 mSv, and collective doses cause negligible health effects. All the assessments show that Ignitor can be effectively located in the ENEL-TERNA site, satisfying environmental and safety requirements.

  5. Research. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    McAlister, Kim, Ed.; Curtis, Reagan, Ed.

    This document contains the papers on research from the SITE (Society for Information Technology & Teacher Education) 2001 conference. Topics covered include: concerns of administrators and teachers in the diffusion of information technology; preservice elementary mathematics teachers' computer self efficacy, attitudes, and perceptions; information…

  6. Savannah River Site Robotics

    ScienceCinema

    None

    2012-06-14

    Meet Sandmantis and Frankie, two advanced robotic devices that are key to cleanup at Savannah River Site. Sandmantis cleans hard, residual waste off huge underground storage tanks. Frankie is equipped with unique satellite capabilities and sensing abilties that can determine what chemicals still reside in the tanks in a cost effective manner.

  7. Proposed Drill Sites

    DOE Data Explorer

    Lane, Michael

    2013-06-28

    Proposed drill sites for intermediate depth temperature gradient holes and/or deep resource confirmation wells. Temperature gradient contours based on shallow TG program and faults interpreted from seismic reflection survey are shown, as are two faults interpreted by seismic contractor Optim but not by Oski Energy, LLC.

  8. RADIATION SITES TECHNICAL WORKGROUP

    EPA Science Inventory

    Much of the radiation expertise in EPA is located in the Region Offices. The EPA Radiation Sites Technical Workgroup is an interoffice technical workgroup within EPA which provides a focal point for radiation expertise. The Workgroup has members from each region, as well as the...

  9. Library Web Site Innovations.

    ERIC Educational Resources Information Center

    Falk, Howard

    1999-01-01

    Reports on some of the new ways public library sites are presenting themselves to their patrons and to the broader World Wide Web audience. Discusses library virtual tours; calendar display; audio-visual materials; resource listings; book clubs; money-raising activities; fugitive fact files; hot item advisors; periodicals; FAQs (frequently asked…

  10. Elementary Classroom Web Sites

    ERIC Educational Resources Information Center

    Baker, Elizabeth A.

    2007-01-01

    The purpose of this study was to understand how elementary classroom Web sites support children's literacy. From a sociocultural perspective of literacy and a transformative stance toward the integration of literacy and technology, and building on explorations of new literacies, I discuss opportunities provided by the Internet that can support…

  11. Science. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Roach, Linda Easley, Ed.

    This document contains the following papers on science from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Color & Light: Design and Evaluation of a Multimedia-Case for Elementary Teacher-Education" (Peter Blijleven and Ellen van den Berg); (2) "Standards-Based Design of Technology-Integrated Science…

  12. Simulation. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Seymour, Cathy R., Ed.

    This document contains three papers on simulation from the SITE (Society for Information Technology & Teacher Education) 2001 conference. "Simulations in the Learning Cycle: A Case Study Involving 'Exploring the Nardoo'" (William M. Dwyer and Valesca E. Lopez) presents a study of middle school students using a CD-based simulation program,…

  13. Pecan site evaluations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guidance is provided to help pecan growers obtain copies of their County Soil Survey Reports and interpret information concerning climatic, topographic and edaphic variables of pecan orchard sites. As media for plant growth, soils must provide anchorage, water, air, and nutrients. Their ability to...

  14. Theory. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Christensen, Paula, Ed.

    This document contains the following papers on theory from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "The Emerging Ecological Contribution of Online Resources and Tools to K-12 Classrooms" (Therese Laferriere, Robert Bracewell, Alain Breuleux); (2) "Pedagogical Ethnotechnography: A Bifocal Lens To…

  15. Theory. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Christensen, Paula, Ed.

    This document contains the following papers on theory from the SITE (Society for Information Technology & Teacher Education) 2001 Conference: (1) "IT with Integrity" (Savilla Banister); (2) "Applications of Knowledge Based Evaluation in Educational Technology" (Michael Connell); (3) "A Tutor's Advice Trains a Student's Self-Regulation Skill"…

  16. 2014 Site Environmental Report

    SciTech Connect

    Paquette, Douglas; Remien, Jason; Foley, Brian; Burke, John; Dorsch, William; Ratel, Karen; Howe, Robert; Welty, Tim; Williams, Jeffrey; Pohlpt, Peter; Lagattolla, Richard; Metz, Robert; Milligan, James; Lettieri, Lawrence

    2015-10-01

    BNL prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1B, Environment, Safety and Health Reporting. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory’s environmental performance during the calendar year in review.

  17. Savannah River Site Robotics

    SciTech Connect

    2010-01-01

    Meet Sandmantis and Frankie, two advanced robotic devices that are key to cleanup at Savannah River Site. Sandmantis cleans hard, residual waste off huge underground storage tanks. Frankie is equipped with unique satellite capabilities and sensing abilties that can determine what chemicals still reside in the tanks in a cost effective manner.

  18. Lightweight composites for modular panelized construction

    NASA Astrophysics Data System (ADS)

    Vaidya, Amol S.

    Rapid advances in construction materials technology have enabled civil engineers to achieve impressive gains in the safety, economy, and functionality of structures built to serve the common needs of society. Modular building systems is a fast-growing modern, form of construction gaining recognition for its increased efficiency and ability to apply modern technology to the needs of the market place. In the modular construction technique, a single structural panel can perform a number of functions such as providing thermal insulation, vibration damping, and structural strength. These multifunctional panels can be prefabricated in a manufacturing facility and then transferred to the construction site. A system that uses prefabricated panels for construction is called a "panelized construction system". This study focuses on the development of pre-cast, lightweight, multifunctional sandwich composite panels to be used for panelized construction. Two thermoplastic composite panels are proposed in this study, namely Composite Structural Insulated Panels (CSIPs) for exterior walls, floors and roofs, and Open Core Sandwich composite for multifunctional interior walls of a structure. Special manufacturing techniques are developed for manufacturing these panels. The structural behavior of these panels is analyzed based on various building design codes. Detailed descriptions of the design, cost analysis, manufacturing, finite element modeling and structural testing of these proposed panels are included in this study in the of form five peer-reviewed journal articles. The structural testing of the proposed panels involved in this study included flexural testing, axial compression testing, and low and high velocity impact testing. Based on the current study, the proposed CSIP wall and floor panels were found satisfactory, based on building design codes ASCE-7-05 and ACI-318-05. Joining techniques are proposed in this study for connecting the precast panels on the construction

  19. Levitation of superconducting composites

    NASA Technical Reports Server (NTRS)

    Chiang, C. K.; Turchinskaya, M.; Swartzendruber, L. J.; Shull, R. D.; Bennett, L. H.

    1991-01-01

    The inverse levitation of a high temperature superconductor polymer composite consisting of powdered quench melt growth Ba2YCu3O(7-delta) and cyanoacrylate is reported. Magnetic hysteresis loop measurements for the composite are compared to those measured for the bulk material prior to powdering. Differences in the flux pining capability between the two material forms are small but significant.

  20. Biodegradable synthetic bone composites

    DOEpatents

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.