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Sample records for chemical analysis explains

  1. Bark chemical analysis explains selective bark damage by rodents

    Czech Academy of Sciences Publication Activity Database

    Heroldová, Marta; Jánová, Eva; Suchomel, J.; Purchart, L.; Homolka, Miloslav

    2009-01-01

    Roč. 2, č. 2 (2009), s. 137-140 ISSN 1803-2451 R&D Projects: GA MZe QH72075 Institutional research plan: CEZ:AV0Z60930519 Keywords : bark damage * bark selection * bark chemical analysis * rowan * beech * spruce * mountain forest regeneration Subject RIV: GK - Forestry

  2. Integrated chemical and biological analysis to explain estrogenic potency in bile extracts of red mullet (Mullus barbatus)

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Gómez, Concepción, E-mail: concepcion.martinez@mu.ieo.es [Instituto Español de Oceanografía, Oceanografic Centre of Murcia, Varadero 1, San Pedro del Pinatar, 30740 Murcia (Spain); Lamoree, M.; Hamers, T.; Velzen, M. van; Kamstra, J.H. [VU University Amsterdam, Amsterdam Global Change Institute, Institute for Environmental Studies, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Fernández, B.; Benedicto, J.; León, V.M. [Instituto Español de Oceanografía, Oceanografic Centre of Murcia, Varadero 1, San Pedro del Pinatar, 30740 Murcia (Spain); Vethaak, A.D. [VU University Amsterdam, Amsterdam Global Change Institute, Institute for Environmental Studies, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Deltares, Marine and Coastal Systems, P.O. Box 177, 2600 MH Delft (Netherlands)

    2013-06-15

    Highlights: •In vitro estrogenic activity was quantified in male bile extracts of feral red mullet. •Major PAH metabolites and alkylphenols were quantified in the same fish bile extracts. •Contribution of these compounds to the estrogenicity measured was found negligible. •PAH and alkylphenol fish exposure was low in most of the studied Mediterranean sites. •High estrogenicity in male fish from Mar Menor lagoon warrants further studies. -- Abstract: A biological screening was performed to establish the total exposure to estrogenic compounds of red mullet (Mullus barbatus) collected at several sites along the Spanish Mediterranean coast by testing male fish bile extracts using the in vitro ER-LUC reporter gene assay. In addition, major metabolites were identified and measurements of OH-PAHs (1-naphthol, 9-phenantrol, 9-fluorenol, 1-pyrenol, 1OH-BaP and 3OH-BaP) and alkylphenols (4-n-nonylphenol (4-n-NP) and 4-tertoctylphenol (4-tert-OP)) in the same fish bile extracts were taken by gas chromatography–mass spectrometry in electron ionization mode (GC–EI-MS). Relative in vitro estrogenic potencies of the chemically quantified compounds were also tested. The highest biliary concentrations of 1-pyrenol, 9-fluorenol and 4-n-NP were found in fish from Barcelona and from the Mar Menor coastal lagoon. However, these concentrations can be considered relatively low compared to values reported in red mullet from other polluted waters in the Mediterranean Sea. The contribution of 1-pyrenol, 4-n-NP and 4-tert-OP to the total estrogenic potency measured in male fish bile was found to be negligible, indicating the presence of other estrogenic compounds in red mullet bile. Estrogenic potency in bile from male fish was markedly elevated in Mar Menor lagoon (234.8 ± 5.7 pg E2EQ/μl), and further research will be necessary to explain whether the presence of natural and synthetic-hormones in the lagoon contributed to this finding. Values of approximately 15–16 E2EQ pg

  3. Integrated chemical and biological analysis to explain estrogenic potency in bile extracts of red mullet (Mullus barbatus)

    International Nuclear Information System (INIS)

    Martínez-Gómez, Concepción; Lamoree, M.; Hamers, T.; Velzen, M. van; Kamstra, J.H.; Fernández, B.; Benedicto, J.; León, V.M.; Vethaak, A.D.

    2013-01-01

    Highlights: •In vitro estrogenic activity was quantified in male bile extracts of feral red mullet. •Major PAH metabolites and alkylphenols were quantified in the same fish bile extracts. •Contribution of these compounds to the estrogenicity measured was found negligible. •PAH and alkylphenol fish exposure was low in most of the studied Mediterranean sites. •High estrogenicity in male fish from Mar Menor lagoon warrants further studies. -- Abstract: A biological screening was performed to establish the total exposure to estrogenic compounds of red mullet (Mullus barbatus) collected at several sites along the Spanish Mediterranean coast by testing male fish bile extracts using the in vitro ER-LUC reporter gene assay. In addition, major metabolites were identified and measurements of OH-PAHs (1-naphthol, 9-phenantrol, 9-fluorenol, 1-pyrenol, 1OH-BaP and 3OH-BaP) and alkylphenols (4-n-nonylphenol (4-n-NP) and 4-tertoctylphenol (4-tert-OP)) in the same fish bile extracts were taken by gas chromatography–mass spectrometry in electron ionization mode (GC–EI-MS). Relative in vitro estrogenic potencies of the chemically quantified compounds were also tested. The highest biliary concentrations of 1-pyrenol, 9-fluorenol and 4-n-NP were found in fish from Barcelona and from the Mar Menor coastal lagoon. However, these concentrations can be considered relatively low compared to values reported in red mullet from other polluted waters in the Mediterranean Sea. The contribution of 1-pyrenol, 4-n-NP and 4-tert-OP to the total estrogenic potency measured in male fish bile was found to be negligible, indicating the presence of other estrogenic compounds in red mullet bile. Estrogenic potency in bile from male fish was markedly elevated in Mar Menor lagoon (234.8 ± 5.7 pg E2EQ/μl), and further research will be necessary to explain whether the presence of natural and synthetic-hormones in the lagoon contributed to this finding. Values of approximately 15–16 E2EQ pg

  4. Quantum chemical analysis explains hemagglutinin peptide-MHC Class II molecule HLA-DRβ1*0101 interactions

    International Nuclear Information System (INIS)

    Cardenas, Constanza; Villaveces, Jose Luis; Bohorquez, Hugo; Llanos, Eugenio; Suarez, Carlos; Obregon, Mateo; Patarroyo, Manuel Elkin

    2004-01-01

    We present a new method to explore interactions between peptides and major histocompatibility complex (MHC) molecules using the resultant vector of the three principal multipole terms of the electrostatic field expansion. Being that molecular interactions are driven by electrostatic interactions, we applied quantum chemistry methods to better understand variations in the electrostatic field of the MHC Class II HLA-DRβ1*0101-HA complex. Multipole terms were studied, finding strong alterations of the field in Pocket 1 of this MHC molecule, and weak variations in other pockets, with Pocket 1 >> Pocket 4 > Pocket 9 ∼ Pocket 7 > Pocket 6. Variations produced by 'ideal' amino acids and by other occupying amino acids were compared. Two types of interactions were found in all pockets: a strong unspecific one (global interaction) and a weak specific interaction (differential interaction). Interactions in Pocket 1, the dominant pocket for this allele, are driven mainly by the quadrupole term, confirming the idea that aromatic rings are important in these interactions. Multipolar analysis is in agreement with experimental results, suggesting quantum chemistry methods as an adequate methodology to understand these interactions

  5. Chemical process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  6. Chemical Security Analysis Center

    Data.gov (United States)

    Federal Laboratory Consortium — In 2006, by Presidential Directive, DHS established the Chemical Security Analysis Center (CSAC) to identify and assess chemical threats and vulnerabilities in the...

  7. Nutrient analysis explained for non-chemists by using interactive e-learning material

    NARCIS (Netherlands)

    Busstra, M.C.; Hulshof, P.J.M.; Houwen, J.; Elburg, L.; Hollman, P.C.H.

    2012-01-01

    The diverse educational and professional background of individuals involved in food composition data work presents challenges in their training. In particular, it is difficult to explain chemical analysis of nutrients to individuals lacking a background in chemistry. Therefore an interactive

  8. Chemical analysis of geological samples

    International Nuclear Information System (INIS)

    Malhotra, R.K.

    1997-01-01

    Most of the analytical methodology used in geochemical exploration has been based on molecular absorption, atomic absorption, and ICP-AES, ICPMAS etc. Detection limit and precision are factors in the choice of methodology in search of metallic ores and are related to the accuracy of data. A brief outline of the various chemical analysis techniques explaining essentially the basics of measurement principles and instrumentation is discussed

  9. Facilitating High School Students' Use of Multiple Representations to Describe and Explain Simple Chemical Reactions

    Science.gov (United States)

    Chandrasegaran, A. L.; Treagust, David F.; Mocerino, Mauro

    2011-01-01

    This study involved the evaluation of the efficacy of a planned instructional program to facilitate understanding of the macroscopic, submicroscopic and symbolic representational systems when describing and explaining chemical reactions by sixty-five Grade 9 students in a Singapore secondary school. A two-tier multiple-choice diagnostic instrument…

  10. Explaining the judicial independence of international courts: a comparative analysis

    DEFF Research Database (Denmark)

    Beach, Derek

    What factors allow some international courts (ICs) to rule against the express preferences of powerful member states, whereas others routinely defer to governments? While judicial independence is not the only factor explaining the strength of a given international institution, it is a necessary...... condition. The paper first develops three sets of competing explanatory variables that potentially can explain variations in the judicial independence of ICs. The causal effects of these explanatory variables upon variance in judicial independence are investigated in a comparative analysis of the ACJ, ECJ...

  11. Chemical trends in ocean islands explained by plume–slab interaction

    Science.gov (United States)

    Dannberg, Juliane; Gassmöller, Rene

    2018-04-01

    Earth's surface shows many features, of which the genesis can be understood only through their connection with processes in Earth's deep interior. Recent studies indicate that spatial geochemical patterns at oceanic islands correspond to structures in the lowermost mantle inferred from seismic tomographic models. This suggests that hot, buoyant upwellings can carry chemical heterogeneities from the deep lower mantle toward the surface, providing a window to the composition of the lowermost mantle. The exact nature of this link between surface and deep Earth remains debated and poorly understood. Using computational models, we show that subducted slabs interacting with dense thermochemical piles can trigger the ascent of hot plumes that inherit chemical gradients present in the lowermost mantle. We identify two key factors controlling this process: (i) If slabs induce strong lower-mantle flow toward the edges of these piles where plumes rise, the pile-facing side of the plume preferentially samples material originating from the pile, and bilaterally asymmetric chemical zoning develops. (ii) The composition of the melt produced reflects this bilateral zoning if the overlying plate moves roughly perpendicular to the chemical gradient in the plume conduit. Our results explain some of the observed geochemical trends of oceanic islands and provide insights into how these trends may originate.

  12. Chemical analysis report 2014

    International Nuclear Information System (INIS)

    Elbouzidi, Saliha; Elyahyaoui, Adil; Ghassan, Acil; Marah, Hamid

    2014-01-01

    This report highlights the results of chemical analyzes related to Major elements, traces and heavy metals carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 120 samples. The report presents the analytical techniques used (parameters and methods), a legend and the results tables.

  13. Chemical analysis report 2015

    International Nuclear Information System (INIS)

    2015-01-01

    This report highlights the results of chemical analyzes of fluorides, bromides, lithium and boron carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 120 samples. The report presents the analytical techniques used (parameters and methods), a legend and the results tables.

  14. Explaining Interaction Effects within and across Levels of Analysis

    DEFF Research Database (Denmark)

    Andersson, Ulf; Cuervo-Cazurra, Alvaro; Nielsen, Bo Bernhard

    2014-01-01

    Many manuscripts submitted to the Journal of International Business Studies propose an interaction effect in their models in an effort to explain the complexity and contingency of relationships across borders. In this article, we provide guidance on how best to explain the interaction effects...

  15. Chemical substructure analysis in toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Beauchamp, R.O. Jr. [Center for Information on Toxicology and Environment, Raleigh, NC (United States)

    1990-12-31

    A preliminary examination of chemical-substructure analysis (CSA) demonstrates the effective use of the Chemical Abstracts compound connectivity file in conjunction with the bibliographic file for relating chemical structures to biological activity. The importance of considering the role of metabolic intermediates under a variety of conditions is illustrated, suggesting structures that should be examined that may exhibit potential activity. This CSA technique, which utilizes existing large files accessible with online personal computers, is recommended for use as another tool in examining chemicals in drugs. 2 refs., 4 figs.

  16. Chemical Analysis Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Uses state-of-the-art instrumentation for qualitative and quantitative analysis of organic and inorganic compounds, and biomolecules from gas, liquid, and...

  17. Microprocessors in automatic chemical analysis

    International Nuclear Information System (INIS)

    Goujon de Beauvivier, M.; Perez, J.-J.

    1979-01-01

    Application of microprocessors to programming and computing of solutions chemical analysis by a sequential technique is examined. Safety, performances reliability are compared to other methods. An example is given on uranium titration by spectrophotometry [fr

  18. Trace Chemical Analysis Methodology

    Science.gov (United States)

    1980-04-01

    147 65 Modified DR/2 spectrophotometer face ........... ... 150 66 Colorimetric oil analysis field test kit ......... .. 152 67 Pictorial step...Assisted Pattern Recognitio Perhaps the most promising application of pattern recogntiontechniques for this research effort is the elucidation ".f the...large compartment on the spectrophotomer face . The screwdriver is used to adjust the zero adjust and light ad- just knobs, and the stainless steel

  19. Can species-specific prey responses to chemical cues explain prey susceptibility to predation?

    Science.gov (United States)

    Šmejkal, Marek; Ricard, Daniel; Sajdlová, Zuzana; Čech, Martin; Vejřík, Lukáš; Blabolil, Petr; Vejříková, Ivana; Prchalová, Marie; Vašek, Mojmír; Souza, Allan T; Brönmark, Christer; Peterka, Jiří

    2018-05-01

    The perception of danger represents an essential ability of prey for gaining an informational advantage over their natural enemies. Especially in complex environments or at night, animals strongly rely on chemoreception to avoid predators. The ability to recognize danger by chemical cues and subsequent adaptive responses to predation threats should generally increase prey survival. Recent findings suggest that European catfish ( Silurus glanis ) introduction induce changes in fish community and we tested whether the direction of change can be attributed to differences in chemical cue perception. We tested behavioral response to chemical cues using three species of freshwater fish common in European water: rudd ( Scardinius erythrophthalmus ), roach ( Rutilus rutilus ), and perch ( Perca fluviatilis ). Further, we conducted a prey selectivity experiment to evaluate the prey preferences of the European catfish. Roach exhibited the strongest reaction to chemical cues, rudd decreased use of refuge and perch did not alter any behavior in the experiment. These findings suggest that chemical cue perception might be behind community data change and we encourage collecting more community data of tested prey species before and after European catfish introduction to test the hypothesis. We conclude that used prey species can be used as a model species to verify whether chemical cue perception enhances prey survival.

  20. Explaining discontinuity in organizational learning : a process analysis

    NARCIS (Netherlands)

    Berends, J.J.; Lammers, I.S.

    2010-01-01

    This paper offers a process analysis of organizational learning as it unfolds in a social and temporal context. Building upon the 4I framework (Crossan et al. 1999), we examine organizational learning processes in a longitudinal case study of an implementation of knowledge management in an

  1. Explaining Innovation. An Empirical Analysis of Industry Data from Norway

    Directory of Open Access Journals (Sweden)

    Torbjørn Lorentzen

    2016-01-01

    Full Text Available The objective of the paper is to analyse why some firms innovate while others do not. The paper combines different theories of innovation by relating innovation to internal, firm specific assets and external, regional factors. Hypotheses are derived from theories and tested empirically by using logistic regression. The empirical analysis indicates that internal funding of R&D and size of the firm are the most important firm specific attributes for successful innovation. External, regional factors are also important. The analysis shows that firms located in large urban regions have significantly higher innovation rates than firms located in the periphery, and firms involved in regional networking are more likely to innovate compared to firms not involved in networking. The analysis contributes to a theoretical and empirical understanding of factors that influence on innovation and the role innovation plays in the market economy. Innovation policy should be targeted at developing a tax system and building infrastructure which give firms incentives to invest and allocate internal resources to R&D-activities and collaborate with others in innovation. From an economic policy perspective, consideration should be given to allocating more public resources to rural areas in order to compensate for the asymmetric distribution of resources between the centre and periphery. The paper contributes to the scientific literature of innovation by combining the firm oriented perspective with weight on firm specific, internal resources and a system perspective which focuses on external resources and networking as the most important determinants of innovation in firms.

  2. Explaining HIV Risk Multiplexity: A Social Network Analysis.

    Science.gov (United States)

    Felsher, Marisa; Koku, Emmanuel

    2018-04-21

    Risk multiplexity (i.e., overlap in drug-use, needle exchange and sexual relations) is a known risk factor for HIV. However, little is known about predictors of multiplexity. This study uses egocentric data from the Colorado Springs study to examine how individual, behavioral and social network factors influence engagement in multiplex risk behavior. Analyses revealed that compared to Whites, Hispanics were significantly more likely to engage in risk multiplexity and Blacks less so. Respondents who were similar to each other (e.g., in terms of race) had significantly higher odds of being in risk multiplex relationships, and respondents' risk perceptions and network size were significantly associated with engaging in multiplex risk behaviors. Findings from interaction analysis showed the effect of knowing someone with HIV on the odds of multiplexity depends partly on whether respondents' know their HIV status. Findings suggest that demographics, HIV behaviors and network factors impact engagement in multiplex risk behaviors, highlighting the need for multi-level interventions aimed at reducing HIV risk behavior.

  3. Molecular descriptor data explain market prices of a large commercial chemical compound library

    Science.gov (United States)

    Polanski, Jaroslaw; Kucia, Urszula; Duszkiewicz, Roksana; Kurczyk, Agata; Magdziarz, Tomasz; Gasteiger, Johann

    2016-06-01

    The relationship between the structure and a property of a chemical compound is an essential concept in chemistry guiding, for example, drug design. Actually, however, we need economic considerations to fully understand the fate of drugs on the market. We are performing here for the first time the exploration of quantitative structure-economy relationships (QSER) for a large dataset of a commercial building block library of over 2.2 million chemicals. This investigation provided molecular statistics that shows that on average what we are paying for is the quantity of matter. On the other side, the influence of synthetic availability scores is also revealed. Finally, we are buying substances by looking at the molecular graphs or molecular formulas. Thus, those molecules that have a higher number of atoms look more attractive and are, on average, also more expensive. Our study shows how data binning could be used as an informative method when analyzing big data in chemistry.

  4. Rapid chemical analysis of allanite

    International Nuclear Information System (INIS)

    Nishiyama, Goro; Hayashi, Hiroshi

    1981-01-01

    Rapid chemical analysis of allanite was studied by atomic absorption spectrophotometry. Powdered sample was fused with mixture of sodium carbonate anhydrous and borax (4 : 1 weight) in platinum crucible and sample solution was prepared. SiO 2 , Fe 2 O 3 , Al 2 O 3 , MnO and rare earth metals were determined by atomic absorption spectrophotometry, CaO, MgO and Ce 2 O 3 by titration, ThO 2 by colorimetry, and La 2 O 3 by flame photometry respectively. For sample solution treated with hydrofluoric acid and sulfuric acid. Na 2 O and K 2 O were determined by atomic absorption spectrophotometry, TiO 2 and P 2 O 5 by colorimetry. Chemical analyses for four samples were carried out and gave consistent results. (author)

  5. An extended chemical analysis of gallstone

    OpenAIRE

    Chandran, P.; Kuchhal, N. K.; Garg, P.; Pundir, C. S.

    2007-01-01

    Chemical composition of gall stones is essential for aetiopathogensis of gallstone disease. We have reported quantitative chemical analysis of total cholesterol bilirubin, calcium, iron and inorganic phosphate in 120 gallstones from haryana. To extend this chemical analysis of gall stones by studying more cases and by analyzing more chemical constituents. A quantitative chemical analysis of total cholesterol, total bilirubin, fatty acids, triglycerides, phospholipids, bile acids, soluble prot...

  6. Chemical analysis as production guide

    International Nuclear Information System (INIS)

    Bouzigues, H.; Fontaine, A.; Patigny, P.

    1975-01-01

    All piloting data of chemical processing plants are based on the results of analysis. The first part of this article describes a system of analysers adapted to the needs of the Pierrelatte plant, with management of signals collected by the factory computer. Part two shows the influence of analytical development in the establishment of material balance sheets for the Marcoule spent fuel processing plant. Part three stresses the contribution of the automation of analytical test processes at the La Hague spent fuel processing plant. In all three cases the progress in analytical methods greatly improves the safety, reliability and response time of the various operations [fr

  7. Chemical analysis by nuclear techniques

    International Nuclear Information System (INIS)

    Sohn, S. C.; Kim, W. H.; Park, Y. J.; Park, Y. J.; Song, B. C.; Jeon, Y. S.; Jee, K. Y.; Pyo, H. Y.

    2002-01-01

    This state art report consists of four parts, production of micro-particles, analysis of boron, alpha tracking method and development of neutron induced prompt gamma ray spectroscopy (NIPS) system. The various methods for the production of micro-paticles such as mechanical method, electrolysis method, chemical method, spray method were described in the first part. The second part contains sample treatment, separation and concentration, analytical method, and application of boron analysis. The third part contains characteristics of alpha track, track dectectors, pretreatment of sample, neutron irradiation, etching conditions for various detectors, observation of track on the detector, etc. The last part contains basic theory, neutron source, collimator, neutron shields, calibration of NIPS, and application of NIPS system

  8. Chemical analysis by nuclear techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, S. C.; Kim, W. H.; Park, Y. J.; Song, B. C.; Jeon, Y. S.; Jee, K. Y.; Pyo, H. Y

    2002-01-01

    This state art report consists of four parts, production of micro-particles, analysis of boron, alpha tracking method and development of neutron induced prompt gamma ray spectroscopy (NIPS) system. The various methods for the production of micro-paticles such as mechanical method, electrolysis method, chemical method, spray method were described in the first part. The second part contains sample treatment, separation and concentration, analytical method, and application of boron analysis. The third part contains characteristics of alpha track, track dectectors, pretreatment of sample, neutron irradiation, etching conditions for various detectors, observation of track on the detector, etc. The last part contains basic theory, neutron source, collimator, neutron shields, calibration of NIPS, and application of NIPS system.

  9. CAN GALACTIC CHEMICAL EVOLUTION EXPLAIN THE OXYGEN ISOTOPIC VARIATIONS IN THE SOLAR SYSTEM?

    International Nuclear Information System (INIS)

    Lugaro, Maria; Liffman, Kurt; Ireland, Trevor R.; Maddison, Sarah T.

    2012-01-01

    A number of objects in primitive meteorites have oxygen isotopic compositions that place them on a distinct, mass-independent fractionation line with a slope of one on a three-isotope plot. The most popular model for describing how this fractionation arose assumes that CO self-shielding produced 16 O-rich CO and 16 O-poor H 2 O, where the H 2 O subsequently combined with interstellar dust to form relatively 16 O-poor solids within the solar nebula. Another model for creating the different reservoirs of 16 O-rich gas and 16 O-poor solids suggests that these reservoirs were produced by Galactic chemical evolution (GCE) if the solar system dust component was somewhat younger than the gas component and both components were lying on the line of slope one in the O three-isotope plot. We argue that GCE is not the cause of mass-independent fractionation of the oxygen isotopes in the solar system. The GCE scenario is in contradiction with observations of the 18 O/ 17 O ratios in nearby molecular clouds and young stellar objects. It is very unlikely for GCE to produce a line of slope one when considering the effect of incomplete mixing of stellar ejecta in the interstellar medium. Furthermore, the assumption that the solar system dust was younger than the gas requires unusual timescales or the existence of an important stardust component that is not theoretically expected to occur nor has been identified to date.

  10. An Analogy Using Pennies and Dimes to Explain Chemical Kinetics Concepts

    Science.gov (United States)

    Cortes-Figueroa, Jose E.; Perez, Wanda I.; Lopez, Jose R.; Moore-Russo, Deborah A.

    2011-01-01

    In this article, the authors present an analogy that uses coins and graphical analysis to teach kinetics concepts and resolve pseudo-first-order rate constants related to transition-metal complexes ligand-solvent exchange reactions. They describe an activity that is directed to upper-division undergraduate and graduate students. The activity…

  11. Relativistic Spin-Orbit Heavy Atom on the Light Atom NMR Chemical Shifts: General Trends Across the Periodic Table Explained.

    Science.gov (United States)

    Vícha, Jan; Komorovsky, Stanislav; Repisky, Michal; Marek, Radek; Straka, Michal

    2018-05-10

    The importance of relativistic effects on the NMR parameters in heavy-atom (HA) compounds, particularly the SO-HALA (Spin-Orbit Heavy Atom on the Light Atom) effect on NMR chemical shifts, has been known for about 40 years. Yet, a general correlation between the electronic structure and SO-HALA effect has been missing. By analyzing 1 H NMR chemical shifts of the sixth-period hydrides (Cs-At), we discovered general electronic-structure principles and mechanisms that dictate the size and sign of the SO-HALA NMR chemical shifts. In brief, partially occupied HA valence shells induce relativistic shielding at the light atom (LA) nuclei, while empty HA valence shells induce relativistic deshielding. In particular, the LA nucleus is relativistically shielded in 5d 2 -5d 8 and 6p 4 HA hydrides and deshielded in 4f 0 , 5d 0 , 6s 0 , and 6p 0 HA hydrides. This general and intuitive concept explains periodic trends in the 1 H NMR chemical shifts along the sixth-period hydrides (Cs-At) studied in this work. We present substantial evidence that the introduced principles have a general validity across the periodic table and can be extended to nonhydride LAs. The decades-old question of why compounds with occupied frontier π molecular orbitals (MOs) cause SO-HALA shielding at the LA nuclei, while the frontier σ MOs cause deshielding is answered. We further derive connection between the SO-HALA NMR chemical shifts and Spin-Orbit-induced Electron Deformation Density (SO-EDD), a property that can be obtained easily from differential electron densities and can be represented graphically. SO-EDD provides an intuitive understanding of the SO-HALA effect in terms of the depletion/concentration of the electron density at LA nuclei caused by spin-orbit coupling due to HA in the presence of a magnetic field. Using an analogy between the SO-EDD concept and arguments from classic NMR theory, the complex question of the SO-HALA NMR chemical shifts becomes easily understandable for a wide

  12. Molecular activation analysis for chemical speciation studies

    International Nuclear Information System (INIS)

    Chai-Chifang

    1998-01-01

    The term of Molecular Activation Analysis (MAA) refers to an activation analysis method that is able to provide information about the chemical species of elements in system of interests, though its definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the total concentrations are often without any meaning when assessing health or environmental risks of trace elements.In practice, the MAA is a combination of conventional instrumental or radiochemical activation analysis and physical, chemical or biochemical separation techniques. The MAA is able to play a particular role in speciation studies. However, the critical point in the MAA is that it is not permitted to change the primitive chemical species of elements in systems, or the change has to be under control; in the meantime it is not allowed to form the 'new artifact' originally not present in systems. Some practical examples of MAA for chemical species research performed recently in our laboratory will be presented as follows: Chemical species of platinum group elements in sediment; Chemical species of iodine in marine algae; Chemical species of mercury in human tissues; Chemical species of selenium in corn; Chemical species of rare earth elements in natural plant, etc. The merits and limitations of MAA will be described as well. (author)

  13. Chemical analysis of the Fornax Dwarf galaxy

    NARCIS (Netherlands)

    Letarte, Bruno

    2007-01-01

    This thesis is entitled “Chemical Analysis of the Fornax Dwarf Galaxy”, and it’s main goal is to determine what are the chemical elements present in the stars of this galaxy in order to try and understand it’s evolution. Galaxies are not “static” objects, they move, form stars and can interact with

  14. Chemical analysis of reactor and commercial columbium

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The methods cover the chemical analysis of reactor and commercial columbium having chemical compositions within specified limits. The following analytical procedures are discussed along with apparatus, reagents, photometric practice, safety precautions, sampling, and rounding calculated values: nitrogen, by distillation (photometric) method; molybdenum and tungsten by the dithiol (photometric) method; iron by the 1,10-phenanthroline (photometric) method

  15. Optical MEMS for chemical analysis and biomedicine

    CERN Document Server

    Jiang, Hongrui

    2016-01-01

    This book describes the current state of optical MEMS in chemical and biomedical analysis and brings together current trends and highlights topics representing the most exciting progress in recent years in the field.

  16. Chemical analysis of water in hydrogeology

    International Nuclear Information System (INIS)

    Flakova, R.; Zenisova, Z.; Seman, M.

    2010-01-01

    The aim of the monograph is to give complete information on the chemical analysis of water hydrogeology not only for the students program of Geology study (Bachelor degree study), Engineering Geology and Hydrogeology (Master's degree study) and Engineering Geology (doctoral level study), but also for students from other colleges and universities schools in Slovakia, as well as in the Czech Republic, dealing with the chemical composition of water and its quality, from different perspectives. The benefit would be for professionals with hydrogeological, water and environmental practices, who can find there all the necessary information about proper water sampling, the units used in the chemical analysis of water, expressing the proper chemical composition of water in its various parameters through classification of chemical composition of the water up to the basic features of physical chemistry at thermodynamic calculations and hydrogeochemical modelling.

  17. Chemical methods of rock analysis

    National Research Council Canada - National Science Library

    Jeffery, P. G; Hutchison, D

    1981-01-01

    A practical guide to the methods in general use for the complete analysis of silicate rock material and for the determination of all those elements present in major, minor or trace amounts in silicate...

  18. Utilization of chemical derivatives in activation analysis

    International Nuclear Information System (INIS)

    Ehmann, W.D.

    1990-01-01

    Derivative activation analysis (DAA) is a method to enhance the sensitivity of nuclear activation analysis for the more elusive elements. It may also allow a degree of chemical speciation for the element of interest. DAA uses a preirradiation chemical reaction on the sample to initiate the formation of, or an exchange with, a chemical complex which contains a surrogate element, M. As a result, the amount of the element or the chemical species to be determined, X, is now represented by measurement of the amount of the surrogate element, M, that is made part of, or released by the complex species. The surrogate element is selected for its superior properties for nuclear activation analysis and the absence of interference reaction in its final determination by instrumental neutron activation analysis (INAA) after some preconcentration or separation chemistry. Published DAA studies have been limited to neutron activation analysis. DAA can offer the analyst some important advantages. It can determine elements, functional groups, or chemical species which cannot be determined directly by INAA, fast neutron activation analysis (FNAA), prompt gamma neutron activation analysis (PGNAA), or charged particle activation analysis (CPAA) procedures. When compared with conventional RNAA, there are fewer precautions with respect to handling of intensely radioactive samples, since the chemistry is done before the irradiation. The preirradiation chemistry may also eliminate many interferences that might occur in INAA and, through use of an appropriate surrogate element, can place the analytical gamma-ray line in an interference-free region of the gamma-ray spectrum

  19. Spectroscopic Chemical Analysis Methods and Apparatus

    Science.gov (United States)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor); Bhartia, Rohit (Inventor); Lane, Arthur L. (Inventor)

    2018-01-01

    Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted along with photoluminescence spectroscopy (i.e. fluorescence and/or phosphorescence spectroscopy) to provide high levels of sensitivity and specificity in the same instrument.

  20. Explaining pathological changes in axonal excitability through dynamical analysis of conductance-based models

    Science.gov (United States)

    Coggan, Jay S.; Ocker, Gabriel K.; Sejnowski, Terrence J.; Prescott, Steven A.

    2011-10-01

    Neurons rely on action potentials, or spikes, to relay information. Pathological changes in spike generation likely contribute to certain enigmatic features of neurological disease, like paroxysmal attacks of pain and muscle spasm. Paroxysmal symptoms are characterized by abrupt onset and short duration, and are associated with abnormal spiking although the exact pathophysiology remains unclear. To help decipher the biophysical basis for 'paroxysmal' spiking, we replicated afterdischarge (i.e. continued spiking after a brief stimulus) in a minimal conductance-based axon model. We then applied nonlinear dynamical analysis to explain the dynamical basis for initiation and termination of afterdischarge. A perturbation could abruptly switch the system between two (quasi-)stable attractor states: rest and repetitive spiking. This bistability was a consequence of slow positive feedback mediated by persistent inward current. Initiation of afterdischarge was explained by activation of the persistent inward current forcing the system to cross a saddle point that separates the basins of attraction associated with each attractor. Termination of afterdischarge was explained by the attractor associated with repetitive spiking being destroyed. This occurred when ultra-slow negative feedback, such as intracellular sodium accumulation, caused the saddle point and stable limit cycle to collide; in that regard, the active attractor is not truly stable when the slowest dynamics are taken into account. The model also explains other features of paroxysmal symptoms, including temporal summation and refractoriness.

  1. Chemical analysis of high purity graphite

    International Nuclear Information System (INIS)

    1993-03-01

    The Sub-Committee on Chemical Analysis of Graphite was organized in April 1989, under the Committee on Chemical Analysis of Nuclear Fuels and Reactor Materials, JAERI. The Sub-Committee carried out collaborative analyses among eleven participating laboratories for the certification of the Certified Reference Materials (CRMs), JAERI-G5 and G6, after developing and evaluating analytical methods during the period of September 1989 to March 1992. The certified values were given for ash, boron and silicon in the CRM based on the collaborative analysis. The values for ten elements (Al, Ca, Cr, Fe, Mg, Mo, Ni, Sr, Ti, V) were not certified, but given for information. Preparation, homogeneity testing and chemical analyses for certification of reference materials were described in this paper. (author) 52 refs

  2. Molecular activation analysis for chemical species studies

    International Nuclear Information System (INIS)

    Chai Zhifang; Mao Xueying; Wang Yuqi; Sun Jingxin; Qian Qingfang; Hou Xiaolin; Zhang Peiqun; Chen Chunying; Feng Weiyu; Ding Wenjun; Li Xiaolin; Li Chunsheng; Dai Xiongxin

    2001-01-01

    The Molecular Activation Analysis (MAA) mainly refers to an activation analysis method that is able to provide information about the chemical species of elements in systems of interest, though its exact definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the bulk contents or concentrations are often insignificant for judging biological, environmental or geochemical effects of elements. In this paper, the features, methodology and limitation of MAA were outlined. Further, the up-to-date MAA progress made in our laboratory was introduced as well. (author)

  3. Service activities of chemical analysis division

    International Nuclear Information System (INIS)

    Eom, Tae Yoon; Suh, Moo Yul; Park, Kyoung Kyun; Jung, Ki Suk; Joe, Kih Soo; Jee, Kwang Yong; Jung, Woo Sik; Sohn, Se Chul; Yeo, In Heong; Han, Sun Ho

    1988-12-01

    Progress of the Division during the year of 1988 was described on the service activities for various R and D projects carrying out in the Institute, for the fuel fabrication and conversion plant, and for the post-irradiation examination facility. Relevant analytical methodologies developed for the chemical analysis of an irradiated fuel, safeguards chemical analysis, and pool water monitoring were included such as chromatographic separation of lanthanides, polarographic determination of dissolved oxygen in water, and automation on potentiometric titration of uranium. Some of the laboratory manuals revised were also included in this progress report. (Author)

  4. Chemical analysis by nuclear methods. v. 2

    International Nuclear Information System (INIS)

    Alfassi, Z.B.

    1998-01-01

    'Chemical analysis by Nuclear Methods' is an effort of some renowned authors in field of nuclear chemistry and radiochemistry which is compiled by Alfassi, Z.B. and translated into Farsi version collected in two volumes. The second volume consists of the following chapters: Detecting ion recoil scattering and elastic scattering are dealt in the eleventh chapter, the twelfth chapter is devoted to nuclear reaction analysis using charged particles, X-ray emission is discussed at thirteenth chapter, the fourteenth chapter is about using ion microprobes, X-ray fluorescence analysis is discussed in the fifteenth chapter, alpha, beta and gamma ray scattering in chemical analysis are dealt in chapter sixteen, Moessbauer spectroscopy and positron annihilation are discussed in chapter seventeen and eighteen; The last two chapters are about isotope dilution analysis and radioimmunoassay

  5. An extended chemical analysis of gallstone.

    Science.gov (United States)

    Chandran, P; Kuchhal, N K; Garg, P; Pundir, C S

    2007-09-01

    Chemical composition of gall stones is essential for aetiopathogensis of gallstone disease. We have reported quantitative chemical analysis of total cholesterol bilirubin, calcium, iron and inorganic phosphate in 120 gallstones from haryana. To extend this chemical analysis of gall stones by studying more cases and by analyzing more chemical constituents. A quantitative chemical analysis of total cholesterol, total bilirubin, fatty acids, triglycerides, phospholipids, bile acids, soluble proteins, sodium potassium, magnesium, copper, oxalate and chlorides of biliary calculi (52 cholesterol, 76 mixed and 72 pigment) retrieved from surgical operation of 200 patients from Haryana state was carried out. Total cholesterol as the major component and total bilirubin, phospholipids, triglycerides, bile acids, fatty acids (esterified), soluble protein, calcium, magnesium, iron, copper, sodium, potassium, inorganic phosphate, oxalate and chloride as minor components were found in all types of calculi. The cholesterol stones had higher content of total cholesterol, phospholipids, fatty acids (esterified), inorganic phosphate and copper compared to mixed and pigment stones. The mixed stones had higher content of iron and triglycerides than to cholesterol and pigment stones. The pigment stones were richer in total bilirubin, bile acids, calcium, oxalate, magnesium, sodium, potassium, chloride and soluble protein compared to cholesterol and mixed stones. Although total cholesterol was a major component of cholesterol, mixed and pigment gall stone in Haryana, the content of most of the other lipids, cations and anions was different in different gall stones indicating their different mechanism of formation.

  6. Failure analysis on a chemical waste pipe

    International Nuclear Information System (INIS)

    Ambler, J.R.

    1985-01-01

    A failure analysis of a chemical waste pipe illustrates how nuclear technology can spin off metallurgical consultant services. The pipe, made of zirconium alloy (Zr-2.5 wt percent Nb, UNS 60705), had cracked in several places, all at butt welds. A combination of fractography and metallography indicated delayed hydride cracking

  7. Calibrating Detailed Chemical Analysis of M dwarfs

    Science.gov (United States)

    Veyette, Mark; Muirhead, Philip Steven; Mann, Andrew; Brewer, John; Allard, France; Homeier, Derek

    2018-01-01

    The ability to perform detailed chemical analysis of Sun-like F-, G-, and K-type stars is a powerful tool with many applications including studying the chemical evolution of the Galaxy, assessing membership in stellar kinematic groups, and constraining planet formation theories. Unfortunately, complications in modeling cooler stellar atmospheres has hindered similar analysis of M-dwarf stars. Large surveys of FGK abundances play an important role in developing methods to measure the compositions of M dwarfs by providing benchmark FGK stars that have widely-separated M dwarf companions. These systems allow us to empirically calibrate metallicity-sensitive features in M dwarf spectra. However, current methods to measure metallicity in M dwarfs from moderate-resolution spectra are limited to measuring overall metallicity and largely rely on astrophysical abundance correlations in stellar populations. In this talk, I will discuss how large, homogeneous catalogs of precise FGK abundances are crucial to advancing chemical analysis of M dwarfs beyond overall metallicity to direct measurements of individual elemental abundances. I will present a new method to analyze high-resolution, NIR spectra of M dwarfs that employs an empirical calibration of synthetic M dwarf spectra to infer effective temperature, Fe abundance, and Ti abundance. This work is a step toward detailed chemical analysis of M dwarfs at a similar precision achieved for FGK stars.

  8. Use of Principal Components Analysis to Explain Controls on Nutrient Fluxes to the Chesapeake Bay

    Science.gov (United States)

    Rice, K. C.; Mills, A. L.

    2017-12-01

    The Chesapeake Bay watershed, on the east coast of the United States, encompasses about 166,000-square kilometers (km2) of diverse land use, which includes a mixture of forested, agricultural, and developed land. The watershed is now managed under a Total Daily Maximum Load (TMDL), which requires implementation of management actions by 2025 that are sufficient to reduce nitrogen, phosphorus, and suspended-sediment fluxes to the Chesapeake Bay and restore the bay's water quality. We analyzed nutrient and sediment data along with land-use and climatic variables in nine sub watersheds to better understand the drivers of flux within the watershed and to provide relevant management implications. The nine sub watersheds range in area from 300 to 30,000 km2, and the analysis period was 1985-2014. The 31 variables specific to each sub watershed were highly statistically significantly correlated, so Principal Components Analysis was used to reduce the dimensionality of the dataset. The analysis revealed that about 80% of the variability in the whole dataset can be explained by discharge, flux, and concentration of nutrients and sediment. The first two principal components (PCs) explained about 68% of the total variance. PC1 loaded strongly on discharge and flux, and PC2 loaded on concentration. The PC scores of both PC1 and PC2 varied by season. Subsequent analysis of PC1 scores versus PC2 scores, broken out by sub watershed, revealed management implications. Some of the largest sub watersheds are largely driven by discharge, and consequently large fluxes. In contrast, some of the smaller sub watersheds are more variable in nutrient concentrations than discharge and flux. Our results suggest that, given no change in discharge, a reduction in nutrient flux to the streams in the smaller watersheds could result in a proportionately larger decrease in fluxes of nutrients down the river to the bay, than in the larger watersheds.

  9. Probabilistic risk analysis in chemical engineering

    International Nuclear Information System (INIS)

    Schmalz, F.

    1991-01-01

    In risk analysis in the chemical industry, recognising potential risks is considered more important than assessing their quantitative extent. Even in assessing risks, emphasis is not on the probability involved but on the possible extent. Qualitative assessment has proved valuable here. Probabilistic methods are used in individual cases where the wide implications make it essential to be able to assess the reliability of safety precautions. In this case, assessment therefore centres on the reliability of technical systems and not on the extent of a chemical risk. 7 figs

  10. Microfabricated Gas Phase Chemical Analysis Systems

    International Nuclear Information System (INIS)

    FRYE-MASON, GREGORY CHARLES; HELLER, EDWIN J.; HIETALA, VINCENT M.; KOTTENSTETTE, RICHARD; LEWIS, PATRICK R.; MANGINELL, RONALD P.; MATZKE, CAROLYN M.; WONG, CHUNGNIN C.

    1999-01-01

    A portable, autonomous, hand-held chemical laboratory ((micro)ChemLab(trademark)) is being developed for trace detection (ppb) of chemical warfare (CW) agents and explosives in real-world environments containing high concentrations of interfering compounds. Microfabrication is utilized to provide miniature, low-power components that are characterized by rapid, sensitive and selective response. Sensitivity and selectivity are enhanced using two parallel analysis channels, each containing the sequential connection of a front-end sample collector/concentrator, a gas chromatographic (GC) separator, and a surface acoustic wave (SAW) detector. Component design and fabrication and system performance are described

  11. Differences between Lipids Extracted from Five Species Are Not Sufficient To Explain Biomagnification of Nonpolar Organic Chemicals

    DEFF Research Database (Denmark)

    Jahnke, Annika; Holmbäck, Jan; Andersson, Rina Argelia

    2015-01-01

    headspace from spiked olive oil to determine their sorptive capacities. Lipids from seal blubber and pork bacon solely composed of triglycerides had capacities similar to that of olive oil; lipids from mussels, herring, and guillemot egg had quantifiable fractions of phospholipids and cholesterol and showed...... capacities reduced by factors of up to 2.3-fold. Generally, the sorptive capacities of the lipids were not elevated relative to the olive oil controls and are unlikely to explain a substantial part of biomagnification....

  12. SPSS explained

    CERN Document Server

    Hinton, Perry R; Brownlow, Charlotte

    2014-01-01

    SPSS Explained provides the student with all that they need to undertake statistical analysis using SPSS. It combines a step-by-step approach to each procedure with easy to follow screenshots at each stage of the process. A number of other helpful features are provided: regular advice boxes with tips specific to each test explanations divided into 'essential' and 'advanced' sections to suit readers at different levels frequently asked questions at the end of each chapter. The first edition of this popular book has been fully updated for IBM SPSS version 21 and also includes: chapters that expl

  13. Chemical analysis quality assurance at the ICPP

    International Nuclear Information System (INIS)

    Hand, R.L.

    1990-01-01

    This document discusses the chemical analysis quality assurance program at the ICPP which involves records management, analytical methods quality control, analysis procedures and training and qualification. Since 1979, the major portion of the quality assurance program has been implemented on a central analytical computer system. The individual features provided by the system are storage, retrieval, and search capabilities over all general request and sample analysis information, automatic method selection for all process streams, automation of all method calculations, automatic assignment of bias and precision estimates at all analysis levels, with-method-use requalification, untrained or unqualified analyst method lockout, statistical testing of all process stream results for replicate agreement, automatic testing of process results against pre- established operating, safety, or failure limits at varying confidence levels, and automatic transfer and report of all analysis data plus all statistical testing to the Production Department

  14. Chemical analysis of refractories by plasma spectrometry

    International Nuclear Information System (INIS)

    Coutinho, C.A.

    1990-01-01

    X-ray spectrometry has been, since the last two or three decades, the traditional procedure for the chemical analysis of refractories, due to its high degree of accuracy and speed to produce analytical results. An interesting alternative to X-ray fluorescence is provided by the Inductively Coupled Plasma Spectrometry technique, for those laboratories where wet chemistry facilities are already available or process control is not required at high speed, or investiment costs have to be low. This paper presents results obtained by plasma spectroscopy for the analysis of silico - aluminous refractories, showing calibration curves, precion and detection limits. Considerations and comparisons with X-ray fluorescence are also made. (author) [pt

  15. Explaining transgression in respiratory rate observation methods in the emergency department: A classic grounded theory analysis.

    Science.gov (United States)

    Flenady, Tracy; Dwyer, Trudy; Applegarth, Judith

    2017-09-01

    Abnormal respiratory rates are one of the first indicators of clinical deterioration in emergency department(ED) patients. Despite the importance of respiratory rate observations, this vital sign is often inaccurately recorded on ED observation charts, compromising patient safety. Concurrently, there is a paucity of research reporting why this phenomenon occurs. To develop a substantive theory explaining ED registered nurses' reasoning when they miss or misreport respiratory rate observations. This research project employed a classic grounded theory analysis of qualitative data. Seventy-nine registered nurses currently working in EDs within Australia. Data collected included detailed responses from individual interviews and open-ended responses from an online questionnaire. Classic grounded theory (CGT) research methods were utilised, therefore coding was central to the abstraction of data and its reintegration as theory. Constant comparison synonymous with CGT methods were employed to code data. This approach facilitated the identification of the main concern of the participants and aided in the generation of theory explaining how the participants processed this issue. The main concern identified is that ED registered nurses do not believe that collecting an accurate respiratory rate for ALL patients at EVERY round of observations is a requirement, and yet organizational requirements often dictate that a value for the respiratory rate be included each time vital signs are collected. The theory 'Rationalising Transgression', explains how participants continually resolve this problem. The study found that despite feeling professionally conflicted, nurses often erroneously record respiratory rate observations, and then rationalise this behaviour by employing strategies that adjust the significance of the organisational requirement. These strategies include; Compensating, when nurses believe they are compensating for errant behaviour by enhancing the patient's outcome

  16. A path analysis model for explaining unsafe behavior in workplaces: the effect of perceived work pressure.

    Science.gov (United States)

    Ghasemi, Fakhradin; Kalatpour, Omid; Moghimbeigi, Abbas; Mohhamadfam, Iraj

    2018-06-01

    Unsafe behavior is closely related to occupational accidents. Work pressure is one the main factors affecting employees' behavior. The aim of the present study was to provide a path analysis model for explaining how work pressure affects safety behavior. Using a self-administered questionnaire, six variables supposed to affect safety employees' behavior were measured. The path analysis model was constructed based on several hypotheses. The goodness of fit of the model was assessed using both absolute and comparative fit indices. Work pressure was determined not to influence safety behavior directly. However, it negatively influenced other variables. Group attitude and personal attitude toward safety were the main factors mediating the effect of work pressure on safety behavior. Among the variables investigated in the present study, group attitude, personal attitude and work pressure had the strongest effects on safety behavior. Managers should consider that in order to improve employees' safety behavior, work pressure should be reduced to a reasonable level, and concurrently a supportive environment, which ensures a positive group attitude toward safety, should be provided. Replication of the study is recommended.

  17. Chemical detection, identification, and analysis system

    International Nuclear Information System (INIS)

    Morel, R.S.; Gonzales, D.; Mniszewski, S.

    1990-01-01

    The chemical detection, identification, and analysis system (CDIAS) has three major goals. The first is to display safety information regarding chemical environment before personnel entry. The second is to archive personnel exposure to the environment. Third, the system assists users in identifying the stage of a chemical process in progress and suggests safety precautions associated with that process. In addition to these major goals, the system must be sufficiently compact to provide transportability, and it must be extremely simple to use in order to keep user interaction at a minimum. The system created to meet these goals includes several pieces of hardware and the integration of four software packages. The hardware consists of a low-oxygen, carbon monoxide, explosives, and hydrogen sulfide detector; an ion mobility spectrometer for airborne vapor detection; and a COMPAQ 386/20 portable computer. The software modules are a graphics kernel, an expert system shell, a data-base management system, and an interface management system. A supervisory module developed using the interface management system coordinates the interaction of the other software components. The system determines the safety of the environment using conventional data acquisition and analysis techniques. The low-oxygen, carbon monoxide, hydrogen sulfide, explosives, and vapor detectors are monitored for hazardous levels, and warnings are issued accordingly

  18. The development of chemical speciation analysis

    International Nuclear Information System (INIS)

    Martin, R.; Santana, J.L.; Lima, L.; De La Rosa, D.; Melchor, K.

    2003-01-01

    The knowledge of many metals species on the environmental, its bioaccumulation, quantification and its effect in human body has been studied by a wide researchers groups in the last two decades. The development of speciation analysis has an vertiginous advance close to the developing of novel analytical techniques. Separation and quantification at low level is a problem that's has been afford by a coupling of high resolution chromatographic techniques like HPLC and HRGC with a specific method of detection (ICP-MS or CV-AAS). This methodological approach make possible the success in chemical speciation nowadays

  19. Laser chemical analysis: the recent developments

    International Nuclear Information System (INIS)

    Mauchien, P.

    1997-01-01

    This paper gives a general overview and describes the principles of the main laser-based techniques for physical and chemical analysis, and of their recent developments. Analytical techniques using laser radiations were actually developed at the end of the 1970's. The recent evolutions concern the 3 principal techniques of laser spectroscopy currently used: Raman, fluorescence (atomic and molecular) and ablation (ICP laser ablation-plasma coupling, optical emission spectroscopy on laser-induced plasma). The description of these different techniques is illustrated with some examples of applications. (J.S.)

  20. Activation and chemical analysis of drinking waters

    International Nuclear Information System (INIS)

    Sharma, H.K.; Mittal, V.K.; Sahota, H.S.

    1989-01-01

    Ground water samples from Patiala city have been analysed for 22 trace elements using neutron activation analysis and for seven chemical parameters using standard techniques. It was found that alkali and alkaline earth metals have high concentrations in all samples whereas the concentrations of toxic metals are low in the majority of samples. However, chromium and cadmium concentrations are higher in ground water taken from the industrial belt of the city. This indicates that the overall level of pollution is low, but that some measures are still needed to inhibit various industries from polluting the ground water. (author)

  1. Development of chemical equilibrium analysis code 'CHEEQ'

    International Nuclear Information System (INIS)

    Nagai, Shuichiro

    2006-08-01

    'CHEEQ' code which calculates the partial pressure and the mass of the system consisting of ideal gas and pure condensed phase compounds, was developed. Characteristics of 'CHEEQ' code are as follows. All the chemical equilibrium equations were described by the formation reactions from the mono-atomic gases in order to simplify the code structure and input preparation. Chemical equilibrium conditions, Σν i μ i =0 for the gaseous compounds and precipitated condensed phase compounds and Σν i μ i > 0 for the non-precipitated condensed phase compounds, were applied. Where, ν i and μ i are stoichiometric coefficient and chemical potential of component i. Virtual solid model was introduced to perform the calculation of constant partial pressure condition. 'CHEEQ' was consisted of following 3 parts, (1) analysis code, zc132. f. (2) thermodynamic data base, zmdb01 and (3) input data file, zindb. 'CHEEQ' code can calculate the system which consisted of elements (max.20), condensed phase compounds (max.100) and gaseous compounds. (max.200). Thermodynamic data base, zmdb01 contains about 1000 elements and compounds, and 200 of them were Actinide elements and their compounds. This report describes the basic equations, the outline of the solution procedure and instructions to prepare the input data and to evaluate the calculation results. (author)

  2. VALIDATION GUIDELINES FOR LABORATORIES PERFORMING FORENSIC ANALYSIS OF CHEMICAL TERRORISM

    Science.gov (United States)

    The Scientific Working Group on Forensic Analysis of Chemical Terrorism (SWGFACT) has developed the following guidelines for laboratories engaged in the forensic analysis of chemical evidence associated with terrorism. This document provides a baseline framework and guidance for...

  3. Fatty acid composition and its association with chemical and sensory analysis of boar taint.

    Science.gov (United States)

    Liu, Xiaoye; Trautmann, Johanna; Wigger, Ruth; Zhou, Guanghong; Mörlein, Daniel

    2017-09-15

    A certain level of disagreement between the chemical analysis of androstenone and skatole and the human perception of boar taint has been found in many studies. Here we analyze whether the fatty acid composition can explain such inconsistency between sensory evaluation and chemical analysis of boar taint compounds. Therefore, back fat samples (n=143) were selected according to their sensory evaluation by a 10-person sensory panel, and the chemical analysis (stable isotope dilution analysis with headspace solid-phase microextraction and gas chromatography-mass spectrometry) of androstenone and skatole. Subsequently a quantification of fatty acids using gas chromatography-flame ionization detection was conducted. The correlation analyses revealed that several fatty acids are significantly correlated with androstenone, skatole, and the sensory rating. However, multivariate analyses (principal component analysis) revealed no explanation of the fatty acid composition with respect to the (dis-)agreement between sensory and chemical analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Explaining time changes in oral health-related quality of life in England: a decomposition analysis.

    Science.gov (United States)

    Tsakos, Georgios; Guarnizo-Herreño, Carol C; O'Connor, Rhiannon; Wildman, John; Steele, Jimmy G; Allen, Patrick Finbarr

    2017-12-01

    Oral diseases are highly prevalent and impact on oral health-related quality of life (OHRQoL). However, time changes in OHRQoL have been scarcely investigated in the current context of general improvement in clinical oral health. This study aims to examine changes in OHRQoL between 1998 and 2009 among adults in England, and to analyse the contribution of demographics, socioeconomic characteristics and clinical oral health measures. Using data from two nationally representative surveys in England, we assessed changes in the Oral Health Impact Profile-14 (OHIP-14), in both the sample overall (n=12 027) and by quasi-cohorts. We calculated the prevalence and extent of oral impacts and summary OHIP-14 scores. An Oaxaca-Blinder type decomposition analysis was used to assess the contribution of demographics (age, gender, marital status), socioeconomic position (education, occupation) and clinical measures (presence of decay, number of missing teeth, having advanced periodontitis). There were significant improvements in OHRQoL, predominantly among those that experienced oral impacts occasionally, but no difference in the proportion with frequent oral impacts. The decomposition model showed that 43% (-4.07/-9.47) of the decrease in prevalence of oral impacts reported occasionally or more often was accounted by the model explanatory variables. Improvements in clinical oral health and the effect of ageing itself accounted for most of the explained change in OHRQoL, but the effect of these factors varied substantially across the lifecourse and quasi-cohorts. These decomposition findings indicate that broader determinants could be primarily targeted to influence OHRQoL in different age groups or across different adult cohorts. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Systems analysis of past, present, and future chemical terrorism scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Hoette, Trisha Marie

    2012-03-01

    Throughout history, as new chemical threats arose, strategies for the defense against chemical attacks have also evolved. As a part of an Early Career Laboratory Directed Research and Development project, a systems analysis of past, present, and future chemical terrorism scenarios was performed to understand how the chemical threats and attack strategies change over time. For the analysis, the difficulty in executing chemical attack was evaluated within a framework of three major scenario elements. First, historical examples of chemical terrorism were examined to determine how the use of chemical threats, versus other weapons, contributed to the successful execution of the attack. Using the same framework, the future of chemical terrorism was assessed with respect to the impact of globalization and new technologies. Finally, the efficacy of the current defenses against contemporary chemical terrorism was considered briefly. The results of this analysis justify the need for continued diligence in chemical defense.

  6. Integrated ecological and chemical food web accumulation modeling explains PAH temporal trends during regime shifts in a shallow lake.

    Science.gov (United States)

    Kong, Xiangzhen; He, Wei; Qin, Ning; Liu, Wenxiu; Yang, Bin; Yang, Chen; Xu, Fuliu; Mooij, Wolf M; Koelmans, Albert A

    2017-08-01

    Shallow lakes can switch suddenly from a turbid situation with high concentrations of phytoplankton and other suspended solids to a vegetated state with clear water, and vice versa. These alternative stable states may have a substantial impact on the fate of hydrophobic organic compounds (HOCs). Models that are fit to simulate impacts from these complex interactions are scarce. We developed a contaminant fate model which is linked to an ecosystem model (PCLake) for shallow lakes. This integrated model was successful in simulating long-term dynamics (1953-2012) of representative polycyclic aromatic hydrocarbons (PAHs) in the main biotic and abiotic components in a large shallow lake (Chaohu in China), which has undergone regime shifts in this period. Historical records from sediment cores were used to evaluate the model. The model revealed that regime shifts in shallow lakes had a strong impact on the fate of less hydrophobic compounds due to the large storage capacity of macrophytes, which accumulated up to 55.6% of phenanthrene in the clear state. The abrupt disappearance of macrophytes after the regime shift resulted in a sudden change in phenanthrene distribution, as the sediment became the major sink. For more hydrophobic compounds such as benzo(a)pyrene, the modeled impact of the regime shift was negligible for the whole environment, yet large for biotic compartments. This study is the first to provide a full mechanistic analysis of the impact of regime shifts on the fate of PAHs in a real lake ecosystem. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Computational Chemical Synthesis Analysis and Pathway Design

    Directory of Open Access Journals (Sweden)

    Fan Feng

    2018-06-01

    Full Text Available With the idea of retrosynthetic analysis, which was raised in the 1960s, chemical synthesis analysis and pathway design have been transformed from a complex problem to a regular process of structural simplification. This review aims to summarize the developments of computer-assisted synthetic analysis and design in recent years, and how machine-learning algorithms contributed to them. LHASA system started the pioneering work of designing semi-empirical reaction modes in computers, with its following rule-based and network-searching work not only expanding the databases, but also building new approaches to indicating reaction rules. Programs like ARChem Route Designer replaced hand-coded reaction modes with automatically-extracted rules, and programs like Chematica changed traditional designing into network searching. Afterward, with the help of machine learning, two-step models which combine reaction rules and statistical methods became the main stream. Recently, fully data-driven learning methods using deep neural networks which even do not require any prior knowledge, were applied into this field. Up to now, however, these methods still cannot replace experienced human organic chemists due to their relatively low accuracies. Future new algorithms with the aid of powerful computational hardware will make this topic promising and with good prospects.

  8. Comparative Analysis on Chemical Composition of Bentonite Clays ...

    African Journals Online (AJOL)

    2017-09-12

    Sep 12, 2017 ... Comparative Analysis on Chemical Composition of Bentonite Clays. Obtained from Ashaka and ... versatile material for geotechnical engineering and as well as their demand for ..... A PhD thesis submitted to the Chemical ...

  9. Novel chemical analysis for thin films

    International Nuclear Information System (INIS)

    Usui, Toshio; Kamei, Masayuki; Aoki, Yuji; Morishita, Tadataka; Tanaka, Shoji

    1991-01-01

    Scanning electron microscopy and total-reflection-angle X-ray spectroscopy (SEM-TRAXS) was applied for fluorescence X-ray analysis of 50A- and 125A-thick Au thin films on Si(100). The intensity of the AuM line (2.15 keV) emitted from the Au thin films varied as a function of the take-off angle (θ t ) with respect to the film surface; the intensity of AuM line from the 125A-thick Au thin film was 1.5 times as large as that of SiK α line (1.74 keV) emitted from the Si substrate when θ t = 0deg-3deg, in the vicinity of a critical angle for total external reflection of the AuM line at Si (0.81deg). In addition, the intensity of the AuM line emitted from the 50A-thick Au thin film was also sufficiently strong for chemical analysis. (author)

  10. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  11. Social cognitive theories used to explain physical activity behavior in adolescents: a systematic review and meta-analysis.

    Science.gov (United States)

    Plotnikoff, Ronald C; Costigan, Sarah A; Karunamuni, Nandini; Lubans, David R

    2013-05-01

    To systematically review and examine the explanatory power of key social-cognitive theories used to explain physical activity (PA) intention and behavior, among adolescents. A systematic review and meta-analysis of the literature was performed using the electronic databases Medline, Cumulative Index to Nursing and Allied Health Literature, SPORTdiscus, EBSCO and Education Resources Information Center, Proquest Education Journals Collection, Science Direct, Web of Science and Scopus for social-cognitive theories (i.e., Health Promotion Model, Theory of Planned Behavior, Theory of Reasoned Action, Protection Motivation Theory, Social Cognitive Theory/Self-Efficacy Theory, Health Belief Model, Self-Determination Theory, Transtheoretical Model) used to explain PA intention and behavior. Related keywords in titles, abstracts, or indexing fields were searched. Twenty-three studies satisfied the inclusion criteria and were retained for data extraction and analysis; 16 were cross-sectional studies and seven were longitudinal studies. Most studies employed self-report measures. In general, the models explained greater proportions of variance for intention compared to behavior. The meta-analyses revealed 33% and 48% of the variance respectively for PA and intention were explained by social cognitive models. Few studies have tested the predictive capacity of social cognitive theories to explain objectively measured PA. The majority of PA variance remains unexplained and more theoretical research is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Meta-analysis of institutional-economic factors explaining the environmental performance of payments for watershed services

    NARCIS (Netherlands)

    Brouwer, R.; Tesfaye, A.; Pauw, W.P.

    2011-01-01

    Payments for ecosystem services (PES) are a relatively new economic policy instrument, and the factors that drive and explain their environmental performance are poorly understood. Here a meta-analysis of causal relationships between the institutional design and environmental performance of 47

  13. Thermodynamic analysis of chemical heat pumps

    International Nuclear Information System (INIS)

    Obermeier, Jonas; Müller, Karsten; Arlt, Wolfgang

    2015-01-01

    Thermal energy storages and heat pump units represent an important part of high efficient renewable energy systems. By using thermally driven, reversible chemical reactions a combination of thermal energy storage and heat pump can be realized. The influences of thermophysical properties of the involved components on the efficiency of a heat pump cycle is analysed and the relevance of the thermodynamic driving force is worked out. In general, the behaviour of energetic and exergetic efficiency is contrary. In a real cycle, higher enthalpies of reaction decrease the energetic efficiency but increase the exergetic efficiency. Higher enthalpies of reaction allow for lower offsets from equilibrium state for a default thermodynamic driving force of the reaction. - Highlights: • A comprehensive efficiency analysis of gas-solid heat pumps is proposed. • Link between thermodynamic driving force and equilibrium drop is shown. • Calculation of the equilibrium drop based on thermochemical properties. • Reaction equilibria of the decomposition reaction of salt hydrates. • Contrary behavior of energetic and exergetic efficiency

  14. Can individual health differences be explained by workplace characteristics?--A multilevel analysis.

    Science.gov (United States)

    Marklund, Staffan; Bolin, Malin; von Essen, Jan

    2008-02-01

    Research on work-related health has mainly focused on individual factors. The present study expands the focus by exploring the role of organizational characteristics of workplaces for different individual health outcomes. The aim of the study was to look at differences in relative effect of workplace variations on five health outcomes, and to explain those differences in health outcomes by organizational characteristics. The sample encompassed 90 workplaces in Sweden and about 4300 individuals employed within these workplaces. Measurement of the workplace characteristics was carried out independently of the measurement of the individual's working conditions and health. Organizational data were collected by interviews with local managers at participating workplaces, and individual data were obtained by means of a survey of the employees. The results showed that a significant proportion of the variance in sickness absence, work ability, general health, and musculoskeletal disorders was attributed to the workplace. Of eight tested organizational characteristics, customer adaptation, lean production, and performance control could explain some of this workplace variance. The results also showed that only one organizational effect remained significant when controlled for the individual confounder of age and gender. High customer adaptation is associated with higher sickness absence. This association is not mediated via differences in mental and physical job strain.

  15. Factors explaining the North-South differentials in contraceptive use in Nigeria: A nonlinear decomposition analysis

    Directory of Open Access Journals (Sweden)

    Stella Babalola

    2018-01-01

    Full Text Available Background: Northern Nigeria has some of the worst reproductive health indicators worldwide. Conspicuous North-South variations exist in contraceptive use; not much is known about the drivers of contraceptive use disparities in the North compared to the South. Objective: In this study, we examine the relative weights of the factors that contribute to this North-South gap in contraceptive prevalence. Methods: Using the women's 2013 Demographic Health Survey dataset, we applied a nonlinear decomposition technique to determine the contribution of sociodemographic and socioeconomic characteristics, conjugal relationship dynamics, intimate partner violence, ideational variables, and Islamic culture to the North-South disparities in contraceptive use. Results: There was a gap of 12.4 percentage points in contraceptive prevalence between the north and south of Nigeria (5.2Š vs 17.6Š. The largest contributors to the gap were ideational characteristics (explaining 42.0Š of the gap and socio-economic profiles (explaining 42.6Š. Patterns of conjugal relationship dynamics (11.1Š, socio-demographic characteristics (‒11.0Š, Islamic religious culture (7.6Š, and exposure to family planning messaging (6.1Š were also significant contributors. Conclusions: Effective interventions to increase contraceptive use in northern Nigeria should aim at addressing socioeconomic disadvantage in the North, impacting ideational characteristics and specifically targeting poor women and those with low levels of education. Working with Islamic religious leaders is also critical to bridging the gap. Contribution: This paper broadens the knowledge on the determinants of contraceptive use in Nigeria by identifying contextual factors that operate differently in the North compared to the South.

  16. availability analysis of chemicals for water treatment

    African Journals Online (AJOL)

    NIJOTECH

    In most countries, chemicals are generally recognized as being vital in the production of potable water and will ... industries and water utility ventures are being started in Nigeria ... are being dumped into rivers thereby polluting them the more.

  17. Proposed minimum reporting standards for chemical analysis Chemical Analysis Working Group (CAWG) Metabolomics Standards Initiative (MSI)

    Science.gov (United States)

    Amberg, Alexander; Barrett, Dave; Beale, Michael H.; Beger, Richard; Daykin, Clare A.; Fan, Teresa W.-M.; Fiehn, Oliver; Goodacre, Royston; Griffin, Julian L.; Hankemeier, Thomas; Hardy, Nigel; Harnly, James; Higashi, Richard; Kopka, Joachim; Lane, Andrew N.; Lindon, John C.; Marriott, Philip; Nicholls, Andrew W.; Reily, Michael D.; Thaden, John J.; Viant, Mark R.

    2013-01-01

    There is a general consensus that supports the need for standardized reporting of metadata or information describing large-scale metabolomics and other functional genomics data sets. Reporting of standard metadata provides a biological and empirical context for the data, facilitates experimental replication, and enables the re-interrogation and comparison of data by others. Accordingly, the Metabolomics Standards Initiative is building a general consensus concerning the minimum reporting standards for metabolomics experiments of which the Chemical Analysis Working Group (CAWG) is a member of this community effort. This article proposes the minimum reporting standards related to the chemical analysis aspects of metabolomics experiments including: sample preparation, experimental analysis, quality control, metabolite identification, and data pre-processing. These minimum standards currently focus mostly upon mass spectrometry and nuclear magnetic resonance spectroscopy due to the popularity of these techniques in metabolomics. However, additional input concerning other techniques is welcomed and can be provided via the CAWG on-line discussion forum at http://msi-workgroups.sourceforge.net/ or http://Msi-workgroups-feedback@lists.sourceforge.net. Further, community input related to this document can also be provided via this electronic forum. PMID:24039616

  18. Explaining public support for space exploration funding in America: A multivariate analysis

    Science.gov (United States)

    Nadeau, François

    2013-05-01

    Recent studies have identified the need to understand what shapes public attitudes toward space policy. I address this gap in the literature by developing a multivariate regression model explaining why many Americans support government spending on space exploration. Using pooled data from the 2006 and 2008 General Social Surveys, the study reveals that spending preferences on space exploration are largely apolitical and associated instead with knowledge and opinions about science. In particular, the odds of wanting to increase funding for space exploration are significantly higher for white, male Babyboomers with a higher socio-economic status, a fondness for organized science, and a post-secondary science education. As such, I argue that public support for NASA's spending epitomizes what Launius termed "Apollo Nostalgia" in American culture. That is, Americans benefitting most from the old social order of the 1960s developed a greater fondness for science that makes them more likely to lament the glory days of space exploration. The article concludes with suggestions for how to elaborate on these findings in future studies.

  19. Error-based analysis of optimal tuning functions explains phenomena observed in sensory neurons

    Directory of Open Access Journals (Sweden)

    Steve Yaeli

    2010-10-01

    Full Text Available Biological systems display impressive capabilities in effectively responding to environmental signals in real time. There is increasing evidence that organisms may indeed be employing near optimal Bayesian calculations in their decision-making. An intriguing question relates to the properties of optimal encoding methods, namely determining the properties of neural populations in sensory layers that optimize performance, subject to physiological constraints. Within an ecological theory of neural encoding/decoding, we show that optimal Bayesian performance requires neural adaptation which reflects environmental changes. Specifically, we predict that neuronal tuning functions possess an optimal width, which increases with prior uncertainty and environmental noise, and decreases with the decoding time window. Furthermore, even for static stimuli, we demonstrate that dynamic sensory tuning functions, acting at relatively short time scales, lead to improved performance. Interestingly, the narrowing of tuning functions as a function of time was recently observed in several biological systems. Such results set the stage for a functional theory which may explain the high reliability of sensory systems, and the utility of neuronal adaptation occurring at multiple time scales.

  20. Error-based analysis of optimal tuning functions explains phenomena observed in sensory neurons.

    Science.gov (United States)

    Yaeli, Steve; Meir, Ron

    2010-01-01

    Biological systems display impressive capabilities in effectively responding to environmental signals in real time. There is increasing evidence that organisms may indeed be employing near optimal Bayesian calculations in their decision-making. An intriguing question relates to the properties of optimal encoding methods, namely determining the properties of neural populations in sensory layers that optimize performance, subject to physiological constraints. Within an ecological theory of neural encoding/decoding, we show that optimal Bayesian performance requires neural adaptation which reflects environmental changes. Specifically, we predict that neuronal tuning functions possess an optimal width, which increases with prior uncertainty and environmental noise, and decreases with the decoding time window. Furthermore, even for static stimuli, we demonstrate that dynamic sensory tuning functions, acting at relatively short time scales, lead to improved performance. Interestingly, the narrowing of tuning functions as a function of time was recently observed in several biological systems. Such results set the stage for a functional theory which may explain the high reliability of sensory systems, and the utility of neuronal adaptation occurring at multiple time scales.

  1. Cognitive behavioural therapy for MS-related fatigue explained: A longitudinal mediation analysis

    NARCIS (Netherlands)

    Akker, L.E. van den; Beckerman, H.; Collette, E.H.; Knoop, H.; Bleijenberg, G.; Twisk, J.W.; Dekker, J.; Groot, V. de

    2018-01-01

    BACKGROUND: Cognitive behavioural therapy (CBT) effectively reduces fatigue directly following treatment in patients with Multiple Sclerosis (MS), but little is known about the process of change during and after CBT. DESIGN: Additional analysis of a randomized clinical trial. OBJECTIVE: To

  2. Physico-Chemical Analysis and Sensory Evaluation of Bread

    African Journals Online (AJOL)

    Shuaibu et al.

    Physico-Chemical Analysis and Sensory Evaluation of Bread Produced Using ... analysis of the bread samples revealed that the moisture content ..... 72. Jarup, L. ,2003. Hazards of heavy metal contamination. Br Med. Bull; 68, pp.167-82.

  3. Chemical analysis and base-promoted hydrolysis of locally ...

    African Journals Online (AJOL)

    Abstract. The study was on the chemical analysis and base- promoted hydrolysis of extracted shea nut fat. The local method of extraction of the shea nut oil was employed in comparison with literature report. A simple cold-process alkali hydrolysis of the shea nut oil was used in producing the soap. The chemical analysis of ...

  4. Is the "Glasgow effect" of cigarette smoking explained by socio-economic status?: A multilevel analysis

    Directory of Open Access Journals (Sweden)

    Leyland Alastair H

    2009-07-01

    Full Text Available Abstract Background The Glasgow area has elevated levels of deprivation and is known for its poor health and associated negative health-related behaviours, which are socially patterned. Of interest is whether high smoking rates are explained by the area's socio-economic profile. Methods Data on age, sex, current/previous smoking status, area deprivation, social class, education, economic activity, postcode sector, and health board region were available from Scottish Health Surveys conducted in 1995, 1998 and 2003. Multilevel logistic regression models were applied by sex, unadjusted and adjusted for age, survey year, and socio-economic factors, accounting for geographical hierarchy and missing data. Results Compared with the rest of Scotland, men living in Greater Glasgow were 30% and women 43% more likely to smoke [odds ratio (OR = 1.30, (95% CI = 1.08–1.56 and (OR = 1.43, CI = 1.22–1.68, respectively] before adjustment. In adjusted results, the association between living in Greater Glasgow and current smoking was attenuated [OR = 0.92, CI = 0.78–1.09 for men, and OR = 1.08, CI = 0.94–1.23 for women; results based on multiply imputed data to account for missing values remained borderline significant for women]. Accounting for individuals who had been told to give up smoking by a medical person/excluding ex-smokers did not alter results. Conclusion High levels of smoking in Greater Glasgow were attributable to its poorer socio-economic position and the strong social patterning of smoking. Tackling Glasgow's, and indeed Scotland's, poor health must involve policies to alleviate problems associated with poverty.

  5. Factors explaining priority setting at community mental health centres: a quantitative analysis of referral assessments.

    Science.gov (United States)

    Grepperud, Sverre; Holman, Per Arne; Wangen, Knut Reidar

    2014-12-14

    Clinicians at Norwegian community mental health centres assess referrals from general practitioners and classify them into three priority groups (high priority, low priority, and refusal) according to need where need is defined by three prioritization criteria (severity, effect, and cost-effectiveness). In this study, we seek to operationalize the three criteria and analyze to what extent they have an effect on clinical-level priority setting after controlling for clinician characteristics and organisational factors. Twenty anonymous referrals were rated by 42 admission team members employed at 14 community mental health centres in the South-East Health Region of Norway. Intra-class correlation coefficients were calculated and logistic regressions were performed. Variation in clinicians' assessments of the three criteria was highest for effect and cost-effectiveness. An ordered logistic regression model showed that all three criteria for prioritization, three clinician characteristics (education, being a manager or not, and "guideline awareness"), and the centres themselves (fixed effects), explained priority decisions. The relative importance of the explanatory factors, however, depended on the priority decision studied. For the classification of all admitted patients into high- and low-priority groups, all clinician characteristics became insignificant. For the classification of patients, into those admitted and non-admitted, one criterion (effect) and "being a manager or not" became insignificant, while profession ("being a psychiatrist") became significant. Our findings suggest that variation in priority decisions can be reduced by: (i) reducing the disagreement in clinicians' assessments of cost-effectiveness and effect, and (ii) restricting priority decisions to clinicians with a similar background (education, being a manager or not, and "guideline awareness").

  6. Phenotypic Characterization and Multivariate Analysis to Explain Body Conformation in Lesser Known Buffalo (Bubalus bubalis) from North India

    Science.gov (United States)

    Vohra, V.; Niranjan, S. K.; Mishra, A. K.; Jamuna, V.; Chopra, A.; Sharma, Neelesh; Jeong, Dong Kee

    2015-01-01

    Phenotypic characterization and body biometric in 13 traits (height at withers, body length, chest girth, paunch girth, ear length, tail length, length of tail up to switch, face length, face width, horn length, circumference of horn at base, distances between pin bone and hip bone) were recorded in 233 adult Gojri buffaloes from Punjab and Himachal Pradesh states of India. Traits were analysed by using varimax rotated principal component analysis (PCA) with Kaiser Normalization to explain body conformation. PCA revealed four components which explained about 70.9% of the total variation. First component described the general body conformation and explained 31.5% of total variation. It was represented by significant positive high loading of height at wither, body length, heart girth, face length and face width. The communality ranged from 0.83 (hip bone distance) to 0.45 (horn length) and unique factors ranged from 0.16 to 0.55 for all these 13 different biometric traits. Present study suggests that first principal component can be used in the evaluation and comparison of body conformation in buffaloes and thus provides an opportunity to distinguish between early and late maturing to adult, based on a small group of biometric traits to explain body conformation in adult buffaloes. PMID:25656215

  7. Explaining Technology Integration in K-12 Classrooms: A Multilevel Path Analysis Model

    Science.gov (United States)

    Liu, Feng; Ritzhaupt, Albert D.; Dawson, Kara; Barron, Ann E.

    2017-01-01

    The purpose of this research was to design and test a model of classroom technology integration in the context of K-12 schools. The proposed multilevel path analysis model includes teacher, contextual, and school related variables on a teacher's use of technology and confidence and comfort using technology as mediators of classroom technology…

  8. Cognitive behavioural therapy for MS-related fatigue explained: A longitudinal mediation analysis

    NARCIS (Netherlands)

    van den Akker, L. E.; Beckerman, H.; Collette, E. H.; Knoop, H.; Bleijenberg, G.; Twisk, J. W.; Dekker, J.; de Groot, V.

    2018-01-01

    Cognitive behavioural therapy (CBT) effectively reduces fatigue directly following treatment in patients with Multiple Sclerosis (MS), but little is known about the process of change during and after CBT. Additional analysis of a randomized clinical trial. To investigate which psychological factors

  9. Host traits explain the genetic structure of parasites: a meta-analysis

    Czech Academy of Sciences Publication Activity Database

    Blasco-Costa, Maria Isabel; Poulin, R.

    2013-01-01

    Roč. 140, č. 10 (2013), s. 1316-1322 ISSN 0031-1820 EU Projects: European Commission(XE) 252124 - PARAPOPGENE Institutional support: RVO:60077344 Keywords : meta-analysis * host traits * parasite traits * F-statistics * population genetic structure * dispersal * autogenic life cycle * allogenic life cycle Subject RIV: EH - Ecology, Behaviour Impact factor: 2.350, year: 2013

  10. Thermally emissive sensing materials for chemical spectroscopy analysis

    Science.gov (United States)

    Poole, Zsolt; Ohodnicki, Paul R.

    2018-05-08

    A sensor using thermally emissive materials for chemical spectroscopy analysis includes an emissive material, wherein the emissive material includes the thermally emissive materials which emit electromagnetic radiation, wherein the electromagnetic radiation is modified due to chemical composition in an environment; and a detector adapted to detect the electromagnetic radiation, wherein the electromagnetic radiation is indicative of the chemical interaction changes and hence chemical composition and/or chemical composition changes of the environment. The emissive material can be utilized with an optical fiber sensor, with the optical fiber sensor operating without the emissive material probed with a light source external to the material.

  11. Does weather explain cost and quality performance? An analysis of UK electricity distribution companies

    International Nuclear Information System (INIS)

    Yu, William; Jamasb, Tooraj; Pollitt, Michael

    2009-01-01

    In recent years, a number of empirical studies and energy regulators have applied benchmarking techniques to measuring the efficiency and performance of network utilities. An important issue has been the extent to which the results are influenced by contextual factors. Among these, weather factors are frequently discussed as being important. We use factor analysis and two-stage data envelopment analysis techniques to examine the effect of a set of important weather factors (gale, hail, temperatures, rainfall and thunder) on the performance of electricity distribution networks in the UK. The results indicate that such factors often do not have a significant economic and statistical effect on the overall performance of the utilities. The weather parameters in some models are significant in terms of economic efficiency. The results echo our previous findings of the importance of extending the basic model to include other inputs such as total expenditure (Totex), customer minutes lost (CML) and network energy losses in regulatory benchmarking.

  12. Chemical and thermal analysis for characterisation of building materials

    International Nuclear Information System (INIS)

    Kumar, S.C.; Sudersanan, M.; Ravindran, P.V.; Kalekar, B.B.; Mathur, P.K.

    2000-01-01

    Cement and other construction materials are extensively used for the construction of shielding materials for nuclear and high energy radiations. The design and optimum utilisation of such materials need an accurate analysis of their chemical composition. The moisture content and presence of bound water and other volatile materials are also important. The use of thermal analysis supplements the data obtained by chemical analysis and enables a distinction of moisture and chemically bound water. It also enables an identification of the process leading to the loss on ignition. The work carried out on the analysis of sand, cement and other aggregate materials used for the preparation of concrete is described in the paper. (author)

  13. Chemical Diversity, Origin, and Analysis of Phycotoxins

    DEFF Research Database (Denmark)

    Rasmussen, Silas Anselm; Andersen, Aaron John Christian; Andersen, Nikolaj Gedsted

    2016-01-01

    , yessotoxins, azaspiracids, brevetoxins, and pinnatoxins. Other toxins, such as ciguatoxins and maitotoxins, accumulate in fish, where, as is the case for the latter compounds, they can be metabolized to even more toxic metabolites. On the other hand, much less is known about the chemical nature of compounds...

  14. Environmental Risk Assessment: Spatial Analysis of Chemical Hazards and Risks in South Korea

    Science.gov (United States)

    Yu, H.; Heo, S.; Kim, M.; Lee, W. K.; Jong-Ryeul, S.

    2017-12-01

    This study identified chemical hazard and risk levels in Korea by analyzing the spatial distribution of chemical factories and accidents. The number of chemical factories and accidents in 5-km2 grids were used as the attribute value for spatial analysis. First, semi-variograms were conducted to examine spatial distribution patterns and to identify spatial autocorrelation of chemical factories and accidents. Semi-variograms explained that the spatial distribution of chemical factories and accidents were spatially autocorrelated. Second, the results of the semi-variograms were used in Ordinary Kriging to estimate chemical hazard and risk level. The level values were extracted from the Ordinary Kriging result and their spatial similarity was examined by juxtaposing the two values with respect to their location. Six peaks were identified in both the hazard and risk estimation result, and the peaks correlated with major cities in Korea. Third, the estimated hazard and risk levels were classified with geometrical interval and could be classified into four quadrants: Low Hazard and Low Risk (LHLR), Low Hazard and High Risk (LHHR), High Hazard and Low Risk (HHLR), and High Hazard and High Risk (HHHR). The 4 groups identified different chemical safety management issues in Korea; relatively safe LHLR group, many chemical reseller factories were found in HHLR group, chemical transportation accidents were in the LHHR group, and an abundance of factories and accidents were in the HHHR group. Each quadrant represented different safety management obstacles in Korea, and studying spatial differences can support the establishment of an efficient risk management plan.

  15. Measuring and explaining eco-efficiencies of wastewater treatment plants in China: An uncertainty analysis perspective.

    Science.gov (United States)

    Dong, Xin; Zhang, Xinyi; Zeng, Siyu

    2017-04-01

    In the context of sustainable development, there has been an increasing requirement for an eco-efficiency assessment of wastewater treatment plants (WWTPs). Data envelopment analysis (DEA), a technique that is widely applied for relative efficiency assessment, is used in combination with the tolerances approach to handle WWTPs' multiple inputs and outputs as well as their uncertainty. The economic cost, energy consumption, contaminant removal, and global warming effect during the treatment processes are integrated to interpret the eco-efficiency of WWTPs. A total of 736 sample plants from across China are assessed, and large sensitivities to variations in inputs and outputs are observed for most samples, with only three WWTPs identified as being stably efficient. Size of plant, overcapacity, climate type, and influent characteristics are proven to have a significant influence on both the mean efficiency and performance sensitivity of WWTPs, while no clear relationships were found between eco-efficiency and technology under the framework of uncertainty analysis. The incorporation of uncertainty quantification and environmental impact consideration has improved the liability and applicability of the assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Astronomy Explained

    Science.gov (United States)

    North, Gerald

    Every year large numbers of people take up the study of astronomy, mostly at amateur level. There are plenty of elementary books on the market, full of colourful photographs, but lacking in proper explanations of how and why things are as they are. Many people eventually wish to go beyond the 'coffee-table book' stage and study this fascinating subject in greater depth. This book is written for them. In addition, many people sit for public examinations in this subject each year and this book is also intended to be of use to them. All the topics from the GCSE syllabus are covered here, with sample questions at the end of each chapter. Astronomy Explained provides a comprehensive treatment of the subject in more depth than is usually found in elementary works, and will be of interest to both amateur astronomers and students of astronomy.

  17. Explaining the failure of the Dutch innovation system for biomass digestion-A functional analysis

    International Nuclear Information System (INIS)

    Negro, Simona O.; Hekkert, Marko P.; Smits, Ruud E.

    2007-01-01

    Since the 1970s research on energy conversion technologies, such as biomass digestion, has been carried out in the Netherlands. However, after 30 years biomass digestion has not been implemented on large scale. The aim of this paper is to create insight into the underlying factors of this troublesome trajectory by applying the 'Functions of Innovation Systems' framework. This results in clear understanding of the (lack of) activities that took place in the innovation system of biomass digestion and the role of government policy in both inducing and blocking this development. The analysis provides several lessons to take into account when developing policies for the acceleration of the development and diffusion of biomass energy

  18. Analysis of chemical constituents in Cistanche species.

    Science.gov (United States)

    Jiang, Yong; Tu, Peng-Fei

    2009-03-13

    Species of the genus of Cistanche (Rou Cong Rong in Chinese) are perennial parasite herbs, and are mainly distributed in arid lands and warm deserts. As a superior tonic for the treatment of kidney deficiency, impotence, female infertility, morbid leucorrhea, profuse metrorrhagia and senile constipation, Cistanche herbs earned the honor of "Ginseng of the desert". Recently, there has been increasing scientific attention on Herba Cistanche for its remarkable bioactivities including antioxidation, neuroprotection, and anti-aging. The chemical constituents of Cistanche plants mainly include volatile oils and non-volatile phenylethanoid glycosides (PhGs), iridoids, lignans, alditols, oligosaccharides and polysaccharides. Pharmacological studies show that PhGs are the main active components for curing kidney deficiency, antioxidation and neuroprotection; galactitol and oligosaccharides are the representatives for the treatment of senile constipation, while polysaccharides are responsible for improving body immunity. In this paper, the advances on the chemical constituents of Cistanche plants and their corresponding analyses are reviewed.

  19. Hybrid chemical and nondestructive-analysis technique

    International Nuclear Information System (INIS)

    Hsue, S.T.; Marsh, S.F.; Marks, T.

    1982-01-01

    A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities

  20. Explaining nutritional habits and behaviors of low socioeconomic status women in Sanandaj: a qualitative content analysis.

    Science.gov (United States)

    Abdi, Nasrin; Sadeghi, Roya; Zamani-Alavijeh, Fereshteh; Taghdisi, Mohammad Hossein; Shojaeezadeh, Davoud

    2016-01-01

    Health and behavior are closely related subjects because disease is typically rooted in individuals' unhealthy behaviors and habits. This study aims to identify women's nutritional habits and behaviors in order to design interventions to promote nutritional literacy. This qualitative research is part of a mixed method (quantitative-qualitative) study, conducted based on content analysis. Data were collected using semistructured interviews, group discussions, and in-depth interviews with married women, aged 18-50 years, who were referred to four health care centers in Sanandaj in 2013-2014. Nutritional habits and behaviors of participants were classified into two categories: representation of nutritional behavior based on consumption pattern and representation of nutritional behavior based on consumption method. For the former, eight consumption pattern subcategories were formed: meat, dairy, fast food, local foods, fruits and vegetables, soft drinks, and oils. The latter (representation of nutritional behavior based on consumption method), included two subcategories: consumption method in line with health and consumption method inconsistent with health. Results of this qualitative study provide a solid foundation for development and designing interventions to nutritional literacy promotion based on needs. The designed intervention to healthy nutritional behavior should be based on empowering women and providing facilitator factors of a healthy diet. While designing this study, with a holistic perspective, individual and social aspects of a healthy diet should be taken into account.

  1. Controlling the accuracy of chemical analysis

    International Nuclear Information System (INIS)

    Suschny, O.; Danesi, P.R.

    1991-01-01

    The involvement of the IAEA in quantitative analysis began in the early 1960's with radiochemical work connected with the environment. It than expanded to cover analysis (mostly by nuclear techniques) of samples for projects associated with human health, agriculture, hydrology and international safeguards. This article highlights the IAEA activities in the field of quality control in quantitative analysis

  2. Cognitive behavioural therapy for MS-related fatigue explained: A longitudinal mediation analysis.

    Science.gov (United States)

    van den Akker, L E; Beckerman, H; Collette, E H; Knoop, H; Bleijenberg, G; Twisk, J W; Dekker, J; de Groot, V

    2018-03-01

    Cognitive behavioural therapy (CBT) effectively reduces fatigue directly following treatment in patients with Multiple Sclerosis (MS), but little is known about the process of change during and after CBT. Additional analysis of a randomized clinical trial. To investigate which psychological factors mediate change in fatigue during and after CBT. TREFAMS-CBT studied the effectiveness of a 16-week CBT treatment for MS-related fatigue. Ninety-one patients were randomized (44 to CBT, 47 to the MS-nurse consultations). Mediation during CBT treatment was studied using assessments at baseline, 8 and 16weeks. Mediation of the change in fatigue from post-treatment to follow-up was studied separately using assessments at 16, 26 and 52weeks. Proposed mediators were: changes in illness cognitions, general self-efficacy, coping styles, daytime sleepiness, concentration and physical activity, fear of disease progression, fatigue perceptions, depression and physical functioning. Mediators were separately analysed according to the product-of-coefficients approach. Confidence intervals were calculated with a bootstrap procedure. During treatment the decrease in fatigue brought on by CBT was mediated by improved fatigue perceptions, increased physical activity, less sleepiness, less helplessness, and improved physical functioning. Post-treatment increases in fatigue levels were mediated by reduced physical activity, reduced concentration, and increased sleepiness. These results suggests that focusing on improving fatigue perceptions, perceived physical activity, daytime sleepiness, helplessness, and physical functioning may further improve the effectiveness of CBT for fatigue in patients with MS. Maintenance of treatment effects may be obtained by focusing on improving physical activity, concentration and sleepiness. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Chemical considerations in severe accident analysis

    International Nuclear Information System (INIS)

    Malinauskas, A.P.; Kress, T.S.

    1988-01-01

    The Reactor Safety Study presented the first systematic attempt to include fission product physicochemical effects in the determination of expected consequences of hypothetical nuclear reactor power plant accidents. At the time, however, the data base was sparse, and the treatment of fission product behavior was not entirely consistent or accurate. Considerable research has since been performed to identify and understand chemical phenomena that can occur in the course of a nuclear reactor accident, and how these phenomena affect fission product behavior. In this report, the current status of our understanding of the chemistry of fission products in severe core damage accidents is summarized and contrasted with that of the Reactor Safety Study

  4. The Resilience of Dependency Effects in Explaining Income Inequality in the Global Economy: A Cross National Analysis, 1975-1995

    Directory of Open Access Journals (Sweden)

    Linda Beer

    2015-08-01

    Full Text Available The contemporary era is one of both accelerated economic globalization and rising inequality. There is an increasing awareness among both academic scholars and development professionals that globalization puts certain populations at risk. However, there has been inadequate theoretical analysis and a lack of up to date empirical studies that explain just how contemporary globalization a?ects inequality and the well being of individuals. This study explores the conditions under which TNC penetration and other globalization processes in?uence change in domestic income distribution. Its aim is to investigate whether theoretical models that have proven successful in explaining di?erences in income inequality cross-sectionally also allow for an understanding of the dynamics of income distribution during the 1980s and early 1990s, an era characterized by a dramatic acceleration of globalization. We present an analysis of change in national income distribution using linear regression models with a panel design. This study suggests that dependence on foreign investment as a development strategy, especially compared to domestic and human capital investment, may be misguided for nations concerned with equality. Net of other factors, foreign investment dependence bene?ts the elite segments of the income-earning population over the poorer eighty percent. Our analysis provides evidence of a shift in capital/labor relations brought about by globalization that has signi? cantly contributed to the rise in income inequality seen throughout the world.

  5. WAP explained

    International Nuclear Information System (INIS)

    Kaiser, M.J.; Pulsipher, A.G.

    2004-01-01

    The Weatherization Assistance Program (WAP) is a federal block grant program administered by all 50 states and the District of Columbia through community action agencies, state energy offices, local government, and other nonprofit organizations to provide weatherization services to eligible households. The WAP was established in 1976 to increase the energy efficiency, reduce the energy expenditures, and improve the health and safety of low-income households, especially those households that are particularly vulnerable such as families with children, persons with disabilities, and the elderly. The manner in which WAP funds have been allocated to states, however, has been a contentious issue since the inception of the program. Southern states have argued that too much of the federal funding goes to cold-climate and rural states. Northern states disagree. In 1990, Congress amended the Energy Conservation and Production Act and required the Department of Energy to develop a new funding formula. The Department of Energy currently uses a three-factor formula developed in 1995 in conjunction with a two-factor formula developed in 1977 and a hold-harmless provision to allocate WAP funding. The purpose of this paper is to explain the WAP allocation mechanism and the assumptions associated with the 1977 and the 1995 funding formula. The factors that compose each funding formula are critically assessed and various implementation issues are reviewed, including the selection of the trigger point and program capacity levels. It is not possible to define the need for weatherization assistance objectively and in a unique manner, and this ambiguity is the main reason why the WAP allocation mechanism is expected to remain a lively topic of debate and contention

  6. Analysis of chemical constituents in medicinal plants of selected ...

    African Journals Online (AJOL)

    Analysis of chemical constituents in medicinal plants of selected districts of Pakhtoonkhwa, Pakistan. I Hussain, R Ullah, J Khan, N Khan, M Zahoor, N Ullah, MuR Khattak, FA Khan, A Baseer, M Khurram ...

  7. Chemical analysis of cyanide in cyanidation process: review of methods

    International Nuclear Information System (INIS)

    Nova-Alonso, F.; Elorza-Rodriguez, E.; Uribe-Salas, A.; Perez-Garibay, R.

    2007-01-01

    Cyanidation, the world wide method for precious metals recovery, the chemical analysis of cyanide, is a very important, but complex operation. Cyanide can be present forming different species, each of them with different stability, toxicity, analysis method and elimination technique. For cyanide analysis, there exists a wide selection of analytical methods but most of them present difficulties because of the interference of species present in the solution. This paper presents the different available methods for chemical analysis of cyanide: titration, specific electrode and distillation, giving special emphasis on the interferences problem, with the aim of helping in the interpretation of the results. (Author)

  8. Chemical composition analysis and authentication of whisky.

    Science.gov (United States)

    Wiśniewska, Paulina; Dymerski, Tomasz; Wardencki, Waldemar; Namieśnik, Jacek

    2015-08-30

    Whisky (whiskey) is one of the most popular spirit-based drinks made from malted or saccharified grains, which should mature for at least 3 years in wooden barrels. High popularity of products usually causes a potential risk of adulteration. Thus authenticity assessment is one of the key elements of food product marketing. Authentication of whisky is based on comparing the composition of this alcohol with other spirit drinks. The present review summarizes all information about the comparison of whisky and other alcoholic beverages, the identification of type of whisky or the assessment of its quality and finally the authentication of whisky. The article also presents the various techniques used for analyzing whisky, such as gas and liquid chromatography with different types of detectors (FID, AED, UV-Vis), electronic nose, atomic absorption spectroscopy and mass spectrometry. In some cases the application of chemometric methods is also described, namely PCA, DFA, LDA, ANOVA, SIMCA, PNN, k-NN and CA, as well as preparation techniques such SPME or SPE. © 2014 Society of Chemical Industry.

  9. Analysis of blood spots for polyfluoroalkyl chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Kayoko; Wanigatunga, Amal A.; Needham, Larry L. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Calafat, Antonia M., E-mail: acalafat@cdc.gov [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States)

    2009-12-10

    Polyfluoroalkyl chemicals (PFCs) have been detected in humans, in the environment, and in ecosystems around the world. The potential for developmental and reproductive toxicities of some PFCs is of concern especially to children's health. In the United States, a sample of a baby's blood, called a 'dried blood spot' (DBS), is obtained from a heel stick within 48 h of a child's birth. DBS could be useful for assessing prenatal exposure to PFCs. We developed a method based on online solid phase extraction coupled with high performance liquid chromatography-isotope dilution tandem mass spectrometry for measuring four PFCs in DBS, perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate, perfluorooctanoate (PFOA), and perfluorononanoate. The analytical limits of detection using one whole DBS ({approx}75 {mu}L of blood) were <0.5 ng mL{sup -1}. To validate the method, we analyzed 98 DBS collected in May 2007 in the United States. PFOS and PFOA were detected in all DBS at concentrations in the low ng mL{sup -1} range. These data suggest that DBS may be a suitable matrix for assessing perinatal exposure to PFCs, but additional information related to sampling and specimen storage is needed to demonstrate the utility of these measures for assessing exposure.

  10. Droplet microfluidics in (bio) chemical analysis

    Czech Academy of Sciences Publication Activity Database

    Basova, E. Y.; Foret, František

    2015-01-01

    Roč. 140, č. 1 (2015), s. 22-38 ISSN 0003-2654 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : droplet chemistry * bio analysis * microfluidics * protein Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.033, year: 2015

  11. Chemical aspects of nuclear methods of analysis

    International Nuclear Information System (INIS)

    1985-01-01

    This final report includes papers which fall into three general areas: development of practical pre-analysis separation techniques, uranium/thorium separation from other elements for analytical and processing operations, and theory and mechanism of separation techniques. A separate abstract was prepared for each of the 9 papers

  12. Chemical composition, antimicrobial activity, proximate analysis and ...

    African Journals Online (AJOL)

    Detarium senegalense JF Gmelin (Caesalpiniaceae), commonly known as tallow tree, is used traditionally for the treatment of bronchitis, pneumonia, internal complaints and skin diseases in Tropical Africa. The seed is used as a soup thickener in Eastern Nigeria. Analysis of the petroleum ether extract of the seeds with ...

  13. Chemical analysis developments for fusion materials studies

    International Nuclear Information System (INIS)

    McCown, J.J.; Baldwin, D.L.; Keough, R.F.; Van der Cook, B.P.

    1985-04-01

    Several projects at Hanford under the management of the Westinghouse Hanford Company have involved research and development (R and D) on fusion materials. They include work on the Fusion Materials Irradiation Test Facility and its associated Experimental Lithium System; testing of irradiated lithium compounds as breeding materials; and testing of Li and Li-Pb alloy reactions with various atmospheres, concrete, and other reactor materials for fusion safety studies. In the course of these projects, a number of interesting and challenging analytical chemistry problems were encountered. They include sampling and analysis of lithium while adding and removing elements of interest; sampling, assaying and compound identification efforts on filters, aerosol particles and fire residues; development of dissolution and analysis techniques for measuring tritium and helium in lithium ceramics including oxides, aluminates, silicates and zirconates. An overview of the analytical chemistry development problems plus equipment and procedures used will be presented

  14. Chemical analysis of rare earth elements

    International Nuclear Information System (INIS)

    Tsukahara, Ryoichi; Sakoh, Takefumi; Nagai, Iwao

    1994-01-01

    Recently attention has been paid to ICP-AES or ICP-MS, and the reports on the analysis of rare earth elements by utilizing these methods continue to increase. These reports have become to take about 30% of the reports on rare earth analysis, and this is because these methods are highly sensitive to rare earth elements, and also these methods have spread widely. In ICP-AES and ICP-MS, mostly solution samples are measured, therefore, solids must be made into solution. At the time of quantitatively determining the rare earth elements of low concentration, separation and concentration are necessary. Referring to the literatures reported partially in 1990 and from 1991 to 1993, the progress of ICP-AES and ICP-MS is reported. Rare earth oxides and the alloys containing rare earth elements are easily decomposed with acids, but the decomposition of rocks is difficult, and its method is discussed. The separation of the rare earth elements from others in geochemical samples, cation exchange process is frequently utilized. Also solvent extraction process has been studied. For the separation of rare earth elements mutually, chromatography is used. The spectral interference in spectral analysis was studied. The comparison of these methods with other methods is reported. (K.I)

  15. Advanced chemical analysis service for elements, radionuclides and phases

    International Nuclear Information System (INIS)

    Sansoni, B.

    1986-01-01

    A review is given on the structure, organisation and performance of the chemical analysis service of the Central Department for Chemical Analysis at the Kernforschungsanlage Juelich GmbH. The research and development programs together with the infrastructure of the Centre afford to analyse almost all stable elements of the periodical table in almost any material. The corresponding chemical analysis service has been organized according to a new modular system of analytical steps. According to this, the most complicated and, therefore, most general case of an analytical scheme for element and radionuclide analysis in any type of material can be differentiated into about 14 different steps, the modules. They are more or less independent of the special problem. The laboratory is designed and organized according to these steps. (orig./PW) [de

  16. Chemical kinetic functional sensitivity analysis: Elementary sensitivities

    International Nuclear Information System (INIS)

    Demiralp, M.; Rabitz, H.

    1981-01-01

    Sensitivity analysis is considered for kinetics problems defined in the space--time domain. This extends an earlier temporal Green's function method to handle calculations of elementary functional sensitivities deltau/sub i//deltaα/sub j/ where u/sub i/ is the ith species concentration and α/sub j/ is the jth system parameter. The system parameters include rate constants, diffusion coefficients, initial conditions, boundary conditions, or any other well-defined variables in the kinetic equations. These parameters are generally considered to be functions of position and/or time. Derivation of the governing equations for the sensitivities and the Green's funciton are presented. The physical interpretation of the Green's function and sensitivities is given along with a discussion of the relation of this work to earlier research

  17. An Evaluation of a Teaching Intervention to Promote Students' Ability to Use Multiple Levels of Representation when Describing and Explaining Chemical Reactions

    Science.gov (United States)

    Chandrasegaran, A. L.; Treagust, David F.; Mocerino, Mauro

    2008-01-01

    Students are generally known to memorise and regurgitate chemical equations without sufficient understanding of the changes that occur at the particulate level. In addition, they often fail to recognise the significance of the symbols and formulas that are used to represent chemical reactions. This article describes an evaluation of the ability of…

  18. Handbook of Basic Tables for Chemical Analysis. Final report

    International Nuclear Information System (INIS)

    Bruno, T.J.; Svoronos, P.D.N.

    1988-04-01

    This work began as a slim booklet prepared by one of the authors (TJB) to accompany a course on chemical instrumentation presented at the National Bureau of Standards, Boulder Laboratories. The booklet contained tables on chromatography, spectroscopy, and chemical (wet) methods, and was intended to provide the students with enough basic data to design their own analytical methods and procedures. Shortly thereafter, with the co-authorship of Prof. Paris D. N. Svoronos, it was expanded into a more-extensive compilation entitled Basic Tables for Chemical Analysis, published as National Bureau of Standards Technical Note 1096. That work has now been expanded and updated into the present body of tables. Although there have been considerable changes since the first version of these tables, the aim has remained essentially the same. The authors have tried to provide a single source of information for those practicing scientists and research students who must use various aspects of chemical analysis in their work. In this respect, it is geared less toward the researcher in analytical chemistry than to those practitioners in other chemical disciplines who must have routine use of chemical analysis

  19. A model to explain plant growth promotion traits: a multivariate analysis of 2,211 bacterial isolates.

    Directory of Open Access Journals (Sweden)

    Pedro Beschoren da Costa

    Full Text Available Plant growth-promoting bacteria can greatly assist sustainable farming by improving plant health and biomass while reducing fertilizer use. The plant-microorganism-environment interaction is an open and complex system, and despite the active research in the area, patterns in root ecology are elusive. Here, we simultaneously analyzed the plant growth-promoting bacteria datasets from seven independent studies that shared a methodology for bioprospection and phenotype screening. The soil richness of the isolate's origin was classified by a Principal Component Analysis. A Categorical Principal Component Analysis was used to classify the soil richness according to isolate's indolic compound production, siderophores production and phosphate solubilization abilities, and bacterial genera composition. Multiple patterns and relationships were found and verified with nonparametric hypothesis testing. Including niche colonization in the analysis, we proposed a model to explain the expression of bacterial plant growth-promoting traits according to the soil nutritional status. Our model shows that plants favor interaction with growth hormone producers under rich nutrient conditions but favor nutrient solubilizers under poor conditions. We also performed several comparisons among the different genera, highlighting interesting ecological interactions and limitations. Our model could be used to direct plant growth-promoting bacteria bioprospection and metagenomic sampling.

  20. Airborne chemistry: acoustic levitation in chemical analysis.

    Science.gov (United States)

    Santesson, Sabina; Nilsson, Staffan

    2004-04-01

    This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals.

  1. Development of chemical analysis techniques: pt. 3

    International Nuclear Information System (INIS)

    Kim, K.J.; Chi, K.Y.; Choi, G.C.

    1981-01-01

    For the purpose of determining trace rare earths a spectrofluorimetric method has been studied. Except Ce and Tb, the fluorescence intensities are not enough to allow satisfactory analysis. Complexing agents such as tungstate and hexafluoroacetylacetone should be employed to increase fluorescence intensities. As a preliminary experiment for the separation of individual rare earth element and uranium, the distribution coefficient, % S here, are obtained on the Dowex 50 W against HCl concentration by a batch method. These % S data are utilized to obtain elution curves. The % S data showed a minimum at around 4 M HCl. To understand this previously known phenomenon the adsorption of Cl - on Dowex 50 W is examined as a function of HCl concentration and found to be decreasing while % S of rare earths increasing. It is interpreted that Cl - and rare earth ions are moved into the resin phase separately and that the charge and the charge densities of these ions are responsible for the different % S curves. Dehydration appears to play an important role in the upturn of the % S curves at higher HCl concentrations

  2. ANALYSIS OF SAMPLES FROM TANK 5F CHEMICAL CLEANING

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.; Fink, S.

    2011-03-07

    The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. The conclusions from this work are: (1) With the exception of iron, the dissolution of sludge components from Tank 5F agreed with results from the actual waste demonstration performed in 2007. The fraction of iron removed from Tank 5F by chemical cleaning was significantly less than the fraction removed in the SRNL demonstrations. The likely cause of this difference is the high pH following the first oxalic acid strike. (2) Most of the sludge mass remaining in the tank is iron and nickel. (3) The remaining sludge contains approximately 26 kg of barium, 37 kg of chromium, and 37 kg of mercury. (4) Most of the radioactivity remaining in the residual material is beta emitters and {sup 90}Sr. (5) The chemical cleaning removed more than {approx} 90% of the uranium isotopes and {sup 137}Cs. (6) The chemical cleaning removed {approx} 70% of the neptunium, {approx} 83% of the {sup 90}Sr, and {approx} 21% of the {sup 60}Co. (7) The chemical cleaning removed less than 10% of the plutonium, americium, and curium isotopes. (8) The chemical cleaning removed more than 90% of the aluminium, calcium, and sodium from the tank. (9) The cleaning operations removed 61% of lithium, 88% of non-radioactive strontium, and 65% of zirconium. The {sup 90}Sr and non-radioactive strontium were

  3. Computational singular perturbation analysis of stochastic chemical systems with stiffness

    Science.gov (United States)

    Wang, Lijin; Han, Xiaoying; Cao, Yanzhao; Najm, Habib N.

    2017-04-01

    Computational singular perturbation (CSP) is a useful method for analysis, reduction, and time integration of stiff ordinary differential equation systems. It has found dominant utility, in particular, in chemical reaction systems with a large range of time scales at continuum and deterministic level. On the other hand, CSP is not directly applicable to chemical reaction systems at micro or meso-scale, where stochasticity plays an non-negligible role and thus has to be taken into account. In this work we develop a novel stochastic computational singular perturbation (SCSP) analysis and time integration framework, and associated algorithm, that can be used to not only construct accurately and efficiently the numerical solutions to stiff stochastic chemical reaction systems, but also analyze the dynamics of the reduced stochastic reaction systems. The algorithm is illustrated by an application to a benchmark stochastic differential equation model, and numerical experiments are carried out to demonstrate the effectiveness of the construction.

  4. Chemical analysis of steel by optical emission spectrometry

    International Nuclear Information System (INIS)

    Hayakawa, M.O.; Kajita, T.; Jeszensky, G.

    1981-01-01

    The development of the chemical analysis for special steels by optical emission spectrometry direct reading method with computer, at the Siderurgica N.S. Aparecida S.A. is presented. Results are presented for the low alloy steels and high speed steel. Also, the contribution of this method to the special steel preparation is commented. (Author) [pt

  5. Physico-chemical analysis and sensory evaluation of bread ...

    African Journals Online (AJOL)

    This study carried out the physico-chemical analysis and sensory evaluation of bread produced using different indigenous yeast isolates in order to offer an insight into the overall quality of the bread. Four (4) different yeast species were isolated from sweet orange, pineapple and palm wine. The yeasts were characterized ...

  6. Chemical and antimicrobial analysis of husk fiber aqueous extract ...

    African Journals Online (AJOL)

    Chemical and antimicrobial analysis of husk fiber aqueous extract from Cocos nucifera L. Davi Oliveira e Silva, Gabriel Rocha Martins, Antônio Jorge Ribeiro da Silva, Daniela Sales Alviano, Rodrigo Pires Nascimento, Maria Auxiliadora Coelho Kaplan, Celuta Sales Alviano ...

  7. The Role of Culture, Competitiveness and Economic Performance in Explaining Academic Performance: A Global Market Analysis for International Student Segmentation

    Science.gov (United States)

    Baumann, Chris; Hamin

    2011-01-01

    A nation's culture, competitiveness and economic performance explain academic performance. Partial Least Squares (PLS) testing of 2252 students shows culture affects competitiveness and academic performance. Culture and economic performance each explain 32%; competitiveness 36%. The model predicts academic performance when culture, competitiveness…

  8. Neutron activation analysis of high-purity iron in comparison with chemical analysis

    International Nuclear Information System (INIS)

    Kinomura, Atsushi; Horino, Yuji; Takaki, Seiichi; Abiko, Kenji

    2000-01-01

    Neutron activation analysis of iron samples of three different purity levels has been performed and compared with chemical analysis for 30 metallic and metalloid impurity elements. The concentration of As, Cl, Cu, Sb and V detected by neutron activation analysis was mostly in agreement with that obtained by chemical analysis. The sensitivity limits of neutron activation analysis of three kinds of iron samples were calculated and found to be reasonable compared with measured values or detection limits of chemical analysis; however, most of them were above the detection limits of chemical analysis. Graphite-shielded irradiation to suppress fast neutron reactions was effective for Mn analysis without decreasing sensitivity to the other impurity elements. (author)

  9. Activation and chemical analysis of drinking water from shallow aquifers

    International Nuclear Information System (INIS)

    Sharma, H.K.; Mittal, V.K.; Sahota, H.S.

    1991-01-01

    In most of the Indian cities drinking water is drawn from shallow aqiufers with the help of hand pumps. These shallow aquifers get easilyl polluted. In the present work we have measured 20 trace elements using Neutron Activation Analysis (NAA) and 8 chemical parameters using standard chemical methods of drinking water drawn from Rajpura city. It was found that almost all water samples are highly polluted. We attribute this to unplaned disposal of industrial and domestic waste over a period of many decades. (author) 11 refs.; 1 fig.; 1 tab

  10. Activation analysis. A basis for chemical similarity and classification

    Energy Technology Data Exchange (ETDEWEB)

    Beeck, J OP de [Ghent Rijksuniversiteit (Belgium). Instituut voor Kernwetenschappen

    1977-01-01

    It is shown that activation analysis is especially suited to serve as a basis for determining the chemical similarity between samples defined by their trace-element concentration patterns. The general problem of classification and identification is discussed. The nature of possible classification structures and their appropriate clustering strategies is considered. A practical computer method is suggested and its application as well as the graphical representation of classification results are given. The possibility for classification using information theory is mentioned. Classification of chemical elements is discussed and practically realized after Hadamard transformation of the concentration variation patterns in a series of samples.

  11. Chemical analysis of plasma-assisted antimicrobial treatment on cotton

    International Nuclear Information System (INIS)

    Kan, C W; Lam, Y L; Yuen, C W M; Luximon, A; Lau, K W; Chen, K S

    2013-01-01

    This paper explores the use of plasma treatment as a pretreatment process to assist the application of antimicrobial process on cotton fabric with good functional effect. In this paper, antimicrobial finishing agent, Microfresh Liquid Formulation 9200-200 (MF), and a binder (polyurethane dispersion, Microban Liquid Formulation R10800-0, MB) will be used for treating the cotton fabric for improving the antimicrobial property and pre-treatment of cotton fabric by plasma under atmospheric pressure will be employed to improve loading of chemical agents. The chemical analysis of the treated cotton fabric will be conducted by Fourier transform Infrared Spectroscopy.

  12. Positron annihilation spectroscopy for chemical analysis (PASCA). Chapter 9

    International Nuclear Information System (INIS)

    Cheng, K.L.; Jean, Y.C.

    1988-01-01

    This chapter gives an up to date overview of positron annihilation spectroscopy for chemical analysis (PASCA). As an in situ technique PASCA is especially suitable for studying processes occurring at surfaces. The in situ characteristics of PASCA are treated. The principes of positron annihilation life time spectroscopy (PAL) are discussed and some important analytical applications such as, in determining of total surface areas and cavity volumes in chemical reactions, in the study of chemisorption and catalytic reactions on porous surfaces, in the analysis of bulk materials, in determining molecular association constants in biological systems, in proton and neutron activation analysis, in thin layer chromatography and in tracer technology. 28 refs.; 15 figs.; 8 tabs

  13. Implementation of the NMR CHEmical Shift Covariance Analysis (CHESCA): A Chemical Biologist's Approach to Allostery.

    Science.gov (United States)

    Boulton, Stephen; Selvaratnam, Rajeevan; Ahmed, Rashik; Melacini, Giuseppe

    2018-01-01

    Mapping allosteric sites is emerging as one of the central challenges in physiology, pathology, and pharmacology. Nuclear Magnetic Resonance (NMR) spectroscopy is ideally suited to map allosteric sites, given its ability to sense at atomic resolution the dynamics underlying allostery. Here, we focus specifically on the NMR CHEmical Shift Covariance Analysis (CHESCA), in which allosteric systems are interrogated through a targeted library of perturbations (e.g., mutations and/or analogs of the allosteric effector ligand). The atomic resolution readout for the response to such perturbation library is provided by NMR chemical shifts. These are then subject to statistical correlation and covariance analyses resulting in clusters of allosterically coupled residues that exhibit concerted responses to the common set of perturbations. This chapter provides a description of how each step in the CHESCA is implemented, starting from the selection of the perturbation library and ending with an overview of different clustering options.

  14. All-Russia conference on chemical analysis of substances and materials. Abstracts of reports

    International Nuclear Information System (INIS)

    2000-01-01

    Collection contains abstracts of reports on chemical analysis of foods, drugs, environmental materials. Methods of chemical analysis used in such regions as chemical control in agriculture, criminology, art and archaeology, biotechnology, geology, chemistry and petrochemistry, metallurgy, metrology are presented. Theoretical, methodological and applied aspects of chemical analysis are considered [ru

  15. The collection and field chemical analysis of water samples

    International Nuclear Information System (INIS)

    Korte, N.E.; Ealey, D.T.; Hollenbach, M.H.

    1984-01-01

    A successful water sampling program requires a clear understanding of appropriate measurement and sampling procedures in order to obtain reliable field data and representative samples. It is imperative that the personnel involved have a thorough knowledge of the limitations of the techniques being used. Though this seems self-evident, many sampling and field-chemical-analysis programs are still not properly conducted. Recognizing these problems, the Department of Energy contracted with Bendix Field Engineering Corporation through the Technical Measurements Center to develop and select procedures for water sampling and field chemical analysis at waste sites. The fundamental causese of poor field programs are addressed in this paper, largely through discussion of specific field-measurement techniques and their limitations. Recommendations for improvement, including quality-assurance measures, are also presented

  16. Regression analysis of a chemical reaction fouling model

    International Nuclear Information System (INIS)

    Vasak, F.; Epstein, N.

    1996-01-01

    A previously reported mathematical model for the initial chemical reaction fouling of a heated tube is critically examined in the light of the experimental data for which it was developed. A regression analysis of the model with respect to that data shows that the reference point upon which the two adjustable parameters of the model were originally based was well chosen, albeit fortuitously. (author). 3 refs., 2 tabs., 2 figs

  17. Gas analysis during the chemical vapor deposition of carbon

    International Nuclear Information System (INIS)

    Lieberman, M.L.; Noles, G.T.

    1973-01-01

    Gas chromatographic analyses were performed during the chemical vapor deposition of carbon in both isothermal and thermal gradient systems. Such data offer insight into the gas phase processes which occur during deposition and the interrelations which exist between gas composition, deposition rate, and resultant structure of the deposit. The results support a carbon CVD model presented previously. The application of chromatographic analysis to research, development, and full-scale facilities is shown. (U.S.)

  18. Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone, E-mail: wspereira@inb.gov.br [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Coordenacao de Protecao Radiologica. Grupo Multidisciplinar de Radioprotecao; Kelecom, Alphonse [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Coordenacao de Desenvolvimento de Processos; Dores, Luis Augusto de Carvalho Bresser [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Gerencia de Descomissionamento

    2011-07-01

    The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

  19. Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

    International Nuclear Information System (INIS)

    Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone; Kelecom, Alphonse; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova; Dores, Luis Augusto de Carvalho Bresser

    2011-01-01

    The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

  20. Comparative proteomic analysis of rice after seed ground simulated radiation and spaceflight explains the radiation effects of space environment

    Science.gov (United States)

    Wang, Wei; Shi, Jinming; Liang, Shujian; Lei, Huang; Shenyi, Zhang; Sun, Yeqing

    In previous work, we compared the proteomic profiles of rice plants growing after seed space-flights with ground controls by two-dimensional difference gel electrophoresis (2-D DIGE) and found that the protein expression profiles were changed after seed space environment exposures. Spaceflight represents a complex environmental condition in which several interacting factors such as cosmic radiation, microgravity and space magnetic fields are involved. Rice seed is in the process of dormant of plant development, showing high resistance against stresses, so the highly ionizing radiation (HZE) in space is considered as main factor causing biological effects to seeds. To further investigate the radiation effects of space environment, we performed on-ground simulated HZE particle radiation and compared between the proteomes of seed irra-diated plants and seed spaceflight (20th recoverable satellite) plants from the same rice variety. Space ionization shows low-dose but high energy particle effects, for searching the particle effects, ground radiations with the same low-dose (2mGy) but different liner energy transfer (LET) values (13.3KeV/µm-C, 30KeV/µm-C, 31KeV/µm-Ne, 62.2KeV/µm-C, 500Kev/µm-Fe) were performed; using 2-D DIGE coupled with clustering and principle component analysis (PCA) for data process and comparison, we found that the holistic protein expression patterns of plants irradiated by LET-62.2KeV/µm carbon particles were most similar to spaceflight. In addition, although space environment presents a low-dose radiation (0.177 mGy/day on the satellite), the equivalent simulated radiation dose effects should still be evaluated: radiations of LET-62.2KeV/µm carbon particles with different cumulative doses (2mGy, 20mGy, 200mGy, 2000mGy) were further carried out and resulted that the 2mGy radiation still shared most similar proteomic profiles with spaceflight, confirming the low-dose effects of space radiation. Therefore, in the protein expression level

  1. Shotgun lipidomic analysis of chemically sulfated sterols compromises analytical sensitivity

    DEFF Research Database (Denmark)

    Casanovas, Albert; Hannibal-Bach, Hans Kristian; Jensen, Ole Nørregaard

    2014-01-01

    Shotgun lipidomics affords comprehensive and quantitative analysis of lipid species in cells and tissues at high-throughput [1 5]. The methodology is based on direct infusion of lipid extracts by electrospray ionization (ESI) combined with tandem mass spectrometry (MS/MS) and/or high resolution F...... low ionization efficiency in ESI [7]. For this reason, chemical derivatization procedures including acetylation [8] or sulfation [9] are commonly implemented to facilitate ionization, detection and quantification of sterols for global lipidome analysis [1-3, 10]....

  2. Can Research Design Explain Variation in Head Start Research Results? A Meta-Analysis of Cognitive and Achievement Outcomes

    Science.gov (United States)

    Shager, Hilary M.; Schindler, Holly S.; Magnuson, Katherine A.; Duncan, Greg J.; Yoshikawa, Hirokazu; Hart, Cassandra M. D.

    2013-01-01

    This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

  3. AN ANALYSIS OF HATCHLING RESTING METABOLISM - IN SEARCH OF ECOLOGICAL CORRELATES THAT EXPLAIN DEVIATIONS FROM ALLOMETRIC RELATIONS

    NARCIS (Netherlands)

    KLAASSEN, M; DRENT, R

    From data in the literature, an allometric equation is compiled for hatchling resting metabolic rate and an attempt is made to explain residual variation in terms of hatchling type, yolk and water content, embryonic and postnatal growth rate, and environmental circumstances (latitudinal

  4. Role of Working Memory in Explaining the Performance of Individuals with Specific Reading Comprehension Difficulties: A Meta-Analysis

    Science.gov (United States)

    Carretti, Barbara; Borella, Erika; Cornoldi, Cesare; De Beni, Rossana

    2009-01-01

    It is well established that working memory is related to reading comprehension ability. However, its role in explaining specific reading comprehension difficulties is still under debate: the issue mainly concerns whether the contribution of working memory is dependent on task modality (verbal tasks being more predictive than visuo-spatial tasks)…

  5. Explaining the acceptance and use of government Internet services: a multivariate analysis of 2006 survey data in the Netherlands

    NARCIS (Netherlands)

    van Dijk, Johannes A.G.M.; Peters, O.; Ebbers, Wolfgang E.

    2008-01-01

    In this article, an attempt is made to explain the descriptive data of a large-scale representative survey of the use of government Internet services by the Dutch population in 2006 by means of a multidisciplinary model of technology acceptance and use that is applied to these services. Ultimately,

  6. Chemical Abundance Analysis of Moving Group W11450 (Latham 1)

    Science.gov (United States)

    O'Connell, Julia E.; Martens, Kylee; Frinchaboy, Peter M.

    2016-12-01

    We present elemental abundances for all seven stars in Moving Group W11450 (Latham 1) to determine if they may be chemically related. These stars appear to be both spatially and kinematically related, but no spectroscopic abundance analysis exists in literature. Abundances for eight elements were derived via equivalent width analyses of high-resolution (R ˜ 60,000), high-signal-to-noise ratio ( ˜ 100) spectra obtained with the Otto Struve 2.1 m telescope and the Sandiford Echelle Spectrograph at McDonald Observatory. The large star-to-star scatter in metallicity, -0.55 ≤ [Fe/H] ≤slant 0.06 dex (σ = 0.25), implies these stars were not produced from the same chemically homogeneous molecular cloud, and are therefore not part of a remnant or open cluster as previously proposed. Prior to this analysis, it was suggested that two stars in the group, W11449 and W11450, are possible wide binaries. The candidate wide binary pair show similar chemical abundance patterns with not only iron but with other elements analyzed in this study, suggesting the proposed connection between these two stars may be real.

  7. QSAR modeling and chemical space analysis of antimalarial compounds

    Science.gov (United States)

    Sidorov, Pavel; Viira, Birgit; Davioud-Charvet, Elisabeth; Maran, Uko; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

    2017-05-01

    Generative topographic mapping (GTM) has been used to visualize and analyze the chemical space of antimalarial compounds as well as to build predictive models linking structure of molecules with their antimalarial activity. For this, a database, including 3000 molecules tested in one or several of 17 anti- Plasmodium activity assessment protocols, has been compiled by assembling experimental data from in-house and ChEMBL databases. GTM classification models built on subsets corresponding to individual bioassays perform similarly to the earlier reported SVM models. Zones preferentially populated by active and inactive molecules, respectively, clearly emerge in the class landscapes supported by the GTM model. Their analysis resulted in identification of privileged structural motifs of potential antimalarial compounds. Projection of marketed antimalarial drugs on this map allowed us to delineate several areas in the chemical space corresponding to different mechanisms of antimalarial activity. This helped us to make a suggestion about the mode of action of the molecules populating these zones.

  8. Method for fractional solid-waste sampling and chemical analysis

    DEFF Research Database (Denmark)

    Riber, Christian; Rodushkin, I.; Spliid, Henrik

    2007-01-01

    four subsampling methods and five digestion methods, paying attention to the heterogeneity and the material characteristics of the waste fractions, it was possible to determine 61 substances with low detection limits, reasonable variance, and high accuracy. For most of the substances of environmental...... of variance (20-85% of the overall variation). Only by increasing the sample size significantly can this variance be reduced. The accuracy and short-term reproducibility of the chemical characterization were good, as determined by the analysis of several relevant certified reference materials. Typically, six...... to eight different certified reference materials representing a range of concentrations levels and matrix characteristics were included. Based on the documentation provided, the methods introduced were considered satisfactory for characterization of the chemical composition of waste-material fractions...

  9. Application of bioelectrical impedance analysis in prediction of light kid carcass and muscle chemical composition.

    Science.gov (United States)

    Silva, S R; Afonso, J; Monteiro, A; Morais, R; Cabo, A; Batista, A C; Guedes, C M; Teixeira, A

    2018-06-01

    Carcass data were collected from 24 kids (average live weight of 12.5±5.5 kg; range 4.5 to 22.4 kg) of Jarmelista Portuguese native breed, to evaluate bioelectrical impedance analysis (BIA) as a technique for prediction of light kid carcass and muscle chemical composition. Resistance (Rs, Ω) and reactance (Xc, Ω), were measured in the cold carcasses with a single frequency bioelectrical impedance analyzer and, together with impedance (Z, Ω), two electrical volume measurements (VolA and VolB, cm2/Ω), carcass cold weight (CCW), carcass compactness and several carcass linear measurements were fitted as independent variables to predict carcass composition by stepwise regression analysis. The amount of variation explained by VolA and VolB only reached a significant level (Pcarcass fat weight (0.814⩽R 2⩽0.862; Pcarcass fat weight (combined with carcass length, CL; R 2=0.943; Pcarcass composition.

  10. Can Momentum Factors Be Used to Enhance Accounting Information based Fundamental Analysis in Explaining Stock Price Movements?

    OpenAIRE

    KiHoon Jimmy Hong; Eliza Wu

    2014-01-01

    This paper provides new empirical evidence that price-based momentum indicator variables can enhance the ability of accounting variables in explaining cross-sectional stock returns. We apply both OLS and state-space modelling to a sample of firms included in the Russell 3000 index over the period from 1999-2012 to compare the roles of the two main types of information typically used by equity investors. Empirical results reveal the importance of accounting variables over longer term horizons ...

  11. Tissue chemical analysis with muonic X-rays

    International Nuclear Information System (INIS)

    Hutson, R.L.; Reidy, J.J.; Springer, K.; Daniel, H.; Knowles, H.B.

    1976-01-01

    The stopped muon channel at the Clinton P. Anderson Meson Physics Facility (LAMPF) was used as a source of muons for studying the elemental composition of tissue with muonic X rays. The X ray spectra from several types of tissue were used to determine the amounts of carbon, nitrogen, and oxygen present. These determinations agree with the results of more conventional chemical analysis. The results show that muonic X rays offer a non-invasive technique for determining the amounts of the more abundant elements present in selected regions of the body. (orig.) [de

  12. Analysis of the chemical equilibrium of combustion at constant volume

    Directory of Open Access Journals (Sweden)

    Marius BREBENEL

    2014-04-01

    Full Text Available Determining the composition of a mixture of combustion gases at a given temperature is based on chemical equilibrium, when the equilibrium constants are calculated on the assumption of constant pressure and temperature. In this paper, an analysis of changes occurring when combustion takes place at constant volume is presented, deriving a specific formula of the equilibrium constant. The simple reaction of carbon combustion in pure oxygen in both cases (constant pressure and constant volume is next considered as example of application, observing the changes occurring in the composition of the combustion gases depending on temperature.

  13. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    International Nuclear Information System (INIS)

    Bharti, Amardeep; Goyal, Navdeep; Singh, Suman; Singla, M. L.

    2015-01-01

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM)

  14. Treatment systems for liquid wastes generated in chemical analysis laboratories

    International Nuclear Information System (INIS)

    Linda Berrio; Oscar Beltran; Edison Agudelo; Santiago Cardona

    2012-01-01

    Nowadays, handling of liquid wastes from chemical analysis laboratories is posing problems to different public and private organizations because of its requirements of an integrated management. This article reviews various treatment technologies and its removal efficiencies in order to establish criteria for selecting the system and the appropriate variables to achieve research objectives as well as environmental sustainability. Review begins with a description of the problem and continues with the study of treatments for laboratory wastes. These technologies are segregated into physicochemical and biological treatments that comprise a variety of processes, some of which are considered in this review.

  15. Chemical analysis of dairy cattle feed from Brazil

    International Nuclear Information System (INIS)

    Luis Gustavo Cofani dos Santos; De Nadai Fernandes, E.A.; Marcio Arruda Bacchi; Lucimara Blumer; Gabriel Adrian Sarries; Fernando Barbosa Junior

    2009-01-01

    The bovine dairy cattle demand diets of high nutritional value being essential to know chemical composition of feed supplied to cows to achieve high levels of quality, safety and productivity of milk. Different roughages and concentrates from Minas Gerais and Rio Grande do Sul states, Brazil, were analyzed by instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). Concentrate and roughage samples were differentiated by mass fractions of As, Ba, Mg, P, Rb and Sr. Samples of concentrate from both origins were differentiated by mass fractions of As, Cd, Co, Cr, Cs, Ni and Rb. (author)

  16. Integrated polymer waveguides for absorbance detection in chemical analysis systems

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; El-Ali, Jamil; Wolff, Anders

    2003-01-01

    A chemical analysis system for absorbance detection with integrated polymer waveguides is reported for the first time. The fabrication procedure relies on structuring of a single layer of the photoresist SU-8, so both the microfluidic channel network and the optical components, which include planar....... The emphasis of this paper is on the signal-to-noise ratio of the detection and its relation to the sensitivity. Two absorbance cells with an optical path length of 100 μm and 1000 μm were characterized and compared in terms of sensitivity, limit of detection and effective path length for measurements...

  17. Imaging, structural, and chemical analysis of silicon nanowires

    International Nuclear Information System (INIS)

    Barsotti, R.J. Jr.; Fischer, J.E.; Lee, C.H.; Mahmood, J.; Adu, C.K.W.; Eklund, P.C.

    2002-01-01

    Laser ablation has been used to grow silicon nanowires with an average silicon crystal core diameter of 6.7 nm±2.9 nm surrounded by an amorphous SiO x sheath of 1-2 nm, the smallest silicon wires reported in the literature. Imaging, chemical, and structural analysis of these wires are reported. Due to the growth temperature and the presence of calcium impurities and trace oxygen, two distinct types of wires are found. They appear to grow by two different processes. One requires a metal catalyst, the other is catalyzed by oxygen. Suggestions for controlled synthesis based on these growth mechanisms are made

  18. Determination of air pollutants by nuclear chemical analysis

    International Nuclear Information System (INIS)

    Lesny, J.; Toelgyessy, J.

    1975-01-01

    Nuclear analytical methods are discussed with a view to their applicability in the determination of air pollutants. It is shown that some methods (use of radioactive kryptonates in automatic analyzers, application of activation analysis, X-ray fluorescence methods) are developed in theory and proven in practice in such an extent to be widely used in the near future in the control of the environment. Many other methods are becoming increasingly important for the solution of specific problems of environmental protection (such as the control of sudden environmental contamination in the proximity of chemical plants and industrial centers). (author)

  19. Crystal-Chemical Analysis of Soil at Rocknest, Gale Crater

    Science.gov (United States)

    Morrison, S. M.; Downs, R. T.; Blake, D. F.; Bish, D. L.; Ming, D. W.; Morris, R. V.; Yen, A. S.; Chipera, S. J.; Treiman, A. H.; Vaniman, D. T.; hide

    2013-01-01

    The CheMin instrument on the Mars Science Laboratory rover Curiosity performed X-ray diffraction analysis on Martian soil [1] at Rocknest in Gale Crater. In particular, crystalline phases from scoop 5 were identified and analyzed with the Rietveld method [2]. Refined unit-cell parameters are reported in Table 1. Comparing these unit-cell parameters with those in the literature provides an estimate of the chemical composition of the crystalline phases. For instance, Fig. 1 shows the Mg-content of Fa-Fo olivine as a function of the b unit-cell parameter using literature data. Our refined b parameter is indicated by the black triangle.

  20. Physcio chemical analysis of browning inhibitors treated solanum turberosum powder

    International Nuclear Information System (INIS)

    Alizai, M.N.K.; Abid, H.

    2008-01-01

    White potatoes (Solanum turberosum) were procured from agriculture Research Institute Tarnab Farm Peshawar to use for the preparation of potato powder. The process involves sorting. Washing, peeling slicing, blanching, treating with poly phenol oxidase inhibitors, dehydration, grinding and packing. All these parameters used in process were standardized. Chemical analysis of fresh potato and potato powder were carried out. Microbiological examination, functional properties and storage life studies of the potato powder were also performed. The product prepared by drying in cabinet dryer at 55 C for 7 hours was off white colour potatoes chips which was grinded to make off white potato powder. The potato powder possessed taste and texture. (author)

  1. Fast analysis of narcotic drugs by optical chemical imaging

    International Nuclear Information System (INIS)

    Fisher, Michal; Bulatov, Vallery; Schechter, Israel

    2003-01-01

    A new technique is proposed for fast detection, identification and imaging of narcotic drugs in their solid phase. This technique, which requires only a tiny sample of a few microns, is based on microscopic chemical imaging. Minor sample preparation is required, and results are obtained within seconds. As far as we know, this is the most sensitive detection system available today for solid drugs. The technique can be applied for fast analysis of minute drug residues, and therefore is of considerable importance for forensic applications. It is shown that identification of drug traces in realistic matrixes is possible. Two main methods were applied in this study for detection of drugs and drug derivatives. The first method was based on direct detection and chemical imaging of the auto-fluorescence of the analyzed drugs. This method is applicable when the analyzed drug emits fluorescence under the experiment conditions, such as lysergic acid diethylamide (known as LSD). The second method was used for obtaining chemical imaging of drugs that do not fluoresce under the experiment conditions. In these cases fluorescent labeling dyes were applied to the examined samples (including the drug and the matrix). Both methods are simple and rapid, and require minor or no sample preparation at all. Detection limits are very low in the picogram range

  2. QUALITY ASSURANCE GUIDELINES FOR LABORATORIES PERFORMING FORENSIC ANALYSIS OF CHEMICAL TERRORISM

    Science.gov (United States)

    The Scientific Working Group on Forensic Analysis of Chemical Terrorism (SWGFACT) has developed the following quality assurance guidelines to provide laboratories engaged in forensic analysis of chemical evidence associated with terrorism a framework to implement a quality assura...

  3. Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game

    Science.gov (United States)

    Orbey, Nese; Clay, Molly; Russell, T.W. Fraser

    2014-01-01

    An approach to explain chemical engineering through a Web-based interactive game design was developed and used with college freshman and junior/senior high school students. The goal of this approach was to demonstrate how to model a lab-scale experiment, and use the results to design and operate a chemical reactor. The game incorporates both…

  4. Some comments on misuse of terms related to chemical analysis

    International Nuclear Information System (INIS)

    Steinnes, E.

    2007-01-01

    Complet text of publication follows. I have been involved in scientific studies involving chemical analysis for more than 49 years. Over this period I have observed an increasing tendency to incorrect use of terms 'analysis' and 'determination' and the corresponding verbum forms. According to correct terminology in English, samples are analyzed, analytes (e.g., trace elements) are determined. However, too often expressions such as 'analysis of copper in blood' are seen in the literature, especially in papers written by non-chemists. The reason why I am raising this point at the present time in that I observed the problem in several recent titles of papers published over the last few years in the Journal of Radioanalytical and Nuclear Chemistry: Preconcentration and neutron activation analysis of thorium and uranium in natural waters. Use of activated carbon as pre-separation agent in NAA of selenium, cobalt and iodine. Recent developments in the analysis of transuranics (Np, Pu, Am) in sea water. Automated radiochemical analysis of total 99 Tc in aged nuclear waste processing streams. Photon activation analysis of carbon in glasses for fiber amplifiers by using the flow method for the rapid separation of 11 C. Preconcentration neutron activation analysis of lanthanides by cloudpoint extraction using PAN. Analysis of the chemical elements in leaves infected by fumagina by X-ray fluorescence technique. Rapid method for 226 Ra and 228 Ra analysis in water samples. The above list is far from exhaustive. I believe that this incorrect use of terminology should be avoided at least in the titles of scientific papers, in Journal of Radioanalytical and Nuclear Chemistry as well as in other scientific journals. In some of the above cases replacing 'of' with 'for the determination of', or just with 'for', would have solved the problem. In other cases it would be preferable to reverse the order of words in the sentence, such as e.g., 'Determination of selenium, cobalt and

  5. Comparison of descriptive sensory analysis and chemical analysis for oxidative changes in milk

    DEFF Research Database (Denmark)

    Hedegaard, R V; Kristensen, D; Nielsen, Jacob Holm

    2006-01-01

    and lipolytic changes occurring in the milk during chill storage for 4 d. Sensory analysis and chemical analysis showed high correlation between the typical descriptors for oxidation such as cardboard, metallic taste, and boiled milk and specific chemical markers for oxidation such as hexanal. Notably, primary......Oxidation in 3 types of bovine milk with different fatty acid profiles obtained through manipulation of feed was evaluated by analytical methods quantifying the content of potential antioxidants, the tendency of formation of free radicals, and the accumulation of primary and secondary oxidation...... products. The milk samples were evaluated in parallel by descriptive sensory analysis by a trained panel, and the correlation between the chemical analysis and the descriptive sensory analysis was evaluated. The fatty acid composition of the 3 types of milk was found to influence the oxidative...

  6. Comparison of descriptive sensory analysis and chemical analysis for oxidative changes in milk

    DEFF Research Database (Denmark)

    Hedegaard, Rikke Susanne Vingborg; Kristensen, D.; Nielsen, J. H.

    2006-01-01

    products. The milk samples were evaluated in parallel by descriptive sensory analysis by a trained panel, and the correlation between the chemical analysis and the descriptive sensory analysis was evaluated. The fatty acid composition of the 3 types of milk was found to influence the oxidative...... and lipolytic changes occurring in the milk during chill storage for 4 d. Sensory analysis and chemical analysis showed high correlation between the typical descriptors for oxidation such as cardboard, metallic taste, and boiled milk and specific chemical markers for oxidation such as hexanal. Notably, primary...... oxidation products (i.e., lipid hydroperoxides) and even the tendency of formation of radicals as measured by electron spin resonance spectroscopy were also highly correlated to the sensory descriptors for oxidation. Electron spin resonance spectroscopy should accordingly be further explored as a routine...

  7. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  8. ANALYSIS OF CHEMICAL COMPOUNDS DISTINGUISHER FOR AGARWOOD QUALITIES

    Directory of Open Access Journals (Sweden)

    Gunawan Trisandi Pasaribu

    2015-04-01

    Full Text Available Gaharu (Agarwood is described as a fragrant-smelling wood that is usually derived from the trunk of the genus Aquilaria and Gyrinops (both of the family Thymelaeaceae, which have been infected by a particular disease. Based on Indonesian National Standard, agarwood can be classified into various grades, i.e. gubal gaharu, kemedangan and serbuk gaharu. The grading system is based on the color, weight and odor. It seems that such a grading is too subjective for agarwood classification. Therefore, to minimize the subjectivity, more objective agarwood grading is required, which incorporates its chemical composition and resin content. This research was conducted focusing on the analysis of the particular grade of agarwood originating from West Sumatra. The different types of agarwood qualities are: kemedangan C, teri C, kacangan C and super AB. Initially, the obtained agarwood samples were grounded to powder, extracted on a Soxhlet extractor using various organic solvents (i.e. n-hexane, acetone, and methanol. The agarwood-acetone extracts were analyzed using GC-MS to determine its chemical composition. The results showed a positive, linier relationship in which the resin yield increased with the increase in agarwood quality grades. GC-MS analysis revealed that several sesquiterpene groups can be found in kemedangan C, teri C, kacangan C and super AB qualities. It is interesting that aromadendrene could be identified or found in all agarwood quality grades. Therefore, it is presumed that the aromadendrene compounds can act as an effective chemical distinguisher for agarwood, whereby the greater the aromadendrene content, the better is the agarwood grade.

  9. Microbiological and chemical analysis of land snails commercialised in Sicily

    Directory of Open Access Journals (Sweden)

    Antonello Cicero

    2015-05-01

    Full Text Available In this study 160 samples of snails belonging to the species Helix aspersa maxima and Helix aspersa muller were examined for chemical and microbiological analysis. Samples came from Greece and Poland. Results showed mean concentration of cadmium (0.35±0.036 mg/kg and lead (0.05±0.013 mg/kg much higher than the limit of detection. Mercury levels in both species were not detected. Microbiological analysis revealed the absence of Salmonella spp. and Clostridium spp. in both examined species. E. coli and K. oxytoca were observed in Helix aspersa maxima and Helix aspersa muller. Furthermore, one case of fungi positivity in samples of Helix aspersa muller was found. The reported investigations highlight the need to create and adopt a reference legislation to protect the health of consumers.

  10. Chemical analysis for waste management in paint industries

    International Nuclear Information System (INIS)

    Nawaz, Z.; Naveed, S.; Shiekh, N.A.; Sagheer, K.

    2005-01-01

    The chemical analysis of paint industries waste has been carried out; the main emission sources are the heating of raw materials and lacquer. Also the waste from other applications and production contains high concentration of heavy metals, VOC's, COD, TDS with notable acidity and alkalinity. Based on the analysis it was observed that the major losses of production could be minimized. Further toxic effects of the waste material can be minimized. In this reference measures to minimize production losses should be adopted along with the proper management. These laboratory results also lead to the areas of emissions and waste production during manufacturing process. Solutions have been proposed for process development and integrated waste minimization. (author)

  11. Cosmetics chemical composition characterization by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Ana Paula; Pereira, Gustavo Jose; Amaral, Angela Maria; Ferreira, Andrea Vidal, E-mail: ana_allves2008@hotmail.co [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2009-07-01

    Brazil is in the third position in the world's cosmetics market. It is an expanding and growing market where new products and manufacturing processes are in a constant and steady expansion. Therefore, it is mandatory that the composition of the products is well known in order to guarantee safety and quality of daily used cosmetics. The Brazilian National Health Surveillance Agency (ANVISA) has issued a resolution, RDC No. 48, March 16, 2006, which defines a 'List of Substances which can not be used in personal hygiene products, cosmetics and perfumes'. In this work, samples of locally manufactured and imported cosmetics (lipsticks, eye shadows, etc.) were analyzed using the Instrumental Neutron Activation Analysis technique. The samples were irradiated in the TRIGA IPR-R1 reactor of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), on a 100kW thermal power, with a thermal neutron fluence rate about 8x10{sup 11}ncm{sup -2}s{sup -1}. The analysis has detected the chemical elements Br, Ba, Ga, Na, K, Sc, Fe, Cr, Zn, Sm, W, La, Rb, Cs, Ta, Ge, Co, U, Ti, V, Cl, Al, Mn and Cu. The concentrations of these elements are on a range from 5 to 3000mug.g{sup -1}. Some chemical elements observed in samples (Cl, Br, Cr, U) are included at ANVISA prohibitive list. (author)

  12. Cosmetics chemical composition characterization by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Alves, Ana Paula; Pereira, Gustavo Jose; Amaral, Angela Maria; Ferreira, Andrea Vidal

    2009-01-01

    Brazil is in the third position in the world's cosmetics market. It is an expanding and growing market where new products and manufacturing processes are in a constant and steady expansion. Therefore, it is mandatory that the composition of the products is well known in order to guarantee safety and quality of daily used cosmetics. The Brazilian National Health Surveillance Agency (ANVISA) has issued a resolution, RDC No. 48, March 16, 2006, which defines a 'List of Substances which can not be used in personal hygiene products, cosmetics and perfumes'. In this work, samples of locally manufactured and imported cosmetics (lipsticks, eye shadows, etc.) were analyzed using the Instrumental Neutron Activation Analysis technique. The samples were irradiated in the TRIGA IPR-R1 reactor of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), on a 100kW thermal power, with a thermal neutron fluence rate about 8x10 11 ncm -2 s -1 . The analysis has detected the chemical elements Br, Ba, Ga, Na, K, Sc, Fe, Cr, Zn, Sm, W, La, Rb, Cs, Ta, Ge, Co, U, Ti, V, Cl, Al, Mn and Cu. The concentrations of these elements are on a range from 5 to 3000μg.g -1 . Some chemical elements observed in samples (Cl, Br, Cr, U) are included at ANVISA prohibitive list. (author)

  13. Safety- and Risk Analysis Activities in Chemical Industry in Europe

    International Nuclear Information System (INIS)

    Kozine, Igor; Duijm, Nijs Jan; Lauridsen Kurt

    2001-01-01

    The current paper gives an overview of the legislation and the methods used in safety and risk management in the chemical industry within Europe and in particular within the European Union. The paper is based on a report that has been written for the SOS-1 project under the Nordic nuclear safety research (NKS). Safety- and risk-related matters in the process industry, in particular, in chemical, within the EU are subject to consideration at three levels: (1) EU legislation, (2) European/intemational standardisation, and (3) socio-economic analysis. EC Directives define the 'essential requirements', e.g., protection of health and safety, that must be fulfilled when goods are placed on the market or some industry is put into operation. The European standards bodies (CEN, CENELEC and ETSI) have the task of establishing the corresponding technical specifications, meeting the essential requirements of the Directives, compliance with which will provide a presumption of conformity with the essential requirements. Such specifications are referred to as 'harmonised standards'. Compliance with harmonised standards remains voluntary, and manufacturers are free to choose any other technical solution that provides compliance with the essential requirements. This view is stated in the 'New Approach' to technical harmonisation and standardisation (details can be found on the web page: http://europe.eu.int/comm/enterprise/newapproach/standardization/index .html). Standardisation as well as the regulation of technical risks is increasingly being undertaken at European or international level. The European legislator limits its role to the affirmation of overall objectives, and leaves it to the economic players to draw up the technical procedures and standards to specify in detail the ways and means of attaining them. Many countries have introduced requirements that new legislation and/or administrative regulations be subject to socio-economic analysis. In this respect there is a

  14. Genomic analysis of thermophilic Bacillus coagulans strains: efficient producers for platform bio-chemicals.

    Science.gov (United States)

    Su, Fei; Xu, Ping

    2014-01-29

    Microbial strains with high substrate efficiency and excellent environmental tolerance are urgently needed for the production of platform bio-chemicals. Bacillus coagulans has these merits; however, little genetic information is available about this species. Here, we determined the genome sequences of five B. coagulans strains, and used a comparative genomic approach to reconstruct the central carbon metabolism of this species to explain their fermentation features. A novel xylose isomerase in the xylose utilization pathway was identified in these strains. Based on a genome-wide positive selection scan, the selection pressure on amino acid metabolism may have played a significant role in the thermal adaptation. We also researched the immune systems of B. coagulans strains, which provide them with acquired resistance to phages and mobile genetic elements. Our genomic analysis provides comprehensive insights into the genetic characteristics of B. coagulans and paves the way for improving and extending the uses of this species.

  15. Uranium complexes with macrosyclic polyethers. Synthesis and structural chemical analysis

    International Nuclear Information System (INIS)

    Elbasyouny, A.

    1983-01-01

    This dissertation reports about studies on the chemical coordination behaviour of uranium of oxidation stages IV and VI with regard to twelve different macrocyclic ligands. For the preparation of the complexes, for every system a different method has been developed. The elementary analysis of the various complexes including the uranium had been done by X-ray fluorescence analysis, and the structural characterization proceeded via vibrational, uv-vis and emission spectroscopy as well as 1 H-NMR and 13 C-spin-lattice relaxation time studies. Conformational analysis of the polyethers used allowed the structural changes in the complexes to be observed. The structural analysis of the hydrous uranium VI crown ether complexes yielded information of characteristic features of these types of complexes. The first coordination sphere of the uranyl ion with covalently bonded anion remains unchanged. As to the water content, there is a certain range. Depending upon the solvent used, the complexes have two or four H 2 O molecules per formula unit. (orig./EF) [de

  16. Avogadro: an advanced semantic chemical editor, visualization, and analysis platform.

    Science.gov (United States)

    Hanwell, Marcus D; Curtis, Donald E; Lonie, David C; Vandermeersch, Tim; Zurek, Eva; Hutchison, Geoffrey R

    2012-08-13

    The Avogadro project has developed an advanced molecule editor and visualizer designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas. It offers flexible, high quality rendering, and a powerful plugin architecture. Typical uses include building molecular structures, formatting input files, and analyzing output of a wide variety of computational chemistry packages. By using the CML file format as its native document type, Avogadro seeks to enhance the semantic accessibility of chemical data types. The work presented here details the Avogadro library, which is a framework providing a code library and application programming interface (API) with three-dimensional visualization capabilities; and has direct applications to research and education in the fields of chemistry, physics, materials science, and biology. The Avogadro application provides a rich graphical interface using dynamically loaded plugins through the library itself. The application and library can each be extended by implementing a plugin module in C++ or Python to explore different visualization techniques, build/manipulate molecular structures, and interact with other programs. We describe some example extensions, one which uses a genetic algorithm to find stable crystal structures, and one which interfaces with the PackMol program to create packed, solvated structures for molecular dynamics simulations. The 1.0 release series of Avogadro is the main focus of the results discussed here. Avogadro offers a semantic chemical builder and platform for visualization and analysis. For users, it offers an easy-to-use builder, integrated support for downloading from common databases such as PubChem and the Protein Data Bank, extracting chemical data from a wide variety of formats, including computational chemistry output, and native, semantic support for the CML file format. For developers, it can be easily extended via a powerful

  17. ANALYSIS OF THERMAL-CHEMICAL CHARACTERISTICS OF BIOMASS ENERGY PELLETS

    Directory of Open Access Journals (Sweden)

    Zorica Gluvakov

    2014-09-01

    Full Text Available In modern life conditions, when emphasis is on environmental protection and sustainable development, fuels produced from biomass are increasingly gaining in importance, and it is necessary to consider the quality of end products obtained from biomass. Based on the existing European standards, collected literature and existing laboratory methods, this paper presents results of testing individual thermal - chemical properties of biomass energy pellets after extrusion and cooling the compressed material. Analysing samples based on standard methods, data were obtained on the basis of which individual thermal-chemical properties of pellets were estimated. Comparing the obtained results with the standards and literature sources, it can be said that moisture content, ash content and calorific values are the most important parameters for quality analysis which decide on applicability and use-value of biomass energy pellets, as biofuel. This paper also shows the impact of biofuels on the quality of environmental protection. The conclusion provides a clear statement of quality of biomass energy pellets.

  18. Methods of chemical and phase composition analysis of gallstones

    Science.gov (United States)

    Suvorova, E. I.; Pantushev, V. V.; Voloshin, A. E.

    2017-11-01

    This review presents the instrumental methods used for chemical and phase composition investigation of gallstones. A great body of data has been collected in the literature on the presence of elements and their concentrations, obtained by fluorescence microscopy, X-ray fluorescence spectroscopy, neutron activation analysis, proton (particle) induced X-ray emission, atomic absorption spectroscopy, high-resolution gamma-ray spectrometry, electron paramagnetic resonance. Structural methods—powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy—provide information about organic and inorganic phases in gallstones. Stone morphology was studied at the macrolevel with optical microscopy. Results obtained by analytical scanning and transmission electron microscopy with X-ray energy dispersive spectrometry are discussed. The chemical composition and structure of gallstones determine the strategy of removing stone from the body and treatment of patients: surgery or dissolution in the body. Therefore one chapter of the review describes the potential of dissolution methods. Early diagnosis and appropriate treatment of the disease depend on the development of clinical methods for in vivo investigation, which gave grounds to present the main characteristics and potential of ultrasonography (ultrasound scanning), magnetic resonance imaging, and X-ray computed tomography.

  19. Study of discharges produced by surface waves under medium and high pressure: application to chemical analysis

    International Nuclear Information System (INIS)

    Laye epouse Granier, Agnes

    1986-01-01

    This report deals with the study of microwave discharges produced in argon gas by surface waves in the 20-760 Torr pressure range. Application to chemical analysis by emission optical spectroscopy is also investigated. First of all we study the propagation of a surface wave in a bounded plasma in which the effective collision frequency for momentum transfer ν is higher than the excitation one. The axial electron density profile is determined from two diagnostic techniques, i.e., phase variations of the wave field and Stark broadening of H β line. Then we deduce the discharge characteristics ν, θ (maintaining power of an electron-ion pair) and E eff (effective electric field for discharge sustaining) from the electron density profile. Then an energy balance of the discharge is developed. It explains the change of operating conditions in the 20-50 Torr range. At low pressure the discharge is governed by ambipolar diffusion whereas at high pressure, the electrons are mainly lost by volume recombination of Ar 2 + . Finally, we report on chemical analysis experiment of gases (optimum sensibility in found near 100 Torr) and of metallic solutions sprayed by a graphite oven. Performances of such a design and ICP plasma torches are compared. (author) [fr

  20. Experimental and numerical reaction analysis on sodium-water chemical reaction field

    International Nuclear Information System (INIS)

    Deguchi, Yoshihiro; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

    2015-01-01

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. A quasi one-dimensional flame model is applied to a sodium-water counter-flow reaction field. The analysis contains 25 elementary reactions, which consist of 17 H_2-O_2 and 8 Na-H_2O reactions. Temperature and species concentrations in the counter-flow reaction field were measured using laser diagnostics such as LIF and CARS. The main reaction in the experimental conditions is Na+H_2O → NaOH+H and OH is produced by H_2O+H → H_2+OH. It is demonstrated that the reaction model in this study well explains the structure of the sodium-water counter-flow diffusion flame. (author)

  1. Explaining variation in nascent entrepreneurship

    NARCIS (Netherlands)

    A.J. van Stel (André); A.R.M. Wennekers (Sander); P. Reynolds (Paul); A.R. Thurik (Roy)

    2004-01-01

    textabstractThis paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship

  2. Explaining nascent entrepreneurship across countries

    NARCIS (Netherlands)

    A.R. Thurik (Roy); A.J. van Stel (André); A.R.M. Wennekers (Sander); P. Reynolds (Paul)

    2003-01-01

    textabstractThis paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship

  3. Chemical analysis and potential health risks of hookah charcoal

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, Yehya, E-mail: yelsayed@aus.edu; Dalibalta, Sarah, E-mail: sdalibalta@aus.edu; Abu-Farha, Nedal

    2016-11-01

    Hookah (waterpipe) smoking is a very common practice that has spread globally. There is growing evidence on the hazardous consequences of smoking hookah, with studies indicating that its harmful effects are comparable to cigarette smoking if not worse. Charcoal is commonly used as a heating source for hookah smoke. Although charcoal briquettes are thought to be one of the major contributors to toxicity, their composition and impact on the smoke generated remains largely unidentified. This study aims to analyze the elemental composition of five different raw synthetic and natural charcoals by using Carbon-Hydrogen-Nitrogen (CHN) analysis, inductively coupled plasma (ICP), and scanning electron microscopy coupled with energy dispersive X-Ray spectrometry (SEM-EDS). Elemental analysis showed that the raw charcoals contain heavy metals such as zinc, iron, cadmium, vanadium, aluminum, lead, chromium, manganese and cobalt at concentrations similar, if not higher than, cigarettes. In addition, thermal desorption-gas chromatography–mass spectrometry (TD-GC–MS) was used to analyze the chemical composition of the smoke produced from burning the charcoal samples. The smoke emitted from charcoal was found to be the source of numerous compounds which could be hazardous to health. A total of seven carcinogens, 39 central nervous system depressants and 31 respiratory irritants were identified. - Highlights: • Hookah charcoals, mainly synthetic brands, contains trace/heavy metals in concentrations exceeding those in cigarettes. • The concentration of lead in synthetic charcoal briquettes may impose adverse effects on human health. • The amount of nitrogen in synthetic charcoal is comparable to that reported in cigarettes. • Chemical profiling of smoke emitted from hookah charcoal reveals many compounds associated with potential health risks.

  4. Chemical analysis and potential health risks of hookah charcoal

    International Nuclear Information System (INIS)

    Elsayed, Yehya; Dalibalta, Sarah; Abu-Farha, Nedal

    2016-01-01

    Hookah (waterpipe) smoking is a very common practice that has spread globally. There is growing evidence on the hazardous consequences of smoking hookah, with studies indicating that its harmful effects are comparable to cigarette smoking if not worse. Charcoal is commonly used as a heating source for hookah smoke. Although charcoal briquettes are thought to be one of the major contributors to toxicity, their composition and impact on the smoke generated remains largely unidentified. This study aims to analyze the elemental composition of five different raw synthetic and natural charcoals by using Carbon-Hydrogen-Nitrogen (CHN) analysis, inductively coupled plasma (ICP), and scanning electron microscopy coupled with energy dispersive X-Ray spectrometry (SEM-EDS). Elemental analysis showed that the raw charcoals contain heavy metals such as zinc, iron, cadmium, vanadium, aluminum, lead, chromium, manganese and cobalt at concentrations similar, if not higher than, cigarettes. In addition, thermal desorption-gas chromatography–mass spectrometry (TD-GC–MS) was used to analyze the chemical composition of the smoke produced from burning the charcoal samples. The smoke emitted from charcoal was found to be the source of numerous compounds which could be hazardous to health. A total of seven carcinogens, 39 central nervous system depressants and 31 respiratory irritants were identified. - Highlights: • Hookah charcoals, mainly synthetic brands, contains trace/heavy metals in concentrations exceeding those in cigarettes. • The concentration of lead in synthetic charcoal briquettes may impose adverse effects on human health. • The amount of nitrogen in synthetic charcoal is comparable to that reported in cigarettes. • Chemical profiling of smoke emitted from hookah charcoal reveals many compounds associated with potential health risks.

  5. Microarray technology for major chemical contaminants analysis in food: current status and prospects.

    Science.gov (United States)

    Zhang, Zhaowei; Li, Peiwu; Hu, Xiaofeng; Zhang, Qi; Ding, Xiaoxia; Zhang, Wen

    2012-01-01

    Chemical contaminants in food have caused serious health issues in both humans and animals. Microarray technology is an advanced technique suitable for the analysis of chemical contaminates. In particular, immuno-microarray approach is one of the most promising methods for chemical contaminants analysis. The use of microarrays for the analysis of chemical contaminants is the subject of this review. Fabrication strategies and detection methods for chemical contaminants are discussed in detail. Application to the analysis of mycotoxins, biotoxins, pesticide residues, and pharmaceutical residues is also described. Finally, future challenges and opportunities are discussed.

  6. Chemical hazards analysis of resilient flooring for healthcare.

    Science.gov (United States)

    Lent, Tom; Silas, Julie; Vallette, Jim

    2010-01-01

    This article addresses resilient flooring, evaluating the potential health effects of vinyl flooring and the leading alternatives-synthetic rubber, polyolefin, and linoleum-currently used in the healthcare marketplace. The study inventories chemicals incorporated as components of each of the four material types or involved in their life cycle as feedstocks, intermediary chemicals, or emissions. It then characterizes those chemicals using a chemical hazard-based framework that addresses persistence and bioaccumulation, human toxicity, and human exposures.

  7. Explaining the effects of a 1-year intervention promoting a low fat diet in adolescent girls: a mediation analysis

    Directory of Open Access Journals (Sweden)

    Maes Lea

    2007-11-01

    Full Text Available Abstract Background Although it is important to investigate how interventions work, no formal mediation analyses have been conducted to explain behavioral outcomes in school-based fat intake interventions in adolescents. The aim of the present study was to examine mediation effects of changes in psychosocial determinants of dietary fat intake (attitude, social support, self-efficacy, perceived benefits and barriers on changes in fat intake in adolescent girls. Methods Data from a 1-year prospective intervention study were used. A random sample of 804 adolescent girls was included in the study. Girls in the intervention group (n = 415 were exposed to a multi-component school-based intervention program, combining environmental changes with a computer tailored fat intake intervention and parental support. Fat intake and psychosocial determinants of fat intake were measured with validated self-administered questionnaires. To assess mediating effects, a product-of-coefficient test, appropriate for cluster randomized controlled trials, was used. Results None of the examined psychosocial factors showed a reliable mediating effect on changes in fat intake. The single-mediator model revealed a statistically significant suppression effect of perceived barriers on changes in fat intake (p = 0.011. In the multiple-mediator model, this effect was no longer significant, which was most likely due to changes in perceived barriers being moderately related to changes in self-efficacy (-0.30 and attitude (-0.25. The overall mediated-suppressed effect of the examined psychosocial factors was virtually zero (total mediated effect = 0.001; SE = 7.22; p = 0.992. Conclusion Given the lack of intervention effects on attitudes, social support, self-efficacy and perceived benefits and barriers, it is suggested that future interventions should focus on the identification of effective strategies for changing these theoretical mediators in the desired direction

  8. Meta-Analysis of the Chemical and Non-Chemical Stressors Affecting Childhood Obesity

    Science.gov (United States)

    Worldwide, approximately 42 million children under the age of 5 years are considered overweight or obese. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-chemical stres...

  9. Explaining Away Intuitions

    Directory of Open Access Journals (Sweden)

    Jonathan Ichikawa

    2009-12-01

    Full Text Available What is it to explain away an intuition? Philosophers regularly attempt to explain intuitions away, but it is often unclear what the success conditions for their project consist in. I attempt to articulate some of these conditions, taking philosophical case studies as guides, and arguing that many attempts to explain away intuitions underestimate the challenge the project of explaining away involves. I will conclude, therefore, that explaining away intuitions is a more difficult task than has sometimes been appreciated; I also suggest, however, that the importance of explaining away intuitions has often been exaggerated.

  10. COLLABORATIVE TRIAL AND QUALITY CONTROL IN CHEMICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Narsito Narsito

    2010-06-01

    Full Text Available Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of

  11. Safety- and Risk Analysis Activities in Chemical Industry in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Kozine, Igor; Duijm, Nijs Jan; Lauridsen Kurt [Risoe National Laboratory, Roskilde (Denmark). Systems Analysis Department

    2001-07-01

    The current paper gives an overview of the legislation and the methods used in safety and risk management in the chemical industry within Europe and in particular within the European Union. The paper is based on a report that has been written for the SOS-1 project under the Nordic nuclear safety research (NKS). Safety- and risk-related matters in the process industry, in particular, in chemical, within the EU are subject to consideration at three levels: (1) EU legislation, (2) European/intemational standardisation, and (3) socio-economic analysis. EC Directives define the 'essential requirements', e.g., protection of health and safety, that must be fulfilled when goods are placed on the market or some industry is put into operation. The European standards bodies (CEN, CENELEC and ETSI) have the task of establishing the corresponding technical specifications, meeting the essential requirements of the Directives, compliance with which will provide a presumption of conformity with the essential requirements. Such specifications are referred to as 'harmonised standards'. Compliance with harmonised standards remains voluntary, and manufacturers are free to choose any other technical solution that provides compliance with the essential requirements. This view is stated in the 'New Approach' to technical harmonisation and standardisation (details can be found on the web page: http://europe.eu.int/comm/enterprise/newapproach/standardization/index .html). Standardisation as well as the regulation of technical risks is increasingly being undertaken at European or international level. The European legislator limits its role to the affirmation of overall objectives, and leaves it to the economic players to draw up the technical procedures and standards to specify in detail the ways and means of attaining them. Many countries have introduced requirements that new legislation and/or administrative regulations be subject to socio-economic analysis

  12. Process Equipment Failure Mode Analysis in a Chemical Industry

    Directory of Open Access Journals (Sweden)

    J. Nasl Seraji

    2008-04-01

    Full Text Available Background and aims   Prevention of potential accidents and safety promotion in chemical processes requires systematic safety management in them. The main objective of this study was analysis of important process equipment components failure modes and effects in H2S and CO2  isolation from extracted natural gas process.   Methods   This study was done in sweetening unit of an Iranian gas refinery. Failure Mode and Effect Analysis (FMEA used for identification of process equipments failures.   Results   Totally 30 failures identified and evaluated using FMEA. P-1 blower's blade breaking and sour gas pressure control valve bearing tight moving had maximum risk Priority number (RPN, P-1 body corrosion and increasing plug lower side angle of reach DEAlevel control valve  in tower - 1 were minimum calculated RPN.   Conclusion   By providing a reliable documentation system for equipment failures and  incidents recording, maintaining of basic information for later safety assessments would be  possible. Also, the probability of failures and effects could be minimized by conducting preventive maintenance.

  13. Avogadro: an advanced semantic chemical editor, visualization, and analysis platform

    Directory of Open Access Journals (Sweden)

    Hanwell Marcus D

    2012-08-01

    Full Text Available Abstract Background The Avogadro project has developed an advanced molecule editor and visualizer designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas. It offers flexible, high quality rendering, and a powerful plugin architecture. Typical uses include building molecular structures, formatting input files, and analyzing output of a wide variety of computational chemistry packages. By using the CML file format as its native document type, Avogadro seeks to enhance the semantic accessibility of chemical data types. Results The work presented here details the Avogadro library, which is a framework providing a code library and application programming interface (API with three-dimensional visualization capabilities; and has direct applications to research and education in the fields of chemistry, physics, materials science, and biology. The Avogadro application provides a rich graphical interface using dynamically loaded plugins through the library itself. The application and library can each be extended by implementing a plugin module in C++ or Python to explore different visualization techniques, build/manipulate molecular structures, and interact with other programs. We describe some example extensions, one which uses a genetic algorithm to find stable crystal structures, and one which interfaces with the PackMol program to create packed, solvated structures for molecular dynamics simulations. The 1.0 release series of Avogadro is the main focus of the results discussed here. Conclusions Avogadro offers a semantic chemical builder and platform for visualization and analysis. For users, it offers an easy-to-use builder, integrated support for downloading from common databases such as PubChem and the Protein Data Bank, extracting chemical data from a wide variety of formats, including computational chemistry output, and native, semantic support for the CML file format

  14. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  15. Flow Injection Analysis and Liquid Chromatography for Multifunctional Chemical Analysis (MCA) Systems

    Science.gov (United States)

    Mayo, Ana V.; Loegel, Thomas N.; Bretz, Stacey Lowery; Danielson, Neil D.

    2013-01-01

    The large class sizes of first-year chemistry labs makes it challenging to provide students with hands-on access to instrumentation because the number of students typically far exceeds the number of research-grade instruments available to collect data. Multifunctional chemical analysis (MCA) systems provide a viable alternative for large-scale…

  16. Comprehensive analysis to explain reduced or increased SOD1 enzymatic activity in ALS patients and their relatives.

    Science.gov (United States)

    Keskin, Isil; Birve, Anna; Berdynski, Mariusz; Hjertkvist, Karin; Rofougaran, Reza; Nilsson, Torbjörn K; Glass, Jonathan D; Marklund, Stefan L; Andersen, Peter M

    2017-08-01

    To characterise stabilities in erythrocytes of mutant SOD1 proteins, compare SOD1 enzymatic activities between patients with different genetic causes of ALS and search for underlying causes of deviant SOD1 activities in individuals lacking SOD1 mutations. Blood samples from 4072 individuals, ALS patients with or without a SOD1 mutation, family members and controls were studied. Erythrocyte SOD1 enzymatic activities normalised to haemoglobin content were determined, and effects of haemoglobin disorders on dismutation assessed. Coding SOD1 sequences were analysed by Sanger sequencing, exon copy number variations by fragment length analysis and by TaqMan Assay. Of the 44 SOD1 mutations found, 75% caused severe destabilisation of the mutant protein but in 25% it was physically stable. Mutations producing structural changes caused halved erythrocyte SOD1 activities. There were no differences in SOD1 activities between patients without a SOD1 mutation and control individuals or carriers of TBK1 mutations and C9orf72 HRE . In the low and high SOD1 activity groups no deviations were found in exon copy numbers and intron gross structures. Thalassemias and iron deficiency were associated with increased SOD1 activity/haemoglobin ratios. Adjunct erythrocyte SOD1 activity analysis reliably signals destabilising SOD1 mutations including intronic mutations that are missed by exon sequencing.

  17. Mediation Analysis Demonstrates That Trans-eQTLs Are Often Explained by Cis-Mediation: A Genome-Wide Analysis among 1,800 South Asians

    Science.gov (United States)

    Pierce, Brandon L.; Tong, Lin; Chen, Lin S.; Rahaman, Ronald; Argos, Maria; Jasmine, Farzana; Roy, Shantanu; Paul-Brutus, Rachelle; Westra, Harm-Jan; Franke, Lude; Esko, Tonu; Zaman, Rakibuz; Islam, Tariqul; Rahman, Mahfuzar; Baron, John A.; Kibriya, Muhammad G.; Ahsan, Habibul

    2014-01-01

    A large fraction of human genes are regulated by genetic variation near the transcribed sequence (cis-eQTL, expression quantitative trait locus), and many cis-eQTLs have implications for human disease. Less is known regarding the effects of genetic variation on expression of distant genes (trans-eQTLs) and their biological mechanisms. In this work, we use genome-wide data on SNPs and array-based expression measures from mononuclear cells obtained from a population-based cohort of 1,799 Bangladeshi individuals to characterize cis- and trans-eQTLs and determine if observed trans-eQTL associations are mediated by expression of transcripts in cis with the SNPs showing trans-association, using Sobel tests of mediation. We observed 434 independent trans-eQTL associations at a false-discovery rate of 0.05, and 189 of these trans-eQTLs were also cis-eQTLs (enrichment Pmediator based on Sobel Pmediation signals in two European cohorts, and while only 7 trans-eQTL associations were present in one or both cohorts, 6 showed evidence of cis-mediation. Analyses of simulated data show that complete mediation will be observed as partial mediation in the presence of mediator measurement error or imperfect LD between measured and causal variants. Our data demonstrates that trans-associations can become significantly stronger or switch directions after adjusting for a potential mediator. Using simulated data, we demonstrate that this phenomenon is expected in the presence of strong cis-trans confounding and when the measured cis-transcript is correlated with the true (unmeasured) mediator. In conclusion, by applying mediation analysis to eQTL data, we show that a substantial fraction of observed trans-eQTL associations can be explained by cis-mediation. Future studies should focus on understanding the mechanisms underlying widespread cis-mediation and their relevance to disease biology, as well as using mediation analysis to improve eQTL discovery. PMID:25474530

  18. Explaining the increasing heritability of cognitive ability across development: a meta-analysis of longitudinal twin and adoption studies.

    Science.gov (United States)

    Briley, Daniel A; Tucker-Drob, Elliot M

    2013-09-01

    Genes account for increasing proportions of variation in cognitive ability across development, but the mechanisms underlying these increases remain unclear. We conducted a meta-analysis of longitudinal behavioral genetic studies spanning infancy to adolescence. We identified relevant data from 16 articles with 11 unique samples containing a total of 11,500 twin and sibling pairs who were all reared together and measured at least twice between the ages of 6 months and 18 years. Longitudinal behavioral genetic models were used to estimate the extent to which early genetic influences on cognition were amplified over time and the extent to which innovative genetic influences arose with time. Results indicated that in early childhood, innovative genetic influences predominate but that innovation quickly diminishes, and amplified influences account for increasing heritability following age 8 years.

  19. A dated phylogeny complements macroecological analysis to explain the diversity patterns in Geonoma (Arecaceae)

    DEFF Research Database (Denmark)

    Roncal, Julissa; Overgaard, Anne Blach; Borchsenius, Finn

    2011-01-01

    pattern. To test for a time-for-diversification effect, we correlated four different species richness measures with the diversification time of the earliest large lineage that is characteristic of each cluster. In support of this hypothesis, we found that geographic areas with higher richness contained...... coherent floristic clusters. We then evaluated the extent to which the spatial variation in species composition reflects present-day environmental variation vs. nonenvironmental spatial effects, as expected if the pattern reflects historical biogeography. We also examined the degree of geographic structure...... in the Geonoma phylogeny. Finally, we used a dated phylogeny to assess whether species richness within the floristic clusters was constrained by a specific historical biogeographic driver, namely time-for-diversification. A cluster analysis identified six spatially coherent floristic clusters, four of which were...

  20. Application of factor analysis to chemically analyzed data in environmental samples after x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    El-Sayed, A.A.

    2005-01-01

    The underlying principle of factorial analysis is frequency distribution and description of reaction in between and through the element series in specific environmental samples. Application of this factor analysis was elaborated to interpret the variance and covariance of certain elements Si, Al, Ca. K, Fe, Ti and Mg in three different types of common materials in environmental sediments, soil, and rock. These evaluations were proceeded after x-ray fluorescence measurements. Results of applications of factorial statistical data analysis show that three factors cause relationship between the above elements in a certain type of environmental samples are mainly recognized. In such cases, these factors represent the main reason for findings and interpret all hidden relationship between the chemical analyzed data. Factor one, the effect of weathering type alteration and oxidation reaction processes as a main one in case of soil and rock where they are characterized by the close covariance of a group of metals, like iron and manganese, commonly derived from weathered and altered igneous rocks. Factor two and three represents other processes. In case of soil, formation of alumino-silicate is revealed in factor two due to the positive covariance of these elements and also the presence of aluminum oxide, titanium oxide and silicon dioxide together is explained by these positive values. The inverse relation between Ca, K, Fe and Mg while indicate the presence of mineral salts which may be due to fertilization and water of irrigation. In case of factor three in that soil, it is the weakest factor that can be used to explain the relationship between the above elements

  1. Using a model based fourth-corner analysis to explain vegetation change following an extraordinary fire disturbance.

    Science.gov (United States)

    Venn, S E; Pickering, C M; Butler, S A; Letten, A D

    2016-11-01

    In ecosystems where large-scale disturbances are infrequent, the mode of succession may be difficult to discern and floristic surveys alone cannot be used determine the underlying processes causing vegetation change. To determine the causes of vegetation change in response to a large-scale fire event, we combined traditional floristic survey data, plant functional traits and environmental variables in a model-based solution to the fourth-corner problem. This approach allowed us to describe the trait-environment relationship and provides an intuitive matrix of environment by trait interaction coefficients. We could then quantify the strength and direction of associations between plant traits, species life-forms and environmental factors in two alpine plant communities over nine years post-fire. Initially, the fire drastically reduced vegetation cover and species density to very low levels. The fourth-corner analysis interaction coefficients indicated that over the course of the nine-year study a high abundance of graminoids, a low abundance of shrubs, tall species and those with high leaf dry matter content had the strongest associations with the two plant communities. We also found evidence for functional homogenisation between these two communities using this novel technique. Analysing plant traits and species responses post-fire in this manner can be used to infer the ecological processes driving shifts in vegetation.

  2. Explaining differences in stakeholder take up of disease management programmes: A comparative analysis of policy implementation in Austria and Germany.

    Science.gov (United States)

    Schang, Laura; Thomson, Sarah; Czypionka, Thomas

    2016-03-01

    Understanding why policies to improve care for people with chronic conditions fail to be implemented is a pressing issue in health system reform. We explore reasons for the relatively high uptake of disease management programmes (DMPs) in Germany, in contrast to low uptake in Austria. We focus on the motivation, information and power of key stakeholder groups (payers, physician associations, individual physicians and patients). We conducted a comparative stakeholder analysis using qualitative data from interviews (n=15 in Austria and n=26 in Germany), legal documents and media reports. Stakeholders in Germany appeared to have systematically stronger motivation, exposure to more positive information about DMPs and better ability to implement DMPs than their counterparts in Austria. Policy in Austria focused on financial incentives to physicians only. In Germany, limited evidence about the quality improvement and cost savings potential of DMPs was mitigated by strong financial incentives to sickness funds but proved a fundamental obstacle in Austria. Efforts to promote DMPs should seek to ensure the cooperation of payers and patients, not just physicians, using a mix of financial and non-financial instruments suited to the context. A singular focus on financially incentivising providers is unlikely to stimulate uptake of DMPs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. A multivalent adsorption apparatus explains the broad host range of phage phi92: a comprehensive genomic and structural analysis.

    Science.gov (United States)

    Schwarzer, David; Buettner, Falk F R; Browning, Christopher; Nazarov, Sergey; Rabsch, Wolfgang; Bethe, Andrea; Oberbeck, Astrid; Bowman, Valorie D; Stummeyer, Katharina; Mühlenhoff, Martina; Leiman, Petr G; Gerardy-Schahn, Rita

    2012-10-01

    Bacteriophage phi92 is a large, lytic myovirus isolated in 1983 from pathogenic Escherichia coli strains that carry a polysialic acid capsule. Here we report the genome organization of phi92, the cryoelectron microscopy reconstruction of its virion, and the reinvestigation of its host specificity. The genome consists of a linear, double-stranded 148,612-bp DNA sequence containing 248 potential open reading frames and 11 putative tRNA genes. Orthologs were found for 130 of the predicted proteins. Most of the virion proteins showed significant sequence similarities to proteins of myoviruses rv5 and PVP-SE1, indicating that phi92 is a new member of the novel genus of rv5-like phages. Reinvestigation of phi92 host specificity showed that the host range is not limited to polysialic acid-encapsulated Escherichia coli but includes most laboratory strains of Escherichia coli and many Salmonella strains. Structure analysis of the phi92 virion demonstrated the presence of four different types of tail fibers and/or tailspikes, which enable the phage to use attachment sites on encapsulated and nonencapsulated bacteria. With this report, we provide the first detailed description of a multivalent, multispecies phage armed with a host cell adsorption apparatus resembling a nanosized Swiss army knife. The genome, structure, and, in particular, the organization of the baseplate of phi92 demonstrate how a bacteriophage can evolve into a multi-pathogen-killing agent.

  4. Microplasmas for chemical analysis: analytical tools or research toys?

    International Nuclear Information System (INIS)

    Karanassios, Vassili

    2004-01-01

    An overview of the activities of the research groups that have been involved in fabrication, development and characterization of microplasmas for chemical analysis over the last few years is presented. Microplasmas covered include: miniature inductively coupled plasmas (ICPs); capacitively coupled plasmas (CCPs); microwave-induced plasmas (MIPs); a dielectric barrier discharge (DBD); microhollow cathode discharge (MCHD) or microstructure electrode (MSE) discharges, other microglow discharges (such as those formed between 'liquid' electrodes); microplasmas formed in micrometer-diameter capillary tubes for gas chromatography (GC) or high-performance liquid chromatography (HPLC) applications, and a stabilized capacitive plasma (SCP) for GC applications. Sample introduction into microplasmas, in particular, into a microplasma device (MPD), battery operation of a MPD and of a mini- in-torch vaporization (ITV) microsample introduction system for MPDs, and questions of microplasma portability for use on site (e.g., in the field) are also briefly addressed using examples of current research. To emphasize the significance of sample introduction into microplasmas, some previously unpublished results from the author's laboratory have also been included. And an overall assessment of the state-of-the-art of analytical microplasma research is provided

  5. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  6. Quantum chemical calculations in the structural analysis of phloretin

    Science.gov (United States)

    Gómez-Zavaglia, Andrea

    2009-07-01

    In this work, a conformational search on the molecule of phloretin [2',4',6'-Trihydroxy-3-(4-hydroxyphenyl)-propiophenone] has been performed. The molecule of phloretin has eight dihedral angles, four of them taking part in the carbon backbone and the other four, related with the orientation of the hydroxyl groups. A systematic search involving a random variation of the dihedral angles has been used to generate input structures for the quantum chemical calculations. Calculations at the DFT(B3LYP)/6-311++G(d,p) level of theory permitted the identification of 58 local minima belonging to the C 1 symmetry point group. The molecular structures of the conformers have been analyzed using hierarchical cluster analysis. This method allowed us to group conformers according to their similarities, and thus, to correlate the conformers' stability with structural parameters. The dendrogram obtained from the hierarchical cluster analysis depicted two main clusters. Cluster I included all the conformers with relative energies lower than 25 kJ mol -1 and cluster II, the remaining conformers. The possibility of forming intramolecular hydrogen bonds resulted the main factor contributing for the stability. Accordingly, all conformers depicting intramolecular H-bonds belong to cluster I. These conformations are clearly favored when the carbon backbone is as planar as possible. The values of the νC dbnd O and νOH vibrational modes were compared among all the conformers of phloretin. The redshifts associated with intramolecular H-bonds were correlated with the H-bonds distances and energies.

  7. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    Kim, Jong Seog

    2013-01-01

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  8. Nonradiological chemical pathway analysis and identification of chemicals of concern for environmental monitoring at the Hanford Site

    International Nuclear Information System (INIS)

    Blanton, M.L.; Cooper, A.T.; Castleton, K.J.

    1995-11-01

    Pacific Northwest's Surface Environmental Surveillance Project (SESP) is an ongoing effort tot design, review, and conducted monitoring on and off the Hanford site. Chemicals of concern that were selected are listed. Using modeled exposure pathways, the offsite cancer incidence and hazard quotient were calculated and a retrospective pathway analysis performed to estimate what onsite concentrations would be required in the soil for each chemical of concern and other detected chemicals that would be required to obtain an estimated offsite human-health risk of 1.0E-06 cancer incidence or 1.0 hazard quotient. This analysis indicates that current nonradiological chemical contamination occurring on the site does not pose a significant offsite human-health risk; the highest cancer incidence to the offsite maximally exposed individual was from arsenic (1.76E-10); the highest hazard quotient was chromium(VI) (1.48E-04). The most sensitive pathways of exposure were surfacewater and aquatic food consumption. Combined total offsite excess cancer incidence was 2.09E-10 and estimated hazard quotient was 2.40E-04. Of the 17 identified chemicals of concern, the SESP does not currently (routinely) monitor arsenic, benzo(a)pyrene, bis(2- ethylhexyl)phthalate (BEHP), and chrysene. Only 3 of the chemicals of concern (arsenic, BEHP, chloroform) could actually occur in onsite soil at concern high enough to cause a 1.0E-06 excess cancer incidence or a 1.0 hazard index for a given offsite exposure pathway. During the retrospective analysis, 20 other chemicals were also evaluated; only vinyl chloride and thallium could reach targeted offsite risk values

  9. Methodology for national risk analysis and prioritization of toxic industrial chemicals.

    Science.gov (United States)

    Taxell, Piia; Engström, Kerstin; Tuovila, Juha; Söderström, Martin; Kiljunen, Harri; Vanninen, Paula; Santonen, Tiina

    2013-01-01

    The identification of chemicals that pose the greatest threat to human health from incidental releases is a cornerstone in public health preparedness for chemical threats. The present study developed and applied a methodology for the risk analysis and prioritization of industrial chemicals to identify the most significant chemicals that pose a threat to public health in Finland. The prioritization criteria included acute and chronic health hazards, physicochemical and environmental hazards, national production and use quantities, the physicochemical properties of the substances, and the history of substance-related incidents. The presented methodology enabled a systematic review and prioritization of industrial chemicals for the purpose of national public health preparedness for chemical incidents.

  10. Sustainability in the Design, Synthesis and Analysis of Chemical Engineering Processes 1st edition (Preface)

    Science.gov (United States)

    This book preface explains the needs found by the book editors for assembling the state of the art of technical and scientific knowledge relevant to chemical engineering, sustainability, and sustainable uses of wastes and materials management, and to do so in an accessible and c...

  11. Meta-Analysis of the Chemical and Non-Chemical Stressors Affecting Childhood Obesity?

    Science.gov (United States)

    Background: Worldwide, approximately 42 million children under the age of 5 years are considered overweight or obese. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-ch...

  12. Sampling and chemical analysis of groundwaters from the exploratory boreholes

    International Nuclear Information System (INIS)

    Wittwer, C.

    1986-10-01

    As a part of the Nagra geological investigation programme in northern Switzerland, numerous water samples were taken in the Boettstein, Weiach, Riniken, Schafisheim, Kaisten and Leuggern boreholes to obtain information on the chemistry and residence times of deep groundwaters. This report contains a compilation of hydrochemical data, comments on the individual water sampling actions and an evaluation of sample quality with respect to admixing of drilling fluids. The samples were taken from separate test intervals in the sediments and the crystalline rock. After removal of various types of drilling fluids such as mud as well as fresh water or deionised water during a cleaning phase, the samples were taken at the surface or at depth using pressure vessels. The tracers added to the drilling fluids (uranine, m-TFMBA) as well as the tritium content were used for a quantiative estimation of the content of drilling fluid in the samples (contamination). With a view fo further geochemical modelling, the samples were assessed with reference to the effect of contamination on the results of the chemical analyses. A total of 68 water samples were taken from 53 different intervals: - 27 samples had problem-free cleaning phases and were taken with negligible contamination. - 23 samples were taken under difficult conditions. Problems with hydraulic communication around packers, uncertain origin, inaccuracy as to extent of contamination, presence of cement, possible traces of salt from drilling fluid etc. meant that the analyses could only be used with extreme caution or after additional data-processing. - The analysis results from 18 samples will be disregarded due to significant drilling fluid content or because more reliable data are available for the same test interval. (author)

  13. Analysis of selected chemical parameters in Piemontese wines.

    Science.gov (United States)

    Stępień, Agnieszka E; Stawarczyk, Kinga; Bilek, Maciej; Kędziora, Katarzyna M

    2015-01-01

    Piemontese wines are well known and valued all over the world. The most popular of them are Barolo and Barbaresco wines. However, in Poland, they are still little known and only now are being gradually introduced to a wider range of consumers. The aim of this study was to evaluate the content of inorganic anions, minerals, sugars and glycerol of Piemontese wines from micro-region Langhe, classified as DOCG ("Denominazione di Origine Controllata e Garantita", ie. controlled designation of origin guaranteed) and DOC ("Denominazione di Origine Controllata", ie. controlled designation of origin) products. Seven types of red wines and one type of white wine were tested. High Performance Ion Chromatography with conductometric detection (HPLC-CD) was used to measure the content of inorganic anions, ie. fluorides, chlorides, sulfates and phosphates. Flame atomic absorption spectrometry (F-AAS) was used to measure the content of minerals, ie. magnesium, calcium, sodium, copper, potassium, zinc and iron, while High Performance Liquid Chromatography with charged aerosol detection (HPLC-CAD) was used to measure the content of glycerol and sugars, ie. fructose, glucose and sucrose. Our studies show that although Piemontese wines are characterized by a relatively low content of minerals in comparison with the wines from other regions, they contain a lot of ingredients that have beneficial effects for human health. Moreover, we observed that the studied wines contain particularly high concentration of inorganic ions--phosphates and fluorides. Furthermore, all tested red wines show far reaching similarities in their chemical properties, which is possibly a direct consequence of using in their production locally cultivated grape varieties. Analysis of the wines from the Piemont region, classified as DOCG, DOC, confirmed that these are dry wines of a high quality.

  14. Understanding Land Use Impacts on Groundwater Quality Using Chemical Analysis

    Science.gov (United States)

    Nitka, A.; Masarik, K.; Masterpole, D.; Johnson, B.; Piette, S.

    2017-12-01

    Chippewa County, in western Wisconsin, has a unique historical set of groundwater quality data. The county conducted extensive groundwater sampling of private wells in 1985 (715 wells) and 2007 (800 wells). In 2016, they collaborated with UW-Extension and UW-Stevens Point to evaluate the current status of groundwater quality in Chippewa County by sampling of as many of the previously studied wells as possible. Nitrate was a primary focus of this groundwater quality inventory. Of the 744 samples collected, 60 were further analyzed for chemical indicators of agricultural and septic waste, two major sources of nitrate contamination. Wells for nitrate source analysis were selected from the 2016 participants based upon certain criteria. Only wells with a Wisconsin Unique Well Number were considered to ensure well construction information was available. Next, an Inverse Distance Weighting tool in ESRI ArcMap was used to assign values categorizing septic density. Two-thirds of the wells were selected in higher density areas and one-third in lower density areas. Equally prioritized was an even distribution of nitrate - N concentrations, with 28 of the wells having nitrate - N concentrations higher than the drinking water standard of 10 mg/L and 32 wells with concentrations between 2 and 10 mg/L. All wells with WUWN and nitrate - N concentrations greater than 20 mg/L were selected. The results of the nitrate source analyses will aid in determining temporal changes and spatial relationships of groundwater quality to soils, geology and land use in Chippewa County.

  15. Association rule mining data for census tract chemical exposure analysis

    Data.gov (United States)

    U.S. Environmental Protection Agency — Chemical concentration, exposure, and health risk data for U.S. census tracts from National Scale Air Toxics Assessment (NATA). This dataset is associated with the...

  16. Microbiological and Physico-chemical Analysis of Compost and its ...

    African Journals Online (AJOL)

    microbial counts, the physico-chemical parameters of compost and to assess the ... showed that application of municipal solid waste ... cattle manure and food wastes (leaves of avocado, .... Organic matter is decomposed and transformed to.

  17. Disclosure of hydraulic fracturing fluid chemical additives: analysis of regulations.

    Science.gov (United States)

    Maule, Alexis L; Makey, Colleen M; Benson, Eugene B; Burrows, Isaac J; Scammell, Madeleine K

    2013-01-01

    Hydraulic fracturing is used to extract natural gas from shale formations. The process involves injecting into the ground fracturing fluids that contain thousands of gallons of chemical additives. Companies are not mandated by federal regulations to disclose the identities or quantities of chemicals used during hydraulic fracturing operations on private or public lands. States have begun to regulate hydraulic fracturing fluids by mandating chemical disclosure. These laws have shortcomings including nondisclosure of proprietary or "trade secret" mixtures, insufficient penalties for reporting inaccurate or incomplete information, and timelines that allow for after-the-fact reporting. These limitations leave lawmakers, regulators, public safety officers, and the public uninformed and ill-prepared to anticipate and respond to possible environmental and human health hazards associated with hydraulic fracturing fluids. We explore hydraulic fracturing exemptions from federal regulations, as well as current and future efforts to mandate chemical disclosure at the federal and state level.

  18. Analysis of very thin organic fibres by means of small spots electron spectroscopy for chemical analysis

    International Nuclear Information System (INIS)

    Daiser, S.M.; Cormia, R.D.; Scharpen, L.

    1985-01-01

    ESCA analysis of very thin organic fibres as small as a few micrometer diameter is now possible using the small spot X-ray capability of the SSX100 ESCA system. The sampling method involves suspending the material in the SSX100 chamber, and illuminating it with a monochromatized X-ray beam of 150-300 μm diameter. From the small spot ESCA spectra one can determine the chemical character of the organic layer and the thickness. (Author)

  19. Process Analysis in Chemical Plant by Means of Radioactive Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T.; Hamada, K.; Osada, K. [Showa Denko K.K., Tokyo (Japan)

    1967-06-15

    Following the movement of solids and fluids is important in chemical processes to determine mixing efficiency and residence time. Since it is necessary to follow many complex substances such as raw materials, intermediates and reactants in plant investigations, it is often necessary to ascertain whether the behaviour of the radioisotope tracer and the substance to be traced are identical. The most difficult problem is to determine the best method of labelling, a factor which is a substantial key to the success of an experiment. Usually, there are three labelling techniques: radioisotope labelling, pre-.activation of the material and post-activation of the material. This paper deals with practical examples of the double-tracer technique, a combination of conventional radioisotope labelling and post-activation methods by means of activation analysis. In process analysis by means of tracers, a practical measurement method should also be devised and developed for each experiment. Phosphorus-32 and gold (non-radioactive) were used to measure retention time in a carbon-black plant. The radioisotope was pumped into a feed-stock pipe positioned before the reactor and samples were taken from each process of the plant, including the bag filter, mixer and product tank. After sampling from each step of the process, {sup 32}P in a semi-infinite powder sample was measured in situ by beta counting, and the gold was measured by gamma counting after activating the sample in a reactor. The experiment showed that both tracers had the same residence time, which was shorter than expected. Useful data were also obtained from the dispersion pattern of the material flow for future operation controls, including the time required to change from one grade of product to another. Practical tracer techniques to measure mixing characteristics in high-speed gas flows using {sup 85}Kr have been developed. A study of the measurement method was conducted by calculating the differential values of

  20. Chemical analysis of carbonates and carbonate rocks by atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tardon, S

    1981-01-01

    Evaluates methods of determining chemical composition of rocks surrounding black coal seams. Carbonate rock samples were collected in the Ostrava-Karvina coal mines. Sampling methods are described. Determination of the following elements and compounds in carbonate rocks is discussed: calcium, magnesium, iron, manganese, barium, silicon, aluminium, titanium, sodium, potassium, sulfur trioxide, phosphorus pentoxide, water and carbon dioxide. Proportion of compounds insoluble in water in the investigated rocks is also determined. Most of the elements are determined by means of atomic absorption analysis. Phosphorus is also determined by atomic absorption analysis. Other compounds are determined gravimetrically. The described procedure permits weight of a rock sample to be reduced to 0.5 g without reducing analysis accuracy. The results of determining carbonate rock components by X-ray analysis and by chemical analysis are compared. Equipment used for atomic absorption analysis is characterized (the 503 Perkin-Elmer and the CF-4 Optica-Milano spectrophotometers). The analyzed method for determining carbonate rock permits more accurate classification of rocks surrounding coal seams and rock impurities in run-of-mine coal. (22 refs.) (In Czech)

  1. Plagiarism explainer for students

    OpenAIRE

    Barba, Lorena A.

    2016-01-01

    A slide deck to serve as an explainer of plagiarism in academic settings, with a personal viewpoint. For my students.Also on SpeakerDeck:https://speakerdeck.com/labarba/plagiarism-explainer-for-students(The slide viewer on SpeakerDeck is much nicer.)

  2. Ultrastructural Analysis of Urinary Stones by Microfocus Computed Tomography and Comparison with Chemical Analysis

    Directory of Open Access Journals (Sweden)

    Tolga Karakan

    2016-06-01

    Full Text Available Objective: To investigate the ultra-structure of urinary system stones using micro-focus computed tomography (MCT, which makes non-destructive analysis and to compare with wet chemical analysis. Methods: This study was carried out at the Ankara Train­ing and Research hospital. Renal stones, removed from 30 patients during percutaneous nephrolithotomy (PNL surgery, were included in the study. The stones were blindly evaluated by the specialists with MCT and chemi­cal analysis. Results: The comparison of the stone components be­tween chemical analysis and MCT, showed that the rate of consistence was very low (p0.05. It was also seen that there was no significant relation between its 3D structure being heterogeneous or homogenous. Conclusion: The stone analysis with MCT is a time con­suming and costly method. This method is useful to un­derstand the mechanisms of stone formation and an im­portant guide to develop the future treatment modalities.

  3. Analysis of Chemical Bioactivity through In Vitro Profiling ...

    Science.gov (United States)

    Safety assessment of drugs and environmental chemicals relies extensively on animal testing. However, the quantity of chemicals needing assessment and challenges of species extrapolation drive the development of alternative approaches. The EPA’s ToxCast and the multiagency Tox21 programs address this through use of an extensive in vitro screening program to generate data on a large library of important environmental chemicals. These in vitro assays encompass both cell-free, biochemical assays targeting proteins that may be potential molecular initiating events and cellular assays that provide coverage of critical signaling pathways and toxicity phenotypes. Effects on model organisms such as the developing zebrafish, are also part of the testing strategy. A variety of computational approaches are used to analyze the resulting complex data sets to gain insight in to inherent biological activity of chemicals and possible mechanisms of toxicity. Several case studies including identification of modulators of estrogen receptor and aromatic hydrocarbon receptor pathways with effects in primary human cell systems will be described. In addition, existing in vivo data from a subset of the chemicals was used to anchor predictive models using in vitro data for a number of adverse endpoints including reproductive and developmental toxicities. The strengths and weaknesses of this approach will be described. This work does not necessarily reflect official Agency policy. Pres

  4. Cheminformatics Analysis of EPA ToxCast Chemical Libraries ...

    Science.gov (United States)

    An important goal of toxicology research is the development of robust methods that use in vitro and chemical structure information to predict in vivo toxicity endpoints. The US EPA ToxCast program is addressing this goal using ~600 in vitro assays to create bioactivity profiles on a set of 320 compounds, mostly pesticide actives, that have well characterized in vivo toxicity. These 320 compounds (EPA-320 set evaluated in Phase I of ToxCast) are a subset of a much larger set of ~10,000 candidates that are of interest to the EPA (called here EPA-10K). Predictive models of in vivo toxicity are being constructed from the in vitro assay data on the EPA-320 chemical set. These models require validation on additional chemicals prior to wide acceptance, and this will be carried out by evaluating compounds from EPA-10K in Phase II of ToxCast. We have used cheminformatics approaches including clustering, data visualization, and QSAR to develop models for EPA-320 that could help prioritizing EPA-10K validation chemicals. Both chemical descriptors, as well as calculated physicochemical properties have been used. Compounds from EPA-10K are prioritized based on their similarity to EPA-320 using different similarity metrics, with similarity thresholds defining the domain of applicability for the predictive models built for EPA-320 set. In addition, prioritized lists of compounds of increasing dissimilarity from the EPA-320 have been produced, to test the ability of the EPA-320

  5. Modular verification of chemical reaction network encodings via serializability analysis

    Science.gov (United States)

    Lakin, Matthew R.; Stefanovic, Darko; Phillips, Andrew

    2015-01-01

    Chemical reaction networks are a powerful means of specifying the intended behaviour of synthetic biochemical systems. A high-level formal specification, expressed as a chemical reaction network, may be compiled into a lower-level encoding, which can be directly implemented in wet chemistry and may itself be expressed as a chemical reaction network. Here we present conditions under which a lower-level encoding correctly emulates the sequential dynamics of a high-level chemical reaction network. We require that encodings are transactional, such that their execution is divided by a “commit reaction” that irreversibly separates the reactant-consuming phase of the encoding from the product-generating phase. We also impose restrictions on the sharing of species between reaction encodings, based on a notion of “extra tolerance”, which defines species that may be shared between encodings without enabling unwanted reactions. Our notion of correctness is serializability of interleaved reaction encodings, and if all reaction encodings satisfy our correctness properties then we can infer that the global dynamics of the system are correct. This allows us to infer correctness of any system constructed using verified encodings. As an example, we show how this approach may be used to verify two- and four-domain DNA strand displacement encodings of chemical reaction networks, and we generalize our result to the limit where the populations of helper species are unlimited. PMID:27325906

  6. X-ray texture analysis of paper coating pigments and the correlation with chemical composition analysis

    Science.gov (United States)

    Roine, J.; Tenho, M.; Murtomaa, M.; Lehto, V.-P.; Kansanaho, R.

    2007-10-01

    The present research experiments the applicability of x-ray texture analysis in investigating the properties of paper coatings. The preferred orientations of kaolin, talc, ground calcium carbonate, and precipitated calcium carbonate particles used in four different paper coatings were determined qualitatively based on the measured crystal orientation data. The extent of the orientation, namely, the degree of the texture of each pigment, was characterized quantitatively using a single parameter. As a result, the effect of paper calendering is clearly seen as an increase on the degree of texture of the coating pigments. The effect of calendering on the preferred orientation of kaolin was also evident in an independent energy dispersive spectrometer analysis on micrometer scale and an electron spectroscopy for chemical analysis on nanometer scale. Thus, the present work proves x-ray texture analysis to be a potential research tool for characterizing the properties of paper coating layers.

  7. Femoral anteversion and tibial torsion only explain 25% of variance in regression analysis of foot progression angle in children with diplegic cerebral palsy

    Science.gov (United States)

    2013-01-01

    Background The relationship between torsional bony deformities and rotational gait parameters has not been sufficiently investigated. This study was to investigate the degree of contribution of torsional bony deformities to rotational gait parameters in patients with diplegic cerebral palsy (CP). Methods Thirty three legs from 33 consecutive ambulatory patients (average age 9.5 years, SD 6.9 years; 20 males and 13 females) with diplegic CP who underwent preoperative three dimensional gait analysis, foot radiographs, and computed tomography (CT) were included. Adjusted foot progression angle (FPA) was retrieved from gait analysis by correcting pelvic rotation from conventional FPA, which represented the rotational gait deviation of the lower extremity from the tip of the femoral head to the foot. Correlations between rotational gait parameters (FPA, adjusted FPA, average pelvic rotation, average hip rotation, and average knee rotation) and radiologic measurements (acetabular version, femoral anteversion, knee torsion, tibial torsion, and anteroposteriortalo-first metatarsal angle) were analyzed. Multiple regression analysis was performed to identify significant contributing radiographic measurements to adjusted FPA. Results Adjusted FPA was significantly correlated with FPA (r=0.837, pregression analysis, femoral anteversion (p=0.026) and tibial torsion (p=0.034) were found to be the significant contributing structural deformities to the adjusted FPA (R2=0.247). Conclusions Femoral anteversion and tibial torsion were found to be the significant structural deformities that could affect adjusted FPA in patients with diplegic CP. Femoral anteversion and tibial torsion could explain only 24.7% of adjusted FPA. PMID:23767833

  8. Analysis of forward and inverse problems in chemical dynamics and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rabitz, H. [Princeton Univ., NJ (United States)

    1993-12-01

    The overall scope of this research concerns the development and application of forward and inverse analysis tools for problems in chemical dynamics and chemical kinetics. The chemical dynamics work is specifically associated with relating features in potential surfaces and resultant dynamical behavior. The analogous inverse research aims to provide stable algorithms for extracting potential surfaces from laboratory data. In the case of chemical kinetics, the focus is on the development of systematic means to reduce the complexity of chemical kinetic models. Recent progress in these directions is summarized below.

  9. International Research Project on the Effects of Chemical Ageing of Polymers on Performance Properties: Chemical and Thermal Analysis

    Science.gov (United States)

    Bulluck, J. W.; Rushing, R. A.

    1996-01-01

    Work during the past six months has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted small changes in the molecular weight distribution. Again these changes may result in variations in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Ultra- Violet Scanning Analysis, GC/Mass Spectrometry, Differential Scanning Calorimetry and Thermomechanical Analysis. In the ultra-violet analysis we noted the presence of an absorption band indicative of triene formation. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. We also cast films at SWT and subjected these films to a refluxing methanol 1% ethylene diamine solution. An updated literature search was conducted using Dialog and DROLLS to identify any new papers that may have been published in the open literature since the start of this project. The updated literature search and abstracts are contained in the Appendix section of this report.

  10. Chemical analysis and biological potential of Valerian root as used ...

    African Journals Online (AJOL)

    The herb prepared from this plant was studied to determine the chemical composition of its essential oil, carried out phytochemical screening and biological activities on ... rat paw oedema model comparable to aspirin, indicating anti-inflammatory activity; but lacked analgesic activity on the acetic acid-induced writhing test.

  11. HBCUs and Chemical Engineering: Analysis of Baccalaureate Programs

    Science.gov (United States)

    Reeves, Sheena; Thompson, Audie

    2018-01-01

    Historically Black Colleges and Universities (HBCUs) provide significant STEM degrees to African Americans. Initiatives toward increasing diversity in STEM fields have been implemented by government and industry leaders. HBCUs annually award over 20% of all African American baccalaureate chemical engineering degrees. This speaks volume to the…

  12. Chemical analysis of the Assale (Ethiopia) rock salt deposit | Binega ...

    African Journals Online (AJOL)

    contaminants) elements found in the Assale (Ethiopia) rock salt. The results showed that the rock salt is found to be the best natural common salt. This was proved by comparison with the chemical requirement and trace elements in common ...

  13. Probabilistic thermo-chemical analysis of a pultruded composite rod

    DEFF Research Database (Denmark)

    Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

    2012-01-01

    In the present study the deterministic thermo-chemical pultrusion simulation of a composite rod taken from the literature [7] is used as a validation case. The predicted centerline temperature and cure degree profiles of the rod match well with those in the literature [7]. Following the validation...

  14. CHEMICAL ANALYSIS OF DENSE-GAS EXTRACTS FROM LIME FLOWERS

    Directory of Open Access Journals (Sweden)

    Demyanenko DV

    2015-04-01

    Full Text Available The purpose of this work was to make qualitative and quantitative analysis of phenolic biologically active substances (BAS in the extracts produced from lime flowers with condensed gases, using method of high-performance liquid chromatography (HPLC. Materials and methods: materials for this study were the extracts obtained by consequent processing of the herbal drug and marcs thereof with various condensed gases: difluorochloromethane (Freon R22, difluoromethane (Freon R32, azeotropic mixture of difluoromethane with pentafluoroethane (Freon 410A and freon-ammonium mixture. Extracts obtained with the latter were subjected to further fractionation by liquidliquid separation into hexane, chloroform, ethyl acetate and aqueous-alcohol phases. Besides, the supercritical СО2 extract, obtained from the herbal drug under rather strong conditions (at temperature 60°С and pressure 400 bar, was studied in our previous research. Presence of phenolic BAS and their quantity in the researched samples were determined by method of HPLC with UVspectrometric detection. Results and discussion: It has been found that Freon R22 extracted trace amounts of rutin from lime flowers – its content was only 0.08% of the total extract weight. On the other hand, Freons R32 and R410А showed good selectivity to moderately polar BAS of lime flowers (derivatives of flavonoids and hydroxycinnamic acids: in particular, the extract obtained with freon R32 contained about 1.3% of the total phenolic substances, and it was the only one of the investigated condensed gases used by us which took the basic flavonoid of lime flowers tiliroside – its content was 0.42% of extract weight. Also Freons R32 and R410А were able to withdraw another compound dominating among phenolic substances in the yielded extracts. Its quantity was rather noticeable – up to 0.87% of extract weight. This substance was not identified by existing database, but its UV-spectrum was similar to those of

  15. Silica sol as grouting material: a physio-chemical analysis.

    Science.gov (United States)

    Sögaard, Christian; Funehag, Johan; Abbas, Zareen

    2018-01-01

    At present there is a pressing need to find an environmentally friendly grouting material for the construction of tunnels. Silica nanoparticles hold great potential of replacing the organic molecule based grouting materials currently used for this purpose. Chemically, silica nanoparticles are similar to natural silicates which are essential components of rocks and soil. Moreover, suspensions of silica nanoparticles of different sizes and desired reactivity are commercially available. However, the use of silica nanoparticles as grouting material is at an early stage of its technological development. There are some critical parameters such as long term stability and functionality of grouted silica that need to be investigated in detail before silica nanoparticles can be considered as a reliable grouting material. In this review article we present the state of the art regarding the chemical properties of silica nanoparticles commercially available, as well as experience gained from the use of silica as grouting material. We give a detailed description of the mechanisms underlying the gelling of silica by different salt solutions such as NaCl and KCl and how factors such as particle size, pH, and temperature affect the gelling and gel strength development. Our focus in this review is on linking the chemical properties of silica nanoparticles to the mechanical properties to better understand their functionality and stability as grouting material. Along the way we point out areas which need further research.

  16. Miniaturised wireless smart tag for optical chemical analysis applications.

    Science.gov (United States)

    Steinberg, Matthew D; Kassal, Petar; Tkalčec, Biserka; Murković Steinberg, Ivana

    2014-01-01

    A novel miniaturised photometer has been developed as an ultra-portable and mobile analytical chemical instrument. The low-cost photometer presents a paradigm shift in mobile chemical sensor instrumentation because it is built around a contactless smart card format. The photometer tag is based on the radio-frequency identification (RFID) smart card system, which provides short-range wireless data and power transfer between the photometer and a proximal reader, and which allows the reader to also energise the photometer by near field electromagnetic induction. RFID is set to become a key enabling technology of the Internet-of-Things (IoT), hence devices such as the photometer described here will enable numerous mobile, wearable and vanguard chemical sensing applications in the emerging connected world. In the work presented here, we demonstrate the characterisation of a low-power RFID wireless sensor tag with an LED/photodiode-based photometric input. The performance of the wireless photometer has been tested through two different model analytical applications. The first is photometry in solution, where colour intensity as a function of dye concentration was measured. The second is an ion-selective optode system in which potassium ion concentrations were determined by using previously well characterised bulk optode membranes. The analytical performance of the wireless photometer smart tag is clearly demonstrated by these optical absorption-based analytical experiments, with excellent data agreement to a reference laboratory instrument. © 2013 Elsevier B.V. All rights reserved.

  17. Body Composition Explains Greater Variance in Weight-for-Length Z-scores than Mid-Upper Arm Circumference during Infancy - A Secondary Data Analysis

    International Nuclear Information System (INIS)

    Grijalva-Eternod, Carlos; Andersen, Gregers Stig; Girma, Tsinuel; Admassu, Bitiya; Kæstel, Pernille; Michaelsen, Kim F; Friis, Henrik; Wells, Jonathan CK

    2014-01-01

    Full text: Background: Traditionally, weight-for-length/height z-score (WLZ) was used to assess wasting (a mortality risk factor) in children 0-59 months. A recent consultation reached a majority position that mid-upper arm circumference (MUAC) is a better mortality predictor than WLZ in children 6-59 months. In addition, MUAC collected at the ages of 6-14 weeks has shown to identify infants more likely to die before reaching one year. To understand which body compartment is most affected by undernutrition, associations between anthropometric indicators and body composition data have been studied in children aged 6-59 months. To our knowledge, no such study has been done in children aged 0-6 months. We aimed to study these associations. Methods: Weight, length, MUAC, and lean and fat mass (LM and FM, respectively) obtained by air-displacement plethysmography of infants aged 0-6 months were obtained from an Ethiopian birth cohort study. The data, originally used to construct body composition reference data, measured infants at birth, 1.5, 2.5, 3.5, 4.5, and 6 months of age. A complete set of measurements available for 2506 out of a total of 2777 child measurements (563/598, 403/436, 414/444, 413/446, 368/415, and 345/441 in each age, respectively) was used for this analys, E-mail: is. Weight and length data were transformed to sex-and age-specific weight-for-length z-score (WLZ) values using the 2006 WHO growth standards. To remove the confounding positive association between LM or FM and length, we calculated sex- and age-specific standardised residuals values obtained from regressing LM or FM on length, separately by sex and age of measurement. The associations between MUAC, WLZ, length, and body composition residuals were assessed using correlation analysis. We used regression analysis to assess the independent contribution of body composition residuals to MUAC and WLZ. All analyses were done separately by age. Results: MUAC was strongly and positively correlated

  18. Using H/V Spectral Ratio Analysis to Map Sediment Thickness and to Explain Macroseismic Intensity Variation of a Low-Magnitude Seismic Swarm in Central Belgium

    Science.gov (United States)

    Van Noten, K.; Lecocq, T.; Camelbeeck, T.

    2013-12-01

    Between 2008 and 2010, the Royal Observatory of Belgium received numerous ';Did You Feel It'-reports related to a 2-year lasting earthquake swarm at Court-Saint-Etienne, a small town in a hilly area 20 km SE of Brussels, Belgium. These small-magnitude events (-0.7 ≤ ML ≤ 3.2, n = c. 300 events) were recorded both by the permanent seismometer network in Belgium and by a locally installed temporary seismic network deployed in the epicentral area. Relocation of the hypocenters revealed that the seismic swarm can be related to the reactivation of a NW-SE strike-slip fault at 3 to 6 km depth in the basement rocks of the Lower Palaeozoic London-Brabant Massif. This sequence caused a lot of emotion in the region because more than 60 events were felt by the local population. Given the small magnitudes of the seismic swarm, most events were more often heard than felt by the respondents, which is indicative of a local high-frequency earthquake source. At places where the bedrock is at the surface or where it is covered by thin alluvial sediments ( 30 m). In those river valleys that have a considerable alluvial sedimentary cover, macroseismic intensities are again lower. To explain this variation in macroseismic intensity we present a macroseismic analysis of all DYFI-reports related to the 2008-2010 seismic swarm and a pervasive H/V spectral ratio (HVSR) analysis of ambient noise measurements to model the thickness of sediments covering the London-Brabant Massif. The HVSR method is a very powerful tool to map the basement morphology, particularly in regions of unknown subsurface structure. By calculating the soil's fundamental frequency above boreholes, we calibrated the power-law relationship between the fundamental frequency, shear wave velocity and the thickness of sediments. This relationship is useful for places where the sediment thickness is unknown and where the fundamental frequency can be calculated by H/V spectral ratio analysis of ambient noise. In a

  19. Computer jargon explained

    CERN Document Server

    Enticknap, Nicholas

    2014-01-01

    Computer Jargon Explained is a feature in Computer Weekly publications that discusses 68 of the most commonly used technical computing terms. The book explains what the terms mean and why the terms are important to computer professionals. The text also discusses how the terms relate to the trends and developments that are driving the information technology industry. Computer jargon irritates non-computer people and in turn causes problems for computer people. The technology and the industry are changing so rapidly; it is very hard even for professionals to keep updated. Computer people do not

  20. Forecasting global developments in the basic chemical industry for environmental policy analysis

    NARCIS (Netherlands)

    Broeren, M.L.M.|info:eu-repo/dai/nl/371687438; Saygin, D.; Patel, M.K.

    The chemical sector is the largest industrial energy user, but detailed analysis of its energy use developments lags behind other energy-intensive sectors. A cost-driven forecasting model for basic chemicals production is developed, accounting for regional production costs, demand growth and stock

  1. Chemical Analysis of the Moon at the Surveyor VII Landing Site: Preliminary Results.

    Science.gov (United States)

    Turkevich, A L; Franzgrote, E J; Patterson, J H

    1968-10-04

    The alpha-scattering experiment aboard Surveyor VII has provided a chemical analysis of the moon in the area of the crater Tycho. The preliminary results indicate a chemical composition similar to that already found at two mare sites, but with a lower concentration of elements of the iron group (titanium through copper).

  2. Exploring the Potential for Using Inexpensive Natural Reagents Extracted from Plants to Teach Chemical Analysis

    Science.gov (United States)

    Hartwell, Supaporn Kradtap

    2012-01-01

    A number of scientific articles report on the use of natural extracts from plants as chemical reagents, where the main objective is to present the scientific applications of those natural plant extracts. The author suggests that natural reagents extracted from plants can be used as alternative low cost tools in teaching chemical analysis,…

  3. Sample preparation for combined chemical analysis and bioassay application in water quality assessment

    NARCIS (Netherlands)

    Kolkman, A.; Schriks, M.; Brand, W; Bäuerlein, P.S.; van der Kooi, M.M.E.; van Doorn, R.H.; Emke, E.; Reus, A.; van der Linden, S.; de Voogt, P.; Heringa, M.B.

    2013-01-01

    The combination of in vitro bioassays and chemical screening can provide a powerful toolbox to determine biologically relevant compounds in water extracts. In this study, a sample preparation method is evaluated for the suitability for both chemical analysis and in vitro bioassays. A set of 39

  4. Neutron activation analysis for chemical characterization of Brazilian oxo-biodegradable plastics

    International Nuclear Information System (INIS)

    Mateus Eugenio Boscaro; De Nadai Fernandes, E.A.; Marcio Arruda Bacchi; Luis Gustavo Cofani dos Santos; Cofani dos Santos, S.N.S.; Sandra Mara Martins-Franchetti

    2015-01-01

    The chemical characterization of oxo-biodegradable plastic bags was performed by neutron activation analysis. The presence of several chemical elements (As, Br, Ca, Co, Cr, Fe, Hf, K, La, Na, Sb, Sc, Ta and Zn) with large variability of mass fractions amongst samples indicates that these plastics receive additives and may have been contaminated during manufacturing process thereby becoming potential environmental pollutants. (author)

  5. Comprehensive Mass Analysis for Chemical Processes, a Case Study on L-Dopa Manufacture

    Science.gov (United States)

    To evaluate the “greenness” of chemical processes in route selection and process development, we propose a comprehensive mass analysis to inform the stakeholders from different fields. This is carried out by characterizing the mass intensity for each contributing chemical or wast...

  6. Development of international standards for surface analysis by ISO technical committee 201 on surface chemical analysis

    International Nuclear Information System (INIS)

    Powell, C.J.

    1999-01-01

    Full text: The International Organization for Standardization (ISO) established Technical Committee 201 on Surface Chemical Analysis in 1991 to develop documentary standards for surface analysis. ISO/TC 201 met first in 1992 and has met annually since. This committee now has eight subcommittees (Terminology, General Procedures, Data Management and Treatment, Depth Profiling, AES, SIMS, XPS, and Glow Discharge Spectroscopy (GDS)) and one working group (Total X-Ray Fluorescence Spectroscopy). Each subcommittee has one or more working groups to develop standards on particular topics. Australia has observer-member status on ISO/TC 201 and on all ISO/TC 201 subcommittees except GDS where it has participator-member status. I will outline the organization of ISO/TC 201 and summarize the standards that have been or are being developed. Copyright (1999) Australian X-ray Analytical Association Inc

  7. Chemical analysis of acoustically levitated drops by Raman spectroscopy.

    Science.gov (United States)

    Tuckermann, Rudolf; Puskar, Ljiljana; Zavabeti, Mahta; Sekine, Ryo; McNaughton, Don

    2009-07-01

    An experimental apparatus combining Raman spectroscopy with acoustic levitation, Raman acoustic levitation spectroscopy (RALS), is investigated in the field of physical and chemical analytics. Whereas acoustic levitation enables the contactless handling of microsized samples, Raman spectroscopy offers the advantage of a noninvasive method without complex sample preparation. After carrying out some systematic tests to probe the sensitivity of the technique to drop size, shape, and position, RALS has been successfully applied in monitoring sample dilution and preconcentration, evaporation, crystallization, an acid-base reaction, and analytes in a surface-enhanced Raman spectroscopy colloidal suspension.

  8. Statistical analysis of DNT detection using chemically functionalized microcantilever arrays

    DEFF Research Database (Denmark)

    Bosco, Filippo; Bache, M.; Hwu, E.-T.

    2012-01-01

    The need for miniaturized and sensitive sensors for explosives detection is increasing in areas such as security and demining. Micrometer sized cantilevers are often used for label-free detection, and have previously been reported to be able to detect explosives. However, only a few measurements...... on the chemically treated surfaces results in significant bending of the cantilevers and in a decrease of their resonant frequencies. We present averaged measurements obtained from up to 72 cantilevers being simultaneously exposed to the same sample. Compared to integrated reference cantilevers with non...

  9. Integrated Process Design, Control and Analysis of Intensified Chemical Processes

    DEFF Research Database (Denmark)

    Mansouri, Seyed Soheil

    chemical processes; for example, intensified processes such as reactive distillation. Most importantly, it identifies and eliminates potentially promising design alternatives that may have controllability problems later. To date, a number of methodologies have been proposed and applied on various problems......, that the same principles that apply to a binary non-reactive compound system are valid also for a binary-element or a multi-element system. Therefore, it is advantageous to employ the element based method for multicomponent reaction-separation systems. It is shown that the same design-control principles...

  10. The wireless internet explained

    CERN Document Server

    Rhoton, John

    2001-01-01

    The Wireless Internet Explained covers the full spectrum of wireless technologies from a wide range of vendors, including initiatives by Microsoft and Compaq. The Wireless Internet Explained takes a practical look at wireless technology. Rhoton explains the concepts behind the physics, and provides an overview that clarifies the convoluted set of standards heaped together under the umbrella of wireless. It then expands on these technical foundations to give a panorama of the increasingly crowded landscape of wireless product offerings. When it comes to actual implementation the book gives abundant down-to-earth advice on topics ranging from the selection and deployment of mobile devices to the extremely sensitive subject of security.Written by an expert on Internet messaging, the author of Digital Press''s successful Programmer''s Guide to Internet Mail and X.400 and SMTP: Battle of the E-mail Protocols, The Wireless Internet Explained describes and evaluates the current state of the fast-growing and crucial...

  11. Self-explaining roads

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Kaptein, N.

    1999-01-01

    As a means to a sustainable safe traffic environment the concept of Self-Explaining Roads (SER) has been developed. The SER concept advocates a traffic environment that elicits safe driving behaviour simply by its design. In order to support safe driving behaviour and appropriate speed choice,

  12. On the tracks of sandarac, review and chemical analysis.

    Science.gov (United States)

    Azémard, Clara; Ménager, Matthieu; Vieillescazes, Cathy

    2017-12-01

    The sandarac resin (Tetraclinis articulata) has been long used for its properties, mostly as a varnish component. Called juniper resin until the nineteenth century, the real botanical origin of sandarac is still unclear. The first approach to this issue is the review of the evolution of the etymology, terminology, and botanical description of sandarac through time. It seems that sandarac was mainly coming from T. articulata but the use of some juniper resins before the twentieth century is not to be excluded. The second approach is a chemical one; we used gas chromatography coupled to mass spectrometry to characterise the resin. As sandarac was the main component of the famous Italian varnish Vernice liquida, its characterisation is important for old paintings studies. However, although we could hope to differentiate sandarac, Juniperus communis and Juniperus oxycedrus resins by looking at their chemical composition, it appears that these resins are very similar. Besides, we notice a lack of old varnishes containing sandarac which complicates our work.

  13. Crystal-Chemical Analysis Martian Minerals in Gale Crater

    Science.gov (United States)

    Morrison, S. M.; Downs, R. T.; Blake, D. F.; Bish, D. L.; Ming, D. W.; Morris, R. V.; Yen, A. S.; Chipera, S. J.; Treiman, A. H.; Vaniman, D. T.; hide

    2015-01-01

    The CheMin instrument on the Mars Science Laboratory rover Curiosity performed X-ray diffraction analyses on scooped soil at Rocknest and on drilled rock fines at Yellowknife Bay (John Klein and Cumberland samples), The Kimberley (Windjana sample), and Pahrump (Confidence Hills sample) in Gale crater, Mars. Samples were analyzed with the Rietveld method to determine the unit-cell parameters and abundance of each observed crystalline phase. Unit-cell parameters were used to estimate compositions of the major crystalline phases using crystal-chemical techniques. These phases include olivine, plagioclase and clinopyroxene minerals. Comparison of the CheMin sample unit-cell parameters with those in the literature provides an estimate of the chemical compositions of the major crystalline phases. Preliminary unit-cell parameters, abundances and compositions of crystalline phases found in Rocknest and Yellowknife Bay samples were reported in. Further instrument calibration, development of 2D-to- 1D pattern conversion corrections, and refinement of corrected data allows presentation of improved compositions for the above samples.

  14. A kinetic and equilibrium analysis of silicon carbide chemical vapor deposition on monofilaments

    Science.gov (United States)

    Gokoglu, S. A.; Kuczmarski, M. A.

    1993-01-01

    Chemical kinetics of atmospheric pressure silicon carbide (SiC) chemical vapor deposition (CVD) from dilute silane and propane source gases in hydrogen is numerically analyzed in a cylindrical upflow reactor designed for CVD on monofilaments. The chemical composition of the SiC deposit is assessed both from the calculated total fluxes of carbon and silicon and from chemical equilibrium considerations for the prevailing temperatures and species concentrations at and along the filament surface. The effects of gas and surface chemistry on the evolution of major gas phase species are considered in the analysis.

  15. Laser Applications to Chemical, Security, and Environmental Analysis: introduction to the feature issue

    International Nuclear Information System (INIS)

    Dreizler, Andreas; Fried, Alan; Gord, James R.

    2007-01-01

    This Applied Optics feature issue on Laser Applications to Chemical, Security,and Environmental Analysis (LACSEA) highlights papers presented at theLACSEA 2006 Tenth Topical Meeting sponsored by the Optical Society ofAmerica

  16. Laser applications to chemical, security, and environmental analysis: introduction to the feature issue.

    Science.gov (United States)

    Seeger, Thomas; Dreier, Thomas; Chen, Weidong; Kearny, Sean; Kulatilaka, Waruna

    2017-04-10

    This Applied Optics feature issue on laser applications to chemical, security, and environmental analysis (LACSEA) highlights papers presented at the LACSEA 2016 Fifteenth Topical Meeting sponsored by the Optical Society of America.

  17. DRES Database of Methods for the Analysis of Chemical Warfare Agents

    National Research Council Canada - National Science Library

    D'Agostino, Paul

    1997-01-01

    .... Update of the database continues as an ongoing effort and the DRES Database of Methods for the Analysis of Chemical Warfare Agents is available panel in hardcopy form or as a softcopy Procite or Wordperfect file...

  18. Chemical risk evaluation, importance of the risk analysis framework uses: Latin America development restrictions

    International Nuclear Information System (INIS)

    Carrillo, M.

    2013-01-01

    The power point presentation is about reach and results of the risk analysis in Venezuela, chemical dangers in food, human damage, injuries , technologies news in fodd development, toxicity, microbiological risk, technical recommendations

  19. Environmental Impact Assessment for Socio-Economic Analysis of Chemicals

    DEFF Research Database (Denmark)

    Calow, Peter; Biddinger, G; Hennes, C

    This report describes the requirements for, and illustrates the application of, a methodology for a socio-economic analysis (SEA) especially as it might be adopted in the framework of REACH.......This report describes the requirements for, and illustrates the application of, a methodology for a socio-economic analysis (SEA) especially as it might be adopted in the framework of REACH....

  20. Engineering and Functional Analysis of Mitotic Kinases Through Chemical Genetics.

    Science.gov (United States)

    Jones, Mathew J K; Jallepalli, Prasad V

    2016-01-01

    During mitosis, multiple protein kinases transform the cytoskeleton and chromosomes into new and highly dynamic structures that mediate the faithful transmission of genetic information and cell division. However, the large number and strong conservation of mammalian kinases in general pose significant obstacles to interrogating them with small molecules, due to the difficulty in identifying and validating those which are truly selective. To overcome this problem, a steric complementation strategy has been developed, in which a bulky "gatekeeper" residue within the active site of the kinase of interest is replaced with a smaller amino acid, such as glycine or alanine. The enlarged catalytic pocket can then be targeted in an allele-specific manner with bulky purine analogs. This strategy provides a general framework for dissecting kinase function with high selectivity, rapid kinetics, and reversibility. In this chapter we discuss the principles and techniques needed to implement this chemical genetic approach in mammalian cells.

  1. Chemical effects in materials studies using Auger analysis

    International Nuclear Information System (INIS)

    Rye, R.R.

    1985-01-01

    Core-valence-valence Auger spectra (AES) afford a unique local view of valence electron structure. The direct involvement in the Auger process of both core and valence states means that the transition matrix element will have a large value only for that portion of the valence electron density which covers the same spatial extent as the core wave function. Thus, the information content of AES is local to the atomic site containing the initial core hole. Our approach in understanding the local information content of AES has been mainly experimental through the intercomparison of model systems, both molecular and solid. The use of molecules in this regard is particularly useful since the vast array of molecular species of known geometric and electronic structures allows one to both vary these properties in a systematic fashion to observe trends and to choose a molecule to probe a specific chemical question

  2. CFD analysis of hypersonic, chemically reacting flow fields

    Science.gov (United States)

    Edwards, T. A.

    1993-01-01

    Design studies are underway for a variety of hypersonic flight vehicles. The National Aero-Space Plane will provide a reusable, single-stage-to-orbit capability for routine access to low earth orbit. Flight-capable satellites will dip into the atmosphere to maneuver to new orbits, while planetary probes will decelerate at their destination by atmospheric aerobraking. To supplement limited experimental capabilities in the hypersonic regime, computational fluid dynamics (CFD) is being used to analyze the flow about these configurations. The governing equations include fluid dynamic as well as chemical species equations, which are being solved with new, robust numerical algorithms. Examples of CFD applications to hypersonic vehicles suggest an important role this technology will play in the development of future aerospace systems. The computational resources needed to obtain solutions are large, but solution adaptive grids, convergence acceleration, and parallel processing may make run times manageable.

  3. Recommendations for Future Army Analysis Efforts. Volume 4. Key Questions and Recommendations for Future Analysis Efforts on Explaining the Army and Supporting the Soldier

    Science.gov (United States)

    1988-04-14

    McDonalds or Burger King for snack shops, Marriott for messing/billeting facilities, etc.? RECOMMENDED ELEMENTS OF ANALYSIS/TOPICAL AREAS: DATE RESULTS ITEM...e.g., a Burger King on post) now brings in about SI million per month to the family support coffers. It began in 1984 and has returned $21 million...Army, private sector franchises and family support. - The first or leading question is whether the family affects retention and, if so, what the Army

  4. Chemical Fingerprint Analysis and Quantitative Analysis of Rosa rugosa by UPLC-DAD

    Directory of Open Access Journals (Sweden)

    Sanawar Mansur

    2016-12-01

    Full Text Available A method based on ultra performance liquid chromatography with a diode array detector (UPLC-DAD was developed for quantitative analysis of five active compounds and chemical fingerprint analysis of Rosa rugosa. Ten batches of R. rugosa collected from different plantations in the Xinjiang region of China were used to establish the fingerprint. The feasibility and advantages of the used UPLC fingerprint were verified for its similarity evaluation by systematically comparing chromatograms with professional analytical software recommended by State Food and Drug Administration (SFDA of China. In quantitative analysis, the five compounds showed good regression (R2 = 0.9995 within the test ranges, and the recovery of the method was in the range of 94.2%–103.8%. The similarities of liquid chromatography fingerprints of 10 batches of R. rugosa were more than 0.981. The developed UPLC fingerprint method is simple, reliable, and validated for the quality control and identification of R. rugosa. Additionally, simultaneous quantification of five major bioactive ingredients in the R. rugosa samples was conducted to interpret the consistency of the quality test. The results indicated that the UPLC fingerprint, as a characteristic distinguishing method combining similarity evaluation and quantification analysis, can be successfully used to assess the quality and to identify the authenticity of R. rugosa.

  5. ANALYSIS AND IDENTIFICATION SPIKING CHEMICAL COMPOUNDS RELATED TO CHEMICAL WEAPON CONVENTION IN UNKNOWN WATER SAMPLES USING GAS CHROMATOGRAPHY AND GAS CHROMATOGRAPHY ELECTRON IONIZATION MASS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Harry Budiman

    2010-06-01

    Full Text Available The identification and analysis of chemical warfare agents and their degradation products is one of important component for the implementation of the convention. Nowadays, the analytical method for determination chemical warfare agent and their degradation products has been developing and improving. In order to get the sufficient analytical data as recommended by OPCW especially in Proficiency Testing, the spiking chemical compounds related to Chemical Weapon Convention in unknown water sample were determined using two different techniques such as gas chromatography and gas chromatography electron-impact ionization mass spectrometry. Neutral organic extraction, pH 11 organic extraction, cation exchanged-methylation, triethylamine/methanol-silylation were performed to extract the chemical warfare agents from the sample, before analyzing with gas chromatography. The identification of chemical warfare agents was carried out by comparing the mass spectrum of chemicals with mass spectrum reference from the OPCW Central Analytical Database (OCAD library while the retention indices calculation obtained from gas chromatography analysis was used to get the confirmation and supported data of  the chemical warfare agents. Diisopropyl methylphosphonate, 2,2-diphenyl-2-hydroacetic acid and 3-quinuclidinol were found in unknown water sample. Those chemicals were classified in schedule 2 as precursor or reactant of chemical weapons compound in schedule list of Chemical Weapon Convention.   Keywords: gas chromatography, mass spectrometry, retention indices, OCAD library, chemical warfare agents

  6. Quantum chemical analysis of potential anti-Parkinson agents

    Indian Academy of Sciences (India)

    Intermolecular binding energy components could not be analyzed by docking and due to this .... Cluster analysis was performed on the docked results with regard to RMS ... gard, docking simulation is a key tool in structural mo- lecular biology ...

  7. Chemical analysis of useful trace elements in sea water

    International Nuclear Information System (INIS)

    Katoh, Shunsaku; Fujii, Ayako; Miyai, Yoshitaka; Sakane, Kohji; Ogata, Noboru.

    1983-01-01

    The methods for the analysis of useful trace elements in sea water which have been tried so far are reviewed, and these methods are described briefly from the standpoint of studying the collection of resources. Ag and Au can be determined by concentrating sea water by ion-exchange method, solvent extraction method and electrodeposition method, then the elements are measured quantitatively by activation analysis and atomic absorption spectrochemical analysis. Sr, B and Li, which exist in relatively high concentration in sea water, are determined easily by atomic absorption spectrochemical analysis and absorption spectrometry. U, Mo and V are measured suitably by concentrating the elements by coprecipitation or solvent extraction method, and measuring by fluorescence analysis and arsenazo-3 method for U and through graphite-atomic absorption analysis for Mo and V. It has been revealed that the concentration of Ag and Au in sea water is extremely low, accordingly the recovery study is not conducted recently. On the other hand, the adsorption method using hydrated titanium oxide and amidoxim adsorbents for U, Mo and V, the adsorption method using aluminum adsorbent for Li, and the adsorption method using magnesium oxide and zirconium hydroxide and the solvent extraction method for B are hopeful to recover these elements. (Yoshitake, I.)

  8. An analysis framework for characterizing and explaining development of EIA legislation in developing countries-Illustrated for Georgia, Ghana and Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Kolhoff, Arend J., E-mail: akolhoff@eia.nl [Netherlands Commission for Environmental Assessment, P.O. Box 2345, 3500 GH Utrecht (Netherlands); Driessen, Peter P.J., E-mail: p.driessen@uu.nl [Copernicus Institute of Sustainable Development, Utrecht University, P.O. Box 80115, 3508 TC (Netherlands); Runhaar, Hens A.C., E-mail: h.a.c.runhaar@uu.nl [Copernicus Institute of Sustainable Development, Utrecht University, P.O. Box 80115, 3508 TC (Netherlands)

    2013-01-15

    Actors in the field of international development co-operation supporting the development of EIA legislation in developing countries often do not achieve the results envisaged. The performance of EIA in these countries often remains weak. One reason, we assume, is that often those actors support the establishment of overly ambitious EIA legislation that cannot achieve its objectives in the light of constraining contexts. To provide more effective support we need to better understand the enabling and constraining contextual factors that influence the development of EIA legislation and to which support actors should align itself. In this article a new analysis framework for classifying, characterizing and explaining the development of EIA legislation is described, measured in terms of ambition levels. Ambitions are defined as intentions the EIA authorities aim to fulfill, expressed in formal EIA legislation. Three country cases, Yemen, Georgia and Ghana are used to illustrate the usefulness of our framework and as a first test to refine the framework. We have formulated the following five hypotheses that complement and refine our analysis framework. One, EIA legislation may develop multilinearly in terms of ambition levels. Two, ambitions in EIA legislation seem to be influenced to a great extent by the power and capacity of, on the one hand, the environmental authorities supporting EIA and, on the other hand, the sector authorities hindering the development of EIA. Three, the political system is the most important context factor influencing the rules of policy-making and the power of the different actors involved. Four, the importance of context factors on the development of ambitions is dependent on the phase of EIA system development. Five, some ambitions seem to be influenced by particular factors; for instance the ambitions for the object of study seem to be influenced by the level of environmental awareness of the sector ministries and parliament. The analysis

  9. Explaining the increased health care expenditures associated with gastroesophageal reflux disease among elderly Medicare beneficiaries with chronic obstructive pulmonary disease: a cost-decomposition analysis

    Directory of Open Access Journals (Sweden)

    Ajmera M

    2014-04-01

    Full Text Available Mayank Ajmera,1 Amit D Raval,1 Chan Shen,2 Usha Sambamoorthi1 1Department of Pharmaceutical Systems and Policy, School of Pharmacy, School of Medicine, West Virginia University, Morgantown, WV, USA; 2Department of Biostatistics and Health Services Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA Objective: To estimate excess health care expenditures associated with gastroesophageal reflux disease (GERD among elderly individuals with chronic obstructive pulmonary disease (COPD and examine the contribution of predisposing characteristics, enabling resources, need variables, personal health care practices, and external environment factors to the excess expenditures, using the Blinder-Oaxaca linear decomposition technique. Methods: This study utilized a cross-sectional, retrospective study design, using data from multiple years (2006-2009 of the Medicare Current Beneficiary Survey linked with fee-for-service Medicare claims. Presence of COPD and GERD was identified using diagnoses codes. Health care expenditures consisted of inpatient, outpatient, prescription drugs, dental, medical provider, and other services. For the analysis, t-tests were used to examine unadjusted subgroup differences in average health care expenditures by the presence of GERD. Ordinary least squares regressions on log-transformed health care expenditures were conducted to estimate the excess health care expenditures associated with GERD. The Blinder-Oaxaca linear decomposition technique was used to determine the contribution of predisposing characteristics, enabling resources, need variables, personal health care practices, and external environment factors, to excess health care expenditures associated with GERD. Results: Among elderly Medicare beneficiaries with COPD, 29.3% had co-occurring GERD. Elderly Medicare beneficiaries with COPD/GERD had 1.5 times higher ($36,793 vs $24,722 [P<0.001] expenditures than did those with COPD/no GERD. Ordinary

  10. Factors that could explain the increasing prevalence of type 2 diabetes among adults in a Canadian province: a critical review and analysis

    Directory of Open Access Journals (Sweden)

    Véronique Thibault

    2016-11-01

    Full Text Available Abstract Background The prevalence of diabetes has increased since the last decade in New Brunswick. Identifying factors contributing to the increase in diabetes prevalence will help inform an action plan to manage the condition. The objective was to describe factors that could explain the increasing prevalence of type 2 diabetes in New Brunswick since 2001. Methods A critical literature review was conducted to identify factors potentially responsible for an increase in prevalence of diabetes. Data from various sources were obtained to draw a repeated cross-sectional (2001–2014 description of these factors concurrently with changes in the prevalence of type 2 diabetes in New Brunswick. Linear regressions, Poisson regressions and Cochran Armitage analysis were used to describe relationships between these factors and time. Results Factors identified in the review were summarized in five categories: individual-level risk factors, environmental risk factors, evolution of the disease, detection effect and global changes. The prevalence of type 2 diabetes has increased by 120% between 2001 and 2014. The prevalence of obesity, hypertension, prediabetes, alcohol consumption, immigration and urbanization increased during the study period and the consumption of fruits and vegetables decreased which could represent potential factors of the increasing prevalence of type 2 diabetes. Physical activity, smoking, socioeconomic status and education did not present trends that could explain the increasing prevalence of type 2 diabetes. During the study period, the mortality rate and the conversion rate from prediabetes to diabetes decreased and the incidence rate increased. Suggestion of a detection effect was also present as the number of people tested increased while the HbA1c and the age at detection decreased. Period and birth cohort effect were also noted through a rise in the prevalence of type 2 diabetes across all age groups, but greater increases were

  11. Sampling and chemical analysis of urban street runoff

    International Nuclear Information System (INIS)

    Daub, J.; Striebel, T.; Robien, A.; Herrmann, R.

    1993-01-01

    In order to characterize the environmentally relevant physical and chemical properties of urban street runoff, an automatic sampling device was developed. Precipitation samples were collected together with runoff samples. Organic and inorganic compounds were analysed in the runoff. Dissolved and particle bound substances were analysed separately. The concentrations in runoff are generally considerably higher than in precipitation. Concentrations of lead, fluoranthene and benzo(a)pyrene, in particular are higher in runoffs at sites with high traffic densities than at sites with low traffic densities. Preceding dry period normally has no effect on the measured concentrations. The typical chemograph of a dissolved substance shows a maximum at the beginning of the event dropping quickly to a minimum, which often coincides with the maximum in runoff rate. A slight rise is observed with decreasing runoff rates at the end of the event. Applying a mathematical model, chemographs may be described by three terms: - Relatively large amounts of easily soluble material at the beginning of the event decrease with increasing runoff. Conservative behaviour is assumed. - A part which varies inversely to the runoff rate. This term assumes zero-order kinetics; the amount dissolved from surfaces is constant with time. - A small constant term. Concentrations of particle bound substances correlate with amounts of total suspended solids. Frequently a negative correlation between the specific concentration of substances and the concentration of total suspended solids is observed. (orig.) [de

  12. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred Paul Mark; Badu-Tawiah, Abraham K.; Li, Anyin; Soparawalla, Santosh; Roqan, Iman S.; Cooks, Robert Graham

    2013-01-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  13. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-07-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  14. Comprehensive Analysis Competence and Innovative Approaches for Sustainable Chemical Production.

    Science.gov (United States)

    Appel, Joerg; Colombo, Corrado; Dätwyler, Urs; Chen, Yun; Kerimoglu, Nimet

    2016-01-01

    Humanity currently sees itself facing enormous economic, ecological, and social challenges. Sustainable products and production in specialty chemistry are an important strategic element to address these megatrends. In addition to that, digitalization and global connectivity will create new opportunities for the industry. One aspect is examined in this paper, which shows the development of comprehensive analysis of production networks for a more sustainable production in which the need for innovative solutions arises. Examples from data analysis, advanced process control and automated performance monitoring are shown. These efforts have significant impact on improved yields, reduced energy and water consumption, and better product performance in the application of the products.

  15. Controlling organic chemical hazards in food manufacturing: a hazard analysis critical control points (HACCP) approach.

    Science.gov (United States)

    Ropkins, K; Beck, A J

    2002-08-01

    Hazard analysis by critical control points (HACCP) is a systematic approach to the identification, assessment and control of hazards. Effective HACCP requires the consideration of all hazards, i.e., chemical, microbiological and physical. However, to-date most 'in-place' HACCP procedures have tended to focus on the control of microbiological and physical food hazards. In general, the chemical component of HACCP procedures is either ignored or limited to applied chemicals, e.g., food additives and pesticides. In this paper we discuss the application of HACCP to a broader range of chemical hazards, using organic chemical contaminants as examples, and the problems that are likely to arise in the food manufacturing sector. Chemical HACCP procedures are likely to result in many of the advantages previously identified for microbiological HACCP procedures: more effective, efficient and economical than conventional end-point-testing methods. However, the high costs of analytical monitoring of chemical contaminants and a limited understanding of formulation and process optimisation as means of controlling chemical contamination of foods are likely to prevent chemical HACCP becoming as effective as microbiological HACCP.

  16. The application of atomic absorption spectrometry to chemical analysis

    International Nuclear Information System (INIS)

    Walsh, A.

    1980-01-01

    YhThe history of the development of atomic absorption methods of elemental analysis is outlined. The theoretical basis of atomic absorption methods is discussed and the principle of modern methods of atomic absorption measurements is described. The advantages, scope and limations of these methods are discussed. Related methods based on the measurement of atomic fluorescence are also described

  17. Chemical Analysis of Asymptotic Giant Branch Stars in M62

    NARCIS (Netherlands)

    Lapenna, E.; Mucciarelli, A.; Ferraro, F. R.; Origlia, L.; Lanzoni, B.; Massari, D.; Dalessandro, E.

    2015-01-01

    We have collected UVES-FLAMES high-resolution spectra for a sample of 6 asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in the Galactic globular cluster (GC) M62 (NGC 6266). Here we present the detailed abundance analysis of iron, titanium, and light elements (O, Na, Mg, and Al).

  18. The Impact of Flow Injection on Modern Chemical Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    and preconcentration procedures. In recent years, FIA has been supplemented by Sequential Injection Analysis (SIA) and the Lab-on-Valve (LOV) approach. Following a brief historic introduction and an account of the impact of FIA in academia, the lecture will describe these two new generations of FIA, accompanied...

  19. Surface variations affecting human dental enamel studied using nanomechanical and chemical analysis

    Science.gov (United States)

    Dickinson, Michelle Emma

    The enamel surface is the interface between the tooth and its ever changing oral environment. Cavity (caries) formation and extrinsic tooth staining are due, respectively, to degradation of the enamel structure under low pH conditions and interactions between salivary pellicle and dietary elements. Both of these occur at the enamel surface and are caused by the local environment changing the chemistry of the surface. The results can be detrimental to the enamel's mechanical integrity and aesthetics. Incipient carious lesions are the precursor to caries and form due to demineralisation of enamel. These carious lesions are a reversible structure where ions (e.g. Ca2+, F -) can diffuse in (remineralisation) to preserve the tooth's structural integrity. This investigation used controlled in vitro demineralisation and remineralisation to study artificial carious lesion formation and repair. The carious lesions were cross-sectioned and characterised using nanoindentation, electron probe micro-analysis and time of flight secondary ion mass spectrometry. Mechanical and chemical maps showed the carious lesion had a significantly reduced hardness and elastic modulus, and the calcium and phosphate content was lower than in sound enamel. Fluoride based remineralisation treatments gave a new phase (possibly fluorohydroxyapatite) within the lesion with mechanical properties higher than sound enamel. The acquired salivary pellicle is a protein-rich film formed by the physisorption of organic molecules in saliva onto the enamel surface. Its functions include lubrication during mastication and chemical protection. However, pellicle proteins react with dietary elements such as polyphenols (tannins in tea) causing a brown stain. This study has used in vitro dynamic nanoindentation and atomic force microscopy to examine normal and stained pellicles formed in vivo. The effects of polyphenols on the pellicle's mechanical properties and morphology have been studied. It was found that the

  20. MAGMADIM: Young Explainers Program

    International Nuclear Information System (INIS)

    Paltiel, Z.

    2005-01-01

    Full Text:Physics teachers and educators constantly face the problem of inspiring their students to major in physics. On the other hand, science museums are designed to provide a pleasant environment which will stimulate and encourage a science associated experience to the general public. Typically, there is no intention to teach science as such in science museums. One may, however, use the science museum to teach and inspire certain groups of students in a much deeper sense. In fact they may actually enthusiastically learn much of the school physics curriculum at the museum. This report discusses the Magmadim program through which 10th graders are trained to be young explainers at the Weizmann Institutes Clore Garden of Science. To this end they study the physics underlying its exhibits in an after-school course. The ultimate goal is for the 'magmadim' to become the best possible explainers and be able to face all sorts of museum visitors. Along with learning how to instruct visitors, they must learn the physics behind the exhibits to give a full explanation of the exhibit and be able to answer any question that may arise. Our 5 year experience with the program shows that its self-selected participants not only study a lot of science, but also like it and learn how to explain the content to other people. This program, along with similar programs at the Bloomfield Science Museum and the Madatzim (young physics tutors) program of Ort, help in promoting the interest in science in general and physics in particular among school students. Various ways to expand the programs will also be discussed

  1. Linear Algebra Thoroughly Explained

    CERN Document Server

    Vujičić, Milan

    2008-01-01

    Linear Algebra Thoroughly Explained provides a comprehensive introduction to the subject suitable for adoption as a self-contained text for courses at undergraduate and postgraduate level. The clear and comprehensive presentation of the basic theory is illustrated throughout with an abundance of worked examples. The book is written for teachers and students of linear algebra at all levels and across mathematics and the applied sciences, particularly physics and engineering. It will also be an invaluable addition to research libraries as a comprehensive resource book for the subject.

  2. Continuous-flow centrifugation to collect suspended sediment for chemical analysis

    Science.gov (United States)

    Conn, Kathleen E.; Dinicola, Richard S.; Black, Robert W.; Cox, Stephen E.; Sheibley, Richard W.; Foreman, James R.; Senter, Craig A.; Peterson, Norman T.

    2016-12-22

    Recent advances in suspended-sediment monitoring tools and surrogate technologies have greatly improved the ability to quantify suspended-sediment concentrations and to estimate daily, seasonal, and annual suspended-sediment fluxes from rivers to coastal waters. However, little is known about the chemical composition of suspended sediment, and how it may vary spatially between water bodies and temporally within a single system owing to climate, seasonality, land use, and other natural and anthropogenic drivers. Many water-quality contaminants, such as organic and inorganic chemicals, nutrients, and pathogens, preferentially partition in sediment rather than water. Suspended sediment-bound chemical concentrations may be undetected during analysis of unfiltered water samples, owing to small water sample volumes and analytical limitations. Quantification of suspended sediment‑bound chemical concentrations is needed to improve estimates of total chemical concentrations, chemical fluxes, and exposure levels of aquatic organisms and humans in receiving environments. Despite these needs, few studies or monitoring programs measure the chemical composition of suspended sediment, largely owing to the difficulty in consistently obtaining samples of sufficient quality and quantity for laboratory analysis.A field protocol is described here utilizing continuous‑flow centrifugation for the collection of suspended sediment for chemical analysis. The centrifuge used for development of this method is small, lightweight, and portable for the field applications described in this protocol. Project scoping considerations, deployment of equipment and system layout options, and results from various field and laboratory quality control experiments are described. The testing confirmed the applicability of the protocol for the determination of many inorganic and organic chemicals sorbed on suspended sediment, including metals, pesticides, polycyclic aromatic hydrocarbons, and

  3. Archaeological and chemical analysis of Tell el Yahudiyeh ware

    International Nuclear Information System (INIS)

    Kaplan, M.F.; Harbottle, G.; Sayre, E.V.

    1978-01-01

    Typological and geographic analyses indicate that Tell el Yahudiyeh ware (found in Cyprus, Egypt, Nubia, and the Levant during the Middle Bronze period, c. 1750-1550 B.C.) were probably manufactured in two areas, the Nile Valley and the Levant. Activation analysis was carried out and correlated with the archaeological analyses. Results confirm the two ''families'' of the ware, one Egyptian and one Levantine. Speculations are offered on the social interaction of the period. 11 figures, 2 tables

  4. Assessing the Relevance of Anomie Theory for Explaining Spatial Variation in Lethal Criminal Violence: An Aggregate-Level Analysis of Homicide within the United States

    Directory of Open Access Journals (Sweden)

    Eric P. Baumer

    2008-11-01

    Full Text Available One of the most influential statements in the anomie theory tradition has been Merton’s argument that the volume of instrumental property crime should be higher where there is a greater imbalance between the degree of commitment to monetary success goals and the degree of commitment to legitimate means of pursuing such goals. Contemporary anomie theories stimulated by Merton’s perspective, most notably Messner and Rosenfeld’s institutional anomie theory, have expanded the scope conditions by emphasizing lethal criminal violence as an outcome to which anomie theory is highly relevant, and virtually all contemporary empirical studies have focused on applying the perspective to explaining spatial variation in homicide rates. In the present paper, we argue that current explications of Merton’s theory and IAT have not adequately conveyed the relevance of the core features of the anomie perspective to lethal violence. We propose an expanded anomie model in which an unbalanced pecuniary value system – the core causal variable in Merton’s theory and IAT – translates into higher levels of homicide primarily in indirect ways by increasing levels of firearm prevalence, drug market activity, and property crime, and by enhancing the degree to which these factors stimulate lethal outcomes. Using aggregate-level data collected during the mid-to-late 1970s for a sample of relatively large social aggregates within the U.S., we find a significant effect on homicide rates of an interaction term reflecting high levels of commitment to monetary success goals and low levels of commitment to legitimate means. Virtually all of this effect is accounted for by higher levels of property crime and drug market activity that occur in areas with an unbalanced pecuniary value system. Our analysis also reveals that property crime is more apt to lead to homicide under conditions of high levels of structural disadvantage. These and other findings underscore the

  5. Variability of chemical analysis of reinforcing bar produced in Saudi Arabia

    Science.gov (United States)

    Salman, A.; Djavanroodi, F.

    2018-04-01

    In view of the importance and demanding roles of steel rebar’s in the reinforced concrete structures, accurate information on the properties of the steels is important at the design stage. In the steelmaking process, production variations in chemical composition are unavoidable. The aim of this work is to study the variability of the chemical composition of reinforcing steel produced throughout the Saudi Arabia and asses the quality of steel rebar’s acoording to ASTM A615. 68 samples of ASTM A615 Grade 60 from different manufacturers were collected and tested using the Spectrometer test to obtain Chemical Compositions. EasyFit (5.6) software is utilized to conducted statistical analysis. Chemical compositions distributions and, control charts are generated for the compositions. Results showed that some compositions are above the upper line of the control chart. Finally, the analyses show that less than 3% of the steel failed to meet minimum ASTM standards for chemical composition.

  6. Conformational, structural, vibrational and quantum chemical analysis on 4-aminobenzohydrazide and 4-hydroxybenzohydrazide--a comparative study.

    Science.gov (United States)

    Arjunan, V; Jayaprakash, A; Carthigayan, K; Periandy, S; Mohan, S

    2013-05-01

    Experimental and theoretical quantum chemical studies were carried out on 4-hydroxybenzohydrazide (4HBH) and 4-aminobenzohydrazide (4ABH) using FTIR and FT-Raman spectral data. The structural characteristics and vibrational spectroscopic analysis were carried performed by quantum chemical methods with the hybrid exchange-correlation functional B3LYP using 6-31G(**), 6-311++G(**) and aug-cc-pVDZ basis sets. The most stable conformer of the title compounds have been determined from the analysis of potential energy surface. The stable molecular geometries, electronic and thermodynamic parameters, IR intensities, harmonic vibrational frequencies, depolarisation ratio and Raman intensities have been computed. Molecular electrostatic potential and frontier molecular orbitals were constructed to understand the electronic properties. The potential energy distributions (PEDs) were calculated to explain the mixing of fundamental modes. The theoretical geometrical parameters and the fundamental frequencies were compared with the experimental. The interactions of hydroxy and amino group substitutions on the characteristic vibrations of the ring and hydrazide group have been analysed. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Physical, chemical and microbial analysis of bottled drinking water.

    Science.gov (United States)

    Sasikaran, S; Sritharan, K; Balakumar, S; Arasaratnam, V

    2012-09-01

    People rely on the quality of the bottled drinking water, expecting it to be free of microbial contamination and health hazards. To evaluate the quality of bottled drinking water sold in Jaffna peninsula by analysing the physical, chemical and microbial contents and comparing with the recommended Sri Lankan Standard (SLS) values. All bottled water samples sold in Jaffna peninsula were collected. Electrical conductivity, total dissolved solid, pH, calcium, nitrate, total aerobic and anaerobic count, coliform bacterial count and faecal contamination were checked. These are 22 brands of bottled drinking water sold in Jaffna peninsula. The sample had very low electrical conductivity when compared with SLS (750 μS/ cm) and varied from 19 to 253 μS/cm with the mean of 80.53 (±60.92) μS/cm. The pH values of the bottled drinking water brands varied from 4.11 to 7.58 with a mean of 6.2 (±0.75). The total dissolved solid content of the bottled drinking water brands varied from 9 to 123.67 mg/l with a mean of 39.5 (±30.23) mg/l. The calcium content of the bottled drinking water brands varied from 6.48 to 83.77 mg/l with a mean of 49.9 (±25.09) mg/l. The nitrate content of the bottled drinking water brands varied from 0.21 to 4.19 mg/l with the mean of 1.26 (±1.08) mg/l. Aerobic bacterial count varied from 0 to 800 colony forming unit per ml (cfu/ml) with a mean of 262.6 (±327.50) cfu/ml. Among the 22 drinking bottled water brands 14 and 9% of bottled drinking water brands showed fungal and coliform bacterial contaminants respectively. The water brands which contained faecal contamination had either Escherichia coli or Klebsiella spp. The bottled drinking water available for sale do not meet the standards stipulated by SLS.

  8. Inorganic chemical analysis of environmental materials—A lecture series

    Science.gov (United States)

    Crock, J.G.; Lamothe, P.J.

    2011-01-01

    At the request of the faculty of the Colorado School of Mines, Golden, Colorado, the authors prepared and presented a lecture series to the students of a graduate level advanced instrumental analysis class. The slides and text presented in this report are a compilation and condensation of this series of lectures. The purpose of this report is to present the slides and notes and to emphasize the thought processes that should be used by a scientist submitting samples for analyses in order to procure analytical data to answer a research question. First and foremost, the analytical data generated can be no better than the samples submitted. The questions to be answered must first be well defined and the appropriate samples collected from the population that will answer the question. The proper methods of analysis, including proper sample preparation and digestion techniques, must then be applied. Care must be taken to achieve the required limits of detection of the critical analytes to yield detectable analyte concentration (above "action" levels) for the majority of the study's samples and to address what portion of those analytes answer the research question-total or partial concentrations. To guarantee a robust analytical result that answers the research question(s), a well-defined quality assurance and quality control (QA/QC) plan must be employed. This QA/QC plan must include the collection and analysis of field and laboratory blanks, sample duplicates, and matrix-matched standard reference materials (SRMs). The proper SRMs may include in-house materials and/or a selection of widely available commercial materials. A discussion of the preparation and applicability of in-house reference materials is also presented. Only when all these analytical issues are sufficiently addressed can the research questions be answered with known certainty.

  9. Sample handling and chemical procedures for efficacious trace analysis of urine by neutron activation analysis

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Rack, E.P.; Roman, F.R.

    1988-01-01

    Important for the determination of trace elements, ions, or compounds in urine by chemical neutron activation analysis is the optimization of sample handling, preirradiation chemistry, and radioassay procedures necessary for viable analysis. Each element, because of its natural abundance in the earth's crust and, hence, its potential for reagent and environmental contamination, requires specific procedures for storage, handling, and preirradiation chemistry. Radioassay techniques for radionuclides vary depending on their half-lives and decay characteristics. Described in this paper are optimized procedures for aluminum and selenium. While 28 Al (T 1/2 = 2.24 min) and 77m Se(T 1/2 = 17.4s) have short half-lives, their gamma-ray spectra are quite different. Aluminum-28 decays by a 1779-keV gamma and 77m Se by a 162-keV gamma. Unlike selenium, aluminum is a ubiquitous element in the environment requiring special handling to minimize contamination in all phases of its analytical determination

  10. Analysis of chemical signatures of alkaliphiles using fatty acid methyl ester analysis

    Directory of Open Access Journals (Sweden)

    Basha Sreenivasulu

    2017-01-01

    Full Text Available Background: Fatty acids occur in nearly all living organisms as the important predominant constituents of lipids. While all fatty acids have essentially the same chemical nature, they are an extremely diverse group of compounds. Materials and Methods: To test the hypothesis, fatty acids of alkaliphiles isolates, Bacillus subtilis SVUNM4, Bacillus licheniformis SVUNM8, Bacillus methylotrohicus SVUNM9, and Paenibacillus dendritiformis SVUNM11, were characterized compared using gas chromatography-mass spectrometry (GC-MS analysis. Results: The content of investigated ten fatty acids, 1, 2-benzenedicarboxylic acid butyl 2-methylpropyl ester, phthalic acid, isobutyl 2-pentyl ester, dibutyl phthalate, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane, octamethyl, dodecamethyl, heptasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13-etradecamethyl, 7,15-dihydroxydehydroabietic acid, methyl ester, di (trimethylsilyl ether, hentriacontane, 2-thiopheneacetic acid, undec-2-enyl ester, obviously varied among four species, suggesting each species has its own fatty acid pattern. Conclusions: These findings demonstrated that GC-MS-based fatty acid profiling analysis provides the reliable platform to classify these four species, which is helpful for ensuring their biotechnological interest and novel chemotaxonomic.

  11. Basic chemically recuperated gas turbines--power plant optimization and thermodynamics second law analysis

    International Nuclear Information System (INIS)

    Alves, Lourenco Gobira; Nebra, Silvia Azucena

    2004-01-01

    One of the proposals to increase the performance of the gas turbines is to improve chemical recuperated cycle. In this cycle, the heat in the turbine exhaust gases is used to heat and modify the chemical characteristics of the fuel. One mixture of natural gas and steam receives heat from the exhaust turbine gases; the mixture components react among themselves producing hot synthesis gas. In this work, an analysis and nonlinear optimization of the cycle were made in order to investigate the temperature and pressure influence on the global cycle performance. The chemical composition in the reformer was assumed according to chemical equilibrium equations, which presents good agreement with data from literature. The mixture of hot gases was treated like ideal gases. The maximum net profit was achieved and a thermodynamic second law analysis was made in order to detect the greatest sources of irreversibility

  12. Explaining category-related effects in the retrieval of conceptual and lexical knowledge for concrete entities: operationalization and analysis of factors.

    Science.gov (United States)

    Tranel, D; Logan, C G; Frank, R J; Damasio, A R

    1997-10-01

    ): high homomorphy, low characteristic motion and manipulability; Component 3 (items with characteristic sound): hearing mode of transaction, highly distinctive sounds. In another analysis, we found that the categories of animals versus tools/utensils differed significantly on the factors of homomorphy, familiarity, value, manipulability, characteristic motion, and touch. The factor structure we identified in this study may help explain category-related performance defects in brain-damaged subjects. The results lend support to our proposal that systematic differences in physical characteristics and contextual specification of concrete entities constitute a driving force behind the regionalization of neural systems related to the acquisition and retrieval of conceptual and lexical knowledge.

  13. The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards.

    Science.gov (United States)

    Anna, Sobek; Sofia, Bejgarn; Christina, Rudén; Magnus, Breitholtz

    2016-08-10

    A major challenge for society is to manage the risks posed by the many chemicals continuously emitted to the environment. All chemicals in production and use cannot be monitored and science-based strategies for prioritization are essential. In this study we review available data to investigate which substances are included in environmental monitoring programs and published research studies reporting analyses of chemicals in Baltic Sea fish between 2000 and 2012. Our aim is to contribute to the discussion of priority settings in environmental chemical monitoring and research, which is closely linked to chemical management. In total, 105 different substances or substance groups were analyzed in Baltic Sea fish. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were the most studied substances or substance groups. The majority, 87%, of all analyses comprised 20% of the substances or substance groups, whereas 46 substance groups (44%) were analyzed only once. Almost three quarters of all analyses regarded a POP-substance (persistent organic pollutant). These results demonstrate that the majority of analyses on environmental contaminants in Baltic Sea fish concern a small number of already regulated chemicals. Legacy pollutants such as POPs pose a high risk to the Baltic Sea due to their hazardous properties. Yet, there may be a risk that prioritizations for chemical analyses are biased based on the knowns of the past. Such biases may lead to society failing in identifying risks posed by yet unknown hazardous chemicals. Alternative and complementary ways to identify priority chemicals are needed. More transparent communication between risk assessments performed as part of the risk assessment process within REACH and monitoring programs, and information on chemicals contained in consumer articles, would offer ways to identify chemicals for environmental analysis.

  14. Analysis of abused drugs by selected ion monitoring: quantitative comparison of electron impact and chemical ionization

    International Nuclear Information System (INIS)

    Foltz, R.L.; Knowlton, D.A.; Lin, D.C.K.; Fentiman, A.F. Jr.

    1975-01-01

    A comparison was made of the relative sensitivities of electron impact and chemical ionization when used for selected ion monitoring analysis of commonly abused drugs. For most of the drugs examined chemical ionization using ammonia as the reactant gas gave the largest single m/e ion current response per unit weight of sample. However, if maximum sensitivity is desired it is important to evaluate electron impact and chemical ionization with respect to both maximum response and degree of interference from background and endogenous materials

  15. The challenge of predicting problematic chemicals using a decision analysis tool: Triclosan as a case study.

    Science.gov (United States)

    Perez, Angela L; Gauthier, Alison M; Ferracini, Tyler; Cowan, Dallas M; Kingsbury, Tony; Panko, Julie

    2017-01-01

    Manufacturers lack a reliable means for determining whether a chemical will be targeted for deselection from their supply chain. In this analysis, 3 methods for determining whether a specific chemical (triclosan) would meet the criteria necessary for being targeted for deselection are presented. The methods included a list-based approach, use of a commercially available chemical assessment software tool run in 2 modes, and a public interest evaluation. Our results indicated that triclosan was included on only 6 of the lists reviewed, none of which were particularly influential in chemical selection decisions. The results from the chemical assessment tool evaluations indicated that human and ecological toxicity for triclosan is low and received scores indicating that the chemical would be considered of low concern. However, triclosan's peak public interest tracked several years in advance of increased regulatory scrutiny of this chemical suggesting that public pressure may have been influential in deselection decisions. Key data gaps and toxicity endpoints not yet regulated such as endocrine disruption potential or phototoxicity, but that are important to estimate the trajectory for deselection of a chemical, are discussed. Integr Environ Assess Manag 2017;13:198-207. © 2016 SETAC. © 2016 SETAC.

  16. Techniques for SMM/THz Chemical Analysis: Investigations and Exploitation of the Large Molecule Limit

    Science.gov (United States)

    2014-03-03

    SECURITY CLASSIFICATION OF: It has long been recognized that the SMM /THz has a unique combinations of attributes that make it attractive as a basis for...applicability of SMM chemical sensors; the second is to explore infrared – SMM double resonance as a basis for atmospheric remote sensing; and the third...2014 12-Aug-2009 11-Aug-2013 Approved for Public Release; Distribution Unlimited Techniques for SMM /THz Chemical Analysis: Investigations and

  17. Instrumental neutron activation analysis, a valuable link in chemical metrology

    International Nuclear Information System (INIS)

    Zeisler, R.; Lindstrom, R.M.; Greenberg, R.R.

    2002-01-01

    Instrumental neutron activation analysis (INAA) is sufficiently versatile to establish a direct link to the amount of substance determined. The inherent quality parameters of INAA, such as being virtually free of blank, having fully accountable effects of matrix and physical form, and operating over a huge range of amounts, allows the comparison of a mole (or its fraction) of a pure element with the amount of substance in the sample analyzed with the same direct relationship as a beam balance provides. Indeed, varieties of this approach are in common use in INAA in the comparator methods of quantitation. To eliminate possible perturbations of the traceability chain as they may occur in common INAA practice, experimental measurements have been set up that only involve the fraction of a mole of the element(s) of interest in form of the pure element, compound or certified standard and the unknown sample. This principle has been used in INAA measurements for certification value assignment of high temperature alloy SRMs. To further demonstrate the performance parameters of INAA, we selected the determination of chromium in SRM 1152a Stainless Steel by direct non-destructive comparison with the pure metal in form of crystalline chromium. The measurements were validated with weighed aliquots of SRM 3112a dried on filter paper pellets. The experimental results do not show deviations beyond the uncertainties of the SRMs (≤ 0.2 % relative), and the assessment of the uncertainty budget indicates that expanded uncertainties of ≤ 0.3 % are achievable. The measurements demonstrate that INAA can meet the CCQM definition of a primary ratio method of analysis

  18. Matlab for engineers explained

    CERN Document Server

    Gustafsson, Fredrik

    2003-01-01

    This book is written for students at bachelor and master programs and has four different purposes, which split the book into four parts: 1. To teach first or early year undergraduate engineering students basic knowledge in technical computations and programming using MATLAB. The first part starts from first principles and is therefore well suited both for readers with prior exposure to MATLAB but lacking a solid foundational knowledge of the capabilities of the system and readers not having any previous experience with MATLAB. The foundational knowledge gained from these interactive guided tours of the system will hopefully be sufficient for an effective utilization of MATLAB in the engineering profession, in education and in research. 2. To explain the foundations of more advanced use of MATLAB using the facilities added the last couple of years, such as extended data structures, object orientation and advanced graphics. 3. To give an introduction to the use of MATLAB in typical undergraduate courses in elec...

  19. Statistic analysis of grouping in evaluation of the behavior of stable chemical elements and physical-chemical parameters in effluent from uranium mining

    International Nuclear Information System (INIS)

    Pereira, Wagner de S.

    2013-01-01

    The Ore Treatment Unit (UTM) is a uranium mine off. The statistical analysis of clustering was used to evaluate the behavior of stable chemical elements and physico-chemical variables in their effluents. The use of cluster analysis proved effective in the evaluation, allowing to identify groups of chemical elements in physico-chemical variables and group analyzes (element and variables ). As a result, we can say, based on the analysis of the data, a strong link between Ca and Mg and between Al and TR 2 O 3 (rare earth oxides) in the UTM effluents. The SO 4 was also identified as strongly linked to total solids and dissolved and these linked to electrical conductivity. Other associations existed, but were not as strongly linked. Additional collections for seasonal evaluation are required so that assessments can be confirmed. Additional statistics analysis (ordination techniques) should be used to help identify the origins of the groups identified in this analysis. (author)

  20. Environmental Chemical Analysis (by B. B. Kebbekus and S. Mitra)

    Science.gov (United States)

    Bower, Reviewed By Nathan W.

    1999-11-01

    This text helps to fill a void in the market, as there are relatively few undergraduate instrumental analysis texts designed specifically for the expanding population of environmental science students. R. N. Reeve's introductory, open-learning Environmental Analysis (Wiley, 1994) is one of the few, and it is aimed at a lower level and is less appropriate for traditional classroom study. Kebbekus and Mitra's book appears to be an update of I. Marr and M. Cresser's excellent 1983 text by the same name (and also published under the Chapman and Hall imprint). It assumes no background in instrumental methods of analysis but it does depend upon a good general chemistry background in kinetic and equilibrium calculations and the standard laboratory techniques found in a classical introduction to analytical chemistry. The slant taken by the authors is aimed more toward engineers, not only in the choice of topics, but also in how they are presented. For example, the statistical significance tests presented follow an engineering format rather than the standard used in analytical chemistry. This approach does not detract from the book's clarity. The writing style is concise and the book is generally well written. The earlier text, which has become somewhat of a classic, took the unusual step of teaching the instruments in the context of their environmental application. It was divided into sections on the "atmosphere", the "hydrosphere", the "lithosphere", and the "biosphere". This text takes a similar approach in the second half, with chapters on methods for air, water, and solid samples. Users who intend to use the book as a text instead of a reference will appreciate the addition of chapters in the first half of the book on spectroscopic, chromatographic, and mass spectrometric methods. The six chapters in these two parts of the book along with four chapters scattered throughout on environmental measurements, sampling, sample preparation, and quality assurance make a nice

  1. Chemical analysis of bioactive substances in seven siberian Saussurea species

    Science.gov (United States)

    Avdeeva, Elena; Reshetov, Yaroslav; Shurupova, Margarita; Zibareva, Larisa; Borisova, Evgeniia; Belousov, Mikhail

    2017-11-01

    Main groups of biologically active substances of seven siberian Saussurea species (S. controversa DC., S. latifolia Ledeb., S. parviflora (Poir.) DC., S. frolowii Ledeb, S. amara (L.) DC., S. salicifolia (L.) DC. and S. daurica Adams) have been studied using paper, thin-layer, performance liquid chromatography, IR spectroscopy, spectrophotometry and mass spectrometry with inductively coupled plasma. Siberian Saussurea species have a rich elemental composition and contain a variety of phenolic compounds, amino acids, polysaccharides. The majority of polysaccharides are accumulated by S. controversa, S. salicifolia and S. frolowii. These plants contain a significant amount of calcium that may be a species characteristic. All plants contain quercetin and its glycosides, in some species luteolin, kaempferol, glycosides of apigenin and myricetin were revealed. Phenolic acids with predominant content of caffeic, chlorogenic and cinnamic acids were found in all the species. The maximum amount of phenolic acids and flavonoids was determined in the grass of S. latifolia, S. controversa and S. daurica. Characteristic absorption bands of lactone carbonyl of sesquiterpenoids in IR spectrum found in S. latifolia, S. controversa, S. daurica, S. amara and S. salicifolia. HPLC / UV analysis showed that peaks with absorption maxima of 242-246 nm due to the presence of α,β-unsaturated ketone group in the structure of ecdysteroids were found in S. salicifolia, S. controversa, S. daurica and S. latifolia.

  2. Hydrogen fluoride (HF) substance flow analysis for safe and sustainable chemical industry.

    Science.gov (United States)

    Kim, Junbeum; Hwang, Yongwoo; Yoo, Mijin; Chen, Sha; Lee, Ik-Mo

    2017-11-01

    In this study, the chemical substance flow of hydrogen fluoride (hydrofluoric acid, HF) in domestic chemical industries in 2014 was analyzed in order to provide a basic material and information for the establishment of organized management system to ensure safety during HF applications. A total of 44,751 tons of HF was made by four domestic companies (in 2014); import amount was 95,984 tons in 2014 while 21,579 tons of HF was imported in 2005. The export amount of HF was 2180 tons, of which 2074 ton (China, 1422 tons, U.S. 524 tons, and Malaysia, 128 tons) was exported for the manufacturing of semiconductors. Based on the export and import amounts, it can be inferred that HF was used for manufacturing semiconductors. The industries applications of 161,123 tons of HF were as follows: manufacturing of basic inorganic chemical substance (27,937 tons), manufacturing of other chemical products such as detergents (28,208 tons), manufacturing of flat display (24,896 tons), and manufacturing of glass container package (22,002 tons). In this study, an analysis of the chemical substance flow showed that HF was mainly used in the semiconductor industry as well as glass container manufacturing. Combined with other risk management tools and approaches in the chemical industry, the chemical substance flow analysis (CSFA) can be a useful tool and method for assessment and management. The current CSFA results provide useful information for policy making in the chemical industry and national systems. Graphical abstract Hydrogen fluoride chemical substance flows in 2014 in South Korea.

  3. Chemical Analysis of Counterfeit Hepatitis C Drug Found in Japan.

    Science.gov (United States)

    Uchiyama, Nahoko; Kamakura, Hiroyuki; Masada, Sayaka; Tsujimoto, Takashi; Hosoe, Junko; Tokumoto, Hiroko; Maruyama, Takuro; Goda, Yukihiro; Hakamatsuka, Takashi

    2017-10-01

    In January 2017, counterfeits of the hepatitis C drug 'HARVONI ® Combination Tablets' (HARVONI ® ) were found at a pharmacy chain through unlicensed suppliers in Japan. A total of five lots of counterfeit HARVONI ® (samples 1-5) bottles were found, and the ingredients of the bottles were all in tablet form. Among them, two differently shaped tablets were present in two of the bottles (categorized as samples 2A, 2B, 4A, and 4B). We analyzed the total of seven samples by high-resolution LC-MS, GC-MS and NMR. In samples 2A, 3 and 4B, sofosbuvir, the active component of another hepatitis C drug, SOVALDI ® Tablets 400 mg (SOVALDI ® ), was detected. In sample 4A, sofosbuvir and ledipasvir, the active components of HARVONI ® , were found. A direct comparison of the four samples and genuine products showed that three samples (2A, 3, 4B) are apparently SOVALDI ® and that sample 2A is HARVONI ® . In samples 1 and 5, several vitamins but none of the active compounds usually found in HARVONI ® (i.e., sofosbuvir and ledipasvir) were detected. Our additional investigation indicates that these two samples are likely to be a commercial vitamin supplement distributed in Japan. Sample 2B, looked entirely different from HARVONI ® and contained several herbal constitutents (such as ephedrine and glycyrrhizin) that are used in Japanese Kampo formulations. A further analysis indicated that sample 2B is likely to be a Kampo extract tablet of Shoseiryuto which is distributed in Japan. Considering this case, it is important to be vigilant to prevent a recurrence of distribution of counterfeit drugs.

  4. Development of a Mechanical Analysis System Considering Chemical Transitions of Barrier Materials

    International Nuclear Information System (INIS)

    Sahara, F.; Murakami, T.; Ito, H.; Kobayashi, I.; Yokozeki, K.

    2006-01-01

    An analysis system for the long-term mechanical behavior of barrier materials (MACBECE: Mechanical Analysis system considering Chemical transitions of Bentonite-based and Cement-based materials) was developed in order to improve the reliability of the evaluation of the hydraulic field that is one of the important environmental conditions in the safety assessment of the TRU waste disposal in Japan. The MACBECE is a system that calculates the deformation of barrier materials using their chemical property changes as inputs, and subsequently their hydraulic conductivity taking both their chemical property changes and deformation into consideration. This paper provides a general description of MACBECE and the results of experimental analysis carried out using MACBECE. (authors)

  5. Endocrine-disrupting Chemicals: Review of Toxicological Mechanisms Using Molecular Pathway Analysis

    Science.gov (United States)

    Yang, Oneyeol; Kim, Hye Lim; Weon, Jong-Il; Seo, Young Rok

    2015-01-01

    Endocrine disruptors are known to cause harmful effects to human through various exposure routes. These chemicals mainly appear to interfere with the endocrine or hormone systems. As importantly, numerous studies have demonstrated that the accumulation of endocrine disruptors can induce fatal disorders including obesity and cancer. Using diverse biological tools, the potential molecular mechanisms related with these diseases by exposure of endocrine disruptors. Recently, pathway analysis, a bioinformatics tool, is being widely used to predict the potential mechanism or biological network of certain chemicals. In this review, we initially summarize the major molecular mechanisms involved in the induction of the above mentioned diseases by endocrine disruptors. Additionally, we provide the potential markers and signaling mechanisms discovered via pathway analysis under exposure to representative endocrine disruptors, bisphenol, diethylhexylphthalate, and nonylphenol. The review emphasizes the importance of pathway analysis using bioinformatics to finding the specific mechanisms of toxic chemicals, including endocrine disruptors. PMID:25853100

  6. Surface characterization and chemical analysis of bamboo substrates pretreated by alkali hydrogen peroxide.

    Science.gov (United States)

    Song, Xueping; Jiang, Yan; Rong, Xianjian; Wei, Wei; Wang, Shuangfei; Nie, Shuangxi

    2016-09-01

    The surface characterization and chemical analysis of bamboo substrates by alkali hydrogen peroxide pretreatment (AHPP) were investigated in this study. The results tended to manifest that AHPP prior to enzymatic and chemical treatment was potential for improving accessibility and reactivity of bamboo substrates. The inorganic components, organic solvent extractives and acid-soluble lignin were effectively removed by AHPP. X-ray photoelectron spectroscopy (XPS) analysis indicated that the surface of bamboo chips had less lignin but more carbohydrate after pre-treatment. Fiber surfaces became etched and collapsed, and more pores and debris on the substrate surface were observed with Scanning Electron Microscopy (SEM). Brenauer-Emmett-Teller (BET) results showed that both of pore volume and surface area were increased after AHPP. Although XRD analysis showed that AHPP led to relatively higher crystallinity, pre-extraction could overall enhance the accessibility of enzymes and chemicals into the bamboo structure. Copyright © 2016. Published by Elsevier Ltd.

  7. Chemical-genetic profile analysis of five inhibitory compounds in yeast.

    Science.gov (United States)

    Alamgir, Md; Erukova, Veronika; Jessulat, Matthew; Azizi, Ali; Golshani, Ashkan

    2010-08-06

    Chemical-genetic profiling of inhibitory compounds can lead to identification of their modes of action. These profiles can help elucidate the complex interactions between small bioactive compounds and the cell machinery, and explain putative gene function(s). Colony size reduction was used to investigate the chemical-genetic profile of cycloheximide, 3-amino-1,2,4-triazole, paromomycin, streptomycin and neomycin in the yeast Saccharomyces cerevisiae. These compounds target the process of protein biosynthesis. More than 70,000 strains were analyzed from the array of gene deletion mutant yeast strains. As expected, the overall profiles of the tested compounds were similar, with deletions for genes involved in protein biosynthesis being the major category followed by metabolism. This implies that novel genes involved in protein biosynthesis could be identified from these profiles. Further investigations were carried out to assess the activity of three profiled genes in the process of protein biosynthesis using relative fitness of double mutants and other genetic assays. Chemical-genetic profiles provide insight into the molecular mechanism(s) of the examined compounds by elucidating their potential primary and secondary cellular target sites. Our follow-up investigations into the activity of three profiled genes in the process of protein biosynthesis provided further evidence concerning the usefulness of chemical-genetic analyses for annotating gene functions. We termed these genes TAE2, TAE3 and TAE4 for translation associated elements 2-4.

  8. Chemical-genetic profile analysis of five inhibitory compounds in yeast

    Directory of Open Access Journals (Sweden)

    Alamgir Md

    2010-08-01

    Full Text Available Abstract Background Chemical-genetic profiling of inhibitory compounds can lead to identification of their modes of action. These profiles can help elucidate the complex interactions between small bioactive compounds and the cell machinery, and explain putative gene function(s. Results Colony size reduction was used to investigate the chemical-genetic profile of cycloheximide, 3-amino-1,2,4-triazole, paromomycin, streptomycin and neomycin in the yeast Saccharomyces cerevisiae. These compounds target the process of protein biosynthesis. More than 70,000 strains were analyzed from the array of gene deletion mutant yeast strains. As expected, the overall profiles of the tested compounds were similar, with deletions for genes involved in protein biosynthesis being the major category followed by metabolism. This implies that novel genes involved in protein biosynthesis could be identified from these profiles. Further investigations were carried out to assess the activity of three profiled genes in the process of protein biosynthesis using relative fitness of double mutants and other genetic assays. Conclusion Chemical-genetic profiles provide insight into the molecular mechanism(s of the examined compounds by elucidating their potential primary and secondary cellular target sites. Our follow-up investigations into the activity of three profiled genes in the process of protein biosynthesis provided further evidence concerning the usefulness of chemical-genetic analyses for annotating gene functions. We termed these genes TAE2, TAE3 and TAE4 for translation associated elements 2-4.

  9. Size distribution measurements and chemical analysis of aerosol components

    Energy Technology Data Exchange (ETDEWEB)

    Pakkanen, T.A.

    1995-12-31

    The principal aims of this work were to improve the existing methods for size distribution measurements and to draw conclusions about atmospheric and in-stack aerosol chemistry and physics by utilizing size distributions of various aerosol components measured. A sample dissolution with dilute nitric acid in an ultrasonic bath and subsequent graphite furnace atomic absorption spectrometric analysis was found to result in low blank values and good recoveries for several elements in atmospheric fine particle size fractions below 2 {mu}m of equivalent aerodynamic particle diameter (EAD). Furthermore, it turned out that a substantial amount of analyses associated with insoluble material could be recovered since suspensions were formed. The size distribution measurements of in-stack combustion aerosols indicated two modal size distributions for most components measured. The existence of the fine particle mode suggests that a substantial fraction of such elements with two modal size distributions may vaporize and nucleate during the combustion process. In southern Norway, size distributions of atmospheric aerosol components usually exhibited one or two fine particle modes and one or two coarse particle modes. Atmospheric relative humidity values higher than 80% resulted in significant increase of the mass median diameters of the droplet mode. Important local and/or regional sources of As, Br, I, K, Mn, Pb, Sb, Si and Zn were found to exist in southern Norway. The existence of these sources was reflected in the corresponding size distributions determined, and was utilized in the development of a source identification method based on size distribution data. On the Finnish south coast, atmospheric coarse particle nitrate was found to be formed mostly through an atmospheric reaction of nitric acid with existing coarse particle sea salt but reactions and/or adsorption of nitric acid with soil derived particles also occurred. Chloride was depleted when acidic species reacted

  10. Chemical sensors for breath gas analysis: the latest developments at the Breath Analysis Summit 2013.

    Science.gov (United States)

    Tisch, Ulrike; Haick, Hossam

    2014-06-01

    Profiling the body chemistry by means of volatile organic compounds (VOCs) in the breath opens exciting new avenues in medical diagnostics. Gas sensors could provide ideal platforms for realizing portable, hand-held breath testing devices in the near future. This review summarizes the latest developments and applications in the field of chemical sensors for diagnostic breath testing that were presented at the Breath Analysis Summit 2013 in Wallerfangen, Germany. Considerable progress has been made towards clinically applicable breath testing devices, especially by utilizing chemo-sensitive nanomaterials. Examples of several specialized breath testing applications are presented that are either based on stand-alone nanomaterial-based sensors being highly sensitive and specific to individual breath compounds over others, or on combinations of several highly specific sensors, or on experimental nanomaterial-based sensors arrays. Other interesting approaches include the adaption of a commercially available MOx-based sensor array to indirect breath testing applications, using a sample pre-concentration method, and the development of compact integrated GC-sensor systems. The recent trend towards device integration has led to the development of fully integrated prototypes of point-of-care devices. We describe and compare the performance of several prototypes that are based on different sensing technologies and evaluate their potential as low-cost and readily available next-generation medical devices.

  11. Explaining as Mediated Action: An Analysis of Pre-Service Teachers' Account of Forces of Inertia in Non-Inertial Frames of Reference

    Science.gov (United States)

    de Pereira, Alexsandro Pereira; Lima Junior, Paulo; Rodrigues, Renato Felix

    2016-01-01

    Explaining is one of the most important everyday practices in science education. In this article, we examine how scientific explanations could serve as cultural tools for members of a group of pre-service physics teachers. Specifically, we aim at their use of explanations about forces of inertia in non-inertial frames of reference. A basic…

  12. Chemical imaging and solid state analysis at compact surfaces using UV imaging

    DEFF Research Database (Denmark)

    Wu, Jian X.; Rehder, Sönke; van den Berg, Frans

    2014-01-01

    and excipients in a non-invasive way, as well as mapping the glibenclamide solid state form. An exploratory data analysis supported the critical evaluation of the mapping results and the selection of model parameters for the chemical mapping. The present study demonstrated that the multi-wavelength UV imaging......Fast non-destructive multi-wavelength UV imaging together with multivariate image analysis was utilized to visualize distribution of chemical components and their solid state form at compact surfaces. Amorphous and crystalline solid forms of the antidiabetic compound glibenclamide...

  13. Chemical Analysis of Plants that Poison Livestock: Successes, Challenges, and Opportunities.

    Science.gov (United States)

    Welch, Kevin D; Lee, Stephen T; Cook, Daniel; Gardner, Dale R; Pfister, James A

    2018-04-04

    Poisonous plants have a devastating impact on the livestock industry as well as human health. To fully understand the effects of poisonous plants, multiple scientific disciplines are required. Chemical analysis of plant secondary compounds is key to identifying the responsible toxins, characterizing their metabolism, and understanding their effects on animals and humans. In this review, we highlight some of the successes in studying poisonous plants and mitigating their toxic effects. We also highlight some of the remaining challenges and opportunities with regards to the chemical analysis of poisonous plants.

  14. Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Matthew W. [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

  15. Participation in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Joe, Kih Soo; Choi, Kwang Soon; Han, Sun Ho; Suh, Moo Yul; Park, Kyung Kyun; Choi, Ke Chun; Kim, Won Ho

    2000-08-01

    KAERI analytical laboratory participated in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater organized by IAEA Hydrology Laboratory(RAS/8/084). 13 items such as pH, electroconductivity, HCO{sub 3}, Cl, SO{sub 4}, NO{sub 3}, SiO{sub 2}, B, Li, Na, K, Ca, Mg were analyzed. The result of this program showed that KAERI laboratory was ranked within 10% range from top level. An analytical expert in KAERI attended the 'Consultants' Meeting' at IAEA headquater and prepared the guideline for chemical analysis of groundwater.

  16. Participation in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater

    International Nuclear Information System (INIS)

    Joe, Kih Soo; Choi, Kwang Soon; Han, Sun Ho; Suh, Moo Yul; Park, Kyung Kyun; Choi, Ke Chun; Kim, Won Ho

    2000-08-01

    KAERI analytical laboratory participated in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater organized by IAEA Hydrology Laboratory(RAS/8/084). 13 items such as pH, electroconductivity, HCO 3 , Cl, SO 4 , NO 3 , SiO 2 , B, Li, Na, K, Ca, Mg were analyzed. The result of this program showed that KAERI laboratory was ranked within 10% range from top level. An analytical expert in KAERI attended the 'Consultants' Meeting' at IAEA headquater and prepared the guideline for chemical analysis of groundwater

  17. Development of a robotics system for automated chemical analysis of sediments, sludges, and soils

    International Nuclear Information System (INIS)

    McGrail, B.P.; Dodson, M.G.; Skorpik, J.R.; Strachan, D.M.; Barich, J.J.

    1989-01-01

    Adaptation and use of a high-reliability robot to conduct a standard laboratory procedure for soil chemical analysis are reported. Results from a blind comparative test were used to obtain a quantitative measure of the improvement in precision possible with the automated test method. Results from the automated chemical analysis procedure were compared with values obtained from an EPA-certified lab and with results from a more extensive interlaboratory round robin conducted by the EPA. For several elements, up to fivefold improvement in precision was obtained with the automated test method

  18. Biological and chemical removal of Cr(VI) from waste water: cost and benefit analysis.

    Science.gov (United States)

    Demir, Aynur; Arisoy, Münevver

    2007-08-17

    The objective of the present study is cost and benefit analysis of biological and chemical removal of hexavalent chromium [Cr(VI)] ions. Cost and benefit analysis were done with refer to two separate studies on removal of Cr(VI), one of heavy metals with a crucial role concerning increase in environmental pollution and disturbance of ecological balance, through biological adsorption and chemical ion-exchange. Methods of biological and chemical removal were compared with regard to their cost and percentage in chrome removal. According to the result of the comparison, cost per unit in chemical removal was calculated 0.24 euros and the ratio of chrome removal was 99.68%, whereas those of biological removal were 0.14 and 59.3% euros. Therefore, it was seen that cost per unit in chemical removal and chrome removal ratio were higher than those of biological removal method. In the current study where chrome removal is seen as immeasurable benefit in terms of human health and the environment, percentages of chrome removal were taken as measurable benefit and cost per unit of the chemicals as measurable cost.

  19. An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

    Science.gov (United States)

    Willis, Matthew P.; Stevenson, Shawn M.; Pearl, Thomas P.; Mantooth, Brent A.

    2014-01-01

    The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in understanding contaminant mass transport and the ability to decontaminate materials. If a material is contaminated, over time, the transport of highly toxic chemicals (such as chemical warfare agent species) out of the material can result in vapor exposure or transfer to the skin, which can result in percutaneous exposure to personnel who interact with the material. Due to the high toxicity of chemical warfare agents, the release of trace chemical quantities is of significant concern. Mapping subsurface concentration distribution and transport characteristics of absorbed agents enables exposure hazards to be assessed in untested conditions. Furthermore, these tools can be used to characterize subsurface reaction dynamics to ultimately design improved decontaminants or decontamination procedures. To achieve this goal, an inverse analysis mass transport modeling approach was developed that utilizes time-resolved mass spectroscopy measurements of vapor emission from contaminated paint coatings as the input parameter for calculation of subsurface concentration profiles. Details are provided on sample preparation, including contaminant and material handling, the application of mass spectrometry for the measurement of emitted contaminant vapor, and the implementation of inverse analysis using a physics-based diffusion model to determine transport properties of live chemical warfare agents including distilled mustard (HD) and the nerve agent VX. PMID:25226346

  20. Simultaneous on-line size and chemical analysis of gas phase and particulate phase of mainstream tobacco smoke

    International Nuclear Information System (INIS)

    McAughey, J; McGrath, C; Adam, T; Mocker, C; Zimmermann, R

    2009-01-01

    Tobacco smoke is a complex and dynamic physical and chemical matrix in which about 4800 components have been identified. It is known that deposition efficiencies of smoke particles in the lung in the lung (60-80%) are greater than expected for smoke particles of 150-- 250 nm count median diameter (CMD). Various mechanisms have been put forward to explain this enhanced deposition pattern, including coagulation, hygroscopic growth, condensation and evaporation, changes in composition, or changes in inhalation behaviour. This paper represents one of three studies seeking to better quantify smoke chemistry, inhalation behaviour and cumulative particle growth. This information will improve dosimetry estimates in quantitative risk assessment tools as part of a harm reduction process. In this study smoke particle size and chemistry were measured simultaneously in real-time using electrical mobility spectrometry and soft-ionisation, time-of-flight mass spectrometry respectively. Qualitative puff-by-puff resolved yields of three selected compounds (acetaldehyde, phenol, and styrene) are shown and compared with particle number and count median diameter from different smoking intensities and filter ventilation. Yields of chemical analysis, particle diameter and concentration are in good agreement with the intensity of the smoking regime and the dilution of smoke by filter ventilation.

  1. Material Cycles and Chemicals: Dynamic Material Flow Analysis of Contaminants in Paper Recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Laner, David; Astrup, Thomas Fruergaard

    2016-01-01

    material source-segregation and collection was the least effective strategy for reducing chemical contamination, if the overall recycling rates should be maintained at the current level (approximately 70% for Europe). The study provides a consistent approach for evaluating contaminant levels in material......This study provides a systematic approach for assessment of contaminants in materials for recycling. Paper recycling is used as an illustrative example. Three selected chemicals, bisphenol A (BPA), diethylhexyl phthalate (DEHP) and mineral oil hydrocarbons (MOHs), are evaluated within the paper...... cycle. The approach combines static material flow analysis (MFA) with dynamic material and substance flow modeling. The results indicate that phasing out of chemicals is the most effective measure for reducing chemical contamination. However, this scenario was also associated with a considerable lag...

  2. Multivariate Analysis of Multiple Datasets: a Practical Guide for Chemical Ecology.

    Science.gov (United States)

    Hervé, Maxime R; Nicolè, Florence; Lê Cao, Kim-Anh

    2018-03-01

    Chemical ecology has strong links with metabolomics, the large-scale study of all metabolites detectable in a biological sample. Consequently, chemical ecologists are often challenged by the statistical analyses of such large datasets. This holds especially true when the purpose is to integrate multiple datasets to obtain a holistic view and a better understanding of a biological system under study. The present article provides a comprehensive resource to analyze such complex datasets using multivariate methods. It starts from the necessary pre-treatment of data including data transformations and distance calculations, to the application of both gold standard and novel multivariate methods for the integration of different omics data. We illustrate the process of analysis along with detailed results interpretations for six issues representative of the different types of biological questions encountered by chemical ecologists. We provide the necessary knowledge and tools with reproducible R codes and chemical-ecological datasets to practice and teach multivariate methods.

  3. Prompt gamma-ray spectroscopy and its use for the elemental chemical analysis

    International Nuclear Information System (INIS)

    Deconninck, G.; Demortier, G.; Bodart, F.

    The elemental chemical analysis by nuclear techniques has been widely developed since a quarter of century. In this review the analysis by irradiation of the the sample (solid or liquid) of a majority of chemical elements by means of the charged particles and the detection during this irradiation of the gamma photons characteristic of the element are considered. After a brief account of the physical phenomena peculiar to the prompt detection of photons in comparison with the activation methods where a delayed activity is measured, a brief description of the experimental equipment for this kind of analysis is given. A comprehensive critical survey of the recent applications to the analysis of metals, semiconductors and electric insulating substances is presented. The necessary informations for the choice of the nuclear reaction to use for a specific analysis are contained in a set of tables. (AF)

  4. Forecasting global developments in the basic chemical industry for environmental policy analysis

    International Nuclear Information System (INIS)

    Broeren, M.L.M.; Saygin, D.; Patel, M.K.

    2014-01-01

    The chemical sector is the largest industrial energy user, but detailed analysis of its energy use developments lags behind other energy-intensive sectors. A cost-driven forecasting model for basic chemicals production is developed, accounting for regional production costs, demand growth and stock turnover. The model determines the global production capacity placement, implementation of energy-efficient Best Practice Technology (BPT) and global carbon dioxide (CO 2 ) emissions for the period 2010–2030. Subsequently, the effects of energy and climate policies on these parameters are quantified. About 60% of new basic chemical production capacity is projected to be placed in non-OECD regions by 2030 due to low energy prices. While global production increases by 80% between 2010 and 2030, the OECD's production capacity share decreases from 40% to 20% and global emissions increase by 50%. Energy pricing and climate policies are found to reduce 2030 CO 2 emissions by 5–15% relative to the baseline developments by increasing BPT implementation. Maximum BPT implementation results in a 25% reduction. Further emission reductions require measures beyond energy-efficient technologies. The model is useful to estimate general trends related to basic chemicals production, but improved data from the chemical sector is required to expand the analysis to additional technologies and chemicals. - Highlights: • We develop a global cost-driven forecasting model for the basic chemical sector. • We study regional production, energy-efficient technology, emissions and policies. • Between 2010 and 2030, 60% of new chemicals capacity is built in non-OECD regions. • Global CO 2 emissions rise by 50%, but climate policies may limit this to 30–40%. • Measures beyond energy efficiency are needed to prevent increasing CO 2 emissions

  5. [Relativity of commercial specification of Menthae Herba based on chemical analysis].

    Science.gov (United States)

    Ye, Dan; Zhao, Ming; Shao, Yang; Ouyang, Zhen; Peng, Hua-sheng; Han Bang-xing; Zhang, Wei-wan-qi; Gu, Xue-mei

    2015-01-01

    In order to compare the differences of 35 Menthae Herba samples collected on the market and at producing areas, the contents of six total terpenoids, the essential oil and chromatographic fingerprints were analyzed, which provided evidences for drawing up the commodity specifications and grading criteria of Menthae Herba. GC-MS method was used to analyze the chemical constituents of 35 different samples. The chromatographic fingerprints obtained by using GC were then evaluated by similarity analysis, hierarchical clustering analysis and principal component analysis. The relativity between the content of six terpenoids and the essential oil were studied. In this study, the chemical profiles of 35 samples from different producing areas had significant disparity. All samples collected in the report could be categorized into four chemical types, L-menthol, pulegone, carvone and L-menthone, but the chemical profiles had no relationship with the areas. The chromatographic fingerprints of the samples from different types were dissimilar, while the different producing areas were difficult to be separated. It was indicated that the content of volatile oil was positively correlated with the content of L-menthol and the sum of six total terpenoids. The content of the essential oil, L-menthol and the sum of six total terpenoids of Menthae Herba were considered as one of the commercial specifications and grading criteria. These results in the research could be helpful to draw up the commercial specification and grading criteria of Menthae Herba from a view of chemical information.

  6. Estimating and explaining the effect of education and income on head and neck cancer risk: INHANCE consortium pooled analysis of 31 case-control studies from 27 countries.

    Science.gov (United States)

    Conway, David I; Brenner, Darren R; McMahon, Alex D; Macpherson, Lorna M D; Agudo, Antonio; Ahrens, Wolfgang; Bosetti, Cristina; Brenner, Hermann; Castellsague, Xavier; Chen, Chu; Curado, Maria Paula; Curioni, Otávio A; Dal Maso, Luigino; Daudt, Alexander W; de Gois Filho, José F; D'Souza, Gypsyamber; Edefonti, Valeria; Fabianova, Eleonora; Fernandez, Leticia; Franceschi, Silvia; Gillison, Maura; Hayes, Richard B; Healy, Claire M; Herrero, Rolando; Holcatova, Ivana; Jayaprakash, Vijayvel; Kelsey, Karl; Kjaerheim, Kristina; Koifman, Sergio; La Vecchia, Carlo; Lagiou, Pagona; Lazarus, Philip; Levi, Fabio; Lissowska, Jolanta; Luce, Daniele; Macfarlane, Tatiana V; Mates, Dana; Matos, Elena; McClean, Michael; Menezes, Ana M; Menvielle, Gwenn; Merletti, Franco; Morgenstern, Hal; Moysich, Kirsten; Müller, Heiko; Muscat, Joshua; Olshan, Andrew F; Purdue, Mark P; Ramroth, Heribert; Richiardi, Lorenzo; Rudnai, Peter; Schantz, Stimson; Schwartz, Stephen M; Shangina, Oxana; Simonato, Lorenzo; Smith, Elaine; Stucker, Isabelle; Sturgis, Erich M; Szeszenia-Dabrowska, Neonila; Talamini, Renato; Thomson, Peter; Vaughan, Thomas L; Wei, Qingyi; Winn, Deborah M; Wunsch-Filho, Victor; Yu, Guo-Pei; Zhang, Zuo-Feng; Zheng, Tongzhang; Znaor, Ariana; Boffetta, Paolo; Chuang, Shu-Chun; Ghodrat, Marianoosh; Amy Lee, Yuan-Chin; Hashibe, Mia; Brennan, Paul

    2015-03-01

    Low socioeconomic status has been reported to be associated with head and neck cancer risk. However, previous studies have been too small to examine the associations by cancer subsite, age, sex, global region and calendar time and to explain the association in terms of behavioral risk factors. Individual participant data of 23,964 cases with head and neck cancer and 31,954 controls from 31 studies in 27 countries pooled with random effects models. Overall, low education was associated with an increased risk of head and neck cancer (OR = 2.50; 95% CI = 2.02 - 3.09). Overall one-third of the increased risk was not explained by differences in the distribution of cigarette smoking and alcohol behaviors; and it remained elevated among never users of tobacco and nondrinkers (OR = 1.61; 95% CI = 1.13 - 2.31). More of the estimated education effect was not explained by cigarette smoking and alcohol behaviors: in women than in men, in older than younger groups, in the oropharynx than in other sites, in South/Central America than in Europe/North America and was strongest in countries with greater income inequality. Similar findings were observed for the estimated effect of low versus high household income. The lowest levels of income and educational attainment were associated with more than 2-fold increased risk of head and neck cancer, which is not entirely explained by differences in the distributions of behavioral risk factors for these cancers and which varies across cancer sites, sexes, countries and country income inequality levels. © 2014 UICC.

  7. Quantum-chemical analysis of formation reactions of Со2+ complexes

    Directory of Open Access Journals (Sweden)

    Viktor F. Vargalyuk

    2017-11-01

    Full Text Available Based on the analysis of quantum chemical calculations results (GAMESS, density functional theory, B3LYP method as to coordination compounds of Co2+ions with H2O, NH3, OH–, F–, Cl–, Br–, I–, CN–, Ac–, Ak– generally given by [Co(H2O6–nLn]2+nx, it has been demonstrated that within the selected series of ligands, there is no correlation between the amount of energy of monosubstituted cobalt aqua complexes formation(∆Е and pK1,just like between the effective nuclear charge of the central atom (z*Со and pK1. According to the behavior of ∆Е and z*Со,we identified two groups of ligands. The first group (OH–, F–, Ac–, Ak–, CN–, NH3 demonstrates logical ∆Е decrease caused by the growth of z*Со. On the contrary, the second group (Cl–, Br–, I– demonstrates ∆Е increase caused by the growth of z*Со. This phenomenon is explained by the change in electronegativity and polarizability of donor atoms in groups and periods of the periodic table. It is established that linear correlations given by lgK = A + B·z*Со can be actualized only for complexes having ligands with similar donor atoms. Referring to the literature on stepwise complex formation of hydroxide, amine and chloride cobalt complexes in combination with z*Со calculations results, we determined A and B constants of lgK, z*Со-correlations for the atoms of oxygen (30.2, –17.7; nitrogen (125.4, –69.9 and chlorine (–6.3, 5.8. The existence of the detected correlation series enables us to lean on lgK,z*М–dependence parameters for the fixed donor atom and to determine Kn values for various complexes with complex-based ligands using calculations and z*М data. This applies to complexes having central atoms of the same nature as well as simple monodentate ligands. The mentioned approach was used to calculate the stability constants for acrylate cobalt complexes (lgK1 = 1.2 и lgК2 = 4.3, which are not covered in literature.

  8. Chemical analysis of bleach and hydroxide-based solutions after decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX).

    Science.gov (United States)

    Hopkins, F B; Gravett, M R; Self, A J; Wang, M; Chua, Hoe-Chee; Hoe-Chee, C; Lee, H S Nancy; Sim, N Lee Hoi; Jones, J T A; Timperley, C M; Riches, J R

    2014-08-01

    Detailed chemical analysis of solutions used to decontaminate chemical warfare agents can be used to support verification and forensic attribution. Decontamination solutions are amongst the most difficult matrices for chemical analysis because of their corrosive and potentially emulsion-based nature. Consequently, there are relatively few publications that report their detailed chemical analysis. This paper describes the application of modern analytical techniques to the analysis of decontamination solutions following decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). We confirm the formation of N,N-diisopropylformamide and N,N-diisopropylamine following decontamination of VX with hypochlorite-based solution, whereas they were not detected in extracts of hydroxide-based decontamination solutions by nuclear magnetic resonance (NMR) spectroscopy or gas chromatography-mass spectrometry. We report the electron ionisation and chemical ionisation mass spectroscopic details, retention indices, and NMR spectra of N,N-diisopropylformamide and N,N-diisopropylamine, as well as analytical methods suitable for their analysis and identification in solvent extracts and decontamination residues.

  9. Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

    Directory of Open Access Journals (Sweden)

    Fuensanta Sánchez Rojas

    2006-10-01

    Full Text Available Optical techniques for chemical analysis are well established and sensors based on thesetechniques are now attracting considerable attention because of their importance in applications suchas environmental monitoring, biomedical sensing, and industrial process control. On the other hand,flow injection analysis (FIA is advisable for the rapid analysis of microliter volume samples and canbe interfaced directly to the chemical process. The FIA has become a widespread automatic analyticalmethod for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, andease of assembling. In this paper, an overview of flow injection determinations by using opticalchemical sensors is provided, and instrumentation, sensor design, and applications are discussed. Thiswork summarizes the most relevant manuscripts from 1980 to date referred to analysis using opticalchemical sensors in FIA.

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

    Science.gov (United States)

    Arslan, Ozcan; Er, Ismail Deha

    2008-06-15

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

  11. Meta-analysis of toxicity and teratogenicity of 133 chemicals from zebrafish developmental toxicity studies

    Science.gov (United States)

    Zebrafish developmental toxicity testing is an emerging field, which faces considerable challenges regarding data meta-analysis and the establishment of standardized test protocols. Here, we present an initial correlation study on toxicity of 133 chemicals based on data in the li...

  12. Chemical analysis by X-ray fluorescence, of niobium in high-strength plate steels

    International Nuclear Information System (INIS)

    Iozzi, F.B.; Dias, M.J.P.

    1981-01-01

    The use of X-ray fluorescence spectrometry in quantitative analysis of niobium in steels, as an alternative solution for optical emission spectrometry, in the rapid chemical control of steel fabrication by LD type converters, is presented. (M.C.K.) [pt

  13. Chemical Analysis of the Moon at the Surveyor VI Landing Site: Preliminary Results.

    Science.gov (United States)

    Turkevich, A L; Patterson, J H; Franzgrote, E J

    1968-06-07

    The alpha-scattering experiment aboard soft-landing Surveyor VI has provided a chemical analysis of the surface of the moon in Sinus Medii. The preliminary results indicate that, within experimental errors, the composition is the same as that found by Surveyor V in Mare Tranquillitatis. This finding suggests that large portions of the lunar maria resemble basalt in composition.

  14. Solubilization of advanced ceramic materials controlled by chemical analysis by means of atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Amarante Junior, A.

    1992-01-01

    This paper purpose is to show the techniques used in chemical analysis laboratory at Escola SENAI Mario Amato in the ceramic nucleus for opening and solubilization of Advanced Ceramic materials, where the elements in its majority are determined for atomic absorption spectroscopy. (author)

  15. Physio-Chemical Analysis of Industrial Effluents in parts of Edo ...

    African Journals Online (AJOL)

    Physio-Chemical Analysis of Industrial Effluents in parts of Edo States Nigeria. ... Journal of Applied Sciences and Environmental Management ... particularly, surface water results from all activities of man involving indiscriminate waste disposal from industry such as effluents into waterways, waste, agricultural waste, and all ...

  16. Direct chemical analysis of frozen ice cores by UV-laser ablation ICPMS

    DEFF Research Database (Denmark)

    Müller, Wolfgang; Shelley, J. Michael G.; Rasmussen, Sune Olander

    2011-01-01

    Cryo-cell UV-LA-ICPMS is a new technique for direct chemical analysis of frozen ice cores at high spatial resolution (dust records and annual layer signatures at unprecedented spatial/time resolution. Uniquely......, the location of cation impurities relative to grain boundaries in recrystallized ice can be assessed....

  17. Quantitative analysis of chemical elements in single cells using nuclear microprobe and nano-probe

    International Nuclear Information System (INIS)

    Deves, Guillaume

    2010-01-01

    The study of the role of trace elements at cellular level requires the use of state-of-the-art analytical tools that could achieve enough sensitivity and spatial resolution. We developed a new methodology for the accurate quantification of chemical element distribution in single cells based on a combination of ion beam analysis techniques STIM, PIXE and RBS. The quantification procedure relies on the development of a STIM data analysis software (Paparamborde). Validity of this methodology and limits are discussed here. The method allows the quantification of trace elements (μg/g) with a 19.8 % uncertainty in cellular compartments with mass below 0.1 ng. The main limit of the method lies in the poor number of samples that can be analyzed, due to long irradiation times required and limited access to ion beam analysis facilities. This is the reason why we developed a database for cellular chemical composition capitalization (BDC4). BDC4 has been designed in order to use cellular chemical composition as a tracer for biological activities and is expected to provide in the future reference chemical compositions for any cellular type or compartment. Application of the STIM-PIXE-RBS methodology to the study of nuclear toxicology of cobalt compounds is presented here showing that STIM analysis is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. (author)

  18. Comparison of sodium content of workplace and homemade meals through chemical analysis and salinity measurements.

    Science.gov (United States)

    Shin, Eun-Kyung; Lee, Yeon-Kyung

    2014-10-01

    Most Koreans consume nearly 70-80% of the total sodium through their dishes. The use of a salinometer to measure salinity is recommended to help individuals control their sodium intake. The purpose of this study was to compare sodium content through chemical analysis and salinity measurement in foods served by industry foodservice operations and homemade meals. Workplace and homemade meals consumed by employees in 15 cafeterias located in 8 districts in Daegu were collected and the sodium content was measured through chemical analysis and salinity measurements and then compared. The foods were categorized into 9 types of menus with 103 workplace meals and 337 homemade meals. Workplace meals did not differ significantly in terms of sodium content per 100 g of food but had higher sodium content via chemical analysis in roasted foods per portion. Homemade meals had higher broth salt content and higher salt content by chemical analysis per 100 g of roasted foods and hard-boiled foods. One-dish workplace meals had higher salinity (P content (P content per 100 g of foods was higher in one-dish workplace meals (P content in foods and control one's sodium intake within the daily intake target as a way to promote cooking bland foods at home. However, estimated and actual measured values may differ.

  19. On the graph and systems analysis of reversible chemical reaction networks with mass action kinetics

    NARCIS (Netherlands)

    Rao, Shodhan; Jayawardhana, Bayu; Schaft, Arjan van der

    2012-01-01

    Motivated by the recent progresses on the interplay between the graph theory and systems theory, we revisit the analysis of reversible chemical reaction networks described by mass action kinetics by reformulating it using the graph knowledge of the underlying networks. Based on this formulation, we

  20. Chemical analysis of plants that poison livestock: Successes, challenges, and opportunities

    Science.gov (United States)

    Poisonous plants have a devastating impact on the livestock industry, as well as human health. In order to fully understand the effects of poisonous plants, multiple scientific disciplines are required. Chemical analysis of plant secondary compounds is key to identifying the responsible toxins, char...

  1. Chemical analysis and quality control of Ginkgo biloba leaves, extracts, and phytopharmaceuticals

    NARCIS (Netherlands)

    Beek, van T.A.; Montoro, P.

    2009-01-01

    The chemical analysis and quality control of Ginkgo leaves, extracts, phytopharmaceuticals and some herbal supplements is comprehensively reviewed. The review is an update of a similar, earlier review in this journal [T.A. van Beek, J. Chromatogr. A 967 (2002) 21¿55]. Since 2001 over 3000 papers on

  2. Identification of differences in chemical composition among whole stick and sliced Nitran salamis trough principal component analysis

    Directory of Open Access Journals (Sweden)

    Tomáš Fekete

    2016-05-01

    Full Text Available The subject of this work was to examine differences in chemical composition of sliced and whole stick Nitran salamis, purchased from various manufacturers. Nitran salamis are traditional dry fermented meat products of Slovak origin. Taking into account variations in raw materials, production process and potential adulteration, differences in chemical composition within one brand of salami from different manufacturers might be expected. Ten salamis were determined for basic chemical composition attributes and Principal Component Analysis was applied on data matrix to identify anomalous ones. It has been shown that six attributes, namely: protein without collagen of total protein, total protein, total meat, total fat, collagen of total protein and NaCl, were the most important for salamis as first two Principal Components together explained 70.16% of variance among them. Nitran D was found to be the most anomalous salami, as had the lowest value of protein without collagen of total protein (14.14% ±0.26%, total protein (17.42% ±0.44%, total meat (120.29% ±0.98% and the highest one of total fat (50.85% ±0.95%, collagen of total protein (18.83% ±0.50% and NaCl (9.55% ±1.93%, when compared to its whole stick variant Nitran C and other samples. In addition to collagen of total protein content, Nitran D together with Nitran A, F and H did not satisfied the legislatively determined criterion, which is ≤16%. This suggested that extra connective tissues were added to intermediate products, which resulted in high variability and inferior quality of final products. It is a common practice in the meat industry to increase the protein content or water binding properties of meat products.

  3. Inline chemical process analysis in micro-plants based on thermoelectric flow and impedimetric sensors

    International Nuclear Information System (INIS)

    Jacobs, T; Kutzner, C; Hauptmann, P; Kropp, M; Lang, W; Brokmann, G; Steinke, A; Kienle, A

    2010-01-01

    In micro-plants, as used in chemical micro-process engineering, an integrated inline analytics is regarded as an important factor for the development and optimization of chemical processes. Up to now, there is a lack of sensitive, robust and low-priced micro-sensors for monitoring mixing and chemical conversion in micro-fluidic channels. In this paper a novel sensor system combining an impedimetric sensor and a novel pressure stable thermoelectric flow sensor for monitoring chemical reactions in micro-plants is presented. The CMOS-technology-based impedimetric sensor mainly consists of two capacitively coupled interdigital electrodes on a silicon chip. The thermoelectric flow sensor consists of a heater in between two thermopiles on a perforated membrane. The pulsed and constant current feeds of the heater were analyzed. Both sensors enable the analysis of chemical conversion by means of changes in the thermal and electrical properties of the liquid. The homogeneously catalyzed synthesis of n-butyl acetate as a chemical model system was studied. Experimental results revealed that in an overpressure regime, relative changes of less than 1% in terms of thermal and electrical properties can be detected. Furthermore, the transition from one to two liquid phases accompanied by the change in slug flow conditions could be reproducibly detected

  4. Stereospecific assignment of the asparagine and glutamine sidechain amide protons in proteins from chemical shift analysis

    Energy Technology Data Exchange (ETDEWEB)

    Harsch, Tobias; Schneider, Philipp; Kieninger, Bärbel; Donaubauer, Harald; Kalbitzer, Hans Robert, E-mail: hans-robert.kalbitzer@biologie.uni-regensburg.de [University of Regensburg, Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine (Germany)

    2017-02-15

    Side chain amide protons of asparagine and glutamine residues in random-coil peptides are characterized by large chemical shift differences and can be stereospecifically assigned on the basis of their chemical shift values only. The bimodal chemical shift distributions stored in the biological magnetic resonance data bank (BMRB) do not allow such an assignment. However, an analysis of the BMRB shows, that a substantial part of all stored stereospecific assignments is not correct. We show here that in most cases stereospecific assignment can also be done for folded proteins using an unbiased artificial chemical shift data base (UACSB). For a separation of the chemical shifts of the two amide resonance lines with differences ≥0.40 ppm for asparagine and differences ≥0.42 ppm for glutamine, the downfield shifted resonance lines can be assigned to H{sup δ21} and H{sup ε21}, respectively, at a confidence level >95%. A classifier derived from UASCB can also be used to correct the BMRB data. The program tool AssignmentChecker implemented in AUREMOL calculates the Bayesian probability for a given stereospecific assignment and automatically corrects the assignments for a given list of chemical shifts.

  5. Urine storage under refrigeration preserves the sample in chemical, cellularity and bacteriuria analysis of ACS

    OpenAIRE

    Karen Cristina Barcellos Ribeiro; Bruno Rotondo Levenhagem Serabion; Eduardo Lima Nolasco; Chislene Pereira Vanelli; Harleson Lopes de Mesquita; José Otávio do Amaral Corrêa

    2013-01-01

    INTRODUCTION: The analysis of urine abnormal constituents and sediment (ACS) comprises tests of great diagnostic and prognostic value in clinical practice. When the analysis of ACS cannot be performed within two hours after collection, the sample must be preserved in order to avoid pre-analytical interferences. Refrigeration is the most applied technique due to its cost effectiveness. Moreover, it presents fewer inconveniences when compared to chemical preservation. However, changes in ACS ma...

  6. Analysis of soil chemical parameters of an uncleaned crude oil spill ...

    African Journals Online (AJOL)

    Analysis of soil chemical parameters of an uncleaned crude oil spill site at Biara was carried out. Soil samples were collected at 0 -15 cm and 15 – 30 cm soil depths from both polluted and unpolluted sites for analysis. Significant increase in high total hydrocarbon content (1015±80.5 – 1150±90.1 mg/kg) in polluted site was ...

  7. Modern sample preparation techniques for gas chromatography-mass spectrometry analysis of environmental markers of chemical warfare agents use

    NARCIS (Netherlands)

    Terzic, O.; de Voogt, P.; Banoub, J.

    2014-01-01

    The chapter introduces problematics of on-site chemical analysis in the investigations of past chemical warfare agents (CWA) events. An overview of primary environmental degradation pathways of CWA leading to formation of chemical markers of their use is given. Conventional and modern sample

  8. Application of hazard analysis critical control points (HACCP) to organic chemical contaminants in food.

    Science.gov (United States)

    Ropkins, K; Beck, A J

    2002-03-01

    Hazard Analysis Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards that was developed as an effective alternative to conventional end-point analysis to control food safety. It has been described as the most effective means of controlling foodborne diseases, and its application to the control of microbiological hazards has been accepted internationally. By contrast, relatively little has been reported relating to the potential use of HACCP, or HACCP-like procedures, to control chemical contaminants of food. This article presents an overview of the implementation of HACCP and discusses its application to the control of organic chemical contaminants in the food chain. Although this is likely to result in many of the advantages previously identified for microbiological HACCP, that is, more effective, efficient, and economical hazard management, a number of areas are identified that require further research and development. These include: (1) a need to refine the methods of chemical contaminant identification and risk assessment employed, (2) develop more cost-effective monitoring and control methods for routine chemical contaminant surveillance of food, and (3) improve the effectiveness of process optimization for the control of chemical contaminants in food.

  9. Explaining governance outcomes

    DEFF Research Database (Denmark)

    Fawcett, Paul; Daugbjerg, Carsten

    2012-01-01

    network analysis school, which has focused on the relationship between processes of interest intermediation and their impact on policy-making outcomes.We examine how each school is underpinned by important epistemological differences between positivist, interpretivist and critical realist approaches.......We argue that these differences complicate and make contestable what would otherwise seem to be an intuitively attractive argument in favour of combining these two schools. In seeking to understand better how these two schools might be combined, we adopt a critical realist approach and make a distinction...

  10. Analysis of the Precursors, Simulants and Degradation Products of Chemical Warfare Agents.

    Science.gov (United States)

    Witkiewicz, Zygfryd; Neffe, Slawomir; Sliwka, Ewa; Quagliano, Javier

    2018-09-03

    Recent advances in analysis of precursors, simulants and degradation products of chemical warfare agents (CWA) are reviewed. Fast and reliable analysis of precursors, simulants and CWA degradation products is extremely important at a time, when more and more terrorist groups and radical non-state organizations use or plan to use chemical weapons to achieve their own psychological, political and military goals. The review covers the open source literature analysis after the time, when the chemical weapons convention had come into force (1997). The authors stated that during last 15 years increased number of laboratories are focused not only on trace analysis of CWA (mostly nerve and blister agents) in environmental and biological samples, but the growing number of research are devoted to instrumental analysis of precursors and degradation products of these substances. The identification of low-level concentration of CWA degradation products is often more important and difficult than the original CWA, because of lower level of concentration and a very large number of compounds present in environmental and biological samples. Many of them are hydrolysis products and are present in samples in the ionic form. For this reason, two or three instrumental methods are used to perform a reliable analysis of these substances.

  11. Chemical ecotoxicology

    International Nuclear Information System (INIS)

    Paasivirta, J.

    1991-01-01

    This book discusses risk assessment, chemical cycles, structure-activity relations, organohalogens, oil residues, mercury, sampling and analysis of trace chemicals, and emissions from the forestry industry. Topics include: Cycles of chemicals in the environment. Rick assessment and management, strucuture and toxicity, sampling and analysis of trace chemicals in environment, interpretation of the environmental analysis results, mercury in the environment, organohalogen compounds in the environment, emissions from forestry industry, oil residues in the environment: oil spills in the marine environment

  12. Comparing chemical analysis with literature studies to identify micropollutants in a catchment of Copenhagen (DK)

    DEFF Research Database (Denmark)

    Lützhøft, Hans-Christian Holten; Birch, Heidi; Eriksson, Eva

    2011-01-01

    on urban surface runoff originating from a well defined catchment of Copenhagen (Denmark) with an inventory of potential pollution sources for the same catchment. The selected catchment covers an area with roads, a shopping centre, a parking lot, office buildings, a gymnasium and some restaurants....... The literature approach is limited to the range of included PSs and to how and which information is compiled, whereas the analytical chemical approach is limited to the selection of analyzed substances, sensitivity and precision. Comparing the two approaches of chemical analysis with literature study to identify...

  13. Chemical analysis of minerals in granitic rocks by electron probe micro analyser

    International Nuclear Information System (INIS)

    Hiraoka, Yoshihiro

    1994-01-01

    The chemical compositions of minerals in a few granitic rocks were determined by electron probe micro analyser (EPMA). The accurate analytical data for standard feldspar groups were obtained by correcting the low analytical values of sodium and potassium that were arised from the damage in EPMA analysis. Using this method, feldspar groups and biotites in three granitic rocks gathered from Hiei, Hira and Kurama areas respectively, were analyzed. As the results, the local characteristics were observed in the kinds of feldspar groups and the chemical compositions of biotites that were contained in granitic rocks. (author)

  14. Overview on Analysis of Free Metabolites for Detection of Exposure to Chemical Warfare Agents

    Directory of Open Access Journals (Sweden)

    Grigoriu Nicoleta

    2015-06-01

    Full Text Available Chemical warfare agents (CWA’s induce complex toxicological effects with major adverse consequences for those exposed. For many chemical agents there is a need for research and development of analytical toxicological methods for a rapid and certain confirmation of those exposures. The certain methods will help for establishing the laboratory diagnosis for applying the proper therapy; the treatment of only contaminated people, decreasing the stress level in the medical community in management of crisis situations, increasing the survival rate of the population exposed to the contamination, supervision of professional exposure, judicial analysis in case of suspicious terrorist activities.

  15. Determinants of job stress in chemical process industry: A factor analysis approach.

    Science.gov (United States)

    Menon, Balagopal G; Praveensal, C J; Madhu, G

    2015-01-01

    Job stress is one of the active research domains in industrial safety research. The job stress can result in accidents and health related issues in workers in chemical process industries. Hence it is important to measure the level of job stress in workers so as to mitigate the same to avoid the worker's safety related problems in the industries. The objective of this study is to determine the job stress factors in the chemical process industry in Kerala state, India. This study also aims to propose a comprehensive model and an instrument framework for measuring job stress levels in the chemical process industries in Kerala, India. The data is collected through a questionnaire survey conducted in chemical process industries in Kerala. The collected data out of 1197 surveys is subjected to principal component and confirmatory factor analysis to develop the job stress factor structure. The factor analysis revealed 8 factors that influence the job stress in process industries. It is also found that the job stress in employees is most influenced by role ambiguity and the least by work environment. The study has developed an instrument framework towards measuring job stress utilizing exploratory factor analysis and structural equation modeling.

  16. Analysis of mechanism of complex chemical reaction taking radiation chemical purification of gases from impurities as an example

    International Nuclear Information System (INIS)

    Gerasimov, G.Ya.; Makarov, V.N.

    1997-01-01

    Algorithm of selecting optimal mechanism of complex chemical reaction, enabling to reduce the number of its stages, is suggested. Main steps of constructing the kinetic model of the medium are considered, taking the radiation chemical purification (using fast electron radiation) of gases (N 2 , CO 2 , O 2 and others) from impurities as an example. 17 refs., 3 figs., 2 tabs

  17. Do provisions to advance chemical facility safety also advance chemical facility security? An analysis of possible synergies

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2012-01-01

    The European Commission has launched a study on the applicability of existing chemical industry safety provisions to enhancing security of chemical facilities covering the situation in 18 EU Member States. This paper reports some preliminary analytical findings regarding the extent to which exist...

  18. Sampling and chemical analysis in environmental samples around Nuclear Power Plants and some environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2002-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, a grain of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that sere sampled at 60 point of district in Korea were analyzed. Tritium were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied from KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin Npps and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  19. Analysis of hybrid membrane and chemical absorption systems for CO2 capture

    International Nuclear Information System (INIS)

    Binns, Michael; Oh, Se-Young; Kwak, Dong-Hun; Kim, Jin-Kuk

    2015-01-01

    Amine-based absorption of CO 2 is currently the industry standard technology for capturing CO 2 emitted from power plants, refineries and other large chemical plants. However, more recently there have been a number of competing technologies under consideration, including the use of membranes for CO 2 separation and purification. We constructed and analyzed two different hybrid configurations combining and connecting chemical absorption with membrane separation. For a particular flue gas which is currently treated with amine-based chemical absorption at a pilot plant we considered and tested how membranes could be integrated to improve the performance of the CO 2 capture. In particular we looked at the CO 2 removal efficiency and the energy requirements. Sensitivity analysis was performed varying the size of the membranes and the solvent flow rate

  20. ANALYSIS OF THE MANAGEMENT SYSTEM IN THE FIELD OF ENVIRONMENTAL PROTECTION OF RUSSIAN CHEMICAL COMPANIES

    Directory of Open Access Journals (Sweden)

    Anna Makarov

    2018-03-01

    Full Text Available Since 2007, many chemical industrial companies in the Russian Federation have been actively involved in the Responsible Care® international voluntary program. To implement this program, vast bodies of data on environmental impact assessments needs to be collected. This allows us to analyse the environment-oriented trends in economic and social activities, and to record the achievements and problems in this field. The collected large bodies of data are in many cases heterogeneous, since the report has been a voluntary initiative. To analyse the existing trends in business processes, authors applied the methodology for system analysis of large bodies of data and used their own heuristic approximation algorithm for the treatment of accumulated data. This algorithm gives us the unique possibility of evaluating the performance of both individual chemical companies in the framework of the Responsible Care® program and the Russian chemical industry as a whole.

  1. Development and Analysis of Group Contribution Plus Models for Property Prediction of Organic Chemical Systems

    DEFF Research Database (Denmark)

    Mustaffa, Azizul Azri

    for the GIPs are then used in the UNIFAC model to calculate activity coefficients. This approach can increase the application range of any “host” UNIFAC model by providing a reliable predictive model towards fast and efficient product development. This PhD project is focused on the analysis and further......Prediction of properties is important in chemical process-product design. Reliable property models are needed for increasingly complex and wider range of chemicals. Group-contribution methods provide useful tool but there is a need to validate them and improve their accuracy when complex chemicals...... are present in the mixtures. In accordance with that, a combined group-contribution and atom connectivity approach that is able to extend the application range of property models has been developed for mixture properties. This so-called Group-ContributionPlus (GCPlus) approach is a hybrid model which combines...

  2. The Matthew effect in environmental science publication: a bibliometric analysis of chemical substances in journal articles.

    Science.gov (United States)

    Grandjean, Philippe; Eriksen, Mette L; Ellegaard, Ole; Wallin, Johan A

    2011-11-10

    While environmental research addresses scientific questions of possible societal relevance, it is unclear to what degree research focuses on environmental chemicals in need of documentation for risk assessment purposes. In a bibliometric analysis, we used SciFinder to extract Chemical Abstract Service (CAS) numbers for chemicals addressed by publications in the 78 major environmental science journals during 2000-2009. The Web of Science was used to conduct title searches to determine long-term trends for prominent substances and substances considered in need of research attention. The 119,636 journal articles found had 760,056 CAS number links during 2000-2009. The top-20 environmental chemicals consisted of metals, (chlorinated) biphenyls, polyaromatic hydrocarbons, benzene, and ethanol and contributed 12% toward the total number of links- Each of the top-20 substances was covered by 2,000-10,000 articles during the decade. The numbers for the 10-year period were similar to the total numbers of pre-2000 articles on the same chemicals. However, substances considered a high priority from a regulatory viewpoint, due to lack of documentation, showed very low publication rates. The persistence in the scientific literature of the top-20 chemicals was only weakly related to their publication in journals with a high impact factor, but some substances achieved high citation rates. The persistence of some environmental chemicals in the scientific literature may be due to a 'Matthew' principle of maintaining prominence for the very reason of having been well researched. Such bias detracts from the societal needs for documentation on less well known environmental hazards, and it may also impact negatively on the potentials for innovation and discovery in research.

  3. The Matthew effect in environmental science publication: A bibliometric analysis of chemical substances in journal articles

    Directory of Open Access Journals (Sweden)

    Grandjean Philippe

    2011-11-01

    Full Text Available Abstract Background While environmental research addresses scientific questions of possible societal relevance, it is unclear to what degree research focuses on environmental chemicals in need of documentation for risk assessment purposes. Methods In a bibliometric analysis, we used SciFinder to extract Chemical Abstract Service (CAS numbers for chemicals addressed by publications in the 78 major environmental science journals during 2000-2009. The Web of Science was used to conduct title searches to determine long-term trends for prominent substances and substances considered in need of research attention. Results The 119,636 journal articles found had 760,056 CAS number links during 2000-2009. The top-20 environmental chemicals consisted of metals, (chlorinated biphenyls, polyaromatic hydrocarbons, benzene, and ethanol and contributed 12% toward the total number of links- Each of the top-20 substances was covered by 2,000-10,000 articles during the decade. The numbers for the 10-year period were similar to the total numbers of pre-2000 articles on the same chemicals. However, substances considered a high priority from a regulatory viewpoint, due to lack of documentation, showed very low publication rates. The persistence in the scientific literature of the top-20 chemicals was only weakly related to their publication in journals with a high impact factor, but some substances achieved high citation rates. Conclusions The persistence of some environmental chemicals in the scientific literature may be due to a 'Matthew' principle of maintaining prominence for the very reason of having been well researched. Such bias detracts from the societal needs for documentation on less well known environmental hazards, and it may also impact negatively on the potentials for innovation and discovery in research.

  4. Antibacterial Efficiency of Benzalkonium Chloride Base Disinfectant According To European Standard 13727, Chemical Analysis and Validation Studies

    OpenAIRE

    Yıldırım, Çinel; Çelenk, Veysel

    2018-01-01

    Antibacterial Efficiency of Benzalkonium Chloride Base Disinfectant According To European Standard 13727, Chemical Analysis and Validation Studies This study was aimed to provide principle of the chemical analyses, antibacterial efficiency test and validation procedures of the most commonly used benzalkonium chloride (BAC) base disinfectant as a biocide. Disinfectant which comprised 20 % BAC concentration was used as a prototype product and active substance was verified with chemical analysis...

  5. Explaining Ethnic Variability of Transporter Substrate Pharmacokinetics in Healthy Asian and Caucasian Subjects with Allele Frequencies of OATP1B1 and BCRP: A Mechanistic Modeling Analysis.

    Science.gov (United States)

    Li, Rui; Barton, Hugh A

    2018-04-01

    Ethnic variability in the pharmacokinetics of organic anion transporting polypeptide (OATP) 1B1 substrates has been observed, but its basis is unclear. A previous study hypothesizes that, without applying an intrinsic ethnic variability in transporter activity, allele frequencies of transporters cannot explain observed ethnic variability in pharmacokinetics. However, this hypothesis contradicts the data collected from compounds that are OATP1B1 substrates but not breast cancer resistance protein (BCRP) substrates. The objective of this study is to evaluate a hypothesis that is physiologically reasonable and more consistent with clinical observations. We evaluated if allele frequencies of two transporters (OATP1B1 and BCRP) are key contributors to ethnic variability. In this hypothesis, the same genotype leads to the same activity independent of ethnicity, in contrast to the previous hypothesis of intrinsic ethnic variability in OATP1B1 activity. As a validation, we perform mechanistic pharmacokinetic modeling for SLCO1B1 (encoding OATP1B1) and ABCG2 (encoding BCRP) genotyped pharmacokinetic data from 18 clinical studies with healthy Caucasian and/or Asian subjects. Simulations based on the current hypothesis reasonably describe SLCO1B1 and ABCG2 genotyped pharmacokinetic time course data for five transporter substrates (atorvastatin, pitavastatin, pravastatin, repaglinide, and rosuvastatin) in Caucasian and Asian populations. This hypothesis covers the observations that can (e.g., ethnic differences in rosuvastatin pharmacokinetics) or cannot (e.g., lack of differences for pitavastatin pharmacokinetics) be explained by the previous hypothesis. It helps to characterize sources of ethnic variability and provides a foundation for predicting ethnic variability in transporter substrate pharmacokinetics.

  6. USE OF AMAZONIAN SPECIES FOR AGING DISTILLED BEVERAGES: PHYSICAL AND CHEMICAL WOOD ANALYSIS

    Directory of Open Access Journals (Sweden)

    Jonnys Paz Castro

    2015-06-01

    Full Text Available The process of storing liquor in wooden barrels is a practice that aims to improve the sensory characteristics, such as color, aroma and flavor, of the beverage. The quality of the liquor stored in these barrels depends on wood characteristics such as density, permeability, chemical composition, anatomy, besides the wood heat treatment used to fabricate the barrels. Brazil has a great diversity of forests, mainly in the north, in the Amazon. This region is home to thousands of tree species, but is limited to the use of only a few native species to store liquors. The objective of this study was to determine some of the physical and chemical characteristics for four Amazon wood species. The results obtained in this study will be compared with others from woods that are traditionally used for liquor storage. The species studied were angelim-pedra (Hymenolobium petraeum Ducke cumarurana (Dipteryx polyphylla (Huber Ducke, jatobá (Hymenaea courbaril L. and louro-vermelho (Nectandra rubra (Mez CK Allen. The trees were collected from Precious Woods Amazon Company forest management area, in Silves, Amazonas. Analyzes such as: concentration of extractives, lignin amount, percentage of minerals (ash and tannin content, density, elemental analysis (CHNS-O and thermal analysis were done. It was observed that the chemical composition (lignin, holocellulose and elemental analysis (percentage of C, H, N and O of the woods have significant differences. The jatobá wood presented higher tannin content, and in the thermal analysis, was that which had the lowest mass loss.

  7. Letters from China: A History of the Origins of the Chemical Analysis of Ceramics.

    Science.gov (United States)

    Pollard, A M

    2015-02-01

    This paper is an attempt to document the early history of the quantitative chemical analysis of ceramic materials in Europe, with a specific interest in the analysis of archaeological ceramics. This inevitably leads to a study of the attempts made in Europe to imitate the miraculous material--porcelain--imported from China from the fourteenth century onwards. It is clear that before the end of the eighteenth century progress was made in this endeavor by systematic but essentially trial-and-error firing of various raw materials, culminating in the successful production of European porcelain by Böttger and von Tschirnhaus in 1709. Shortly after this, letters describing the Chinese manufacture of porcelain, and, more importantly, samples of raw and fired material, began to arrive in Europe from French Jesuit missionaries, which were subjected to intense study. Following the perfection of gravimetric methods of chemical analysis in the late eighteenth century, these Chinese samples, and samples of porcelain from various European factories, were regularly analysed, particularly by Brongniart at Sèvres. Similar work was carried out on English porcelain by Simeon Shaw and Sir Arthur Church. The origins of the chemical analysis of archaeological ceramics are still somewhat obscure, but must date to the late eighteenth or early nineteenth centuries, by the likes of Vauquelin and Chaptal.

  8. Chemical and physical analysis of core materials for advanced high temperature reactors with process heat applications

    International Nuclear Information System (INIS)

    Nickel, H.

    1985-08-01

    Various chemical and physical methods for the analysis of structural materials have been developed in the research programmes for advanced high temperature reactors. These methods are discussed using as examples the structural materials of the reactor core - the fuel elements consisting of coated particles in a graphite matrix and the structural graphite. Emphasis is given to the methods of chemical analysis. The composition of fuel kernels is investigated using chemical analysis methods to determine the heavy metals content (uranium, plutonium, thorium and metallic impurity elements) and the amount of non-metallic constituents. The properties of the pyrocarbon and silicon carbide coatings of fuel elements are investigated using specially developed physiochemical methods. Regarding the irradiation behaviour of coated particles and fuel elements, methods have been developed for examining specimens in hot cells following exposures under reactor operating conditions, to supplement the measurements of in-reactor performance. For the structural graphite, the determination of impurities is important because certain impurities may cause pitting corrosion during irradiation. The localized analysis of very low impurity concentrations is carried out using spectrochemical d.c. arc excitation, local laser and inductively coupled plasma methods. (orig.)

  9. Analysis of pharmaceutical pellets: An approach using near-infrared chemical imaging

    International Nuclear Information System (INIS)

    Sabin, Guilherme P.; Breitkreitz, Marcia C.; Souza, Andre M. de; Fonseca, Patricia da; Calefe, Lupercio; Moffa, Mario; Poppi, Ronei J.

    2011-01-01

    Highlights: → Near-Infrared Chemical Imaging was used for pellets analysis. → Distribution of the components throughout the coatings layers and core of the pellets was estimated. → Classical Least Squares (CLS) was used for calculation of the concentration maps. - Abstract: Pharmaceutical pellets are spherical or nearly spherical multi-unit dosage forms designed to optimize pharmacokinetics and pharmacodynamics features of drug release. The distribution of the pharmaceutical ingredients in the layers and core is a very important parameter for appropriate drug release, especially for pellets manufactured by the process of layer gain. Physical aspects of the sample are normally evaluated by Scanning Electron Microscopy (SEM), but it is in many cases unsuitable to provide conclusive chemical information about the distribution of the pharmaceutical ingredients in both layers and core. On the other hand, methods based on spectroscopic imaging can be very promising for this purpose. In this work, a Near-Infrared Chemical Imaging (NIR-CI) method was developed and applied to the analysis of diclophenac sodium pellets. Since all the compounds present in the sample were known in advance, Classical Least Squares (CLS) was used for calculations. The results have shown that the method was capable of providing chemical information about the distribution of the active ingredient and excipients in the core and coating layers and therefore can be complementary to SEM for the pharmaceutical development of pellets.

  10. Phthalic Acid Chemical Probes Synthesized for Protein-Protein Interaction Analysis

    Directory of Open Access Journals (Sweden)

    Chin-Jen Wu

    2013-06-01

    Full Text Available Plasticizers are additives that are used to increase the flexibility of plastic during manufacturing. However, in injection molding processes, plasticizers cannot be generated with monomers because they can peel off from the plastics into the surrounding environment, water, or food, or become attached to skin. Among the various plasticizers that are used, 1,2-benzenedicarboxylic acid (phthalic acid is a typical precursor to generate phthalates. In addition, phthalic acid is a metabolite of diethylhexyl phthalate (DEHP. According to Gene_Ontology gene/protein database, phthalates can cause genital diseases, cardiotoxicity, hepatotoxicity, nephrotoxicity, etc. In this study, a silanized linker (3-aminopropyl triethoxyslane, APTES was deposited on silicon dioxides (SiO2 particles and phthalate chemical probes were manufactured from phthalic acid and APTES–SiO2. These probes could be used for detecting proteins that targeted phthalic acid and for protein-protein interactions. The phthalic acid chemical probes we produced were incubated with epithelioid cell lysates of normal rat kidney (NRK-52E cells to detect the interactions between phthalic acid and NRK-52E extracted proteins. These chemical probes interacted with a number of chaperones such as protein disulfide-isomerase A6, heat shock proteins, and Serpin H1. Ingenuity Pathways Analysis (IPA software showed that these chemical probes were a practical technique for protein-protein interaction analysis.

  11. Standardization of Cassia spectabilis with Respect to Authenticity, Assay and Chemical Constituent Analysis

    Directory of Open Access Journals (Sweden)

    Angeline Torey

    2010-05-01

    Full Text Available Quality control standardizations of the various medicinal plants used in traditional medicine is becoming more important today in view of the commercialization of formulations based on these plants. An attempt at standardization of Cassia spectabilis leaf has been carried out with respect to authenticity, assay and chemical constituent analysis. The authentication involved many parameters, including gross morphology, microscopy of the leaves and functional group analysis by Fourier Transform Infrared (FTIR spectroscopy. The assay part of standardization involved determination of the minimum inhibitory concentration (MIC of the extract which could help assess the chemical effects and establish curative values. The MIC of the C. spectabilis leaf extracts was investigated using the Broth Dilution Method. The extracts showed a MIC value of 6.25 mg/mL, independent of the extraction time. The chemical constituent aspect of standardization involves quantification of the main chemical components in C. spectabilis. The GCMS method used for quantification of 2,4-(1H,3H-pyrimidinedione in the extract was rapid, accurate, precise, linear (R2 = 0.8685, rugged and robust. Hence this method was suitable for quantification of this component in C. spectabilis. The standardization of C. spectabilis is needed to facilitate marketing of medicinal plants, with a view to promoting the export of valuable Malaysian Traditional Medicinal plants such as C. spectabilis.

  12. Standardization of Cassia spectabilis with respect to authenticity, assay and chemical constituent analysis.

    Science.gov (United States)

    Torey, Angeline; Sasidharan, Sreenivasan; Yeng, Chen; Latha, Lachimanan Yoga

    2010-05-10

    Quality control standardizations of the various medicinal plants used in traditional medicine is becoming more important today in view of the commercialization of formulations based on these plants. An attempt at standardization of Cassia spectabilis leaf has been carried out with respect to authenticity, assay and chemical constituent analysis. The authentication involved many parameters, including gross morphology, microscopy of the leaves and functional group analysis by Fourier Transform Infrared (FTIR) spectroscopy. The assay part of standardization involved determination of the minimum inhibitory concentration (MIC) of the extract which could help assess the chemical effects and establish curative values. The MIC of the C. spectabilis leaf extracts was investigated using the Broth Dilution Method. The extracts showed a MIC value of 6.25 mg/mL, independent of the extraction time. The chemical constituent aspect of standardization involves quantification of the main chemical components in C. spectabilis. The GCMS method used for quantification of 2,4-(1H,3H)-pyrimidinedione in the extract was rapid, accurate, precise, linear (R(2) = 0.8685), rugged and robust. Hence this method was suitable for quantification of this component in C. spectabilis. The standardization of C. spectabilis is needed to facilitate marketing of medicinal plants, with a view to promoting the export of valuable Malaysian Traditional Medicinal plants such as C. spectabilis.

  13. Comparative analysis of chemical similarity methods for modular natural products with a hypothetical structure enumeration algorithm.

    Science.gov (United States)

    Skinnider, Michael A; Dejong, Chris A; Franczak, Brian C; McNicholas, Paul D; Magarvey, Nathan A

    2017-08-16

    Natural products represent a prominent source of pharmaceutically and industrially important agents. Calculating the chemical similarity of two molecules is a central task in cheminformatics, with applications at multiple stages of the drug discovery pipeline. Quantifying the similarity of natural products is a particularly important problem, as the biological activities of these molecules have been extensively optimized by natural selection. The large and structurally complex scaffolds of natural products distinguish their physical and chemical properties from those of synthetic compounds. However, no analysis of the performance of existing methods for molecular similarity calculation specific to natural products has been reported to date. Here, we present LEMONS, an algorithm for the enumeration of hypothetical modular natural product structures. We leverage this algorithm to conduct a comparative analysis of molecular similarity methods within the unique chemical space occupied by modular natural products using controlled synthetic data, and comprehensively investigate the impact of diverse biosynthetic parameters on similarity search. We additionally investigate a recently described algorithm for natural product retrobiosynthesis and alignment, and find that when rule-based retrobiosynthesis can be applied, this approach outperforms conventional two-dimensional fingerprints, suggesting it may represent a valuable approach for the targeted exploration of natural product chemical space and microbial genome mining. Our open-source algorithm is an extensible method of enumerating hypothetical natural product structures with diverse potential applications in bioinformatics.

  14. Analysis of pharmaceutical pellets: An approach using near-infrared chemical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sabin, Guilherme P.; Breitkreitz, Marcia C.; Souza, Andre M. de [Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, SP (Brazil); Fonseca, Patricia da; Calefe, Lupercio; Moffa, Mario [Zelus Servicos para Industria Farmaceutica Ltda., Av. Professor Lineu Prestes n. 2242, Sao Paulo, SP (Brazil); Poppi, Ronei J., E-mail: ronei@iqm.unicamp.br [Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

    2011-11-07

    Highlights: {yields} Near-Infrared Chemical Imaging was used for pellets analysis. {yields} Distribution of the components throughout the coatings layers and core of the pellets was estimated. {yields} Classical Least Squares (CLS) was used for calculation of the concentration maps. - Abstract: Pharmaceutical pellets are spherical or nearly spherical multi-unit dosage forms designed to optimize pharmacokinetics and pharmacodynamics features of drug release. The distribution of the pharmaceutical ingredients in the layers and core is a very important parameter for appropriate drug release, especially for pellets manufactured by the process of layer gain. Physical aspects of the sample are normally evaluated by Scanning Electron Microscopy (SEM), but it is in many cases unsuitable to provide conclusive chemical information about the distribution of the pharmaceutical ingredients in both layers and core. On the other hand, methods based on spectroscopic imaging can be very promising for this purpose. In this work, a Near-Infrared Chemical Imaging (NIR-CI) method was developed and applied to the analysis of diclophenac sodium pellets. Since all the compounds present in the sample were known in advance, Classical Least Squares (CLS) was used for calculations. The results have shown that the method was capable of providing chemical information about the distribution of the active ingredient and excipients in the core and coating layers and therefore can be complementary to SEM for the pharmaceutical development of pellets.

  15. Chemical analysis of fish bile extracts for monitoring endocrine disrupting chemical exposure in water: Bisphenol A, alkylphenols, and norethindrone.

    Science.gov (United States)

    Wu, Minghong; Pan, Chenyuan; Yang, Ming; Xu, Bentuo; Lei, Xiangjie; Ma, Jing; Cai, Ling; Chen, Jingsi

    2016-01-01

    The present study determined concentrations of estrogenic bisphenol A (BPA), nonylphenol, octylphenol (4-tert-octylphenol), butylphenol (4-tert-butylphenol), and progestogenic norethindrone by liquid chromatography-tandem mass spectrometry in bile extracts from field fish from the Xin'an River and market fish in Shanghai, China. Compared with the field fish, endocrine disrupting chemical (EDC) concentrations in market fish bile were at relatively high levels with high detectable rates. The average concentrations of BPA, nonylphenol, 4-tert-octylphenol, 4-tert-butylphenol, and norethindrone in field fish bile were 30.1 µg/L, 203 µg/L, 4.69 µg/L, 7.84 µg/L, and 0.514 µg/L, respectively; in market fish bile they were 240 µg/L, 528 µg/L, 76.5 µg/L, 12.8 µg/L, and 5.26 µg/L, respectively; and in the surface water of Xin'an River they were 38.8 ng/L, 7.91 ng/L, 1.98 ng/L, 2.66 ng/L, and 0.116 ng/L, respectively. The average of total estrogenic activity of river water was 3.32 ng/L estradiol equivalents. High bioconcentration factors (BCFs) were discovered for all 5 EDCs (≧998-fold) in field fish bile. Furthermore, the authors analyzed the BCF value of BPA in fish bile after 30-d exposure to environmentally relevant concentrations of BPA in the laboratory, and the analysis revealed that BCF in fish bile (BCF(Fish bile)) changed in an inverse concentration-dependent manner based on the log10-transformed BPA concentration in water. Strikingly, the data from the field study were well fitted within this trend. The data together suggested that analysis of fish bile extracts could be an efficient method for assessing waterborne EDCs exposure for aquatic biota. © 2015 SETAC.

  16. Do provisions to advance chemical facility safety also advance chemical facility security? - An analysis of possible synergies

    OpenAIRE

    Hedlund, Frank Huess

    2012-01-01

    The European Commission has launched a study on the applicability of existing chemical industry safety provisions to enhancing security of chemical facilities covering the situation in 18 EU Member States. This paper reports some preliminary analytical findings regarding the extent to which existing provisions that have been put into existence to advance safety objectives due to synergy effects could be expected advance security objectives as well.The paper provides a conceptual definition of...

  17. Metal-assisted chemical etching of CIGS thin films for grain size analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Chaowei [Research and Development Centre, Hanergy Thin Film Power Group Limited, Chengdu (China); Loi, Huu-Ha; Duong, Anh; Parker, Magdalena [Failure Analysis Department, MiaSole Hi-Tech Corp., Santa Clara, CA (United States)

    2016-09-15

    Grain size of the CIGS absorber is an important monitoring factor in the CIGS solar cell manufacturing. Electron backscatter diffraction (EBSD) analysis is commonly used to perform CIGS grain size analysis in the scanning electron microscope (SEM). Although direct quantification on SEM image using the average grain intercept (AGI) method is faster and simpler than EBSD, it is hardly applicable on CIGS thin films. The challenge is that, not like polycrystalline silicon, to define grain boundaries by selective chemical etching is not easily realizable for the multi-component CIGS alloy. In this Letter, we present direct quantification of CIGS thin film grain size using the AGI method by developing metal-assisted wet chemical etching process to define CIGS grain boundaries. The calculated value is similar to EBSD result. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Isotopic Abundance and Chemical Purity Analysis of Stable Isotope Deuterium Labeled Sudan I

    Directory of Open Access Journals (Sweden)

    CAI Yin-ping;LEI Wen;ZHENG Bo;DU Xiao-ning

    2014-02-01

    Full Text Available It is important that to analysis of the isotopic abundance and chemical purity of Sudan I-D5, which is the internal standard of isotope dilution mass spectrometry. The isotopic abundance of Sudan I-D5 is detected by “mass cluster” classification method and LC-MS. The repeatability and reproducibility experiments were carried out by using different mass spectrometers and different operators. The RSD was less than 0.1%, so the repeatability and reproducibility were satisfactory. The accuracy and precision of the isotopic abundance analysis method was good with the results of F test and t test. The high performance liquid chromatography (HPLC had been used for detecting the chemical purity of Sudan I-D5 as external standard method.

  19. Theoretical considerations of Flow Injection Analysis in the Absence of Chemical Reactions

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2000-01-01

    The fundamental mechanism of flow injection analysis (FIA) is assumed to be simple dissusion and the response of the detector is included in a model description that provide information about the shape of the FIA peak in terms of, basically, five parameters. Two of the five parameters are associa...... that any deviation from the features of the present model and the results of a tentative chemical reaction with one of the test compounds, is related to chemical kinetics.......The fundamental mechanism of flow injection analysis (FIA) is assumed to be simple dissusion and the response of the detector is included in a model description that provide information about the shape of the FIA peak in terms of, basically, five parameters. Two of the five parameters...

  20. Quantitative analysis of abused drugs in physiological fluids by gas chromatography/chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Foltz, R.L.

    1978-01-01

    Methods have been developed for quantitative analysis of commonly abused drugs in physiological fluids using gas chromatography/chemical ionization mass spectrometry. The methods are being evaluated in volunteer analytical and toxicological laboratories, and analytical manuals describing the methods are being prepared. The specific drug and metabolites included in this program are: Δ 9 -tetrahydrocannabinol, methadone, phencyclidine, methaqualone, morphine, amphetamine, methamphetamine, mescaline, 2,5-dimethoxy-4-methyl amphetamine, cocaine, benzoylecgonine, diazepam, and N-desmethyldiazepam. The current analytical methods utilize relatively conventional instrumentation and procedures, and are capable of measuring drug concentrations as low as 1 ng/ml. Various newer techniques such as sample clean-up by high performance liquid chromatography, separation by glass capillary chromatography, and ionization by negative ion chemical ionization are being investigated with respect to their potential for achieving higher sensitivity and specificity, as well as their ability to facilitate simultaneous analysis of more than one drug and metabolite. (Auth.)

  1. Quality system of the Chemical Analysis Laboratory to fulfill the requirements with Certification Organizations

    International Nuclear Information System (INIS)

    Merlo S, L.; Rodriguez L, R.; Cota S, G.

    1996-01-01

    In the present work was described the Quality System established in the Chemical Analysis Department to fulfill with the Organization requirements, personnel, measurement equipment, calibration, working procedures, etc. to get official acknowledgment by the National Assurance System for Testing laboratories, dependent of the General Standards Direction. There are described the available resources, the performance and control of each of one principal points of the system. (Author)

  2. Adaptation of chemical methods of analysis to the matrix of pyrite-acidified mining lakes

    International Nuclear Information System (INIS)

    Herzsprung, P.; Friese, K.

    2000-01-01

    Owing to the unusual matrix of pyrite-acidified mining lakes, the analysis of chemical parameters may be difficult. A number of methodological improvements have been developed so far, and a comprehensive validation of methods is envisaged. The adaptation of the available methods to small-volume samples of sediment pore waters and the adaptation of sensitivity to the expected concentration ranges is an important element of the methods applied in analyses of biogeochemical processes in mining lakes [de

  3. Control charts technique - a tool to data analysis for chemical experiments

    International Nuclear Information System (INIS)

    Yadav, M.B.; Venugopal, V.

    1999-01-01

    A procedure using control charts technique has been developed to analyse data of a chemical experiment which was conducted to assign a value to uranium content in Rb 2 U(SO 4 ) 3 . A value of (34.164 ± 0.031)% has been assigned against (34.167 ± 0.042)% already assigned by analysis of variance (ANOVA) technique. These values do not differ significantly. Merits and demerits of the two techniques have been discussed. (author)

  4. Qualitative analysis of the crystalline and chemical content of the Teredo sp. (Turu)

    International Nuclear Information System (INIS)

    Matos, E.; Matos, M.; Matos, P.

    1990-01-01

    A qualitative analysis of the crystalline and elementary content of the Teredo sp. (Turu) is realised by diffraction and fluorescence Phillips equipment. A diffractogram and X-ray spectra are studied. The head constitution is almost exclusively formed by aragonite and calcite, visceral mass and coat, formed by Ca, K, S, P, Cl, Si, Fe and Ti. The relative amount of these chemical elements is the difference between each part of the Teredo sp. (Turu). (M.A.C.)

  5. Chemical and Hydro-Geologic Analysis of Ikogosi Warm Spring Water in Nigeria

    OpenAIRE

    Akinola Ikudayisi; Folasade Adeyemo; Josiah Adeyemo

    2015-01-01

    This study focuses on the hydro-geology and chemical constituents analysis of Ikogosi Warm Spring waters in South West Nigeria. Ikogosi warm spring is a global tourist attraction because it has both warm and cold spring sources. Water samples from the cold spring, warm spring and the meeting point were collected, analyzed and the result shows close similarity in temperature, hydrogen iron concentration (pH), alkalinity, hardness, Calcium, Magnesium, Sodium, Iron, total di...

  6. Method and multichannel equipment for chemical analysis by X-ray emission

    International Nuclear Information System (INIS)

    Bacso, J.; Horkay, Gy.; Kalinka, G.; Kertesz, Zs.; Kiss Varga, M.; Lakatos, T.; Mathe, Gy.; Paal, A.; Sulik, B.

    1978-01-01

    In the patent a simple method and an apparatus are described for chemical analysis based on X-ray emission generated by irradiation. The concentrations of pre-selected elements can be determined easily by this method using an equipment containing microprocessor. The number of channels and the elements to be determined can be modified by a simple change in the program. (Sz.J.)

  7. The approach to risk analysis in three industries: nuclear power, space systems, and chemical process

    International Nuclear Information System (INIS)

    Garrick, B.J.

    1988-01-01

    The aerospace, nuclear power, and chemical processing industries are providing much of the incentive for the development and application of advanced risk analysis techniques to engineered systems. Risk analysis must answer three basic questions: What can go wrong? How likely is it? and What are the consequences? The result of such analyses is not only a quantitative answer to the question of 'What is the risk', but, more importantly, a framework for intelligent and visible risk management. Because of the societal importance of the subject industries and the amount of risk analysis activity involved in each, it is interesting to look for commonalities, differences, and, hopefully, a basis for some standardization. Each industry has its strengths: the solid experience base of the chemical industry, the extensive qualification and testing procedures of the space industry, and the integrative and quantitative risk and reliability methodologies developed for the nuclear power industry. In particular, most advances in data handling, systems interaction modeling, and uncertainty analysis have come from the probabilistic risk assessment work in the nuclear safety field. In the final analysis, all three industries would greatly benefit from a more deliberate technology exchange program in the rapidly evolving discipline of quantitative risk analysis. (author)

  8. Ultrasonic nebulization extraction/low pressure photoionization mass spectrometry for direct analysis of chemicals in matrices.

    Science.gov (United States)

    Liu, Chengyuan; Zhu, Yanan; Zhou, Zhongyue; Yang, Jiuzhong; Qi, Fei; Pan, Yang

    2015-09-03

    A novel ultrasonic nebulization extraction/low-pressure photoionization (UNE-LPPI) system has been designed and employed for the rapid mass spectrometric analysis of chemicals in matrices. An ultrasonic nebulizer was used to extract the chemicals in solid sample and nebulize the solvent in the nebulization cell. Aerosols formed by ultrasonic were evaporated by passing through a transferring tube, and desolvated chemicals were ionized by the emitted light (10.6 eV) from a Krypton discharge lamp at low pressure (∼68 Pa). First, a series of semi/non-volatile compounds with different polarities, such as polycyclic aromatic hydrocarbons (PAHs), amino acids, dipeptides, drugs, nucleic acids, alkaloids, and steroids were used to test the system. Then, the quantification capability of UNE-LPPI was checked with: 1) pure chemicals, such as 9,10-phenanthrenequinone and 1,4-naphthoquinone dissolved in solvent; 2) soil powder spiked with different amounts of phenanthrene and pyrene. For pure chemicals, the correlation coefficient (R(2)) for the standard curve of 9,10-phenanthrenequinone in the range of 3 ng-20 μg mL(-1) was 0.9922, and the measured limits of detection (LOD) was 1 ng ml(-1). In the case of soil powder, linear relationships for phenanthrene and pyrene from 10 to 400 ng mg(-1) were obtained with correlation coefficients of 0.9889 and 0.9893, respectively. At last, the feasibility of UNE-LPPI for the detection of chemicals in real matrices such as tablets and biological tissues (tea, Citrus aurantium peel and sage (Salvia officinalis) leaf) were successfully demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Interactions between toxic chemicals and natural environmental factors--a meta-analysis and case studies.

    Science.gov (United States)

    Laskowski, Ryszard; Bednarska, Agnieszka J; Kramarz, Paulina E; Loureiro, Susana; Scheil, Volker; Kudłek, Joanna; Holmstrup, Martin

    2010-08-15

    The paper addresses problems arising from effects of natural environmental factors on toxicity of pollutants to organisms. Most studies on interactions between toxicants and natural factors, including those completed in the EU project NoMiracle (Novel Methods for Integrated Risk Assessment of Cumulative Stressors in Europe) described herein, showed that effects of toxic chemicals on organisms can differ vastly depending purely on external conditions. We compiled data from 61 studies on effects of temperature, moisture and dissolved oxygen on toxicity of a range of chemicals representing pesticides, polycyclic aromatic hydrocarbons, plant protection products of bacterial origin and trace metals. In 62.3% cases significant interactions (pnatural factors and chemicals were found, reaching 100% for the effect of dissolved oxygen on toxicity of waterborne chemicals. The meta-analysis of the 61 studies showed that the null hypothesis assuming no interactions between toxic chemicals and natural environmental factors should be rejected at p=2.7 x 10(-82) (truncated product method probability). In a few cases of more complex experimental designs, also second-order interactions were found, indicating that natural factors can modify interactions among chemicals. Such data emphasize the necessity of including information on natural factors and their variation in time and across geographic regions in ecological risk assessment. This can be done only if appropriate ecotoxicological test designs are used, in which test organisms are exposed to toxicants at a range of environmental conditions. We advocate designing such tests for the second-tier ecological risk assessment procedures. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Tooth Matrix Analysis for Biomonitoring of Organic Chemical Exposure: Current Status, Challenges, and Opportunities

    Science.gov (United States)

    Andra, Syam S.; Austin, Christine; Arora, Manish

    2015-01-01

    Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers to

  11. Thermal and Chemical Characterization of Non-Metallic Materials Using Coupled Thermogravimetric Analysis and Infrared Spectroscopy

    Science.gov (United States)

    Huff, Timothy L.

    2002-01-01

    Thermogravimetric analysis (TGA) is widely employed in the thermal characterization of non-metallic materials, yielding valuable information on decomposition characteristics of a sample over a wide temperature range. However, a potential wealth of chemical information is lost during the process, with the evolving gases generated during thermal decomposition escaping through the exhaust line. Fourier Transform-Infrared spectroscopy (FT-IR) is a powerful analytical technique for determining many chemical constituents while in any material state, in this application, the gas phase. By linking these two techniques, evolving gases generated during the TGA process are directed into an appropriately equipped infrared spectrometer for chemical speciation. Consequently, both thermal decomposition and chemical characterization of a material may be obtained in a single sample run. In practice, a heated transfer line is employed to connect the two instruments while a purge gas stream directs the evolving gases into the FT-IR. The purge gas can be either high purity air or an inert gas such as nitrogen to allow oxidative and pyrolytic processes to be examined, respectively. The FT-IR data is collected realtime, allowing continuous monitoring of chemical compositional changes over the course of thermal decomposition. Using this coupled technique, an array of diverse materials has been examined, including composites, plastics, rubber, fiberglass epoxy resins, polycarbonates, silicones, lubricants and fluorocarbon materials. The benefit of combining these two methodologies is of particular importance in the aerospace community, where newly developing materials have little available data with which to refer. By providing both thermal and chemical data simultaneously, a more definitive and comprehensive characterization of the material is possible. Additionally, this procedure has been found to be a viable screening technique for certain materials, with the generated data useful in

  12. Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate

    Science.gov (United States)

    Oyler, Benjamin L.; Khan, Mohd M.; Smith, Donald F.; Harberts, Erin M.; Kilgour, David P. A.; Ernst, Robert K.; Cross, Alan S.; Goodlett, David R.

    2018-02-01

    Recent advances in lipopolysaccharide (LPS) biology have led to its use in drug discovery pipelines, including vaccine and vaccine adjuvant discovery. Desirable characteristics for LPS vaccine candidates include both the ability to produce a specific antibody titer in patients and a minimal host inflammatory response directed by the innate immune system. However, in-depth chemical characterization of most LPS extracts has not been performed; hence, biological activities of these extracts are unpredictable. Additionally, the most widely adopted workflow for LPS structure elucidation includes nonspecific chemical decomposition steps before analyses, making structures inferred and not necessarily biologically relevant. In this work, several different mass spectrometry workflows that have not been previously explored were employed to show proof-of-principle for top down LPS primary structure elucidation, specifically for a rough-type mutant (J5) E. coli-derived LPS component of a vaccine candidate. First, ion mobility filtered precursor ions were subjected to collision induced dissociation (CID) to define differences in native J5 LPS v. chemically detoxified J5 LPS (dLPS). Next, ultra-high mass resolving power, accurate mass spectrometry was employed for unequivocal precursor and product ion empirical formulae generation. Finally, MS3 analyses in an ion trap instrument showed that previous knowledge about dissociation of LPS components can be used to reconstruct and sequence LPS in a top down fashion. A structural rationale is also explained for differential inflammatory dose-response curves, in vitro, when HEK-Blue hTLR4 cells were administered increasing concentrations of native J5 LPS v. dLPS, which will be useful in future drug discovery efforts. [Figure not available: see fulltext.

  13. Urine storage under refrigeration preserves the sample in chemical, cellularity and bacteriuria analysis of ACS

    Directory of Open Access Journals (Sweden)

    Karen Cristina Barcellos Ribeiro

    2013-12-01

    Full Text Available INTRODUCTION: The analysis of urine abnormal constituents and sediment (ACS comprises tests of great diagnostic and prognostic value in clinical practice. When the analysis of ACS cannot be performed within two hours after collection, the sample must be preserved in order to avoid pre-analytical interferences. Refrigeration is the most applied technique due to its cost effectiveness. Moreover, it presents fewer inconveniences when compared to chemical preservation. However, changes in ACS may also occur in samples under refrigeration. OBJECTIVE: To analyze the influence of refrigeration at 2 to 8ºC on the storage of urine samples within 24 hours. MATERIAL AND METHOD: A total of 80 urine samples were selected from patients admitted at Universidade Federal de Juiz de Fora (UFJF university hospital, which were tested for ACS at room temperature and stored under refrigeration for 6, 12 and 24 hours. RESULTS: The results showed that refrigeration proved to be effective when compared to samples kept at room temperature, inasmuch as the physical, chemical, microbial and cellularity features were preserved. Nevertheless, crystalluria was present after a 6- hour storage period. CONCLUSION: The tests revealed that cooling preserved cellularity and chemical characteristics of urine samples for up to 12 hours. Nonetheless, the precipitation of crystals was evident in this storage method. Thus, the possible consequences of storing urine samples for ACS test under these conditions should be included in the analysis report.

  14. Chemical Differentiation of Osseous, Dental, and Non-skeletal Materials in Forensic Anthropology using Elemental Analysis.

    Science.gov (United States)

    Zimmerman, Heather A; Meizel-Lambert, Cayli J; Schultz, John J; Sigman, Michael E

    2015-03-01

    Forensic anthropologists are generally able to identify skeletal materials (bone and tooth) using gross anatomical features; however, highly fragmented or taphonomically altered materials may be problematic to identify. Several chemical analysis techniques have been shown to be reliable laboratory methods that can be used to determine if questionable fragments are osseous, dental, or non-skeletal in nature. The purpose of this review is to provide a detailed background of chemical analysis techniques focusing on elemental compositions that have been assessed for use in differentiating osseous, dental, and non-skeletal materials. More recently, chemical analysis studies have also focused on using the elemental composition of osseous/dental materials to evaluate species and provide individual discrimination, but have generally been successful only in small, closed groups, limiting their use forensically. Despite significant advances incorporating a variety of instruments, including handheld devices, further research is necessary to address issues in standardization, error rates, and sample size/diversity. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Body composition of two human cadavers by neutron activation and chemical analysis

    International Nuclear Information System (INIS)

    Knight, G.S.; Beddoe, A.H.; Streat, S.J.; Hill, G.L.

    1986-01-01

    In vivo neutron activation analysis (NAA) is currently used to measure body composition in metabolic and nutritional studies in many clinical situations, but has not previously been validated by comparison with chemical analysis of human cadavers. Total body nitrogen (TBN) and chlorine (TBCl) were measured in two human cadavers by NAA before homogenization and chemical analysis (CHEM) after (cadaver 1: TBN, 1.47 NAA, 1.51 CHEM; TBCl, 0.144 NAA, 0.147 CHEM; cadaver 2: TBN, 0.576 NAA, 0.572 CHEM; TBCl, 0.0227 NAA, 0.0250 CHEM). The homogenates were also analyzed by NAA, and no significant differences were found, indicating that the effects of elemental inhomogeneity on the measurement of TBN and TBCl are insignificant. Total body water, fat, protein, minerals, and carbohydrates were measured chemically for each cadaver and compared with estimates for these compartments obtained from a body composition model, which when used in vivo involves NAA and tritium dilution. The agreement found justifies the use of the model for the measurement of changes in total body protein, water, and fat in sequential studies in groups of patients

  16. Chemical characterization of ancient pottery from the southwest Amazonia using neutron activation analysis

    International Nuclear Information System (INIS)

    Carvalho, Patricia R.; Munita, Casimiro S.; Neves, Eduardo G.; Zimpel, Carlos A.; Universidade de Sao Paulo

    2017-01-01

    The analyzes carried out in this work aims to contribute to the discussion about the ceramic objects founded in Monte Castelo's sambaqui located at Southwest Amazonia. The first study accomplished by Miller in 1980 suggests that this archaeological site is inserted in the old contexts of production of ceramics in the Amazon. Until today, there are not any physical and chemical analysis studies in this ceramics and this kind of studies may help archaeological studies performed at the sambaqui. With this purpose, this work presents a preliminary study of chemical characterization of eighty-seven ceramic samples using the Neutron Activation Analysis (NAA). The analyzed elements were: As, K, La, Lu, Na, Nd, Sm, U, Yb, Ce, Co, Cr, Cs, Eu, Fe, Hf, Rb, Sc, Ta, Tb, Th. With the purpose to study the similarity/dissimilarity between the samples cluster and discriminant analysis were used. The results showed the existence of three different chemical groups that are in agreement with the archaeological studies made by Miller which found a sequence of cultural development, with three main occupational components whose dating ranging from 8.400 to 4.000 b.P. In this way, the results of this work are in agreement with miller's studies and suggest Bacabal's phase as the oldest ceramist culture in the Southwest of the Amazon. (author)

  17. Chemical characterization of ancient pottery from the southwest Amazonia using neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Patricia R.; Munita, Casimiro S.; Neves, Eduardo G.; Zimpel, Carlos A., E-mail: camunita@ipen.br, E-mail: edgneves@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de Sao Paulo (MAE/USP), SP (Brazil). Museu de Arqueologia e Etnologia

    2017-11-01

    The analyzes carried out in this work aims to contribute to the discussion about the ceramic objects founded in Monte Castelo's sambaqui located at Southwest Amazonia. The first study accomplished by Miller in 1980 suggests that this archaeological site is inserted in the old contexts of production of ceramics in the Amazon. Until today, there are not any physical and chemical analysis studies in this ceramics and this kind of studies may help archaeological studies performed at the sambaqui. With this purpose, this work presents a preliminary study of chemical characterization of eighty-seven ceramic samples using the Neutron Activation Analysis (NAA). The analyzed elements were: As, K, La, Lu, Na, Nd, Sm, U, Yb, Ce, Co, Cr, Cs, Eu, Fe, Hf, Rb, Sc, Ta, Tb, Th. With the purpose to study the similarity/dissimilarity between the samples cluster and discriminant analysis were used. The results showed the existence of three different chemical groups that are in agreement with the archaeological studies made by Miller which found a sequence of cultural development, with three main occupational components whose dating ranging from 8.400 to 4.000 b.P. In this way, the results of this work are in agreement with miller's studies and suggest Bacabal's phase as the oldest ceramist culture in the Southwest of the Amazon. (author)

  18. Explaining Physics – What Skills does a good Explainer Need?

    CERN Multimedia

    CERN. Geneva; Bartels, Hauke

    2018-01-01

    Explaining physics in a way that it is both scientifically correct and comprehensible is a highly demanding practice. But are explanations an effective way to teach physics? Under which circumstances should a physics teacher explain – and is there such a thing as a guideline for effective instructional explanations? Of course, explaining is more than just presenting content knowledge in clear language – but what more? In our talk, we want to discuss empirical studies on instructional explanations from science education and psychology to address these questions. Among other things, we will refer to results from a large study aiming to research whether teacher education contributes to the development of explaining skills. Besides, we will give insights into a project that seeks to measure explaining skills with an interactive online test instrument.

  19. Chemical sensors and the development of potentiometric methods for liquid media analysis

    International Nuclear Information System (INIS)

    Vlasov, Yu.G.; Kolodnikov, V.V.; Ermolenko, Yu.E.; Mikhajlova, S.S.

    1996-01-01

    Aspects of applying indirect potentiometric determination to chemical analysis are considered. Among them are the standard and modified addition and subtraction methods, the multiple addition method, and potentiometric titration using ion-selective electrodes as indicators. These methods significantly extend the capabilities of ion-selective potentiometric analysis. Conditions for the applicability of the above-mentioned methods to various samples (Cd, REE, Th, iodides and others) are discussed using all available ion-selective electrodes as examples. 162 refs., 2 figs., 5 tabs

  20. Pathway analysis and exposure assessment: MEPAS modeling for nonradiological chemical contaminants at the Hanford Site

    International Nuclear Information System (INIS)

    Blanton, M.L.; Dirkes, R.; Buck, J.; Cooper, A.; Castieton, K.; Glantz, C.

    1995-01-01

    A Chemical Pathway Analysis and Exposure Assessment was performed by the Surface Environmental Surveillance Project (SESP). The SESP monitors air, surface water, sediment, agricultural products, vegetation, soil, and wildlife in order to assess onsite of offsite environmental impacts and offsite human health risk at the Hanford Site. The objectives of this study are (1) determine if a nonradiological chemical monitoring program is warranted for the Hanford Site, (2) ensure that the selection of surveillance parameters such as media, sampling location, and analytes are chosen in a manner that is scientifically sound and cost-efficient, and (3) identify specific nonradiological chemicals of concern (COC) for the Hanford Site. The basis for identification of COC for the Hanford Site was an extensive literature review. The model was also used to predict COC concentrations required onsite to achieve an offsite cancer incidence of 1 E-6 and a hazard quotient of 1.0. This study indicated that nonradiological chemical contamination occurring onsite does not pose a significant offsite human health risk. The highest cancer incidence to the offsite maximally exposed individual from COC was from arsenic (1.76E-1 0); the highest hazard quotient was chromium VI (1.48E-04)

  1. Congruence between patient characteristics and interventions may partly explain medication adherence intervention effectiveness: an analysis of 190 randomized controlled trials from a Cochrane systematic review.

    Science.gov (United States)

    Allemann, Samuel S; Nieuwlaat, Robby; Navarro, Tamara; Haynes, Brian; Hersberger, Kurt E; Arnet, Isabelle

    2017-11-01

    Due to the negative outcomes of medication nonadherence, interventions to improve adherence have been the focus of countless studies. The congruence between adherence-related patient characteristics and interventions may partly explain the variability of effectiveness in medication adherence studies. In their latest update of a Cochrane review reporting inconsistent effects of adherence interventions, the authors offered access to their database for subanalysis. We aimed to use this database to assess congruence between adherence-related patient characteristics and interventions and its association with intervention effects. We developed a congruence score consisting of six features related to inclusion criteria, patient characteristics at baseline, and intervention design. Two independent raters extracted and scored items from the 190 studies available in the Cochrane database. We correlated overall congruence score and individual features with intervention effects regarding adherence and clinical outcomes using Kruskal-Wallis rank sum test and Fisher's exact test. Interrater reliability for newly extracted data was almost perfect with a Cohen's Kappa of 0.92 [95% confidence interval (CI) = 0.89-0.94; P congruence score nor any other individual feature (i.e., "determinants of nonadherence as inclusion criteria," "tailoring of interventions to the inclusion criteria," "reasons for nonadherence assessed at baseline," "adjustment of intervention to individual patient needs," and "theory-based interventions") was significantly associated with intervention effects. The presence of only six studies that included nonadherent patients and the interdependency of this feature with the remaining five might preclude a conclusive assessment of congruence between patient characteristics and adherence interventions. In order to obtain clinical benefits from effective adherence interventions, we encourage researchers to focus on the inclusion of nonadherent patients. Copyright

  2. A chemical profiling strategy for semi-quantitative analysis of flavonoids in Ginkgo extracts.

    Science.gov (United States)

    Yang, Jing; Wang, An-Qi; Li, Xue-Jing; Fan, Xue; Yin, Shan-Shan; Lan, Ke

    2016-05-10

    Flavonoids analysis in herbal products is challenged by their vast chemical diversity. This work aimed to develop a chemical profiling strategy for the semi-quantification of flavonoids using extracts of Ginkgo biloba L. (EGB) as an example. The strategy was based on the principle that flavonoids in EGB have an almost equivalent molecular absorption coefficient at a fixed wavelength. As a result, the molecular-contents of flavonoids were able to be semi-quantitatively determined by the molecular-concentration calibration curves of common standards and recalculated as the mass-contents with the characterized molecular weight (MW). Twenty batches of EGB were subjected to HPLC-UV/DAD/MS fingerprinting analysis to test the feasibility and reliability of this strategy. The flavonoid peaks were distinguished from the other peaks with principle component analysis and Pearson correlation analysis of the normalized UV spectrometric dataset. Each flavonoid peak was subsequently tentatively identified by the MS data to ascertain their MW. It was highlighted that the flavonoids absorption at Band-II (240-280 nm) was more suitable for the semi-quantification purpose because of the less variation compared to that at Band-I (300-380 nm). The semi-quantification was therefore conducted at 254 nm. Beyond the qualitative comparison results acquired by common chemical profiling techniques, the semi-quantitative approach presented the detailed compositional information of flavonoids in EGB and demonstrated how the adulteration of one batch was achieved. The developed strategy was believed to be useful for the advanced analysis of herbal extracts with a high flavonoid content without laborious identification and isolation of individual components. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Directory of Open Access Journals (Sweden)

    José A. Centeno

    2014-01-01

    Full Text Available Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU, tungsten (W, lead (Pb, and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF, scanning electron microscopy (SEM, laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS, and confocal laser Raman

  4. ISS Expeditions 16 through 20: Chemical Analysis Results for Potable Water

    Science.gov (United States)

    Straub, John E., II; Plumlee, Debrah K.; Schultz, John R.

    2010-01-01

    During the 2-year span from Expedition 16 through Expedition 20, the chemical quality of the potable water onboard the International Space Station (ISS) was verified safe for crew consumption through the return and chemical analysis of archival water samples by the Water and Food Analytical Laboratory (WAFAL) at Johnson Space Center (JSC). Reclaimed cabin humidity condensate and Russian ground-supplied water were the principal sources of potable water for Expeditions 16 through 18. During Expedition 18 the U.S. water processor assembly was delivered, installed, and tested during a 90-day checkout period. Beginning with Expedition 19, U.S. potable water recovered from a combined waste stream of humidity condensate and pretreated urine was also available for ISS crew use. A total of 74 potable water samples were collected using U.S. sampling hardware during Expeditions 16 through 20 and returned on both Shuttle and Soyuz vehicles. The results of JSC chemical analyses of these ISS potable water samples are presented in this paper. Eight potable water samples collected in flight with Russian hardware were also received for analysis, as well as 5 preflight samples of Rodnik potable water delivered to ISS on Russian Progress vehicles 28 to 34. Analytical results for these additional potable water samples are also reported and discussed.

  5. Humidity independent mass spectrometry for gas phase chemical analysis via ambient proton transfer reaction.

    Science.gov (United States)

    Zhu, Hongying; Huang, Guangming

    2015-03-31

    In this work, a humidity independent mass spectrometric method was developed for rapid analysis of gas phase chemicals. This method is based upon ambient proton transfer reaction between gas phase chemicals and charged water droplets, in a reaction chamber with nearly saturate humidity under atmospheric pressure. The humidity independent nature enables direct and rapid analysis of raw gas phase samples, avoiding time- and sample-consuming sample pretreatments in conventional mass spectrometry methods to control sample humidity. Acetone, benzene, toluene, ethylbenzene and meta-xylene were used to evaluate the analytical performance of present method. The limits of detection for benzene, toluene, ethylbenzene and meta-xylene are in the range of ∼0.1 to ∼0.3 ppbV; that of benzene is well below the present European Union permissible exposure limit for benzene vapor (5 μg m(-3), ∼1.44 ppbV), with linear ranges of approximately two orders of magnitude. The majority of the homemade device contains a stainless steel tube as reaction chamber and an ultrasonic humidifier as the source of charged water droplets, which makes this cheap device easy to assemble and facile to operate. In addition, potential application of this method was illustrated by the real time identification of raw gas phase chemicals released from plants at different physiological stages. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Quality in the chemical analysis of biological matrices by fluorescence X-ray by energy dispersive

    International Nuclear Information System (INIS)

    Sousa, Evely E. de; Paiva, Jose Daniel S. de; Franca, Elvis J. de; Almeida, Macio E.S.; Cantinha, Rebeca S.; Hazin, Clovis A.

    2013-01-01

    The aim of this study was to obtain multielement analytical curves of high analytical rigor to the analysis of biological matrices by the technique of fluorescence x-ray energy dispersive - EDXRF. Calibration curves were constructed from the reference materials IAEA 140, IAEA 155, IAEA V8, V10 to the International Atomic Energy Agency - IAEA, and SRM1515, SRM 1547, SRM 1570a, SRM 1573a, SEM 1567a, to the National Institute of Standards and Technology - NIST. After energy calibration, all samples were subjected to vacuum to the analyzes by 100 seconds for each group of chemical elements. The voltages used were respectively 15 keV for chemical elements with less than atomic number 22 and 50 keV for the others. After the construction of the curves, the analytical quality was assessed by the analysis of a portion-test of the reference material SRM 2976, also produced by NIST. Based on the number of certified reference materials used for construction of calibration curves in this work, quality analytical protocol was originated with considerable reliability for quantification of chemical elements in biological samples by EDXR

  7. Chemical composition dispersion in bi-metallic nanoparticles: semi-automated analysis using HAADF-STEM

    International Nuclear Information System (INIS)

    Epicier, T.; Sato, K.; Tournus, F.; Konno, T.

    2012-01-01

    We present a method using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) to determine the chemical composition of bi-metallic nanoparticles. This method, which can be applied in a semi-automated way, allows large scale analysis with a statistical number of particles (several hundreds) in a short time. Once a calibration curve has been obtained, e.g., using energy-dispersive X-ray spectroscopy (EDX) measurements on a few particles, the HAADF integrated intensity of each particle can indeed be directly related to its chemical composition. After a theoretical description, this approach is applied to the case of iron–palladium nanoparticles (expected to be nearly stoichiometric) with a mean size of 8.3 nm. It will be shown that an accurate chemical composition histogram is obtained, i.e., the Fe content has been determined to be 49.0 at.% with a dispersion of 10.4 %. HAADF-STEM analysis represents a powerful alternative to fastidious single particle EDX measurements, for the compositional dispersion in alloy nanoparticles.

  8. Methodology for the physical and chemical exergetic analysis of steam boilers

    International Nuclear Information System (INIS)

    Ohijeagbon, Idehai O.; Waheed, M. Adekojo; Jekayinfa, Simeon O.

    2013-01-01

    This paper presents a framework of thermodynamic, energy and exergy, analyses of industrial steam boilers. Mass, energy, and exergy analysis were used to develop a methodology for evaluating thermodynamic properties, energy and exergy input and output resources in industrial steam boilers. Determined methods make available an analytic procedure for the physical and chemical exergetic analysis of steam boilers for appropriate applications. The energy and exergy efficiencies obtained for the entire boiler was 69.56% and 38.57% at standard reference state temperature of 25 °C for an evaporation ratio of 12. Chemical exergy of the material streams was considered to offer a more comprehensive detail on energy and exergy resource allocation and losses of the processes in a steam boiler. - Highlights: ► We evaluated thermodynamic properties and performance variables associated with material streams. ► We analysed resources allocation, and magnitude of exergetic losses in steam boilers. ► Chemical exergy of material streams contributed to improved exergy values. ► High operational parameter will lead to higher boiler exergy. ► Exergy destroyed was higher in the combustion as against the heat exchanging unit

  9. Enhanced Botrytis cinerea resistance of Arabidopsis plants grown in compost may be explained by increased expression of defense-related genes, as revealed by microarray analysis.

    Directory of Open Access Journals (Sweden)

    Guillem Segarra

    Full Text Available Composts are the products obtained after the aerobic degradation of different types of organic matter waste and can be used as substrates or substrate/soil amendments for plant cultivation. There is a small but increasing number of reports that suggest that foliar diseases may be reduced when using compost, rather than standard substrates, as growing medium. The purpose of this study was to examine the gene expression alteration produced by the compost to gain knowledge of the mechanisms involved in compost-induced systemic resistance. A compost from olive marc and olive tree leaves was able to induce resistance against Botrytis cinerea in Arabidopsis, unlike the standard substrate, perlite. Microarray analyses revealed that 178 genes were differently expressed, with a fold change cut-off of 1, of which 155 were up-regulated and 23 were down-regulated in compost-grown, as against perlite-grown plants. A functional enrichment study of up-regulated genes revealed that 38 Gene Ontology terms were significantly enriched. Response to stress, biotic stimulus, other organism, bacterium, fungus, chemical and abiotic stimulus, SA and ABA stimulus, oxidative stress, water, temperature and cold were significantly enriched, as were immune and defense responses, systemic acquired resistance, secondary metabolic process and oxireductase activity. Interestingly, PR1 expression, which was equally enhanced by growing the plants in compost and by B. cinerea inoculation, was further boosted in compost-grown pathogen-inoculated plants. Compost triggered a plant response that shares similarities with both systemic acquired resistance and ABA-dependent/independent abiotic stress responses.

  10. PACSY, a relational database management system for protein structure and chemical shift analysis.

    Science.gov (United States)

    Lee, Woonghee; Yu, Wookyung; Kim, Suhkmann; Chang, Iksoo; Lee, Weontae; Markley, John L

    2012-10-01

    PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.edu.

  11. Mass spectrographic analysis of selected chemical elements by microbial leaching of zircon

    International Nuclear Information System (INIS)

    Becker, S.; Dietze, H.J.; Bullmann, M.; Iske, U.

    1986-01-01

    Spark source mass spectrometry is a useful method for chemical element analysis of geological and biological samples. This sensitive technique (detection limit down to the ppb-range) is used to analyze leaching processes by means of several microorganisms. The problem of microbial leaching of chemical resistent materials was tested under laboratory conditions with regard to possible analytical and technical applications. Leaching of metals with chemolithotrophic and heterotrophic, organic acids producing microorganisms has been investigated with zircon from the Baltic Shield containing 0.7% rare earth elements and 1.67% hafnium. When zircon is leached with strains of thiobacillus ferrooxidans about 80% of the rare earth elements, Hf, Th and U can be recovered. (orig.) [de

  12. Chemical analysis and antioxidant activity in vitro of polysaccharides extracted from Boletus edulis.

    Science.gov (United States)

    Zhang, Anqiang; Xiao, Nannan; He, Pengfei; Sun, Peilong

    2011-12-01

    Boletus edulis is a well-known delicious mushroom. In this study, three crude polysaccharides (BEPF30, BEPF60 and BEPF80) were isolated from the fruiting bodies of B. edulis with boiling water. Chemical and physical characteristics of the three crude polysaccharides were investigated by the combination of chemical and instrumental analysis methods. Their antioxidant activities were investigated in vitro systems including hydroxyl assay, superoxide radical assay, reducing power and chelating activity. Among these three polysaccharides, BEPF60 showed more significant reducing power and chelating activity; and highest inhibitory effects on superoxide radical and hydroxyl radical. These results indicated that polysaccharides extracted from B. edulis might be employed as ingredients in healthy and functional food to alleviate the oxidative stress. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Fault detection in nonlinear chemical processes based on kernel entropy component analysis and angular structure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Qingchao; Yan, Xuefeng; Lv, Zhaomin; Guo, Meijin [East China University of Science and Technology, Shanghai (China)

    2013-06-15

    Considering that kernel entropy component analysis (KECA) is a promising new method of nonlinear data transformation and dimensionality reduction, a KECA based method is proposed for nonlinear chemical process monitoring. In this method, an angle-based statistic is designed because KECA reveals structure related to the Renyi entropy of input space data set, and the transformed data sets are produced with a distinct angle-based structure. Based on the angle difference between normal status and current sample data, the current status can be monitored effectively. And, the confidence limit of the angle-based statistics is determined by kernel density estimation based on sample data of the normal status. The effectiveness of the proposed method is demonstrated by case studies on both a numerical process and a simulated continuous stirred tank reactor (CSTR) process. The KECA based method can be an effective method for nonlinear chemical process monitoring.

  14. Fault detection in nonlinear chemical processes based on kernel entropy component analysis and angular structure

    International Nuclear Information System (INIS)

    Jiang, Qingchao; Yan, Xuefeng; Lv, Zhaomin; Guo, Meijin

    2013-01-01

    Considering that kernel entropy component analysis (KECA) is a promising new method of nonlinear data transformation and dimensionality reduction, a KECA based method is proposed for nonlinear chemical process monitoring. In this method, an angle-based statistic is designed because KECA reveals structure related to the Renyi entropy of input space data set, and the transformed data sets are produced with a distinct angle-based structure. Based on the angle difference between normal status and current sample data, the current status can be monitored effectively. And, the confidence limit of the angle-based statistics is determined by kernel density estimation based on sample data of the normal status. The effectiveness of the proposed method is demonstrated by case studies on both a numerical process and a simulated continuous stirred tank reactor (CSTR) process. The KECA based method can be an effective method for nonlinear chemical process monitoring

  15. PACSY, a relational database management system for protein structure and chemical shift analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woonghee, E-mail: whlee@nmrfam.wisc.edu [University of Wisconsin-Madison, National Magnetic Resonance Facility at Madison, and Biochemistry Department (United States); Yu, Wookyung [Center for Proteome Biophysics, Pusan National University, Department of Physics (Korea, Republic of); Kim, Suhkmann [Pusan National University, Department of Chemistry and Chemistry Institute for Functional Materials (Korea, Republic of); Chang, Iksoo [Center for Proteome Biophysics, Pusan National University, Department of Physics (Korea, Republic of); Lee, Weontae, E-mail: wlee@spin.yonsei.ac.kr [Yonsei University, Structural Biochemistry and Molecular Biophysics Laboratory, Department of Biochemistry (Korea, Republic of); Markley, John L., E-mail: markley@nmrfam.wisc.edu [University of Wisconsin-Madison, National Magnetic Resonance Facility at Madison, and Biochemistry Department (United States)

    2012-10-15

    PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.eduhttp://pacsy.nmrfam.wisc.edu.

  16. Prediction of chemical, physical and sensory data from process parameters for frozen cod using multivariate analysis

    DEFF Research Database (Denmark)

    Bechmann, Iben Ellegaard; Jensen, H.S.; Bøknæs, Niels

    1998-01-01

    Physical, chemical and sensory quality parameters were determined for 115 cod (Gadus morhua) samples stored under varying frozen storage conditions. Five different process parameters (period of frozen storage, frozen storage. temperature, place of catch, season for catching and state of rigor) were...... varied systematically at two levels. The data obtained were evaluated using the multivariate methods, principal component analysis (PCA) and partial least squares (PLS) regression. The PCA models were used to identify which process parameters were actually most important for the quality of the frozen cod....... PLS models that were able to predict the physical, chemical and sensory quality parameters from the process parameters of the frozen raw material were generated. The prediction abilities of the PLS models were good enough to give reasonable results even when the process parameters were characterised...

  17. Chemical contents in Lygeum spartum L. using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Nedjimi, Bouzid

    2015-01-01

    The present investigation was conducted to determine the chemical contents of Lygeum spartum L. (Poaceae). Samples were analyzed in order to determine essential (Ca, K, Na, Fe, Co) and some potentially toxic elements (Eu, Sb, Tb) using instrumental neutron activation analysis (INAA). In general chemical element contents were in substantial amounts to meet adult sheep requirements. Potential intake of Ca, K, Zn, Co and Fe by ruminant weighing 50 kg BW consuming 2.0 kg per day DM was sufficient to satisfy their requirements. However, only Na level was still insufficient to meet the requirements for grazing ruminants. Potential toxic elements in this species were within the safety baseline of all the assayed elements recommended by NRC. Na supplementation would seem to be necessary in this zone, for optimum productivity of grazing animals.

  18. PACSY, a relational database management system for protein structure and chemical shift analysis

    Science.gov (United States)

    Lee, Woonghee; Yu, Wookyung; Kim, Suhkmann; Chang, Iksoo

    2012-01-01

    PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.edu. PMID:22903636

  19. PACSY, a relational database management system for protein structure and chemical shift analysis

    International Nuclear Information System (INIS)

    Lee, Woonghee; Yu, Wookyung; Kim, Suhkmann; Chang, Iksoo; Lee, Weontae; Markley, John L.

    2012-01-01

    PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.eduhttp://pacsy.nmrfam.wisc.edu.

  20. Hyperplane distance neighbor clustering based on local discriminant analysis for complex chemical processes monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chunhong; Xiao, Shaoqing; Gu, Xiaofeng [Jiangnan University, Wuxi (China)

    2014-11-15

    The collected training data often include both normal and faulty samples for complex chemical processes. However, some monitoring methods, such as partial least squares (PLS), principal component analysis (PCA), independent component analysis (ICA) and Fisher discriminant analysis (FDA), require fault-free data to build the normal operation model. These techniques are applicable after the preliminary step of data clustering is applied. We here propose a novel hyperplane distance neighbor clustering (HDNC) based on the local discriminant analysis (LDA) for chemical process monitoring. First, faulty samples are separated from normal ones using the HDNC method. Then, the optimal subspace for fault detection and classification can be obtained using the LDA approach. The proposed method takes the multimodality within the faulty data into account, and thus improves the capability of process monitoring significantly. The HDNC-LDA monitoring approach is applied to two simulation processes and then compared with the conventional FDA based on the K-nearest neighbor (KNN-FDA) method. The results obtained in two different scenarios demonstrate the superiority of the HDNC-LDA approach in terms of fault detection and classification accuracy.

  1. Molecular structure, vibrational analysis (IR and Raman) and quantum chemical investigations of 1-aminoisoquinoline

    Science.gov (United States)

    Sivaprakash, S.; Prakash, S.; Mohan, S.; Jose, Sujin P.

    2017-12-01

    Quantum chemical calculations of energy and geometrical parameters of 1-aminoisoquinoline [1-AIQ] were carried out by using DFT/B3LYP method using 6-311G (d,p), 6-311G++(d,p) and cc-pVTZ basis sets. The vibrational wavenumbers were computed for the energetically most stable, optimized geometry. The vibrational assignments were performed on the basis of potential energy distribution (PED) using VEDA program. The NBO analysis was done to investigate the intra molecular charge transfer of the molecule. The frontier molecular orbital (FMO) analysis was carried out and the chemical reactivity descriptors of the molecule were studied. The Mulliken charge analysis, molecular electrostatic potential (MEP), HOMO-LUMO energy gap and the related properties were also investigated at B3LYP level. The absorption spectrum of the molecule was studied from UV-Visible analysis by using time-dependent density functional theory (TD-DFT). Fourier Transform Infrared spectrum (FT-IR) and Raman spectrum of 1-AIQ compound were analyzed and recorded in the range 4000-400 cm-1 and 3500-100 cm-1 respectively. The experimentally determined wavenumbers were compared with those calculated theoretically and they complement each other.

  2. Scanning photoelectron microscope for nanoscale three-dimensional spatial-resolved electron spectroscopy for chemical analysis.

    Science.gov (United States)

    Horiba, K; Nakamura, Y; Nagamura, N; Toyoda, S; Kumigashira, H; Oshima, M; Amemiya, K; Senba, Y; Ohashi, H

    2011-11-01

    In order to achieve nondestructive observation of the three-dimensional spatially resolved electronic structure of solids, we have developed a scanning photoelectron microscope system with the capability of depth profiling in electron spectroscopy for chemical analysis (ESCA). We call this system 3D nano-ESCA. For focusing the x-ray, a Fresnel zone plate with a diameter of 200 μm and an outermost zone width of 35 nm is used. In order to obtain the angular dependence of the photoelectron spectra for the depth-profile analysis without rotating the sample, we adopted a modified VG Scienta R3000 analyzer with an acceptance angle of 60° as a high-resolution angle-resolved electron spectrometer. The system has been installed at the University-of-Tokyo Materials Science Outstation beamline, BL07LSU, at SPring-8. From the results of the line-scan profiles of the poly-Si/high-k gate patterns, we achieved a total spatial resolution better than 70 nm. The capability of our system for pinpoint depth-profile analysis and high-resolution chemical state analysis is demonstrated. © 2011 American Institute of Physics

  3. Application of quantum dots as analytical tools in automated chemical analysis: A review

    International Nuclear Information System (INIS)

    Frigerio, Christian; Ribeiro, David S.M.; Rodrigues, S. Sofia M.; Abreu, Vera L.R.G.; Barbosa, João A.C.; Prior, João A.V.; Marques, Karine L.; Santos, João L.M.

    2012-01-01

    Highlights: ► Review on quantum dots application in automated chemical analysis. ► Automation by using flow-based techniques. ► Quantum dots in liquid chromatography and capillary electrophoresis. ► Detection by fluorescence and chemiluminescence. ► Electrochemiluminescence and radical generation. - Abstract: Colloidal semiconductor nanocrystals or quantum dots (QDs) are one of the most relevant developments in the fast-growing world of nanotechnology. Initially proposed as luminescent biological labels, they are finding new important fields of application in analytical chemistry, where their photoluminescent properties have been exploited in environmental monitoring, pharmaceutical and clinical analysis and food quality control. Despite the enormous variety of applications that have been developed, the automation of QDs-based analytical methodologies by resorting to automation tools such as continuous flow analysis and related techniques, which would allow to take advantage of particular features of the nanocrystals such as the versatile surface chemistry and ligand binding ability, the aptitude to generate reactive species, the possibility of encapsulation in different materials while retaining native luminescence providing the means for the implementation of renewable chemosensors or even the utilisation of more drastic and even stability impairing reaction conditions, is hitherto very limited. In this review, we provide insights into the analytical potential of quantum dots focusing on prospects of their utilisation in automated flow-based and flow-related approaches and the future outlook of QDs applications in chemical analysis.

  4. Hyperplane distance neighbor clustering based on local discriminant analysis for complex chemical processes monitoring

    International Nuclear Information System (INIS)

    Lu, Chunhong; Xiao, Shaoqing; Gu, Xiaofeng

    2014-01-01

    The collected training data often include both normal and faulty samples for complex chemical processes. However, some monitoring methods, such as partial least squares (PLS), principal component analysis (PCA), independent component analysis (ICA) and Fisher discriminant analysis (FDA), require fault-free data to build the normal operation model. These techniques are applicable after the preliminary step of data clustering is applied. We here propose a novel hyperplane distance neighbor clustering (HDNC) based on the local discriminant analysis (LDA) for chemical process monitoring. First, faulty samples are separated from normal ones using the HDNC method. Then, the optimal subspace for fault detection and classification can be obtained using the LDA approach. The proposed method takes the multimodality within the faulty data into account, and thus improves the capability of process monitoring significantly. The HDNC-LDA monitoring approach is applied to two simulation processes and then compared with the conventional FDA based on the K-nearest neighbor (KNN-FDA) method. The results obtained in two different scenarios demonstrate the superiority of the HDNC-LDA approach in terms of fault detection and classification accuracy

  5. Comprehensive default methodology for the analysis of exposures to mixtures of chemicals accidentally released to the atmosphere

    International Nuclear Information System (INIS)

    Craig, D.K.; Baskett, R.L.; Powell, T.J.; Davis, J.S.; Dukes, L.L.; Hansen, D.J.; Petrocchi, A.J.; Sutherland, P.J.

    1997-01-01

    Safety analysis of Department of Energy (DOE) facilities requires consideration of potential exposures to mixtures of chemicals released to the atmosphere. Exposure to chemical mixtures may lead to additive, synergistic, or antagonistic health effects. In the past, the consequences of each chemical have been analyzed separately. This approach may not adequately protect the health of persons exposed to mixtures. However, considerable time would be required to evaluate all possible mixtures. The objective of this paper is to present reasonable default methodology developed by the EFCOG Safety Analysis Working Group Nonradiological Hazardous Material Subgroup (NHMS) for use in safety analysis within the DOE Complex

  6. Microfluidic electrochemical device and process for chemical imaging and electrochemical analysis at the electrode-liquid interface in-situ

    Science.gov (United States)

    Yu, Xiao-Ying; Liu, Bingwen; Yang, Li; Zhu, Zihua; Marshall, Matthew J.

    2016-03-01

    A microfluidic electrochemical device and process are detailed that provide chemical imaging and electrochemical analysis under vacuum at the surface of the electrode-sample or electrode-liquid interface in-situ. The electrochemical device allows investigation of various surface layers including diffuse layers at selected depths populated with, e.g., adsorbed molecules in which chemical transformation in electrolyte solutions occurs.

  7. Pressure fluctuation analysis for charging pump of chemical and volume control system of nuclear power plant

    Directory of Open Access Journals (Sweden)

    Chen Qiang

    2016-01-01

    Full Text Available Equipment Failure Root Cause Analysis (ERCA methodology is employed in this paper to investigate the root cause for charging pump’s pressure fluctuation of chemical and volume control system (RCV in pressurized water reactor (PWR nuclear power plant. RCA project task group has been set up at the beginning of the analysis process. The possible failure modes are listed according to the characteristics of charging pump’s actual pressure fluctuation and maintenance experience during the analysis process. And the failure modes are analysed in proper sequence by the evidence-collecting. It suggests that the gradually untightened and loosed shaft nut in service should be the root cause. And corresponding corrective actions are put forward in details.

  8. Kinematic analysis of in situ measurement during chemical mechanical planarization process

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hongkai; Wang, Tongqing; Zhao, Qian; Meng, Yonggang; Lu, Xinchun, E-mail: xclu@tsinghua.edu.cn [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2015-10-15

    Chemical mechanical planarization (CMP) is the most widely used planarization technique in semiconductor manufacturing presently. With the aid of in situ measurement technology, CMP tools can achieve good performance and stable productivity. However, the in situ measurement has remained unexplored from a kinematic standpoint. The available related resources for the kinematic analysis are very limited due to the complexity and technical secret. In this paper, a comprehensive kinematic analysis of in situ measurement is provided, including the analysis model, the measurement trajectory, and the measurement time of each zone of wafer surface during the practical CMP process. In addition, a lot of numerical calculations are performed to study the influences of main parameters on the measurement trajectory and the measurement velocity variation of the probe during the measurement process. All the efforts are expected to improve the in situ measurement system and promote the advancement in CMP control system.

  9. The geographical origin and chemical composition in phellinus mushrooms measured by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Lim, J.M.; Sun, G.M.; Moon, J.H.; Chung, Y.S.; Lee, J.H.; Kim, K.H.

    2012-01-01

    In order to expand the utilization of phellinus mushrooms as a dietary supplement, we attempted to evaluate the chemical composition by measuring its inorganic elemental content with the aid of instrumental neutron activation analysis (INAA). Twenty seven phellinus mushrooms samples were collected from Korea, Cambodia, and Vietnam. A total of 28 elements were analyzed in the phellinus mushroom samples using the INAA. The concentrations of Ca, K, and Mg are much higher than those of other elements in phellinus mushroom samples. The sum of determined elemental concentration in Cambodia samples was about 2-6 times higher than those in Korea and Vietnam samples, respectively. Based on our measurement data, we attempted to discriminate the geographical origin using principal components analysis (PCA) and linear discriminant analysis (LDA). The geographical origins of all samples were clearly classified with correct classification rate of 100%. (author)

  10. Analysis of radiation and chemical factors which define the ecological situation of environment

    International Nuclear Information System (INIS)

    Trofimenko, A.P.

    1996-01-01

    A new method of large information set statistical analysis is proposed. It permits to define the main directions of work in a given field in the world or in a particular country, to find the most important investigated problems and to evaluate the role each of them quantitatively, as well as to study the dynamics of work development in time, the methods of research used, the centres in which this research is mostly developed, authors of publications etc. Statistical analysis may be supplemented with subject analysis of selected publications. Main factors which influence on different environment components and on public health are presented as an example of this method use, and the role of radiation and chemical factors is evaluated. 18 refs., 6 tab

  11. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

  12. Chemical and Microbiological Analysis of Certain Water Sources and Industrial Wastewater Samples in Dakahlia Governorate

    International Nuclear Information System (INIS)

    El-Fadaly, H.; El-Defrawy, M.M.; El-Zawawy, F.; Makia, D.

    1999-01-01

    The chemical analysis included quantitative measurement of electrical conductivity, alkalinity , hardness sulphate, ph, total dissolved solids, chloride, as well as dissolved oxygen was carried out. The microbiological examination for different water sources and industrial wastewater samples was also conducted. some of heavy metals, Co 2+ Cu 2+ Fe 3+ and Mn 2+ were determined in fresh water, while other metals, such as Cr 6+ , Co 2+ , Zn 2+ and Ni 2+ were measured in industrial wastewater. Results of the chemical analysis showed that all measured parameters were found within the limitation either national or international law, except some samples which showed higher values than the permissible limits for some measured parameters. The microbiological analysis exhibited presence of yeasts, fungi and bacteria. Most bacterial isolates were short rod, spore formers as well as coccoid shaped bacteria. The efficiency of water treatment process on the reduction of microbial load was also calculated. Regarding the pathogenic bacteria, data showed that neither water samples nor industrial wastewater contain pathogens when using specific cultivation media for the examination. Furthermore, data proved the possibility of recycling of the tested industrial wastewater on which some microorganisms can grow. Data showed that the percent of heavy metals removal can reach to more than 70% in some cases as a result to bacterial treatment of industrial wastewater

  13. Impact analysis of different chemical pre-treatments on colour of apple discs during drying process

    Directory of Open Access Journals (Sweden)

    Jasmina Lukinac

    2009-01-01

    Full Text Available The main purpose of this study was to compare colour changes of chemically pre-treated dried apple discs. Changes were observed by chromameter in L*a*b* colour model by using Minolta chromameter CR-400 and by image analysis system in RGB colour model. Apple discs variety "Gold Rush" were pre-treated and dried in laboratory tray drier at drying temperature 70 °C and at airflow velocity of 1.5 ms-1. Different chemical pre-treatments were applied on apple discs (dipping in 0.5% ascorbic acid solution; 0.3% L–cysteine solution; 0.1% 4–hexyl resorcinol solution and 1% sodium metabisulphite solution. Mean values of colour parameters, colour changes and correlation coefficients for apple discs were calculated for both colour models. The analysis showed statistically significant influence of pre-treatment method on total colour changes for both chosen colour models of dried apples. Calculated correlation coefficient between colour changes for used models was found to be 0.894. According to colour characteristics the best results were achieved when samples were pre-treated with 0.5% ascorbic acid solution. According to calculated results it was found that image analysis method as well as colorimetric method can be used to observe the colour changes on dried apple discs.

  14. Analysis of iodine chemical form noted from severe fuel damage experiments

    International Nuclear Information System (INIS)

    Cronenberg, A.W.; Osetek, D.J.

    1986-01-01

    Data from the TMI-2 accident has shown that only small amounts of iodine (I) escaped the plant. The postulated reason for such limited release is the formation of CsI (a salt) within fuel, which remains stable in a reducing high-temperature steam-H 2 environment. Upon cooldown CsI would dissolve in water condensate to form an ionic solution. However, recent data from fuel destruction experiments indicate different iodine release behavior that is tied to fuel burnup and oxidation conditions, as well as fission product concentration levels in the steam/H 2 effluent. Analysis of the data indicate that at low-burnup conditions, atomic I release from fuel is favored. Likewise, at low fission product concentration conditions HI is the favored chemical form in the steam/H 2 environment, not CsI. Results of thermochemical equilibria and chemical kinetics analysis support the data trends noted from the PBF-SFD tests. An a priori assumption of CsI for risk analysis of all accident sequences may therefore be inappropriate

  15. A new TXRF vacuum chamber with sample changer for chemical analysis using silicon drift chamber detector

    International Nuclear Information System (INIS)

    Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

    2003-01-01

    Full text: Several TXRF spectrometers for chemical analysis as well as for wafer surface analysis are commercially available. But there is no one available for chemical analysis offering the possibility to measure the samples in vacuum conditions. Vacuum of 10 -2 mbar in the sample environment helps to reduce the background due to scattering from air, thus to improve the detection limits as well as to reduce the absorption of low energy fluorescence radiation from low Z elements and extend the elemental range to be measured and removes the Ar lines from the spectrum. The x-ray group of the Atominstitut designed and fabricated a new vacuum chamber for TXRF equipped with a 12 position sample changer from Italstructures, Riva, Italy. The detector used was a 10 mm 2 silicon drift detector (KETEK, Munich, Germany), offering the advantage of electrically cooling, so no LN2 is required. The chamber was designed to be attached to a diffraction tube housing, e.g. with a fine focus Mo-x-ray tube and uses a multilayer monochromator. Spectra are stored by a small AMTEK MCA and control between sample changer and MCA communication is done by a modified AMPTEK software. The performance is expressed in detection limits of 1 pg Rb for Mo Ka excitation with 50 kV, 40 mA excitation conditions, 1000 s lifetime, obtained from a sample containing 600 pg Rb as single element standard. Details on performance, reproducibility and light element excitation and detection are presented. (author)

  16. Nuclear and radiochemical techniques in chemical analysis. Progress report, 1 June 1974--31 May 1975

    International Nuclear Information System (INIS)

    Finston, H.L.; Williams, E.T.

    1975-01-01

    Progress on the project to determine the neutron-absorption cross section of 22 Na is described. Upper limits for the thermal-neutron cross sections of 88 Y and 139 Ce have been set at 100 barns. The experiment to search for a change in the ratio of electron capture to positron emission due to difference in chemical environment is underway. The mechanical aspects of the system for analysis by proton-induced x-ray emission are described. Recent results on solvent extraction of mercury by pure solvents and propylene carbonate are described. Recent measurements in a study of an acid-base hypothesis are described. (U.S.)

  17. Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

    International Nuclear Information System (INIS)

    Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

    2013-01-01

    A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt % or 2 wt %) were used at 55 deg C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results

  18. Multielement analysis of reagents used in chemical identification of transuranic elements

    International Nuclear Information System (INIS)

    Montalvan Estrada, A.; Brigido Flores, O.; Maslov, O.D.; Dmitriev, S.N.

    2006-01-01

    For more than 40 years, chemical identification of transuranic elements has been used at the Laboratory of Nuclear Reactions of the Join Institute for Nuclear Research, Dubna, Russia, as a secondary method of identification. Chlorination of transuranic elements obtained by nuclear reactions is an important step of the procedure in order to obtain volatile compounds able to pass through a thermo chromatographic process. To access the quality of the reagents TiCl 4 and SOCl 2 multielement analysis was carried out using both X-rays fluorescence and gamma activation. It was followed the simplest procedure for reagents samples pretreatment, so further interferences from other chemical products were avoided. X-rays fluorescence analysis was performed in a spectrometer with Si(Li) detector with a resolution for Fe (K?) of 190 eV. Both Cd-109 and Am-241 were used as isotopic sources of excitation. Gamma activation analysis was carried out using the compact electron accelerator MT-25, where gamma rays are produced in a stopping target. Among the parameters of the MT-25 are the following: energy range-10-25 MeV, gamma-ray flux-10 14 photon/s, power consumption-20 kw. Measurements of the induced activity were performed with the help of a HPGe detector, thin and coaxial Ge(Li) detectors. There were identified two elements in SOCl 2 -Nickel (3*10 -6 g/g) and Antimony (2*10 -7 g/g), while there were identified three elements in TiCl 4 - Zirconium (8*10 -7 g/g), Arsenic (9*10 -7 g/g) and Antimony (5*10 -7 g/g). Only five elements were detected in trace concentrations in the two analyzed reagents, that is for more than 57 elements capable of being detected using gamma activation analysis with the MT-25 only 5 had concentrations above the detection limits of the method. Not being chemical analogs of the synthesized transuranic elements (Z-104 and 106) and not being able to alpha or fission disintegrations there is not expected any interference from them in the chemical

  19. The role of neutron activation analysis at The Dow Chemical Company

    International Nuclear Information System (INIS)

    Rigot, W.L.; Buchmann, M.E.; Quinn, T.J.; Romick, J.D.; Yusuf, S.O.

    2000-01-01

    The role of neutron activation analysis (NAA) at The Dow Chemical Company has not changed significantly since the first operations, which were conducted in July, 1967. That role is threefold; provide results with appropriate precision, accuracy and sensitivity; provide results in a timely manner; and provide results for a reasonable cost. What has changed, are the requirements for satisfying each of the three components of the role. In a business-focused environment, analyses need to be performed faster with better sensitivity and/or precision and be more cost efficient. In order to meet these requirements, operations at The Dow TRIGA Research Reactor are devoted to NAA activities. (author)

  20. An Intelligent System for Modelling, Design and Analysis of Chemical Processes

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    ICAS, Integrated Computer Aided System, is a software that consists of a number of intelligent tools, which are very suitable, among others, for computer aided modelling, sustainable design of chemical and biochemical processes, and design-analysis of product-process monitoring systems. Each...... the computer aided modelling tool will illustrate how to generate a desired process model, how to analyze the model equations, how to extract data and identify the model and make it ready for various types of application. In sustainable process design, the example will highlight the issue of integration...

  1. Deconvolution-based resolution enhancement of chemical ice core records obtained by continuous flow analysis

    DEFF Research Database (Denmark)

    Rasmussen, Sune Olander; Andersen, Katrine K.; Johnsen, Sigfus Johann

    2005-01-01

    Continuous flow analysis (CFA) has become a popular measuring technique for obtaining high-resolution chemical ice core records due to an attractive combination of measuring speed and resolution. However, when analyzing the deeper sections of ice cores or cores from low-accumulation areas...... of the data for high-resolution studies such as annual layer counting. The presented method uses deconvolution techniques and is robust to the presence of noise in the measurements. If integrated into the data processing, it requires no additional data collection. The method is applied to selected ice core...

  2. Determination of mercury in ppb level by activation analysis and chemical separation

    International Nuclear Information System (INIS)

    Requejo, C.S.

    1983-02-01

    A method for determining mercury in steel samples was developed. Activation analysis using thermal neutrons, followed by radiochemical separations to eliminate 75 Se interferences, were applied. Sixty hours after the end of the irradiation, the samples were processed and distillation of mercury and selenium bromides were carried out. Selenium was separated as an element and mercury sulfide was precipitaded. The chemical separation procedure was tested by using a tracer technique; the recovery yield was 99,2% + - 2,7%. (C.L.B.) [pt

  3. Quantitative chemical state XPS analysis of first row transition metals, oxides and hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, M C; Payne, B P; McIntryre, N S [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Hart, B R; Lau, L Wm [Surface Science Western, Room G1, Western Science Centre, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Grosvenor, A P [Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Smart, R StC [ACeSSS, Applied Centre for Structural and Synchrotron Studies, University of South Australia, Mawson Lakes, SA 5095 (Australia)], E-mail: biesingr@uwo.ca

    2008-03-15

    Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available.

  4. Quantitative chemical state XPS analysis of first row transition metals, oxides and hydroxides

    International Nuclear Information System (INIS)

    Biesinger, M C; Payne, B P; McIntryre, N S; Hart, B R; Lau, L Wm; Grosvenor, A P; Smart, R StC

    2008-01-01

    Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available

  5. A large scale analysis of information-theoretic network complexity measures using chemical structures.

    Directory of Open Access Journals (Sweden)

    Matthias Dehmer

    Full Text Available This paper aims to investigate information-theoretic network complexity measures which have already been intensely used in mathematical- and medicinal chemistry including drug design. Numerous such measures have been developed so far but many of them lack a meaningful interpretation, e.g., we want to examine which kind of structural information they detect. Therefore, our main contribution is to shed light on the relatedness between some selected information measures for graphs by performing a large scale analysis using chemical networks. Starting from several sets containing real and synthetic chemical structures represented by graphs, we study the relatedness between a classical (partition-based complexity measure called the topological information content of a graph and some others inferred by a different paradigm leading to partition-independent measures. Moreover, we evaluate the uniqueness of network complexity measures numerically. Generally, a high uniqueness is an important and desirable property when designing novel topological descriptors having the potential to be applied to large chemical databases.

  6. Quantum chemical and spectroscopic analysis of calcium hydroxyapatite and related materials

    International Nuclear Information System (INIS)

    Khavryuchenko, V.D.; Khavryuchenko, O.V.; Lisnyak, V.V.

    2007-01-01

    Amorphous calcium hydroxyapatite was examined by vibrational spectroscopy (Raman and infra-red (IR)) and quantum chemical simulation techniques. The structures and vibrational (IR, Raman and inelastic neutron scattering) spectra of PO 4 3- ion, Ca 3 (PO 4 ) 2 , [Ca 3 (PO 4 ) 2 ] 3 , Ca 5 (PO 4 ) 3 OH, CaHPO 4 , [CaHPO 4 ] 2 , Ca 3 (PO 4 ) 2 .H 2 O, Ca 3 (PO 4 ) 2 .2H 2 O and Ca 3 (PO 4 ) 2 .3H 2 O clusters were quantum chemically simulated at ab initio and semiempirical levels of approximation. A complete coordinate analysis of the vibrational spectra was performed. The comparison of the theoretically simulated spectra with the experimental ones allows to identify correctly the phase composition of the amorphous calcium hydroxyapatite and related materials. The shape of the bands in the IR spectra of the hydroxoapatite can be used in order to characterize the structural properties of the material, e.g., the PO 4 3- ion status, the degree of hydrolysis of the material and the presence of hydrolysis products. - Graphical abstract: The structure of the quantum chemically optimized Ca 5 (PO 4 ) 3 (OH) cluster, which was used for vibrations spectra simulation

  7. Isolation and chemical analysis of nanoparticles from English ivy (Hedera helix L.)

    Science.gov (United States)

    Lenaghan, Scott C.; Burris, Jason N.; Chourey, Karuna; Huang, Yujian; Xia, Lijin; Lady, Belinda; Sharma, Ritin; Pan, Chongle; LeJeune, Zorabel; Foister, Shane; Hettich, Robert L.; Stewart, C. Neal; Zhang, Mingjun

    2013-01-01

    Bio-inspiration for novel adhesive development has drawn increasing interest in recent years with the discovery of the nanoscale morphology of the gecko footpad and mussel adhesive proteins. Similar to these animal systems, it was discovered that English ivy (Hedera helix L.) secretes a high strength adhesive containing uniform nanoparticles. Recent studies have demonstrated that the ivy nanoparticles not only contribute to the high strength of this adhesive, but also have ultraviolet (UV) protective abilities, making them ideal for sunscreen and cosmetic fillers, and may be used as nanocarriers for drug delivery. To make these applications a reality, the chemical nature of the ivy nanoparticles must be elucidated. In the current work, a method was developed to harvest bulk ivy nanoparticles from an adventitious root culture system, and the chemical composition of the nanoparticles was analysed. UV/visible spectroscopy, inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy and electrophoresis were used in this study to identify the chemical nature of the ivy nanoparticles. Based on this analysis, we conclude that the ivy nanoparticles are proteinaceous. PMID:23883948

  8. Summer 2012 Testing and Analysis of the Chemical Mixture Methodology -- Part I

    Energy Technology Data Exchange (ETDEWEB)

    Glantz, Clifford S.; Yu, Xiao-Ying; Coggin, Rebekah L.; Ponder, Lashaundra A.; Booth, Alexander E.; Petrocchi, Achille J.; Horn, Sarah M.; Yao, Juan

    2012-07-01

    This report presents the key findings made by the Chemical Mixture Methodology (CMM) project team during the first stage of their summer 2012 testing and analysis of the CMM. The study focused on answering the following questions: o What is the percentage of the chemicals in the CMM Rev 27 database associated with each Health Code Number (HCN)? How does this result influence the relative importance of acute HCNs and chronic HCNs in the CMM data set? o What is the benefit of using the HCN-based approach? Which Modes of Action and Target Organ Effects tend to be important in determining the HCN-based Hazard Index (HI) for a chemical mixture? o What are some of the potential issues associated with the current HCN-based approach? What are the opportunities for improving the performance and/or technical defensibility of the HCN-based approach? How would those improvements increase the benefit of using the HCN-based approach? o What is the Target Organ System Effect approach and how can it be used to improve upon the current HCN-based approach? How does the benefits users would derive from using the Target Organ System Approach compare to the benefits available from the current HCN-based approach?

  9. Advancing alternatives analysis: The role of predictive toxicology in selecting safer chemical products and processes.

    Science.gov (United States)

    Malloy, Timothy; Zaunbrecher, Virginia; Beryt, Elizabeth; Judson, Richard; Tice, Raymond; Allard, Patrick; Blake, Ann; Cote, Ila; Godwin, Hilary; Heine, Lauren; Kerzic, Patrick; Kostal, Jakub; Marchant, Gary; McPartland, Jennifer; Moran, Kelly; Nel, Andre; Ogunseitan, Oladele; Rossi, Mark; Thayer, Kristina; Tickner, Joel; Whittaker, Margaret; Zarker, Ken

    2017-09-01

    Alternatives analysis (AA) is a method used in regulation and product design to identify, assess, and evaluate the safety and viability of potential substitutes for hazardous chemicals. It requires toxicological data for the existing chemical and potential alternatives. Predictive toxicology uses in silico and in vitro approaches, computational models, and other tools to expedite toxicological data generation in a more cost-effective manner than traditional approaches. The present article briefly reviews the challenges associated with using predictive toxicology in regulatory AA, then presents 4 recommendations for its advancement. It recommends using case studies to advance the integration of predictive toxicology into AA, adopting a stepwise process to employing predictive toxicology in AA beginning with prioritization of chemicals of concern, leveraging existing resources to advance the integration of predictive toxicology into the practice of AA, and supporting transdisciplinary efforts. The further incorporation of predictive toxicology into AA would advance the ability of companies and regulators to select alternatives to harmful ingredients, and potentially increase the use of predictive toxicology in regulation more broadly. Integr Environ Assess Manag 2017;13:915-925. © 2017 SETAC. © 2017 SETAC.

  10. An organizational analysis of road traffic crash prevention to explain the difficulties of a national program in a low income country.

    Science.gov (United States)

    Vogel, Tania; Reinharz, Daniel; Gripenberg, Marissa; Barennes, Hubert

    2015-09-28

    Road traffic crashes (RTC), that daily kill 3400 people and leave 15,000 with a permanent disability could be prevented through the implementation of safety programs developed in partnership with governments and institutions. The relationship between key stakeholders can be a crucial determinant to the effectiveness of road safety programs. This issue has rarely been addressed. We conducted a detailed organizational analysis of the stakeholders involved in road safety programs in Lao People's Democratic Republic (Lao PDR). A case study was performed. The framework used was a snowball effect in which the characterization of all key stakeholders and the links between them, as well as the factors that led to these links, were determined. The effect of the relations between key stakeholders on the prevention of RTC was assessed through an analysis of the transactional, intangible and controlling factors that influence these relationships. The design and implementation of road safety programs in Lao PDR suffer from weak relationships between stakeholders and a poorly functional bicephal leadership between the Ministry of Public Works and Transport and the non-governmental organisation called Handicap International. This poor coordination between key stakeholders is evident, particularly in the area of collective action and is reinforced by a lack of interest from several different stakeholders. Most agencies do not prioritize road safety. Uneven distribution of funding is another contributing factor. Strengthening the leadership is crucial to the success of the program. Some organisations have skills, power the decision making and the allocation of resources in regards to road safety programs. Encouraging participation of these organizations through a more prominent position would thus result in a better collaboration. Non-monetary rewards would further help to strengthen collaborative work. The bicephal nature of the leadership of road safety programs proves

  11. Your Radiologist Explains Nuclear Medicine

    Medline Plus

    Full Text Available ... Disorders Video: The Basketball Game: An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org Hello! I’m Dr. Ramji ...

  12. Your Radiologist Explains Nuclear Medicine

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org Hello! ... d like to talk to you about nuclear medicine. Nuclear medicine offers the potential to identify disease ...

  13. Your Radiologist Explains Nuclear Medicine

    Medline Plus

    Full Text Available ... An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript ... by a special camera and computer to create images of the inside of your body. If you’ ...

  14. Your Radiologist Explains Nuclear Medicine

    Medline Plus

    Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org ... I’d like to talk to you about nuclear medicine. Nuclear medicine offers the potential to identify ...

  15. Meta-analysis Reveals that Hydraulic Traits Explain Cross-Species Patterns of Drought-Induced Tree Mortality across the Globe

    Science.gov (United States)

    Anderegg, W.

    2016-12-01

    Drought-induced tree mortality has been observed globally and is expected to increase under climate change scenarios, with large potential consequences for the terrestrial carbon sink. Predicting mortality across species is crucial for assessing the effects of climate extremes on forest community biodiversity, composition, and carbon sequestration. However, the physiological traits associated with elevated risk of mortality in diverse ecosystems remain unknown, though these could greatly improve understanding and prediction of tree mortality in forests. We performed a meta-analysis on species' mortality rates across 475 species from 33 studies around the globe to assess which traits determine a species' mortality risk. We found that species-specific mortality anomalies from community mortality rate in a given drought were associated with plant hydraulic traits. Across all species, mortality was best predicted by a low hydraulic safety margin - the difference between typical minimum xylem water potential and that causing xylem dysfunction - and xylem vulnerability to embolism. Angiosperms and gymnosperms experienced roughly equal mortality risk. Our results provide broad support that hydraulic traits capture key mechanisms determining tree death and highlight that physiological traits can improve vegetation models' prediction of tree mortality during climate extremes. We conclude with thoughts about a revised framework for future tree mortality research.

  16. Analysis of air mass trajectories to explain observed variability of tritium in precipitation at the Southern Sierra Critical Zone Observatory, California, USA.

    Science.gov (United States)

    Visser, Ate; Thaw, Melissa; Esser, Brad

    2018-01-01

    Understanding the behavior of tritium, a radioactive isotope of hydrogen, in the environment is important to evaluate the exposure risk of anthropogenic releases, and for its application as a tracer in hydrology and oceanography. To understand and predict the variability of tritium in precipitation, HYSPLIT air mass trajectories were analyzed for 16 aggregate precipitation samples collected over a 2 year period at irregular intervals at a research site located at 2000 m elevation in the southern Sierra Nevada (California, USA). Attributing the variation in tritium to specific source areas confirms the hypothesis that higher latitude or inland sources bring higher tritium levels in precipitation than precipitation originating in the lower latitude Pacific Ocean. In this case, the source of precipitation accounts for 79% of the variation observed in tritium concentrations. Air mass trajectory analysis is a promising tool to improve the predictions of tritium in precipitation at unmonitored locations and thoroughly understand the processes controlling transport of tritium in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Analysis of a Stochastic Chemical System Close to a SNIPER Bifurcation of Its Mean-Field Model

    KAUST Repository

    Erban, Radek; Chapman, S. Jonathan; Kevrekidis, Ioannis G.; Vejchodský , Tomá š

    2009-01-01

    A framework for the analysis of stochastic models of chemical systems for which the deterministic mean-field description is undergoing a saddle-node infinite period (SNIPER) bifurcation is presented. Such a bifurcation occurs, for example

  18. Chromatographic analysis with different detectors in the chemical characterisation and dereplication of African propolis.

    Science.gov (United States)

    Zhang, Tong; Omar, Ruwida; Siheri, Weam; Al Mutairi, Sultan; Clements, Carol; Fearnley, James; Edrada-Ebel, RuAngelie; Watson, David

    2014-03-01

    Propolis or bee glue has very diverse composition and is potentially a source of biologically active compounds. Comprehensive chemical profiling was performed on 22 African propolis samples collected from the sub-Saharan region of Africa by using various hyphenated analytical techniques including Liquid Chromatography (LC)-UltraViolet Detection (UV)-Evaporative Light Scattering Detection (ELSD), LC-High Resolution Mass Spectrometry (HRMS), Gas Chromatography (GC)-MS and LC-Diode Array Detector (DAD)-HRMS/MS. The diversity of the composition of these African propolis samples could be observed by heat mapping the LC-UV and ELSD data. The characteristic chemical components were uncovered by applying Principal Component Analysis (PCA) to the LC-HRMS data and a preliminary dereplication was carried out by searching their accurate masses in the Dictionary of Natural Products (DNP). A further identification was achieved by comparing their GC-MS or LC-DAD-HRMS/MS spectra with previously published data. Generally no clear geographic delineation was observed in the classification of these African propolis samples. Triterpenoids were found as the major chemical components in more than half of the propolis samples analysed in this study and some others were classified as temperate and Eastern Mediterranean type of propolis. Based on the comparative chemical profiling and dereplication studies one uncommon propolis from southern Nigeria stood out from others by presenting prenylated isoflavonoids, which indicated that it was more like Brazilian red propolis, and more significantly a high abundance of stilbenoid compounds which could be novel in propolis. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Explaining the effects of a point-of-purchase nutrition-information intervention in university canteens: a structural equation modelling analysis.

    Science.gov (United States)

    Hoefkens, Christine; Pieniak, Zuzanna; Van Camp, John; Verbeke, Wim

    2012-09-11

    The importance of canteen meals in the diet of many university students makes the provision of simple point-of-purchase (POP) nutrition information in university canteens a potentially effective way to promote healthier diets in an important group of young adults. However, modifications to environments such as the posting of POP nutrition information in canteens may not cause an immediate change in meal choices and nutrient intakes. The present study aimed at understanding the process by which the POP nutrition information achieved its effects on the meal choice and energy intake, and whether the information was more effective in changing the meal choice of subgroups of university canteen customers. The POP nutrition-information intervention used a one-group pretest-posttest design. A sample of 224 customers of two university canteens completed the baseline and 6-months follow-up surveys. A multi-group structural equation modelling analysis was used to test mediation effects of individual difference variables (liking, understanding and use of the information, subjective knowledge and attitude) on the energy intake from canteen meals, moderated by the objective nutrition knowledge and motivation to change diet. Significant relations were identified between liking of the information and its use on one hand and a positive effect in attitude towards healthy canteen meals on the other hand. Motivation to change diet and sufficient objective nutrition knowledge were required to maintain a recommended energy intake from canteen meals or to lead to a decrease in energy intake. Participants with greater objective nutrition knowledge had a greater understanding of the POP nutrition information which also resulted in a more effective use of the information. The results suggest that nutrition-information interventions may be more effective when using nutrition information that is generally liked by the target population in combination with an educational intervention to

  20. Explaining the effects of a point-of-purchase nutrition-information intervention in university canteens: a structural equation modelling analysis

    Directory of Open Access Journals (Sweden)

    Hoefkens Christine

    2012-09-01

    Full Text Available Abstract Background The importance of canteen meals in the diet of many university students makes the provision of simple point-of-purchase (POP nutrition information in university canteens a potentially effective way to promote healthier diets in an important group of young adults. However, modifications to environments such as the posting of POP nutrition information in canteens may not cause an immediate change in meal choices and nutrient intakes. The present study aimed at understanding the process by which the POP nutrition information achieved its effects on the meal choice and energy intake, and whether the information was more effective in changing the meal choice of subgroups of university canteen customers. Methods The POP nutrition-information intervention used a one-group pretest-posttest design. A sample of 224 customers of two university canteens completed the baseline and 6-months follow-up surveys. A multi-group structural equation modelling analysis was used to test mediation effects of individual difference variables (liking, understanding and use of the information, subjective knowledge and attitude on the energy intake from canteen meals, moderated by the objective nutrition knowledge and motivation to change diet. Results Significant relations were identified between liking of the information and its use on one hand and a positive effect in attitude towards healthy canteen meals on the other hand. Motivation to change diet and sufficient objective nutrition knowledge were required to maintain a recommended energy intake from canteen meals or to lead to a decrease in energy intake. Participants with greater objective nutrition knowledge had a greater understanding of the POP nutrition information which also resulted in a more effective use of the information. Conclusions The results suggest that nutrition-information interventions may be more effective when using nutrition information that is generally liked by the target

  1. Reduction and Uncertainty Analysis of Chemical Mechanisms Based on Local and Global Sensitivities

    Science.gov (United States)

    Esposito, Gaetano

    Numerical simulations of critical reacting flow phenomena in hypersonic propulsion devices require accurate representation of finite-rate chemical kinetics. The chemical kinetic models available for hydrocarbon fuel combustion are rather large, involving hundreds of species and thousands of reactions. As a consequence, they cannot be used in multi-dimensional computational fluid dynamic calculations in the foreseeable future due to the prohibitive computational cost. In addition to the computational difficulties, it is also known that some fundamental chemical kinetic parameters of detailed models have significant level of uncertainty due to limited experimental data available and to poor understanding of interactions among kinetic parameters. In the present investigation, local and global sensitivity analysis techniques are employed to develop a systematic approach of reducing and analyzing detailed chemical kinetic models. Unlike previous studies in which skeletal model reduction was based on the separate analysis of simple cases, in this work a novel strategy based on Principal Component Analysis of local sensitivity values is presented. This new approach is capable of simultaneously taking into account all the relevant canonical combustion configurations over different composition, temperature and pressure conditions. Moreover, the procedure developed in this work represents the first documented inclusion of non-premixed extinction phenomena, which is of great relevance in hypersonic combustors, in an automated reduction algorithm. The application of the skeletal reduction to a detailed kinetic model consisting of 111 species in 784 reactions is demonstrated. The resulting reduced skeletal model of 37--38 species showed that the global ignition/propagation/extinction phenomena of ethylene-air mixtures can be predicted within an accuracy of 2% of the full detailed model. The problems of both understanding non-linear interactions between kinetic parameters and

  2. Chemical Analysis of the Herbal Medicine Salviae miltiorrhizae Radix et Rhizoma (Danshen

    Directory of Open Access Journals (Sweden)

    Hanqing Pang

    2016-01-01

    Full Text Available Radix Salviae miltiorrhizae et Rhizoma, known as Danshen in China, is one of the most popular traditional Chinese medicines. Recently, there has been increasing scientific attention on Danshen for its remarkable bioactivities, such as promoting blood circulation, removing blood stasis, and clearing away heat. This review summarized the advances in chemical analysis of Danshen and its preparations since 2009. Representative established methods were reviewed, including spectroscopy, thin layer chromatography, gas chromatography, liquid chromatography (LC, liquid chromatography-mass spectrometry (LC-MS, capillary electrophoresis, electrochemistry, and bioanalysis. Especially the analysis of polysaccharides in Danshen was discussed for the first time. Some proposals were also put forward to benefit quality control of Danshen.

  3. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide powder and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Total Carbon by Combustion and Gravimetry 7-17 Total Boron by Titrimetry 18-28 Isotopic Composition by Mass Spectrometry 29-38 Chloride and Fluoride Separation by Pyrohydrolysis 39-45 Chloride by Constant-Current Coulometry 46-54 Fluoride by Ion-Selective Electrode 55-63 Water by Constant-Voltage Coulometry 64-72 Impurities by Spectrochemical Analysis 73-81 Soluble Boron by Titrimetry 82-95 Soluble Carbon by a Manometric Measurement 96-105 Metallic Impurities by a Direct Reader Spectrometric Method 106-114

  4. The Imbalance Attitude of the Journalists in Six Chemical Castration Texts: An SFLCritical Discourse Analysis

    Directory of Open Access Journals (Sweden)

    Mustofa Kamal

    2017-10-01

    Full Text Available This research investigates how journalists behave in texts. The analysis focuses on the exploitation of attitudinal lexis. This is qualitatively explored through attitude and graduation. The data sources were columns of news, taken from an online version of The Jakarta Post on June sixth 2016. Having been selected using criterion-based sampling technique, the sources of data resulted in six chemical castration texts. The procedure of investigation consists of domain, taxonomic, componential, and cultural value analysis. The result shows that journalists are relatively subjective in reporting news by unbalancing the pros and cons, relatively inconsistent in work from delivering news to criticizing government officials, and relatively provocative by up-scaling critical evaluations against the government policy on sex offenders.

  5. Refractometry and interferometry in chemical analysis; Refractometrie et interferometrie en analyse chimique

    Energy Technology Data Exchange (ETDEWEB)

    Veret, C [Faculte des Sciences de Paris, 75 (France)

    2000-03-01

    In vacuum, an electromagnetic radiation is propagated at a constant velocity. But, when it has to pass through a physical medium, it is submitted to different interactions (for instance: absorption, diffusion, refraction, polarization, dispersion, fluorescence) which lead to a modification of its propagation. In the frequency ranges of the radiation for which the absorption is not very important, the modifications of the propagation velocity of a radiation can bring data on the nature and/or the physical conditions (pressure, temperature) of a medium, whatever its state be: gas, liquid or solid. Thus, the absolute refractive index of a medium in relation to vacuum is defined as the ratio c/v of the propagation velocity c of a monochromatic electromagnetic radiation in vacuum at its velocity v in this medium. The photonic refractometry (field of ultraviolet, visible and infrared radiations) is the set of the measure techniques of the refractive indexes having a role in chemical analysis. The refractometry measures can only be applied to media which are optically transparent. After having described these techniques, the author presents their uses in chemical analysis. (O.M.)

  6. Extractive Atmospheric Pressure Photoionization (EAPPI) Mass Spectrometry: Rapid Analysis of Chemicals in Complex Matrices.

    Science.gov (United States)

    Liu, Chengyuan; Yang, Jiuzhong; Wang, Jian; Hu, Yonghua; Zhao, Wan; Zhou, Zhongyue; Qi, Fei; Pan, Yang

    2016-10-01

    Extractive atmospheric pressure photoionization (EAPPI) mass spectrometry was designed for rapid qualitative and quantitative analysis of chemicals in complex matrices. In this method, an ultrasonic nebulization system was applied to sample extraction, nebulization, and vaporization. Mixed with a gaseous dopant, vaporized analytes were ionized through ambient photon-induced ion-molecule reactions, and were mass-analyzed by a high resolution time-of-flight mass spectrometer (TOF-MS). After careful optimization and testing with pure sample solution, EAPPI was successfully applied to the fast screening of capsules, soil, natural products, and viscous compounds. Analysis was completed within a few seconds without the need for preseparation. Moreover, the quantification capability of EAPPI for matrices was evaluated by analyzing six polycyclic aromatic hydrocarbons (PAHs) in soil. The correlation coefficients (R (2) ) for standard curves of all six PAHs were above 0.99, and the detection limits were in the range of 0.16-0.34 ng/mg. In addition, EAPPI could also be used to monitor organic chemical reactions in real time. Graphical Abstract ᅟ.

  7. Chemical characterization of diets consumed in the COSEAS restaurant, by neutron activation analysis

    International Nuclear Information System (INIS)

    Favaro, Deborah I.T.; Chioccola, Gabriella S.; Bortoli, Maritsa C.; Cozzolino, Silvia M.F.

    2005-01-01

    This study presents the results of chemical characterization of meals (lunch) offered by COSEAS/USP-SP restaurant, during 5 non consecutive days. These meals were collected in triplicate, in the same way they are offered to the users, being freeze-dried and prepared for chemical analysis. In the total, 15 samples were collected. The proximate composition was determined by using the standard methodologies according to AOAC (1995). The contents of some micronutrients (Ca, Fe, K, Na, Se and Zn) were determined by instrumental neutron activation analysis. The methodology validation was performed by certified reference materials analyses: Oyster Tissue (NIST SRM 1566 b ), Orchard Leaves (NIST SRM 1541) and Peach Leaves (NIST SRM 1547). >From concentration results the daily intake of each micronutrient was calculated considering this meal as 40% of the total daily intake and the values were compared to the new dietary recommendations of micronutrients (Dietary Reference Intakes-DRIs, Institute of Medicine, USA), for the women in the life stage from 19 to 30 years. Comparing the average values found with the recommended values, it was verified that macronutrients and Fe, Se and Zn micronutrients reached the values set by new DRIs. For Ca and K the daily intake was inadequate and Na, exceeded the recommended value. (author)

  8. Chemical investigation, isolation and structural analysis of flavones from primula veris

    International Nuclear Information System (INIS)

    Huck, Ch.

    1998-01-01

    The chemical investigation, isolation and structural analysis of six flavones present in flowers of Primula veris is described. Sample preparation of substances G from Primula veris comprised methanol extraction, low pressure chromatography on aluminum oxide, medium pressure chromatography on silica gel, and RP-HPLC on ODS. The six flavones, which were identified by their blue fluorescence after separation by thin layer chromatography, were named substance G1, G2, G3, G4, G5 and G6 according to their Rf-values. Fractions were collected during each of the separation processes and the fractions were analyzed by NP-HPLC and RP-HPLC. Higher resolution was obtained by NP-HPLC on a silica gel column and an n-hexane/ isopropanol (92:8 v/v) eluent, where 6 peaks (G1, G2, G3, G4, G5 and G6) were obtained. Diode array detection from 190 - 350 nm was utilized for the recording of UV-spectra for peak identification and peak-purity-analysis. The structures of Substance G4 and Substance G6 were established on the basis of UV, NMR, EI-MS and APCI-MS. The structure of the isolated substance G4 was verified by chemical synthesis. (author)

  9. Backside versus frontside advanced chemical analysis of high-k/metal gate stacks

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E., E-mail: eugenie.martinez@cea.fr [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Saidi, B. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Veillerot, M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Caubet, P. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Fabbri, J-M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Piallat, F. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Gassilloud, R. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Schamm-Chardon, S. [CEMES-CNRS et Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France)

    2015-08-15

    Highlights: • The backside approach is a promising solution for advanced chemical characterization of future MOSFETs. • Frontside ToF-SIMS and Auger depth profiles are affected by cumulative mixing effects and thus not relevant for analyzing ultra-thin layers. • Higher in-depth resolution is possible in the backside approach for Auger and ToF-SIMS depth profiling. • Backside depth profiling allows revealing ultra-thin layers and elemental in-depth redistribution inside high-k/metal gate stacks. • Backside XPS allows preserving the full metal gate, thus enabling the analysis of real technological samples. - Abstract: Downscaling of transistors beyond the 14 nm technological node requires the implementation of new architectures and materials. Advanced characterization methods are needed to gain information about the chemical composition of buried layers and interfaces. An effective approach based on backside analysis is presented here. X-ray photoelectron spectroscopy, Auger depth profiling and time-of-flight secondary ions mass spectrometry are combined to investigate inter-diffusion phenomena. To highlight improvements related to the backside method, backside and frontside analyses are compared. Critical information regarding nitrogen, oxygen and aluminium redistribution inside the gate stacks is obtained only in the backside configuration.

  10. Risk analysis in the chemical industry; Analisis de riesgos en la industria quimica

    Energy Technology Data Exchange (ETDEWEB)

    Rea Soto, Rogelio; Sandoval Valenzuela, Salvador [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    The Instituto de Investigaciones Electricas has a group of risk analysis (GAR), specialized in the most advanced methodologies to apply them in diverse industries of the productive sector, such as the nuclear, the oil and the chemical industries. In this work the integrated methodology that the GAR uses to make risk analysis in the chemical and oil industries is described. These analyses have as an objective to make a meticulous evaluation of the system design, the operation practices, the maintenance and inspection policies and the emergency plans. [Spanish] El Instituto de Investigaciones Electricas cuenta con un grupo de analisis de riesgo (GAR), especializado en las metodologias mas avanzadas para aplicarlas en diversas industrias del sector productivo, como lo son la nuclear, la petrolera y la quimica. En este trabajo se describe la metodologia integrada que el GAR utiliza para realizar analisis de riesgos en las industrias quimica y petrolera. Estos analisis tienen como objetivo realizar una minuciosa evaluacion del diseno del sistema, las practicas de operacion, las politicas de mantenimiento e inspeccion y los planes de emergencia.

  11. High-throughput peptide mass fingerprinting and protein macroarray analysis using chemical printing strategies

    International Nuclear Information System (INIS)

    Sloane, A.J.; Duff, J.L.; Hopwood, F.G.; Wilson, N.L.; Smith, P.E.; Hill, C.J.; Packer, N.H.; Williams, K.L.; Gooley, A.A.; Cole, R.A.; Cooley, P.W.; Wallace, D.B.

    2001-01-01

    We describe a 'chemical printer' that uses piezoelectric pulsing for rapid and accurate microdispensing of picolitre volumes of fluid for proteomic analysis of 'protein macroarrays'. Unlike positive transfer and pin transfer systems, our printer dispenses fluid in a non-contact process that ensures that the fluid source cannot be contaminated by substrate during a printing event. We demonstrate automated delivery of enzyme and matrix solutions for on-membrane protein digestion and subsequent peptide mass fingerprinting (pmf) analysis directly from the membrane surface using matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). This approach bypasses the more commonly used multi-step procedures, thereby permitting a more rapid procedure for protein identification. We also highlight the advantage of printing different chemistries onto an individual protein spot for multiple microscale analyses. This ability is particularly useful when detailed characterisation of rare and valuable sample is required. Using a combination of PNGase F and trypsin we have mapped sites of N-glycosylation using on-membrane digestion strategies. We also demonstrate the ability to print multiple serum samples in a micro-ELISA format and rapidly screen a protein macroarray of human blood plasma for pathogen-derived antigens. We anticipate that the 'chemical printer' will be a major component of proteomic platforms for high-throughput protein identification and characterisation with widespread applications in biomedical and diagnostic discovery

  12. Kinematics analysis on hinges of robot arm gripper for harmful chemical handling

    Science.gov (United States)

    Razali, Zol Bahri; Kader, Mohamed Mydin M. Abdul; Mustafa, Nurul Fahimah; Daud, Mohd Hisam

    2017-09-01

    The development of manufacturing industry is booming the application of industrial robot, and proportional to the use of robot arm. Some of the purpose of robot arm gripper is to sort things and place to the proper place. And some of the things are harmful to human, such as harmful chemical. By using robot arm to do picking and placing, it is expected to replace human tasks, as well as to reduce human from the harmful job. The problem of the robot arm gripper, most likely the problem of hinge, thus the analysis on the hinges of robot arm gripper to prevent claw is essential. By using robot arm, instead of human, is labored to do the harmful tasks and unexpected accident happen, costs and expenses in handling injured employee due to the harmful chemicals can be minimized. Thus the objective of this project is to make a kinematics analysis on the hinges of the robot arm gripper. Suitable material such as steel structure has also been selected for the construction of this hinges. This material has properties associated with compressive strength, fire resistance, corrosion and has a shape that is easy to move. Solid Works and ANSYS software is used to create animated movement on the design model and to detect deficiencies in the hinges. Detail methodology is described in this paper.

  13. Electric propulsion reliability: Statistical analysis of on-orbit anomalies and comparative analysis of electric versus chemical propulsion failure rates

    Science.gov (United States)

    Saleh, Joseph Homer; Geng, Fan; Ku, Michelle; Walker, Mitchell L. R.

    2017-10-01

    With a few hundred spacecraft launched to date with electric propulsion (EP), it is possible to conduct an epidemiological study of EP's on orbit reliability. The first objective of the present work was to undertake such a study and analyze EP's track record of on orbit anomalies and failures by different covariates. The second objective was to provide a comparative analysis of EP's failure rates with those of chemical propulsion. Satellite operators, manufacturers, and insurers will make reliability- and risk-informed decisions regarding the adoption and promotion of EP on board spacecraft. This work provides evidence-based support for such decisions. After a thorough data collection, 162 EP-equipped satellites launched between January 1997 and December 2015 were included in our dataset for analysis. Several statistical analyses were conducted, at the aggregate level and then with the data stratified by severity of the anomaly, by orbit type, and by EP technology. Mean Time To Anomaly (MTTA) and the distribution of the time to (minor/major) anomaly were investigated, as well as anomaly rates. The important findings in this work include the following: (1) Post-2005, EP's reliability has outperformed that of chemical propulsion; (2) Hall thrusters have robustly outperformed chemical propulsion, and they maintain a small but shrinking reliability advantage over gridded ion engines. Other results were also provided, for example the differentials in MTTA of minor and major anomalies for gridded ion engines and Hall thrusters. It was shown that: (3) Hall thrusters exhibit minor anomalies very early on orbit, which might be indicative of infant anomalies, and thus would benefit from better ground testing and acceptance procedures; (4) Strong evidence exists that EP anomalies (onset and likelihood) and orbit type are dependent, a dependence likely mediated by either the space environment or differences in thrusters duty cycles; (5) Gridded ion thrusters exhibit both

  14. Chemical study of sediments from Solimoes and Negro rivers by Instrumental Neutron Activation Analysis (INAA)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose O. dos [Coordenacao de Cursos Tecnicos e Superiores. Instituto Federal de Educacao, Ciencia e Tecnologia de Sergipe, Lagarto, SE (Brazil); Munita, Casimiro S., E-mail: camunita@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Soares, Emilio A.A., E-mail: easores@ufam.edu.br [Departamento de Geociencias. Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil)

    2011-07-01

    The events of the last 70,000 yrs of the history of the Solimoes-Amazon river system are recorded in the fluvial terraces at region of confluence of the Negro and Solimoes rivers, and are markers of changes in the landscape of the Amazon region and it can be observed by analyzing the sedimentary deposits quaternary in Amazon fluvial system. The aim of this work was to contribute with the characterization sedimentological - stratigraphic of Pleistocene succession of the confluence zone of the Negro and Solimoes rivers by means of elemental chemical analysis. To provenance study, 24 elements were determined by Instrumental Neutron Activation Analysis from sediment samples collected at confluence of Negro and Solimoes rivers and the results were interpreted using cluster and linear discriminant analysis, which classification to priori were samples previously defined according to Pleistocene stratigraphic units individualized at study area. According to discriminant analysis, one can infer that samples from the basin of the Solimoes River and Parana do Ariau grabens (GPA) are not significantly different, but there was a clear separation of sediments from Negro and GPA groups. It was also obtained that samples from highest and lowest terraces that the of the Solimoes river and Parana do Ariau are different, suggesting that it is a process that reflects the influence of chemical weathering on the uppermost terrace deposits. Thus, this work contributes to determine the contribution of the sediments deposited by the Solimoes and Negro rivers in the filling of tectonic depressions and in the variations of degree of weathering between younger and older units, and provides additional subsidies to build the geological evolution of the area. (author)

  15. Comparative analysis of the aroma chemicals of Melissa officinalis using hydrodistillation and HS-SPME techniques

    Directory of Open Access Journals (Sweden)

    Shakeel-u- Rehman

    2017-05-01

    Full Text Available Headspace solid-phase micro extraction (HS-SPME coupled with gas chromatography–mass spectrometry (GC–MS has been used for the chemical analysis of Melissa officinalis (leaves cultivated in Institute Germplasm. The HS-SPME analysis led to the identification of 22 components constituting 99.1% of the total volatile constituents present in the leaves whereas its hydrodistillate led to the identification of 24 volatile constituents constituting 98.1% of the volatile material. The chemical composition of the SPME and hydrodistilled extract of M. officinalis leaves comprised mainly of oxygenated monoterpenes (78.5% and 57.8% respectively and sesquiterpene hydrocarbons (14.9% and 29.7% respectively. The major components identified in the HS-SPME extract were citronellal (31.1%, citronellol (18.3%, β-caryophyllene (12.0%, (E-citral (11.9%, (Z-citral (9.6%, geraniol (3.6%, (Z-β-ocimene (3.1% and 1-octen-3-ol (2.0% whereas hydrodistilled essential oil was rich in (Z-citral (19.6%, β-caryophyllene (13.2%, (E-citral (11.2%, citronellal (10.2%, germacrene-d (8.3%, δ-3-carene (5.0%, 6-methyl-5-hepten-2-one (3.7% and citronellyl acetate (3.7%. The comparative analysis of volatile constituents of M. officinalis leaf extract using HS-SPME and hydrodistillation techniques shows both qualitative as well as quantitative differences. The current study is the first report involving rapid analysis of volatile components of M. officinalis by HS-SPME.

  16. Chemical study of sediments from Solimoes and Negro rivers by Instrumental Neutron Activation Analysis (INAA)

    International Nuclear Information System (INIS)

    Santos, Jose O. dos; Munita, Casimiro S.; Soares, Emilio A.A.

    2011-01-01

    The events of the last 70,000 yrs of the history of the Solimoes-Amazon river system are recorded in the fluvial terraces at region of confluence of the Negro and Solimoes rivers, and are markers of changes in the landscape of the Amazon region and it can be observed by analyzing the sedimentary deposits quaternary in Amazon fluvial system. The aim of this work was to contribute with the characterization sedimentological - stratigraphic of Pleistocene succession of the confluence zone of the Negro and Solimoes rivers by means of elemental chemical analysis. To provenance study, 24 elements were determined by Instrumental Neutron Activation Analysis from sediment samples collected at confluence of Negro and Solimoes rivers and the results were interpreted using cluster and linear discriminant analysis, which classification to priori were samples previously defined according to Pleistocene stratigraphic units individualized at study area. According to discriminant analysis, one can infer that samples from the basin of the Solimoes River and Parana do Ariau grabens (GPA) are not significantly different, but there was a clear separation of sediments from Negro and GPA groups. It was also obtained that samples from highest and lowest terraces that the of the Solimoes river and Parana do Ariau are different, suggesting that it is a process that reflects the influence of chemical weathering on the uppermost terrace deposits. Thus, this work contributes to determine the contribution of the sediments deposited by the Solimoes and Negro rivers in the filling of tectonic depressions and in the variations of degree of weathering between younger and older units, and provides additional subsidies to build the geological evolution of the area. (author)

  17. Dynamical structure analysis of crystalline-state reaction and elucidation of chemical reactivity in crystalline environment

    International Nuclear Information System (INIS)

    Ohashi, Yuji

    2010-01-01

    It was found that a chiral alkyl group bonded to the cobalt atom in a cobalt complex crystal was racemized with retention of the single crystal form on exposure to visible light. Such reactions, which are called crystalline-state reactions, have been found in a variety of cobalt complex crystals. The concept of reaction cavity was introduced to explain the reaction rate quantitatively and the chirality of the photo-product. The new diffractometers and detectors were made for rapid data collection. The reaction mechanism was also elucidated using neutron diffraction analysis. The unstable reaction intermediates were analyzed using cryo-trapping method. The excited-state structures were obtained at the equilibrium state between ground and excited states. (author)

  18. Chemical and physical analysis on hard tissues after irradiation with short pulse Nd:YAG laser

    International Nuclear Information System (INIS)

    Pereira, Andrea Antunes

    2003-01-01

    This work reports on a study that was designed to investigate chemical, physical and morphological alterations in the dental enamel surface. The influence of application of laser in enamel surface by microscopic technical, X-ray fluorescence for chemical analysis, physical property as well as hardness and thermal analysis with Nd:YAG laser is also pointed out. A prototype of Nd:YAG (Q-switched) laser developed at the Center of Lasers and Applications - Institute of Energetic and Nuclear Research, aiming applications in the Medical Sciences that typical wavelength of 1.064 nm was used. The modifications in human dental enamel chemical composition for major and trace elements are here outlined. The accuracy of procedures was performed by analysis of natural hydroxyapatite as standard reference material. The identification and quantification of the chemical elements presented in the dental tissue samples were performed trough EDS, XRF and INAA. We determined the rate Calcium/Phosphorus (Ca/P) for different techniques. We performed an analysis in different regions of the surface and for different areas allowing a description of the chemical change in the total area of the specimen and the assessment of the compositional homogeneity of the each specimen. A comparison between XRF and INAA is presented. Based on morphological analysis of the irradiated surfaces with short pulse Nd:YAG laser we determined the area surrounded by the irradiation for the parameters for this thesis, and this technique allowed us to visualize the regions of fusion and re-solidification. The energy densities ranged from 10 J/cm 2 to 40 J/cm 2 , with pulse width of 6, 10 e 200 ns, and repetition rates of 5 and 7 Hz. In this thesis, FTIR-spectroscopy is used to analyze powder of mineralized tissue as well as enamel, dentine, root and cementum for human and bovine teeth after irradiation with short-pulse Nd:YAG laser. Characteristic spectra were obtained for the proteins components and mineral

  19. Process and device of elementary and chemical analysis of a sample through a spectral analysis of the secondary electron energies

    International Nuclear Information System (INIS)

    Le Gressus, Claude; Massignon, Daniel; Sopizet, Rene.

    1975-01-01

    The present invention relates to a method of chemical and elementary analysis of samples through a spectral analysis of secondary electrons (Auger electrons) emitted from said sample under a primary monokinetic electron beam concentrated on its surface. Said method is characterized in that the intensity of the primary monokinetic electron beam emitted from an electron gun is modulated at a frequency ω; and in that the secondary electrons of energy E emitted from the sample are then collected. A reference voltage corresponding to the modulation in intensity of the primary electron beam is applied at the input of a phase sensitive detector together with a voltage proportional to the intensity of the flux of said collected secondary electrons to obtain at the output of said detector a voltage proportional to the number of the secondary electrons of energy E. The secondary emission energy spectrum of the sample is then plotted [fr

  20. Analysis of exergy loss of gasoline surrogate combustion process based on detailed chemical kinetics

    International Nuclear Information System (INIS)

    Sun, Hongjie; Yan, Feng; Yu, Hao; Su, W.H.

    2015-01-01

    Highlights: • We explored the exergy loss sources of gasoline engine like combustion process. • The model combined non-equilibrium thermodynamics with detailed chemical kinetics. • We explored effects of initial conditions on exergy loss of combustion process. • Exergy loss decreases 15% of fuel chemical exergy by design of initial conditions. • Correspondingly, the second law efficiency increases from 38.9% to 68.9%. - Abstract: Chemical reaction is the most important source of combustion irreversibility in premixed conditions, but details of the exergy loss mechanisms have not been explored yet. In this study numerical analysis based on non-equilibrium thermodynamics combined with detailed chemical kinetics is conducted to explore the exergy loss mechanism of gasoline engine like combustion process which is simplified as constant volume combustion. The fuel is represented by the common accepted gasoline surrogates which consist of four components: iso-octane (57%), n-heptane (16%), toluene (23%), and 2-pentene (4%). We find that overall exergy loss is mainly composed of three peaks along combustion generated from chemical reactions in three stages, the conversion from large fuel molecules into small molecules (as Stage 1), the H 2 O 2 loop-related reactions (as Stage 2), and the violent oxidation reactions of CO, H, and O (as Stage 3). The effects of individual combustion boundaries, including temperature, pressure, equivalence ratio, oxygen concentration, on combustion exergy loss have been widely investigated. The combined effects of combustion boundaries on the total loss of gasoline surrogates are also investigated. We find that in a gasoline engine with a compression ratio of 10, the total loss can be reduced from 31.3% to 24.3% using lean combustion. The total loss can be further reduced to 22.4% by introducing exhaust gas recirculation and boosting the inlet charge. If the compression ratio is increased to 17, the total loss can be decreased to

  1. Development and Assessment of Self-explaining Skills in College Chemistry Instruction

    Science.gov (United States)

    Villalta-Cerdas, Adrian

    The prevalent trend in chemistry instruction relies on what has been described as the classroom game. In this model, students take a passive role and the instructor does all the explaining (thinking), and learning is trivialized to knowing the correct answers (memorizing) and being able to produce them when prompted (regurgitating). The generation of explanations is central to scientific and technological development. In the process of figuring out explanations, the generation of inferences relies on the application of skills associated with scientific behaviors (e.g., analytical reasoning and critical thinking). The process of explanation generation causes a deeper analysis and revision of the scientific models, thus impacting the conceptual understanding of such models. Although the process of generating authentic explanations is closer to the experience of doing science, this process is seldom replicated in science instruction. Self-explaining refers to the generation of inferences about causal connections between objects and events. In science, this may be summarized as making sense of how and why actual or hypothetical phenomena take place. Research findings in educational psychology show that implementing activities that elicit self-explaining improves learning in general and specifically enhances authentic learning in the sciences. Research also suggests that self-explaining influences many aspects of cognition, including acquisition of problem-solving skills and conceptual understanding. Although the evidence that links self-explaining and learning is substantial, most of the research has been conducted in experimental settings. The purpose of this work was to advance knowledge in this area by investigating the effect of different self-explaining tasks on self-explaining behavior and the effect of engaging in different levels of self-explaining on learning chemistry concepts. Unlike most of the research in the field, this work did not focus on advancing

  2. An analysis of chemical ingredients network of Chinese herbal formulae for the treatment of coronary heart disease.

    Directory of Open Access Journals (Sweden)

    Fan Ding

    Full Text Available As a complex system, the complicated interactions between chemical ingredients, as well as the potential rules of interactive associations among chemical ingredients of traditional Chinese herbal formulae are not yet fully understood by modern science. On the other hand, network analysis is emerging as a powerful approach focusing on processing complex interactive data. By employing network approach in selected Chinese herbal formulae for the treatment of coronary heart disease (CHD, this article aims to construct and analyze chemical ingredients network of herbal formulae, and provide candidate herbs, chemical constituents, and ingredient groups for further investigation. As a result, chemical ingredients network composed of 1588 ingredients from 36 herbs used in 8 core formulae for the treatment of CHD was produced based on combination associations in herbal formulae. In this network, 9 communities with relative dense internal connections are significantly associated with 14 kinds of chemical structures with P<0.001. Moreover, chemical structural fingerprints of network communities were detected, while specific centralities of chemical ingredients indicating different levels of importance in the network were also measured. Finally, several distinct herbs, chemical ingredients, and ingredient groups with essential position in the network or high centrality value are recommended for further pharmacology study in the context of new drug development.

  3. In vivo chemical and structural analysis of plant cuticular waxes using stimulated Raman scattering microscopy.

    Science.gov (United States)

    Littlejohn, George R; Mansfield, Jessica C; Parker, David; Lind, Rob; Perfect, Sarah; Seymour, Mark; Smirnoff, Nicholas; Love, John; Moger, Julian

    2015-05-01

    The cuticle is a ubiquitous, predominantly waxy layer on the aerial parts of higher plants that fulfils a number of essential physiological roles, including regulating evapotranspiration, light reflection, and heat tolerance, control of development, and providing an essential barrier between the organism and environmental agents such as chemicals or some pathogens. The structure and composition of the cuticle are closely associated but are typically investigated separately using a combination of structural imaging and biochemical analysis of extracted waxes. Recently, techniques that combine stain-free imaging and biochemical analysis, including Fourier transform infrared spectroscopy microscopy and coherent anti-Stokes Raman spectroscopy microscopy, have been used to investigate the cuticle, but the detection sensitivity is severely limited by the background signals from plant pigments. We present a new method for label-free, in vivo structural and biochemical analysis of plant cuticles based on stimulated Raman scattering (SRS) microscopy. As a proof of principle, we used SRS microscopy to analyze the cuticles from a variety of plants at different times in development. We demonstrate that the SRS virtually eliminates the background interference compared with coherent anti-Stokes Raman spectroscopy imaging and results in label-free, chemically specific confocal images of cuticle architecture with simultaneous characterization of cuticle composition. This innovative use of the SRS spectroscopy may find applications in agrochemical research and development or in studies of wax deposition during leaf development and, as such, represents an important step in the study of higher plant cuticles. © 2015 American Society of Plant Biologists. All Rights Reserved.

  4. Method for the Collection, Gravimetric and Chemical Analysis of Nonvolatile Residue (NVR) on Surfaces

    Science.gov (United States)

    Gordon, Keith; Rutherford, Gugu; Aranda, Denisse

    2017-01-01

    Nonvolatile residue (NVR), sometimes referred to as molecular contamination is the term used for the total composition of the inorganic and high boiling point organic components in particulates and molecular films deposited on critical surfaces surrounding space structures, with the particulate and NVR contamination originating primarily from pre-launch operations. The "nonvolatile" suggestion from the terminology NVR implies that the collected residue will not experience much loss under ambient conditions. NVR has been shown to have a dramatic impact on the ability to perform optical measurements from platforms based in space. Such contaminants can be detected early by the controlled application of various detection techniques and contamination analyses. Contamination analyses are the techniques used to determine if materials, components, and subsystems can be expected to meet the performance requirements of a system. Of particular concern is the quantity of NVR contaminants that might be deposited on critical payload surfaces from these sources. Subsequent chemical analysis of the contaminant samples by infrared spectroscopy and gas chromatography mass spectrometry identifies the components, gives semi-quantitative estimates of contaminant thickness, indicates possible sources of the NVR, and provides guidance for effective cleanup procedures. In this report, a method for the collection and determination of the mass of NVR was generated by the authors at NASA Langley Research Center. This report describes the method developed and implemented for collecting NVR contaminants, and procedures for gravimetric and chemical analysis of the residue obtained. The result of this NVR analysis collaboration will help pave the way for Langley's ability to certify flight hardware outgassing requirements in support of flight projects such as Stratospheric Aerosol and Gas Experiment III (SAGE III), Clouds and the Earth's Radiant Energy System (CERES), Materials International

  5. Anions Analysis in Ground and Tap Waters by Sequential Chemical and CO2-Suppressed Ion Chromatography

    Directory of Open Access Journals (Sweden)

    Glen Andrew D. De Vera

    2011-06-01

    Full Text Available An ion chromatographic method using conductivity detection with sequential chemical and CO2 suppression was optimized for the simultaneous determination of fluoride, chloride, bromide, nitrate,phosphate and sulfate in ground and tap water. The separation was done using an anion exchange column with an eluent of 3.2 mM Na2CO3 and 3.2 mM NaHCO3 mixture. The method was linear in the concentration range of 5 to 300 μg/L with correlation coefficients greater than 0.99 for the six inorganic anions. The method was also shown to be applicable in trace anions analysis as given by the low method detection limits (MDL. The MDL was 1μg/L for both fluoride and chloride. Bromide, nitrate, phosphate and sulfate had MDLs of 7 μg/L, 10 μg/L, 9 μg/L and 2 μg/L, respectively. Good precision was obtained as shown in the relative standard deviation of 0.1 to 12% for peak area and 0.1 to 0.3% for retention time. The sensitivity of the method improved with the addition of CO2 suppressor to chemical suppression as shown in the lower background conductivity and detection limits. The recoveries of the anions spiked in water at 300 μg/L level ranged from 100 to 104%. The method was demonstrated to be sensitive, accurate and precise for trace analysis of the six anions and was applied in the anions analysis in ground and tap waters in Malolos, Bulacan. The water samples were found to contain high concentrations of chloride of up to 476 mg/L followed by sulfate (38 mg/L, bromide (1 mg/L, phosphate (0.4 mg/L, fluoride (0.2 mg/L and nitrate (0.1 mg/L.

  6. RETRAN code analysis of Tsuruga-2 plant chemical volume control system (CVCS) reactor coolant leakage incident

    International Nuclear Information System (INIS)

    Kawai, Hiroshi

    2002-01-01

    In the Chemical Volume Control System (CVCS) reactor primary coolant leakage incident, which occurred in Tsuruga-2 (4-loop PWR, 3,423 MWt, 1,160 MWe) on July 12, 1999, it took about 14 hours before the leakage isolation. The delayed leakage isolation and a large amount of leakage have become a social concern. Effective procedure modification was studied. Three betterments were proposed based on a qualitative analysis to reduce the pressure and temperature of the primary loop as fast as possible by the current plant facilities while maintaining enough subcooling of the primary loop. I analyzed the incident with RETRAN code in order to quantitatively evaluate the leakage reduction when these betterments are adopted. This paper is very new because it created a typical analysis method for PWR plant behavior during plant shutdown procedure which conventional RETRAN transient analyses rarely dealt with. Also the event time is very long. To carry out this analysis successfully, I devised new models such as an Residual Heat Removal System (RHR) model etc. and simplified parts of the conventional model. Based on the analysis results, I confirmed that leakage can be reduced by about 30% by adopting these betterments. Then the Japan Atomic Power Company (JAPC) modified the operational procedure for reactor primary coolant leakage events adopting these betterments. (author)

  7. CFX-10 Analysis of the High Temperature Thermal- Chemical Experiment (CS28-2)

    International Nuclear Information System (INIS)

    Kim, Hyoung Tae; Park, Joo Hwan; Rhee, Bo Wook

    2008-02-01

    A Computational Fluid Dynamics (CFD) model of a post-blowdown fuel channel analysis for aged CANDU reactors with crept pressure tube has been developed, and validated against a high temperature thermal-chemical experiment: CS28-2. The CS28-2 experiment is one of three series of experiments to simulate the thermal-chemical behavior of a 28-element fuel channel at a high temperature and a low steam flow rate which may occur in severe accident conditions such as a LBLOCA (Large Break Loss of Coolant Accident) of CANDU reactors. Pursuant to the objective of this study, the current study has focused on understanding the involved phenomena such as the thermal radiation and convection heat transfer, and the high temperature zirconium-steam reaction in a multi-ring geometry. Therefore, a zirconium-steam oxidation model based on a parabolic rate law was implemented into the CFX-10 code, which is a commercial CFD code offered from ANSYS Inc., and other heat transfer mechanisms in the 28-element fuel channel were modeled by the original CFX-10 heat transfer packages. To assess the capability of the CFX-10 code to model the thermal-chemical behavior of the 28-element fuel channel, the measured temperatures of the Fuel Element Simulators (FES) of three fuel rings in the test bundle and the pressure tube, and the hydrogen production in the CS28-2 experiment were compared with the CFX-10 predictions. In spite of some discrepancy between the measurement data and CFX results, it was found that the CFX-10 prediction based on the Urbanic-Heidrick correlation of the zirconium-steam reaction as well as the Discrete Transfer Model for a radiation heat transfer among the FES of three rings and the pressure tube are quite accurate and sound even for the offset a cluster fuel bundle of an aged fuel channel

  8. Forensic analysis methodology for thermal and chemical characterization of homemade explosives

    International Nuclear Information System (INIS)

    Nazarian, Ashot; Presser, Cary

    2014-01-01

    Highlights: • Identification of homemade explosives (HME) is critical for determining the origin of explosive precursor materials. • A novel laser-heating technique was used to obtain the thermal/chemical signatures of HME precursor materials. • Liquid-fuel saturation of the pores of a solid porous oxidizer affected the total specific heat release. • Material thermal signatures were dependent on sample mass and heating rate. • This laser-heating technique can be a useful diagnostic tool for characterizing the thermochemical behavior of HMEs. - Abstract: Forensic identification of homemade explosives is critical for determining the origin of the explosive materials and precursors, and formulation procedures. Normally, the forensic examination of the pre- and post-blast physical evidence lacks specificity for homemade-explosive identification. The focus of this investigation was to use a novel measurement technique, referred to as the laser-driven thermal reactor, to obtain the thermal/chemical signatures of homemade-explosive precursor materials. Specifically, nitromethane and ammonium nitrate were studied under a variety of operating conditions and protocols. Results indicated that liquid-fuel saturation of the internal pores of a solid particle oxidizer appear to be a limiting parameter for the total specific heat release during exothermic processes. Results also indicated that the thermal signatures of these materials are dependent on sample mass and heating rate, for which this dependency may not be detectable by other commercially available thermal analysis techniques. This study has demonstrated that the laser-driven thermal reactor can be a useful diagnostic tool for characterizing the thermal and chemical behavior of trace amounts of homemade-explosive materials

  9. White mineral trioxide aggregate mixed with calcium chloride dihydrate: chemical analysis and biological properties

    Directory of Open Access Journals (Sweden)

    Hany Mohamed Aly Ahmed

    2017-04-01

    Full Text Available Objectives This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA, which was WMTA combined with calcium chloride dihydrate (CaCl2·2H2O, compared to that of WMTA. Materials and Methods Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM, energy dispersive X-ray microanalysis (EDX, and X-ray diffraction (XRD, respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs using methyl-thiazol-diphenyltetrazolium (MTT assay and under SEM after 24 and 72 hours, respectively. Results Results showed that the addition of CaCl2·2H2O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05. HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. Conclusions The addition of CaCl2·2H2O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.

  10. CFX-10 Analysis of the High Temperature Thermal- Chemical Experiment (CS28-2)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoung Tae; Park, Joo Hwan; Rhee, Bo Wook

    2008-02-15

    A Computational Fluid Dynamics (CFD) model of a post-blowdown fuel channel analysis for aged CANDU reactors with crept pressure tube has been developed, and validated against a high temperature thermal-chemical experiment: CS28-2. The CS28-2 experiment is one of three series of experiments to simulate the thermal-chemical behavior of a 28-element fuel channel at a high temperature and a low steam flow rate which may occur in severe accident conditions such as a LBLOCA (Large Break Loss of Coolant Accident) of CANDU reactors. Pursuant to the objective of this study, the current study has focused on understanding the involved phenomena such as the thermal radiation and convection heat transfer, and the high temperature zirconium-steam reaction in a multi-ring geometry. Therefore, a zirconium-steam oxidation model based on a parabolic rate law was implemented into the CFX-10 code, which is a commercial CFD code offered from ANSYS Inc., and other heat transfer mechanisms in the 28-element fuel channel were modeled by the original CFX-10 heat transfer packages. To assess the capability of the CFX-10 code to model the thermal-chemical behavior of the 28-element fuel channel, the measured temperatures of the Fuel Element Simulators (FES) of three fuel rings in the test bundle and the pressure tube, and the hydrogen production in the CS28-2 experiment were compared with the CFX-10 predictions. In spite of some discrepancy between the measurement data and CFX results, it was found that the CFX-10 prediction based on the Urbanic-Heidrick correlation of the zirconium-steam reaction as well as the Discrete Transfer Model for a radiation heat transfer among the FES of three rings and the pressure tube are quite accurate and sound even for the offset a cluster fuel bundle of an aged fuel channel.

  11. Cell behavior related to implant surfaces with different microstructure and chemical composition: an in vitro analysis.

    Science.gov (United States)

    Conserva, Enrico; Lanuti, Anna; Menini, Maria

    2010-01-01

    This paper reports on an in vitro comparison of osteoblast and mesenchymal stem cell (MSC) adhesion, proliferation, and differentiation related to two different surface treatments applied to the same implant design to determine whether the interaction between cells and implants is influenced by surface structure and chemical composition of the implants. Thirty-nine implants with a sandblasted (SB) surface and 39 implants with a grit-blasted and high-temperature acid-etched (GBAE) surface were used. The implant macrostructures and microstructures were analyzed by high- and low-voltage scanning electron microscopy (SEM) and by stereo-SEM. The surface chemical composition was investigated by energy dispersive analysis and x-ray photoemission spectroscopy. SaOS-2 osteoblasts and human MSCs were used for the evaluation of cell proliferation and alkaline phosphatase enzymatic activity in contact with the two surfaces. The GBAE surface showed fewer contaminants and a very high percentage of titanium (19.7%) compared to the SB surface (14.2%). The two surfaces showed similar mean roughness (Ra), but the depth (Rz) and density (RSm) of the porosity were significantly increased in the GBAE surface. The GBAE surface presented more osteoblast and MSC proliferation than the SB surface. No statistically significant differences in alkaline phosphatase activity were found between surfaces for either cellular line. The GBAE surface showed less surface contaminants and a higher percentage of titanium (19.7%) than the SB surface. The macro/micropore structured design and chemical composition of the GBAE surface allowed greater cell adhesion and proliferation and an earlier cell spreading but did not play an obvious role in in vitro cellular differentiation.

  12. Quantitative assessment of chemical artefacts produced by propionylation of histones prior to mass spectrometry analysis.

    Science.gov (United States)

    Soldi, Monica; Cuomo, Alessandro; Bonaldi, Tiziana

    2016-07-01

    Histone PTMs play a crucial role in regulating chromatin structure and function, with impact on gene expression. MS is nowadays widely applied to study histone PTMs systematically. Because histones are rich in arginine and lysine, classical shot-gun approaches based on trypsin digestion are typically not employed for histone modifications mapping. Instead, different protocols of chemical derivatization of lysines in combination with trypsin have been implemented to obtain "Arg-C like" digestion products that are more suitable for LC-MS/MS analysis. Although widespread, these strategies have been recently described to cause various side reactions that result in chemical modifications prone to be misinterpreted as native histone marks. These artefacts can also interfere with the quantification process, causing errors in histone PTMs profiling. The work of Paternoster V. et al. is a quantitative assessment of methyl-esterification and other side reactions occurring on histones after chemical derivatization of lysines with propionic anhydride [Proteomics 2016, 16, 2059-2063]. The authors estimate the effect of different solvents, incubation times, and pH on the extent of these side reactions. The results collected indicate that the replacement of methanol with isopropanol or ACN not only blocks methyl-esterification, but also significantly reduces other undesired unspecific reactions. Carefully titrating the pH after propionic anhydride addition is another way to keep methyl-esterification under control. Overall, the authors describe a set of experimental conditions that allow reducing the generation of various artefacts during histone propionylation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Journalism and Explaining News Content

    NARCIS (Netherlands)

    Albæk, E.; Skovsgaard, M.; de Vreese, C.H.; Nussbaum, J.F.

    Three models are presented to explain variation in news content. In the first model the explanation is based on the individual journalist, in the second model on the professional journalist, and in the third model on the organized journalist. The individual journalist model focuses on how the

  14. Can Marxism Explain America's Racism?

    Science.gov (United States)

    Willhelm, Sidney M.

    1980-01-01

    The Marxist interpretation of the Black experience in America has always had difficulty explaining various noneconomic aspects of racism. A perspective is needed that can blend racism as a variable in relationship with economic variables. To reach this perspective, the labor process within capitalism must be more fully understood. (Author/GC)

  15. Does market competition explain fairness?

    Science.gov (United States)

    Descioli, Peter

    2013-02-01

    The target article by Baumard et al. uses their previous model of bargaining with outside options to explain fairness and other features of human sociality. This theory implies that fairness judgments are determined by supply and demand but humans often perceive prices (divisions of surplus) in competitive markets to be unfair.

  16. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    International Nuclear Information System (INIS)

    Eriksson, E.; Andersen, H. R.; Ledin, A.

    2008-01-01

    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens

  17. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, E., E-mail: eve@env.dtu.dk; Andersen, H. R.; Ledin, A. [Technical University of Denmark, Department of Environmental Engineering (Denmark)

    2008-12-15

    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens.

  18. Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

    Directory of Open Access Journals (Sweden)

    Gonos Efstathios

    2011-06-01

    Full Text Available Abstract Background Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated. Results Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique. Conclusions The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.

  19. Repeatability, correlation and path analysis of physical and chemical characteristics of peach fruits

    Directory of Open Access Journals (Sweden)

    Rosana Gonçalves Pires Matias

    2014-12-01

    Full Text Available This study aimed to determine the number of measurements necessary to evaluate physical and chemical characteristics of peach fruits, study the relationships between them and their direct and indirect effects on the content of ascorbic acid and total carotenoids. The characteristics skin and pulp color, fruit weight, suture, equatorial and polar diameters, firmness, soluble solids (SS, titratable acidity (TA, SS/TA ratio, ascorbic acid and total carotenoids were evaluated in 39 cultivars of peach and 3 cultivars of nectarine from the orchard of the Universidade Federal de Viçosa. The repeatability coefficient was estimated by ANOVA and CPCOR. Phenotypic correlation coefficients (rf were estimated and, after the multicollinearity diagnostics, they were unfolded to direct and indirect effects of the explanatory variables on the response variable using path analysis. There was agreement on the magnitude of repeatability coefficients obtained by the two methods; however, they varied among the 14 characteristics. The highest correlations were found between FW, SD, ED and PD. Seven fruits are sufficient to evaluate the physical and chemical characteristics of peach with a correlation coefficient of 90%. The characteristics considered in the path diagrams (b* skin, hº skin, b* pulp, hº pulp, ED, PD, FIR, SS, SS/AT and TC are not the main determinants of the ascorbic acid. The yellow hue of the pulp (hº pulp has the potential to be used in indirect selection for total carotenoids.

  20. Artificial intelligence/fuzzy logic method for analysis of combined signals from heavy metal chemical sensors

    International Nuclear Information System (INIS)

    Turek, M.; Heiden, W.; Riesen, A.; Chhabda, T.A.; Schubert, J.; Zander, W.; Krueger, P.; Keusgen, M.; Schoening, M.J.

    2009-01-01

    The cross-sensitivity of chemical sensors for several metal ions resembles in a way the overlapping sensitivity of some biological sensors, like the optical colour receptors of human retinal cone cells. While it is difficult to assign crisp classification values to measurands based on complex overlapping sensory signals, fuzzy logic offers a possibility to mathematically model such systems. Current work goes into the direction of mixed heavy metal solutions and the combination of fuzzy logic with heavy metal-sensitive, silicon-based chemical sensors for training scenarios of arbitrary sensor/probe combinations in terms of an electronic tongue. Heavy metals play an important role in environmental analysis. As trace elements as well as water impurities released from industrial processes they occur in the environment. In this work, the development of a new fuzzy logic method based on potentiometric measurements performed with three different miniaturised chalcogenide glass sensors in different heavy metal solutions will be presented. The critical validation of the developed fuzzy logic program will be demonstrated by means of measurements in unknown single- and multi-component heavy metal solutions. Limitations of this program and a comparison between calculated and expected values in terms of analyte composition and heavy metal ion concentration will be shown and discussed.