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Sample records for sulfate columns analytical

  1. Radiochemical applications of insoluble sulfate columns. Analytical possibilities in the field of the fission product solutions

    International Nuclear Information System (INIS)

    Barrachina, M.; Sauvagnac, R.

    1962-01-01

    In this paper we go on with our study of the heterogeneous ion-isotopic exchange in column. At present, we apply it to determine the radiochemical composition of the raw solutions used in the industrial recuperation of the long-lived fission products. The separation of the radioelements contained in these solutions is carried out mainly by making use of small columns, 1-3 cm height, of BaSO 4 or SrSO 4 , under selected experimental conditions. These columns behave like a special type of inorganic exchangers, working by absorption or by ion-isotopic exchange depending on the cases,a nd they provide the means for the selective separation of several important fission products employing very small volumes of fixing and eluting solutions. (Author) 11 refs

  2. European Analytical Column

    DEFF Research Database (Denmark)

    Karlberg, B.; Grasserbauer, M.; Andersen, Jens Enevold Thaulov

    2009-01-01

    for European analytical chemistry. During the period 2002–07, Professor Grasserbauer was Director of the Institute for Environment and Sustainability, Joint Research Centre of the European Commission (EC), Ispra, Italy. There is no doubt that many challenges exist at the present time for all of us representing...

  3. Effect of sulfate fertilization on soil biota in grassland columns

    Science.gov (United States)

    Ikoyi, Israel; Donohue, John; Fowler, Andrew; Schmalenberger, Achim

    2017-04-01

    Sulfur (S) is an important macronutrient element in plant nutrition as a component of protein, enzymes, enzyme cofactors as well as being the major constituent of the amino acids cysteine and methionine. Organically bound S is the predominant form of S in the soil constituting up to 95% of S in agricultural soils. The most important form of S in terms of plant nutrition is inorganic sulfate which forms only about 5% of the total soil S content. Air pollution was the major source of S (as SO2) for plants, with up to 80% of the S obtained from this source. However, common effects of S limitation on crops such as chlorosis, yield reduction, and decrease in crop quality are becoming increasingly evident as atmospheric S supply has decreased in recent years. Recent research has shown that organically-bound S in soils is also plant-bioavailable, likely due to interconversion of organic S forms to inorganic sulfate by soil microbes. In this study, soil columns were setup in a greenhouse using moderate S (equivalent to Wisconsin S soil availability index of below 30) soils. The columns were planted with Lolium perenne and fertilized with 0 (control), 5 (low), 10 (medium) and 20 (high) kg/ha sulfate S alongside a full complement of other nutrients. Results after 14 weeks of management show a significant decrease (Pbacterial abundance of heterotrophs and aromatic sulfonate-utilizing bacteria upon S fertilization. In addition, soil from the top 20 cm of the column had significantly higher sulfatase activity compared to the bottom 20 cm. The medium and high S treatments had significantly higher grass dry matter yield compared to the control and low S treatments. All S treatments significantly shifted the bacterial community structure compared to the control. Overall, our preliminary results suggest that applying 5 kg/ ha S had similar effects on the soil biota as the control while the application of medium and high S had similar effects on most parameters. Moreover, this study

  4. The general packed column : an analytical solution

    NARCIS (Netherlands)

    Gielen, J.L.W.

    2000-01-01

    The transient behaviour of a packed column is considered. The column, uniformly packed on a macroscopic scale, is multi-structured on the microscopic level: the solid phase consists of particles, which may differ in incidence, shape or size, and other relevant physical properties. Transport in the

  5. Radiochemical applications of insoluble sulfate columns. Analytical possibilities in the field of the fission product solutions; Aplicaciones radioquimica de las columnas de precipitados de sulfatos insolubles. Contribucion al estudio de las soluciones envejecidas de productos de fision

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, M; Sauvagnac, R

    1962-07-01

    In this paper we go on with our study of the heterogeneous ion-isotopic exchange in column. At present, we apply it to determine the radiochemical composition of the raw solutions used in the industrial recuperation of the long-lived fission products. The separation of the radioelements contained in these solutions is carried out mainly by making use of small columns, 1-3 cm height, of BaSO{sub 4} or SrSO{sub 4}, under selected experimental conditions. These columns behave like a special type of inorganic exchangers, working by absorption or by ion-isotopic exchange depending on the cases,a nd they provide the means for the selective separation of several important fission products employing very small volumes of fixing and eluting solutions. (Author) 11 refs.

  6. Effect of bioaugmentation and biostimulation on sulfate-reducing column startup captured by functional gene profiling.

    Science.gov (United States)

    Pereyra, Luciana P; Hiibel, Sage R; Perrault, Elizabeth M; Reardon, Kenneth F; Pruden, Amy

    2012-10-01

    Sulfate-reducing permeable reactive zones (SR-PRZs) depend upon a complex microbial community to utilize a lignocellulosic substrate and produce sulfides, which remediate mine drainage by binding heavy metals. To gain insight into the impact of the microbial community composition on the startup time and pseudo-steady-state performance, functional genes corresponding to cellulose-degrading (CD), fermentative, sulfate-reducing, and methanogenic microorganisms were characterized in columns simulating SR-PRZs using quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE). Duplicate columns were bioaugmented with sulfate-reducing or CD bacteria or biostimulated with ethanol or carboxymethyl cellulose and compared with baseline dairy manure inoculum and uninoculated controls. Sulfate removal began after ~ 15 days for all columns and pseudo-steady state was achieved by Day 30. Despite similar performance, DGGE profiles of 16S rRNA gene and functional genes at pseudo-steady state were distinct among the column treatments, suggesting the potential to control ultimate microbial community composition via bioaugmentation and biostimulation. qPCR revealed enrichment of functional genes in all columns between the initial and pseudo-steady-state time points. This is the first functional gene-based study of CD, fermentative and sulfate-reducing bacteria and methanogenic archaea in a lignocellulose-based environment and provides new qualitative and quantitative insight into startup of a complex microbial system. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  7. CHROMIUM(VI REDUCTION BY A MIXED CULTURE OF SULFATE REDUCING BACTERIA DEVELOPED IN COLUMN REACTOR

    Directory of Open Access Journals (Sweden)

    Cynthia Henny

    2008-03-01

    Full Text Available A lactate enriched mixed sulfate reducing bacteria (SRB culture was examined for the reduction of Cr(VI in a continuous flow system. The influent was mineral salts media added with lactate and sulfate with amounts of 8 and 6 mM respectively as electron donor and electron acceptor. The SRB culture was allowed to stabilize in the column before adding the Cr(VI to the influent. Chromium and sulfate reduction and lactate oxidation were examined by measuring the concentrations of Cr(Vl, sulfate and lactate in the influent and the effluent over time. The experiment was discontinued when Cr(VI concentration in the effiuent was breakthrough. In the absence of Cr(VI, sulfate was not completely reduced in the column, although lactate was completely oxidized and acetate as an intermediate product was not often detected. Almost all of Cr(VI loaded was reduced in the column seeded with the SRB culture at influent Cr(VI concentrations of 192,385 and769 mM. There was no significant Cr(VI loss in the control column, indicating that Cr(VI removal was due to the reduction of Cr(VI to Cr (lll by the SRB culture. The instantaneous Cr(VI removal decreased to a minimum of 32%, 24 days after the influent Cr(VI concentration was increased to 1540 mM, ancl sulfate removal efficiency decreased to a minimum of 17%. The SRB population in the column decreased 100 days after C(VI was added to the column. The total mass of Cr(VI reduced was approximately 878 mmol out of 881 mmol of Cr(Vl loaded in 116 days. The results clearly show that our developed SRB culture could reduced Cr(Vl considerably.

  8. Column-Oriented Databases, an Alternative for Analytical Environment

    Directory of Open Access Journals (Sweden)

    Gheorghe MATEI

    2010-12-01

    Full Text Available It is widely accepted that a data warehouse is the central place of a Business Intelligence system. It stores all data that is relevant for the company, data that is acquired both from internal and external sources. Such a repository stores data from more years than a transactional system can do, and offer valuable information to its users to make the best decisions, based on accurate and reliable data. As the volume of data stored in an enterprise data warehouse becomes larger and larger, new approaches are needed to make the analytical system more efficient. This paper presents column-oriented databases, which are considered an element of the new generation of DBMS technology. The paper emphasizes the need and the advantages of these databases for an analytical environment and make a short presentation of two of the DBMS built in a columnar approach.

  9. Copper (II) Removal In Anaerobic Continuous Column Reactor System By Using Sulfate Reducing Bacteria

    Science.gov (United States)

    Bilgin, A.; Jaffe, P. R.

    2017-12-01

    Copper is an essential element for the synthesis of the number of electrons carrying proteins and the enzymes. However, it has a high level of toxicity. In this study; it is aimed to treat copper heavy metal in anaerobic environment by using anaerobic continuous column reactor. Sulfate reducing bacteria culture was obtained in anaerobic medium using enrichment culture method. The column reactor experiments were carried out with bacterial culture obtained from soil by culture enrichment method. The system is operated with continuous feeding and as parallel. In the first rector, only sand was used as packing material. The first column reactor was only fed with the bacteria nutrient media. The same solution was passed through the second reactor, and copper solution removal was investigated by continuously feeding 15-600 mg/L of copper solution at the feeding inlet in the second reactor. When the experiment was carried out by adding the 10 mg/L of initial copper concentration, copper removal in the rate of 45-75% was obtained. In order to determine the use of carbon source during copper removal of mixed bacterial cultures in anaerobic conditions, total organic carbon TOC analysis was used to calculate the change in carbon content, and it was calculated to be between 28% and 75%. When the amount of sulphate is examined, it was observed that it changed between 28-46%. During the copper removal, the amounts of sulphate and carbon moles were equalized and more sulfate was added by changing the nutrient media in order to determine the consumption of sulphate or carbon. Accordingly, when the concentration of added sulphate is increased, it is calculated that between 35-57% of sulphate is spent. In this system, copper concentration of up to 15-600 mg / L were studied.

  10. A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Restaino, Odile Francesca, E-mail: odilefrancesca.restaino@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Finamore, Rosario, E-mail: rosario.finamore@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Diana, Paola, E-mail: paola.diana@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Marseglia, Mariacarmela, E-mail: marimars84@hotmail.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Vitiello, Mario, E-mail: mariovitiello.ita@gmail.com [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Casillo, Angela, E-mail: angela.casillo@unina.it [Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); Bedini, Emiliano, E-mail: emiliano.bedini@unina.it [Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); Parrilli, Michelangelo, E-mail: michelangelo.parrilli@unina.it [Department of Biology, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); and others

    2017-03-15

    Chondroitin sulfate is a glycosaminoglycan widely used as active principle of anti-osteoarthritis drugs and nutraceuticals, manufactured by extraction from animal cartilaginous tissues. During the manufacturing procedures, another glycosaminoglycan, the keratan sulfate, might be contemporarily withdrawn, thus eventually constituting a contaminant difficult to be determined because of its structural similarity. Considering the strict regulatory rules on the pureness of pharmaceutical grade chondrotin sulfate there is an urgent need and interest to determine the residual keratan sulfate with specific, sensitive and reliable methods. To pursue this aim, in this paper, for the first time, we set up a multi-analytical and preparative approach based on: i) a newly developed method by high performance anion-exchange chromatography with pulsed amperometric detection, ii) gas chromatography-mass spectrometry analyses, iii) size exclusion chromatography analyses coupled with triple detector array module and on iv) strong anion exchange chromatography separation. Varied KS percentages, in the range from 0.1 to 19.0% (w/w), were determined in seven pharmacopeia and commercial standards and nine commercial samples of different animal origin and manufacturers. Strong anion exchange chromatography profiles of the samples showed three or four different peaks. These peaks analyzed by high performance anion-exchange with pulsed amperometric detection and size exclusion chromatography with triple detector array, ion chromatography and by mono- or two-dimensional nuclear magnetic resonance revealed a heterogeneous composition of both glycosaminoglycans in terms of sulfation grade and molecular weight. High molecular weight species (>100 KDa) were also present in the samples that counted for chains still partially linked to a proteoglycan core. - Highlights: • A multi-analytical approach was set up, for the first time, for the determination of the residual keratan sulfate

  11. A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate

    International Nuclear Information System (INIS)

    Restaino, Odile Francesca; Finamore, Rosario; Diana, Paola; Marseglia, Mariacarmela; Vitiello, Mario; Casillo, Angela; Bedini, Emiliano; Parrilli, Michelangelo

    2017-01-01

    Chondroitin sulfate is a glycosaminoglycan widely used as active principle of anti-osteoarthritis drugs and nutraceuticals, manufactured by extraction from animal cartilaginous tissues. During the manufacturing procedures, another glycosaminoglycan, the keratan sulfate, might be contemporarily withdrawn, thus eventually constituting a contaminant difficult to be determined because of its structural similarity. Considering the strict regulatory rules on the pureness of pharmaceutical grade chondrotin sulfate there is an urgent need and interest to determine the residual keratan sulfate with specific, sensitive and reliable methods. To pursue this aim, in this paper, for the first time, we set up a multi-analytical and preparative approach based on: i) a newly developed method by high performance anion-exchange chromatography with pulsed amperometric detection, ii) gas chromatography-mass spectrometry analyses, iii) size exclusion chromatography analyses coupled with triple detector array module and on iv) strong anion exchange chromatography separation. Varied KS percentages, in the range from 0.1 to 19.0% (w/w), were determined in seven pharmacopeia and commercial standards and nine commercial samples of different animal origin and manufacturers. Strong anion exchange chromatography profiles of the samples showed three or four different peaks. These peaks analyzed by high performance anion-exchange with pulsed amperometric detection and size exclusion chromatography with triple detector array, ion chromatography and by mono- or two-dimensional nuclear magnetic resonance revealed a heterogeneous composition of both glycosaminoglycans in terms of sulfation grade and molecular weight. High molecular weight species (>100 KDa) were also present in the samples that counted for chains still partially linked to a proteoglycan core. - Highlights: • A multi-analytical approach was set up, for the first time, for the determination of the residual keratan sulfate

  12. Radial heterogeneity of some analytical columns used in high-performance liquid chromatography.

    Science.gov (United States)

    Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

    2009-04-10

    An on-column electrochemical microdetector was used to determine accurately the radial distribution of the mobile phase velocity and of the column efficiency at the exit of three common analytical columns, namely a 100 mm x 4.6mm C18 bonded silica-based monolithic column, a 150 mm x 4.6mm column packed with 2.7 microm porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6mm column packed with 3 microm fully porous C18 bonded silica particles (LUNA). The results obtained demonstrate that all three columns are not radially homogeneous. In all three cases, the efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius). The decrease in local efficiency from the core to the wall regions was lower in the case of the monolith (ca. 25%) than in that of the two particle-packed columns (ca. 35-50%). The mobile phase velocity was found to be ca. 1.5% higher in the wall than in the core region of the monolithic column while, in contrast, it was ca. 2.5-4.0% lower in the wall region for the two particle-packed columns.

  13. European analytical column No. 36 from the Division of Analytical Chemistry (DAC) of the European Association for Chemical and Molecular Sciences (EuCheMS)

    DEFF Research Database (Denmark)

    Karlberg, Bo; Emons, Hendrik; Andersen, Jens Enevold Thaulov

    2008-01-01

    European analytical column no. 36 from the division of analytical chemistry (DAC) of the European association for chemical and molecular sciences (EuCheMS)......European analytical column no. 36 from the division of analytical chemistry (DAC) of the European association for chemical and molecular sciences (EuCheMS)...

  14. 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]....

  15. A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate.

    Science.gov (United States)

    Restaino, Odile Francesca; Finamore, Rosario; Diana, Paola; Marseglia, Mariacarmela; Vitiello, Mario; Casillo, Angela; Bedini, Emiliano; Parrilli, Michelangelo; Corsaro, Maria Michela; Trifuoggi, Marco; De Rosa, Mario; Schiraldi, Chiara

    2017-03-15

    Chondroitin sulfate is a glycosaminoglycan widely used as active principle of anti-osteoarthritis drugs and nutraceuticals, manufactured by extraction from animal cartilaginous tissues. During the manufacturing procedures, another glycosaminoglycan, the keratan sulfate, might be contemporarily withdrawn, thus eventually constituting a contaminant difficult to be determined because of its structural similarity. Considering the strict regulatory rules on the pureness of pharmaceutical grade chondrotin sulfate there is an urgent need and interest to determine the residual keratan sulfate with specific, sensitive and reliable methods. To pursue this aim, in this paper, for the first time, we set up a multi-analytical and preparative approach based on: i) a newly developed method by high performance anion-exchange chromatography with pulsed amperometric detection, ii) gas chromatography-mass spectrometry analyses, iii) size exclusion chromatography analyses coupled with triple detector array module and on iv) strong anion exchange chromatography separation. Varied KS percentages, in the range from 0.1 to 19.0% (w/w), were determined in seven pharmacopeia and commercial standards and nine commercial samples of different animal origin and manufacturers. Strong anion exchange chromatography profiles of the samples showed three or four different peaks. These peaks analyzed by high performance anion-exchange with pulsed amperometric detection and size exclusion chromatography with triple detector array, ion chromatography and by mono- or two-dimensional nuclear magnetic resonance revealed a heterogeneous composition of both glycosaminoglycans in terms of sulfation grade and molecular weight. High molecular weight species (>100 KDa) were also present in the samples that counted for chains still partially linked to a proteoglycan core. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.

  16. DCODE: A Distributed Column-Oriented Database Engine for Big Data Analytics

    OpenAIRE

    Liu, Yanchen; Cao, Fang; Mortazavi, Masood; Chen, Mengmeng; Yan, Ning; Ku, Chi; Adnaik, Aniket; Morgan, Stephen; Shi, Guangyu; Wang, Yuhu; Fang, Fan

    2015-01-01

    Part 10: Big Data and Text Mining; International audience; We propose a novel Distributed Column-Oriented Database Engine (DCODE) for efficient analytic query processing that combines advantages of both column storage and parallel processing. In DCODE, we enhance an existing open-source columnar database engine by adding the capability for handling queries over a cluster. Specifically, we studied parallel query execution and optimization techniques such as horizontal partitioning, exchange op...

  17. Analytical modeling of post-tensioned precast beam-to-column connections

    International Nuclear Information System (INIS)

    Kaya, Mustafa; Arslan, A. Samet

    2009-01-01

    In this study, post-tensioned precast beam-to-column connections are tested experimentally at different stress levels, and are modelled analytically using 3D nonlinear finite element modelling method. ANSYS finite element software is used for this purposes. Nonlinear static analysis is used to determine the connection strength, behavior and stiffness when subjected to cyclic inelastic loads simulating ground excitation during an earthquake. The results obtained from the analytical studies are compared with the test results. In terms of stiffness, it was seen that the initial stiffness of the analytical models was lower than that of the tested specimens. As a result, modelling of these types of connection using 3D FEM can give crucial beforehand information, and overcome the disadvantages of time consuming workmanship and cost of experimental studies.

  18. The influence of Methanol and Acetonitrile in the Borate-Gluconate eluent the separation of Nitrate, Phosphate and Sulfate Anions by IC A column

    International Nuclear Information System (INIS)

    Djokowidodo; Bambang-Edi HB; Budi-Setiawan

    1996-01-01

    The modified of Borate-Gluconate solution has been used for the separation of nitrate, phosphate, sulfate anions with methanol and acetonitrile additions. The addition of acetonitrile increased the resolution of nitrate-phosphate, meanwhile the resolution of phosphate-sulfate decreased. The addition of methanol increased the resolutions of nitrate-phosphate, and phosphate-sulfate. The best separation of nitrate, phosphate and sulfate anions with IC. A column were done at the mixture of eluent Natrium Borate Gluconate:Butanol:Acetonitril:water = 1: 1: 10: 38. The best resolution of nitrate-phosphate was 2.4 with the eluent mixture at the ratio of 1 part of borate-gluconate, 1 part of butanol, and 10 part of acetonitrile, and the best resolution of the phosphate-sulfate, was done by the eluent mixture at the with of 1 part of borate-gluconate, 1 part of butanol, and 10 parts of methanol

  19. Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography

    Directory of Open Access Journals (Sweden)

    Nicole Riddell

    2016-11-01

    Full Text Available Hexabromocyclododecane (HBCDD is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+ and (− enantiomers of α-, β-, and γ-HBCDD were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD, was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

  20. Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography.

    Science.gov (United States)

    Riddell, Nicole; Mullin, Lauren Gayle; van Bavel, Bert; Ericson Jogsten, Ingrid; McAlees, Alan; Brazeau, Allison; Synnott, Scott; Lough, Alan; McCrindle, Robert; Chittim, Brock

    2016-11-10

    Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+) and (-) enantiomers of α-, β-, and γ-HBCDD) were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC) separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC) methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD), was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

  1. An integrated approach using orthogonal analytical techniques to characterize heparan sulfate structure.

    Science.gov (United States)

    Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Gunay, Nur Sibel; Wang, Jing; Sun, Elaine Y; Pradines, Joël R; Farutin, Victor; Shriver, Zachary; Kaundinya, Ganesh V; Capila, Ishan

    2017-02-01

    Heparan sulfate (HS), a glycosaminoglycan present on the surface of cells, has been postulated to have important roles in driving both normal and pathological physiologies. The chemical structure and sulfation pattern (domain structure) of HS is believed to determine its biological function, to vary across tissue types, and to be modified in the context of disease. Characterization of HS requires isolation and purification of cell surface HS as a complex mixture. This process may introduce additional chemical modification of the native residues. In this study, we describe an approach towards thorough characterization of bovine kidney heparan sulfate (BKHS) that utilizes a variety of orthogonal analytical techniques (e.g. NMR, IP-RPHPLC, LC-MS). These techniques are applied to characterize this mixture at various levels including composition, fragment level, and overall chain properties. The combination of these techniques in many instances provides orthogonal views into the fine structure of HS, and in other instances provides overlapping / confirmatory information from different perspectives. Specifically, this approach enables quantitative determination of natural and modified saccharide residues in the HS chains, and identifies unusual structures. Analysis of partially digested HS chains allows for a better understanding of the domain structures within this mixture, and yields specific insights into the non-reducing end and reducing end structures of the chains. This approach outlines a useful framework that can be applied to elucidate HS structure and thereby provides means to advance understanding of its biological role and potential involvement in disease progression. In addition, the techniques described here can be applied to characterization of heparin from different sources.

  2. Analytical methodology for determination of the sulfate in vinasse samples; Metodologia analitica para a determinacao de sulfato em vinhoto

    Energy Technology Data Exchange (ETDEWEB)

    Prada, Silvio Miranda; Guekezian, Marcia; Suarez-Ilha, Maria Encarnacion V. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica

    1998-05-01

    When sulfate is present in high concentrations, it acts as an inhibitor in the production of methane (Biogas Formation) in anaerobic biodigestion processes. In this way it is very important to know the sulfate concentration in vinasse samples before to make the biodigester design. A previous developed and indirect method (Anal. Chim. Acta. 1996, 329, 197), was used to determine sulfate in samples of vinasse, after previous treatments, done in order to eliminate organic matter with hydrogen peroxide 30% and concentrated nitric acid mixture (3:1), under heating. Interferent cationic ions were isolated by using ion exchange columns. The results obtained for some samples from Araraquara and Penapolis are here presented. The phosphate concentration was also determined. (author) 23 refs., 3 tabs.

  3. An Analytical Method for Determining the Load Distribution of Single-Column Multibolt Connection

    Directory of Open Access Journals (Sweden)

    Nirut Konkong

    2017-01-01

    Full Text Available The purpose of this research was to investigate the effect of geometric variables on the bolt load distributions of a cold-formed steel bolt connection. The study was conducted using an experimental test, finite element analysis, and an analytical method. The experimental study was performed using single-lap shear testing of a concentrically loaded bolt connection fabricated from G550 cold-formed steel. Finite element analysis with shell elements was used to model the cold-formed steel plate while solid elements were used to model the bolt fastener for the purpose of studying the structural behavior of the bolt connections. Material nonlinearities, contact problems, and a geometric nonlinearity procedure were used to predict the failure behavior of the bolt connections. The analytical method was generated using the spring model. The bolt-plate interaction stiffness was newly proposed which was verified by the experiment and finite element model. It was applied to examine the effect of geometric variables on the single-column multibolt connection. The effects were studied of varying bolt diameter, plate thickness, and the plate thickness ratio (t2/t1 on the bolt load distribution. The results of the parametric study showed that the t2/t1 ratio controlled the efficiency of the bolt load distribution more than the other parameters studied.

  4. European analytical column no. 37 (January 2009) Division of Analytical Chemistry (DAC) of the European Association for Chemical and Molecular Sciences (EuCheMS)

    DEFF Research Database (Denmark)

    Karlberg, Bo; Grasserbauer, Manfred; Andersen, Jens Enevold Thaulov

    2009-01-01

    This issue of the European Analytical Column has again a somewhat different format: once more DAC invited a guest columnist to give his views on various matters related to Analytical Chemistry in Europe. This year, Professor Manfred Grasserbauer of the Vienna University of Technology focuses...... representing a major branch of chemistry, namely analytical chemistry. The global financial crisis is affecting all branches of chemistry, especially analytical chemistry since our discipline by tradition has many close links to industry. Already now a decrease of industrial commitment with respect to new...... research projects and sponsoring of conferences can be observed. It is therefore important to strengthen all efforts and to keep the presence of analytical chemists at meetings and conferences unchanged. Recent activities of DAC and details regarding the major analytical-chemistry event this year in Europe...

  5. European analytical column No. 37 from the Division of Analytical Chemistry (DAC) of the European Association for Chemical and Molecular Sciences (EuCheMS)

    DEFF Research Database (Denmark)

    Karlberg, Bo; Grasserbauer, Manfred; Andersen, Jens Enevold Thaulov

    2009-01-01

    The European Analytical Column again has a somewhat different format. We have once more invited a guest columnist to give his views on various matters related to analytical chemistry in Europe. This year we have invited Prof. Manfred Grasserbauer of Vienna University of Technology to present some...... representing a major branch of chemistry, namely, analytical chemistry. The global financial crisis is affecting all branches of chemistry, but analytical chemistry in particular since our discipline by tradition has many close links to industry. We are already noticing a decreased industrial commitment...... with respect to new research projects and sponsoring of conferences. It is therefore important that we strengthen our efforts and that we keep our presence at analytical chemistry meetings and conferences unchanged. Recent activities of the Division of Analytical Chemistry (DAC) and details regarding the major...

  6. Lateral force resisting mechanisms in slab-column connections: An analytical approach

    OpenAIRE

    Drakatos, Iaonnis; Beyer, Katrin; Muttoni, Aurelio

    2014-01-01

    In many countries reinforced concrete (RC) flat slabs supported on columns is one of the most commonly used structural systems for office and industrial buildings. To increase the lateral stiffness and strength of the structure, RC walls are typically added and carry the largest portion of the horizontal loads generated during earthquakes. While the slab-column system is typically not relevant with regard to the lateral stiffness and strength of the structure, each slab-column connection has ...

  7. The art and science of forming packed analytical high-performance liquid chromatography columns.

    Science.gov (United States)

    Kirkland, J J; Destefano, J J

    2006-09-08

    Columns of packed particles still are the most popular devices for high-performance liquid chromatography (HPLC) separations because of their great utility, excellent performance and wide variety. However, the forming of packed beds for efficient, stable columns traditionally has been an art where the basics of how to form optimum beds generally was not well understood. The recent development of monolith rods was introduced in part to overcome the difficulty of producing stable beds of packing particles. However, these materials are less versatile than packed particle columns. Technology developments in recent years have produced a better understanding among those skilled in the practice of how to form optimized packed beds, and this has led to widely available, high-quality commercial columns. This presentation discusses the developments that led to the present state of column packing technology. Important steps in the packing of efficient, stable beds are described. The key step of selecting the best solvent for the slurry packing method is emphasized. Factors affecting the mechanical stability of packed columns also are discussed. The early art of packing columns now has evolved into a more scientific approach that allows the packing of good columns with a minimum of effort and time.

  8. Two-column sequential injection chromatography for fast isocratic separation of two analytes of greatly differing chemical properties.

    Science.gov (United States)

    Šatínský, Dalibor; Chocholouš, Petr; Válová, Olga; Hanusová, Lucia; Solich, Petr

    2013-09-30

    This paper deals with a novel approach to separate two analytes with different chemical properties and different lipophilicity. The newly described methodology is based on the two column system that was used for isocratic separation of two analytes with very different lipophilicity-dexamethasone and cinchocaine. Simultaneous separation of model compounds cinchocaine and dexamethasone was carried under the following conditions in two-column sequential injection chromatography system (2-C SIC). A 25×4.6 mm C-18 monolithic column was used in the first dimension for retention and separation of dexamethasone with mobile phase acetonitrile:water 30:70 (v/v), flow rate 0.9 mL min(-1) and consumption of 1.7 mL. A 10×4.6 mm C-18 monolithic column with 5×4.6 mm C-18 precolumn was used in the second dimension for retention and separation of cinchocaine using mobile phase acetonitrile:water 60:40 (v/v), flow rate 0.9 mL min(-1) and consumption 1.5 mL. Whole analysis time including both mobile phase's aspirations and both column separations was performed in less than 4 min. The method was fully validated and used for determination of cinchocaine and dexamethasone in pharmaceutical otic drops. The developed 2-C SIC method was compared with HPLC method under the isocratic conditions of separation on monolithic column (25×4.6 mm C-18). Spectrophotometric detection of both compounds was performed at wavelength 240 nm. System repeatability and method precision were found in the range (0.39-3.12%) for both compounds. Linearity of determination was evaluated in the range 50-500 μg mL(-1) and coefficients of determination were found to be r(2)=0.99912 for dexamethasone and r(2)=0.99969 for cinchocaine. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Mercury mobilization and speciation linked to bacterial iron oxide and sulfate reduction: A column study to mimic reactive transfer in an anoxic aquifer.

    Science.gov (United States)

    Hellal, Jennifer; Guédron, Stéphane; Huguet, Lucie; Schäfer, Jörg; Laperche, Valérie; Joulian, Catherine; Lanceleur, Laurent; Burnol, André; Ghestem, Jean-Philippe; Garrido, Francis; Battaglia-Brunet, Fabienne

    2015-09-01

    Mercury (Hg) mobility and speciation in subsurface aquifers is directly linked to its surrounding geochemical and microbial environment. The role of bacteria on Hg speciation (i.e., methylation, demethylation and reduction) is well documented, however little data is available on their impact on Hg mobility. The aim of this study was to test if (i) Hg mobility is due to either direct iron oxide reduction by iron reducing bacteria (IRB) or indirect iron reduction by sulfide produced by sulfate reducing bacteria (SRB), and (ii) to investigate its subsequent fate and speciation. Experiments were carried out in an original column setup combining geochemical and microbiological approaches that mimic an aquifer including an interface of iron-rich and iron depleted zones. Two identical glass columns containing iron oxides spiked with Hg(II) were submitted to (i) direct iron reduction by IRB and (ii) to indirect iron reduction by sulfides produced by SRB. Results show that in both columns Hg was leached and methylated during the height of bacterial activity. In the column where IRB are dominant, Hg methylation and leaching from the column was directly correlated to bacterial iron reduction (i.e., Fe(II) release). In opposition, when SRB are dominant, produced sulfide induced indirect iron oxide reduction and rapid adsorption of leached Hg (or produced methylmercury) on neoformed iron sulfides (e.g., Mackinawite) or its precipitation as HgS. At the end of the SRB column experiment, when iron-oxide reduction was complete, filtered Hg and Fe concentrations increased at the outlet suggesting a leaching of Hg bound to FeS colloids that may be a dominant mechanism of Hg transport in aquifer environments. These experimental results highlight different biogeochemical mechanisms that can occur in stratified sub-surface aquifers where bacterial activities play a major role on Hg mobility and changes in speciation. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Modelling by partial least squares the relationship between the HPLC mobile phases and analytes on phenyl column.

    Science.gov (United States)

    Markopoulou, Catherine K; Kouskoura, Maria G; Koundourellis, John E

    2011-06-01

    Twenty-five descriptors and 61 structurally different analytes have been used on a partial least squares (PLS) to latent structure technique in order to study chromatographically their interaction mechanism on a phenyl column. According to the model, 240 different retention times of the analytes, expressed as Y variable (log k), at different % MeOH mobile-phase concentrations have been correlated with their theoretical most important structural or molecular descriptors. The goodness-of-fit was estimated by the coefficient of multiple determinations r(2) (0.919), and the root mean square error of estimation (RMSEE=0.1283) values with a predictive ability (Q(2)) of 0.901. The model was further validated using cross-validation (CV), validated by 20 response permutations r(2) (0.0, 0.0146), Q(2) (0.0, -0.136) and validated by external prediction. The contribution of certain mechanism interactions between the analytes, the mobile phase and the column, proportional or counterbalancing is also studied. Trying to evaluate the influence on Y of every variable in a PLS model, VIP (variables importance in the projection) plot provides evidence that lipophilicity (expressed as Log D, Log P), polarizability, refractivity and the eluting power of the mobile phase are dominant in the retention mechanism on a phenyl column. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Analytical theory relating the depth of the sulfate-methane transition to gas hydrate distribution and saturation

    Science.gov (United States)

    Bhatnagar, Gaurav; Chatterjee, Sayantan; Chapman, Walter G.; Dugan, Brandon; Dickens, Gerald R.; Hirasaki, George J.

    2011-03-01

    We develop a theory that relates gas hydrate saturation in marine sediments to the depth of the sulfate-methane transition (SMT) zone below the seafloor using steady state, analytical expressions. These expressions are valid for systems in which all methane transported into the gas hydrate stability zone (GHSZ) comes from deeper external sources (i.e., advective systems). This advective constraint causes anaerobic oxidation of methane to be the only sulfate sink, allowing us to link SMT depth to net methane flux. We also develop analytical expressions that define the gas hydrate saturation profile based on SMT depth and site-specific parameters such as sedimentation rate, methane solubility, and porosity. We evaluate our analytical model at four drill sites along the Cascadia Margin where methane sources from depth dominate. With our model, we calculate average gas hydrate saturations across GHSZ and the top occurrence of gas hydrate at these sites as 0.4% and 120 mbsf (Site 889), 1.9% and 70 mbsf (Site U1325), 4.7% and 40 mbsf (Site U1326), and 0% (Site U1329), mbsf being meters below seafloor. These values compare favorably with average saturations and top occurrences computed from resistivity log and chloride data. The analytical expressions thus provide a fast and convenient method to calculate gas hydrate saturation and first-order occurrence at a given geologic setting where vertically upward advection dominates the methane flux.

  12. Comparison of Influenza Virus Particle Purification Using Magnetic Sulfated Cellulose Particles with an Established Centrifugation Method for Analytics.

    Science.gov (United States)

    Serve, Anja; Pieler, Michael Martin; Benndorf, Dirk; Rapp, Erdmann; Wolff, Michael Werner; Reichl, Udo

    2015-11-03

    A method for the purification of influenza virus particles using novel magnetic sulfated cellulose particles is presented and compared to an established centrifugation method for analytics. Therefore, purified influenza A virus particles from adherent and suspension MDCK host cell lines were characterized on the protein level with mass spectrometry to compare the viral and residual host cell proteins. Both methods allowed one to identify all 10 influenza A virus proteins, including low-abundance proteins like the matrix protein 2 and nonstructural protein 1, with a similar impurity level of host cell proteins. Compared to the centrifugation method, use of the novel magnetic sulfated cellulose particles reduced the influenza A virus particle purification time from 3.5 h to 30 min before mass spectrometry analysis.

  13. Two-Dimensional Model for Reactive-Sorption Columns of Cylindrical Geometry: Analytical Solutions and Moment Analysis.

    Science.gov (United States)

    Khan, Farman U; Qamar, Shamsul

    2017-05-01

    A set of analytical solutions are presented for a model describing the transport of a solute in a fixed-bed reactor of cylindrical geometry subjected to the first (Dirichlet) and third (Danckwerts) type inlet boundary conditions. Linear sorption kinetic process and first-order decay are considered. Cylindrical geometry allows the use of large columns to investigate dispersion, adsorption/desorption and reaction kinetic mechanisms. The finite Hankel and Laplace transform techniques are adopted to solve the model equations. For further analysis, statistical temporal moments are derived from the Laplace-transformed solutions. The developed analytical solutions are compared with the numerical solutions of high-resolution finite volume scheme. Different case studies are presented and discussed for a series of numerical values corresponding to a wide range of mass transfer and reaction kinetics. A good agreement was observed in the analytical and numerical concentration profiles and moments. The developed solutions are efficient tools for analyzing numerical algorithms, sensitivity analysis and simultaneous determination of the longitudinal and transverse dispersion coefficients from a laboratory-scale radial column experiment. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. The influence of salt chaotropicity, column hydrophobicity and analytes' molecular properties on the retention of pramipexole and its impurities.

    Science.gov (United States)

    Vemić, Ana; Kalinić, Marko; Erić, Slavica; Malenović, Anđelija; Medenica, Mirjana

    2015-03-20

    The aim of this study was to examine the interaction of the chaotropic salts of different position in Hofmeister series (CF3COONa, NaClO4, NaPF6) added to the mobile phase with the stationary phases of different hydrophobicity (C8 and C18 XTerra(®) columns), as well as their common influence on the retention behavior of pramipexole and its structurally related impurities. The extended thermodynamic approach enabled the understanding of the underlying separation mechanism. Comparing six different column-salt systems it was observed that general system hydrophobicity presented by salt chaotropicity and column hydrophobicity favors stationary phase ion-pairing over the ion-pair formation in the eluent. Further, an attempt was made to describe the influence of analytes' nature on their retention behavior in such chromatographic systems. An analysis is performed in order to select and elucidate the molecular descriptors (electrostatical, quantum-chemical, geometrical, topological, and constitutional) that best explain the experimental evidence and findings obtained by the thermodynamic approach. The results of this analysis suggest that analytes' charge distribution and its complementarity to the structure of the electric double layer formed on the surface of the stationary phase upon the addition of chaotropic additives can be useful for understanding the differences in retention of structurally related analytes. These findings provide a novel understanding of the interactions between all the components of the chromatographic system containing chaotropic additive and a good basis for further investigations suggesting the development of generally applicable predictors in structure-retention relationship studies in related chromatographic systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Preparation of Barley Storage Protein, Hordein, for Analytical Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis

    DEFF Research Database (Denmark)

    Doll, Hans; Andersen, Bente

    1981-01-01

    The extraction, reduction, and alkylation of barley hordein for routine electrophoresis in sodium dodecyl sulfate-polyacrylamide gels were studied to set up a simple preparation procedure giving well-resolved bands in the electrophoresis gel. Hordein was extracted from single crushed seeds or flour...... by aqueous 50% propan-2-ol containing a Tris-borate buffer, pH 8.6. The presence of the buffer facilitates the consecutive complete reduction of the extracted protein in the alcohol. Reduction and alkylation in the buffer containing propan-2-ol give sharper bands in the electrophoresis than reduction...

  16. MonetDB/DataCell: Online Analytics in a Streaming Column-Store

    NARCIS (Netherlands)

    E. Liarou (Erietta); S. Idreos (Stratos); S. Manegold (Stefan); M.L. Kersten (Martin)

    2012-01-01

    textabstractIn DataCell, we design streaming functionalities in a mod- ern relational database kernel which targets big data analyt- ics. This includes exploitation of both its storage/execution engine and its optimizer infrastructure. We investigate the opportunities and challenges that arise with

  17. MonetDB/DataCell: online analytics in a streaming column-store

    NARCIS (Netherlands)

    Liarou, E.; Idreos, S.; Manegold, S.; Kersten, M.

    2012-01-01

    In DataCell, we design streaming functionalities in a modern relational database kernel which targets big data analytics. This includes exploitation of both its storage/execution engine and its optimizer infrastructure. We investigate the opportunities and challenges that arise with such a direction

  18. Semi-permeable surface analytical reversed-phase column for the improved trace analysis of acidic pesticides in water with coupled-column reversed-phase liquid chromatography with UV detection. Determination of bromoxynil and bentazone in surface water.

    Science.gov (United States)

    Hogendoorn, E A; Westhuis, K; Dijkman, E; Heusinkveld, H A; den Boer, A C; Evers, E A; Baumann, R A

    1999-10-08

    The coupled-column (LC-LC) configuration consisting of a 3 microm C18 column (50 x 4.6 mm I.D.) as the first column and a 5 microm C18 semi-permeable-surface (SPS) column (150 x 4.6 mm I.D.) as the second column appeared to be successful for the screening of acidic pesticides in surface water samples. In comparison to LC-LC employing two C18 columns, the combination of C18/SPS-C18 significantly decreased the baseline deviation caused by the hump of the co-extracted humic substances when using UV detection (217 nm). The developed LC-LC procedure allowed the simultaneous determination of the target analytes bentazone and bromoxynil in uncleaned extracts of surface water samples to a level of 0.05 microg/l in less than 15 min. In combination with a simple solid-phase extraction step (200 ml of water on a 500 mg C18-bonded silica) the analytical procedure provides a high sample throughput. During a period of about five months more than 200 ditch-water samples originating from agricultural locations were analyzed with the developed procedure. Validation of the method was performed by randomly analyzing recoveries of water samples spiked at levels of 0.1 microg/l (n=10), 0.5 microg/l (n=7) and 2.5 microg/l (n=4). Weighted regression of the recovery data showed that the method provides overall recoveries of 95 and 100% for bentazone and bromoxynil, respectively, with corresponding intra-laboratory reproducibilities of 10 and 11%, respectively. Confirmation of the analytes in part of the samples extracts was carried out with GC-negative ion chemical ionization MS involving a derivatization step with bis(trifluoromethyl)benzyl bromide. No false negatives or positives were observed.

  19. Microwave assisted solvent extraction and coupled-column reversed-phase liquid chromatography with UV detection use of an analytical restricted-access-medium column for the efficient multi-residue analysis of acidic pesticides in soils.

    Science.gov (United States)

    Hogendoom, E A; Huls, R; Dijkman, E; Hoogerbrugge, R

    2001-12-14

    A screening method has been developed for the determination of acidic pesticides in various types of soils. Methodology is based on the use of microwave assisted solvent extraction (MASE) for fast and efficient extraction of the analytes from the soils and coupled-column reversed-phase liquid chromatography (LC-LC) with UV detection at 228 nm for the instrumental analysis of uncleaned extracts. Four types of soils, including sand, clay and peat, with a range in organic matter content of 0.3-13% and ten acidic pesticides of different chemical families (bentazone, bromoxynil, metsulfuron-methyl, 2,4-D, MCPA, MCPP, 2,4-DP, 2,4,5-T, 2,4-DB and MCPB) were selected as matrices and analytes, respectively. The method developed included the selection of suitable MASE and LC-LC conditions. The latter consisted of the selection of a 5-microm GFF-II internal surface reversed-phase (ISRP, Pinkerton) analytical column (50 x 4.6 mm, I.D.) as the first column in the RAM-C18 configuration in combination with an optimised linear gradient elution including on-line cleanup of sample extracts and reconditioning of the columns. The method was validated with the analysis of freshly spiked samples and samples with aged residues (120 days). The four types of soils were spiked with the ten acidic pesticides at levels between 20 and 200 microg/kg. Weighted regression of the recovery data showed for most analyte-matrix combinations, including freshly spiked samples and aged residues, that the method provides overall recoveries between 60 and 90% with relative standard deviations of the intra-laboratory reproducibility's between 5 and 25%; LODs were obtained between 5 and 50 microg/kg. Evaluation of the data set with principal component analysis revealed that the parameters (i) increase of organic matter content of the soil samples and (ii) aged residues negatively effect the recovery of the analytes.

  20. The passivation of calcite by acid mine water. Column experiments with ferric sulfate and ferric chloride solutions at pH 2

    Energy Technology Data Exchange (ETDEWEB)

    Soler, Josep M. [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain)], E-mail: jsoler@ija.csic.es; Boi, Marco [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain); Mogollon, Jose Luis [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Instituto de Ciencias de la Tierra, Universidad Central de Venezuela, Caracas 1020-A (Venezuela, Bolivarian Republic of); Cama, Jordi; Ayora, Carlos [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain); Nico, Peter S.; Tamura, Nobumichi; Kunz, Martin [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2008-12-15

    Column experiments, simulating the behavior of passive treatment systems for acid mine drainage, have been performed. Acid solutions (HCl or H{sub 2}SO{sub 4}, pH 2), with initial concentrations of Fe(III) ranging from 250 to 1500 mg L{sup -1}, were injected into column reactors packed with calcite grains at a constant flow rate. The composition of the solutions was monitored during the experiments. At the end of the experiments (passivation of the columns), the composition and structure of the solids were measured. The dissolution of calcite in the columns caused an increase in pH and the release of Ca into the solution, leading to the precipitation of gypsum and Fe-oxyhydroxysulfates (Fe(III)-SO{sub 4}-H{sup +} solutions) or Fe-oxyhydroxychlorides (Fe(III)-Cl-H{sup +} solutions). The columns worked as an efficient barrier for some time, increasing the pH of the circulating solutions from 2 to {approx}6-7 and removing its metal content. However, after some time (several weeks, depending on the conditions), the columns became chemically inert. The results showed that passivation time increased with decreasing anion and metal content of the solutions. Gypsum was the phase responsible for the passivation of calcite in the experiments with Fe(III)-SO{sub 4}-H{sup +} solutions. Schwertmannite and goethite appeared as the Fe(III) secondary phases in those experiments. Akaganeite was the phase responsible for the passivation of the system in the experiments with Fe(III)-Cl-H{sup +} solutions.

  1. Electrophoretic extraction of low molecular weight cationic analytes from sodium dodecyl sulfate containing sample matrices for their direct electrospray ionization mass spectrometry.

    Science.gov (United States)

    Kinde, Tristan F; Lopez, Thomas D; Dutta, Debashis

    2015-03-03

    While the use of sodium dodecyl sulfate (SDS) in separation buffers allows efficient analysis of complex mixtures, its presence in the sample matrix is known to severely interfere with the mass-spectrometric characterization of analyte molecules. In this article, we report a microfluidic device that addresses this analytical challenge by enabling inline electrospray ionization mass spectrometry (ESI-MS) of low molecular weight cationic samples prepared in SDS containing matrices. The functionality of this device relies on the continuous extraction of analyte molecules into an SDS-free solvent stream based on the free-flow zone electrophoresis (FFZE) technique prior to their ESI-MS analysis. The reported extraction was accomplished in our current work in a glass channel with microelectrodes fabricated along its sidewalls to realize the desired electric field. Our experiments show that a key challenge to successfully operating such a device is to suppress the electroosmotically driven fluid circulations generated in its extraction channel that otherwise tend to vigorously mix the liquid streams flowing through this duct. A new coating medium, N-(2-triethoxysilylpropyl) formamide, recently demonstrated by our laboratory to nearly eliminate electroosmotic flow in glass microchannels was employed to address this issue. Applying this surface modifier, we were able to efficiently extract two different peptides, human angiotensin I and MRFA, individually from an SDS containing matrix using the FFZE method and detect them at concentrations down to 3.7 and 6.3 μg/mL, respectively, in samples containing as much as 10 mM SDS. Notice that in addition to greatly reducing the amount of SDS entering the MS instrument, the reported approach allows rapid solvent exchange for facilitating efficient analyte ionization desired in ESI-MS analysis.

  2. A column exchange chromatographic procedure for the automated purification of analytical samples in nuclear spent fuel reprocessing and plutonium fuel fabrication

    International Nuclear Information System (INIS)

    Zahradnik, P.; Swietly, H.; Doubek, N.; Bagliano, G.

    1992-11-01

    A Column Exchange Chromatographic procedure using Tri-n-Octyl-Phosphine-Oxide (TOPO) as stationary phase, is in routine use at SAL since 1984 on nuclear spent fuel reprocessing and on Pu product samples, prior to alpha and mass spectrometric analysis. This standard procedure was further on modified in view of its automation in a glove box; the resulting new procedure is described in this paper. Laboratory Robot Compatible (LRC) disposable columns were selected because their dimensions are particularly favorable and reproducible. A less corrosive HNO 3 -HI mixture substituted the former HC1-HI plutonium eluant. The inorganic support of the stationary phase used to test the above mentioned changes was unexpectedly withdrawn from the market so that another support had to be selected and the procedure reoptimized accordingly. The resulting procedure was tested with the robot and validated against the manual procedure taken as reference: the comparison showed that the modified procedure meets the analytical requirements and has the same performance than the original procedure. (author). Refs, figs and tabs

  3. "In situ" extraction of essential oils by use of Dean-Stark glassware and a Vigreux column inside a microwave oven: a procedure for teaching green analytical chemistry.

    Science.gov (United States)

    Chemat, Farid; Perino-Issartier, Sandrine; Petitcolas, Emmanuel; Fernandez, Xavier

    2012-08-01

    One of the principal objectives of sustainable and green processing development remains the dissemination and teaching of green chemistry in colleges, high schools, and academic laboratories. This paper describes simple glassware that illustrates the phenomenon of extraction in a conventional microwave oven as energy source and a process for green analytical chemistry. Simple glassware comprising a Dean-Stark apparatus (for extraction of aromatic plant material and recovery of essential oils and distilled water) and a Vigreux column (as an air-cooled condenser inside the microwave oven) was designed as an in-situ extraction vessel inside a microwave oven. The efficiency of this experiment was validated for extraction of essential oils from 30 g fresh orange peel, a by-product in the production of orange juice. Every laboratory throughout the world can use this equipment. The microwave power is 100 W and the irradiation time 15 min. The method is performed at atmospheric pressure without added solvent or water and furnishes essential oils similar to those obtained by conventional hydro or steam distillation. By use of GC-MS, 22 compounds in orange peel were separated and identified; the main compounds were limonene (72.1%), β-pinene (8.4%), and γ-terpinene (6.9%). This procedure is appropriate for the teaching laboratory, does not require any special microwave equipment, and enables the students to learn the skills of extraction, and chromatographic and spectroscopic analysis. They are also exposed to a dramatic visual example of rapid, sustainable, and green extraction of an essential oil, and are introduced to successful sustainable and green analytical chemistry.

  4. Evaluation of Fire Resistance for H-Section Columns Made of Rolled Steels for General Structures and for Welded Structures by Analytic Method

    International Nuclear Information System (INIS)

    Kwon, In-Kyu

    2014-01-01

    Fire resistance is an important factor in sustaining the structural stability of steel framed buildings on fire. However, evaluation of the fire resistance of steel columns has been conducted using rolled steels for general structures, SS 400. Recently, rolled steels for welded structures, such as SM 400 and SM 490, have been used frequently because they have better performance of welding than the SS 400. However, there has been doubt about how much fire resistance SM 400 and SM 490 have. To evaluate by calculation the fire resistance of an H-section column made of SS 400 its mechanical and thermal properties were derived and suggested respectively in the form of regressive equations and the analysis was done based on heat transfer and thermal stress analysis. In this study, the results of the evaluation of H-section columns made of SS 400 with loaded fire tests turned out to be conservative. As a result, a new guideline is required to get the exact fire resistance of another structural steel.

  5. Significant role of organic sulfur in supporting sedimentary sulfate reduction in low-sulfate environments

    Science.gov (United States)

    Fakhraee, Mojtaba; Li, Jiying; Katsev, Sergei

    2017-09-01

    Dissimilatory sulfate reduction (DSR) is a major carbon mineralization pathway in aquatic sediments, soils, and groundwater, which regulates the production of hydrogen sulfide and the mobilization rates of biologically important elements such as phosphorus and mercury. It has been widely assumed that water-column sulfate is the main sulfur source to fuel this reaction in sediments. While this assumption may be justified in high-sulfate environments such as modern seawater, we argue that in low-sulfate environments mineralization of organic sulfur compounds can be an important source of sulfate. Using a reaction-transport model, we investigate the production of sulfate from sulfur-containing organic matter for a range of environments. The results show that in low sulfate environments (50%) of sulfate reduction. In well-oxygenated systems, porewater sulfate profiles often exhibit sub-interface peaks so that sulfate fluxes are directed out of the sediment. Our measurements in Lake Superior, the world's largest lake, corroborate this conclusion: offshore sediments act as sources rather than sinks of sulfate for the water column, and sediment DSR is supported entirely by the in-sediment production of sulfate. Sulfate reduction rates are correlated to the depth of oxygen penetration and strongly regulated by the supply of reactive organic matter; rate co-regulation by sulfate availability becomes appreciable below 500 μM level. The results indicate the need to consider the mineralization of organic sulfur in the biogeochemical cycling in low-sulfate environments, including several of the world's largest freshwater bodies, deep subsurface, and possibly the sulfate-poor oceans of the Early Earth.

  6. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  7. Barium Sulfate

    Science.gov (United States)

    ... uses a computer to put together x-ray images to create cross-sectional or three dimensional pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque contrast media. It works by coating the esophagus, stomach, or ...

  8. Column-to-column packing variation of disposable pre-packed columns for protein chromatography.

    Science.gov (United States)

    Schweiger, Susanne; Hinterberger, Stephan; Jungbauer, Alois

    2017-12-08

    In the biopharmaceutical industry, pre-packed columns are the standard for process development, but they must be qualified before use in experimental studies to confirm the required performance of the packed bed. Column qualification is commonly done by pulse response experiments and depends highly on the experimental testing conditions. Additionally, the peak analysis method, the variation in the 3D packing structure of the bed, and the measurement precision of the workstation influence the outcome of qualification runs. While a full body of literature on these factors is available for HPLC columns, no comparable studies exist for preparative columns for protein chromatography. We quantified the influence of these parameters for commercially available pre-packed and self-packed columns of disposable and non-disposable design. Pulse response experiments were performed on 105 preparative chromatography columns with volumes of 0.2-20ml. The analyte acetone was studied at six different superficial velocities (30, 60, 100, 150, 250 and 500cm/h). The column-to-column packing variation between disposable pre-packed columns of different diameter-length combinations varied by 10-15%, which was acceptable for the intended use. The column-to-column variation cannot be explained by the packing density, but is interpreted as a difference in particle arrangement in the column. Since it was possible to determine differences in the column-to-column performance, we concluded that the columns were well-packed. The measurement precision of the chromatography workstation was independent of the column volume and was in a range of±0.01ml for the first peak moment and±0.007 ml 2 for the second moment. The measurement precision must be considered for small columns in the range of 2ml or less. The efficiency of disposable pre-packed columns was equal or better than that of self-packed columns. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  9. Solid-phase extraction of polar pesticides from environmental water samples on graphitized carbon and Empore-activated carbon disks and on-line coupling to octadecyl-bonded silica analytical columns.

    Science.gov (United States)

    Slobodník, J; Oztezkizan, O; Lingeman, H; Brinkman, U A

    1996-10-25

    The suitability of Empore-activated carbon disks (EACD), Envi-Carb graphitized carbon black (GCB) and CPP-50 graphitized carbon for the trace enrichment of polar pesticides from water samples was studied by means of off-line and on-line solid-phase extraction (SPE). In the off-line procedure, 0.5-2 l samples spiked with a test mixture of oxamyl, methomyl and aldicarb sulfoxide were enriched on EnviCarb SPE cartridges or 47 mm diameter EACD and eluted with dichloromethane-methanol. After evaporation, a sample was injected onto a C18-bonded silica column and analysed by liquid chromatography with ultraviolet (LC-UV) detection. EACD performed better than EnviCarb cartridges in terms of breakthrough volumes (> 2 l for all test analytes), reproducibility (R.S.D. of recoveries, 4-8%, n = 3) and sampling speed (100 ml/min); detection limits in drinking water were 0.05-0.16 microgram/l. In the on-line experiments, 4.6 mm diameter pieces cut from original EACD and stacked onto each other in a 9 mm long precolumn, and EnviCarb and CPP-50 packed in 10 x 2.0 mm I.D. precolumn, were tested, and 50-200 ml spiked water samples were preconcentrated. Because of the peak broadening caused by the strong sorption of the analytes on carbon, the carbon-packed precolumns were eluted by a separate stream of 0.1 ml/min acetonitrile which was mixed with the gradient LC eluent in front of the C18 analytical column. The final on-line procedure was also applied for the less polar propoxur, carbaryl and methiocarb. EnviCarb could not be used due to its poor pressure resistance. CPP-50 provided less peak broadening than EACD: peak widths were 0.1-0.3 min and R.S.D. of peak heights 4-14% (n = 3). In terms of analyte trapping efficiency on-line SPE-LC-UV with a CPP-50 precolumn also showed better performance than when Bondesil C18/OH or polymeric PLRP-S was used, but chromatographic resolution was similar. With the CPP-50-based system, detection limits of the test compounds were 0.05-1 microgram

  10. Dehalogenation of chlorinated ethenes and immobilization of nickel in anaerobic sediment columns under sulfidogenic conditions

    NARCIS (Netherlands)

    Drzyzga, O; EL Mamouni, R; Agathos, SN; Gottschal, JC

    2002-01-01

    A sediment column study was carried out to demonstrate the bioremediation of chloroethene- and nickel-contaminated sediment in a single anaerobic step under sulfate-reducing conditions. Four columns (one untreated control column and three experimental columns) with sediment from a chloroethene- and

  11. Sulfate was a trace constituent of Archean seawater

    DEFF Research Database (Denmark)

    Crowe, Sean Andrew; Paris, Guillaume; Katsev, Sergei

    2014-01-01

    In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations. In the water column...

  12. Identification of glycosaminoglycans using high-performance liquid chromatography on a hydroxyapatite column.

    Science.gov (United States)

    Narita, H; Takeda, Y; Takagaki, K; Nakamura, T; Harata, S; Endo, M

    1995-11-20

    Glycosaminoglycans (heparin, heparan sulfate, dermatan sulfate, chondroitin sulfate, and hyaluronic acid) were labeled with a fluorescent reagent, 2-aminopyridine. The fluoro-labeled glycosaminoglycans were subjected to high-performance liquid chromatography on a hydroxyapatite column. The binding property of each glycosaminoglycan to hydroxyapatite was different. The structural properties of glycosaminoglycans bound to hydroxyapatite were then investigated using chemical desulfated or enzymic depolymerized glycosaminoglycans. This revealed that the sulfate content and molecular weight of the glycosaminoglycans correlated with their binding properties to hydroxyapatite. Desulfated dermatan sulfate but not desulfated chondroitin 6-sulfate bound to the hydroxyapatite. These data indicate that iduronic acid residues of glycosaminoglycans are important for the binding property. The method described which uses hydroxyapatite columns facilitates rapid separation and microanalysis of the glycosaminoglycans, especially dermatan sulfate and chondroitin sulfate.

  13. Recent advances in column switching sample preparation in bioanalysis.

    Science.gov (United States)

    Kataoka, Hiroyuki; Saito, Keita

    2012-04-01

    Column switching techniques, using two or more stationary phase columns, are useful for trace enrichment and online automated sample preparation. Target fractions from the first column are transferred online to a second column with different properties for further separation. Column switching techniques can be used to determine the analytes in a complex matrix by direct sample injection or by simple sample treatment. Online column switching sample preparation is usually performed in combination with HPLC or capillary electrophoresis. SPE or turbulent flow chromatography using a cartridge column and in-tube solid-phase microextraction using a capillary column have been developed for convenient column switching sample preparation. Furthermore, various micro-/nano-sample preparation devices using new polymer-coating materials have been developed to improve extraction efficiency. This review describes current developments and future trends in novel column switching sample preparation in bioanalysis, focusing on innovative column switching techniques using new extraction devices and materials.

  14. Sulfate adsorption on goethite

    Energy Technology Data Exchange (ETDEWEB)

    Rietra, R P.J.J.; Hiemstra, T; Riemsdijk, W.H. van

    1999-10-15

    Recent spectroscopic work has suggested that only one surface species of sulfate is dominant on hematite. Sulfate is therefore a very suitable anion to test and develop adsorption models for variable charge minerals. The authors have studied sulfate adsorption on goethite covering a large range of sulfate concentrations, surface coverages, pH values, and electrolyte concentrations. Four different techniques were used to cover the entire range of conditions. For characterization at low sulfate concentrations, below the detection limit of sulfate with ICP-AES, the authors used proton-sulfate titrations at constant pH. Adsorption isotherms were studied for the intermediate sulfate concentration range. Acid-base titrations in sodium sulfate and electromobility were used for high sulfate concentrations. All the data can be modeled with one adsorbed species if it is assumed that the charge of adsorbed sulfate is spatially distributed in the interface. The charge distribution of sulfate follows directly from modeling the proton-sulfate adsorption stoichoimemtry sine this stoichiometry is independent of the intrinsic affinity constant of sulfate. The charge distribution can be related to the structure of the surface complex by use of the Pauling bond valence concept and is in accordance with the microscopic structure found by spectroscopy. The intrinsic affinity constant follows from the other measurements. Modeling of the proton-ion stoichoimetry with the commonly used 2-pK models, where adsorbed ions are treated as point charges, is possible only if at least two surface species for sulfate are used.

  15. Sequential injection chromatography with post-column reaction/derivatization for the determination of transition metal cations in natural water samples.

    Science.gov (United States)

    Horstkotte, Burkhard; Jarošová, Patrícia; Chocholouš, Petr; Sklenářová, Hana; Solich, Petr

    2015-05-01

    In this work, the applicability of Sequential Injection Chromatography for the determination of transition metals in water is evaluated for the separation of copper(II), zinc(II), and iron(II) cations. Separations were performed using a Dionex IonPAC™ guard column (50mm×2mm i.d., 9 µm). Mobile phase composition and post-column reaction were optimized by modified SIMPLEX method with subsequent study of the concentration of each component. The mobile phase consisted of 2,6-pyridinedicarboxylic acid as analyte-selective compound, sodium sulfate, and formic acid/sodium formate buffer. Post-column addition of 4-(2-pyridylazo)resorcinol was carried out for spectrophotometric detection of the analytes׳ complexes at 530nm. Approaches to achieve higher robustness, baseline stability, and detection sensitivity by on-column stacking of the analytes and initial gradient implementation as well as air-cushion pressure damping for post-column reagent addition were studied. The method allowed the rapid separation of copper(II), zinc(II), and iron(II) within 6.5min including pump refilling and aspiration of sample and 1mmol HNO3 for analyte stacking on the separation column. High sensitivity was achieved applying an injection volume of up to 90µL. A signal repeatability of<2% RSD of peak height was found. Analyte recovery evaluated by spiking of different natural water samples was well suited for routine analysis with sub-micromolar limits of detection. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Determination of sulfate in thorium salts using gravimetric technique with previous thorium separation

    International Nuclear Information System (INIS)

    Silva, C.M. da; Pires, M.A.F.

    1994-01-01

    Available as short communication only. A simple analytical method to analyze sulfates in thorium salt, is presented. The method is based on the thorium separation as hydroxide. The gravimetric technique is used to analyze the sulfate in the filtered as barium sulfate. Using this method, the sulfate separation from thorium has been reach 99,9% yield, and 0,1% precision. This method is applied to thorium salts specifically thorium sulfate, carbonate and nitrate. (author). 5 refs, 2 tabs

  17. Performance of RC columns with partial length corrosion

    International Nuclear Information System (INIS)

    Wang Xiaohui; Liang Fayun

    2008-01-01

    Experimental and analytical studies on the load capacity of reinforced concrete (RC) columns with partial length corrosion are presented, where only a fraction of the column length was corroded. Twelve simply supported columns were eccentrically loaded. The primary variables were partial length corrosion in tensile or compressive zone and the corrosion level within this length. The failure of the corroded column occurs in the partial length, mainly developed from or located nearby or merged with the longitudinal corrosion cracks. For RC column with large eccentricity, load capacity of the column is mainly influenced by the partial length corrosion in tensile zone; while for RC column with small eccentricity, load capacity of the column greatly decreases due to the partial length corrosion in compressive zone. The destruction of the longitudinally mechanical integrality of the column in the partial length leads to this great reduction of the load capacity of the RC column

  18. Post column derivatisation analyses review. Is post-column derivatisation incompatible with modern HPLC columns?

    Science.gov (United States)

    Jones, Andrew; Pravadali-Cekic, Sercan; Dennis, Gary R; Shalliker, R Andrew

    2015-08-19

    Post Column derivatisation (PCD) coupled with high performance liquid chromatography or ultra-high performance liquid chromatography is a powerful tool in the modern analytical laboratory, or at least it should be. One drawback with PCD techniques is the extra post-column dead volume due to reaction coils used to enable adequate reaction time and the mixing of reagents which causes peak broadening, hence a loss of separation power. This loss of efficiency is counter-productive to modern HPLC technologies, -such as UHPLC. We reviewed 87 PCD methods published from 2009 to 2014. We restricted our review to methods published between 2009 and 2014, because we were interested in the uptake of PCD methods in UHPLC environments. Our review focused on a range of system parameters including: column dimensions, stationary phase and particle size, as well as the geometry of the reaction loop. The most commonly used column in the methods investigated was not in fact a modern UHPLC version with sub-2-micron, (or even sub-3-micron) particles, but rather, work-house columns, such as, 250 × 4.6 mm i.d. columns packed with 5 μm C18 particles. Reaction loops were varied, even within the same type of analysis, but the majority of methods employed loop systems with volumes greater than 500 μL. A second part of this review illustrated briefly the effect of dead volume on column performance. The experiment evaluated the change in resolution and separation efficiency of some weak to moderately retained solutes on a 250 × 4.6 mm i.d. column packed with 5 μm particles. The data showed that reaction loops beyond 100 μL resulted in a very serious loss of performance. Our study concluded that practitioners of PCD methods largely avoid the use of UHPLC-type column formats, so yes, very much, PCD is incompatible with the modern HPLC column. Copyright © 2015. Published by Elsevier B.V.

  19. Simultaneous analysis of heparan sulfate, chondroitin/dermatan sulfates, and hyaluronan disaccharides by glycoblotting-assisted sample preparation followed by single-step zwitter-ionic-hydrophilic interaction chromatography.

    Science.gov (United States)

    Takegawa, Yasuhiro; Araki, Kayo; Fujitani, Naoki; Furukawa, Jun-ichi; Sugiyama, Hiroaki; Sakai, Hideaki; Shinohara, Yasuro

    2011-12-15

    Glycosaminoglycans (GAGs) play important roles in cell adhesion and growth, maintenance of extracellular matrix (ECM) integrity, and signal transduction. To fully understand the biological functions of GAGs, there is a growing need for sensitive, rapid, and quantitative analysis of GAGs. The present work describes a novel analytical technique that enables high throughput cellular/tissue glycosaminoglycomics for all three families of uronic acid-containing GAGs, hyaluronan (HA), chondroitin sulfate (CS)/dermatan sulfate (DS), and heparan sulfate (HS). A one-pot purification and labeling procedure for GAG Δ-disaccharides was established by chemo-selective ligation of disaccharides onto high density hydrazide beads (glycoblotting) and subsequent labeling by fluorescence. The 17 most common disaccharides (eight comprising HS, eight CS/DS, and one comprising HA) could be separated with a single chromatography for the first time by employing a zwitter-ionic type of hydrophilic-interaction chromatography column. These novel analytical techniques were able to precisely characterize the glycosaminoglycome in various cell types including embryonal carcinoma cells and ocular epithelial tissues (cornea, conjunctiva, and limbus).

  20. Modeling Stone Columns.

    Science.gov (United States)

    Castro, Jorge

    2017-07-11

    This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the "unit cell", longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns.

  1. ( Anogeissus leiocarpus ) timber columns

    African Journals Online (AJOL)

    A procedure for designing axially loaded Ayin (Anogeissus leiocarpus) wood column or strut has been investigated. Instead of the usual categorization of columns into short, intermediate and slender according to the value of slenderness ratio, a continuous column formula representing the three categories was derived.

  2. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  3. Rare earth sulfates

    International Nuclear Information System (INIS)

    Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

    1986-01-01

    Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

  4. Behaviour of normal reinforced concrete columns exposed to different soils

    Directory of Open Access Journals (Sweden)

    Rasheed Laith

    2018-01-01

    Full Text Available Concrete resistance to sulfate attack is one of the most important characteristics for maintaining the durability of concrete. In this study, the effect of the attack of sulfate salts on normal reinforced concrete column was investigated by burying these columns in two types of soils (sandy and clayey in two pits at a depth of 3 m in one of the agricultural areas in the holy city of Karbala, one containing sandy soil (SO3 = 10.609% and the other containing clayey soil with (SO3 = 2.61%. The tests were used (pure axial compression test of reinforced concrete columns, compressive strength test, and splitting tensile strength test, absorption, voids ratio and finally density. It`s found that the strength of RC columns decreasing by (12.51% for age (240 days, for columns buried in clayey soil, where the strength increased by (11.71% for the same period, for columns buried in sandy soils, with respect to the reference column.

  5. The ceric sulfate dosimeter

    DEFF Research Database (Denmark)

    Bjergbakke, Erling

    1970-01-01

    The process employed for the determination of absorbed dose is the reduction of ceric ions to cerous ions in a solution of ceric sulfate and cerous sulfate in 0.8N sulfuric acid: Ce4+→Ce 3+ The absorbed dose is derived from the difference in ceric ion concentration before and after irradiation...

  6. Heparan sulfate biosynthesis

    DEFF Research Database (Denmark)

    Multhaupt, Hinke A B; Couchman, John R

    2012-01-01

    Heparan sulfate is perhaps the most complex polysaccharide known from animals. The basic repeating disaccharide is extensively modified by sulfation and uronic acid epimerization. Despite this, the fine structure of heparan sulfate is remarkably consistent with a particular cell type. This suggests...... that the synthesis of heparan sulfate is tightly controlled. Although genomics has identified the enzymes involved in glycosaminoglycan synthesis in a number of vertebrates and invertebrates, the regulation of the process is not understood. Moreover, the localization of the various enzymes in the Golgi apparatus has......-quality resolution of the distribution of enzymes. The EXT2 protein, which when combined as heterodimers with EXT1 comprises the major polymerase in heparan sulfate synthesis, has been studied in depth. All the data are consistent with a cis-Golgi distribution and provide a starting point to establish whether all...

  7. Small Column Ion Exchange

    International Nuclear Information System (INIS)

    Huff, Thomas

    2010-01-01

    Small Column Ion Exchange (SCIX) leverages a suite of technologies developed by DOE across the complex to achieve lifecycle savings. Technologies are applicable to multiple sites. Early testing supported multiple sites. Balance of SRS SCIX testing supports SRS deployment. A forma Systems Engineering Evaluation (SEE) was performed and selected Small Column Ion Exchange columns containing Crystalline Silicotitanate (CST) in a 2-column lead/lag configuration. SEE considered use of Spherical Resorcinol-Formaldehyde (sRF). Advantages of approach at SRS include: (1) no new buildings, (2) low volume of Cs waste in solid form compared to aqueous strip effluent; and availability of downstream processing facilities for immediate processing of spent resin.

  8. Column Selection for Biomedical Analysis Supported by Column Classification Based on Four Test Parameters.

    Science.gov (United States)

    Plenis, Alina; Rekowska, Natalia; Bączek, Tomasz

    2016-01-21

    This article focuses on correlating the column classification obtained from the method created at the Katholieke Universiteit Leuven (KUL), with the chromatographic resolution attained in biomedical separation. In the KUL system, each column is described with four parameters, which enables estimation of the FKUL value characterising similarity of those parameters to the selected reference stationary phase. Thus, a ranking list based on the FKUL value can be calculated for the chosen reference column, then correlated with the results of the column performance test. In this study, the column performance test was based on analysis of moclobemide and its two metabolites in human plasma by liquid chromatography (LC), using 18 columns. The comparative study was performed using traditional correlation of the FKUL values with the retention parameters of the analytes describing the column performance test. In order to deepen the comparative assessment of both data sets, factor analysis (FA) was also used. The obtained results indicated that the stationary phase classes, closely related according to the KUL method, yielded comparable separation for the target substances. Therefore, the column ranking system based on the FKUL-values could be considered supportive in the choice of the appropriate column for biomedical analysis.

  9. SPEEDUPtrademark ion exchange column model

    International Nuclear Information System (INIS)

    Hang, T.

    2000-01-01

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUptrademark software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLigtrademark ion exchange resins, once the experimental data are complete

  10. Mechanisms and Effectivity of Sulfate Reducing Bioreactors ...

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of which is the substrate composition. Chitinous materials have demonstrated high metal removal rates, particularly for the two recalcitrant MIW contaminants Zn and Mn, but their removal mechanisms need further study. We studied Cd, Fe, Zn, and Mn removal in bioactive and abiotic SRBRs to elucidate the metal removal mechanisms and the differences in metal and sulfate removal rates using a chitinous material as substrate. We found that sulfate-reducing bacteria are effective in increasing metal and sulfate removal rates and duration of operation in SRBRs, and that the main mechanism involved was metal precipitation as sulfides. The solid residues provided evidence of the presence of sulfides in the bioactive column, more specifically ZnS, according to XPS analysis. The feasibility of passive treatments with a chitinous substrate could be an important option for MIW remediation. Mining influenced water (MIW) remediation is still one of the top priorities for the agency because it addresses the most important environmental problem associated with the mining industry and that affects thousands of communities in the U.S. and worldwide. In this paper, the MIW bioremediation mechanisms are studied

  11. JCE Feature Columns

    Science.gov (United States)

    Holmes, Jon L.

    1999-05-01

    The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

  12. Comparison of monolithic silica and polymethacrylate capillary columns for LC

    Czech Academy of Sciences Publication Activity Database

    Moravcová, D.; Jandera, P.; Urban, J.; Planeta, Josef

    2004-01-01

    Roč. 27, 10-11 (2004), s. 789-800 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA203/02/0023 Keywords : monolithic column s * capillary HPLC * column testing Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.927, year: 2004

  13. Dynamic stability of a lightly damped column trapped by a ...

    African Journals Online (AJOL)

    In this paper we initiate an analytical approach for determining the dynamic buckling load of a finite viscously damped column acted upon by a harmonically slowly varying explicitly time dependent load. The viscous damping is considered light and the column rests on an elastic foundation that produces a nonlinear ...

  14. Application of copper sulfate pentahydrate as an ammonia removal reagent for the determination of trace impurities in ammonia by gas chromatography.

    Science.gov (United States)

    Aomura, Yoko; Kobayashi, Yoshihiko; Miyazawa, Yuzuru; Shimizu, Hideharu

    2010-03-12

    Rapid analysis of trace permanent gas impurities in high purity ammonia gas for the microelectronics industry is described, using a gas chromatograph equipped with a phtoionization detector. Our system incorporates a reactive precolumn in combination with the analytical column to remove the ammonia matrix peak that otherwise would complicate the measurements due to baseline fluctuations and loss of analytes. The performance of 21 precolumn candidate materials was evaluated. Copper sulfate pentahydrate (CuSO(4).5H(2)O) was shown to selectively react with ammonia at room temperature and atmospheric column pressures, without affecting the hydrogen, oxygen, nitrogen, methane or carbon monoxide peak areas. To prevent loss of trace carbon dioxide, an additional boron trioxide reactant layer was inserted above the copper sulfate pentahydrate bed in the reactive precolumn. Using the combined materials, calibration curves for carbon dioxide proved to be equivalent in both ammonia and helium matrix gases. These curves were equivalent in both matrix gases. The quantitative performance of the system was also evaluated. Peak repeatabilities, based on eight injections, were in the range of 4.1-8.2% relative standard deviation; and detection limits were 6.9 ppb for H(2), 1.8 ppb for O(2), 1.6 ppb for N(2), 6.4 ppb for CH(4), 13 ppb for CO, and 5.4 ppb for CO(2). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  15. Ferrous Sulfate (Iron)

    Science.gov (United States)

    ... are allergic to ferrous sulfate, any other medications tartrazine (a yellow dye in some processed foods and ... in, tightly closed, and out of reach of children. Store it at room temperature and away from ...

  16. Holothurian Fucosylated Chondroitin Sulfate

    Directory of Open Access Journals (Sweden)

    Vitor H. Pomin

    2014-01-01

    Full Text Available Fucosylated chondroitin sulfate (FucCS is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein.

  17. DHEA-sulfate test

    Science.gov (United States)

    ... DHEA sulfate may be due to: Adrenal gland disorders that produce lower than normal amounts of adrenal hormones, including adrenal insufficiency and Addison disease The pituitary gland not producing normal amounts of its hormones ( hypopituitarism ) ...

  18. Development of an analytical method for separation of phenolic acids by ultra-performance convergence chromatography (UPC2) using a column packed with a sub-2-μm particle.

    Science.gov (United States)

    Jiang, Hai; Yang, Liu; Xing, Xudong; Yan, Meiling; Guo, Xinyue; Yang, Bingyou; Wang, Qiu-Hong; Kuang, Hai-Xue

    2018-05-10

    Phenolic acids are important active components of certain Traditional Chinese Medicines (TCM) and have a wide range of biological effects. Separation and purification of phenolic acids remains challenging due to difficulties with quality control using existing chromatographic methods The purpose of this study was to compare the effects of different chromatographic columns and conditions for the separation of phenolic acids. The BEH column was determined to be optimal, providing efficient separation in the shortest time (17.00 min) using gradient elution with carbon dioxide as the mobile phase, methanol/acetonitrile (70:30, v/v) with 1% TFA as the modifier, and a flow rate of 0.8 mL/min. Good peak shapes were obtained, and the peak asymmetry values were close to 1.00 for all phenolic acids. The resolution was more than 2.83 for all separated peaks. The developed method was subsequently applied to the determination of phenolic acids in Xanthii Fructus. These results are beneficial for quality control and standardization of herbal drugs using UPC 2 , providing an efficient, rapid and environmentally friendly scientific basis for future analysis of phenolic acids. Copyright © 2018. Published by Elsevier B.V.

  19. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  20. Nuclear reactor control column

    International Nuclear Information System (INIS)

    Bachovchin, D.M.

    1982-01-01

    The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest crosssectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor

  1. Improvements in solvent extraction columns

    International Nuclear Information System (INIS)

    Aughwane, K.R.

    1987-01-01

    Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

  2. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  3. Biological sulfate removal from gypsum contaminated construction and demolition debris.

    Science.gov (United States)

    Kijjanapanich, Pimluck; Annachhatre, Ajit P; Esposito, Giovanni; van Hullebusch, Eric D; Lens, Piet N L

    2013-12-15

    Construction and demolition debris (CDD) contains high levels of sulfate that can cause detrimental environmental impacts when disposed without adequate treatment. In landfills, sulfate can be converted to hydrogen sulfide under anaerobic conditions. CDD can thus cause health impacts or odor problems to landfill employees and surrounding residents. Reduction of the sulfate content of CDD is an option to overcome these problems. This study aimed at developing a biological sulfate removal system to reduce the sulfate content of gypsum contaminated CDD in order to decrease the amount of solid waste, to improve the quality of CDD waste for recycling purposes and to recover sulfur from CDD. The treatment leached out the gypsum contained in CDD by water in a leaching column. The sulfate loaded leachate was then treated in a biological sulfate reducing Upflow Anaerobic Sludge Blanket (UASB) reactor to convert the sulfate to sulfide. The UASB reactor was operated at 23 ± 3 °C with a hydraulic retention time and upflow velocity of 15.5 h and 0.1 m h(-1), respectively while ethanol was added as electron donor at a final organic loading rate of 3.46 g COD L(-1) reactor d(-1). The CDD leachate had a pH of 8-9 and sulfate dissolution rates of 526.4 and 609.8 mg L(-1) d(-1) were achieved in CDD gypsum and CDD sand, respectively. Besides, it was observed that the gypsum dissolution was the rate limiting step for the biological treatment of CDD. The sulfate removal efficiency of the system stabilized at around 85%, enabling the reuse of the UASB effluent for the leaching step, proving the versatility of the bioreactor for practical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Skeletal keratan sulfate chain molecular weight calibration by high-performance gel-permeation chromatography

    International Nuclear Information System (INIS)

    Dickenson, J.M.; Morris, H.G.; Nieduszynski, I.A.; Huckerby, T.N.

    1990-01-01

    A method has been developed for the molecular sizing of skeletal keratan sulfate chains using an HPLC gel-permeation chromatography system. Keratan sulfate chains and keratanase-derived oligosaccharides were prepared from the nucleus pulposus of bovine intervertebral disc (6-year-old animals). A Bio-Gel TSK 30 XL column eluted in 0.2 M NaCl and at 30 degrees C was calibrated with keratan sulfate oligosaccharides of known size as well as 3H-end-labeled keratan sulfate chains to yield the relationship

  5. Buckling of liquid columns

    NARCIS (Netherlands)

    Habibi, M.; Rahmani, Y.; Bonn, D.; Ribe, N.M.

    2010-01-01

    Under appropriate conditions, a column of viscous liquid falling onto a rigid surface undergoes a buckling instability. Here we show experimentally and theoretically that liquid buckling exhibits a hitherto unsuspected complexity involving three different modes—viscous, gravitational, and

  6. Solvent extraction columns

    International Nuclear Information System (INIS)

    Middleton, P.; Smith, J.R.

    1979-01-01

    In pulsed columns for use in solvent extraction processes, e.g. the reprocessing of nuclear fuel, the horizontal perforated plates inside the column are separated by interplate spacers manufactured from metallic neutron absorbing material. The spacer may be in the form of a spiral or concentric circles separated by radial limbs, or may be of egg-box construction. Suitable neutron absorbing materials include stainless steel containing boron or gadolinium, hafnium metal or alloys of hafnium. (UK)

  7. The design of a new concept chromatography column.

    Science.gov (United States)

    Camenzuli, Michelle; Ritchie, Harald J; Ladine, James R; Shalliker, R Andrew

    2011-12-21

    Active Flow Management is a new separation technique whereby the flow of mobile phase and the injection of sample are introduced to the column in a manner that allows migration according to the principles of the infinite diameter column. A segmented flow outlet fitting allows for the separation of solvent or solute that elutes along the central radial section of the column from that of the sample or solvent that elutes along the wall region of the column. Separation efficiency on the analytical scale is increased by 25% with an increase in sensitivity by as much as 52% compared to conventional separations.

  8. The fractioning factor and the number of theorical plates in isotopic enrichment columns determined simultaneously

    International Nuclear Information System (INIS)

    Ducatti, Carlos

    1997-01-01

    Using an analytical approach and an analytical graphical method, it was determined simultaneously the fractioning factor and the number of theoretical plates in isotopic enrichment columns during the conditions of dinamical isotopic equilibrium. (author). 5 refs., 2 figs., 2 tabs

  9. Multi-core parallelism in a column-store

    NARCIS (Netherlands)

    Gawade, M.M.

    2017-01-01

    The research reported in this thesis addresses several challenges of improving the efficiency and effectiveness of parallel processing of analytical database queries on modern multi- and many-core systems, using an open-source column-oriented analytical database management system, MonetDB, for

  10. A stochastic view on column efficiency.

    Science.gov (United States)

    Gritti, Fabrice

    2018-03-09

    A stochastic model of transcolumn eddy dispersion along packed beds was derived. It was based on the calculation of the mean travel time of a single analyte molecule from one radial position to another. The exchange mechanism between two radial positions was governed by the transverse dispersion of the analyte across the column. The radial velocity distribution was obtained by flow simulations in a focused-ion-beam scanning electron microscopy (FIB-SEM) based 3D reconstruction from a 2.1 mm × 50 mm column packed with 2 μm BEH-C 18 particles. Accordingly, the packed bed was divided into three coaxial and uniform zones: (1) a 1.4 particle diameter wide, ordered, and loose packing at the column wall (velocity u w ), (2) an intermediate 130 μm wide, random, and dense packing (velocity u i ), and (3) the bulk packing in the center of the column (velocity u c ). First, the validity of this proposed stochastic model was tested by adjusting the predicted to the observed reduced van Deemter plots of a 2.1 mm × 50 mm column packed with 2 μm BEH-C 18 fully porous particles (FPPs). An excellent agreement was found for u i  = 0.93u c , a result fully consistent with the FIB-SEM observation (u i  = 0.95u c ). Next, the model was used to measure u i  = 0.94u c for 2.1 mm × 100 mm column packed with 1.6 μm Cortecs-C 18 superficially porous particles (SPPs). The relative velocity bias across columns packed with SPPs is then barely smaller than that observed in columns packed with FPPs (+6% versus + 7%). u w =1.8u i is measured for a 75 μm × 1 m capillary column packed with 2 μm BEH-C 18 particles. Despite this large wall-to-center velocity bias (+80%), the presence of the thin and ordered wall packing layer has no negative impact on the kinetic performance of capillary columns. Finally, the stochastic model of long-range eddy dispersion explains why analytical (2.1-4.6 mm i.d.) and capillary (columns can all be

  11. Novel field emission SEM column with beam deceleration technology

    Energy Technology Data Exchange (ETDEWEB)

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-11-15

    A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications.

  12. Novel field emission SEM column with beam deceleration technology

    International Nuclear Information System (INIS)

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-01-01

    A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications

  13. Assembly for connecting the column ends of two capillary columns

    International Nuclear Information System (INIS)

    Kolb, B.; Auer, M.; Pospisil, P.

    1984-01-01

    In gas chromatography, the column ends of two capillary columns are inserted into a straight capillary from both sides forming annular gaps. The capillary is located in a tee out of which the capillary columns are sealingly guided, and to which carrier gas is supplied by means of a flushing flow conduit. A ''straight-forward operation'' having capillary columns connected in series and a ''flush-back operation'' are possible. The dead volume between the capillary columns can be kept small

  14. Biogeochemical impacts of aquifer thermal energy storage at 5, 12, 25 and 60°C investigated with anoxic column experiments

    Science.gov (United States)

    Bonte, M.; van Breukelen, B. M.; Van Der Wielen, P. W. J. J.; Stuyfzand, P. J.

    2012-04-01

    Aquifer thermal energy storage (ATES) uses groundwater to store energy for heating or cooling purposes in the built environment. ATES systems are often located in the same aquifers used for public drinking water supply, leading to urgent questions on its environmental impacts. This contribution presents the results of research on the biogeochemical impacts of ATES in anoxic column experiments at 5, 12, 25, and 60° C. In- and effluents are analyzed for major ions, trace elements, heavy metals, dissolved organic carbon (DOC) and UV extinction. Terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA genes and analysis of adenosine triphosphate (ATP) were used to detect changes in the microbiological population and activity. Results from the column experiments at 5, 25, and 60° C compared to the reference column at 12° C showed a number of changes in biogeochemical conditions: At 5° C, only changes were observed in alkalinity and calcium concentrations, resulting from calcite dissolution. The 25° C and 60° C column effluents from a sediment containing Fe-(hydr)oxides showed an increase in arsenic concentrations, well above the drinking water limit. This is due to either (reductive) dissolution of, or desorption from, iron(hydro)xides containing arsenic. In addition, at these two temperatures sulfate reduction occurred while this was undetectable at 5 and 12° C within the given timeframe (25 days) and analytical accuracy. The carbon source for sulfate reduction is inferred to be sedimentary organic carbon. Increasing DOC with residence time in the 60° C effluent suggests that at 60° C the terminal sulfate reduction step is rate limiting, while at 25° C the enzymatic hydrolization step in sulfate reducing bacteria is overall rate limiting. Specific ultraviolet absorption (SUVA, the ratio of UV extinction and DOC) however shows a clear decrease in reactivity of the humic acid fraction in DOC. This means that the DOC accumulation at 60° C could

  15. Sulfate metabolism. I. Sulfate uptake and redistribution of acid rain sulfate by edible plants

    International Nuclear Information System (INIS)

    Dallam, R.D.

    1987-01-01

    Sulfur is the major component of polluted air in industrialized societies. Atmospheric sulfur is converted to sulfuric acid through a series of chemical reactions which can eventually reenter many ecosystems. When edible plants are grown in soils containing varying amounts of sulfate, the roots take up and transport inorganic sulfate to the stems and leaves. The sulfate taken up by the roots and the amount transported to the stem and leaves was found to be a function of the concentration of sulfate in the soil. Inorganic sulfate taken up by a corn plant seedling can be rapidly converted to organic sulfate by the root system. Nine days after one of a pair of pea plants was inoculated with artificial acid rain sulfate (dilute H 2 35 SO 4 ) it was found that the sulfate was translocated not only in the inoculated plant, but also to the uninoculated pea plant in the same container. Also, when the leaves of a mature potato plant were inoculated with artificial acid rain sulfate it was found that the sulfate was translocated into the edible potatoes. Fractionation of the potatoes showed that most of the sulfate was water soluble of which 30% was inorganic sulfate and 70% was in the form of organic sulfur. One third of the non-water soluble translocated acid rain sulfate was equally divided between lipid and non-lipid organic sulfur of the potato. 9 references, 2 figures, 5 tables

  16. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  17. Slender CRC Columns

    DEFF Research Database (Denmark)

    Aarup, Bendt; Jensen, Lars Rom; Ellegaard, Peter

    2005-01-01

    CRC is a high-performance steel fibre reinforced concrete with a typical compressive strength of 150 MPa. Design methods for a number of structural elements have been developed since CRC was invented in 1986, but the current project set out to further investigate the range of columns for which...

  18. Practical column design guide

    CERN Document Server

    Nitsche, M

    2017-01-01

    This book highlights the aspects that need to be considered when designing distillation columns in practice. It discusses the influencing parameters as well as the equations governing them, and presents several numerical examples. The book is intended both for experienced designers and for those who are new to the subject.

  19. Validated high-performance anion-exchange chromatography with pulsed amperometric detection method for the determination of residual keratan sulfate and other glucosamine impurities in sodium chondroitin sulfate.

    Science.gov (United States)

    Bottelli, Susanna; Grillo, Gianluca; Barindelli, Edoardo; Nencioni, Alessandro; Di Maria, Alessandro; Fossati, Tiziano

    2017-07-07

    An efficient and sensitive analytical method based on high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was devised for the determination of glucosamine (GlcN) in sodium chondroitin sulfate (CS). Glucosamine (GlcN) is intended as marker of residual keratan sulfate (KS) and other impurities generating glucosamine by acidic hydrolyzation. The latter brings CS and KS to their respective monomers. Since GlcN is present only in KS we developed a method that separates GlcN from GalN, the principal hydrolytic product of CS, and then we validated it in order to quantify GlcN. Method validation was performed by spiking CS raw material with known amounts of KS. Detection limit was 0.5% of KS in CS (corresponding to 0.1μg/ml), and the linear range was 0.5-5% of KS in CS (corresponding to 0.1-1μg/ml). The optimized analysis was carried out on an ICS-5000 system (Dionex, Sunnyvale, CA, USA) equipped with a Dionex Amino Trap guard column (3mm×30mm), Dionex CarboPac-PA20 (3mm×30mm) and a Dionex CarboPac-PA20 analytical column (3mm×150mm) using gradient elution at a 0.5ml/min flow rate. Regression equations revealed good linear relationship (R 2 =0.99, n=5) within the test ranges. Quality parameters, including precision and accuracy, were fully validated and found to be satisfactory. The fully validated HPAEC-PAD method was readily applied for the quantification of residual KS in CS in several raw materials and USP/EP reference substance. Results confirmed that the HPAEC-PAD method is more specific than the electrophoretic method for related substance reported in EP and provides sensitive determination of KS in acid-hydrolyzed CS samples, enabling the quantitation of KS and other impurities (generating glucosamine) in CS. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Adiabatic packed column supercritical fluid chromatography using a dual-zone still-air column heater.

    Science.gov (United States)

    Helmueller, Shawn C; Poe, Donald P; Kaczmarski, Krzysztof

    2018-02-02

    An approach to conducting SFC separations under pseudo-adiabatic condition utilizing a dual-zone column heater is described. The heater allows for efficient separations at low pressures above the critical temperature by imposing a temperature profile along the column wall that closely matches that for isenthalpic expansion of the fluid inside the column. As a result, the efficiency loss associated with the formation of radial temperature gradients in this difficult region can be largely avoided in packed analytical scale columns. For elution of n-octadecylbenzene at 60 °C with 5% methanol modifier and a flow rate of 3 mL/min, a 250 × 4.6-mm column packed with 5-micron Kinetex C18 particles began to lose efficiency (8% decrease in the number of theoretical plates) at outlet pressures below 142 bar in a traditional forced air oven. The corresponding outlet pressure for onset of excess efficiency loss was decreased to 121 bar when the column was operated in a commercial HPLC column heater, and to 104 bar in the new dual-zone heater operated in adiabatic mode, with corresponding increases in the retention factor for n-octadecylbenzene from 2.9 to 6.8 and 14, respectively. This approach allows for increased retention and efficient separations of otherwise weakly retained analytes. Applications are described for rapid SFC separation of an alkylbenzene mixture using a pressure ramp, and isobaric separation of a cannabinoid mixture. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Dissolution of sulfate scales

    Energy Technology Data Exchange (ETDEWEB)

    Hen, J.

    1991-11-26

    This patent describes a composition for the removal of sulfate scale from surfaces. It comprises: an aqueous solution of about 0.1 to 1.0 molar concentration of an aminopolycarboxylic acid (APCA) containing 1 to 4 amino groups or a salt thereof, and about 0.1 to 1.0 molar concentration of a second component which is diethylenetriaminepenta (methylenephosphonic acid) (DTPMP) or a salt thereof, or aminotri (methylenephosphonic acid) (ATMP) or a salt thereof as an internal phase enveloped by a hydrocarbon membrane phase which is itself emulsified in an external aqueous phase, the hydrocarbon membrane phase continuing a complexing agent weaker for the cations of the sulfate scale than the APCA and DTPMP or ATMP, any complexing agent for the cations in the external aqueous phase being weaker than that in the hydrocarbon membrane phase.

  2. Radioimmunoassay of dehydroepiandrosterone sulfate

    International Nuclear Information System (INIS)

    Vieira, J.G.H.; Furlanetto, R.P.; Russo, E.M.K.; Noguti, K.O.; Chacra, A.R.

    1980-01-01

    The development of a radioimmunological method for the measurement of dehydroepiandrosterone sulfate in serum is described. For the immunization of rabbits, a DHA-3-hemissuccinate-bovine serum albumin conjugate was synthetized and a highly specific anti-serum was produced. The method developed requires only simple dilution prior to assay and the normal values for the different age groups were determined in 146 normal individuals. (Author) [pt

  3. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    International Nuclear Information System (INIS)

    Sugumaran, G.; Silbert, J.E.

    1988-01-01

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

  4. Nine Words - Nine Columns

    DEFF Research Database (Denmark)

    Trempe Jr., Robert B.; Buthke, Jan

    2016-01-01

    This book records the efforts of a one-week joint workshop between Master students from Studio 2B of Arkitektskolen Aarhus and Master students from the Harbin Institute of Technology in Harbin, China. The workshop employed nine action words to instigate team-based investigation into the effects o...... as formwork for the shaping of wood veneer. The resulting columns ‘wear’ every aspect of this design pipeline process and display the power of process towards an architectural resolution....

  5. Flow-through Column Experiments and Modeling of Microbially Mediated Cr(VI) Reduction at Hanford 100H

    Science.gov (United States)

    Yang, L.; Molins, S.; Beller, H. R.; Brodie, E. L.; Steefel, C.; Nico, P. S.; Han, R.

    2010-12-01

    Microbially mediated Cr(VI) reduction at the Hanford 100H area was investigated by flow-through column experiments. Three separate experiments were conducted to promote microbial activities associated with denitrification, iron and sulfate reduction, respectively. Replicate columns packed with natural sediments from the site under anaerobic environment were injected with 5mM Lactate as the electron donor and 5 μM Cr(VI) in all experiments. Sulfate and nitrate solutions were added to act as the main electron acceptors in the respective experiments, while iron columns relied on the indigenous sediment iron (and manganese) oxides as electron acceptors. Column effluent solutions were analyzed by IC and ICP-MS to monitor the microbial consumption/conversion of lactate and the associated Cr(VI) reduction. Biogeochemical reactive transport modeling was performed to gain further insights into the reaction mechanisms and Cr(VI) bioreduction rates. All experimental columns showed a reduction of the injected Cr(VI). Columns under denitrifying conditions showed the least Cr(VI) reduction at early stages (simulations indicated that biomass growth completely depleted influent ammonium, and called for an additional source of N to account for the measured reduction rates. Iron columns were the least active with undetectable consumption of the injected lactate, slowest cell growth, and the smallest change in Cr(VI) concentrations during the course of the experiment. In contrast, columns under sulfate-reducing/fermentative conditions exhibited the greatest Cr(VI) reduction capacity. Two sulfate columns evolved to complete lactate fermentation with acetate and propionate produced in the column effluent after 40 days of experiments. These fermenting columns showed a complete removal of injected Cr(VI), visible precipitation of sulfide minerals, and a significant increase in effluent Fe and Mn concentrations. Reactive transport simulations suggested that direct reduction of Cr(VI) by

  6. Web Analytics

    Science.gov (United States)

    EPA’s Web Analytics Program collects, analyzes, and provides reports on traffic, quality assurance, and customer satisfaction metrics for EPA’s website. The program uses a variety of analytics tools, including Google Analytics and CrazyEgg.

  7. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage.

    Science.gov (United States)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A

    2016-11-05

    This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu(2+). Sulfate, sulfide, Cu(2+) and pH were monitored throughout the experiment of 123d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7mg SO4(2-) d(-1)) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu(2+) removal were observed in the endogenous control. In algae amended-columns, Cu(2+) was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. NMFS Water Column Sonar Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water column sonar data are an important component of fishery independent surveys, habitat studies and other research. NMFS water column sonar data are archived here.

  9. Local buckling of composite channel columns

    Science.gov (United States)

    Szymczak, Czesław; Kujawa, Marcin

    2018-05-01

    The investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic material modelling are performed: the homogenization with the aid of theory of mixture and periodicity cell or homogenization upon the Voigt-Reuss hypothesis. The fundamental differential equation of local buckling is derived with the aid of the stationary total potential energy principle. The critical buckling stress corresponding to a number of buckling half-waves is assumed to be a minimum eigenvalue of the equation. Some numerical examples dealing with columns are given here. The analytical results are compared with the finite element stability analysis carried out by means of ABAQUS software. The paper is focused on a close analytical solution of the critical buckling stress and the associated buckling mode while the web-flange cooperation is assumed.

  10. Study on Predicting Axial Load Capacity of CFST Columns

    Science.gov (United States)

    Ravi Kumar, H.; Muthu, K. U.; Kumar, N. S.

    2017-11-01

    This work presents an analytical study and experimental study on the behaviour and ultimate load carrying capacity of axially compressed self-compacting concrete-filled steel tubular columns. Results of tests conducted by various researchers on 213 samples concrete-filled steel tubular columns are reported and present authors experimental data are reported. Two theoretical equations were derived for the prediction of the ultimate axial load strength of concrete-filled steel tubular columns. The results from prediction were compared with the experimental data. Validation to the experimental results was made.

  11. Enhanced sulfate reduction with acidogenic sulfate-reducing bacteria

    International Nuclear Information System (INIS)

    Wang Aijie; Ren Nanqi; Wang Xu; Lee Duujong

    2008-01-01

    Sulfate reduction in a continuous flow, acidogenic reactor using molasses wastewater as the carbon source was studied at varying chemical oxygen demand/sulfate (COD/SO 4 2- ) ratios. At a critical COD/SO 4 2- ratio of 2.7, neither COD nor sulfate were in excess for extra production of ethanol or acetate in the reactor. An acetic-type microbial metabolism was established with sulfate-reducing bacteria (SRB) significantly consuming hydrogen and volatile fatty acids produced by acidogenic bacteria and hydrogen producing acetogens in degrading COD, thereby yielding sulfate removal rate >94.6%. A low critical COD/SO 4 2- ratio of 1.6 was also observed with the enriched ASRB population in reactor which overcomes the barrier to the treatment capability of sulfate-laden wastewater treatment with limited COD supply

  12. Trace Level Determination of Mesityl Oxide and Diacetone Alcohol in Atazanavir Sulfate Drug Substance by a Gas Chromatography Method.

    Science.gov (United States)

    Raju, K V S N; Pavan Kumar, K S R; Siva Krishna, N; Madhava Reddy, P; Sreenivas, N; Kumar Sharma, Hemant; Himabindu, G; Annapurna, N

    2016-01-01

    A capillary gas chromatography method with a short run time, using a flame ionization detector, has been developed for the quantitative determination of trace level analysis of mesityl oxide and diacetone alcohol in the atazanavir sulfate drug substance. The chromatographic method was achieved on a fused silica capillary column coated with 5% diphenyl and 95% dimethyl polysiloxane stationary phase (Rtx-5, 30 m x 0.53 mm x 5.0 µm). The run time was 20 min employing programmed temperature with a split mode (1:5) and was validated for specificity, sensitivity, precision, linearity, and accuracy. The detection and quantitation limits obtained for mesityl oxide and diacetone alcohol were 5 µg/g and 10 µg/g, respectively, for both of the analytes. The method was found to be linear in the range between 10 µg/g and 150 µg/g with a correlation coefficient greater than 0.999, and the average recoveries obtained in atazanavir sulfate were between 102.0% and 103.7%, respectively, for mesityl oxide and diacetone alcohol. The developed method was found to be robust and rugged. The detailed experimental results are discussed in this research paper.

  13. Experimental data sulfate and metal removal from mining impacted water collected at the Formosa Mine, OR, and sulfur speciation in the obtained solid residues.

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set contains the elemental composition, pH, and sulfate content of the utilized mining impacted water used as influent in the columns study, the data for...

  14. Elevator frames two columns

    OpenAIRE

    Marín Jiménez, Juan Francisco

    2015-01-01

    This project aims to solve the problem of vertical transport of charges raised by a company with the standard UNE 58-132-91/6. The purpose of this project is the industrial design of a system of load handling by a bi-columned lifting device, tractioned by flat belts and steel cables from a transport level to a different level in order to connect two different assembly lines situated at different heights. The goal of this project is lifting a 780 Kg load at a 2.400 mm height....

  15. Column: Every Last Byte

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-06-01

    Full Text Available Inheritance powder is the name that was given to poisons, especially arsenic, that were commonly used in the 17th and early 18th centuries to hasten the death of the elderly. For most of the 17th century, arsenic was deadly but undetectable, making it nearly impossible to prove that someone had been poisoned. The first arsenic test produced a gas—hardly something that a scientist could show to a judge. Faced with a growing epidemic of poisonings, doctors and chemists spent decades searching for something better.(see PDF for full column

  16. Syndecan heparan sulfate proteoglycans

    DEFF Research Database (Denmark)

    Gomes, Angélica Maciel; Sinkeviciute, Dovile; Multhaupt, Hinke A.B.

    2016-01-01

    discuss how, in partial catabolic processes, new roles for HSPGs emerge that affect cell behavior. Examples from tumor studies are emphasized, since HSPGs may be altered in composition and distribution and may also represent targets for the development of new therapeutics....... signaling can therefore be complex, but it is now known that syndecans are capable of independent signaling. This review is divided in two sections, and will first discuss how the assembly of heparan sulfate, the anabolic process, encodes information related to ligand binding and signaling. Second, we...

  17. Annular pulse column development studies

    International Nuclear Information System (INIS)

    Benedict, G.E.

    1980-01-01

    The capacity of critically safe cylindrical pulse columns limits the size of nuclear fuel solvent extraction plants because of the limited cross-sectional area of plutonium, U-235, or U-233 processing columns. Thus, there is a need to increase the cross-sectional area of these columns. This can be accomplished through the use of a column having an annular cross section. The preliminary testing of a pilot-plant-scale annular column has been completed and is reported herein. The column is made from 152.4-mm (6-in.) glass pipe sections with an 89-mm (3.5-in.) o.d. internal tube, giving an annular width of 32-mm (1.25-in.). Louver plates are used to swirl the column contents to prevent channeling of the phases. The data from this testing indicate that this approach can successfully provide larger-cross-section critically safe pulse columns. While the capacity is only 70% of that of a cylindrical column of similar cross section, the efficiency is almost identical to that of a cylindrical column. No evidence was seen of any non-uniform pulsing action from one side of the column to the other

  18. 2-Amino-4-hydroxyethylaminoanisole sulfate

    DEFF Research Database (Denmark)

    Madsen, Jakob T; Andersen, Klaus E

    2016-01-01

    positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. METHODS: Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. RESULTS......: A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions....... CONCLUSIONS: 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen....

  19. Morpholine-4-carboxamidinium sulfate

    Directory of Open Access Journals (Sweden)

    Ioannis Tiritiris

    2016-01-01

    Full Text Available The asymmetric unit of the title salt, 2C5H12N3O+·SO42−, comprises two cations and one sulfate ion. In both cations, the C, N and O atoms of the morpholine rings are disordered over two sets of sites, with refined occupancies of 0.849 (3:0.151 (3 for cation I and 0.684 (4:0.316 (4 for cation II. The C—N bond lengths in both central C3N units of the carboxamidinium ions range between 1.253 (12 and 1.362 (5 Å, indicating a degree of double-bond character. The central C atoms are bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charges are delocalized in both CN3 planes. The crystal structure is stabilized by a three-dimensional network of N—H...O hydrogen bonds between the cations and the sulfate ion. Scheme tiny font, charges and delocalized bonds almost invisible

  20. Radio-chemical applications of columns of precipitated insoluble sulphates - contribution to the study of fission product solutions (1962); Applications en radiochimie de colonnes de precipites de sulfates insolubles - contribution a l'etude des solutions vieillies de produits de fission (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Sauvagnac, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Barrachina, M [Junta de la Energia Nuclear, Madrid (Spain)

    1962-07-01

    After describing the preparation of SrSO{sub 4} and BaS0{sub 4} columns, the authors study the following variables affecting fixation of Sr{sup 90}: - influence of pH, of the SO{sub 4}{sup --} concentration in the solution studied, of the column density, of the flow rate, of the use of the EDTA complex. A mechanism is proposed for the exchange and fixation. Once the column characteristics had been chosen, the fixation of rare-earths in the absence or presence of EDTA was studied. - it was observed that for nitrate or chloride concentrations of over 2 mg/ml, or in the presence of stronger than 1 N HNO{sub 3} or HCl, barium was fixed selectively. - these results were applied to radiochemical separations in fission product solutions: Ba{sup 140} and Sr{sup 90} separation, and that of the ceric earth group and the yttric earth group. - In order to establish a complete scheme for the radio-chemical separation in fission product solution, after at least one year ageing, the techniques of column separation and of solvent extraction using thenoyltrifluoroacetone and bis di-ethylhexylphosphoric acid are combined. (authors) [French] Apres avoir decrit la preparation des colonnes de SrS0{sub 4} et BaS0{sub 4}, on etudie les variables suivantes pour la fixation de {sup 90}Sr: - influence du pH, de la concentration en SO{sub 4}{sup --} dans la solution etudiee, de la densite de la colonne, de la vitesse de passage, de l'emploi du complexant EDTA. On propose une explication du mode d'echange et de fixation. Les caracteristiques de la colonne etant choisies, on a etudie la fixation des terres rares en presence ou non de EDTA. - on a d'autre part constate qu'en milieu chlorure ou nitrate, de concentration superieure a 2 mg/ml, ou en presence de HNO{sub 3} ou HCl superieur a 1 N, on fixait selectivement le baryum. - on a applique ces resultats a des separations radiochimiques dans des solutions de produits de fission: separation de {sup 140}Ba, {sup 90}Sr, separation du groupe des

  1. Plant-Scale Concentration Column Designs for SHINE Target Solution Utilizing AG 1 Anion Exchange Resin

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, G. F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-30

    Argonne is assisting SHINE Medical Technologies (SHINE) in their efforts to develop SHINE, an accelerator-driven process that will utilize a uranyl-sulfate solution for the production of fission product Mo-99. An integral part of the process is the development of a column for the separation and recovery of Mo-99, followed by a concentration column to reduce the product volume from 15-25 L to <1 L. Argonne has collected data from batch studies and breakthrough column experiments to utilize the VERSE (Versatile Reaction Separation) simulation program (Purdue University) to design plant-scale product recovery and concentration processes.

  2. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A., E-mail: jimfield@email.arizona.edu

    2016-11-05

    Highlights: • Algal biomass can serve as an electron donor to drive reduction of sulfate to sulfide. • Biogenic sulfide precipitates Cu{sup 2+} as stable sulfide mineral. • Cu{sup +2} removal in sulfidogenic bioreactors amended with algal biomass exceeded 99.5%. • Acidity in synthetic acid rock drainage was consumed by sulfate reduction. - Abstract: This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H{sub 2}SO{sub 4} and Cu{sup 2+}. Sulfate, sulfide, Cu{sup 2+} and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO{sub 4}{sup 2−} d{sup −1}) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu{sup 2+} removal were observed in the endogenous control. In algae amended-columns, Cu{sup 2+} was precipitated with biogenic H{sub 2}S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.

  3. Preparation and Characterization of a Polymeric Monolithic Column for Use in High-Performance Liquid Chromatography (HPLC)

    Science.gov (United States)

    Bindis, Michael P.; Bretz, Stacey Lowery; Danielson, Neil D.

    2011-01-01

    The high-performance liquid chromatography (HPLC) experiment, most often done in the undergraduate analytical instrumentation laboratory course, generally illustrates reversed-phase chromatography using a commercial C[subscript]18 silica column. To avoid the expense of periodic column replacement and introduce a choice of columns with different…

  4. Column: File Cabinet Forensics

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-12-01

    Full Text Available Researchers can spend their time reverse engineering, performing reverse analysis, or making substantive contributions to digital forensics science. Although work in all of these areas is important, it is the scientific breakthroughs that are the most critical for addressing the challenges that we face.Reverse Engineering is the traditional bread-and-butter of digital forensics research. Companies like Microsoft and Apple deliver computational artifacts (operating systems, applications and phones to the commercial market. These artifacts are bought and used by billions. Some have evil intent, and (if society is lucky, the computers end up in the hands of law enforcement. Unfortunately the original vendors rarely provide digital forensics tools that make their systems amenable to analysis by law enforcement. Hence the need for reverse engineering.(see PDF for full column

  5. Linking Microbial Ecology to Geochemistry in Sulfate Reducing Systems

    Science.gov (United States)

    Drennan, D. M.; Lee, I.; Landkamer, L.; Almstrand, R.; Figueroa, L. A.; Sharp, J. H.

    2013-12-01

    Sulfate reducing bioreactors (SRBRs) can serve as passive treatment systems for mining influenced waters (MIW). An enhanced understanding of the biogeochemistry and efficacy of SRBRs can be achieved by combining molecular biological and geochemical techniques in both field and column settings. To this end, a spatial and temporal sequence of eight pilot-scale columns were analyzed employing a multidisciplinary approach using ICP-AES, next-generation sequencing, and SEM-EDX to explore the effects of variable substrate on community structure and performance (measured by Zn removal). All pilot scale reactors contained 30% limestone by mass, 7 of the 8 had variable amounts of woodchips, sawdust, and alfalfa hay, and an 8th column where the only carbon source was walnut shells. High throughput sequencing of DNA extracted from liquid in pilot-scale columns reveals, similarly to an analogous field system in Arizona, a dominance of Proteobacteria. However, after the first pore volume, performance differences between substrate permutations emerged, where columns containing exclusively walnut shells or sawdust exhibited a more effective startup and metal removal than did columns containing exclusively woodchips or alfalfa hay. SEM-EDX analysis revealed the initial formation of gypsum (CaSO4) precipitates regardless of substrate. Zn was observed in the presence of Ca, S, and O in some column samples, suggesting there was co-precipitation of Zn and CaSO4. This is congruent with micro-XAS analysis of field data suggesting iron sulfides were co-precipitating with gypsum. A SEM-EDX analysis from a subsequent sampling event (8 months into operation) indicated that precipitation may be shifting to ZnS and ZnCO3. Biplots employing Canonical Correspondence Analysis (CCA) describe how diversity scales with performance and substrate selection, and how community shifts may result in differential performance and precipitation in response to selective pressure of bioreactor material on

  6. Structural performance of circular columns confined by recycled GFRP stirrups and exposed to severe conditions

    Directory of Open Access Journals (Sweden)

    Mohamed S. Sayed

    2012-08-01

    Full Text Available Since 1980, Egyptian government investment has been directed to the infrastructure projects. Water supply and water drainage networks are among those projects which are very costly; therefore they are designed with a life span of about one hundred years. There is a new trend toward the use of durable and maintenance free systems. The “GFRP” pipes are one of the economic solutions if the project life span is taken into consideration. A number of investors currently produce the “GFRP” pipes in the Egyptian market and although they follow the latest technologies in their production lines, they still suffer 2–5% deficiency of their produced pipes which consequently regarded as rejected pipes. This percentage has a negative impact on the environmental and economical issues. This research is a trial to investigate the behavior of circular columns confined by GFRP stirrups and exposed to severe conditions. A number of waste pipes were randomly selected and sliced to be used as circular column transverse reinforcement. An experimental program consisting of ten short circular columns was designed to study the effect of corrosion, high degrees of temperature, and sulfate attack on the structural behavior of the axially loaded short circular columns. The experimental results showed that columns laterally reinforced by GFRP slices have a comparable behavior to conventionally reinforced concrete columns especially for those columns exposed to corrosion and sulfate attack.

  7. INTRACELLULAR SYNTHESIS OF CHONDROITIN SULFATE

    Science.gov (United States)

    Dziewiatkowski, Dominic D.

    1962-01-01

    In autoradiograms of slices of costal cartilage, incubated for 4 hours in a salt solution containing S35-sulfate and then washed extensively and dehydrated, about 85 per cent of the radioactivity was assignable to the chondrocytes. From alkaline extracts of similarly prepared slices of cartilage, 64 to 83 per cent of the total sulfur-35 in the slices was isolated as chondroitin sulfate by chromatography on an anion-exchange resin. In view of the estimate that only about 15 per cent of the radioactivity was in the matrix, the isolation of 64 to 83 per cent of the total sulfur-35 as chondroitin sulfate is a strong argument that the chondrocytes are the loci in which chondroitin sulfate(s) is synthesized. PMID:13888910

  8. Compact electron beam focusing column

    Science.gov (United States)

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-12-01

    A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

  9. Asymptotic Structure of the Seismic Radiation from an Explosive Column

    Directory of Open Access Journals (Sweden)

    Marco Rosales-Vera

    2018-01-01

    Full Text Available We study the structure of the seismic radiation in the far field produced by an explosive column. Using an asymptotic solution for the far field of vibration (Heelan’s solution, we find analytical expressions to the peak particle velocity (PPV diagrams. These results are extended to the case of a charge with finite velocity of detonation.

  10. Positive column of the discharge in a cylindrical shell

    International Nuclear Information System (INIS)

    Uehara, M.; Maciel, H.S.

    1991-01-01

    A Schottky type theoretical model is presented for the positive column of a discharge on a cylindric shell contained gas, with the discharge current flowing in the longitudinal direction. Some analytical results and the conclusion are presented. (L.C.J.A.). 5 refs

  11. LC-MS n Analysis of Isomeric Chondroitin Sulfate Oligosaccharides Using a Chemical Derivatization Strategy

    Science.gov (United States)

    Huang, Rongrong; Pomin, Vitor H.; Sharp, Joshua S.

    2011-09-01

    Improved methods for structural analyses of glycosaminoglycans (GAGs) are required to understand their functional roles in various biological processes. Major challenges in structural characterization of complex GAG oligosaccharides using liquid chromatography-mass spectrometry (LC-MS) include the accurate determination of the patterns of sulfation due to gas-phase losses of the sulfate groups upon collisional activation and inefficient on-line separation of positional sulfation isomers prior to MS/MS analyses. Here, a sequential chemical derivatization procedure including permethylation, desulfation, and acetylation was demonstrated to enable both on-line LC separation of isomeric mixtures of chondroitin sulfate (CS) oligosaccharides and accurate determination of sites of sulfation by MS n . The derivatized oligosaccharides have sulfate groups replaced with acetyl groups, which are sufficiently stable to survive MS n fragmentation and reflect the original sulfation patterns. A standard reversed-phase LC-MS system with a capillary C18 column was used for separation, and MS n experiments using collision-induced dissociation (CID) were performed. Our results indicate that the combination of this derivatization strategy and MS n methodology enables accurate identification of the sulfation isomers of CS hexasaccharides with either saturated or unsaturated nonreducing ends. Moreover, derivatized CS hexasaccharide isomer mixtures become separable by LC-MS method due to different positions of acetyl modifications.

  12. Bubble column fermenter modeling: a comparison for pressure effects

    Energy Technology Data Exchange (ETDEWEB)

    Shioya, S; Dang, N D.P.; Dunn, I J

    1978-01-01

    Two models which describe the oxygen transfer, oxygen uptake, and axial mixing in a bubble column fermenter are described. Model I includes no pressure effects and can be solved analytically. Model II incorporates the influence of hydrostatic pressure on oxygen solubility and gas expansion and must be solved numerically. The liquid phase oxygen concentration profiles from both models are compared to ascertain for what parametric conditions and for what maximum column height Model I is valid. Results show that for many situations Model I can approximate the oxygen profiles in a 10 m column within 20%. As the transfer and uptake rates increase, the deviation of Model I can reach 80% for a 10 m column. 7 figures.

  13. Safety barriers and lighting columns.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1972-01-01

    Problems arising from the sitting of lighting columns on the central reserve are reviewed, and remedial measures such as break-away lighting supports and installation of safety fences on the central reserve on both sides of the lighting columns are examined.

  14. Heparan sulfate and cell division

    Directory of Open Access Journals (Sweden)

    Porcionatto M.A.

    1999-01-01

    Full Text Available Heparan sulfate is a component of vertebrate and invertebrate tissues which appears during the cytodifferentiation stage of embryonic development. Its structure varies according to the tissue and species of origin and is modified during neoplastic transformation. Several lines of experimental evidence suggest that heparan sulfate plays a role in cellular recognition, cellular adhesion and growth control. Heparan sulfate can participate in the process of cell division in two distinct ways, either as a positive or negative modulator of cellular proliferation, or as a response to a mitogenic stimulus.

  15. Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics.

    Science.gov (United States)

    Fiume, Monice; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

    2010-05-01

    Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

  16. Effects of static pre-loading on the dynamic stability of a column on ...

    African Journals Online (AJOL)

    This paper presents, from strictly analytical consideration, the dynamic analysis of a finite column stressed by a step load but in the presence of a previously imposed static load. The results show that (a) the dynamic buckling load for this type of loading is relatively higher than that of a similar column stressed by a step load ...

  17. Microbial ecology of the stratified water column of the Black Sea as revealed by a comprehensive biomarker study

    DEFF Research Database (Denmark)

    Wakeham, Stuart G.; Amann, Rudi; Freemann, Katherine H.

    2007-01-01

    The stratified water column of the Black Sea is partitioned into oxic, suboxic, and euxinic zones, each characterized by different biogeochemical processes and by distinct microbial communities. In 2003, we collected particulate matter by large volume in situ filtration at the highest resolution...... reduction, and sulfide oxidation at the chemocline, and bacterial sulfate reduction and anaerobic oxidation of methane by archaea in the anoxic zone. Cell densities for archaea and sulfate reducing bacteria are estimated based on water column biomarker concentrations and compared with CARD-FISH results....

  18. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  19. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A., E-mail: jimfield@email.arizona.edu

    2016-05-05

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  20. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    International Nuclear Information System (INIS)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A.

    2016-01-01

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  1. Analytic trigonometry

    CERN Document Server

    Bruce, William J; Maxwell, E A; Sneddon, I N

    1963-01-01

    Analytic Trigonometry details the fundamental concepts and underlying principle of analytic geometry. The title aims to address the shortcomings in the instruction of trigonometry by considering basic theories of learning and pedagogy. The text first covers the essential elements from elementary algebra, plane geometry, and analytic geometry. Next, the selection tackles the trigonometric functions of angles in general, basic identities, and solutions of equations. The text also deals with the trigonometric functions of real numbers. The fifth chapter details the inverse trigonometric functions

  2. Immunological characterization of a basement membrane-specific chondroitin sulfate proteoglycan

    DEFF Research Database (Denmark)

    McCarthy, K J; Accavitti, M A; Couchman, J R

    1989-01-01

    with the proteoglycan preparation and four mAbs recognizing the core protein of a high-density, buoyant chondroitin sulfate proteoglycan were raised. Confirmation of antibody specificity was carried out by the preparation of affinity columns made from each of the mAbs. Chondroitin sulfate proteoglycans (CSPGs) were...... (Mr = 5-6 x 10(5)), with a core protein of Mr = approximately 1.5-1.6 x 10(5) and composed exclusively of chondroitin sulfate chains with an average Mr = 1.6-1.8 x 10(4). In addition, a CSPG was purified from adult rat kidney, whose core protein was also Mr = 1.6 x 10(5). The proteoglycan and its core...... sulfate proteoglycans, it therefore appears that at least one CSPG is a widespread basement membrane component....

  3. Analytical Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Analytical Labspecializes in Oil and Hydraulic Fluid Analysis, Identification of Unknown Materials, Engineering Investigations, Qualification Testing (to support...

  4. Cost and Ductility Effectiveness of Concrete Columns Strengthened with CFRP and SFRP Sheets

    Directory of Open Access Journals (Sweden)

    Khaled Abdelrahman

    2014-05-01

    Full Text Available Recently, steel fibre reinforced polymers (SFRP sheets have been introduced for the repair and rehabilitation of concrete structures. Few researchers studied the behaviour of the concrete columns wrapped with SFRP sheets; however, several critical parameters such as the cost and ductility effectiveness of the SFRP wrapped concrete columns have been lightly addressed. Thus, the main objective of this paper is to study the cost and ductility effectiveness of SFRP wrapped concrete columns and compare the results with the conventionally used carbon FRP (CFRP wrapped concrete columns. In addition, an analytical procedure to predict the cost effectiveness of SFRP wrapped concrete columns is also suggested, from which, a parametric study was conducted. The parametric study investigated the effect of the concrete strength, the number of SFRP layers, and the size and slenderness effects on the cost effectiveness of the concrete columns wrapped with SFRP sheets. The results from the cost and ductility effectiveness study indicated that the SFRP wrapped concrete columns showed enhanced performance over the CFRP wrapped concrete columns. The suggested analytical procedure proved to be a reliable and accurate method to predict the cost effectiveness parameter of SFRP wrapped concrete columns. The parametric study showed the significant impact of the investigated parameters on the cost effectiveness of concrete columns wrapped with SFRP sheets.

  5. Column-Oriented Database Systems (Tutorial)

    NARCIS (Netherlands)

    D. Abadi; P.A. Boncz (Peter); S. Harizopoulos

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as

  6. Dominance of sulfur-fueled iron oxide reduction in low-sulfate freshwater sediments.

    Science.gov (United States)

    Hansel, Colleen M; Lentini, Chris J; Tang, Yuanzhi; Johnston, David T; Wankel, Scott D; Jardine, Philip M

    2015-11-01

    A central tenant in microbial biogeochemistry is that microbial metabolisms follow a predictable sequence of terminal electron acceptors based on the energetic yield for the reaction. It is thereby oftentimes assumed that microbial respiration of ferric iron outcompetes sulfate in all but high-sulfate systems, and thus sulfide has little influence on freshwater or terrestrial iron cycling. Observations of sulfate reduction in low-sulfate environments have been attributed to the presumed presence of highly crystalline iron oxides allowing sulfate reduction to be more energetically favored. Here we identified the iron-reducing processes under low-sulfate conditions within columns containing freshwater sediments amended with structurally diverse iron oxides and fermentation products that fuel anaerobic respiration. We show that despite low sulfate concentrations and regardless of iron oxide substrate (ferrihydrite, Al-ferrihydrite, goethite, hematite), sulfidization was a dominant pathway in iron reduction. This process was mediated by (re)cycling of sulfur upon reaction of sulfide and iron oxides to support continued sulfur-based respiration--a cryptic sulfur cycle involving generation and consumption of sulfur intermediates. Although canonical iron respiration was not observed in the sediments amended with the more crystalline iron oxides, iron respiration did become dominant in the presence of ferrihydrite once sulfate was consumed. Thus, despite more favorable energetics, ferrihydrite reduction did not precede sulfate reduction and instead an inverse redox zonation was observed. These findings indicate that sulfur (re)cycling is a dominant force in iron cycling even in low-sulfate systems and in a manner difficult to predict using the classical thermodynamic ladder.

  7. Cell-associated proteoheparan sulfate from bovine arterial smooth muscle cells

    International Nuclear Information System (INIS)

    Schmidt, A.; Buddecke, E.

    1988-01-01

    Cell-associated proteoheparan sulfate has been isolated from bovine arterial smooth muscle cells preincubated with [ 35 S]sulfate or a combination of [ 3 H]glucosamine and [ 35 S]methionine. The purified proteoheparan sulfate had an apparent M r of 200,000 on calibrated Sepharose CL-2B columns. The glycosaminoglycan component (M r ∼30,000) was identified as heparan sulfate by its susceptibility to specific enzymatic and chemical degradation. After degradation of the proteoheparan sulfate by microbial heparitinase the resulting protein core had an apparent M r of 92,000 on SDS-polyacrylamide gels. Its mobility was similar in the absence and presence of reducing agents indicating that the protein core consists of a single polypeptide chain. Pulse-chase experiments revealed that about 40% of the cell layer-associated proteoheparan sulfate was released into the medium, while the remainder was internalized and converted to smaller species through a series of degradation steps. Initially there was a proteolytical cleavage of the protein core generating glycosaminoglycan peptide intermediates with polysaccharides chains similar in size to the original. The half-life of the native proteoheparan sulfate was found to be about 4 h

  8. An HPLC Method for Microanalysis and Pharmacokinetics of Marine Sulfated Polysaccharide PSS-Loaded Poly Lactic-co-Glycolic Acid (PLGA Nanoparticles in Rat Plasma

    Directory of Open Access Journals (Sweden)

    Hua-Shi Guan

    2013-04-01

    Full Text Available This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with d-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD at 250 nm (excitation and 435 nm (emission using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1–500 μg/mL, and the lower limit of detection (LLOD was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA nanoparticles (PSS-NP in rat plasma after a single intravenous (PSS only and oral administration (PSS and PSS-NP. Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability.

  9. Water Column Sonar Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The collection and analysis of water column sonar data is a relatively new avenue of research into the marine environment. Primary uses include assessing biological...

  10. The Effect of Column and Eluent Fluorination on the Retention and Separation of non-Fluorinated Amino Acids and Proteins by HPLC

    Science.gov (United States)

    Joyner, Katherine; Wang, Weizhen; Yu, Yihua Bruce

    2011-01-01

    The effect of column and eluent fluorination on the retention and separation of non-fluorinated amino acids and proteins in HPLC is investigated. A side-by-side comparison of fluorocarbon column and eluents (F-column and F-eluents) with their hydrocarbon counterparts (H-column and H-eluents) in the separation of a group of 33 analytes, including 30 amino acids and 3 proteins, is conducted. The H-column and the F-column contain the n-C8H17 group and n-C8F17 group, respectively, in their stationary phases. The H-eluents include ethanol (EtOH) and isopropanol (ISP) while the F-eluents include trifluoroethanol (TFE) and hexafluorosopropanol (HFIP). The 2 columns and 4 eluents generated 8 (column, eluent) pairs that produce 264 retention time data points for the 33 analytes. A statistical analysis of the retention time data reveals that although the H-column is better than the F-column in analyte separation and H-eluents are better than F-eluents in analyte retention, the more critical factor is the proper pairing of column with eluent. Among the conditions explored in this project, optimal retention and separation is achieved when the fluorocarbon column is paired with ethanol, even though TFE is the most polar one among the 4 eluents. This result shows fluorocarbon columns have much potential in chromatographic analysis and separation of non-fluorinated amino acids and proteins. PMID:21318121

  11. Combining measurements to estimate properties and characterization extent of complex biochemical mixtures; applications to Heparan Sulfate

    Science.gov (United States)

    Pradines, Joël R.; Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Farutin, Victor; Huang, Yongqing; Gunay, Nur Sibel; Capila, Ishan

    2016-04-01

    Complex mixtures of molecular species, such as glycoproteins and glycosaminoglycans, have important biological and therapeutic functions. Characterization of these mixtures with analytical chemistry measurements is an important step when developing generic drugs such as biosimilars. Recent developments have focused on analytical methods and statistical approaches to test similarity between mixtures. The question of how much uncertainty on mixture composition is reduced by combining several measurements still remains mostly unexplored. Mathematical frameworks to combine measurements, estimate mixture properties, and quantify remaining uncertainty, i.e. a characterization extent, are introduced here. Constrained optimization and mathematical modeling are applied to a set of twenty-three experimental measurements on heparan sulfate, a mixture of linear chains of disaccharides having different levels of sulfation. While this mixture has potentially over two million molecular species, mathematical modeling and the small set of measurements establish the existence of nonhomogeneity of sulfate level along chains and the presence of abundant sulfate repeats. Constrained optimization yields not only estimations of sulfate repeats and sulfate level at each position in the chains but also bounds on these levels, thereby estimating the extent of characterization of the sulfation pattern which is achieved by the set of measurements.

  12. Use of a pulsed column with discs and crowns for uranium extraction from phosphoric acid

    International Nuclear Information System (INIS)

    1982-04-01

    The physico-chemistry of the system phosphoric acid-uranium-dioctylpyrophosphoric acid is studied for the determination of analytical methods and extraction parameters (oxidation state of uranium and iron, phosphorus concentration, extractant concentration). Extraction is then realized on a pilot scale with a liquid-liquid extraction column 4m high and of 50 mm in diameter with a column packing made of discs and crowns. Column efficiency is evaluated by studying uranium transfer as a function of operating conditions. The results obtained are extrapolated to an industrial scale and a comparative economic evaluation is made between a pulsed column and a mixer-settler [fr

  13. LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  14. Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography

    Science.gov (United States)

    Belisle, A.A.; Swineford, D.M.

    1988-01-01

    A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

  15. Chondroitin sulfate/dermatan sulfate sulfatases from mammals and bacteria.

    Science.gov (United States)

    Wang, Shumin; Sugahara, Kazuyuki; Li, Fuchuan

    2016-12-01

    Sulfatases that specifically catalyze the hydrolysis of the sulfate groups on chondroitin sulfate (CS)/dermatan sulfate (DS) poly- and oligosaccharides belong to the formylglycine-dependent family of sulfatases and have been widely found in various mammalian and bacterial organisms. However, only a few types of CS/DS sulfatase have been identified so far. Recently, several novel CS/DS sulfatases have been cloned and characterized. Advanced studies have provided significant insight into the biological function and mechanism of action of CS/DS sulfatases. Moreover, further studies will provide powerful tools for structural and functional studies of CS/DS as well as related applications. This article reviews the recent progress in CS/DS sulfatase research and is expected to initiate further research in this field.

  16. Column-Oriented Database Systems (Tutorial)

    OpenAIRE

    Abadi, D.; Boncz, Peter; Harizopoulos, S.

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as opposed to traditional database systems that store entire records (rows) one after the other. Reading a subset of a table’s columns becomes faster, at the potential expense of excessive disk-head s...

  17. Empirical Approach for Determining Axial Strength of Circular Concrete Filled Steel Tubular Columns

    Science.gov (United States)

    Jayalekshmi, S.; Jegadesh, J. S. Sankar; Goel, Abhishek

    2018-03-01

    The concrete filled steel tubular (CFST) columns are highly regarded in recent years as an interesting option in the construction field by designers and structural engineers, due to their exquisite structural performance, with enhanced load bearing capacity and energy absorption capacity. This study presents a new approach to simulate the capacity of circular CFST columns under axial loading condition, using a large database of experimental results by applying artificial neural network (ANN). A well trained network is established and is used to simulate the axial capacity of CFST columns. The validation and testing of the ANN is carried out. The current study is focused on proposing a simplified equation that can predict the ultimate strength of the axially loaded columns with high level of accuracy. The predicted results are compared with five existing analytical models which estimate the strength of the CFST column. The ANN-based equation has good prediction with experimental data, when compared with the analytical models.

  18. Empirical Approach for Determining Axial Strength of Circular Concrete Filled Steel Tubular Columns

    Science.gov (United States)

    Jayalekshmi, S.; Jegadesh, J. S. Sankar; Goel, Abhishek

    2018-06-01

    The concrete filled steel tubular (CFST) columns are highly regarded in recent years as an interesting option in the construction field by designers and structural engineers, due to their exquisite structural performance, with enhanced load bearing capacity and energy absorption capacity. This study presents a new approach to simulate the capacity of circular CFST columns under axial loading condition, using a large database of experimental results by applying artificial neural network (ANN). A well trained network is established and is used to simulate the axial capacity of CFST columns. The validation and testing of the ANN is carried out. The current study is focused on proposing a simplified equation that can predict the ultimate strength of the axially loaded columns with high level of accuracy. The predicted results are compared with five existing analytical models which estimate the strength of the CFST column. The ANN-based equation has good prediction with experimental data, when compared with the analytical models.

  19. Analytic geometry

    CERN Document Server

    Burdette, A C

    1971-01-01

    Analytic Geometry covers several fundamental aspects of analytic geometry needed for advanced subjects, including calculus.This book is composed of 12 chapters that review the principles, concepts, and analytic proofs of geometric theorems, families of lines, the normal equation of the line, and related matters. Other chapters highlight the application of graphing, foci, directrices, eccentricity, and conic-related topics. The remaining chapters deal with the concept polar and rectangular coordinates, surfaces and curves, and planes.This book will prove useful to undergraduate trigonometric st

  20. Methane and sulfate dynamics in sediments from mangrove-dominated tropical coastal lagoons, Yucatan, Mexico

    Science.gov (United States)

    Chuang, P. C.; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A.; Paytan, Adina

    2016-01-01

    Porewater profiles in sediment cores from mangrove-dominated coastal lagoons (Celestún and Chelem) on the Yucatán Peninsula, Mexico, reveal the widespread coexistence of dissolved methane and sulfate. This observation is interesting since dissolved methane in porewaters is typically oxidized anaerobically by sulfate. To explain the observations we used a numerical transport-reaction model that was constrained by the field observations. The model suggests that methane in the upper sediments is produced in the sulfate reduction zone at rates ranging between 0.012 and 31 mmol m−2 d−1, concurrent with sulfate reduction rates between 1.1 and 24 mmol SO42− m−2 d−1. These processes are supported by high organic matter content in the sediment and the use of non-competitive substrates by methanogenic microorganisms. Indeed sediment slurry incubation experiments show that non-competitive substrates such as trimethylamine (TMA) and methanol can be utilized for microbial methanogenesis at the study sites. The model also indicates that a significant fraction of methane is transported to the sulfate reduction zone from deeper zones within the sedimentary column by rising bubbles and gas dissolution. The shallow depths of methane production and the fast rising methane gas bubbles reduce the likelihood for oxidation, thereby allowing a large fraction of the methane formed in the sediments to escape to the overlying water column.

  1. Semi-synthesis of chondroitin sulfate-E from chondroitin sulfate-A

    OpenAIRE

    Cai, Chao; Solakyildirim, Kemal; Yang, Bo; Beaudet, Julie M.; Weyer, Amanda; Linhardt, Robert J.; Zhang, Fuming

    2012-01-01

    Chondroitin sulfate-E (chondroitin-4, 6-disulfate) was prepared from chondroitin sulfate-A (chondroitin-4 - sulfate) by regioselective sulfonation, performed using trimethylamine sulfur trioxide in formamide under argon. The structure of semi-synthetic chondroitin sulfate-E was analyzed by PAGE, 1H NMR, 13C NMR, 2D NMR and disaccharide analysis and compared with natural chondroitin sulfate-E. Both semi-synthetic and natural chondroitin sulfate-E were each biotinylated and immobilized on BIAco...

  2. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    DEFF Research Database (Denmark)

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

  3. Analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Myeong Hu; Lee, Hu Jun; Kim, Ha Seok

    1989-02-15

    This book give explanations on analytical chemistry with ten chapters, which deal with development of analytical chemistry, the theory of error with definition and classification, sample and treatment gravimetry on general process of gravimetry in aqueous solution and non-aqueous solution, precipitation titration about precipitation reaction and types, complexometry with summary and complex compound, oxidation-reduction equilibrium on electrode potential and potentiometric titration, solvent extraction and chromatograph and experiment with basic operation for chemical experiment.

  4. Analytical chemistry

    International Nuclear Information System (INIS)

    Chae, Myeong Hu; Lee, Hu Jun; Kim, Ha Seok

    1989-02-01

    This book give explanations on analytical chemistry with ten chapters, which deal with development of analytical chemistry, the theory of error with definition and classification, sample and treatment gravimetry on general process of gravimetry in aqueous solution and non-aqueous solution, precipitation titration about precipitation reaction and types, complexometry with summary and complex compound, oxidation-reduction equilibrium on electrode potential and potentiometric titration, solvent extraction and chromatograph and experiment with basic operation for chemical experiment.

  5. Radiotracer Imaging of Sediment Columns

    Science.gov (United States)

    Moses, W. W.; O'Neil, J. P.; Boutchko, R.; Nico, P. S.; Druhan, J. L.; Vandehey, N. T.

    2010-12-01

    Nuclear medical PET and SPECT cameras routinely image radioactivity concentration of gamma ray emitting isotopes (PET - 511 keV; SPECT - 75-300 keV). We have used nuclear medical imaging technology to study contaminant transport in sediment columns. Specifically, we use Tc-99m (T1/2 = 6 h, Eγ = 140 keV) and a SPECT camera to image the bacteria mediated reduction of pertechnetate, [Tc(VII)O4]- + Fe(II) → Tc(IV)O2 + Fe(III). A 45 mL bolus of Tc-99m (32 mCi) labeled sodium pertechnetate was infused into a column (35cm x 10cm Ø) containing uranium-contaminated subsurface sediment from the Rifle, CO site. A flow rate of 1.25 ml/min of artificial groundwater was maintained in the column. Using a GE Millennium VG camera, we imaged the column for 12 hours, acquiring 44 frames. As the microbes in the sediment were inactive, we expected most of the iron to be Fe(III). The images were consistent with this hypothesis, and the Tc-99m pertechnetate acted like a conservative tracer. Virtually no binding of the Tc-99m was observed, and while the bolus of activity propagated fairly uniformly through the column, some inhomogeneity attributed to sediment packing was observed. We expect that after augmentation by acetate, the bacteria will metabolically reduce Fe(III) to Fe(II), leading to significant Tc-99m binding. Imaging sediment columns using nuclear medicine techniques has many attractive features. Trace quantities of the radiolabeled compounds are used (micro- to nano- molar) and the half-lives of many of these tracers are short (Image of Tc-99m distribution in a column containing Rifle sediment at four times.

  6. Evaluation of pesticide adsorption in gas chromatographic injector and column

    Directory of Open Access Journals (Sweden)

    Gevany Paulino de Pinho

    2012-01-01

    Full Text Available Components in complex matrices can cause variations in chromatographic response during analysis of pesticides by gas chromatography. These variations are related to the competition between analytes and matrix components for adsorption sites in the chromatographic system. The capacity of the pesticides chlorpyrifos and deltamethrin to be adsorbed in the injector and chromatographic column was evaluated by constructing three isotherms and changing the column heating rate to 10 and 30 ºC min-1. By using ANCOVA to compare the slope of calibration graphs, results showed that the higher the injector temperature (310 ºC the lower the pesticide adsorption. Also, deltamethrin influenced the adsorption of chlorpyrifos on the column chromatographic.

  7. Performance evaluation of a rectifier column using gamma column scanning

    Directory of Open Access Journals (Sweden)

    Aquino Denis D.

    2017-12-01

    Full Text Available Rectifier columns are considered to be a critical component in petroleum refineries and petrochemical processing installations as they are able to affect the overall performance of these facilities. It is deemed necessary to monitor the operational conditions of such vessels to optimize processes and prevent anomalies which could pose undesired consequences on product quality that might lead to huge financial losses. A rectifier column was subjected to gamma scanning using a 10-mCi Co-60 source and a 2-inch-long detector in tandem. Several scans were performed to gather information on the operating conditions of the column under different sets of operating parameters. The scan profiles revealed unexpected decreases in the radiation intensity at vapour levels between trays 2 and 3, and between trays 4 and 5. Flooding also occurred during several scans which could be attributed to parametric settings.

  8. Novel approach to determine ghrelin analogs by liquid chromatography with mass spectrometry using a monolithic column

    Czech Academy of Sciences Publication Activity Database

    Zemenová, Jana; Sýkora, D.; Adámková, H.; Maletínská, Lenka; Elbert, Tomáš; Marek, Aleš; Blechová, Miroslava

    2017-01-01

    Roč. 40, č. 5 (2017), s. 1032-1039 ISSN 1615-9306 Institutional support: RVO:61388963 Keywords : enzyme-linked immunosorbent assay * ghrelin * lipopeptides * liquid chromatography mass spectrometry * monolithic columns Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.557, year: 2016

  9. Sulfate reduction in freshwater peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Oequist, M.

    1996-12-31

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO{sub 4}{sup 2-} concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 {mu}M. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 {mu}M h{sup -1} while in B and C they were 1 and 0.05 {mu}M h{sup -1}, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 {mu}g d{sup -1} g{sup -1}) were found 10 cm below the water table, in B (ca. 1.0 {mu}g d{sup -1} g{sup -1}) in the vicinity of the water table, and in C (0.75 {mu}g d{sup -1} g{sup -1}) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m{sup -2} d{sup -1}, while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m{sup -2} d{sup -1}, respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination

  10. Sulfate reduction in freshwater peatlands

    International Nuclear Information System (INIS)

    Oequist, M.

    1996-01-01

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO 4 2- concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 μM. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 μM h -1 while in B and C they were 1 and 0.05 μM h -1 , respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 μg d -1 g -1 ) were found 10 cm below the water table, in B (ca. 1.0 μg d -1 g -1 ) in the vicinity of the water table, and in C (0.75 μg d -1 g -1 ) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m -2 d -1 , while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m -2 d -1 , respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  11. Acid Sulfate Alteration on Mars

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  12. Attribution of modeled atmospheric sulfate and SO2 in the Northern Hemisphere for June–July 1997

    Directory of Open Access Journals (Sweden)

    C. M. Benkovitz

    2006-01-01

    Full Text Available Anthropogenic sulfate aerosol is a major contributor to shortwave radiative forcing of climate change by direct light scattering and by perturbing cloud properties and to local concentrations of atmospheric particulate matter. Here we analyze results from previously published calculations with an Eulerian transport model for atmospheric sulfur species in the Northern Hemisphere in June–July, 1997 to quantify the absolute and relative contributions of specific source regions (North America, Europe, and Asia and SO2-to-sulfate conversion mechanisms (gas-phase, aqueous-phase and primary sulfate to sulfate and SO2 column burdens as a function of location and time. Although material emitted within a given region dominates the sulfate and SO2 column burden in that region, examination of time series at specific locations shows that material imported from outside can make a substantial and occasionally dominant contribution. Frequently the major fraction of these exogenous contributions to the sulfate column burden was present aloft, thus minimally impacting air quality at the surface, but contributing substantially to the burden and, by implication, to radiative forcing and diminution of surface irradiance. Although the dominant sulfate formation pathway in the domain as a whole is aqueous-phase reaction in clouds (62%, in regions with minimum opportunity for aqueous-phase reaction gas-phase oxidation is dominant, albeit with considerable temporal variability depending on meteorological conditions. These calculations highlight the importance of transoceanic transport of sulfate, especially at the western margins of continents under the influence of predominantly westerly transport winds.

  13. Compressive Strength Prediction of Square Concrete Columns Retrofitted with External Steel Collars

    Directory of Open Access Journals (Sweden)

    Pudjisuryadi, P.

    2013-01-01

    Full Text Available Transverse confining stress in concrete members, commonly provided by transverse reinforcement, has been recognized to enhance strength and ductility. Nowadays, the confining method has been further developed to external confinement approach. This type of confinement can be used for retrofitting existing concrete columns. Many external confining techniques have been proven to be successful in retrofitting circular columns. However, for square or rectangular columns, providing effective confining stress by external retrofitting method is not a simple task due to high stress concentration at column’s corners. This paper proposes an analytical model to predict the peak strength of square concrete columns confined by external steel collars. Comparison with the experimental results showed that the model can predict the peak strength reasonably well. However, it should be noted that relatively larger amount of steel is needed to achieve comparable column strength enhancement when it is compared with those of conve tional internally-confined columns.

  14. High-throughput liquid chromatography for drug analysis in biological fluids: investigation of extraction column life.

    Science.gov (United States)

    Zeng, Wei; Fisher, Alison L; Musson, Donald G; Wang, Amy Qiu

    2004-07-05

    A novel method was developed and assessed to extend the lifetime of extraction columns of high-throughput liquid chromatography (HTLC) for bioanalysis of human plasma samples. In this method, a 15% acetic acid solution and 90% THF were respectively used as mobile phases to clean up the proteins in human plasma samples and residual lipids from the extraction and analytical columns. The 15% acetic acid solution weakens the interactions between proteins and the stationary phase of the extraction column and increases the protein solubility in the mobile phase. The 90% THF mobile phase prevents the accumulation of lipids and thus reduces the potential damage on the columns. Using this novel method, the extraction column lifetime has been extended to about 2000 direct plasma injections, and this is the first time that high concentration acetic acid and THF are used in HTLC for on-line cleanup and extraction column lifetime extension.

  15. Microbial sulfate reduction under sequentially acidic conditions in an upflow anaerobic packed bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Jong, T.; Parry, D.L. [Charles Darwin University, Darwin, NT (Australia). Faculty for Educational Health & Science

    2006-07-15

    The aim of this study was to operate an upflow anaerobic packed bed reactor (UAPB) containing sulfate reducing bacteria (SRB) under acidic conditions similar to those found in acid mine drainage (AMD). The UAPB was filled with sand and operated under continuous flow at progressively lower pH and was shown to be capable of supporting sulfate reduction at pH values of 6.0, 5.0, 4.5, 4.0 and 3.5 in a synthetic medium containing 53.5 mmol l{sup -1} lactate. Sulfate reduction rates of 553-1052 mmol m{sup -3} d{sup -1} were obtained when the influent solution pH was progressively lowered from pH 6.0 to 4.0, under an optimal flow rate of 2.61 ml min{sup -1}. When the influent pH was further lowered to pH 3.5, sulfate reduction was substantially reduced with only about 1% sulfate removed at a rate of 3.35 mmol m{sup -3} d{sup -1} after 20 days of operation. However, viable SRB were recovered from the column, indicating that the SRB population was capable of surviving and metabolizing at low levels even at pH 3.5 conditions for at least 20 days. The changes in conductivity in the SRB column did not always occur with changes in pH and redox potential, suggesting that conductivity measurements may be more sensitive to SRB activity and could be used as an additional tool for monitoring SRB activity. The bioreactor containing SRB was able to reduce sulfate and generate alkalinity even when challenged with influent as low as pH 3.5, indicating that such treatment systems have potential for bioremediating highly acidic, sulfate contaminated waste waters.

  16. Immobilization of cobalt by sulfate-reducing bacteria in subsurface sediments

    Science.gov (United States)

    Krumholz, Lee R.; Elias, Dwayne A.; Suflita, Joseph M.

    2003-01-01

    We investigated the impact of sulfate-reduction on immobilization of metals in subsurface aquifers. Co 2+ was used as a model for heavy metals. Factors limiting sulfate-reduction dependent Co 2+ immobilization were tested on pure cultures of sulfate-reducing bacteria, and in sediment columns from a landfill leachate contaminated aquifer. In the presence of 1 mM Co 2+ , the growth of pure cultures of sulfate-reducing bacteria was not impacted. Cultures of Desulfovibrio desulfuricans, Desulfotomaculum gibsoniae , and Desulfomicrobium hypogeia removed greater than 99.99% of the soluble Co 2+ when CoCl 2 was used with no chelators. The above cultures and Desulfoarcula baarsi removed 98-99.94% of the soluble Co(II) when the metal was complexed with the model ligand nitrilotriacetate (Co-NTA). Factors controlling the rate of sulfate-reduction based Co 2+ precipitation were investigated in sediment-cobalt mixtures. Several electron donors were tested and all but toluene accelerated soluble Co 2+ loss. Ethanol and formate showed the greatest stimulation. All complex nitrogen sources tested slowed and decreased the extent of Co 2+ removal from solution relative to formate-amended sediment incubations. A range of pH values were tested (6.35-7.81), with the more alkaline incubations exhibiting the largest precipitation of Co 2+ . The immobilization of Co 2+ in sediments was also investigated with cores to monitor the flow of Co 2+ through undisturbed sediments. An increase in the amount of Co 2+ immobilized as CoS was observed as sulfate reduction activity was stimulated in flow through columns. Both pure culture and sediment incubation data indicate that stimulation of sulfate reduction is a viable strategy in the immobilization of contaminating metals in subsurface systems.

  17. Sulfate Transporters in Dissimilatory Sulfate Reducing Microorganisms: A Comparative Genomics Analysis

    Directory of Open Access Journals (Sweden)

    Angeliki Marietou

    2018-03-01

    Full Text Available The first step in the sulfate reduction pathway is the transport of sulfate across the cell membrane. This uptake has a major effect on sulfate reduction rates. Much of the information available on sulfate transport was obtained by studies on assimilatory sulfate reduction, where sulfate transporters were identified among several types of protein families. Despite our growing knowledge on the physiology of dissimilatory sulfate-reducing microorganisms (SRM there are no studies identifying the proteins involved in sulfate uptake in members of this ecologically important group of anaerobes. We surveyed the complete genomes of 44 sulfate-reducing bacteria and archaea across six phyla and identified putative sulfate transporter encoding genes from four out of the five surveyed protein families based on homology. We did not find evidence that ABC-type transporters (SulT are involved in the uptake of sulfate in SRM. We speculate that members of the CysP sulfate transporters could play a key role in the uptake of sulfate in thermophilic SRM. Putative CysZ-type sulfate transporters were present in all genomes examined suggesting that this overlooked group of sulfate transporters might play a role in sulfate transport in dissimilatory sulfate reducers alongside SulP. Our in silico analysis highlights several targets for further molecular studies in order to understand this key step in the metabolism of SRMs.

  18. NOx retention in scrubbing column

    International Nuclear Information System (INIS)

    Nakazone, A.K.; Costa, R.E.; Lobao, A.S.T.; Matsuda, H.T.; Araujo, B.F.

    1988-07-01

    During the UO 2 dissolution in nitric acid, some different species of NO x are released. The off gas can either be refluxed to the dissolver or be released and retained on special columns. The final composition of the solution is the main parameter to take in account. A process for nitrous gases retention using scubber columns containing H 2 O or diluted HNO 3 is presented. Chemiluminescence measurement was employed to NO x evalution before and after scrubbing. Gas flow, temperature, residence time are the main parameters considered in this paper. For the dissolution of 100g UO 2 in 8M nitric acid, a 6NL/h O 2 flow was the best condition for the NO/NO 2 oxidation with maximum adsorption in the scrubber columns. (author) [pt

  19. Seismic fragility analysis of lap-spliced reinforced concrete columns retrofitted by SMA wire jackets

    International Nuclear Information System (INIS)

    Choi, Eunsoo; Park, Sun-Hee; Chung, Young-Soo; Kim, Hee Sun

    2013-01-01

    The aim of this study is to provide seismic fragility curves of reinforced concrete columns retrofitted by shape memory alloy wire jackets and thus assess the seismic performance of the columns against earthquakes, comparing them with reinforced concrete columns with lap-spliced and continuous reinforcement. For that purpose, this study first developed analytical models of the experimental results of the three types of columns, (1) lap-spliced reinforcement, (2) continuous reinforcement and (3) lap-spliced reinforcement and retrofitted by SMA wire jackets, using the OpenSEES program, which is oriented to nonlinear dynamic analysis. Then, a suite of ten recorded ground motions was used to conduct dynamic analyses of the analytical models with scaling of the peak ground acceleration from 0.1g to 1.0g in steps of 0.1g. From the static experimental tests, the column retrofitted with SMA wire jackets had a larger displacement ductility by a factor of 2.3 times that of the lap-spliced column, which was 6% larger compared with the ductility of the continuous reinforcement column. From the fragility analyses, the SMA wire jacketed column had median values of 0.162g and 0.567g for yield and collapse, respectively. For the yield damage state, the SMA wire jacketed column had a median value similar to the continuous reinforcement column. However, for the complete damage state, the SMA wire jacketed column showed a 1.33 times larger median value than the continuously reinforcement column. (paper)

  20. European analytical column no. 39. Analytical chemistry and bioanalytical chemistrya yet unshaped social relationship

    DEFF Research Database (Denmark)

    Horvai, George; Worsfold, Paul; Karlberg, Bo

    2011-01-01

    /Km) than BxlB towards para-nitrophenyl β-d-xylopyranoside (pNPX) and β-1,4-xylo-oligosaccharides (degree of polymerisation 2–6). For both enzymes kcat/Km decreased with increasing β-1,4-xylo-oligosaccharide chain length. Using pNPX as donor with 9 monosaccharides, 7 disaccharides and two sugar alcohols...

  1. Sulfate transport in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting...... apical Na+ for K+. 3. Following voltage activation of the passive Cl- permeability of the mitochondria-rich (m.r.) cells sulfate flux-ratio increased to a value predicted from the Ussing flux-ratio equation for a monovalent anion. 4. In such skins, which were shown to exhibit vanishingly small leakage...... conductances, the variation of the rate coefficient for sulfate influx (y) was positively correlated with the rate coefficient for Cl- influx (x), y = 0.035 x - 0.0077 cm/sec (r = 0.9935, n = 15). 5. Addition of the phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine to the serosal bath of short...

  2. Analytical mechanics

    CERN Document Server

    Lemos, Nivaldo A

    2018-01-01

    Analytical mechanics is the foundation of many areas of theoretical physics including quantum theory and statistical mechanics, and has wide-ranging applications in engineering and celestial mechanics. This introduction to the basic principles and methods of analytical mechanics covers Lagrangian and Hamiltonian dynamics, rigid bodies, small oscillations, canonical transformations and Hamilton–Jacobi theory. This fully up-to-date textbook includes detailed mathematical appendices and addresses a number of advanced topics, some of them of a geometric or topological character. These include Bertrand's theorem, proof that action is least, spontaneous symmetry breakdown, constrained Hamiltonian systems, non-integrability criteria, KAM theory, classical field theory, Lyapunov functions, geometric phases and Poisson manifolds. Providing worked examples, end-of-chapter problems, and discussion of ongoing research in the field, it is suitable for advanced undergraduate students and graduate students studying analyt...

  3. Exogenous factors contributing to column bed heterogeneity: Part 1: Consequences of 'air' injections in liquid chromatography.

    Science.gov (United States)

    Samuelsson, Jörgen; Fornstedt, Torgny; Shalliker, Andrew

    2015-08-07

    It has been shown that not only the packing homogeneity, but also factors external to the column bed, such as, frits and distributors can have important effects on the column performance. This current communication is the first in a series focusing on the impact of exogenous factors on the column bed heterogeneity. This study is based on several observations by us and others that chromatographic runs often, for technical reasons, include more or less portions of air in the injections. It is therefore extremely important to find out the impact of air on the column performance, the reliability of the results derived from analyses where air was injected, and the effect on the column homogeneity. We used a photographic approach for visualising the air transport phenomena, and found that the air transport through the column is comprised of many different types of transport phenomena, such as laminal flow, viscous fingering like flows, channels and bulbs, and pulsations. More particularly, the air clouds within the column definitely interact in the adsorption, i.e. mobile phase adsorbed to the column surface is displaced. In addition, irrespective of the type of air transport phenomena, the air does not penetrate the column homogeneously. This process is strongly flow dependent. In this work we study air transport both in an analytical scale and a semi-prep column. Copyright © 2015. Published by Elsevier B.V.

  4. Analytical quadrics

    CERN Document Server

    Spain, Barry; Ulam, S; Stark, M

    1960-01-01

    Analytical Quadrics focuses on the analytical geometry of three dimensions. The book first discusses the theory of the plane, sphere, cone, cylinder, straight line, and central quadrics in their standard forms. The idea of the plane at infinity is introduced through the homogenous Cartesian coordinates and applied to the nature of the intersection of three planes and to the circular sections of quadrics. The text also focuses on paraboloid, including polar properties, center of a section, axes of plane section, and generators of hyperbolic paraboloid. The book also touches on homogenous coordi

  5. 21 CFR 184.1261 - Copper sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food and... Substances Affirmed as GRAS § 184.1261 Copper sulfate. (a) Copper sulfate (cupric sulfate, CuSO4·5H2O, CAS... the reaction of sulfuric acid with cupric oxide or with copper metal. (b) The ingredient must be of a...

  6. Periodate Oxidation for Sulfated Glycosaminoglycans, with Special Reference to the Position of Extra Sulfate Groups in Chondroitin Polysulfates, Chondroitin Sulfate D and Chondroitin Sulfate K

    OpenAIRE

    Seno, Nobuko; Murakami, Keiko; Shibusawa, Haru

    1981-01-01

    The optimum conditions for periodate oxidation of sulfated disaccharides were investigated to determine the position of extra sulfate groups on the saturated disulfated disaccharides obtained from chondroitin polysulfates, chondroitin sulfates D and K. Under the conditions: 2mM saturated disulfated disaccharide with 20mM sodium periodate at 37°in the dark, the uronic acid residue in the disulfated disaccharide from chondroitin sulfate D was rapidly and completely destroyed, whereas that in th...

  7. 21 CFR 582.5230 - Calcium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sulfate. 582.5230 Section 582.5230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  8. 21 CFR 184.1643 - Potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... hydroxide or potassium carbonate. (b) The ingredient meets the specifications of the “Food Chemicals Codex... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg...

  9. 21 CFR 184.1443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization...

  10. EFFECT OF MAGNESIUM SULFATE (A LAXATIVE) ON ...

    African Journals Online (AJOL)

    use with little success . Magnesium sulfate also known as Epsom salt or bitter salt is a hydrate salt with a chemical name of magnesium sulfate heptahydrate . Chemical formula is MgSO. 7HO and trade name is. Andrews liver salt. Dried magnesium sulfate is an osmotic laxative or a saline laxative that acts by increasing the.

  11. 21 CFR 582.5443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  12. Modeling and minimization of barium sulfate scale

    Science.gov (United States)

    Alan W. Rudie; Peter W. Hart

    2006-01-01

    The majority of the barium present in the pulping process exits the digester as barium carbonate. Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and sulfate concentrations are too high, begins to precipitate as barium sulfate. Barium is difficult to control because a mill cannot avoid this carbonate-to-sulfate transition using...

  13. 21 CFR 582.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  14. 21 CFR 182.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  15. Ion Exchange Studies for Removal of Sulfate from Hanford Tank Waste Envelope C (241-AN-107) Using SuperLig 655 Resin

    International Nuclear Information System (INIS)

    Kurath, D.E.; Bontha, J.R.; Blanchard, D.L.; Fiskum, S.K.; Rapko, B.M.

    2000-01-01

    BNFL Inc. is evaluating various pretreatment technologies to mitigate the impacts of sulfate on the LAW vitrification system. One pretreatment technology for separating sulfate from LAW solutions involves the use of SuperLig(reg. sign) 655 (SL-655), a proprietary ion exchange material developed and supplied by IBC Advanced Technologies, Inc., American Fork, UT. This report describes testing of SL-655 with diluted ([Na] approximately 5 M) waste from Hanford Tank 241-AN-107 at Battelle, Pacific Northwest Division. Batch contact studies were conducted from 4 to 96 hours to determine the sulfate distribution coefficient and reaction kinetics. A small-scale ion exchange column test was conducted to evaluate sulfate removal, loading, breakthrough, and elution from the SL-655. In all of these tests, an archived 241-AN-107 tank waste sample (pretreated to remove Cs, Sr, and transuranics elements) was used. The experimental details and results are described in this report. Under the test conditions, SL-655 was found to have no significant ion exchange affinity for sulfate in this matrix. The batch contact study resulted in no measurable difference in the aqueous sulfate concentration following resin contact (K d ∼ 0). The column test also demonstrated SL-655 had no practical affinity for sulfate in the tested matrix. Within experimental error, the sulfate concentration in the column effluent was equal to the concentration in the feed after passing 3 bed volumes of sample through the columns. Furthermore, some, if not all, of the decreased sulfate concentration in these first three column volumes of effluent can be ascribed to mixing and dilution of the 241-AN-107 feed with the interstitial liquid present in the column at the start of the loading cycle. Finally, ICP-AES measurements on the eluate solutions showed the presence of barium as soon as contact with the feed solution is completed. Barium is a metal not detected in the feed solution. Should the loss of barium be

  16. Insights into Tikhonov regularization: application to trace gas column retrieval and the efficient calculation of total column averaging kernels

    Directory of Open Access Journals (Sweden)

    T. Borsdorff

    2014-02-01

    Full Text Available Insights are given into Tikhonov regularization and its application to the retrieval of vertical column densities of atmospheric trace gases from remote sensing measurements. The study builds upon the equivalence of the least-squares profile-scaling approach and Tikhonov regularization method of the first kind with an infinite regularization strength. Here, the vertical profile is expressed relative to a reference profile. On the basis of this, we propose a new algorithm as an extension of the least-squares profile scaling which permits the calculation of total column averaging kernels on arbitrary vertical grids using an analytic expression. Moreover, we discuss the effective null space of the retrieval, which comprises those parts of a vertical trace gas distribution which cannot be inferred from the measurements. Numerically the algorithm can be implemented in a robust and efficient manner. In particular for operational data processing with challenging demands on processing time, the proposed inversion method in combination with highly efficient forward models is an asset. For demonstration purposes, we apply the algorithm to CO column retrieval from simulated measurements in the 2.3 μm spectral region and to O3 column retrieval from the UV. These represent ideal measurements of a series of spaceborne spectrometers such as SCIAMACHY, TROPOMI, GOME, and GOME-2. For both spectral ranges, we consider clear-sky and cloudy scenes where clouds are modelled as an elevated Lambertian surface. Here, the smoothing error for the clear-sky and cloudy atmosphere is significant and reaches several percent, depending on the reference profile which is used for scaling. This underlines the importance of the column averaging kernel for a proper interpretation of retrieved column densities. Furthermore, we show that the smoothing due to regularization can be underestimated by calculating the column averaging kernel on a too coarse vertical grid. For both

  17. Chromatographic properties PLOT multicapillary columns.

    Science.gov (United States)

    Nikolaeva, O A; Patrushev, Y V; Sidelnikov, V N

    2017-03-10

    Multicapillary columns (MCCs) for gas chromatography make it possible to perform high-speed analysis of the mixtures of gaseous and volatile substances at a relatively large amount of the loaded sample. The study was performed using PLOT MCCs for gas-solid chromatography (GSC) with different stationary phases (SP) based on alumina, silica and poly-(1-trimethylsilyl-1-propyne) (PTMSP) polymer as well as porous polymers divinylbenzene-styrene (DVB-St), divinylbenzene-vinylimidazole (DVB-VIm) and divinylbenzene-ethylene glycol dimethacrylate (DVB-EGD). These MCCs have the efficiency of 4000-10000 theoretical plates per meter (TP/m) and at a column length of 25-30cm can separate within 10-20s multicomponent mixtures of substances belonging to different classes of chemical compounds. The sample amount not overloading the column is 0.03-1μg and depends on the features of a porous layer. Examples of separations on some of the studied columns are considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Schedule Analytics

    Science.gov (United States)

    2016-04-30

    Warfare, Naval Sea Systems Command Acquisition Cycle Time : Defining the Problem David Tate, Institute for Defense Analyses Schedule Analytics Jennifer...research was comprised of the following high- level steps :  Identify and review primary data sources 1...research. However, detailed reviews of the OMB IT Dashboard data revealed that schedule data is highly aggregated. Program start date and program end date

  19. A simple method for the small scale synthesis and solid-phase extraction purification of steroid sulfates.

    Science.gov (United States)

    Waller, Christopher C; McLeod, Malcolm D

    2014-12-01

    Steroid sulfates are a major class of steroid metabolite that are of growing importance in fields such as anti-doping analysis, the detection of residues in agricultural produce or medicine. Despite this, many steroid sulfate reference materials may have limited or no availability hampering the development of analytical methods. We report simple protocols for the rapid synthesis and purification of steroid sulfates that are suitable for adoption by analytical laboratories. Central to this approach is the use of solid-phase extraction (SPE) for purification, a technique routinely used for sample preparation in analytical laboratories around the world. The sulfate conjugates of sixteen steroid compounds encompassing a wide range of steroid substitution patterns and configurations are prepared, including the previously unreported sulfate conjugates of the designer steroids furazadrol (17β-hydroxyandrostan[2,3-d]isoxazole), isofurazadrol (17β-hydroxyandrostan[3,2-c]isoxazole) and trenazone (17β-hydroxyestra-4,9-dien-3-one). Structural characterization data, together with NMR and mass spectra are reported for all steroid sulfates, often for the first time. The scope of this approach for small scale synthesis is highlighted by the sulfation of 1μg of testosterone (17β-hydroxyandrost-4-en-3-one) as monitored by liquid chromatography-mass spectrometry (LCMS). Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Transformation of thorium sulfate in thorium nitrate by ion exchange resin

    International Nuclear Information System (INIS)

    Pereira, W.

    1991-01-01

    A procedure for transforming thorium sulfate into thorium nitrate by means of a strong cationic ion exchanger is presented. The thorium sulfate solution (approximately 15 g/L Th (SO 4 ) 2 ) is percolate through the resin and the column is washed first with water, with a 0,2 M N H 4 OH solution and then with a 0.2 M N H 4 NO 3 solution in order to eliminate sulfate ion. Thorium is eluted with a 2 M solution of (N H 4 ) 2 CO 3 . This eluate is treated with a solution of nitric acid in order to obtain the complete transformation into Th (NO 3 ) 4 . The proposed procedure leads to good quality thorium nitrate with high uranium decontamination. (author)

  1. The influence of cut off lows on sulfate burdens over the North Atlantic during April, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Benkovitz, C.M.; Miller, M.A.; Schwartz, S.E.; Kwon, O.U.

    2001-01-14

    The authors have presented examples from a modeling study of the development of sulfur burdens over North America, the North Atlantic Ocean and Europe during April, 1987 using observation-derived meteorological data to represent the actual conditions for this period, focusing on the influence of cut-off lows on SO{sub 2} and sulfate column burdens over the North Atlantic Ocean. The analysis demonstrates that these systems can serve either as sources or sinks of sulfate, and that the major factor governing their resulting effect is the position during its formative stages relative to (a) sources of moisture, and (b) sulfur emissions, which regulates the availability of sulfur, cloud liquid water for sulfur oxidation, and the amount of precipitation for sulfate removal produced in the later stages of the life cycle.

  2. Regeneration of sulfated metal oxides and carbonates

    Science.gov (United States)

    Hubble, Bill R.; Siegel, Stanley; Cunningham, Paul T.

    1978-03-28

    Alkali metal or alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate found in dolomite or limestone are employed for removal of sulfur dioxide from combustion exhaust gases. The sulfated carbonates are regenerated to oxides through use of a solid-solid reaction, particularly calcium sulfide with calcium sulfate to form calcium oxide and sulfur dioxide gas. The regeneration is performed by contacting the sulfated material with a reductant gas such as hydrogen within an inert diluent to produce calcium sulfide in mixture with the sulfate under process conditions selected to permit the sulfide-sulfate, solid-state reaction to occur.

  3. Analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Seong

    1993-02-15

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  4. Analytical chemistry

    International Nuclear Information System (INIS)

    Choi, Jae Seong

    1993-02-01

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  5. Analytical chemistry

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The division for Analytical Chemistry continued to try and develope an accurate method for the separation of trace amounts from mixtures which, contain various other elements. Ion exchange chromatography is of special importance in this regard. New separation techniques were tried on certain trace amounts in South African standard rock materials and special ceramics. Methods were also tested for the separation of carrier-free radioisotopes from irradiated cyclotron discs

  6. Effect of pre- and post-column band broadening on the performance of high-speed chromatography columns under isocratic and gradient conditions.

    Science.gov (United States)

    Vanderlinden, Kim; Broeckhoven, Ken; Vanderheyden, Yoachim; Desmet, Gert

    2016-04-15

    We report on the results of an experimental and theoretical study of the effect of the extra-column band broadening (ECBB) on the performance of narrow-bore columns filled with the smallest particles that are currently commercially available. Emphasis is on the difference between the effect of ECBB under gradient and isocratic conditions, as well as on the ability to model and predict the ECBB effects using well-established band broadening expressions available from the theory of chromatography. The fine details and assumptions that need to be taken into account when using these expressions are discussed. The experiments showed that, the steeper the gradient, the more pronounced the extra-column band broadening losses become. Whereas the pre-column band broadening can in both isocratic and gradient elution be avoided by playing on the possibilities to focus the analytes on top of the column (e.g. by using the POISe injection method when running isocratic separations), the post-column extra-column band broadening is inescapable in both cases. Inducing extra-column band broadening by changing the inner diameter of the post-column tubing from 65 to 250 μm, we found that all peaks in the chromatogram are strongly affected (around a factor of 1.9 increase in relative peak width) when running steep gradients, while usually only the first eluting peak was affected in the isocratic mode or when running shallow gradients (factor 1.6-1.8 increase in relative peak width for the first eluting analyte). Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Numerical Evaluation on the Different Shapes of Gravelly Sand Columns to Increase the Loading Capacity of Soft Clay

    Directory of Open Access Journals (Sweden)

    Meghzili Sif Allah

    2017-01-01

    Full Text Available Improvement on soft clay by the installation of stone column is one of the most popular methods followed worldwide. Different analytical and numerical solutions have already been developed for understanding the load transfer mechanism of soft soil reinforced with stone column. This study investigated a bearing capacity of the gravelly sand column, installed in soft clay bed at 15kpa of undrained shear strength. The column variable of length and diameter ratio at 7, 8 and 9 were evaluated. On top of that, the combination of two diameters in single column was tested and the uniform diameter was used as a control. In the numerical analysis, Mohrcoulomb model was adopted in the idealization of the behaviour of the gravelly sand column and soft clay materials. The results revealed that the optimum design that gave the highest loading capacity of the combination 11=12 of column diameter was the length and diameter ratio of 8.

  8. Reduced sulfation of chondroitin sulfate but not heparan sulfate in kidneys of diabetic db/db mice.

    Science.gov (United States)

    Reine, Trine M; Grøndahl, Frøy; Jenssen, Trond G; Hadler-Olsen, Elin; Prydz, Kristian; Kolset, Svein O

    2013-08-01

    Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes.

  9. Evaluation of chromatographic columns packed with semi- and fully porous particles for benzimidazoles separation.

    Science.gov (United States)

    Gonzalo-Lumbreras, Raquel; Sanz-Landaluze, Jon; Cámara, Carmen

    2015-07-01

    The behavior of 15 benzimidazoles, including their main metabolites, using several C18 columns with standard or narrow-bore diameters and different particle size and type were evaluated. These commercial columns were selected because their differences could affect separation of benzimidazoles, and so they can be used as alternative columns. A simple screening method for the analysis of benzimidazole residues and their main metabolites was developed. First, the separation of benzimidazoles was optimized using a Kinetex C18 column; later, analytical performances of other columns using the above optimized conditions were compared and then individually re-optimized. Critical pairs resolution, analysis run time, column type and characteristics, and selectivity were considered for chromatographic columns comparison. Kinetex XB was selected because it provides the shortest analysis time and the best resolution of critical pairs. Using this column, the separation conditions were re-optimized using a factorial design. Separations obtained with the different columns tested can be applied to the analysis of specific benzimidazoles residues or other applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Modeling of column apparatus processes

    CERN Document Server

    Boyadjiev, Christo; Boyadjiev, Boyan; Popova-Krumova, Petya

    2016-01-01

    This book presents a new approach for the modeling of chemical and interphase mass transfer processes in industrial column apparatuses, using convection-diffusion and average-concentration models. The convection-diffusion type models are used for a qualitative analysis of the processes and to assess the main, small and slight physical effects, and then reject the slight effects. As a result, the process mechanism can be identified. It also introduces average concentration models for quantitative analysis, which use the average values of the velocity and concentration over the cross-sectional area of the column. The new models are used to analyze different processes (simple and complex chemical reactions, absorption, adsorption and catalytic reactions), and make it possible to model the processes of gas purification with sulfur dioxide, which form the basis of several patents.

  11. Studies of column supported towers

    International Nuclear Information System (INIS)

    Chauvel, D.; Costaz, J.-L.

    1991-01-01

    As a result of a research and development programme into the civil engineering of cooling towers launched in 1978 by Electricite de France, very high cooling towers were built at Golfech and Chooz, in France, using column supports. This paper discusses the evolution of this new type of support from classical diagonal supports, presents some of the results of design calculations and survey measurements taken during construction of the shell and analyses the behaviour of the structure. (author)

  12. Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

    2013-01-01

    Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

  13. Direct Down-scale Experiments of Concentration Column Designs for SHINE Process

    Energy Technology Data Exchange (ETDEWEB)

    Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-05-01

    Argonne is assisting SHINE Medical Technologies in their efforts to become a domestic Mo-99 producer. The SHINE accelerator-driven process uses a uranyl-sulfate target solution for the production of fission-product Mo-99. Argonne has developed a molybdenum recovery and purification process for this target solution. The process includes an initial Mo recovery column followed by a concentration column to reduce the product volume from 15-25 L to < 1 L prior to entry into the LEU Modified Cintichem (LMC) process for purification.1 This report discusses direct down-scale experiments of the plant-scale concentration column design, where the effects of loading velocity and temperature were investigated.

  14. Development of an HPLC post-column antioxidant assay for Solidago canadensis radical scavengers.

    Science.gov (United States)

    Marksa, Mindaugas; Radušienė, Jolita; Jakštas, Valdas; Ivanauskas, Liudas; Marksienė, Rūta

    2016-01-01

    The aim of this work was to modify and validate the post-column high-performance liquid chromatography (HPLC)-ABTS and DPPH methods for evaluating the antioxidant activity of the methanolic extracts of Solidago canadensis (Canadian goldenrod) leaves and flowers. Separation of the analytes was performed via the HPLC-PDA method on a YMC analytical column using a gradient elution program. Three compounds with antioxidant properties - chlorogenic acid, rutin and isoquercitrin - and two unidentified antioxidants were established. The research showed that the coil temperature regimes and loop length combinations influence the optimised post-column assay method for detecting the antioxidant activity of goldenrod radical scavengers. Investigations established that the temperature in the reaction coil was a substantial factor contributing to the signal strength of the analytes after reacting with the DPPH and ABTS radicals.

  15. Structural analysis of isomeric chondroitin sulfate oligosaccharides using regioselective 6-O-desulfation method and tandem mass spectrometry.

    Science.gov (United States)

    Chen, Shu-Ting; Her, Guor-Rong

    2014-09-16

    A strategy based on a regioselective 6-O-desulfation reaction and negative ion electrospray ionization tandem mass spectrometry (ESI-MS(n)) was developed for the structural delineation of isomeric chondroitin sulfate oligosaccharides. Product ions resulting from the glycosidic cleavage provided information about the number of sulfate groups in each sugar residue. After the regioselective 6-O-desulfation reaction, the number of sulfate groups on each residue was obtained using a tandem mass spectrometry analysis of the reaction product. The sulfation pattern could be obtained based on the product ions of analytes before and after the desulfation reaction. The strategy was demonstrated using a series of tetrasaccharides prepared from shark cartilage chondroitin sulfate D. Among the 12 identified tetrasaccharides, six structures had not been reported before. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Two generalizations of column-convex polygons

    International Nuclear Information System (INIS)

    Feretic, Svjetlan; Guttmann, Anthony J

    2009-01-01

    Column-convex polygons were first counted by area several decades ago, and the result was found to be a simple, rational, generating function. In this work we generalize that result. Let a p-column polyomino be a polyomino whose columns can have 1, 2, ..., p connected components. Then column-convex polygons are equivalent to 1-convex polyominoes. The area generating function of even the simplest generalization, namely 2-column polyominoes, is unlikely to be solvable. We therefore define two classes of polyominoes which interpolate between column-convex polygons and 2-column polyominoes. We derive the area generating functions of those two classes, using extensions of existing algorithms. The growth constants of both classes are greater than the growth constant of column-convex polyominoes. Rather tight lower bounds on the growth constants complement a comprehensive asymptotic analysis.

  17. Sulfur cycling in contaminated aquifers: What can we learn from oxygen isotopes in sulfate? (Invited)

    Science.gov (United States)

    Knoeller, K.; Vogt, C.; Hoth, N.

    2009-12-01

    abandoned lignite mine. Due to the heterogeneous isotopic composition of the sulfate source (oxidation of sedimentary sulfide), sulfur isotopes alone are inappropriate for the recognition of BSR. Only the application of oxygen isotopes in sulfate provides clear evidence for the activity of sulfate reducing bacteria. However, the obtained small θ value indicates a significant influence of sulfide re-oxidation. In the second example we applied the dual isotope system to investigate the relevance of BSR for natural biodegradation in an aquifer contaminated with BTEX. Isotope fractionation parameters were determined in column experiments operated under near in situ conditions. The differences between field derived and experimental fractionation parameters revealed essential information on the occurrence of sulfur transformations competing with the actual biodegradation reactions. Most important of those processes is the re-oxidation of reduced sulfur species consuming electron acceptors that would be relevant for contaminant oxidation.

  18. Second dimension column ensemble pressure tuning in comprehensive two-dimensional gas chromatography.

    Science.gov (United States)

    Sharif, Khan M; Kulsing, Chadin; Junior, Ademario I da Silva; Marriott, Philip J

    2018-02-09

    A pressure tunable (PT) coupled column ensemble has been implemented for the second dimension ( 2 D) separation in comprehensive two dimensional gas chromatography (GC×PTGC). This process requires two columns to be connected by a pressure junction, as a replacement for a single narrow bore, short column in 2 D. Various 2 D 1 and 2 D 2 columns may be selected to provide complementary selectivity (polarity) compared to the 1 D column. The tunable residence time arising from differential pressure drop in each 2 D column results in a tunable fractional contribution of each column in the 2 D separation. A sample mixture comprising different chemical classes, including alkanes and alcohols, is used to identify the feasibility and extent of selectivity tuning possible in GC×PTGC. The column length is also varied due to the imposed challenge of wraparound in the PT coupled column system as pressures are adjusted in the 2 D separation. Different experimental parameters, stationary phase materials and column lengths have been applied to investigate and understand the separation behaviour of the 2 D PT coupled column GC×GC system. Results are discussed considering analyte retention time, peak width, linear velocity and the contribution of each 2 D column. A specific and unexpected example of GC×GC separation was demonstrated where the peak positions of polar and apolar compounds could almost swap their 2 D retention position by application of PT. Kerosene was analysed as an example of complex sample analysis by GC×PTGC system. This process is shown to be a practical approach for altering different stationary phase selectivities in a single 2 D arrangement in GC×GC. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. New method for evaluating irreversible adsorption and stationary phase bleed in gas chromatographic capillary columns.

    Science.gov (United States)

    Wright, Bob W; Wright, Cherylyn W

    2012-10-26

    A novel method is described for the evaluation of irreversible adsorption and column bleed in gas chromatographic (GC) columns using a tandem GC approach. This work specifically determined the degree of irreversible adsorption behavior of specific sulfur and phosphorous containing test probe compounds at levels ranging from approximately 50 picograms (pg) to 1 nanogram (ng) on selected gas chromatographic columns. This method does not replace existing evaluation methods that characterize reversible adsorption but provides an additional tool. The test compounds were selected due to their ease of adsorption and their importance in the specific trace analytical detection methodology being developed. Replicate chromatographic columns with 5% phenylmethylpolysiloxane (PMS), polyethylene glycol (wax), trifluoropropylpolysiloxane (TFP), or 78% cyanopropylpolysiloxane stationary phases from a variety of vendors were evaluated. As expected, the results demonstrate that the different chromatographic phases exhibit differing degrees of irreversible adsorption behavior. The results also indicate that all manufacturers do not produce equally inert columns nor are columns from a given manufacturer identical. The wax-coated columns for the test probes used were more inert as a group than 5% PMS coated columns, and they were more reproducibly manufactured. Both TFP and 78% cyanopropylpolysiloxane columns displayed superior inertness to the test compounds compared to either 5% PMS- or wax-coated columns. Irreversible adsorption behavior was characterized for a limited range of stationary phase film thicknesses. In addition, the method was shown effective for characterizing column bleed and methods to remove bleed components. This method is useful in screening columns for demanding applications and to obtain diagnostic information related to improved preparation methods. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Effects of sodium dodecyl sulfate of polyphenoloxidase

    International Nuclear Information System (INIS)

    Moore, B.M.; Flurkey, W.H.

    1989-01-01

    The effects of sodium dodecyl sulfate (SDS) on the enzymatic and physical characteristics of purified broad bean polyphenoloxidase (PPO) were examined. A sigmoidal increase in PPO activation was observed with increasing SDS concentrations. Half maximal activation occurred at .9 mM SDS well below the CMC of 3.5 mM. No apparent changes in the Km for catechol, pH optimum, of I 50 for tropolone were observed in the presence vs absence of SDS. Thermal inactivation and binding of 14 C dopa increased in the presence of SDS. Analytical ultracentrifugation and HPLC-SEC indicated that SDS did not change the apparent size of the PPO under nondenaturing conditions. Scanning fluorescence spectroscopy showed an increase in intrinsic trp/tyr fluorescence at approximately the same concentration in which SDS activation began. Further addition of SDS caused a large increase in intrinsic fluorescence. These results suggest the SDS causes an apparent conformational change induced by SDS binding which leads to enzyme activation

  1. Inhibition of synthesis of heparan sulfate by selenate: Possible dependence on sulfation for chain polymerization

    International Nuclear Information System (INIS)

    Dietrich, C.P.; Nader, H.B.; Buonassisi, V.; Colburn, P.

    1988-01-01

    Selenate, a sulfation inhibitor, blocks the synthesis of heparan sulfate and chondroitin sulfate by cultured endothelial cells. In contrast, selenate does not affect the production of hyaluronic acid, a nonsulfated glycosaminoglycan. No differences in molecular weight, [ 3 H]glucosamine/[ 35 S]sulfuric acid ratios, or disaccharide composition were observed when the heparan sulfate synthesized by selenate-treated cells was compared with that of control cells. The absence of undersulfated chains in preparations from cultures exposed to selenate supports the concept that, in the intact cell, the polymerization of heparan sulfate might be dependent on the sulfation of the saccharide units added to the growing glycosaminoglycan chain

  2. 29 CFR 1926.755 - Column anchorage.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Column anchorage. 1926.755 Section 1926.755 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.755 Column anchorage. (a) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4 anchor...

  3. Adsorption columns for use in radioimmunoassays

    International Nuclear Information System (INIS)

    1976-01-01

    Adsorption columns are provided which can be utilized in radioimmunoassay systems such as those involving the separation of antibody-antigen complexes from free antigens. The preparation of the columns includes the treatment of retaining substrate material to render it hydrophilic, preparation and degassing of the separation material and loading the column

  4. Thermal process of an air column

    International Nuclear Information System (INIS)

    Lee, F.T.

    1994-01-01

    Thermal process of a hot air column is discussed based on laws of thermodynamics. The kinetic motion of the air mass in the column can be used as a power generator. Alternatively, the column can also function as a exhaust/cooler

  5. Cytotoxic and anti-colorectal tumor effects of sulfated saponins from sea cucumber Holothuria moebii.

    Science.gov (United States)

    Yu, Siran; Ye, Xuewei; Chen, Lu; Xie, Xin; Zhou, Qian; Lian, Xiao-Yuan; Zhang, Zhizhen

    2015-11-15

    Whether sulfated saponins from Holothuria moebii inhibit the proliferation of colorectal cancer cells and have anti-colorectal tumor effects in animal model has not been investigated. To evaluate the cytotoxic and anti-colorectal tumor effects of sulfated saponins from sea cucumber Holothuria moebii. (1) Column chromatography was used to prepare the total and individual saponins and HPLC was applied to define the components of the total saponins; (2) the activity of the total and individual saponins inhibiting the proliferation of human colorectal cancer cells was determined by SRB assay and the apoptosis induced by the saponins was qualified using cytometric analysis with Annexin V-FITC/PI double staining; and (3) the antitumor effects of the sulfated saponins on colorectal CT-26 tumor-bearing Balb/c mice were tested. The total and individual sulfated saponins significantly inhibited the proliferation of four different human colorectal cancer cells with IC50 values ranging from 1.04 to 4.08 μM (or 1.46 to 3.24 μg/ml for total saponins) and induced late apoptosis at an early treatment time in cancer cells. The total saponins (120 mg/kg) had antitumor activity in colorectal CT-26 tumor-bearing Balb/c mice. The sulfated saponins from H. moebii remarkably inhibited the proliferation of different human colorectal cancer cells and had significant anti-colorectal tumor activity in animal model. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Extracellular matrix of smooth muscle cells: interaction of collagen type V with heparan sulfate proteoglycan

    International Nuclear Information System (INIS)

    Gay, S.; Hoeoek, M.; Gay, R.E.; Magargal, W.W.; Reynertson, R.H.

    1986-01-01

    Alteration in the extracellular matrix produced by smooth muscle cells may play a role in the development of atherosclerotic lesions. Consequently the authors have initiated studies on the structural organization of the extracellular matrix produced by cultured smooth muscle cells. Immunohisotological examination of this matrix using well-characterized mono- and polyclonal antibodies showed a partial codistribution of heparan sulfate (HS) proteoglycans with a number of different matrix components including collagen types I, III, IV, V and VI, laminin and fibronectin. Subsequent binding studies between isolated matrix proteins and HS showed that the polysaccharide interacts strongly with type V collagen and to a lesser extent with fibronectin as well as collagen types III and VI. The interaction between type V and HS was readily inhibited by heparin and highly sulfated HS but not be dermatan sulfate, chondroitin sulfate or HS with a low sulfate content. Furthermore, [ 35 S]-HS proteoglycans isolated from cultured smooth muscle cells could be adsorbed on a column of sepharose conjugated with native type V collagen and eluted in a salt gradient. Hence, the interaction between type V and HS may play a major part in stabilizing the extracellular matrix of the vessel wall

  7. Stress corrosion cracking of Ni-Fe-Cr alloys in acid sulfate environments relevant to CANDU steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, S.Y.; Carcea, A.G., E-mail: suraj.persaud@mail.utoronto.ca [Univ. of Toronto, Toronto, ON (Canada); Huang, J.; Korinek, A.; Botton, G.A. [McMaster Univ., Hamilton, ON (Canada); Newman, R.C. [Univ. of Toronto, Toronto, ON (Canada)

    2014-07-01

    Ni-Fe-Cr alloys used in nuclear plants have been found susceptible to stress corrosion cracking (SCC) in acid sulfate environments. Electrochemical measurements and SCC tests were done using Ni, Alloy 600, and Alloy 800 in acid sulfate solutions at 315 {sup o}C. Electrochemical measurements suggested that sulfate is a particularly aggressive anion in mixed chloride systems. Cracks with lengths in excess of 300 μm were present on stressed Alloy 800 samples after 60 hours. High resolution analytical electron microscopy was used to extract a crack tip from an Alloy 800 sample and draw final conclusions with respect to the mechanism of SCC. (author)

  8. Analysis of tyrosine-O-sulfation

    DEFF Research Database (Denmark)

    Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

    2008-01-01

    Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

  9. [Online enrichment ability of restricted-access column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride].

    Science.gov (United States)

    Zhang, Xiaohui; Wang, Rong; Xie, Hua; Yin, Qiang; Li, Xiaoyun; Jia, Zhengping; Wu, Xiaoyu; Zhang, Juanhong; Li, Wenbin

    2013-05-01

    The online enrichment ability of the restricted-access media (RAM) column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride in plasma was studied. The RAM-HPLC system consisted of an RAM column as enrichment column and a C18 column as analytical column coupled via the column switching technique. The effects of the injection volume on the peak area and the systematic pressure were studied. When the injection volume was less than 100 microL, the peak area increased with the increase of the injection volume. However, when the injection volume was more than 80 microL, the pressure of whole system increased obviously. In order to protect the whole system, 80 microL was chosen as the maximum injection volume. The peak areas of ordinary injection and the large volume injection showed a good linear relationship. The enrichment ability of RAM-HPLC system was satisfactory. The system was successfully used for the separation and detection of the trace benazepril hydrochloride in rat plasma after its administration. The sensitivity of HPLC can be improved by RAM pre-enrichment. It is a simple and economic measurement method.

  10. Jurin's law revisited: Exact meniscus shape and column height.

    Science.gov (United States)

    Liu, Sai; Li, Shanpeng; Liu, Jianlin

    2018-03-30

    Capillary rise of a liquid column is a historical problem, which has normally been formulated by Jurin's law. In the present study, we investigate the exact solutions of the column height, considering the real shape of the meniscus according to the Young-Laplace equation. The analytical solution in the planar model and the numerical solution in the axisymmetric model on the meniscus shape are both given, which are compared with the results from Jurin's law, modified Jurin's law and Surface Evolver simulation. The results quantitatively show that when the distance between the two plates or the diameter of the tube becomes bigger, Jurin's law and modified Jurin's law would cause serious errors, and the profile morphology of the meniscus must be calculated according to the Young-Laplace equation. These findings are beneficial for us to better understand the mechanism of capillarity and wetting, which are promising for such areas as oil displacement, ore floatation, building materials, fabrics, etc.

  11. Bactericide for sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M

    1981-01-01

    The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

  12. Growth of sulfate reducers in deep-subseafloor sediments stimulated by crustal fluids

    Directory of Open Access Journals (Sweden)

    Katja eFichtel

    2012-02-01

    Full Text Available On a global scale, crustal fluids fuel a substantial part of the deep subseafloor biosphere by providing electron acceptors for microbial respiration. In this study, we examined bacterial cultures from a sediment column of the Juan de Fuca Ridge, Northeast Pacific (IODP Site U1301 which is divided into three distinctive compartments: an upper sulfate-containing zone, formed by bottom-seawater diffusion, a sulfate-depleted zone and a second (~140 m thick sulfate-containing zone influenced by fluid diffusion from the basaltic aquifer. Sulfate reducers were isolated from near-surface and near-basement sediments. All initial enrichments harboured specific communities of heterotrophic microorganisms. Among those, the number of isolated spore-forming Firmicutes decreased from 60% to 21% with sediment depth. Strains affiliated to Desulfosporosinus lacus, Desulfotomaculum sp. and Desulfovibrio aespoeensis were recovered from the upper sediment layers (1.3-9.1 meters below seafloor, mbsf. Several strains of Desulfovibrio indonesiensis and one relative of Desulfotignum balticum were isolated from near-basement sediments (240-262 mbsf. The physiological investigation of strains affiliated to D. aespoeensis, D. indonesiensis and D. balticum indicated that they were all able to use sulfate, thiosulfate and sulfite as electron acceptors. In the presence of sulfate, they grew strain-specifically on a few short-chain n-alcohols and fatty acids, only. The strains fermented either ethanol, pyruvate or betaine. Interestingly, all strains utilized hydrogen and the isolate affiliated to D. indonesiensis even exhibited an autotrophic life-mode. Thus, in the deep subseafloor where organic substrates are limited or hardly degradable, hydrogen might become an essential electron donor. The isolation of non-sporeforming sulfate reducers from fluid-influenced layers indicates that they have survived the long-term burial as active populations even after the separation from

  13. Temperature-assisted On-column Solute Focusing: A General Method to Reduce Pre-column Dispersion in Capillary High Performance Liquid Chromatography

    Science.gov (United States)

    Groskreutz, Stephen R.; Weber, Stephen G.

    2014-01-01

    Solvent-based on-column focusing is a powerful and well known approach for reducingthe impact of pre-column dispersion in liquid chromatography. Here we describe an orthogonal temperature-based approach to focusing called temperature-assisted on-column solute focusing (TASF). TASF is founded on the same principles as the more commonly used solvent-based method wherein transient conditions are created thatlead to high solute retention at the column inlet. Combining the low thermal mass of capillary columns and the temperature dependence of solute retentionTASF is used effectivelyto compress injection bands at the head of the column through the transient reduction in column temperature to 5 °C for a defined 7 mm segment of a 6 cm long 150 μm I.D. column. Following the 30 second focusing time, the column temperature is increased rapidly to the separation temperature of 60 °C releasing the focused band of analytes. We developed a model tosimulate TASF separations based on solute retention enthalpies, focusing temperature, focusing time, and column parameters. This model guides the systematic study of the influence of sample injection volume on column performance.All samples have solvent compositions matching the mobile phase. Over the 45 to 1050 nL injection volume range evaluated, TASF reducesthe peak width for all soluteswith k’ greater than or equal to 2.5, relative to controls. Peak widths resulting from injection volumes up to 1.3 times the column fluid volume with TASF are less than 5% larger than peak widths from a 45 nL injection without TASF (0.07 times the column liquid volume). The TASF approach reduced concentration detection limits by a factor of 12.5 relative to a small volume injection for low concentration samples. TASF is orthogonal to the solvent focusing method. Thus, it canbe used where on-column focusing is required, but where implementation of solvent-based focusing is difficult. PMID:24973805

  14. Analytical mechanics

    CERN Document Server

    Helrich, Carl S

    2017-01-01

    This advanced undergraduate textbook begins with the Lagrangian formulation of Analytical Mechanics and then passes directly to the Hamiltonian formulation and the canonical equations, with constraints incorporated through Lagrange multipliers. Hamilton's Principle and the canonical equations remain the basis of the remainder of the text. Topics considered for applications include small oscillations, motion in electric and magnetic fields, and rigid body dynamics. The Hamilton-Jacobi approach is developed with special attention to the canonical transformation in order to provide a smooth and logical transition into the study of complex and chaotic systems. Finally the text has a careful treatment of relativistic mechanics and the requirement of Lorentz invariance. The text is enriched with an outline of the history of mechanics, which particularly outlines the importance of the work of Euler, Lagrange, Hamilton and Jacobi. Numerous exercises with solutions support the exceptionally clear and concise treatment...

  15. A numerical study on seismic response of self-centring precast segmental columns at different post-tensioning forces

    Directory of Open Access Journals (Sweden)

    Ehsan Nikbakht

    Full Text Available Precast bridge columns have shown increasing demand over the past few years due to the advantages of such columns when compared against conventional bridge columns, particularly due to the fact that precast bridge columns can be constructed off site and erected in a short period of time. The present study analytically investigates the behaviour of self-centring precast segmental bridge columns under nonlinear-static and pseudo-dynamic loading at different prestressing strand levels. Self-centring segmental columns are composed of prefabricated reinforced concrete segments which are connected by central post-tensioning (PT strands. The present study develops a three dimensional (3D nonlinear finite element model for hybrid post-tensioned precast segmental bridge columns. The model is subjected to constant axial loading and lateral reverse cyclic loading. The lateral force displacement results of the analysed columns show good agreement with the experimental response of the columns. Bonded post-tensioned segmental columns at 25%, 40% and 70% prestressing strand stress levels are analysed and compared with an emulative monolithic conventional column. The columns with a higher initial prestressing strand levels show greater initial stiffness and strength but show higher stiffness reduction at large drifts. In the time-history analysis, the column samples are subjected to different earthquake records to investigate the effect post-tensioning force levels on their lateral seismic response in low and higher seismicity zones. The results indicate that, for low seismicity zones, post-tensioned segmental columns with a higher initial stress level deflect lower lateral peak displacement. However, in higher seismicity zones, applying a high initial stress level should be avoided for precast segmental self-centring columns with low energy dissipation capacity.

  16. Discovery of a Heparan sulfate 3- o -sulfation specific peeling reaction

    NARCIS (Netherlands)

    Huang, Yu; Mao, Yang; Zong, Chengli; Lin, Cheng; Boons, Geert Jan|info:eu-repo/dai/nl/088245489; Zaia, Joseph

    2015-01-01

    Heparan sulfate (HS) 3-O-sulfation determines the binding specificity of HS/heparin for antithrombin III and plays a key role in herpes simplex virus (HSV) infection. However, the low natural abundance of HS 3-O-sulfation poses a serious challenge for functional studies other than the two cases

  17. 21 CFR 172.822 - Sodium lauryl sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium lauryl sulfate. 172.822 Section 172.822 Food... Multipurpose Additives § 172.822 Sodium lauryl sulfate. The food additive sodium lauryl sulfate may be safely... specifications: (1) It is a mixture of sodium alkyl sulfates consisting chiefly of sodium lauryl sulfate [CH2(CH2...

  18. Fine resolution atmospheric sulfate model driven by operational meteorological data: Comparison with observations

    International Nuclear Information System (INIS)

    Benkovitz, C.M.; Schwartz, S.E.; Berkowitz, C.M.; Easter, R.C.

    1993-09-01

    The hypothesis that anthropogenic sulfur aerosol influences clear-sky and cloud albedo and can thus influence climate has been advanced by several investigators; current global-average climate forcing is estimated to be of comparable magnitude, but opposite sign, to longwave forcing by anthropogenic greenhouse gases. The high space and time variability of sulfate concentrations and column aerosol burdens have been established by observational data; however, geographic and time coverage provided by data from surface monitoring networks is very limited. Consistent regional and global estimates of sulfate aerosol loading, and the contributions to this loading from different sources can be obtained only by modeling studies. Here we describe a sub-hemispheric to global-scale Eulerian transport and transformation model for atmospheric sulfate and its precursors, driven by operational meteorological data, and report results of calculations for October, 1986 for the North Atlantic and adjacent continental regions. The model, which is based on the Global Chemistry Model uses meteorological data from the 6-hour forecast model of the European Center for Medium-Range Weather Forecast to calculate transport and transformation of sulfur emissions. Time- and location-dependent dry deposition velocities were estimated using the methodology of Wesely and colleagues. Chemical reactions includes gaseous oxidation of SO 2 and DMS by OH, and aqueous oxidation of SO 2 by H 2 O 2 and O 3 . Anthropogenic emissions were from the NAPAP and EMEP 1985 inventories and biogenic emissions based on Bates et al. Calculated sulfate concentrations and column burdens exhibit high variability on spatial scale of hundreds of km and temporal scale of days. Calculated daily average sulfate concentrations closely reproduce observed concentrations at locations widespread over the model domain

  19. Fiber-based monolithic columns for liquid chromatography.

    Science.gov (United States)

    Ladisch, Michael; Zhang, Leyu

    2016-10-01

    Fiber-based monoliths for use in liquid chromatographic separations are defined by columns packed with aligned fibers, woven matrices, or contiguous fiber structures capable of achieving rapid separations of proteins, macromolecules, and low molecular weight components. A common denominator and motivating driver for this approach, first initiated 25 years ago, was reducing the cost of bioseparations in a manner that also reduced residence time of retained components while achieving a high ratio of mass to momentum transfer. This type of medium, when packed into a liquid chromatography column, minimized the fraction of stagnant liquid and resulted in a constant plate height for non-adsorbing species. The uncoupling of dispersion from eluent flow rate enabled the surface chemistry of the stationary phase to be considered separately from fluid transport phenomena and pointed to new ways to apply chemistry for the engineering of rapid bioseparations. This paper addresses developments and current research on fiber-based monoliths and explains how the various forms of this type of chromatographic stationary phase have potential to provide new tools for analytical and preparative scale separations. The different stationary phases are discussed, and a model that captures the observed constant plate height as a function of mobile phase velocity is reviewed. Methods that enable hydrodynamically stable fiber columns to be packed and operated over a range of mobile phase flow rates, together with the development of new fiber chemistries, are shown to provide columns that extend the versatility of liquid chromatography using monoliths, particularly at the preparative scale. Graphical Abstract Schematic representation of a sample mixture being separated by a rolled-stationary phase column, resulting separated peaks shown in the chromatogram.

  20. The chondroitin sulfate/dermatan sulfate 4-O-endosulfatase from marine bacterium Vibrio sp FC509 is a dimeric species: Biophysical characterization of an endosulfatase.

    Science.gov (United States)

    Neira, José L; Medina-Carmona, Encarnación; Hernández-Cifre, José G; Montoliu-Gaya, Laia; Cámara-Artigás, Ana; Seffouh, Ilham; Gonnet, Florence; Daniel, Régis; Villegas, Sandra; de la Torre, José García; Pey, Angel L; Li, Fuchuan

    2016-12-01

    Sulfatases catalyze hydrolysis of sulfate groups. They have a key role in regulating the sulfation states that determine the function of several scaffold molecules. Currently, there are no studies of the conformational stability of endosulfatases. In this work, we describe the structural features and conformational stability of a 4-O-endosulfatase (EndoV) from a marine bacterium, which removes specifically the 4-O-sulfate from chondroitin sulfate/dermatan sulfate. For that purpose, we have used several biophysical techniques, namely, fluorescence, circular dichroism (CD), FTIR spectroscopy, analytical ultracentrifugation (AUC), differential scanning calorimetry (DSC), mass spectrometry (MS), dynamic light scattering (DLS) and size exclusion chromatography (SEC). The protein was a dimer with an elongated shape. EndoV acquired a native-like structure in a narrow pH range (7.0-9.0); it is within this range where the protein shows the maximum of enzymatic activity. The dimerization did not involve the presence of disulphide-bridges as suggested by AUC, SEC and DLS experiments in the presence of β-mercaptoethanol (β-ME). EndoV secondary structure is formed by a mixture of α and β-sheet topology, as judged by deconvolution of CD and FTIR spectra. Thermal and chemical denaturations showed irreversibility and the former indicates that protein did not unfold completely during heating. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Brittlestars contain highly sulfated chondroitin sulfates/dermatan sulfates that promote fibroblast growth factor 2-induced cell signaling.

    Science.gov (United States)

    Ramachandra, Rashmi; Namburi, Ramesh B; Ortega-Martinez, Olga; Shi, Xiaofeng; Zaia, Joseph; Dupont, Sam T; Thorndyke, Michael C; Lindahl, Ulf; Spillmann, Dorothe

    2014-02-01

    Glycosaminoglycans (GAGs) isolated from brittlestars, Echinodermata class Ophiuroidea, were characterized, as part of attempts to understand the evolutionary development of these polysaccharides. A population of chondroitin sulfate/dermatan sulfate (CS/DS) chains with a high overall degree of sulfation and hexuronate epimerization was the major GAG found, whereas heparan sulfate (HS) was below detection level. Enzymatic digestion with different chondroitin lyases revealed exceptionally high proportions of di- and trisulfated CS/DS disaccharides. The latter unit appears much more abundant in one of four individual species of brittlestars, Amphiura filiformis, than reported earlier in other marine invertebrates. The brittlestar CS/DS was further shown to bind to growth factors such as fibroblast growth factor 2 and to promote FGF-stimulated cell signaling in GAG-deficient cell lines in a manner similar to that of heparin. These findings point to a potential biological role for the highly sulfated invertebrate GAGs, similar to those ascribed to HS in vertebrates.

  2. An investigation of transient pressures and plasma properties in a pinched plasma column. M.S. Thesis

    Science.gov (United States)

    Stover, E. K.; York, T. M.

    1971-01-01

    The transient pinched plasma column generated in a linear Z-pinch was studied experimentally and analytically. The plasma column was investigated experimentally with several plasma diagnostics; they were: a rapid response pressure transducer, a magnetic field probe, a voltage probe, and discharge luminosity. Axial pressure profiles on the discharge chamber axis were used to identify three characteristic regions of plasma column behavior: (1) strong axial pressure asymmetry noted early in plasma column lifetime, (2) followed by plasma heating in which there is a rapid rise in static pressure, and (3) a slight decrease static pressure before plasma column breakup. Plasma column lifetime was approximately 5 microseconds. The axial pressure asymmetry was attributed to nonsimultaneous pinching of the imploding current sheet along the discharge chamber axis. The rapid heating could be attributed in part to viscous effects introduced by radial gradients in the axial streaming velocity.

  3. Differential pulse voltammetric determination of salbutamol sulfate in syrup pharmaceutical formulation using poly(4-amino-3-hydroxynaphthalene sulfonic acid modified glassy carbon electrode

    Directory of Open Access Journals (Sweden)

    Meareg Amare

    2017-10-01

    Full Text Available A new method for determination of salbutamol sulfate has been developed using poly(4-amino-3-hydroxynaphthalene sulfonic acid/GCE. Cyclic voltammetric investigation of the electrochemical behavior of salbutamol sulfate at the polymer modified glassy carbon unveiled electrocatalytic activity of the modifier towards irreversible oxidation of salbutamol sulfate. Dependence of peak current predominantly on scan rate than on square root of scan rate, and peak potential shift with pH demonstrated that oxidation of salbutamol sulfate at the polymer modified electrode follows adsorption reaction kinetics with proton participation.Under optimized solution and differential pulse voltammetric parameters, the oxidative peak current showed linear dependence on salbutamol sulfate concentration in the range 0.2 to 8 μM with method detection limit (3s/m and determination coefficient (R2 of 6.8 × 10−8 M and 0.99786, respectively. Low method detection limit, relatively wide linear range, and recovery results of spiked standard salbutamol sulfate in syrup samples in the range 96.7–98.9% validated the method for determination of salbutamol sulfate in pharmaceutical formulations.Differential pulse voltammetric analysis of salbutamol sulfate syrup formulation for its salbutamol sulfate content revealed 98.8 to 99.3% of the labeled value confirming the applicability of the developed method for determination of salbutamol sulfate in real samples. Keywords: Electrochemistry, Analytical chemistry

  4. Bridged polysilsesquioxane-based wide-bore monolithic capillary columns for hydrophilic interaction chromatography

    Czech Academy of Sciences Publication Activity Database

    Šesták, Jozef; Moravcová, Dana; Křenková, Jana; Planeta, Josef; Roth, Michal; Foret, František

    2017-01-01

    Roč. 1479, JAN (2017), s. 204-209 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA14-06319S; GA ČR(CZ) GA16-03749S Institutional support: RVO:68081715 Keywords : silica monolithic column * HILIC * oligosaccharides * nucleosides Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  5. Evaluation of Packed Distillation Columns I - Atmospheric Pressure

    National Research Council Canada - National Science Library

    Reynolds, Thaine

    1951-01-01

    .... Four column-packing combinations of the glass columns and four column-packing combinations of the steel columns were investigated at atmospheric pressure using a test mixture of methylcyclohexane...

  6. The anaerobic treatment of sulfate containing wastewater

    NARCIS (Netherlands)

    Visser, A.

    1995-01-01


    In the anaerobic treatment of sulfate containing wastewater sulfate reducing bacteria (SRB) will compete with methanogenic- (MB) and acetogenic bacteria (AB) for the available substrates such as hydrogen, acetate, propionate and butyrate. The outcome of this competition will

  7. Simultaneous determination of palladium, platinum and rhodium by on-line column enrichment and HPLC with 2,4-dihydroxybenzylidenethiorhodanine as pre-column derivatization reagent

    Directory of Open Access Journals (Sweden)

    Dong Xuechang

    2006-01-01

    Full Text Available A new method for the simultaneous determination of palladium, platinum and rhodium ions as metal-DHBTR chelates was developed. The palladium, platinum and rhodium ions were pre-column derivatized with 2,4-dihydroxybenzylidenethiorhodanine (DHBTR to form colored chelates. The Pd-DHBTR, Pt-DHBTR and Rh-DHBTR chelates can be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column with a 0.05 mol L-1 sodium acetate-acetic acid buffer solution (pH 3.5 as mobile phase. After the enrichment had finished, by switching the six ports switching valve, the retained chelates were back-flushed by mobile phase and traveling towards the analytical column. These chelates separation on the analytical column was satisfactory with 62% (v/v acetonitrile (containing 0.05 mol L-1 of pH 3.5 sodium acetate-acetic acid buffer salt and 0.1% (m/v of tritonX-100 as mobile phase. The Limits of detection of palladium, platinum and rhodium are 3.6 ng L-1, 3.2 ng L-1 and 4.5 ng L-1, respectively. This method was applied to the determination of palladium, platinum and rhodium in water, urine and soil samples with good results.

  8. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  9. Metabolic Flexibility of Sulfate Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Caroline M. Plugge

    2011-05-01

    Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

  10. A novel ionic liquid monolithic column and its separation properties in capillary electrochromatography

    International Nuclear Information System (INIS)

    Wang Yu; Deng Qiliang; Fang Guozhen; Pan Mingfei; Yu Yang; Wang Shuo

    2012-01-01

    Highlights: ► ILs as functional monomer for capillary monolithic column. ► Separation of alkylbenzenes, thiourea analogues, and amino acids. ► The column generate a stable reversed EOF from pH 2.0 to 12.0. ► The column efficiency of 147,000 plates m −1 was obtained for thiourea. - Abstract: A novel ionic liquid (IL) monolithic capillary column was successfully prepared by thermal free radical copolymerization of IL (1-vinyl-3-octylimidazolium chloride, ViOcIm + Cl − ) together with lauryl methacrylate (LMA) as the binary functional monomers and ethylene dimethacrylate (EDMA) as the cross-linker in binary porogen. The proportion of monomers, porogens and cross-linker in the polymerization mixture was optimized in detail. The resulting IL-monolithic column could not only generate a stable reversed electroosmotic flow (EOF) in a wide pH range (2.0–12.0), but also effectively eliminate the wall adsorption of the basic analytes. The obtained IL-monolithic columns were examined by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). These results indicated that the IL-monolithic capillary column possessed good pore properties, mechanical stability and permeability. The column performance was also evaluated by separating different kinds of compounds, such as alkylbenzenes, thiourea and its analogues, and amino acids. The lowest plate height of ∼6.8 μm was obtained, which corresponded to column efficiency (theoretical plates, N) of ∼147,000 plates m −1 for thiourea. ILs, as a new type of functional monomer, present a promising option in the fabrication of the organic polymer-based monolithic columns in CEC.

  11. Picobubble enhanced column flotation of fine coal

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Yu, S.; Parekh, B.K. [University of Kentucky, Lexington, KY (United States). Mining Engineering

    2006-07-01

    The purpose is to study the effectiveness of picobubbles in the column flotation of -28 mesh fine coal particles. A flotation column with a picobubble generator was developed and tested for enhancing the recovery of ultrafine coal particles. The picobubble generator was designed using the hydrodynamic cavitation principle. A metallurgical and a steam coal were tested in the apparatus. The results show that the use of picobubbles in a 2in. flotation column increased the recovery of fine coal by 10 to 30%. The recovery rate varied with feed rate, collector dosage, and other column conditions. 40 refs., 8 figs., 2 tabs.

  12. Thermally stable dexsil-400 glass capillary columns

    International Nuclear Information System (INIS)

    Maskarinec, M.P.; Olerich, G.

    1980-01-01

    The factors affecting efficiency, thermal stability, and reproducibility of Dexsil-400 glass capillary columns for gas chromatography in general, and for polycyclic aromatic hydrocarbons (PAHs) in particular were investigated. Columns were drawn from Kimble KG-6 (soda-lime) glass or Kimox (borosilicate) glass. All silylation was carried out at 200 0 C. Columns were coated according to the static method. Freshly prepared, degassed solutions of Dexsil-400 in pentane or methylene chloride were used. Thermal stability of the Dexsil 400 columns with respect to gas chromatography/mass spectrometry (GC/MS) were tested. Column-to-column variability is a function of each step in the fabrication of the columns. The degree of etching, extent of silylation, and stationary phase film thickness must be carefully controlled. The variability in two Dexsil-400 capillary column prepared by etching, silylation with solution of hexa methyl disilazone (HMDS), and static coating is shown and also indicates the excellent selectivity of Dexsil-400 for the separation of alkylated aromatic compounds. The wide temperature range of Dexsil-400 and the high efficiency of the capillary columns also allow the analysis of complex mixtures with minimal prefractionation. Direct injection of a coal liquefaction product is given. Analysis by GC/MS indicated the presence of parent PAHs, alkylated PAHs, nitrogen and sulfur heterocycles, and their alkylated derivatives. 4 figures

  13. Laser surface wakefield in a plasma column

    International Nuclear Information System (INIS)

    Gorbunov, L.M.; Mora, P.; Ramazashvili, R.R.

    2003-01-01

    The structure of the wakefield in a plasma column, produced by a short intense laser pulse, propagating through a gas affected by tunneling ionization is investigated. It is shown that besides the usual plasma waves in the bulk part of the plasma column [see Andreev et al., Phys. Plasmas 9, 3999 (2002)], the laser pulse also generates electromagnetic surface waves propagating along the column boundary. The length of the surface wake wave substantially exceeds the length of the plasma wake wave and its electromagnetic field extends far outside the plasma column

  14. MonetDB: Two Decades of Research in Column-oriented Database Architectures

    NARCIS (Netherlands)

    S. Idreos (Stratos); F.E. Groffen (Fabian); N.J. Nes (Niels); S. Manegold (Stefan); K.S. Mullender (Sjoerd); M.L. Kersten (Martin)

    2012-01-01

    textabstractMonetDB is a state-of-the-art open-source column-store database management system targeting applications in need for analytics over large collections of data. MonetDB is actively used nowadays in health care, in telecommunications as well as in scientific databases and in data management

  15. MonetDB: Two Decades of Research in Column-oriented Database Architectures

    NARCIS (Netherlands)

    Idreos, S.; Groffen, F.; Nes, N.; Manegold, S.; Mullender, S.; Kersten, M.

    2012-01-01

    MonetDB is a state-of-the-art open-source column-store database management system targeting applications in need for analytics over large collections of data. MonetDB is actively used nowadays in health care, in telecommunications as well as in scientific databases and in data management research,

  16. Hydrogen production in the K-Basin ion exchange columns, modules and cartridge filters

    International Nuclear Information System (INIS)

    1994-01-01

    K-Basin uses ion exchange modules and ion exchange (IX) columns for removing radionuclides from the basin water. When the columns and modules are loaded, they are removed from service, drained and stored. After a few IX columns accumulate in storage, they are moved to a burial box. One of the burial box contains 33 columns and the other, six. The radionuclides act on the liquid left within and adhering to the beads to produce hydrogen. This report describes the generation rate, accumulation rate and significance of that accumulation. This summary also highlights those major areas of concern to the external (to Westinghouse Hanford Company [WHC]) reviewers. Appendix H presents the comments made by the external reviewers and, on a separate sheet, the responses to those comments. The concerns regarding the details of the analytical approach, are addressed in Appendix H and in the appropriate section

  17. Hydrogen production in the K-Basin ion exchange columns, modules and cartridge filters

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-21

    K-Basin uses ion exchange modules and ion exchange (IX) columns for removing radionuclides from the basin water. When the columns and modules are loaded, they are removed from service, drained and stored. After a few IX columns accumulate in storage, they are moved to a burial box. One of the burial box contains 33 columns and the other, six. The radionuclides act on the liquid left within and adhering to the beads to produce hydrogen. This report describes the generation rate, accumulation rate and significance of that accumulation. This summary also highlights those major areas of concern to the external (to Westinghouse Hanford Company [WHC]) reviewers. Appendix H presents the comments made by the external reviewers and, on a separate sheet, the responses to those comments. The concerns regarding the details of the analytical approach, are addressed in Appendix H and in the appropriate section.

  18. Detection of stanozolol O- and N-sulfate metabolites and their evaluation as additional markers in doping control.

    Science.gov (United States)

    Balcells, Georgina; Matabosch, Xavier; Ventura, Rosa

    2017-07-01

    Stanozolol (STAN) is one of the most frequently detected anabolic androgenic steroids in sports drug testing. STAN misuse is commonly detected by monitoring metabolites excreted conjugated with glucuronic acid after enzymatic hydrolysis or using direct detection by liquid chromatography-tandem mass spectrometry (LC-MS/MS). It is well known that some of the previously described metabolites are the result of the formation of sulfate conjugates in C17, which are converted to their 17-epimers in urine. Therefore, sulfation is an important phase II metabolic pathway of STAN that has not been comprehensively studied. The aim of this work was to evaluate the sulfate fraction of STAN metabolism by LC-MS/MS to establish potential long-term metabolites valuable for doping control purposes. STAN was administered to six healthy male volunteers involving oral or intramuscular administration and urine samples were collected up to 31 days after administration. Sulfation of the phase I metabolites commercially available as standards was performed in order to obtain MS data useful to develop analytical strategies (neutral loss scan, precursor ion scan and selected reaction monitoring acquisitions modes) to detect potential sulfate metabolites. Eleven sulfate metabolites (M-I to M-XI) were detected and characterized by LC-MS/MS. This paper provides valuable data on the ionization and fragmentation of O-sulfates and N-sulfates. For STAN, results showed that sulfates do not improve the retrospectivity of the detection compared to the previously described long-term metabolite (epistanozolol-N-glucuronide). However, sulfate metabolites could be additional markers for the detection of STAN misuse. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Novel thermally stable poly(vinyl chloride) composites for sulfate removal

    Energy Technology Data Exchange (ETDEWEB)

    Nadagouda, Mallikarjuna N., E-mail: Nadagouda.mallikarjuna@epa.gov [Water Supply and Water Resources Division, National Risk Management Research Laboratory U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive Cincinnati, Ohio 45268 (United States); Pressman, Jonathan; White, Colin; Speth, Thomas F.; McCurry, Daniel L. [Water Supply and Water Resources Division, National Risk Management Research Laboratory U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive Cincinnati, Ohio 45268 (United States)

    2011-04-15

    Graphical abstract: Barium carbonate and/or barium carbonate-loaded silica aero-gels dispersed polyvinyl chloride (PVC) composites were prepared by dissolving PVC in tetrahydrofuran (THF), dispersing BaCO{sub 3} and/or BaCO{sub 3}-loaded silica aero-gels, re-precipitating the PVC with water at room temperature. The PVC composites were then characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The obtained composites had better thermal properties than the control PVC. The composites were tested for sulfate removal and found to significantly reduce sulfate when compared with control PVC. - Abstract: BaCO{sub 3} dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthesize barium carbonate-loaded silica aero-gels-polyvinyl chloride (PVC) polymer composites. The PVC composites were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The method has advantages over conventional sulfate precipitation (sulfate removal process) using BaCO{sub 3} wherein clogging of the filter can be avoided. The method is environmentally friendly and does not interfere with natural organic matter as the conventional resin does. Some of the composites were thermally more stable as compared with the pure PVC discussed in the literature.

  20. Novel thermally stable poly(vinyl chloride) composites for sulfate removal

    International Nuclear Information System (INIS)

    Nadagouda, Mallikarjuna N.; Pressman, Jonathan; White, Colin; Speth, Thomas F.; McCurry, Daniel L.

    2011-01-01

    Graphical abstract: Barium carbonate and/or barium carbonate-loaded silica aero-gels dispersed polyvinyl chloride (PVC) composites were prepared by dissolving PVC in tetrahydrofuran (THF), dispersing BaCO 3 and/or BaCO 3 -loaded silica aero-gels, re-precipitating the PVC with water at room temperature. The PVC composites were then characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The obtained composites had better thermal properties than the control PVC. The composites were tested for sulfate removal and found to significantly reduce sulfate when compared with control PVC. - Abstract: BaCO 3 dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthesize barium carbonate-loaded silica aero-gels-polyvinyl chloride (PVC) polymer composites. The PVC composites were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The method has advantages over conventional sulfate precipitation (sulfate removal process) using BaCO 3 wherein clogging of the filter can be avoided. The method is environmentally friendly and does not interfere with natural organic matter as the conventional resin does. Some of the composites were thermally more stable as compared with the pure PVC discussed in the literature.

  1. Bernstein modes in a non-neutral plasma column

    Science.gov (United States)

    Walsh, Daniel; Dubin, Daniel H. E.

    2018-05-01

    This paper presents theory and numerical calculations of electrostatic Bernstein modes in an inhomogeneous cylindrical plasma column. These modes rely on finite Larmor radius effects to propagate radially across the column until they are reflected when their frequency matches the upper hybrid frequency. This reflection sets up an internal normal mode on the column and also mode-couples to the electrostatic surface cyclotron wave (which allows the normal mode to be excited and observed using external electrodes). Numerical results predicting the mode spectra, using a novel linear Vlasov code on a cylindrical grid, are presented and compared to an analytical Wentzel Kramers Brillouin (WKB) theory. A previous version of the theory [D. H. E. Dubin, Phys. Plasmas 20(4), 042120 (2013)] expanded the plasma response in powers of 1/B, approximating the local upper hybrid frequency, and consequently, its frequency predictions are spuriously shifted with respect to the numerical results presented here. A new version of the WKB theory avoids this approximation using the exact cold fluid plasma response and does a better job of reproducing the numerical frequency spectrum. The effect of multiple ion species on the mode spectrum is also considered, to make contact with experiments that observe cyclotron modes in a multi-species pure ion plasma [M. Affolter et al., Phys. Plasmas 22(5), 055701 (2015)].

  2. A novel ionic liquid monolithic column and its separation properties in capillary electrochromatography.

    Science.gov (United States)

    Wang, Yu; Deng, Qi-Liang; Fang, Guo-Zhen; Pan, Ming-Fei; Yu, Yang; Wang, Shuo

    2012-01-27

    A novel ionic liquid (IL) monolithic capillary column was successfully prepared by thermal free radical copolymerization of IL (1-vinyl-3-octylimidazolium chloride, ViOcIm(+)Cl(-)) together with lauryl methacrylate (LMA) as the binary functional monomers and ethylene dimethacrylate (EDMA) as the cross-linker in binary porogen. The proportion of monomers, porogens and cross-linker in the polymerization mixture was optimized in detail. The resulting IL-monolithic column could not only generate a stable reversed electroosmotic flow (EOF) in a wide pH range (2.0-12.0), but also effectively eliminate the wall adsorption of the basic analytes. The obtained IL-monolithic columns were examined by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). These results indicated that the IL-monolithic capillary column possessed good pore properties, mechanical stability and permeability. The column performance was also evaluated by separating different kinds of compounds, such as alkylbenzenes, thiourea and its analogues, and amino acids. The lowest plate height of ~6.8 μm was obtained, which corresponded to column efficiency (theoretical plates, N) of ~147,000 plates m(-1) for thiourea. ILs, as a new type of functional monomer, present a promising option in the fabrication of the organic polymer-based monolithic columns in CEC. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Demonstration of motionless Knudsen pump based micro-gas chromatography featuring micro-fabricated columns and on-column detectors.

    Science.gov (United States)

    Liu, Jing; Gupta, Naveen K; Wise, Kensall D; Gianchandani, Yogesh B; Fan, Xudong

    2011-10-21

    This paper reports the investigation of a micro-gas chromatography (μGC) system that utilizes an array of miniaturized motionless Knudsen pumps (KPs) as well as microfabricated separation columns and optical detectors. A prototype system was built to achieve a flow rate of 1 mL min(-1) and 0.26 mL min(-1) for helium and dry air, respectively, when they were used as carrier gas. This system was then employed to evaluate GC performance compromises and demonstrate the ability to separate and detect gas mixtures containing analytes of different volatilities and polarities. Furthermore, the use of pressure programming of the KP array was demonstrated to significantly shorten the analysis time while maintaining a high detection resolution. Using this method, we obtained a high resolution detection of 5 alkanes of different volatilities within 5 min. Finally, we successfully detected gas mixtures of various polarities using a tandem-column μGC configuration by installing two on-column optical detectors to obtain complementary chromatograms.

  4. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  5. Gaseous carbon dioxide absorbing column

    International Nuclear Information System (INIS)

    Harashina, Heihachi.

    1994-01-01

    The absorbing column of the present invention comprises a cyclone to which CO 2 gas and Ca(OH) 2 are blown to form CaCO 3 , a water supply means connected to an upper portion of the cyclone for forming a thin water membrane on the inner wall thereof, and a water processing means connected to a lower portion of the cyclone for draining water incorporating CaCO 3 . If a mixed fluid of CO 2 gas and Ca(OH) 2 is blown in a state where a flowing water membrane is formed on the inner wall of the cyclone, formation of CaCO 3 is promoted also in the inside of the cyclone in addition to the formation of CaCO 3 in the course of blowing. Then, formed CaCO 3 is discharged from the lower portion of the cyclone together with downwardly flowing water. With such procedures, solid contents such as CaCO 3 separated at the inner circumferential wall are sent into the thin water membrane, adsorbed and captured, and the solid contents are successively washed out, so that a phenomenon that the solid contents deposit and grow on the inner wall of the cyclone can be prevented effectively. (T.M.)

  6. Extraction of uranyl sulfate with primary amine

    International Nuclear Information System (INIS)

    Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

    1984-01-01

    PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

  7. Chlorate: a reversible inhibitor of proteoglycan sulfation

    International Nuclear Information System (INIS)

    Humphries, D.E.; Silbert, J.E.

    1988-01-01

    Bovine aorta endothelial cells were cultured in medium containing [ 3 H]glucosamine, [ 35 S]sulfate, and various concentrations of chlorate. Cell growth was not affected by 10 mM chlorate, while 30 mM chlorate had a slight inhibitory effect. Chlorate concentrations greater than 10 mM resulted in significant undersulfation of chondroitin. With 30 mM chlorate, sulfation of chondroitin was reduced to 10% and heparan to 35% of controls, but [ 3 H]glucosamine incorporation on a per cell basis did not appear to be inhibited. Removal of chlorate from the culture medium of cells resulted in the rapid resumption of sulfation

  8. Synergetic treatment of uranium-bearing waste water with sulfate reducing bacteria and zero-valent iron

    International Nuclear Information System (INIS)

    Zhou Quanyu; Tan Kaixuan; Zeng Sheng; Liu Dong

    2009-01-01

    The treatment of uranium-bearing wastewater from uranium mine and using microorganism to treat wastewater were paid much attention to environmental researchers. Based on column experiments, we investigated the potential using sulfate reducing bacteria (SRB) and zero-valent iron (ZVI) to synergetic treat contamination in wastewater such as sulfate, uranium, etc. SRB+ZVI can effectively remove contamination U(VI) and SO 4 2- in wastewater. The removal rate is 99.4% and 86.2% for U(VI) and SO 4 2- , respectively. The pH of wastewater can be basified to neutral. U(VI) and SO 4 2- as electron acceptor of sulfate reducing bacteria are removed by biological reduction. The corrosion of ZVI is benefit to enhance the pH of wastewater, forms anaerobic reducing environment, strengthens survival and metabolism reaction of SRB, and plays a synergetic enhancement. (authors)

  9. Rasch models with exchangeable rows and columns

    DEFF Research Database (Denmark)

    Lauritzen, Steffen Lilholt

    The article studies distributions of doubly infinite binary matrices with exchangeable rows and columns which satify the further property that the probability of any $m \\times n$ submatrix is a function of the row- and column sums of that matrix. We show that any such distribution is a (unique...

  10. Fringing-field effects in acceleration columns

    International Nuclear Information System (INIS)

    Yavor, M.I.; Weick, H.; Wollnik, H.

    1999-01-01

    Fringing-field effects in acceleration columns are investigated, based on the fringing-field integral method. Transfer matrices at the effective boundaries of the acceleration column are obtained, as well as the general transfer matrix of the region separating two homogeneous electrostatic fields with different field strengths. The accuracy of the fringing-field integral method is investigated

  11. Center column design of the PLT

    International Nuclear Information System (INIS)

    Citrolo, J.; Frankenberg, J.

    1975-01-01

    The center column of the PLT machine is a secondary support member for the toroidal field coils. Its purpose is to decrease the bending moment at the nose of the coils. The center column design was to have been a stainless steel casting with the toroidal field coils grouped around the casting at installation, trapping it in place. However, the castings developed cracks during fabrication and were unsuitable for use. Installation of the coils proceeded without the center column. It then became necessary to redesign a center column which would be capable of installation with the toroidal field coils in place. The final design consists of three A-286 forgings. This paper discusses the final center column design and the influence that new knowledge, obtained during the power tests, had on the new design

  12. Polymorphism of nickel sulfate hexahydrate

    International Nuclear Information System (INIS)

    Angel, R.J.; Finger, L.W.

    1988-01-01

    NiSO 4 .6H 2 O, M r =262.85; data collections with Mo Kα radiation, λ=0.7093 A, room temperature. Monoclinic polymorph: C2/c, a=9.880(3), b=7.228(2), c=24.130(3) A, β=98.38(2) 0 , V=1704.7(6) A 3 , Z=8, D x =2.05 g cm -3 , μ=25.54 cm -1 , F(000)=1088, R=0.031 (wR=0.038) for 2176 observed reflections. Tetragonal polymorph: P4 1 2 1 2, a=6.780 (1), c=18.285 (2) A, V=840.5 (3) A 3 , Z=4, D x =2.07 g cm -3 , μ=25.81 cm -1 , F(000)=544, R=0.045 (wR=0.050) for 2102 observed reflections. The structure of the tetragonal polymorph originally determined (without H positions) by Beevers and Lipson and refined by O'Connor and Dale and Stadnicka, Glazer and Koralewski, is confirmed by refinement of X-ray diffraction data. The structure of the monoclinic polymorph is confirmed as being isostructural with NiSO 4 .6D 2 O, and a number of other hexahydrate sulfates, e.g. MgSO 4 .6H 2 O. Both structures contain isolated [Ni(H 2 O 6 ] octahedra and [SO 4 ] tetrahedra linked by hydrogen bonding. (orig.)

  13. Chromatographic selectivity of poly(alkyl methacrylate-co-divinylbenzene) monolithic columns for polar aromatic compounds by pressure-driven capillary liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shu-Ling; Wang, Chih-Chieh; Fuh, Ming-Ren, E-mail: msfuh@scu.edu.tw

    2016-10-05

    In this study, divinylbenzene (DVB) was used as the cross-linker to prepare alkyl methacrylate (AlMA) monoliths for incorporating π-π interactions between the aromatic analytes and AlMA-DVB monolithic stationary phases in capillary LC analysis. Various AlMA/DVB ratios were investigated to prepare a series of 30% AlMA-DVB monolithic stationary phases in fused-silica capillaries (250-μm i.d.). The physical properties (such as porosity, permeability, and column efficiency) of the synthesized AlMA-DVB monolithic columns were investigated for characterization. Isocratic elution of phenol derivatives was first employed to evaluate the suitability of the prepared AlMA-DVB columns for small molecule separation. The run-to-run (0.16–1.20%, RSD; n = 3) and column-to-column (0.26–2.95%, RSD; n = 3) repeatabilities on retention times were also examined using the selected AlMA-DVB monolithic columns. The π-π interactions between the aromatic ring and the DVB-based stationary phase offered better recognition on polar analytes with aromatic moieties, which resulted in better separation resolution of aromatic analytes on the AlMA-DVB monolithic columns. In order to demonstrate the capability of potential environmental and/or food safety applications, eight phenylurea herbicides with single benzene ring and seven sulfonamide antibiotics with polyaromatic moieties were analyzed using the selected AlMA-DVB monolithic columns. - Highlights: • First investigation on chromatographic selectivity of AlMA-DVB monolithic columns. • Good run-to-run/column-to-column repeatability (<3%) on AlMA-DVB monolithic columns. • Efficient separation of phenylurea herbicides and sulfonamides on AlMA-DVB columns.

  14. Admittance Scanning for Whole Column Detection.

    Science.gov (United States)

    Stamos, Brian N; Dasgupta, Purnendu K; Ohira, Shin-Ichi

    2017-07-05

    Whole column detection (WCD) is as old as chromatography itself. WCD requires an ability to interrogate column contents from the outside. Other than the obvious case of optical detection through a transparent column, admittance (often termed contactless conductance) measurements can also sense changes in the column contents (especially ionic content) from the outside without galvanic contact with the solution. We propose here electromechanically scanned admittance imaging and apply this to open tubular (OT) chromatography. The detector scans across the column; the length resolution depends on the scanning velocity and the data acquisition frequency, ultimately limited by the physical step resolution (40 μm in the present setup). Precision equal to this step resolution was observed for locating an interface between two immiscible liquids inside a 21 μm capillary. Mechanically, the maximum scanning speed was 100 mm/s, but at 1 kHz sampling rate and a time constant of 25 ms, the highest practical scan speed (no peak distortion) was 28 mm/s. At scanning speeds of 0, 4, and 28 mm/s, the S/N for 180 pL (zone length of 1.9 mm in a 11 μm i.d. column) of 500 μM KCl injected into water was 6450, 3850, and 1500, respectively. To facilitate constant and reproducible contact with the column regardless of minor variations in outer diameter, a double quadrupole electrode system was developed. Columns of significant length (>1 m) can be readily scanned. We demonstrate its applicability with both OT and commercial packed columns and explore uniformity of retention along a column, increasing S/N by stopped-flow repeat scans, etc. as unique applications.

  15. Sulfate reduction and methanogenesis at a freshwater

    DEFF Research Database (Denmark)

    Iversen, Vibeke Margrethe Nyvang; Andersen, Martin Søgaard; Jakobsen, Rasmus

    The freshwater-seawater interface was studied in a ~9-m thick anaerobic aquifer located in marine sand and gravel with thin peat lenses. Very limited amounts of iron-oxides are present. Consequently, the dominating redox processes are sulfate reduction and methanogenesis, and the groundwater...... is enriched in dissolved sulfide, methane and bicarbonate. Under normal conditions the seawater-freshwater interface is found at a depth of 4 m at the coastline and reaches the bottom of the aquifer 40 m inland. However, occasional flooding of the area occurs, introducing sulfate to the aquifer. Groundwater...... chemistry was studied in a 120 m transect perpendicular to the coast. Cores were taken for radiotracer rate measurements of sulfate reduction and methanogenesis. In the saline part of the aquifer 35 m inland, sulfate reduction was the dominant process with rates of 0.1-10 mM/year. In the freshwater part 100...

  16. Lymphocyte mobilization by dextran sulfate in beagles

    International Nuclear Information System (INIS)

    Ragan, H.A.; Debban, K.H.

    1978-01-01

    Dogs manifesting 239 Pu-induced lymphopenia responded to the lymphocyte-mobilizing agent, dextran sulfate, to a degree similar to that observed in control dogs. No life-threatening increase in prothrombin times or hemorrhagic tendencies were observed

  17. Sulfated cellulose thin films with antithrombin affinity

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Cellulose thin films were chemically modified by in situ sulfation to produce surfaces with anticoagulant characteristics. Two celluloses differing in their degree of polymerization (DP: CEL I (DP 215–240 and CEL II (DP 1300–1400 were tethered to maleic anhydride copolymer (MA layers and subsequently exposed to SO3•NMe3 solutions at elevated temperature. The impact of the resulting sulfation on the physicochemical properties of the cellulose films was investigated with respect to film thickness, atomic composition, wettability and roughness. The sulfation was optimized to gain a maximal surface concentration of sulfate groups. The scavenging of antithrombin (AT by the surfaces was determined to conclude on their potential anticoagulant properties.

  18. COMBINED ALUMINIUM SULFATE/HYDROXIDE PROCESS FOR ...

    African Journals Online (AJOL)

    sulfate, and used for fluoride removal from water by combining with Nalgonda Technique. ... effects on human health and could result in fluorosis. ... [23], nanoscale aluminium oxide hydroxide (AlOOH) [24] and natural zeolite [25], were among.

  19. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  20. Liquid chromatography coupled to on-line post column derivatization for the determination of organic compounds: A review on instrumentation and chemistries

    International Nuclear Information System (INIS)

    Zacharis, Constantinos K.; Tzanavaras, Paraskevas D.

    2013-01-01

    Graphical abstract: -- Highlights: •Review on liquid chromatography coupled to post-column derivatization. •Overview of instrumentation for post-column derivatization. •Post-column chemistries for analysis of organic compounds. -- Abstract: Analytical derivatization either in pre or post column modes is one of the most widely used sample pretreatment techniques coupled to liquid chromatography. In the present review article we selected to discuss the post column derivatization mode for the analysis of organic compounds. The first part of the review focuses to the instrumentation of post-column setups including not only fundamental components such as pumps and reactors but also less common parts such as static mixers and back-pressure regulators; the second part of the article discusses the most popular “chemistries” that are involved in post column applications, including reagent-less approaches and new sensing platforms such as the popular gold nanoparticles. Some representative recent applications are also presented as tables

  1. Liquid chromatography coupled to on-line post column derivatization for the determination of organic compounds: A review on instrumentation and chemistries

    Energy Technology Data Exchange (ETDEWEB)

    Zacharis, Constantinos K., E-mail: zacharis@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotelian University of Thessaloniki, GR-54124 Thessaloniki (Greece); Department of Food Technology, School of Food Technology and Nutrition, Alexander Technological Educational Institute (ATEI) of Thessaloniki, 57400 Thessaloniki (Greece); Tzanavaras, Paraskevas D., E-mail: ptzanava@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotelian University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2013-10-10

    Graphical abstract: -- Highlights: •Review on liquid chromatography coupled to post-column derivatization. •Overview of instrumentation for post-column derivatization. •Post-column chemistries for analysis of organic compounds. -- Abstract: Analytical derivatization either in pre or post column modes is one of the most widely used sample pretreatment techniques coupled to liquid chromatography. In the present review article we selected to discuss the post column derivatization mode for the analysis of organic compounds. The first part of the review focuses to the instrumentation of post-column setups including not only fundamental components such as pumps and reactors but also less common parts such as static mixers and back-pressure regulators; the second part of the article discusses the most popular “chemistries” that are involved in post column applications, including reagent-less approaches and new sensing platforms such as the popular gold nanoparticles. Some representative recent applications are also presented as tables.

  2. Arsenic removal in a sulfidogenic fixed-bed column bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Altun, Muslum, E-mail: muslumaltun@hotmail.com [Hacettepe University, Department of Chemistry, Beytepe, Ankara (Turkey); Sahinkaya, Erkan [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey); Durukan, Ilknur; Bektas, Sema [Hacettepe University, Department of Chemistry, Beytepe, Ankara (Turkey); Komnitsas, Kostas [Technical University of Crete, Department of Mineral Resources Engineering, Chania (Greece)

    2014-03-01

    Highlights: • Sulfidogenic treatment of As-containing AMD was investigated. • High rate simultaneous removal of As and Fe was achieved. • As was removed without adding alkalinity or adjusting pH. • As and Fe removal mechanisms were elucidated. - Abstract: In the present study, the bioremoval of arsenic from synthetic acidic wastewater containing arsenate (As{sup 5+}) (0.5–20 mg/L), ferrous iron (Fe{sup 2+}) (100–200 mg/L) and sulfate (2000 mg/L) was investigated in an ethanol fed (780–1560 mg/L chemical oxygen demand (COD)) anaerobic up-flow fixed bed column bioreactor at constant hydraulic retention time (HRT) of 9.6 h. Arsenic removal efficiency was low and averaged 8% in case iron was not supplemented to the synthetic wastewater. Neutral to slightly alkaline pH and high sulfide concentration in the bioreactor retarded the precipitation of arsenic. Addition of 100 mg/L Fe{sup 2+} increased arsenic removal efficiency to 63%. Further increase of influent Fe{sup 2+} concentration to 200 mg/L improved arsenic removal to 85%. Decrease of influent COD concentration to its half, 780 mg/L, resulted in further increase of As removal to 96% when Fe{sup 2+} and As{sup 5+} concentrations remained at 200 mg/L and 20 mg/L, respectively. As a result of the sulfidogenic activity in the bioreactor the effluent pH and alkalinity concentration averaged 7.4 ± 0.2 and 1736 ± 239 mg CaCO{sub 3}/L respectively. Electron flow from ethanol to sulfate averaged 72 ± 10%. X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the nature of the precipitate generated by sulfate reducing bacteria (SRB) activity. Precipitation of arsenic in the form of As{sub 2}S{sub 3} (orpiment) and co-precipitation with ferrous sulfide (FeS), pyrite (FeS{sub 2}) or arsenopyrite (FeAsS) were the main arsenic removal mechanisms.

  3. Preparation of β-cyclodextrin-gold nanoparticles modified open tubular column for capillary electrochromatographic separation of chiral drugs.

    Science.gov (United States)

    Zhou, Li; Jiang, Shenmeng; Zhang, Xue; Fang, Linlin; Guo, Xingjie

    2018-04-01

    In this paper, β-cyclodextrin (β-CD) modified gold nanoparticles (AuNPs) coated open tubular column (OT column) was prepared for capillary electrochromatography. The open tubular column was constructed through self-assembly of gold nanoparticles on 3-mercaptopropyl-trimethoxysilane (MPTMS) prederivatized capillary and subsequent modification of thiols β-cyclodextrin (SH-β-CD). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet visible spectroscopy were carried out to characterize the prepared open tubular column and synthesized gold nanoparticles. By comparing different coating times of gold nanoparticles and thiols β-cyclodextrin, we got the optimal conditions for preparing the open tubular column. Also, the separation parameters were optimized including buffer pH, buffer concentration and applied voltage. Separation effectiveness of open tubular column was verified by the separation of four pairs of drug enantiomers including bifonazole, fexofenadine, omeprazole and lansoprazole, and satisfactory separation results were achieved for these analytes studied. In addition, the column showed good stability and repeatability. The relative standard deviation values less than 5% were obtained through intra-day, inter-day, and column-to-column investigations. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Regulation of bacterial sulfate reduction and hydrogen sulfide fluxes in the central Namibian coastal upwelling zone

    DEFF Research Database (Denmark)

    Bruchert, V.; Jørgensen, BB; Neumann, K.

    2003-01-01

    The coastal upwelling system off central Namibia is one of the most productive regions of the oceans and is characterized by frequently occurring shelf anoxia with severe effects for the benthic life and fisheries. We present data on water column dissolved oxygen, sulfide, nitrate and nitrite, pore......-depleted bottom waters, the oxygen minimum zone on the continental slope, and the lower continental slope below the oxygen minimum zone. High concentrations of dissolved sulfide, up to 22 mM, in the near-surface sediments of the inner shelf result from extremely high rates of bacterial sulfate reduction...

  5. Effect of metakaolin on external sulfate attack

    Energy Technology Data Exchange (ETDEWEB)

    Ramlochan, T.; Thomas, M. [Toronto Univ., Dept. of Civil Engineering, ON (Canada)

    2000-07-01

    The effect of high reactivity metakaolin (HRM) on the sulfate resistance of mortars was studied. Mortar bars with three cements of varying C{sub 3}A content were used for the experiment. After a six month exposure to a 5 per cent solution of sodium sulfate, mortar bars incorporating any level of HRM as a partial replacement for a high-C{sub 3}A was considered 'moderately sulfate resistant'; mortar bars with HRM and a moderate or low C{sub 3}A content as 'high sulfate resistant'. It was also determined that for long term sulfate resistance 15 per cent HRM or more may be required, depending on the C{sub 3}A content. The performance of HRM was found to be significantly influenced by the water-cementitious material ratio, and in turn, by permeability, suggesting that HRM might increase sulfate resistance more by lowering the permeability of the concrete than by any chemical action. 7 refs., 4 tabs., 7 figs.

  6. Recent advances in the preparation and application of monolithic capillary columns in separation science

    International Nuclear Information System (INIS)

    Hong, Tingting; Yang, Xi; Xu, Yujing; Ji, Yibing

    2016-01-01

    Novel column technologies involving various materials and efficient reactions have been investigated for the fabrication of monolithic capillary columns in the field of analytical chemistry. In addition to the development of these miniaturized systems, a variety of microscale separation applications have achieved noteworthy results, providing a stepping stone for new types of chromatographic columns with improved efficiency and selectivity. Three novel strategies for the preparation of capillary monoliths, including ionic liquid-based approaches, nanoparticle-based approaches and “click chemistry”, are highlighted in this review. Furthermore, we present the employment of state-of-the-art capillary monolithic stationary phases for enantioseparation, solid-phase microextraction, mixed-mode separation and immobilized enzyme reactors. The review concludes with recommendations for future studies and improvements in this field of research. - Highlights: • Preparation of novel monolithic capillary columns have shown powerful potential in analytical chemistry field. • Various materials including ionic liquids and nanoparticles involved into capillary monolithic micro-devices are concluded. • Click chemistry strategy applied for preparing monolithic capillary columns is reviewed. • Recent strategies utilized in constructing different capillary monoliths for enantiomeric separation are summarized. • Advancement of capillary monoliths for complex samples analysis is comprehensively described.

  7. Recent advances in the preparation and application of monolithic capillary columns in separation science

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Tingting; Yang, Xi; Xu, Yujing [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, 210009 (China); Ji, Yibing, E-mail: jiyibing@msn.com [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, 210009 (China)

    2016-08-10

    Novel column technologies involving various materials and efficient reactions have been investigated for the fabrication of monolithic capillary columns in the field of analytical chemistry. In addition to the development of these miniaturized systems, a variety of microscale separation applications have achieved noteworthy results, providing a stepping stone for new types of chromatographic columns with improved efficiency and selectivity. Three novel strategies for the preparation of capillary monoliths, including ionic liquid-based approaches, nanoparticle-based approaches and “click chemistry”, are highlighted in this review. Furthermore, we present the employment of state-of-the-art capillary monolithic stationary phases for enantioseparation, solid-phase microextraction, mixed-mode separation and immobilized enzyme reactors. The review concludes with recommendations for future studies and improvements in this field of research. - Highlights: • Preparation of novel monolithic capillary columns have shown powerful potential in analytical chemistry field. • Various materials including ionic liquids and nanoparticles involved into capillary monolithic micro-devices are concluded. • Click chemistry strategy applied for preparing monolithic capillary columns is reviewed. • Recent strategies utilized in constructing different capillary monoliths for enantiomeric separation are summarized. • Advancement of capillary monoliths for complex samples analysis is comprehensively described.

  8. Investigation of in-plane moment connections of I-beams to square concrete-filled steel tube columns under gravity loads

    Directory of Open Access Journals (Sweden)

    Abdelrahim K. Dessouki

    2015-04-01

    Full Text Available This paper focuses on experimental and analytical behavior of the ultimate moment of the connections of steel I-beams to square concrete-filled steel tube columns. External stiffeners around the columns are used at the beam flange levels. Five specimens are tested monotonically. The test parameters are the column stiffener dimensions and filling the steel tube column with concrete. Two types of failure modes are observed; beam flange failure and stiffener failure. The experimental results show that the ultimate moment of the connection is increased by increasing stiffener’s dimensions and filling the steel tube column with concrete. ANSYS finite element program is used to simulate the behavior, taking into account both geometric and material nonlinearities. Analytical results that are in fair agreement with the experimental ones are then used to discuss the influence of the main geometric parameters on the connection behavior. The parameters are the stiffener and column dimensions as well as filling the steel tube column with concrete. Different square column cross sections are chosen to cover the three classes of section classifications according to Egyptian code of practice, which are: compact, non compact or slender. The increase in the ultimate moment of the connections is based upon both column cross sections’ compactness and stiffener dimensions while the maximum advantages occur with slender columns.

  9. Relating gas hydrate saturation to depth of sulfate-methane transition

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, G.; Chapman, W.G.; Hirasaki, G.J. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Dickens, G.R.; Dugan, B. [Rice Univ., Houston, TX (United States). Dept. of Earth Sciences

    2008-07-01

    The stability of gas hydrates which often form in pore spaces of marine sediment along continental margins, depends on temperature, pressure, salinity and gas composition. Gas hydrate can precipitate in pore space of marine sediment when gas concentrations exceed solubility conditions within a gas hydrate stability zone (GHSZ). The amount of gas hydrate present in the GHSZ can vary significantly because it relates to dynamic inputs and outputs of gas, primarily methane, over a long timescale. In anoxic marine sediments, depletion of pore water sulfate occurs when sulfate is reduced through bacteria or when anaerobic oxidation of methane occurs. The presence of gas hydrates in shallow sediments implies a significant methane flux towards the seafloor, which can make the second route for sulfate depletion significant. This paper presented a numerical model that incorporates a dynamic sulfate-methane transition (SMT) for gas hydrate systems where methane is supplied from depth. The approach has the advantage of needing only pore water data from shallow piston cores. The analytical expressions are only valid for steady-state systems in which all gas is methane, all methane enters the GHSZ from the base, and no methane escapes the top through seafloor venting. These constraints mean that anaerobic oxidation of methane (AOM) is the only sink of gas, allowing a direct coupling of SMT depth to net methane flux. This study showed that a basic gas hydrate saturation profile can be determined from the SMT depth via analytical expressions if site-specific parameters such as sedimentation rate, methane solubility and porosity are known. This analytical model was verified at gas hydrate bearing sites along the Cascadia margin where methane is mostly sourced from depth. It was concluded that the analytical expressions provides a fast and convenient method to calculate gas hydrate saturation for a given geologic setting, including deep-source systems. 28 refs., 2 tabs., 5 figs., 1

  10. Aerosol Effects on Radiation and Climate: Column Closure Experiments with Towers, Aircraft, and Satellites

    Science.gov (United States)

    Russell, Philip B.

    1994-01-01

    Many theoretical studies have shown that anthropogenic aerosol particles can change the radiation balance in an atmospheric column and might thereby exert a significant effect on the Earth's climate. In particular, recent calculations have shown that sulfate particles from anthropogenic combustion may already exert a cooling influence on the Earth that partially offsets the warming caused by the greenhouse gases from the same combustion. Despite the potential climatic importance of anthropogenic aerosols, simultaneous measurements of anthropogenic aerosol properties and their effect on atmospheric radiation have been very rare. Successful comparisons of measured radiation fields with those calculated from aerosol measurements - now referred to as column closure comparisons - are required to improve the accuracy and credibility of climate predictions. This paper reviews the column closure experiment performed at the Mt. Sutro Tower in San Francisco in 1975, in which elevated radiometers measured the change in Earth-plus-atmosphere albedo caused by an aerosol layer, while a lidar, sunphotometer, nephelometer, and other radiometers measured properties of the responsible aerosol. The time-dependent albedo calculated from the measured aerosol properties agreed with that measured by the tower radiometers. Also presented are designs for future column closure studies using radiometers and aerosol instruments on the ground, aircraft, and satellites. These designs draw upon algorithms and experience developed in the Sutro Tower study, as well as more recent experience with current measurement and analysis capabilities.

  11. Collapse of tall granular columns in fluid

    Science.gov (United States)

    Kumar, Krishna; Soga, Kenichi; Delenne, Jean-Yves

    2017-06-01

    Avalanches, landslides, and debris flows are geophysical hazards, which involve rapid mass movement of granular solids, water, and air as a multi-phase system. In order to describe the mechanism of immersed granular flows, it is important to consider both the dynamics of the solid phase and the role of the ambient fluid. In the present study, the collapse of a granular column in fluid is studied using 2D LBM - DEM. The flow kinematics are compared with the dry and buoyant granular collapse to understand the influence of hydrodynamic forces and lubrication on the run-out. In the case of tall columns, the amount of material destabilised above the failure plane is larger than that of short columns. Therefore, the surface area of the mobilised mass that interacts with the surrounding fluid in tall columns is significantly higher than the short columns. This increase in the area of soil - fluid interaction results in an increase in the formation of turbulent vortices thereby altering the deposit morphology. It is observed that the vortices result in the formation of heaps that significantly affects the distribution of mass in the flow. In order to understand the behaviour of tall columns, the run-out behaviour of a dense granular column with an initial aspect ratio of 6 is studied. The collapse behaviour is analysed for different slope angles: 0°, 2.5°, 5° and 7.5°.

  12. Field Applications of Gamma Column Scanning Technology

    International Nuclear Information System (INIS)

    Aquino, Denis D.; Mallilin, Janice P.; Nuñez, Ivy Angelica A.; Bulos, Adelina DM.

    2015-01-01

    The Isotope Techniques Section (ITS) under the Nuclear Service Division (NSD) of the Philippine Nuclear Research Institute (PNRI) conducts services, research and development on radioisotope and sealed source application in the industry. This aims to benefit the manufacturing industries such as petroleum, petrochemical, chemical, energy, waste, column treatment plant, etc. through on line inspection and troubleshooting of a process vessel, column or pipe that could optimize the process operation and increase production efficiency. One of the most common sealed source techniques for industrial applications is the gamma column scanning technology. Gamma column scanning technology is an established technique for inspection, analysis and diagnosis of industrial columns for process optimization, solving operational malfunctions and management of resources. It is a convenient non-intrusive, cost effective and cost-efficient technique to examine inner details of an industrial process vessel such as a distillation column while it is in operation. The Philippine Nuclear Research Institute (PNRI) recognize the importance and benefits of this technology and has implemented activities to make gamma column scanning locally available to benefit the Philippine industries. Continuous effort for capacity building is being pursued thru the implementation of in-house and on-the-job training abroad and upgrading of equipment. (author)

  13. Polymorphism of nickel sulfate hexahydrate

    Energy Technology Data Exchange (ETDEWEB)

    Angel, R.J.; Finger, L.W.

    1988-11-15

    NiSO/sub 4/.6H/sub 2/O, M/sub r/=262.85; data collections with Mo K..cap alpha.. radiation, lambda=0.7093 A, room temperature. Monoclinic polymorph: C2/c, a=9.880(3), b=7.228(2), c=24.130(3) A, ..beta..=98.38(2)/sup 0/, V=1704.7(6) A/sup 3/, Z=8, D/sub x/=2.05 g cm/sup -3/, ..mu..=25.54 cm/sup -1/, F(000)=1088, R=0.031 (wR=0.038) for 2176 observed reflections. Tetragonal polymorph: P4/sub 1/2/sub 1/2, a=6.780 (1), c=18.285 (2) A, V=840.5 (3) A/sup 3/, Z=4, D/sub x/=2.07 g cm/sup -3/, ..mu..=25.81 cm/sup -1/, F(000)=544, R=0.045 (wR=0.050) for 2102 observed reflections. The structure of the tetragonal polymorph originally determined (without H positions) by Beevers and Lipson and refined by O'Connor and Dale and Stadnicka, Glazer and Koralewski, is confirmed by refinement of X-ray diffraction data. The structure of the monoclinic polymorph is confirmed as being isostructural with NiSO/sub 4/.6D/sub 2/O, and a number of other hexahydrate sulfates, e.g. MgSO/sub 4/.6H/sub 2/O. Both structures contain isolated (Ni(H/sub 2/O/sub 6/) octahedra and (SO/sub 4/) tetrahedra linked by hydrogen bonding.

  14. Isotopic Zonation Within Sulfate Evaporite Mineral Crystals Reveal Quantitative Paleoenvironment Details

    Science.gov (United States)

    Coleman, M.; Rhorssen, M.; Mielke, R. E.

    2008-12-01

    developed a new analytical method [2]. We use a modification of the standard TC/EA continuous-flow protocol to measure both hydrogen and oxygen of water of hydration from the same small sample. We have proved the concept of this new approach by analyzing zones within crystals and individual grains, growing epsomite (magnesium sulfate heptahydrate) in the laboratory and by analysis of natural gypsum evaporites. We are now exploring the effects of varying the controlling parameters. Eventual application to Martian sulfates will reveal amount of water involved in sulfate formation, its isotopic composition(s) and details of the paleo-atmospheric humidity. [1] Gat JR and Gonfiantini R, (Eds) (1981) IAEA Technical Report Series. [2] Rohrssen MK, Brunner B Mielke RE and Coleman M (2008) Analyt. Chem. (in press).

  15. Dynamic effects of diabatization in distillation columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2013-01-01

    The dynamic effects of diabatization in distillation columns are investigated in simulation emphasizing the heat-integrated distillation column (HIDiC). A generic, dynamic, first-principle model has been formulated, which is flexible enough to describe various diabatic distillation configurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found and control...

  16. Dynamic Effects of Diabatization in Distillation Columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2012-01-01

    The dynamic eects of diabatization in distillation columns are investigated in simulation with primary focus on the heat-integrated distillation column (HIDiC). A generic, dynamic, rst-principle model has been formulated, which is exible to describe various diabatic distillation congurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found. Control...

  17. Column-oriented database management systems

    OpenAIRE

    Možina, David

    2013-01-01

    In the following thesis I will present column-oriented database. Among other things, I will answer on a question why there is a need for a column-oriented database. In recent years there have been a lot of attention regarding a column-oriented database, even if the existence of a columnar database management systems dates back in the early seventies of the last century. I will compare both systems for a database management – a colum-oriented database system and a row-oriented database system ...

  18. Separation of hydroxynorketamine stereoisomers using capillary electrophoresis with sulfated β-cyclodextrin and highly sulfated γ-cyclodextrin.

    Science.gov (United States)

    Sandbaumhüter, Friederike A; Theurillat, Regula; Thormann, Wolfgang

    2017-08-01

    The racemic N-methyl-d-aspartate receptor antagonist ketamine is used in anesthesia, analgesia and the treatment of depressive disorders. It is known that interactions of hydroxylated norketamine metabolites and 5,6-dehydronorketamine (DHNK) with the α 7 -nicotinic acetylcholine receptor and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are responsible for the antidepressive effects. Ketamine and its first metabolite norketamine are not active on these receptors. As stereoselectivity plays a role in ketamine metabolism, a cationic capillary electrophoresis based method capable of resolving and analyzing the stereoisomers of four hydroxylated norketamine metabolites, norketamine and DHNK was developed. The assay is based on liquid/liquid extraction of the analytes from the biological matrix, electrokinetic sample injection across a buffer plug and analysis of the stereoisomers in a phosphate background electrolyte (BGE) at pH 3 comprising a mixture of sulfated β-cyclodextrin (5 mg/mL) and highly sulfated γ-cyclodextrin (0.1%). The method was used to analyze samples of an in vitro study in which ketamine was incubated with equine liver microsomes and in plasma samples of dogs and horses that were collected after an i.v. bolus injection of racemic ketamine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A Pilot Study On A Moment Carrying Beam-column Connection For Precast Structures

    OpenAIRE

    Kaplan, Vedat

    2010-01-01

    In this study, a moment carrying beam-column connection detail for precast structures has been investigated in the experimental and analytical manner. The 1/2 scaled beam-column test specimen is representing a real exterior precast connection detail. The cast-in-situ welded connection is applied at bottom face of the beams and additional re-bars and cast-in-situ concrete is introduced at the upper part of the beams. The experimental study is conducted in the form of varying beam top diplaceme...

  20. Flow rate dependent extra-column variance from injection in capillary liquid chromatography.

    Science.gov (United States)

    Aggarwal, Pankaj; Liu, Kun; Sharma, Sonika; Lawson, John S; Dennis Tolley, H; Lee, Milton L

    2015-02-06

    Efficiency and resolution in capillary liquid chromatography (LC) can be significantly affected by extra-column band broadening, especially for isocratic separations. This is particularly a concern in evaluating column bed structure using non-retained test compounds. The band broadening due to an injector supplied with a commercially available capillary LC system was characterized from experimental measurements. The extra-column variance from the injection valve was found to have an extra-column contribution independent of the injection volume, showing an exponential dependence on flow rate. The overall extra-column variance from the injection valve was found to vary from 34 to 23 nL. A new mathematical model was derived that explains this exponential contribution of extra-column variance on chromatographic performance. The chromatographic efficiency was compromised by ∼130% for a non-retained analyte because of injection valve dead volume. The measured chromatographic efficiency was greatly improved when a new nano-flow pumping system with integrated injection valve was used. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Estimations of temperature deviations in chromatographic columns using isenthalpic plots. I. Theory for isocratic systems.

    Science.gov (United States)

    Tarafder, Abhijit; Iraneta, Pamela; Guiochon, Georges; Kaczmarski, Krzysztof; Poe, Donald P

    2014-10-31

    We propose to use constant enthalpy or isenthalpic diagrams as a tool to estimate the extent of the temperature variations caused by the mobile phase pressure drop along a chromatographic column, e.g. of its cooling in supercritical fluid and its heating in ultra-performance liquid chromatography. Temperature strongly affects chromatographic phenomena. Any of its variations inside the column, whether intended or not, can lead to significant changes in separation performance. Although instruments use column ovens in order to keep constant the column temperature, operating conditions leading to a high pressure drop may cause significant variations of the column temperature, both in the axial and the radial directions, from the set value. Different ways of measuring these temperature variations are available but they are too inconvenient to be employed in many practical situations. In contrast, the thermodynamic plot-based method that we describe here can easily be used with only a ruler and a pencil. They should be helpful in developing methods or in analyzing results in analytical laboratories. Although the most effective application area for this approach should be SFC (supercritical fluid chromatography), it can be applied to any chromatographic conditions in which temperature variations take place along the column due to the pressure drop, e.g. in ultra-high pressure liquid chromatography (UHPLC). The method proposed here is applicable to isocractic conditions only. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Preparation and evaluation of a novel hybrid monolithic column based on pentafluorobenzyl imidazolium bromide ionic liquid.

    Science.gov (United States)

    Shan, Yuanhong; Qiao, Lizhen; Shi, Xianzhe; Xu, Guowang

    2015-01-02

    To develop a novel hybrid monolithic column based on pentafluorobenzyl imidazolium bromide ionic liquid, a new ionic liquid monomer was synthesized from 1-vinylimidazole and pentafluorobenzyl bromide. By employing a facile one-step copolymerization of polyhedral-oligomeric-silsesquioxane-type (POSS) cross-linking agent and the home-made ionic liquid monomer, the hybrid monolithic columns were in situ fabricated in fused-silica capillary. The morphology of monolithic column was characterized by scanning electron microscope (SEM) and the chemical composition was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and elemental analysis. Excellent mechanical stability and slight swelling propensity were exhibited which was ascribed to the rigid hybrid monolithic skeleton. Reproducibility results of run-to-run, column-to-column, batch-to-batch and day-to-day were investigated and the RSDs were less than 0.46%, 1.84%, 3.96% and 3.17%, respectively. The mixed-mode retention mechanism with hydrophobic interaction, π-π stacking, ion-exchange, electrostatic interaction and dipole-dipole interaction was explored systematically using analytes with different structure types. Satisfied separation capability and column efficiency were achieved for the analysis of small molecular compounds such as alkylbenzenes, polycyclic aromatic hydrocarbons, nucleosides and halogenated compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Oxygen isotopic fractionation during bacterial sulfate reduction

    Science.gov (United States)

    Balci, N.; Turchyn, A. V.; Lyons, T.; Bruchert, V.; Schrag, D. P.; Wall, J.

    2006-12-01

    Sulfur isotope fractionation during bacterial sulfate reduction (BSR) is understood to depend on a variety of environmental parameters, such as sulfate concentration, temperature, cell specific sulfate reduction rates, and the carbon substrate. What controls oxygen isotope fractionation during BSR is less well understood. Some studies have suggested that carbon substrate is important, whereas others concluded that there is a stoichiometric relationship between the fractionations of sulfur and oxygen during BSR. Studies of oxygen fractionation are complicated by isotopic equilibration between sulfur intermediates, particularly sulfite, and water. This process can modify the isotopic composition of the extracellular sulfate pool (δ18OSO4 ). Given this, the challenge is to distinguish between this isotopic equilibration and fractionations linked to the kinetic effects of the intercellular enzymes and the incorporation of sulfate into the bacterial cell. The δ18OSO4 , in concert with the sulfur isotope composition of sulfate (δ34SSO4), could be a powerful tool for understanding the pathways and environmental controls of BSR in natural systems. We will present δ18OSO4 data measured from batch culture growth of 14 different species of sulfate reducing bacteria for which sulfur isotope data were previously published. A general observation is that δ18OSO4 shows little isotopic change (kinetic effect during BSR and/or equilibration between sulfur intermediates and the isotopically light water (~-5‰) of the growth medium. Our present batch culture data do not allow us to convincingly isolate the magnitude and the controlling parameters of the kinetic isotope effect for oxygen. However, ongoing growth of mutant bacteria missing enzymes critical in the different steps of BSR may assist in this mission.

  4. Family of columns isospectral to gravity-loaded columns with tip force: A discrete approach

    Science.gov (United States)

    Ramachandran, Nirmal; Ganguli, Ranjan

    2018-06-01

    A discrete model is introduced to analyze transverse vibration of straight, clamped-free (CF) columns of variable cross-sectional geometry under the influence of gravity and a constant axial force at the tip. The discrete model is used to determine critical combinations of loading parameters - a gravity parameter and a tip force parameter - that cause onset of dynamic instability in the CF column. A methodology, based on matrix-factorization, is described to transform the discrete model into a family of models corresponding to weightless and unloaded clamped-free (WUCF) columns, each with a transverse vibration spectrum isospectral to the original model. Characteristics of models in this isospectral family are dependent on three transformation parameters. A procedure is discussed to convert the isospectral discrete model description into geometric description of realistic columns i.e. from the discrete model, we construct isospectral WUCF columns with rectangular cross-sections varying in width and depth. As part of numerical studies to demonstrate efficacy of techniques presented, frequency parameters of a uniform column and three types of tapered CF columns under different combinations of loading parameters are obtained from the discrete model. Critical combinations of these parameters for a typical tapered column are derived. These results match with published results. Example CF columns, under arbitrarily-chosen combinations of loading parameters are considered and for each combination, isospectral WUCF columns are constructed. Role of transformation parameters in determining characteristics of isospectral columns is discussed and optimum values are deduced. Natural frequencies of these WUCF columns computed using Finite Element Method (FEM) match well with those of the given gravity-loaded CF column with tip force, hence confirming isospectrality.

  5. Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler

    Energy Technology Data Exchange (ETDEWEB)

    Brostroem, Markus; Backman, Rainer; Nordin, Anders [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden); Kassman, Haakan [Vattenfall Power Consultant AB, Box 1046, SE-611 29 Nykoeping (Sweden); Helgesson, Anna; Berg, Magnus; Andersson, Christer [Vattenfall Research and Development AB, SE-814 26 Aelvkarleby (Sweden)

    2007-12-15

    Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as ''ChlorOut''. IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW{sub th}/25MW{sub e} circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (author)

  6. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... ophthalmic solution. 524.1484e Section 524.1484e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a...

  7. Unbonded Prestressed Columns for Earthquake Resistance

    Science.gov (United States)

    2012-05-01

    Modern structures are able to survive significant shaking caused by earthquakes. By implementing unbonded post-tensioned tendons in bridge columns, the damage caused by an earthquake can be significantly lower than that of a standard reinforced concr...

  8. PRTR ion exchange vault column sampling

    International Nuclear Information System (INIS)

    Cornwell, B.C.

    1995-01-01

    This report documents ion exchange column sampling and Non Destructive Assay (NDA) results from activities in 1994, for the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. The objective was to obtain sufficient information to prepare disposal documentation for the ion exchange columns found in the PRTR Ion exchange vault. This activity also allowed for the monitoring of the liquid level in the lower vault. The sampling activity contained five separate activities: (1) Sampling an ion exchange column and analyzing the ion exchange media for purpose of waste disposal; (2) Gamma and neutron NDA testing on ion exchange columns located in the upper vault; (3) Lower vault liquid level measurement; (4) Radiological survey of the upper vault; and (5) Secure the vault pending waste disposal

  9. Approximate transient and long time limit solutions for the band broadening induced by the thin sidewall-layer in liquid chromatography columns.

    Science.gov (United States)

    Broeckhoven, Ken; Desmet, Gert

    2007-11-16

    Using a combination of both analytical and numerical techniques, approximate analytical expressions have been established for the transient and long time limit band broadening, originating from the presence of a thin disturbed sidewall layer in liquid chromatography columns, including packed, monolithic as well as microfabricated columns. The established expressions can be used to compare the importance of a thin disturbed sidewall layer with that of other radial heterogeneity effects (such as transcolumn packing density variations due to the relief of packing stresses). The expressions are independent of the actual velocity profile inside the layer as long as the disturbed sidewall layer occupies less than 2.5% of the column width.

  10. Let's Talk... Analytics

    Science.gov (United States)

    Oblinger, Diana G.

    2012-01-01

    Talk about analytics seems to be everywhere. Everyone is talking about analytics. Yet even with all the talk, many in higher education have questions about--and objections to--using analytics in colleges and universities. In this article, the author explores the use of analytics in, and all around, higher education. (Contains 1 note.)

  11. Analytics for Education

    Science.gov (United States)

    MacNeill, Sheila; Campbell, Lorna M.; Hawksey, Martin

    2014-01-01

    This article presents an overview of the development and use of analytics in the context of education. Using Buckingham Shum's three levels of analytics, the authors present a critical analysis of current developments in the domain of learning analytics, and contrast the potential value of analytics research and development with real world…

  12. Analytical chemistry instrumentation

    International Nuclear Information System (INIS)

    Laing, W.R.

    1986-01-01

    In nine sections, 48 chapters cover 1) analytical chemistry and the environment 2) environmental radiochemistry 3) automated instrumentation 4) advances in analytical mass spectrometry 5) fourier transform spectroscopy 6) analytical chemistry of plutonium 7) nuclear analytical chemistry 8) chemometrics and 9) nuclear fuel technology

  13. Capacity of columns with splice imperfections

    International Nuclear Information System (INIS)

    Popov, E.P.; Stephen, R.M.

    1977-01-01

    To study the behavior of spliced columns subjected to tensile forces simulating situations which may develop in an earthquake, all of the spliced specimens were tested to failure in tension after first having been subjected to large compressive loads. The results of these tests indicate that the lack of perfect contact at compression splices of columns may not be important, provided that the gaps are shimmed and welding is used to maintain the sections in alignment

  14. High performance liquid chromatography column efficiency enhancement by zero dead volume recycling and practical approach using park and recycle arrangement.

    Science.gov (United States)

    Minarik, Marek; Franc, Martin; Minarik, Milan

    2018-06-15

    A new instrumental approach to recycling HPLC is described. The concept is based on fast reintroduction of incremental peak sections back onto the separation column. The re-circulation is performed within a closed loop containing only the column and two synchronized switching valves. By having HPLC pump out of the cycle, the method minimizes peak broadening due to dead volume. As a result the efficiency is dramatically increased allowing for the most demanding analytical applications. In addition, a parking loop is employed for temporary storage of analytes from the middle section of the separated mixture prior to their recycling. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Using the hydrophobic subtraction model to choose orthogonal columns for online comprehensive two-dimensional liquid chromatography

    DEFF Research Database (Denmark)

    Græsbøll, Rune; Nielsen, Nikoline Juul; Christensen, Jan H.

    2014-01-01

    A method for choosing orthogonal columns for a specific sample set in on-line comprehensive two-dimensional liquid chromatography (LC×LC) was developed on the basis of the hydrophobic subtraction model. The method takes into account the properties of the sample analytes by estimating new F...... neutral and 4 acidic oxygenated polycyclic aromatic compounds (PACs) and 3 nitrogen-containing PAC bases was measured isocratically on 12 columns. The isocratic runs were used to determine the hydrophobic subtraction model analyte parameters, and these were used to estimate new F-weights and predict...

  16. Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Aho, Martti

    2013-01-01

    Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

  17. The electrical and thermal properties of sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide

    International Nuclear Information System (INIS)

    Imanaka, N.; Yamaguchi, Y.; Adachi, G.; Shiokawa, J.

    1986-01-01

    Sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide was prepared. The thermal and electrical properties of its phases were investigated. The Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 SiO 2 samples are similar to the Na 2 SO 4 -I phase (a high temperature phase), which is appreciably effective for Na + ionic conduction. Phase transformation was considerably suppressed by mixing. Electromotive force (EMF) was measured, using Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 -SiO 2 as a solid electrolyte, by constructing an SO 2 gas concentration cell. The measured EMF's at 823 and 773 K were in fairly good accordance with the calculated EMF's for inlet SO 2 gas concentration between 30 ppm and 1%, and 500 ppm and 0.5% respectively

  18. Heparan sulfate-chondroitin sulfate hybrid proteoglycan of the cell surface and basement membrane of mouse mammary epithelial cells

    International Nuclear Information System (INIS)

    David, G.; Van den Berghe, H.

    1985-01-01

    Chondroitin sulfate represents approximately 15% of the 35 SO 4 -labeled glycosaminoglycans carried by the proteoglycans of the cell surface and of the basolateral secretions of normal mouse mammary epithelial cells in culture. Evidence is provided that these chondroitin sulfate-carrying proteoglycans are hybrid proteoglycans, carrying both chondroitin sulfate and heparan sulfate chains. Complete N-desulfation but limited O-desulfation, by treatment with dimethyl sulfoxide, of the proteoglycans decreased the anionic charge of the chondroitin sulfate-carrying proteoglycans to a greater extent than it decreased the charge of their constituent chondroitin sulfate chains. Partial depolymerization of the heparan sulfate residues of the proteoglycans with nitrous acid or with heparin lyase also reduced the effective molecular radius of the chondroitin sulfate-carrying proteoglycans. The effect of heparin lyase on the chondroitin sulfate-carrying proteoglycans was prevented by treating the proteoglycan fractions with dimethyl sulfoxide, while the effect of nitrous acid on the dimethyl sulfoxide-treated proteoglycans was prevented by acetylation. This occurrence of heparan sulfate-chondroitin sulfate hybrid proteoglycans suggests that the substitution of core proteins by heparan sulfate or chondroitin sulfate chains may not solely be determined by the specific routing of these proteins through distinct chondroitin sulfate and heparan sulfate synthesizing mechanisms. Moreover, regional and temporal changes in pericellular glycosaminoglycan compositions might be due to variable postsynthetic modification of a single gene product

  19. Co-existence of Methanogenesis and Sulfate Reduction with Common Substrates in Sulfate-Rich Estuarine Sediments

    Directory of Open Access Journals (Sweden)

    Michal Sela-Adler

    2017-05-01

    Full Text Available The competition between sulfate reducing bacteria and methanogens over common substrates has been proposed as a critical control for methane production. In this study, we examined the co-existence of methanogenesis and sulfate reduction with shared substrates over a large range of sulfate concentrations and rates of sulfate reduction in estuarine systems, where these processes are the key terminal sink for organic carbon. Incubation experiments were carried out with sediment samples from the sulfate-methane transition zone of the Yarqon (Israel estuary with different substrates and inhibitors along a sulfate concentrations gradient from 1 to 10 mM. The results show that methanogenesis and sulfate reduction can co-exist while the microbes share substrates over the tested range of sulfate concentrations and at sulfate reduction rates up to 680 μmol L-1 day-1. Rates of methanogenesis were two orders of magnitude lower than rates of sulfate reduction in incubations with acetate and lactate, suggesting a higher affinity of sulfate reducing bacteria for the available substrates. The co-existence of both processes was also confirmed by the isotopic signatures of δ34S in the residual sulfate and that of δ13C of methane and dissolved inorganic carbon. Copy numbers of dsrA and mcrA genes supported the dominance of sulfate reduction over methanogenesis, while showing also the ability of methanogens to grow under high sulfate concentration and in the presence of active sulfate reduction.

  20. Gas Chromatograph Method Optimization Trade Study for RESOLVE: 20-meter Column v. 8-meter Column

    Science.gov (United States)

    Huz, Kateryna

    2014-01-01

    RESOLVE is the payload on a Class D mission, Resource Prospector, which will prospect for water and other volatile resources at a lunar pole. The RESOLVE payload's primary scientific purpose includes determining the presence of water on the moon in the lunar regolith. In order to detect the water, a gas chromatograph (GC) will be used in conjunction with a mass spectrometer (MS). The goal of the experiment was to compare two GC column lengths and recommend which would be best for RESOLVE's purposes. Throughout the experiment, an Inficon Fusion GC and an Inficon Micro GC 3000 were used. The Fusion had a 20m long column with 0.25mm internal diameter (Id). The Micro GC 3000 had an 8m long column with a 0.32mm Id. By varying the column temperature and column pressure while holding all other parameters constant, the ideal conditions for testing with each column length in their individual instrument configurations were determined. The criteria used for determining the optimal method parameters included (in no particular order) (1) quickest run time, (2) peak sharpness, and (3) peak separation. After testing numerous combinations of temperature and pressure, the parameters for each column length that resulted in the most optimal data given my three criteria were selected. The ideal temperature and pressure for the 20m column were 95 C and 50psig. At this temperature and pressure, the peaks were separated and the retention times were shorter compared to other combinations. The Inficon Micro GC 3000 operated better at lower temperature mainly due to the shorter 8m column. The optimal column temperature and pressure were 70 C and 30psig. The Inficon Micro GC 3000 8m column had worse separation than the Inficon Fusion 20m column, but was able to separate water within a shorter run time. Therefore, the most significant tradeoff between the two column lengths was peak separation of the sample versus run time. After performing several tests, it was concluded that better

  1. The handedness of historiated spiral columns.

    Science.gov (United States)

    Couzin, Robert

    2017-09-01

    Trajan's Column in Rome (AD 113) was the model for a modest number of other spiral columns decorated with figural, narrative imagery from antiquity to the present day. Most of these wind upwards to the right, often with a congruent spiral staircase within. A brief introductory consideration of antique screw direction in mechanical devices and fluted columns suggests that the former may have been affected by the handedness of designers and the latter by a preference for symmetry. However, for the historiated columns that are the main focus of this article, the determining factor was likely script direction. The manner in which this operated is considered, as well as competing mechanisms that might explain exceptions. A related phenomenon is the reversal of the spiral in a non-trivial number of reproductions of the antique columns, from Roman coinage to Renaissance and baroque drawings and engravings. Finally, the consistent inattention in academic literature to the spiral direction of historiated columns and the repeated publication of erroneous earlier reproductions warrants further consideration.

  2. Interpretation of the lime column penetration test

    International Nuclear Information System (INIS)

    Liyanapathirana, D S; Kelly, R B

    2010-01-01

    Dry soil mix (DSM) columns are used to reduce the settlement and to improve the stability of embankments constructed on soft clays. During construction the shear strength of the columns needs to be confirmed for compliance with technical assumptions. A specialized blade shaped penetrometer known as the lime column probe, has been developed for testing DSM columns. This test can be carried out as a pull out resistance test (PORT) or a push in resistance test (PIRT). The test is considered to be more representative of average column shear strength than methods that test only a limited area of the column. Both PORT and PIRT tests require empirical correlations of measured resistance to an absolute measure of shear strength, in a similar manner to the cone penetration test. In this paper, finite element method is used to assess the probe factor, N, for the PORT test. Due to the large soil deformations around the probe, an Arbitrary Lagrangian Eulerian (ALE) based finite element formulation has been used. Variation of N with rigidity index and the friction at the probe-soil interface are investigated to establish a range for the probe factor.

  3. Sulfation in lead-acid batteries

    Science.gov (United States)

    Catherino, Henry A.; Feres, Fred F.; Trinidad, Francisco

    Virtually, all military land vehicle systems use a lead-acid battery to initiate an engine start. The maintainability of these batteries and as a consequence, system readiness, has suffered from a lack of understanding of the reasons for battery failure. Often, the term most commonly heard for explaining the performance degradation of lead-acid batteries is the word, sulfation. Sulfation is a residual term that came into existence during the early days of lead-acid battery development. The usage is part of the legend that persists as a means for interpreting and justifying the eventual performance deterioration and failure of lead-acid batteries. The usage of this term is confined to the greater user community and, over time, has encouraged a myriad of remedies for solving sulfation problems. One can avoid the connotations associated with the all-inclusive word, sulfation by visualizing the general "sulfation" effect in terms of specific mechanistic models. Also, the mechanistic models are essential for properly understanding the operation and making proper use this battery system. It is evident that the better the model, the better the level of understanding.

  4. Mass transfer model liquid phase catalytic exchange column simulation applicable to any column composition profile

    Energy Technology Data Exchange (ETDEWEB)

    Busigin, A. [NITEK USA Inc., Ocala, FL (United States)

    2015-03-15

    Liquid Phase Catalytic Exchange (LPCE) is a key technology used in water detritiation systems. Rigorous simulation of LPCE is complicated when a column may have both hydrogen and deuterium present in significant concentrations in different sections of the column. This paper presents a general mass transfer model for a homogenous packed bed LPCE column as a set of differential equations describing composition change, and equilibrium equations to define the mass transfer driving force within the column. The model is used to show the effect of deuterium buildup in the bottom of an LPCE column from non-negligible D atom fraction in the bottom feed gas to the column. These types of calculations are important in the design of CECE (Combined Electrolysis and Catalytic Exchange) water detritiation systems.

  5. Development of spent salt treatment technology by zeolite column system. Performance evaluation of zeolite column

    International Nuclear Information System (INIS)

    Miura, Hidenori; Uozumi, Koichi

    2009-01-01

    At electrorefining process, fission products(FPs) accumulate in molten salt. To avoid influence on heating control by decay heat and enlargement of FP amount in the recovered fuel, FP elements must be removed from the spent salt of the electrorefining process. For the removal of the FPs from the spent salt, we are investigating the availability of zeolite column system. For obtaining the basic data of the column system, such as flow property and ion-exchange performance while high temperature molten salt is passing through the column, and experimental apparatus equipped with fraction collector was developed. By using this apparatus, following results were obtained. 1) We cleared up the flow parameter of column system with zeolite powder, such as flow rate control by argon pressure. 2) Zeolite 4A in the column can absorb cesium that is one of the FP elements in molten salt. From these results, we got perspective on availability of the zeolite column system. (author)

  6. Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

    DEFF Research Database (Denmark)

    Sannes, P L; Burch, K K; Khosla, J

    1993-01-01

    Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entactin...

  7. Structural Decoupling and Disturbance Rejection in a Distillation Column

    DEFF Research Database (Denmark)

    Bahar, Mehrdad; Jantzen, Jan; Commault, C.

    1996-01-01

    Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references.......Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references....

  8. Optimization of SHINE Process: Design and Verification of Plant-Scale AG 1 Anion-Exchange Concentration Column and Titania Sorbent Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Abdul, Momen [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-06-01

    Argonne National Laboratory has developed a Mo-recovery and -purification system for the SHINE medical technologies process, which uses a uranyl sulfate solution for the accelerator-driven production of Mo-99. The objective of this effort is to reduce the processing time for the acidification of the Mo-99 product prior to loading onto a concentration column and concentration of the Mo-99 product solution. Two methods were investigated: (1) the replacement of the titania concentration column by an anion-exchange column to decrease processing time and increase the radioiodine-decontamination efficiency and (2) pretreatment of the titania sorbent to improve its effectiveness for the Mo-recovery and -concentration columns. Promising results are reported for both methods.

  9. The three-dimensional model for helical columns on type-J synchronous counter-current chromatography.

    Science.gov (United States)

    Guan, Y H; van den Heuvel, Remco

    2011-08-05

    Unlike the existing 2-D pseudo-ring model for helical columns undergoing synchronous type-J planetary motion of counter-current chromatograph (CCC), the 3-D "helix" model developed in this work shows that there is a second normal force (i.e. the binormal force) applied virtually in the axial direction of the helical column. This force alternates in the two opposite directions and intensifies phase mixing with increasing the helix angle. On the contrary, the 2-D spiral column operated on the same CCC device lacks this third-dimensional mixing force. The (principal) normal force quantified by this "helix" model has been the same as that by the pseudo-ring model. With β>0.25, this normal centrifugal force has been one-directional and fluctuates cyclically. Different to the spiral column, this "helix" model shows that the centrifugal force (i.e. the hydrostatic force) does not contribute to stationary phase retention in the helical column. Between the popular helical columns and the emerging spiral columns for type-J synchronous CCC, this work has thus illustrated that the former is associated with better phase mixing yet poor retention for the stationary phase whereas the latter has potential for better retention for the stationary phase yet poor phase mixing. The methodology developed in this work may be regarded as a new platform for designing optimised CCC columns for analytical and engineering applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. p-Cresyl sulfate and indoxyl sulfate in pediatric patients on chronic dialysis

    Directory of Open Access Journals (Sweden)

    Hye Sun Hyun

    2013-04-01

    Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Indoxyl sulfate and p- cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p- cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. &lt;b&gt;Methods:&lt;/b&gt; We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p- cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p- cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. &lt;b&gt;Results:&lt;/b&gt; The baseline serum levels of indoxyl sulfate and p- cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p- cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. &lt;b&gt;Conclusion:&lt;/b&gt; The levels of the uremic toxins p- cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by

  11. Sulfated glycopeptide nanostructures for multipotent protein activation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungsoo S.; Fyrner, Timmy; Chen, Feng; Álvarez, Zaida; Sleep, Eduard; Chun, Danielle S.; Weiner, Joseph A.; Cook, Ralph W.; Freshman, Ryan D.; Schallmo, Michael S.; Katchko, Karina M.; Schneider, Andrew D.; Smith, Justin T.; Yun, Chawon; Singh, Gurmit; Hashmi, Sohaib Z.; McClendon, Mark T.; Yu, Zhilin; Stock, Stuart R.; Hsu, Wellington K.; Hsu, Erin L.; Stupp , Samuel I. (NWU)

    2017-06-19

    Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.

  12. Formation of the natural sulfate aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Kerminen, V.M.; Hillamo, R.; Maekinen, M.; Virkkula, A.; Maekelae, T.; Pakkanen, T. [Helsinki Univ. (Finland). Dept. of Physics

    1996-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  13. Formation of the natural sulfate aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Kerminen, V M; Hillamo, R; Maekinen, M; Virkkula, A; Maekelae, T; Pakkanen, T [Helsinki Univ. (Finland). Dept. of Physics

    1997-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  14. Longitudinal On-Column Thermal Modulation for Comprehensive Two-Dimensional Liquid Chromatography.

    Science.gov (United States)

    Creese, Mari E; Creese, Mathew J; Foley, Joe P; Cortes, Hernan J; Hilder, Emily F; Shellie, Robert A; Breadmore, Michael C

    2017-01-17

    Longitudinal on-column thermal modulation for comprehensive two-dimensional liquid chromatography is introduced. Modulation optimization involved a systematic investigation of heat transfer, analyte retention, and migration velocity at a range of temperatures. Longitudinal on-column thermal modulation was realized using a set of alkylphenones and compared to a conventional valve-modulator employing sample loops. The thermal modulator showed a reduced modulation-induced pressure impact than valve modulation, resulting in reduced baseline perturbation by a factor of 6; yielding a 6-14-fold improvement in signal-to-noise. A red wine sample was analyzed to demonstrate the potential of the longitudinal on-column thermal modulator for separation of a complex sample. Discrete peaks in the second dimension using the thermal modulator were 30-55% narrower than with the valve modulator. The results shown herein demonstrate the benefits of an active focusing modulator, such as reduced detection limits and increased total peak capacity.

  15. Liquid-chromatographic analysis for cyclosporine with use of a microbore column and small sample volume.

    Science.gov (United States)

    Annesley, T; Matz, K; Balogh, L; Clayton, L; Giacherio, D

    1986-07-01

    This liquid-chromatographic assay requires 0.2 to 0.5 mL of whole blood, avoids the use of diethyl ether, and consumes only 10 to 20% of the solvents used in prior methods. Sample preparation involves an acidic extraction with methyl-t-butyl ether, performed in a 13 X 100 mm disposable glass tube, then a short second extraction of the organic phase with sodium hydroxide. After evaporation of the methyl-t-butyl ether, chromatography is performed on an "Astec" 2.0-mm (i.d.) octyl column. We compared results by this procedure with those by use of earlier larger-scale extractions and their respective 4.6-mm (i.d.) columns; analytical recoveries of cyclosporins A and D were comparable with previous findings and results for patients' specimens were equivalent, but the microbore columns provided greatly increased resolution and sensitivity.

  16. Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

    Science.gov (United States)

    Preti, Raffaella

    2016-01-01

    The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC) has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large amount of samples must be analyzed fast using reliable and solvent-saving apparatus. The literature hereby described shows how the outstanding performances provided by core-shell particles column on a traditional HPLC instruments are comparable to those obtained with a costly UHPLC instrumentation, making this novel column a promising key tool in food analysis. PMID:27143972

  17. Twin column chromatography: A new technique for treating limited amounts of waste

    International Nuclear Information System (INIS)

    Wenzel, U.

    1995-01-01

    The authors set up a chromatographic unit for the decontamination of analytical discards from Am and Pu. The unit is based on the twin column concept, i.e. the chromatographic support is accommodated in two identical columns and the detector placed between the columns. Thus, they could employ the wall effects model allowing the evaluation of breakthrough chromatograms at low effluent concentrations and the determination of the design parameters for the lay-out of the unit. The authors verified the model with the unit and obtained a good agreement between measured and calculated parameters. In the test phase, they processed 47 liters discards, they obtained 56 liters decontaminated waste with a DF Am of 770 and a total DF α of 7,000 and 22 liters eluate which was reduced by evaporation to 0.8 liters

  18. Inhibition of sulfate reduction in paddy soils

    Energy Technology Data Exchange (ETDEWEB)

    Vamos, R

    1958-12-13

    The hydrogen sulfide formed in waterlogged soils is a serious problem in rice cultivation. It inhibits the uptake of water and nutrients and may even cause root-rot. Results can best be obtained by preventing the formation of hydrogen sulfide. It is formed mainly by reduction of sulfate for which the cellulose-butyric acid fermentation provides the hydrogen source. Addition of ammonium or potassium nitrate prevents the formation of H/sub 2/S. The hydrogen produced by butyric acid fermentation is used to reduce nitrate and consequently cannot be utilized by the sulfate-reducing bacteria as a source of energy. 6 references.

  19. Measurement of chemical leaching potential of sulfate from landfill disposed sulfate containing wastes.

    Science.gov (United States)

    Sun, Wenjie; Barlaz, Morton A

    2015-02-01

    A number of sulfate-containing wastes are disposed in municipal solid wastes (MSW) landfills including residues from coal, wood, and MSW combustion, and construction and demolition (C&D) waste. Under anaerobic conditions that dominate landfills, the sulfate can be reduced to hydrogen sulfide which is problematic for several reasons including its low odor threshold, toxicity, and corrosive nature. The overall objective of this study was to evaluate existing protocols for the quantification of total leachable sulfate from solid samples and to compare their effectiveness and efficiency with a new protocol described in this study. Methods compared include two existing acid extraction protocols commonly used in the U.S., a pH neutral protocol that requires multiple changes of the leaching solution, and a new acid extraction method. The new acid extraction method was shown to be simple and effective to measure the leaching potential of sulfate from a range of landfill disposed sulfate-containing wastes. However, the acid extraction methods do not distinguish between sulfate and other forms of sulfur and are thus most useful when sulfate is the only form of sulfur present. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Ultra high pressure liquid chromatography. Column permeability and changes of the eluent properties.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2008-04-11

    The behavior of four similar liquid chromatography columns (2.1mm i.d. x 30, 50, 100, and 150 mm, all packed with fine particles, average d(p) approximately 1.7 microm, of bridged ethylsiloxane/silica hybrid-C(18), named BEH-C(18)) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived, using the column permeabilities and applying the Kozeny-Carman and the heat balance equations. The heat lost through the external surface area of the chromatographic column was directly derived from the wall temperature of the stainless steel tube measured with a precision of +/-0.2 degrees C in still air and +/-0.1 degrees C in the oven compartment. The variations of the density and viscosity of pure acetonitrile as a function of the temperature and pressure was derived from empirical correlations based on precise experimental data acquired between 298 and 373 K and at pressures up to 1.5 kbar. The measurements were made with the Acquity UPLC chromatograph that can deliver a maximum flow rate of 2 mL/min and apply a maximum column inlet pressure of 1038 bar. The average Kozeny-Carman permeability constant of the columns was 144+/-3.5%. The temperature hence the viscosity and the density profiles of the eluent along the column deviate significantly from linear behavior under high-pressure gradients. For a 1000 bar pressure drop, we measured DeltaT=25-30 K, (Deltaeta/eta) approximately 100%, and (Deltarho/rho) approximately 10%. These results show that the radial temperature profiles are never fully developed within 1% for any of the columns, even under still-air conditions. This represents a practical advantage regarding the apparent column efficiency at high flow rates, since the impact of the differential analyte velocity between the column center and the column wall is not maximum. The interpretation of the peak profiles recorded in

  1. Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates

    Science.gov (United States)

    Wang, A.; Freeman, J.J.; Jolliff, B.L.; Chou, I.-Ming

    2006-01-01

    The martian orbital and landed surface missions, OMEGA on Mar Express and the two Mars Explorations Rovers, respectively, have yielded evidence pointing to the presence of magnesium sulfates on the martian surface. In situ identification of the hydration states of magnesium sulfates, as well as the hydration states of other Ca- and Fe- sulfates, will be crucial in future landed missions on Mars in order to advance our knowledge of the hydrologic history of Mars as well as the potential for hosting life on Mars. Raman spectroscopy is a technique well-suited for landed missions on the martian surface. In this paper, we report a systematic study of the Raman spectra of the hydrates of magnesium sulfate. Characteristic and distinct Raman spectral patterns were observed for each of the 11 distinct hydrates of magnesium sulfates, crystalline and non-crystalline. The unique Raman spectral features along with the general tendency of the shift of the position of the sulfate ??1 band towards higher wavenumbers with a decrease in the degree of hydration allow in situ identification of these hydrated magnesium sulfates from the raw Raman spectra of mixtures. Using these Raman spectral features, we have started the study of the stability field of hydrated magnesium sulfates and the pathways of their transformations at various temperature and relative humidity conditions. In particular we report on the Raman spectrum of an amorphous hydrate of magnesium sulfate (MgSO4??2H2O) that may have specific relevance for the martian surface. ?? 2006 Elsevier Inc. All rights reserved.

  2. Novel processes for anaerobic sulfate production from elemental sulfur by sulfate-reducing bacteria

    Science.gov (United States)

    Lovley, D.R.; Phillips, E.J.P.

    1994-01-01

    Sulfate reducers and related organisms which had previously been found to reduce Fe(III) with H2 or organic electron donors oxidized S0 to sulfate when Mn(IV) was provided as an electron acceptor. Organisms catalyzing this reaction in washed cell suspensions included Desulfovibrio desulfuricans, Desulfomicrobium baculatum. Desulfobacterium autotrophicum, Desulfuromonas acetoxidans, and Geobacter metallireducens. These organisms produced little or no sulfate from S0 with Fe(III) as a potential electron acceptor or in the absence of an electron acceptor. In detailed studies with Desulfovibrio desulfuricans, the stoichiometry of sulfate and Mn(II) production was consistent with the reaction S0 + 3 MnO2 + 4H+ ???SO42- + 3Mn(II) + 2H2O. None of the organisms evaluated could be grown with S0 as the sole electron donor and Mn(IV) as the electron acceptor. In contrast to the other sulfate reducers evaluated, Desulfobulbus propionicus produced sulfate from S0 in the absence of an electron acceptor and Fe(III) oxide stimulated sulfate production. Sulfide also accumulated in the absence of Mn(IV) or Fe(III). The stoichiometry of sulfate and sulfide production indicated that Desulfobulbus propionicus disproportionates S0 as follows: 4S0 + 4H2O???SO42- + 3HS- + 5 H+. Growth of Desulfobulbus propionicus with S0 as the electron donor and Fe(III) as a sulfide sink and/or electron acceptor was very slow. The S0 oxidation coupled to Mn(IV) reduction described here provides a potential explanation for the Mn(IV)-dependent sulfate production that previous studies have observed in anoxic marine sediments. Desulfobulbus propionicus is the first example of a pure culture known to disproportionate S0.

  3. Contributions to reversed-phase column selectivity: III. Column hydrogen-bond basicity.

    Science.gov (United States)

    Carr, P W; Dolan, J W; Dorsey, J G; Snyder, L R; Kirkland, J J

    2015-05-22

    Column selectivity in reversed-phase chromatography (RPC) can be described in terms of the hydrophobic-subtraction model, which recognizes five solute-column interactions that together determine solute retention and column selectivity: hydrophobic, steric, hydrogen bonding of an acceptor solute (i.e., a hydrogen-bond base) by a stationary-phase donor group (i.e., a silanol), hydrogen bonding of a donor solute (e.g., a carboxylic acid) by a stationary-phase acceptor group, and ionic. Of these five interactions, hydrogen bonding between donor solutes (acids) and stationary-phase acceptor groups is the least well understood; the present study aims at resolving this uncertainty, so far as possible. Previous work suggests that there are three distinct stationary-phase sites for hydrogen-bond interaction with carboxylic acids, which we will refer to as column basicity I, II, and III. All RPC columns exhibit a selective retention of carboxylic acids (column basicity I) in varying degree. This now appears to involve an interaction of the solute with a pair of vicinal silanols in the stationary phase. For some type-A columns, an additional basic site (column basicity II) is similar to that for column basicity I in primarily affecting the retention of carboxylic acids. The latter site appears to be associated with metal contamination of the silica. Finally, for embedded-polar-group (EPG) columns, the polar group can serve as a proton acceptor (column basicity III) for acids, phenols, and other donor solutes. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. ON THE ORIGIN OF THE HIGH COLUMN DENSITY TURNOVER IN THE H I COLUMN DENSITY DISTRIBUTION

    International Nuclear Information System (INIS)

    Erkal, Denis; Gnedin, Nickolay Y.; Kravtsov, Andrey V.

    2012-01-01

    We study the high column density regime of the H I column density distribution function and argue that there are two distinct features: a turnover at N H I ≈ 10 21 cm –2 , which is present at both z = 0 and z ≈ 3, and a lack of systems above N H I ≈ 10 22 cm –2 at z = 0. Using observations of the column density distribution, we argue that the H I-H 2 transition does not cause the turnover at N H I ≈ 10 21 cm –2 but can plausibly explain the turnover at N H I ∼> 10 22 cm –2 . We compute the H I column density distribution of individual galaxies in the THINGS sample and show that the turnover column density depends only weakly on metallicity. Furthermore, we show that the column density distribution of galaxies, corrected for inclination, is insensitive to the resolution of the H I map or to averaging in radial shells. Our results indicate that the similarity of H I column density distributions at z = 3 and 0 is due to the similarity of the maximum H I surface densities of high-z and low-z disks, set presumably by universal processes that shape properties of the gaseous disks of galaxies. Using fully cosmological simulations, we explore other candidate physical mechanisms that could produce a turnover in the column density distribution. We show that while turbulence within giant molecular clouds cannot affect the damped Lyα column density distribution, stellar feedback can affect it significantly if the feedback is sufficiently effective in removing gas from the central 2-3 kpc of high-redshift galaxies. Finally, we argue that it is meaningful to compare column densities averaged over ∼ kpc scales with those estimated from quasar spectra that probe sub-pc scales due to the steep power spectrum of H I column density fluctuations observed in nearby galaxies.

  5. COMPUTATIONAL AND EXPERIMENTAL MODELING OF THREE-PHASE SLURRY-BUBBLE COLUMN REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    Isaac K. Gamwo; Dimitri Gidaspow

    1999-09-01

    Considerable progress has been achieved in understanding three-phase reactors from the point of view of kinetic theory. In a paper in press for publication in Chemical Engineering Science (Wu and Gidaspow, 1999) we have obtained a complete numerical solution of bubble column reactors. In view of the complexity of the simulation a better understanding of the processes using simplified analytical solutions is required. Such analytical solutions are presented in the attached paper, Large Scale Oscillations or Gravity Waves in Risers and Bubbling Beds. This paper presents analytical solutions for bubbling frequencies and standing wave flow patterns. The flow patterns in operating slurry bubble column reactors are not optimum. They involve upflow in the center and downflow at the walls. It may be possible to control flow patterns by proper redistribution of heat exchangers in slurry bubble column reactors. We also believe that the catalyst size in operating slurry bubble column reactors is not optimum. To obtain an optimum size we are following up on the observation of George Cody of Exxon who reported a maximum granular temperature (random particle kinetic energy) for a particle size of 90 microns. The attached paper, Turbulence of Particles in a CFB and Slurry Bubble Columns Using Kinetic Theory, supports George Cody's observations. However, our explanation for the existence of the maximum in granular temperature differs from that proposed by George Cody. Further computer simulations and experiments involving measurements of granular temperature are needed to obtain a sound theoretical explanation for the possible existence of an optimum catalyst size.

  6. Vertebral Column Resection for Rigid Spinal Deformity.

    Science.gov (United States)

    Saifi, Comron; Laratta, Joseph L; Petridis, Petros; Shillingford, Jamal N; Lehman, Ronald A; Lenke, Lawrence G

    2017-05-01

    Broad narrative review. To review the evolution, operative technique, outcomes, and complications associated with posterior vertebral column resection. A literature review of posterior vertebral column resection was performed. The authors' surgical technique is outlined in detail. The authors' experience and the literature regarding vertebral column resection are discussed at length. Treatment of severe, rigid coronal and/or sagittal malalignment with posterior vertebral column resection results in approximately 50-70% correction depending on the type of deformity. Surgical site infection rates range from 2.9% to 9.7%. Transient and permanent neurologic injury rates range from 0% to 13.8% and 0% to 6.3%, respectively. Although there are significant variations in EBL throughout the literature, it can be minimized by utilizing tranexamic acid intraoperatively. The ability to correct a rigid deformity in the spine relies on osteotomies. Each osteotomy is associated with a particular magnitude of correction at a single level. Posterior vertebral column resection is the most powerful posterior osteotomy method providing a successful correction of fixed complex deformities. Despite meticulous surgical technique and precision, this robust osteotomy technique can be associated with significant morbidity even in the most experienced hands.

  7. Effect of backmixing on pulse column performance

    International Nuclear Information System (INIS)

    Miao, Y.W.

    1979-05-01

    A critical survey of the published literature concerning dispersed phase holdup and longitudinal mixing in pulsed sieve-plate extraction columns has been made to assess the present state-of-the-art in predicting these two parameters, both of which are of critical importance in the development of an accurate mathematical model of the pulse column. Although there are many conflicting correlations of these variables as a function of column geometry, operating conditions, and physical properties of the liquid systems involved it has been possible to develop new correlations which appear to be useful and which are consistent with much of the available data over the limited range of variables most likely to be encountered in plant sized equipment. The correlations developed were used in a stagewise model of the pulse column to predict product concentrations, solute inventory, and concentration profiles in a column for which limited experimental data were available. Reasonable agreement was obtained between the mathematical model and the experimental data. Complete agreement, however, can only be obtained after a correlation for the extraction efficiency has been developed. The correlation of extraction efficiency was beyond the scope of this work

  8. Activation and transfer of sulfate in biological systems (1960); Activation biologique du sulfate et son transfert (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    It examines in this review the successive stages of active sulfate formation and its role in biological synthesis of sulfuric esters. The possible role of active sulfate as intermediary in sulfate reduction is also discussed. (author) [French] On examine dans cette etude les stades successifs de la mise en evidence du sulfate actif, son role dans la formation des esters sulfuriques de natures diverses, ainsi que sa participation eventuelle comme intermediaire au cours de la reduction du sulfate. On decrit aussi un procede de preparation du systeme biologique, generateur du sulfate actif et une methode de synthese chimique. (auteur)

  9. Quantitation of promethazine and metabolites in urine samples using on-line solid-phase extraction and column-switching

    Science.gov (United States)

    Song, Q.; Putcha, L.; Harm, D. L. (Principal Investigator)

    2001-01-01

    A chromatographic method for the quantitation of promethazine (PMZ) and its three metabolites in urine employing on-line solid-phase extraction and column-switching has been developed. The column-switching system described here uses an extraction column for the purification of PMZ and its metabolites from a urine matrix. The extraneous matrix interference was removed by flushing the extraction column with a gradient elution. The analytes of interest were then eluted onto an analytical column for further chromatographic separation using a mobile phase of greater solvent strength. This method is specific and sensitive with a range of 3.75-1400 ng/ml for PMZ and 2.5-1400 ng/ml for the metabolites promethazine sulfoxide, monodesmethyl promethazine sulfoxide and monodesmethyl promethazine. The lower limits of quantitation (LLOQ) were 3.75 ng/ml with less than 6.2% C.V. for PMZ and 2.50 ng/ml with less than 11.5% C.V. for metabolites based on a signal-to-noise ratio of 10:1 or greater. The accuracy and precision were within +/- 11.8% in bias and not greater than 5.5% C.V. in intra- and inter-assay precision for PMZ and metabolites. Method robustness was investigated using a Plackett-Burman experimental design. The applicability of the analytical method for pharmacokinetic studies in humans is illustrated.

  10. Mathematical modeling of alcohol distillation columns

    Directory of Open Access Journals (Sweden)

    Ones Osney Pérez

    2011-04-01

    Full Text Available New evaluation modules are proposed to extend the scope of a modular simulator oriented to the sugar cane industry, called STA 4.0, in a way that it can be used to carry out x calculation and analysis in ethanol distilleries. Calculation modules were developed for the simulation of the columns that are combined in the distillation area. Mathematical models were supported on materials and energy balances, equilibrium relations and thermodynamic properties of the ethanol-water system. Ponchon-Savarit method was used for the evaluation of the theoretical stages in the columns. A comparison between the results using Ponchon- Savarit method and those obtained applying McCabe-Thiele method was done for a distillation column. These calculation modules for ethanol distilleries were applied to a real case for validation.

  11. Inert carriers for column extraction chromatography

    International Nuclear Information System (INIS)

    Katykhin, G.S.

    1978-01-01

    Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

  12. Computational analysis of ozonation in bubble columns

    International Nuclear Information System (INIS)

    Quinones-Bolanos, E.; Zhou, H.; Otten, L.

    2002-01-01

    This paper presents a new computational ozonation model based on the principle of computational fluid dynamics along with the kinetics of ozone decay and microbial inactivation to predict the performance of ozone disinfection in fine bubble columns. The model can be represented using a mixture two-phase flow model to simulate the hydrodynamics of the water flow and using two transport equations to track the concentration profiles of ozone and microorganisms along the height of the column, respectively. The applicability of this model was then demonstrated by comparing the simulated ozone concentrations with experimental measurements obtained from a pilot scale fine bubble column. One distinct advantage of this approach is that it does not require the prerequisite assumptions such as plug flow condition, perfect mixing, tanks-in-series, uniform radial or longitudinal dispersion in predicting the performance of disinfection contactors without carrying out expensive and tedious tracer studies. (author)

  13. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  14. Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

    OpenAIRE

    Preti, Raffaella

    2016-01-01

    The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC) has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large am...

  15. Adaptation of Boynton's mathematical model to hydrogen isotope separation column by cryogenic distillation

    International Nuclear Information System (INIS)

    Kinoshita, Masahiro; Naruse, Yuji

    1981-08-01

    Boynton's mathematical simulation procedure for multi-component distillation calculations has the advantage that the Jacobian matrix is calculated analytically. The purpose of the present study is to adapt this procedure to hydrogen isotope separation columns by cryogenic distillation. The Boynton's model is modified so that the model can incorporate decay heat of tritium, nonideality of the hydrogen isotope solutions, multiple feeds and multiple sidestreams. Basic equations are derived and the mathematical simulation procedure is briefly explained. (author)

  16. Zwitterionic silica-based monolithic capillary columns for isocratic and gradient hydrophilic interaction liquid chromatography

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Planeta, Josef; Kahle, Vladislav; Roth, Michal

    2012-01-01

    Roč. 1270, DEC 28 (2012), s. 178-185 ISSN 0021-9673 R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP206/11/0138; GA ČR(CZ) GAP106/12/0522 Institutional support: RVO:68081715 Keywords : HILIC * Monolithic silica column * Nucleoside separation * Nucleic acid base Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.612, year: 2012

  17. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS ...

    African Journals Online (AJOL)

    Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random ...

  18. Determination of boron spectrophotometry in thorium sulfate

    International Nuclear Information System (INIS)

    Federgrun, L.; Abrao, A.

    1976-01-01

    A procedure for the determination of microquantities of boron in nuclear grade thorium sulfate is described. The method is based on the extraction of BF - 4 ion associated to monomethylthionine (MMT) in 1,2 - dichloroethane. The extraction of the colored BF - 4 -MMT complex does not allow the presence of sulfuric and phosphoric acids; other anions interfere seriously. This fact makes the dissolution of the thorium sulfate impracticable, since it is insoluble in both acids. On the other hand, the quantitative separation of thorium is mandatory, to avoid the precipitation of ThF 4 . To overcome this difficulty, the thorium sulfate is dissolved using a strong cationic ion exchanger, Th 4+ being totally retained into the resin. Boron is then analysed in the effluent. The procedure allows the determination of 0.2 to 10.0 microgramas of B, with a maximum error of 10%. Thorium sulfate samples with contents of 0.2 to 2.0μg B/gTh have being analysed [pt

  19. Sulfate reducing potential in an estuarine beach

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Chandramohan, D.

    Sulfate reducing bacteria (SRB) and their activity (SRA) together with total anaerobic and aerobic bacterial flora were estimated during July 1982-April 1983 and July-August 1984 from 1, 3 and 5 cm depths using core samples. The average number (no...

  20. Sulfate-reducing bacteria in anaerobic bioreactors

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the

  1. Controlling sulfate attack in Mississippi Department of Transportation structures.

    Science.gov (United States)

    2010-08-01

    At some construction sites in Mississippi, deterioration of concrete in contact with the surrounding soil could be related to the high sulfate content of the adjacent soils. Studies dating to 1966 have documented sulfate attack associated with specif...

  2. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG; Zhang, Jianqin; Sun, Xun; Zhang, Qiang; Zhao, Xian; Zhang, Xixiang

    2013-01-01

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property

  3. Controlling sulfate attack in Mississippi Department of Transportation structures

    Science.gov (United States)

    2010-08-01

    At some construction sites in Mississippi, deterioration of concrete in contact with the surrounding soil could be related to the high sulfate content of the adjacent soils. Studies dating to 1966 have documented sulfate attack associated with sp...

  4. Bone sialoprotein II synthesized by cultured osteoblasts contains tyrosine sulfate

    International Nuclear Information System (INIS)

    Ecarot-Charrier, B.; Bouchard, F.; Delloye, C.

    1989-01-01

    Isolated mouse osteoblasts that retain their osteogenic activity in culture were incubated with [35S] sulfate. Two radiolabeled proteins, in addition to proteoglycans, were extracted from the calcified matrix of osteoblast cultures. All the sulfate label in both proteins was in the form of tyrosine sulfate as assessed by amino acid analysis and thin layer chromatography following alkaline hydrolysis. The elution behavior on DEAE-Sephacel of the major sulfated protein and the apparent Mr on sodium dodecyl sulfate gels were characteristic of bone sialoprotein II extracted from rat. This protein was shown to cross-react with an antiserum raised against bovine bone sialoprotein II, indicating that bone sialoprotein II synthesized by cultured mouse osteoblasts is a tyrosine-sulfated protein. The minor sulfated protein was tentatively identified as bone sialoprotein I or osteopontin based on its elution properties on DEAE-Sephacel and anomalous behavior on sodium dodecyl sulfate gels similar to those reported for rat bone sialoprotein I

  5. Galactose 6-sulfate sulfatase activity in Morquio syndrome

    International Nuclear Information System (INIS)

    Yutaka, T.; Okada, S.; Kato, T.; Inui, K.; Yabuuhi, H.

    1982-01-01

    The authors have prepared a new substrate, o-β-D-sulfo-galactosyl-(1-4)-β-D-6-sulfo-2-acetamido-2-deoxyglucosyl-(1-4)-D-[1- 3 H]galactitol, from shark cartilage keratan sulfate, for the assay of galactose 6-sulfate sulfatase activity. Using this substrate, they found there was a striking deficiency of galactose 6-sulfate sulfatase activity, in addition to the known deficiency of N-acetylgalactosamine 6-sulfate sulfatase, in the cultured skin fibroblasts of patients with Morquio syndrome. Their results could be explained by the hypothesis that accumulation of keratan sulfate and chondroitin 6-sulfate in Morquio syndrome is due to a deficiency of galactose 6-sulfate sulfatase and N-acetylgalactosamine 6-sulfate sulfatase activity, which are necessary for the degradation of these two mucopolysaccharides. (Auth.)

  6. Galactose 6-sulfate sulfatase activity in Morquio syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yutaka, T.; Okada, S.; Kato, T.; Inui, K.; Yabuuhi, H. (Osaka Univ. (Japan). Faculty of Medicine)

    1982-07-01

    The authors have prepared a new substrate, o-..beta..-D-sulfo-galactosyl-(1-4)-..beta..-D-6-sulfo-2-acetamido-2-deoxyglucosyl-(1-4)-D-(1-/sup 3/H)galactitol, from shark cartilage keratan sulfate, for the assay of galactose 6-sulfate sulfatase activity. Using this substrate, they found there was a striking deficiency of galactose 6-sulfate sulfatase activity, in addition to the known deficiency of N-acetylgalactosamine 6-sulfate sulfatase, in the cultured skin fibroblasts of patients with Morquio syndrome. Their results could be explained by the hypothesis that accumulation of keratan sulfate and chondroitin 6-sulfate in Morquio syndrome is due to a deficiency of galactose 6-sulfate sulfatase and N-acetylgalactosamine 6-sulfate sulfatase activity, which are necessary for the degradation of these two mucopolysaccharides.

  7. Continuous electrophoretic purification of individual analytes from multicomponent mixtures.

    Science.gov (United States)

    McLaren, David G; Chen, David D Y

    2004-04-15

    Individual analytes can be isolated from multicomponent mixtures and collected in the outlet vial by carrying out electrophoretic purification through a capillary column. Desired analytes are allowed to migrate continuously through the column under the electric field while undesired analytes are confined to the inlet vial by application of a hydrodynamic counter pressure. Using pressure ramping and buffer replenishment techniques, 18% of the total amount present in a bulk sample can be purified when the resolution to the adjacent peak is approximately 3. With a higher resolution, the yield could be further improved. Additionally, by periodically introducing fresh buffer into the sample, changes in pH and conductivity can be mediated, allowing higher purity (>or=99.5%) to be preserved in the collected fractions. With an additional reversed cycle of flow counterbalanced capillary electrophoresis, any individual component in a sample mixture can be purified providing it can be separated in an electrophoresis system.

  8. CUB DI (Deionization) column control system

    International Nuclear Information System (INIS)

    Seino, K.C.

    1999-01-01

    For the old MR (Main Ring), deionization was done with two columns in CUB, using an ion exchange process. Typically 65 GPM of LCW flew through a column, and the resistivity was raised from 3 Mohm-cm to over 12 Mohm-cm. After a few weeks, columns lost their effectiveness and had to be regenerated in a process involving backwashing and adding hydrochloric acid and sodium hydroxide. For normal MR operations, LCW returned from the ring and passed through the two columns in parallel for deionization, although the system could have been operated satisfactorily with only one in use. A 3000 gallon reservoir (the Spheres) provided a reserve of LCW for allowing water leaks and expansions in the MR. During the MI (Main Injector) construction period, the third DI column was added to satisfy requirements for the MI. When the third column was added, the old regeneration controller was replaced with a new controller based on an Allen-Bradley PLC (i.e., SLC-5/04). The PLC is widely used and well documented, and therefore it may allow us to modify the regeneration programs in the future. In addition to the above regeneration controller, the old control panels (which were used to manipulate pumps and valves to supply LCW in Normal mode and to do Int. Recir. (Internal Recirculation) and Makeup) were replaced with a new control system based on Sixtrak Gateway and I/O modules. For simplicity, the new regeneration controller is called as the US Filter system, and the new control system is called as the Fermilab system in this writing

  9. Analyticity without Differentiability

    Science.gov (United States)

    Kirillova, Evgenia; Spindler, Karlheinz

    2008-01-01

    In this article we derive all salient properties of analytic functions, including the analytic version of the inverse function theorem, using only the most elementary convergence properties of series. Not even the notion of differentiability is required to do so. Instead, analytical arguments are replaced by combinatorial arguments exhibiting…

  10. Understanding Business Analytics

    Science.gov (United States)

    2015-01-05

    analytics have been used in organizations for a variety of reasons for quite some time; ranging from the simple (generating and understanding business analytics...process. understanding business analytics 3 How well these two components are orchestrated will determine the level of success an organization has in

  11. Operation of the annular pulsed column, (2)

    International Nuclear Information System (INIS)

    Takahashi, Keiki; Tsukada, Takeshi

    1988-01-01

    The heat of reaction generated form the uranium extraction is considered to from the temperature profile inside the pulsed column. A simulation code was developed to estimate the temperature profile, considering heat generation and counter-current heat transfer. The temperature profiles calculated using this code was found to depend on both the position of the extraction zone and the operating condition. The reported experimental result was fairly represented by this simulation code. We consider that this presented simulation code is capable of providing with the temperature profile in the pulsed column and useful for the monitoring of the uranium extraction zone. (author)

  12. Distillation columns inspection through gamma scanning

    International Nuclear Information System (INIS)

    Garcia, Marco

    1999-09-01

    The application of nuclear energy is very wide and it allows the saving of economic resources since the investigation of a certain process is carried out without stop the plant. The gamma scanning of oil c racking c olumns are practical examples, they allow to determine the hydraulic operation of the inspected columns. A source of Co-60 22mCi and a detector with a crystal of INa(TI) are used. This paper shows the results got from a profile carried out in a column distillation

  13. Reference mean temperature for evaluation of performance of thermal diffusion column for isotope separation

    International Nuclear Information System (INIS)

    Yamamoto, Ichiro; Kanagawa, Akira

    1987-01-01

    In order to evaluate separative performance of a thermal diffusion column, a simplification is usually made in which the temperature dependence of the relevant properties such as thermal diffusion constant is ignored and some proper mean values evaluated at a specific ''mean'' temperature are used. Adoption of weighted average of temperature distribution is common for the ''mean'' temperature, but there exists no definite way of determining mean temperature. The present paper proposes a new reference mean temperature determined by the equation governing the free convection. It is based on the fact that the multiplication effect of free convection is essential to separation by thermal diffusion column. The reference mean temperature is related to pressure difference between top and bottom of column and is higher than a mass-averaged temperature (due to gravitational force) by a contribution of viscous force. The reference mean temperature was calculated, as a reference, for an Ar isotope separating column with an inner hot radius of 0.2 mm and an outer cold radius of 5 mm. The results confirmed the validity of an approximate formula expressing effects of temperature difference and ratio of inner and outer radii of column explicitly for the temperature. The reference mean temperature calculated from pressure difference given by axisymmetric solution of equations of change was in good agreement with the analytical solution. (author)

  14. One stacked-column vibration test and analysis for VHTR core

    International Nuclear Information System (INIS)

    Ikushima, Takeshi; Ishizuka, Hiroshi; Ide, Akira; Hayakawa, Hitoshi; Shingai, Kazuteru.

    1978-07-01

    This paper describes experimental results of the vibration test on a single stacked-column and compares them with the analytical results. A 1/2 scale model of the core element of a very high temperature gas-cooled reactor (VHTR) was set on a shaking table. Sinusoidal waves, response time history waves, beat wave and step wave of input acceleration 100 - 900 gal in the frequency of 0.5 to 15 Hz were used to vibrate the table horizontally. Results are as follows: (1) The column has a non-linear resonance and exhibits a hysteresis response with jump points. (2) The column vibration characteristics is similar to that of the finite beams connected with non-linear soft spring. (3) The column resonance frequency decreases with increasing input acceleration. (4) The impact force increases with increasing input acceleration and boundary gap width. (5) Good correlation in vibration behavior of the stacked-column and impact force on the boundary between test and analysis was obtained. (auth.)

  15. Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

    Directory of Open Access Journals (Sweden)

    Mónica Díaz-Bao

    2015-02-01

    Full Text Available Monolithic columns are gaining interest as excellent substitutes to conventional particle-packed columns. These columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monoliths possess also great potential for the clean-up and preparation of complex mixtures. In situ polymerization inside appropriate supports allows the development of several microextraction formats, such as in-tube solid-phase and pipette tip-based extractions. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, time-saving LC columns and preparative applications applied to the analysis of residues and contaminants in food in 2010–2014 are described, focusing on recent improvements in design and with emphasis in automated on-line systems and innovative materials and formats.

  16. Buckling of Nonprismatic Column on Varying Elastic Foundation with Arbitrary Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Ahmad A. Ghadban

    2017-01-01

    Full Text Available Buckling of nonprismatic single columns with arbitrary boundary conditions resting on a nonuniform elastic foundation may be considered as the most generalized treatment of the subject. The buckling differential equation for such columns is extremely difficult to solve analytically. Thus, the authors propose a numerical approach by discretizing the column into a finite number of segments. Each segment has constants E (modulus of elasticity, I (moment of inertia, and β (subgrade stiffness. Next, an exact analytical solution is derived for each prismatic segment resting on uniform elastic foundation. These segments are then assembled in a matrix from which the critical buckling load is obtained. The derived formulation accounts for different end boundary conditions. Validation is performed by benchmarking the present results against analytical solutions found in the literature, showing excellent agreement. After validation, more examples are solved to illustrate the power and flexibility of the proposed method. Overall, the proposed method provides reasonable results, and the examples solved demonstrate the versatility of the developed approach and some of its many possible applications.

  17. Ion chromatographic determination of fluoride and chloride in UO2 using microbore anion exchange columns

    International Nuclear Information System (INIS)

    Kelkar, Anoop; Meena, D.L.; Das, D.K.; Behere, P.G.; Mohd Afzal

    2015-01-01

    Chemical characterization of nuclear fuels is required to ensure that nuclear fuel meets the technical specifications of the fuel. Trace non- metallic impurities like Cl and F is important as they affect clad corrosion. Their effect is more severe in presence of moisture. Chlorine and Fluorine is routinely analysed by ion selective electrode or conventional ion chromatography after pyrohydrolyzing the sample in moist O 2 atmosphere at 950°. Both the technique generates large quantity of liquid waste. Generally 1 ml/min flow rate required for the separation of F - and Cl - in conventional ion-chromatographic separation of F - and Cl - on 4.6- 4.0 mm id analytical column. The waste produced per sample injection is ∼ 30-40 ml with suppressed conductivity detection in ion chromatography. There is a need to reduce this analytical waste in analyzing the radioactive samples for the determination of F - and Cl - . Waste generation could be effectively reduced by using microbore anion exchange analytical column. Present paper describe the use of Metrosep A Supp 16 - 100/2.0 column with Na 2 CO 3 +NaOH mobile phase for the determination of F - and Cl - in UO 2 samples using suppressed conductivity detection

  18. Ion mobility based on column leaching of South African gold tailings dam with chemometric evaluation.

    Science.gov (United States)

    Cukrowska, Ewa M; Govender, Koovila; Viljoen, Morris

    2004-07-01

    New column leaching experiments were designed and used as an alternative rapid screening approach to element mobility assessment. In these experiments, field-moist material was treated with an extracting solution to assess the effects of acidification on element mobility in mine tailings. The main advantage of this version of column leaching experiments with partitioned segments is that they give quick information on current element mobility in conditions closely simulating field conditions to compare with common unrepresentative air-dried, sieved samples used for column leaching experiments. Layers from the tailings dump material were sampled and packed into columns. The design of columns allows extracting leachates from each layer. The extracting solutions used were natural (pH 6.8) and acidified (pH 4.2) rainwater. Metals and anions were determined in the leachates. The concentrations of metals (Ca, Mg, Fe, Mn, Al, Cr, Ni, Co, Zn, and Cu) in sample leachates were determined using ICP OES. The most important anions (NO3-, Cl-, and SO4(2)-) were determined using the closed system izotacophoresis ITP analyser. The chemical analytical data from tailings leaching and physico-chemical data from field measurements (including pH, conductivity, redox potential, temperature) were used for chemometric evaluation of element mobility. Principal factor analysis (PFA) was used to evaluate ions mobility from different layers of tailings dump arising from varied pH and redox conditions. It was found that the results from the partitioned column leaching illustrate much better complex processes of metals mobility from tailings dump than the total column. The chemometric data analysis (PFA) proofed the differences in the various layers leachability that are arising from physico-chemical processes due to chemical composition of tailings dump deposit. Copyright 2004 Elsevier Ltd.

  19. Isolation of a sulfate reducing bacterium and its application in sulfate ...

    African Journals Online (AJOL)

    The results show that the effect of C. freundii in removing sulfate was best when the temperature was 32°C, pH was 7.0, COD/SO42- was 5.0 and the initial SO42- concentration was 1500 mg/L. Also, the SRB was inoculated onto an up-flow anaerobic sludge bed (UASB) to remove sulfate in actual tannery wastewater.

  20. Analytical chromatography. Methods, instrumentation and applications

    International Nuclear Information System (INIS)

    Yashin, Ya I; Yashin, A Ya

    2006-01-01

    The state-of-the-art and the prospects in the development of main methods of analytical chromatography, viz., gas, high performance liquid and ion chromatographic techniques, are characterised. Achievements of the past 10-15 years in the theory and general methodology of chromatography and also in the development of new sorbents, columns and chromatographic instruments are outlined. The use of chromatography in the environmental control, biology, medicine, pharmaceutics, and also for monitoring the quality of foodstuffs and products of chemical, petrochemical and gas industries, etc. is considered.

  1. Microbial methanogenesis in the sulfate-reducing zone of sediments in the Eckernförde Bay, SW Baltic Sea

    Science.gov (United States)

    Maltby, Johanna; Steinle, Lea; Löscher, Carolin R.; Bange, Hermann W.; Fischer, Martin A.; Schmidt, Mark; Treude, Tina

    2018-01-01

    Benthic microbial methanogenesis is a known source of methane in marine systems. In most sediments, the majority of methanogenesis is located below the sulfate-reducing zone, as sulfate reducers outcompete methanogens for the major substrates hydrogen and acetate. The coexistence of methanogenesis and sulfate reduction has been shown before and is possible through the usage of noncompetitive substrates by methanogens such as methanol or methylated amines. However, knowledge about the magnitude, seasonality, and environmental controls of this noncompetitive methane production is sparse. In the present study, the presence of methanogenesis within the sulfate reduction zone (SRZ methanogenesis) was investigated in sediments (0-30 cm below seafloor, cm b.s.f.) of the seasonally hypoxic Eckernförde Bay in the southwestern Baltic Sea. Water column parameters such as oxygen, temperature, and salinity together with porewater geochemistry and benthic methanogenesis rates were determined in the sampling area Boknis Eck quarterly from March 2013 to September 2014 to investigate the effect of seasonal environmental changes on the rate and distribution of SRZ methanogenesis, to estimate its potential contribution to benthic methane emissions, and to identify the potential methanogenic groups responsible for SRZ methanogenesis. The metabolic pathway of methanogenesis in the presence or absence of sulfate reducers, which after the addition of a noncompetitive substrate was studied in four experimental setups: (1) unaltered sediment batch incubations (net methanogenesis), (2) 14C-bicarbonate labeling experiments (hydrogenotrophic methanogenesis), (3) manipulated experiments with the addition of either molybdate (sulfate reducer inhibitor), 2-bromoethanesulfonate (methanogen inhibitor), or methanol (noncompetitive substrate, potential methanogenesis), and (4) the addition of 13C-labeled methanol (potential methylotrophic methanogenesis). After incubation with methanol, molecular

  2. Silica-based monolithic capillary columns modified by liposomes for characterization of analyte–liposome interactions by capillary liquid chromatography

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Planeta, Josef; Wiedmer, S. K.

    2013-01-01

    Roč. 1317, SI (2013), s. 159-166 ISSN 0021-9673 R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP206/11/0138 Institutional support: RVO:68081715 Keywords : monolithic silica capillary column * immobilized liposomes * biomimicking stationary phase Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.258, year: 2013

  3. Comparison of magnesium sulfate and sodium sulfate for removal of water from pesticide extracts of foods.

    Science.gov (United States)

    Schenck, Frank J; Callery, Patrick; Gannett, Peter M; Daft, Jonathan R; Lehotay, Steven J

    2002-01-01

    Water-miscible solvents, such as acetone and acetonitrile, effectively extract both polar and nonpolar pesticide residues from nonfatty foods. The addition of sodium chloride to the resulting acetonitrile-water or acetone-water extract (salting out) results in the separation of the water from the organic solvent. However, the organic solvent layer (pesticide extract) still contains some residual water, which can adversely affect separation procedures that follow, such as solid-phase extraction and/or gas chromatography. Drying agents, such as sodium sulfate or magnesium sulfate, are used to remove the water from the organic extracts. In the present study, we used nuclear magnetic resonance spectroscopy to study the composition of the phases resulting from salting out and to compare the effectiveness of sodium sulfate and magnesium sulfate as drying agents. The study showed that considerable amounts of water remained in the organic phase after phase separation. Sodium sulfate was a relatively ineffective drying agent, removing little or no residual water from the organic solvent. Magnesium sulfate proved to be a much more effective drying agent.

  4. Scalability of pre-packed preparative chromatography columns with different diameters and lengths taking into account extra column effects.

    Science.gov (United States)

    Schweiger, Susanne; Jungbauer, Alois

    2018-02-16

    Small pre-packed columns are commonly used to estimate the optimum run parameters for pilot and production scale. The question arises if the experiments obtained with these columns are scalable, because there are substantial changes in extra column volume when going from a very small scale to a benchtop column. In this study we demonstrate the scalability of pre-packed disposable and non-disposable columns of volumes in the range of 0.2-20 ml packed with various media using superficial velocities in the range of 30-500 cm/h. We found that the relative contribution of extra column band broadening to total band broadening was not only high for columns with small diameters, but also for columns with a larger volume due to their wider diameter. The extra column band broadening can be more than 50% for columns with volumes larger than 10 ml. An increase in column diameter leads to high additional extra column band broadening in the filter, frits, and adapters of the columns. We found a linear relationship between intra column band broadening and column length, which increased stepwise with increases in column diameter. This effect was also corroborated by CFD simulation. The intra column band broadening was the same for columns packed with different media. An empirical engineering equation and the data gained from the extra column effects allowed us to predict the intra, extra, and total column band broadening just from column length, diameter, and flow rate. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  5. Use of 2-mercaptopyridine for the determination of alkylating agents in complex matrices: application to dimethyl sulfate.

    Science.gov (United States)

    Hoogerheide, J G; Scott, R A

    2005-01-30

    A rapid and sensitive method for the determination of alkylating agents in complex reaction mixtures was developed and characterized. Analyses are based on the alkylation of 2-mercaptopyridine by the analyte; the derivative is separated by RP-HPLC and measured by fluorescence detection. When applied to the determination of dimethyl sulfate, the method is linear over four orders of magnitude: 0.01-10mugmL(-1). By using recrystallized 2-mercaptopyridine, quantitation limits of 10ngmL(-1) can be achieved. Precision of the assay is 2% R.S.D. in the 1-10mugmL(-1) range and about 15% R.S.D. at 10ngmL(-1). Studies on the pH dependence of the derivatization reaction were key to minimizing interference from the dimethyl sulfate degradation product, monomethyl sulfate, in quenched reaction samples.

  6. Convolutional Codes with Maximum Column Sum Rank for Network Streaming

    OpenAIRE

    Mahmood, Rafid; Badr, Ahmed; Khisti, Ashish

    2015-01-01

    The column Hamming distance of a convolutional code determines the error correction capability when streaming over a class of packet erasure channels. We introduce a metric known as the column sum rank, that parallels column Hamming distance when streaming over a network with link failures. We prove rank analogues of several known column Hamming distance properties and introduce a new family of convolutional codes that maximize the column sum rank up to the code memory. Our construction invol...

  7. Optimization and simulation of tandem column supercritical fluid chromatography separations using column back pressure as a unique parameter.

    Science.gov (United States)

    Wang, Chunlei; Tymiak, Adrienne A; Zhang, Yingru

    2014-04-15

    Tandem column supercritical fluid chromatography (SFC) has demonstrated to be a useful technique to resolve complex mixtures by serially coupling two columns of different selectivity. The overall selectivity of a tandem column separation is the retention time weighted average of selectivity from each coupled column. Currently, the method development merely relies on extensive screenings and is often a hit-or-miss process. No attention is paid to independently adjust retention and selectivity contributions from individual columns. In this study, we show how tandem column SFC selectivity can be optimized by changing relative dimensions (length or inner diameter) of the coupled columns. Moreover, we apply column back pressure as a unique parameter for SFC optimization. Continuous tuning of tandem column SFC selectivity is illustrated through column back pressure adjustments of the upstream column, for the first time. In addition, we show how and why changing coupling order of the columns can produce dramatically different separations. Using the empirical mathematical equation derived in our previous study, we also demonstrate a simulation of tandem column separations based on a single retention time measurement on each column. The simulation compares well with experimental results and correctly predicts column order and back pressure effects on the separations. Finally, considerations on instrument and column hardware requirements are discussed.

  8. Influence of pressure on the properties of chromatographic columns. II. The column hold-up volume.

    Science.gov (United States)

    Gritti, Fabrice; Martin, Michel; Guiochon, Georges

    2005-04-08

    The effect of the local pressure and of the average column pressure on the hold-up column volume was investigated between 1 and 400 bar, from a theoretical and an experimental point of view. Calculations based upon the elasticity of the solids involved (column wall and packing material) and the compressibility of the liquid phase show that the increase of the column hold-up volume with increasing pressure that is observed is correlated with (in order of decreasing importance): (1) the compressibility of the mobile phase (+1 to 5%); (2) in RPLC, the compressibility of the C18-bonded layer on the surface of the silica (+0.5 to 1%); and (3) the expansion of the column tube (columns packed with the pure Resolve silica (0% carbon), the derivatized Resolve-C18 (10% carbon) and the Symmetry-C18 (20% carbon) adsorbents, using water, methanol, or n-pentane as the mobile phase. These solvents have different compressibilities. However, 1% of the relative increase of the column hold-up volume that was observed when the pressure was raised is not accounted for by the compressibilities of either the solvent or the C18-bonded phase. It is due to the influence of the pressure on the retention behavior of thiourea, the compound used as tracer to measure the hold-up volume.

  9. Two-Column Aerosol Project (TCAP) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Larry K [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-05-01

    This study included the deployment of the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Mobile Facility (AMF), ARM Mobile Aerosol Observing System (MAOS) and the ARM Aerial Facility (AAF). The study was a collaborative effort involving scientists from DOE national laboratories, NOAA, NASA, and universities. The AAF and MAOS were deployed for two approximately month-long Intensive Operational Periods (IOPs) conducted in June 2012 and February 2013. Seasonal differences in the aerosol chemical and optical properties observed using the AMF, AAF, and MAOS are presented in this report. The total mass loading of aerosol is found to be much greater in the summer than in the winter, with the difference associated with greater amounts of organic aerosol. The mass fraction of organic aerosol is much reduced in the winter, when sulfate is the dominant aerosol type. Surprisingly, very little sea-salt aerosol was observed in the summer. In contrast, much more sea salt aerosol was observed in the winter. The mass loading of black carbon is nearly the same in both seasons. These differences lead to a relative increase in the aerosol light absorption in the winter and an associated decrease in observed single-scattering albedo. Measurements of aerosol mixing state were made using a single-particle mass spectrometer, which showed that the majority of the summertime aerosol consisted of organic compounds mixed with various amounts of sulfate. A number of other findings are also summarized in the report, including: impact of aerosol layers aloft on the column aerosol optical depth; documentation of the aerosol properties at the AMF; differences in the aerosol properties associated with both columns, which are not systematic but reflect the complicated meteorological and chemical processes that impact aerosol as it is advected away from North America; and new instruments and data-processing techniques for measuring both aerosol and

  10. Acid Sulfate Alteration in Gusev Crater, Mars

    Science.gov (United States)

    Morris, R. V.; Ming, D. W.; Catalano, J. G.

    2016-01-01

    The Mars Exploration Rover (MER) Spirit landed on the Gusev Crater plains west of the Columbia Hills in January, 2004, during the Martian summer (sol 0; sol = 1 Martian day = 24 hr 40 min). Spirit explored the Columbia Hills of Gusev Crater in the vicinity of Home Plate at the onset on its second winter (sol approximately 900) until the onset of its fourth winter (sol approximately 2170). At that time, Spirit became mired in a deposit of fined-grained and sulfate-rich soil with dust-covered solar panels and unfavorable pointing of the solar arrays toward the sun. Spirit has not communicated with the Earth since sol 2210 (January, 2011). Like its twin rover Opportunity, which landed on the opposite side of Mars at Meridiani Planum, Spirit has an Alpha Particle X-Ray Spectrometer (APXS) instrument for chemical analyses and a Moessbauer spectrometer (MB) for measurement of iron redox state, mineralogical speciation, and quantitative distribution among oxidation (Fe(3+)/sigma Fe) and coordination (octahedral versus tetrahedral) states and mineralogical speciation (e.g., olivine, pyroxene, ilmenite, carbonate, and sulfate). The concentration of SO3 in Gusev rocks and soils varies from approximately 1 to approximately 34 wt%. Because the APXS instrument does not detect low atomic number elements (e.g., H and C), major-element oxide concentrations are normalized to sum to 100 wt%, i.e., contributions of H2O, CO2, NO2, etc. to the bulk composition care not considered. The majority of Gusev samples have approximately 6 plus or minus 5 wt% SO3, but there is a group of samples with high SO3 concentrations (approximately 30 wt%) and high total iron concentrations (approximately 20 wt%). There is also a group with low total Fe and SO3 concentrations that is also characterized by high SiO2 concentrations (greater than 70 wt%). The trend labeled "Basaltic Soil" is interpreted as mixtures in variable proportions between unaltered igneous material and oxidized and SO3-rich basaltic

  11. Pulsing flow in trickle bed columns

    NARCIS (Netherlands)

    Blok, Jan Rudolf

    1981-01-01

    In the operation of a packed column with cocurrent downflow of gas and liquid (trickle bed) several flowpatterns can be observed depending on the degree of interaction between gas and liquid. At low liquid and gas flow rates - low interaction - gascontinuous flow occurs. In this flowregime, the

  12. Revive your columns with cyclic distillation

    NARCIS (Netherlands)

    Kiss, Anton A.; Bîldea, Costin Sorin

    2015-01-01

    The process intensification (PI) technique involves changing a tower?s internals and operating mode and the separate movement of the liquid and vapor phases. This can significantly increase column throughput and reduce energy requirements, while improving separation performance. PI is a set of

  13. Robust Geometric Control of a Distillation Column

    DEFF Research Database (Denmark)

    Kymmel, Mogens; Andersen, Henrik Weisberg

    1987-01-01

    A frequency domain method, which makes it possible to adjust multivariable controllers with respect to both nominal performance and robustness, is presented. The basic idea in the approach is that the designer assigns objectives such as steady-state tracking, maximum resonance peaks, bandwidth, m...... is used to examine and improve geometric control of a binary distillation column....

  14. On Row Rank Equal Column Rank

    Science.gov (United States)

    Khalili, Parviz

    2009-01-01

    We will prove a well-known theorem in Linear Algebra, that is, for any "m x n" matrix the dimension of row space and column space are the same. The proof is based on the subject of "elementary matrices" and "reduced row-echelon" form of a matrix.

  15. On Stability of a Bubble Column

    Czech Academy of Sciences Publication Activity Database

    Růžička, Marek

    2013-01-01

    Roč. 91, č. 2 (2013), s. 191-203 ISSN 0263-8762 R&D Projects: GA ČR GA104/07/1110 Institutional support: RVO:67985858 Keywords : bubble column * flow regimes * steady solution Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.281, year: 2013

  16. Thermal Analysis of LANL Ion Exchange Column

    International Nuclear Information System (INIS)

    Laurinat, J.E.

    1999-01-01

    This document reports results from an ion exchange column heat transfer analysis requested by Los Alamos National Laboratory (LANL). The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades

  17. Column Stores as an IR Prototyping Tool

    NARCIS (Netherlands)

    H.F. Mühleisen (Hannes); T. Samar (Thaer); J.J.P. Lin (Jimmy); A.P. de Vries (Arjen)

    2014-01-01

    textabstract. We make the suggestion that instead of implementing custom index structures and query evaluation algorithms, IR researchers should simply store document representations in a column-oriented relational database and write ranking models using SQL. For rapid prototyping, this is

  18. Constraining Δ33S signatures of Archean seawater sulfate with carbonate-associated sulfate

    Science.gov (United States)

    Peng, Y.; Bao, H.; Bekker, A.; Hofmann, A.

    2017-12-01

    Non-mass dependent sulfur isotope deviation of S-bearing phases in Archean sedimentary strata, and expressed as Δ33S, has a consistent pattern, i.e., sulfide (pyrite) predominantly bear positive Δ33S values, while Paleoarchean sulfate (barite) has negative Δ33S values. This pattern was later corroborated by observations of negative Δ33S values in Archean volcanogenic massive sulfide deposits and negative Δ33S values in early diagenetic nodular pyrite with a wide range of δ34S values, which is thought to be due to microbial sulfate reduction. These signatures have provided a set of initial conditions for a mechanistic interpretation at physical chemistry level. Unlike the younger geological times when large bodies of seawater evaporite deposits are common, to expand seawater sulfate records, carbonate-associated sulfate (CAS) was utilized as a proxy for ancient seawater sulfate. CAS extracted from the Archean carbonates carries positive Δ33S values. However, CAS could be derived from pyrite oxidation following exposure to modern oxidizing conditions and/or during laboratory extraction procedures. It is, therefore, important for us understanding context of the overall early earth atmospheric condition to empirically confirm whether Archean seawater sulfate was generally characterized by negative Δ33S signatures. Combined δ18O, Δ17O, δ34S, and Δ33S analyses of sequentially extracted water-leachable sulfate (WLS) and acid-leachable sulfate (ALS = CAS) and δ34S and Δ33S analyses of pyrite can help to identify the source of extracted sulfate. We studied drill-core samples of Archean carbonates from the 2.55 Ga Malmani and Campell Rand supgroups, South Africa. Our preliminary results show that 1) neither WLS nor ALS were extracted from samples with extremely low pyrite contents (less than 0.05 wt.%); 2) extractable WLS and ALS is present in samples with relatively high pyrite contents (more than 1 wt.%), and that δ34S and Δ33S values of WLS, ALS, and

  19. Single column and two-column H-D-T distillation experiments at TSTA

    International Nuclear Information System (INIS)

    Yamanishi, T.; Yoshida, H.; Hirata, S.; Naito, T.; Naruse, Y.; Sherman, R.H.; Bartlit, J.R.; Anderson, J.L.

    1988-01-01

    Cryogenic distillation experiments were peformed at TSTA with H-D-T system by using a single column and a two-column cascade. In the single column experiment, fundamental engineering data such as the liquid holdup and the HETP were measured under a variety of operational condtions. The liquid holdup in the packed section was about 10 /approximately/ 15% of its superficial volume. The HETP values were from 4 to 6 cm, and increased slightly with the vapor velocity. The reflux ratio had no effect on the HETP. For the wo-colunn experiemnt, dynamic behavior of the cascade was observed. 8 refs., 7 figs., 2 tabs

  20. The central column structure in SPHEX

    International Nuclear Information System (INIS)

    Duck, R.C.; French, P.A.; Browning, P.K.; Cunningham, G.; Gee, S.J.; al-Karkhy, A.; Martin, R.; Rusbridge, M.G.

    1994-01-01

    SPHEX is a gun injected spheromak in which a magnetised Marshall gun generates and maintains an approximately axisymmetric toroidal plasma within a topologically spherical flux conserving vessel. The central column has been defined as a region of high mean floating potential, f > up to ∼ 150 V, aligned with the geometric axis of the device. It has been suggested that this region corresponds to the open magnetic flux which is connected directly to the central electrode of the gun and links the toroidal annulus (in which f > ∼ 0 V). Poynting vector measurements have shown that the power required to drive toroidal current in the annulus is transmitted out of the column by the coherent 20 kHz mode which pervades the plasma. Measurements of the MHD dynamo in the column indicate an 'antidynamo' electric field due to correlated fluctuations in v and B at the 20 kHz mode frequency which is consistent with the time-averaged Ohm's Law. On shorting the gun electrodes, the density in the column region decays rapidly leaving a 'hole' of radius R c ∼ 7 cm. This agrees with the estimated dimension of the open flux from mean internal B measurements and axisymmetric force-free equilibrium modelling, but is considerably smaller than the radius of ∼ 13 cm inferred from the time-averaged potential. In standard operating conditions the gun delivers a current of I G ∼ 60 kA at V G ∼ 500 V for ∼ 1 ms, driving a toroidal current of I t ∼ 60 kA. Ultimately we wish to understand the mechanism which drives toroidal current in the annulus; the central column is of interest because of the crucial role it plays in this process. (author) 8 refs., 6 figs

  1. High rates of sulfate reduction in a low-sulfate hot spring microbial mat are driven by a low level of diversity of sulfate-respiring microorganisms

    DEFF Research Database (Denmark)

    Dillon, Jesse G; Fishbain, Susan; Miller, Scott R

    2007-01-01

    The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community...... was shown to sustain a highly active sulfur cycle. The highest rates of sulfate respiration were measured close to the surface of the mat late in the day when photosynthetic oxygen production ceased and were associated with a Thermodesulfovibrio-like population. Reduced activity at greater depths...... was correlated with novel populations of sulfate-reducing microorganisms, unrelated to characterized species, and most likely due to both sulfate and carbon limitation....

  2. Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

    Science.gov (United States)

    Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2014-06-01

    Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  3. Chinese hamster ovary cell mutants defective in heparan sulfate biosynthesis

    International Nuclear Information System (INIS)

    Bame, K.J.; Kiser, C.S.; Esko, J.D.

    1987-01-01

    The authors have isolated Chinese hamster ovary cell mutants defective in proteoglycan synthesis by radiographic screening for cells unable to incorporate 35 SO 4 into acid-precipitable material. Some mutants did not incorporate 35 SO 4 into acid-precipitable material, whereas others incorporated about 3-fold less radioactivity. HPLC anion exchange chromatographic analysis of radiolabelled glycosaminoglycans isolated from these mutants revealed many are defective in heparan sulfate biosynthesis. Mutants 803 and 677 do not synthesize heparan sulfate, although they produce chondroitin sulfate: strain 803 makes chondroitin sulfate normally, whereas 677 overaccumulates chondroitin sulfate by a factor of three. These mutants fall into the same complementation group, suggesting that the mutations are allelic. A second group of heparan sulfate biosynthetic mutants, consisting of cell lines 625, 668 and 679, produce undersulfated heparan sulfate and normal chondroitin sulfate. Treatment of the chains with nitrous acid should determine the position of the sulfate groups along the chain. These mutants may define a complementation group that is defective in the enzymes which modify the heparan sulfate chain. To increase the authors repertoire of heparan sulfate mutants, they are presently developing an in situ enzyme assay to screen colonies replica plated on filter discs for sulfotransferase defects

  4. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)

    ISAKSEN, MF; BAK, F.; JØRGENSEN, BB

    1994-01-01

    sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...... C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... P60, were isolated and characterized as Desulfotomaculum kuznetsovii. The temperature response of growth and respiration of strain P60 agreed well with the measured sulfate reduction at 50 degrees-70 degrees C. Bacteria similar to strain P60 could thus be responsible for the measured thermophilic...

  5. DEPENDENCY OF SULFATE SOLUBILITY ON MELT COMPOSITION AND MELT POLYMERIZATION

    International Nuclear Information System (INIS)

    JANTZEN, CAROL M.

    2004-01-01

    Sulfate and sulfate salts are not very soluble in borosilicate waste glass. When sulfate is present in excess it can form water soluble secondary phases and/or a molten salt layer (gall) on the melt pool surface which is purported to cause steam explosions in slurry fed melters. Therefore, sulfate can impact glass durability while formation of a molten salt layer on the melt pool can impact processing. Sulfate solubility has been shown to be compositionally dependent in various studies, (e.g. , B2O3, Li2O, CaO, MgO, Na2O, and Fe2O3 were shown to increase sulfate solubility while Al2O3 and SiO2 decreased sulfate solubility). This compositional dependency is shown to be related to the calculated melt viscosity at various temperatures and hence the melt polymerization

  6. Chondroitin-4-sulfation negatively regulates axonal guidance and growth

    Science.gov (United States)

    Wang, Hang; Katagiri, Yasuhiro; McCann, Thomas E.; Unsworth, Edward; Goldsmith, Paul; Yu, Zu-Xi; Tan, Fei; Santiago, Lizzie; Mills, Edward M.; Wang, Yu; Symes, Aviva J.; Geller, Herbert M.

    2008-01-01

    Summary Glycosaminoglycan (GAG) side chains endow extracellular matrix proteoglycans with diversity and complexity based upon the length, composition, and charge distribution of the polysaccharide chain. Using cultured primary neurons, we show that specific sulfation in the GAG chains of chondroitin sulfate (CS) mediates neuronal guidance cues and axonal growth inhibition. Chondroitin-4-sulfate (CS-A), but not chondroitin-6-sulfate (CS-C), exhibits a strong negative guidance cue to mouse cerebellar granule neurons. Enzymatic and gene-based manipulations of 4-sulfation in the GAG side chains alter their ability to direct growing axons. Furthermore, 4-sulfated CS GAG chains are rapidly and significantly increased in regions that do not support axonal regeneration proximal to spinal cord lesions in mice. Thus, our findings provide the evidence showing that specific sulfation along the carbohydrate backbone carries instructions to regulate neuronal function. PMID:18768934

  7. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)

    ISAKSEN, MF; BAK, F.; JØRGENSEN, BB

    1994-01-01

    C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...... P60, were isolated and characterized as Desulfotomaculum kuznetsovii. The temperature response of growth and respiration of strain P60 agreed well with the measured sulfate reduction at 50 degrees-70 degrees C. Bacteria similar to strain P60 could thus be responsible for the measured thermophilic...

  8. Sulfate and acid resistant concrete and mortar

    Science.gov (United States)

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance.

  9. Biosynthesis and function of chondroitin sulfate.

    Science.gov (United States)

    Mikami, Tadahisa; Kitagawa, Hiroshi

    2013-10-01

    Chondroitin sulfate proteoglycans (CSPGs) are principal pericellular and extracellular components that form regulatory milieu involving numerous biological and pathophysiological phenomena. Diverse functions of CSPGs can be mainly attributed to structural variability of their polysaccharide moieties, chondroitin sulfate glycosaminoglycans (CS-GAG). Comprehensive understanding of the regulatory mechanisms for CS biosynthesis and its catabolic processes is required in order to understand those functions. Here, we focus on recent advances in the study of enzymatic regulatory pathways for CS biosynthesis including successive modification/degradation, distinct CS functions, and disease phenotypes that have been revealed by perturbation of the respective enzymes in vitro and in vivo. Fine-tuned machineries for CS production/degradation are crucial for the functional expression of CS chains in developmental and pathophysiological processes. Control of enzymes responsible for CS biosynthesis/catabolism is a potential target for therapeutic intervention for the CS-associated disorders. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Analysis of packing microstructure and wall effects in a narrow-bore ultrahigh pressure liquid chromatography column using focused ion-beam scanning electron microscopy.

    Science.gov (United States)

    Reising, Arved E; Schlabach, Sabine; Baranau, Vasili; Stoeckel, Daniela; Tallarek, Ulrich

    2017-09-01

    Column wall effects are well recognized as major limiting factor in achieving high separation efficiency in HPLC. This is especially important for modern analytical columns packed with small particles, where wall effects dominate the band broadening. Detailed knowledge about the packing microstructure of packed analytical columns has so far not been acquired. Here, we present the first three-dimensional reconstruction protocol for these columns utilizing focused ion-beam scanning electron microscopy (FIB-SEM) on a commercial 2.1mm inner diameter×50mm length narrow-bore analytical column packed with 1.7μm bridged-ethyl hybrid silica particles. Two sections from the packed bed are chosen for reconstruction by FIB-SEM: one from the bulk packing region of the column and one from its critical wall region. This allows quantification of structural differences between the wall region and the center of the bed due to effects induced by the hard, confining column wall. Consequences of these effects on local flow velocity in the column are analyzed with flow simulations utilizing the lattice-Boltzmann method. The reconstructions of the bed structures reveal significant structural differences in the wall region (extending radially over approximately 62 particle diameters) compared to the center of the column. It includes the local reduction of the external porosity by up to 10% and an increase of the mean particle diameter by up to 3%, resulting in a decrease of the local flow velocity by up to 23%. In addition, four (more ordered) layers of particles in the direct vicinity of the column wall induce local velocity fluctuations by up to a factor of three regarding the involved velocity amplitudes. These observations highlight the impact of radial variations in packing microstructure on band migration and column performance. This knowledge on morphological peculiarities of column wall effects helps guiding us towards further optimization of the packing process for analytical

  11. Column, particularly extraction column, for fission and/or breeder materials

    International Nuclear Information System (INIS)

    Vietzke, H.; Pirk, H.

    1980-01-01

    An absorber rod with a B 4 C insert is situated in the long extraction column for a uranyl nitrate solution or a plutonium nitrate solution. The geometrical dimensions are designed for a high throughput with little corrosion. (DG) [de

  12. HETP evaluation of structured packing distillation column

    Directory of Open Access Journals (Sweden)

    A. E. Orlando Jr.

    2009-09-01

    Full Text Available Several tests with a hydrocarbon mixture of known composition (C8-C14, obtained from DETEN Chemistry S.A., have been performed in a laboratory distillation column, having 40mm of nominal diameter and 2.2m high, with internals of Sulzer DX gauze stainless steel structured packing. The main purpose of this work was to evaluate HETP of a structured packing laboratory scale distillation column, operating continuously. Six HETP correlations available in the literature were compared in order to find out which is the most appropriate for structured packing columns working with medium distillates. Prior to the experimental tests, simulation studies using commercial software PRO/II® were performed in order to establish the optimum operational conditions for the distillation, especially concerning operating pressure, top and bottom temperatures, feed location and reflux ratio. The results of PRO/II® were very similar to the analysis of the products obtained during continuous operation, therefore permitting the use of the properties calculated by that software on the theoretical models investigated. The theoretical models chosen for HETP evaluation were: Bravo, Rocha and Fair (1985; Rocha, Bravo and Fair (1993, 1996; Brunazzi and Pagliant (1997; Carlo, Olujić and Pagliant (2006; Olujić et al., (2004. Modifications concerning calculation of specific areas were performed on the correlations in order to fit them for gauze packing HETP evaluation. As the laboratory distillation column was operated continuously, different HETP values were found by the models investigated for each section of the column. The low liquid flow rates in the top section of the column are a source of error for HETP evaluation by the models; therefore, more reliable HETP values were found in the bottom section, in which liquid flow rates were much greater. Among the theoretical models, Olujić et al. (2004 has shown good results relative to the experimental tests. In addition, the

  13. Regional transport model of atmospheric sulfates

    International Nuclear Information System (INIS)

    Rao, K.S.; Thomson, I.; Egan, B.A.

    1977-01-01

    As part of the Sulfate Regional Experiment (SURE) Design Project, a regional transport model of atmospheric sulfates has been developed. This quasi-Lagrangian three-dimensional grid numerical model uses a detailed SO 2 emission inventory of major anthropogenic sources in the Eastern U.S. region, and observed meteorological data during an episode as inputs. The model accounts for advective transport and turbulent diffusion of the pollutants. The chemical transformation of SO 2 and SO 4 /sup =/ and the deposition of the species at the earth's surface are assumed to be linear processes at specified constant rates. The numerical model can predict the daily average concentrations of SO 2 and SO 4 /sup =/ at all receptor locations in the grid region during the episode. Because of the spatial resolution of the grid, this model is particularly suited to investigate the effect of tall stacks in reducing the ambient concentration levels of sulfur pollutants. This paper presents the formulations and assumptions of the regional sulfate transport model. The model inputs and results are discussed. Isopleths of predicted SO 2 and SO 4 /sup =/ concentrations are compared with the observed ground level values. The bulk of the information in this paper is directed to air pollution meteorologists and environmental engineers interested in the atmospheric transport modeling studies of sulfur oxide pollutants

  14. Determination of betaine, l-carnitine, and choline in human urine using a self-packed column and column-switching ion chromatography with nonsuppressed conductivity detection.

    Science.gov (United States)

    Wei, Dan; Liu, Junwei; Guo, Ming; Zhu, Yan

    2017-11-01

    A simple method for the determination of betaine, l-carnitine, and choline in human urine was developed based on column-switching ion chromatography coupled with nonsuppressed conductivity detection by using a self-packed column. A pretreatment column (50 mm × 4.6 mm, id) packed with poly(glycidyl methacrylate-divinylbenzene) microspheres was used for the extraction and cleanup of analytes. Chromatographic separation was achieved within 10 min on a cationic exchange column (150 mm × 4.6 mm, id) using maleic anhydride modified poly(glycidyl methacrylate-divinylbenzene) as the particles for packing. The detection was performed by ion chromatography with nonsuppressed conductivity detection. Parameters including column-switching time, eluent type, flow rates of eluent, and interfering effects were optimized. Linearity (r 2 ≥ 0.99) was obtained for the concentration range of 0.50-100, 0.75-100, and 0.25-100 μg/mL for betaine, l-carnitine, and choline, respectively. Detection limits were 0.12, 0.20, and 0.05 μg/mL for betaine, l-carnitine, and choline, respectively. The intra- and interday accuracy and precision for all quality controls were within ±10.11%. Satisfactory recovery was observed between 92.5 and 105.0%. The validated method was successfully applied for the determination of betaine, l-carnitine, and choline in urine samples from healthy people. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Microbial methanogenesis in the sulfate-reducing zone of sediments in the Eckernförde Bay, SW Baltic Sea

    Directory of Open Access Journals (Sweden)

    J. Maltby

    2018-01-01

    Full Text Available Benthic microbial methanogenesis is a known source of methane in marine systems. In most sediments, the majority of methanogenesis is located below the sulfate-reducing zone, as sulfate reducers outcompete methanogens for the major substrates hydrogen and acetate. The coexistence of methanogenesis and sulfate reduction has been shown before and is possible through the usage of noncompetitive substrates by methanogens such as methanol or methylated amines. However, knowledge about the magnitude, seasonality, and environmental controls of this noncompetitive methane production is sparse. In the present study, the presence of methanogenesis within the sulfate reduction zone (SRZ methanogenesis was investigated in sediments (0–30 cm below seafloor, cm b.s.f. of the seasonally hypoxic Eckernförde Bay in the southwestern Baltic Sea. Water column parameters such as oxygen, temperature, and salinity together with porewater geochemistry and benthic methanogenesis rates were determined in the sampling area Boknis Eck quarterly from March 2013 to September 2014 to investigate the effect of seasonal environmental changes on the rate and distribution of SRZ methanogenesis, to estimate its potential contribution to benthic methane emissions, and to identify the potential methanogenic groups responsible for SRZ methanogenesis. The metabolic pathway of methanogenesis in the presence or absence of sulfate reducers, which after the addition of a noncompetitive substrate was studied in four experimental setups: (1 unaltered sediment batch incubations (net methanogenesis, (2 14C-bicarbonate labeling experiments (hydrogenotrophic methanogenesis, (3 manipulated experiments with the addition of either molybdate (sulfate reducer inhibitor, 2-bromoethanesulfonate (methanogen inhibitor, or methanol (noncompetitive substrate, potential methanogenesis, and (4 the addition of 13C-labeled methanol (potential methylotrophic methanogenesis. After incubation with

  16. Analytic nuclear scattering theories

    International Nuclear Information System (INIS)

    Di Marzio, F.; University of Melbourne, Parkville, VIC

    1999-01-01

    A wide range of nuclear reactions are examined in an analytical version of the usual distorted wave Born approximation. This new approach provides either semi analytic or fully analytic descriptions of the nuclear scattering processes. The resulting computational simplifications, when used within the limits of validity, allow very detailed tests of both nuclear interaction models as well as large basis models of nuclear structure to be performed

  17. Sulfation and cation effects on the conformational properties of the glycan backbone of chondroitin sulfate disaccharides.

    Science.gov (United States)

    Faller, Christina E; Guvench, Olgun

    2015-05-21

    Chondroitin sulfate (CS) is one of several glycosaminoglycans that are major components of proteoglycans. A linear polymer consisting of repeats of the disaccharide -4GlcAβ1-3GalNAcβ1-, CS undergoes differential sulfation resulting in five unique sulfation patterns. Because of the dimer repeat, the CS glycosidic "backbone" has two distinct sets of conformational degrees of freedom defined by pairs of dihedral angles: (ϕ1, ψ1) about the β1-3 glycosidic linkage and (ϕ2, ψ2) about the β1-4 glycosidic linkage. Differential sulfation and the possibility of cation binding, combined with the conformational flexibility and biological diversity of CS, complicate experimental efforts to understand CS three-dimensional structures at atomic resolution. Therefore, all-atom explicit-solvent molecular dynamics simulations with Adaptive Biasing Force sampling of the CS backbone were applied to obtain high-resolution, high-precision free energies of CS disaccharides as a function of all possible backbone geometries. All 10 disaccharides (β1-3 vs β1-4 linkage × five different sulfation patterns) were studied; additionally, ion effects were investigated by considering each disaccharide in the presence of either neutralizing sodium or calcium cations. GlcAβ1-3GalNAc disaccharides have a single, broad, thermodynamically important free-energy minimum, whereas GalNAcβ1-4GlcA disaccharides have two such minima. Calcium cations but not sodium cations bind to the disaccharides, and binding is primarily to the GlcA -COO(-) moiety as opposed to sulfate groups. This binding alters the glycan backbone thermodynamics in instances where a calcium cation bound to -COO(-) can act to bridge and stabilize an interaction with an adjacent sulfate group, whereas, in the absence of this cation, the proximity of a sulfate group to -COO(-) results in two like charges being both desolvated and placed adjacent to each other and is found to be destabilizing. In addition to providing information

  18. Transport Modeling of Modified Magnetite Nanoparticles with Sodium Dodecyl Sulfate in a Saturated Sandy Soil

    Directory of Open Access Journals (Sweden)

    Ahmad Farrokhian Firouzi

    2017-02-01

    Full Text Available Introduction: Nanoparticles due to their large specific area and reactivity recently have been used in several environmental remediation applications such as degradation of organic compounds and pesticides and adsorption of heavy metals and inorganic anions. Because of concern over potential threats of nanoparticle releases into the soil–water environment, a number of studies have been carried out to investigate the transport, retention and deposition of nanoparticles in saturated porous media. Many of these studies are based on measurements of transport in columns packed with idealized porous media consisting of spherical glass beads or sand. The nanoparticles are usually introduced into the column and breakthrough curve concentrations are measured at the column outlet. To examine the effect of various parameters on the transport of nanoparticles in porous medium, for convenience, all the parameters considered the same in the experiments, and only one parameter in the experiments is changed and investigated. Materials and Methods: The objective of this research is quantitative study of modified magnetite nanoparticles transport in saturated sand-repacked columns. The modified magnetite nanoparticles with Sodium dodecyl sulfate were synthesized following the protocol described by Si et al. (2004. The experimental setup included a suspension reservoir, Teflon tubing, a HPLC pump, and a glass column (2.5 cm i.d. and 20 cm height. Therefore, breakthrough curves of modified magnetite nanoparticles with Sodium dodecyl sulfate and chloride were determined under saturated conditions and influence of nanoparticles concentration (0.1 and 0.5 g.L-1 and pore velocity (pressure head of 2 and 10 cm on nanoparticles transport were investigated. For each medium bed, the background solution were first pumped through the column in the up-flow mode to obtain a steady flow state. Then, a tracer test was conducted by introducing CaCl2 solution into the column

  19. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  20. Purification and sequence characterization of chondroitin sulfate and dermatan sulfate from fishes.

    Science.gov (United States)

    Lin, Na; Mo, Xiaoli; Yang, Yang; Zhang, Hong

    2017-04-01

    Chondroitin sulfate (CS) and dermatan sulfate (DS) were extracted and purified from skins or bones of salmon (Salmo salar), snakehead (Channa argus), monkfish (Lophius litulon) and skipjack tuna (Katsuwonus pelamis). Size, structural sequences and sulfate groups of oligosaccharides in the purified CS and DS could be characterized and identified using high performance liquid chromatography (HPLC) combined with Orbitrap mass spectrometry. CS and DS chain structure varies depending on origin, but motif structure appears consistent. Structures of CS and DS oligosaccharides with different size and sulfate groups were compared between fishes and other animals, and results showed that some minor differences of special structures could be identified by hydrophilic interaction chromatography-liquid chromatography-fourier transform-mass/mass spectrometry (HILIC-LC-FT-MS/MS). For example, data showed that salmon and skipjack CS had a higher percentage content of high-level sulfated oligosaccharides than that porcine CS. In addition, structural information of different origins of CS and DS was analyzed by principal component analysis (PCA) and results showed that CS and DS samples could be differentiated according to their molecular conformation and oligosaccharide fragments information. Understanding CS and DS structure derived from different origins may lead to the production of CS or DS with unique disaccharides or oligosaccharides sequence composition and biological functions.

  1. Mitigating oil spills in the water column

    International Nuclear Information System (INIS)

    Barry, Edward; Libera, Joseph A.; Mane, Anil University; Avila, Jason R.; DeVitis, David

    2017-01-01

    The scale and scope of uncontrolled oil spills can be devastating. Diverse marine environments and fragile ecologies are some of the most susceptible to the many ill effects, while the economic costs can be crippling. A notoriously difficult challenge with no known technological solution is the successful removal of oil dispersed in the water column. Here, we address this problem through cheap and reusable oil sorbents based on the chemical modification of polymer foams. Interfacial chemistry was optimized and subsequently tested in a simulated marine environment at the National Oil Spill Response Research & Renewable Energy Test Facility, Ohmsett. We find favorable performance for surface oil mitigation and, for the first time, demonstrate the advanced sorbent's efficiency and efficacy at pilot scale in extraction of crude oil and refined petroleum products dispersed in the water column. As a result, this is a potentially disruptive technology, opening a new field of environmental science focused on sub-surface pollutant sequestration.

  2. Assembly procedure for column cutting platform

    International Nuclear Information System (INIS)

    Routh, R.D.

    1995-01-01

    This supporting document describes the assembly procedure for the Column Cutting Platform and Elevation Support. The Column Cutting Platform is a component of the 241-SY-101 Equipment Removal System. It is set up on the deck of the Strongback Trailer to provide work access to cut off the upper portion of the Mitigation Pump Assembly (MPA). The Elevation Support provides support for the front of the Storage Container with the Strongback at an inclined position. The upper portion of the MPA must be cut off to install the Containment Caps on the Storage Container. The storage Container must be maintained in an inclined position until the Containment Caps are installed to prevent any residual liquids from migrating forward in the Storage Container

  3. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    International Nuclear Information System (INIS)

    Walker, D.D.

    1999-01-01

    Non-elutable ion exchange is being considered as a potential replacement for the In-Tank Precipitation process for removing cesium from Savannah River Site (SRS) radioactive waste. Crystalline silicotitanate (CST) particles are the reference ion exchange medium for the process. A major factor in the construction cost of this process is the size of the ion exchange column required to meet product specifications for decontaminated waste. To validate SRS column sizing calculations, SRS subcontracted two reknowned experts in this field to perform similar calculations: Professor R. G. Anthony, Department of Chemical Engineering, Texas A ampersand 038;M University, and Professor S. W. Wang, Department of Chemical Engineering, Purdue University. The appendices of this document contain reports from the two subcontractors. Definition of the design problem came through several meetings and conference calls between the participants and SRS personnel over the past few months. This document summarizes the problem definition and results from the two reports

  4. Measurement of bromate in bread by liquid chromatography with post-column flow reactor detection.

    Science.gov (United States)

    Himata, K; Noda, M; Ando, S; Yamada, Y

    2000-01-01

    This method is suitable for the determination of bromate residues in a variety of baked goods. The peer-verified method trial was performed on white bread, multigrain bread, and coffee cake spiked with known levels of potassium bromate. The analytical portion is extracted with deionized water to remove bromate from the bulk of the baked product. The aqueous extract is carried through a series of steps to remove co-extractives that would interfere with the liquid chromatography (LC) in the determinative step or hasten the deterioration of the LC column. The extract is filtered before passing it through a reversed-phase solid-phase extraction (SPE) column and a cation-exchange column in the silver form to remove lipids and chloride, respectively. Ultrafiltration is then used to remove proteins with molecular weights of >30,000 daltons. Finally, a cation-exchange column in the sodium form is used to remove silver ions from the extract. The determinative step uses LC with a reversed-phase column and an ion-pairing agent in the mobile phase. Detection is based on the post-column reaction of bromate with o-dianisidine to form an oxidation product that is quantitated spectrophotometrically at 450 nm. Overall agreement between the submitting and peer laboratories was quite good. For bromate levels of 10-52 ppb, overall mean recoveries were 76.9 and 78.8% for the submitting and peer laboratories, respectively. The standard deviations were higher for the results of the peer laboratory, probably because of the generally higher level of baseline noise present in the chromatograms. The results demonstrate that the method provides adequate accuracy with low-fat as well as high-fat foods. Bromate at levels as low as 5 ppb (ng/g) can be detected with the method.

  5. Heritability and clinical determinants of serum indoxyl sulfate and p-cresyl sulfate, candidate biomarkers of the human microbiome enterotype.

    Directory of Open Access Journals (Sweden)

    Liesbeth Viaene

    Full Text Available BACKGROUND: Indoxyl sulfate and p-cresyl sulfate are unique microbial co-metabolites. Both co-metabolites have been involved in the pathogenesis of accelerated cardiovascular disease and renal disease progression. Available evidence suggests that indoxyl sulfate and p-cresyl sulfate may be considered candidate biomarkers of the human enterotype and may help to explain the link between diet and cardiovascular disease burden. OBJECTIVE AND DESIGN: Information on clinical determinants and heritability of indoxyl sulfate and p-cresyl sulfate serum is non-existing. To clarify this issue, the authors determined serum levels of indoxyl sulfate and p-cresyl sulfate in 773 individuals, recruited in the frame of the Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO study. RESULTS: Serum levels of indoxyl sulfate and p-cresyl sulfate amounted to 3.1 (2.4-4.3 and 13.0 (7.4-21.5 μM, respectively. Regression analysis identified renal function, age and sex as independent determinants of both co-metabolites. Both serum indoxyl sulfate (h2 = 0.17 and p-cresyl sulfate (h2 = 0.18 concentrations showed moderate but significant heritability after adjustment for covariables, with significant genetic and environmental correlations for both co-metabolites. LIMITATIONS: Family studies cannot provide conclusive evidence for a genetic contribution, as confounding by shared environmental effects can never be excluded. CONCLUSIONS: The heritability of indoxyl sulfate and p-cresyl sulfate is moderate. Besides genetic host factors and environmental factors, also renal function, sex and age influence the serum levels of these co-metabolites.

  6. LIQUID CHROMATOGRAPHIC / MASS SPECTROMETRIC DETERMINATION OF MORPHINE, CODEINE AND COCAINE IN HUMAN SERA USING A NEW INTERNAL SURFACE REVERSED PHASE COLUMN

    OpenAIRE

    Hattori, Hideki; Arinobu, Tetsuya; Iwai, Masae; Suzuki, Osamu; Seno, Hiroshi

    2003-01-01

    A new internal surface reversed phase column (Shim-pack MAYI-ODS) was used for analysis of morphine, codeine and cocaine in human sera by LC/MS/MS. The column enabled direct injection of crude biological samples without pretreatment realizing a rapid analytical procedure. Therecoveries of morphine, codeine and cocaine spiked into human sera were 50-60 %. The regression equations for morphine, codeine and cocaine in sera, using atropine as internal standard, showed good linearity in the ranges...

  7. Simple column-switching ion chromatography method for determining eight monosaccharides and oligosaccharides in honeydew and nectar.

    Science.gov (United States)

    Ni, Chengzhu; Zhu, Binhe; Wang, Nani; Wang, Muhua; Chen, Suqing; Zhang, Jiajie; Zhu, Yan

    2016-03-01

    Honeydew is excreted by aphids as a sweet waste and nectar is floral honey. Honeydew and nectar are complicated samples which consist of various sugars and amino acids. In this work, a simple ion chromatography with column-switching method was developed for the simultaneous analysis of 8 monosaccharides and oligosaccharides in honeydew and nectar. A reversed-phase column was used as a pretreatment column to eliminate organics on-line and sugars were eluted from a collection loop to analytical column by using column-switching technique. This method showed good linearity (r⩾0.9994) and afforded low limits of detection ranging from 1.55 to 10.17μgL(-1) for all the analytes. Recoveries ranged from 95% to 105% and repeatability results were acceptable with relative standard deviation of less than 3.21% (n=6). This method was successfully applied to quantification of these sugars in honeydew and nectar. These results showed honeydew had much more oligosaccharides than nectar. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Optimization of the isotope separation in columns

    International Nuclear Information System (INIS)

    Kaminskij, V.A.; Vetsko, V.M.; Tevzadze, G.A.; Devdariani, O.A.; Sulaberidze, G.A.

    1982-01-01

    The general method for the multi-parameter optimization of cascade plants of packed columns is proposed. As an optimization effectiveness function a netcost of the isotopic product is selected. The net cost is comprehensively characterizing the sum total of capital costs for manufacturing the products as well as determining the choice of the most effective directions for capital investments and rational limits of improvement of the products quality. The method is based on main representations of the cascade theory, such as the ideal flow profile and form efficiency as well as mathematical model of the packed column specifying the bonds between its geometric and operating parameters. As a result, the isotopic products cost function could be bound with such parameters as the equilibrium stage height, ultimate packing capacity, its element dimensions, column diameter. It is concluded that the suggested approach to the optimization of isotope separation processes is rather a general one. It permits to solve a number of special problems, such as estimation of advisability of using heat-pump circuits and determining the rational automation level. Besides, by means of the method suggested one can optimize the process conditions with regard to temperature and pressure

  9. Employing anatomical knowledge in vertebral column labeling

    Science.gov (United States)

    Yao, Jianhua; Summers, Ronald M.

    2009-02-01

    The spinal column constitutes the central axis of human torso and is often used by radiologists to reference the location of organs in the chest and abdomen. However, visually identifying and labeling vertebrae is not trivial and can be timeconsuming. This paper presents an approach to automatically label vertebrae based on two pieces of anatomical knowledge: one vertebra has at most two attached ribs, and ribs are attached only to thoracic vertebrae. The spinal column is first extracted by a hybrid method using the watershed algorithm, directed acyclic graph search and a four-part vertebra model. Then curved reformations in sagittal and coronal directions are computed and aggregated intensity profiles along the spinal cord are analyzed to partition the spinal column into vertebrae. After that, candidates for rib bones are detected using features such as location, orientation, shape, size and density. Then a correspondence matrix is established to match ribs and vertebrae. The last vertebra (from thoracic to lumbar) with attached ribs is identified and labeled as T12. The rest of vertebrae are labeled accordingly. The method was tested on 50 CT scans and successfully labeled 48 of them. The two failed cases were mainly due to rudimentary ribs.

  10. One-step microwave synthesis of photoluminescent carbon nanoparticles from sodium dextran sulfate water solution

    Science.gov (United States)

    Kokorina, Alina A.; Goryacheva, Irina Y.; Sapelkin, Andrei V.; Sukhorukov, Gleb B.

    2018-04-01

    Photoluminescent (PL) carbon nanoparticles (CNPs) have been synthesized by one-step microwave irradiation from water solution of sodium dextran sulfate (DSS) as the sole carbon source. Microwave (MW) method is very simple and cheap and it provides fast synthesis of CNPs. We have varied synthesis time for obtaining high luminescent CNPs. The synthesized CNPs exhibit excitation-dependent photoluminescent. Final CNPs water solution has a blue- green luminescence. CNPs have low cytotoxicity, good photostability and can be potentially suitable candidates for bioimaging, analysis or analytical tests.

  11. Identification and quantification of flavonoids in human urine samples by column switching liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, S. E.; Freese, R.; Cornett, Claus

    2000-01-01

    A rapid and sensitive high-performance liquid chromatographic mass spectrometric (HPLC-MS) method is described for the determination and quantification of 12 dietary flavonoid glycosides and aglycons in human urine samples. Chromatographic separation of the analytes of interest was achieved...... by column-switching, using the first column (a Zorbax 300SB C-3 column) for sample cleanup and eluting the heart-cut flavonoid fraction onto the second column (a Zorbax SE C-18 column) for separation and detection by ultraviolet and atmospheric pressure chemical ionization MS using single ion monitoring...... of variation for the analysis of the 12 different flavonoids in quality control urine samples were 12.3% on average (range 11.0-13.7%, n = 24, reproducibility) and the repeatability of the assay were 5.0% (mean, range 0.1-14.8%, it = 12). A subset of 10 urine samples from a human dietary intervention study...

  12. Sulfation pattern of fucose branches affects the anti-hyperlipidemic activities of fucosylated chondroitin sulfate.

    Science.gov (United States)

    Wu, Nian; Zhang, Yu; Ye, Xingqian; Hu, Yaqin; Ding, Tian; Chen, Shiguo

    2016-08-20

    Fucosylated chondroitin sulfates (fCSs) are glycosaminoglycans extracted from sea cucumbers, consisting of chondroitin sulfate E (CSE) backbones and sulfated fucose branches. The biological properties of fCSs could be affected by the sulfation pattern of their fucose branches. In the present study, two fCSs were isolated from sea cucumbers Isostichopus badionotus (fCS-Ib) and Pearsonothuria graeffei (fCS-Pg). Their monosaccharide compositions of glucuronic acid (GlcA), N-acetylgalactosamine (GalNAc), fucose (Fuc) and sulfate were at similar molar ratio with 1.0/0.7/0.9/3.1 for fCS-Ib and 1.0/0.8/1.5/2.6 for fCS-Pg. The two fCSs have different sulfation patterns on their fucose branches, fCS-Pg with 3,4-O-disulfation while fCS-Ib with 2,4-O-disulfation. Their antihyperlipidemic effects were compared using a high-fat high-fructose diet (HFFD)-fed C57BL/6J mice model. Both fCS-Ib and fCS-Pg had significant effects on lipid profile improvement, liver protection, blood glucose diminution and hepatic glycogen synthesis. Specifically, fCS-Pg with 3,4-O-disulfation fucose branches was more effective in reduction of blood cholesterol (TC), low density lipoprotein (LDL) and atherogenic index (AI). Our results indicate that both fCSs, especially fCS-Pg, could be used as a potential anti-hyperlipidemic drug. Copyright © 2016. Published by Elsevier Ltd.

  13. A potential role for chondroitin sulfate/dermatan sulfate in arm regeneration in Amphiura filiformis.

    Science.gov (United States)

    Ramachandra, Rashmi; Namburi, Ramesh B; Dupont, Sam T; Ortega-Martinez, Olga; van Kuppevelt, Toin H; Lindahl, Ulf; Spillmann, Dorothe

    2017-05-01

    Glycosaminoglycans (GAGs), such as chondroitin sulfate (CS) and dermatan sulfate (DS) from various vertebrate and invertebrate sources are known to be involved in diverse cellular mechanisms during repair and regenerative processes. Recently, we have identified CS/DS as the major GAG in the brittlestar Amphiura filiformis, with high proportions of di- and tri-O-sulfated disaccharide units. As this echinoderm is known for its exceptional regeneration capacity, we aimed to explore the role of these GAG chains during A. filiformis arm regeneration. Analysis of CS/DS chains during the regeneration process revealed an increase in the proportion of the tri-O-sulfated disaccharides. Conversely, treatment of A. filiformis with sodium chlorate, a potent inhibitor of sulfation reactions in GAG biosynthesis, resulted in a significant reduction in arm growth rates with total inhibition at concentrations higher than 5 mM. Differentiation was less impacted by sodium chlorate exposure or even slightly increased at 1-2 mM. Based on the structural changes observed during arm regeneration we identified chondroitin synthase, chondroitin-4-O-sulfotransferase 2 and dermatan-4-O-sulfotransferase as candidate genes and sought to correlate their expression with the expression of the A. filiformis orthologue of bone morphogenetic factors, AfBMP2/4. Quantitative amplification by real-time PCR indicated increased expression of chondroitin synthase and chondroitin-4-O-sulfotransferase 2, with a corresponding increase in AfBMP2/4 during regeneration relative to nonregenerating controls. Our findings suggest that proper sulfation of GAGs is important for A. filiformis arm regeneration and that these molecules may participate in mechanisms controlling cell proliferation. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. The Analytical Hierarchy Process

    DEFF Research Database (Denmark)

    Barfod, Michael Bruhn

    2007-01-01

    The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use.......The technical note gathers the theory behind the Analytical Hierarchy Process (AHP) and present its advantages and disadvantages in practical use....

  15. Signals: Applying Academic Analytics

    Science.gov (United States)

    Arnold, Kimberly E.

    2010-01-01

    Academic analytics helps address the public's desire for institutional accountability with regard to student success, given the widespread concern over the cost of higher education and the difficult economic and budgetary conditions prevailing worldwide. Purdue University's Signals project applies the principles of analytics widely used in…

  16. Analytic Moufang-transformations

    International Nuclear Information System (INIS)

    Paal, Eh.N.

    1988-01-01

    The paper is aimed to be an introduction to the concept of an analytic birepresentation of an analytic Moufang loop. To describe the deviation of (S,T) from associativity, the associators (S,T) are defined and certain constraints for them, called the minimality conditions of (S,T) are established

  17. Quine's "Strictly Vegetarian" Analyticity

    NARCIS (Netherlands)

    Decock, L.B.

    2017-01-01

    I analyze Quine’s later writings on analyticity from a linguistic point of view. In Word and Object Quine made room for a “strictly vegetarian” notion of analyticity. In later years, he developed this notion into two more precise notions, which I have coined “stimulus analyticity” and “behaviorist

  18. Learning analytics dashboard applications

    NARCIS (Netherlands)

    Verbert, K.; Duval, E.; Klerkx, J.; Govaerts, S.; Santos, J.L.

    2013-01-01

    This article introduces learning analytics dashboards that visualize learning traces for learners and teachers. We present a conceptual framework that helps to analyze learning analytics applications for these kinds of users. We then present our own work in this area and compare with 15 related

  19. Learning Analytics Considered Harmful

    Science.gov (United States)

    Dringus, Laurie P.

    2012-01-01

    This essay is written to present a prospective stance on how learning analytics, as a core evaluative approach, must help instructors uncover the important trends and evidence of quality learner data in the online course. A critique is presented of strategic and tactical issues of learning analytics. The approach to the critique is taken through…

  20. Analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  1. Analytical mass spectrometry. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  2. Ductility of reinforced concrete columns confined with stapled strips

    International Nuclear Information System (INIS)

    Tahir, M.F.; Khan, Q.U.Z.; Shabbir, F.; Sharif, M.B.; Ijaz, N.

    2015-01-01

    Response of three 150x150x450mm short reinforced concrete (RC) columns confined with different types of confining steel was investigated. Standard stirrups, strips and stapled strips, each having same cross-sectional area, were employed as confining steel around four comer column bars. Experimental work was aimed at probing into the affect of stapled strip confinement on post elastic behavior and ductility level under cyclic axial load. Ductility ratios, strength enhancement factor and core concrete strengths were compared to study the affect of confinement. Results indicate that strength enhancement in RC columns due to strip and stapled strip confinement was not remarkable as compared to stirrup confined column. It was found that as compared to stirrup confined column, stapled strip confinement enhanced the ductility of RC column by 183% and observed axial capacity of stapled strip confined columns was 41 % higher than the strip confined columns. (author)

  3. EX0904 Water Column Summary Report and Profile Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX0904: Water Column Exploration Field...

  4. On the roles and regulation of chondroitin sulfate and heparan sulfate in zebrafish pharyngeal cartilage morphogenesis

    DEFF Research Database (Denmark)

    Holmborn, Katarina; Habicher, Judith; Kasza, Zsolt

    2012-01-01

    The present study addresses the roles of heparan sulfate (HS) proteoglycans and chondroitin sulfate (CS) proteoglycans in the development of zebrafish pharyngeal cartilage structures. uxs1 and b3gat3 mutants, predicted to have impaired biosynthesis of both HS and CS because of defective formation...... levels of CS than control larvae, whereas morpholino-mediated suppression of csgalnact1/csgalnact2 resulted in increased HS biosynthesis. Thus, the balance of the Extl3 and Csgalnact1/Csgalnact2 proteins influences the HS/CS ratio. A characterization of the pharyngeal cartilage element morphologies...

  5. Quo vadis, analytical chemistry?

    Science.gov (United States)

    Valcárcel, Miguel

    2016-01-01

    This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed.

  6. Impact of column and stationary phase properties on the productivity in chiral preparative LC.

    Science.gov (United States)

    Forssén, Patrik; Fornstedt, Torgny

    2018-03-01

    By generating 1500 random chiral separation systems, assuming two-site Langmuir interactions, we investigated numerically how the maximal productivity (P R,max ) was affected by changes in stationary phase adsorption properties. The relative change in P R,max , when one adsorption property changed 10%, was determined for each system and for each studied parameter the corresponding productivity change distribution of the systems was analyzed. We could conclude that there is no reason to have columns with more than 500 theoretical plates and larger selectivity than 3. More specifically, we found that changes in selectivity have a major impact on P R,max if it is below ∼2 and, interestingly, increasing selectivity when it is above ∼3 decreases P R,max . Increase in relative saturation capacity will have a major impact on P R,max if it is below ∼40%, but only modest above this percent. Increasing total monolayer saturation capacity, or decreasing the first eluting enantiomer's retention factor, will have a modest effect on P R,max and increased efficiency will have almost no effect at all on P R,max unless it is below ∼500 theoretical plates. Finally, we showed that chiral columns with superior analytic performance might have inferior preparative performance, or vice versa. It is, therefore, not possible to assess columns based on their analytical performance alone. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Effects of sulfate deprivation on the production of chondroitin/dermatan sulfate by cultures of skin fibroblasts from normal and diabetic individuals

    International Nuclear Information System (INIS)

    Silbert, C.K.; Humphries, D.E.; Palmer, M.E.; Silbert, J.E.

    1991-01-01

    Human skin fibroblast monolayer cultures from two normal men, three Type I diabetic men, and one Type I diabetic woman were incubated with [3H]glucosamine in the presence of diminished concentrations of sulfate. Although total synthesis of [3H]chondroitin/dermatan glycosaminoglycans varied somewhat between cell lines, glycosaminoglycan production was not affected within any line when sulfate levels were decreased from 0.3 mM to 0.06 mM to 0.01 mM to 0 added sulfate. Lowering of sulfate concentrations resulted in diminished sulfation of chondroitin/dermatan in a progressive manner, so that overall sulfation dropped to as low as 19% for one of the lines. Sulfation of chondroitin to form chondroitin 4-sulfate and chondroitin 6-sulfate was progressively and equally affected by decreasing the sulfate concentration in the culture medium. However, sulfation to form dermatan sulfate was preserved to a greater degree, so that the relative proportion of dermatan sulfate to chondroitin sulfate increased. Essentially all the nonsulfated residues were susceptible to chondroitin AC lyase, indicating that little epimerization of glucuronic acid residues to iduronic acid had occurred in the absence of sulfation. These results confirm the previously described dependency of glucuronic/iduronic epimerization on sulfation, and indicate that sulfation of the iduronic acid-containing disaccharide residues of dermatan can take place with sulfate concentrations lower than those needed for 6-sulfation and 4-sulfation of the glucuronic acid-containing disaccharide residues of chondroitin. There were considerable differences among the six fibroblast lines in susceptibility to low sulfate medium and in the proportion of chondroitin 6-sulfate, chondroitin 4-sulfate, and dermatan sulfate. However, there was no pattern of differences between normals and diabetics

  8. Cross flow cyclonic flotation column for coal and minerals beneficiation

    Science.gov (United States)

    Lai, Ralph W.; Patton, Robert A.

    2000-01-01

    An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

  9. Behaviour of FRP confined concrete in square columns

    OpenAIRE

    Diego Villalón, Ana de; Arteaga Iriarte, Ángel; Fernandez Gomez, Jaime Antonio; Perera Velamazán, Ricardo; Cisneros, Daniel

    2015-01-01

    A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and duc...

  10. Modalization in the Political Column of Tempo Magazine

    OpenAIRE

    Rahmah, Maria Betti Sinaga and

    2017-01-01

    The study focuses on analyzing the use of modalization in the Political Column of Tempo Magazine. The objectives were to find out the type of modalization and to describe the use of modalization in the Political Column of Tempo magazine. The data were taken from Political Column of Tempo magazine published in June and July 2017. The source of data was Political Column in Tempo magazine. The data analysis applied descriptive qualitative research. There were 135 clauses which contained Modaliza...

  11. Numerical Simulations of Settlement of Jet Grouting Columns

    Directory of Open Access Journals (Sweden)

    Juzwa Anna

    2016-03-01

    Full Text Available The paper presents the comparison of results of numerical analyses of interaction between group of jet grouting columns and subsoil. The analyses were conducted for single column and groups of three, seven and nine columns. The simulations are based on experimental research in real scale which were carried out by authors. The final goal for the research is an estimation of an influence of interaction between columns working in a group.

  12. Optimum pressure for total-reflux operated thermal diffusion column for isotope separation

    International Nuclear Information System (INIS)

    Yamamoto, Ichiro; Makino, Hitoshi; Kanagawa, Akira

    1990-01-01

    A formula for prediction of the optimum operating pressure P opt of the thermal diffusion columns at total reflux is derived based on the approximate formulae for the column constants which can be evaluated analytically. The formula is expressed explicitly in terms of (1) physical properties of gases to be separated, (2) ratio of radii between hot wire and cold wall of the column, and (3) the ratio of the temperature difference to the cold wall temperature. The result is compared with experimental data; (1) binary monatomic gas systems, (2) multicomponent monatomic gas systems, (3) isotopically substituted polyatomic systems, (4) systems of low atomic or molecular weight, and (5) mixtures of unlike gases; mainly obtained by Rutherford and coworkers. Although the formula is based on the rather rough approximation for the column constants, the optimum pressures predicted by the present formula are in successfully good agreement with the experimental data even for the systems of low atomic or molecular weight and that of mixtures of unlike gases. (author)

  13. Residual diesel measurement in sand columns after surfactant/alcohol washing

    International Nuclear Information System (INIS)

    Martel, R.; Gelinas, P.J.

    1996-01-01

    A new simple gravimetric technique has been designed to determine residual oil saturation of complex hydrocarbon mixtures (e.g., diesel) in sand column experiments because reliable methods are lacking. The He/N 2 technique is based on drying of sand columns by circulating helium gas to drag oil droplets in a cold trap (liquid nitrogen). With this technique, residual diesel measurement can be performed easily immediately after alcohol/surfactant washing and in the same lab. For high residual diesel content in Ottawa sand (25 to 30 g/kg), the technique is much more accurate (± 2% or 600 mg/kg) than the standard analytical methods for the determination of mineral oil and grease. The average relative error on partial diesel dissolution in sand column estimated after alcohol/surfactant flooding (residual saturation of 10 to 15 g/kg) is as low as 5%. The precision of the He/N 2 technique is adequate to compare relative efficiency of washing solutions when partial extraction of residual oil in Ottawa sand columns is performed. However, this technique is not adapted for determination of traces of oil in sediment or for environmental control of contaminated soils. Each diesel determination by the He/N 2 technique costs less than $8 in chemical products (helium and liquid nitrogen). A simple laboratory drying setup can be built for less than $400 which makes this technique valuable for diesel analyses when a large number of tests are required

  14. A column experiment for the study of colloidal radionuclide migration in Gorleben aquifer systems

    International Nuclear Information System (INIS)

    Kim, J.I.; Delakowitz, B.; Zeh, P.; Klotz, D.; Lazik, D.

    1994-01-01

    A column experiment is performed for the assessment of the migration behaviour of trivalent 152 Eu, 241 Am and tetra- and pentavalent 237 Np, 233 Pa in the presence of humic colloids. Groundwater of an organic rich aquifer from the geological site at Gorleben is chosen for the experiment, as this has been well characterized during the earlier work and contains a substantial amount of humic colloids. The chemical and mineralogical composition of the pleistocene quartz-sand used in the column experiment is characterized by various analytical and mineralogical methods. Prior to the actinide migration experiment, the hydraulic properties (flow velocity, effective porosity, longitudinal dispersion coefficient) are determined in order to ascertain stable conditions for the experiment. In addition, the microstructure parameters (sediment surface, pore size distribution) of the groundwater-sand system in the column are determined. Radiotracers used for the determination of the hydraulic properties are 3 HHO and 82 Br - . Results obtained to date indicate a relatively high mobility of the lanthanide and actinide ions loaded on aquatic humic colloids. The recovery of injected radiotracer ions in eluates is found to depend on the flow velocity of groundwater through the column. The results help to elucidate the actinide migration behaviour in the presence of natural humic colloids. (orig.)

  15. A simple subcritical chromatographic test for an extended ODS high performance liquid chromatography column classification.

    Science.gov (United States)

    Lesellier, Eric; Tchapla, Alain

    2005-12-23

    This paper describes a new test designed in subcritical fluid chromatography (SFC) to compare the commercial C18 stationary phase properties. This test provides, from a single analysis of carotenoid pigments, the absolute hydrophobicity, the silanol activity and the steric separation factor of the ODS stationary phases. Both the choice of the analytical conditions and the validation of the information obtained from the chromatographic measurements are detailed. Correlations of the carotenoid test results with results obtained from other tests (Tanaka, Engelhard, Sander and Wise) performed both in SFC and HPLC are discussed. Two separation factors, calculated from the retention of carotenoid pigments used as probe, allowed to draw a first classification diagram. Columns, which present identical chromatographic behaviors are located in the same area on this diagram. This location can be related to the stationary phase properties: endcapping treatments, bonding density, linkage functionality, specific area or silica pore diameter. From the first classification, eight groups of columns are distinguished. One group of polymer coated silica, three groups of polymeric octadecyl phases, depending on the pore size and the endcapping treatment, and four groups of monomeric stationary phases. An additional classification of the four monomeric groups allows the comparison of these stationary phases inside each group by using the total hydrophobicity. One hundred and twenty-nine columns were analysed by this simple and rapid test, which allows a comparison of columns with the aim of helping along their choice in HPLC.

  16. Regeneration of pilot-scale ion exchange columns for hexavalent chromium removal.

    Science.gov (United States)

    Korak, Julie A; Huggins, Richard; Arias-Paic, Miguel

    2017-07-01

    Due to stricter regulations, some drinking water utilities must implement additional treatment processes to meet potable water standards for hexavalent chromium (Cr(VI)), such as the California limit of 10 μg/L. Strong base anion exchange is effective for Cr(VI) removal, but efficient resin regeneration and waste minimization are important for operational, economic and environmental considerations. This study compared multiple regeneration methods on pilot-scale columns on the basis of regeneration efficiency, waste production and salt usage. A conventional 1-Stage regeneration using 2 N sodium chloride (NaCl) was compared to 1) a 2-Stage process with 0.2 N NaCl followed by 2 N NaCl and 2) a mixed regenerant solution with 2 N NaCl and 0.2 N sodium bicarbonate. All methods eluted similar cumulative amounts of chromium with 2 N NaCl. The 2-Stage process eluted an additional 20-30% of chromium in the 0.2 N fraction, but total resin capacity is unaffected if this fraction is recycled to the ion exchange headworks. The 2-Stage approach selectively eluted bicarbonate and sulfate with 0.2 N NaCl before regeneration using 2 N NaCl. Regeneration approach impacted the elution efficiency of both uranium and vanadium. Regeneration without co-eluting sulfate and bicarbonate led to incomplete uranium elution and potential formation of insoluble uranium hydroxides that could lead to long-term resin fouling, decreased capacity and render the resin a low-level radioactive solid waste. Partial vanadium elution occurred during regeneration due to co-eluting sulfate suppressing vanadium release. Waste production and salt usage were comparable for the 1- and 2-Stage regeneration processes with similar operational setpoints with respect to chromium or nitrate elution. Published by Elsevier Ltd.

  17. Global source attribution of sulfate aerosol and its radiative forcing

    Science.gov (United States)

    Yang, Y.; Wang, H.; Smith, S.; Easter, R. C.; Ma, P. L.; Qian, Y.; Li, C.; Yu, H.; Rasch, P. J.

    2017-12-01

    Sulfate is an important aerosol that poses health risks and influences climate. Due to long-range atmospheric transport, local sulfate pollution could result from intercontinental influences, making domestic efforts of improving air quality inefficient. Accurate understanding of source attribution of sulfate and its radiative forcing is important for both regional air quality improvement and global climate mitigation. In this study, for the first time, a sulfur source-tagging capability is implemented in the Community Atmosphere Model (CAM5) to quantify the global source-receptor relationships of sulfate and its direct and indirect radiative forcing (DRF and IRF). Near-surface sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate is primarily attributed to non-local sources from long-range transport. The export of SO2 and sulfate from Europe contributes 20% of sulfate concentrations over North Africa, Russia and Central Asia. Sources from the Middle East account for 20% of sulfate over North Africa, Southern Africa and Central Asia in winter and autumn, and 20% over South Asia in spring. East Asia accounts for about 50% of sulfate over Southeast Asia in winter and autumn, 15% over Russia in summer, and 10% over North America in spring. South Asia contributes to 25% of sulfate over Southeast Asia in spring. Lifetime of aerosols, together with regional export, is found to determine regional air quality. The simulated global total sulfate DRF is -0.42 W m-2, with 75% contributed by anthropogenic sulfate and 25% contributed by natural sulfate. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes the most to the total DRF. East Asia has the largest contribution of 20-30% over the Northern Hemisphere mid- and high-latitudes. A 20% perturbation of sulfate and its precursor emissions gives a sulfate IRF of -0.44 W m-2. DMS has the

  18. An investigation of transient pressure and plasma properties in a pinched plasma column. M.S. Thesis

    Science.gov (United States)

    Stover, E. K.; York, T. M.

    1971-01-01

    The transient pinched plasma column generated in a linear Z-pinch was studied experimentally and analytically. The plasma column was investigated experimentally with the following plasma diagnostics: a special rapid response pressure transducer, a magnetic field probe, a voltage probe and discharge luminosity. Axial pressure profiles on the discharge chamber axis were used to identify three characteristic regions of plasma column behavior; they were in temporal sequence: strong axial pressure asymmetry noted early in plasma column lifetime followed by plasma heating in which there is a rapid rise in static pressure and a slight decrease static pressure before plasma column breakup. Plasma column lifetime was approximately 5 microseconds. The axial pressure asymmetry was attributed to nonsimultaneous pinching of the imploding current sheet along the discharge chamber axis. The rapid heating is attributed in part to viscous effects introduced by radial gradients in the axial streaming velocity. Turbulent heating arising from discharge current excitation of the ion acoustic wave instability is also considered a possible heating mechanism.

  19. Evaluation of an ambient air sampling system for tritium (as tritiated water vapor) using silica gel adsorbent columns

    International Nuclear Information System (INIS)

    Patton, G.W.; Cooper, A.T.; Tinker, M.R.

    1995-08-01

    Ambient air samples for tritium analysis (as the tritiated water vapor [HTO] content of atmospheric moisture) are collected for the Hanford Site Surface Environmental Surveillance Project (SESP) using the solid adsorbent silica gel. The silica gel has a moisture sensitive indicator which allows for visual observation of moisture movement through a column. Despite using an established method, some silica gel columns showed a complete change in the color indicator for summertime samples suggesting that breakthrough had occurred; thus a series of tests was conducted on the sampling system in an environmental chamber. The purpose of this study was to determine the maximum practical sampling volume and overall collection efficiency for water vapor collected on silica gel columns. Another purpose was to demonstrate the use of an impinger-based system to load water vapor onto silica gel columns to provide realistic analytical spikes and blanks for the Hanford Site SESP. Breakthrough volumes (V b ) were measured and the chromatographic efficiency (expressed as the number of theoretical plates [N]) was calculated for a range of environmental conditions. Tests involved visual observations of the change in the silica gel's color indicator as a moist air stream was drawn through the column, measurement of the amount of a tritium tracer retained and then recovered from the silica gel, and gravimetric analysis for silica gel columns exposed in the environmental chamber

  20. Assessing the Role of Iron Sulfides in the Long Term Sequestration of Uranium by Sulfate-Reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, Kim F. [Univ. of Michigan, Ann Arbor, MI (United States); Bi, Yuqiang [Univ. of Michigan, Ann Arbor, MI (United States); Carpenter, Julian [Univ. of Michigan, Ann Arbor, MI (United States); Hyng, Sung Pil [Univ. of Michigan, Ann Arbor, MI (United States); Rittmann, Bruce E. [Arizona State Univ., Tempe, AZ (United States); Zhou, Chen [Arizona State Univ., Tempe, AZ (United States); Vannela, Raveender [Arizona State Univ., Tempe, AZ (United States); Davis, James A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-12-31

    scavenger to retard UO2 dissolution. The results indicate that FeS is an effective oxygen scavenger, and can lower the rate of oxidative dissolution of UO2 by over an order of magnitude compared to the absence of FeS, depending on pH, FeS content, and DO concentrations. Column reactor studies were performed at UM to assess the impact of mackinawite on uraninite oxidation under hydrodynamic flow conditions more representative of packed porous media at contaminated groundwater sites. In these studies, Rifle sediments were packed in the two columns which were subjected to different bioreduction steps and then run in parallel. The first column was bioreduced under SRCs (i.e., with sulfate in the influent) to generate mackinawite, mixed with uraninite, gamma-sterilized to inhibit subsequent microbiological activity, and then subjected to groundwater influent containing first nitrite and then oxygen. The second column was bioreduced (but in absence of sulfate in the influent) so that no iron sulfides would form, and then subjected to identical steps and influent as the first column. When nitrite was introduced in the influent of both columns, no significant release of U(VI) relative to the anoxic flow prior to nitrite addition occurred. However, when oxygen was introduced, the column which had undergone sulfate reduction (and had produced mackinawite as later verified by XAS) significantly lowered the peak U(VI) effluent concentrations, and in general, slowed U(VI) release considerably compared to the column with no FeS. Overall, these studies demonstrated that the presence of mackinawite can be a significant scavenger of oxygen and inhibit the oxidation of uraninite by oxygen, whereas nitrite had little impact on uraninite oxidation either in the presence or absence of FeS.

  1. column frame for design of reinforced concrete sway frames

    African Journals Online (AJOL)

    adminstrator

    design of slender reinforced concrete columns in sway frames according .... concrete,. Ac = gross cross-sectional area of the columns. Step 3: Effective Buckling Length Factors. The effective buckling length factors of columns in a sway frame shall be computed by .... shall have adequate resistance to failure in a sway mode ...

  2. Behavior of reinforced concrete columns strenghtened by partial jacketing

    Directory of Open Access Journals (Sweden)

    D. B. FERREIRA

    Full Text Available This article presents the study of reinforced concrete columns strengthened using a partial jacket consisting of a 35mm self-compacting concrete layer added to its most compressed face and tested in combined compression and uniaxial bending until rupture. Wedge bolt connectors were used to increase bond at the interface between the two concrete layers of different ages. Seven 2000 mm long columns were tested. Two columns were cast monolithically and named PO (original column e PR (reference column. The other five columns were strengthened using a new 35 mm thick self-compacting concrete layer attached to the column face subjected to highest compressive stresses. Column PO had a 120mm by 250 mm rectangular cross section and other columns had a 155 mm by 250mm cross section after the strengthening procedure. Results show that the ultimate resistance of the strengthened columns was more than three times the ultimate resistance of the original column PO, indicating the effectiveness of the strengthening procedure. Detachment of the new concrete layer with concrete crushing and steel yielding occurred in the strengthened columns.

  3. 46 CFR 174.085 - Flooding on column stabilized units.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is subdivided...

  4. Water hammer with column separation : a historical review

    NARCIS (Netherlands)

    Bergant, A.; Simpson, A.R.; Tijsseling, A.S.

    2006-01-01

    Column separation refers to the breaking of liquid columns in fully filled pipelines. This may occur in a water-hammer event when the pressure in a pipeline drops to the vapor pressure at specific locations such as closed ends, high points or knees (changes in pipe slope). The liquid columns are

  5. Determination of pyrophosphate and sulfate using polyhexamethylene guanidine hydrochloride-stabilized silver nanoparticles.

    Science.gov (United States)

    Terenteva, E A; Apyari, V V; Dmitrienko, S G; Garshev, A V; Volkov, P A; Zolotov, Yu A

    2018-04-01

    Positively charged polyhexamethylene guanidine hydrochloride-stabilized silver nanoparticles (PHMG-AgNPs) were prepared and applied as a colorimetric probe for single-step determination of pyrophosphate and sulfate. The approach is based on the nanoparticles aggregation leading to change in their absorption spectra and color of the solution. Due to both electrostatic and steric stabilization these nanoparticles show decreased sensitivity relatively to many common anions, which allows for simple and rapid direct single-step determination of pyrophosphate and sulfate. Effects of different factors (time of interaction, pH, concentrations of anions and the nanoparticles) on aggregation of PHMG-AgNPs and analytical performance of the procedure were investigated. The method allows for the determination of pyrophosphate and sulfate in the range of 0.16-2μgmL -1 and 20-80μgmL -1 with RSD of 2-5%, respectively. The analysis can be performed using either spectrophotometry or naked-eye detection. Practical application of the method was shown by the example of pyrophosphate determination in baking powder sample. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Removal of Sulfate Ion From AN-107 by Evaporation

    International Nuclear Information System (INIS)

    GJ Lumetta; GS Klinger; DE Kurath; RL Sell; LP Darnell; LR Greenwood; CZ Soderquist; MJ Steele; MW Urie; JJ Wagner

    2000-01-01

    Hanford low-activity waste solutions contain sulfate, which can cause accelerated corrosion of the vitrification melter and unacceptable operating conditions. A method is needed to selectively separate sulfate from the waste. An experiment was conducted to evaluate evaporation for removing sulfate ion from Tank AN-107 low-activity waste. Two evaporation steps were performed. In the first step, the volume was reduced by 55% while in the second step, the liquid volume was reduced another 22%. Analysis of the solids precipitated during these evaporations revealed that large amounts of sodium nitrate and nitrite co-precipitated with sodium sulfate. Many other waste components precipitated as well. It can be concluded that sulfate removal by precipitation is not selective, and thus, evaporation is not a viable option for removing sulfate from the AN-107 liquid

  7. Metabolic interactions in methanogenic and sulfate-reducing bioreactors.

    Science.gov (United States)

    Stams, A J M; Plugge, C M; de Bok, F A M; van Houten, B H G W; Lens, P; Dijkman, H; Weijma, J

    2005-01-01

    In environments where the amount of electron acceptors is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic consortia of acetogenic bacteria and methanogenic archaea. Hydrogen consumption by methanogens is essential for acetogenic bacteria to convert organic acids to acetate and hydrogen. Several syntrophic cocultures growing on propionate and butyrate have been described. These syntrophic fatty acid-degrading consortia are affected by the presence of sulfate. When sulfate is present sulfate-reducing bacteria compete with methanogenic archaea for hydrogen and acetate, and with acetogenic bacteria for propionate and butyrate. Sulfate-reducing bacteria easily outcompete methanogens for hydrogen, but the presence of acetate as carbon source may influence the outcome of the competition. By contrast, acetoclastic methanogens can compete reasonably well with acetate-degrading sulfate reducers. Sulfate-reducing bacteria grow much faster on propionate and butyrate than syntrophic consortia.

  8. Process for removing sulfate anions from waste water

    Science.gov (United States)

    Nilsen, David N.; Galvan, Gloria J.; Hundley, Gary L.; Wright, John B.

    1997-01-01

    A liquid emulsion membrane process for removing sulfate anions from waste water is disclosed. The liquid emulsion membrane process includes the steps of: (a) providing a liquid emulsion formed from an aqueous strip solution and an organic phase that contains an extractant capable of removing sulfate anions from waste water; (b) dispersing the liquid emulsion in globule form into a quantity of waste water containing sulfate anions to allow the organic phase in each globule of the emulsion to extract and absorb sulfate anions from the waste water and (c) separating the emulsion including its organic phase and absorbed sulfate anions from the waste water to provide waste water containing substantially no sulfate anions.

  9. Immobilization of calcium sulfate contained in demolition waste

    International Nuclear Information System (INIS)

    Ambroise, J.; Pera, J.

    2008-01-01

    This paper presents the results of a laboratory study undertaken to examine the treatment of demolition waste containing calcium sulfate by means of calcium sulfoaluminate clinker (CSA). The quantity of CSA necessary to entirely consume calcium sulfate was determined. Using infrared spectrometry analysis and X-ray diffraction, it was shown that calcium sulfate was entirely consumed when the ratio between CSA and calcium sulfate was 4. Standard sand was polluted by 4% calcium sulfate. Two solutions were investigated: ·either global treatment of sand by CSA, ·or immobilization of calcium sulfate by CSA, followed by the introduction of this milled mixture in standard sand. Regardless of the type of treatment, swelling was almost stabilized after 28 days of immersion in water

  10. A radioimmunoassay for measurement of thyroxine sulfate

    International Nuclear Information System (INIS)

    Chopra, I.J.; Santini, F.; Hurd, R.E.; Chua Teco, G.N.

    1993-01-01

    A highly sensitive, specific, and reproducible RIA has been developed to measure T 4 sulfate (T 4 S) in ethanol extracts of serum. rT 3 sulfate (rT 3 S) cross-reacted 7.1%, and T 3 S cross-reacted 0.59% in the RIA; T 4 , T 3 , rT 3 and 3,3'-diiodothyronine cross-reacted 0.004% or less. The recovery of nonradioactive T 4 S added to serum averaged 95%. The detection threshold of the RIA was 18 pmol/L. The coefficient of variation averaged 6.9% within an assay and 12% between assays. T 4 S was bound by T 4 -binding globulin and albumin in serum. The free fraction of T 4 S in four normal sera averaged 0.06% compared to a value of 0.03% for T 4 (P 4 S was (mean ± SE) 19 ± 1.2 pmol/L in normal subjects, 33 ± 10 in hyperthyroid patients with Graves disease, 42 ± 15 in hypothyroid patients, 34 ± 6.9 in patients with systematic nonthyroidal illnesses, 21 ± 4.3 in pregnant women at 15-40 weeks gestation, and 245 ± 26 in cord blood sera of newborns; the value in the newborn was significantly different from normal (P 4 S. The T 4 S content of the thyroid gland was less than 1/4000th that of T 4 . We conclude that (1) T 4 S is a normal component of human serum, and its levels are markedly increased in newborn serum and amniotic fluid; and (2) the sulfation pathway plays an important role in the metabolism of T 4 in man. 28 refs., 4 figs., 2 tabs

  11. Sequence determination of synthesized chondroitin sulfate dodecasaccharides.

    Science.gov (United States)

    Shioiri, Tatsumasa; Tsuchimoto, Jun; Watanabe, Hideto; Sugiura, Nobuo

    2016-06-01

    Chondroitin sulfate (CS) is a linear acidic polysaccharide composed of repeating disaccharide units of glucuronic acid and N-acetyl-d-galactosamine. The polysaccharide is modified with sulfate groups at different positions by a variety of sulfotransferases. CS chains exhibit various biological and pathological functions by interacting with cytokines and growth factors and regulating their signal transduction. The fine structure of the CS chain defines its specific biological roles. However, structural analysis of CS has been restricted to disaccharide analysis, hampering the understanding of the structure-function relationship of CS chains. Here, we chemo-enzymatically synthesized CS dodecasaccharides having various sulfate modifications using a bioreactor system of bacterial chondroitin polymerase mutants and various CS sulfotransferases. We developed a sequencing method for CS chains using the CS dodecasaccharides. The method consists of (i) labeling a reducing end with 2-aminopyridine (PA), (ii) partial digestion of CS with testicular hyaluronidase, followed by separation of PA-conjugated oligosaccharides with different chain lengths, (iii) limited digestion of these oligosaccharides with chondroitin lyase AC II into disaccharides, followed by labeling with 2-aminobenzamide, (iv) CS disaccharide analysis using a dual-fluorescence HPLC system (reversed-phase ion-pair and ion-exchange chromatography), and (v) estimation of the composition by calculating individual disaccharide ratios. This CS chain sequencing allows characterization of CS-modifying enzymes and provides a useful tool toward understanding the structure-function relationship of CS chains. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Sulfated oligosaccharide structures, as determined by NMR techniques

    International Nuclear Information System (INIS)

    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Cerezo, A.S.

    1997-01-01

    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a λ-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author)

  13. Application of Multi-Analyte Methods for Pesticide Formulations

    Energy Technology Data Exchange (ETDEWEB)

    Lantos, J.; Virtics, I. [Plant Protection & Soil Conservation Service of Szabolcs-Szatmár-Bereg County, Nyíregyháza (Hungary)

    2009-07-15

    The application of multi-analyte methods for pesticide formulations by GC analysis is discussed. HPLC was used to determine active ingredients. HPLC elution sequences were related to individual n-octanol/water partition coefficients. Real laboratory data are presented and evaluated with regard to validation requirements. The retention time data of pesticides on different HPLC columns under gradient and isocratic conditions are compared to illustrate the applicability of the methodologies. (author)

  14. Applications of DHDECMP extraction chromatography to nuclear analytical chemistry

    International Nuclear Information System (INIS)

    Marsh, S.F.; Simi, O.R.

    1981-01-01

    Dihexyl-N,N-diethylcarbamylmethylenephosphonate (DHDECMP) is a highly selective extractant for actinides and lanthanides. This reagent, extensively studied for process-scale operations, also has valuable analytical applications. Extraction chromatographic columns of DHDECMP, supported on inert, porous, polymer beads effectively separate most metallic impurity elements from the retained inner transition elements. The retained elements can be separated into individual fractions of (1) lanthanides, (2) americium, (3) plutonium, and (4) uranium by mixed-solvent anion exchange

  15. Second-order Data by Flow Injection Analysis with Spectrophotometric Diode-array Detection and Incorporated Gel-filtration Chromatographic Column

    DEFF Research Database (Denmark)

    Bechmann, Iben Ellegaard

    1997-01-01

    A flow injection analysis (FIA) system furnished with a gel-filtration chromatographic column and with photodiode-array detection was used for the generation of second-order data. The system presented is a model system in which the analytes are blue dextran, potassium hexacyanoferrate(III) and he......A flow injection analysis (FIA) system furnished with a gel-filtration chromatographic column and with photodiode-array detection was used for the generation of second-order data. The system presented is a model system in which the analytes are blue dextran, potassium hexacyanoferrate...

  16. Google analytics integrations

    CERN Document Server

    Waisberg, Daniel

    2015-01-01

    A roadmap for turning Google Analytics into a centralized marketing analysis platform With Google Analytics Integrations, expert author Daniel Waisberg shows you how to gain a more meaningful, complete view of customers that can drive growth opportunities. This in-depth guide shows not only how to use Google Analytics, but also how to turn this powerful data collection and analysis tool into a central marketing analysis platform for your company. Taking a hands-on approach, this resource explores the integration and analysis of a host of common data sources, including Google AdWords, AdSens

  17. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    Science.gov (United States)

    Zaromb, Solomon; Lawson, Daniel B.

    1994-01-01

    A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

  18. Purification, structural characterization and antiproliferative properties of chondroitin sulfate/dermatan sulfate from tunisian fish skins.

    Science.gov (United States)

    Krichen, Fatma; Volpi, Nicola; Sila, Assaâd; Maccari, Francesca; Mantovani, Veronica; Galeotti, Fabio; Ellouz-Chaabouni, Semia; Bougatef, Ali

    2017-02-01

    Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72KDa and 23.8KDa, respectively. HCT116 cell proliferation was inhibited (p<0.05) by 70.6% and 72.65% at 200μg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Inter vs. intraglycosidic acetal linkages control sulfation pattern in semi-synthetic chondroitin sulfate.

    Science.gov (United States)

    Laezza, Antonio; De Castro, Cristina; Parrilli, Michelangelo; Bedini, Emiliano

    2014-11-04

    Microbial-sourced unsulfated chondroitin could be converted into chondroitin sulfate (CS) polysaccharide by a multi-step strategy relying upon benzylidenation and acetylation reactions as key-steps for its regioselective protection. By conducting the two reactions one- or two-pots, CSs with different sulfation patterns could be obtained at the end of the semi-synthesis. In particular, a CS polysaccharide possessing sulfate groups randomly distributed between positions 4 and 6 of N-acetyl-galactosamine (GalNAc) units could be obtained through the two-pots route, whereas the one-pot pathway allowed an additional sulfation at position 3 of some glucuronic acid (GlcA) units. This difference was ascribed to the stabilization of a labile interglycosidic benzylidene acetal involving positions O-3 and O-6 of some GlcA and GalNAc, respectively, when the benzylidene-acetylation reactions were conducted in a one-pot fashion. Isolation and characterization of a polysaccharide intermediate showing interglycosidic acetal moieties was accomplished. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Optimum Parameters of a Tuned Liquid Column Damper in a Wind Turbine Subject to Stochastic Load

    Science.gov (United States)

    Alkmim, M. H.; de Morais, M. V. G.; Fabro, A. T.

    2017-12-01

    Parameter optimization for tuned liquid column dampers (TLCD), a class of passive structural control, have been previously proposed in the literature for reducing vibration in wind turbines, and several other applications. However, most of the available work consider the wind excitation as either a deterministic harmonic load or random load with white noise spectra. In this paper, a global direct search optimization algorithm to reduce vibration of a tuned liquid column damper (TLCD), a class of passive structural control device, is presented. The objective is to find optimized parameters for the TLCD under stochastic load from different wind power spectral density. A verification is made considering the analytical solution of undamped primary system under white noise excitation by comparing with result from the literature. Finally, it is shown that different wind profiles can significantly affect the optimum TLCD parameters.

  1. Sulfate Formation on Mars by Volcanic Aerosols: A New Look

    Science.gov (United States)

    Blaney, D. L.

    1996-03-01

    Sulfur was measured at both Viking Lander sites in abundances of 5-9 wt % SO3. Because the sulfur was more concentrated in clumps which disintegrated and the general oxidized nature of the Martian soil, these measurements led to the assumption that a sulfate duricrust existed. Two types of models for sulfate formation have been proposed. One is a formation by upwardly migrating ground water. The other is the formation of sulfates by the precipitation of volcanic aerosols. Most investigators have tended to favor the ground water origin of sulfates on Mars. However, evidence assemble since Viking may point to a volcanic aerosol origin.

  2. Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles

    International Nuclear Information System (INIS)

    Meier, P.J.; Valantinas, J.; Hugentobler, G.; Rahm, I.

    1987-01-01

    The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven [ 35 S]-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4'-isothiocyanostilbene-2,2'-disulfonic acid, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (IC 50 , ∼40 μM). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation

  3. Mencegah Pembentukan Kalsium Sulfat pada Desalinasi Air Laut

    Directory of Open Access Journals (Sweden)

    Mirna Rahmah Lubis

    2007-06-01

    Full Text Available Resin penukar-anion, Relite MG 1/P, dapat digunakan untuk memisahkan sulfat dalam air laut guna mencegah pembentukan kerak kalsium sulfat pada heat exchanger. Resin tersebut menunjukkan selektivitas sulfat yang tinggi dalam air laut sintetis. Resin yang telah dipakai dapat diregenerasi menggunakan air asin yang dipekatkan dengan asam hingga mencapai pH 4. Untuk waktu pemakaian dan regenerasi yang sama, faktor konsentrasi desalinasi (misalnya 2 hingga 4 menaikkan konsentrasi klorida dalam air asin yang diblowdown. Dengan faktor konsentrasi yang tetap, kenaikan laju alir (pengurangan waktu pemakaian dan regenerasi memperendah efisiensi regenerasi dan menaikkan pemisahan sulfat. Akibat kelarutan kalsium sulfat yang bersifat terbalik tersebut, temperatur air asin yang tinggi memerlukan pemisahan sulfat yang lebih banyak, yang dapat dicapai dengan mengurangi laju alir air laut. Pengurangan laju alir tersebut membutuhkan peralatan yang lebih besar dan resin yang lebih banyak, sehingga biaya modal bertambah. Untuk pabrik desalinasi dengan kapasitas produksi 1 juta gallon per hari dan faktor konsentrasi sebesar 2, biaya pemisahan sulfat meliputi biaya resin dan biaya peralatan. Biaya tersebut bervariasi dari $0.246 hingga $0.356/kgalon (per ribu galon air yang diproduksi karena temperatur maksimum air asin berubah dari 140°C menjadi 180°C. Keywords: desalinasi air laut, ion exchange, kalsium sulfat, kerak; mechanical vapor compression (MVC, pemisahan sulfat, resin penukar-anion basa lemah

  4. Hydrodynamic Study Of Column Bioleaching Processes

    Directory of Open Access Journals (Sweden)

    Sadowski Zygmunt

    2015-06-01

    Full Text Available The modelling of flow leaching solution through the porous media has been considered. The heap bioleaching process can be tested using the column experimental equipment. This equipment was employed to the hydrodynamic studies of copper ore bioleaching. The copper ore (black shale ore with the support, inertial materials (glass small balls and polyethylene beads was used to the bioleaching tests. The packed beds were various composition, the ore/support ratio was changed. The correlation between the bed porosity and bioleaching kinetics, and copper recovery was investigated.

  5. Column leaching from biomass combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2015-01-01

    The utilization of biomass combustion ashes for forest soil liming and fertilizing has been addressed in literature. Though, a deep understanding of the ash chemical composition and leaching behavior is necessary to predict potential benefits and environmental risks related to this practice....... In this study, a fly ash sample from an operating Danish power plant based on wood biomass was collected, chemically characterized and investigated for its leaching release of nutrients and heavy metals. A column leaching test was employed. The strongly alkaline pH of all the collected eluates suggested...

  6. Design of Steel Beam-Column Connections

    Directory of Open Access Journals (Sweden)

    Bogatinoski Z.

    2014-05-01

    Full Text Available In this paper a theoretical and experimental research of the steel beam-column connections is presented. Eight types of specimens were being researched, composed of rigid and semi-rigid connections from which 4 connections are with IPE - profile and 4 connections with tube's section for the beam. From the numerical analysis of the researched models, and especially from the experimental research at the Laboratory for Structures in the Faculty of Mechanical Engineering - Skopje, specific conclusions were received that ought to have theoretical and practical usage for researchers in this area of interest.

  7. Buckling driven debonding in sandwich columns

    DEFF Research Database (Denmark)

    Østergaard, Rasmus Christian

    2008-01-01

    results from two mechanisms: (a) interaction of local debond buckling and global buckling and (b) the development of a damaged zone at the debond crack tip. Based on the pronounced imperfection sensitivity, the author predicts that an experimental measurement of the strength of sandwich structures may......A compression loaded sandwich column that contains a debond is analyzed using a geometrically non-linear finite element model. The model includes a cohesive zone along one face sheet/core interface whereby the debond can extend by interface crack growth. Two geometrical imperfections are introduced...

  8. Dynamic Deformation and Collapse of Granular Columns

    Science.gov (United States)

    Uenishi, K.; Tsuji, K.; Doi, S.

    2009-12-01

    Large dynamic deformation of granular materials may be found in nature not only in the failure of slopes and cliffs — due to earthquakes, rock avalanches, debris flows and landslides — but also in earthquake faulting itself. Granular surface flows often consist of solid grains and intergranular fluid, but the effect of the fluid may be usually negligible because the volumetric concentration of grains is in many cases high enough for interparticle forces to dominate momentum transport. Therefore, the investigation of dry granular flow of a mass might assist in further understanding of the above mentioned geophysical events. Here, utilizing a high-speed digital video camera system, we perform a simple yet fully-controlled series of laboratory experiments related to the collapse of granular columns. We record, at an interval of some microseconds, the dynamic transient granular mass flow initiated by abrupt release of a tube that contains dry granular materials. The acrylic tube is partially filled with glass beads and has a cross-section of either a fully- or semi-cylindrical shape. Upon sudden removal of the tube, the granular solid may fragment under the action of its own weight and the particles spread on a rigid horizontal plane. This study is essentially the extension of the previous ones by Lajeunesse et al. (Phys. Fluids 2004) and Uenishi and Tsuji (JPGU 2008), but the striped layers of particles in a semi-cylindrical tube, newly introduced in this contribution, allow us to observe the precise particle movement inside the granular column: The development of slip lines inside the column and the movement of particles against each other can be clearly identified. The major controlling parameters of the spreading dynamics are the initial aspect ratio of the granular (semi-)cylindrical column, the frictional properties of the horizontal plane (substrate) and the size of beads. We show the influence of each parameter on the average flow velocity and final radius

  9. A review of oscillating water columns.

    Science.gov (United States)

    Heath, T V

    2012-01-28

    This paper considers the history of oscillating water column (OWC) systems from whistling buoys to grid-connected power generation systems. The power conversion from the wave resource through to electricity via pneumatic and shaft power is discussed in general terms and with specific reference to Voith Hydro Wavegen's land installed marine energy transformer (LIMPET) plant on the Scottish island of Islay and OWC breakwater systems. A report on the progress of other OWC systems and power take-off units under commercial development is given, and the particular challenges faced by OWC developers reviewed.

  10. Preinjector for Linac 1, accelerating column

    CERN Multimedia

    1974-01-01

    For a description of the Linac 1 preinjector, please see first 7403070X. High up on the wall of the Faraday cage (7403073X) is this drum-shaped container of the ion source (7403083X). It is mounted at the HV end of the accelerating column through which the ions (usually protons; many other types of ions in the course of its long history) proceed through the Faraday cage wall to the low-energy end (at ground potential) of Linac 1. The 520 kV accelerating voltage was supplied by a SAMES generator (7403074X).

  11. Stability of elastic columns with periodic retarded follower forces

    Science.gov (United States)

    Ma, Haitao; Butcher, Eric A.

    2005-09-01

    The objective of this work is to present a stability analysis for elastic columns under the influence of periodically varying follower forces whose orientation is retarded, i.e., depends on the position of the system at a previous time. One- and two-degree-of-freedom (dof) discretized systems under the simultaneous influence of both parametric excitation and time-delay, whose effects on such systems have previously been only considered separately, are studied. By employing an orthogonal polynomial approximation, the infinite-dimensional Floquet transition matrix associated with the time-periodic differential-delay system is approximated. The stability criteria that all the eigenvalues (Floquet multipliers) of this matrix must lie within the unit circle is then applied. The stability charts for different combinations of the remaining system parameters are shown, and the previously reported results for the special cases where either the parametric excitation or the time-delay vanishes are verified. Two cases, when the parametric forcing period is equal to or twice the delay period are taken into consideration in this work. For special cases of the single dof system, the numerical stability plots are verified by considering the analytical expressions for the corresponding stability boundaries for an analogous delayed Mathieu equation.

  12. Flute instability growth on a magnetized plasma column

    International Nuclear Information System (INIS)

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r i , where R is the Gaussian characteristic radius and r i is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation

  13. Divergent Synthesis of Chondroitin Sulfate Disaccharides and Identification of Sulfate Motifs that Inhibit Triple Negative Breast Cancer

    Science.gov (United States)

    Wei Poh, Zhong; Heng Gan, Chin; Lee, Eric J.; Guo, Suxian; Yip, George W.; Lam, Yulin

    2015-09-01

    Glycosaminoglycans (GAGs) regulate many important physiological processes. A pertinent issue to address is whether GAGs encode important functional information via introduction of position specific sulfate groups in the GAG structure. However, procurement of pure, homogenous GAG motifs to probe the “sulfation code” is a challenging task due to isolation difficulty and structural complexity. To this end, we devised a versatile synthetic strategy to obtain all the 16 theoretically possible sulfation patterns in the chondroitin sulfate (CS) repeating unit; these include rare but potentially important sulfated motifs which have not been isolated earlier. Biological evaluation indicated that CS sulfation patterns had differing effects for different breast cancer cell types, and the greatest inhibitory effect was observed for the most aggressive, triple negative breast cancer cell line MDA-MB-231.

  14. Anticoagulant activity of a sulfated polysaccharide isolated from the green seaweed Caulerpa cupressoides

    Directory of Open Access Journals (Sweden)

    José Ariévilo Gurgel Rodrigues

    2011-08-01

    Full Text Available The aim of this study was to evaluate certain molecular characteristics of a sulfated polysaccharide (SPs with anticoagulant properties, isolated from Caulerpa cupressoides (Chlorophyta. Crude SPs were extracted by proteolytic digestion (papain, followed by ion-exchange chromatography on a DEAE-cellulose column. The fractions obtained were analyzed for molecular mass, 0.5% agarose gel electrophoresis and chemical composition. The activated partial thromboplastin time (APTT test was applied using normal human plasma and standard heparin (HEP (193 IU mg-1. The yield was ~ 3%, and the chromatography procedure separated the material into three different SP fractions (F I, F II and F III, eluted at the concentrations of 0.50, 0.75 and 1.00 M of NaCl, respectively. Only fraction F II was active (24.62 IU mg-1, with high sulfate content (23.79% and number of molecular mass peaks. Therefore, the APTT of a fraction isolated from C. cupressoides was less potent than HEP.

  15. Sulfate as a pivotal factor in regulation of Serratia sp. strain S2B pigment biosynthesis.

    Science.gov (United States)

    Rastegari, Banafsheh; Karbalaei-Heidari, Hamid Reza

    2016-10-01

    In the present work, we investigated the prodiginine family as secondary metabolite members. Bacterial strain S2B, with the ability to produce red pigment, was isolated from the Sarcheshmeh copper mine in Iran. 16S rDNA gene sequencing revealed that the strain was placed in the Serratia genus. Pigment production was optimized using low-cost culture medium and the effects of various physicochemical factors were studied via statistical approaches. Purification of the produced pigment by silica gel column chromatography showed a strong red pigment fraction and a weaker orange band. Mass spectrometry, FT-IR spectroscopy and (1)H NMR analysis revealed that the red pigment was prodigiosin and the orange band was a prodigiosin-like analog, with molecular weights of 323 and 317 Da, respectively. Genotoxicity and cytotoxicity studies confirmed their membership in the prodiginine family. Analysis of the production pattern of the pigments in the presence of different concentrations of ammonium salts revealed the role of sulfate as an important factor in regulation of the pigment biosynthesis pathway. Overall, the data showed that regulation of the pigment biosynthesis pathway in Serratia sp. strain S2B was affected by inorganic micronutrients, particularly the sulfate ions. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  16. Characterization and application of automated in-vacuum PIXE/EBS system for direct analysis of chloride and sulfate ions attack in cementitious materials

    Science.gov (United States)

    Rihawy, M. S.; Alwazzeh, M.; Abbas, K.

    2018-01-01

    Ion beam analysis (IBA) techniques (Particle Induced X-ray Emission, PIXE and Elastic Backscattering Spectrometry, EBS), were applied to investigate chloride and sulfate ions diffusion into laboratory prepared mortar samples. Development and characterization of an automated in-vacuum macro PIXE/EBS system is thoroughly discussed. Depth profile information of both chloride and sulfate ions in laboratory prepared mortar samples, after immersion in sea water for nine months, was rapidly and easily obtained at fairly low cost and with standardless analysis, demonstrating the value of the application of IBA to elemental depth profiling in cementitious materials. Chloride and sulfate depth profiles were obtained for two sets of mortar samples, one prepared with different water/cement (W/C) ratios and the other with different sand/cement (S/C) ratios. Results showed higher diffusion rates of both chloride and sulfate ions when both ratios are increased. Additionally, the W/C ratio has a stronger influence in both sulfate and chloride penetration than the S/C ratio, and chloride ions penetrate faster than sulfates. Advantages and limitations of applying IBA techniques in this investigation are discussed. The comparison between PIXE and other X-ray based analytical techniques, namely X-ray fluorescence (XRF) and energy and wavelength dispersive X-rays (EDX/WDX), as well as other traditional wet chemical methods is reviewed, and industrial applications are discussed.

  17. Oncofetal Chondroitin Sulfate Glycosaminoglycans are Key Players in Integrin Signaling and Tumor Cell Motility

    Science.gov (United States)

    Clausen, Thomas Mandel; Pereira, Marina Ayres; Al Nakouzi, Nader; Oo, Htoo Zarni; Agerbæk, Mette Ø; Lee, Sherry; Ørum-Madsen, Maj Sofie; Christensen, Anders Riis; El-Naggar, Amal; Grandgenett, Paul M.; Grem, Jean L.; Hollingsworth, Michael A.; Holst, Peter J.; Theander, Thor; Sorensen, Poul H.; Daugaard, Mads; Salanti, Ali

    2016-01-01

    Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum. We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion and anchorage-independent growth of tumor cells in vitro. Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns, revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin β1 (ITGB1) and integrin α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core CS synthesis enzymes Beta-1,3-Glucuronyltransferase 1 (B3GAT1) and Chondroitin Sulfate N-Acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and pre-incubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target. Implications The cancer specific expression of oncofetal chondroitin sulfate aids in metastatic phenotypes and is a candidate target for therapy. PMID:27655130

  18. Radionuclides in analytical chemistry

    International Nuclear Information System (INIS)

    Tousset, J.

    1984-01-01

    Applications of radionuclides in analytical chemistry are reviewed in this article: tracers, radioactive sources and activation analysis. Examples are given in all these fields and it is concluded that these methods should be used more widely [fr

  19. Mobility Data Analytics Center.

    Science.gov (United States)

    2016-01-01

    Mobility Data Analytics Center aims at building a centralized data engine to efficiently manipulate : large-scale data for smart decision making. Integrating and learning the massive data are the key to : the data engine. The ultimate goal of underst...

  20. Analytical strategies for phosphoproteomics

    DEFF Research Database (Denmark)

    Thingholm, Tine E; Jensen, Ole N; Larsen, Martin R

    2009-01-01

    sensitive and specific strategies. Today, most phosphoproteomic studies are conducted by mass spectrometric strategies in combination with phospho-specific enrichment methods. This review presents an overview of different analytical strategies for the characterization of phosphoproteins. Emphasis...