WorldWideScience

Sample records for chemical state analysis

  1. 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...

  2. 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.

  3. 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

  4. Forensic analysis of tire rubbers based on their sulfur chemical states.

    Science.gov (United States)

    Funatsuki, Atsushi; Shiota, Kenji; Takaoka, Masaki; Tamenori, Yusuke

    2015-05-01

    The chemical states of sulfur in 11 tires were analyzed using X-ray absorption near-edge structure (XANES) in order to discriminate between various tire rubbers. All tires had peaks around 2471.5 and 2480.5eV, and the shapes and heights of these peaks differed among tires, suggesting that the sulfur chemical state could be used for discrimination between tire rubbers. Based on t-tests on the results of XANES, 43 of 55 combinations were different at a significance level of 5%. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Chemical state analysis of oxidation products on steel surface by conversion electron Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Ujihira, Yusuke; Nomura, Kiyoshi

    1978-01-01

    The polished NT-70H steel (Fe: 95.97%, C: 0.56%, diameter: 5 cm, thickness: 0.5 cm) was immersed in deionized water or in solutions containing (0.25 -- 0.5) M of chloride, sulfate and nitrate ions. The chemical states of oxidation products of iron on the surface were identified through the analysis of conversion electron Moessbauer spectra (CEMS). CEMS of the steel surface, which had been dipped in deionized water, revealed that γ-FeOOH was formed on the surface. The thickness of γ-FeOOH layer increased with the increase of the duration of dipping. Dissolved oxygen in the solution played an essential role in the oxidation of iron to γ-FeOOH. Oxidation product of iron dipped in the 0.5 M sodium chloride solution was identified as γ-FeOOH. Amorphous paramagnetic iron (III) compound tended to form in the presence of hydrogen peroxide or ammonium ions in the solutions. The increase of alkalinity of the solution up to pH 12 suppressed the oxidation rate and assisted the formation of green rust, which was confirmed by the appearance of the quadrupole splitting peaks of the green rust. In the 0.25 M sodium sulfate solution, oxidation of the steel surface proceeded slowly and the quadrupole splitting peaks of Fe(OH) 2 were seen in the CEMS. The peak intensity of Fe(OH) 2 gradually decreased and that of γ-FeOOH increased by the extension of immersion of steel in the solution. Magnetite (Fe 3 O 4 ) layer was developed beneath the γ-FeOOH layer, when steel was dipped in 0.5 M sodium nitrate solution. However, the peaks of Fe 3 O 4 were not seen on CEMS of steel surface immersed in 0.5 M ammonium nitrate solution. Thus, applying the feasibility of CEMS for the characterization of oxidated compounds of iron on the steel surface formed by the immersion in solutions, the oxidation mechanism of the steel surface was discussed based upon the results of chemical state analyses. (author)

  6. Chemical state analysis of conversion coatings by SR-XPS and TEY-XANES

    CERN Document Server

    Noro, H; Nagoshi, M

    2002-01-01

    Chromate coatings on galvanized steel have been studied by Synchrotron Radiation (SR) based techniques that include X-ray Photoelectron Spectroscopy (XPS) and Total-Electron-Yield X-ray Absorption Near Edge Structure (TEY-XANES). Non-destructive depth profiling of the coatings by SR-XPS reveals the enhancement of Cr sup 6 sup + in the outer surface. TEY-XANES spectroscopy based on simple specimen current measurement is demonstrated as an effective technique for analyzing chemical states of conversion coatings on general bulk substrates. The sampling depth of this technique, which exceeds several tens of nanometer, is determined by the penetration length of Auger electrons excited by X-ray and the inelastic mean free path of secondary electrons excited by inelastically scattered Auger electrons. The chemical states of phosphoric acid added chromate coatings are studied using this technique. The phosphoric acid is taken into the chromate coatings as partially changed into zinc and chromium phosphates, and the r...

  7. Islamic State and Chemical Weapons

    Directory of Open Access Journals (Sweden)

    Lukáš Rafay

    2016-09-01

    Full Text Available The article deals with topic of Islamic State and chemical weapons. The issue is analysed in three dimensions: origin of used chemical weapons and possibility of independent production; known chemical attacks and tactical regularities in their execution; and traits of future chemical terrorist attacks. By providing a thorough examination of the problem, the article aims at predicting the future development of the group’s chemical program as well as describing any prospective chemical terrorist attacks in Europe

  8. In situ chemical state analysis of buried polymer/metal adhesive interface by hard X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Ozawa, Kenichi; Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya; Mase, Kazuhiko; Ikenaga, Eiji; Nakamura, Tetsuya; Kinoshita, Toyohiko; Oji, Hiroshi

    2014-01-01

    Highlights: • Chemical state analysis of the buried rubber/brass interface is conducted by HAXPES. • Ultrathin rubber films are prepared on the brass surface by two methods. • A high density of Cu 2 S is found on the rubber side of the buried adhesive layer. • The chemical states of the buried and exposed interfaces are compared. - Abstract: Chemical state analysis of adhesive interfaces is important to understand an adhesion mechanism between two different materials. Although photoelectron spectroscopy (PES) is an ideal tool for such an analysis, the adhesive interfaces must be exposed to the surface because PES is essentially a surface sensitive technique. However, an in situ observation is possible by hard X-ray PES (HAXPES) owing to its large probing depth. In the present study, HAXPES is applied to investigate the adhesive interface between rubber and brass without exposing the interface. It is demonstrated that copper sulfides formed at the buried rubber/brass interface are distinguished from S-containing species in the rubber overlayer. The chemical state of the buried interface is compared with that of the “exposed” interface prepared by so-called a filter-paper method

  9. 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...

  10. 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)

  11. Chemical state analysis of oxide thin films using a high resolution double crystal X-ray fluorescence spectrometer

    International Nuclear Information System (INIS)

    Masuda, Hirohisa; Morinaga, Kenji; Ohta, Yoshio.

    1995-01-01

    The chemical state analysis of r.f.-sputtered amorphous oxide thin films was determined by a high resolution X-ray fluorescence spectrometer with double crystals. The polymerization degree of silicate anions in the silicate film was as same as a target (α-Quartz). The oxygen coordination number of Al 3+ ions in the aluminate film was different from a target (α-Al 2 O 3 ), and it was a mixture of 4 and 6 in a spinel-like structure. In CaO-SiO 2 and CaO-Al 2 O 3 films, when the film thickness is thin at the beginning of sputtering, the composition of films are in the shortage of CaO. But when the film thickness become thicker, the composition of films become as same as the target. From the results above, the chemical state of films and their variations with film thickness can be clarified by using the apparatus. (author)

  12. Chemical bonding analysis for solid-state systems using intrinsic oriented quasiatomic minimal-basis-set orbitals

    International Nuclear Information System (INIS)

    Yao, Y.X.; Wang, C.Z.; Ho, K.M.

    2010-01-01

    A chemical bonding scheme is presented for the analysis of solid-state systems. The scheme is based on the intrinsic oriented quasiatomic minimal-basis-set orbitals (IO-QUAMBOs) previously developed by Ivanic and Ruedenberg for molecular systems. In the solid-state scheme, IO-QUAMBOs are generated by a unitary transformation of the quasiatomic orbitals located at each site of the system with the criteria of maximizing the sum of the fourth power of interatomic orbital bond order. Possible bonding and antibonding characters are indicated by the single particle matrix elements, and can be further examined by the projected density of states. We demonstrate the method by applications to graphene and (6,0) zigzag carbon nanotube. The oriented-orbital scheme automatically describes the system in terms of sp 2 hybridization. The effect of curvature on the electronic structure of the zigzag carbon nanotube is also manifested in the deformation of the intrinsic oriented orbitals as well as a breaking of symmetry leading to nonzero single particle density matrix elements. In an additional study, the analysis is performed on the Al 3 V compound. The main covalent bonding characters are identified in a straightforward way without resorting to the symmetry analysis. Our method provides a general way for chemical bonding analysis of ab initio electronic structure calculations with any type of basis sets.

  13. Comparison among chemical, mineralogical and physical analysis from alluvial clays from counties of Southwest of Minas Gerais state (Brazil)

    International Nuclear Information System (INIS)

    Gaspar Junior, L.A.; Varajao, A.F.D.C.; Souza, M.H.O.; Moreno, M.M.T.

    2011-01-01

    The studied area is located in the southwestern portion of Minas Gerais State, encompassing the counties of Alfenas, Areado, Machado, Poco Fundo, Campestre, Serrania, Monte Belo, Bandeira do Sul, Botelhos and Cabo Verde. This region is dominated by strongly weathered pre-cambrian rocks in association with colluvial-alluvial sediments. The present work consisted in a comparison among the mineralogical (X-Ray Diffraction), textural (Laser Granulometry), chemical (X-Ray Fluorescence) and technological (mechanical resistance, water absorption, etc, made in specimen tests) properties of the clays collected on potteries located in these counties. The mineralogical and chemical analysis displayed the kaolinitic nature of the clays from this region, showing also small amount of interlayered clays and large amount of quartz. The best results of physical analysis were obtained for clays from the counties of Cabo Verde and Monte Belo due to the presence of lower values of SiO 2 (quartz) associated with a finer particle size distribution. (author)

  14. Nanoscale chemical state analysis of resistance random access memory device reacting with Ti

    Science.gov (United States)

    Shima, Hisashi; Nakano, Takashi; Akinaga, Hiro

    2010-05-01

    The thermal stability of the resistance random access memory material in the reducing atmosphere at the elevated temperature was improved by the addition of Ti. The unipolar resistance switching before and after the postdeposition annealing (PDA) process at 400 °C was confirmed in Pt/CoO/Ti(5 nm)/Pt device, while the severe degradation of the initial resistance occurs in the Pt/CoO/Pt and Pt/CoO/Ti(50 nm)/Pt devices. By investigating the chemical bonding states of Co, O, and Ti using electron energy loss spectroscopy combined with transmission electron microscopy, it was revealed that excess Ti induces the formation of metallic Co, while the thermal stability was improved by trace Ti. Moreover, it was indicated that the filamentary conduction path can be thermally induced after PDA in the oxide layer by analyzing electrical properties of the degraded devices. The adjustment of the reducing elements is quite essential in order to participate in their profits.

  15. Demystifying "oxi" cocaine: Chemical profiling analysis of a "new Brazilian drug" from Acre State.

    Science.gov (United States)

    da Silva Junior, Ronaldo C; Gomes, Cezar S; Goulart Júnior, Saulo S; Almeida, Fernanda V; Grobério, Tatiane S; Braga, Jez W B; Zacca, Jorge J; Vieira, Maurício L; Botelho, Elvio D; Maldaner, Adriano O

    2012-09-10

    Recent information from various sources suggests that a new illicit drug, called "oxi", is being spread across Brazil. It would be used in the smoked form and it would look like to crack cocaine: usually small yellowish or light brown stones. As fully released in the media, "oxi" would differ from crack cocaine in the sense that crack would contain carbonate or bicarbonate salts whereas "oxi" would include the addition of calcium oxide and kerosene (or gasoline). In this context, this work presents a chemical profiling comparative study between "oxi" street samples seized by the Civil Police of the State of Acre (CP/AC) and samples associated with both international and interstate drug trafficking seized by the Brazilian Federal Police in Acre (FP/AC). The outcome of this work assisted Brazilian authorities to stop inaccurate and alarmist releases on this issue. It may be of good use by the forensic community in order to better understand matters in their efforts to guide local law enforcement agencies in case such claims reach the international illicit market. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

    Science.gov (United States)

    Reynolds, Z. A.

    2015-12-01

    Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how

  17. 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...

  18. 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.

  19. Quality Parameters and Chemical Analysis for Biodiesel Produced in the United States in 2011

    Energy Technology Data Exchange (ETDEWEB)

    Alleman, T. L.; Fouts, L.; Chupka, G.

    2013-03-01

    Samples of biodiesel (B100) from producers and terminals in 2011were tested for critical properties: free and total glycerin, flash point, cloud point, oxidation stability, cold soak filterability, and metals. Failure rates for cold soak filterability and oxidation stability were below 5%. One sample failed flash point due to excess methanol. One sample failed oxidation stability and metal content. Overall, 95% of the samples from this survey met biodiesel quality specification ASTM D6751. In 2007, a sampling of B100 from production facilities showed that nearly 90% met D6751. In samples meeting D6751, calcium was found above the method detection limit in nearly half the samples. Feedstock analysis revealed half the biodiesel was produced from soy and half was from mixed feedstocks. The saturated fatty acid methyl ester concentration of the B100 was compared to the saturated monoglyceride concentration as a percent of total monoglyceride. The real-world correlation of these properties was very good. The results of liquid chromatograph measurement of monoglycerides were compared to ASTM D6751. Agreement between the two methods was good, particularly for total monoglycerides and unsaturated monoglycerides. Because only very low levels of saturated monoglycerides measured, the two methods had more variability, but the correlation was still acceptable.

  20. Micro-strain, dislocation density and surface chemical state analysis of multication thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jayaram, P., E-mail: jayarampnair@gmail.com [Department of Physics, MES Ponnani College Ponnani, Kerala (India); Pradyumnan, P.P. [Department of Physics, University of Calicut, Kerala 673 635 (India); Karazhanov, S.Zh. [Department for Solar Energy, Institute for Energy Technology, Kjeller (Norway)

    2016-11-15

    Multication complex metal oxide thin films are rapidly expanding the class of materials with many technologically important applications. Herein this work, the surface of the pulsed laser deposited thin films of Zn{sub 2}SnO{sub 4} and multinary compounds obtained by substitution/co-substitution of Sn{sup 4+} with In{sup 3+} and Ga{sup 3+} are studied by X-ray photoelectron emission spectroscopy (X-PES) method. Peaks corresponding to the elements of Zn, Sn, Ga, In and O on the film surface has been identified and contribution of the elements has been studied by the computer aided surface analysis (CASA) software. Binding energies, full-width at half maximum (FWHM), spin-orbit splitting energies, asymmetric peak-shape fitting parameters and quantification of elements in the films are discussed. Studies of structural properties of the films by x-ray diffraction (XRD) technique showed inverse spinel type lattice with preferential orientation. Micro-strain, dislocation density and crystallite sizes in the film surface have been estimated.

  1. Level crossing analysis of chemically induced dynamic nuclear polarization: Towards a common description of liquid-state and solid-state cases

    Energy Technology Data Exchange (ETDEWEB)

    Sosnovsky, Denis V.; Ivanov, Konstantin L., E-mail: ivanov@tomo.nsc.ru [International Tomography Centre of SB RAS, Institutskaya 3a, 630090, Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova 2, 630090, Novosibirsk (Russian Federation); Jeschke, Gunnar [Institut für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Matysik, Jörg [Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, D-04103 Leipzig (Germany); Vieth, Hans-Martin [International Tomography Centre of SB RAS, Institutskaya 3a, 630090, Novosibirsk (Russian Federation); Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin (Germany)

    2016-04-14

    Chemically Induced Dynamic Nuclear Polarization (CIDNP) is an efficient method of creating non-equilibrium polarization of nuclear spins by using chemical reactions, which have radical pairs as intermediates. The CIDNP effect originates from (i) electron spin-selective recombination of radical pairs and (ii) the dependence of the inter-system crossing rate in radical pairs on the state of magnetic nuclei. The CIDNP effect can be investigated by using Nuclear Magnetic Resonance (NMR) methods. The gain from CIDNP is then two-fold: it allows one to obtain considerable amplification of NMR signals; in addition, it provides a very useful tool for investigating elusive radicals and radical pairs. While the mechanisms of the CIDNP effect in liquids are well established and understood, detailed analysis of solid-state CIDNP mechanisms still remains challenging; likewise a common theoretical frame for the description of CIDNP in both solids and liquids is missing. Difficulties in understanding the spin dynamics that lead to the CIDNP effect in the solid-state case are caused by the anisotropy of spin interactions, which increase the complexity of spin evolution. In this work, we propose to analyze CIDNP in terms of level crossing phenomena, namely, to attribute features in the CIDNP magnetic field dependence to Level Crossings (LCs) and Level Anti-Crossings (LACs) in a radical pair. This approach allows one to describe liquid-state CIDNP; the same holds for the solid-state case where anisotropic interactions play a significant role in CIDNP formation. In solids, features arise predominantly from LACs, since in most cases anisotropic couplings result in perturbations, which turn LCs into LACs. We have interpreted the CIDNP mechanisms in terms of the LC/LAC concept. This consideration allows one to find analytical expressions for a wide magnetic field range, where several different mechanisms are operative; furthermore, the LAC description gives a way to determine CIDNP sign

  2. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and Ni

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, Mark C., E-mail: biesingr@uwo.ca [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia); Payne, Brad P. [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Grosvenor, Andrew P. [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C9 (Canada); Lau, Leo W.M. [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Gerson, Andrea R.; Smart, Roger St.C. [ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2011-01-15

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of their 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. Our previous paper [M.C. Biesinger et al., Appl. Surf. Sci. 257 (2010) 887-898.] in which we examined Sc, Ti, V, Cu and Zn species, has shown that all the values of the spectral fitting parameters for each specific species, i.e. binding energy (eV), full wide at half maximum (FWHM) value (eV) for each pass energy, spin-orbit splitting values and asymmetric peak shape fitting parameters, are not all normally provided in the literature and data bases, and are necessary for reproducible, quantitative chemical state analysis. A more consistent, practical and effective approach to curve fitting was developed based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of literature references and (3) specific literature references where fitting procedures are available. This paper extends this approach to the chemical states of Cr, Mn, Fe, Co and Ni metals, and various oxides and hydroxides where intense, complex multiplet splitting in many of the chemical states of these elements poses unique difficulties for chemical state analysis. The curve fitting procedures proposed use the same criteria as proposed previously but with the additional complexity of fitting of multiplet split spectra which has been done based on spectra of numerous reference materials and theoretical XPS modeling of these transition metal species. Binding energies, FWHM values, asymmetric peak shape fitting parameters, multiplet peak separation and peak area percentages are presented. The procedures developed can be utilized to remove uncertainties in the analysis of surface states in nano

  3. Screening of antibiotics and chemical analysis of penicillin residue in fresh milk and traditional dairy products in Oyo state, Nigeria

    Directory of Open Access Journals (Sweden)

    Isaac Olufemi Olatoye

    2016-09-01

    Full Text Available Background and Aim: There are global public health and economic concerns on chemical residues in food of animal origin. The use of antibiotics in dairy cattle for the treatment of diseases such as mastitis has contributed to the presence of residues in dairy products. Penicillin residues as low as 1 ppb can lead to allergic reactions and shift of resistance patterns in microbial population as well as interfere with the processing of several dairy products. Antibiotic monitoring is an essential quality control measure in safe milk production. This study was aimed at determining antibiotic residue contamination and the level of penicillin in dairy products from Fulani cattle herds in Oyo State. Materials and Methods: The presence of antibiotic residues in 328 samples of fresh milk, 180 local cheese (wara, and 90 fermented milk (nono from Southwest, Nigeria were determined using Premi® test kit (R-Biopharm AG, Germany followed by high-performance liquid chromatography analysis of penicillin-G residue. Results: Antibiotic residues were obtained in 40.8%, 24.4% and 62.3% fresh milk, wara and nono, respectively. Penicillin-G residue was also detected in 41.1% fresh milk, 40.2% nono and 24.4% wara at mean concentrations of 15.22±0.61, 8.24±0.50 and 7.6±0.60 μg/L with 39.3%, 36.7% and 21.1%, respectively, containing penicillin residue above recommended Codex maximum residue limit (MRL of 5 μg/L in dairy. There was no significant difference between the mean penicillin residues in all the dairy products in this study. Conclusion: The results are of food safety concern since the bulk of the samples and substantial quantities of dairy products in Oyo state contained violative levels of antibiotic residues including penicillin residues in concentrations above the MRL. This could be due to indiscriminate and unregulated administration of antibiotics to dairy cattle. Regulatory control of antibiotic use, rapid screening of milk and dairy farmers

  4. 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.

  5. 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

  6. 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.

  7. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn

    International Nuclear Information System (INIS)

    Biesinger, Mark C.; Lau, Leo W.M.; Gerson, Andrea R.; Smart, Roger St.C.

    2010-01-01

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of the 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. A review of current literature shows that all values necessary for reproducible, quantitative chemical state analysis are usually not provided. This paper reports a more consistent, practical and effective approach to curve-fitting the various chemical states in a variety of Sc, Ti, V, Cu and Zn metals, oxides and hydroxides. The curve-fitting procedures proposed are based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of the literature references, and (3) specific literature references where fitting procedures are available. Binding energies, full-width at half maximum (FWHM) values, spin-orbit splitting values, asymmetric peak-shape fitting parameters, and, for Cu and Zn, Auger parameters values are presented. The quantification procedure for Cu species details the use of the shake-up satellites for Cu(II)-containing compounds and the exact binding energies of the Cu(0) and Cu(I) peaks. The use of the modified Auger parameter for Cu and Zn species allows for corroborating evidence when there is uncertainty in the binding energy assignment. These procedures can remove uncertainties in analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.

  8. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, Mark C., E-mail: biesingr@uwo.ca [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia); Lau, Leo W.M. [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Gerson, Andrea R.; Smart, Roger St.C. [ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2010-11-15

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of the 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. A review of current literature shows that all values necessary for reproducible, quantitative chemical state analysis are usually not provided. This paper reports a more consistent, practical and effective approach to curve-fitting the various chemical states in a variety of Sc, Ti, V, Cu and Zn metals, oxides and hydroxides. The curve-fitting procedures proposed are based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of the literature references, and (3) specific literature references where fitting procedures are available. Binding energies, full-width at half maximum (FWHM) values, spin-orbit splitting values, asymmetric peak-shape fitting parameters, and, for Cu and Zn, Auger parameters values are presented. The quantification procedure for Cu species details the use of the shake-up satellites for Cu(II)-containing compounds and the exact binding energies of the Cu(0) and Cu(I) peaks. The use of the modified Auger parameter for Cu and Zn species allows for corroborating evidence when there is uncertainty in the binding energy assignment. These procedures can remove uncertainties in analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.

  9. Chemical equilibration due to heavy Hagedorn states

    International Nuclear Information System (INIS)

    Greiner, C; Koch-Steinheimer, P; Liu, F M; Shovkovy, I A; Stoecker, H

    2005-01-01

    A scenario of heavy resonances, called massive Hagedorn states, is proposed which exhibits a fast (t ∼ 1 fm/c) chemical equilibration of (strange) baryons and anti-baryons at the QCD critical temperature T c . For relativistic heavy ion collisions this scenario predicts that hadronization is followed by a brief expansion phase during which the equilibration rate is higher than the expansion rate, so that baryons and antibaryons reach chemical equilibrium before chemical freeze-out occurs

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Validation of a CATHENA fuel channel model for the post blowdown analysis of the high temperature thermal-chemical experiment CS28-1, I - Steady state

    International Nuclear Information System (INIS)

    Rhee, Bo Wook; Kim, Hyoung Tae; Park, Joo Hwan

    2008-01-01

    To form a licensing basis for the new methodology of the fuel channel safety analysis code system for CANDU-6, a CATHENA model for the post-blowdown fuel channel analysis for a Large Break LOCA has been developed, and tested for the steady state of a high temperature thermal-chemical experiment CS28-1. As the major concerns of the post-blowdown fuel channel analysis of the current CANDU-6 design are how much of the decay heat can be discharged to the moderator via a radiation and a convective heat transfer at the expected accident conditions, and how much zirconium sheath would be oxidized to generate H 2 at how high a fuel temperature, this study has focused on understanding these phenomena, their interrelations, and a way to maintain a good accuracy in the prediction of the fuel and the pressure tube temperatures without losing the important physics of the involved phenomena throughout the post-blowdown phase of a LBLOCA. For a better prediction, those factors that may significantly contribute to the prediction accuracy of the steady state of the test bundles were sought. The result shows that once the pressure tube temperature is predicted correctly by the CATHENA heat transfer model between the pressure tube and the calandria tube through a gap thermal resistance adjustment, all the remaining temperatures of the inner ring, middle ring and outer ring FES temperatures can be predicted quite satisfactorily, say to within an accuracy range of 20-25 deg. C, which is comparable to the reported accuracy of the temperature measurement, ±2%. Also the analysis shows the choice of the emissivity of the solid structures (typically, 0.80, 0.34, 0.34 for FES, PT, CT), and the thermal resistance across the CO 2 annulus are factors that significantly affect the steady state prediction accuracy. A question on the legitimacy of using 'transparent' assumption for the CO 2 gas annulus for the radiation heat transfer between the pressure tube and the calandria tube in CATHENA

  16. Molecular and Silica-Supported Molybdenum Alkyne Metathesis Catalysts: Influence of Electronics and Dynamics on Activity Revealed by Kinetics, Solid-State NMR, and Chemical Shift Analysis.

    Science.gov (United States)

    Estes, Deven P; Gordon, Christopher P; Fedorov, Alexey; Liao, Wei-Chih; Ehrhorn, Henrike; Bittner, Celine; Zier, Manuel Luca; Bockfeld, Dirk; Chan, Ka Wing; Eisenstein, Odile; Raynaud, Christophe; Tamm, Matthias; Copéret, Christophe

    2017-12-06

    Molybdenum-based molecular alkylidyne complexes of the type [MesC≡Mo{OC(CH 3 ) 3-x (CF 3 ) x } 3 ] (MoF 0 , x = 0; MoF 3 , x = 1; MoF 6 , x = 2; MoF 9 , x = 3; Mes = 2,4,6-trimethylphenyl) and their silica-supported analogues are prepared and characterized at the molecular level, in particular by solid-state NMR, and their alkyne metathesis catalytic activity is evaluated. The 13 C NMR chemical shift of the alkylidyne carbon increases with increasing number of fluorine atoms on the alkoxide ligands for both molecular and supported catalysts but with more shielded values for the supported complexes. The activity of these catalysts increases in the order MoF 0 molecular and supported species. Detailed solid-state NMR analysis of molecular and silica-supported metal alkylidyne catalysts coupled with DFT/ZORA calculations rationalize the NMR spectroscopic signatures and discernible activity trends at the frontier orbital level: (1) increasing the number of fluorine atoms lowers the energy of the π*(M≡C) orbital, explaining the more deshielded chemical shift values; it also leads to an increased electrophilicity and higher reactivity for catalysts up to MoF 6 , prior to a sharp decrease in reactivity for MoF 9 due to the formation of stable metallacyclobutadiene intermediates; (2) the silica-supported catalysts are less active than their molecular analogues because they are less electrophilic and dynamic, as revealed by their 13 C NMR chemical shift tensors.

  17. Chemical Analysis of Suspected Unrecorded Alcoholic Beverages from the States of São Paulo and Minas Gerais, Brazil.

    Science.gov (United States)

    Negri, Giuseppina; Soares Neto, Julino Assunção Rodrigues; de Araujo Carlini, Elisaldo Luiz

    2015-01-01

    Our study analyzed 152 samples of alcoholic beverages collected from the states of São Paulo and Minas Gerais, Brazil, using gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR), and inductively coupled plasma atomic emission spectrometry (ICP-AES). The methanol content varied from 20 to 180 ppm in 28 samples, and the limit of the accepted level of 200 ppm was exceeded in only one sample. High content of cyanide derivatives and ethyl carbamate, above the accepted level of 150 ppb, was observed in 109 samples. Carbonyl compounds were also observed in 111 samples, showing hydroxy 2-propanone, 4-methyl-4-hepten-3-one, furfural, and 2-hydroxyethylcarbamate as main constituents. Copper was found at concentrations above 5 ppm in 26 samples; the maximum value observed was 28 ppm. This work evaluated the human health risk associated with the poor quality of suspected unrecorded alcohols beverages.

  18. On inverse methods for combining chemical and physical oceanographic data: A steady-state analysis of the Atlantic Ocean

    International Nuclear Information System (INIS)

    Bolin, Bert; Bjoerkstroem, Anders; Holmen, Kim; Moore, Berrien

    1987-08-01

    An attempt has been made to increase the spatial resolution in the vise of inverse methods to deduce rates of water circulation and detritus formation by the simultaneous use of tracer data and the condition of quasi-geostrophic flow. It is shown that an overdetermined system of equations is desirable to permit analysis of the sensitivity of a solution to errors in the data fields. The method has been tested for the Atlantic Ocean, in which case we employ an 84-box model (eight layers in the vertical and 12 regions in the horizontal define the box configuration). As quasi-steady tracers we consider dissolved inorganic carbon (DIC), radiocarbon, alkalinity, phosphorus, oxygen, salinity and enthalpy. The condition of quasi-geostrophic flow is employed for flow across all vertical surfaces between regions except close to the equator. Water continuity is required to be exactly satisfied by the use of a set of closed loops to describe the advective flow. The method of least squares is used to derive a solution and in . . so doing we also require, that turbulence only transfers matter down tracer gradients (i.e. eddy diffusivity is nonnegative) and that detritus is formed only in surface boxes and is destroyed in the water column below. It is shown how appropriate weighting of the equations in the set is decisive for the solutions that we derive and that great care must be taken to ascertain that the interior tracer distributions and the boundary conditions in terms of exchange of tracer material with the exterior are compatible. The enthalpy equations turn out not to fulfil such a demand and have not been used in deriving the solutions presented in the paper. A basic solution with an ageostrophic flow component of about 15% is derived and compared with current knowledge about the general circulation of the Atlantic Ocean and the rates of detritus formation and destruction. The sensitivity of the solution to uncertainties in the data field is presented. It is shown that

  19. 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

  20. Diamond-like carbon coatings on a CoCrMo implant alloy: A detailed XPS analysis of the chemical states at the interface

    International Nuclear Information System (INIS)

    Mueller, U.; Falub, C.V.; Thorwarth, G.; Voisard, C.; Hauert, R.

    2011-01-01

    Low friction and wear resistant coatings have a long history of successful applications in industry. It has long been hoped that these coatings, especially diamond-like carbon (DLC), could also be used successfully in load-bearing joint implants, extending implant life time considerably. However, despite several medical studies carried out so far, no regular DLC-coated implants are available on the market. In most cases, failure was due to insufficient long-term stability of the adhesion of such coatings on implants in vivo. That is because introducing a coated implant not only brings the coating into contact with the body environment but also the interface that controls the adhesion. This usually reactively formed interface must be considered to be at least one additional material which must be not only biocompatible, but also unsusceptible to corrosive attack. The aim of this paper is to analyze in detail the interface, i.e., the transition region between the substrate and the coating. This knowledge is necessary in order to find the right measures to ensure the long-term stability of the adhesion. Results for DLC coatings on a cobalt-chromium-molybdenum alloy are presented. It is shown that a very thin interface layer is formed, with the alloy on one side and the carbon film on the other side. This layer consists of a mixture of carbides from all the metals of the base material. This result is obtained by means of measuring depth profiles using X-ray photoelectron spectroscopy because these spectra yield not only the chemical composition of the interface but a detailed analysis provides information on the chemical states across the interface.

  1. 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.

  2. 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)

  3. 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...

  4. Perturbation of longitudinal relaxation rate in rotating frame (PLRF) analysis for quantification of chemical exchange saturation transfer signal in a transient state.

    Science.gov (United States)

    Wang, Yi; Zhang, Yaoyu; Zhao, Xuna; Wu, Bing; Gao, Jia-Hong

    2017-11-01

    To develop a novel analytical method for quantification of chemical exchange saturation transfer (CEST) in the transient state. The proposed method aims to reduce the effects of non-chemical-exchange (non-CE) parameters on the CEST signal, emphasizing the effect of chemical exchange. The difference in the longitudinal relaxation rate in the rotating frame ( ΔR1ρ) was calculated based on perturbation of the Z-value by R1ρ, and a saturation-pulse-amplitude-compensated exchange-dependent relaxation rate (SPACER) was determined with a high-exchange-rate approximation. In both phantom and human subject experiments, MTRasym (representative of the traditional CEST index), ΔR1ρ, and SPACER were measured, evaluated, and compared by altering the non-CE parameters in a transient-state continuous-wave CEST sequence. In line with the theoretical expectation, our experimental data demonstrate that the effects of the non-CE parameters can be more effectively reduced using the proposed indices (  ΔR1ρ and SPACER) than using the traditional CEST index ( MTRasym). The proposed method allows for the chemical exchange weight to be better emphasized in the transient-state CEST signal, which is beneficial, in practice, for quantifying the CEST signal. Magn Reson Med 78:1711-1723, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  5. The hyperbolic chemical bond: Fourier analysis of ground and first excited state potential energy curves of HX (X = H-Ne).

    Science.gov (United States)

    Harrison, John A

    2008-09-04

    RHF/aug-cc-pVnZ, UHF/aug-cc-pVnZ, and QCISD/aug-cc-pVnZ, n = 2-5, potential energy curves of H2 X (1) summation g (+) are analyzed by Fourier transform methods after transformation to a new coordinate system via an inverse hyperbolic cosine coordinate mapping. The Fourier frequency domain spectra are interpreted in terms of underlying mathematical behavior giving rise to distinctive features. There is a clear difference between the underlying mathematical nature of the potential energy curves calculated at the HF and full-CI levels. The method is particularly suited to the analysis of potential energy curves obtained at the highest levels of theory because the Fourier spectra are observed to be of a compact nature, with the envelope of the Fourier frequency coefficients decaying in magnitude in an exponential manner. The finite number of Fourier coefficients required to describe the CI curves allows for an optimum sampling strategy to be developed, corresponding to that required for exponential and geometric convergence. The underlying random numerical noise due to the finite convergence criterion is also a clearly identifiable feature in the Fourier spectrum. The methodology is applied to the analysis of MRCI potential energy curves for the ground and first excited states of HX (X = H-Ne). All potential energy curves exhibit structure in the Fourier spectrum consistent with the existence of resonances. The compact nature of the Fourier spectra following the inverse hyperbolic cosine coordinate mapping is highly suggestive that there is some advantage in viewing the chemical bond as having an underlying hyperbolic nature.

  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 state analysis of heat-treated 6, 13-bis(triisopropylsilylethynyl) pentacene investigated by XPS valence band spectra, XANES spectra and first-principles calculation

    International Nuclear Information System (INIS)

    Muro, Maiko; Natsume, Yutaka; Kikuma, Jun; Setoyama, Hiroyuki

    2014-01-01

    X-ray photoelectron spectroscopy (XPS) valence band spectra reflect the chemical bonding states. To take this advantage, we tried to interpret experimental spectra by the occupied density of states (DOS) based on first principles calculation. In this work, we discussed XPS and X-ray Absorption Near Edge Structure (XANES) spectra of 6, 13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pen), which is well known as an organic semiconductor. We studied chemical structure change of TIPS-Pen caused by heat-treatment at 300degC under nitrogen and under the air. It has been suggested that the structural change of pentacene skeleton by Diels-Alder type reaction occurs in both cases. In addition, the sample heat-treated under the air showed desorption of the isopropyl group and increase of oxygen concentration. (author)

  8. Chemical state analysis of heavily phosphorus-doped epitaxial silicon films grown on Si (1 0 0) by X-ray photoelectron spectroscopy

    Science.gov (United States)

    Lee, Minhyeong; Kim, Sungtae; Ko, Dae-Hong

    2018-06-01

    In this work, we investigated the chemical bonding states in highly P-doped Si thin films epitaxially grown on Si (0 0 1) substrates using high-resolution X-ray photoelectron spectroscopy (HR-XPS). HR-XPS P 2p core-level spectra clearly show spin-orbital splitting between P 2p1/2 and P 2p3/2 peaks in Si films doped with a high concentration of P. Moreover, the intensities of P 2p1/2 and P 2p3/2 peaks for P-doped Si films increase with P concentrations, while their binding energies remained almost identical. These results indicate that more P atoms are incorporated into the substitutional sites of the Si lattice with the increase of P concentrations. In order to identify the chemical states of P-doped Si films shown in XPS Si 2p spectra, the spectra of bulk Si were subtracted from those of Si:P samples, which enables us to clearly identify the new chemical state related to Sisbnd P bonds. We observed that the presence of the two well-resolved new peaks only for the Si:P samples at the binding energy higher than those of a Sisbnd Si bond, which is due to the strong electronegativity of P than that of Si. Experimental findings in this study using XPS open up new doors for evaluating the chemical states of P-doped Si materials in fundamental researches as well as in industrial applications.

  9. Chemical states of molybdenum in radioactive waste glass

    International Nuclear Information System (INIS)

    Ishiguro, Katsuhiko; Kawanishi, Nobuo; Nagaki, Hiroshi; Naito, Aritsune

    1982-01-01

    In order to confirm an expectation that the chemical state of molybdenum in glass reflects the phase separation tendency of the yellow solid from the melt of borosilicate glass, simulated waste glasses were prepared, and ESCA analysis was performed using a commercially available electron spectrometer (PHI550 E) with an excitation source consisting of Mg Kα-ray. The effects of the concentration of Mo and FE 2 O 3 and the melting atmosphere (oxidizing or reducing) in which the samples were prepared on the chemical state of Mo and the solubility of MoO 3 were examined. From the observation of Mo spectra, it was shown that Mo in waste glass had several valencies, e.g., Mo(3), Mo(4), Mo(5) and Mo(6), while Mo in the yellow solid separated from the melts exhibited hexa-valent state, the peak intensity of higher valencies increased relatively with the increase of MoO 3 concentration, but the chemical state of Mo did not change remarkably around the solubility limit of MoO 3 , the melting atmosphere influenced on the Mo state in the waste glass, the peak intensity of Mo(6) increased relatively with the increasing Fe 2 O 3 concentration, and Mo in devitrified glass exhibited hexa-valent state. (Yoshitake, I.)

  10. Study of solid chemical evolution in torrefaction of different biomasses through solid-state "1"3C cross-polarization/magic angle spinning NMR (nuclear magnetic resonance) and TGA (thermogravimetric analysis)

    International Nuclear Information System (INIS)

    Rodriguez Alonso, Elvira; Dupont, Capucine; Heux, Laurent; Da Silva Perez, Denilson; Commandre, Jean-Michel; Gourdon, Christophe

    2016-01-01

    The objective of this work is to compare mass loss and chemical evolution of the solid phase, versus time, during dynamic torrefaction of different types of biomass. For this purpose, two experiments, ThermoGravimetric Analysis and solid-state "1"3C Cross-Polarization/Magic Angle Spinning Nuclear Magnetic Resonance, were run on four representative biomasses. Overall mass loss and chemical evolution of the solid phase were followed, respectively, as a function of temperature and time. Thanks to this coupled information, it was shown that the knowledge of both solid mass loss and chemical evolution is necessary to characterize torrefaction severity. Moreover, biomasses containing higher proportions of xylan lost mass faster than those containing lower proportions. Lignin showed a protecting role towards cellulose, which would lead to a faster degradation of non-woody biomasses in comparison with woody biomasses. Three parameters would have an influence on solid chemical evolution during torrefaction: xylan content in hemicellulose, lignin content in biomass, and cellulose crystallinity. - Highlights: • Torrefaction of four biomasses was studied with TGA and solid-state NMR. • Both solid mass loss and chemical evolution characterize torrefaction severity. • Biomasses containing a higher proportion of xylan lose mass faster. • Lignin shows a stronger protecting role in degradation of woody biomasses. • Xylan, lignin and crystalline cellulose values influence solid chemical evolution.

  11. 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)

  12. United States Chemical Policy: Response Considerations

    Science.gov (United States)

    1991-06-07

    nTcn aapplicable. entew induiy r~ epr dates (g.10~Saeet o ehia Jun 87.- 30 Jun 88). rot gDocuments. DOE See authorities Block 4. Title and $ubtitle...introduction of mustard gas and gas shells to the battlefield. Between World War I and the 1980’s, infrequent use of chemical warfare occurred. In 1935 and...The period just prior to World War II included at least two known cases of chemical warfare use. In 1935 -36, Italy used mustard gas against Abyssinia

  13. Chemical state analysis of iron(III) compounds precipitated homogeneously from solutions containing urea by means of Moessbauer spectrometry and x-ray diffractometry

    International Nuclear Information System (INIS)

    Ujihira, Yusuke; Ohyabu, Matashige; Murakami, Tetsuro; Horie, Tsuyoshi.

    1978-01-01

    Chemical states of iron(III) compounds, precipitated homogeneously by heating the iron(III) salt solution at 363 K in the presence of urea, was studied by means of Moessbauer spectrometry and X-ray diffractometry. The pH-time relation of urea hydrolysis revealed that the precipitation process from homogeneous solution is identical to the hydrolysis of iron(III) ion at pH around 2 under the homogeneous supply of OH - ion, which is generated by hydrolysis of urea. Accordingly, iron(III) oxide hydroxide or similar compounds to the hydrolysis products of iron(III) ion was precipitated by the precipitation from homogeneous solution methods. Akaganeite (β-FeOOH) was crystallized from 0.1 M iron(III) chloride solution. Goethite(α-FeOOH) and hematite(α-Fe 2 O 3 ) was precipitated from 0.1 M iron(III) nitrate solution, vigorous liberation of OH - ion favoring the crystallization of hematite. The addition of chloride ion to the solution resulted in the formation of akaganeite. Basic salt of iron sulfate[NH 4 Fe 3 (OH) 6 (SO 4 ) 2 ] and goethite were formed from 0.1 M iron(III) sulfate solution, the former being obtained in the more moderate condition of the urea hydrolysis ( 363 K). (author)

  14. Analysis of chemical bond states and electrical properties of stacked AlON/HfO{sub 2} gate oxides formed by using a layer-by-layer technique

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Wonjoon; Lee, Jonghyun; Yang, Jungyup; Kim, Chaeok; Hong, Jinpyo; Nahm, Tschanguh; Byun, Byungsub; Kim, Moseok [Hanyang University, Seoul (Korea, Republic of)

    2006-06-15

    Stacked AlON/HfO{sub 2} thin films for gate oxides in metal-oxide-semiconductor devices are successfully prepared on Si substrates by utilizing a layer-by-layer technique integrated with an off-axis RF remote plasma sputtering process at room temperature. This off-axis structure is designed to improve the uniformity and the quality of gate oxide films. Also, a layer-by-layer technique is used to control the interface layer between the gate oxide and the Si substrate. The electrical properties of our stacked films are characterized by using capacitance versus voltage and leakage current versus voltage measurements. The stacked AlON/HfO{sub 2} gate oxide exhibits a low leakage current of about 10{sup -6} A/cm{sup 2} and a high dielectric constant value of 14.26 by effectively suppressing the interface layer between gate oxide and Si substrate. In addition, the chemical bond states and the optimum thickness of each AlON and HfO{sub 2} thin film are analyzed using X-ray photoemission spectroscopy and transmission electron microscopy measurement.

  15. 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

  16. 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

  17. Cob(I)alamin: insight into the nature of electronically excited states elucidated via quantum chemical computations and analysis of absorption, CD and MCD data.

    Science.gov (United States)

    Kornobis, Karina; Ruud, Kenneth; Kozlowski, Pawel M

    2013-02-07

    The nature of electronically excited states of the super-reduced form of vitamin B(12) (i.e., cob(I)alamin or B(12s)), a ubiquitous B(12) intermediate, was investigated by performing quantum-chemical calculations within the time-dependent density functional theory (TD-DFT) framework and by establishing their correspondence to experimental data. Using response theory, the electronic absorption (Abs), circular dichroism (CD) and magnetic CD (MCD) spectra of cob(I)alamin were simulated and directly compared with experiment. Several issues have been taken into considerations while performing the TD-DFT calculations, such as strong dependence on the applied exchange-correlation (XC) functional or structural simplification imposed on the cob(I)alamin. In addition, the low-lying transitions were also validated by performing CASSCF/MC-XQDPT2 calculations. By comparing computational results with existing experimental data a new level of understanding of electronic excitations has been established at the molecular level. The present study extends and confirms conclusions reached for other cobalamins. In particular, the better performance of the BP86 functional, rather than hybrid-type, was observed in terms of the excitations associated with both Co d and corrin π localized transitions. In addition, the lowest energy band was associated with multiple metal-to-ligand charge transfer excitations as opposed to the commonly assumed view of a single π → π* transition followed by vibrational progression. Finally, the use of the full cob(I)alamin structure, instead of simplified molecular models, shed new light on the spectral analyses of cobalamin systems and revealed new challenges of this approach related to long-range charge transfer excitations involving side chains.

  18. 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.

  19. 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...

  20. Homemade chemical bomb incidents - 15 states, 2003-2011.

    Science.gov (United States)

    2013-06-21

    Homemade chemical bombs (HCBs) are made from commonly found chemicals. The volume of news reports of HCB explosions suggests they are not uncommon. To determine the number of events involving HCBs in the United States and describe the factors associated with them, the Agency for Toxic Substances and Disease Registry (ATSDR) analyzed data from its surveillance system that tracks spills and leaks of hazardous substances. This report describes the results of that analysis, which indicated that, during 2003-2011, a total of 134 events involving HCBs were reported from 15 states. Among those events, 21 (16%) resulted in adverse health effects (i.e., respiratory symptoms, burns, and skin irritation) for 53 persons. The majority (35 [66%]) of these persons were youths.HCBs are hazardous and especially dangerous if detonated in public areas. Increasing awareness of HCBs and their dangers (particularly during summer months) among first-responders, parents, school staff members and others who work with youths might help reduce injuries associated with HCBs.

  1. 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

  2. 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.

  3. Chemical characterization of bottom sediments from Ribeira de Iguape river, Parana and Sao Paulo states, Brazil, by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Francisco J.V.; Quinaglia, Gilson A., E-mail: fjcastro@sp.gov.br, E-mail: gquinaglia@sp.gov.br [Companhia Ambiental do Estado de Sao Paulo(ELTA/CETESB), Sao Paulo, SP (Brazil). Setor de Analises Toxicologicas; Favaro, Deborah I.T., E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (LAN-CRPq/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. por Ativacao Neutronica

    2013-07-01

    During several decades the Alto Vale of Ribeira region (SP-PR) suffered under lead mining activities in the region. Although in 1996 all such activities ceased, the mining activities left behind a huge amount of environmental liabilities mainly in the hydrographic basin of Ribeira de Iguape river. In the present study the chemical characterization of bottom sediments was undertaken and the concentration of the major (Ca, Fe, K and Na), trace (As, Ba, Br, Co, Cs, Hf, Rb, Sb, Ta, Th, U, Zn) and rare earth elements (La, Ce, Eu, Nd, Sm, Lu, Tb, Yb and Sc) by instrumental neutron activation analysis (INAA) were determined. The validation of the analytical methodology was performed by means of certified reference materials analyses and Z-score criterion was used. Eight points were sampled at the Ribeira de Iguape river and its majorities from Adrianopolis (Pr) (site 01) to Registro (SP) (site 08). Granulometric analyses and textural classification were undertaken in the sediment samples. The results obtained by using INAA were compared to UCC (Upper Continental Crust) reference values. The environmental tools of Enrichment Factor (EF) and Geochemical Index (GI) were used to assess the degree of metal contamination in the sediment samples. Samples from site 5 (Betari river - Iporanga, SP) presented high values for As, Sb and Zn and greater IGeo (3.1 - 5.5) and EF (>7.0) values for these elements classifying this point as highly polluted for these elements as well as a strong anthropogenic contribution. Site 7 (Ribeira river - Eldorado, SP) was considered moderately polluted for As, Br and Sb. The high concentration levels of some metals and metalloids reflect the contribution of mining activities from the past in the region. From the results it can be seen that although mining activities no longer exist since 1996, the deleterious effects in the environment are still present and strong. (author)

  4. Chemical characterization of bottom sediments from Ribeira de Iguape river, Parana and Sao Paulo states, Brazil, by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Castro, Francisco J.V.; Quinaglia, Gilson A.; Favaro, Deborah I.T.

    2013-01-01

    During several decades the Alto Vale of Ribeira region (SP-PR) suffered under lead mining activities in the region. Although in 1996 all such activities ceased, the mining activities left behind a huge amount of environmental liabilities mainly in the hydrographic basin of Ribeira de Iguape river. In the present study the chemical characterization of bottom sediments was undertaken and the concentration of the major (Ca, Fe, K and Na), trace (As, Ba, Br, Co, Cs, Hf, Rb, Sb, Ta, Th, U, Zn) and rare earth elements (La, Ce, Eu, Nd, Sm, Lu, Tb, Yb and Sc) by instrumental neutron activation analysis (INAA) were determined. The validation of the analytical methodology was performed by means of certified reference materials analyses and Z-score criterion was used. Eight points were sampled at the Ribeira de Iguape river and its majorities from Adrianopolis (Pr) (site 01) to Registro (SP) (site 08). Granulometric analyses and textural classification were undertaken in the sediment samples. The results obtained by using INAA were compared to UCC (Upper Continental Crust) reference values. The environmental tools of Enrichment Factor (EF) and Geochemical Index (GI) were used to assess the degree of metal contamination in the sediment samples. Samples from site 5 (Betari river - Iporanga, SP) presented high values for As, Sb and Zn and greater IGeo (3.1 - 5.5) and EF (>7.0) values for these elements classifying this point as highly polluted for these elements as well as a strong anthropogenic contribution. Site 7 (Ribeira river - Eldorado, SP) was considered moderately polluted for As, Br and Sb. The high concentration levels of some metals and metalloids reflect the contribution of mining activities from the past in the region. From the results it can be seen that although mining activities no longer exist since 1996, the deleterious effects in the environment are still present and strong. (author)

  5. 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

  6. 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

  7. Revisiting the chemical reactivity indices as the state function derivatives. The role of classical chemical hardness

    Energy Technology Data Exchange (ETDEWEB)

    Malek, Ali; Balawender, Robert, E-mail: rbalawender@ichf.edu.pl [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw (Poland)

    2015-02-07

    The chemical reactivity indices as the equilibrium state-function derivatives are revisited. They are obtained in terms of the central moments (fluctuation formulas). To analyze the role of the chemical hardness introduced by Pearson [J. Am. Chem. Soc. 105, 7512 (1983)], the relations between the derivatives up to the third-order and the central moments are obtained. As shown, the chemical hardness and the chemical potential are really the principal indices of the chemical reactivity theory. It is clear from the results presented here that the chemical hardness is not the derivative of the Mulliken chemical potential (this means also not the second derivative of the energy at zero-temperature limit). The conventional quadratic dependence of energy, observed at finite temperature, reduces to linear dependence on the electron number at zero-temperature limit. The chemical hardness plays a double role in the admixture of ionic states to the reference neutral state energy: it determines the amplitude of the admixture and regulates the damping of its thermal factor.

  8. Revisiting the chemical reactivity indices as the state function derivatives. The role of classical chemical hardness

    International Nuclear Information System (INIS)

    Malek, Ali; Balawender, Robert

    2015-01-01

    The chemical reactivity indices as the equilibrium state-function derivatives are revisited. They are obtained in terms of the central moments (fluctuation formulas). To analyze the role of the chemical hardness introduced by Pearson [J. Am. Chem. Soc. 105, 7512 (1983)], the relations between the derivatives up to the third-order and the central moments are obtained. As shown, the chemical hardness and the chemical potential are really the principal indices of the chemical reactivity theory. It is clear from the results presented here that the chemical hardness is not the derivative of the Mulliken chemical potential (this means also not the second derivative of the energy at zero-temperature limit). The conventional quadratic dependence of energy, observed at finite temperature, reduces to linear dependence on the electron number at zero-temperature limit. The chemical hardness plays a double role in the admixture of ionic states to the reference neutral state energy: it determines the amplitude of the admixture and regulates the damping of its thermal factor

  9. 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)

  10. 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)

  11. 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

  12. Reaction diffusion and solid state chemical kinetics handbook

    CERN Document Server

    Dybkov, V I

    2010-01-01

    This monograph deals with a physico-chemical approach to the problem of the solid-state growth of chemical compound layers and reaction-diffusion in binary heterogeneous systems formed by two solids; as well as a solid with a liquid or a gas. It is explained why the number of compound layers growing at the interface between the original phases is usually much lower than the number of chemical compounds in the phase diagram of a given binary system. For example, of the eight intermetallic compounds which exist in the aluminium-zirconium binary system, only ZrAl3 was found to grow as a separate

  13. 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

  14. 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.

  15. Radiation-chemical aspects of solid state hot atom chemistry

    International Nuclear Information System (INIS)

    Matsuura, T.; Collins, K.E.; Collins, C.H.

    1984-01-01

    The study of nuclear hot atom chemical (NHAC) processes occurring in solids is seriously limited by the lack of adequate methods for directly studying the chemical species containing hot atoms. In the present review the effects of ionizing radiation on parent and non-parent yields from solid state targets is surveyed and qualitative interpretations are given. After a few general remarks of the relationship of radiation chemistry to solid state NHAC, a detailed description of the radiation effects is given (radiation annealing, neutron activation, changes in separable yield). (Auth.)

  16. 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

  17. 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

  18. CFD Analysis for the Steady State Test of CS28-1 Simulating High Temperature Chemical Reactions in CANDU Fuel Channel

    International Nuclear Information System (INIS)

    Park, Ju Hwan; Kang, Hyung Seok; Rhee, Bo Wook

    2006-05-01

    The establishment of safety analysis system and technology for CANDU reactors has been performed at KAERI. As for one of these researches, single CANDU fuel bundle has been simulated by CATHENA for the post-blowdown event to consider the complicated geometry and heat transfer in the fuel channel. In the previous LBLOCA analysis methodology adopted for Wolsong 2, 3, 4 licensing, the fuel channel blowdown phase was analyzed by a CANDU system analysis code CATHENA and the post-blowdown phase of fuel channel was analyzed by CHAN-IIA code. The use of one computer code in consecutive analyses appeared to be desirable for consistency and simplicity in the safety analysis process. However, validation of the high temperature post-blowdown fuel channel model in the CATHENA before being used in the accident analysis is necessary. Experimental data for the 37-element fuel bundle that fueled CANDU-6 has not been performed. The benchmark problems for the 37-element fuel bundle using CFD code will be compared with the test results of the 28-element fuel bundle in the CS28-1 experiment. A full grid model of FES to the calandria tube simulating the test section was generated. The number of the generated mesh in the grid model was 4,324,340 cells. The boundary and heat source conditions, and properties data in the CFD analysis were given according to the test results and reference data. Thermal hydraulic phenomena in the fuel channel were simulated by a compressible flow, a highly turbulent flow, and a convection/conduction/radiation heat transfer. The natural convection flow of CO 2 due to a large temperature difference in the gap between the pressure and the calandria tubes was treated by Boussinesq's buoyancy model. The CFD results showed good agreement with the test results as a whole. The inner/middle/outer FES temperature distributions of the CFD results showed a small overestimated value of about 30 .deg. C at the entrance region, but good agreement at the outlet region. The

  19. Chemical Compositions of Soils in Parts of Edo State, Southwest ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    www.bioline.org.br/ja. Chemical Compositions of Soils in Parts of Edo State, Southwest Nigeria and their ... the soil in agriculture and engineering (Imasuen et al. 1989b). Clay mineral ..... Unpublished Ph.D. Thesis, The. University of Western ...

  20. Nevada state revenues analysis

    International Nuclear Information System (INIS)

    1988-06-01

    This report analyzes the major sources of revenue to the Nevada State General Fund for purposes of estimating impacts associated with the siting of a nuclear waste repository at Yucca Mountain in Nye County, Nevada. Each major revenue source is analyzed to identify relationships among the economic or demographic base, the revenue base, and the revenues generated. Trends and changes in the rates and/or base are highlighted. A model is developed for each revenue source to allow impact estimation

  1. 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

  2. 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

  3. The analysis of the drainage network state near town Seversk after the radiation accident at the Siberian Chemical Plant, April, 6, 1993

    International Nuclear Information System (INIS)

    Nosov, A.V.

    1997-01-01

    The main results of the field studies of water objects on contaminated territory near the town Seversk realized in April-June 1993 are discussed. The data characterizing the levels of the territory radioactive contamination by 95 Nb, 95 Zr and 106 Ru near the Samus'ka river and its main inflows, namely the Kantes and Talovka rivers are given. The results of analysis of snow and soil samples from the Samus'ka river drainage basin, as well as samples of water and sediments of this river and its inflow Talovka are considered. The mechanism of aerosol radioactive contamination of the rivers is discussed, and forecasting estimation of the levels of possible contaminations of water and sediments in the Samus'ka river for the case if radioactive fallout trace would go through the river water surface mirror is made. The trace concentration (less than 8 Bq/m 3 ) of 106 Ru only is detected in water but not other radioisotopes contaminating the Samus'ka river drainage basin. The technogenic radioisotopes typical for fallout are found in only one of 16 sediment samples

  4. 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

  5. Chemical protective clothing - State of the art and the future

    International Nuclear Information System (INIS)

    Perkins, J.L.

    1990-01-01

    Clothing used to protect the skin from exposure to chemicals (CPC) is an integral part of many work-places. Only 10-15 years ago the strategy behind selecting CPC to afford this protection was to find a type of CPC which was essentially liquid-proof and would therefore protect the skin from exposure to a liquid chemical. However, in the last 10 years there has been an explosion of data in the industrial hygiene field related to the permeation of chemical protective clothing by liquid chemicals. These data indicate clearly that when CPC is exposed to a chemical, it may not disintegrate or degrade, but nevertheless, will be permeated by the chemical and the skin will be exposed. This has led to a new strategy for selecting CPC which essentially assumes that any exposure of the skin is harmful. Consequently, a worst-case scenario is assumed when selecting CPC and often the garment with the best permeation properties is selected regardless of cost. This philosophy is prompted by a lack of knowledge concerning the skin and how it is permeated by industrial chemicals in their liquid and vapor states. The interests in the last 10 years in CPC has led to new developments and an exciting future for protective clothing. Several new laminated polymeric materials are now being used in both gloves and full-body suits. These polymers are plastic rather than elastomeric and therefore do not afford good dexterity properties. However, their permeability properties are extremely good. In addition, further research on dermal penetration should give the industrial hygienist the necessary information to perform risk assessments for skin exposure. These new risk assessment strategies should negate the current need to overprotect workers. Overprotection often leads to unnecessary costs and can lead to increased stress on the worker in the form of heat stress

  6. Physico-chemical studies on samarium soaps in solid state

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Chauhan, M.; Shukla, R.K.

    1989-01-01

    The physico-chemical characteristics of samarium soaps (caproate and caprate) in solid state were investigated by IR, X-ray diffraction and TGA measurements. The IR results revealed that the fatty acids exist in dimeric state through hydrogen bonding and samarium soaps possess partial ionic character. The X-ray diffraction measurements were used to calculate the long spacings and the results confirmed the double layer structure of samarium soaps. The decomposition reaction was found kinetically of zero order and the values of energy of activation for the decomposition process for caproate and caprate were found to be 8,0 and 7,8 kcal mol -1 , respectively. (Authors)

  7. 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

  8. 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.)

  9. 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)

  10. State estimation of chemical engineering systems tending to multiple solutions

    Directory of Open Access Journals (Sweden)

    N. P. G. Salau

    2014-09-01

    Full Text Available A well-evaluated state covariance matrix avoids error propagation due to divergence issues and, thereby, it is crucial for a successful state estimator design. In this paper we investigate the performance of the state covariance matrices used in three unconstrained Extended Kalman Filter (EKF formulations and one constrained EKF formulation (CEKF. As benchmark case studies we have chosen: a a batch chemical reactor with reversible reactions whose system model and measurement are such that multiple states satisfy the equilibrium condition and b a CSTR with exothermic irreversible reactions and cooling jacket energy balance whose nonlinear behavior includes multiple steady-states and limit cycles. The results have shown that CEKF is in general the best choice of EKF formulations (even if they are constrained with an ad hoc clipping strategy which avoids undesired states for such case studies. Contrary to a clipped EKF formulation, CEKF incorporates constraints into an optimization problem, which minimizes the noise in a least square sense preventing a bad noise distribution. It is also shown that, although the Moving Horizon Estimation (MHE provides greater robustness to a poor guess of the initial state, converging in less steps to the actual states, it is not justified for our examples due to the high additional computational effort.

  11. 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)

  12. 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...

  13. State waste discharge permit application, 200-E chemical drain field

    International Nuclear Information System (INIS)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect ground would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). The Consent Order No. DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. This document presents the State Waste Discharge Permit (SWDP) application for the 200-E Chemical Drain Field. Waste water from the 272-E Building enters the process sewer line directly through a floor drain, while waste water from the 2703-E Building is collected in two floor drains, (north and south) that act as sumps and are discharged periodically. The 272-E and 2703-E Buildings constitute the only discharges to the process sewer line and the 200-E Chemical Drain Field

  14. State waste discharge permit application, 200-E chemical drain field

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect ground would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). The Consent Order No. DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. This document presents the State Waste Discharge Permit (SWDP) application for the 200-E Chemical Drain Field. Waste water from the 272-E Building enters the process sewer line directly through a floor drain, while waste water from the 2703-E Building is collected in two floor drains, (north and south) that act as sumps and are discharged periodically. The 272-E and 2703-E Buildings constitute the only discharges to the process sewer line and the 200-E Chemical Drain Field.

  15. Applicability of federal and state hazardous waste regulatory programs to waste chemical weapons and chemical warfare agents.; TOPICAL

    International Nuclear Information System (INIS)

    Haffenden, R.; Kimmell, T.

    2002-01-01

    This report reviews federal and state hazardous waste regulatory programs that govern the management of chemical weapons or chemical warfare agents. It addresses state programs in the eight states with chemical weapon storage facilities managed by the U.S. Army: Alabama, Arkansas, Colorado, Indiana, Kentucky, Maryland, Oregon, and Utah. It also includes discussions on 32 additional states or jurisdictions with known or suspected chemical weapons or chemical warfare agent presence (e.g., disposal sites containing chemical agent identification sets): Alaska, Arizona, California, Florida, Georgia, Hawaii, Idaho, Illinois, Iowa, Kansas, Louisiana, Massachusetts, Michigan, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, the U.S. Virgin Islands, Virginia, Washington, Washington, D.C., and Wyoming. Resource Conservation and Recovery Act (RCRA) hazardous waste programs are reviewed to determine whether chemical weapons or chemical warfare agents are listed hazardous wastes or otherwise defined or identified as hazardous wastes. Because the U.S. Environmental Protection Agency (EPA) military munitions rule specifically addresses the management of chemical munitions, this report also indicates whether a state has adopted the rule and whether the resulting state regulations have been authorized by EPA. Many states have adopted parts or all of the EPA munitions rule but have not yet received authorization from EPA to implement the rule. In these cases, the states may enforce the adopted munitions rule provisions under state law, but these provisions are not federally enforceable

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. Chemical modulation of electronic structure at the excited state

    Science.gov (United States)

    Li, F.; Song, C.; Gu, Y. D.; Saleem, M. S.; Pan, F.

    2017-12-01

    Spin-polarized electronic structures are the cornerstone of spintronics, and have thus attracted a significant amount of interest; in particular, researchers are looking into how to modulate the electronic structure to enable multifunctional spintronics applications, especially in half-metallic systems. However, the control of the spin polarization has only been predicted in limited two-dimensional systems with spin-polarized Dirac structures and is difficult to achieve experimentally. Here, we report the modulation of the electronic structure in the light-induced excited state in a typical half-metal, L a1 /2S r1 /2Mn O3 -δ . According to the spin-transport measurements, there appears a light-induced increase in magnetoresistance due to the enhanced spin scattering, which is closely associated with the excited spin polarization. Strikingly, the light-induced variation can be enhanced via alcohol processing and reduced by oxygen annealing. X-ray photoelectron spectroscopy measurements show that in the chemical process, a redox reaction occurs with a change in the valence of Mn. Furthermore, first-principles calculations reveal that the change in the valence of Mn alters the electronic structure and consequently modulates the spin polarization in the excited state. Our findings thus report a chemically tunable electronic structure, demonstrating interesting physics and the potential for multifunctional applications and ultrafast spintronics.

  1. 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 ...

  2. 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)

  3. Conditions for extinction events in chemical reaction networks with discrete state spaces.

    Science.gov (United States)

    Johnston, Matthew D; Anderson, David F; Craciun, Gheorghe; Brijder, Robert

    2018-05-01

    We study chemical reaction networks with discrete state spaces and present sufficient conditions on the structure of the network that guarantee the system exhibits an extinction event. The conditions we derive involve creating a modified chemical reaction network called a domination-expanded reaction network and then checking properties of this network. Unlike previous results, our analysis allows algorithmic implementation via systems of equalities and inequalities and suggests sequences of reactions which may lead to extinction events. We apply the results to several networks including an EnvZ-OmpR signaling pathway in Escherichia coli.

  4. Modelling of the chemical state in groundwater infiltration systems

    International Nuclear Information System (INIS)

    Zysset, A.

    1993-01-01

    Groundwater is replenished by water stemming either from precipitations, lakes or rivers. The area where such an infiltration occurs is characterized by a change in the environmental conditions, such as a decrease of the flow velocity and an increase in the solid surface marking the boundary of the flow field. With these changes new chemical processes may become relevant to the transport behavior of contaminants. Since the rates of chemical processes usually are a function of the concentrations of several species, an understanding of infiltration sites may require a multicomponent approach. The present study aims at formulating a mathematical model together with its numerical solution for groundwater infiltration sites. Such a model should improve the understanding of groundwater quality changes related to infiltrating contaminants. The groundwater quality is of vital interest to men because at many places most of the drinking water originates from groundwater. In the first part of the present study two partial models are formulated: one accounting for the transport in a one-dimensional, homogeneous and saturated porous medium, the other accounting for chemical reactions. This second model is initially stated for general kinetic systems. Then, it is specified for two systems, namely for a system governed only by reactions which are fast compared to the transport processes and for a system with biologically mediated redox reactions of dissolved substrates. In the second part of the study a numerical solution to the model is developed. For this purpose, the two partial models are coupled. The coupling is either iterative as in the case of a system with fast reactions or sequential as in all other cases. The numerical solutions of simple test cases are compared to analytical solutions. In the third part the model is evaluated using observations of infiltration sites reported in the literature. (author) figs., tabs., 155 refs

  5. Zirconia-based solid state chemical gas sensors

    CERN Document Server

    Zhuiykov, S

    2000-01-01

    This paper presents an overview of chemical gas sensors, based on solid state technology, that are sensitive to environmental gases, such as O sub 2 , SO sub x , NO sub x , CO sub 2 and hydrocarbons. The paper is focussed on performance of electrochemical gas sensors that are based on zirconia as a solid electrolyte. The paper considers sensor structures and selection of electrode materials. Impact of interfaces on sensor performance is discussed. This paper also provides a brief overview of electrochemical properties of zirconia and their effect on sensor performance. Impact of auxiliary materials on sensors performance characteristics, such as sensitivity, selectivity, response time and recovery time, is also discussed. Dual gas sensors that can be applied for simultaneous monitoring of the concentration of both oxygen and other gas phase components, are briefly considered

  6. 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.

  7. 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

  8. 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.

  9. 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 ...

  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. 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)

  12. 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...

  13. Polyadenylation state microarray (PASTA) analysis.

    Science.gov (United States)

    Beilharz, Traude H; Preiss, Thomas

    2011-01-01

    Nearly all eukaryotic mRNAs terminate in a poly(A) tail that serves important roles in mRNA utilization. In the cytoplasm, the poly(A) tail promotes both mRNA stability and translation, and these functions are frequently regulated through changes in tail length. To identify the scope of poly(A) tail length control in a transcriptome, we developed the polyadenylation state microarray (PASTA) method. It involves the purification of mRNA based on poly(A) tail length using thermal elution from poly(U) sepharose, followed by microarray analysis of the resulting fractions. In this chapter we detail our PASTA approach and describe some methods for bulk and mRNA-specific poly(A) tail length measurements of use to monitor the procedure and independently verify the microarray data.

  14. 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.

  15. 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

  16. Chemical state of mercury and selenium in sewage sludge ash based P-fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Christian, E-mail: cv.vogel@yahoo.de [Division 4.4 Thermochemical Residues Treatment and Resource Recovery, Bundesanstalt für Materialforschung und −prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany); Krüger, Oliver; Herzel, Hannes [Division 4.4 Thermochemical Residues Treatment and Resource Recovery, Bundesanstalt für Materialforschung und −prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany); Amidani, Lucia [ESRF—The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble (France); Adam, Christian [Division 4.4 Thermochemical Residues Treatment and Resource Recovery, Bundesanstalt für Materialforschung und −prüfung (BAM), Unter den Eichen 87, 12205 Berlin (Germany)

    2016-08-05

    Highlights: • Mercury bonded to carbon/organic material was detected in some sewage sludge ashes. • After thermochemcial treatment some mercury remains stabilized in the SSA matrix. • Analysis of the chemical state of mercury and selenium in highly diluted samples. - Abstract: Phosphorus-fertilizers from secondary resources such as sewage sludge ash (SSA) will become more important in the future as they could substitute conventional fertilizers based on the nonrenewable resource phosphate rock. Thermochemical approaches were developed which remove heavy metals from SSA prior to its fertilizer application on farmlands. We analyzed the chemical state of mercury and selenium in SSA before and after thermochemical treatment under different conditions for P-fertilizer production by X-ray absorption near edge structure (XANES) spectroscopy. In some incineration plants the mercury loaded carbon adsorber from off-gas cleaning was collected together with the SSA for waste disposal. SSAs from those plants contained mercury mainly bound to carbon/organic material. The other SSAs contained inorganic mercury compounds which are most probably stabilized in the SSA matrix and were thus not evaporated during incineration. During thermochemical treatment, carbon-bound mercury was removed quantitatively. In contrast, a certain immobile fraction of inorganic mercury compounds remained in thermochemically treated SSA, which were not clearly identified. HgSe might be one of the inorganic compounds, which is supported by results of Se K-edge XANES spectroscopy. Furthermore, the chemical state of selenium in the SSAs was very sensitive to the conditions of the thermochemical treatment.

  17. Reaction Hamiltonian and state-to-state description of chemical reactions

    International Nuclear Information System (INIS)

    Ruf, B.A.; Kresin, V.Z.; Lester, W.A. Jr.

    1985-08-01

    A chemical reaction is treated as a quantum transition from reactants to products. A specific reaction Hamiltonian (in second quantization formalism) is introduced. The approach leads to Franck-Condon-like factor, and adiabatic method in the framework of the nuclear motion problems. The influence of reagent vibrational state on the product energy distribution has been studied following the reaction Hamiltonian method. Two different cases (fixed available energy and fixed translational energy) are distinguished. Results for several biomolecular reactions are presented. 40 refs., 5 figs

  18. Shallow nitrogen ion implantation: Evolution of chemical state and defect structure in titanium

    Energy Technology Data Exchange (ETDEWEB)

    Manojkumar, P.A., E-mail: manoj@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chirayath, V.A.; Balamurugan, A.K.; Krishna, Nanda Gopala; Ilango, S.; Kamruddin, M.; Amarendra, G.; Tyagi, A.K. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Raj, Baldev [National Institute of Advanced Studies, Bangalore 560 012 (India)

    2016-09-15

    Highlights: • Low energy nitrogen ion implantation in titanium was studied. • Chemical and defect states were analyzed using SIMS, XPS and PAS. • SIMS and depth resolved XPS data showed good agreement. • Depth resolved defect and chemical states information were revealed. • Formation of 3 layers of defect states proposed to fit PAS results. - Abstract: Evolution of chemical states and defect structure in titanium during low energy nitrogen ion implantation by Plasma Immersion Ion Implantation (PIII) process is studied. The underlying process of chemical state evolution is investigated using secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The implantation induced defect structure evolution as a function of dose is elucidated using variable energy positron annihilation Doppler broadening spectroscopy (PAS) and the results were corroborated with chemical state. Formation of 3 layers of defect state was modeled to fit PAS results.

  19. 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

  20. 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

  1. 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

  2. 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 ...

  3. Incorporation of a Chemical Equilibrium Equation of State into LOCI-Chem

    Science.gov (United States)

    Cox, Carey F.

    2005-01-01

    Renewed interest in development of advanced high-speed transport, reentry vehicles and propulsion systems has led to a resurgence of research into high speed aerodynamics. As this flow regime is typically dominated by hot reacting gaseous flow, efficient models for the characteristic chemical activity are necessary for accurate and cost effective analysis and design of aerodynamic vehicles that transit this regime. The LOCI-Chem code recently developed by Ed Luke at Mississippi State University for NASA/MSFC and used by NASA/MSFC and SSC represents an important step in providing an accurate, efficient computational tool for the simulation of reacting flows through the use of finite-rate kinetics [3]. Finite rate chemistry however, requires the solution of an additional N-1 species mass conservation equations with source terms involving reaction kinetics that are not fully understood. In the equilibrium limit, where the reaction rates approach infinity, these equations become very stiff. Through the use of the assumption of local chemical equilibrium the set of governing equations is reduced back to the usual gas dynamic equations, and thus requires less computation, while still allowing for the inclusion of reacting flow phenomenology. The incorporation of a chemical equilibrium equation of state module into the LOCI-Chem code was the primary objective of the current research. The major goals of the project were: (1) the development of a chemical equilibrium composition solver, and (2) the incorporation of chemical equilibrium solver into LOCI-Chem. Due to time and resource constraints, code optimization was not considered unless it was important to the proper functioning of the code.

  4. 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.

  5. Determination of chemical states of sulphur 35 obtained from the 35Cl (n, p)35S

    International Nuclear Information System (INIS)

    Rossi Filho, S.

    1980-01-01

    The chemical states of sulphur-35 obtained from the 35 Cl(n,p) 35 S reaction by the irradiation of potassium chloride without any previous treatment and with previous heating under vacuum, were determined. The influence of irradiation time and temperature after irradiation was examined. Paper electrophoresis technique was employed for the determination of the chemical states. (Author) [pt

  6. 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)

  7. 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.

  8. 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

  9. 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

  10. 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 ...

  11. Surface functionalization of solid state ultra-high molecular weight polyethylene through chemical grafting

    Science.gov (United States)

    Sherazi, Tauqir A.; Rehman, Tayyiba; Naqvi, Syed Ali Raza; Shaikh, Ahson Jabbar; Shahzad, Sohail Anjum; Abbas, Ghazanfar; Raza, Rizwan; Waseem, Amir

    2015-12-01

    The surface of ultra-high molecular weight polyethylene (UHMWPE) powder was functionalized with styrene using chemical grafting technique. The grafting process was initiated through radical generation on base polymer matrix in the solid state by sodium thiosulfate, while peroxides formed at radical sites during this process were dissociated by ceric ammonium nitrate. Various factors were optimized and reasonably high level of monomer grafting was achieved, i.e., 15.6%. The effect of different acids as additive and divinyl benzene (DVB) as a cross-linking agent was also studied. Post-grafting sulfonation was conducted to introduce the ionic moieties to the grafted polymer. Ion-exchange capacity (IEC) was measured experimentally and is found to be 1.04 meq g-1, which is in close agreement with the theoretical IEC values. The chemical structure of grafted and functionalized polymer was characterized by attenuated total reflection infrared spectroscopy (ATR-FTIR) and thermal properties were investigated by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal analysis depicts that the presence of radicals on the polymer chain accelerates the thermal decomposition process. The results signify that the chemical grafting is an effective tool for substantial surface modification and subsequent functionalization of polyethylene.

  12. Oxidation state analyses of uranium with emphasis on chemical speciation in geological media

    International Nuclear Information System (INIS)

    Ervanne, H.

    2004-01-01

    This thesis focuses on chemical methods suitable for the determination of uranium redox species in geological materials. Nd-coprecipitation method was studied for the determination of uranium oxidation states in ground waters. This method is ideally suited for the separation of uranium oxidation states in the field, which means that problems associated with the instability of U(IV) during transport are avoided. An alternative method, such as ion exchange, is recommended for the analysis of high saline and calcium- and iron-rich ground waters. U(IV)/Utot was 2.8-7.2% in ground waters in oxidizing conditions and 60-93% in anoxic conditions. From thermodynamic model calculations applied to results from anoxic ground waters it was concluded that uranium can act as redox buffer in granitic ground waters. An ion exchange method was developed for the analysis of uranium oxidation states in different solid materials of geological origin. These included uranium minerals, uraniumbearing minerals, fracture coatings and bulk rock. U(IV)/Utot was 50-70% in uraninites, 5.8-8.7% in secondary uranium minerals, 15-49% in different fracture coatings and 64- 77% in samples from deep bedrock. In the uranium-bearing minerals, U(IV)/Utot was 33-43% (allanites), 5.9% (fergusonite) and 93% (monazite). Although the ion exchange method gave reliable results, there is a risk for the conversion of uranium oxidation states during analysis of heterogeneous samples due to the redox reactions that take place in the presence of some iron compounds. This risk was investigated in a study of several common iron-bearing minerals. The risk for conversion of uranium oxidation states can be screened by sample selection and minimized with use of a redox buffer compound such as polyacrylic acid (PAA). In studies of several carboxylic acids, PAA was found to be the most suitable for extending the application of the method. The stability of uranium oxidation states during analysis and the selectivity

  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. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Siegel, G.; Tapp, E.; Haehn, J.; Hannig, H.; Dlaske, R.; Martinek, K.

    1977-01-01

    Papers published in 1976 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in vitro and in vivo, the biochemical, pharmacological and toxic effects, the mechanisms of protection of radioprotective agents and the trends in this field of research are described. (author)

  16. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Siegel, G.; Tapp, E.; Hannig, H.; Dlaske, R.; Haehn, J.; Martinek, K.

    1980-01-01

    Papers published in 1978 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in in-vivo and model systems, the biochemical, pharmacological and toxic effects, and modes of action of radioprotective agents are described and the trends in this field of research appreciated. (author)

  17. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Siegel, G.; Tapp, E.; Hannig, H.; Dlaske, R.; Papendieck, W.; Martinek, K.; Haehn, J.

    1982-01-01

    Papers published in 1979 and 1980 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in in-vivo and model systems, the biochemical, pharmacological and toxic effects, and modes of action of radioprotective agents are described and the trends in this field of research estimated. (author)

  18. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Siegel, G.; Tapp, E.; Haehn, J.; Hannig, H.; Dlaske, R.

    1976-03-01

    Papers published in 1974 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in vitro and in vivo, the biochemical, pharmacological and toxic effects, the mechanisms of protection of radioprotective agents and the trends in this field of research are described. (author)

  19. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Siegel, G.; Tapp, E.; Haehn, J.; Hannig, H.; Dlaske, R.; Martinek, K.

    1977-01-01

    Papers published in 1975 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in vitro and in vivo, the biochemical, pharmacological and toxic effects, the mechanisms of protection of radioprotective agents and the trends in this field of research are described. (author)

  20. Radiolytic effect on the chemical state of iodine in aqueous solution

    International Nuclear Information System (INIS)

    Shiraishi, H.; Kimiya, T.; Ohmae, M.; Ishigure, K.

    1988-01-01

    The oxidation state of iodine dissolved in an aqueous solution is easily changed in the presence of radiation field. Hence, it is essential to take the radiolytic effect into account when one is to estimate chemical forms of iodine after being released into the containment under an LOCA condition. This paper summarizes results of γ-radiolysis experiments on aqueous solutions containing iodine species, which have been carried out to extend the previously reported study on the same system. Variation in iodine product distribution with time has been examined as before, utilizing a flow system under irradiation. Attention has been paid to the effect of oxygen, to that of an initial oxidation state of iodine, and to the influence of temperature. Some kinetic analysis on the system was also undertaken

  1. 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

  2. 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 ...

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Chemically-induced solid-state dewetting of thin Au films

    International Nuclear Information System (INIS)

    Gazit, Nimrod; Klinger, Leonid; Rabkin, Eugen

    2017-01-01

    We employed the solid state dewetting technique to produce nanoparticles of silver-gold alloy on a sapphire substrate. We deposited a thin gold layer on the substrate with alloy nanoparticles, and studied its thermal stability at low homological temperatures. We demonstrated that a large number of densely spaced holes form at the initial stages of dewetting of the gold layer with nanoparticles. A similar homogeneous gold film deposited on a bare sapphire substrate remained stable under identical annealing conditions, exhibiting the onset of dewetting at higher temperatures, and with a lower number of holes. We attributed the decreased thermal stability of the gold film deposited on the substrate with the silver-gold nanoparticles to accelerated grooving at the grain boundaries and triple junctions in the film. The grooving process is accelerated by the diffusion fluxes of Au atoms driven from the film towards the nanoparticles by the gradient of chemical potential. We developed a quantitative model of this chemically-induced dewetting process, and discussed its applicability for the design of better catalytic systems. Our work demonstrates that the chemical driving forces have to be reckoned with in the analysis of thermal stability of multicomponent thin films.

  8. Influence of short range chemical order on density of states in α-ZrNi

    International Nuclear Information System (INIS)

    Duarte Junior, J.

    1986-01-01

    Calculations of the density of electronic states for amorphous alloys of ZrNi and ZrCu with different chemical order degrees, in order to verify the effect of chemical ordering on this property, are presented. The results obtained for ZrCu shown that the density of states at Fermi level do not vary significantly with the ordering. The results for ZrNi shown that the introduction of short range chemical order can decrease significantly the density of states at Fermi level, leading to better agreement with experimental results. (M.C.K.) [pt

  9. State-Space Formulation for Circuit Analysis

    Science.gov (United States)

    Martinez-Marin, T.

    2010-01-01

    This paper presents a new state-space approach for temporal analysis of electrical circuits. The method systematically obtains the state-space formulation of nondegenerate linear networks without using concepts of topology. It employs nodal/mesh systematic analysis to reduce the number of undesired variables. This approach helps students to…

  10. 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

  11. Chemical reaction rates and non-equilibrium pressure of reacting gas mixtures in the state-to-state approach

    International Nuclear Information System (INIS)

    Kustova, Elena V.; Kremer, Gilberto M.

    2014-01-01

    Highlights: • State-to-state approach for coupled vibrational relaxation and chemical reactions. • Self-consistent model for rates of non-equilibrium reactions and energy transitions. • In viscous flows mass action law is violated. • Cross coupling between reaction rates and non-equilibrium pressure in viscous flow. • Results allow implementing the state-to-state approach for viscous flow simulations. - Abstract: Viscous gas flows with vibrational relaxation and chemical reactions in the state-to-state approach are analyzed. A modified Chapman–Enskog method is used for the determination of chemical reaction and vibrational transition rates and non-equilibrium pressure. Constitutive equations depend on the thermodynamic forces: velocity divergence and chemical reaction/transition affinity. As an application, N 2 flow with vibrational relaxation across a shock wave is investigated. Two distinct processes occur behind the shock: for small values of the distance the affinity is large and vibrational relaxation is in its initial stage; for large distances the affinity is small and the chemical reaction is in its final stage. The affinity contributes more to the transition rate than the velocity divergence and the effect of these two contributions are more important for small distances from the shock front. For the non-equilibrium pressure, the term associated with the bulk viscosity increases by a small amount the hydrostatic pressure

  12. Chemical reaction rates and non-equilibrium pressure of reacting gas mixtures in the state-to-state approach

    Energy Technology Data Exchange (ETDEWEB)

    Kustova, Elena V., E-mail: e.kustova@spbu.ru [Department of Mathematics and Mechanics, Saint Petersburg State University, 198504 Universitetskiy pr. 28, Saint Petersburg (Russian Federation); Kremer, Gilberto M., E-mail: kremer@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba (Brazil)

    2014-12-05

    Highlights: • State-to-state approach for coupled vibrational relaxation and chemical reactions. • Self-consistent model for rates of non-equilibrium reactions and energy transitions. • In viscous flows mass action law is violated. • Cross coupling between reaction rates and non-equilibrium pressure in viscous flow. • Results allow implementing the state-to-state approach for viscous flow simulations. - Abstract: Viscous gas flows with vibrational relaxation and chemical reactions in the state-to-state approach are analyzed. A modified Chapman–Enskog method is used for the determination of chemical reaction and vibrational transition rates and non-equilibrium pressure. Constitutive equations depend on the thermodynamic forces: velocity divergence and chemical reaction/transition affinity. As an application, N{sub 2} flow with vibrational relaxation across a shock wave is investigated. Two distinct processes occur behind the shock: for small values of the distance the affinity is large and vibrational relaxation is in its initial stage; for large distances the affinity is small and the chemical reaction is in its final stage. The affinity contributes more to the transition rate than the velocity divergence and the effect of these two contributions are more important for small distances from the shock front. For the non-equilibrium pressure, the term associated with the bulk viscosity increases by a small amount the hydrostatic pressure.

  13. Sacrifice zones: the front lines of toxic chemical exposure in the United States

    National Research Council Canada - National Science Library

    Lerner, Steve

    2010-01-01

    ... States of America. Library of Congress Cataloging-in-Publication Data Lerner, Steve. Sacrifice zones: the front lines of toxic chemical exposure in the United States / Steve Lerner. p. cm. Includes bibliographical references and index. ISBN 978-0-262-01440-3 (hardcover : alk. paper) 1. Environmental toxicology- United States- Case studies. 2. Che...

  14. 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

  15. 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

  16. Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge.

    Science.gov (United States)

    Martins, Joana; Vasconcelos, Vitor

    2015-11-13

    Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

  17. Chemical Weapons: FEMA and Army Must Be Proactive in Preparing States for Emergencies

    National Research Council Canada - National Science Library

    2001-01-01

    .... Such an accident could affect people in 10 different states. The Army plans to destroy its entire chemical weapons stockpile by 2007 and is taking measures to protect the public before and during the demilitarization process...

  18. [Changes in functional state during occupational activities in workers at objects for chemical weapons destruction].

    Science.gov (United States)

    2010-01-01

    The authors studied functional state before and after the working shift in workers at objects for chemical weapons destruction, analyzed changes in central and peripheral hemodynamics parameters, vegetative regulation of heart rhythm, stabilographic and psychophysiologic values.

  19. 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.

  20. Use of chemical analysis and assays of semipermeable membrane devices extracts to assess the response of bioavailable organic pollutants in streams to urbanization in six metropolitan areas of the United States

    Science.gov (United States)

    Bryant, Wade L.; Goodbred, Steve L.; Leiker, Thomas L.; Inouye, Laura; Johnson, B. Thomas

    2007-01-01

    Studies to assess the effects of urbanization on stream ecosystems are being conducted as part of the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program. The overall objectives of these studies are to (1) determine how hydrologic, geomorphic, water quality, habitat, and biological characteristics respond to land-use changes associated with urbanization in specific environmental settings, and (2) compare these responses across environmental settings. As part of an integrated assessment, semipermeable membrane devices (SPMDs) were deployed in streams along a gradient of urban land-use intensity in and around Atlanta, Georgia; Raleigh-Durham, North Carolina; and Denver-Fort Collins, Colorado, in 2003; and Dallas-Fort Worth, Texas; Milwaukee-Green Bay, Wisconsin; and Portland, Oregon, in 2004. Sites were selected to avoid point-source discharge and to minimize natural variability within each of the six metropolitan areas. In addition to standard chemical analysis for hydrophobic organic contaminants, three assays were used to address mixtures and potential toxicity: (1) Fluoroscan provides an estimate of the total concentration of polycyclic aromatic hydrocarbons (PAHs); (2) the P450RGS assay indicates the presence and levels of aryl hydrocarbon receptor agonists; and (3) Microtox® measures toxicological effects on photo-luminescent bacteria.Of the 140 compounds targeted or identified by gas chromatography/mass spectrometry analysis in this study, 67 were not detected. In terms of numbers and types of compounds, the following were detected: 2 wood preservatives, 6 insecticides (parent compounds), 5 herbicides, 22 polycyclic aromatic hydrocarbons, 2 dibenzofurans, 4 polychlorinated biphenyls, 7 compounds associated with fragrances or personal care products, 4 steroids associated with wastewater, 5 polydibromated diphenyl ethers (flame retardants), 3 plasticizers, 3 antimicrobials/disinfectants, and 3 detergent metabolites.Of the 73

  1. An extrapolation scheme for solid-state NMR chemical shift calculations

    Science.gov (United States)

    Nakajima, Takahito

    2017-06-01

    Conventional quantum chemical and solid-state physical approaches include several problems to accurately calculate solid-state nuclear magnetic resonance (NMR) properties. We propose a reliable computational scheme for solid-state NMR chemical shifts using an extrapolation scheme that retains the advantages of these approaches but reduces their disadvantages. Our scheme can satisfactorily yield solid-state NMR magnetic shielding constants. The estimated values have only a small dependence on the low-level density functional theory calculation with the extrapolation scheme. Thus, our approach is efficient because the rough calculation can be performed in the extrapolation scheme.

  2. 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

  3. 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 ...

  4. 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 ...

  5. 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

  6. Characterization of Chemical Suicides in the United States and Its Adverse Impact on Responders and Bystanders

    Directory of Open Access Journals (Sweden)

    Ayana R. Anderson

    2016-11-01

    Full Text Available Introduction: A suicide trend that involves mixing household chemicals to produce hydrogen sulfide or hydrogen cyanide, commonly referred to as a detergent, hydrogen sulfide, or chemical suicide is a continuing problem in the United States (U.S.. Because there is not one database responsible for tracking chemical suicides, the actual number of incidents in the U.S. is unknown. To prevent morbidity and mortality associated with chemical suicides, it is important to characterize the incidents that have occurred in the U.S. Methods: The author analyzed data from 2011-2013 from state health departments participating in the Agency for Toxic Substances and Disease Registry’s National Toxic Substance Incidents Program (NTSIP. NTSIP is a web-based chemical incident surveillance system that tracks the public health consequences (e.g., morbidity, mortality from acute chemical releases. Reporting sources for NTSIP incidents typically include first responders, hospitals, state environmental agencies, and media outlets. To find chemical suicide incidents in NTSIP’s database, the author queried open text fields in the comment, synopsis, and contributing factors variables for potential incidents. Results: Five of the nine states participating in NTSIP reported a total of 22 chemical suicide incidents or attempted suicides during 2011-2013. These states reported a total of 43 victims: 15 suicide victims who died, seven people who attempted suicide but survived, eight responders, and four employees working at a coroner’s office; the remainder were members of the general public. None of the injured responders reported receiving HazMat technician-level training, and none had documented appropriate personal protective equipment. Conclusion: Chemical suicides produce lethal gases that can pose a threat to responders and bystanders. Describing the characteristics of these incidents can help raise awareness among responders and the public about the dangers of

  7. [On new screening biomarker to evaluate health state in personnel engaged into chemical weapons extinction].

    Science.gov (United States)

    Voitenko, N G; Garniuk, V V; Prokofieva, D S; Gontcharov, N V

    2015-01-01

    The work was aimed to find new screeding parameters (biomarkers) for evaluation of health state of workers engaged into enterprises with hazardous work conditions, as exemplified by "Maradykovskyi" object of chemical weapons extinction. Analysis of 27 serum cytokines was conducted in donors and the object personnel with various work conditions. Findings are statistically significant increase of serum eotaxin in the personnel of "dirty" zone, who are regularly exposed to toxic agents in individual filter protective means over the working day. For screening detection of health disorders in the object personnel, the authors suggested new complex biomarker--ratio Eotaxin* IFNγ/TNFα that demonstrates 67.9% sensitivity and 87.5% specificity in differentiating the "dirty" zone personnel and other staffers.

  8. Chemical behavior of residential lead in urban yards in the United States.

    Science.gov (United States)

    Elless, M P; Bray, C A; Blaylock, M J

    2007-07-01

    Long after federal regulations banned the use of lead-based paints and leaded gasoline, residential lead remains a persistent challenge. Soil lead is a significant contributor to this hazard and an improved understanding of physicochemical properties is likely to be useful for in situ abatement techniques such as phytoremediation and chemical stabilization. A laboratory characterization of high-lead soils collected from across the United States shows that the lead contaminants were concentrating in the silt and clay fractions, in the form of discrete particles of lead, as observed by scanning electron microscopy coupled with energy dispersive X-ray analysis. Soil lead varied widely in its solubility behavior as assessed by sequential and chelate extractions. Because site-specific factors (e.g., soil pH, texture, etc.) are believed to govern the solubility of the lead, understanding the variability in these characteristics at each site is necessary to optimize in situ remediation or abatement of these soils.

  9. Contribution to isotopic and chemical study of the aquifers in the area of Frecheirinha, State of Ceara, Brazil

    International Nuclear Information System (INIS)

    Siqueira, H.B. de; Santiago, M.M.F.

    1982-01-01

    The isotopic and chemical characteristics of the aquifers in the area of Frecheirinha (State of Ceara) have been analyzed. In a area of 3,000 scquare Kilometers three aquifers has been identified. Oxygen-18 measurements show that during the rainy season the piezometric level rises until reaching the surface. Thus the flow-water is a mixture of rainwater with stored under-groundwater. Chemical analysis shows all waters (except for samples 1, 2 and 3) are potable. (L.H.L.L.) [pt

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. Moessbauer study of the chemical state of gold in gold ores

    International Nuclear Information System (INIS)

    Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

    1986-01-01

    Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

  15. Resonant power processors. I - State plane analysis

    Science.gov (United States)

    Oruganti, R.; Lee, F. C.

    1984-01-01

    State-plane techniques in conjunction with piecewise-linear analysis is employed to study the steady-state and transient characteristics of a series resonant converter. With the direct viewing of the resonant tank energy and the device switching instants, the state portrayal provides unique insights into the complex behavior of the converter. Operation of the converter under both continuous and discontinuous current modes and at frequencies both below and above resonant frequency are discussed.

  16. 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

  17. Nonspherical atomic ground-state densities and chemical deformation densities from x-ray scattering

    International Nuclear Information System (INIS)

    Ruedenberg, K.; Schwarz, W.H.E.

    1990-01-01

    Presuming that chemical insight can be gained from the difference between the molecular electron density and the superposition of the ground-state densities of the atoms in a molecule, it is pointed out that, for atoms with degenerate ground states, an unpromoted ''atom in a molecule'' is represented by a specific ensemble of the degenerate atomic ground-state wave functions and that this ensemble is determined by the anisotropic local surroundings. The resulting atomic density contributions are termed oriented ground state densities, and the corresponding density difference is called the chemical deformation density. The constraints implied by this conceptual approach for the atomic density contributions are formulated and a method is developed for determining them from x-ray scattering data. The electron density of the appropriate promolecule and its x-ray scattering are derived, the determination of the parameters of the promolecule is outlined, and the chemical deformation density is formulated

  18. 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.

  19. 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.

  20. 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

  1. Some Considerations on the Fundamentals of Chemical Kinetics: Steady State, Quasi-Equilibrium, and Transition State Theory

    Science.gov (United States)

    Perez-Benito, Joaquin F.

    2017-01-01

    The elementary reaction sequence A ? I ? Products is the simplest mechanism for which the steady-state and quasi-equilibrium kinetic approximations can be applied. The exact integrated solutions for this chemical system allow inferring the conditions that must fulfill the rate constants for the different approximations to hold. A graphical…

  2. 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

  3. 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

  4. 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.)

  5. 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.

  6. 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)

  7. 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)

  8. 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]....

  9. 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...

  10. Chemical composition and trophic state of shallow saline steppe lakes in central Asia (North Kazakhstan).

    Science.gov (United States)

    Boros, Emil; Jurecska, Laura; Tatár, Enikő; Vörös, Lajos; Kolpakova, Marina

    2017-10-09

    The purpose of this study was to identify the prevailing chemical composition and trophic state of the shallow saline steppe lakes of North Kazakhstan along a wide size range (SO 4 and Na-Cl (n = 16; 64%); the Ca, Mg, HCO 3 , and SO 4 ions precipitate with increasing salinity (2-322 g L -1 ); and ion composition shifts from Na>Mg-Cl>SO 4 to Na-Cl. The most of the chemical variables positively, but chlorophyll a negatively, correlated with total dissolved solids, and the total phosphorus had no significant correlation with any variables. The trophic state of these lakes in most cases exceeded the hypertrophic level. The increase in salinity causes change in chemical composition and effects on the phytoplankton development independently from the size of water surface, and the human disturbances had negligible effect on the trophic state of shallow saline lakes in this region of Kazakhstan.

  11. Coherent states, pseudodifferential analysis and arithmetic

    Science.gov (United States)

    Unterberger, André

    2012-06-01

    Basic questions regarding families of coherent states include describing some constructions of such and the way they can be applied to operator theory or partial differential equations. In both questions, pseudodifferential analysis is important. Recent developments indicate that they can contribute to methods in arithmetic, especially modular form theory. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’.

  12. Looking for chemical reaction networks exhibiting a drift along a manifold of marginally stable states.

    Science.gov (United States)

    Brogioli, Doriano

    2013-02-07

    I recently reported some examples of mass-action equations that have a continuous manifold of marginally stable stationary states [Brogioli, D., 2010. Marginally stable chemical systems as precursors of life. Phys. Rev. Lett. 105, 058102; Brogioli, D., 2011. Marginal stability in chemical systems and its relevance in the origin of life. Phys. Rev. E 84, 031931]. The corresponding chemical reaction networks show nonclassical effects, i.e. a violation of the mass-action equations, under the effect of the concentration fluctuations: the chemical system drifts along the marginally stable states. I proposed that this effect is potentially involved in abiogenesis. In the present paper, I analyze the mathematical properties of mass-action equations of marginally stable chemical reaction networks. The marginal stability implies that the mass-action equations obey some conservation law; I show that the mathematical properties of the conserved quantity characterize the motion along the marginally stable stationary state manifold, i.e. they allow to predict if the fluctuations give rise to a random walk or a drift under the effect of concentration fluctuations. Moreover, I show that the presence of the drift along the manifold of marginally stable stationary-states is a critical property, i.e. at least one of the reaction constants must be fine tuned in order to obtain the drift. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. 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.

  14. 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.

  15. 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)

  16. 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.

  17. 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...

  18. Environmentally relevant chemical mixtures of concern in waters of United States tributaries to the Great Lakes

    Science.gov (United States)

    Elliott, Sarah M.; Brigham, Mark E.; Kiesling, Richard L.; Schoenfuss, Heiko L.; Jorgenson, Zachary G.

    2018-01-01

    The North American Great Lakes are a vital natural resource that provide fish and wildlife habitat, as well as drinking water and waste assimilation services for millions of people. Tributaries to the Great Lakes receive chemical inputs from various point and nonpoint sources, and thus are expected to have complex mixtures of chemicals. However, our understanding of the co‐occurrence of specific chemicals in complex mixtures is limited. To better understand the occurrence of specific chemical mixtures in the US Great Lakes Basin, surface water from 24 US tributaries to the Laurentian Great Lakes was collected and analyzed for diverse suites of organic chemicals, primarily focused on chemicals of concern (e.g., pharmaceuticals, personal care products, fragrances). A total of 181 samples and 21 chemical classes were assessed for mixture compositions. Basin wide, 1664 mixtures occurred in at least 25% of sites. The most complex mixtures identified comprised 9 chemical classes and occurred in 58% of sampled tributaries. Pharmaceuticals typically occurred in complex mixtures, reflecting pharmaceutical‐use patterns and wastewater facility outfall influences. Fewer mixtures were identified at lake or lake‐influenced sites than at riverine sites. As mixture complexity increased, the probability of a specific mixture occurring more often than by chance greatly increased, highlighting the importance of understanding source contributions to the environment. This empirically based analysis of mixture composition and occurrence may be used to focus future sampling efforts or mixture toxicity assessments. 

  19. Poison politics: a contentious history of consumer protection against dangerous household chemicals in the United States.

    Science.gov (United States)

    Jones, Marian Moser; Benrubi, Isidore Daniel

    2013-05-01

    The history of consumer protection against household poisons presents a key case study of the uniquely American struggle to balance public health and safety with the interests of business. By the late 19th century, package designs, warning labels, and state statutes had formed an uneven patchwork of protective mechanisms against accidental poisonings. As household chemicals proliferated in the early 20th century, physicians concerned with childhood poisonings pressured the federal government to enact legislation mandating warning labels on packaging for these substances. Manufacturers of household chemicals agreed to labeling requirements for caustic poisons but resisted broader regulation. Accidental poisonings of children continued to increase until the enactment of broad labeling and packaging legislation in the 1960s and 1970s. This history suggests that voluntary agreements between government agencies and manufacturers are inadequate to protect consumers against household poisonings and that, in the United States, protective household chemical regulation proceeds in a reactive rather than a precautionary manner.

  20. 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

  1. 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.

  2. 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)

  3. 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.

  4. 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...

  5. 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

  6. 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)

  7. 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.

  8. 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)

  9. 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

  10. SURFACE AND LIGHTNING SOURCES OF NITROGEN OXIDES OVER THE UNITED STATES: MAGNITUDES, CHEMICAL EVOLUTION, AND OUTFLOW

    Science.gov (United States)

    We use observations from two aircraft during the ICARTT campaign over the eastern United States and North Atlantic during summer 2004, interpreted with a global 3-D model of tropospheric chemistry (GEOS-Chem) to test current understanding of regional sources, chemical evolution...

  11. Aggregate formation in a freshwater bacterial strain induced by growth state and conspecific chemical cues

    Czech Academy of Sciences Publication Activity Database

    Blom, J. F.; Horňák, Karel; Šimek, Karel; Pernthaler, J.

    2010-01-01

    Roč. 12, č. 9 (2010), s. 2486-2495 ISSN 1462-2912 R&D Projects: GA ČR(CZ) GA206/08/0015 Institutional research plan: CEZ:AV0Z60170517 Keywords : aggregate formation * Sphingobium sp. * chemical cues * growth state Subject RIV: EE - Microbiology, Virology Impact factor: 5.537, year: 2010

  12. 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...

  13. 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.

  14. 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

  15. 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...

  16. 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...

  17. Chemical signature study of tupiguarani ceramic tradition from Central region of the Rio Grande do Sul state, Brazil

    International Nuclear Information System (INIS)

    Bona, Irene Akemy Tomiyoshi

    2006-01-01

    In this work a model based on experimental results using chemical composition data of the pottery sherds applied to Spearmann's no parametric test, principal component analysis and discriminant analysis, was applied. The samples are soils and Tupiguarani Tradition pottery sherd from the central area of the Rio Grande do Sul State. The chemical elements , Al, Ba, Ca, Cr, Fe, K Mn, Pb, Rb, S, Si, Sr, Ti, V and Zn were determined by energy dispersive X-ray fluorescence (EDXFR) while Ce, Cu, Gd, La, Nd, Pr, Sm, Th and Y by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) techniques. Relationships among the pottery characteristics, studied sites and sherd dispersion in the several sites were proposed. Indications of chemical signature of the small pottery with function to go or not to the fire were observed. The largest dispersion is of small pottery with surface treatment no corrugated. The potteries chemical fingerprints from Ijui River, Ibicui-Vacacai Mirim River and Jacui River were verified. (author)

  18. Chemical portioning and speciation of some trace elements in soil and street dust from Khartoum state, Sudan

    International Nuclear Information System (INIS)

    Ahmed, Amel Yousif

    2000-09-01

    In this study, surface soil and street dust samples were collected from Khartoum State, from areas exposed to industrial and traffic emission and from areas expected to be free from elemental emission to serve as control. Samples were digested using wet digestion method to determine the total concentration of Na, K, Cr, Mn, Fe, Cu, Zn and Pb using Atomic Absorption spectrophotometer (Aas), X-Ray fluorescence and flame photometer. Also samples were chemically fractionated using chemical specification method, and the solutions analyzed using Aas to determine the chemical form of the elements. Quality assurance of the data was achieved through the analysis of certified reference material. The range of the total concentration for Na, K, Mn, Fe, Cu, Zn and Pb are 400-5175, 220-4690, 0.07-315.25, 20-250, 2050.8-46000, 0.5-2305, 4.5-280, 9.5-6200 mg/kg respectively. results obtained agree with expected emission profile as inferred from the emitting source locations. Distribution of elements from emitting source locations and control samples in different chemical fractions was carried out, and the findings reinforced by enrichment factors calculations as well by the results obtained by statistical multi-variate analysis methods such as principle compared with previous literature.(Author)

  19. 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

  20. Regulation of chemical safety at fuel cycle facilities by the United States Nuclear Regulatory Commission

    International Nuclear Information System (INIS)

    Ramsey, Kevin M.

    2013-01-01

    When the U.S. Nuclear Regulatory Commission (NRC) was established in 1975, its regulations were based on radiation dose limits. Chemical hazards rarely influenced NRC regulations. After the Three Mile Island reactor accident in 1979, the NRC staff was directed to address emergency planning at non-reactor facilities. Several fuel cycle facilities were ordered to submit emergency plans consistent with reactor emergency plans because no other guidance was available. NRC published a notice that it was writing regulations to codify the requirements in the Orders and upgrade the emergency plans to address all hazards, including chemical hazards. The legal authority of NRC to regulate chemical safety was questioned. In 1986, an overfilled uranium hexafluoride cylinder ruptured and killed a worker. The NRC staff was directed to address emergency planning for hazardous chemicals in its regulations. The final rule included a requirement for fuel cycle facilities to certify compliance with legislation requiring local authorities to establish emergency plans for hazardous chemicals. As with emergency planning, NRC's authority to regulate chemical safety during routine operations was limited. NRC established memoranda of understanding (MOUs) with other regulatory agencies to encourage exchange of information between the agencies regarding occupational hazards. In 2000, NRC published new, performance-based, regulations for fuel cycle facilities. The new regulations required an integrated safety analysis (ISA) which used quantitative standards to assess chemical exposures. Some unique chemical exposure cases were addressed while implementing the new regulations. In addition, some gaps remain in the regulation of hazardous chemicals at fuel cycle facilities. The status of ongoing efforts to improve regulation of chemical safety at fuel cycle facilities is discussed. (authors)

  1. Linear Covariance Analysis and Epoch State Estimators

    Science.gov (United States)

    Markley, F. Landis; Carpenter, J. Russell

    2014-01-01

    This paper extends in two directions the results of prior work on generalized linear covariance analysis of both batch least-squares and sequential estimators. The first is an improved treatment of process noise in the batch, or epoch state, estimator with an epoch time that may be later than some or all of the measurements in the batch. The second is to account for process noise in specifying the gains in the epoch state estimator. We establish the conditions under which the latter estimator is equivalent to the Kalman filter.

  2. 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.

  3. Chemical Composition and Disruption of Quorum Sensing Signaling in Geographically Diverse United States Propolis

    Directory of Open Access Journals (Sweden)

    Michael A. Savka

    2015-01-01

    Full Text Available Propolis or bee glue has been used for centuries for various purposes and is especially important in human health due to many of its biological and pharmacological properties. In this work we showed quorum sensing inhibitory (QSI activity of ten geographically distinct propolis samples from the United States using the acyl-homoserine lactone- (AHL- dependent Chromobacterium violaceum strain CV026. Based on GC-MS chemical profiling the propolis samples can be classified into several groups that are as follows: (1 rich in cinnamic acid derivatives, (2 rich in flavonoids, and (3 rich in triterpenes. An in-depth analysis of the propolis from North Carolina led to the isolation and identification of a triterpenic acid that was recently isolated from Hondurian propolis (Central America and ethyl ether of p-coumaric alcohol not previously identified in bee propolis. QSI activity was also observed in the second group US propolis samples which contained the flavonoid pinocembrin in addition to other flavonoid compounds. The discovery of compounds that are involved in QSI activity has the potential to facilitate studies that may lead to the development of antivirulence therapies that can be complementary and/or alternative treatments against antibiotic resistant bacterial pathogens and/or emerging pathogens that have yet to be identified.

  4. Chemical behavior of residential lead in urban yards in the United States

    International Nuclear Information System (INIS)

    Elless, M.P.; Bray, C.A.; Blaylock, M.J.

    2007-01-01

    Long after federal regulations banned the use of lead-based paints and leaded gasoline, residential lead remains a persistent challenge. Soil lead is a significant contributor to this hazard and an improved understanding of physicochemical properties is likely to be useful for in situ abatement techniques such as phytoremediation and chemical stabilization. A laboratory characterization of high-lead soils collected from across the United States shows that the lead contaminants were concentrating in the silt and clay fractions, in the form of discrete particles of lead, as observed by scanning electron microscopy coupled with energy dispersive X-ray analysis. Soil lead varied widely in its solubility behavior as assessed by sequential and chelate extractions. Because site-specific factors (e.g., soil pH, texture, etc.) are believed to govern the solubility of the lead, understanding the variability in these characteristics at each site is necessary to optimize in situ remediation or abatement of these soils. - Site-specific solubility behavior of lead in soils has important implications for the selection of remediation approaches

  5. A field study of physico-chemical states of artificial radionuclides in seawater

    International Nuclear Information System (INIS)

    Nagaya, Yutaka; Nakamura, Kiyoshi

    1974-01-01

    The physico-chemical states of artificial radionuclides, 90 Sr, 137 Cs and 144 Ce in seawater were investigated by radiochemical analysis of filtered and unfiltered seawater. The difference of radionuclide concentrations between unfiltered and filtered seawaters was defined as the ''particulate form'' radioisotope and its ''particle ratio'' was discussed. Practically no particulate 90 Sr, greater than 0.22 μ in size, was observed in both coastal and open seawaters, but some of 137 Cs seemed to be insoluble in some circumstances, especially in coastal waters. A considerable amount of 144 Ce was found to be particulate. An estimation of the radionuclides in particulate form was made for Kashima-nada seawaters collected in 1970 to 1972, and it was shown that the possible occurrence of particulate radionuclides, greater than 0.22 μ in size, were 1% or less for 90 Sr and 6% for 137 Cs. In the coastal water, 80% of 144 Ce were seemed to be in particulate form, but in the open seawater only a few %. The influences of suspended materials to 137 Cs and 144 Ce concentration levels in seawater were not negligible and further investigations are desirable. (auth.)

  6. 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.

  7. 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)

  8. 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)

  9. 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)

  10. 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

  11. Moisture-induced solid state instabilities in α-chymotrypsin and their reduction through chemical glycosylation

    Directory of Open Access Journals (Sweden)

    Solá Ricardo J

    2010-08-01

    Full Text Available Abstract Background Protein instability remains the main factor limiting the development of protein therapeutics. The fragile nature (structurally and chemically of proteins makes them susceptible to detrimental events during processing, storage, and delivery. To overcome this, proteins are often formulated in the solid-state which combines superior stability properties with reduced operational costs. Nevertheless, solid protein pharmaceuticals can also suffer from instability problems due to moisture sorption. Chemical protein glycosylation has evolved into an important tool to overcome several instability issues associated with proteins. Herein, we employed chemical glycosylation to stabilize a solid-state protein formulation against moisture-induced deterioration in the lyophilized state. Results First, we investigated the consequences of moisture sorption on the stability and structural conformation of the model enzyme α-chymotrypsin (α-CT under controlled humidity conditions. Results showed that α-CT aggregates and inactivates as a function of increased relative humidity (RH. Furthermore, α-CT loses its native secondary and tertiary structure rapidly at increasing RH. In addition, H/D exchange studies revealed that α-CT structural dynamics increased at increasing RH. The magnitude of the structural changes in tendency parallels the solid-state instability data (i.e., formation of buffer-insoluble aggregates, inactivation, and loss of native conformation upon reconstitution. To determine if these moisture-induced instability issues could be ameliorated by chemical glycosylation we proceeded to modify our model protein with chemically activated glycans of differing lengths (lactose and dextran (10 kDa. The various glycoconjugates showed a marked decrease in aggregation and an increase in residual activity after incubation. These stabilization effects were found to be independent of the glycan size. Conclusion Water sorption leads to

  12. 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...

  13. Radon: Chemical and physical states of radon progeny. Final technical report

    International Nuclear Information System (INIS)

    Castleman, A.W. Jr.

    1996-01-01

    The evolving chemical and physical form of radon progeny influence their transport to the bioreceptor and the extent to which that receptor can take up these species into various tissues. When first born following radioactive decay processes, the potentially deleterious radon progeny undergo various physical and chemical transformations as they transcend from a highly charged to a neutral state, and interact with various constituents of the environment. These transformations impact on the extent to which the radon progeny become associated with aerosol particles on the one hand, and their ultimate chemical form that is available for uptake in the biosystem, on the other. The program, which originally commenced in 1987, dealt with the basic chemistry and physics of radon progeny and hence impacted on several themes of importance to the DOE/OHER radon program. One of these is dose response, which is governed by the physical forms of the radon progeny, their transport to the bioreceptor and the chemical forms that govern their uptake. The second theme had to do with cellular responses, one of the major issues motivating the work. It is well known that various sizes of ions and molecules are selectively transported across cell membrane to differing degrees. This ultimately has to do with their chemical and physical forms, charge and size. The overall objective of the work was threefold: (1) quantifying the mechanisms and rates of the chemical and physical transformation; (2) ascertaining the ultimate chemical forms, and (3) determining the potential interactions of these chemical species with biological functional groups to ascertain their ultimate transport and incorporation within cells

  14. 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

  15. Direct Reprogramming of Fibroblasts via a Chemically Induced XEN-like State.

    Science.gov (United States)

    Li, Xiang; Liu, Defang; Ma, Yantao; Du, Xiaomin; Jing, Junzhan; Wang, Lipeng; Xie, Bingqing; Sun, Da; Sun, Shaoqiang; Jin, Xueqin; Zhang, Xu; Zhao, Ting; Guan, Jingyang; Yi, Zexuan; Lai, Weifeng; Zheng, Ping; Huang, Zhuo; Chang, Yanzhong; Chai, Zhen; Xu, Jun; Deng, Hongkui

    2017-08-03

    Direct lineage reprogramming, including with small molecules, has emerged as a promising approach for generating desired cell types. We recently found that during chemical induction of induced pluripotent stem cells (iPSCs) from mouse fibroblasts, cells pass through an extra-embryonic endoderm (XEN)-like state. Here, we show that these chemically induced XEN-like cells can also be induced to directly reprogram into functional neurons, bypassing the pluripotent state. The induced neurons possess neuron-specific expression profiles, form functional synapses in culture, and further mature after transplantation into the adult mouse brain. Using similar principles, we were also able to induce hepatocyte-like cells from the XEN-like cells. Cells in the induced XEN-like state were readily expandable over at least 20 passages and retained genome stability and lineage specification potential. Our study therefore establishes a multifunctional route for chemical lineage reprogramming and may provide a platform for generating a diverse range of cell types via application of this expandable XEN-like state. Copyright © 2017 Elsevier Inc. All rights reserved.

  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. 15 CFR 745.1 - Advance notification and annual report of all exports of Schedule 1 chemicals to other States...

    Science.gov (United States)

    2010-01-01

    ... § 745.1 Advance notification and annual report of all exports of Schedule 1 chemicals to other States... Prohibition of Chemical Weapons (OPCW) not less than 30 days in advance of every export of a Schedule 1...: “Advance Notification of Schedule 1 Chemical Export”. (3) Upon receipt of the notification, BIS will inform...

  18. Multi-GPU unsteady 2D flow simulation coupled with a state-to-state chemical kinetics

    Science.gov (United States)

    Tuttafesta, Michele; Pascazio, Giuseppe; Colonna, Gianpiero

    2016-10-01

    In this work we are presenting a GPU version of a CFD code for high enthalpy reacting flow, using the state-to-state approach. In supersonic and hypersonic flows, thermal and chemical non-equilibrium is one of the fundamental aspects that must be taken into account for the accurate characterization of the plasma and state-to-state kinetics is the most accurate approach used for this kind of problems. This model consists in writing a continuity equation for the population of each vibrational level of the molecules in the mixture, determining at the same time the species densities and the distribution of the population in internal levels. An explicit scheme is employed here to integrate the governing equations, so as to exploit the GPU structure and obtain an efficient algorithm. The best performances are obtained for reacting flows in state-to-state approach, reaching speedups of the order of 100, thanks to the use of an operator splitting scheme for the kinetics equations.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Chemical states of fission products in irradiated uranium-plutonium mixed oxide fuel

    International Nuclear Information System (INIS)

    Kurosaki, Ken; Uno, Masayoshi; Yamanaka, Shinsuke

    1999-01-01

    The chemical states of fission products (FPs) in irradiated uranium-plutonium mixed oxide (MOX) fuel for the light water reactor (LWR) were estimated by thermodynamic equilibrium calculations on system of fuel and FPs by using ChemSage program. A stoichiometric MOX containing 6.1 wt. percent PuO 2 was taken as a loading fuel. The variation of chemical states of FPs was calculated as a function of oxygen potential. Some pieces of information obtained by the calculation were compared with the results of the post-irradiation examination (PIE) of UO 2 fuel. It was confirmed that the multicomponent and multiphase thermodynamic equilibrium calculation between fuel and FPs system was an effective tool for understanding the behavior of FPs in fuel. (author)

  4. Rich Ground State Chemical Ordering in Nanoparticles: Exact Solution of a Model for Ag-Au Clusters

    DEFF Research Database (Denmark)

    Larsen, Peter Mahler; Jacobsen, Karsten Wedel; Schiøtz, Jakob

    2018-01-01

    We show that nanoparticles can have very rich ground state chemical order. This is illustrated by determining the chemical ordering of Ag-Au 309-atom Mackay icosahedral nanoparticles. The energy of the nanoparticles is described using a cluster expansion model, and a Mixed Integer Programming (MIP......) approach is used to find the exact ground state configurations for all stoichiometries. The chemical ordering varies widely between the different stoichiometries, and display a rich zoo of structures with non-trivial ordering....

  5. Application of Photocured Polymer Ion Selective Membranes for Solid-State Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Natalia Abramova

    2015-06-01

    Full Text Available Application of conducting polymers with additional functional groups for a solid contact formation and photocurable membranes as sensitive elements of solid-state chemical sensors is discussed. Problems associated with application of UV-curable polymers for sensors are analyzed. A method of sensor fabrication using copolymerized conductive layer and sensitive membrane is presented and the proof of concept is confirmed by two examples of solid-contact electrodes for Ca ions and pH.

  6. Stability of racemic and chiral steady states in open and closed chemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Ribo, Josep M. [Departament de Quimica Organica, Universitat de Barcelona, c. Marti i Franques 1, Barcelona (Spain); Hochberg, David [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir Km. 4, 28850 Torrejon de Ardoz, Madrid (Spain)], E-mail: hochbergd@inta.es

    2008-12-22

    The stability properties of models of spontaneous mirror symmetry breaking in chemistry are characterized algebraically. The models considered here all derive either from the Frank model or from autocatalysis with limited enantioselectivity. Emphasis is given to identifying the critical parameter controlling the chiral symmetry breaking transition from racemic to chiral steady-state solutions. This parameter is identified in each case, and the constraints on the chemical rate constants determined from dynamic stability are derived.

  7. Stability of racemic and chiral steady states in open and closed chemical systems

    International Nuclear Information System (INIS)

    Ribo, Josep M.; Hochberg, David

    2008-01-01

    The stability properties of models of spontaneous mirror symmetry breaking in chemistry are characterized algebraically. The models considered here all derive either from the Frank model or from autocatalysis with limited enantioselectivity. Emphasis is given to identifying the critical parameter controlling the chiral symmetry breaking transition from racemic to chiral steady-state solutions. This parameter is identified in each case, and the constraints on the chemical rate constants determined from dynamic stability are derived

  8. Trends in the chemical state of polonium-210 in the atmosphere

    International Nuclear Information System (INIS)

    Abe, M.; Abe, S.

    1980-01-01

    Trends of the chemial state of 210 Po in airborne dusts at Chiba, Japan, between 1963 and 1976 are discussed. A sublimination method is used to determine the chemical state of the 210 Po. The results show that the fraction of the component volatilizing at low temperature varies yearly in the range between 0 and 50%. If we assume the component comes from an artificial source, it may be suggested that a large fraction of 210 Po in airborne dusts comes from artificial sources. Additional reference data that show local properties of our sampling site are presented

  9. Moessbauer spectroscopy-nuclear hyperfine technique for studying dynamic chemical states of iron complexes

    International Nuclear Information System (INIS)

    Maeda, Y.

    2005-01-01

    A brief introduction of Moessbauer spectroscopy will be presented, followed by a discussion of the Moessbauer parameters, isomer shifts, quadrupole splittings, and spectral shapes of complexes in the presence of relaxation of the electronic states of the iron atoms. The usefulness of Moessbauer spectroscopy to demonstrate the dynamic phenomena of electronic states will be discussed in this lecture. (1) The Moessbauer spectra of mixed valence dinuclear and trinuclear iron complexes will be discussed in connection with the chemical structure of the complexes: The values of the quadrupole splittings and isomer shifts of [Fe II Fe III (bpmp) (ppa) 2 ](BF 4 ) 2 increase on raising the temperature, where Hbpmp represents 2,6-bis[bis(2- pyridylmethyl)aminoethyl]-4-methylphenol and ppa is 3-n-phenylpropionic acid. The spectra can be accounted for by postulating intramolecular electron exchange between two energetically inequivalent vibronic states Fe A 2+ Fe B 3+ and Fe A 3+ Fe B 2+ : The apparent time averaged valence states of the iron atoms are 2.2 and 2.8 on the Moessbauer time scale at 293 K. (2) The Moessbauer spectra of iron(III) spin-crossover complexes will be discussed in connection with the spin-transition rate and chemical structure of the complexes. The Moessbauer spectra of spin-crossover iron(III) complexes with LIESST (Light Induced Electronic Spin-State Transition) and of metallomesogens will be discussed to illustrate the extension of this research area by the use of Moessbauer spectroscopy.

  10. Chemical-state-selective mapping at nanometer scale using synchrotron radiation and photoelectron emission microscopy

    International Nuclear Information System (INIS)

    Hirao, Norie; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Honda, Mitsunori

    2010-01-01

    For surface analyses of semiconductor devices and various functional materials, it has become indispensable to analyze valence states at nanometer scale due to the rapid developments of nanotechnology. Since a method for microscopic mapping dependent on the chemical bond states has not been established so far, we have developed a photoelectron emission microscopy (PEEM) system combined with synchrotron soft X-ray excitation. The samples investigated were Si/SiO x micro-patterns prepared by O 2 + ion implantation in Si(001) wafer using a mask. PEEM images excited by various photon energies around the Si K-edge were observed. The lateral spatial resolution of the system was about 41 nm. The brightness of each spot in PEEM images changed depending on the photon energy, due to the X-ray absorption intensity of the respective chemical state. Since the surface of this sample was topographically flat, it has been demonstrated that the present method can be applied to observations of the microscopic pattern, depending not on the morphology, but only on the valence states of silicon. We have also in-situ measured the changes of the PEEM images upon annealing, and elucidated the mechanism of the lateral diffusion of oxygen and valence states of silicon at the nanometer scale. (author)

  11. Chemical-state-selective mapping at nanometer scale using synchrotron radiation and photoelectron emission microscopy

    International Nuclear Information System (INIS)

    Hirao, Norie; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Honda, Mitsunori

    2008-01-01

    For surface analyses of semiconductor devices and various functional materials, it has become indispensable to analyze the valence states at the nanometer scale due to the rapid developments of nanotechnology. Since a method for microscopic mapping dependent on the chemical bond states has not been established so far, we have developed a photoelectron emission microscopy (PEEM) system combined with synchrotron soft X-ray excitation. The samples investigated were Si/SiO x micro-patterns prepared by O 2 + ion implantation in a Si(001) wafer using a mask. PEEM images excited by various photon energies around the Si K-edge were observed. The lateral spatial resolution of the system was about 41 nm. The brightness of each spot in PEEM images changed depending on the photon energy, due to the X-ray absorption intensity of the respective chemical state. Since the surface of this sample is topographically flat, it has been demonstrated that the present method can be applied to observations of the microscopic pattern, depending not on the morphology, but only on the valence states of silicon. We have also in-situ measured the changes of PEEM images upon annealing, and elucidated the mechanism of the lateral diffusion of oxygen and valence states of silicon at the nanometer scale. (author)

  12. 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.

  13. Soft x-ray spectroscopy for probing electronic and chemical states of battery materials

    International Nuclear Information System (INIS)

    Yang Wanli; Qiao Ruimin

    2016-01-01

    The formidable challenge of developing high-performance battery system stems from the complication of battery operations, both mechanically and electronically. In the electrodes and at the electrode–electrolyte interfaces, chemical reactions take place with evolving electron states. In addition to the extensive studies of material synthesis, electrochemical, structural, and mechanical properties, soft x-ray spectroscopy provides unique opportunities for revealing the critical electron states in batteries. This review discusses some of the recent soft x-ray spectroscopic results on battery binder, transition-metal based positive electrodes, and the solid-electrolyte-interphase. By virtue of soft x-ray’s sensitivity to electron states, the electronic property, the redox during electrochemical operations, and the chemical species of the interphases could be fingerprinted by soft x-ray spectroscopy. Understanding and innovating battery technologies need a multimodal approach, and soft x-ray spectroscopy is one of the incisive tools to probe the chemical and physical evolutions in batteries. (topical review)

  14. 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.

  15. 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...

  16. 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...

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. Determination of Chemical States of Mercury on Activated Carbon Using XANES

    International Nuclear Information System (INIS)

    Takaoka, Masaki; Takeda, Nobuo; Oshita, Kazuyuki; Yamamoto, Takashi; Tanaka, Tsunehiro; Uruga, Tomoya

    2007-01-01

    Although the adsorption of mercury vapor onto activated carbon is a widely used technology to prevent environmental release, the adsorption mechanism is not clearly understood. In this study, we determined the chemical states of mercury on two kinds of activated carbon using X-ray absorption near-edge spectroscopy (XANES) to elucidate the adsorption mechanism. The adsorption experiments of elemental mercury onto activated carbon were conducted under air and nitrogen atmospheres at temperatures of 20 and 160 deg. C. Two types of activated carbon were prepared. X-ray absorption fine structure (XAFS) measurements were carried out on beamline BL01B1 at SPring-8. Hg-LIII edge XANES spectra suggested that chemical adsorption of elemental mercury on the activated carbon occurred in the 20-160 deg. C temperature range. According to the XANES spectra, a difference occurred in the chemical states of mercury between AC no. 1 and AC no. 2. The Hg XANES spectra on AC no. 1 were similar to those of Hg2Cl2 and HgS, and the Hg XANES spectra on AC no. 2 were similar to that of HgO, which suggested that nitric acid treatment removed sulfur from AC no. 1 and functional groups that were strong oxidizers on the surface of AC no. 2 created HgO. According to the EXAFS oscillation, a difference occurred in the chemical states of mercury on AC no. 1 between 20 and 160 deg. C. We found that impurities and oxidant functional groups on activated carbon play key roles in mercury adsorption

  3. 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…

  4. Emergence of a super-synchronized mobbing state in a large population of coupled chemical oscillators

    Science.gov (United States)

    Ghoshal, Gourab; Muñuzuri, Alberto P.; Pérez-Mercader, Juan

    2016-01-01

    Oscillatory phenomena are ubiquitous in Nature. The ability of a large population of coupled oscillators to synchronize constitutes an important mechanism to express information and establish communication among members. To understand such phenomena, models and experimental realizations of globally coupled oscillators have proven to be invaluable in settings as varied as chemical, biological and physical systems. A variety of rich dynamical behavior has been uncovered, although usually in the context of a single state of synchronization or lack thereof. Through the experimental and numerical study of a large population of discrete chemical oscillators, here we report on the unexpected discovery of a new phenomenon revealing the existence of dynamically distinct synchronized states reflecting different degrees of communication. Specifically, we discover a novel large-amplitude super-synchronized state separated from the conventionally reported synchronized and quiescent states through an unusual sharp jump transition when sampling the strong coupling limit. Our results assume significance for further elucidating globally coherent phenomena, such as in neuropathologies, bacterial cell colonies, social systems and semiconductor lasers.

  5. Analysis of chemical warfare using a transient semi-Markov formulation.

    OpenAIRE

    Kierzewski, Michael O.

    1988-01-01

    Approved for public release; distribution is unlimited This thesis proposes an analytical model to test various assumptions about conventional/chemical warfare. A unit's status in conventional/chemical combat is modeled as states in a semi-Markov chain with transient and absorbing states. The effects of differing chemical threat levels, availability of decontamination assets and assumed personnel degradation rates on expected unit life and capabilities are tested. The ...

  6. Data gaps in toxicity testing of chemicals allowed in food in the United States.

    Science.gov (United States)

    Neltner, Thomas G; Alger, Heather M; Leonard, Jack E; Maffini, Maricel V

    2013-12-01

    In the United States, chemical additives cannot be used in food without an affirmative determination that their use is safe by FDA or additive manufacturer. Feeding toxicology studies designed to estimate the amount of a chemical additive that can be eaten safely provide the most relevant information. We analyze how many chemical additives allowed in human food have feeding toxicology studies in three toxicological information sources including the U.S. Food and Drug Administration's (FDA) database. Less than 38% of FDA-regulated additives have a published feeding study. For chemicals directly added to food, 21.6% have feeding studies necessary to estimate a safe level of exposure and 6.7% have reproductive or developmental toxicity data in FDA's database. A program is needed to fill these significant knowledge gaps by using in vitro and in silico methods complemented with targeted in vivo studies to ensure public health is protected. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Measuring 13Cβ chemical shifts of invisible excited states in proteins by relaxation dispersion NMR spectroscopy

    International Nuclear Information System (INIS)

    Lundstroem, Patrik; Lin Hong; Kay, Lewis E.

    2009-01-01

    A labeling scheme is introduced that facilitates the measurement of accurate 13 C β chemical shifts of invisible, excited states of proteins by relaxation dispersion NMR spectroscopy. The approach makes use of protein over-expression in a strain of E. coli in which the TCA cycle enzyme succinate dehydrogenase is knocked out, leading to the production of samples with high levels of 13 C enrichment (30-40%) at C β side-chain carbon positions for 15 of the amino acids with little 13 C label at positions one bond removed (∼5%). A pair of samples are produced using [1- 13 C]-glucose/NaH 12 CO 3 or [2- 13 C]-glucose as carbon sources with isolated and enriched (>30%) 13 C β positions for 11 and 4 residues, respectively. The efficacy of the labeling procedure is established by NMR spectroscopy. The utility of such samples for measurement of 13 C β chemical shifts of invisible, excited states in exchange with visible, ground conformations is confirmed by relaxation dispersion studies of a protein-ligand binding exchange reaction in which the extracted chemical shift differences from dispersion profiles compare favorably with those obtained directly from measurements on ligand free and fully bound protein samples

  8. Novel chemically cross-linked solid state electrolyte for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Yin Xiong; Tan Weiwei; Xiang Wangchun; Lin Yuan; Zhang Jingbo; Xiao Xurui; Li Xueping; Zhou Xiaowen; Fang Shibi

    2010-01-01

    Poly(vinylpyridine-co-ethylene glycol methyl ether methacrylate) (P(VP-co-MEOMA)) and α,ω-diiodo poly(ethylene oxide-co-propylene oxide) (I[(EO) 0.8 -co-(PO) 0.2 ] y I) were synthesized and used as chemically cross-linked precursors of the electrolyte for dye-sensitized solar cells. Meanwhile, α-iodo poly(ethylene oxide-co-propylene oxide) methyl ether (CH 3 O[(EO) 0.8 -co-(PO) 0.2 ] x I) was synthesized and added into the electrolyte as an internal plasticizer. Novel polymer electrolyte resulting from chemically cross-linked precursors was obtained by the quaterisation at 90 o C for 30 min. The characteristics for this kind of electrolyte were investigated by means of ionic conductivity, thermogravimetric and photocurrent-voltage. The ambient ionic conductivity was significantly enhanced to 2.3 x 10 -4 S cm -1 after introducing plasticizer, modified-ionic liquid. The weight loss of the solid state electrolyte at 200 o C was 1.8%, and its decomposition temperature was 287 o C. Solid state dye-sensitized solar cell based on chemically cross-linked electrolyte presented an overall conversion efficiency of 2.35% under AM1.5 irradiation (100 mW cm -2 ). The as-fabricated device maintained 88% of its initial performance at room temperature even without sealing for 30 days, showing a good stability.

  9. Chemical equilibrium model for high- Tc and heavy fermion superconductors: the density of states

    International Nuclear Information System (INIS)

    Kallio, A.; Hissa, J.; Hayrynen, T.; Braysy, V.; Sakkinen, T.

    1998-01-01

    The chemical equilibrium model is based on the idea of correlated electron pairs, which in singlet state can exist as quasimolecules in the superfluid and normal states of a superconductor. These preformed pairs are bosons which can undergo a Bose-Einstein condensation in analogy with the superfluidity of 4 He+ 3 He-mixture. The bosons (B ++ ) and the fermions (h + ) are in chemical equilibrium with respect to the reaction B ++ ↔ 2h + , at any temperature. The mean densities of bosons and fermions (quasiholes) n B (T) and n h (T) are determined from the thermodynamics of the equilibrium reaction in terms of a single function f(T). By thermodynamics the function f(T) is connected to equilibrium constant φ(T) by 1-f(T) = [1 + φ(T)] -1/2 . Using a simple power law, known to be valid near T = 0, for the chemical constant φ(T) α/t 2γ , t = T/T*, the mean density of quasiholes is given in closed form. This enables one to calculate the corresponding density of states (DOS) D(E) N s /N(0), by solving an integral equation. The NIS- tunneling conductivity near T = 0, given by D(E) compares well with the most recent experiments: D(E) ∼ E γ , for small E and a finite maximum of right size, corresponding to 'finite quasiparticle lifetime'. The corresponding SIS-tunneling conductivity is obtained from a simple convolution and is also in agreement with recent break junction experiments of Hancotte et al. The position of the maximum can be used to obtain the scaling temperature T*, which comes close to the one measured by Hall coefficient in the normal state. A simple explanation for the spingap effect in NMR is given. (Copyright (1998) World Scientific Publishing Co. Pte. Ltd)

  10. Enabling Collaborative Analysis: State Evaluation Groups, the Electronic State File, and Collaborative Analysis Tools

    International Nuclear Information System (INIS)

    Eldridge, C.; Gagne, D.; Wilson, B.; Murray, J.; Gazze, C.; Feldman, Y.; Rorif, F.

    2015-01-01

    The timely collection and analysis of all safeguards relevant information is the key to drawing and maintaining soundly-based safeguards conclusions. In this regard, the IAEA has made multidisciplinary State Evaluation Groups (SEGs) central to this process. To date, SEGs have been established for all States and tasked with developing State-level approaches (including the identification of technical objectives), drafting annual implementation plans specifying the field and headquarters activities necessary to meet technical objectives, updating the State evaluation on an ongoing basis to incorporate new information, preparing an annual evaluation summary, and recommending a safeguards conclusion to IAEA senior management. To accomplish these tasks, SEGs need to be staffed with relevant expertise and empowered with tools that allow for collaborative access to, and analysis of, disparate information sets. To ensure SEGs have the requisite expertise, members are drawn from across the Department of Safeguards based on their knowledge of relevant data sets (e.g., nuclear material accountancy, material balance evaluation, environmental sampling, satellite imagery, open source information, etc.) or their relevant technical (e.g., fuel cycle) expertise. SEG members also require access to all available safeguards relevant data on the State. To facilitate this, the IAEA is also developing a common, secure platform where all safeguards information can be electronically stored and made available for analysis (an electronic State file). The structure of this SharePoint-based system supports IAEA information collection processes, enables collaborative analysis by SEGs, and provides for management insight and review. In addition to this common platform, the Agency is developing, deploying, and/or testing sophisticated data analysis tools that can synthesize information from diverse information sources, analyze diverse datasets from multiple viewpoints (e.g., temporal, geospatial

  11. Chimera and phase-cluster states in populations of coupled chemical oscillators

    Science.gov (United States)

    Tinsley, Mark R.; Nkomo, Simbarashe; Showalter, Kenneth

    2012-09-01

    Populations of coupled oscillators may exhibit two coexisting subpopulations, one with synchronized oscillations and the other with unsynchronized oscillations, even though all of the oscillators are coupled to each other in an equivalent manner. This phenomenon, discovered about ten years ago in theoretical studies, was then further characterized and named the chimera state after the Greek mythological creature made up of different animals. The highly counterintuitive coexistence of coherent and incoherent oscillations in populations of identical oscillators, each with an equivalent coupling structure, inspired great interest and a flurry of theoretical activity. Here we report on experimental studies of chimera states and their relation to other synchronization states in populations of coupled chemical oscillators. Our experiments with coupled Belousov-Zhabotinsky oscillators and corresponding simulations reveal chimera behaviour that differs significantly from the behaviour found in theoretical studies of phase-oscillator models.

  12. 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

  13. Correlação entre a resposta do algodoeiro à adubação fosfatada e a análise química do solo, nas condições do Estado de São Paulo Correlation between cotton responses to phosphorous fertilization and chemical analysis on State of São Paulo soils

    Directory of Open Access Journals (Sweden)

    Milton Geraldo Fuzatto

    1966-01-01

    Full Text Available Uma regressão múltipla, descrevendo a resposta do algodoeiro à adubação fosfatada em função do teor de PO4-3 solúvel e da acidez do solo, aquêle dado por dois métodos de análise, é discutida em 126 experimentos de adubação realizados em vários tipos de solo do Estado de São Paulo. Em geral, o índice de acidez se mostrou tão importante quanto o teor de fósforo solúvel, para explicar o efeito da adubação fosfatada, sendo maiores êstes, em solos mais ácidos. Os dois métodos de análise de fósforo no solo, utilizando respectivamente ácido sulfúrico 0,05 Ne ácido oxálico + oxalato de potássio N,como soluções extratoras, foram comparados no estudo das correlações. A separação dos ensaios em dois grupos, se conduzidos em solos argilosos ou arenosos, revelou interação entre os métodos de análise e êsses grupos, o que possibilitou apreciar as vantagens e inconvenientes de cada método, nas condições estudadas.In this paper the correlation between cotton responses to phosphorus application and chemical analysis of soils is discussed, based on 126 experiments conducted in the State of São Paulo. The results indicate the possibilities of estimating the effects due to phosphorous fertilization on the basis of the amount of soluble phosphorus and soil acidity, by means of a multiple regression equation. Two methods of chemical analysis, utilizing respectively sulphuric acid 0.05 Nand oxalic acid + potassium oxalate N,as extractor of phosphorus, were compared in the correlation studies. Both method show advantages and inconvenients, mainly when applied specifically to the clay or sandy soils. It was suggested that another method, with extraction capacity intermediate to those discussed, would be more appropriate for fertilizer recomen-dations, irrespective of the soil types considered.

  14. Plasma flow reactor for steady state monitoring of physical and chemical processes at high temperatures.

    Science.gov (United States)

    Koroglu, Batikan; Mehl, Marco; Armstrong, Michael R; Crowhurst, Jonathan C; Weisz, David G; Zaug, Joseph M; Dai, Zurong; Radousky, Harry B; Chernov, Alex; Ramon, Erick; Stavrou, Elissaios; Knight, Kim; Fabris, Andrea L; Cappelli, Mark A; Rose, Timothy P

    2017-09-01

    We present the development of a steady state plasma flow reactor to investigate gas phase physical and chemical processes that occur at high temperature (1000 flow injector). We have modeled the system using computational fluid dynamics simulations that are bounded by measured temperatures. In situ line-of-sight optical emission and absorption spectroscopy have been used to determine the structures and concentrations of molecules formed during rapid cooling of reactants after they pass through the plasma. Emission spectroscopy also enables us to determine the temperatures at which these dynamic processes occur. A sample collection probe inserted from the open end of the reactor is used to collect condensed materials and analyze them ex situ using electron microscopy. The preliminary results of two separate investigations involving the condensation of metal oxides and chemical kinetics of high-temperature gas reactions are discussed.

  15. 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

  16. In vitro chemical and cellular tests applied to uranium trioxide with different hydration states

    International Nuclear Information System (INIS)

    Ansoborlo, E.; Chalabreysse, J.; Henge-Napoli, M.H.; Pujol, E.

    1992-01-01

    A simple and rapid in vitro chemical solubility test applicable to industrial uranium trioxide (UO 3 ) was developed together with two in vitro cellular tests using rat alveolar macrophages maintained either in gas phase or in alginate beads at 37 degrees C. Industrial UO 3 was characterized by particle size, X-ray, and IR spectra, and chemical transformation (e.g., aging and hydration of the dust) was also studied. Solvents used for the in vitro chemical solubility study included carbonates, citrates, phosphates, water, Eagle's basal medium, and Gamble's solution (simulated lung fluid), alone, with oxygen, or with superoxide ions. Results, expressed in terms of the half-time of dissolution, according to International Commission on Radiological Protection (ICRP) classification (D,W,Y), varied for different hydration states of UO 3 , showing a lower solubility of hydrated UO 3 in solvents compared to basic UO 3 or UO 3 heated at 450 degrees C. Two in vitro cellular tests on cultured rat alveolar macrophages (cells maintained in gas phase and cells immobilized in alginate beads) were used on the same UO 3 samples and generally showed a lower solution transfer rate in the presence of macrophages than in the culture medium alone. The results of in vitro chemical and cellular tests were compared, with four main conclusions; a good reproducibility of the three tests in Eagle's basal medium of the effect of hydration state on solubility, the classification of UO 3 in terms of ICRP solubility criteria, and the ability of macrophoges to decrease uranium solubility in medium. 16 refs., 3 figs., 4 tabs

  17. 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.

  18. 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.

  19. 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

  20. Attempts to identify a control system for chemical reactivity in the living state using virtual energy.

    Science.gov (United States)

    Reid, B L; Bourke, C

    2001-07-01

    This thesis explores the activation of chemicals in metabolic systems from the viewpoint that this activation is under the control of elements of the space-sea in which the chemicals are immersed. Themselves inert, the chemicals are theorised to exploit a force or action issuing from space (fluctuation) and characterized by the homogeneity (termed symmetry) of this medium. The fluctuation is heterogenized upon collision with matter from the intervention of well recognized fields of gravity and electromagnetism at the instant of its issue to form the near field of radiation. Fractions of original space waves and of their intrinsic spin are produced resulting in the activation of the orbitals (valency) in the chemical itself. The thesis continues: the disturbed fluctuation must return to space, obliging in turn, a prior return to the homogeneous state requiring special restorative wave rearrangements known as resonance. The success of the restorative resonance is signalled by a singularity of the fluctuation now propelled to infinity (space), and the contingent chemical reactions thereby terminated. Compromise to this return can occur from many causes and, in its presence, activation of the orbitals continues. They now effectively constitute autonomous reactions alienated from the system as a whole. The thesis is supported from evidence from diverse fields such as space theory, history of quantum field theory in attempts to derive its meaning, dielectrics and the near field of electromagnetic radiation, electron-space interactions at the Fermi surface during phase transitions and evolution of equilibrium conditions in resonance phenomena. The utility of the hypothesis rests on recognition of the resonance condition at various points in the system sufficiently macroscopic as to be available clinically as an abrupt interface between physiology and pathology. Copyright 2001 Harcourt Publishers Ltd.

  1. Analysis of 165Er excited state properties

    International Nuclear Information System (INIS)

    Morozov, V.A.; Budzynski, M.

    1982-01-01

    It is shown by the analysis of 165 Tm decay that the precision measurements of γ-ray and internal conversion electron intensities together with the measurements o.f angular correlation coefficients provide more data for the determination of γ-ray multipole composition and intensities of γ-transitions with small enerqy difference. The spin of the 589.868 ke tate is found to be I=1/2 - . Doublet transitions of different parity from the states 1103.495, 920.645 and 745.968 keV to the levels of the 590 keV region with energy difference ΔE=(108+-22) eV are identified

  2. 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

  3. Generalized fault tree analysis combined with state analysis

    International Nuclear Information System (INIS)

    Caldarola, L.

    1980-02-01

    An analytical theory has been developed which allows one to calculate the occurrence probability of the top event of a fault tree with multistate (two or more than two states) components. It is shown that, in order to correctly describe a system with multistate components, a special type of boolean algebra is required. This is called 'boolean algebra with restrictions on variables' and its basic rules are the same as those of the traditional boolean algebra with some additional restrictions on the variables. These restrictions are extensively discussed in the paper. It is also shown that the boolean algebra with restrictions on variables facilitates the task of formally combining fault tree analysis with state analysis. The computer program MUSTAFA 1 based on the above theory has been developed. It can analyse fault trees of system containing statistically independent as well as dependent components with two or more than two states. MUSTAFA 1 can handle coherent as well as non coherent boolean functions. (orig.) 891 HP/orig. 892 MB [de

  4. 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.

  5. Chemical states of p-boronophenylalanine in aqueous carboxylic acids and polyols

    International Nuclear Information System (INIS)

    Kobayashi, Mitsue; Kitaoka, Yoshinori

    1995-01-01

    Chemical states of p-boronophenylalanine were studied by infrared (IR) spectroscopy in aqueous carboxylic acids and in aqueous fructose. For BPA in water, the absorption band due to the B-O stretching of trigonal boron was observed, while that of tetrahedral boron was observed for BPA in aqueous oxalic acid. This means BPA forms a complex of tetrahedral boron with oxalate. It was proved that BPA also formed complexes of tetrahedral boron with citric acid as well as with fructose. No appreciable interaction was detected between BPA and maleic acid. (author)

  6. Solid State and Chemical Radiation Dosimetry in Medicine and Biology. Proceedings of a Symposium

    International Nuclear Information System (INIS)

    1967-01-01

    Proceedings of a Symposium organized by the IAEA and held in Vienna, 3-7 October 1966. The meeting was attended by 104 participants from 21 countries and three international organizations. Contents: Solid state dosimetry (17 papers); Chemical dosimetry (10 papers); Invited lectures (2 papers); General aspects and other methods of dosimetry (6 papers); Panel discussion on research and development needed in dosimetry. Each paper is in its original language (32 English, 2 French and 1 Spanish) and is preceded by an abstract in English and one in the original language, if this is not English. Discussions are in English. (author)

  7. Solid State and Chemical Radiation Dosimetry in Medicine and Biology. Proceedings of a Symposium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-03-15

    Proceedings of a Symposium organized by the IAEA and held in Vienna, 3-7 October 1966. The meeting was attended by 104 participants from 21 countries and three international organizations. Contents: Solid state dosimetry (17 papers); Chemical dosimetry (10 papers); Invited lectures (2 papers); General aspects and other methods of dosimetry (6 papers); Panel discussion on research and development needed in dosimetry. Each paper is in its original language (32 English, 2 French and 1 Spanish) and is preceded by an abstract in English and one in the original language, if this is not English. Discussions are in English. (author)

  8. LIQUIDITY ANALYSIS OF STATE BANK OF INDIA

    Directory of Open Access Journals (Sweden)

    Kumar Gandhi R

    2011-12-01

    Full Text Available Modern customer has a high demand for quality of service than he/she had before. There is an urgent need for improving the customer service levels currently provided in the banking industry. Banks need to understand, foresee, the needs and expected levels of customer support which the customer expects when he/she steps into the branch and strive to stand up and excel in providing the service and making banking a truly delightful experience. The banker should change his/her agenda from Customer Satisfaction to Customer delight and then march towards Customer Ecstasy. This will be possible by maintaining the financial soundness of the firm. In this connection it has been given importance through this study. Since most of the Banking slightly deviate into the other areas like insurance, financial services and modern banking services such as Advisory services, Agent for receivables, custodian, instant loan provider, Forfeiter services and factoring services. A conscious attempt has been made to analysis the liquidity of state bank of India (SBI. The present study aimed to understand the financial soundness of the bank, the ratio analysis taken as tool. In this research work the secondary data mainly used, it has been collected in the form of the company manuals, Balance sheets and other documents. The data analyzed by some of the statistical tools such as ANOVA test and Multi variate test is used to analyze the interferences about the operating efficiency.

  9. State Teacher Salary Schedules. Policy Analysis

    Science.gov (United States)

    Griffith, Michael

    2016-01-01

    In the United States most teacher compensation issues are decided at the school district level. However, a group of states have chosen to play a role in teacher pay decisions by instituting statewide teacher salary schedules. Education Commission of the States has found that 17 states currently make use of teacher salary schedules. This education…

  10. Chemical composition of sage (Salvia officinalis L. essential oil from the Rio de Janeiro State (Brazil

    Directory of Open Access Journals (Sweden)

    A. Porte

    2013-01-01

    Full Text Available The purpose of this study was to investigate the chemical composition of the essential oil from fresh leaves of sage (Salvia officinalis L. from Petrópolis, Rio de Janeiro State, for international trade. The oil was isolated by hydrodistillation in a Clevenger-type apparatus and analyzed through a combination of GC-FID and GC-MS. The yield was 2.3 % on dry basis. Forty-seven constituents were identified according to their chromatographic retention indices and mass spectra, corresponding to 94.90 % of the compounds present. The major constituents of the oil were α-thujone (40.90 %, camphor (26.12 %, α-pinene (5.85 % and β-thujone (5.62 %. The essential oil studied was similar to those found in several European countries and can be a valuable product for the small farmers from the Petrópolis region in Rio de Janeiro State.

  11. Localized chemical switching of the charge state of nitrogen-vacancy luminescence centers in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Shanley, Toby W.; Martin, Aiden A.; Aharonovich, Igor, E-mail: Igor.Aharonovich@uts.edu.au; Toth, Milos, E-mail: Milos.Toth@uts.edu.au [School of Physics and Advanced Materials, University of Technology, Sydney, P.O. Box 123, Broadway, New South Wales 2007 (Australia)

    2014-08-11

    We present a direct-write chemical technique for controlling the charge state of near-surface nitrogen vacancy centers (NVs) in diamond by surface fluorination. Fluorination of H-terminated diamond is realized by electron beam stimulated desorption of H{sub 2}O in the presence of NF{sub 3} and verified with environmental photoyield spectroscopy (EPYS) and photoluminescence (PL) spectroscopy. PL spectra of shallow NVs in H- and F-terminated nanodiamonds show the expected dependence of the NV charge state on their energetic position with respect to the Fermi-level. EPYS reveals a corresponding difference between the ionization potential of H- and F-terminated diamond. The electron beam fluorination process is highly localized and can be used to fluorinate H-terminated diamond, and to increase the population of negatively charged NV centers.

  12. 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...

  13. 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)

  14. 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.

  15. 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.

  16. A finite state projection algorithm for the stationary solution of the chemical master equation

    Science.gov (United States)

    Gupta, Ankit; Mikelson, Jan; Khammash, Mustafa

    2017-10-01

    The chemical master equation (CME) is frequently used in systems biology to quantify the effects of stochastic fluctuations that arise due to biomolecular species with low copy numbers. The CME is a system of ordinary differential equations that describes the evolution of probability density for each population vector in the state-space of the stochastic reaction dynamics. For many examples of interest, this state-space is infinite, making it difficult to obtain exact solutions of the CME. To deal with this problem, the Finite State Projection (FSP) algorithm was developed by Munsky and Khammash [J. Chem. Phys. 124(4), 044104 (2006)], to provide approximate solutions to the CME by truncating the state-space. The FSP works well for finite time-periods but it cannot be used for estimating the stationary solutions of CMEs, which are often of interest in systems biology. The aim of this paper is to develop a version of FSP which we refer to as the stationary FSP (sFSP) that allows one to obtain accurate approximations of the stationary solutions of a CME by solving a finite linear-algebraic system that yields the stationary distribution of a continuous-time Markov chain over the truncated state-space. We derive bounds for the approximation error incurred by sFSP and we establish that under certain stability conditions, these errors can be made arbitrarily small by appropriately expanding the truncated state-space. We provide several examples to illustrate our sFSP method and demonstrate its efficiency in estimating the stationary distributions. In particular, we show that using a quantized tensor-train implementation of our sFSP method, problems admitting more than 100 × 106 states can be efficiently solved.

  17. A finite state projection algorithm for the stationary solution of the chemical master equation.

    Science.gov (United States)

    Gupta, Ankit; Mikelson, Jan; Khammash, Mustafa

    2017-10-21

    The chemical master equation (CME) is frequently used in systems biology to quantify the effects of stochastic fluctuations that arise due to biomolecular species with low copy numbers. The CME is a system of ordinary differential equations that describes the evolution of probability density for each population vector in the state-space of the stochastic reaction dynamics. For many examples of interest, this state-space is infinite, making it difficult to obtain exact solutions of the CME. To deal with this problem, the Finite State Projection (FSP) algorithm was developed by Munsky and Khammash [J. Chem. Phys. 124(4), 044104 (2006)], to provide approximate solutions to the CME by truncating the state-space. The FSP works well for finite time-periods but it cannot be used for estimating the stationary solutions of CMEs, which are often of interest in systems biology. The aim of this paper is to develop a version of FSP which we refer to as the stationary FSP (sFSP) that allows one to obtain accurate approximations of the stationary solutions of a CME by solving a finite linear-algebraic system that yields the stationary distribution of a continuous-time Markov chain over the truncated state-space. We derive bounds for the approximation error incurred by sFSP and we establish that under certain stability conditions, these errors can be made arbitrarily small by appropriately expanding the truncated state-space. We provide several examples to illustrate our sFSP method and demonstrate its efficiency in estimating the stationary distributions. In particular, we show that using a quantized tensor-train implementation of our sFSP method, problems admitting more than 100 × 10 6 states can be efficiently solved.

  18. 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...

  19. 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.

  20. 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)

  1. 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

  2. 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)

  3. An investigation of changes in element distribution and chemical states during differentiation of embryonic stem cells

    International Nuclear Information System (INIS)

    Sugimoto, T.; Ide-Ektessabi, A.; Ishihara, R.; Tanigaki, M.

    2004-01-01

    Metallic elements and their organic compounds have dynamic regulatory functions in cells. In this study, we implemented a new approach to investigate the mechanism of differentiation of embryonic stem cells, by measuring and analyzing the change in distribution and chemical states of intracellular trace elements. We anticipate that trace metal elements and metalloproteins play important roles in the direction of differentiation, both as active centers, and as factors in the death of neural cells in neurodegenerative disorders. The aim of this study is to analyze the distribution and chemical states of trace elements during the process of differentiation of mouse embryonic stem cells, and to understand how these factors relate to the differentiation process. Using the experimental results, some previously unexplained points are considered, namely (1) how the intracellular elements change during the process of neuronal differentiation, and (2) what the optimal conditions of such elements are for neuronal differentiation. The information obtained during this study is relevant to nervous system development and evolution

  4. An investigation of changes in element distribution and chemical states during differentiation of embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, T.; Ide-Ektessabi, A. E-mail: h51167@sakura.kudpc.kyoto-u.ac.jp; Ishihara, R.; Tanigaki, M

    2004-07-01

    Metallic elements and their organic compounds have dynamic regulatory functions in cells. In this study, we implemented a new approach to investigate the mechanism of differentiation of embryonic stem cells, by measuring and analyzing the change in distribution and chemical states of intracellular trace elements. We anticipate that trace metal elements and metalloproteins play important roles in the direction of differentiation, both as active centers, and as factors in the death of neural cells in neurodegenerative disorders. The aim of this study is to analyze the distribution and chemical states of trace elements during the process of differentiation of mouse embryonic stem cells, and to understand how these factors relate to the differentiation process. Using the experimental results, some previously unexplained points are considered, namely (1) how the intracellular elements change during the process of neuronal differentiation, and (2) what the optimal conditions of such elements are for neuronal differentiation. The information obtained during this study is relevant to nervous system development and evolution.

  5. Biodegradation of toxic chemicals by Pleurotus eryngii in submerged fermentation and solid-state fermentation.

    Science.gov (United States)

    Chang, Bea-Ven; Chang, Yi-Ming

    2016-04-01

    The toxic chemicals bisphenol A (BPA), bisphenol F (BPF), nonylphenol (NP), and tetrabromobisphenol A (TBBPA) are endocrine-disrupting chemicals that have consequently drawn much concern regarding their effect on the environment. The objectives of this study were to investigate the degradation of BPA, BPF, NP, and TBBPA by enzymes from Pleurotus eryngii in submerged fermentation (SmF) and solid-state fermentation (SSF), and also to assess the removal of toxic chemicals in spent mushroom compost (SMC). BPA and BPF were analyzed by high-performance liquid chromatography; NP and TBBPA were analyzed by gas chromatography. NP degradation was enhanced by adding CuSO4 (1 mM), MnSO4 (0.5 mM), gallic acid (1 mM), tartaric acid (20 mM), citric acid (20 mM), guaiacol (1 mM), or 2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid; 1 mM), with the last yielding a higher NP degradation rate than the other additives from SmF. The optimal conditions for enzyme activity from SSF were a sawdust/wheat bran ratio of 1:4 and a moisture content of 5 mL/g. The enzyme activities were higher with sawdust/wheat bran than with sawdust/rice bran. The optimal conditions for the extraction of enzyme from SMC required using sodium acetate buffer (pH 5.0, solid/solution ratio 1:5), and extraction over 3 hours. The removal rates of toxic chemicals by P. eryngii, in descending order of magnitude, were SSF > SmF > SMC. The removal rates were BPF > BPA > NP > TBBPA. Copyright © 2014. Published by Elsevier B.V.

  6. Comparative Demand Analysis for Rice in Three States of South ...

    African Journals Online (AJOL)

    Dauda Omoba

    However, combined application of 42g NPKMg compound fertilizer ... second to that of Soybean oil in terms of world .... assuming that free gravitational water would ..... by the action of micro-organisms. .... Analysis Part 3–Chemical Methods,.

  7. State of the Climate - Global Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The State of the Climate is a collection of periodic summaries recapping climate-related occurrences on both a global and national scale. The State of the Climate...

  8. Analysis of equations of state for ICF

    International Nuclear Information System (INIS)

    Ogando, F.; Velarde, P.

    1998-01-01

    In the field of inertial confinement fusion (ICF), numerical simulation plays a very important role reproducing real results with a good accuracy. Once considered the needed simplificative approximations, it is obtained and equation system that has to be solved in a more or less complex way. Anyway these simulation codes have to fit the behaviour of real materials with the help of some flexible parameters. In the case of fluid dynamics, the key to fit the equation system to the real material behaviour are the equations of state (EOS) involved in the problem. This is why there is an actual need of using accurate data in order to obtain results that match the real behaviour of materials. Nowadays there are several available sources of real EOS data. These sources are based either in theoretical models fixed with experimental results or in analytical approximations to those models. In this article a comparative analysis is made between two of the most used EOS data sources in simulations. The aim of this work is to check the quality of these data that is commonly used and on which the accuracy of the results depend. (Author) 3 refs

  9. 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.

  10. 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

  11. 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

  12. 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

  13. Recurrence quantification analysis of chimera states

    International Nuclear Information System (INIS)

    Santos, M.S.; Szezech, J.D.; Batista, A.M.; Caldas, I.L.; Viana, R.L.; Lopes, S.R.

    2015-01-01

    Chimera states, characterised by coexistence of coherence and incoherence in coupled dynamical systems, have been found in various physical systems, such as mechanical oscillator networks and Josephson-junction arrays. We used recurrence plots to provide graphical representations of recurrent patterns and identify chimera states. Moreover, we show that recurrence plots can be used as a diagnostic of chimera states and also to identify the chimera collapse. - Highlights: • Chimera states have been found in various physical systems. • Recurrence plots is a graphical method useful to locate recurring patterns. • We used recurrence plots to identify the chimera states. • We show also the recurrence plots can identify the chimera collapse

  14. Recurrence quantification analysis of chimera states

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.S. [Pós-Graduação em Ciências/Física, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Szezech, J.D., E-mail: jdanilo@gmail.com [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Batista, A.M., E-mail: antoniomarcosbatista@gmail.com [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Caldas, I.L. [Instituto de Física, Universidade de São Paulo, 05315-970, São Paulo, SP (Brazil); Viana, R.L.; Lopes, S.R. [Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, PR (Brazil)

    2015-10-02

    Chimera states, characterised by coexistence of coherence and incoherence in coupled dynamical systems, have been found in various physical systems, such as mechanical oscillator networks and Josephson-junction arrays. We used recurrence plots to provide graphical representations of recurrent patterns and identify chimera states. Moreover, we show that recurrence plots can be used as a diagnostic of chimera states and also to identify the chimera collapse. - Highlights: • Chimera states have been found in various physical systems. • Recurrence plots is a graphical method useful to locate recurring patterns. • We used recurrence plots to identify the chimera states. • We show also the recurrence plots can identify the chimera collapse.

  15. Methods used to characterize the chemical composition and biological activity of environmental waters throughout the United States, 2012-14

    Science.gov (United States)

    Romanok, Kristin M.; Reilly, Timothy J.; Barber, Larry B.; Boone, J. Scott; Buxton, Herbert T.; Foreman, William T.; Furlong, Edward T.; Hladik, Michelle; Iwanowicz, Luke R.; Journey, Celeste A.; Kolpin, Dana W.; Kuivila, Kathryn; Loftin, Keith A.; Mills, Marc A.; Meyer, Michael T.; Orlando, James L.; Smalling, Kelly L.; Villeneuve, Daniel L.; Bradley, Paul M.

    2017-03-22

    A vast array of chemical compounds are in wide commercial use in the United States, and the potential ecological and human-health effect of exposure to chemical mixtures has been identified as a high priority in environment health science. Awareness of the potential effects of low-level chemical exposures is rising. The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, conducted a study in which samples were collected from 38 streams in 25 States to provide an overview of contaminants found in stream water across the Nation. Additionally, biological screening assays were used to help determine any potential ecological and human-health effects of these chemical mixtures and to prioritize target chemicals for future toxicological studies. This report describes the site locations and the sampling and analytical methods and quality-assurance procedures used in the study.

  16. 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.

  17. 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.)

  18. 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.

  19. 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.

  20. Chemically durable polymer electrolytes for solid-state alkaline water electrolysis

    Science.gov (United States)

    Park, Eun Joo; Capuano, Christopher B.; Ayers, Katherine E.; Bae, Chulsung

    2018-01-01

    Generation of high purity hydrogen using electrochemical splitting of water is one of the most promising methods for sustainable fuel production. The materials to be used as solid-state electrolytes for alkaline water electrolyzer require high thermochemical stability against hydroxide ion attack in alkaline environment during the operation of electrolysis. In this study, two quaternary ammonium-tethered aromatic polymers were synthesized and investigated for anion exchange membrane (AEM)-based alkaline water electrolyzer. The membranes properties including ion exchange capacity (IEC), water uptake, swelling degree, and anion conductivity were studied. The membranes composed of all C-C bond polymer backbones and flexible side chain terminated by cation head groups exhibited remarkably good chemical stability by maintaining structural integrity in 1 M NaOH solution at 95 °C for 60 days. Initial electrochemical performance and steady-state operation performance were evaluated, and both membranes showed a good stabilization of the cell voltage during the steady-state operation at the constant current density at 200 mA/cm2. Although both membranes in current form require improvement in mechanical stability to afford better durability in electrolysis operation, the next generation AEMs based on this report could lead to potentially viable AEM candidates which can provide high electrolysis performance under alkaline operating condition.

  1. Spiral wave chimera states in large populations of coupled chemical oscillators

    Science.gov (United States)

    Totz, Jan Frederik; Rode, Julian; Tinsley, Mark R.; Showalter, Kenneth; Engel, Harald

    2018-03-01

    The coexistence of coherent and incoherent dynamics in a population of identically coupled oscillators is known as a chimera state1,2. Discovered in 20023, this counterintuitive dynamical behaviour has inspired extensive theoretical and experimental activity4-15. The spiral wave chimera is a particularly remarkable chimera state, in which an ordered spiral wave rotates around a core consisting of asynchronous oscillators. Spiral wave chimeras were theoretically predicted in 200416 and numerically studied in a variety of systems17-23. Here, we report their experimental verification using large populations of nonlocally coupled Belousov-Zhabotinsky chemical oscillators10,18 in a two-dimensional array. We characterize previously unreported spatiotemporal dynamics, including erratic motion of the asynchronous spiral core, growth and splitting of the cores, as well as the transition from the chimera state to disordered behaviour. Spiral wave chimeras are likely to occur in other systems with long-range interactions, such as cortical tissues24, cilia carpets25, SQUID metamaterials26 and arrays of optomechanical oscillators9.

  2. 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.

  3. 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…

  4. 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 ...

  5. 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...

  6. Matching Element Symbols with State Abbreviations: A Fun Activity for Browsing the Periodic Table of Chemical Elements

    Science.gov (United States)

    Woelk, Klaus

    2009-01-01

    A classroom activity is presented in which students are challenged to find matches between the United States two-letter postal abbreviations for states and chemical element symbols. The activity aims to lessen negative apprehensions students might have when the periodic table of the elements with its more than 100 combinations of letters is first…

  7. Evaluation study between the chemical and electrochemical etching for solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Ramos, S.; Espinosa, G.; Golzarri, J.I.

    1991-01-01

    Since there are several methods of etching in the solid state nuclear track detectors (SSNTD) it is necessary to know which gives the best results for a specific problem. The purpose of this work is to analyze and compare both the chemical etching and the electrochemical etching. The SSNTD has a preferential response to certain kinds of particles and energies, according to the material used as detector. On the other hand the efficiency is a function of the incidence angle of the radiation and some other parameters such as temperature, concentration and type of solvent used in the etching process, and the method used for the etching. Therefore, it is necessary to extend as much as possible our knowledge of such parameters in order to choose the more efficient one for a specific problem

  8. Development of an Electrolyte CPA Equation of state for Applications in the Petroleum and Chemical Industries

    DEFF Research Database (Denmark)

    Maribo-Mogensen, Bjørn

    to the CPA EoS in the absence of electrolytes, making it possible to extend the applicability of the CPA EoS while retaining backwards compatibility and resuing the parameters for non-electrolyte systems . There are many challenges related to thermodynamic modeling of mixtures containing electrolytes......This thesis extends the Cubic Plus Association (CPA) equation of state (EoS) to handle mixtures containing ions from fully dissociated salts. The CPA EoS has during the past 18 years been applied to thermodynamic modeling of a wide range of industrially important chemicals, mainly in relation...... rarely been applied to all types of thermodynamic equilibrium calculations relevant to electrolyte solutions. This project has aimed to determine the best recipe to deliver a complete thermodynamic model capable of handling electrolytes in mixed solvents and at a wide range of temperature and pressure...

  9. A computational approach to extinction events in chemical reaction networks with discrete state spaces.

    Science.gov (United States)

    Johnston, Matthew D

    2017-12-01

    Recent work of Johnston et al. has produced sufficient conditions on the structure of a chemical reaction network which guarantee that the corresponding discrete state space system exhibits an extinction event. The conditions consist of a series of systems of equalities and inequalities on the edges of a modified reaction network called a domination-expanded reaction network. In this paper, we present a computational implementation of these conditions written in Python and apply the program on examples drawn from the biochemical literature. We also run the program on 458 models from the European Bioinformatics Institute's BioModels Database and report our results. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Analysis of dried fish marketing in Kwara State, Nigeria. | Fadipe ...

    African Journals Online (AJOL)

    Analysis of dried fish marketing in Kwara State, Nigeria. ... This study was carried out to examine marketing of dried fish in Kwara State, Nigeria. The study used a combination of information ... Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

  11. Analysis of fresh maize marketing in Anambra state, Nigeria ...

    African Journals Online (AJOL)

    Analysis of fresh maize marketing in Anambra state, Nigeria. ... on marketing income in Anambra State, this study utilized descriptive statistic, Sherpherd-futrel model of determining marketing efficiency ... EMAIL FULL TEXT EMAIL FULL TEXT

  12. Prediction of monomer reactivity in radical copolymerizations from transition state quantum chemical descriptors

    Directory of Open Access Journals (Sweden)

    Zhengde Tan

    2013-01-01

    Full Text Available In comparison with the Q-e scheme, the Revised Patterns Scheme: the U, V Version (the U-V scheme has greatly improved both its accessibility and its accuracy in interpreting and predicting the reactivity of a monomer in free-radical copolymerizations. Quantitative structure-activity relationship (QSAR models were developed to predict the reactivity parameters u and v of the U-V scheme, by applying genetic algorithm (GA and support vector machine (SVM techniques. Quantum chemical descriptors used for QSAR models were calculated from transition state species with structures C¹H3 - C²HR³• or •C¹H2 - C²H2R³ (formed from vinyl monomers C¹H²=C²HR³ + H•, using density functional theory (DFT, at the UB3LYP level of theory with 6-31G(d basis set. The optimum support vector regression (SVR model of the reactivity parameter u based on Gaussian radial basis function (RBF kernel (C = 10, ε = 10- 5 and γ = 1.0 produced root-mean-square (rms errors for the training, validation and prediction sets being 0.220, 0.326 and 0.345, respectively. The optimal SVR model for v with the RBF kernel (C = 20, ε = 10- 4 and γ = 1.2 produced rms errors for the training set of 0.123, the validation set of 0.206 and the prediction set of 0.238. The feasibility of applying the transition state quantum chemical descriptors to develop SVM models for reactivity parameters u and v in the U-V scheme has been demonstrated.

  13. Thermodynamic analysis of processes proceeding on (111) faces of diamond during chemical vapour deposition

    International Nuclear Information System (INIS)

    Piekarczyk, W.; Prawer, S.

    1992-01-01

    Chemically vapour deposited diamond is commonly synthesized from activated hydrogen-rich, carbon/hydrogen gas mixtures under conditions which should, from a thermodynamic equilibrium point of view, favour the production of graphite. Much remains to be understood about why diamond, and not graphite, forms under these conditions. However, it is well known that the presence of atomic hydrogen, is crucial to the success of diamond deposition. As part of an attempt to better understand the deposition process, a thermodynamic analysis of the process was performed on diamond (111) faces in hydrogen rich environments. It is shown that the key role of atomic hydrogen is to inhibit the reconstruction of the (111) face to an sp 2 -bonded structure, which would provide a template for graphite, rather than diamond formation. The model correctly predicts experimentally determined trends in growth rate and diamond film quality as a function of methane concentration in the stating gas mixture. 17 refs., 4 figs

  14. Nuclear and radiochemical techniques in chemical analysis. Progress report, June 1, 1975--July 31, 1976

    International Nuclear Information System (INIS)

    Finston, H.L.; Williams, E.T.

    1976-01-01

    There has been significant progress on the project to measure the neutron-capture cross sections of reactor produced radionuclides, in particular, centering on the problems with nuclides such as 22 Na which may have a resonance for thermal-neutron capture. The thermal capture cross section of less than 40 b has been verified for 54 Mn, and cadmium ratios have been determined for 184 Re in the V-11 and V-14 positions in the HFBR. Lutetium has been used as a neutron temperature monitor for the Brookhaven reactors. Preliminary results on the project to determine the effect of chemical state on the branching ratio in 58 Co are reported. Procedures for aerosol collection and analysis by proton-induced x-ray emission (PIXE) are reported. A program to analyze aerosols for polycyclic aromatic hydrocarbons has been initiated. Progress is reported on the experimental verification of the proposed acid-base hypothesis

  15. State-Recovery Analysis of Spritz

    DEFF Research Database (Denmark)

    Ankele, Ralph; Kölbl, Stefan; Rechberger, Christian

    2015-01-01

    evidence that they may exist, the situation for Spritz is however not clear, as resistance against such attacks was not a design goal. In this paper, we provide the first cryptanalytic results on Spritz and introduce three different state recovery algorithms. Our first algorithm recovers an internal state...

  16. 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.

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

    Science.gov (United States)

    Childhood obesity is not a new notion but it is a growing epidemic around the world. There is approximately 42 million children under 5 around the world who are considered overweight or obese and here in the united states that is 12.7 million children between the ages of 2 and 19...

  18. 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

  19. Diversity of Chemical Bonding and Oxidation States in MS4 Molecules of Group 8 Elements.

    Science.gov (United States)

    Huang, Wei; Jiang, Ning; Schwarz, W H Eugen; Yang, Ping; Li, Jun

    2017-08-04

    The geometric and electronic ground-state structures of 30 isomers of six MS 4 molecules (M=Group 8 metals Fe, Ru, Os, Hs, Sm, and Pu) have been studied by using quantum-chemical density functional theory and correlated wavefunction approaches. The MS 4 species were compared to analogous MO 4 species recently investigated (W. Huang, W.-H. Xu, W. H. E. Schwarz, J. Li, Inorg. Chem. 2016, 55, 4616). A metal oxidation state (MOS) with a high value of eight appeared in the low-spin singlet T d geometric species (Os,Hs)S 4 and (Ru,Os,Hs)O 4 , whereas a low MOS of two appeared in the high-spin septet D 2d species Fe(S 2 ) 2 and (slightly excited) metastable Fe(O 2 ) 2 . The ground states of all other molecules had intermediate MOS values, with S 2- , S 2 2- , S 2 1- (and O 2- , O 1- , O 2 2- , O 2 1- ) ligands bonded by ionic, covalent, and correlative contributions. The known tendencies toward lower MOS on going from oxides to sulfides, from Hs to Os to Ru, and from Pu to Sm, and the specific behavior of Fe, were found to arise from the different atomic orbital energies and radii of the (n-1)p core and (n-1)d and (n-2)f valence shells of the metal atoms in row n of the periodic table. The comparative results of the electronic and geometric structures of the MO 4 and MS 4 species provides insight into the periodicity of oxidation states and bonding. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Determination of chemical state of Al doping element in ZnO layer

    International Nuclear Information System (INIS)

    Csik, A.; Toth, J.; Lovics, R.; Takats, V.; Hakl, J.; Vad, K.

    2011-01-01

    Complete text of publication follows. Transparent and conducting oxides (TCO) thin films are very important from the scientific and technological point of view. The coexistence of electrical conductivity and optical transparency in these materials makes it possible to use them in modern technologies: transparent electrodes for flat panel displays and photovoltaic cells, low emissivity windows, transparent thin films transistors, light emitting diodes. One of the important TCO semiconductors is the impurity-doped zinc-oxide (ZnO) layer, for example aluminium doped zinc-oxide layer (AZO), due to its unique physical and chemical properties. It has wide band gap (3.44 eV) and large exciton binding energy (60 meV). ZnO thin layers have a great interest for potential applications in optical and optoelectronic devices. Furthermore, high quality single crystal ZnO wafers has already been available as a result of new developments in ZnO growth technologies with the capability to scale up wafer size, which is an important factor for increasing efficiency of solar cells. Nonetheless, in order to enable the use of ZnO layers with enhanced electrical properties, higher conductivities can be obtained by doping with donor elements such as aluminium, gallium, indium, boron or fluorine. Investigation of p-type doping possibilities, diffusion processes and thermal stability of these layers are in the focus of interest in the interpretation of their optical and electrical properties, and the prediction of their lifetime. In our SNMS/SIMS-XPS laboratory, experiments on TCO layered structures were carried on. Depth profile and chemical state analyses of ZnO/AlO/ZnO layered structures were performed by Secondary Neutral Mass Spectrometry (SNMS) and X-ray photoelectron spectroscopy (XPS). The samples were produced by atomic layer deposition technique with the following layered structure: between a few hundred atomic layers of ZnO was an AlO atomic layer. The SNMS was used for depth

  1. 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.

  2. Potential external contamination with bisphenol A and other ubiquitous organic environmental chemicals during biomonitoring analysis: an elusive laboratory challenge.

    Science.gov (United States)

    Ye, Xiaoyun; Zhou, Xiaoliu; Hennings, Ryan; Kramer, Joshua; Calafat, Antonia M

    2013-03-01

    Biomonitoring studies are conducted to assess internal dose (i.e., body burden) to environmental chemicals. However, because of the ubiquitous presence in the environment of some of these chemicals, such as bisphenol A (BPA), external contamination during handling and analysis of the biospecimens collected for biomonitoring evaluations could compromise the reported concentrations of such chemicals. We examined the contamination with the target analytes during analysis of biological specimens in biomonitoring laboratories equipped with state-of-the-art analytical instrumentation. We present several case studies using the quantitative determination of BPA and other organic chemicals (i.e., benzophenone-3, triclosan, parabens) in human urine, milk, and serum to identify potential contamination sources when the biomarkers measured are ubiquitous environmental contaminants. Contamination with target analytes during biomonitoring analysis could result from solvents and reagents, the experimental apparatus used, the laboratory environment, and/or even the analyst. For biomonotoring data to be valid-even when obtained from high-quality analytical methods and good laboratory practices-the following practices must be followed to identify and track unintended contamination with the target analytes during analysis of the biological specimens: strict quality control measures including use of laboratory blanks; replicate analyses; engineering controls (e.g., clean rooms, biosafety cabinets) as needed; and homogeneous matrix-based quality control materials within the expected concentration ranges of the study samples.

  3. Chromatography and mass spectrometry of chemical warfare agents, toxins and related compounds: state of the art and future prospects

    NARCIS (Netherlands)

    Kientz, C.E.

    1998-01-01

    Methods for the identification of chemical warfare agents, toxins, bioregulators and related products are frequently reported in literature. These methods are often based on instrumental analysis using chromatography (gas and liquid) and mass spectrometry. Here, these instrumental techniques are

  4. Analysis of United States' Broadband Policy

    National Research Council Canada - National Science Library

    Uzarski, Joel S

    2007-01-01

    .... With every month that passes, the United States fails to close the gap in the digital divide both inside its borders as well as among the other countries that lead the world in broadband penetration...

  5. Use of thermogravimetry on rational analysis of clay minerals from state of Mato Grosso do Sul

    International Nuclear Information System (INIS)

    Salvetti, Alfredo Roque; Rodrigues, Henrique Mauro

    1997-01-01

    The rational analysis on clay minerals, normally uses as structural water, the mass loss by firing. The presence of organic materials, sulphur or others minerals, can cause an error on quantification of structural water. With the use of thermal gravimetric analysis, we can calculate, in a more precise way, the quantity of mass loss by dehydroxylation, without take into account the loss of mass from others process. We compared the rational chemical analysis on some clay minerals from state of Mato Grosso do Sul using burning loss and thermal gravimetric analysis. (author)

  6. Practical use of chemical shift databases for protein solid-state NMR: 2D chemical shift maps and amino-acid assignment with secondary-structure information

    International Nuclear Information System (INIS)

    Fritzsching, K. J.; Yang, Y.; Schmidt-Rohr, K.; Hong Mei

    2013-01-01

    We introduce a Python-based program that utilizes the large database of 13 C and 15 N chemical shifts in the Biological Magnetic Resonance Bank to rapidly predict the amino acid type and secondary structure from correlated chemical shifts. The program, called PACSYlite Unified Query (PLUQ), is designed to help assign peaks obtained from 2D 13 C– 13 C, 15 N– 13 C, or 3D 15 N– 13 C– 13 C magic-angle-spinning correlation spectra. We show secondary-structure specific 2D 13 C– 13 C correlation maps of all twenty amino acids, constructed from a chemical shift database of 262,209 residues. The maps reveal interesting conformation-dependent chemical shift distributions and facilitate searching of correlation peaks during amino-acid type assignment. Based on these correlations, PLUQ outputs the most likely amino acid types and the associated secondary structures from inputs of experimental chemical shifts. We test the assignment accuracy using four high-quality protein structures. Based on only the Cα and Cβ chemical shifts, the highest-ranked PLUQ assignments were 40–60 % correct in both the amino-acid type and the secondary structure. For three input chemical shifts (CO–Cα–Cβ or N–Cα–Cβ), the first-ranked assignments were correct for 60 % of the residues, while within the top three predictions, the correct assignments were found for 80 % of the residues. PLUQ and the chemical shift maps are expected to be useful at the first stage of sequential assignment, for combination with automated sequential assignment programs, and for highly disordered proteins for which secondary structure analysis is the main goal of structure determination.

  7. Practical use of chemical shift databases for protein solid-state NMR: 2D chemical shift maps and amino-acid assignment with secondary-structure information

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsching, K. J.; Yang, Y.; Schmidt-Rohr, K.; Hong Mei, E-mail: mhong@iastate.edu [Iowa State University, Department of Chemistry (United States)

    2013-06-15

    We introduce a Python-based program that utilizes the large database of {sup 13}C and {sup 15}N chemical shifts in the Biological Magnetic Resonance Bank to rapidly predict the amino acid type and secondary structure from correlated chemical shifts. The program, called PACSYlite Unified Query (PLUQ), is designed to help assign peaks obtained from 2D {sup 13}C-{sup 13}C, {sup 15}N-{sup 13}C, or 3D {sup 15}N-{sup 13}C-{sup 13}C magic-angle-spinning correlation spectra. We show secondary-structure specific 2D {sup 13}C-{sup 13}C correlation maps of all twenty amino acids, constructed from a chemical shift database of 262,209 residues. The maps reveal interesting conformation-dependent chemical shift distributions and facilitate searching of correlation peaks during amino-acid type assignment. Based on these correlations, PLUQ outputs the most likely amino acid types and the associated secondary structures from inputs of experimental chemical shifts. We test the assignment accuracy using four high-quality protein structures. Based on only the C{alpha} and C{beta} chemical shifts, the highest-ranked PLUQ assignments were 40-60 % correct in both the amino-acid type and the secondary structure. For three input chemical shifts (CO-C{alpha}-C{beta} or N-C{alpha}-C{beta}), the first-ranked assignments were correct for 60 % of the residues, while within the top three predictions, the correct assignments were found for 80 % of the residues. PLUQ and the chemical shift maps are expected to be useful at the first stage of sequential assignment, for combination with automated sequential assignment programs, and for highly disordered proteins for which secondary structure analysis is the main goal of structure determination.

  8. Analysis of the trend to equilibrium of a chemically reacting system

    International Nuclear Information System (INIS)

    Kremer, Gilberto M; Bianchi, Miriam Pandolfi; Soares, Ana Jacinta

    2007-01-01

    In this present paper, a quaternary gaseous reactive mixture, for which the chemical reaction is close to its final stage and the elastic and reactive frequencies are comparable, is modelled within the Boltzmann equation extended to reacting gases. The main objective is a detailed analysis of the non-equilibrium effects arising in the reactive system A 1 + A 2 ↔ A 3 + A 4 , in a flow regime which is considered not far away from thermal, mechanical and chemical equilibrium. A first-order perturbation solution technique is applied to the macroscopic field equations for the spatially homogeneous gas system, and the trend to equilibrium is studied in detail. Adopting elastic hard-spheres and reactive line-of-centres cross sections and an appropriate choice of the input distribution functions-which allows us to distinguish the two cases where the constituents are either at same or different temperatures-explicit computations of the linearized production terms for mass, momentum and total energy are performed for each gas species. The departures from the equilibrium states of densities, temperatures and diffusion fluxes are characterized by small perturbations of their corresponding equilibrium values. For the hydrogen-chlorine system, the perturbations are plotted as functions of time for both cases where the species are either at the same or different temperatures. Moreover, the trend to equilibrium of the reaction rates is represented for the forward and backward reaction H 2 + Cl ↔ HCl + H

  9. 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

  10. 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).

  11. 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,…

  12. 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

  13. 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)

  14. 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...

  15. 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

  16. 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.

  17. 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...

  18. 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...

  19. Realisation and crossed molecular beams study of H2/O chemical reactions at several excited states

    International Nuclear Information System (INIS)

    Marx, Jacqueline

    1986-01-01

    This work is devoted to the study of the reactive collision O + H 2 OH + H in a crossed beam experiment. This process including several channels taken a part in the chemistry of the upper atmosphere as well as in the combustion of hydrogen. According to the electronic or vibrational state of the reactants, the OH radical is produced in its ground electronic state OH (X 2 π) or in its first excited state OH (A 2 Σ + ). When the reactants are in their ground state, the reaction is endothermic in the conditions of the experiment (center of mass kinetic energy ≅ 0.12 eV). The following reactions have been obtained: O( 1 D) +H 2 (v=O) → OH (X 2 π) +H( 2 S) and O( 1 D) +H 2 (v≥5) → OH (A 2 Σ + ) +H( 2 S). The atomic oxygen is produced in its excited state O( 1 D) in a radio-frequency discharge which dissociates the molecular oxygen seeded in a carrier gas (He or Ar) and the hydrogen molecules are excited vibrationally by electron bombardment. The first reaction is studied by time-of-flight measurements. In this way, it has been possible to observe the different vibrational levels on which the OH radical is produced. The analysis of this vibrational distribution shows the competition between the abstraction and insertion-dissociation mechanisms. In the second reaction, the analysis of the spontaneous fluorescence of OH (A 2 Σ + ) reveals a very hot and non-Boltzmann rotational excitation. (author) [fr

  20. 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.

  1. 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.

  2. Dendrogeomorphology in landslide analysis: State of art

    Energy Technology Data Exchange (ETDEWEB)

    Margottini, C [ENEA, Casaccia (Italy). Area Energia Ambiente e Salute; Fantucci, R

    1994-01-01

    This article summarizes the uses of dendrogeomorphological techniques in landslide analysis. It shows how to study different landslides events through the analysis of living trees. Living trees record any slope inclination variation as if they were natural inclinometers moreover they can be used to date landslide and their stabilization process with time.

  3. 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.

  4. Chemical or Biological Terrorist Attacks: An Analysis of the Preparedness of Hospitals for Managing Victims Affected by Chemical or Biological Weapons of Mass Destruction

    Science.gov (United States)

    Bennett, Russell L.

    2006-01-01

    The possibility of a terrorist attack employing the use of chemical or biological weapons of mass destruction (WMD) on American soil is no longer an empty threat, it has become a reality. A WMD is defined as any weapon with the capacity to inflict death and destruction on such a massive scale that its very presence in the hands of hostile forces is a grievous threat. Events of the past few years including the bombing of the World Trade Center in 1993, the Murrah Federal Building in Oklahoma City in 1995 and the use of planes as guided missiles directed into the Pentagon and New York’s Twin Towers in 2001 (9/11) and the tragic incidents involving twenty-three people who were infected and five who died as a result of contact with anthrax-laced mail in the Fall of 2001, have well established that the United States can be attacked by both domestic and international terrorists without warning or provocation. In light of these actions, hospitals have been working vigorously to ensure that they would be “ready” in the event of another terrorist attack to provide appropriate medical care to victims. However, according to a recent United States General Accounting Office (GAO) nationwide survey, our nation’s hospitals still are not prepared to manage mass causalities resulting from chemical or biological WMD. Therefore, there is a clear need for information about current hospital preparedness in order to provide a foundation for systematic planning and broader discussions about relative cost, probable effectiveness, environmental impact and overall societal priorities. Hence, the aim of this research was to examine the current preparedness of hospitals in the State of Mississippi to manage victims of terrorist attacks involving chemical or biological WMD. All acute care hospitals in the State were selected for inclusion in this study. Both quantitative and qualitative methods were utilized for data collection and analysis. Six hypotheses were tested. Using a

  5. Chemical disorder influence on magnetic state of optimally-doped La0.7Ca0.3MnO3

    Science.gov (United States)

    Rozenberg, E.; Auslender, M.; Shames, A. I.; Jung, G.; Felner, I.; Tsindlekht, M. I.; Mogilyansky, D.; Sominski, E.; Gedanken, A.; Mukovskii, Ya. M.; Gorodetsky, G.

    2011-10-01

    X-band electron magnetic resonance and dc/ac magnetic measurements have been employed to study the effects of chemical disorder on magnetic ordering in bulk and nanometer-sized single crystals and bulk ceramics of optimally-doped La0.7Ca0.3MnO3 manganite. The magnetic ground state of bulk samples appeared to be ferromagnetic with the lower Curie temperature and higher magnetic homogeneity in the vicinity of the ferromagnetic-paramagnetic phase transition in the crystal, as compared with those characteristics in the ceramics. The influence of technological driven "macroscopic" fluctuations of Ca-dopant level in crystal and "mesoscopic" disorder within grain boundary regions in ceramics was proposed to be responsible for these effects. Surface spin disorder together with pronounced inter-particle interactions within agglomerated nano-sample results in well defined core/shell spin configuration in La0.7Ca0.3MnO3 nano-crystals. The analysis of the electron paramagnetic resonance data enlightened the reasons for the observed difference in the magnetic order. Lattice effects dominate the first-order nature of magnetic phase transition in bulk samples. However, mesoscale chemical disorder seems to be responsible for the appearance of small ferromagnetic polarons in the paramagnetic state of bulk ceramics. The experimental results and their analysis indicate that a chemical/magnetic disorder has a strong impact on the magnetic state even in the case of mostly stable optimally hole-doped manganites.

  6. Chemical composition, mixing state, size and morphology of Ice nucleating particles at the Jungfraujoch research station, Switzerland

    Science.gov (United States)

    Ebert, Martin; Worringen, Annette; Kandler, Konrad; Weinbruch, Stephan; Schenk, Ludwig; Mertes, Stephan; Schmidt, Susan; Schneider, Johannes; Frank, Fabian; Nilius, Björn; Danielczok, Anja; Bingemer, Heinz

    2014-05-01

    An intense field campaign from the Ice Nuclei Research Unit (INUIT) was performed in January and February of 2013 at the High-Alpine Research Station Jungfraujoch (3580 m a.s.l., Switzerland). Main goal was the assessment of microphysical and chemical properties of free-tropospheric ice-nucelating particles. The ice-nucleating particles were discriminated from the total aerosol with the 'Fast Ice Nucleation CHamber' (FINCH; University Frankfurt) and the 'Ice-Selective Inlet' (ISI, Paul Scherer Institute) followed by a pumped counter-stream virtual impactor. The separated ice-nucleating particles were then collected with a nozzle-type impactor. With the 'FRankfurt Ice nuclei Deposition freezinG Experiment' (FRIDGE), aerosol particles are sampled on a silicon wafer, which is than exposed to ice-activating conditions in a static diffusion chamber. The locations of the growing ice crystals are recorded for later analysis. Finally, with the ICE Counter-stream Virtual Impactor (ICE-CVI) atmospheric ice crystals are separated from the total aerosol and their water content is evaporated to retain the ice residual particles, which are then collected also by impactor sampling. All samples were analyzed in a high-resolution scanning electron microscope. By this method, for each particle its size, morphology, mixing-state and chemical composition is obtained. In total approximately 1700 ice nucleating particles were analyzed. Based on their chemical composition, the particles were classified into seven groups: silicates, metal oxides, Ca-rich particles, (aged) sea-salt, soot, sulphates and carbonaceous matter. Sea-salt is considered as artifact and is not regarded as ice nuclei here. The most frequent ice nucleating particles/ice residuals at the Jungfraujoch station are silicates > carbonaceous particles > metal oxides. Calcium-rich particles and soot play a minor role. Similar results are obtained by quasi-parallel measurements with an online single particle laser ablation

  7. Chemical analysis of DC745 Materials: DEV Lot 1 reinvestigation; barcodes P053387, P053388, and P053389

    Energy Technology Data Exchange (ETDEWEB)

    Dirmyer, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-09

    This report serves as a follow up to our initial development lot 1 chemical analysis report (LA-UR-16-21970). The purpose of that report was to determine whether or not certain combinations of resin lots and curing agent lots resulted in chemical differences in the final material. One finding of that report suggested that pad P053389 was different from the three other pads analyzed. This report consists of chemical analysis of P053387, P053388, and a reinvestigation of P053389 all of which came from the potentially suspect combination of resin and curing agents lot. The goal of this report is to determine whether the observations relating to P053389 were isolated to that particular pad or systemic to that combination of resin and curing agent lot. The following suite of analyses were performed on the pads: Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR), and Solid State Nuclear Magnetic Resonance (NMR). The overall conclusions of the study are that pads P053387 and P053388 behave more consistently with the pads of other resin lot and curing agent lot combinations and that the chemical observations made regarding pad P053389 are isolated to that pad and not representative of an issue with that resin lot and curing agent lot combination.

  8. 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

  9. 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.

  10. 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...

  11. 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

  12. 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....

  13. Analysis of Some Clay Samples from Yauri (Kebbi State), Goronyo ...

    African Journals Online (AJOL)

    Analysis of some clay samples presumed to be kaolin obtained from different deposits in Yauri (kebbi state), Goronyo, Munwadata, Atokonyo (Sokoto state), Nigeria was carried out. The samples were subjected to quantitative analysis to determine major and trace constituents using gravimetric, colorimetric, titrimetric and ...

  14. State Analysis: A Control Architecture View of Systems Engineering

    Science.gov (United States)

    Rasmussen, Robert D.

    2005-01-01

    A viewgraph presentation on the state analysis process is shown. The topics include: 1) Issues with growing complexity; 2) Limits of common practice; 3) Exploiting a control point of view; 4) A glimpse at the State Analysis process; 5) Synergy with model-based systems engineering; and 6) Bridging the systems to software gap.

  15. In Situ Solid-State Reactions Monitored by X-ray Absorption Spectroscopy: Temperature-Induced Proton Transfer Leads to Chemical Shifts.

    Science.gov (United States)

    Stevens, Joanna S; Walczak, Monika; Jaye, Cherno; Fischer, Daniel A

    2016-10-24

    The dramatic colour and phase alteration with the solid-state, temperature-dependent reaction between squaric acid and 4,4'-bipyridine has been probed in situ with X-ray absorption spectroscopy. The electronic and chemical sensitivity to the local atomic environment through chemical shifts in the near-edge X-ray absorption fine structure (NEXAFS) revealed proton transfer from the acid to the bipyridine base through the change in nitrogen protonation state in the high-temperature form. Direct detection of proton transfer coupled with structural analysis elucidates the nature of the solid-state process, with intermolecular proton transfer occurring along an acid-base chain followed by a domino effect to the subsequent acid-base chains, leading to the rapid migration along the length of the crystal. NEXAFS thereby conveys the ability to monitor the nature of solid-state chemical reactions in situ, without the need for a priori information or long-range order. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. 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.

  17. 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.

  18. ASAP: An Extensible Platform for State Space Analysis

    DEFF Research Database (Denmark)

    Westergaard, Michael; Evangelista, Sami; Kristensen, Lars Michael

    2009-01-01

    The ASCoVeCo State space Analysis Platform (ASAP) is a tool for performing explicit state space analysis of coloured Petri nets (CPNs) and other formalisms. ASAP supports a wide range of state space reduction techniques and is intended to be easy to extend and to use, making it a suitable tool fo...... for students, researchers, and industrial users that would like to analyze protocols and/or experiment with different algorithms. This paper presents ASAP from these two perspectives....

  19. Pathway analysis: State of the art

    Directory of Open Access Journals (Sweden)

    Miguel Angel eGarcía-Campos

    2015-12-01

    Full Text Available Pathway analysis is a set of widely used tools for research in life sciences intended to give meaning to high-throughput biological data. The methodology of these tools settles in the gathering and usage of knowledge that comprise biomolecular functioning, coupled with statistical testing and other algorithms. Despite their wide employment, pathway analysis foundations and overall background may not be fully understood, leading to misinterpretation of analysis results. This review attempts to comprise the fundamental knowledge to take into consideration when using pathway analysis as a hypothesis generation tool. We discuss the key elements that are part of these methodologies, their capabilities and current deficiencies. We also present an overview of current and all-time popular methods, highlighting different classes across them. In doing so, we show the exploding diversity of methods that pathway analysis encompasses, point out commonly overlooked caveats, and direct attention to a potential new class of methods that attempt to zoom the analysis scope to the sample scale.

  20. State space analysis of minimal channel flow

    Energy Technology Data Exchange (ETDEWEB)

    Neelavara, Shreyas Acharya; Duguet, Yohann; Lusseyran, François, E-mail: acharya@limsi.fr [LIMSI-CNRS, Campus Universitaire d’Orsay, Université Paris-Saclay, F-91405 Orsay (France)

    2017-06-15

    Turbulence and edge states are investigated numerically in a plane Poiseuille flow driven by a fixed pressure gradient. Simulations are carried out within the minimal flow unit, a concept introduced by Jiménez and Moin (1991 J . Fluid Mech. 225 213–40) to unravel the dynamics of near-wall structures in the absence of outer large-scale motions. For both turbulent and edge regimes the activity appears to be localised near only one wall at a time, and the long term dynamics features abrupt reversals. The dynamics along one reversal is structured around the transient visit to a subspace of symmetric flow fields. An exact travelling wave solution is found to exist very close to this subspace. Additionally the self-similarity of the asymmetric states is addressed. Contrary to most studies focusing on symmetric solutions, the present study suggests that edge states, when localised near one wall, do not scale in outer units. The current study suggests a composite scaling. (paper)

  1. 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

  2. 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 ...

  3. Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds

    Science.gov (United States)

    Ebert, M.; Worringen, A.; Benker, N.; Mertes, S.; Weingartner, E.; Weinbruch, S.

    2010-10-01

    During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI). Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated) aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN) were identified from the significant enrichment of particle groups in the ice residual (IR) samples relative to the interstitial aerosol. In terms of number lead-bearing particles are enriched by a factor of approximately 25, complex internal mixtures with silicates or metal oxides as major components by a factor of 11, and mixtures of secondary aerosol and soot (C-O-S particles) by a factor of 2. Other particle groups (sulfates, sea salt, Ca-rich particles, external silicates) observed in the ice-residual samples cannot be assigned unambiguously as IN. Between 9 and 24% of all IR are Pb-bearing particles. Pb was found as major component in around 10% of these particles (PbO, PbCl2). In the other particles, Pb was found as some 100 nm sized agglomerates consisting of 3-8 nm sized primary particles (PbS, elemental Pb). C-O-S particles are present in the IR at an abundance of 17-27%. The soot component within these particles is strongly aged. Complex internal mixtures occur in the IR at an abundance of 9-15%. Most IN identified at the Jungfraujoch station are internal mixtures containing anthropogenic components (either as main or minor constituent), and it is concluded that admixture of the anthropogenic component is responsible for the increased IN efficiency within mixed phase clouds. The mixing state appears to be a key parameter for the ice nucleation behaviour that cannot be predicted from the separate components contained within the individual particles.

  4. 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.)

  5. THE BACTERIOLOGICAL AND PHYSICO-CHEMICAL STUDIES ON OLUMIRIN WATERFALL ERIN- IJESHA, OSUN STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    Oluwakemi Akindolapo

    2011-10-01

    Full Text Available The potability and qualities of Olumirin waterfall, Erin-Ijesa were investigated by determining the total bacteria and coliform count with antibiotic susceptibility of the isolated bacteria and physico-chemical qualities of the water samples. Total bacteria and coliform enumeration were determined using pour plating and multiple tube techniques, the antibiotic susceptibility were carried out using disc diffusion method, while physico-chemical and mineral studies were also carried out using standard methods. The mean total viable count of the water samples ranged 14.8 x 102 CFU.ml-1 - 21.3 x 103 CFU.ml-1 while the coliform count ranged 13 -175 MPN/100ml. The identified bacteria isolates and their percentage distribution were E.coli (43.1%, Klebsiella spp (20.7%, Proteus spp (12.1%, Salmonella spp (6.99%, Pseudomonas spp (5.17%, Shigella spp (6.9%, and Enterococcus spp (5.17 %. Antibiotic resistance shown by bacteria isolates were exhibited as follow; Nalixidic acid (31%, Ampicilin (76%, Cotrimoxazole (60%, Gentamicin (19%, Nitrofurantoin (24%, Colitin (48%, Streptomycin (34% and tetracycline (52%. 82.8% of the isolate exhibited multiple antibiotic resistance. The physico-chemical analysis also revealed the presence of some mineral elements in the water samples. The mineral value of the water samples include; magnesium (84.8 - 93.4 mg.L-1, phosphate (12.6 - 17.1 mg.L-1, sodium (47.8 - 87.6 mg.L-1, potassium (76.6 - 104.5 mg.L-1, chloride (59.0 - 90.2 mg.L-1, zinc (0.75 - 1.82 mg.L-1, lead (0.12 - 0.33 mg.L-1, iron (0.52 - 0.60 mg.L-1, copper (0.12 - 0.27 mg.L-1 while nickel and arsenic were not detected in any of the water samples. Comparing the experimental results with the international water standard for natural water, the waterfall is not fit for consumption or for any domestic purpose unless being treated. Also, problems that may arise from the resistance bacteria strains can be tackled while the new antibiotics can also be developed.

  6. Rate constants of chemical reactions from semiclassical transition state theory in full and one dimension

    Energy Technology Data Exchange (ETDEWEB)

    Greene, Samuel M., E-mail: samuel.greene@chem.ox.ac.uk; Shan, Xiao, E-mail: xiao.shan@chem.ox.ac.uk; Clary, David C., E-mail: david.clary@chem.ox.ac.u [Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)

    2016-06-28

    Semiclassical Transition State Theory (SCTST), a method for calculating rate constants of chemical reactions, offers gains in computational efficiency relative to more accurate quantum scattering methods. In full-dimensional (FD) SCTST, reaction probabilities are calculated from third and fourth potential derivatives along all vibrational degrees of freedom. However, the computational cost of FD SCTST scales unfavorably with system size, which prohibits its application to larger systems. In this study, the accuracy and efficiency of 1-D SCTST, in which only third and fourth derivatives along the reaction mode are used, are investigated in comparison to those of FD SCTST. Potential derivatives are obtained from numerical ab initio Hessian matrix calculations at the MP2/cc-pVTZ level of theory, and Richardson extrapolation is applied to improve the accuracy of these derivatives. Reaction barriers are calculated at the CCSD(T)/cc-pVTZ level. Results from FD SCTST agree with results from previous theoretical and experimental studies when Richardson extrapolation is applied. Results from our implementation of 1-D SCTST, which uses only 4 single-point MP2/cc-pVTZ energy calculations in addition to those for conventional TST, agree with FD results to within a factor of 5 at 250 K. This degree of agreement and the efficiency of the 1-D method suggest its potential as a means of approximating rate constants for systems too large for existing quantum scattering methods.

  7. Physico-chemical state influences in vitro release profile of curcumin from pectin beads.

    Science.gov (United States)

    Nguyen, An Thi-Binh; Winckler, Pascale; Loison, Pauline; Wache, Yves; Chambin, Odile

    2014-09-01

    Curcumin is a polyphenolic compound with diverse effects interesting to develop health benefit products but its formulation in functional foods or in food supplement is hampered by its poor water solubility and susceptibility to alkaline conditions, light, oxidation and heat. Encapsulation of curcumin could be a mean to overcome these difficulties. In this paper, curcumin was encapsulated by ionotropic gelation method in low methoxyl pectin beads associated with different surfactants: Solutol(®), Transcutol(®) and sodium caseinate. After encapsulation, physico-chemical properties of encapsulated curcumin such as its solubility, physical state, tautomeric forms and encapsulation efficiency as well as encapsulation yield were characterized. In vitro dissolution of curcumin from beads displayed different kinetic profiles according to bead composition due to different matrix network. As Solutol(®) was a good solvent for curcumin, the drug was present into amorphous form in these beads inducing a rapid release of curcumin in the simulated digestive fluids. In contrast, drug release was slower from sodium caseinate beads since curcumin was not totally dissolved during the manufacturing process. Moreover, the FLIM studies showed that a part of curcumin was encapsulated in caseinate micelles and that 34% of this drug was in keto form which may delay the curcumin release. The Transcutol beads showed also a slow drug release because of the low curcumin solubility and the high density of the matrix. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Chemical Bonding States of TiC Films before and after Hydrogen Ion Irradiation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    TiC films deposited by rf magnetron sputtering followed by Ar+ ion bombardment were irradiated with a hydrogen ion beam. X-ray photoelectron spectroscopy (XPS) was used for characterization of the chemical bonding states of C and Ti elements of the TiC films before and after hydrogen ion irradiation, in order to understand the effect of hydrogen ion irradiation on the films and to study the mechanism of hydrogen resistance of TiC films. Conclusions can be drawn that ion bombardment at moderate energy can cause preferential physical sputtering of carbon atoms from the surface of low atomic number (Z) material. This means that ion beam bombardment leads to the formation of a non-stoichiometric composition of TiC on the surface.TiC films prepared by ion beam mixing have the more excellent characteristic of hydrogen resistance. One important cause, in addition to TiC itself, is that there are many vacant sites in TiC created by ion beam mixing.These defects can easily trap hydrogen and effectively enhance the effect of hydrogen resistance.

  9. Role of Chemical Reactivity and Transition State Modeling for Virtual Screening.

    Science.gov (United States)

    Karthikeyan, Muthukumarasamy; Vyas, Renu; Tambe, Sanjeev S; Radhamohan, Deepthi; Kulkarni, Bhaskar D

    2015-01-01

    Every drug discovery research program involves synthesis of a novel and potential drug molecule utilizing atom efficient, economical and environment friendly synthetic strategies. The current work focuses on the role of the reactivity based fingerprints of compounds as filters for virtual screening using a tool ChemScore. A reactant-like (RLS) and a product- like (PLS) score can be predicted for a given compound using the binary fingerprints derived from the numerous known organic reactions which capture the molecule-molecule interactions in the form of addition, substitution, rearrangement, elimination and isomerization reactions. The reaction fingerprints were applied to large databases in biology and chemistry, namely ChEMBL, KEGG, HMDB, DSSTox, and the Drug Bank database. A large network of 1113 synthetic reactions was constructed to visualize and ascertain the reactant product mappings in the chemical reaction space. The cumulative reaction fingerprints were computed for 4000 molecules belonging to 29 therapeutic classes of compounds, and these were found capable of discriminating between the cognition disorder related and anti-allergy compounds with reasonable accuracy of 75% and AUC 0.8. In this study, the transition state based fingerprints were also developed and used effectively for virtual screening in drug related databases. The methodology presented here provides an efficient handle for the rapid scoring of molecular libraries for virtual screening.

  10. Stochastic theory of nonequilibrium steady states. Part II: Applications in chemical biophysics

    International Nuclear Information System (INIS)

    Ge Hao; Qian Min; Qian Hong

    2012-01-01

    The mathematical theory of nonequilibrium steady state (NESS) has a natural application in open biochemical systems which have sustained source(s) and sink(s) in terms of a difference in their chemical potentials. After a brief introduction in Section , in Part II of this review, we present the widely studied biochemical enzyme kinetics, the workhorse of biochemical dynamic modeling, in terms of the theory of NESS (Section ). We then show that several phenomena in enzyme kinetics, including a newly discovered activation–inhibition switching (Section ) and the well-known non-Michaelis–Menten-cooperativity (Section ) and kinetic proofreading (Section ), are all consequences of the NESS of driven biochemical systems with associated cycle fluxes. Section is focused on nonlinear and nonequilibrium systems of biochemical reactions. We use the phosphorylation–dephosphorylation cycle (PdPC), one of the most important biochemical signaling networks, as an example (Section ). It starts with a brief introduction of the Delbrück–Gillespie process approach to mesoscopic biochemical kinetics (Sections ). We shall discuss the zeroth-order ultrasensitivity of PdPC in terms of a new concept — the temporal cooperativity (Sections ), as well as PdPC with feedback which leads to biochemical nonlinear bistability (Section ). Also, both are nonequilibrium phenomena. PdPC with a nonlinear feedback is kinetically isomorphic to a self-regulating gene expression network, hence the theory of NESS discussed here could have wide applications to many other biochemical systems.

  11. An automated method to find transition states using chemical dynamics simulations.

    Science.gov (United States)

    Martínez-Núñez, Emilio

    2015-02-05

    A procedure to automatically find the transition states (TSs) of a molecular system (MS) is proposed. It has two components: high-energy chemical dynamics simulations (CDS), and an algorithm that analyzes the geometries along the trajectories to find reactive pathways. Two levels of electronic structure calculations are involved: a low level (LL) is used to integrate the trajectories and also to optimize the TSs, and a higher level (HL) is used to reoptimize the structures. The method has been tested in three MSs: formaldehyde, formic acid (FA), and vinyl cyanide (VC), using MOPAC2012 and Gaussian09 to run the LL and HL calculations, respectively. Both the efficacy and efficiency of the method are very good, with around 15 TS structures optimized every 10 trajectories, which gives a total of 7, 12, and 83 TSs for formaldehyde, FA, and VC, respectively. The use of CDS makes it a powerful tool to unveil possible nonstatistical behavior of the system under study. © 2014 Wiley Periodicals, Inc.

  12. Finite state projection based bounds to compare chemical master equation models using single-cell data

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Zachary [School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Neuert, Gregor [Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 (United States); Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Biomedical Engineering, Vanderbilt University School of Engineering, Nashville, Tennessee 37232 (United States); Munsky, Brian [School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2016-08-21

    Emerging techniques now allow for precise quantification of distributions of biological molecules in single cells. These rapidly advancing experimental methods have created a need for more rigorous and efficient modeling tools. Here, we derive new bounds on the likelihood that observations of single-cell, single-molecule responses come from a discrete stochastic model, posed in the form of the chemical master equation. These strict upper and lower bounds are based on a finite state projection approach, and they converge monotonically to the exact likelihood value. These bounds allow one to discriminate rigorously between models and with a minimum level of computational effort. In practice, these bounds can be incorporated into stochastic model identification and parameter inference routines, which improve the accuracy and efficiency of endeavors to analyze and predict single-cell behavior. We demonstrate the applicability of our approach using simulated data for three example models as well as for experimental measurements of a time-varying stochastic transcriptional response in yeast.

  13. Evaluating chemical extraction techniques for the determination of uranium oxidation state in reduced aquifer sediments

    Science.gov (United States)

    Stoliker, Deborah L.; Campbell, Kate M.; Fox, Patricia M.; Singer, David M.; Kaviani, Nazila; Carey, Minna; Peck, Nicole E.; Barger, John R.; Kent, Douglas B.; Davis, James A.

    2013-01-01

    Extraction techniques utilizing high pH and (bi)carbonate concentrations were evaluated for their efficacy in determining the oxidation state of uranium (U) in reduced sediments collected from Rifle, CO. Differences in dissolved concentrations between oxic and anoxic extractions have been proposed as a means to quantify the U(VI) and U(IV) content of sediments. An additional step was added to anoxic extractions using a strong anion exchange resin to separate dissolved U(IV) and U(VI). X-ray spectroscopy showed that U(IV) in the sediments was present as polymerized precipitates similar to uraninite and/or less ordered U(IV), referred to as non-uraninite U(IV) species associated with biomass (NUSAB). Extractions of sediment containing both uraninite and NUSAB displayed higher dissolved uranium concentrations under oxic than anoxic conditions while extractions of sediment dominated by NUSAB resulted in identical dissolved U concentrations. Dissolved U(IV) was rapidly oxidized under anoxic conditions in all experiments. Uraninite reacted minimally under anoxic conditions but thermodynamic calculations show that its propensity to oxidize is sensitive to solution chemistry and sediment mineralogy. A universal method for quantification of U(IV) and U(VI) in sediments has not yet been developed but the chemical extractions, when combined with solid-phase characterization, have a narrow range of applicability for sediments without U(VI).

  14. Advanced surface chemical analysis of continuously manufactured drug loaded composite pellets.

    Science.gov (United States)

    Hossain, Akter; Nandi, Uttom; Fule, Ritesh; Nokhodchi, Ali; Maniruzzaman, Mohammed

    2017-04-15

    The aim of the present study was to develop and characterise polymeric composite pellets by means of continuous melt extrusion techniques. Powder blends of a steroid hormone (SH) as a model drug and either ethyl cellulose (EC N10 and EC P7 grades) or hydroxypropyl methylcellulose (HPMC AS grade) as polymeric carrier were extruded using a Pharma 11mm twin screw extruder in a continuous mode of operation to manufacture extruded composite pellets of 1mm length. Molecular modelling study using commercial Gaussian 09 software outlined a possible drug-polymer interaction in the molecular level to develop solid dispersions of the drug in the pellets. Solid-state analysis conducted via a differential scanning calorimetry (DSC), hot stage microscopy (HSM) and X-ray powder diffraction (XRPD) analyses revealed the amorphous state of the drug in the polymer matrices. Surface analysis using SEM/energy dispersive X-ray (EDX) of the produced pellets arguably showed a homogenous distribution of the C and O atoms in the pellet matrices. Moreover, advanced chemical surface analysis conducted via atomic force microscopy (AFM) showed a homogenous phase system having the drug molecule dispersed onto the amorphous matrices while Raman mapping confirmed the homogenous single-phase drug distribution in the manufactured composite pellets. Such composite pellets are expected to deliver multidisciplinary applications in drug delivery and medical sciences by e.g. modifying drug solubility/dissolutions or stabilizing the unstable drug (e.g. hormone, protein) in the composite network. Copyright © 2016. Published by Elsevier Inc.

  15. Quantum chemical analysis of binary and ternary ferromagnetic alloys; Quantenchemische Untersuchungen binaerer und ternaerer ferromagnetischer Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Yasemin Erika Charlotte

    2007-02-23

    In this work the electronic structures, densities of states, chemical bonding, magnetic exchange Parameters and Curie temperatures of binary and ternary ferromagnetic alloys are analyzed. The electronic structure of ferromagnetic MnAl has been calculated using density-functional techniques (TB-LMTO-ASA, FPLAPW) and quantum chemically analyzed by means of the crystal orbital Hamilton population analysis. The crystal structure of the ferromagnetic tetragonal MnAl may be understood to originate from the structure of nonmagnetic cubic MnAl with a CsCl motif through a two-step process. While the nonmagnetic cubic structure is stable against a structural deformation, antibonding Mn-Mn interactions at the Fermi level lead to spin polarization and the onset of magnetism, i.e., a symmetry reduction taking place solely in the electronic degrees of freedom, by that emptying antibonding Mn-Mn states. Residual antibonding Al--Al states can only be removed by a subsequent, energetically smaller structural deformation towards the tetragonal system. As a final result, homonuclear bonding is strengthened and heteronuclear bonding is weakened. Corresponding DFT calculations of the electronic structure as well as the calculation of the chemical bonding and the magnetic exchange interactions have been performed on the basis of LDA and GGA for a series of ferromagnetic full Heusler alloys of general formula Co2MnZ (Z=Ga,Si,Ge,Sn), Rh2MnZ (Z=Ge,Sn,Pb), Ni2MnZ (Z=Ga,In,Sn), Pd2MnZ (Z=Sn,Sb) and Cu2MnZ (Z=Al,In,Sn). The connection between the electronic spectra and the magnetic interactions have been studied. Correlations between the chemical bondings in Heusler alloys derived from COHP analysis and magnetic phenomena are obvious, and different mechanisms leading to spin polarization and ferromagnetism are derived. The band dependence of the exchange parameters, their dependence on volume and valence electron concentration have been thoroughly analyzed within the Green function technique

  16. PEPSI deep spectra. III. Chemical analysis of the ancient planet-host star Kepler-444

    Science.gov (United States)

    Mack, C. E.; Strassmeier, K. G.; Ilyin, I.; Schuler, S. C.; Spada, F.; Barnes, S. A.

    2018-04-01

    Context. With the Large Binocular Telescope (LBT), we obtained a spectrum with PEPSI, its new optical high-resolution échelle spectrograph. The spectrum has very high resolution and a high signal-to-noise (S/N) and is of the K0V host Kepler-444, which is known to host five sub-Earth-sized rocky planets. The spectrum has a resolution of R ≈ 250 000, a continuous wavelength coverage from 4230 Å to 9120 Å, and an S/N between 150-550:1 (blue to red). Aim. We performed a detailed chemical analysis to determine the photospheric abundances of 18 chemical elements. These were used to place constraints on the bulk composition of the five rocky planets. Methods: Our spectral analysis employs the equivalent-width method for most of our spectral lines, but we used spectral synthesis to fit a small number of lines that required special care. In both cases, we derived our abundances using the MOOG spectral analysis package and Kurucz model atmospheres. Results: We find no correlation between elemental abundance and condensation temperature among the refractory elements (TC > 950 K). In addition, using our spectroscopic stellar parameters and isochrone fitting, we find an age of 10 ± 1.5 Gyr, which is consistent with the asteroseismic age of 11 ± 1 Gyr. Finally, from the photospheric abundances of Mg, Si, and Fe, we estimate that the typical Fe-core mass fraction for the rocky planets in the Kepler-444 system is approximately 24%. Conclusions: If our estimate of the Fe-core mass fraction is confirmed by more detailed modeling of the disk chemistry and simulations of planet formation and evolution in the Kepler-444 system, then this would suggest that rocky planets in more metal-poor and α-enhanced systems may tend to be less dense than their counterparts of comparable size in more metal-rich systems. Based on data acquired with PEPSI using the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the United States, Italy, and

  17. Biological Sampling and Analysis in Sinclair and Dyes Inlets, Washington: Chemical Analyses for 2007 Puget Sound Biota Study

    Energy Technology Data Exchange (ETDEWEB)

    Brandenberger, Jill M.; Suslick, Carolynn R.; Johnston, Robert K.

    2008-10-09

    Evaluating spatial and temporal trends in contaminant residues in Puget Sound fish and macroinvertebrates are the objectives of the Puget Sound Ambient Monitoring Program (PSAMP). In a cooperative effort between the ENVironmental inVESTment group (ENVVEST) and Washington State Department of Fish and Wildlife, additional biota samples were collected during the 2007 PSAMP biota survey and analyzed for chemical residues and stable isotopes of carbon (δ13C) and nitrogen (δ15N). Approximately three specimens of each species collected from Sinclair Inlet, Georgia Basin, and reference locations in Puget Sound were selected for whole body chemical analysis. The muscle tissue of specimens selected for chemical analyses were also analyzed for δ13C and δ15N to provide information on relative trophic level and food sources. This data report summarizes the chemical residues for the 2007 PSAMP fish and macro-invertebrate samples. In addition, six Spiny Dogfish (Squalus acanthias) samples were necropsied to evaluate chemical residue of various parts of the fish (digestive tract, liver, embryo, muscle tissue), as well as, a weight proportional whole body composite (WBWC). Whole organisms were homogenized and analyzed for silver, arsenic, cadmium, chromium, copper, nickel, lead, zinc, mercury, 19 polychlorinated biphenyl (PCB) congeners, PCB homologues, percent moisture, percent lipids, δ13C, and δ15N.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Generalized molybdenum oxide surface chemical state XPS determination via informed amorphous sample model

    Energy Technology Data Exchange (ETDEWEB)

    Baltrusaitis, Jonas, E-mail: job314@lehigh.edu [Department of Chemical Engineering, Lehigh University, B336 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 (United States); PhotoCatalytic Synthesis group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands); Mendoza-Sanchez, Beatriz [CRANN, Chemistry School, Trinity College Dublin, Dublin (Ireland); Fernandez, Vincent [Institut des Matériaux Jean Rouxel, 2 rue de la Houssinière, BP 32229, F-44322 Nantes Cedex 3 (France); Veenstra, Rick [PhotoCatalytic Synthesis group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands); Dukstiene, Nijole [Department of Physical and Inorganic Chemistry, Kaunas University of Technology, Radvilenu pl. 19, LT-50254 Kaunas (Lithuania); Roberts, Adam [Kratos Analytical Ltd, Trafford Wharf Road, Wharfside, Manchester, M17 1GP (United Kingdom); Fairley, Neal [Casa Software Ltd, Bay House, 5 Grosvenor Terrace, Teignmouth, Devon TQ14 8NE (United Kingdom)

    2015-01-30

    Highlights: • We analyzed and modeled spectral envelopes of complex molybdenum oxides. • Molybdenum oxide films of varying valence and crystallinity were synthesized. • MoO{sub 3} and MoO{sub 2} line shapes from experimental data were created. • Informed amorphous sample model (IASM) developed. • Amorphous molybdenum oxide XPS envelopes were interpreted. - Abstract: Accurate elemental oxidation state determination for the outer surface of a complex material is of crucial importance in many science and engineering disciplines, including chemistry, fundamental and applied surface science, catalysis, semiconductors and many others. X-ray photoelectron spectroscopy (XPS) is the primary tool used for this purpose. The spectral data obtained, however, is often very complex and can be subject to incorrect interpretation. Unlike traditional XPS spectra fitting procedures using purely synthetic spectral components, here we develop and present an XPS data processing method based on vector analysis that allows creating XPS spectral components by incorporating key information, obtained experimentally. XPS spectral data, obtained from series of molybdenum oxide samples with varying oxidation states and degree of crystallinity, were processed using this method and the corresponding oxidation states present, as well as their relative distribution was elucidated. It was shown that monitoring the evolution of the chemistry and crystal structure of a molybdenum oxide sample due to an invasive X-ray probe could be used to infer solutions to complex spectral envelopes.

  3. Transition-state destabilization reveals how human DNA polymerase β proceeds across the chemically unstable lesion N7-methylguanine

    Science.gov (United States)

    Ouzon-Shubeita, Hala; Lee, Seongmin

    2014-01-01

    N7-Methyl-2′-deoxyguanosine (m7dG) is the predominant lesion formed by methylating agents. A systematic investigation on the effect of m7dG on DNA replication has been difficult due to the chemical instability of m7dG. To gain insights into the m7dG effect, we employed a 2′-fluorine-mediated transition-state destabilzation strategy. Specifically, we determined kinetic parameters for dCTP insertion opposite a chemically stable m7dG analogue, 2′-fluoro-m7dG (Fm7dG), by human DNA polymerase β (polβ) and solved three X-ray structures of polβ in complex with the templating Fm7dG paired with incoming dCTP or dTTP analogues. The kinetic studies reveal that the templating Fm7dG slows polβ catalysis ∼300-fold, suggesting that m7dG in genomic DNA may impede replication by some DNA polymerases. The structural analysis reveals that Fm7dG forms a canonical Watson–Crick base pair with dCTP, but metal ion coordination is suboptimal for catalysis in the polβ-Fm7dG:dCTP complex, which partially explains the slow insertion of dCTP opposite Fm7dG by polβ. In addition, the polβ-Fm7dG:dTTP structure shows open protein conformations and staggered base pair conformations, indicating that N7-methylation of dG does not promote a promutagenic replication. Overall, the first systematic studies on the effect of m7dG on DNA replication reveal that polβ catalysis across m7dG is slow, yet highly accurate. PMID:24966350

  4. Chemical composition of Ilex paraguariensis St. Hil. under different management conditions in seven localities of Paraná State

    Directory of Open Access Journals (Sweden)

    Carlos Bruno Reissmann

    1999-01-01

    Full Text Available Ilex paraguariensis St. Hil. (erva-mate, the mate tea, is a forest tree whose natural distribution in the Brazilian territory embraces the States of Mato Grosso do Sul, Paraná, Santa Catarina and Rio Grande do Sul. Its economical importance is moreover related to tea production. The purpose of this study is to characterize the leaf chemical composition in relation to different plantation and management conditions. Chemical analysis were performed on plants of different ages,in naturally occurring areas, planted stands, and seedbeds. The most remarkable elements observed in the study were P with average values ranging from 0,5 - 3,2 g kg-1 D.W., Mn values from 346 - 3.330 mg kg-1 D.W., and Al values from 167 - 1.235 mg kg-1 D.W.A erva-mate (Ilex paraguariensis St. Hil., no Brasil, distribui-se nos Estados do Mato Grosso do Sul, Paraná, Santa Catarina e Rio Grande do Sul. Sua importância econômica refere-se basicamente à produção do chá e chimarrão. O objetivo deste trabalho foi caracterizar a composição química foliar de acordo com diferentes sistemas de plantio e manejo. A análise química foi efetuada em plantas de diversas idades e sob condições distintas de manejo, ou seja, ocorrência natural, plantios e viveiros. Os elementos que mais chamaram a atenção, neste estudo, foram o P, cujos teores variaram de 0,5 - 3,2 g kg-1 M.S.; Mn de 346-3330 mg kg-1 M.S. e Al de 167-1235 mg kg-1 M.S.

  5. Chemical analysis of fogwater at Delhi, North India

    Science.gov (United States)

    Kapoor, R. K.; Tiwari, S.; Ali, K.; Singh, G.

    Fogwater collected at Delhi (28° 35'N, 77°12'E, 217 m a.s.l.) during winter 1989-1990 was found to be acidic compared to pure water pH of 7. This was attributed to highway widening work in progress and an increase in vehicular traffic on the nearby road, apart from construction work in a residential complex and an increase in industrial activity within 6 km to the southwest. Results are compared with the earlier studies at Delhi and those with highly acidic fog data published for some regions of California in the United States of America.

  6. Electron nature of chemically active state of spiropyran with nitro group. Dependence of efficiency of radiation colouring of spiropyrans on their structure

    International Nuclear Information System (INIS)

    Kholmanskij, A.S.; Zubkov, A.V.; Dyumaev, K.M.

    1980-01-01

    Using the theory of solvatochromy it is shown that chemically active state of spiropyran with nitro group is its highly polar electron-excitated state. On the basis of the image on the electron nature of chemically active state of spiropyran the dependence of the values of radiation yield of the coloured forms of spiropyrans upon their structure is explained

  7. Comparative Demand Analysis for Rice in Three States of South ...

    African Journals Online (AJOL)

    Dauda Omoba

    Agro-Science Journal of Tropical Agriculture, Food, Environment and Extension ... study the effect of sources of organic manures on the growth and yield of two cultivars of .... Result of physico-chemical analysis of the soils in ... (WAT) in Makurdi application of moringa leaf, ..... properties that transform into high fertility.

  8. 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.

  9. 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.

  10. 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

  11. 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).

  12. 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...

  13. 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

  14. 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

  15. Complete Bell-state analysis for a single-photon hybrid entangled state

    International Nuclear Information System (INIS)

    Sheng Yu-Bo; Zhou Lan; Cheng Wei-Wen; Gong Long-Yan; Wang Lei; Zhao Sheng-Mei

    2013-01-01

    We propose a scheme capable of performing complete Bell-state analysis for a single-photon hybrid entangled state. Our single-photon state is encoded in both polarization and frequency degrees of freedom. The setup of the scheme is composed of polarizing beam splitters, half wave plates, frequency shifters, and independent wavelength division multiplexers, which are feasible using current technology. We also show that with this setup we can perform complete two-photon Bell-state analysis schemes for polarization degrees of freedom. Moreover, it can also be used to perform the teleportation scheme between different degrees of freedom. This setup may allow extensive applications in current quantum communications

  16. Evidence for excited-state intramolecular proton transfer in 4-chlorosalicylic acid from combined experimental and computational studies: Quantum chemical treatment of the intramolecular hydrogen bonding interaction

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bijan Kumar [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India); Guchhait, Nikhil, E-mail: nikhil.guchhait@rediffmail.com [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Experimental and computational studies on the photophysics of 4-chlorosalicylic acid. Black-Right-Pointing-Pointer Spectroscopically established ESIPT reaction substantiated by theoretical calculation. Black-Right-Pointing-Pointer Quantum chemical treatment of IMHB unveils strength, nature and directional nature. Black-Right-Pointing-Pointer Superiority of quantum chemical treatment of H-bond over geometric criteria. Black-Right-Pointing-Pointer Role of H-bond as a modulator of aromaticity. -- Abstract: The photophysical study of a pharmaceutically important chlorine substituted derivative of salicylic acid viz., 4-chlorosalicylic acid (4ClSA) has been carried out by steady-state absorption, emission and time-resolved emission spectroscopy. A large Stokes shifted emission band with negligible solvent polarity dependence marks the spectroscopic signature of excited-state intramolecular proton transfer (ESIPT) reaction in 4ClSA. Theoretical calculation by ab initio and Density Functional Theory methods yields results consistent with experimental findings. Theoretical potential energy surfaces predict the occurrence of proton transfer in S{sub 1}-state. Geometrical and energetic criteria, Atoms-In-Molecule topological parameters, Natural Bond Orbital population analysis have been exploited to evaluate the intramolecular hydrogen bond (IMHB) interaction and to explore its directional nature. The inter-correlation between aromaticity and resonance assisted H-bond is also discussed in this context. Our results unveil that the quantum chemical treatment is a more accurate tool to assess hydrogen bonding interaction in comparison to geometrical criteria.

  17. Bioassay of Lake Onego bottom sediments toxicity based on their chemical composition and deepwater macrozoobenthos state

    Directory of Open Access Journals (Sweden)

    Kalinkina Nataliya Michailovna

    2017-03-01

    Full Text Available The bioassay of the toxicity of bottom sediments sampled in different areas of Lake Onega was carried out by crustaceans biotesting (Ceriodaphnia affinis Lillijeborg. It was shown that in the most areas of Lake Onega there are non-toxic bottom sediments. Toxic bottom sediments were found in Kondopogskaya Bay, intensively polluted with pulp-and-paper mill wastewaters. For the first time in the deep central part of Lake Onega the area was revealed where the toxic bottom sediments contain a high content of iron, manganese and other trace elements typical for the central areas of the lake. The mapping of the bottom of Lake Onega was accomplished, and three zones were identified based on the analysis of the data concerning the chemical composition of bottom sediments, bioassay toxicity data and the results of the deepwater macrozoobenthos assessment. For each zone the parameters of the main groups of benthos (Amphipoda, Oligochaeta, Chironomidae were defined. The first zone is located in the area of intensive anthropogenic influence (Kondopogskaya Bay, Petrozavodskaya Bay, Povenets Bay, Kizhi Skerries. The second zone is located mostly in the deep part of Petrozavodskaya Bay, where the most intensive development of amphipods is observed. The third area is identified for the first time: it is located in the central deep part of Lake Onega, where the communities of macrozoobenthos are limited by a natural toxic factor.

  18. State Space Analysis of Hierarchical Coloured Petri Nets

    DEFF Research Database (Denmark)

    Christensen, Søren; Kristensen, Lars Michael

    2003-01-01

    In this paper, we consider state space analysis of Coloured Petri Nets. It is well-known that almost all dynamic properties of the considered system can be verified when the state space is finite. However, state space analysis is more than just formulating a set of formal requirements and invokin...... supporting computation and storage of state spaces which exploi the hierarchical structure of the models....... in which formal verification, partial state spaces, and analysis by means of graphical feedback and simulation are integrated entities. The focus of the paper is twofold: the support for graphical feedback and the way it has been integrated with simulation, and the underlying algorithms and data-structures......In this paper, we consider state space analysis of Coloured Petri Nets. It is well-known that almost all dynamic properties of the considered system can be verified when the state space is finite. However, state space analysis is more than just formulating a set of formal requirements and invoking...

  19. 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.

  20. The composition-explicit distillation curve technique: Relating chemical analysis and physical properties of complex fluids.

    Science.gov (United States)

    Bruno, Thomas J; Ott, Lisa S; Lovestead, Tara M; Huber, Marcia L

    2010-04-16

    The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. The analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. By far, the most widely used analytical technique we have used with the ADC is gas chromatography. This has enabled us to study finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this special issue of the Journal of Chromatography, specifically dedicated to extraction technologies, we describe the essential features of the advanced distillation curve metrology as an analytical strategy for complex fluids. Published by Elsevier B.V.

  1. 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.

  2. 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.

  3. Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds

    Directory of Open Access Journals (Sweden)

    M. Ebert

    2011-03-01

    Full Text Available During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI. Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN were identified from the significant enrichment of particle groups in the ice residual (IR samples relative to the interstitial aerosol. In terms of number lead-bearing particles are enriched by a factor of approximately 25, complex internal mixtures with silicates or metal oxides as major components by a factor of 11, and mixtures of secondary aerosol and carbonaceous material (C-O-S particles by a factor of 2. Other particle groups (sulfates, sea salt, Ca-rich particles, external silicates observed in the ice-residual samples cannot be assigned unambiguously as IN. Between 9 and 24% of all IR are Pb-bearing particles. Pb was found as major component in around 10% of these particles (PbO, PbCl2. In the other particles, Pb was found as some 100 nm sized agglomerates consisting of 3–8 nm sized primary particles (PbS, elemental Pb. C-O-S particles are present in the IR at an abundance of 17–27%. The soot component within these particles is strongly aged. Complex internal mixtures occur in the IR at an abundance of 9–15%. Most IN identified at the Jungfraujoch station are internal mixtures containing anthropogenic components (either as main or minor constituent, and it is concluded that admixture of the anthropogenic component is responsible for the increased IN efficiency within mixed phase clouds. The mixing state appears to be a key parameter for the ice nucleation behaviour that cannot be predicted from the sole knowledge of the main component of an individual particle.

  4. 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

  5. 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.

  6. Physico-chemical state of mercury, cadmium, and zinc in surface waters of arid zone of the USSR

    International Nuclear Information System (INIS)

    Kulmatov, R.A.; Rakhmatov, U.; Kist, A.A.; Savenko, V.S.

    1983-01-01

    Experimental study was made on physico-chemical state of high-toxic heavy metals (Zn, Cd, and Hg) in waters of the Aral Sea and the Syr Darya and the Amu Darya rivers, representing the basic resrevoirs of surface waters of the Middle Asia. The complex of high-sensitive and selective radioanalytical techniques was developed for solution of the problem. The complex uncludes ultrafiltration, centrifugation, electrodialysis, sorption on sorbents of different nature, as well as neutron activation analysis. It was established that the major part of Hg, Cd and Zn can migrate in surface waters of the Middle Asia in the form of real and colloidal solutions. Zn and Cd are characterized by the prevalence of cationic really dissolved forms and Hg-anionic neutral and colloidal forms. The presence of the major mass of the given elements in the form of real and the finest colloids which are rather stable forms and can be transfered to long distances points to the promising character of applying hydrochemical methods of prospecting in arid zone of the USSR, because dispersion aureoles must be sufficiently wide. Possibility of formation of large aureoles of natural water contamination in the regions of mining and metallurgical enterprises must be considered as well

  7. 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

  8. Microfluidic Devices for Chemical and Biochemical Analysis in Microgravity

    Science.gov (United States)

    Roman, Gregory T.; Culbertson, Christopher T.; Meyer, Amanda; Ramsey, J. Michael; Gonda, Steven R.

    2004-01-01

    One often touted benefit of "Lab-on-a-Chip" devices is their potential for use in remote environments. The ultimate remote environment is outer space, and NASA has multiple needs in the area of analytical sensing capability in such an environment. In particular, we are interested in integrating microfluidic devices with NASA bioreactor systems. In such an integrated system, the microfluidic device will serve as a biosensor and be used for both feedback control and for detecting various bioproducts produced by cells cultured in the NASA bioreactors. As a first step in demonstrating the ability of microfluidic devices to operate under the extreme environmental conditions found in outer space, we constructed a portable, battery operated platform for testing under reduced gravity conditions on a NASA KC-135 reduced gravity research aircraft, (AKA "the vomit comet"). The test platform consisted of a microchip, two 0-8kV high voltage power supplies, a high voltage switch, a solid-state diode-pumped green laser, a channel photomultiplier, and an inertial mass measurement unit, all under the control of a laptop computer and powered by 10 D-cell alkaline batteries. Over the course of 4 KC-135 flights, 1817 fast electrophoretic separations of 4 amino acids and/or proteins were performed in a variety of gravitational environments including zero-G, Martian-G, lunar-G, and 2-G. Results from these experiments will be presented and discussed.

  9. 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.

  10. 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

  11. 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.

  12. Analysis of food demand among rural households in Kwara State ...

    African Journals Online (AJOL)

    Analysis of food demand among rural households in Kwara State, North Central ... Nigerian Journal of Technological Research ... Contrary to the law of demand, this study shows that the demand for animal products and fats/oil increased with ...

  13. Economic Analysis Of Sesame Marketing In Jigawa State | Kudi ...

    African Journals Online (AJOL)

    Economic Analysis Of Sesame Marketing In Jigawa State. ... The paper examines the marketing channel, structure, conduct, performance and marketing margin and efficiency of sesame. A sample of ... EMAIL FULL TEXT EMAIL FULL TEXT

  14. Profitability Analysis of Rice Processing and Marketing in Kano State ...

    African Journals Online (AJOL)

    Profitability Analysis of Rice Processing and Marketing in Kano State, Nigeria. ... added to the commodity at each stage in the study area and determine the most efficient services produce. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  15. 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

  16. 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

  17. [Management of chemical burns and inhalation poisonings in acute medical care procedures of the State Fire Service].

    Science.gov (United States)

    Chomoncik, Mariusz; Nitecki, Jacek; Ogonowska, Dorota; Cisoń-Apanasewicz, Urszula; Potok, Halina

    2013-01-01

    Emergency Medical Services (EMS) were founded by the government to perform tasks aimed at providing people with help in life-threatening conditions. The system comprises two constituent parts. The first one is public administrative bodies which are to organise, plan, coordinate and supervise the completion of the tasks. The other constituent is EMS units which keep people, resources and units in readiness. Supportive services, which include: the State Fire Service (SFS) and the National Firefighting and Rescue System (NFRS), are of great importance for EMS because they are eligible for providing acute medical care (professional first aid). Acute medical care covers actions performed by rescue workers to help people in life-threatening conditions. Rescue workers provide acute medical care in situations when EMS are not present on the spot and the injured party can be accessed only with the use of professional equipment by trained workers of NFRS. Whenever necessary, workers of supportive services can assist paramedics' actions. Cooperation of all units of EMS and NFRS is very important for rescue operations in the integrated rescue system. Time is a key aspect in delivering first aid to a person in life-threatening conditions. Fast and efficient first aid given by the accident's witness, as well as acute medical care performed by a rescue worker can prevent death and minimise negative effects of an injury or intoxication. It is essential that people delivering first aid and acute medical care should act according to acknowledged and standardised procedures because only in this way can the process of decision making be sped up and consequently, the number of possible complications following accidents decreased. The present paper presents an analysis of legal regulations concerning the management of chemical burn and inhalant intoxication in acute medical care procedures of the State Fire Service. It was observed that the procedures for rescue workers entitled to

  18. Key study on the potential of hydrazine bisborane for solid- and liquid-state chemical hydrogen storage.

    Science.gov (United States)

    Pylypko, Sergii; Petit, Eddy; Yot, Pascal G; Salles, Fabrice; Cretin, Marc; Miele, Philippe; Demirci, Umit B

    2015-05-04

    Hydrazine bisborane N2H4(BH3)2 (HBB; 16.8 wt %) recently re-emerged as a potential hydrogen storage material. However, such potential is controversial: HBB was seen as a hazardous compound up to 2010, but now it would be suitable for hydrogen storage. In this context, we focused on fundamentals of HBB because they are missing in the literature and should help to shed light on its effective potential while taking into consideration any risk. Experimental/computational methods were used to get a complete characterization data sheet, including, e.g., XRD, NMR, FTIR, Raman, TGA, and DSC. From the reported results and discussion, it is concluded that HBB has potential in the field of chemical hydrogen storage given that both thermolytic and hydrolytic dehydrogenations were analyzed. In solid-state chemical hydrogen storage, it cannot be used in the pristine state (risk of explosion during dehydrogenation) but can be used for the synthesis of derivatives with improved dehydrogenation properties. In liquid-state chemical hydrogen storage, it can be studied for room-temperature dehydrogenation, but this requires the development of an active and selective metal-based catalyst. HBB is a thus a candidate for chemical hydrogen storage.

  19. Evolution analysis of the states of the EZ model

    International Nuclear Information System (INIS)

    Qing-Hua, Chen; Yi-Ming, Ding; Hong-Guang, Dong

    2009-01-01

    Based on suitable choice of states, this paper studies the stability of the equilibrium state of the EZ model by regarding the evolution of the EZ model as a Markov chain and by showing that the Markov chain is ergodic. The Markov analysis is applied to the EZ model with small number of agents, the exact equilibrium state for N = 5 and numerical results for N = 18 are obtained. (cross-disciplinary physics and related areas of science and technology)

  20. 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)

  1. 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...

  2. 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

  3. Impacts of the mixing state and chemical composition on the cloud condensation nuclei (CCN) activity in Beijing during winter, 2016

    Science.gov (United States)

    Ren, J.; Zhang, F.

    2017-12-01

    Abstract.Understanding aerosol chemical composition and mixing state on CCN activity in polluted urban area is crucial to determine NCCN accurately and thus to quantify aerosol indirect effects. Aerosol hrgroscopicity, size-resolved cloud condensation nuclei (CCN) concentration and chemical composition are measured under polluted and background conditions in Beijing based on the Air Pollution and Human Health (APHH) field campaign in winter 2016. The CCN number concentration (NCCN) is predicted by using κ-Köhler theory from the PNSD and five simplified of the mixing state and chemical composition. The assumption of EIS (sulfate, nitrate and SOA internally mixed, and POA and BC externally mixed with size-resolved chemical composition) shows the best closure to predict NCCN with the ratio of predicted to measured NCCN of 0.96-1.12 both in POL and BG conditions. Under BG conditions, IB (internal mixture with bulk chemical composition) scheme achieves the best CCN closure during any periods of a day. In polluted days, EIS and IS (internal mixture with size-resolved chemical composition) scheme may achieve better closure than IB scheme due to the heterogeneity in particles composition across different size. ES (external mixture with size-resolved chemical composition) and EB (external mixture with bulk chemical composition) scheme markedly underestimate the NCCN with the ratio of predicted to measured NCCN of 0.6-0.8. In addition, we note that assumptions of size-resolved composition (IS or ES) show very limited promotes by comparing with the assumptions of bulk composition (IB or EB), furthermore, the prediction becomes worse by using size-resolved assumption in clean days. The predicted NCCN during eve-rush periods shows the most sensitivity to the five different assumptions, with ratios of the predicted and measured NCCN ranging from 0.5 to 1.4, reflecting great impacts from evening traffic and cooking sources. The result from the sensitivity examination of predict

  4. The Health of the Public Charter School Movement: A State-by-State Analysis. Second Edition

    Science.gov (United States)

    Ziebarth, Todd; Bierlein Palmer, Louann

    2016-01-01

    In October 2014, the first edition of "The Health of the Public Charter School Movement: A State-by-State Analysis" was released. Both encouraging words and constructive criticism for how to improve the report going forward were received. This second edition builds on the solid foundation of the inaugural version, while making…

  5. 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.

  6. 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.

  7. 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.

  8. Criteria to average out the chemical shift anisotropy in solid-state NMR when irradiated with BABA I, BABA II, and C7 radiofrequency pulse sequences.

    Science.gov (United States)

    Stephane Mananga, Eugene

    2013-01-01

    Floquet-Magnus expansion is used to study the effect of chemical shift anisotropy in solid-state NMR of rotating solids. The chemical shift interaction is irradiated with two types of radiofrequency pulse sequences: BABA and C7. The criteria for the chemical shift anisotropy to be averaged out in each rotor period are obtained. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. 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)

  10. 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

  11. 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.

  12. 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

  13. Linear analysis near a steady-state of biochemical networks: control analysis, correlation metrics and circuit theory

    Directory of Open Access Journals (Sweden)

    Qian Hong

    2008-05-01

    Full Text Available Abstract Background: Several approaches, including metabolic control analysis (MCA, flux balance analysis (FBA, correlation metric construction (CMC, and biochemical circuit theory (BCT, have been developed for the quantitative analysis of complex biochemical networks. Here, we present a comprehensive theory of linear analysis for nonequilibrium steady-state (NESS biochemical reaction networks that unites these disparate approaches in a common mathematical framework and thermodynamic basis. Results: In this theory a number of relationships between key matrices are introduced: the matrix A obtained in the standard, linear-dynamic-stability analysis of the steady-state can be decomposed as A = SRT where R and S are directly related to the elasticity-coefficient matrix for the fluxes and chemical potentials in MCA, respectively; the control-coefficients for the fluxes and chemical potentials can be written in terms of RT BS and ST BS respectively where matrix B is the inverse of A; the matrix S is precisely the stoichiometric matrix in FBA; and the matrix eAt plays a central role in CMC. Conclusion: One key finding that emerges from this analysis is that the well-known summation theorems in MCA take different forms depending on whether metabolic steady-state is maintained by flux injection or concentration clamping. We demonstrate that if rate-limiting steps exist in a biochemical pathway, they are the steps with smallest biochemical conductances and largest flux control-coefficients. We hypothesize that biochemical networks for cellular signaling have a different strategy for minimizing energy waste and being efficient than do biochemical networks for biosynthesis. We also discuss the intimate relationship between MCA and biochemical systems analysis (BSA.

  14. Biopesticides: State of the Art and Future Opportunities by the American Chemical Society

    Science.gov (United States)

    This chapter from an American Chemical Society symposium reviews areas including how EPA views the benefits of biopesticides, related laws and legal requirements, biopesticide registration, and biopesticide data requirements.

  15. Institute of Chemical Process Fundamentals of the ASCR: State of the Art

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří

    2013-01-01

    Roč. 62, 5-6 (2013), s. 210-241 ISSN 0022-9830 Institutional support: RVO:67985858 Keywords : fundamental research * multi-disciplinary character * external cooperation Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  16. Laser-enhanced chemical reactions and the liquid state. II. Possible applications to nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Rofer-DePoorter, C.K.

    1976-01-01

    Laser photochemistry is surveyed as a possible improvement upon the Purex process for reprocessing spent nuclear fuel. Most of the components of spent nuclear fuel are photochemically active, and lasers can be used to selectively excite individual chemical species. The great variety of chemical species present and the degree of separation that must be achieved present difficulties in reprocessing. Lasers may be able to improve the necessary separations by photochemical reaction or effects on rates and equilibria of reactions

  17. State of chemical modeling modules for the degradation of concrete and cements

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.

    1997-04-15

    This report describes the conceptual framework upon which modeling activities will be needed to predict the chemistry of water in contact with concrete and its degradation products cover a broad area, from developing databases for existing abiotic codes, to developing codes that can simulate the chemical impact of microbial activities at a level of sophistication equivalent to that of the abiotic modeling codes, and ultimately, to simulating drift-scale chemical systems in support of hydrological, geochemical,a nd engineering efforts.

  18. Chemical vapor deposition diamond based multilayered radiation detector: Physical analysis of detection properties

    International Nuclear Information System (INIS)

    Almaviva, S.; Marinelli, Marco; Milani, E.; Prestopino, G.; Tucciarone, A.; Verona, C.; Verona-Rinati, G.; Angelone, M.; Pillon, M.; Dolbnya, I.; Sawhney, K.; Tartoni, N.

    2010-01-01

    Recently, solid state photovoltaic Schottky diodes, able to detect ionizing radiation, in particular, x-ray and ultraviolet radiation, have been developed at the University of Rome 'Tor Vergata'. We report on a physical and electrical properties analysis of the device and a detailed study of its detection capabilities as determined by its electrical properties. The design of the device is based on a metal/nominally intrinsic/p-type diamond layered structure obtained by microwave plasma chemical vapor deposition of homoepitaxial single crystal diamond followed by thermal evaporation of a metallic contact. The device can operate in an unbiased mode by using the built-in potential arising from the electrode-diamond junction. We compare the expected response of the device to photons of various energies calculated through Monte Carlo simulation with experimental data collected in a well controlled experimental setup i.e., monochromatic high flux x-ray beams from 6 to 20 keV, available at the Diamond Light Source synchrotron in Harwell (U.K.).

  19. Synthesis, Crystal Structure, and Chemical-Bonding Analysis of BaZn(NCN2

    Directory of Open Access Journals (Sweden)

    Alex J. Corkett

    2017-12-01

    Full Text Available The ternary carbodiimide BaZn(NCN2 was prepared by a solid-state metathesis reaction between BaF2, ZnF2, and Li2NCN in a 1:1:2 molar ratio, and its crystal structure was determined from Rietveld refinement of X-ray data. BaZn(NCN2 represents the aristotype of the LiBa2Al(NCN4 structure which is unique to carbodiimide/cyanamide chemistry and is well regarded as being constructed from ZnN4 tetrahedra, sharing edges and vertices through NCN2− units to form corrugated layers with Ba2+ in the interlayer voids. Structural anomalies in the shape of the cyanamide units are addressed via IR spectrometry and DFT calculations, which suggest the presence of slightly bent N=C=N2− carbodiimide units with C2v symmetry. Moreover, chemical-bonding analysis within the framework of crystal orbital Hamilton population (COHP reveals striking similarities between the bonding interactions in BaZn(NCN2 and SrZn(NCN2 despite their contrasting crystal structures. BaZn(NCN2 is only the second example of a ternary post-transition metal carbodiimide, and its realization paves the way for the preparation of analogues featuring divalent transition metals at the tetrahedral Zn2+ site.

  20. 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.

  1. Mortality among flavour and fragrance chemical plant workers in the United States.

    Science.gov (United States)

    Thomas, T L

    1987-01-01

    Vital status on 1 January 1981 was determined for a cohort of 1412 white men employed in a flavour and fragrance chemical plant between 1945 and 1965 in order to investigate the risks from fatal diseases among men exposed to multiple chemicals in the manufacture of fragrances, flavours, aroma chemicals, and other organic substances. Cause specific standardised mortality ratios (SMRs) were calculated for the entire study population and for several subsets by likelihood of exposure to chemicals, duration of employment, and year of hire. SMRs for rectal cancer and ischaemic heart disease were raised among white male employees whose jobs were in production, maintenance, laboratory, or other jobs that would involve exposure to multiple chemicals used and produced in the plant. The excess of rectal cancer was confined to employees who had worked as chemical operators and mortality was significantly raised among men who worked for ten or more years. Traces of dioxin were recently found in and around plant buildings that used trichlorophenol in the production of hexachlorophene. The study group was small and had limited power to detect excess risk of rare causes of death; however, no soft tissue sarcomas were observed during the study period. PMID:3689704

  2. Spin-echo based diagonal peak suppression in solid-state MAS NMR homonuclear chemical shift correlation spectra

    Science.gov (United States)

    Wang, Kaiyu; Zhang, Zhiyong; Ding, Xiaoyan; Tian, Fang; Huang, Yuqing; Chen, Zhong; Fu, Riqiang

    2018-02-01

    The feasibility of using the spin-echo based diagonal peak suppression method in solid-state MAS NMR homonuclear chemical shift correlation experiments is demonstrated. A complete phase cycling is designed in such a way that in the indirect dimension only the spin diffused signals are evolved, while all signals not involved in polarization transfer are refocused for cancellation. A data processing procedure is further introduced to reconstruct this acquired spectrum into a conventional two-dimensional homonuclear chemical shift correlation spectrum. A uniformly 13C, 15N labeled Fmoc-valine sample and the transmembrane domain of a human protein, LR11 (sorLA), in native Escherichia coli membranes have been used to illustrate the capability of the proposed method in comparison with standard 13C-13C chemical shift correlation experiments.

  3. Steady and dynamic states analysis of induction motor: FEA approach

    African Journals Online (AJOL)

    This paper deals with the steady and dynamic states analysis of induction motor using finite element analysis (FEA) approach. The motor has aluminum rotor bars and is designed for direct-on-line operation at 50 Hz. A study of the losses occurring in the motor performed at operating frequency of 50Hz showed that stator ...

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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

  11. Incorporation of low energy activated nitrogen onto HOPG surface: Chemical states and thermal stability studies by in-situ XPS and Raman spectroscopy

    Science.gov (United States)

    Chandran, Maneesh; Shasha, Michal; Michaelson, Shaul; Hoffman, Alon

    2016-09-01

    In this paper we report the chemical states analysis of activated nitrogen incorporated highly oriented pyrolytic graphite (HOPG) surface under well-controlled conditions. Nitrogen incorporation is carried out by two different processes: an indirect RF nitrogen plasma and low energy (1 keV) N2+ implantation. Bonding configuration, concentration and thermal stability of the incorporated nitrogen species by aforesaid processes are systematically compared by in-situ X-ray photoelectron spectroscopy (XPS). Relatively large concentration of nitrogen is incorporated onto RF nitride HOPG surface (16.2 at.%), compared to N2+ implanted HOPG surface (7.7 at.%). The evolution of N 1s components (N1, N2, N3) with annealing temperature is comprehensively discussed, which indicates that the formation and reorganization of local chemical bonding states are determined by the process of nitridation and not by the prior chemical conditioning (i.e., amorphization or hydrogenation) of the HOPG surface. A combined XPS and Raman spectroscopy studies revealed that N2+ implantation process resulted in a high level of defects to the HOPG surface, which cannot be annealed-out by heat treatment up to 1000 °C. On the other hand, the RF nitrogen plasma process did not produce a high level of surface defects, while incorporating nearly the same amount of stable nitrogen species.

  12. 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...

  13. 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.

  14. Effects of water scarcity and chemical pollution in aquatic ecosystems: State of the art.

    Science.gov (United States)

    Arenas-Sánchez, Alba; Rico, Andreu; Vighi, Marco

    2016-12-01

    Water scarcity is an expanding climate and human related condition, which drives and interacts with other stressors in freshwater ecosystems such as chemical pollution. In this study we provide an overview of the existing knowledge regarding the chemical fate, biological dynamics and the ecological risks of chemicals under water scarcity conditions. We evaluated a total of 15 studies dealing with the combined effects of chemicals and water scarcity under laboratory conditions and in the field. The results of these studies have been elaborated in order to evaluate additive, synergistic or antagonistic responses of the studied endpoints. As a general rule, it can be concluded that, in situations of water scarcity, the impacts of extreme water fluctuations are much more relevant than those of an additional chemical stressor. Nevertheless, the presence of chemical pollution may result in exacerbated ecological risks in some particular cases. We conclude that further investigations on this topic would take advantage on the focus on some specific issues. Experimental (laboratory and model ecosystem) studies should be performed on different biota groups and life stages (diapausing eggs, immature stages), with particular attention to those including traits relevant for the adaptation to water scarcity. More knowledge on species adaptations and recovery capacity is essential to predict community responses to multiple stressors and to assess the community vulnerability. Field studies should be performed at different scales, particularly in lotic systems, in order to integrate different functional dynamics of the river ecosystem. Combining field monitoring and experimental studies would be the best option to reach more conclusive, causal relationships on the effects of co-occurring stressors. Contribution of these studies to develop ecological models and scenarios is also suggested as an improvement for the prospective aquatic risk assessment of chemicals in (semi-)arid areas

  15. 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)

  16. The multi-flavor Schwinger model with chemical potential. Overcoming the sign problem with matrix product states

    International Nuclear Information System (INIS)

    Banuls, Mari Carmen; Cirac, J. Ignacio; Kuehn, Stefan; Cichy, Krzysztof

    2016-11-01

    During recent years there has been an increasing interest in the application of matrix product states, and more generally tensor networks, to lattice gauge theories. This non-perturbative method is sign problem free and has already been successfully used to compute mass spectra, thermal states and phase diagrams, as well as real-time dynamics for Abelian and non-Abelian gauge models. In previous work we showed the suitability of the method to explore the zero-temperature phase structure of the multi-flavor Schwinger model at non-zero chemical potential, a regime where the conventional Monte Carlo approach suffers from the sign problem. Here we extend our numerical study by looking at the spatially resolved chiral condensate in the massless case. We recover spatial oscillations, similar to the theoretical predictions for the single-flavor case, with a chemical potential dependent frequency and an amplitude approximately given by the homogeneous zero density condensate value.

  17. The multi-flavor Schwinger model with chemical potential. Overcoming the sign problem with matrix product states

    Energy Technology Data Exchange (ETDEWEB)

    Banuls, Mari Carmen; Cirac, J. Ignacio; Kuehn, Stefan [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, Krzysztof [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Saito, Hana [AISIN AW Co., Ltd., Aichi (Japan)

    2016-11-15

    During recent years there has been an increasing interest in the application of matrix product states, and more generally tensor networks, to lattice gauge theories. This non-perturbative method is sign problem free and has already been successfully used to compute mass spectra, thermal states and phase diagrams, as well as real-time dynamics for Abelian and non-Abelian gauge models. In previous work we showed the suitability of the method to explore the zero-temperature phase structure of the multi-flavor Schwinger model at non-zero chemical potential, a regime where the conventional Monte Carlo approach suffers from the sign problem. Here we extend our numerical study by looking at the spatially resolved chiral condensate in the massless case. We recover spatial oscillations, similar to the theoretical predictions for the single-flavor case, with a chemical potential dependent frequency and an amplitude approximately given by the homogeneous zero density condensate value.

  18. Development of a Chemical Equilibrium Model for a Molten Core-Concrete Interaction Analysis Module

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jae Uk; Lee, Dae Young; Park, Chang Hwan [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    This molten core could interact with the reactor cavity region which consists of concrete. In this process, components of molten core react with components of concrete through a lot of chemical reactions. As a result, many kinds of gas species are generated and those move up forming rising bubbles into the reactor containment atmosphere. These rising bubbles are the carrier of the many kinds of the aerosols coming from the MCCI (Molten Core Concrete Interaction) layers. To evaluate the amount of the aerosols released from the MCCI layers, the amount of the gas species generated from those layers should be calculated. The chemical equilibrium state originally implies the final state of the multiple chemical reactions; therefore, investigating the equilibrium composition of molten core can be applicable to predict the gas generation status. The most common way for finding the chemical equilibrium state is a minimization of total Gibbs free energy of the system. In this paper, the method to make good guess of initial state is suggested and chemical reaction results are compared with results of CSSI report No 164. Total mass of system and the number of atoms of each element are conserved. The tendency of calculation results is similar with results presented in CSNI Report except a few species. These differences may be caused by absence of Gibbs energy data of the species such as Fe{sub 2}SiO{sub 4}, CaFe{sub 2}O{sub 4}, U(OH){sub 3}, UO(OH), UO{sub 2}(OH), U{sub 3}O{sub 7}, La, Ce.

  19. Plant operational states analysis in low power and shutdown PSA

    International Nuclear Information System (INIS)

    He Jiandong; Qiu Yongping; Zhang Qinfang; An Hongzhen; Li Maolin

    2013-01-01

    The purpose of Plant Operational States (POS) analysis is to disperse the continuous and dynamic process of low power and shutdown operation, which is the basis of developing event tree models for accident sequence analysis. According to the design of a 300 MW Nuclear Power Plant Project, operating experience and procedures of the reference plant, a detailed POS analysis is carried out based on relative criteria. Then, several kinds of POS are obtained, and the duration of each POS is calculated according to the operation records of the reference plant. The POS analysis is an important element in low power and shutdown PSA. The methodology and contents provide reference for POS analysis. (authors)

  20. 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

  1. Investigation of the Factors Influencing Volatile Chemical Fate During Steady-state Accretion on Wet-growing Hail

    Science.gov (United States)

    Michael, R. A.; Stuart, A. L.

    2007-12-01

    Phase partitioning during freezing affects the transport and distribution of volatile chemical species in convective clouds. This consequently can have impacts on tropospheric chemistry, air quality, pollutant deposition, and climate change. Here, we discuss the development, evaluation, and application of a mechanistic model for the study and prediction of volatile chemical partitioning during steady-state hailstone growth. The model estimates the fraction of a chemical species retained in a two-phase freezing hailstone. It is based upon mass rate balances over water and solute for accretion under wet-growth conditions. Expressions for the calculation of model components, including the rates of super-cooled drop collection, shedding, evaporation, and hail growth were developed and implemented based on available cloud microphysics literature. Solute fate calculations assume equilibrium partitioning at air-liquid and liquid-ice interfaces. Currently, we are testing the model by performing mass balance calculations, sensitivity analyses, and comparison to available experimental data. Application of the model will improve understanding of the effects of cloud conditions and chemical properties on the fate of dissolved chemical species during hail growth.

  2. [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.

  3. Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States.

    Science.gov (United States)

    Kim, Min-Uk; Moon, Kyong Whan; Sohn, Jong-Ryeul; Byeon, Sang-Hoon

    2018-05-18

    We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA) tools. We used OCA tools Korea Offsite Risk Assessment (KORA) and Areal Location of Hazardous Atmospheres (ALOHA) in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH₃), 35% hydrogen chloride (HCl), 50% hydrofluoric acid (HF), and 69% nitric acid (HNO₃). The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS) program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

  4. Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States

    Directory of Open Access Journals (Sweden)

    Min-Uk Kim

    2018-05-01

    Full Text Available We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA tools. We used OCA tools Korea Offsite Risk Assessment (KORA and Areal Location of Hazardous Atmospheres (ALOHA in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH3, 35% hydrogen chloride (HCl, 50% hydrofluoric acid (HF, and 69% nitric acid (HNO3. The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

  5. The role of MgCl2 compounds in preparation of Tin oxide micro particles by one-step solid - state chemical reaction method and characterization of microstructure

    International Nuclear Information System (INIS)

    Hojabry, A.; Rezainik, Y.; Abdoljavad, N.; Moghimi, N.; Shakib, M.

    2007-01-01

    In this paper, Tin oxide (SnO 2 ) nano crystals have been synthesized by one-step solid-state chemical reactions method. In the first step, the powder of SnCl 4 . 5H 2 O was mixed with MgCl 2 and Mg(OH) 2 with a weight ratio of Sn to Mg (2:1) in the air atmosphere at room, and then annealed at 200 d egree C , 400 d egree C and 600 d egree C in air for 4 h to give different size of nanoparticles. This method is a simple, efficient and economic preparation for SnO 2 nanoparticles with adjustable grain sizes in the range of 7-32 nm in high yield. The microstructure and morphology of SnO 2 nanoparticles have been studied by X-ray diffraction (XRD), scanning electron microscopy and thermal analysis (thermogravimetric analysis -differential thermal analysis).

  6. Chemical effects of Iron-ore mining and processing at Itakpe, Kogi State

    International Nuclear Information System (INIS)

    Audu, D. A.; Ibeanu, I. G. E.; Yusuf, J. Z.

    2011-01-01

    X-ray fluorescence (XRF) technique was employed to generate data from soil samples collected from mine, industrial plant, and mill tailing deposit sites of National Iron-Ore Mining Project, Itakpe, Kogi State. The vertical profile analysis showed that As, Pb, Th, and U which are all toxic have their highest mean values of 91±8(81-100), 138±28(110-183), 49±12(39-68), and 37±2(34-40) ppm, respectively at the tailing deposit site. The result also showed a common occurrence of high concentrations of Pb and As at some depths in the vertical profiles after initial decline from the earth surface at the three sites thereby suggesting that absolute reclamation of old mines may not be possible immediately and that any new use or practice of such reclaimed mines should be carefully chosen. Correlation coefficients between arsenic and Pb, Cu, Mn, Zn, and Fe, at the industrial plant site (which is very close to an unmodified environment) were 0.997, 0.942, 0.896, 0.972, and 0.932, respectively. These values therefore suggest strong associations of As with ores of these minerals. The soil samples mean pH value of 6.5±0.1(5.7-7.2) was measured indicating non existence of Acid Mine Drainage at the company.

  7. Characterization of soil chemical properties of strawberry fields using principal component analysis

    Directory of Open Access Journals (Sweden)

    Gláucia Oliveira Islabão

    2013-02-01

    Full Text Available One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS is Turuçu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA. Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM, soil total nitrogen (N, available phosphorus (P and potassium (K, exchangeable calcium (Ca and magnesium (Mg, soil pH (pH, cation exchange capacity (CEC at pH 7.0, soil base (V% and soil aluminum saturation(m%. No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content.

  8. Current state and temporal evolution of the chemical composition of atmospheric depositions in forest areas of the CONECOFOR network

    Directory of Open Access Journals (Sweden)

    Marchetto A

    2014-04-01

    Full Text Available Current state and temporal evolution of the chemical composition of atmospheric depositions in forest areas of the CONECOFOR network. Since 1997, atmospheric deposition was sampled and analyzed in the permanent plots of the Italian network for the evaluation of forest health (CONECOFOR, under the coordination of the Italian Forest Service. This paper presents the results of the activity carried out in 2009, when the EU-funded LIFE+ “FutMon” project allowed to extend the sampling network to 22 sites. Long-term trends will also be evaluated for the sampling sites with the longest time series. The sampling of open field bulk deposition was performed in a clearance close to the CONECOFOR permanent plots, while throughfall deposition and stemflow (in beech stand, only were sampled in the plot. Deposition samples were collected weekly and sent to the laboratories, where they were analyzed for pH, conductivity, major ions, and total carbon and nitrogen. Most measured variables showed a strong geographical gradient. For example, nitrogen deposition was relatively high in the Po plain (where the emissions of nitrogen oxides and ammonia are the highest and surrounding hills, reaching 10-20 kgN ha-1 y-1 in the open field and 13-25 kgN ha-1 y-1 in the throughfall. Sulphate deposition also showed a marked geographical gradient. Deposition of marine aerosol also had an important impact on the chemical composition of atmospheric deposition in Italy, together with the episodic deposition of Saharan dust, which showed a marked gradient, with highest values in the southernmost plots. Trend analysis was carried out on 10 sites running since the beginning of the program. A general negative trend in sulphate concentration was detected, paralleled in most plots by a positive trend in deposition pH, in good agreement with the strong reduction in the emission of sulphur dioxide recorded in the last decades. Nitrogen concentration also showed a significant decrease

  9. Practical chemical analysis of Pt and Pd based heterogeneous catalysts with hard X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, H., E-mail: YOSHIKAWA.Hideki@nims.go.jp [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Matolínová, I.; Matolín, V. [Charles University in Prague, Faculty of Mathematics and Physics, V Holešovičkách 2, 18000 Prague 8 (Czech Republic)

    2013-10-15

    Highlights: •Hard X-ray photoelectron spectroscopy (HAXPES) enables interface analysis of catalyst. •HAXPES enables overall analysis of porous film of Pt-doped CeO{sub 2} and related catalyst. •HAXPES enables analysis of trace elements for Pd and Pt{sub 3}Ni nanoparticle catalysts. -- Abstract: Interfacial properties including configuration, porosity, chemical states, and atomic diffusion greatly affect the performance of supported heterogeneous catalysts. Hard X-ray photoelectron spectroscopy (HAXPES) can be used to analyze the interfaces of heterogeneous catalysts because of its large information depth of more than 20 nm. We use HAXPES to examine Pt-doped CeO{sub 2} and related thin film catalysts evaporated on Si, carbon, and carbon nanotube substrates, because Pt-doped CeO{sub 2} has great potential as a noble metal-based heterogeneous catalyst for fuel cells. The HAXPES measurements clarify that the dopant material, substrate material, and surface pretreatment of substrate are important parameters that affect the interfacial properties of Pt-doped CeO{sub 2} and related thin film catalysts. Another advantage of HAXPES measurement of heterogeneous catalysts is that it can be used for chemical analysis of trace elements by detecting photoelectrons from deep core levels, which have large photoionization cross-sections in the hard X-ray region. We use HAXPES for chemical analysis of trace elements in Pd nanoparticle catalysts immobilized on sulfur-terminated substrates and Pt{sub 3}Ni nanoparticle catalysts enveloped by dendrimer molecules.

  10. 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.

  11. Countering Islamic State Messaging Through “Linkage-Based” Analysis

    Directory of Open Access Journals (Sweden)

    J.M. Berger

    2017-08-01

    Full Text Available The Islamic State’s recent losses on the battlefield, including significant casualties within its media and propaganda division, offer a unique opportunity to inject competing and alternative messages into the information space. This paper proposes that the content of such messages should be guided by a linkage-based analysis of existing Islamic State messaging. A linkage-based analysis of a top-level 2017 audio message by Islamic State spokesperson Abu Hasan al Muhajir offers several potential insights into crafting effective content for competing and alternative messages. A comparison of the 2017 work to earlier Islamic State messaging also reveals specific opportunities to undermine the credibility of the organisation’s broader propaganda programme by highlighting the organisation’s repeated failure to follow through on its extravagantly promised commitment to achieving its stated goals.

  12. Steepest-entropy-ascent quantum thermodynamic modeling of the relaxation process of isolated chemically reactive systems using density of states and the concept of hypoequilibrium state

    Science.gov (United States)

    Li, Guanchen; von Spakovsky, Michael R.

    2016-01-01

    This paper presents a study of the nonequilibrium relaxation process of chemically reactive systems using steepest-entropy-ascent quantum thermodynamics (SEAQT). The trajectory of the chemical reaction, i.e., the accessible intermediate states, is predicted and discussed. The prediction is made using a thermodynamic-ensemble approach, which does not require detailed information about the particle mechanics involved (e.g., the collision of particles). Instead, modeling the kinetics and dynamics of the relaxation process is based on the principle of steepest-entropy ascent (SEA) or maximum-entropy production, which suggests a constrained gradient dynamics in state space. The SEAQT framework is based on general definitions for energy and entropy and at least theoretically enables the prediction of the nonequilibrium relaxation of system state at all temporal and spatial scales. However, to make this not just theoretically but computationally possible, the concept of density of states is introduced to simplify the application of the relaxation model, which in effect extends the application of the SEAQT framework even to infinite energy eigenlevel systems. The energy eigenstructure of the reactive system considered here consists of an extremely large number of such levels (on the order of 10130) and yields to the quasicontinuous assumption. The principle of SEA results in a unique trajectory of system thermodynamic state evolution in Hilbert space in the nonequilibrium realm, even far from equilibrium. To describe this trajectory, the concepts of subsystem hypoequilibrium state and temperature are introduced and used to characterize each system-level, nonequilibrium state. This definition of temperature is fundamental rather than phenomenological and is a generalization of the temperature defined at stable equilibrium. In addition, to deal with the large number of energy eigenlevels, the equation of motion is formulated on the basis of the density of states and a set of

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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.

  18. 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)

  19. 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....

  20. 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.